Mold vibrating apparatus in continuous casting equipment

ES 2 154 658 T3

DESCRIPTION

Apparatus for vibrating a mold in continuous casting equipment.

Scope of the invention

The present invention relates to a device for vibrating a mold designed to apply a predetermined vibrating device to the mold during a continuous casting operation. Background of the invention

The vibrations are applied to the mold in a continuous casting equipment, using a vibrating device.

Patent application document EP-A 0 570 935, which has not been published before the earliest priority date of this patent, describes a device designed to move a mold by shaking up and down the entire structure of the mold. A control device comprises position sensing means fixed on the piston rod. A control signal is produced using the set horizontal position, the actual horizontal position and the preset offset value. Such a control signal indicates a difference between the horizontal position of the setpoint and the actual horizontal position detected. A driving means actuates a hydraulic cylinder according to the control signal.

Another known vibrating device of this type is described in Japanese patent application Kokai No. 63 562/1988. In this vibrating device, the mold is supported in such a way that it performs up and down movements in a vertical plane, by means of a connection of four bars and a beam, a hydraulic cylinder being coupled to the front end of that beam to vibrate the mold. The hydraulic circuit designed to supply said hydraulic cylinder to hydraulic pressure is provided with a servo valve and a control circuit to control said servo valve.

In this control circuit, the position of the hydraulic cylinder rod and the acceleration of the mold are detected by the respective sensors. The arrangement is such that the individual sensed values ​​are returned to improve the vibrating transfer characteristic, in order to allow the vibrations of the mold to present a preset vibrating waveform. The reason why the vibration transfer characteristic should be improved in this way is as follows. Attempts have recently been made to produce a sawtooth vibrating waveform in the mold, adapted to increase and decrease the up and down movements of the mold, respectively, so as to improve the quality of the mold. the casting surfaces produced by a continuous casting. Such a non-sinusoidal, sawtooth waveform contains harmonic wave components, such as second and third order harmonics. Furthermore, under certain conditions of setting in vibration, the mechanical support structure, which includes beams to support the entire mold, enters into resonance with said harmonic wave components, making it impossible to obtain a pre-set wave form of setting in vibration. Therefore, attempts are intended to prevent such a phenomenon from occurring. In this sense, it should be mentioned that the aforementioned provision is based on the principle of detecting the position of the hydraulic cylinder rod and the acceleration of the mold, and the return of these detected values ​​so as to obtain a setting waveform. in pre-set vibration. However, since the question of control is complicated and the pickup attachment locations are limited, a problem arises that it is difficult to obtain a preset vibrating waveform. Furthermore, in a continuous casting equipment, given that the environmental conditions are poor, the collectors have a tendency to break down. Consequently, if a collector breaks down, the hydraulic cylinder is packed and roasted, therefore, the vibrating must be stopped. In other words, it is necessary to stop the casting, raising the problem that waste results, when the molten metal has to be returned back to the casting ladle, and that a residue formation occurs.

Summary of the invention

Accordingly, an object of the present invention is to accurately vibrate the mold and to allow control of the vibrating of the mold to continue even if a pick-up fails.

To achieve this objective, the device for placing the mold in vibration of a continuous casting equipment according to the present invention comprises: a support structure that must mechanically support the mold; a cylinder device for applying vibrations to the mold, by means of said support structure; a hydraulic unit for supplying hydraulic fluid to said cylinder device, by means of a hydraulic circuit; and a control unit for supplying an actuating signal to an actuating section of said cylinder device, the aforementioned apparatus for placing the mold in vibration being characterized in that an electrohydraulic cylinder is used as the aforementioned cylinder device for step-by-step displacement. step or a servomechanism, comprising the aforementioned control unit: a set waveform signal generator for generating a set waveform signal for the mold; a mechanical offset signal generator to add a mechanical offset waveform signal to the set waveform signal, supplied from the set waveform signal generator, to override a displacement transfer delay caused due to the elastic deformation of the aforementioned support structure; A hydraulic compensation signal generator to add a hydraulic cylinder compensation waveform signal to the waveform signal, which comes from the aforementioned mechanical compensation signal generator, to remedy the disturbance caused to the waveform by the operating delay of the mentioned step-by-step displacement electrohydraulic cylinder;

ES 2 154 658 T3 a feedback signal generator for receiving a position signal, which comes from a position detector that detects the state or the displaced position of said mold; calculating the difference between the shifted state signal and a shifted state signal obtained from said setpoint waveform signal generator; the addition of the difference signal or the difference obtained for that subtraction to the signal with the waveform supplied either from the mentioned signal generator with the setpoint waveform or the mentioned mechanical compensation signal generator.

Following the provisions described above, to apply a pre-set vibration waveform to the mold, that is, a setpoint waveform through the support structure by means of the step-by-step displacement electrohydraulic cylinder, a compensation of direct action that adds: (a) the compensation signal that cancels the displacement transfer delay caused by an elastic deformation of the support structure, and (b) a compensation signal to remedy the operation delay of the stepper displacement electrohydraulic cylinder, and a feedback control is also used, correcting the difference between the actual vibration waveform of the mold and the setpoint waveform signal or the waveform signal supplied by the mechanical compensation signal generator; deviation from the actual mold vibration waveform can be corrected based on real time. Consequently, very fine control can be made which is little affected by disturbance.

In addition, since the displaced state and / or the position of the mold is the objective of a return of information, the formation of noise or other signal processing is facilitated in the feedback control compared to the case in which, in addition from the displaced state of the mold, the feedback information is constituted by the position of the stem of the hydraulic cylinder, which is the actuating device for a mold setting, the position of the rod of the step displacement electrohydraulic cylinder and the rotational position of the drive servomotor, to do so. In addition, even if a pickup fails to stop the feedback control operation, direct action compensation alone is capable of allowing the mold start-up control to continue.

Another embodiment of the mold vibrating device according to the invention comprises: a filtering circuit for receiving the setpoint waveform signal from said setpoint waveform signal generator to provide a setpoint-shaped signal. wave correction to produce the average gain in its frequency characteristic; an adaptive control circuit for controlling the control coefficient intervening in said filtering circuit, to provide an optimal value as a function of the difference signal between said signal with a set waveform and the signal of shifted state; a feedback control section to generate a feedback control signal based on the difference signal obtained by subtracting the signal with correction waveform supplied from the aforementioned filtering circuit, from the aforementioned shifted state signal that comes of the aforementioned displaced state detector; and a second hydraulic compensation signal generator to add a hydraulic compensation signal to the feedback control signal output from the aforementioned feedback control section, the arrangement being such that the difference signal to which the feedback signal is added output of said second hydraulic compensation signal generator is added to the waveform signal supplied from said mechanical compensation signal generator.

