Sensor device, vehicle and method for operating a sensor device

Abstract

The invention relates to a sensor device comprising a plurality of sensors (3), the sensors (3) each being designed to emit at least one signal (11, 12) at various transmission times, the transmission times of the sensors (3) each being predefined by a transmission rule associated with the respective sensor (3), the sensor device (2) being designed, in the event that a transmission time of one of the sensors (3) coincides with a further transmission time of a further of the sensors (3), to skip the signal (11, 12) of the first sensor (3) assigned to the transmission time or to emit it in dependence on a measure changing the transmission time and / or a signal characteristic.

Description

[0001] Description

[0002] Sensor device, vehicle and method for operating a sensor device

[0003] The invention relates to a sensor device comprising a plurality of sensors, each of which is configured to transmit at least one signal at different transmission times, the transmission times of the sensors being predetermined by a transmission rule assigned to the respective sensor. Furthermore, the invention relates to a vehicle and a method for operating a sensor device comprising a plurality of sensors.

[0004] Sensor devices with multiple sensors can be used, for example, in the automotive sector, where, for example, sensor devices comprising multiple ultrasonic sensors are used to measure the distance between a vehicle and objects in the vehicle's surroundings. Such sensor devices can be used, for example, to implement systems for automatic parking, collision avoidance, automatic braking, and / or other types of driver assistance systems.

[0005] To achieve sufficient coverage of the vehicle's surroundings for the respective driver assistance system, sensor systems with multiple sensors are typically used, for example, with six or more ultrasonic sensors per vehicle bumper. This allows the vehicle's surroundings in front of, behind, and possibly also to the side of the vehicle to be recorded.

[0006] Ultrasonic sensors usually emit individual ultrasonic pulses and then wait for the echo generated by the signal reflected from an object in order to clearly assign the echoes to the emitted signals or the respective sensors. In order to increase the transmission frequency of the sensors, especially when there are multiple identical sensors and at least partially overlapping detection ranges, transmission times can be specified for the individual sensors, for example using a specific code, continuously and at intervals that are characteristic for each sensor. This allows the sensors to each emit their signals as a pulse sequence without having to wait for the echoes and without the sensors interfering with one another. The characteristic intervals between the transmission times of the signals then allow received echoes to be assigned to the respective sensors.

[0007] In such a process, it may happen that two or more sensors transmit a signal simultaneously. Due to the high energy consumption during transmission, a high power or supply current can be drawn from the sensors' power supply, which can have undesirable consequences.

[0008] The invention is therefore based on the object of providing an improved sensor device which in particular avoids the occurrence of such current peaks.

[0009] To achieve this object, in a sensor device of the type mentioned at the outset, the invention provides that the sensor device is designed to omit the signal of the first sensor associated with the transmission time when a transmission time of one of the sensors coincides with a further transmission time of another of the sensors, or to transmit it as a function of a measure that changes the transmission time and / or a signal quality.

[0010] The coincidence of transmission times refers to the coincidence of the transmission times at the same time or within a predetermined time interval, resulting in at least a partial overlap of the transmission duration resulting from the transmission of the signal at the transmission time. Thus, the transmission times coincide when the signals transmitted at the transmission times at least partially overlap in time.

[0011] If the transmission time of the sensor coincides with the transmission time of another sensor, and it is therefore foreseeable that both sensors would transmit a signal at the same transmission time, at least one sensor can omit its signal instead or transmit it depending on the measure that changes the transmission time and / or the signal quality. If the signal is omitted, the other sensor can, for example, transmit its signal normally.

[0012] If the transmission time for at least one sensor and / or the signal quality are adjusted according to the intended measure, it is possible for the additional sensor, for example if the sensor's transmission specification is known, to also adjust its signal according to the measure. Alternatively, it is possible for the additional sensor's signal to be transmitted normally at the transmission time, i.e., without being altered by any measure.

[0013] By omitting the signal, the sensor does not require any energy to generate the signal, thus preventing the occurrence of a current spike in a power supply device or on a supply line to the sensors. Changing the transmission time and / or signal quality can also reduce the energy consumption of the sensors at the original transmission time, thus also preventing the occurrence of current spikes.

