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 the Movement of power-operated parts of a vehicle body according to the Preamble of the first claim. Particularly advantageously, their use is as 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 purpose different technical principles. one distinguishes between those that are tied to a direct physical contact, and contactless systems.

From DE-OS 22 46 337 a generic safety device is known, the a determinant of an acoustic source, z. B. the sound intensity, measures, the acoustic receiver via an airborne sound conductive transmission line with the associated acoustic source. The transmission path may comprise a portion of a Closing edge arranged to be elastic tube. In its deformation by a Obstacle reduces the recipient reaching sound intensity. A Evaluation responds with a control command to the motor.

The disadvantage of this safety device is the risk of damage or Destruction of the transmission path in their use as anti-trap for Windows of a motor vehicle. In addition, the attachment of the hose leads to the circumferential edge of the disk to attachment problems, in the area at right angles inflected slice edges transmission problems. Within the guide frame consists of which the risk of inadvertent triggering of the safety device.

DE 24 32 063 B2 describes a device for monitoring the Door closing operation in mass transit vehicles using the principle of a Photocell. Radiation source and the sensor are substantially in a plane arranged region of the closing edge. The transmission within the relative bulky elastic cover is a reflector on opposite end of the closing edge completes. When deformation of the Cover takes place attenuation of light transmission, leading to over the sensor intended response of the device leads.

A disadvantage is that the device is not described or only after extensive Internal mirror for monitoring curved closing edge as to Windows of a motor vehicle are present, can be used.

From DE 27 19 955 C2 is a non-contact field sensor to detect Persons or objects in a straight line before moving edges known whose Antenna capacitors by approaching objects asymmetric Learn capacitance change and run through an evaluation to control commands.

Unfortunately, field sensors are often not sufficiently limited (narrow) Scope, so that reactions of objects can be triggered on that are not directly in the direction of movement of the closing edge. For example, when Use this security system as a pinch power window in Motor vehicles, the approach of the head or shoulder of a passenger in the Slice the same lead to reversing.

The DE 30 34 118 C2 and DE 31 36 746 C2 describe methods 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 electrical is influenced actuator. In one of the divided areas into several sections closing is during the closing process, the speed or the speed of the unit regularly determined 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 the system responds as a result of during Movement or deceleration of Verstellobjekte acting, sometimes considerable Inertia forces relatively sluggish. In the clamped objects can therefore act fairly large forces.

The generation and transmission of the surface acoustic waves as well as a Methods of measurement for the duration and amplitude are as such known from the documents DE 35 28 380 A1, DE 34 38 050A1 and DE 32 36 631A1 known; Known are also the so-called "Rayleigh waves", a special form of surface waves on the may occur unstressed surface elastic media. These surface waves sound like the depth exponentially and are made up of perpendicular to the surface oscillating shear waves and tangential oscillating compression waves together (see Meyer's physics lexicon, Bibliographical Institute Mannheim 1973).

The invention has for its object to provide a device of the type mentioned to develop,

<ul><li>- Which, inter alia, for use as a separate or additional Collision protection is, the triggering force is to be reduced considerably and a done response to the collision protection only in the immediate danger zone should and</li><li>- The reliability of external influences such as dirt, water, ice, Wear and aging of the parts is not compromised. </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 a donor and at least one mechanical-electrical transducer as a sensor and an electronic From value- and control means solved, the encoder and the sensor a common, ie contiguously extending acoustic transmis are transmission link arranged, forming part of a power-operated Part, z. B. a windowpane or a tailgate of a motor driving zeugs is, and for the man's hands, or even inanimate counter stands particularly accessible or these can be brought into contact. The transducer generates the acoustic transmission path Oberflächenwel len (Rayleigh waves). of which at least one sensor charac cal parameter, z. B. detects the amplitude or frequency and the off value- and controller forwards.

can one by changing the properties of the transmission path require adaptation of the inventive device. The modifier derten 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 encoder. To minimize the technical complexity are transmitter and the sensor advantageously in radio tion unit made in one piece, whereby their functions one after time another run. Suitable for this purpose are piezoelectric crystals.

However, the use of multiple encoders and sensors can sense be. namely to allow the diagnosis of aging Transmission path or communicating with their 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, this is done via an electronic unit automatically.

On the undesirable discontinuities free transmission itself, the Mounting one (or possibly more) defined discontinuity to be increasing the system speed advantage. The discontinuity changed the Propagation characteristics of the surface waves in a predetermined degree and serves so as the reference point on the transmission path.

Different types of discontinuities are applicable. As abrupt Widening or narrowing of the transmission orthogonal to the propagation direction they change the surface wave suddenly the absorption coefficient or the Reflection behavior. Other variants are single or Ausknickungen, waves or edge in the transmission path. The radius of the discontinuities is of the order of Wavelength of the first harmonic surface acoustic wave and to the improve Signalauswertbarkeit, usually but preferably much less than this kept.

