Unmanned vehicle brake-by-wire system and control method thereof

Abstract

The present invention provides a brake-by-wire system for an unmanned vehicle and a control method thereof, belonging to the technical field of brake-by-wire technology. The system comprises a strategy formulation module, a pressure adjustment module, an environment adjustment module and a control module. An ECU formulates a strategy according to braking requirements, adjusts the strategy through a pressure sensor and an accumulator, and further adjusts the strategy in combination with environmental data to form and implement a final braking strategy, so that the unmanned vehicle can achieve precise braking in different environments, improve safety, enhance adaptability, and optimize braking performance.

Description

Technical Field

[0001] The present invention relates to the technical field of brake-by-wire technology, and in particular to a brake-by-wire system for an unmanned vehicle and a control method thereof. Background Art

[0002] With the development of autonomous driving technology, traditional mechanical or hydraulic braking systems can no longer meet the complex control requirements of driverless cars, especially for special vehicle braking systems, which are required to have the function of large-slope parking brakes. Therefore, the wire control brake system is proposed to improve braking accuracy, improve response speed, and achieve advanced integration with other vehicle systems to achieve the parking function of special vehicles at large slopes (not less than 32°). At the same time, the braking control strategy also needs to be transformed from the traditional fixed algorithm to an adaptive strategy that can perceive the current state of the vehicle and changes in the external environment. However, the early wire control brake system did not have enough reaction speed to deal with emergency braking situations or complex traffic environments, and it was difficult to perfectly integrate with other vehicle control systems, such as power control and vehicle stability control.

[0003] Therefore, the present invention provides a brake-by-wire system for an unmanned vehicle and a control method thereof. Summary of the invention

[0004] The present invention provides a brake-by-wire system for an unmanned vehicle and a control method thereof. An ECU formulates a strategy according to braking requirements, adjusts the strategy through a pressure sensor and an accumulator, and further adjusts the strategy in combination with environmental data to form and implement a final braking strategy, so that the unmanned vehicle can achieve precise braking in different environments, improve safety, enhance adaptability, and optimize braking performance.

[0005] The present invention provides a brake-by-wire system for an unmanned vehicle, comprising:

[0006] Strategy formulation module: The ECU determines the primary braking strategy based on the received braking request and issues a braking command to execute the primary braking strategy;

[0007] Pressure adjustment module: monitors the execution of instructions according to the preset pressure sensor, determines the pressure change point and feeds it back to the ECU, which analyzes the pressure change point and makes the first adjustment to the primary braking strategy based on the analysis result and the accumulator device;

[0008] Environmental adjustment module: collects environmental data according to the current environment of the unmanned vehicle, evaluates the impact of environmental data on the primary braking strategy, and makes a second adjustment to the primary braking strategy by setting the environmental window;

[0009] Control module: forms a final braking strategy according to the first adjustment and the second adjustment results, controls the control valve group according to the final braking strategy, and thus realizes control of the unmanned vehicle.

[0010] The present invention provides a brake-by-wire system for an unmanned vehicle, a strategy formulation module, comprising:

[0011] Analysis unit: The ECU receives a braking request signal from the unmanned vehicle driving system, analyzes the braking request signal, and determines the type and urgency of the braking request;

[0012] Demand determination unit: combining the current running state of the unmanned vehicle with the type and urgency of the braking request to determine the braking demand of the unmanned vehicle, and the ECU selects the first braking mode according to the braking demand;

[0013] Distribution unit: determining the required total braking torque according to the first braking mode and the vehicle state, and determining the primary distribution of the control valve group according to the dynamic stability requirements of the unmanned vehicle;

[0014] Strategy unit: The ECU determines the corresponding parameter distribution based on the primary distribution, and then determines the primary braking strategy.

[0015] The present invention provides a brake-by-wire system for an unmanned vehicle, a pressure adjustment module, comprising:

[0016] Comparison unit: performing a first comparison between the real-time monitoring data of the pressure sensor and the standard data to determine whether the braking performance is within the allowable error. If not, performing a second comparison between the real-time monitoring data and the historical data to determine the overall pressure loss of the unmanned vehicle, adding a loss coefficient to the standard data according to the loss, and performing a third comparison between the real-time monitoring data and the additional standard data;

[0017] Analysis unit: If it is still not within the allowable error, the point beyond the range will be marked as a pressure change point and fed back to the ECU for analysis. Based on the analysis results and the state of the accumulator device, the primary braking strategy will be adjusted first.

