Combined accelerometer for high and low collision detection of autonomous vehicles

Abstract

An acceleration sensor for a vehicle, in one embodiment, includes a microelectromechanical system (MEMS) high-G sensing element and a low-G sensing element disposed within a single MEMS housing. In another embodiment, the high-G and low-G sensors are integrated into a single MEMS low / high-G sensing element, and in yet another embodiment, the high-G and low-G sensing elements are disposed in separate MEMS housings deployed within the same acceleration sensor housing. An application-specific integrated circuit (ASIC) processes signals from one or more of the high-G / low-G sensing elements. A collision determination system for an autonomous vehicle processes high-G / low-G signals to actuate airbags and / or provide collision information to remote systems.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to provisional application US 63 / 151,372, filed February 19, 2021, the disclosure of which is incorporated herein by reference in its entirety. Background Technology

[0003] This arrangement involves acceleration sensors for high and low collision detection of autonomous vehicles.

[0004] Typically, a vehicle includes multiple acceleration sensors. Each acceleration sensor is typically paired with an application-specific integrated circuit (ASIC) to provide acceleration signals to the electronic controller. Summary of the Invention

[0005] The combined accelerometer provides both high and low collision detection while reducing the number of sensing elements and ASICs required for acceleration sensing. By reducing the number of sensing elements and ASICs, the accelerometer is more compact and utilizes less space in the vehicle. Furthermore, it requires fewer sensing elements and ASICs while providing the same performance, and is also cheaper.

[0006] One embodiment is an acceleration sensor for a vehicle, comprising: a microelectromechanical system (MEMS) high-G (high gravity) sensing element configured to detect a vehicle collision for triggering an airbag; a MEMS low-G (low gravity) sensing element configured to detect a minor vehicle collision for providing an indication of a minor collision; and an application-specific integrated circuit (ASIC) communicating with the MEMS high-G and low-G sensing elements. The ASIC is housed in the same acceleration sensor housing as the MEMS high-G and low-G sensing elements. The ASIC is configured to: receive a high-G signal from the MEMS high-G sensing element, receive a low-G signal from the MEMS low-G sensing element, process the high-G and low-G signals, output a high-G signal during a first time slot, and output a low-G signal during a second time slot. N The signal, and the low-G output during the third time slot. N+1 Signal, where G N G represents one of the X, Y, and Z directions, and G N+1 It represents one of the X, Y, and Z directions.

[0007] In another embodiment, an acceleration sensor for a vehicle includes: an acceleration sensor housing including a base and having a plurality of contacts; a single MEMS housing disposed in the acceleration sensor housing and including a microelectromechanical system (MEMS) high-G sensing element configured to detect a vehicle crash for triggering an airbag, and a microelectromechanical system (MEMS) low-G sensing element configured to detect a minor vehicle crash for providing a minor vehicle crash indication; and an application specific integrated circuit (ASIC) disposed in the acceleration sensor housing, the ASIC in communication with the MEMS high-G sensing element and the MEMS low-G sensing element for receiving signals therefrom.

[0008] Another embodiment relates to a crash determination system for an autonomous vehicle. The crash determination system includes a plurality of acceleration sensors. Each acceleration sensor includes: a microelectromechanical system (MEMS) high-G sensing element configured to detect a vehicle crash for triggering an airbag; a microelectromechanical system (MEMS) low-G sensing element configured to detect a minor vehicle crash for providing an indication of the minor vehicle crash; and an application specific integrated circuit (ASIC) in communication with the MEMS high-G sensing element and the MEMS low-G sensing element. The ASIC is configured to: receive a high-G signal from the MEMS high-G sensing element, receive a low-G signal from the MEMS low-G sensing element, process the high-G signal and the low-G signal, and output a high-G sensor signal, output a low-G N signal, and output a low-G N+1 signal. The crash determination system further includes: a transceiver for transmitting wireless signals to a remote system; and an electronic controller in communication with the transceiver. The electronic controller is configured to: receive the high-G signal, the low-G N signal, and the low-G N+1 signal from each of the ASICs, determine when the high-G signal is below an airbag deployment threshold, when the low-G signal is above a minor crash threshold, and then transmit crash information to the remote system via the transceiver to determine a severity and cause of the low-G signal indicating a crash.

