Drive-by-wire interaction method for avoiding failure of chassis brake actuator

Abstract

The invention provides a drive-by-wire interaction method for avoiding failure of a chassis brake actuator, which comprises the following steps that a drive-by-wire interaction system suitable for an automatic driving vehicle is constructed, and the system adopts drive-by-wire signals to perform interaction operation and at least comprises a sensor, an automatic driving central processing unit, a brake controller and a brake actuator, the sensor is used for monitoring and transmitting the state of the brake actuator to the automatic driving central processing unit; the automatic driving central processing unit sends a control signal to the brake controller according to the state of the brake actuator and the vehicle information; the brake controller generates an instruction according to the control signal and transmits the instruction to the brake actuator; the brake actuator executes a corresponding brake action according to the instruction; and when an abnormal working condition is detected, processing measures are taken according to an emergency processing strategy. According to the method, the failure risk of the brake actuator of the automatic driving vehicle can be reduced, and the driving stability and the driving safety are improved.

Description

Technical Field

[0001] The present invention relates to the field of automobiles, and in particular to a wire control interaction method for avoiding failure of a chassis brake actuator. Background Art

[0002] An autonomous vehicle is an intelligent vehicle that achieves partial or full autonomous driving through sensors, controllers and other equipment. Among them, the chassis brake actuator is one of the key equipment of an autonomous vehicle, and its performance stability and reliability are directly related to the driving safety of the vehicle. However, during long-term operation, the chassis brake actuator may be affected by factors such as wear, overload and thermal fatigue, resulting in performance degradation or even failure. This will not only affect the normal driving of the vehicle, but also increase the risk of traffic accidents.

[0003] Existing strategies and methods to avoid failure of chassis brake actuators in autonomous vehicles mainly include regular maintenance, condition monitoring, and fault prediction. Among them, regular maintenance is to prevent failures by regularly checking and replacing brake actuator parts. Condition monitoring is to monitor the operating status of the chassis actuator through sensors and take timely measures when abnormalities are found. Fault prediction is to predict possible failures by analyzing the operating data of the chassis actuator and taking measures in advance.

[0004] However, these strategies and methods have certain limitations. Although regular maintenance can prevent failures, it requires regular inspection and replacement of parts, which increases maintenance costs. Condition monitoring can detect abnormal conditions in a timely manner, but there are also cases where the monitoring system fails or misreports. Fault prediction can predict potential failures, but measures must be taken in advance, and there are cases where predictions are inaccurate or measures are ineffective. At present, autonomous driving vehicles generally perform tasks around the clock, and the vehicle's wire-controlled chassis brake actuators also work 24 hours a day. The autonomous driving system basically meets all-scenario working conditions, and these scenarios are inseparable from the cooperation of the wire-controlled chassis brake actuators. When the autonomous driving vehicle encounters congestion or abnormal traffic lights, or there are obstacles in front of the road that cannot be bypassed and can only wait in place, the wire-controlled chassis of the autonomous driving system generally takes a certain deceleration to keep the brakes in place and wait. At this time, the chassis brake actuator is always maintained at a certain pressure and has been in working condition for a long time. Affected by factors such as wear, overload and thermal fatigue, the performance of the chassis brake actuator is reduced or even fails, causing the vehicle's brakes to fail or slip, thereby causing traffic accidents. Summary of the invention

[0005] In view of the defects in the prior art, the purpose of the present invention is to provide a wire-control interaction method for avoiding failure of chassis brake actuators, reducing the risk of brake actuator failure of autonomous driving vehicles, and improving driving stability and driving safety.

[0006] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solution:

[0007] The present invention provides a wire control interaction method for avoiding failure of a chassis brake actuator, comprising the following steps:

[0008] Construct a wire control interactive system suitable for autonomous driving vehicles, the system uses wire control signals for interactive operations, and at least includes a sensor, an autonomous driving central processor, a brake controller, and a brake actuator, wherein the sensor is used to monitor and transmit the brake actuator status to the autonomous driving central processor;

[0009] The autonomous driving central processor sends a control signal to the brake controller based on the brake actuator status and vehicle information;

[0010] The brake controller generates a command according to the control signal and transmits the command to the brake actuator;

[0011] The brake actuator performs corresponding braking actions according to the instructions;

[0012] When an abnormal operating condition is detected, treatment measures are taken according to the emergency treatment strategy, which includes:

[0013] When a brake controller failure is detected, the brake controller sends an ESC fault signal and requests parking. The autonomous driving central processor simultaneously requests parking upon receiving the ESC fault signal.

[0014] A loss of communication with the brake controller is detected and the autonomous driving central processor requests parking.

[0015] When the vehicle is detected to have lost communication with the autonomous driving central processor while in motion, the brake controller commands braking until the vehicle speed drops to 0, requesting parking.