[0018] The present invention provides an unmanned vehicle brake-by-wire system, an analysis unit, comprising:

[0019] Starting point search block: Starting from the pressure change point, the system traces back along the time series, checks the previous data points one by one, compares the difference between each previous data point and the pressure change point, and finds the first point that significantly deviates from the standard pressure range;

[0020] Starting point determination block: evaluates the trend and pattern of the data points, identifies whether the pressure change point corresponds to an emergency or a gradually developing event based on the evaluation results, adjusts the standard pressure range based on the identification results, and then determines the actual starting point corresponding to the pressure change point;

[0021] End point search block: Starting from the pressure change point, the system checks the subsequent data points backward along the time series to find the first data point that returns to the adjusted standard pressure range, and confirms whether the subsequent data points continue to remain within the adjusted standard pressure range;

[0022] End point determination block: Based on the correlation between data points, the trend that may lead to another pressure change point after identifying the end point is marked as the end point of the pressure change once the data continues to be within the adjusted standard pressure range;

[0023] The first adjustment block: a pressure change event is formed according to the starting point, the pressure change point and the end point, the pressure change event is combined with the real-time operation status of the unmanned vehicle, and a comprehensive analysis is performed. According to the analysis result and the state of the energy storage device, the primary braking strategy is adjusted first, and the pressure sensor data after the first adjustment is fed back for verification, and the first adjustment is fed back for optimization;

[0024] Brake adjustment block: Determine whether the motor pressure building unit has a fault based on the comprehensive analysis results, and then supplement the brake system based on the status of the accumulator device.

[0025] The present invention provides an unmanned vehicle brake-by-wire system, an environment adjustment module, comprising:

[0026] Feature recognition unit: performs time synchronization processing on environmental data, uses data fusion algorithm to fuse environmental data collected by different sensors into unified data, and recognizes key environmental features of the unified data;

[0027] Environmental window setting unit: Based on the identified key environmental features, evaluate whether the primary braking strategy is suitable for the current environmental conditions. If not, define the required environmental window based on the results of the key environmental feature identification;

[0028] The second adjustment unit performs a second adjustment of the primary braking strategy according to the set environmental window.

[0029] The present invention provides an unmanned vehicle brake-by-wire system, an environmental window setting unit, comprising:

[0030] Calculation block: Based on the results of key environmental feature recognition, determine the environmental conditions that affect the braking of the unmanned vehicle, and then set the corresponding environmental window :

[0031]

[0032] in, represents the environment window function; , , , They respectively represent the braking function of the unmanned vehicle, the function of the influence of terrain conditions on the braking of the unmanned vehicle, the adjustment function of the accumulator pressure holding capacity, and the function of the influence of weather conditions on the braking of the unmanned vehicle; Indicates the basic value of braking force; , , , They respectively represent the redundant safety factor of the motor pressure building unit affected by the environment, the adjustment factor of the terrain conditions, the adjustment factor based on the strength of the accumulator pressure maintenance function, and the adjustment factor of the weather influence; It represents the parameters describing the influence of the environment on the motor voltage building unit; Indicates the parameters that affect the accumulator's pressure holding capacity; represents weather parameters; Indicates the slope in terrain conditions;

[0033] The current state of the unmanned vehicle is determined according to the braking demand and the environmental window. If the judgment result is that the unmanned vehicle needs to be parked for a long time at a slope of not less than 32°, the primary braking system is adjusted for the second time through the pressure maintenance function of the accumulator.

[0034] The present invention provides a brake-by-wire system for an unmanned vehicle, a control module, comprising:

[0035] Comprehensive unit: forming a final braking strategy that integrates the vehicle pressure state and the external environment according to the primary braking strategy after the first adjustment and the second adjustment;

[0036] Braking unit: The ECU converts the final braking strategy into a corresponding control command and sends it to the control valve group in the braking system. After receiving the control command, the control valve group accurately adjusts the braking pressure of each wheel to ensure the correct application of the braking force and performs braking according to the historical path;

[0037] Feedback unit: Provides feedback and judgment on the braking effect of the unmanned vehicle based on the results of braking, and further optimizes the final braking strategy in real time.

[0038] The present invention provides an unmanned vehicle line control method, comprising:

[0039] Step 1: The ECU determines the primary braking strategy based on the received braking request and issues a braking command to execute the primary braking strategy;

[0040] Step 2: Monitor the execution of the command according to the preset pressure sensor, determine the pressure change point and feed it back to the ECU, the ECU analyzes the pressure change point, and makes the first adjustment to the primary braking strategy according to the analysis result and the accumulator device;

[0041] Step 3: Collect environmental data according to the current environment of the unmanned vehicle, evaluate the impact of the environmental data on the primary braking strategy, and make a second adjustment to the primary braking strategy by setting the environmental window;

[0042] Step 4: A final braking strategy is formed according to the first adjustment and the second adjustment results, and the control valve group is controlled according to the final braking strategy to achieve control of the unmanned vehicle.