[0014] Avoiding current peaks in the power supply and on the supply line has the advantage that the power supply for the sensors can be adjusted to a lower maximum current draw. A particular advantage of the invention is that the required buffering of the sensor power supply has much lower requirements, thus requiring less space and being more cost-effective. This advantageously improves the robustness of the sensor device and its operation.

[0015] Furthermore, negative effects of current spikes, such as a supply voltage collapse, can be avoided. This can, for example, prevent insufficient voltage supply when multiple sensors transmit simultaneously, which could, for example, cause the sensors to enter sleep or reset mode.

[0016] Avoiding current peaks also has the advantage of reducing the impact on the electromagnetic compatibility of the sensor device, as electromagnetic fields induced by the current flow, which may affect other devices, also occur to a lesser extent.

[0017] The method according to the invention advantageously makes it possible to prevent simultaneous transmissions from multiple sensors, even in sensor devices in which the transmission times at which the sensors transmit their signals are determined according to a transmission rule individually assigned to the sensors. Consequently, excessive loads on the current or voltage supply of the sensors can be reduced, particularly in sensor devices in which the individual sensors operate at least substantially autonomously according to a transmission rule stored in the sensors. This advantageously avoids complicated synchronization processes and / or the need for central control of the sensors or for a central, deterministic specification of the respective transmission times of the sensors.

[0018] According to the invention, it can be provided that the measure comprises a shift of the transmission time by a predetermined time interval and / or a reduction of a transmission power of the signal by a predetermined factor.

[0019] One measure that can be provided, for example, is to postpone the transmission time by a predetermined time interval. In this case, the sensor does not transmit the signal at the actual transmission time, but in particular at an alternative transmission time that is postponed into the future by the predetermined time interval. This has the effect that the at least one other sensor, which is also transmitting at the transmission time, transmits alone, thus reducing the load on the power supply. In particular, the at least one sensor transmits alone at the postponed transmission time, so that no excessive loads occur on the power supply even at the postponed transmission time. For this purpose, in particular, a time interval can be specified that differs from the transmission times defined by the transmission regulations.

[0020] Additionally or alternatively, the transmission power for the signal to be transmitted at the transmission time can also be reduced as a measure. This can, in particular, also reduce the energy requirement of the sensor for transmitting the signal, so that the overall load on the energy supply at the transmission time can be reduced. When using a measure that provides for the reduction of the transmission power by a predetermined factor, the additional sensor can, in particular, also take a corresponding measure, so that overall there is no increased energy requirement despite the simultaneous transmission of at least one sensor and the additional sensor at the transmission time. The transmission power can, for example, be reduced by transmitting the signal with a smaller signal amplitude.

[0021] In a preferred embodiment of the invention, it can be provided that the transmission instructions assigned to the respective sensors are stored in the respective sensors, wherein at least one further transmission instruction of a further one of the sensors is stored in at least one of the sensors, wherein the at least one sensor is configured to determine the coincidence of one of its transmission times with at least one further transmission time described by the at least one further transmission instruction.

[0022] In each of the sensors, at least the transmission rule is stored which defines the transmission times for this sensor. It is possible for one or more further transmission rules to be stored in some of the sensors of the sensor device. Alternatively, it is possible for at least one further transmission rule to be stored in all of the sensors. It is also possible for the transmission rules of all sensors of the sensor device to be stored in the sensors. The individual sensors can, for example, each comprise a computing unit for determining the transmission times from the one or more transmission rules. Furthermore, each of the sensors can also have a memory unit in which, for example, the transmission rule and, if applicable, the one or more further transmission rules are stored.The transmission instructions can be assigned to the sensors, for example, by a control device of the sensor device during initialization of the sensor device.

[0023] Alternatively, it can be provided according to the invention that the sensor device comprises a control device, wherein the transmission instructions assigned to the respective sensors are stored in the control device, wherein the control device is designed to determine the coincidence of a transmission time of one of the sensors with at least one further transmission time of at least one further one of the sensors and to control the sensor to omit the signal at the transmission time and / or to transmit the signal depending on a measure changing the transmission time and / or the signal quality.