[0016] Preferably, when manual intervention is detected in the automatic driving mode, the brake controller will suspend entering the automatic driving until the manual intervention is eliminated.

[0017] Preferably, the processing measures further include providing feedback prompts to the driver.

[0018] Preferably, the brake controller is pre-set with a first pressure holding time, and the brake controller requests parking before the first pressure holding time.

[0019] Preferably, the brake controller is also preset with a second pressure-holding time, and will request parking and release pressure before the second pressure-holding time, and the second pressure-holding time is greater than the first pressure-holding time.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention effectively reduces the risk of chassis actuator failure of autonomous commercial vehicles by real-time monitoring and dynamic adjustment of chassis control logic, improves the response speed and stability of the vehicle, and further enhances the safety of autonomous commercial vehicles. At the same time, it has high adaptability and scalability, and can adapt to different types of chassis actuators and different application scenarios of autonomous commercial vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0023] Figure 1 Schematic diagram of the process described in the embodiment. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0026] It should be noted that similar numbers and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in the subsequent figures. In addition, all directional indications in this application (such as up, down, left, right, front, back, bottom...) are only used to explain the relative position relationship, movement, etc. between the components under a certain specific posture (as shown in the figures). If the specific posture changes, the directional indication will also change accordingly. Furthermore, the descriptions involving "first", "second", etc. in the application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated.

[0027] Example

[0028] The present invention provides a wire control interaction method for avoiding chassis brake actuator failure, such as Figure 1 As shown, the following steps are included:

[0029] In step S1, a wire control interactive system suitable for an autonomous driving vehicle is constructed, wherein the system uses wire control signals for interactive operation, and specifically, the system at least includes a sensor, an autonomous driving central processing unit (ADCU), a brake controller (ESC), and a brake actuator. The sensor is used to monitor the state of the brake actuator, including the brake disc speed, temperature, and brake disc wear, and transmit the state data to the autonomous driving central processing unit.

[0030] In step S2, the autonomous driving central processor sends a control signal to the brake controller according to the brake actuator status and vehicle information. The specific logic interaction principle is explained as follows:

[0031] Under normal working conditions, when ESC determines that it can open control to ADCU, the ESC controlled state is 0x1, and the state of 0x1 is normal. When ADCU determines that the ESC controlled state is 0x1, ADCU sends enable ENABLE. At this time, ESC feedbacks 0x2 to enter the automatic driving state. ADCU sends 0x2 automatic driving mode. ESC can decide whether to receive the 0x2 signal sent by ADCU according to the preset strategy. At the same time, ADCU requests the deceleration value according to the driving situation until it needs to exit the automatic driving state. At this time, ADCU will send DISABLE to turn off the enable, ESC exits the automatic driving, and the ESC controlled state returns to the controllable state of 0X1. In the automatic driving mode, when ESC receives the exit automatic driving 0X3 signal requested by ADCU, it also needs to complete the exit automatic driving state, and the ESC controlled state returns to the controllable 0x1. In the automatic driving mode, when ESC fails, a fault signal is issued, and the ESC controlled state changes from 0X2 to 0X3 and cannot enter the automatic driving permanently until the fault is eliminated and changes back to 0X1.

[0032] In step S3, the brake controller generates an instruction according to the control signal and transmits the instruction to the brake actuator. Specifically, this embodiment adopts the standstill signal design, specifically: the ESC only determines whether to maintain pressure according to the standstill signal, when standstill=0, the ESC does not maintain pressure, and when standstill=1, the ESC maintains pressure.

[0033] Preferably, in the automatic driving mode, when manual intervention is detected, ESC will suspend automatic driving until the manual intervention is eliminated. For example, when it is detected that the driver has stepped on the brake, ESC sends a manual intervention signal, and the ESC control state changes from 0X2 to 0X0, temporarily unable to enter automatic driving, until the brake is released, the ESC control state returns to the controllable state of 0x1, implementing the principle of manual priority and giving priority to manual intervention.

[0034] In step S4 , the brake actuator performs corresponding braking actions according to the command, such as clamping and releasing the brake disc.

[0035] In step S5, a fault monitoring and early warning mechanism is set up to monitor the operating status of the brake actuator in real time. When an abnormal operating condition is detected, treatment measures are taken according to the emergency treatment strategy. The treatment measures include switching to a backup redundant brake device or reducing the speed of the vehicle or pulling over to park safely and reporting to the maintenance system. Preferably, the treatment measures also include providing feedback to the driver to help the driver understand the operating status of the brake actuator in a timely manner. Specifically, the emergency treatment strategy includes:

[0036] If the ESC fails in the automatic driving mode, the ESC will send an ESC fault signal and request EPB to park. At the same time, the ADCU will read the ESC fault signal and request EPB (electronic parking system) to park. If the ESC fails in the manual driving mode, the ESC will not operate and the driver will be responsible for manually engaging the EPB.

