DE102018215829A1 - Collision warning of a motor vehicle - Google Patents

Abstract

The invention relates to a collision warning device (14) of a motor vehicle (2), in particular an electromotive adjusting device (4), with a distance sensor (20), which has a transmitter (22) for emitting electromagnetic radiation into a room area (24) and a receiver ( 26) for receiving the electromagnetic radiation reflected and / or scattered in the spatial region (24) and a computing unit (30) for determining a distance of an obstacle (25) within the spatial region (24) on the basis of the time period between the transmission and the reception of the has electromagnetic radiation. The collision warning device (14) further comprises an output device (16) for outputting a warning if the distance is less than a limit distance (34). The space area (24) is subdivided into a number of segments (42), the segments (42) being assigned different boundary distances (34). The invention further relates to a tailgate drive (4) of a motor vehicle (2).

Description

The invention relates to a collision warning device of a motor vehicle, with a distance sensor, and with an output device. The invention further relates to a tailgate drive of a motor vehicle, with a collision warning.

Motor vehicles have electric motor adjustment devices to increase comfort. Here, an adjustment part, such as a tailgate or a side door, is pivoted by means of an electric motor when activated. It is possible that there is an obstacle in the adjustment area. If the user does not have a complete overview of the adjustment area and activates the adjustment device, or if an obstacle is moved into the adjustment area, the adjustment part moves against the obstacle. It is therefore possible for the adjustment part and / or the obstacle to be damaged. To avoid this, collision detectors with a distance sensor are usually used. If it is detected by means of the distance sensor that the obstacle is in the adjustment range, a warning is issued by means of the collision warning and, depending on this, a current supply to the electric motor is changed, for example.

The distance sensor works according to the capacitive principle, for example, and the distance sensor thus has electrodes by means of which an electromagnetic field is created. If an object is located in the vicinity of the electrodes, the electromagnetic field is disturbed and the capacitance of the capacitor formed by means of the electrodes of the distance sensor is changed. By evaluating this, it is possible to detect the obstacle, but only a comparatively low spatial resolution is possible. In addition, the obstacle must be in the area of the electrodes.

An alternative to this is the use of a distance sensor with a radar sensor or an optical sensor. By means of this, electromagnetic waves are emitted during operation, which are reflected or scattered on the obstacle if it has suitable physical properties. The reflected waves are detected again by means of the radar sensor, and the distance of the obstacle to the radar sensor is determined on the basis of the propagation time of the waves. In other words, the time period between the transmission and the reception of the electromagnetic waves is determined and the distance is determined taking into account the propagation speed of the electromagnetic waves.

The electromagnetic waves are recorded, for example, by means of a single receiving unit. In particular, the complete adjustment range is illuminated with the electromagnetic waves. If there is a time period between the transmission and the reception of the waves which is less than a critical time period, it is assumed that the obstacle is in the adjustment range. If the time period is longer than the critical time period, the obstacle is at a greater distance from the distance sensor. A comparatively quick determination of the position of the obstacle is therefore necessary. In this case, however, it is possible, particularly in the case of a comparatively jagged configuration of the adjustment part, that it is erroneously assumed that the obstacle is in the adjustment area.

The invention is based on the object of specifying a particularly suitable collision warning device of a motor vehicle and a particularly suitable tailgate drive of a motor vehicle of a motor vehicle, advantageously reducing manufacturing costs and expediently increasing safety and reliability.

With regard to the collision warning, this object is achieved according to the invention by the features of claim 1 and with regard to the tailgate drive by the features of claim 5. Advantageous further developments and refinements are the subject of the respective subclaims.

The collision warning is part of a motor vehicle and is preferably connected to an adjustment part in the assembled state. At least, however, the adjustment range of the adjustment part is preferably monitored by means of the collision warning. The adjustment part is adjustable and preferably guided in a suitable manner, for example by means of a bearing, hinge or guide rails. The adjusting part is expediently a component of an electromotive adjusting device and is suitably driven by means of an electric motor, for example by means of a worm gear and / or a spindle. The electric motor is designed in particular as a brushed commutator motor or alternatively as a brushless one. The electric motor is expediently a brushless direct current motor (BLDC). For example, the electric motor is an asynchronous motor or a synchronous motor.

