Limiting or controlling of parts moved by external force, esp. for collision protection of window winder, sliding roof, door or tailboard of vehicle - sensing surface acoustic surface waves produced by piezoceramic actuator transmitted over vehicle body part.

The invention relates to a device for limiting or controlling or Regulating the movement of power-operated parts of a vehicle body according to the preamble of the first claim. particularly advantageous is their use as anti-collision protection for windows, sliding roofs, Doors or flaps.

Devices for control and in particular for monitoring of the closing process motor-actuated parts such as doors, hatches or windows of motor vehicles, are known and used for this variety technical principles. A distinction is made such that a direct physical contact are attached, and contactless Systems.

In DE-OS 22 46 337 is a safety device for motorized lockable Openings disclosed a a determinant acoustic source such. as the sound intensity, measured with the acoustic Receiver via an airborne sound conductive transmission line with the associated acoustic source. The transmission line, an elastic be arranged in the region of a closing edge tube. In his Deformation by an obstacle to reducing the recipient reaching sound intensity. An evaluation is responding with an operation command to the motor.

The disadvantage of this safety device is the risk of damage or destruction of the transmission path when used as Pinch protection for window of a motor vehicle. Also leading the Fastening the hose onto the circumferential edge of the disc to mounting problems, in the field at right angles inflected pane edges transmission problems. Within the guide frame there is also the Risk of nuisance tripping of the safety device.

The DE-AS 24 32 063 describes a device for monitoring the door closing process in transport vehicles using the principle of a Photocell. Radiation source and the sensor are substantially in a arranged level in the closing edge. The transmission within the relatively large volume elastic cover is a reflector completed at the opposite end of the closing edge. at Deformation of the cover there is a loss of light transmission, which leads over the sensor to the intended response of the device.

A disadvantage is that the device is not described or only after extensive Internal mirror for monitoring closing edges curved can be used, such as but for the window pane of a motor vehicle would be necessary.

DE-PS 27 19 955 a non-contact sensor for detecting field known people or objects before moving in a straight line edges, its antenna capacitors by approaching objects asymmetric Learn capacitance change and an evaluation device Control commands lead.

Unfortunately, field sensors are often not sufficiently limited (narrow) Effective area, so that also objects of reactions are triggered can that are not directly in the direction of movement of the closing edge. For example could the use of this safety system as a pinch power window in motor vehicles, the approach of Head or the shoulder of a passenger on the disc to a reversing same result.

The DE-PS 30 34 118 and DE-PS 31 36 746 describes a process for electronic monitoring of the opening and closing process of electrically driven units, wherein from the temporal variations of the characteristic Characteristics of the unit and their evaluation in a microcomputer an electric actuator can be influenced. In one of the in several sections divided closed areas is during the closing process the speed or the speed of the unit continuously determines and compared with a limit value. If the limit is exceeded, the message a short-term reversal and then the shutdown.

This method detects pinching very safe, but as a result of during movement or deceleration of Verstellobjekte acting partly considerable inertia forces, the system possesses some inertia. On the trapped objects can therefore act fairly large forces.

The invention is based on the object to provide a device,

<ul><li>- Which, inter alia, for use as a separate or additional Collision protection is, the triggering force significantly should be reduced and a response of the collision protection only will take place in the immediate danger zone and</li><li>- The reliability of external influences such as dirt, water, Ice, wear and aging of the parts, not affected becomes, </li><li>- The without use of separate, locally from the power-operated part separately arranged switch manages,</li><li>- Which increases the ease of use, in particular by linking ergonomic and logical operating sequences.</li></ul>

According to the invention the object is achieved by a device having at least an electrically-mechanical transducer as an actuator and at least one mechanical-electrical transducer as a sensor and an electronic evaluation dissolved and control means, wherein the actuator and the sensor on a common, ie contiguously extending acoustic transmission path are arranged, which form part of a power-operated Part, z. B. a window or a tailgate of a motor vehicle, is and for the man's hands or inanimate objects particularly accessible or these can be brought into contact. The actuator generated in the transmission path surface acoustic wave (Rayleigh waves), at least one of which the sensor characteristic Parameter, z. B. detects the amplitude or frequency and to the evaluation and controller forwards.

