Hardware-in-the-loop simulation system and method for combined braking of EBS system and hydraulic retarder

Abstract

The invention relates to the technical field of commercial vehicle braking system simulation, and discloses a hardware-in-the-loop simulation system and method for combined braking of an EBS system and a hydraulic retarder, and the data acquisition end of an industrial personal computer in the system is connected with the data output ends of the EBS system, the hydraulic retarder system and a braking integrated system; the control end of the industrial personal computer is connected with the hydraulic retarder system, the front and rear axle wheel speed integration system and the driving end of the brake pedal mechanism, and the brake pedal mechanism is connected with the EBS system. The braking end of the EBS system is connected with the braking integration system, and the gas storage end of the EBS system is connected with the braking integration system through the gas storage unit. The control output end of the front and rear axle wheel speed integrated system is connected with the control input end of the EBS system. The hardware-in-the-loop simulation system not only can be used for testing in the aspect of combined braking, but also can be used for independently testing a single EBS system or a hydraulic retarder.

Description

Technical Field

[0001] The present invention relates to the technical field of commercial vehicle braking system simulation, and in particular to a hardware-in-the-loop simulation system and method for combined braking of an EBS system and a hydraulic retarder. Background Art

[0002] In the field of commercial vehicle braking systems, traditional pneumatic brakes currently dominate. However, with the continuous improvement of the regulatory system, in order to improve the braking performance and safety of commercial vehicles, commercial vehicle electronic braking systems (EBS) will be mandatory for installation and use on certain models.

[0003] The EBS system offers numerous significant advantages. On one hand, it significantly improves brake response speed, effectively shortens braking distance, and ensures braking stability. On the other hand, the EBS system also enables functions such as stability control, brake force distribution, and shoe wear monitoring. On vehicles equipped with a hydraulic retarder, the EBS system and the retarder can perform combined braking, enabling multiple braking systems to work in tandem. This combined braking method reduces the adverse effects of brake heating on braking efficiency consistency and addresses the limitations of the hydraulic retarder's limited braking force and speed-dependent torque, which restrict its use in specific scenarios. Through combined braking with the EBS system and retarder, multiple braking systems can be managed and utilized in a unified manner, complementing each other's strengths and offsetting their weaknesses. This extends the life of the braking system, ensures stable and comfortable braking, and precisely aligns with the driver's braking intent.

[0004] However, the calibration, testing, and verification phase of the combined braking function development for the EBS system and hydraulic retarder presents numerous pressing challenges. Currently, development companies primarily rely on real-vehicle testing for verification, a method with significant drawbacks. Real-vehicle testing cycles are long, making comprehensive testing difficult to complete in a short period of time; test conditions are insufficient to cover every possible braking scenario; obtaining road conditions is difficult, increasing testing uncertainty; high requirements are placed on testers, requiring extensive professional knowledge and practical experience; testing costs are high, increasing the company's R&D burden; test data is difficult to categorize and organize, hindering subsequent analysis and optimization; and, most importantly, certain special operating conditions can even pose a threat to the tester's life. Summary of the Invention

[0005] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide a hardware-in-the-loop simulation system and method for combined braking of an EBS system and a hydraulic retarder, so as to solve the technical problems in the prior art such as long actual vehicle testing and verification cycle, insufficient test conditions, difficult to obtain road conditions and low testing efficiency.

[0006] The present invention is achieved through the following technical solutions: In a first aspect, the present invention provides a hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder, comprising an EBS system, a hydraulic retarder system, an industrial computer, a front and rear axle wheel speed integration system, a brake integration system, an air storage unit, and a brake pedal mechanism; The data acquisition terminal of the industrial computer is connected to the data output terminals of the EBS system, the hydraulic retarder system and the brake integration system respectively; The control end of the industrial computer is respectively connected to the hydraulic retarder system, the front and rear axle wheel speed integration system and the drive end of the brake pedal mechanism, wherein the brake pedal mechanism is connected to the EBS system; The braking end of the EBS system is connected to the brake integration system, and the air storage end of the EBS system is connected to the brake integration system via the air storage unit; the control output end of the front and rear axle wheel speed integration system is connected to the control input end of the EBS system.

[0007] Preferably, the industrial computer includes a simulation model module and a motor control host computer; The input end branch of the simulation model module is set, one branch is connected to the data output end of the brake integrated system through the data acquisition equipment, and the other branch is connected to the data output end of the EBS system and the hydraulic retarder system respectively through the CAN1 line; The control end of the motor control host computer is respectively connected to the hydraulic retarder system, the front and rear axle wheel speed integration system and the driving end of the brake pedal mechanism.