The electromotive adjustment device is also a component of the motor vehicle and, for example, an electromotive seat adjustment, an electromotive side window or an electromotive sunroof. In In this case, the adjustment part is a seat, part of a seat, a window pane or a sliding roof. The electromotive adjustment drive is preferably an electromotive door adjustment. The adjustment part is thus a door and part of the electromotive door adjustment. In particular, the door closes an opening in the motor vehicle. During operation, the door is preferably moved from an open to a closed position or vice versa by means of the electric motor. For example, the door is a side door that is pivoted or shifted in particular. The door is particularly preferably a tailgate, and the electromotive adjustment device is a tailgate drive.

The collision warning is suitably used to protect against jamming, in particular to avoid injury to a person. As an alternative or in combination, the collision warning device is used to monitor an adjustment range, in particular a pivoting range, of a door, such as a side door or a tailgate, during operation. During operation, the collision warning device is preferably used to monitor whether a side door is pivoted against a curb or the like. If a curb or the like is identified, the electromotive adjusting device in particular is controlled such that an adjusting movement is interrupted or at least reduced, as shortened, so that the door is prevented from being brought against the curb. If the door is a tailgate, it is monitored in particular that it is not brought against a ceiling or the like. The collision warning is thus used for collision protection.

The collision detector has a distance sensor, by means of which a distance of an obstacle to the collision detector, in particular the distance sensor, is thus detected and / or determined. A further distance of the obstacle from a reference point is suitably determined on the basis of the distance, and / or the presence of the obstacle is determined by means of the distance sensor. For example, a distance of the adjustment part with respect to a reference point and / or an obstacle is determined by means of the collision warning.

The distance sensor has a transmitter for emitting electromagnetic radiation in a spatial area. The transmitter is suitable for this, in particular provided and set up. In other words, the transmitter is used to emit electromagnetic radiation into the spatial area. In the assembled state, the room area is expediently directed away from the motor vehicle and the adjustment area is at least partially, expediently completely within the room area. The electromagnetic radiation is, for example, multi-band or has only a single wavelength. For example, pulsed electromagnetic radiation is emitted by the transmitter during operation.

For example, electromagnetic radiation is visible light. However, the electromagnetic radiation is particularly preferably not perceptible to humans. For example, infrared light is used as electromagnetic radiation. In an alternative embodiment, radar radiation is used as electromagnetic radiation. For this purpose, the transmitter is expediently designed in each case. The transmitter is formed, for example, by means of a lamp, in particular by means of an LED, or comprises this. As an alternative to this, the transmitter has, in particular, an antenna which is suitably controlled. The sensor preferably comprises a control circuit for the antenna.

The distance sensor also has a receiver for receiving the electromagnetic radiation. In particular, the receiver is suitable for this, expediently provided and set up. During operation, it is suitably possible to use the receiver to receive electromagnetic radiation which has the same properties as the electromagnetic radiation emitted by the transmitter, in particular the same wavelength. For example, the receiver has a filter for this. Thus only certain spectral ranges are received, which facilitates an evaluation. In particular, the receiver is arranged in such a way that electromagnetic radiation emitted by the transmitter cannot be detected directly. For example, an aperture is arranged between them.

During operation, an electromagnetic radiation reflected and / or scattered in the spatial area is received by means of the receiver. The receiver is suitably arranged for this. In other words, the reception area of the receiver is directed into the spatial area. If, during operation, there is an obstacle within the spatial area, this is irradiated by means of the electromagnetic radiation which is emitted by the transmitter. The electromagnetic radiation is therefore reflected or scattered at the obstacle and thus at least partially reflected back to the distance sensor. There it is received by the receiver and thus recorded. The receiver is, for example, a photodiode or comprises at least one photodiode. In particular, the receiver comprises a semiconductor substrate that is sensitive to the electromagnetic radiation. In an alternative to this, the receiver and the transmitter are formed, for example, by means of a common component, which is operated successively as a receiver and transmitter.

In addition, the distance sensor comprises a computing unit for determining a distance of an obstacle within the spatial area. The distance of the obstacle to the distance sensor is determined in particular. The determination is made on the basis of the time period between the transmission and the reception of the electromagnetic radiation. For this purpose, the computing unit is expediently coupled to the transmitter and / or the receiver in terms of signal technology, so that the times of transmission and reception are known in the computing unit. However, the transmitter and / or the receiver are particularly preferably controlled by means of the computing unit. Comparatively few components are therefore required for the distance sensor, and this can be manufactured comparatively inexpensively and in a small size.

To determine / calculate the distance, in particular the propagation speed of the electromagnetic radiation is taken into account, and the distance is expediently the same or at least proportional to half the product of the time period and the propagation speed of the electromagnetic radiation. In summary, the transit time of the electromagnetic radiation (propagation speed of the electromagnetic radiation) is used to determine the distance, and the distance is thus determined by means of a transit time method. For example, the distance sensor is a TOF sensor (“Time of Flight” sensor) or a TOF camera (“Time of Flight” camera) or comprises at least one of them.