Following the aforementioned arrangement, to apply a predetermined vibration waveform, that is, a setpoint waveform to the mold, through the support structure through the step-by-step displacement electrohydraulic cylinder, a precompensation is used that adds : (a) the compensation signal that cancels the operating delay of the electrohydraulic stepping displacement cylinder, and (b) a compensation signal to cancel the displacement transfer delay caused by an elastic deformation of the support structure, and A feedback control is also used that provides, as a difference signal, the difference between the signal with the correction waveform, that cancels the resonance attributable to the intronsic frequency of the mold setting system, the arrangement being such that, when the aforementioned signal with a correction waveform is calculated by the filtering circuit, the control parameters of the filtering circuit they are optimized on a real basis. Therefore, the difference of the actual vibration waveform and resonance can be reliably corrected. Therefore, a very fine control can be performed that is little affected by disturbance. In feedback control, since the signal obtained based on the displaced state of the mold is returned in feedback, the case of a control failure or similar, attributable to the failure of a sensor, is minimized. In addition, even if the feedback control function stops as a result of a sensor failure, the direct action compensation allows the mold start-up control to continue, so that the formation of residues attributable to damage can be prevented. casting operation stop. Furthermore, since the arrangement is such that the control parameters of the filtering circuit are corrected on a real-time basis, an optimal control of vibrating start-up can always be ensured even if the characteristics of the electrohydraulic stepper displacement cylinder change. in the course of time, or even if the intrinsic frequency of the mold setting system varies slightly when the mold is exchanged for another of the same weight and the same size.

Brief description of the figures

Figure 1 is a view representing the totali3

ES 2 154 658 T3 of the arrangement of a mold setting device according to a first embodiment of the invention;

Figure 2 is a view showing the entire arrangement of a modification of the device for placing the mold in vibration according to the first embodiment of the invention;

Figure 3 is a view that represents the entire arrangement of a modification of the device for vibrating the mold according to the first case of embodiment of the invention;

Figure 4 is a view showing the entire arrangement of a modification of the device for placing the mold in vibration according to the first embodiment of the invention;

Figure 5 is a view that represents the entire arrangement of a mold setting device according to a second embodiment of the invention;

Figure 6 is a view showing the entire arrangement of a modification of the device for placing the mold in vibration according to the second embodiment of the invention;

Figure 7 is a view showing the entire arrangement of a modification of the device for placing the mold in vibration according to the second embodiment of the invention;

Figure 8 is a view showing the entire arrangement of a modification of the mold setting device according to the second embodiment of the invention;

Figure 9 is a view showing the entire arrangement of a mold setting device according to a third embodiment of the invention;

Figure 10 is a block diagram representing the operation of the main part of the device for placing the mold in vibration according to the third embodiment of the invention;

Figure 11 is a block diagram that represents the operation of the main part of a modification of the mold setting device according to the third embodiment of the invention;

Figure 12 is a view showing the entire arrangement of a mold setting device according to a fourth embodiment of the invention;

Figure 13 is a block diagram representing the operation of the main part of the device for placing the mold in vibration according to the fourth embodiment of the invention; Y

Figure 14 is a block diagram that represents the operation of the main part of a modification of the mold setting device according to the fourth embodiment of the invention.

Description of preferred embodiments

A mold setting device is described, according to a first embodiment of the invention, in relation to the figures

1a4.

In figure 1, the number 1 designates a mold in a continuous molding equipment, said mold being placed on a bench 2. Furthermore, this mold 1 is supported in such a way that it performs an oscillating movement in a vertical plane with respect to a support block 4, by means of bench 2 and a joining mechanism 3, and is vibrated vertically by a step-by-step displacement electrohydraulic cylinder 5 connected to said joining mechanism 3.

The link mechanism 3 comprises an upper link 11 and a lower link 12. The upper and lower connections 11 and 12 are joined by connecting pins at one of their respective ends with bank 2. Furthermore, the other end of said upper joint 11 and the intermediate part of said lower joint 12 are supported by the support foot 4 by means of joint pins, and the other end of said lower joint 12 was coupled by means of pins. of connection to the stem 5a of said cylinder 5 for step-by-step displacement.

A hydraulic unit 21 destined to supply hydraulic fluid was connected to said cylinder 5 for step-by-step displacement by means of a hydraulic tube 22. In addition, a stepper displacement electric motor 25 (drive section) was provided, which moves a coil 24 to drive successive preset amounts of hydraulic fluid from the hydraulic unit 21 to a chamber 23 of the cylinder, and a drive unit 26 designed to drive said stepper displacement motor 25.

A control unit 27 (for which a high speed numerical control organ is used) was further provided to control the drive unit 26 of the stepping motor 25.

This control unit 27 comprises a signal generator 31 with a set waveform for generating a signal with a set waveform for vibrating the mold 1; a mechanical compensation signal generator 32 for adding, to a set waveform signal supplied by said set waveform signal generator 31, a compensation waveform signal to override a transfer delay of displacement, caused by the elastic deformation of the mechaonic support structure, which comprises the joining mechanism 3 and the bank 2; a stepper displacement cylinder compensation signal generator 33 (hydraulic compensation signal generator) for adding, to a waveform signal from said mechanical compensation signal generator 32, a waveform signal of compensation to remedy the waveform disturbance caused by the delay in the operation of the stepping cylinder 5; a feedback circuit 35 (feedback signal generator) to receive an acceleration signal (displaced state signal) from an acceleration sensor 34 (displaced state detector) which is fixed to said mold 1 to detect the displaced state, for example, an acceleration of mold 1, said received signal being converted, for example, into a speed signal; subtract the aforementioned speed signal from a speed signal

ES 2 154 658 T3 setpoint speed (setpoint offset state signal) supplied by said setpoint waveform position signal generator 31; converting the difference signal obtained by this subtraction into a position signal, and adding the latter to the waveform signal supplied by said mechanical compensation signal generator 32; a pulse converter 36 designed to receive the drive signal obtained by adding the individual compensation signals and supply a pulse signal to said drive unit 26.

Furthermore, the feedback circuit 35 comprises an analog / numeric (A / N) converter 41 to effect an analog / numeric conversion of the acceleration signal from the acceleration pick-up 34 attached to the mold 1; a data processing section 42 to apply a predetermined treatment (for example, an integration) to the numerical acceleration signal that has undergone an A / N conversion; an anomaly decision making section 43 for making a decision regarding an anomaly of the processing signal supplied by the data processing section 42; a signal conversion section 44 to apply a preset numerical operation to the setpoint waveform signal, supplied by the setpoint waveform signal generator 31, and convert it into a setpoint signal of the same type as the aforementioned treatment signal; a conversion treatment section 45 to apply a predetermined conversion treatment (treatment signal / position signal conversion) to the difference signal obtained by subtracting the aforementioned treatment signal from the setpoint signal, supplied by the aforementioned section 44 signal conversion, and to add this converted difference signal serving as position data to the waveform signal supplied by said mechanical compensation signal generator 32. Furthermore, the exit path coming from the mentioned anomaly decision-making section 43 was provided with a signal switch 46 which, when the treatment signal is considered abnormal by the anomaly decision-making section 43, interrupts the emission of said signal. In addition, a direct action control is performed by the mentioned mechanical compensation signal generator 32 and the stepper displacement cylinder compensation signal generator 33.

Let, in the aforementioned provision, be x_or the setpoint waveform signal supplied by the setpoint waveform signal generator 31 for mold 1, (Δχ_ο) the difference signal supplied by the feedback circuit 35, and (Δχ₁) and (Δχ₂) the compensation signals supplied by the mechanical compensation signal generator 32 and the stepping displacement cylinder compensation signal generator 33, respectively, which constitute the direct acting compensation circuit. Then the signal x (drive signal), which is directed to the boost converter 36 is (Χ0 + ΔΧ0 + ΔΧ1 + ΔΧ2).