[0008] Furthermore, the EBS system includes a trailer valve, an ABS valve, a central controller, a front axle valve, a rear axle valve, and a foot valve; The air storage ends of the trailer valve, front axle valve and rear axle valve are all connected to the brake integrated system via the air storage unit; The trailer valve is connected to the brake integrated system via a trailer relay valve; The braking ends of the front axle valve and the rear axle valve are respectively connected to the brake integrated system; the control input ends of the front axle valve and the rear axle valve are respectively connected to the control output ends of the front and rear axle wheel speed integrated system; The data output terminal of the central controller is connected to the input terminal of the simulation model module via the CAN1 line; The foot valve is connected to the brake pedal mechanism.

[0009] Furthermore, the front and rear axle wheel speed integration system includes a front axle wheel speed system and a rear axle wheel speed system; The driving ends of the front axle wheel speed system and the rear axle wheel speed system are respectively connected to the control end of the motor control host computer; the control output ends of the front axle wheel speed system and the rear axle wheel speed system are respectively connected to the control input ends of the front axle valve and the rear axle valve; The front axle wheel speed system includes a front axle wheel speed sensor, a front axle gear plate, a front axle wheel speed servo motor and a front axle motor controller; The rear axle wheel speed system includes a rear axle wheel speed sensor, a rear axle sprocket, a rear axle wheel speed servo motor and a rear axle motor controller.

[0010] Furthermore, the gas storage unit includes a dry gas source unit, a four-circuit protection valve and a gas storage tank; The output end of the dry gas source unit is connected to the gas storage tank through a four-circuit protection valve; The air storage ends of the trailer valve, the front axle valve and the rear axle valve are all connected to the brake integrated system via air storage tanks.

[0011] Furthermore, the integrated brake system includes a front axle brake unit, a rear axle brake unit, and a trailer brake unit; The trailer valve is connected to the trailer brake unit via a trailer relay valve; The braking ends of the front axle valve and the rear axle valve are respectively connected to the front axle brake unit and the rear axle brake unit; The data output ends of the front axle brake unit, the rear axle brake unit and the trailer brake unit are connected to the input end of the simulation model module through a data acquisition device.

[0012] Furthermore, the front axle brake unit includes a front axle brake simulation air chamber, a front axle air chamber simulation load unit, and a first pressure sensor; The rear axle brake unit includes a rear axle brake simulation air chamber, a rear axle air chamber simulation load unit and a second pressure sensor; The trailer brake unit includes a trailer brake simulation air chamber, a trailer air chamber simulation load unit and a third pressure sensor.

[0013] Furthermore, the brake pedal mechanism is provided with a motion conversion mechanism, a pedaling simulation motor and a pedal motor controller; The driving end of the pedal motor controller is connected to the control end of the motor control host computer.

[0014] Furthermore, the hydraulic retarder system includes a retarder controller, a speed reduction mechanism, a retarder input shaft motor, a retarder input shaft motor controller, and a simulated coolant circulation tank; The data output terminal of the retarder controller is connected to the input terminal of the simulation model module via the CAN1 line; The driving end of the retarder input shaft motor controller is connected to the control end of the motor control host computer.

[0015] In a second aspect, the present invention further provides a hardware-in-the-loop simulation method for combined braking of an EBS system and a hydraulic retarder. The method is based on the hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder, and includes the following steps: By driving the brake pedal mechanism, a braking request is sent to the EBS system. The EBS system communicates with the hydraulic retarder system and the industrial computer via CAN1. Distribute braking force according to the current status of the vehicle and retarder, and request the hydraulic retarder system's braking torque to intervene in braking via the CAN1 bus; The brake air pressure is outputted through the air storage unit to the brake integrated system, and the real-time pressure signal is sent to the industrial computer through the brake integrated system and data acquisition equipment. The industrial computer calculates the current actual torque of the hydraulic retarder system based on the received pressure signal and obtained through CAN1, and combines it with the road model to calculate the wheel speed of each wheel, vehicle deceleration, vehicle posture information and transmission output shaft speed; The digital signal of each wheel speed is simulated through the front and rear axle wheel speed integration system, and this wheel speed signal is transmitted to the EBS system via an electrical signal to calculate the tire status and vehicle speed. At the same time, the industrial computer controls the motor to simulate the current retarder input speed, and inputs it into the hydraulic retarder system through the deceleration mechanism and mechanical connection. The hydraulic retarder system responds according to the current input shaft speed and the braking torque request from the EBS system, and outputs real-time braking torque. The real-time braking torque is transmitted to the EBS system and the industrial computer via CAN1 for braking torque feedback. The braking torque feedback result is obtained, completing the hardware-in-the-loop simulation of the combined braking of the EBS system and the hydraulic retarder system.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention provides a hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder. Through the control connection of the EBS system, the hydraulic retarder system, the industrial computer, the front and rear axle wheel speed integration system, the brake integration system, the air storage unit and the brake pedal mechanism, the test conditions can be adjusted arbitrarily to provide a rich variety of road conditions. Even complex test conditions can achieve combined braking testing, allowing R&D personnel to simulate various actual driving scenarios and comprehensively evaluate the performance of the system under different conditions, providing a sufficient basis for product optimization and improvement. All tests are carried out based on the bench system, avoiding the tedious preparation work and long test cycles in actual vehicle testing. The testing process is quick and convenient, greatly shortening the R&D cycle. The same working conditions can be repeatedly tested and verified. By comparing data, the influence of the external environment and accidental factors on the test results can be effectively eliminated, thereby improving the test success rate. This hardware-in-the-loop simulation system can not only perform combined braking tests, but also realize independent testing of a single EBS system or a hydraulic retarder. The system uses a real EBS system and hydraulic retarder, and the air circuit and other parameters are kept as consistent as possible with the actual vehicle. Wheel speed, air pressure, torque, brake pedal depression, etc. are all used as real signal input and output to the EBS system and retarder, ensuring the authenticity and accuracy of the signals during the test, allowing the system to more realistically simulate the actual braking process.