can one by changing the properties of the transmission path require adaptation of the inventive device. The modified external conditions can vary depending on the glass run and wheel position to attenuation of the signal as a result of damage, Dirt or icing lead to reflections of the signal. According to the invention the adjustment is performed by increasing and decreasing the power output and / or the frequency of the actuator. To minimize the technical complexity are actuator and sensor advantageously in functional unit made in one piece, whereby their functions consecutively be executed. Suitable for this purpose are piezoelectric crystals.

However, the use of multiple actuators and sensors can sense be. namely to allow the diagnosis of the aging of the transmission path or with their associated parts (eg. B. the guide or sealing areas of a window or a door a motor vehicle), or even a short-term change in state such. B. by ice. In a simple example, the sensitivity of the system the new external conditions are matched. Logically, happens this automatically via an electronic unit.

On the undesirable discontinuities free se transmission can the application of a (or possibly more) defined Discontinuities to increase system speed advantage be. The discontinuity changes the propagation characteristics of the Surface waves in a predetermined extent and thus serves as a reference point on the transmission path.

Different types of discontinuities are applicable. As sudden widening or narrowing of the transmission orthogonal to the propagation direction of the surface wave suddenly change Absorption coefficient or the reflection behavior. Other variants are inputs or Ausknickungen, waves or edges in the transmission path. The radius of the Discontinuity is in the order of the wavelength of the first harmonic surface acoustic wave and is usually much smaller than this even.

If the transmission path is formed by a glass surface, for. Example, the circumferential End face of a window glass, are suitable for influencing the surface waves scores particularly well. Their shape is desired to Effects very adaptable. Thus, on their shape and depth the ratio of the spectral reflectance values ​​for absorption percentage taken hold will. Also, the generation of a diode effect, wherein the surface acoustic wave in passing through the notch with little attenuation one direction , while the surface acoustic wave in the other direction as a result of has prevented a (quasi) total reflection to propagate beyond the notch.

For a richtungsindifferentes behavior to use symmetrical notch geometries, the approximately the shape of an isosceles triangle have. Asymmetrical notch geometries however, lead to a direction-dependent inverse ratio of reflection to absorption. Runs a Surface wave, for example, only a small (flat tops Angle to the transmission path) plane inclined wedge surface, as is done in each case a further transmission of the surface wave in original direction. Its amplitude is of course in accordance with the Attenuation and reflection properties of the edge is reduced.

However Exceeds surface acoustic wave on a wedge surface which hired steep and is with the direction of transmission at an angle of approximately 90 ° or more including, as it comes at the same time sufficient to notch depth Total reflection. Conversely, a surface acoustic wave propagation direction of the other the notch pass (diode effect).

The use of such notches allows an increase in the sensitivity of the The measuring system, if part of the transmission path to the surveillance area not belongs, but external circumstances its transmission characteristics can significantly affect. An example of this is the vertically extending called sealing or guiding portion of a motor vehicle window pane, its absorption characteristics depending on the position of the Disc, the disc clamping and many environmental influences strongly may vary. The possibility of blanking or the separate evaluation these areas is a reliable monitoring of the freely accessible Upper edge of the disc often crucial. By Differences of the signals of different, limited by notches areas is achieved a substantial increase in sensitivity. To their further increase and adjustment of the measurement and evaluation can be between the upper and lower stop position using a learning program be provided a Eichungslauf.

An evaluation of the sealing and guiding areas can also help control the drive power can be used to an unvarying kinematics to ensure. The use of two transmitter / receiver units, preferably each formed as a one-piece piezoceramic transducer are, results in a redundant operating device. By comparison the independently evaluated measurement results increases the confidence level. Specifically constructed in generally symmetrical Device, the two measuring systems in cold redundancy operation work.

