Vehicle seat for a commercial vehicle

0001The invention relates to a vehicle seat, in particular for a utility vehicle, according to the features of the preamble of claim 1.

0002From JP 09109757 A a vehicle seat is known, of a having active seat suspension by means of electric actuators. There are vibrations from the vehicle floor in the vehicle seat be initiated by means of a vibration sensor detected. At the head office itself is a second acceleration sensor arranged, which measures the acceleration of the seat. These two signals are in a control electronics for controlling the electric actuator processed.

0003The the present invention underlying task to provide a vehicle seat with an active seat suspension, which is especially convenient while a sensitive control having.

0004This object is inventively achieved by a vehicle seat solved with the features of claim 1.

0005The vehicle seat has a seat structure fixed to the vehicle a content Erten seat substructure and preferably a backrest and includes an associated with this seat cushion, which via a supporting device in at least one degree of freedom is movable mounted on the seat structure. To the Seat cushion backrest z. B. a backrest fitment be fixed in the inclination adjustable. A control device with sensors regulates the transmission behavior of Support device. It is provided that the supporting device each for a regulated degree of freedom each one vehicle fixed first sensor for receiving the having vehicle acceleration and a seat structure firmly, preferably on the seat cushion arranged second sensor Recording the acceleration of the seat structure, preferably having the seat cushion acceleration and also a third comprising sensor for receiving the relative motion between the seat structure, preferably the seat cushion and the Vehicle is designed. With this degree of freedom is a Movement along an axis or a rotation or pitching meant about an axis. It may, for. Example, a movement of A seat structure or the seat cushion along the vehicle vertical axis, the seen in the driving direction or vehicle longitudinal axis the seen in the direction of travel transverse axis occur. As well it is possible that the vehicle seat several degrees of freedom has, that is, that a movement along a plurality of such axes.

0006The support device has for each such degree of freedom three sensors, two acceleration sensors for receiving the vehicle acceleration and for receiving acceleration of the seat on the seat structure, preferably at the Seat or connected at one with the seat structure Component are formed, and another sensor for receiving the relative movement and the relative position between the Seat structure, or the seat cushion and the vehicle used. These sensors are the input variables for the control device, ie the sensors are connected to the control device connected and the control device serve as a basis for Changing the transmission behavior of the support device such that a possible vibration and low-vibration Sitting on the vehicle seat by compensating by the Vehicle caused shock and / or vibration allows becomes.

0007Here, the transmission characteristics of the support device, the ever controlled degree of freedom a spring / damper pair and a parallel to the spring / damper pair arranged actuator, preferably a linear motor, which can be influenced, by the spring characteristic and / or the damper characteristic curve and / or control the force and / or the actuator travel of the actuator becomes.

0008The seat structure denotes the moving, preferably spring-mounted parts of the vehicle seat, such as the connecting seat cushion, the backrest and this Seat frame. These parts are connected to each other so that a movement of the seat structure by measuring one of the parts, z. B. of the seat cushion or of the backrest or of the seat frame can take place.

0009About the control device is active on the basis of measured variables influences the transmission behavior of the supporting device. Thus the comfort in the vehicle can significantly be improved. It is provided that the control device the mechanical spring and damper elements present of the seat, such as, for. example, the behavior of the seat cushion or considered an elastic seat suspension and also active, the transmission behavior of the supporting device such controls, ie, the spring characteristic and / or damper characteristic and / or the actuator controlled such that as little as possible transmit vibrations from the vehicle to the vehicle seat will.

0010It has been shown that the control behavior can be significantly improved by using, as input information for the control device in addition to the acceleration values ​​and the Relative position of the seat is determined from the vehicle, as this a particularly sensitive control is enabled.

0011In particular, it is provided that the supporting device of the A seat structure, in particular of the seat cushion in one degree of freedom each having a support spring and a damper support. The control device can thereby the transmission behavior control of the supporting device, either by the spring characteristic of the support spring or the damper characteristic curve the support spring or both controls together or in parallel this provides respective forces parallel to a the support spring and / or the supporting damper working actuator, preferably an electric or electro-hydraulic linear motor, be of the input signal generated in response. This linear motor is connected at one end to the Seat substructure and with its other end to the seat structure connected.

