Brake pedal signal backup system for detecting foot position of driver based on UWB

Abstract

The invention belongs to the technical field of braking systems, and particularly relates to a UWB-based brake pedal signal backup system for detecting the foot position of a driver, which comprises a UWB signal transmitting module, a UWB signal receiving module, a UWB processing module and a main MCU (Microprogrammed Control Unit), when the main signal transmission unit works normally, a main control signal generated by a brake pedal sensor is transmitted to the main MCU, and the UWB signal transmitting module transmits a low-frequency synchronizing signal; when the main signal transmission unit works abnormally, the UWB processing module performs switching, so that the UWB signal transmitting module transmits an ultra wide band signal to the UWB signal receiving module, the ultra wide band signal comprises a foot position signal, and the UWB processing module processes the ultra wide band signal to obtain a standby control signal and transmits the standby control signal to the main MCU; when the main signal transmission unit works abnormally, the main MCU can be switched to a standby control signal for control in time, so that the driving safety is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of brake systems, and in particular to a brake pedal signal backup system based on UWB detection of a driver's foot position. Background Art

[0002] In the automotive braking system, accurate transmission of brake pedal signals plays a key role in the safe braking of the vehicle. Traditional brake pedal signal transmission mainly relies on wired connection or a single wireless transmission method, such as CAN bus or Bluetooth transmission. The main control signal generated by the brake pedal sensor is transmitted to the main MCU through the main signal transmission unit. The main MCU controls the brake mechanism to brake according to the main control signal.

[0003] However, wired connections may have the risk of failures such as line aging, short circuits, and open circuits. When using a single wireless transmission method, signal interruptions or errors are prone to occur when faced with strong electromagnetic interference, signal blocking, etc. These problems may cause the brake pedal signal to be unable to be transmitted normally to the brake control unit, thereby endangering the vehicle's driving safety. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a brake pedal signal backup system based on UWB detection of the driver's foot position, which can switch to the backup control signal in time for control when the main signal transmission unit works abnormally, thereby ensuring driving safety.

[0005] The technical solution adopted by the present invention is as follows: A brake pedal signal backup system based on UWB detection of the driver's foot position includes a main MCU. When the main signal transmission unit works normally, the main control signal generated by the brake pedal sensor is transmitted to the main MCU, and the main MCU controls the braking mechanism to brake according to the main control signal. The system also includes a UWB backup signal transmission unit, and the UWB backup signal transmission unit includes a UWB signal transmitting module, a UWB signal receiving module, and a UWB processing module. When the main signal transmission unit works abnormally, the UWB signal transmitting module transmits an ultra-wideband signal to the UWB signal receiving module, and the ultra-wideband signal includes a foot position signal. The UWB processing module processes the ultra-wideband signal to obtain a backup control signal and transmits it to the main MCU. The main MCU controls the braking mechanism to brake according to the backup control signal.

[0006] Working principle: The main signal transmission unit is a conventional brake control method in existing automobiles, including a brake pedal sensor connected to the main MCU. The main control signal generated by the brake pedal sensor is transmitted to the main MCU, and the main MCU controls the braking mechanism to brake through the main control signal. When the main signal transmission unit works abnormally, it can immediately switch to the UWB signal transmission module to transmit an ultra-wideband signal to the UWB signal receiving module, and control the braking mechanism through the backup control signal to ensure the normal operation of the braking mechanism; although the UWB technology is used to collect the footstep signal position, the accuracy is lower than that of the brake pedal sensor, but it can meet the use requirements as a brake pedal signal backup system.

[0007] Compared with the prior art, the present invention has the following beneficial effects: 1. The UWB technology is adopted, which makes it easy to integrate distance measurement and communication. The UWB signal transmitting module itself has an adaptive power adjustment function, which can automatically adjust the transmitting power according to the distance and signal strength between the UWB signal receiving module to ensure stable signal transmission and make the signal more stable. Therefore, when facing strong electromagnetic interference, signal blocking, etc., the brake pedal signal backup system of the present invention can work normally; 2. When the main control signal unit fails, the brake pedal signal backup system of the present invention can be used for brake control, thereby reducing the possibility of brake failure during driving and improving driving safety.