[0009] Other aspects, features, and embodiments will become apparent by consideration of the detailed description and accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 illustrates a block diagram of one embodiment of a peripheral acceleration sensor for a vehicle;

[0011] Figure 1AOne embodiment of a peripheral acceleration sensor including separate MEMS high-G and low-G housings is shown;

[0012] Figure 1B Another peripheral acceleration sensor of separate MEMS high-G and low-G housings and an ASIC is shown;

[0013] Figure 2 A block diagram of another embodiment of a peripheral acceleration sensor for a vehicle having a single MEMS housing is illustrated;

[0014] Figure 2A MEMS high-G and low-G sensing elements disposed in an acceleration sensor housing are shown;

[0015] Figure 3 A block diagram of another embodiment of a peripheral acceleration sensor for a vehicle having a combined single low / high-G sensing element is illustrated;

[0016] Figure 3A A combined single integrated low / high-G sensing element disposed on the same substrate is shown;

[0017] Figure 4 An operational flow diagram of an acceleration sensor arrangement is illustrated;

[0018] Figure 5 A block diagram of one embodiment of a crash determination system is illustrated;

[0019] Figure 6 An operational flow diagram of a crash determination system is shown. DETAILED DESCRIPTION

[0020] Before any embodiments are explained in detail, it is to be understood that this disclosure is not intended to limit its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the following drawings. Embodiments are capable of other configurations and of being practiced or being carried out in various ways.

[0021] Various embodiments can be implemented using multiple hardware and software-based devices and multiple different structural components. Furthermore, embodiments may include hardware, software, and electronic components or modules, which, for the purposes of discussion, may be illustrated and described as if most components were implemented solely in hardware. However, those skilled in the art, based on reading this detailed description, will recognize that, in at least one embodiment, the electronic aspects of the invention may be implemented in software executable by one or more electronic controllers (e.g., stored on a non-transitory computer-readable medium). For example, the terms "unit," "control unit," and "controller" described in the specification may include one or more electronic controllers, one or more memories including a non-transitory computer-readable medium, one or more input / output interfaces, one or more application-specific integrated circuits (ASICs) and other circuitry, and various connections or connectors (e.g., wires, traces, and buses) connecting the various components. In some embodiments, the ASIC is a programmable ASIC including a memory storage medium. In some embodiments, the ASIC executes one or more software or firmware programs.

[0022] Figure 1 A block diagram view of a peripheral acceleration sensor 20 for a vehicle is shown. The peripheral acceleration sensor 20 includes a microelectromechanical system (“MEMS”) high-G sensing element 22, a MEMS low-G sensing element 24, and an application-specific integrated circuit (“ASIC”) 28 electrically connected to the sensing elements 22, 24 to receive high-G and low-G signals.

[0023] Figure 1A A first embodiment of a peripheral accelerometer 20 is shown, comprising an accelerometer housing 30 that houses a MEMS high-G sensing element 22 deployed in a first MEMS high-G housing 32 and a MEMS low-G sensing element 24 deployed in a second MEMS low-G housing 34. The peripheral accelerometer 20 includes an accelerometer housing base 40 that receives or supports the housings 32, 34 and an application-specific integrated circuit (ASIC) 28. The peripheral accelerometer 20 includes a contact pad 46 and corresponding plurality of contacts 48. Electrical connections are provided between the MEMS high-G sensing element 22, the MEMS low-G sensing element 24, and the ASIC 28. Furthermore, an electrical connection is provided between the ASIC 28 and the contact pad 46.

[0024] Figure 1BAnother arrangement of elements on the acceleration sensor housing base 40 is shown. In this embodiment, the MEMS high-G housing 32 is disposed on the ASIC 28, while the MEMS low-G housing 34 is disposed adjacent thereto. Figure 1B The various elements shown in Figure 1A are electrically connected in a similar manner as

[0025] Figure 2 Another embodiment of a peripheral acceleration sensor 120 is shown. In this embodiment, the MEMS high-G sensing element 122 and the MEMS low-G sensing element 124 are disposed in a single MEMS housing 126. The peripheral acceleration sensor 120 includes an ASIC 128 electrically connected to the sensing elements 122, 124 in the single MEMS housing 126 to receive the high-G signal and the low-G signal.