[0024] In particular, if the sensor transmits the signal at the transmission time as a function of a measure that changes the signal quality, the control device can also control the at least one further sensor to transmit its signal as a function of the measure or measures that change the signal quality. The signal of the further sensor(s) can be modified according to the same measure, in particular a transmission power reduced by the same factor. The factor can be selected such that the total transmission power of all signals transmitted at the transmission time corresponds to the transmission power of a single, unmodified signal.

[0025] According to the invention, it can be provided that the transmission instructions each comprise a table with a plurality of transmission time intervals, in particular as a stochastically generated code, wherein the sensor device is configured to determine the transmission times as a function of the transmission time intervals and a synchronization signal.

[0026] The transmission instructions can be transmitted to the individual sensors, for example, by a control unit of the sensor device during initialization. A different transmission instruction can be transmitted to each sensor. Alternatively, the transmission instructions assigned to the sensors can be generated and stored in the control unit during initialization of the sensor device.

[0027] The transmission instructions can, for example, each be implemented as a table with multiple transmission time intervals, so that the sensors or the control device can determine the respective transmission times based on the specified transmission time intervals. For transmission instructions stored in the sensors, a synchronization signal can be specified, in particular by the control device of the sensor device, which represents a starting point for determining the transmission times and / or a periodically updated reference signal for synchronizing the respective transmission clocks. If the transmission instructions are stored in the control device, the control device can, for example, use a synchronization signal generated internally in the control device or a synchronization signal generated externally and transmitted to the control device to determine the transmission times for the sensors.

[0028] According to the invention, it can be provided that the sensors are connected to a common power supply device which provides a power supply to the sensors.

[0029] The power supply device can be implemented in particular in the control device or a control unit of the sensor device. The control device can provide a power supply for the individual sensors or contain a power supply device for supplying the sensors. A central power supply for the sensors is advantageously implemented, as this can be implemented with particularly low effort and in a compact manner by avoiding simultaneous transmission or by reducing current peaks when multiple signals are transmitted simultaneously. This advantageously facilitates the integration of a power supply for all sensors into a control unit of the sensor device.

[0030] According to the invention, it can be provided that the sensors are each connected to the control device via a separate connection or that the sensors and the control device are connected in a common parallel circuit.

[0031] It is possible for the sensors to be connected to the control device separately via a connection. Such a point-to-point connection can comprise a separate line for the power supply and / or a separate line for data transmission between the sensor and the control device. It is also possible for the power supply and data transmission to be carried out via a common line.

[0032] Alternatively, it is possible for the sensors and the control device to be connected in parallel, at least with regard to their power supply.

[0033] In particular, a power supply device of the control device can be connected in parallel to the sensors so that they can be supplied with a supply voltage together.

[0034] In a preferred embodiment of the invention, the sensors can be designed as ultrasonic sensors. Other sensor designs, such as radar sensors, lidar sensors, or similar, are also possible.

[0035] According to the invention, the sensor device can be configured for distance measurement, fill level measurement, and / or as an anti-theft alarm system. The configuration of the sensor device can be achieved in each case by configuring a control device of the sensor device to perform a distance measurement, a fill level measurement, and / or to detect theft based on echoes or measured values ​​detected by the sensors.

[0036] A vehicle according to the invention is provided with at least one sensor device according to the invention. The sensor device can be designed, for example, for distance measurement and can comprise a plurality of sensors arranged along the circumference of the motor vehicle or along a partial section of the circumference, for example, a bumper of the motor vehicle. Additionally or alternatively, the motor vehicle can also have a sensor device designed for level measurement and / or as an anti-theft alarm system.

[0037] All advantages and details described above with regard to the sensor device according to the invention also apply accordingly to the vehicle according to the invention and vice versa.

[0038] For a method according to the invention for operating a sensor device comprising a plurality of sensors, it is provided that the sensors each transmit at least one signal at different transmission times, wherein the transmission times of the sensors are each predetermined by a transmission rule assigned to the respective sensor, wherein if a transmission time of one of the sensors coincides with a further transmission time of another of the sensors, the signal of the first sensor assigned to the transmission time is omitted or is transmitted depending on a measure that changes the transmission time and / or a signal quality.