Furthermore, the collision warning device has an output device that serves to output a warning. The output device is suitable for this, in particular it is provided and set up. For example, the warning is issued optically or acoustically during operation. In this case, in particular, the output device is a lamp, a display or a loudspeaker. However, the output device is particularly preferably an interface to a bus system of the motor vehicle or at least comprises this. For example, the bus system is a CAN or LIN bus system and the output device is operated accordingly. The warning is thus fed into the bus system during operation, and from there is passed on to further components of the motor vehicle. In particular, the warning is sent to any electric motor or to a control unit of the electric motor of the electric motor adjustment device, and an operation of the electric motor is ended or operated in the opposite direction. In other words, the warning is preferably directed to a control unit of the electromotive adjusting device, provided that the collision warning is part of the electromotive adjusting device, or is used to monitor the electromotive adjusting device.

The warning is issued when the distance to the obstacle is less than a limit distance, that is less than a limit value. In other words, the warning is issued if the time between the transmission and the reception of the electromagnetic radiation is less than a certain limit value which corresponds to the limit distance. The spatial area is divided into several segments, ie at least two segments, preferably between two segments and thirty segments, between five segments and twenty segments and, for example, between twelve segments and fourteen segments. Suitably the segments do not overlap.

Different limit distances are assigned to the segments. In other words, the boundary distances differ between at least two of the segments, the boundary distance being the same for some of the segments, for example. The boundary distances preferably differ between directly adjacent segments. Suitably each of the segments extends up to the distance sensor, so that the distance sensor is directly adjacent to or lies within each of the segments. The limit distance which is assigned to the respective segment is expediently constant within the respective segment, preferably also constant over time. In particular, the limit distance is stored when the collision warning device or the motor vehicle is manufactured. Alternatively, the limit distance can be set later, for example. At least, however, the limit distance is preferably not reset each time the collision warning is operated, and is constant over several operating cycles, in particular monitoring of the room area.

Due to the assignment of different boundary distances to the individual segments, it is possible to take into account a contour of an adjustment part or the like. In this context, it is taken into account in particular by means of the limit distance that in one segment there is no risk of the adjustment part colliding with the obstacle even if the distance is comparatively small, whereas in another segment a comparatively large distance is required to avoid this. It is thus possible to select the (complete) area of the room area in which the warning is issued to be comparatively small and to adapt it to the adjustment part. Therefore, an output of a warning, although no collision is possible, is in the Substantially prevented, nevertheless the area of the room area monitored by means of the collision warning system, in which a warning is output, comprises the complete adjustment range of the possible adjustment part. This increases security.

In particular, the collision detector is operated according to a method in which the electromagnetic radiation is emitted into the spatial area by means of the transmitter. During operation, the electromagnetic radiation is expediently emitted into the entire spatial area at the same time. In other words, the entire room area is illuminated simultaneously by means of the transmitter. In a further step the electromagnetic radiation reflected and / or scattered in the spatial area is received by the receiver. The distance between the obstacle, which is located within the spatial area, and the distance sensor is determined by means of the computing unit by using the time period between the transmission and the reception of the electromagnetic radiation. The distance is proportional, preferably equal, to half the product of the time span and the speed of the electromagnetic radiation, that is to say the transit time. In addition, a warning is issued by means of the output device if the distance is less than a limit distance. Here, the spatial area is divided into the segments, and a different limit distance is assigned to each of the segments. In other words, the warning is only issued when the reflected or scattered electromagnetic radiation is detected from the segment, and it is thus determined that the obstacle is located in the segment of the spatial area. It is checked whether the distance of the obstacle is smaller than the limit distance assigned to this segment. The collision warning device preferably comprises a control unit which is operated according to the method. In other words, the control unit is suitable, in particular provided and set up, for carrying out the method.

For example, the segments are the same. In particular, the segments each have a constant and thus the same solid angle, that is to say the same amount of the solid angle. The angle apex is expediently formed by means of the distance sensor. However, the segments particularly preferably have different solid angles, that is to say different amounts, and are therefore expediently different. The angular apex of the individual segments is formed by means of the distance sensor. For example, there are segments that have the same solid angle. At least the solid angle differs between two segments. The solid angle preferably differs from directly adjacent segments. Due to the different solid angles, it is possible to set the area monitored by means of the collision warning, which leads to the output of a warning, comparatively fine. A faulty output of a warning, that is to say a warning, if the obstacle is at a smaller distance than the limit distance, but is not in the adjustment range of the adjustment direction, is therefore avoided.