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 very well adapted to the desired effects. So can by their form and depth to the relationship of the reflection portion for Absorption percentage be influenced. Also, the generation of a diode effect, wherein the surface wave, the notch at only low attenuation in one direction can happen while the surface acoustic wave in the other direction as a result of (Quasi) total reflection is prevented from propagating beyond the notch, is possible.

For a richtungsindifferentes behavior to use symmetrical notch geometries approximately the shape of an isosceles triangle have. Asymmetric Notch geometries however, lead to a direction-dependent inverse ratio of Reflection to absorption . Runs a surface wave, for example, on an only slightly (in shallow acute angle relative to the transmission path) plane inclined wedge surface, takes place in any case, a further transmission of the surface wave in original direction. Its amplitude is of course according to the attenuation and reflection properties of the Edge decreases.

However Exceeds surface acoustic wave on a wedge surface, which is made steep and the includes transmission direction at an angle of about 90 ° or more, it comes at retaining sufficient notch depth to total reflection. Conversely, a Surface acoustic wave propagation direction of the other notch pass (diode effect).

The use of such notches allows an increase in the sensitivity of the measuring system, when a part of the transmission path not part of the monitoring area, but external conditions may affect its transmission properties significantly. As Example of this is the vertically extending sealing and guide region of a motor vehicle called window pane, whose absorption properties of the function of Position of the disc, the disc clamping and many environmental influences strongly may vary. The possibility of blanking or the separate evaluation of these Areas is a reliable monitoring of the freely accessible upper edge of the disk often crucial. By taking the difference of the signals of various by Notches limited ranges is achieved a substantial increase in sensitivity. To her may further increase and adjustment of the measuring and evaluation system between the upper and lower stop position using a tutorial a be Eichungslauf provided.

An evaluation of the signals of the sealing and guiding areas can also be used Controlling the drive power can be used to an unvarying kinematics to ensure. The use of two transmitter / receiver units, which are preferably are each designed as one-piece piezoceramic oscillator, resulting in a redundantly operating device. By comparing the independently evaluated measurement results will increase the confidence level.

An advantageous application of the inventive apparatus 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 own sheep ten. This registers the sensor and the control device, and causes appropriate control commands. It can be a complete or partial Rever Sieren 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 transmis transmitting path the desired switching effects triggers.

As transmission suitable for use of the invention Vorrich tion for a 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 external and internal discs plane connecting to use as a transfer surface. may advantageously the Transmitter and the sensor or a corresponding functional unit to a not directly visible, not directly accessible and the Fensterbewe supply running non-interfering component of the transmission path disposed who the. It offers itself for this purpose on the lower pane edge. However, if Timer and / or sensor on the transmission path in the region of the closing surfaces (e.g., B. upper edge of the plate) 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 Allow giedichte 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. Show it:

<b>Fig.</b> 1a Schematic representation of the inventive device for a closable opening with a transmitter and a receivers ger at the ends of the transmission path (in the open posi tion).

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

<b>Fig.</b> 2 Schematic representation of the inventive device for is a closable opening having a movable part associated transmission.

<b>Fig.</b> 3a Schematic representation of the inventive device for a closable opening with only at one end the transmission path arranged sensor and receiver (in ge öffneter position).

<b>Fig.</b> 3B are schematic representation of the device according to 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 driving zeugs with arranged on the disk bottom separate Sen and receiver and a force acting on the upper edge of Ge subject matter.

<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 driving zeugs with discs arranged on the lower edge of the sender / Receiver units each surface waves with entge generate gengesetzter propagation direction, said disks upper seam 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 division of the transmission path in accordance with <b>Fig.</b> 5a starting from the first transmitter / receiver unit.

<b>Fig.</b> 5d Schematic division 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 driving arranged zeugs with the edge of the pane edge Transmitter / receiver unit and two different design Notch geometries in the transmission path of the surface acoustic 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 cal waves on its surface as a so-called surface waves along a design-related or specially created Ausbreitungswe ges continued forward and external influences on exposure 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 illustrates the invention in a simplified manner ago direction is for a closable opening of a site at the ends fixed 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 befin det itself. in the open position An electrically-mechanical transducer kop pelt 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. In Depending speed of the material and geometry of the transmission path <b>3</b> , a certain Signal attenuation. In the closed state (see<b>Fig.</b> 1 b), ie, at Reaching the end position of the movable part <b>1</b>, touching the closing surfaces over a large area and connect a large part of the vibrational energy out. The thus considerably increased signal attenuation is the receivers eng <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 BE movable part <b>1</b> is arranged. the sensor are located at the ends<b>4</b> and the donor <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 radio tion unit <b>6</b> on the same end of the transmission path <b>3</b> angeord net. The functional unit is executed in one piece, they then acts alternately as a transmitter and a sensor. Piezoceramic construction elements can be used successfully for this purpose. The end of the tragungsweges <b>3</b> is formed so that as all of the energy from sorbed and therefore 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 Wellenaus achieved or spread of 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 Ausbrei propagation direction of 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 ge is coupled. The coupled-out by this object vibration energy be indicated an additional damping and reduces the amplitude of the harmonic surface waves 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 fol lowing differences:The coupled to the edges of the lower pane edge mechanically - Elek tric converter <b>6</b> serve as transmitter and receiver. also carries the revolving of the disc edge <b>21</b> formed acoustic About transmission path 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 - as well as dampening effects. With its help, the guide portions <b>23, 24</b> of the window pane <b>2</b> not only hide, son countries also separately the damping characteristics evaluated. This in turn can be used for controlling the transmission power of the surface-wave transmitter, a consistent signal to noise ratio ratio (S / N) ratio to have.