[0039] According to the invention, it can be provided that the measure comprises a shift in the transmission time by a predetermined time interval and / or a reduction in transmission power by a predetermined factor, wherein the sensor transmits the signal with a shifted transmission time and / or a reduced transmission power depending on the measure. In a first preferred embodiment of the method, it can be provided according to the invention that the transmission instructions assigned to the respective sensors are stored in the respective sensors, wherein at least one further transmission instruction of a further one of the sensors is stored in at least one of the sensors, wherein the at least one sensor determines the coincidence of one of its transmission times with at least one further transmission time described by the at least one further transmission instruction.

[0040] In a second preferred embodiment of the method, it can be provided according to the invention that the sensor device comprises a control device, wherein the transmission instructions assigned to the respective sensors are stored in the control device, wherein the control device determines the coincidence of a transmission time of one of the sensors with at least one further transmission time of at least one further one of the sensors and controls the sensor to omit the signal at the transmission time and / or to transmit the signal depending on a measure changing the transmission time and / or the signal quality.

[0041] All advantages and details described above in relation to the sensor device according to the invention and / or the vehicle according to the invention also apply accordingly to the method according to the invention and vice versa.

[0042] Further advantages and embodiments of the invention will become apparent from the exemplary embodiments described below and from the drawings. These are schematic representations and show:

[0043] Fig. 1 shows an embodiment of a vehicle according to the invention comprising a first embodiment of a sensor device according to the invention,

[0044] Fig. 2 shows a second embodiment of an inventive

[0045] Sensor device and Fig. 3 two diagrams, each representing the transmission of a signal at different transmission times, to explain an embodiment of a method according to the invention.

[0046] Fig. 1 shows an embodiment of a vehicle 1. The vehicle 1 comprises a sensor device 2, which has a plurality of sensors 3 designed as ultrasonic sensors. The sensor device 2 further comprises a control device 4, which is connected to the sensors 3. In the first embodiment of the sensor device 2, each sensor 3 is connected to the control device 4 via a separate connection 5. Via the separate connections 5, energy can be transferred or a power supply can be provided from the control device 4 to the individual sensors 3. Furthermore, data can also be exchanged between the sensors 3 and the control device 4 via each of the separate connections 5.

[0047] The sensors 3 are arranged in a partial area of ​​the outer circumference of the vehicle 1, in this case on the front bumper of the vehicle 1. It is possible for the sensor device 2 to comprise further sensors 3 which are arranged in other partial areas of the circumference of the vehicle 1, for example in order to also detect the vehicle surroundings behind the vehicle 1 and / or next to the vehicle 1. The sensor device 2 can be designed here as a distance detection device which can determine the distance between the vehicle 1 and other objects in the surroundings of the vehicle 1. Accordingly, the control device 4 of the sensor device 2 is designed to determine distances to other objects from the measurement data of the sensors 3 and / or to create an environment map which describes several objects and their relative arrangement to the vehicle 1.

[0048] Fig. 2 shows a second embodiment of a sensor device 2. In this embodiment, the sensors 3 are connected in a parallel circuit 6. The parallel circuit 6 of the sensors 3 is further connected to a power supply 7, which is embodied as part of the control device 4, so that the sensors 3 can be supplied with power via the parallel circuit 6. The transmission of data between the sensors 3 and the control device 4 can take place, for example, via an additional data communication connection 8.

[0049] In both exemplary embodiments of the sensor device 2, the sensors 3 are each configured to transmit at least one signal at different transmission times. The transmission times of the sensors 3 are each predetermined by a transmission rule assigned to the respective sensor 3. If a transmission time of one of the sensors 3 coincides with another transmission time of another of the sensors 3, the sensor device 2 is configured to omit the signal of the sensor 3 assigned to the transmission time or to transmit it depending on a measure that changes the transmission time and / or a signal quality or a signal property.