[0026] The peripheral acceleration sensor 120 includes an acceleration sensor housing 130 that includes an acceleration sensor housing base 140 to house the MEMS housing 126 and the ASIC 128 thereon. The peripheral acceleration sensor 120 includes a contact pad 132 as Figures 1-1B The contact pad and the corresponding plurality of contacts in the embodiment. Electrical connections are provided between the ASIC 128 and both the MEMS high-G sensing element 122 and the MEMS low-G sensing element 124. Further, as Figures 1-1B Electrical connections are provided between the ASIC 128 and the contact pad as in the embodiment.

[0027] Figure 2A The MEMS high-G sensing element 122 is shown disposed in a first silicon substrate 143. Figure 2A The MEMS low-G sensing element 124 is shown disposed in a second silicon substrate 145. In one embodiment, the sensing elements 122, 124 are micro-sized comb fingers made of silicon. In some embodiments, the comb fingers interlock with each other.

[0028] Figure 3 Another embodiment of a peripheral acceleration sensor 220 is shown. In this embodiment, the MEMS high-G sensing element and the MEMS low-G sensing element are a single MEMS low-G / high-G sensing element 223 disposed in a single MEMS housing 226. The peripheral acceleration sensor 220 includes an ASIC 228 electrically connected to the MEMS low-G / high-G sensing element 223 in the single MEMS housing 226 to receive the high-G signal and the low-G signal.

[0029] The peripheral acceleration sensor 220 includes an acceleration sensor housing 230 that includes an acceleration sensor housing base 240 for housing the MEMS housing 226 and ASIC 228 thereon. The peripheral acceleration sensor 220 includes a plurality of contact pads as Figures 1-1B The contact pads and corresponding plurality of contacts in the ASIC 228 and the MEMS low-G / high-G sensing element 223 are provided with electrical connections therebetween. Further, as Figures 1-1B The contact pads and corresponding plurality of contacts in the ASIC 228 and the MEMS low-G / high-G sensing element 223 are provided with electrical connections therebetween. Further, as

[0030] Figure 3A The MEMS low-G / high-G sensing element 223 is shown as being provided or etched in a silicon substrate 243. In one embodiment, the low-G / high-G sensing element 223 is a plurality of tiny comb fingers made of silicon. In some embodiments, the comb fingers interlock with each other.

[0031] Operation

[0032] Figure 4 An operational flowchart 300 of the peripheral acceleration sensor 20, 120, 220 is shown. In a first step 310, the ASIC 28, 128, 228 is configured to receive high-G and low-G signals from the high-G / low-G sensing element(s) as Figures 1-3 shown in each of the embodiments of the application.

[0033] In a second step 320, the ASIC 28, 128, 228 is configured to process the high-G and low-G signals. In processing the signals, the peripheral acceleration sensor values are at least temporarily stored in memory.

[0034] In a next step 330, the ASIC 28, 128, 228 outputs the high-G signal during a first time slot. In a subsequent step 340, the ASIC 28, 128, 228 outputs the low-G N sensor signal during a second time slot. N+1 In a final step 350, the ASIC 28, 128, 228 outputs the low-G

[0035] In one embodiment, the G signals are 10-bit signals.

[0036] In one embodiment, the MEMS low-G sensing elements 24, 124, 224 sense accelerations in the range from about 0.02 g to about 2 g, and the MEMS high-G sensing elements 22, 122, 222 sense accelerations from impacts in the range from about 2 g to about 120 g.

[0037] Crash determination system

[0038] Figure 5 A crash determination system 400 for a vehicle is shown. An electronic controller 402 analyzes information from peripheral acceleration sensors and controls airbag deployment actuators or provides information to a remote system. The electronic controller 402 includes an electronic processor 404 and one or more non-transitory computer readable memory modules. In Figure 5 In the example shown, the electronic controller 402 includes random access memory ("RAM") 405 and read only memory ("ROM") 406. The electronic controller 402 also includes an input / output interface 408 that transmits and receives data over a communication link 410. In one embodiment, the communication link 410 is a Flex-Ray bus or a controller area network ("CAN") bus. In another embodiment, a wireless communication link is provided.