Furthermore, the difference signal from the feedback circuit 35 is added to the waveform signal supplied by the mechanical compensation signal generator 32; however, the signals are here 'in a state just like after exposure to treatment for a function. Likewise, the conversion into position data is performed at given time intervals in the stepping displacement cylinder compensation signal generator 33.

In the feedback circuit 35, the real acceleration signal for the mold 1 is conducted and converted into a numerical signal, and is subjected to an integration in the data processing section 42 to be converted into a speed signal, being analyzed this last one, to know if there is an anomaly, in section 43 of decision making of anomaly. If this speed signal is considered normal, it is supplied as is. On the other hand, in signal conversion section 44, the signal with a setpoint waveform, which is made up of input position data, is converted (by an arithmetic operation) into a setpoint speed signal, which is supplied then. Furthermore, the speed signal passing through the anomaly decision making section 43 is subtracted from the set speed signal which has undergone a conversion treatment. The difference signal obtained in this subtraction is converted into a difference signal, which serves as position data in the conversion processing section 45, which is then added to the waveform signal supplied by the signal generator 32. mechanical compensation.

In addition, in the direct action compensation section, the signal (Δχ₁) of compensation aimed at canceling the signal transfer delay due to the elastic deformation of the mentioned mechaonic support structure, and the signal (Δχ₂) compensation intended to remedy the operating delay of the stepping cylinder 5. Furthermore, the signals (Δχ₁) and (Δχ₂) Compensation components are compensation components that are found, in theory, so that mold 1 produces the same waveform as the preset vibration waveform, and can be found by the inverse of a transfer function between the input signal applied to the stepping cylinder 5 and the output signal from the mechanical support structure. Such compensation components can also be supplied by a function such as a Fourier series. Furthermore, as described above, the signal (Δχ₂) of compensation obtained in the stepping displacement cylinder compensation signal generator 33 is assigned to a time value and supplied in the form of position data.

The control carried out in the layout of the master above is going to be specifically described now.

As far as the mechanical support structure is concerned, it is not a perfectly rigid body, therefore, if the output waveform component of the stem 5a of the stepping cylinder 5 contains components of the order more elevated, such components force

ES 2 154 658 T3 the mechanical support structure, for example, the bonding mechanism 3, to develop a resonance phenomenon.

In particular, in the case where the signal waveform is a non-sinusoidal waveform, such as a sawtooth waveform, the signal with the setpoint waveform itself contains a series of components of order more high, having a tendency to cause resonance.

Consequently, the arrangement is such that a waveform signal containing a signal component is supplied, which cancels the resonance of the mechanical support structure constituted by the joining mechanism 3 and bank 2, by the cylinder 5 scrolling step by step.

The hydraulic operating delay is compensated in the stepping cylinder 5. That is, the displacement of the stem 5a is controlled by controlling the displacement of the valve and the coil 24; However, for the stem 5a to move at a predetermined speed, it is necessary that the degree of opening of the valve is greater than a certain value. Thus, an operating delay (phase delay) occurs between the input and output signals. The input waveform is compensated in such a way as to nullify that operating delay, in order to ensure that the output waveform of the stepping cylinder 5 has the same phase and waveform as the waveform. preset.

That is, the aforementioned signal (Δχ₁compensation) contains a signal component to cancel the resonance produced in the mechanical support structure, such as the link mechanism 3 and bank 2. In addition, the aforementioned signal (Δχ₂compensation) contains a signal component to remedy the lag in operation caused by the stepping cylinder 5.

Furthermore, if the anomaly decision-making section 43 decides that the speed signal is abnormal, that is, when the acceleration sensor 34 fails, the signal switch 46 interrupts the supply of the speed signal. That is to say, the situation in which the feedback control stops working is avoided, with the result that the entire system operates uncontrollably. Of course, in this case, only direct action compensation works.

In this way, since a direct action compensation is used together with a feedback control to correct the deviation value with respect to the signal with setpoint waveform in real time, based on the acceleration that actually acted on the mold 1, it is possible to dispense with the position detection sensor to detect the position of the stem of a hydraulic cylinder, as described above in relation to the example of the previous technique, and it is also possible to correct in real time the difference between the real vibration waveform of mold 1 and the setpoint waveform, which could not be corrected for direct action control only. Consequently, very precise control can be obtained that is little affected by a disturbance.

Furthermore, since the position sensor designed to detect the position of the stepping cylinder rod can be dispensed with, it is no longer necessary to worry about the contingency of a stepping cylinder runaway, which would occur if the position sensor is faulty.

In this first embodiment, it has been indicated that by detecting the position of the mold 1, the acceleration sensor 34 is used and the acceleration signal is converted into a speed signal, so that a deviation signal is supplied; However, the acceleration signal itself can be used as a deviation signal. In this case, in section 43 of signal conversion, the signal with the setpoint waveform is converted into acceleration data and a subtraction was carried out between the acceleration signals, and in section 44 of conversion treatment, after Converting the result to a waveform signal, the latter is added to a waveform signal supplied as a deviation signal by the mechanical compensation signal generator 32.

In this first embodiment, it has been indicated that the acceleration sensor 34 (displaced state detector) was fixed to the mold 1; however, it can be attached to bank 2 or, as shown in dots in figure 1, it can be attached to the end of the upper link 11.

In this regard, in the first embodiment, it has been stated that the signal (Δχ_ο) deviation obtained by the feedback circuit 35 is added to the waveform signal supplied by the mechanical compensation signal generator 32; however, as represented in figure 2, this signal (Δχ_οThe offset) can be added to the setpoint waveform signal (the signal prior to being sent to the mechanical compensation signal generator 32) supplied by the setpoint waveform signal generator 31. In this case, likewise, the same advantages as those of the first embodiment described above can be obtained.

Furthermore, in this first embodiment, an acceleration sensor has been installed to detect the position of the mold 1; However, as shown in figure 3, a position detection sensor 34 '(position detector) can be provided, which serves to directly detect the position of mold 1, to execute a feedback control, using the signal position obtained by the aforementioned position detection sensor. In this case, a subtraction is made between the position signal, which passes through section 43 for decision making of anomaly, and the signal with a setpoint waveform supplied by the signal generator 31 with a setpoint waveform, through section 43 of signal conversion, and the deviation signal obtained in this subtraction is added to the signal with a setpoint waveform supplied by the mentioned signal generator 31 with a setpoint waveform (or it can be added to the signal with a setpoint waveform supplied by the generator). 32 of the mechanical compensation signal, as

ES 2 154 658 T3 has shown in figure 4). Consequently, the conversion treatment section 44 becomes useless. However, even if this is not shown, the gain section is to be appropriately supplied to multiply the offset signal by a preset gain.

In addition, instead of using the aforementioned position detection sensor, the acceleration sensor 34 can be used and the acceleration signal can be integrated twice in the data processing section 42, for a conversion into position data, which can be used to obtain a deviation signal.

Furthermore, it has been indicated that, in the feedback circuit 35, the acceleration signal, the speed signal and the position signal are used separately as signals before being returned in feedback; however, appropriate combinations of these signals can be used. For example, a combination of all signals (acceleration signal + speed signal + position signal) can be used.

Furthermore, in this first embodiment, it has been indicated that vibrations are applied to the mold by means of the bench and the joining mechanism; however, a stepping cylinder connected directly to the bench supporting the mold can be attached. In addition, in this case, the bank will be considered as a mechanical support structure for a signal transfer.

