Sensor unit

Abstract

The present invention relates to a sensor unit comprising a first sensor element and a second sensor element, wherein the first sensor element and the second sensor element are configured to transmit and / or receive an ultra-wideband signal, wherein the first sensor element and the second sensor element are arranged in a predetermined orientation relative to each other, wherein the first sensor element and the second sensor element are configured to receive a timestamp in an ultra-wideband signal from an initiator element, wherein the first sensor element is configured to transmit a first response signal based on the reception of the timestamp, wherein the second sensor element is configured to receive the first response signal and, based on the predetermined orientation, the timestamp and the first response signal, to adjust a time of the second sensor element to a time of the initiator element.

Description

State of the art

[0001] The present invention relates to a sensor unit and a vehicle.

[0002] Currently, a wide variety of solutions exist for position determination using ultra-wideband sensor units. Due to the increasing number of application scenarios for ultra-wideband sensors and the rising demands on both quality and performance, the need for innovative and robust systems for measuring ultra-wideband signals is constantly growing.

[0003] The continuous reduction of weight in the vehicle sector to reduce fuel consumption, as well as increasing competition, is causing cost pressure, leading to a greater demand for cheaper and more efficient vehicle components. Disclosure of the invention

[0004] The sensor unit according to the invention, with the features of claim 1, has the advantage over the known device that the position determination of end devices such as smartphones, key fobs, or similar devices can be significantly improved. Furthermore, the energy consumption of an end device such as a key fob or similar device can preferably be reduced, since the number of sensor elements required for communication with the key fob can be significantly reduced.

[0005] This is achieved according to the invention by the sensor unit comprising a first sensor element and a second sensor element, wherein the first sensor element and the second sensor element are configured to transmit and / or receive an ultra-wideband signal, wherein the first sensor element and the second sensor element are arranged in a predetermined orientation relative to each other, wherein the first sensor element and the second sensor element are configured to receive a timestamp in an ultra-wideband signal from an initiator element, wherein the first sensor element is configured to transmit a first response signal based on the reception of the timestamp, and wherein the second sensor element is configured to receive the second response signal and, based on the predetermined orientation,to adjust the time of the second sensor element to a time of the initiator element based on the timestamp and the first response signal.

[0006] In other words, by synchronizing the response signal of the first and second sensor elements, the times of all elements, especially the first and second sensor elements, can be synchronized. This synchronized time significantly improves the positional accuracy of devices such as key fobs.

[0007] The dependent claims describe preferred embodiments of the invention.

[0008] Preferably, the second sensor element is configured to send a second response signal in response to the first response signal, wherein the first sensor element is configured to adjust a time of the first sensor element to the time of the initiator element based on the second response signal and the timestamp.

[0009] One advantage of this embodiment is that both the first sensor element and the second sensor element can synchronize their timings to improve detection accuracy.

[0010] Preferably, the adjusted time of the first sensor element and the adjusted time of the second sensor element are essentially the same.

[0011] One advantage of this embodiment is that, with the same time displayed on both sensor elements, a variety of additional functions are enabled. "Essentially the same" here specifically means a deviation of up to + / - 5%.

[0012] Preferably, the first sensor element and the second sensor element are configured to transmit the first response signal and the second response signal using a bidirectional 2-way ranging protocol.

[0013] One advantage of this embodiment is that the transmission of the first and second response signals can be integrated into the usual frequencies used in ultra-wideband communication. This prevents any further increase in data consumption.

[0014] Preferably, the first sensor element and the second sensor element are configured to generate a time difference arrival information based on their adjusted times, wherein the first sensor element and / or the second sensor element are configured to adjust a further received ultra-wideband signal based on the time difference arrival information signal.

[0015] One advantage of this design is that, based on the time difference which can be determined based on the synchronized time, all further received signals can be adjusted accordingly in order to improve further communication.

[0016] Furthermore, the sensor unit is preferably configured to update the time difference arrival information cyclically and / or based on a trigger.

[0017] One advantage of this embodiment is that, depending on an application scenario, the time difference arrival information can be provided cyclically, for example every five seconds or based on a trigger, when increased synchronization is required, for example.

[0018] Preferably, the first sensor element and / or the second sensor element are configured to determine the position of an end device using ultra-wideband signals, wherein the first sensor element and / or the second sensor element are configured to adjust the position using the time difference information.

[0019] One advantage of this embodiment is that, based on the time difference arrival information, the transit times of the signals for position determination can be adjusted in order to improve the position detection accuracy.

[0020] Preferably, the first sensor element and / or the second sensor element is configured to determine a delta based on the duration of a transmission of the first response signal and the predetermined orientation, wherein the first sensor element and / or the second sensor element are configured to adjust the time based on the delta.

[0021] One advantage of this embodiment is that the predetermined alignment of the sensor elements to each other significantly simplifies the determination of the delta, thus enabling a synchronized time to be obtained.

[0022] Preferably, the first sensor element and / or the second sensor element are configured to integrate the first response signal and / or the second response signal into a two-way, two-way measurement using ultra-wideband signals.

[0023] One advantage of this design is that a received device or the measurement capabilities can be improved.

[0024] Preferably, after the vehicle's UWB sensors receive the initiator's poll frame, each UWB sensor can transmit a specific response in designated ranging slots. This sequence is preferably determined internally during vehicle initialization. When other UWB sensors in the vehicle receive this response, all sensors can accurately determine the clock offset between their own clock and the clock of the transmitting sensor.

[0025] In the DSTWR ranging protocol, the first and second sensor units preferentially send UWB responses in defined time slots after receiving the poll frame. By comparing the transmission and reception times of the UWB frames, as well as the known propagation delay between the sensors, the clock deviation between the sensors can be determined. This allows for the calculation of a TDOA value, which can be used for localization.