[0008] As a preferred implementation manner of the present invention, when the main signal transmission unit works normally, the UWB signal transmitting module transmits a synchronization signal to the UWB signal receiving module and maintains connection with the UWB signal receiving module.

[0009] Beneficial effect: A synchronization signal is transmitted from the UWB signal transmitting module to the UWB signal receiving module, so that the UWB signal transmitting module and the UWB signal receiving module remain connected, thereby confirming that the signal backup system is in normal working condition, avoiding failure to use the backup system when it is necessary to switch to the backup system, thereby affecting driving safety.

[0010] As a preferred implementation manner of the present invention, the synchronization signal adopts a low-frequency synchronization signal.

[0011] Beneficial effect: Since the synchronization signal transmitted by the UWB signal transmission module is only used for verification, a low-frequency synchronization signal can be used to reduce power consumption.

[0012] As a preferred embodiment of the present invention, the UWB processing module monitors the working status of the main signal transmission unit in real time. When the main signal transmission unit is abnormal, the UWB processing module controls the UWB signal transmission module to switch from transmitting the synchronization signal to transmitting the ultra-wideband signal.

[0013] Beneficial effects: The UWB processing module has the functions of real-time monitoring and switching to ensure that when an abnormality occurs in the main signal transmission unit, it switches to the ultra-wideband signal in time, which is beneficial for the main MCU to control.

[0014] As a preferred implementation manner of the present invention, the synchronization signal includes a foot position signal, and the UWB processing module processes the synchronization signal to obtain a verification signal.

[0015] Beneficial effect: When the main signal transmission unit is working, the UWB signal transmission module also transmits a low-frequency synchronization signal; the main MCU can obtain the main control signal for the braking mechanism from the signal generated by the brake pedal sensor, and can also obtain a verification signal through the pedal position data in the low-frequency synchronization signal. The verification signal obtained by the low-frequency synchronization signal is taken as the basis and compared with the main control signal to determine whether the main signal transmission unit is working abnormally.

[0016] As a preferred embodiment of the present invention, when the main MCU does not receive the main control signal and the UWB signal receiving module receives the synchronization signal, the UWB processing module determines that the signal is interrupted; The main MCU compares the main control signal with the verification signal. When the error exceeds a preset range, the main MCU transmits the comparison result to the UWB processing module, and the UWB processing module determines that the signal is abnormal; When the signal is interrupted or abnormal, the UWB processing module controls the UWB signal transmitting module to switch from transmitting the synchronization signal to transmitting the ultra-wideband signal.

[0017] Beneficial effects: 1. The main signal transmission unit may be abnormal due to a variety of reasons. When there is a problem with the internal circuit (such as a short circuit), the main MCU can diagnose its own fault. When the brake pedal sensor itself is damaged, or is blocked by the signal or electromagnetic interference, the main MCU may no longer receive the corresponding signal and cannot diagnose its own abnormal operation. Therefore, this solution sets a low-frequency synchronization signal with pedal position data. Under low power consumption, the pedal position data of the low-frequency synchronization signal can be used as the basis for comparison. As long as the brake pedal position changes, the main MCU can receive the main control signal and verification signal, and can promptly detect whether the main signal transmission unit is abnormal; 2. The pedal position data of the low-frequency synchronous signal can directly control the brake mechanism. In the event of emergency braking, it can be switched to the signal backup system for control in a timely manner, avoiding short-term unresponsiveness of the brake mechanism as much as possible, thereby improving driving safety.

[0018] As a preferred implementation manner of the present invention, both the synchronization signal and the ultra-wideband signal are transmitted in an encrypted manner.

[0019] Beneficial effect: Through encrypted transmission of signals, malicious tampering of signals is prevented, thus ensuring driving safety.

[0020] As a preferred implementation manner of the present invention, signal transmission is performed between the main MCU and the UWB processing module via an SPI communication interface.