For example, the receiver has only a single receiving unit, for example a photodiode. In this case, the assignment of the received electromagnetic radiation to the segments takes place in particular by means of successive activation / irradiation of the segments by the transmitter. However, a receiving unit of the receiver is particularly preferably assigned to each segment. In other words, the electromagnetic radiation that arises from one of the segments, in particular was reflected / scattered there, is only detected by means of the respective assigned receiving unit. The assignment to the individual segments is thus essentially clear and at least improved. As a result, erroneous issuance of a warning is further suppressed.

Particularly preferably, each of the segments is assigned a plurality of receiving units, so that the receiver has more receiving units than segments. This enables a comparatively fine monitoring of the room area. It is expedient for the individual receiving units to always monitor an equally large part of the room area. In other words, each of the receiving units has an equally large solid angle from which an electromagnetic radiation can be received. The receiving units are expediently identical to one another. Thus, identical parts can be used, which reduces manufacturing costs. In this case, for example, the segments are assigned a different number of receiving units, so that they have a different solid angle. The solid angles of the segments therefore always differ by a multiple of the solid angle which is assigned to the area monitored by means of one of the receiving units.

For example, the receiver has a lens or the like, by means of which the reception range of the respective reception unit is set. If the receiver has several receiving units, these are expediently combined into a single component. Assembly is thus simplified. In particular, the receiver is formed by means of a multipixel chip, each pixel in particular forming an individual receiving unit. Alternatively, each receiving unit has several such pixels.

For example, the transmitter has a plurality of transmission units, one of the transmission units being assigned to each segment. Thus, in particular, successive emission of the electromagnetic radiation into the individual segments is possible, so that a comparatively precise assignment of the received electromagnetic radiation to the segments is made possible. Particularly preferably, however, the transmitter has only a single transmission unit. During operation, the electromagnetic radiation is preferably emitted into the complete spatial area by means of the transmitter unit. Manufacturing costs are reduced due to the single transmission unit. In an alternative to this, the transmitter points up to a plurality of transmission units, with one of the transmission units being assigned to a plurality of segments, for example. In particular, the individual segments are directly adjacent to one another. In a further alternative, a transmission unit is assigned to each segment. Assignment of the reception of the electromagnetic radiation to the individual segments is thus simplified. If the transmitter has a plurality of transmitter units, these are expediently combined to form a common component, in particular to form an array, for example an emitter array. Assembly is thus simplified. Alternatively, the transmitter is formed, for example, by means of a multipixel chip.

For example, each of the segments is assigned at least one transmitting unit and at least one receiving unit. These are preferably combined as a structural unit, which simplifies assembly. For example, several such structural units are combined into one assembly unit, which further facilitates assembly.

If several units, for example the transmitter unit, receiver unit and / or structural unit, are combined, these expediently comprise a common printed circuit board to which the respective electrical / electronic components are connected, by means of which the respective function is performed, for example the sensors. The circuit board is, for example, rigid, which reduces manufacturing costs. The circuit board is particularly preferably flexible and, for example, made of a flexible plastic substrate, such as polyamide, PEEK or transparent conductive polyester film. The flexible printed circuit board is expediently placed on a carrier, for example fastened to it, which has, for example, a plurality of surfaces inclined to one another. This is used to suitably assign the components to the segments. In a further alternative, the printed circuit board is created using 3D printing.

The tailgate drive is a component of a motor vehicle and has an electric motor, by means of which a tailgate is driven. During operation, the tailgate is pivoted along an adjustment range by means of the electric motor, in particular between an open and a closed position. For example, the tailgate is suitable for a sedan or a station wagon. The electric motor is, for example, a brushed commutator motor. However, the electric motor is particularly preferably designed to be brushless and expediently a brushless commutator motor (BLDC). In particular, the tailgate drive has two electric motors, by means of which the tailgate is driven. In this way, warping of the tailgate is avoided. A gear mechanism, for example a worm gear mechanism, is preferably arranged mechanically between the tailgate and the electric motor. By means of this, self-locking is preferably implemented. It is thus possible to arrange the tailgate in an at least partially open state for a period of time.