A mold setting device will now be described according to a second embodiment in connection with Figures 5 to 8.

The point that differs from the first embodiment is that the cylinder device intended to apply vibrations to the mold was constituted by an electrohydraulic cylinder with step-by-step displacement in the first embodiment, while in the second embodiment, it was made up of an electro-hydraulic servo cylinder.

In figure 5, the number 101 designates a mold of a continuous molding equipment, said mold being placed on a bench 102. Furthermore, this mold 101 is supported in such a way that it performs an oscillating movement in a vertical plane, with respect to a support foot 104, by means of the bench 102 and a link mechanism 103, and is vertically vibrated by an electrohydraulic servo cylinder 105 connected to said link mechanism 103.

The link mechanism 103 comprises an upper link 111 and a lower link 112. The upper and lower junctions 111 and 112 are attached by link pins at one of their respective ends to bank 102. Furthermore, the other end of said upper joint 111 and the intermediate part of said lower joint 112 are supported by the support foot 104 by means of joint pins, and the other end of said lower joint 112 is joined by pins. of union to the rod 105a of the mentioned servo cylinder 105.

A hydraulic unit 121 designed to feed hydraulic fluid is connected to said servo cylinder 105 through a tube.

122 hydraulic. Furthermore, an electric servomotor 125 (drive section) was provided that moves a coil 124 to supply successive predetermined quantities of hydraulic fluid from the hydraulic unit 121 to a cylinder chamber 123, and a drive unit 126 designed to drive said servomotor 125.

In addition, a control unit 127 (for which a high speed numerical control body is used) was provided to control the drive unit 126 of the servo motor 125.

This control unit 127 comprises a set waveform signal generator 131 for generating a set waveform signal to vibrate the mold 101; a mechanical compensation signal generator 132 for adding, to a setpoint waveform signal supplied by said setpoint waveform signal generator 131, a compensation waveform signal to override a transfer delay of displacement caused by elastic deformation of the mechanical support structure, which comprises the joining mechanism 103 and the bench 102; a cylinder compensation signal generator 133 (hydraulic compensation signal generator) for adding, to a waveform signal from said mechanical compensation signal generator 132, a compensation waveform signal to remedy the disturbance waveform caused by the operating delay of the servo cylinder 105; a feedback circuit 135 (feedback signal generator) to receive an acceleration signal (offset state signal) from an acceleration pickup 134 (offset state detector) which is attached to the mold 101 to detect the offset state, by For example, an acceleration of the mold 101, the aforementioned received signal being converted, for example, into a speed signal, subtracting said speed signal from a setpoint speed signal (setpoint offset state signal) supplied by said setpoint waveform position signal generator 131, converting the difference signal obtained by this subtraction into a signal position, and add the latter to the waveform signal supplied by said mechanical compensation signal generator 132; a servo motor rotation angle converter 136 designed to receive the drive signal obtained by adding the individual compensation signals and supply a rotation angle signal from said drive unit 126.

The aforementioned drive unit 126 comprises an N / A converter 141 to convert the rotation angle signal supplied by the servo motor rotation angle converter 136 into a numerical signal, and a servo amplifier 142 to amplify the output signal from said converter 141 N / A, the arrangement being such that the real angle of rotation of the servomotor 125 is detected by the angle detector 143 installed in the servomotor 125, and the rotation angle signal thus detected is sent to the control signal to be

ES 2 154 658 T3 driven to servo amplifier 142.

Furthermore, the feedback circuit 135 comprises an A / N converter 151 for an A / N conversion of the acceleration signal from the acceleration pickup 134 attached to the mold 101; a data processing section 142 for applying a preset processing (eg, an integration) to the numerical acceleration signal that has undergone an A / N conversion; a section

153 anomaly decision making to make a decision in relation to an anomaly of the treatment signal supplied by data processing section 152; a section

154 signal conversion to apply a preset arithmotic operation to the signal with a setpoint waveform, and converting into a setpoint signal of the same type as said processing signal; and a conversion treatment section 155 to apply a predetermined conversion treatment (treatment signal / position signal conversion) to the difference signal obtained by subtracting said treatment signal from the reference signal supplied by said section. 154 signal conversion, and to add this converted turn signal, which serves as position data, to the waveform signal supplied by said mechanical compensation signal generator 132. In addition, the exit path from the aforementioned anomaly decision-making section 153 interrupts the emission of the aforementioned signal. Furthermore, direct action control is performed by said mechanical compensation signal generator 132 and cylinder compensation signal generator 133.

Let, in the aforementioned arrangement, be x_or the setpoint waveform signal supplied by the setpoint waveform signal generator 131 for the mold 101, (Δχ_ο) the difference signal supplied by the feedback circuit 135, and (Δχ₁) and (Δχ₂) the compensation signals supplied by the mechanical compensation signal generator 132 and the cylinder compensation signal generator 133, respectively, which constitute the direct acting compensation circuit. Next, the signal x (drive signal) that is fed to the servomotor rotation angle converter 136 is (xo + ΔΧ0 + ΔΧ1 + ΔΧ2).

Furthermore, the difference signal from the feedback circuit 135 is added to the waveform signal supplied by the mechanical compensation signal generator 132; however, the signals are here in such a state as after exposure to treatment for a function. Furthermore, the conversion into position data was performed at given time intervals in the cylinder compensation signal generator 133.

In the feedback circuit 135, the real acceleration signal for the mold 101 is carried and converted into a numerical signal, and it is exposed to an integration in the data processing section 152 to supply a speed signal, the latter being analyzed. in what refers to the presence of an anomaly in section 153 of decision making of anomaly. If this speed signal is considered normal, it is supplied as is. On the other hand, in the signal conversion section 154, the signal with a setpoint waveform, which consisted of input position data, is converted (by an arithmetic operation) into a setpoint speed signal, which is then supply. In addition, the speed signal that passes through section 153 of decision making of anomaly is subtracted from the set speed signal that has undergone a conversion treatment. The difference signal obtained in this subtraction is converted into a difference signal that serves as a position signal in section 155 of the conversion treatment, which is then added to the waveform signal supplied by the compensation signal generator 132. mechanical.

In addition, the signal (Δ,₁) of compensation aimed at canceling the signal transfer delay due to the elastic deformation of the mentioned mechanical support structure, and the signal (Δ₂) of compensation to remedy the delay of operation of the servo cylinder 105. In addition, the signals (Δχ₁) and (Δχ₂Compensation) are compensation components that are found, in theory, such that the mold 101 produces the same waveform as the preset vibration waveform, and can be found using the inverse transfer function between the input signal, applied to the servo cylinder, and the output signal from the mechanical support structure. Such compensation components can also be supplied by a function such as a Fourier series. Furthermore, as described above, the signal (Δχ₂The compensation obtained in the cylinder compensation signal generator 133 is to be affected by a time value and is supplied as position data.

We are going to describe now the control in the arrangement of masses up.

As regards the mechaonic support structure, it does not constitute a perfectly rigid body; Thus, therefore, if the output waveform of the rod 105a of the servo cylinder 105 contains higher order components, such components force the mechanical support structure, for example the link mechanism 103, to develop a resonance phenomenon.

In particular, in the case that the signal waveform is a non-sinusoidal waveform, such as a sawtooth waveform, the signal with the setpoint waveform itself contains a series of components of the order móas high, having a tendency to cause resonance.