[0017] Furthermore, the input end of the simulation model module is equipped with a branch circuit, which connects to the integrated braking system through data acquisition equipment, and to the EBS system and hydraulic retarder system through the CAN1 line. This multi-source data acquisition method can comprehensively obtain data from all key components of the braking system, ensuring that the simulation model can accurately reflect the various states and parameter changes during the actual braking process. The input end of the simulation model module is equipped with a branch circuit, which connects to the integrated braking system through data acquisition equipment, and to the EBS system and hydraulic retarder system through the CAN1 line. This multi-source data acquisition method can comprehensively obtain data from all key components of the braking system, ensuring that the simulation model can accurately reflect the various states and parameter changes during the actual braking process.

[0018] Furthermore, the air storage terminals of the trailer valve, front axle valve, and rear axle valve are all connected to the integrated brake system via an air storage unit. This design ensures a stable air supply to each brake valve, simulating the air supply requirements of an actual vehicle during braking within the hardware-in-the-loop simulation system. The braking terminals of the front and rear axle valves are each connected to the integrated brake system, with their control inputs connected to the control outputs of the front and rear axle wheel speed integration systems, respectively. This enables the front and rear axle valves to precisely control braking based on wheel speed information provided by the front and rear axle wheel speed integration systems. The central controller is the core component of the EBS system, responsible for collecting and processing various sensor information and issuing brake control commands. Through its connection to the simulation model module, data from the central controller is transmitted to the simulation model in real time, enabling dynamic simulation based on actual system conditions. This real-time data exchange more accurately simulates the control logic and operating conditions of the EBS system during actual braking, providing a more realistic testing environment for brake system development and optimization. The foot valve is connected to the brake pedal mechanism to simulate the driver's control of the brake system through the brake pedal.

[0019] Furthermore, the drive ends of the front and rear axle speed systems are each connected to a motor control host computer, enabling the host computer to precisely control the speed of the front and rear axle speed servo motors according to test requirements. Centralized control of the front and rear axle speed systems by the motor control host computer facilitates coordinated adjustment of front and rear axle speeds. The front and rear axle speed systems are equipped with front and rear axle speed sensors, respectively, enabling real-time and accurate detection of front and rear axle speed information.

[0020] Furthermore, the dry air source unit ensures that the air source entering the brake system is dry, making the simulation test closer to actual working conditions and improving the accuracy and reliability of the test results. The four-circuit protection valve can also prevent mutual interference between the circuits and ensure the stability of the air source pressure in each circuit. The air tank can store a certain amount of compressed air. When the brake system requires a large amount of air, the air source can be quickly replenished to stabilize the air source pressure. In the hardware-in-the-loop simulation system, when simulating working conditions such as frequent braking and rapid inflation during the braking process, the air tank can ensure the stability of the air source pressure, so that the simulation test more realistically reflects the dynamic characteristics of the actual brake system.

[0021] Furthermore, the trailer valve is connected to the trailer brake unit via a trailer relay valve. The braking ends of the front axle valve and rear axle valve are connected to the front axle brake unit and rear axle brake unit, respectively, enabling the braking system to accurately distribute braking force to the front axle, rear axle, and trailer according to different braking requirements. The front axle brake unit, rear axle brake unit, and trailer brake unit are relatively independent, yet work in conjunction with each other. In the hardware-in-the-loop simulation system, each brake unit can be independently tested and controlled to study the performance characteristics of different brake units under different operating conditions. At the same time, by simulating braking scenarios during actual driving, the ability of the various brake units to work together is tested to ensure that the braking system can operate stably and reliably under various complex conditions.