0012In one embodiment, it is provided that the supporting damper a electric or pneumatic or hydraulic actuator which is preferably arranged parallel to the support spring is. In particular, the actuator is designed as a linear motor, between the seat structure and the seat structure is arranged. By means of such actuator, the transmission behavior the supporting device by the control device influenced to a large extent and thus the scheme are particularly sensitive controlled.

0013In one embodiment, it is provided that the control device for each one controlled degree of freedom, z. B. in the x direction, in the y-direction or z-direction, in each case a separate having loop. The first degree of freedom is the vertical upward and downward movement of the seat in the direction of Vehicle vertical axis, that is the z-axis. A second degree of freedom can the movement of the seat in the vehicle longitudinal direction, Thus, the x-axis be. In addition, a third degree of freedom be taken into account, the example. The vehicle transverse axis, the y-axis comprises. Alternatively, a further Degree of freedom a pitching or rolling motion about consider a longitudinal or transverse axis of the seat and be corrected accordingly by means of the support device.

0014The aim of the scheme is a vibration-free sitting. That means, that the state variables of the seat to settle to zero are and the draft regulation regarding optimal. the disturbance behavior make is. If the seating arrangements in a parent integrated vehicle dynamics control, then under ergonomic aspects guiding the seat movement on prove the setpoints to be advantageous, which in detail here is looked at.

0015In one embodiment, it is provided that the control device Compensation measures, preferably a decoupling network, are provided, the inherent coupling between the individual degrees of freedom to compensate. The control device is in particular formed so that each controlled Degree of freedom, the signals of the first sensor and the second Sensor and the third sensor as an indication of the determination a manipulated variable for the control of the supporting device in accordance with a predetermined for the respective degree of freedom used or desired Störübertragungsverhaltens becomes. In particular, can be a feedforward parameterize preferably by feedforward compensation.

0016In an advantageous embodiment, it is provided that the Control apparatus having a Störübertragungsverhalten that from the combination of a vibrating controller and a Position controller yields. In particular, it is provided that the control device to the vibration controller than the measured variables Acceleration values ​​of the first sensor and / or the second Sensor feeds. The vibration controller then determines from the supplied acceleration values ​​each associated rate values and its position values ​​by approximating integration. This is an observer structure the state regulation implemented.

0017Furthermore it can be provided that the control device the Position controller as a measure of the relative position of the values third sensor feeds. Thereby, a PID controller reacted will.

0018It is envisaged that the vehicle seat according to the invention in Nutfahrzeugen, ie in heavy-duty vehicles such. B. Trucks and construction machinery, as well as in light commercial vehicles, such. B. Transportation vehicles to use. Likewise, is provided, the vehicle seat according to the invention in a passenger car particularly comfortable controlled driver and / or to use passenger seat.

0019The invention is based on a closer shown in the drawings Embodiment hereinafter described.

0020Show it: <dl tsize="6" compact="compact"><dt>Fig. 1</dt><dd>a schematic side view of one of a Driver occupied vehicle seat with the seat substructure, Seat cushion and backrest,</dd><dt>FIG. 2</dt><dd>a schematic view of a control device for an actively controlled vehicle seat,</dd><dt>Fig. 3</dt><dd>a schematic control structure for a degree of freedom the actively controlled vehicle seat.</dd></dl>

0021In Figure 1 is a schematic side view with a Driver occupied vehicle seat 1 shown. The vehicle seat is located in a commercial vehicle cab, which in the figure 1 schematically shows the instrument panel 15 and a steering wheel 14 and the cab floor is indicated. With the parts can the relative mounting position of the vehicle seat in the cab recognize.

0022The vehicle seat has a seat structure with a seat substructure 2, which is firmly connected to the vehicle floor on. Above on the seat substructure 2 is a seat pedestal 3, Seat 11 is supported. The seat cushion 11 is a Seat frame connected to the backrest 12 of the vehicle seat. At the upper end of the backrest 12, a headrest 13 arranged.