The tailgate drive also has a collision warning system that includes a distance sensor and an output device. The distance sensor has a transmitter for emitting electromagnetic radiation into a room area and a receiver for receiving the electromagnetic radiation reflected and / or scattered in the room area, and a computing unit for determining a distance of an obstacle within the room area based on the time period between the transmission and the Receiving the electromagnetic radiation. The output device serves to issue a warning if the distance between the obstacle within the spatial area is less than a limit distance. The spatial area is divided into several segments, with the segments being assigned different boundary distances.

For example, the individual segments are arranged side by side in the horizontal direction. Alternatively, the segments are arranged one above the other in the vertical direction. The segments are particularly preferably arranged both horizontally next to one another and vertically one above the other, so that in particular the individual segments are arranged in a checkerboard manner relative to one another.

The room area preferably covers the adjustment area of the tailgate. For example, the area is outside the motor vehicle. The collision warning device is expediently operated when the tailgate is opened by means of the electric motor. In other words, the area that is subsequently traversed by means of the tailgate is monitored by means of the collision warning. The limit distances are expediently adapted to the contour or at least the shape of the tailgate. The tailgate drive suitably has a control unit for the electric motor. The control device is expediently coupled to the output device of the collision warning device. If the warning is issued, the control unit is suitably used to stop the electric motor or to rotate it in the opposite direction, at least for a certain angular revolution. Following this, the electric motor is expediently stopped. A collision of the tailgate with the obstacle is thus avoided by means of the collision warning.

The tailgate is preferably symmetrical with respect to a plane of symmetry, which is expediently arranged parallel to the motor vehicle and perpendicular to a lane. This improves the visual impression. Here, the distance sensor is arranged in particular in the plane of symmetry, so that monitoring of the tailgate is simplified. Calibration of the collision warning system is also simplified. For example, the output device of the collision detector is offset from the plane of symmetry, so that an assembly space is used comparatively effectively. The segments are particularly preferably symmetrical with respect to the plane of symmetry, and also their respective limit distances. The distance of the obstacle that leads to the output of the warning is thus treated equally on both sides of the symmetry plane, depending on the respective segment. In particular, there are at least two segments in which the limit distance is the same and which expediently have the same solid angle. Thus, a functionality of the collision warning system can be understood by a user of the tailgate drive, so that acceptance is increased.

The space area is expediently divided into the segments such that an outer contour of the tailgate in each of the segments has a smaller distance than the respective limit distance. In other words, each point of the outer contour of the tailgate has a smaller distance from the distance sensor than the limit distance in the respective segment in which the point is located. The entire tailgate is thus monitored up to its outer contour by means of the collision warning device, and the tailgate is covered by the monitored area. At least, however, the projection of the space region monitored by means of the collision warning device, which leads to the output of the warning, completely covers the outer contour of the tailgate, for example a projection of the outer contour of the tailgate into a plane that is perpendicular to the possible adjustment path. Safety is thus increased and it is not possible to arrange an obstacle in the adjustment area of the tailgate without the warning being issued.

In particular, a maximum distance between each area of the outer contour of the tailgate along a straight line determined by means of the area and the distance sensor is smaller than a limit value. In other words, the monitored area only covers the outer contour around the limit value. Thus, only a maximum of the limit value is monitored around the outer contour by means of the collision warning device in such a way that the warning is output. In particular, the spatial area is divided into the segments in such a way that the limit value is maintained. In other words, the solid angles of the segments are preferably selected in accordance with the limit value. The limit value is determined, for example, as a percentage, in particular with regard to the respective straight line. For example, the limit is between 5% and 50%, between 10% and 30% and, for example, between 15% and 20% of the minimum distance of the outer contour from the distance sensor in the respective segment. As an alternative, the limit value is chosen to be absolute, for example, and is expediently between 1 cm and 20 cm, between 5 cm and 15 cm and in particular essentially equal to 10 cm. This ensures that any obstacle that is more than 10 cm away from the tailgate does not result in the warning being output.

The further developments and advantages in connection with the collision warning system can also be applied to the tailgate drive and vice versa.

• 1 schematisch vereinfacht ein Kraftfahrzeug mit einem Heckklappenantrieb, der einen Kollisionswarner aufweist,
• 2 in einer Rückansicht das Kraftfahrzeug mit dem Kollisionswarner
• 3 schematisch vereinfacht eine alternative Ausführungsform des Kollisionswarners,
• 4 ausschnittsweise eine alternative Ausgestaltungsform des Kollisionswarners.