[0022] Furthermore, the motion conversion mechanism converts the rotational motion of the pedal simulation motor into linear motion of the brake pedal, simulating the action of a driver pressing the brake pedal in a real vehicle. In a hardware-in-the-loop simulation system, testers can obtain an operating experience similar to actual driving, more realistically simulating the driver's braking intentions and providing an environment closer to actual operating conditions for braking system testing. The driver end of the pedal motor controller is connected to the motor control host computer, allowing the motor control host computer to flexibly control the motion of the pedal simulation motor according to different testing requirements. As part of the hardware-in-the-loop simulation system, the brake pedal mechanism is seamlessly integrated with other components such as the integrated braking system. Through the cooperation of the motion conversion mechanism and the pedal simulation motor, the driver's braking operation is converted into control signals for the braking system, ensuring the normal operation of the braking system.

[0023] Furthermore, the data output end of the retarder controller is connected to the input end of the simulation model module via the CAN1 line, so that various data of the hydraulic retarder system during operation, such as speed, torque, working status, etc., can be transmitted to the simulation model module in real time. The drive end of the retarder input shaft motor controller is connected to the motor control host computer, so that the motor control host computer can flexibly control the operation of the retarder input shaft motor according to different test requirements. Through data transmission via the CAN1 line and unified control by the motor control host computer, information interaction and collaborative control between the hydraulic retarder system and other systems are realized. The simulated coolant circulation box provides a simulated cooling environment for the hydraulic retarder system, which can simulate the cooling effect under different coolant flow, temperature and other conditions. In the hardware-in-the-loop simulation system, by controlling the operating parameters of the simulated coolant circulation box, the working performance and reliability of the hydraulic retarder system under different cooling conditions can be evaluated.

[0024] The present invention also provides a hardware-in-the-loop simulation method for combined braking of an EBS system and a hydraulic retarder. By driving the brake pedal mechanism to send a braking request to the EBS system, the braking operation of the driver in actual driving is simulated, so that the entire simulation process is close to the real scene from the source. The EBS system communicates with the hydraulic retarder system and the industrial computer respectively through CAN1, realizing information interaction between the systems; the braking force is distributed according to the current status of the vehicle and the retarder, and the hydraulic retarder system braking torque is requested to intervene in the braking through the CAN1 bus. This process fully considers the actual needs of the vehicle under different working conditions and simulates the reasonable distribution of braking force between the EBS system and the hydraulic retarder system during the actual braking process. The brake air pressure is output through the air storage unit to the brake integrated system, and the real-time pressure signal is sent to the industrial computer through the brake integrated system and the data acquisition equipment. At the same time, the industrial computer can also obtain the current actual torque of the hydraulic retarder system through CAN1. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 Schematic diagram of the principle structure of the hardware-in-the-loop simulation system for combined braking of the EBS system and the hydraulic retarder in an embodiment of the present invention; Figure 2 Flowchart of a hardware-in-the-loop simulation method for combined braking of an EBS system and a hydraulic retarder in an embodiment of the present invention; In the figure: 1. EBS system; 11. Trailer valve; 12. ABS valve; 13. Central controller; 14. Front axle valve; 15. Rear axle valve; 16. Foot valve; 2. Hydraulic retarder system; 21. Retarder controller; 22. Speed ​​reduction mechanism; 23. Retarder input shaft motor; 24. Retarder input shaft motor controller; 25. Simulated coolant circulation box; 3. Industrial computer; 31. Simulation model module; 32. Motor control host computer; 4. Front and rear axle wheel speed integration system; 41. Front axle wheel speed system; 411, front axle wheel speed sensor; 412, front axle sprocket; 413, front axle wheel speed servo motor; 414, front axle motor controller; 42. Rear axle wheel speed system; 421, rear axle wheel speed sensor; 422, rear axle sprocket; 423, rear axle wheel speed servo motor; 424, rear axle motor controller; 5. Braking integrated system; 51. Front axle brake unit; 511, front axle brake simulation air chamber; 512, front axle air chamber simulation load unit; 513, first pressure sensor; 52. Rear axle brake unit; 521, rear axle brake simulation air chamber; 522, rear axle air chamber simulation load unit; 523, second pressure sensor; 53. Trailer brake unit; 531. Trailer brake simulation air chamber; 532. Trailer air chamber simulation load unit; 533. Third pressure sensor; 6. Data acquisition equipment; 7. Trailer relay valve; 8. Gas storage unit; 81. Dry gas source unit; 82. Four-circuit protection valve; 83. Gas storage tank; 9. Brake pedal mechanism; 91. Motion conversion mechanism; 92. Pedal simulation motor; 93. Pedal motor controller. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0026] The purpose of the present invention is to provide a hardware-in-the-loop simulation system and method for combined braking of an EBS system and a hydraulic retarder, so as to solve the technical problems in the prior art such as long actual vehicle testing and verification cycle, insufficient test conditions, difficulty in obtaining road conditions, and low test efficiency.