[0043] Compared with the prior art, the beneficial effects of the present application are as follows: the ECU formulates a strategy according to the braking demand, adjusts the strategy through the pressure sensor and accumulator, and further adjusts it in combination with the environmental data to form and implement the final braking strategy, so that the unmanned vehicle can achieve precise braking in different environments, improve safety, enhance adaptability, and optimize braking performance.

[0044] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0045] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0047] Figure 1 is a schematic structural diagram of a brake-by-wire system for an unmanned vehicle provided by an embodiment of the present invention;

[0048] Figure 2 It is a schematic flow chart of a method for braking-by-wire of an unmanned vehicle provided by an embodiment of the present invention;

[0049] Figure 3 It is a schematic diagram of a hydraulic brake system for an unmanned vehicle provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0051] Embodiment 1:

[0052] The embodiment of the present invention provides a brake-by-wire system for an unmanned vehicle, such as Figure 1 As shown, including:

[0053] Strategy formulation module: The ECU determines the primary braking strategy based on the received braking request and issues a braking command to execute the primary braking strategy;

[0054] Pressure adjustment module: monitors the execution of instructions according to the preset pressure sensor, determines the pressure change point and feeds it back to the ECU, which analyzes the pressure change point and makes the first adjustment to the primary braking strategy based on the analysis result and the accumulator device;

[0055] Environmental adjustment module: collects environmental data according to the current environment of the unmanned vehicle, evaluates the impact of environmental data on the primary braking strategy, and makes a second adjustment to the primary braking strategy by setting the environmental window;

[0056] Control module: forms a final braking strategy according to the first adjustment and the second adjustment results, controls the control valve group according to the final braking strategy, and thus realizes control of the unmanned vehicle.

[0057] In this embodiment, the ECU is a controller that receives a braking command from the vehicle through the CAN bus and controls the operation of the entire braking system.

[0058] In this embodiment, the accumulator device is as follows Figure 3 As shown, the main function is to meet the redundancy of the braking source, that is, the vehicle braking can still be completed when the motor pressure building unit fails. For example, when a sudden failure occurs during the vehicle driving and the system is powered off, the braking system can still provide effective braking to ensure the safety of the vehicle; the second is to meet the long-term parking of the wheels under large slope conditions, that is, through the pressure maintenance function of the accumulator, the vehicle can be reliably parked on a road with a large slope, which can be applied to the requirements of special vehicles for parking at a large slope (not less than 32°). The main components include: 31 zero leakage valve with one-way function, 32 accumulator, 33 pressure sensor, 34 zero leakage valve, etc. The filling process of the accumulator is carried out under non-braking conditions. Valve 31 needs to be opened during filling. When the pressure value of 33 is detected to reach the predetermined value, the filling is completed. The long-term pressure maintenance of the accumulator can be achieved through zero leakage valves 31 and 34.

[0059] In this embodiment, if the vehicle needs to park on a steep slope, the zero leakage valve 34 is energized to open, and the brake wheel cylinder is connected to the accumulator through the boost valve 61, the stop valve 51, and the shuttle valve 41. The parking function of the vehicle on the slope can be realized without power input, wherein the shuttle valve 41 can realize the selective output of the motor pressure building unit and the oil source of the accumulator device without mutual influence.

[0060] In this embodiment, the pressure change point is the specific position or time at which the pressure value monitored by the pressure sensor of the vehicle braking system changes during the braking process. These change points may indicate that the brake pressure needs to be adjusted to meet the braking request. For example, if the brake pressure of a wheel is detected to be lower than the ideal value, this low pressure point is a pressure change point, and the ECU will analyze whether it is necessary to increase the braking force of the wheel to ensure the braking effect and vehicle stability.

[0061] In this embodiment, the specific step of the first adjustment is that after loss compensation, if the data is still not within the allowable error range, the point outside the range will be marked as a pressure change point and fed back to the ECU. The ECU will analyze this data and adjust the primary braking strategy in combination with the state of the accumulator. The specific steps include adjusting the braking torque, braking timing or braking mode, so as to make subtle adjustments to the braking performance to ensure that it is within a reasonable working range.

[0062] In this embodiment, the specific process of the second adjustment is to adjust the braking parameters, such as braking force, reaction time, etc., according to the environmental window determined by the identified key environmental features; apply the new braking parameters in the simulator or actual vehicle test to observe the braking effect; analyze the data to determine whether the braking strategy has effectively adapted to the current environment; if the adjustment effect is not ideal, continue to optimize the adjustment parameters and conduct multiple rounds of testing until the best braking performance is achieved.

[0063] The working principle and beneficial effects of the above technical solution are: the ECU formulates a strategy based on braking requirements, adjusts the strategy through pressure sensors and accumulators, and further adjusts the strategy based on environmental data to form and implement the final braking strategy, so that the unmanned vehicle can achieve precise braking in different environments, improve safety, enhance adaptability, and optimize braking performance.