Accordingly, the arrangement is such that the servo cylinder 105 supplies a waveform signal containing a signal component, which cancels the resonance of the mechanical support structure, constituted by the link mechanism 103 and the bank 102.

In the servo cylinder 105, the hydraulic operating delay was compensated. That is, the displacement of the stem 105a is controlled by controlling the displacement of the valve and of

ES 2 154 658 T3 coil 124; however, for the stem 105a to travel at a predetermined speed, it is necessary that the degree of opening of the valve is greater than a certain value. Thus, there is an operating delay (phase delay) between the input and output signals. The input waveform is compensated in such a way as to override said operating delay to ensure that the output waveform from servo cylinder 105 has the same phase and waveform as the preset waveform.

That is, the aforementioned signal (Δχ₁compensation) contains a signal component to cancel the resonance produced in the mechanical support structure, such as the link mechanism 103 and the bank 102. In addition, the mentioned signal (Δχ₂Compensation) contains a signal component to remedy the run delay caused by servo cylinder 105.

Also, if the abnormality decision making section 153 decides that the speed signal is abnormal, that is, when the acceleration pickup 134 fails, the signal accumulator 156 interrupts the supply of the speed signal. That is, the situation in which the feedback control stops working is avoided, with the result that the entire system runs uncontrollably. Of course, in that case, direct action compensation works alone.

In this way, since a direct action compensation is used in conjunction with a feedback control to correct the deviation value of the signal with setpoint waveform in real time based on the acceleration that actually acted on the mold 101, It is possible to dispense with the position detection sensor to detect the position of the stem of a hydraulic cylinder, as described above in relation to the example of the previous technique, and it is also possible to correct in real time the difference between the actual vibration waveform of the mold 101 and the setpoint waveform, which could not be corrected by the direct action control alone. Consequently, very precise control can be obtained that is little affected by disturbance.

Furthermore, since the position sensor designed to detect the position of the servo cylinder rod can be dispensed with, it is no longer necessary to worry about the contingency of a servo cylinder runaway that would occur if the position sensor were to fail.

In this second embodiment, it has been indicated that by detecting the position of the mold 101, the acceleration sensor 134 is used and the acceleration signal is converted into a speed signal, so as to supply a difference signal; however, the acceleration signal itself can be used as a difference signal. In this case, in the signal conversion section 153, the signal with the setpoint waveform is converted into acceleration data, and a subtraction is made between the acceleration signals, and the latter is added in the treatment section 154 They were converted to a waveform signal, supplied as a difference signal by the mechanical compensation signal generator 132.

In this second embodiment, it has been indicated that the acceleration sensor 134 (displaced state detector) was fixed to the mold 101; however it may be attached to bank 102 or, as shown in dots in FIG. 5, it may be attached to the end of upper link 111.

In this regard, in the second embodiment, it has been indicated that the signal (Δχ_ο) the difference obtained by the feedback circuit 135 is added to the waveform signal supplied by the mechanical compensation signal generator 132; however, as represented in figure 6, this signal (Δχ_οThe difference) can be added to the setpoint waveform signal (the signal prior to being sent to the mechanical compensation signal generator 132) supplied by the setpoint waveform signal generator 131. In this case, the same advantages can also be obtained as those of this second embodiment described above.

Furthermore, in this second embodiment, an acceleration sensor has been installed to detect the position of the mold 101; However, as shown in figure 7, a position sensor 134 '(position detector) can be provided, which serves to directly detect the position of the mold 101, to execute a feedback control, using the position signal obtained. by the aforementioned position detection sensor. In this case, a subtraction is carried out between the position signal, which passes through section 153 for making an anomaly decision, and the signal with a setpoint waveform, supplied by the signal generator 131 with a setpoint waveform. , through section 153 of signal conversion, and the difference signal obtained in this subtraction is added to the signal with a setpoint waveform supplied by the mentioned signal generator 131 with a setpoint waveform (or it can be added to the signal with a setpoint waveform supplied by the generator 132 of mechanical compensation, as represented in figure 8). Therefore, even if it has not been shown, the gain section will be fed appropriately to multiply the difference signal by a preset gain.

Furthermore, instead of using the aforementioned position detection sensor, the acceleration sensor 134 can be used and the acceleration signal can be integrated twice in the data processing section 152 for a position data conversion, which can be used to get a signal of difference.

Furthermore, it has been indicated that in the feedback loop 135, the acceleration signal, the speed signal and the position signal are used separately as signals before being returned in feedback; however, appropriate combinations of these signals can be used. For example, a combination of all signals can be used (acceleration signal + speed signal + position signal).

Furthermore, in this second embodiment, it has been indicated that vibrations are applied to the

ES 2 154 658 T3 mold through bench and joining mechanism; however, a servo cylinder can be connected directly to the bench that supports the mold. In addition, in this case, the bank will be considered as a mechaonic support structure for a signal transfer.

A mold setting device will now be described according to a third embodiment in relation to Figures 9 to 11.

In Figures 9 to 10, the number 201 designates a mold of a continuous molding equipment, said mold being placed on a bench 202. Furthermore, this mold 201 is supported in such a way that it performs an oscillating movement in a vertical plane with respect to a support foot 204, by means of the bench 202 and a joining mechanism 203, and is vertically vibrated by a cylinder 205 step-by-step displacement electrohydraulic connected to the aforementioned joining mechanism 203.

The link mechanism 203 comprises an upper link 211 and a lower link 212. The upper and lower junctions 211 and 212 are attached by link pins at one of their respective ends to bank 202. Furthermore, the other end of said upper joint 211 and the intermediate part of said lower joint 212 are supported by the support foot 204 by means of joint pins, and the other end of said lower joint 21 was joined by pins. of union to the stem 205a of the mentioned cylinder 205a of displacement step by step.

A hydraulic unit 221 intended to supply hydraulic fluid was attached to said cylinder 205 for step-by-step displacement by means of a hydraulic tube 222. In addition, a stepper displacement electric motor 225 (drive section) is provided, which moves a coil 224 to supply successive preset quantities of hydraulic fluid from the hydraulic unit 221 to a cylinder chamber 223, and a cylinder unit 226. drive designed to drive said stepper motor 225.

In addition, a control unit 227 is provided for controlling the drive unit 226 of the stepping motor 225.

This control unit 227 comprises a signal input section 231 having an A / N converter attached to the mold 201 and receiving an actual mold position signal (which is an example of an offset state signal, hereinafter called , simply the real position signal), from a position sensor 228 (displaced state detector) to detect the displaced state, for example, the vibration position of the mold 201, converting the aforementioned converter into a numerical signal the aforementioned real position signal; a first control section 232 to generate a signal with a setpoint waveform destined for the mold; a second control section 233 to supply a signal with a correction waveform, in order to read the gain in its frequency characteristic, towards the position signal coming from the signal input section 231; a third control section 234 to obtain a difference signal by subtracting the signal with correction waveform coming from the second control section 233, from the actual position signal destined for the mold, the calculation of a control signal of predetermined feedback based on the aforementioned difference signal, and the addition of this feedback signal to the exit signal from the first control section 232; and a pulse converter 235 for receiving a drive signal, obtained by adding the output signals of the two control sections 232 and 234, so as to supply a pulse signal to the drive unit 226.