An exemplary embodiment of the invention is explained in more detail below with reference to a drawing. In it show:

• 1 schematically simplified a motor vehicle with a tailgate drive, which has a collision warning,
• 2nd in a rear view the motor vehicle with the collision warning
• 3rd schematically simplified an alternative embodiment of the collision warning,
• 4th sections of an alternative embodiment of the collision warning.

Corresponding parts are provided with the same reference symbols in all figures.

In 1 is schematically simplified a motor vehicle 2nd with a tailgate drive 4th shown. The tailgate drive 4th is an electric motor adjustment device and includes an electric motor 6 which is a brushless DC motor (BLDC). The electric motor 6 is not closer by means of one shown transmission in operative connection with a tailgate 8th so that when the electric motor is operating 6 along an adjustment path 10th is pivoted. Thus, by means of the tailgate 8th pass through an adjustment range which is determined by the dimensions of the tailgate 8th and the adjustment path 10th is determined. In particular, the adjustment range includes all positions of the tailgate 8th this along the adjustment path 10th can accept.

The tailgate drive 4th also includes a control unit 12th , by means of which the electric motor 6 is operated. By means of the control unit 12th becomes a speed and direction of rotation of the electric motor 6 set. To do this, use the control unit 12th an electric current by means of which the electric motor 6 is operated, set accordingly. Operation of the control unit 12th takes place depending on current requirements, for example user input.

The collision warning 14 also has a distance sensor 20th on the one transmitter 22 for emitting electromagnetic radiation in a room area 24th includes. The electromagnetic radiation will, provided there is an obstacle 25th in the room area 24th is scattered and / or reflected on it. The space area 24th covers the adjustment range of the tailgate 8th completely, and the electromagnetic radiation is infrared light. In addition, the distance sensor points 20th a recipient 26 to receive from in the room area 24th reflected and / or scattered electromagnetic radiation. The recipient is for this 26 suitable. The recipient 26 is therefore sensitive in the infrared range.

Furthermore, the distance sensor 20th a computing unit 30th on. The computing unit 30th is signaling with the receiver 26 and the transmitter 22 coupled and serves to determine a distance of the obstacle 25th to the distance sensor 20th , that is, within the space 24th obstacle 25th . Here, the time period between the transmission and the reception of the electromagnetic radiation is used. In other words, the distance sensor 20th operated by means of a transit time method, and based on the transit time of the electromagnetic radiation, the distance of the obstacle 25th certainly.

Furthermore, the collision warning 14 a control unit 32 on. By means of the control unit 32 then when the tailgate 8th by means of the control unit 12th is pivoted into the open position, the distance sensor 20th controlled. This is done using the transmitter 22 the electromagnetic radiation in the room area 24th sent out. By means of the recipient 26 is monitored whether the electromagnetic radiation in the room area 24th is reflected and / or scattered. If this is the case, the obstacle is located 25th within the room area 24th . Using the computing unit 30th the distance between the obstacle is based on the time period between the transmission and the reception of the electromagnetic radiation 25th to the distance sensor 20th certainly. This is equal to half the product of the speed of electromagnetic radiation, i.e. the speed of light in air, and the time span. The distance is sent to the output device 16 passed, and by means of this a warning is issued if the distance is less than a limit distance 34 is. The warning is then in the bus system 18th fed and by means of the control unit 12th receive. This is followed by the control unit 12th the electric motor 6 operated in the opposite direction so that the tailgate 8th of the obstacle 25th Will get removed. If the tailgate 8th a sufficient distance from the obstacle 25th has, the electric motor 6 shut down.

In 2nd is the motor vehicle 2nd shown schematically simplified from behind. The tailgate 8th is with respect to a plane of symmetry 36 designed symmetrically along the longitudinal axis of the motor vehicle 2nd runs and perpendicular to a lane 38 is on which the motor vehicle 2nd is or is moving in the intended condition. The distance sensor 20th is within the plane of symmetry 36 in the vertical direction above the tailgate 8th arranged. The transmitter 22 has a single transmission unit 40 on, which is formed by means of an IR LED (infrared diode). When operating the transmitter unit 40 becomes the full room area 24th irradiated with the electromagnetic radiation.

The space area 24th is in several segments 42 divided into nine segments in the example. The segments 42 are symmetrical with respect to the plane of symmetry 36 and arranged side by side in the horizontal direction, one of the segments 42 on both sides of the plane of symmetry 36 located. Each of the segments 42 is a receiving unit 44 Recipient 26 assigned. Hence each segment 42 one of the receiving units 44 Recipient 26 assigned. The receiving units 44 are formed here by means of photodiodes. When registering the electromagnetic radiation using one of the receiving units 44 it is found that the obstacle 25th in which this receiving unit 44 assigned segment 42 located.