[0027] The present invention is described in further detail below with reference to the accompanying drawings: See also Figure 1In one embodiment of the present invention, a hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder is provided, comprising an EBS system 1, a hydraulic retarder system 2, an industrial computer 3, a front and rear axle wheel speed integration system 4, a brake integration system 5, an air storage unit 8, and a brake pedal mechanism 9; a data acquisition end of the industrial computer 3 is connected to the data output ends of the EBS system 1, the hydraulic retarder system 2, and the brake integration system 5, respectively; a control end of the industrial computer 3 is connected to the hydraulic retarder system 2, the front and rear axle wheel speed integration system 4, and a drive end of the brake pedal mechanism 9, respectively, wherein the brake pedal mechanism 9 is connected to the EBS system 1; a braking end of the EBS system 1 is connected to the brake integration system 5, and an air storage end of the EBS system 1 is connected to the brake integration system 5 via the air storage unit 8; a control output end of the front and rear axle wheel speed integration system 4 is connected to a control input end of the EBS system 1; in this embodiment, solid lines represent electrical signal connections, dashed lines represent motor control signals, dot-dash lines represent air path connections, and dotted lines represent vehicle CAN communication.

[0028] Specifically, the industrial computer 3 includes a simulation model module 31 and a motor control host computer 32; the input end branch of the simulation model module 31 is set, one branch is connected to the data output end of the brake integration system 5 through the data acquisition equipment 6, and the other branch is connected to the data output end of the EBS system 1 and the hydraulic retarder system 2 respectively through the CAN1 line; the control end of the motor control host computer 32 is respectively connected to the hydraulic retarder system 2, the front and rear axle wheel speed integration system 4 and the driving end of the brake pedal mechanism 9.

[0029] Among them, the EBS system 1 includes a trailer valve 11, an ABS valve 12, a central controller 13, a front axle valve 14, a rear axle valve 15 and a foot valve 16; the air storage ends of the trailer valve 11, the front axle valve 14 and the rear axle valve 15 are all connected to the brake integration system 5 through the air storage unit 8; the trailer valve 11 is connected to the brake integration system 5 through the trailer relay valve 7; the braking ends of the front axle valve 14 and the rear axle valve 15 are respectively connected to the brake integration system 5; the control input ends of the front axle valve 14 and the rear axle valve 15 are respectively connected to the control output ends of the front and rear axle wheel speed integration system 4; the data output end of the central controller 13 is connected to the input end of the simulation model module 31 through the CAN1 line; the foot valve 16 is connected to the brake pedal mechanism 9.

[0030] Among them, the front and rear axle wheel speed integration system 4 includes a front axle wheel speed system 41 and a rear axle wheel speed system 42; the driving ends of the front axle wheel speed system 41 and the rear axle wheel speed system 42 are respectively connected to the control end of the motor control host computer 32; the control output ends of the front axle wheel speed system 41 and the rear axle wheel speed system 42 are respectively connected to the control input ends of the front axle valve 14 and the rear axle valve 15; wherein, the front axle wheel speed system 41 includes a front axle wheel speed sensor 411, a front axle sprocket 412, a front axle wheel speed servo motor 413 and a front axle motor controller 414; the rear axle wheel speed system 42 includes a rear axle wheel speed sensor 421, a rear axle sprocket 422, a rear axle wheel speed servo motor 423 and a rear axle motor controller 424.

[0031] In this embodiment, the air storage unit 8 includes a dry air source unit 81, a four-circuit protection valve 82 and an air storage tank 83; the output end of the dry air source unit 81 is connected to the air storage tank 83 through the four-circuit protection valve 82; the air storage ends of the trailer valve 11, the front axle valve 14 and the rear axle valve 15 are all connected to the brake integrated system 5 through the air storage tank 83.

[0032] In this embodiment, the integrated braking system 5 includes a front axle braking unit 51, a rear axle braking unit 52 and a trailer braking unit 53; the trailer valve 11 is connected to the trailer braking unit 53 through the trailer relay valve 7; the braking ends of the front axle valve 14 and the rear axle valve 15 are respectively connected to the front axle braking unit 51 and the rear axle braking unit 52; the data output ends of the front axle braking unit 51, the rear axle braking unit 52 and the trailer braking unit 53 are connected to the input end of the simulation model module 31 through the data acquisition device 6.