The first control section 232 comprises a set waveform signal generator 241 for generating a set wave signal to vibrate the mold 201; a first generator 242 of a stepper displacement cylinder compensation signal (first hydraulic compensation signal generator) to add, to the signal with a setpoint waveform, supplied by said signal generator 241 with a waveform of setpoint, a signal with waveform compensation to remedy waveform disturbance caused by operating delay (for example, the delay attributable to the switching of the valves and the compression of the oil) of the stepper displacement cylinder 205; and a mechanical compensation signal generator 243 (it was carried out, for example, the acceleration correction of the mold) to add a signal with a compensation waveform that allows canceling the motion transfer delay attributable to the elastic deformation of the structure mechanical support, comprising the joining mechanism 203 and the bank 202.

The second control section 233 was provided with a circuit 251 destined to receive the signal with a setpoint waveform from the signal generator 241 with a setpoint waveform to supply a signal with a correction waveform (specifically, a signal with a waveform that allows to cancel the intronsic frequency of the mold vibration system), in order to read the gain of its frequency characteristic according to the aforementioned signal with a setpoint waveform; an adaptive control circuit 252 to optimize the characteristics in said filtering circuit 251, that is, the control parameters in real time according to the real vibration state of the mold 201. As for the aforementioned filtering circuit 252, it is used, for example, a setpoint filter or a reject filter.

The adaptive control circuit 252 comprises a diagnostic circuit 253 with a waveform to receive a real position signal from the aforementioned input section 231, in order to carry out a Fourier series expansion or a fast Fourier transformation, of control that performed the frequency analysis of the real position signal; and a learning circuit 254 to receive the output signal from said waveform diagnostic circuit 253 and the setpoint waveform signal from the setpoint waveform signal generator 241 so that they are optimized.

ES 2 154 658 T3 the control parameters (specifically, the different coefficients of the control transfer function) in the filtering circuit 251, based on the difference signal between those two waveform signals.

A numeric signal processor or the like is used for said learning circuit 254. The learning circuit 254 supplies a signal that optimizes the control parameters in the real-time filtering circuit 251, for example, by selecting the source intronsic frequency from a series of peak values ​​mixed in the actual position signal in order to cancel the intronsic frequency of the vibratory system of the mold 201. Also, in this learning circuit 254, an algorithm applicable to an adaptive filter or the like is used.

A learning decision making section 255 is provided between the learning circuit 254 and the waveform diagnostic circuit 253 to make a decision as to whether or not to use the learning circuit 254. For example, if a motive other than the preceding waveform is driven to it, a signal is supplied through the learning circuit 254.

A third control section 234 comprises a feedback control section 261 to receive the actual position signal from the signal input section 231 in order to supply a feedback control signal (PID-type proportional-integral differential control signal). ) and a feedback compensation signal (for example, a compensation signal based on speed and position signals); a second stepper shift cylinder compensation signal generator 262 (second hydraulic compensation signal generator) to receive the position signal supplied by feedback control section 261 to remedy waveform disturbance caused by delayed operation of the stepping cylinder 205. In addition, the compensated difference signal in said second stepper shift cylinder compensation signal generator 262 is added to the signal with setpoint waveform exposed to said hydraulic and mechanical compensations.

In addition, the feedback control section 261 comprises a feedback control circuit 263 to effect proportional-integral-differential PID type control, and a feedback compensation circuit 264 to supply a compensation signal based on the speed signals. and position. The feedback compensation circuit 264 was intended to stabilize the control system and improve control precision. Furthermore, the aforementioned first stepper displacement cylinder compensation signal generator 242 and mechanical compensation signal generator 243 collaborate with each other to obtain direct acting compensation.

Let, in the aforementioned arrangement, be xo the signal with the setpoint waveform supplied by the signal generator 241 with the setpoint waveform for the mold 201, (Δχ₁) and (Δχ₂) the compensation signals supplied by the first stepper shift cylinder compensation signal generator 242 and the mechanical compensation signal generator 243, respectively, constituting the direct acting compensation circuit, and (Δχ_ο) the difference signal controlled by feedback and compensated based on the actual position signal from the signal input section 231 in the feedback control section 261 and from the second shift cylinder compensation signal generator 262 step by step. He passed. Then the signal taken to the impulse converter 235 is (x_or+ Δχ₁+ Δχ₂).

After a frequency analysis has been performed by the waveform diagnostic circuit 253 of the second control section 233, the waveform signal from the signal input section 231 is taken to section 255. of learning decision-making, in which a decision is made as to the need or not of learning. If it is decided that learning is necessary, the waveform signal, along with the setpoint waveform signal from the setpoint waveform signal generator 241, are led to the learning circuit 254 and the set signal. Difference is calculated between the two waveform signals. In this case, preset calculations were made based on this difference signal per algorithm used in the adaptive filter. For example, control paraometers are supplied to the filter circuit 251 so that a difference signal is found that is the difference between the peak value in the frequency characteristic of the waveform signal, that is, the frequency of the signal. resonance (intronsic frequency), and the signal with a setpoint waveform, and a signal with a waveform is supplied capable of canceling the resonance frequency based on the aforementioned difference signal. Consequently, it turns out that, in the actual vibrating state of the mold 201, the filter circuit 251 supplies a signal (Δχ₃) with a correction waveform that cancels the intronsic frequency.

In addition, the direct acting compensation circuit calculates the signal (Δχ₁) compensation to remedy the stepping cylinder 205 operating delay and the signal (Δχ₂) compensation to cancel the signal transfer delay attributable to the elastic deformation of the mechanical support structure. Furthermore, these signals (Δχ₁) and (Δχ₂Compensation) are compensation components that are found, in theory, so that the mold 201 produces the same waveform as the preset vibration waveform, and these signals can be found by the reciprocal of the function. transfer between the input signal applied to the stepping displacement cylinder 205 and the output signal from the mechanical support structure.

The control of the aforementioned arrangement will now be described more specifically.

First, in the stepping cylinder 205, the operating delay of the hydraulic system is compensated. It is 11

ES 2 154 658 T3 states that the displacement of the stem 205a is controlled by the control of the displacement of the valve and the coil 224; however, in order for the stem 205a to travel at a predetermined speed, it is necessary that the degree of opening of the valve is greater than a certain value. Consequently, an operation delay (phase delay) occurs between the two input and output signals. The input waveform is compensated to override such run delay to ensure that the output waveform from stepping cylinder 205 is identical in phase and waveform with respect to the preset waveform.

As for the mechanical support structure, it does not constitute a perfectly rigid body; Thus, if the output waveform from the rod 205a of the stepping cylinder 205 contains higher order components, such components force the mechanical support structure, for example, the link mechanism 203, to develop a resonance phenomenon. In particular, in the case where the signal waveform is a non-sinusoidal waveform, such as a sawtooth waveform, the setpoint waveform signal itself contains a series of components of the order móas high, having a tendency to cause resonance.

Consequently, the arrangement is such that a waveform signal containing a signal component is supplied, which cancels the resonance of the mechanical support structure constituted by the joining mechanism 203 and the bank 202, by means of the cylinder 205. scrolling step by step.

That is, the aforementioned signal (Δχ₁) contains a signal component to remedy the operating delay produced by the stepping cylinder 205, and that the aforementioned signal (Δχ₂The compensation) contains a signal component to cancel the resonance produced in the mechanical support structure, such as the link mechanism 203 and the bank 202.