An advantageous application of the device according to the invention consists in its use as a collision protection for electrically operated windows, Sunroofs, doors or flaps. Through contact of a colliding Object to the transmission change the transmission characteristics. This registers the sensor and the control device, and causes appropriate control commands. It can be a complete or partial reversal the adjustment (in window regulators), but also the persistence in be determined the position reached.

Other applications may be in the control of end and intermediate layers an adjustment part composed. It is as such. As possible, the upper and lower End position "soft" to approach or even Kurzhubabsenkungen the side window to control, facilitate the closing of doors. In addition, the Principle of operation of the invention require the use of switches because the mere touch of one or more areas provided in the transmission path the desired switching effects triggers.

As transmission suitable for use of the device according to the invention for collision protection such surfaces can be influenced externally, which essentially represent the closing surfaces. runs your level usually at an angle to the direction of the power-operated component. is This component, for example a window pane of a motor vehicle, so is to the circumferential end face, the inner and the outer disc plane connects, use it as a transfer surface. may advantageously the Actuator and the sensor or a corresponding functional unit to a not directly visible, not directly accessible and the window movement non-interfering component of the transmission path are arranged. It offers itself for this purpose on the lower pane edge. However, if Actuator and / or sensor on the transmission path in the region of the closing surfaces (Z. B. upper edge of the disk) are used, then the Power and signal lines at the edge of the disc in the form of printed Conductor tracks provided.

The coupling and decoupling of the energy is either via interconnects or cable or wireless (eg. B. inductive) when the required energy density Allow and reliability of the components this.

a view for signal evaluation or more of the following Principles on the application: Run-time measurement, amplitude modulation, phase and frequency modulation. The decisive factor needs are the Security (including redundancy) and sensitivity.

The invention is described with reference to an embodiment and the Figures explained in greater detail. It shows

<b>Fig.</b> 1a schematic representation of the apparatus of the invention for a closable opening with a transmitter and a receiver at the ends of the transmission path (in open position),

<b>Fig.</b> 1b as <b>Fig.</b> 1a (in closed position)

<b>Fig.</b> 2 schematic representation of the apparatus of the invention for arranged a closable opening having a movable part transmission,

<b>Fig.</b> 3a schematic representation of the apparatus of the invention for a closable opening with only at one end the transmission path arranged sensor and receiver (in open Position),

<b>Fig.</b> 3b schematic representation of the apparatus of the invention for a closable opening with a clamped object (in almost closed position)

<b>Fig.</b> 4a schematic representation of a window pane of a motor vehicle with arranged on the disk bottom separate transmitter and a receiver and acting on the upper edge of the subject,

<b>Fig.</b> 4b qualitative representation of the variation of the amplitude on the way (Transmission) (according <b>Fig.</b> 4a)

<b>Fig.</b> 4c qualitative representation of the variation of the amplitude on the Time (in accordance with <b>Fig.</b> 4a)

<b>Fig.</b> 5a schematic representation of a window pane of a motor vehicle with discs arranged on the lower edge of the sender / Receiver units each surface acoustic waves having the opposite generating propagation direction, wherein the upper edge of is contacted by an obstacle,

<b>Fig.</b> 5b qualitative representation of the amplitude of the reflected and a damped surface wave according <b>Fig.</b> 5a,

<b>Fig.</b> 5c schematic breakdown of the transmission path in accordance with <b>Fig.</b> 5a starting from the first transmitter / receiver unit,

<b>Fig.</b> 5d schematic breakdown of the transmission path in accordance with <b>Fig.</b> 5a starting from the second transmitter / receiver unit,

<b>Fig.</b> 6 schematic representation of a window pane of a motor vehicle arranged with the edge of the pane edge Transmitter / receiver unit and two different design Notch geometries in the transmission path of the surface wave,

<b>Fig.</b> 7 schematic representation of a window pane in a Guide frame with tools for limit position by Coupling into the transmission path of the surface acoustic wave.