[0039] It should be appreciated that the electronic controller 402 can include multiple processors, additional computer readable memory modules, multiple input / output interfaces, and / or additional components or modules (e.g., hardware, software, or combinations thereof).

[0040] The electronic processor 404 receives information from the input / output interface 408 and processes the information by executing instructions of one or more software modules (also referred to as one or more "controllers") stored in memory, such as the ROM 406. The electronic processor 404 stores and retrieves information to and from the RAM 405 (e.g., information received from other vehicle subsystems or sensors over the communication link 410 and information generated by the modules executed by the electronic processor 404). The non-transitory computer readable memory modules of the electronic controller 402 include volatile memory, non-volatile memory, or combinations thereof, and in various configurations, can also store operating system software, application / instruction data, and combinations thereof.

[0041] Various other vehicle subsystems are also connected to the communication link 410 and communicate with the electronic controller 402, various vehicle sensors, and other vehicle subsystems. For example, Figure 5A front high-G and low-G peripheral acceleration sensor 420, a left side high-G and low-G acceleration sensor 422, a rear high-G and low-G acceleration sensor 424, and a right side high-G and low-G acceleration sensor 426 are shown. Each of the high-G and low-G sensors are connected to the communication link 410 and are capable of providing high-G and low-G signals to other devices connected to the communication link. While four acceleration sensors 420, 422, 424, 426 are illustrated, any number of multiple acceleration sensors are contemplated. In one embodiment, at least four sensors 420, 422, 424, 426 are oriented in four different locations around the autonomous vehicle.

[0042] Figure 5 A front camera 430, a left side camera 432, a rear camera 434, and a right side camera 436 are also shown. The cameras have fields of view oriented outward from the vehicle to detect objects that can contact the vehicle. In some embodiments, a panoramic camera is used. Memory stores at least temporarily images obtained by the cameras 430, 432, 434, 436. While four cameras 430, 432, 434, 436 are illustrated, any number of multiple cameras are contemplated. In another embodiment, additional cameras are oriented and secured to the autonomous vehicle and mounted, for example, on the bumpers or on the rear view mirrors for obtaining video information about the autonomous vehicle body at or near the area of impact of a collision.

[0043] Figure 5 An airbag deployment actuator 440 connected to the communication link 410 is also shown. The airbag deployment actuator 440 actuates selected vehicle airbags depending on sensed high-G signals determined by the electronic controller 402.

[0044] Figure 5 A transceiver 450 with an antenna 452 for wireless transmission of information is shown. The transceiver 450 transmits information provided by the electronic controller 402 or other components.

[0045] Figure 5A remote system 460 is also shown, having an antenna 462 for receiving the low-G signals and video signals from the electronic controller 402. In one embodiment, the remote system 460 includes an electronic processor, memory, and other elements similar to the electronic controller 402. The remote system 460 includes other video image analysis applications. In one embodiment, a server is a component of the remote system 460. In response to the video image analysis, the remote system 460 provides a return signal to the transceiver, to, for example, permit the autonomous vehicle to continue driving, disable the autonomous vehicle, or release the passenger and return the autonomous vehicle to a repair location or other destination.

[0046] Operation

[0047] Figure 6 Operation Figure 5 An operational flowchart 500 of the crash determination system 400 is shown. In a first step 510, the electronic controller 402 receives the high-G and low-G signals from the various peripheral acceleration sensors 20, 120, 220.

[0048] In a decision step 520, the electronic processor 404 determines whether the high-G signals or features from the plurality of peripheral acceleration sensors 20, 120, 220 are below an airbag deployment threshold. In one embodiment, the electronic processor 404 calculates a peak or average value of the raw signals from the peripheral acceleration sensors. If so, the calculated signal is below the threshold, and the electronic processor 404 proceeds to a decision step 530.

[0049] In the decision step 530, the electronic processor 404 determines whether the low-G signals or features from the plurality of peripheral acceleration sensors 20, 120, 220 are above a crash threshold. In one embodiment, the electronic processor 404 calculates a peak or average value of the raw low-G signals from the peripheral acceleration sensors. When the calculated low-G signal is not above the threshold, the electronic processor 404 proceeds to step 510 and repeats the crash determination process.

[0050] In the decision step 530, when the low-G signal has a value above the crash threshold, the electronic processor 404 proceeds to a step 540. In one embodiment, the value of the crash threshold is 0.2g. In another embodiment, the value of the crash threshold is 0.7g. Other crash thresholds are contemplated.