[0064] Embodiment 2:

[0065] The embodiment of the present invention provides a brake-by-wire system for an unmanned vehicle, a strategy formulation module, including:

[0066] Analysis unit: The ECU receives a braking request signal from the unmanned vehicle driving system, analyzes the braking request signal, and determines the type and urgency of the braking request;

[0067] Demand determination unit: combining the current running state of the unmanned vehicle with the type and urgency of the braking request to determine the braking demand of the unmanned vehicle, and the ECU selects the first braking mode according to the braking demand;

[0068] Distribution unit: determining the required total braking torque according to the first braking mode and the vehicle state, and determining the primary distribution of the control valve group according to the dynamic stability requirements of the unmanned vehicle;

[0069] Strategy unit: The ECU determines the corresponding parameter distribution based on the primary distribution, and then determines the primary braking strategy.

[0070] In this embodiment, the braking request signal includes an emergency braking signal, a regular deceleration signal, a braking signal of an adaptive cruise control system, etc. These signals describe the braking operation that the unmanned vehicle driving system wishes to perform.

[0071] In this embodiment, the first braking mode is a preset braking parameter mode determined according to the urgency and type of the braking demand, including emergency braking, gradual braking, slight deceleration, etc.

[0072] In this embodiment, the types of braking requests include emergency braking, gradual braking, etc., and the urgency refers to the time sensitivity and intensity requirement of the braking operation.

[0073] In this embodiment, during the brake signal analysis process, after the ECU receives the brake request signal, it will analyze the type of signal (such as whether it is an emergency brake request, etc.) and the vehicle's operating status at the time (such as vehicle speed, acceleration, etc.) to analyze the signal.

[0074] In this embodiment, the braking demand is a braking operation target determined by comprehensive analysis based on the current operating status of the unmanned vehicle and the received braking request signal, such as the speed and acceleration required to decelerate.

[0075] In this embodiment, the dynamic stability of the unmanned vehicle refers to the ability of the unmanned vehicle to maintain a stable posture and driving trajectory during driving, including keeping the vehicle from losing control or skidding during braking.

[0076] In this embodiment, when the ECU determines the corresponding parameter distribution based on the primary distribution, after determining the total braking torque and the primary braking mode, the ECU will further refine the distribution of the braking torque of each wheel, and also take into account the vehicle weight distribution, load conditions, steering and stability control system information to ensure dynamic stability. Specific parameters may include the size of the braking force of each wheel, the distribution ratio, the braking timing, etc.

[0077] The working principle and beneficial effects of the above technical solution are: the ECU analyzes the needs according to the braking request signal, selects the braking mode, calculates the total braking torque, and allocates the primary braking strategy to ensure the dynamic stability and safety of the unmanned vehicle, improves the ability to respond quickly to changes in vehicle status, enhances the driving safety and stability of the unmanned vehicle, and better adapts to complex traffic environments.

[0078] Embodiment 3:

[0079] The embodiment of the present invention provides a brake-by-wire system for an unmanned vehicle, a pressure adjustment module, comprising:

[0080] Comparison unit: performing a first comparison between the real-time monitoring data of the pressure sensor and the standard data to determine whether the braking performance is within the allowable error. If not, performing a second comparison between the real-time monitoring data and the historical data to determine the overall pressure loss of the unmanned vehicle, adding a loss coefficient to the standard data according to the loss, and performing a third comparison between the real-time monitoring data and the additional standard data;

[0081] Analysis unit: If it is still not within the allowable error, the point beyond the range will be marked as a pressure change point and fed back to the ECU for analysis. Based on the analysis results and the state of the accumulator device, the primary braking strategy will be adjusted first.

[0082] In this embodiment, the first comparison process is to compare the real-time monitoring data collected by the pressure sensor with the preset standard data (which may be the normal braking performance index given by the manufacturer) to see whether the braking performance is within an acceptable error range.

[0083] In this embodiment, the overall loss situation is determined by the following process: if the first comparison finds that the data is not within the allowable error range, the system will compare the real-time data with the historical data collected in the past to determine whether the pressure drop or loss is caused by normal wear of the system or other reasons.

[0084] In this embodiment, the addition of the loss coefficient is a compensation mechanism. Based on the loss judgment, the system calculates a loss coefficient and adds it to the standard data. After correction, a set of adjusted standard data will be generated for the third comparison to more accurately reflect the actual condition of the current system.

[0085] In this embodiment, the status of the accumulator device includes the energy storage level in the accumulator, the pressure level, and the health of the system.

[0086] The working principle and beneficial effects of the above technical solution are: multiple comparative analyses of pressure sensor data are performed to ensure accurate braking performance, and the braking strategy is adjusted based on the analysis results to ensure that the unmanned vehicle braking system is efficient and stable, improve the accuracy of braking performance, and adjust the strategy in time according to system losses to maintain optimal braking effect and vehicle stability.