In this way, since a direct action compensation is used, together with a feedback control to correct the deviation value of the signal with the setpoint waveform, in real time, based on the real position of the mold 201, It is possible to dispense with the position sensor to detect the position of the stem of a hydraulic cylinder, as previously described referring to the previous technique, for example, it is also possible to correct, in real time, the difference between the actual vibration waveform of the mold 201 and the setpoint waveform, which would not have been corrected by direct action control alone. Consequently, very precise control can be obtained that is little affected by disturbance.

In addition, since the position sensor can be dispensed with to detect the position of the stepping cylinder rod, it is no longer necessary to worry about a runaway of the stepping cylinder, which would have occurred if the piston rod was driven. position installed on the stepping cylinder rod is faulty.

In this third embodiment, it has been indicated that the control parameters of the filter circuit 251 are optimized by the learning circuit 254 with the aid of the adaptive filter algorithm; However, it is possible, for example, to perform real-time regulation and optimization of the time constants in the individual stepping cylinder compensation sections and of the gain in the feedback control section (the circuit feedback control, the feedback compensation circuit).

In this third embodiment, it has been indicated that, to detect the position, the speed and the acceleration of the mold 201, the position sensor 228 is used, which supplies position signals; however, an acceleration pickup can be used so that its acceleration signal is integrated once to supply the speed signal, and twice to supply the position signal. In addition, the acceleration signal can be driven to the control unit or the speed signal can be used. In addition, a position sensor and an acceleration sensor can be used at the same time.

In this third embodiment, it has been indicated that the position sensor 228 (displaced state detector) is fixed to the mold 201; however, it may be attached to the bench 202. Furthermore, as shown in dots in FIG. 9, it may be attached to the end of the upper link 211. In this case, the bank waveform estimated from the vibration waveform of the mold is used as a signal with a setpoint waveform.

In this third embodiment, it has been indicated that the algorithm placed in the adaptive filter is used for the adaptive control circuit; However, instead of using such an algorithm, analytical means using a fuzzy logic system or a fast Fourier transformation in a neural network can be used, as represented in figure 11.

Furthermore, in this third embodiment, it has been indicated that vibrations are applied to the mold through the bench and the connection mechanism; however, one or more stepping cylinders can be attached directly to the bench supporting the mold. In addition, in this case, the bank will be considered as a mechanical support structure for a signal transfer.

A mold setting device according to a fourth embodiment of the invention will now be described in connection with Figures 12 to 14.

The point that differs from the third embodiment is that, in the third embodiment, the cylinder device designed to apply vibrations to the mold is an electrohydraulic stepping cylinder, and in the fourth embodiment, it is an electrohydraulic servo cylinder.

In Figures 12 and 13, the number 301 designates a mold of a continuous molding equipment, said mold being placed on a

ES 2 154 658 T3 bench 302. Furthermore, this mold 301 is supported in such a way that it performs an oscillating movement in a vertical plane with respect to a support foot 304 by means of the bench 302 and a joining mechanism 303, and is put into vertically vibrating by electrohydraulic servo cylinder 305 connected to the aforementioned joining mechanism 303.

The link mechanism 303 comprises an upper link 311 and a lower link 312. The upper and lower joints 311 and 312 are connected by means of joint pins at one of their respective ends to bank 302. Furthermore, the other end of said upper joint 311 and the middle part of said lower joint 312 are supported by foot 304 by means of joint pins, and the other end of said lower joint 312 is joined by joint pins. to the rod 305a of said servo cylinder 305.

A hydraulic unit 321 destined to feed hydraulic fluid was connected to said servo cylinder 305 through a hydraulic tube 322. In addition, there were provided: an electric servomotor 325 (drive section) that moved a coil 324 to carry successive preset amounts of hydraulic fluid from the hydraulic unit 321 to a cylinder chamber 323; and a drive unit 326 comprising a servo amplifier designed to drive said servo motor 325.

A control unit 327 was further provided for controlling the drive unit 326 of the servo motor 325. This control unit 327 comprises: a signal input section 331 having an A / N converter attached to mold 301 and receiving a real mold signal (which is an example of an offset state signal, hereinafter simply referred to as real position signal), from a position sensor 328 (displaced state detector) to detect the displaced state, for example, the vibrating position of the mold 301, converting the aforementioned converter the aforementioned real position signal into a numerical signal; a first control section 332 to generate a signal with a setpoint waveform destined for the mold; a second control section 333 to supply a signal with a correction waveform, in order to read the gain in its frequency characteristic, towards the position signal coming from the second control section 333, of the intended real position signal the mold, the calculation of a predetermined feedback control signal based on the aforementioned difference signal, and the addition of this feedback control signal to the exit signal from the first control section 332; and a servomotor rotation angle converter 335 for receiving a drive signal contained by adding the output signals of the two control sectors 332 and 334, so that a rotation angle signal is supplied to the drive unit 326 .

The first control section 332 comprises: a set waveform signal generator 341 for generating a set waveform signal to vibrate the mold 301; a first servo-cylinder compensation signal generator 342 (first hydraulic compensation signal generator) to add, to the signal with a setpoint waveform supplied by the mentioned signal generator 341 with a setpoint waveform, a signal with a signal shape waveform compensation to remedy waveform disturbance caused by operating delay (for example, delay attributable to valve switching, and to the compression of the oil) of the servo cylinder 305; and a mechanical compensation signal generator 343 (for example, the acceleration compensation of the mold was performed) to add a signal with a compensation waveform that allows canceling the motion transfer delay attributable to the elastic deformation of the mold structure. mechanical support, comprising the joining mechanism 303 and the bench 302.

The second control section 333 was provided with a filtering circuit 351, destined to receive the signal with a setpoint waveform from the signal generator 341 with a setpoint waveform, to supply a signal with a correction waveform ( specifically, a wave-shaped signal that allows canceling the intronsic frequency of the mold setting system), in order to read the gain of its frequency characteristic according to the aforementioned signal with a setpoint waveform; an adaptive control circuit 352 to optimize the characteristics in the aforementioned filtering circuit 351, that is, the real-time control parameters according to the real state of vibration of the mold 301. As for the aforementioned filtering circuit 351, it is used, for example, a setpoint filter or a reject filter.

The adaptive control circuit 352 comprises a waveform diagnostic circuit 353 for receiving a real position signal from said signal input section 331, in order to carry out a Fourier series expansion, such as a transformation of Fast Fourier, so the frequency analysis of the actual position signal was performed, and a learning circuit 354 to receive the signal with the setpoint waveform from the signal generator 341 with the setpoint waveform, so that the control parameters (specifically, the different coefficients of the control transfer function) are optimized. ) in the filtering circuit 351, based on the difference signal between these two waveform signals.

A numeric signal processor or the like is used for said learning circuit 354. The learning circuit 354 supplies a signal that optimizes the control parameters of the filtering circuit 351 in real time, for example, by selecting the introns source frequency from a series of peak values ​​mixed in the real position signal, in order to cancel the intronsic frequency of the vibratory system of the mold 301. Furthermore, in the learning circuit 354, an algorithm applicable to an adaptive filter or the like is used.

A learning decision making section 355 is arranged between the learning circuit 354 and the waveform diagnostic circuit 353 to make a decision as to whether or not to use the 354 circuit.

ES 2 154 658 T3 of learning. For example, if a motif other than the preceding waveform is brought to it, a signal is output via the learning circuit 354.