0023transmitted between the seat pad 2 and the seat cushion 11 Seat platform 3 is a supporting device 6 which the Seat connects movably to the fixed vehicle seat structure. The movement of the seat cushion can be used as an indicator of a movement of the entire seat surface are used, since the seat cushion with the backrest is firmly connected. The Support device 6 supports the seat cushion 11 and thus also the held to the seat cushion backrest movably on the Seat substructure 2, wherein the seat cushion 11 in the direction of the vehicle vertical axis, the z-direction and in the direction of the vehicle longitudinal axis, the x-direction, is movably mounted. Thus , the vehicle seat in Figure 1 two degrees of freedom x and z on. The support device 6 has a controllable transmission behavior , wherein the Transmission behavior of the supporting device 6 by a control device 4 is controllable.

0024The seat pad 2 comprises a support beam 21, the fixed is connected to the vehicle floor. On the support beam 21 is arranged a support damper 23b and a support spring 22b, which is connected at one end to the support brackets 21 are and at its other end with a Parallelogrammlenkergestänge 24 are connected. The Parallelogrammlenkergestänge 24 allows movement of the seat structure in the form of Seat cushion 11 ensures with backrest in the z direction and while a parallel displacement of the parallelogram 24 associated seat pedestal 3 for all oscillating and Oscillating movements of the vehicle seat. 1

0025The movement of the vehicle seat 1 in the z direction is in this case determined by the spring / damper system 22b, 23b. The transmission behavior this spring damper system, which is part of a represents the support device of the vehicle seat 6, is by controlling the characteristic curve, in particular the forces of the Damper 23b changeable. The damper 23b has an electric Linear motor which between the seat cushion 11 and seat base 2 is arranged. He can so the oscillation amplitudes compensate for the seat in the z direction.

0026assigned to the degree of freedom in the z-direction are three sensors, wherein a first sensor 25 fixed to the vehicle on the support brackets 21 is arranged. This first sensor 25 is an acceleration sensor formed and takes the acceleration values the vehicle or the vehicle cab on. A second sensor 26 seat structure fixed to the seat pedestal 3, that shown in the For seat cushion firmly placed and is also formed as an acceleration sensor 26th This second acceleration sensor 26 serves to receive the acceleration values of the seat cushion 11. Furthermore, for the degree of freedom for a third sensor 27 is provided, which on Damper 23b is arranged, and the relative position of the seat pedestal 3 or the seat cushion 11 relative to the seat structure, or the vehicle or the vehicle cab determined. The three sensors 25,26,27 are connected to the control device 4 connected and delivering it to them the relevant measures of the degree of freedom z.

0027The seat platform 3 comprises a carriage 31 on which a movement the seat structure and thus the seat cushion 11 in the vehicle longitudinal direction allowed. extends the vehicle's longitudinal direction Registered in the direction of travel. The movement of the carriage 31 is Registered by the spring / damper system, consisting of the spring 22a and the damper 23a, controlled. The damper 23a has In this case, a linear electric motor which by the control device 4 is driven to the vibration behavior of the vehicle seat to settle in the x direction.

0028Further, three sensors 31 are arranged on the carriage, which are the degree of freedom x assigned. A first acceleration sensor 35 is fixed to the vehicle connected to the seat pedestal 3, so that the vibrations in the x direction of the vehicle cab be taken up by this accelerometer 35th A second acceleration sensor 36 is attached to the carriage 31 arranged so that he seat cushions fixed to the seat cushion 11 is connected and thereby the acceleration of Seat cushion 11 receives. The third sensor 37 is attached to the Carriage 31 and at the damper 23a is arranged such that it the relative position of the seat cushion in relation to the Cabin or the seat pedestal 3 receives. These three Sensors 35, 36, 37 provide the measures of the control device 4 for the degree of freedom in the x-direction.

0029In the figure 2, the basic schematic configuration of the Control device 4 for the active suspension of the vehicle seat shown. The vehicle seat 1 has three degrees of freedom y in the x and / or and / or z-direction and / or rotary Degrees of freedom around the vehicle or the vehicle transverse axis on. The movement of the seat 1 in any of these Degrees of freedom is taken over three sensors, which are arranged as described in FIG. 1 Here are respectively, an acceleration sensor on the seat and a further Acceleration sensor on the vehicle and a position sensor, the relative to the position of the vehicle seat 1 Vehicle recorded, provided and integrated into the control device. 4

0030The signal flow of the detected by the sensors measured variables in Figure 2 indicated by arrows. The aim of the scheme vibration-free sitting. This means that the state variables the seat must be regulated to zero and the draft regulation perform optimally with respect. the disturbance behavior is.