[0087] Embodiment 4:

[0088] The embodiment of the present invention provides a brake-by-wire system for an unmanned vehicle, an analysis unit, comprising:

[0089] Starting point search block: Starting from the pressure change point, the system traces back along the time series, checks the previous data points one by one, compares the difference between each previous data point and the pressure change point, and finds the first point that significantly deviates from the standard pressure range;

[0090] Starting point determination block: evaluates the trend and pattern of the data points, identifies whether the pressure change point corresponds to an emergency or a gradually developing event based on the evaluation results, adjusts the standard pressure range based on the identification results, and then determines the actual starting point corresponding to the pressure change point;

[0091] End point search block: Starting from the pressure change point, the system checks the subsequent data points backward along the time series to find the first data point that returns to the adjusted standard pressure range, and confirms whether the subsequent data points continue to remain within the adjusted standard pressure range;

[0092] End point determination block: Based on the correlation between data points, the trend that may lead to another pressure change point after identifying the end point is marked as the end point of the pressure change once the data continues to be within the adjusted standard pressure range;

[0093] The first adjustment block: a pressure change event is formed according to the starting point, the pressure change point and the end point, the pressure change event is combined with the real-time operation status of the unmanned vehicle, and a comprehensive analysis is performed. According to the analysis result and the state of the energy storage device, the primary braking strategy is adjusted first, and the pressure sensor data after the first adjustment is fed back for verification, and the first adjustment is fed back for optimization;

[0094] Brake adjustment block: Determine whether the motor pressure building unit has a fault based on the comprehensive analysis results, and then supplement the brake system based on the status of the accumulator device.

[0095] In this embodiment, the process corresponding to evaluating the trend and pattern of data points is to analyze continuous data points to understand the manner and speed of the development of pressure changes, and to determine whether the pressure changes occur suddenly or gradually by identifying the regularity and pattern of changes between data points.

[0096] In this embodiment, an emergency event refers to a situation in which the pressure changes suddenly and significantly, which may be caused by a system failure or an external sudden factor; a gradual event refers to a process in which the pressure change gradually accumulates and reaches a certain threshold, which may be caused by continuous factors such as component wear; the difference between the two lies in the speed and cause of the change. Emergency events usually require rapid intervention, while gradual events may allow more time for adjustment.

[0097] In this embodiment, the comprehensive analysis process involves comparing and integrating the change pattern of pressure data with other sensor data, system logs and operating conditions during vehicle operation; the analysis results include identifying the cause of pressure changes, predicting the trend of changes, evaluating the impact on vehicle performance, and proposing specific suggestions for adjusting braking strategies.

[0098] In this embodiment, the feedback verification process refers to monitoring the new pressure sensor data after adjustment and comparing it with the data before adjustment to verify whether the adjustment has achieved the expected effect and ensure the recovery or improvement of braking performance; the feedback optimization process is that if the verification result is not satisfactory, it may be necessary to further analyze the cause and adjust the strategy, or even update the system parameters or perform hardware maintenance, and then verify again until the system performance reaches the optimal state. This is a continuous improvement and adaptation process aimed at continuously improving the performance and reliability of the braking system.

[0099] The working principle and beneficial effects of the above technical solution are: the system determines the starting and ending points of pressure changes by tracking data point differences and analyzing trends, analyzes the causes, and adjusts and verifies the braking strategy accordingly, thereby improving the response and adaptability of the braking system, ensuring long-term stable operation, reducing the risk of failure, and improving the safety of unmanned vehicles.

[0100] Embodiment 5:

[0101] The embodiment of the present invention provides a brake-by-wire system for an unmanned vehicle, an environment adjustment module, including:

[0102] Feature recognition unit: performs time synchronization processing on environmental data, uses data fusion algorithm to fuse environmental data collected by different sensors into unified data, and recognizes key environmental features of the unified data;

[0103] Environmental window setting unit: Based on the identified key environmental features, evaluate whether the primary braking strategy is suitable for the current environmental conditions. If not, define the required environmental window based on the results of the key environmental feature identification;

[0104] The second adjustment unit performs a second adjustment of the primary braking strategy according to the set environmental window.

[0105] In this embodiment, the time synchronization process is to align the environmental data from different sensors according to time to ensure that the data reflects the environmental status at the same moment.

[0106] In this embodiment, the key environmental characteristics include weather conditions, terrain conditions, and road conditions, wherein the road conditions are mainly reflected in the regulation of the accumulator's pressure maintenance and change capabilities.

[0107] In this embodiment, the specific evaluation process is to analyze the relationship between key environmental characteristics and the current braking performance of the vehicle; simulate the response and effect of the braking system under different environments; and use the corresponding algorithm to determine whether the current braking strategy can meet environmental requirements, taking into account factors such as stopping distance and response time.