The invention utilizes the ability of a solid body, induced mechanical Waves on its surface as a so-called surface waves along a design-related or specially created propagation path continued forward and the effect of external influences with damping and / or to respond reflection of surface waves. Sensors allow the Measurement pulses to an evaluation on, where by way of the algorithm System state is judged that, in turn, the basis for reactions is run commands or the like.

Although the embodiments as far as possible to the use of A device according to the invention as anti-trap for an electric relating windows of a motor vehicle, that its purpose extends in other controlled or controllable systems for which analogously used surface waves and evaluated, and the corresponding suitable transmission paths in the area of ​​safety edge or closing surfaces use of each other moving objects.

<b>Fig.</b> 1 schematically in a simplified manner, the inventive device for a closable opening, which fall at the ends of a stationary transmission path <b>3</b> a transmitter <b>4</b> and a receiver <b>5</b> wearing. in the Distance to a movable part <b>1</b> shown. The device is is. in the open position An electrically-mechanical converter coupled at one end of the transmission path <b>3</b> Energy, which part of a converted into surface waves and to the other end of the transmission path <b>3</b> is transported, where the receiver <b>5</b> receiving signals. Dependent on of material and geometry of the transmission path <b>3</b> , a certain Signal attenuation. In the closed state (see<b>Fig.</b> 1b), so at Reaching the end position of the movable part <b>1</b>, The closing surfaces touch a large area and connect a large part of the vibrational energy out. The thus considerably increased signal attenuation is the recipient<b>5</b> registered and in the evaluation unit for detecting the end position to lead.

A device very similar structure is in <b>Fig.</b> shown 2, however, with the difference that the transmission path <b>3</b> in the lower region of the movable Part <b>1</b> is arranged. the sensor are located at the ends<b>4</b> and the actuator <b>5</b>, Although the movable member is not its final position yet has reached, the sensor registers <b>4</b> a highly attenuated signal due the energy extraction through the transmission path <b>3</b> engaging hand <b>8th</b>,

According to the <b>Fig.</b> 3a and 3b are the transmitter and receiver in the form of a functional unit <b>6</b> on the same end of the transmission path <b>3</b> arranged. The functional unit is executed in one piece, they then acts alternately as actuator and as a sensor. Piezo Ceramic Components can be successfully employed for this purpose. The end of the transmission path<b>3</b> is formed so that the possible total energy absorbed is, thus, the sensor can no longer receive signals. At the Coupling an object <b>9</b> in the transmission path <b>3</b>, for example by pinching, the wave propagation changed by reflection on the nip. The reflected signal reaches the receiver and provides the basis for the recognition of Einklemmzustandes.

An application of the invention for a power window of a The motor vehicle showing the schematic representation of <b>Fig.</b> 4a. To the lateral edges of the lower pane edge of the window pane <b>2</b> are separately one transmitter <b>4</b> and a receiver <b>5</b> arranged. You're in for the propagation of surface waves provided the transmission Windowpane, the orbiting of the pane edge <b>21</b> is formed over a wedge <b>7</b> coupled. This is a preferred direction of wave propagation reached or the wave reception. Preferably, the entire Width of the transmission path from the transmitter <b>4</b> or by the recipient <b>5</b> covered. The near the edge of the pane <b>21</b> lying arrows <b>22</b> give the direction of propagation the surface waves. In the upper edge of is in the form of a triangle symbolically an object <b>10</b> or a body part in which is in contact with this and thus acoustically coupled is. The coupled-out by this object vibrational energy means an additional damping and reduces the amplitude of the surface wave and the intensity of the receiver <b>5</b> recorded signal <b>50</b>, <b>Fig.</b> 4b shows the variation of the amplitude over the transmission path (Disc edge <b>21</b>) High. The analogous thereto qualitative representation shows the course of the amplitude versus time <b>Fig.</b> 4c. After that is when Coupling of a foreign object in the transmission path to the receiver <b>5</b> on signal <b>51</b> with respect to the signal <b>52</b> markedly reduced amplitude to expect.