The segments 42 are spherical sector shaped, and the acute angle is by means of the distance sensor 20th educated. All segments are therefore sufficient 42 up to the distance sensor 20th . The segments 42 have different solid angles 46 where the vertex is the solid angle 46 by means of the Distance sensor 20th is formed. Hence the volume of the segments 42 different from each other. Here is the solid angle 46 of itself with respect to the plane of symmetry 36 corresponding segments 42 equal.

Each of the segments 42 is a different limit distance 34 assigned. So the room area 24th into the segments 42 divided, and the segments 42 are different limit distances 34 assigned. Regarding the plane of symmetry 36 corresponding segments 42 is the same limit distance 34 assigned. So is the middle and an edge area of the tailgate 8th assigned segments 42 compared to the one corner area of the tailgate 8th assigned segments 42 a reduced limit distance 34 assigned.

The division into the segments 42 takes place in such a way that the outer contour 48 the tailgate or at least a projection of the outer contour 48 in a plane perpendicular to the adjustment path 10th completely within the monitored part of the room area 24th lies within the part of the room area 24th which leads to a warning if the obstacle 25th is in it. In other words, the outer contour 48 the tailgate 8th in each of the segments 42 a smaller distance than the respective limit distance 34 on. At least, however, the projection of the outer contour 48 the tailgate 8th in a perpendicular to the adjustment path 10th a closer distance to the distance sensor 20th on than the limit distances 42 projected on the same plane. In other words, the projection of the outer contour 48 from the boundary distances 42 completely covered.

Here is the maximum distance between each area of the outer contour 46 the tailgate 8th along one by means of the respective area and the distance sensor 20th certain straight lines smaller than a limit. In other words, the segments are enough 42 only by a maximum of the limit value over the outer contour 46 over. In other words, the projection of the outer contour 48 from the boundary distances 42 only covered too far by a maximum of the limit. The choice of solid angles 46 takes place in such a way that the condition is fulfilled. For example, the limit value is absolutely determined and in particular is equal to 10 cm.

In 3rd is schematically simplified the collision warning 14 shown in sections. This includes a flexible circuit board 50 that on a carrier 52 is put on. The carrier 52 has, for example, a trapezoidal cross section, and the flexible printed circuit board 50 is placed on three of the sides, so that three sections inclined towards each other 54 are formed. The carrier 52 is, for example, a component of a body of the motor vehicle 2nd or a separate component and in particular rigid. On each of the sections 54 the flexible circuit board 50 is a structural unit 56 attached and soldered, each a transmitter unit 40 and a receiving unit 44 having. The structural units 56 are identical to each other. By means of the individual sections 54 the individual segments 42 determined, in particular based on the contour of the carrier 52 . The segments 42 encounter in the area of the edges of the individual sections 54 to each other.

The structural units are another alternative 56 by means of a stiffener 58 stabilized, which is created for example from the plastic. Here there is stiffening 58 expediently on that of the structural unit 56 opposite side of the flexible circuit board 50 . This means that the structural units are tilted 56 with a comparatively loose installation of the flexible printed circuit board 50 on the carrier 52 prevented. In a variant, not shown, each structural unit 56 one stiffener each 58 assigned, or there is no such stiffening 58 available.

In 4th is an alternative embodiment of the tailgate drive 4th shown in a side view. The tailgate drive 4th and also includes the collision warning 14 as well as the room area 24th that in the segments 42 is divided. Here are the segments 42 compared to that in 2nd shown variant not arranged in the horizontal direction next to each other but in the vertical direction one above the other, with each of the segments 42 a limit distance 34 is assigned, which is between the individual segments 42 differs. The segments are in a variant that is not shown in detail 42 arranged next to each other both in the horizontal direction and one above the other in the vertical direction.

The outer contour 48 the tailgate 8th is due to a kink 60 not in the room area 24th . However, in the case of a projection, the outer contour 48 on the segments 42 the distance of the projection 48 less than the limit distance 34 . The projection takes place according to the adjustment path 10th , at least partially along a curved line. When controlling the electric motor 6 in particular, a wake is taken into account. In other words, when the distance of the obstacle 25th to the collision warning 14 less than the limit distance 34 however larger than the distance of the collision warning 14 to the click 60 is when the tailgate opens 8th this is pivoted further by a caster. So is the tailgate in particular 8th along the adjustment path 10th still panned a certain path (caster) when the obstacle 25th no longer by means of the lowest segment in the vertical direction 42 can be recorded. The amount of the path is expediently dependent on the distance of the obstacle 25th to the collision warning 14