[0050] The transmission instructions describing the respective transmission times of the sensors 3 can, for example, each comprise a table with several transmission time intervals. The transmission instructions can, for example, be generated as a stochastic code. The transmission instructions for the sensors 3 can be stored in the individual sensors 3 or in the control device 4.

[0051] If the transmission instructions are stored in the respective sensors 3, in order to avoid the simultaneous transmission of signals via several of the sensors 3, at least one further transmission instruction of another of the sensors 3 is stored in one or more of the sensors 3. Thus, at least some of the sensors 3 can be made aware of the transmission times of one or more other sensors 3 of the sensor device 2 in addition to their own transmission times. In this case, the sensor 3 can determine the coincidence of two transmission times depending on the transmission instruction assigned to it and the further transmission instruction which describes the transmission times of the other sensor 3. The sensor 3 can therefore determine when one of its transmission times coincides with the transmission time of another of the sensors 3. Since the sensors 3, when transmitting their signals, ieIf the sensors 3 have an increased energy requirement to generate the signal at the respective transmission time, a power supply for the sensors 3, for example, the power supply device 7 integrated into the control device 4, may be overloaded, or voltage compensation measures and / or a design of the power supply device 7 for a higher power may be required. Furthermore, the current peaks generated thereby may be undesirable with regard to the electromagnetic compatibility of the sensor device 2.

[0052] A sensor 3, which determines the coincidence of one of its transmission times with at least one further transmission time described by the at least one further transmission rule, can omit the signal assigned to the transmission time or transmit it depending on a measure changing the transmission time and / or a signal quality.

[0053] Alternatively, it is possible for the respective transmission instructions to be stored in the control device 4, wherein the control device 4 controls the individual sensors 3 at the corresponding transmission times to transmit a signal. Accordingly, when two or more transmission times coincide, the control device 4 can control one or more of the sensors to omit their respective signal and / or to modify their respective signal depending on the measure that changes the transmission time and / or the signal quality.

[0054] The measure can include a shift in the transmission time for one of the sensors 3 by a predetermined time interval and / or a reduction in the signal power or the signal amplitude of the signal by a predetermined factor. In particular, it is possible for the reduction in transmission power to be implemented both for the sensor 3 and for the at least one other sensor 3, i.e., for all sensors 3 whose transmission times coincide.

[0055] It is possible that the factor by which the transmission power is reduced is determined depending on the number of coincident transmission times and thus depending on the number of signals intended for simultaneous transmission. For example, for two signals that are to be transmitted at the same transmission time, the signal amplitude can be reduced in such a way that only half the transmission power is used for transmission for each of the two signals. Thus, the energy requirement or current consumption of the sensors 3 remains the same at the common transmission time.

[0056] In general, for n signals that are to be transmitted at the same transmission time, the transmission power can be reduced by a factor of 1 / n. This can either be specified by the control device 4 if the transmission rules are stored in the control device 4, or determined individually by each of the sensors based on the transmission rules stored in the sensor.

[0057] Fig. 3 schematically shows two diagrams 9, 10. Diagram 9 shows the signals 11 emitted by a first of the sensors 3, and diagram 10 shows the signals 12 emitted by a second of the sensors 3. The abscissa represents time t and the ordinate represents the transmission powers Pi and P2 of the signals 11 and 12, respectively.

[0058] The signals 11, 12 are each transmitted at different transmission times. The transmission times result, for example, from the time intervals stored as transmission specifications, which are selected at least partially differently for the individual sensors 3, so that the individual sensors 3 transmit their signals in a characteristic temporal pattern.

[0059] The transmission times can be generated, for example, from the time intervals depending on a synchronization signal, which is continuously transmitted at specific times, for example, from the control device 4 to the sensors 3. Assigning a characteristic signal transmission pattern allows the assignment of received signals, or echoes resulting from the signals, to the individual sensors 3.

[0060] As can be seen in the example shown in Figure 3, the transmission times ti of the first sensor and t2,s of the second sensor coincide. As a measure, the transmission power of both signals is reduced by a factor of 0.5, so that the overall energy requirement remains constant at the transmission time tu or t2,i.