[0021] Beneficial effects: SPI supports a higher data transmission rate and is suitable for fast transmission of large amounts of data. SPI also allows simultaneous bidirectional data transmission, which improves communication efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a circuit schematic diagram of an embodiment of a brake pedal signal backup system for detecting the driver's foot position based on UWB of the present invention. DETAILED DESCRIPTION

[0023] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially used for illustration purposes rather than for limiting the present invention.

[0024] In the description of the present application, the terms "first", "second", etc. are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the structure referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0025] See also Figure 1 As shown, the brake pedal signal backup system based on UWB detection of the driver's foot position disclosed in this embodiment includes a UWB signal transmitting module, a UWB signal receiving module, a UWB processing module, and a main MCU; when the main signal transmission unit works normally, the main control signal generated by the brake pedal sensor is transmitted to the main MCU, and the main MCU controls the braking mechanism to brake according to the main control signal. At the same time, the UWB signal transmitting module transmits a low-frequency synchronization signal to the UWB signal receiving module to maintain connection with the UWB signal receiving module; when the main signal transmission unit works abnormally, the UWB signal transmitting module transmits an ultra-wideband signal to the UWB signal receiving module, and the ultra-wideband signal includes a foot position signal; the UWB processing module processes the ultra-wideband signal to obtain a backup control signal, and transmits it to the main MCU; the main MCU controls the braking mechanism to brake according to the backup control signal.

[0026] Among them, the UWB processing module adopts a UWB integrated chip (model DW1000), and the UWB receiving module adopts an antenna. An inductor is arranged between the antenna and the 16th and 17th pins of the UWB integrated chip. The 3rd and 4th pins of the UWB integrated chip are connected to a crystal oscillator, and the 47th pin of the UWB integrated chip is connected to the power supply circuit. The 39th, 40th and 41st pins of the UWB integrated chip are connected to the SPI communication interface, and are connected to the main MCU through the SPI transmission line. By monitoring the change of the foot position through the UWB radar, a low-frequency synchronization signal including the foot position signal can be obtained, and the frequency can also be increased as an ultra-wideband signal. The UWB processing module processes the synchronization signal to obtain a verification signal, and processes the ultra-wideband signal to obtain a backup control signal.

[0027] Among them, the main MCU (model Aurix TC234L), when the main signal transmission unit works normally, the main control signal generated by the brake pedal sensor is transmitted to the main MCU, and the main MCU transmits the control signal to the three-phase bridge pre-driver chip according to the main control signal, and the voltage is amplified by the three-phase bridge pre-driver chip, and then the three-phase brushless motor is driven to work through the corresponding three-phase drive bridge, thereby braking; It also includes a power management chip (model TLF35584), and the main control signal (pedal brake signal) is transmitted to the main MCU through the filter circuit; a surge protection unit and a power filter unit are arranged in sequence between the vehicle power supply system and the power management chip, and the power management chip supplies power to loads of 5V and below. The output end of the vehicle power supply system is connected to the surge protection unit and the EMC filter in sequence to supply power to the three-phase drive bridge; The vehicle power supply system is connected to a voltage divider circuit, which is respectively connected to the power management chip and the main MCU. After the vehicle power supply system is ignited, the ignition signal can be transmitted to the power management chip and the main MCU respectively, thereby starting the brake system; The main MCU is also connected to an ambient temperature measurement module and a drive part temperature measurement module for measuring the ambient temperature and the temperature of the brake motor.

[0028] While the main signal transmission unit is working, the UWB signal transmission module transmits a low-frequency synchronization signal to the UWB signal receiving module. The UWB processing module processes the synchronization signal to obtain a verification signal, and transmits it to the main MCU through the SPI transmission line. Therefore, the main MCU will receive the verification signal and the main control signal at the same time. The main MCU compares the two. When the error between the two exceeds the preset range, the comparison result is transmitted to the UWB processing module. The UWB processing module can determine that the signal is abnormal. When the UWB processing module receives the low-frequency synchronization signal and the main MCU does not receive the main control signal, it can be determined that the signal is interrupted, indicating that the main signal transmission unit is working abnormally; When the main signal transmission unit works abnormally, the UWB processing module switches, so that the UWB transmitting module increases the frequency of the low-frequency synchronization signal and transmits the ultra-wideband signal. The UWB processing module processes the ultra-wideband signal to obtain a backup control signal and transmits it to the main MCU through the SPI transmission line. The main MCU only controls the braking mechanism to brake with the backup control signal.