[0108] The working principle and beneficial effects of the above technical solution are: by synchronously analyzing the data of each sensor, identifying the key characteristics of the environment, setting the adaptive environmental window, and optimizing and adjusting the braking strategy accordingly, the system's adaptability to complex environments is enhanced, the accuracy and reliability of the braking strategy are improved, and the safe and stable operation of the unmanned vehicle is ensured.

[0109] Embodiment 6:

[0110] An embodiment of the present invention provides a brake-by-wire system for an unmanned vehicle, an environmental window setting unit, comprising:

[0111] Calculation block: Based on the results of key environmental feature recognition, determine the environmental conditions that affect the braking of the unmanned vehicle, and then set the corresponding environmental window :

[0112] ;

[0113] in, represents the environment window function; , , , They respectively represent the braking function of the unmanned vehicle, the function of the influence of terrain conditions on the braking of the unmanned vehicle, the adjustment function of the accumulator pressure holding capacity, and the function of the influence of weather conditions on the braking of the unmanned vehicle; Indicates the basic value of braking force; , , , They respectively represent the redundant safety factor of the motor pressure building unit affected by the environment, the adjustment factor of the terrain conditions, the adjustment factor based on the strength of the accumulator pressure maintenance function, and the adjustment factor of the weather influence; It represents the parameters describing the influence of the environment on the motor voltage building unit; Indicates the parameters that affect the accumulator's pressure holding capacity; represents weather parameters; Indicates the slope in terrain conditions;

[0114] The current state of the unmanned vehicle is determined according to the braking demand and the environmental window. If the judgment result is that the unmanned vehicle needs to be parked for a long time at a slope of not less than 32°, the primary braking system is adjusted for the second time through the pressure maintenance function of the accumulator.

[0115] In this embodiment, the motor voltage building unit is the main voltage building unit, such as Figure 3As shown, the main functional components include 21 servo motor, 22 ball screw, 23 pressure-building piston, 24 one-way valve, 25 shuttle valve, 26 & 27 unloading valve, 28 pressure sensor, etc. The working principle is that the rotation of the servo motor drives the screw to rotate, so that the piston moves forward and backward to complete the pressure building, and the closed-loop control of the pressure is realized through the 28 pressure sensor. Its characteristics are that the pressure-building chamber is divided into a rod chamber and a rodless chamber by the 23 pressure-building piston, and the oil in the rodless chamber can enter the rod chamber through the one-way valve 24 built into the piston. No matter which direction the piston moves to build pressure, the high-pressure oil in the rod chamber or the rodless chamber can be output through the 25 shuttle valve. When the pressure building unit is working, the unloading valves 26 & 27 are closed, the piston moves forward under the action of the motor, the rodless chamber builds pressure, and half of the oil enters the rod chamber through the one-way valve. After reaching the end of the stroke, the piston moves in the opposite direction under the action of the motor, the valve 26 is opened, the rod chamber is replenished, and the rodless chamber is discharged. After reaching the end of the stroke, the valve 26 is closed, and the piston moves forward to start the next pressure building cycle. This structural method can complete the continuous output of brake oil through the forward and backward movement of the piston within a limited stroke range and without increasing the motor power, thereby meeting the large displacement requirements of large PV characteristic brake calipers and ABS. Compared with the traditional motor pump type pressure building unit, this structure makes full use of the advantages of the high transmission efficiency of the ball screw. When not working, the rodless chamber and the rod chamber are connected to the oil tank through the unloading valves 26 and 27, and the piston returns to the initial position.

[0116] The working principle and beneficial effects of the above technical solution are: setting an adaptive environmental window and optimizing and adjusting the braking strategy accordingly, enhancing the system's adaptability to complex environments, improving the accuracy and reliability of the braking strategy, and ensuring the safe and stable operation of unmanned vehicles.

[0117] Embodiment 7:

[0118] The embodiment of the present invention provides a brake-by-wire system for an unmanned vehicle, a control module, including:

[0119] Comprehensive unit: forming a final braking strategy that integrates the vehicle pressure state and the external environment according to the primary braking strategy after the first adjustment and the second adjustment;

[0120] Braking unit: The ECU converts the final braking strategy into a corresponding control command and sends it to the control valve group in the braking system. After receiving the control command, the control valve group accurately adjusts the braking pressure of each wheel to ensure the correct application of the braking force and performs braking according to the historical path;

[0121] Feedback unit: Provides feedback and judgment on the braking effect of the unmanned vehicle based on the results of braking, and further optimizes the final braking strategy in real time.

[0122] In this embodiment, the method for obtaining the historical path is obtained through the vehicle's navigation system, sensor records and the vehicle's own driving data history accumulation, including the vehicle's movement trajectory, braking event history, speed changes and other information, to assist the system in understanding the vehicle's previous braking performance in similar situations.