[0051] In the step 540, the electronic processor 404 transmits crash information to the remote system 460 via the transceiver 450. In one embodiment, the crash information includes one or more of the values of the low-G signals and video signals from before the crash, during the crash, and after the crash. The electronic processor 404 proceeds to a step 560.

[0052] At step 560, the electronic controller 402 waits for instructions from the remote system 460. Typically, the autonomous vehicle will remain stationary until movement is authorized by the remote system 460 or by a user at the accident scene who is authorized to communicate with the electronic controller 402.

[0053] Returning to decision step 520, when the electronic processor 404 determines that the high-G signal(s) are not below the airbag deployment threshold, the electronic processor 404 proceeds to step 570. At step 570, the electronic processor 404 provides an airbag deployment signal to the airbag deployment actuator 440 over the communication link 410. The airbag deployment actuator 440 receives the actuator signal and actuates one or more selected airbags depending on which high-G signal is greater than the airbag deployment threshold. The electronic processor 404 then proceeds to step 580. In one embodiment, the value of the airbag deployment threshold is 20g. In another embodiment, the value of the airbag deployment threshold is 30g. Depending on the location of the airbags on the autonomous vehicle, different airbag deployment thresholds can be provided for different airbags and different high-G acceleration sensors.

[0054] At step 580, the electronic processor 404 provides airbag deployment information to the remote system 460 via the transceiver 450. The airbag deployment information includes which airbags were deployed. In addition, video signals are provided from the selected cameras 430, 432, 434, 436 corresponding to the peripheral acceleration sensors 420, 422, 424, 426 that exceeded the airbag deployment threshold, before, during, and after airbag deployment.

[0055] Thereafter, the electronic processor proceeds to step 560 and waits for instructions from the remote system 460 or from a user at the accident scene who is authorized to communicate with the electronic controller 402.

[0056] Various features, advantages, and embodiments are set forth in the following claims.

Claims

1. A crash determination system for a vehicle, comprising: an acceleration sensor, comprising: a microelectromechanical system (MEMS) high-G sensing element configured to detect a vehicle crash for triggering an airbag; a microelectromechanical system (MEMS) low-G sensing element configured to detect a vehicle crash for providing an indication of a vehicle crash; and an application specific integrated circuit (ASIC) in communication with the MEMS high-G sensing element and the MEMS low-G sensing element, wherein the ASIC is disposed in the same acceleration sensor housing as the MEMS high-G sensing element and the MEMS low-G sensing element, and wherein the ASIC is configured to: receive a high-G signal from the MEMS high-G sensing element, receive a low-G signal from the MEMS low-G sensing element, process the high-G signal and the low-G signal, output a high-G signal during a first time slot, outputting a low-G signal during a second time slot N and outputting a low-G signal during a third time slot N+1 signal, where G N represents one of the X, Y and Z directions, and G N+1 represents another of the X, Y and Z directions, a transceiver for transmitting wireless signals; an electronic controller that receives a low-G signal output by the low-G sensing element, the electronic controller providing a low-G signal output to the transceiver; and a remote system configured to receive a low-G signal output from the transceiver, the remote system determining a severity and a cause of the low-G signal indicative of a vehicle crash.

2. The crash determination system of claim 1, wherein the MEMS low-G sensing element and the MEMS high-G sensing element are disposed in a single MEMS housing, the single MEMS housing being disposed in the acceleration sensor housing.

3. The crash determination system of claim 2, wherein the MEMS low-G sensing element and the MEMS high-G sensing element are integrated as a single MEMS low-G / high-G sensing element.

4. The crash determination system of claim 1, wherein the MEMS high-G sensing element and the MEMS low-G sensing element are disposed in separate MEMS housings, the separate MEMS housings being disposed in the same acceleration sensor housing.

5. The crash determination system of claim 1, wherein the MEMS low-G sensing element senses accelerations in the range from 0.32 g to 15 g, and wherein the MEMS high-G sensing element senses accelerations from impacts in the range from 2 g to 120 g, wherein, g denotes the force of gravity in 1 g, which is equivalent to the value of the conventional gravitational acceleration on Earth of 9.8 m / s2 2 .