The following <b>Fig.</b> 5b, 5c and 5d illustrate in a simplified manner, the amplitude a Surface wave on the path or versus time, but without reflection effects at the notches <b>11</b> be taken into account. In the foreground here are through an object caused effects due to the pinching between the upper edge of the and Doorway.

The named object <b>10</b> is in any case a damping of the amplitude of the first transmitter / receiver unit <b>61</b> the transmitted signal <b>53</b> (<b>Fig.</b> cause 5b) What of the second transmitter / receiver unit <b>62</b> is registered. This is particularly be the case if, for. example, is clamped the hand of a person who, because of their relative Softness and thus good acoustic coupling barely a noteworthy can cause reflection fraction of the surface wave. In the event, however, that a relatively Hard foreign objects in the transmission path <b>21</b> the freely accessible top of the windowpane <b>2</b> is coupled, an additional reflection signal <b>54</b> of the first transmitter / receiver unit <b>61</b> be registered and thus by the redundancy improve transparency of the device.

The <b>Fig.</b> 5c and 5d to share the transmission path to schematically, wherein for one of the first transmitter / receiver unit <b>61</b> and secondly from the second transmitter / Receiver unit <b>62</b> is assumed. During a Blend of the Surface wave first swept 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 will only disappear when the on the second notch <b>11</b> reflected signal for analysis comes. The same applies to the other transmitter / Receiver unit transmitted signals. Although the notches<b>11</b> to a considerable cause attenuation of the signals, their use can be very beneficial. Finally permits Excluding the guide areas <b>23,24</b> right and left of the window pane <b>2</b> a targeted and largely trouble-free amplification of signals from the control area K, the contributes to a substantial improvement in 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> to second transmitter / receiver unit <b>62</b> and back.S₂-S₁ / E₁-E₂ as above, just in reverse.S₁-B-E₁ duration of the signal from the first transmitter / receiver unit score <b>11</b> at location B and back.S₂-A-E₂ duration of the signal from the second transmitter / receiver unit score <b>11</b> at location A and back.S₁-∇-E₁ duration of the signal from the first transmitter / receiver unit to the subject <b>10</b>Which in the transmission path <b>21</b> coupled , and back.S₂-∇-E₂ duration of the signal from the second transmitter / receiver unit to the subject <b>10</b> and back.S₁-A-E₁ duration of the signal from the first transmitter / receiver unit to the Notch at location A and back. (This guide is in the area Review of a jamming or collision state excluded.)S₂-B-E₂ duration of the signal from the second transmitter / receiver unit to the notch at the location B and back. (This guide region is also excluded when evaluating a collision state.)

From the guide areas <b>23</b>. <b>24</b> including the control area is K. He represents the part of the transmission path <b>21</b>Which is freely accessible. We therefore need to Detecting a collision state only the evaluation of such Signal changes that originate within the duration of the controlled area K have.

A variant of the invention, schematically <b>Fig.</b> 6 illustrates. Only at one of the edges 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</b>. <b>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 Dämpfungsverhal th. 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 to the top surface wave effect, causing the second asymmetrically designed notch <b>13</b> a total reflection of the surface wave. For this purpose has this notch<b>13</b> a steeply inclined notched edge, the one with the upper edge of the pane encloses an angle of preferably approximately 90 °, and 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> are, therefore leading to the area of ​​free -reach 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</b>. <b>15</b> can be obtained by analysis of the region between the Sen / receiver unit <b>6</b> and the first notch <b>12</b> achieve. A Eichungslauf between the stop positions, allows conclusions about the ERAL NEN 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 Führungsbe rich of 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</b>. <b>15</b> with tools <b>17,18</b> for limit position. These aid <b>17</b>. <b>18</b> will vary depending on the disc position and Application of resilient elements in the transmission path of the surfaces waves mechanically coupled and lead to measurable changes in the receiver <b>6</b> incoming signals. The coupling of the aid<b>17</b>. <b>18</b> For the detection of the lower stop and the upper stop to be carried out different locations and are therefore by measurement to be very easy divorce. 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 Ver setting range is selected in which no clamping is possible, and a forcibly retaining the adjusting force to completely close the window opening is necessary.

LIST OF REFERENCE NUMBERS

<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 signal

A amplitude angleK Control PanelA location of a notchB Place a notch