[0123] In this embodiment, the feedback judgment is to judge whether the effect of the wire control brake system meets the expectations by evaluating the actual results after braking, such as braking distance, stability during braking, etc. If the effect is not good, for example, the braking distance is too long or the braking process is not smooth enough, the system will consider that the braking strategy needs to be further improved.

[0124] In this embodiment, the further optimization process is that the system will collect the result data of braking and compare and analyze it with the expected effect; identify possible problems or room for improvement based on the comparison results, such as adjusting the brake pressure distribution, changing the parameters of the control algorithm, etc.; the adjusted strategy will be verified in a simulation environment or actual test; after obtaining feedback, if the system still does not achieve the most ideal braking effect, it will repeat the above process and iterate continuously until the performance of the wire control brake system reaches the optimal state.

[0125] In this embodiment, the control valve group, such as Figure 3 As shown, it includes group valve 51, boost valve 61, and pressure reducing valve 71. The group valve 51 divides the oil circuits of the four brake calipers into two groups, which are redundant to each other; 61 and 71 are used to control the braking force of a single caliper, 61 is a boost valve, and 71 is a pressure reducing valve. The control valve is a high-speed switch valve, which can control the wheel slip rate by adjusting the brake pressure of a single wheel cylinder.

[0126] The working principle and beneficial effects of the above technical solution are: integrating the braking strategies of the two adjustments, issuing control commands through the ECU, adjusting the braking pressure, and performing real-time optimization based on feedback to achieve precise and effective braking control, ensure the braking effect of the unmanned vehicle in various environments, improve driving safety, enhance the vehicle's adjustment capabilities, and realize intelligent and precise wire-controlled brake management.

[0127] Embodiment 8:

[0128] The embodiment of the present invention provides an unmanned vehicle line control method, such as Figure 2 As shown, including:

[0129] Step 1: The ECU determines the primary braking strategy based on the received braking request and issues a braking command to execute the primary braking strategy;

[0130] Step 2: Monitor the execution of the command according to the preset pressure sensor, determine the pressure change point and feed it back to the ECU, the ECU analyzes the pressure change point, and makes the first adjustment to the primary braking strategy according to the analysis result and the accumulator device;

[0131] Step 3: Collect environmental data according to the current environment of the unmanned vehicle, evaluate the impact of the environmental data on the primary braking strategy, and make a second adjustment to the primary braking strategy by setting the environmental window;

[0132] Step 4: A final braking strategy is formed according to the first adjustment and the second adjustment results, and the control valve group is controlled according to the final braking strategy to achieve control of the unmanned vehicle.

[0133] The working principle and beneficial effects of the above technical solution are: ECU formulates a strategy according to the braking demand, adjusts the strategy through pressure sensors and accumulators, and further adjusts it in combination with environmental data to form and implement the final braking strategy, so that the unmanned vehicle can achieve precise braking in different environments, improve safety, enhance adaptability, and optimize braking performance. ECU formulates a strategy according to the braking demand, adjusts the strategy through pressure sensors and accumulators, and further adjusts it in combination with environmental data to form and implement the final braking strategy, so that the unmanned vehicle can achieve precise braking in different environments, improve safety, enhance adaptability, and optimize braking performance.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A brake-by-wire system for an unmanned vehicle, characterized in that: include: Strategy formulation module: The ECU determines the primary braking strategy based on the received braking request and issues a braking command to execute the primary braking strategy; Pressure adjustment module: monitors the execution of instructions according to the preset pressure sensor, determines the pressure change point and feeds it back to the ECU, which analyzes the pressure change point and makes the first adjustment to the primary braking strategy based on the analysis result and the accumulator device; Environmental adjustment module: collects environmental data according to the current environment of the unmanned vehicle, evaluates the impact of environmental data on the primary braking strategy, and makes a second adjustment to the primary braking strategy by setting the environmental window; Control module: forming a final braking strategy according to the first adjustment and the second adjustment results, and controlling the control valve group according to the final braking strategy, thereby realizing control of the unmanned vehicle; Wherein, the strategy formulation module includes: Analysis unit: The ECU receives a braking request signal from the unmanned vehicle driving system, analyzes the braking request signal, and determines the type and urgency of the braking request; Demand determination unit: combining the current running state of the unmanned vehicle with the type and urgency of the braking request to determine the braking demand of the unmanned vehicle, and the ECU selects the first braking mode according to the braking demand; Distribution unit: determining the required total braking torque according to the first braking mode and the vehicle state, and determining the primary distribution of the control valve group according to the dynamic stability requirements of the unmanned vehicle; Strategy unit: The ECU determines the corresponding parameter distribution based on the primary distribution, and then determines the primary braking strategy.