[0033] Among them, the front axle brake unit 51 includes a front axle brake simulation air chamber 511, a front axle air chamber simulation load unit 512 and a first pressure sensor 513; the rear axle brake unit 52 includes a rear axle brake simulation air chamber 521, a rear axle air chamber simulation load unit 522 and a second pressure sensor 523; the trailer brake unit 53 includes a trailer brake simulation air chamber 531, a trailer air chamber simulation load unit 532 and a third pressure sensor 533.

[0034] In this embodiment, the brake pedal mechanism 9 is provided with a motion conversion mechanism 91 , a pedal simulation motor 92 and a pedal motor controller 93 ; the driving end of the pedal motor controller 93 is connected to the control end of the motor control host computer 32 .

[0035] Specifically, the hydraulic retarder system 2 includes a retarder controller 21, a deceleration mechanism 22, a retarder input shaft motor 23, a retarder input shaft motor controller 24 and a simulated coolant circulation box 25; the data output end of the retarder controller 21 is connected to the input end of the simulation model module 31 through the CAN1 line; the drive end of the retarder input shaft motor controller 24 is connected to the control end of the motor control host computer 32.

[0036] In this embodiment, components are selected, arranged, and integrated according to requirements to form a hardware-in-the-loop simulation system capable of testing the combined braking of the EBS system 1 and the hydraulic retarder system 2 under various operating conditions. This system's test conditions are adjustable, allowing for a wide variety of road conditions and even complex combined braking conditions. All tests are conducted on a test bench system, making testing quick, convenient, and cost-effective, with easy data acquisition and recording, and a comfortable and safe environment for testers. A wide variety of test vehicle models can be tested, enabling rapid switching and easy comparison. Universal equipment reduces both practical and economic costs of assembly and disassembly. Repeated testing and verification of the same operating conditions are easily performed, eliminating test uncertainty caused by environmental factors and incidental factors, resulting in a high test success rate. Preliminary testing and verification of program logic during combined braking development improves development efficiency, reduces unnecessary vehicle testing, and reduces costs. This hardware-in-the-loop simulation system not only supports combined braking testing but also enables independent testing of either the EBS system 1 or the hydraulic retarder system 2. The overall system has a high degree of reusability. This system uses a real EBS system 1 and hydraulic retarder system 2. The air circuit and other parameters are kept as consistent as possible with the actual vehicle. Wheel speed, air pressure, torque, brake pedal depression, etc. are all used as real signal input and output for EBS system 1 and hydraulic retarder system 2. The vehicle and road models are digitally modeled. The test results are closer to the actual vehicle test results, and the authenticity of the data is guaranteed, which can provide accurate and reasonable test results for engineering developers.

[0037] In summary, the present invention provides a hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder. Through the control connection of the EBS system 1, the hydraulic retarder system 2, the industrial computer 3, the front and rear axle wheel speed integration system 4, the brake integration system 5, the air storage unit 8 and the brake pedal mechanism 9, the test conditions can be adjusted arbitrarily, and a rich variety of road conditions can be provided. Even complex test conditions can realize combined braking tests, so that R&D personnel can simulate various actual driving scenarios and comprehensively evaluate the performance of the system under different conditions, providing a sufficient basis for product optimization and improvement. All tests are carried out based on the bench system, avoiding the tedious preparation work and long test cycle in the actual vehicle test. The testing process is fast and convenient, greatly shortening the R&D cycle. The same working condition can be repeatedly tested and verified. By comparing the data, the influence of the external environment and accidental factors on the test results can be effectively eliminated, thereby improving the test success rate. This hardware-in-the-loop simulation system can not only perform combined braking tests, but also realize independent testing of a single EBS system 1 or a hydraulic retarder system 2. The system uses a real EBS system 1 and hydraulic retarder system 2. The air circuit and other parameters are kept as consistent as possible with the actual vehicle. Wheel speed, air pressure, torque, brake pedal depression, etc. are all used as real signal input and output for the EBS system 1 and hydraulic retarder system 2. This ensures the authenticity and accuracy of the signals during the test and enables the system to more realistically simulate the actual braking process.