[0026] Preferably, this process is theoretically repeatable in every DSTWR cycle, and the clock drift is negligible. However, depending on the clock accuracy, resynchronization may also occur every xth ranging cycle. The sequence of UWB responses is preferably known after system initialization. The propagation time between the sensors can be determined either manually by measuring the distance or by a calibration measurement.

[0027] Another aspect of the invention relates to a vehicle which has a sensor unit as described above and below. Brief description of the drawings

[0028] Exemplary embodiments of the invention are described in detail below with reference to the accompanying drawings. The drawing shows: Fig. 1 a sensor unit according to an embodiment, Fig. 2 a diagram to illustrate the functioning of the sensor unit according to one embodiment and Fig. 3 a vehicle according to an embodiment Embodiments of the invention

[0029] Preferably, all identical components, units and / or steps in all figures are provided with the same reference symbols.

[0030] Fig. Figure 1 shows a sensor unit 10 according to one embodiment.The sensor unit 10 comprises a first sensor element 12 and a second sensor element 14, wherein the first sensor element 12 and the second sensor element 14 are configured to transmit and / or receive an ultra-wideband signal, wherein the first sensor element 12 and the second sensor element 14 are arranged in a predetermined orientation 16 relative to each other, wherein the first sensor element 12 and the second sensor element 14 are configured to receive a timestamp in an ultra-wideband signal from an initiator element 18, wherein the first sensor element 12 is configured to transmit a first response signal based on the reception of the timestamp, wherein the second sensor element 14 is configured to receive the first response signal and, based on the predetermined orientation, the timestamp and the first response signal, to synchronize a time of the second sensor element 14 with a time of the initiator element 18.

[0031] Fig. Figure 2 shows a diagram 100 illustrating the operation of the sensor unit 10 according to one embodiment. Diagram 200 depicts an initiator element 18 of the time sequence 202 and the time sequence 206 of the first sensor element 12, as well as the time sequence 208 of the second sensor element 14. The time sequence 202 of the initiator element 18 emits a signal 204, which is detected by the first sensor element 12 and the second sensor element 14 at times 208 and 210, respectively. In response to the signal 204, the first sensor element 12 emits the first response signal at time 214. Part of the first response signal is shown in the signal thread 220. The second sensor element 14 can receive the first response signal at time 216 and thus adjust its time based on the predetermined orientation of the sensor elements relative to each other. Furthermore, the second sensor element 14 can preferably receive a second response signal 226 at time 224.222 are sent to both the first sensor element 12 and the initiator element 18. Preferably, the initiator element or another terminal device can send a further signal 230 and 232, which is detected by both the second sensor element 14 and the first sensor element 12, wherein the two sensor elements can determine the time of transmission more precisely based on the synchronized time or by means of the time difference arrival information.

[0032] Fig. Figure 3 shows a vehicle 100 according to one embodiment. The vehicle 100 preferably has a sensor unit 10, as described above and below.

Claims

[1] Sensor unit (10) comprising a first sensor element (12) and a second sensor element (14), wherein the first sensor element (12) and the second sensor element (14) are configured to transmit and / or receive an ultra-wideband signal, wherein the first sensor element (12) and the second sensor element (14) are arranged in a predetermined orientation (18) relative to each other, wherein the first sensor element (12) and the second sensor element (14) are configured to receive a timestamp in an ultra-wideband signal from an initiator element (18), wherein the first sensor element (12) is configured to transmit a first response signal based on the reception of the timestamp, wherein the second sensor element (14) is configured to receive the first response signal and, based on the predetermined orientation (18),to adapt the time of the second sensor element (14) to a time of the initiator element (18) based on the timestamp and the first response signal. [2] Sensor unit (10) according to claim 1, wherein the second sensor element (14) is configured to send a second response signal in response to the first response signal, wherein the first sensor element (12) is configured to adjust a time of the first sensor element (12) to the time of the initiator element (18) based on the second response signal and the timestamp. [3] Sensor unit (10) according to claim 2, wherein the adjusted time of the first sensor element (12) and the adjusted time of the second sensor element (14) are essentially the same. [4] Sensor unit (10) according to one of the preceding claims, wherein the first sensor element (12) and the second sensor element (14) are configured to transmit the first response signal and the second response signal using a bidirectional 2-way ranging protocol. [5] Sensor unit (10) according to one of the preceding claims, wherein the first sensor element (12) and the second sensor element (14) are configured to form a time difference information based on their adapted times, wherein the first sensor element (12) and / or the second sensor element (14) are configured to adapt a further received ultra-wideband signal based on the time difference arrival signal. [6] Sensor unit (10) according to claim 5, wherein the sensor unit (10) is configured to update the time difference arrival information cyclically and / or based on a trigger. [7] Sensor unit (10) according to one of claims 5 to 6, wherein the first sensor element (12) and / or the second sensor element (14) are configured to determine a position of an end device using an ultra-wideband signal, wherein the first sensor element (12) and / or the second sensor element (14) are configured to adjust the position using the time difference arrival information. [8] Sensor unit (10) according to one of the preceding claims, wherein the first sensor element (12) and / or the second sensor element (14) are configured to determine a delta based on a duration of transmission of the first response signal and the predetermined orientation, wherein the first sensor element (12) and / or the second sensor element (14) are configured to adjust the time based on the delta. [9] Sensor unit (10) according to one of the preceding claims, wherein the first sensor element or the second sensor element (14) are configured to integrate the first response signal and / or the second response signal into a two-way 2-way measurement using ultra-wideband signals. [10] Vehicle (100) comprising a sensor unit according to any of the preceding claims.

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