In summary, the obstacle leads 25th if this is inside the outer contour 46 positioned to issue the warning. If the obstacle 25th by more than 10 cm from the outer contour 46 from the tailgate 8th spaced away does not result in the warning being issued. The obstacle leads in the area in between 25th depending on the positioning with respect to the segments 42 to issue the warning. Because of the division into the segments 42 it is possible to choose a comparatively low limit value so that a comparatively fine distinction is possible as to whether the tailgate swivels 8th along the adjustment path 10th this against the obstacle 8th is spent or not. There is only a single distance sensor 20th required, which reduces manufacturing costs.

In summary, the room area 24th into the individual segments 42 divided. Each segment is expedient 42 one receiving unit each 44 Recipient 26 assigned. Due to such a configuration, it is possible to change the angular resolution of the distance sensor 20th on the motor vehicle 2nd adapt. Individual elements of the transmitter can also be used, for example 22 , especially transmission units 40 , and / or receiving units 44 can be saved because in parts of the room area 24th , i.e. the individual segments 42 , where a lower angular resolution is required than in other areas, a lower angular resolution is assigned. In other words, the solid angle 46 enlarged there.

For example, the only sending unit 40 the entire room area 24th assigned to all segments 42 . The transmitter unit is an alternative to this 40 at least several of the segments 42 assigned. In a further alternative, which is not shown, each of the segments 42 a transmission unit 40 assigned so that the transmitter 22 just as many transmission units 40 has like segments 42 available. Each segment is expedient 42 at least one of the receiving units 44 assigned. The respective receiving units 44 or transmitter unit 40 are combined into components, for example. So is the transmitter 22 in particular by means of emitter arrays and / or the receiver 26 formed by means of a multipixel chip.

The invention is not restricted to the exemplary embodiment described above. Rather, other variants of the invention can also be derived therefrom by the person skilled in the art without departing from the subject matter of the invention. In particular, all of the individual features described in connection with the exemplary embodiment can also be combined with one another in other ways without departing from the subject matter of the invention.

Reference list

2nd

Motor vehicle

4th

Tailgate drive

6

Electric motor

8th

Tailgate

10th

Adjustment path

12th

Control unit

14

Collision warning

16

Output device

18th

Bus system

20th

Distance sensor

22

Channel

24th

Room area

25th

obstacle

26

receiver

30th

Arithmetic unit

32

Control unit

34

Limit distance

36

Plane of symmetry

38

lane

40

Transmitter unit

42

segment

44

Receiving unit

46

Solid angle

48

Outer contour

50

flexible circuit board

52

carrier

54

section

56

structural unit

58

stiffening

60

Kink

Claims (7)

Collision warning (14) of a motor vehicle (2), in particular an electromotive adjusting device (4), with a distance sensor (20), which has a transmitter (22) for emitting electromagnetic radiation in a room area (24) and a receiver (26) for reception from the in the Has spatial area (24) reflected and / or scattered electromagnetic radiation and a computing unit (30) for determining a distance of an obstacle (25) within the spatial area (24) based on the time period between sending and receiving the electromagnetic radiation, and with an output device (16) for issuing a warning if the distance is less than a limit distance (34), the space area (24) being divided into a plurality of segments (42), and the segments (42) being assigned different limit distances (34). Collision warning (14) after Claim 1 , characterized in that the segments (42) have different solid angles (46). Collision warning (14) after Claim 1 or 2nd , characterized in that each segment (42) is assigned a receiving unit (44) of the receiver (26). Collision warning device (14) according to one of claims 1 to 3, characterized in that the transmitter (22) has only a single transmission unit (40). Tailgate drive (4) of a motor vehicle (2), with an electric motor (6), by means of which a tailgate (8) is driven, and with a collision warning device (14) according to one of Claims 1 to 4. Tailgate drive (4) after Claim 5 , characterized in that the distance sensor (20) is arranged in a plane of symmetry (36) of the tailgate (8), the segments (42) being symmetrical with respect to the plane of symmetry (36). Tailgate drive (4) after Claim 5 or 6 , characterized in that the space area (24) is divided into the segments (42) in such a way that an outer contour (48) of the tailgate (8) in each of the segments (42) has a smaller distance than the respective limit distance (34), wherein a maximum distance between each area of the outer contour (48) of the tailgate (8) along a straight line determined by means of the area and the distance sensor (20) is smaller than a limit value.

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