[0038] Example 2 This embodiment further provides a hardware-in-the-loop simulation method for combined braking of an EBS system and a hydraulic retarder. The method is based on the hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder described above and includes the following steps: By driving the brake pedal mechanism 9 to send a braking request to the EBS system 1, the EBS system 1 communicates with the hydraulic retarder system 2 and the industrial computer 3 via CAN 1; Distribute braking force according to the current status of the vehicle and retarder, and request the hydraulic retarder system 2 braking torque to intervene in braking through the CAN1 bus; The brake air pressure is outputted through the air storage unit 8 to the brake integrated system 5, and the real-time pressure signal is sent to the industrial computer 3 through the brake integrated system 5 and the data acquisition device 6. The industrial computer 3 calculates the wheel speed, vehicle deceleration, vehicle posture information and transmission output shaft speed based on the received pressure signal and the current actual torque of the hydraulic retarder system 2 obtained through the CAN 1, and combines the road model solution to obtain the wheel speed of each wheel, the vehicle deceleration, the vehicle posture information and the transmission output shaft speed; The digital signal of each wheel speed is simulated by the front and rear axle wheel speed integration system 4, and the wheel speed signal is transmitted to the EBS system 1 via an electrical signal to calculate the tire status and vehicle speed. At the same time, the industrial computer 3 controls the motor to simulate the current retarder input speed, and inputs it into the hydraulic retarder system 2 through the deceleration mechanism 22 and the mechanical connection. The hydraulic retarder system 2 responds according to the current input shaft speed and the braking torque request from the EBS system 1, and outputs the real-time braking torque. The real-time braking torque is transmitted to the EBS system 1 and the industrial computer 3 via CAN1 for braking torque feedback, and the braking torque feedback result is obtained, completing the hardware-in-the-loop simulation of the combined braking of the EBS system 1 and the hydraulic retarder system 2.

[0039] according to Figure 2 As shown, in this embodiment, the tester first powers on the system and supplies air, operates the upper computer to enable the input shaft motor, the wheel speed simulation motor, and the pedal simulation motor, and turns on the model to receive the air chamber pressure signal. At this point, the preparations are complete. Next, the parameters of the vehicle to be tested are configured, and the model is turned on during the test. The motor is then controlled to simulate the brake pedal being pressed, or the tester directly simulates the driver pressing the brake pedal according to the test conditions. The test model and system interact and complete the test, and the entire test data is recorded. When testing other conditions subsequently, the vehicle parameters or road type can be changed to enter the next test. After the system has been configured once, the set parameters can be saved in the project. Subsequent tests only require enabling the corresponding links to complete the operation. The testing process is simple and efficient.

[0040] In summary, the present invention provides a hardware-in-the-loop simulation method for combined braking of an EBS system and a hydraulic retarder. By driving the brake pedal mechanism 9 to send a braking request to the EBS system 1, the method simulates the driver's braking operation in actual driving, making the entire simulation process close to the real scene from the source. The EBS system 1 communicates with the hydraulic retarder system 2 and the industrial computer 3 respectively via CAN1, realizing information exchange between the various systems; the braking force is distributed according to the current state of the vehicle and the retarder, and the hydraulic retarder system 2 braking torque is requested to intervene in the braking via the CAN1 bus. This process fully considers the actual needs of the vehicle under different working conditions and simulates the reasonable distribution of braking force between the EBS system 1 and the hydraulic retarder system 2 during actual braking. The brake air pressure is output to the brake integrated system 5 through the air storage unit 8, and the real-time pressure signal is sent to the industrial computer 3 via the brake integrated system 5 and the data acquisition device 6. At the same time, the industrial computer 3 can also obtain the current actual torque of the hydraulic retarder system 2 via CAN1.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder, characterized in that: It includes an EBS system (1), a hydraulic retarder system (2), an industrial computer (3), a front and rear axle wheel speed integration system (4), a brake integration system (5), an air storage unit (8), and a brake pedal mechanism (9); The data acquisition end of the industrial control computer (3) is respectively connected to the data output ends of the EBS system (1), the hydraulic retarder system (2) and the brake integration system (5); The control end of the industrial control computer (3) is respectively connected to the hydraulic retarder system (2), the front and rear axle wheel speed integration system (4), and the drive end of the brake pedal mechanism (9), wherein the brake pedal mechanism (9) is connected to the EBS system (1); The braking end of the EBS system (1) is connected to the brake integration system (5), and the air storage end of the EBS system (1) is connected to the brake integration system (5) via the air storage unit (8); the control output end of the front and rear axle wheel speed integration system (4) is connected to the control input end of the EBS system (1).

2. A hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder according to claim 1, characterized in that: The industrial control computer (3) includes a simulation model module (31) and a motor control host computer (32); The input end branch of the simulation model module (31) is provided with one branch connected to the data output end of the brake integration system (5) through the data acquisition device (6), and the other branch connected to the data output ends of the EBS system (1) and the hydraulic retarder system (2) respectively through the CAN1 line; The control end of the motor control host computer (32) is respectively connected to the hydraulic retarder system (2), the front and rear axle wheel speed integration system (4), and the drive end of the brake pedal mechanism (9).