[0037] If ESC communication loss occurs, ADCU requests EPB to park the vehicle.

[0038] If ADCU communication is lost when the vehicle is in motion, ESC controls the brakes until the vehicle speed drops to 0 and requests EPB to park. When ADCU communication is lost (more than 10 frames), the ESC controlled state changes from 0X2 to 0x1, and ESC brakes to 0 to request EPB to park and wait for the next request from ADCU. When the vehicle is stationary, this operation is not performed because it is directly taken over by EPB.

[0039] The methods provided in this embodiment all use wire control signals for interactive operation, can monitor the state of the brake actuator in real time, and adjust the control signal as needed to ensure the stable operation of the brake actuator. At the same time, by setting up a fault monitoring and early warning mechanism, abnormal conditions can be discovered in time and corresponding solutions can be taken, thereby avoiding failure of the brake actuator.

[0040] The following is an explanation of the operation logic of the method provided in this embodiment during normal driving and temporary stop conditions. When the vehicle speed is greater than a first preset speed, such as 3 kilometers per hour, ADCU requests a deceleration value, and ESC responds to the deceleration value requested by ADCU; when the speed is less than or equal to the first preset speed, ADCU requests a deceleration value, and ESC first responds to the deceleration value, until ESC fails to obtain the speed, and maintains the original deceleration pressure value.

[0041] The following is an explanation of the operation logic of the method provided by this embodiment in a permanent parking condition. First, compare the vehicle speed with the second preset speed, for example, the second preset speed is 3 kilometers per hour: if the vehicle speed is greater than 3 kilometers per hour, ADCU requests a deceleration value, and ESC responds according to the requested deceleration; if the speed is less than 3 kilometers per hour, ADCU requests a deceleration value, and ESC first responds to the deceleration value until ESC cannot obtain the speed, and maintains the original deceleration pressure value. When ADCU determines that the vehicle speed is equal to 0, it requests STANDSTILL=1, ESC maintains pressure, and ADCU requests EPB parking again. After EPB parking is completed, ADCU requests deceleration of 0 and standstill=0 to release the brake, and ESC releases pressure.

[0042] Preferably, a first pressure holding time is preset for ESC, and ESC requests EPB parking before the first pressure holding time. For example, the preset maximum pressure holding time is 30 seconds, and ESC can release pressure after requesting EPB parking at the 25th second. Preferably, an ESC self-protection mechanism is provided as a redundant protection mechanism, that is, ESC has a second pressure holding time when responding to a deceleration request, and will request parking and release pressure before the second pressure holding time, and the second pressure holding time is greater than the first pressure holding time. For example, the second pressure holding time of ESC is 60 seconds, and it will request parking at 55 seconds, release pressure, and the controlled state becomes 0x0, and the controllable state is restored after 5 seconds, and another 60-second cycle is executed to continue responding to the previous deceleration value.

[0043] The above describes the specific embodiments of the present invention. Based on the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention.

Claims

1. A wire control interactive method for avoiding chassis brake actuator failure, characterized in that: The following steps are included: Construct a wire control interactive system suitable for autonomous driving vehicles, the system uses wire control signals for interactive operations, and at least includes a sensor, an autonomous driving central processor, a brake controller, and a brake actuator, wherein the sensor is used to monitor and transmit the brake actuator status to the autonomous driving central processor; The autonomous driving central processor sends a control signal to the brake controller based on the brake actuator status and vehicle information; The brake controller generates a command according to the control signal and transmits the command to the brake actuator; The brake actuator performs corresponding braking actions according to the instructions; When an abnormal operating condition is detected, treatment measures are taken according to the emergency treatment strategy, which includes: When a brake controller failure is detected, the brake controller sends an ESC fault signal and requests parking. The autonomous driving central processor simultaneously requests parking upon receiving the ESC fault signal. A loss of communication with the brake controller is detected and the autonomous driving central processor requests parking. When the vehicle is detected to have lost communication with the autonomous driving central processor while in motion, the brake controller commands braking until the vehicle speed drops to 0, requesting parking.

2. The wire control interactive method for avoiding chassis brake actuator failure according to claim 1, characterized in that: When human intervention is detected in autonomous driving mode, the brake controller will suspend entering autonomous driving until the human intervention is eliminated.

3. The wire control interactive method for avoiding chassis brake actuator failure according to claim 1, characterized in that: The processing measures also include providing feedback prompts to the driver.

4. The wire control interactive method for avoiding chassis brake actuator failure according to claim 1, characterized in that: The brake controller is preset with a first pressure holding time, and the brake controller requests parking before the first pressure holding time.

5. The wire control interactive method for avoiding chassis brake actuator failure according to claim 4, characterized in that: The brake controller is also preset with a second pressure-holding time, and will request parking and release pressure before the second pressure-holding time, and the second pressure-holding time is greater than the first pressure-holding time.

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