The schematic representation of a window pane <b>2</b> of a motor vehicle according to <b>Fig.</b> 5a shows against the in <b>Fig.</b> 4a variant shown following Differences: The coupled to the edges of the lower pane edge mechanical-electrical converter <b>6</b> serve as transmitter and receiver. also carries the revolving of the disc edge <b>21</b> formed acoustic transmission two symmetrical and identical notches <b>11</b>Whose radii are smaller than the wavelength of the first harmonic surface acoustic wave, to take on wave propagation influence can. The arrangement of the notch <b>11</b> in the transmission path has been chosen so that they freely accessible Disc top, can take place in the region pinching, exactly Include and from both sides subsequent parallel management areas <b>23, 24</b> separate. causes the selected notch geometry both reflection and attenuation effects. With its help, the guide portions <b>23, 24</b> of the window pane <b>2</b> not only hide, but separately the damping characteristics evaluated. This in turn can be used for controlling the transmission power of the SAW transmitter to a to have consistent SIN ratio.

The following <b>Fig.</b> 5b, 5c and 5d illustrate in a simplified manner the Amplitude of a surface wave on the path or with time is, without However, reflection effects at the notches <b>11</b> be taken into account. In the foreground are here caused by an object due to the effects Jamming between the disc and the upper edge of the door frame.

The named object <b>10</b> is in each case, a damping of the amplitude of the from the first transmitter / receiver unit <b>61</b> the transmitted signal <b>53</b> (<b>Fig.</b> 5b) cause what of the second transmitter / receiver unit <b>62</b> is registered. This will be particularly the case if for example. The hand a person is trapped, because of their relative softness and thus good acoustic coupling hardly an appreciable proportion of reflection may cause surface wave. In the event, however, that a relatively hard Foreign objects in the transmission path <b>21</b> the freely accessible top the windowpane <b>2</b> is coupled, an additional reflection signal <b>54</b> from the first transmitter / receiver unit <b>61</b> be registered and thus by redundancy, the validity of the device improve.

The <b>Fig.</b> 5c and 5d divide the transmission schematically, whereby the one of the first transmitter / receiver unit <b>61</b> and secondly on the second transmitter / receiver unit <b>62</b> is assumed. During a Blend the first wave of the surface traversed guide region <b>23, 24</b> Only on the basis of transit time measurement is possible, the next continuous guide area <b>23</b> or. <b>24</b> This surface acoustic wave only hidden when the on the second notch <b>11</b> reflected Signal for evaluation comes. The same applies to the other transmitter / Receiver unit transmitted signals. Although the notches<b>11</b> to a cause significant attenuation of the signals, their use can be very beneficial be. Finally, the suppression of the guide areas allowed<b>23, 24</b> right and left the window pane <b>2</b> targeted and largely trouble-free Amplifying the signals of the controlled area K, the essential to a contributes improving the reliability of the information.

In the <b>Fig.</b> 5c and 5d mean:S₁-S₂ / E₂-E₁ duration of the signal from the first transmitter / receiver unit <b>61</b> the second transmitter / receiver unit <b>62</b> and back.S₂-E₁ as above, just in reverse.S₁-B-E₁ duration of the signal from the first transmitter / receiver unit to notch <b>11</b> at location B and back.S₂-A-E₂ duration of the signal from the second transmitter / receiver unit to notch <b>11</b> at location A and back.S₁-∇-E₁ duration of the signal from the first transmitter / receiver unit up to the object <b>10</b>Which in the transmission path <b>21</b> is coupled, and back.S₂-∇-E₂ duration of the signal from the second transmitter / receiver unit until Gegensttand <b>10</b> and back. S₂-A-E₁ duration of the signal from the first transmitter / receiver unit until the notch at the location A and back. (This Guide portion is in the evaluation of an anti-pinch or butt condition excluded.)S₂-B-E₂ duration of the signal from the second transmitter / receiver unit until the notch at the location B and back. (Even this Guide portion is in the evaluation of a collision state excluded.)