2. The unmanned vehicle brake-by-wire system according to claim 1, characterized in that: Pressure regulation module, comprising: Comparison unit: performing a first comparison between the real-time monitoring data of the pressure sensor and the standard data to determine whether the braking performance is within the allowable error. If not, performing a second comparison between the real-time monitoring data and the historical data to determine the overall pressure loss of the unmanned vehicle, adding a loss coefficient to the standard data according to the loss, and performing a third comparison between the real-time monitoring data and the additional standard data; Analysis unit: If it is still not within the allowable error, the point beyond the range will be marked as a pressure change point and fed back to the ECU for analysis. Based on the analysis results and the state of the accumulator device, the primary braking strategy will be adjusted first.

3. The unmanned vehicle brake-by-wire system according to claim 2, characterized in that: Analysis unit, including: Starting point search block: Starting from the pressure change point, the system traces back along the time series, checks the previous data points one by one, compares the difference between each previous data point and the pressure change point, and finds the first point that significantly deviates from the standard pressure range; Starting point determination block: evaluates the trend and pattern of the data points, identifies whether the pressure change point corresponds to an emergency or a gradually developing event based on the evaluation results, adjusts the standard pressure range based on the identification results, and then determines the actual starting point corresponding to the pressure change point; End point search block: Starting from the pressure change point, the system checks the subsequent data points backward along the time series to find the first data point that returns to the adjusted standard pressure range, and confirms whether the subsequent data points continue to remain within the adjusted standard pressure range; End point determination block: Based on the correlation between data points, the trend that may lead to another pressure change point after identifying the end point is marked as the end point of the pressure change once the data continues to be within the adjusted standard pressure range; The first adjustment block: a pressure change event is formed according to the starting point, the pressure change point and the end point, the pressure change event is combined with the real-time operation status of the unmanned vehicle, and a comprehensive analysis is performed. According to the analysis result and the state of the energy storage device, the primary braking strategy is adjusted first, and the pressure sensor data after the first adjustment is fed back for verification, and the first adjustment is fed back for optimization; Brake adjustment block: Determine whether the motor pressure building unit has a fault based on the comprehensive analysis results, and then supplement the brake system based on the status of the accumulator device.

4. The unmanned vehicle brake-by-wire system according to claim 1, characterized in that: Environmental adjustment module, including: Feature recognition unit: performs time synchronization processing on environmental data, uses data fusion algorithm to fuse environmental data collected by different sensors into unified data, and recognizes key environmental features of the unified data; Environmental window setting unit: Based on the identified key environmental features, evaluate whether the primary braking strategy is suitable for the current environmental conditions. If not, define the required environmental window based on the results of the key environmental feature identification; The second adjustment unit performs a second adjustment of the primary braking strategy according to the set environmental window.

5. The unmanned vehicle brake-by-wire system according to claim 1, characterized in that: Control module, including: Comprehensive unit: forming a final braking strategy that integrates the vehicle pressure state and the external environment according to the primary braking strategy after the first adjustment and the second adjustment; Braking unit: The ECU converts the final braking strategy into a corresponding control command and sends it to the control valve group in the braking system. After receiving the control command, the control valve group accurately adjusts the braking pressure of each wheel to ensure the correct application of the braking force and performs braking according to the historical path; Feedback unit: Provides feedback and judgment on the braking effect of the unmanned vehicle based on the results of braking, and further optimizes the final braking strategy in real time.

6. An unmanned vehicle line control method, characterized in that: include: Step 1: The ECU determines the primary braking strategy based on the received braking request and issues a braking command to execute the primary braking strategy; Step 2: Monitor the execution of the command according to the preset pressure sensor, determine the pressure change point and feed it back to the ECU, the ECU analyzes the pressure change point, and makes the first adjustment to the primary braking strategy according to the analysis result and the accumulator device; Step 3: Collect environmental data according to the current environment of the unmanned vehicle, evaluate the impact of the environmental data on the primary braking strategy, and make a second adjustment to the primary braking strategy by setting the environmental window; Step 4: forming a final braking strategy according to the first adjustment and the second adjustment results, and controlling the control valve group according to the final braking strategy, thereby realizing control of the unmanned vehicle; Wherein, the step 1 comprises: Step 11: The ECU receives a braking request signal from the unmanned vehicle driving system, analyzes the braking request signal, and determines the type and urgency of the braking request; Step 12: combining the current running state of the unmanned vehicle with the type and urgency of the braking request to determine the braking requirement of the unmanned vehicle, and the ECU selects the first braking mode according to the braking requirement; Step 13: determining the required total braking torque according to the first braking mode and the vehicle state, and determining the primary allocation of the control valve group according to the dynamic stability requirements of the unmanned vehicle; Step 14: The ECU determines the corresponding parameter distribution based on the primary distribution, and then determines the primary braking strategy.

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