[0029] Among them, the synchronization signal and ultra-wideband signal are encrypted using AES-128; the DW1000 chip supports the AES-128 symmetric encryption algorithm, which has high security and efficiency, and the DW1000 chip has a built-in AES hardware acceleration module, which can efficiently perform encryption and decryption operations and reduce the burden of software processing.

[0030] Therefore, this solution has the following advantages: When the main signal transmission unit is working normally, it runs in a low-frequency state and its power consumption is low; the low-frequency synchronization signal can maintain the connection between the UWB transmitter and the receiver, and can be processed to obtain a verification signal. The main MCU can make judgments based on the verification signal. When the main signal transmission unit has various faults such as damaged brake pedal sensor, blocked signal, and circuit short circuit, it can be discovered in time and switched to the ultra-wideband signal for control; and when the main control signal is blocked or the brake pedal sensor is damaged, the main MCU may not be able to receive the signal at all. The verification signal can also be used as a preliminary control signal to control the control mechanism, ensuring the continuous switching from the main control signal to the backup control signal, which is particularly critical when the main signal transmission unit fails during emergency braking, ensuring driving safety.

[0031] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A brake pedal signal backup system based on UWB detection of the driver's foot position, comprising a main MCU. When the main signal transmission unit works normally, the main control signal generated by the brake pedal sensor is transmitted to the main MCU. The main MCU controls the brake mechanism to brake according to the main control signal. The system is characterized in that: It also includes a UWB backup signal transmission unit, which includes a UWB signal transmitting module, a UWB signal receiving module, and a UWB processing module; When the main signal transmission unit works abnormally, the UWB signal transmitting module transmits an ultra-wideband signal to the UWB signal receiving module, wherein the ultra-wideband signal includes a foot position signal; The UWB processing module processes the ultra-wideband signal to obtain a standby control signal, and transmits the standby control signal to the main MCU; The main MCU controls the braking mechanism to brake according to the standby control signal.

2. The brake pedal signal backup system based on UWB detection of the driver's foot position according to claim 1 is characterized in that: When the main signal transmission unit works normally, the UWB signal transmitting module transmits a synchronization signal to the UWB signal receiving module and maintains connection with the UWB signal receiving module.

3. The brake pedal signal backup system based on UWB detection of the driver's foot position according to claim 2 is characterized in that: The synchronization signal adopts a low-frequency synchronization signal.

4. The brake pedal signal backup system based on UWB detection of the driver's foot position according to claim 2 is characterized in that: The UWB processing module monitors the working status of the main signal transmission unit in real time. When the main signal transmission unit is abnormal, the UWB processing module controls the UWB signal transmission module to switch from transmitting the synchronization signal to transmitting the ultra-wideband signal.

5. The brake pedal signal backup system based on UWB detection of the driver's foot position according to claim 2 or 4, characterized in that: The synchronization signal includes a foot position signal, and the UWB processing module processes the synchronization signal to obtain a verification signal.

6. The brake pedal signal backup system based on UWB detection of the driver's foot position according to claim 5 is characterized in that: When the main MCU does not receive the main control signal and the UWB signal receiving module receives the synchronization signal, the UWB processing module determines that the signal is interrupted; The main MCU compares the main control signal with the verification signal. When the error exceeds a preset range, the main MCU transmits the comparison result to the UWB processing module, and the UWB processing module determines that the signal is abnormal; When the signal is interrupted or abnormal, the UWB processing module controls the UWB signal transmitting module to switch from transmitting the synchronization signal to transmitting the ultra-wideband signal.

7. The brake pedal signal backup system based on UWB detection of the driver's foot position according to claim 2 is characterized in that: The synchronization signal and the ultra-wideband signal are both transmitted in an encrypted manner.

8. The brake pedal signal backup system based on UWB detection of the driver's foot position according to claim 1 is characterized in that: Signal transmission is performed between the main MCU and the UWB processing module via the SPI communication interface.

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