From the guide areas <b>23, 24</b> Included is the control panel K. It represents the part of the transmission path <b>21</b>, The freely accessible is. We therefore need to detect a collision state exclusively the evaluation of such signal changes that originate within the have duration of the controlled area K.

A variant of the invention, schematically <b>Fig.</b> 6 illustrates. Only at one of the edges of the lower pane edge is a transmitter / receiver unit <b>6</b> arranged and a wedge-shaped element <b>7</b> in the transmission path <b>21</b> the surface wave coupled.

Again, include two notches <b>12, 13</b> the transmission line <b>21</b> at the top Area a of the disk edge. Their geometries are different and are the cause of a different reflection and damping behavior. While the transmitter / receiver unit <b>6</b> closest notch <b>12</b> is symmetrical and except with a damping and a Reflextions with the main transmission portion on the surface acoustic wave effect, causing the second asymmetrically designed notch <b>13</b> a total reflection of the Oberfächenwelle. For this purpose has this notch<b>13</b> a steeply inclined notched edge, the one with the upper edge of the pane Angle α of preferably 90 ° and includes the propagation direction the surface acoustic wave faces. For the evaluation of the system status only signals are evaluated, the first in the time interval between the score <b>12</b> and the second notch <b>13</b> lie that is the range of freely accessible Transmission path of the upper edge of representing. The Evaluation is a suddenly altered damping behavior on a attributed pinch condition and appropriate control commands to the servomotor pass, which is preferably for reversing the window pane <b>2</b> leads. General conclusions about the properties within the guide frame <b>14, 15</b> can be obtained by evaluation of the range between the transmitter / Receiver unit <b>6</b> and the first notch <b>12</b> achieve. A Eichungslauf between the stop positions allows conclusions about the general State to pull the sealing area and an optimal adjustment of the perform sensitivity of the monitoring system. Such adaptation allows especially the elimination of changed external conditions in the Transmission path, which may be caused for example by aging the sealing material by contamination or icing of the guide areas the disc or by material fatigue.

<b>Fig.</b> 7 shows the schematic representation of a window pane <b>2</b> in a guide frame <b>14, 15</b> with tools <b>17, 18</b> for limit position. These aid <b>17, 18</b> will vary depending on the disc position and Application spring-elastic elements in the transmission path of the surface waves mechanically coupled and lead to measurable changes in the receiver <b>6</b> incoming signals. The coupling of the aid<b>17, 18</b> For the detection of the lower stop and the upper stop to be carried out different locations and are therefore very easy to distinguish by measurement. The advantage of the end position is the one that the lower stop "soft" can be approached, creating a lighter, less robust design is made possible. On the other hand, the uppermost Adjusting or closure area (sealing area <b>16</b>) From the rest of adjustment selected in which no clamping is possible, and a forcibly retaining the adjusting force to completely close the window opening is necessary.

List of references used

<b> 1</b> moving part<b> 2</b> windowpane<b> 3</b> transmission path<b> 4</b> transmitter<b> 5</b> receiver<b> 6</b> The transmitter / receiver unit<b>61</b> The transmitter / receiver unit<b>62</b> The transmitter / receiver unit<b> 7</b> wedge<b> 8th</b> hand<b> 9</b> object<b>10</b> Object (animate or inanimate)<b>11</b> Notch (symmetrical)<b>12</b> Notch (symmetrical)<b>13</b> Notch (asymmetric)<b>14</b> guide frame<b>15</b> guide frame<b>16</b> sealing area<b>17</b> aid<b>18</b> aid<b>21</b> Pane edge or link<b>22</b> Direction of propagation of surface waves<b>23</b> management area<b>24</b> management area<b>50</b> signal<b>51</b> signal<b>52</b> signal<b>53</b> signal<b>54</b> reflection signalA ↑ amplitudeα angleK Control PanelA location of a notchB Place a notch