[0061] Additionally or alternatively, it is possible for the transmission time of one of the signals to be shifted by a time interval Ati, as shown schematically in dashed lines for the signal 11 of the first sensor 3.

[0062] As an alternative to postponing the transmission time and / or taking a measure that changes the transmission time and / or the signal quality, the signal 11 of the first sensor 3 or the signal 12 of the second sensor 3 can also be omitted at the transmission time t1 or t2,s, respectively. The respective measures to be implemented can be stored as measure information in the individual sensors 3 and / or in the control device 4, analogous to the transmission instructions.

[0063] In both exemplary embodiments of the sensor device 2, it is possible for the sensors 3 to be connected to a power supply device designed separately from the control unit 4. Furthermore, it is possible for the sensor device 2 to be used in a device other than a vehicle and / or for the sensor device 2 to be designed for level measurement and / or as an anti-theft alarm system. The respective function of the sensor device 2 can be implemented, for example, by the control device 4, which accordingly evaluates the measurement data or echoes of the signals received by the sensors 3.

[0064] As an alternative to designing the sensors 3 as ultrasonic sensors, it is also possible to design the sensors 3 as another type of sensor, for example as radar sensors or as lidar sensors.

Claims

Patent claims 1 . Sensor device comprising a plurality of sensors (3), wherein the sensors (3) are each designed to transmit at least one signal (11, 12) at different transmission times, wherein the transmission times of the sensors (3) are each predetermined by a transmission rule assigned to the respective sensor (3), characterized in that the sensor device (2) is designed to omit the signal (11, 12) of the first sensor (3) assigned to the transmission time if a transmission time of one of the sensors (3) coincides with a further transmission time of another of the sensors (3) or to transmit it depending on a measure which changes the transmission time and / or a signal quality.

2. Sensor device according to claim 1, characterized in that the measure comprises a shift of the transmission time by a predetermined time interval and / or a reduction of a transmission power of the signal (11, 12) by a predetermined factor.

3. Sensor device according to claim 1 or 2, characterized in that the transmission instructions assigned to the respective sensors (3) are stored in the respective sensors (3), wherein at least one further transmission instruction of a further one of the sensors (3) is stored in at least one of the sensors (3), wherein the at least one sensor (3) is set up to determine the coincidence of one of its transmission times with at least one further transmission time described by the at least one further transmission instruction.

4. Sensor device according to claim 1 or 2, characterized in that the sensor device (2) comprises a control device (4), wherein the transmission instructions assigned to the respective sensors (3) are stored in the control device (4), wherein the control device (4) is designed to determine the coincidence of a transmission time of one of the sensors (3) with at least one further transmission time of at least one further one of the sensors (3) and to control the sensor (3) to omit the signal (11, 12) at the transmission time and / or to transmit the signal (11, 12) depending on a measure which changes the transmission time and / or the signal quality.

5. Sensor device according to one of the preceding claims, characterized in that the transmission instructions each comprise a table with a plurality of transmission time intervals, in particular as a stochastically generated code, wherein the sensor device (2) is configured to determine the transmission times as a function of the transmission time intervals and a synchronization signal.

6. Sensor device according to one of the preceding claims, characterized in that the sensors (3) are connected to a common power supply device (7) which provides a power supply to the sensors (3).

7. Sensor device according to one of the preceding claims, characterized in that the sensors (3) are designed as ultrasonic sensors.

8. Sensor device according to one of the preceding claims, characterized in that the sensor device (2) is designed for distance measurement, for level measurement and / or as an anti-theft alarm system.

9. Vehicle comprising at least one sensor device (2) according to one of the preceding claims.

10. Method for operating a sensor device (2) comprising a plurality of sensors (3), wherein the sensors (3) each transmit at least one signal (11, 12) at different transmission times, wherein the transmission times of the sensors (3) are each predetermined by a transmission rule assigned to the respective sensor (3), wherein if a transmission time of one of the sensors (3) coincides with a further transmission time of another of the sensors (3), the signal (11, 12) of the first sensor (3) assigned to the transmission time is omitted or is transmitted depending on a measure changing the transmission time and / or a signal quality.

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