0031If the seating arrangements in a superior vehicle dynamics control integrated, then this can even out the seat movement turn on the setpoints to be advantageous here but what is not considered in detail.

0032In the control device 4 are technical control measures integrated, the decoupling of the inherent model coupling effect between the regulated degrees of freedom. This allows the complex rules in Part Models disassemble, wherein in the control synthesis respectively decoupled considered two-mass oscillator for one degree of freedom separately will. These partial models are then used for parameterization the respective state regulator of the dynamic sitting under Inclusion of the dynamic behavior of actuators and sensors used. As shown at the part state controller in addition to the Acceleration attributed the speed and position are the state variables from the acceleration signal are generate by approximating integration. To avoid statistical units, because always existing offsets in practice, the acceleration signals high-pass filtered.

0033Of crucial importance for the overall dynamics is the Corner frequency of the high-pass filtering. This parameter is used draft the definition of dynamic vibration suppression made of an active seat suspension to the chassis. This is mandatory because space-limited because of Reciprocation and the limited actuator force low Movements must be transmitted to the seat.

0034Only the higher-frequency vibrations above a ceiling set Frequency must be suppressed with the active seat suspension. Taking into account and optimizing these parameters can be a signal processing for the seating arrangements 54 design, the optimized Störübertragungsverhalten and having, in response to the measured values ​​of the acceleration sensors a manipulated variable for the actuator 52 provides. In addition, the transmission behavior of the actuator 51 is taken into account, as well as a disturbance variable compensation 53 performed. This can be with the vehicle seat according to the invention 1 with active control, a very good comfort condition namely a largely vibration and vibration-free reach the seat during the driving operation. The structure the control device 4 provides for controlled for each Degree of freedom is based on a separate controller model and a separate control synthesis is carried out.

00353 shows schematically the structure of such a regulator Degree of freedom shown. Since it is necessary, large relative movements between the cabin and the vehicle seat and occupant to suppress, it is necessary to low Vibrations with large amplitude of vibration largely from to transfer the bracket on the seat. Therefore, the in was Figure 3 illustrated controllers 4 designed one for a Position controller 42 comprises the transmission of low Vibrations accomplished. On the other hand, the Controller structure 4 a vibration controller 41 with state controller structure for suppressing the higher frequency vibrations on. The delimitation of the respective action of the regulator, the carrying out any work in parallel in structure, is Registered by appropriate filtering of the measures used made. The controller structure helps large Relative movements with good possible vibration suppression to avoid.

0036The measures used to control 4 is given to the acceleration the seat available, which as input variables Vibration controller 41 to minimize vibration exposure serve. On the other hand, the part of the actuators available stationary relative movements between seat structure or the seat cushion 11 and seat base 2 used, which the will position controller 42 is supplied as measured variables. In figure 3, this is exemplary of the degree of freedom in the z-direction shown. yield The structures of the other degrees of freedom analogously by replacing the input quantities for the respective degrees of freedom.

0037Since in the vibration controller 41 in addition to the measured acceleration in addition internally, the speed and position be recycled, these state variables are measured from the Acceleration signal by approximating integration to generate. This is an observation of structural Control implemented. As yet, in practice, always offsets are, the acceleration signals are high-pass filtered.

0038Of crucial importance for the overall dynamics of the control device is the cutoff frequency of the high-pass filtering. This parameter is used in the draft of the delimitation dynamic vibration suppression of active seat suspension made to the structure.

0039The position controller 42 shown in Figure 3 uses the Relative sizes between the console, ie the vehicle cabin, and the seat structure or the seat cushion 11, ie the seat pedestal 3. Theoretically, it would be sufficient, only the relative position z-relatively due. The other variables can then by differentiation and integration of this size are obtained, in the manner of a PID controller.

0040The diagram in Figure 3 is for the other degrees of freedom to use in accordance with, in which case the degree of freedom x which are variables z replaced by x and the degree of freedom y are variables z replaced by y. Likewise, the shown in Figure 3 controller structure on a tilting degree of freedom be applied, it must then instead of routing information for the tilting degree of freedom as α angle information be used for such.