6. The crash determination system of claim 1, wherein the high-G sensing element outputs a high-G signal that is received by an electronic controller in the vehicle, wherein the vehicle is an autonomous vehicle.

7. The crash determination system of claim 1, wherein the crash information transmitted to the remote system includes video information from a vehicle-mounted camera disposed in proximity to a crash zone.

8. The crash determination system of claim 1, wherein the ASIC is a programmable ASIC that includes a memory storage medium.

9. A crash determination system for a vehicle, comprising: an acceleration sensor, comprising: an acceleration sensor housing, comprising a base, and having a plurality of contacts; a single MEMS package disposed in an acceleration sensor package and including a microelectromechanical system (MEMS) high-G sensing element configured to detect a vehicle collision for triggering an airbag, and a microelectromechanical system (MEMS) low-G sensing element configured to detect a vehicle collision for providing an indication of a vehicle collision; and an application specific integrated circuit (ASIC) disposed in the acceleration sensor package, the ASIC in communication with the MEMS high-G sensing element and the MEMS low-G sensing element for receiving signals therefrom; a transceiver for transmitting wireless signals; an electronic controller in communication with the transceiver, the electronic controller configured to: receive a high-G signal output by the high-G sensing element and provide an airbag deployment signal to an airbag deployment actuator when the high-G signal is greater than an airbag deployment threshold; and receive a low-G signal output by the low-G sensing element and determine when the low-G signal is above a crash threshold and then provide the low-G signal to the transceiver; and a remote system for receiving the low-G signal from the transceiver, the remote system configured to determine a severity and a cause of the low-G signal.

10. The crash determination system of claim 9, wherein the ASIC is configured to: output the high-G signal during a first time slot, output low-G during the second time slot N sensor signals, and output low-G during the third time slot N+1 sensor signal, wherein G N represents one of the X, Y and Z directions, G N+1 represents another of the X, Y and Z directions.

11. The crash determination system of claim 9, wherein the ASIC is a programmable ASIC including a memory storage medium.

12. The crash determination system of claim 10, wherein the MEMS high-G sensing element and the MEMS low-G sensing element are integrated as a single MEMS low-G / high-G sensing element.

13. The crash determination system of claim 10, wherein the MEMS low-G sensing element senses accelerations in a range of 0.032g to 15g, and wherein the MEMS high-G sensing element senses accelerations from a crash in a range of 2g to 120g.

14. A crash determination system for an autonomous vehicle, comprising: a plurality of acceleration sensors, wherein each acceleration sensor includes a microelectromechanical system (MEMS) high-G sensing element configured to detect a vehicle collision for triggering an airbag; a microelectromechanical system (MEMS) low-G sensing element configured to detect a vehicle collision for providing an indication of a vehicle collision; and an application specific integrated circuit (ASIC) in communication with the MEMS high-G sensing element and the MEMS low-G sensing element, wherein the ASIC is configured to: receive a high-G signal from the MEMS high-G sensing element, receive a low-G signal from the MEMS low-G sensing element, process the high-G signal and the low-G signal, and Outputs a high-G signal, outputs a low-G N sensor signal, and outputs a low-G N+1 sensor signal, a transceiver for transmitting wireless signals to a remote system; and an electronic controller in communication with the transceiver, the electronic controller configured to: receiving a high-G signal, a low-G signal, and a low-G signal from each of the ASICs N signals N+1 signals determine when the high-G signal is below an airbag deployment threshold, and when the low-G signal is above a crash threshold, and then transmit crash information to a remote system via the transceiver to determine the severity and cause of the low-G signal indicative of a crash.

15. The crash determination system of claim 14, wherein the crash information includes video information from one of a plurality of cameras from a crash impact area.

16. The crash determination system of claim 14, wherein the plurality of acceleration sensors includes at least four acceleration sensors oriented in four different locations around the autonomous vehicle.

17. The crash determination system of claim 14, wherein the MEMS high-G sensing element and the MEMS low-G sensing element are integrated as a single MEMS low-G / high-G sensing element.

18. The crash determination system of claim 14, wherein the electronic controller is configured to determine when the high-G signal has a value above an airbag deployment threshold, and provide an airbag deployment signal to an airbag deployment actuator.

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