The third control section 334 comprises a feedback control section 361 to receive the actual position signal from the signal input section 331, in order to supply a feedback control signal (PIR type control signal, proportional -integraldifferential) and a feedback compensation signal (for example, a compensation signal based on speed and position signals); a second servo cylinder compensation signal generator 362 (second hydraulic signal compensation generator) to receive the position signal, supplied by feedback control section 361, to remedy waveform disturbance caused by delay servo cylinder 305. Furthermore, the difference signal, compensated in the aforementioned second servo cylinder compensation signal generator 362, is added to the signal with a setpoint waveform exposed to the different hydraulic and mechaonic compensations.

In addition, the feedback control section 361 comprises a feedback control circuit 363 to effect PID-type, proportional, integral-differential control, and a feedback compensation circuit 364 to supply a compensation signal based on the feedback signals. speed and position. The feedback compensation circuit 364 is intended to stabilize the control system and improve control precision.

The aforementioned drive unit 326 comprises a 371 N / A converter to convert the rotation angle signal supplied by the servo motor rotation angle converter 335 into a numerical signal, and a servo amplifier 372 to amplify the output signal from said 371 N / A converter, the arrangement being such that the actual rotation angle of the servomotor 325 is detected by the angle detector 325a installed in the servomotor 325, and the rotation angle signal thus detected is returned in feedback to the control signal to be taken to the servo amplifier 372. Furthermore, the mentioned first servo cylinder compensation signal generator 342 and the mechanical compensation signal generator 343 collaborate with each other. to obtain direct action compensation.

Let, in the aforementioned arrangement, x_or the signal with setpoint waveform supplied by the signal generator 341 with signal with setpoint waveform for the mold 301, (Δχ₁) and (Δχ₂) the compensation signals supplied by the first servo cylinder compensation signal generator 342 and the mechaonic compensation signal generator 343, respectively, which constitute the direct acting compensation circuit, and (Δχ_ο) the difference signal sent by feedback and compensated, based on the real position signal coming from the signal input section 331 in the feedback control section 361 and the second servo cylinder compensation signal generator 362. Next, the signal brought to the servomotor rotation angle converter 335 is (χ_ο+ Δχ_ο+ Δχ₁+ Δχ₂).

After a frequency analysis has been performed by the waveform diagnostic circuit 353 of the second control section 333, the waveform signal from the signal input section 331 is taken to section 355 of the learning decision-making, in which a decision is made regarding the need or not for learning. If it is decided that learning is necessary, the waveform signal, together with the setpoint waveform signal from the setpoint waveform signal generator 341 are taken to the learning circuit 354 and the signal is calculated. difference between the two waveform signals. In this case, preset calculations were made based on this difference signal by the algorithm used in the adaptive filter. For example, control parameters are supplied to the filter circuit 351 so that a difference signal is found that is the difference between the peak value of the frequency characteristic of the waveform signal, that is, the frequency signal (intronsic frequency), and the signal with a setpoint waveform, and a signal with a waveform capable of canceling the resonance frequency is supplied based on the aforementioned difference signal. Consequently, it turns out that, in the actual vibrating state of the mold 301, the filter circuit 351 supplies a signal (Δχ₃) with the form of correction that cancels the intronsic frequency.

In addition, the direct acting compensation circuit calculates the signal (Δχ₁) compensation to remedy the 305 servo cylinder operation delay and the signal (Δχ₂) of compensation to cancel the signal transfer delay attributable to the elastic deformation of the mechaonic support structure. Furthermore, these signals (Δχ₁) and (Δχ₂) Compensation components are compensation components that are found, in theory, so that the mold 301 produces the same waveform as the preset vibration waveform, and these signals can be found by the reciprocal of the function. transfer between the input signal applied to the servo cylinder 305 and the output signal from the mechaonic support structure.

The control of the aforementioned arrangement will now be described specifically.

First, in the servo cylinder 305, the operating delay of the hydraulic system is compensated. That is, the displacement of the stem 305a is controlled by the control of the displacement of the valve and the coil 324; however, in order for the stem 305a to travel at a predetermined speed, it is necessary that the degree of opening of the valve is greater than a certain value. Consequently, an operation delay (phase delay) occurs between the input and output signals. The input waveform is compensated in such a way as to override such run delay to ensure that the output waveform from servo cylinder 305 is identical in phase and waveform to the waveform.

ES 2 154 658 T3 preset.

As regards the mechanical support structure, it does not constitute a perfectly rigid body; Thus, for example, if the output waveform of the rod 305a of the servo cylinder 305 contains components of a higher order, such components force the mechanical support structure, for example, the link mechanism 303, to develop a phenomenon resonance. In particular, in the case that the signal waveform is a non-sinusoidal waveform, such as a sawtooth waveform, the signal with the setpoint waveform itself contains a series of components of the order móas high, having a tendency to cause resonance.

Consequently, the arrangement is such that a waveform signal containing a signal component that cancels the resonance of the mechanical support structure, constituted by the link mechanism 303 and by the bank 302, is supplied by the servo cylinder 305. .

That is, the aforementioned signal (Δχ₁) of compensation contains a signal component to remedy the delay of operation produced by the servo cylinder 305 and the mentioned signal (Δχ₂The compensation) contains a signal component to cancel the resonance produced in the mechanical support structure, such as the link mechanism 303 and the bank 302.

In this way, since a direct action compensation is used together with a feedback control to correct the deviation value of the signal with the setpoint waveform, in real time, based on the real position of the mold 301, it is It is possible to dispense with the position detection sensor to detect the position of the stem of a hydraulic cylinder, as previously described in relation to the example of the previous technique, and it is equally possible to correct, in real time, the difference between the actual vibration waveform of the mold 301 and the setpoint waveform, which would not have been corrected by direct action control alone. Consequently, very precise control can be obtained that is little affected by disturbance.

Furthermore, since the position sensor can be dispensed with to detect the position of the servo cylinder rod, it is no longer necessary to worry about a servo cylinder runaway that would have occurred if the position sensor installed on the servo cylinder rod had failed.

In this fourth embodiment, it has been indicated that, in view of the position detector, the speed and the acceleration of the mold 301, the position sensor 328 is used which supplies position signals; however, an acceleration pickup can be used so that its acceleration signal is integrated once to supply the speed signal, and twice to supply the position signal. In addition, the acceleration signal can be brought to the control unit or the speed signal can be used. Furthermore, a position sensor and an acceleration sensor can be used at the same time.

In this fourth embodiment, it has been indicated that the position sensor 328 (displaced state detector) is attached to the mold 301; however, it can be attached, for example, to the bank 302 or, as shown in dots in FIG. 9, it can be attached to the end of the upper link 311. In this case, the bank waveform estimated from the vibration waveform of the mold is used as a signal with a setpoint waveform.

In this regard, in this fourth embodiment, it has been indicated that the algorithm placed in the adaptive filter is used by the adaptive control circuit; However, instead of using such an algorithm, means of analysis can be used using a fuzzy logic system or a fast Fourier transformation based on a neural network, as represented in figure 14.

Furthermore, in this fourth embodiment, it has been indicated that vibrations are applied to the mold through the bench and the joining mechanism; however, a servo cylinder can be attached directly to the bench that supports the mold. In addition, in this case, the bank will be considered as a mechanical support structure for a signal transfer.