3. The hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder according to claim 2, characterized in that: The EBS system (1) includes a trailer valve (11), an ABS valve (12), a central controller (13), a front axle valve (14), a rear axle valve (15), and a foot valve (16); The air storage ends of the trailer valve (11), the front axle valve (14) and the rear axle valve (15) are all connected to the brake integrated system (5) via the air storage unit (8); The trailer valve (11) is connected to the brake integration system (5) via the trailer relay valve (7); The braking ends of the front axle valve (14) and the rear axle valve (15) are respectively connected to the brake integration system (5); the control input ends of the front axle valve (14) and the rear axle valve (15) are respectively connected to the control output ends of the front and rear axle wheel speed integration system (4); The data output terminal of the central controller (13) is connected to the input terminal of the simulation model module (31) via the CAN1 line; The foot valve (16) is connected to the brake pedal mechanism (9).

4. The hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder according to claim 3 is characterized in that: The front and rear axle wheel speed integration system (4) includes a front axle wheel speed system (41) and a rear axle wheel speed system (42); The driving ends of the front axle wheel speed system (41) and the rear axle wheel speed system (42) are respectively connected to the control end of the motor control host computer (32); the control output ends of the front axle wheel speed system (41) and the rear axle wheel speed system (42) are respectively connected to the control input ends of the front axle valve (14) and the rear axle valve (15); The front axle wheel speed system (41) includes a front axle wheel speed sensor (411), a front axle gear plate (412), a front axle wheel speed servo motor (413), and a front axle motor controller (414); The rear axle wheel speed system (42) comprises a rear axle wheel speed sensor (421), a rear axle gear plate (422), a rear axle wheel speed servo motor (423), and a rear axle motor controller (424).

5. The hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder according to claim 3 is characterized in that: The gas storage unit (8) comprises a dry gas source unit (81), a four-circuit protection valve (82) and a gas storage tank (83); The output end of the dry gas source unit (81) is connected to the gas storage tank (83) via a four-circuit protection valve (82); The air storage ends of the trailer valve (11), the front axle valve (14) and the rear axle valve (15) are all connected to the brake integration system (5) via an air storage tank (83).

6. The hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder according to claim 3, characterized in that: The brake integration system (5) includes a front axle brake unit (51), a rear axle brake unit (52), and a trailer brake unit (53); The trailer valve (11) is connected to the trailer brake unit (53) via the trailer relay valve (7); The braking ends of the front axle valve (14) and the rear axle valve (15) are respectively connected to the front axle brake unit (51) and the rear axle brake unit (52); The data output ends of the front axle brake unit (51), the rear axle brake unit (52), and the trailer brake unit (53) are connected to the input end of the simulation model module (31) via a data acquisition device (6).

7. The hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder according to claim 6, characterized in that: The front axle brake unit (51) comprises a front axle brake simulation air chamber (511), a front axle air chamber simulation load unit (512), and a first pressure sensor (513); The rear axle brake unit (52) comprises a rear axle brake simulation air chamber (521), a rear axle air chamber simulation load unit (522), and a second pressure sensor (523); The trailer brake unit (53) comprises a trailer brake simulation air chamber (531), a trailer air chamber simulation load unit (532), and a third pressure sensor (533).

8. The hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder according to claim 3, characterized in that: The brake pedal mechanism (9) is provided with a motion conversion mechanism (91), a pedal simulation motor (92), and a pedal motor controller (93); The driving end of the pedal motor controller (93) is connected to the control end of the motor control host computer (32).

9. The hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder according to claim 2, characterized in that: The hydraulic retarder system (2) includes a retarder controller (21), a speed reduction mechanism (22), a retarder input shaft motor (23), a retarder input shaft motor controller (24), and a simulated coolant circulation box (25); The data output end of the retarder controller (21) is connected to the input end of the simulation model module (31) via the CAN1 line; The driving end of the retarder input shaft motor controller (24) is connected to the control end of the motor control host computer (32).

10. A hardware-in-the-loop simulation method for combined braking of an EBS system and a hydraulic retarder, based on a hardware-in-the-loop simulation system for combined braking of an EBS system and a hydraulic retarder according to any one of claims 1 to 9, characterized in that: The process includes the following: By driving the brake pedal mechanism (9), a brake request is sent to the EBS system (1), and the EBS system (1) communicates with the hydraulic retarder system (2) and the industrial control computer (3) through CAN1 respectively; The braking force is distributed according to the current status of the vehicle and the retarder, and the hydraulic retarder system (2) is requested to intervene in the braking through the CAN1 bus; The brake air pressure is outputted through the air storage unit (8) to the brake integrated system (5), and the real-time pressure signal is sent to the industrial control computer (3) through the brake integrated system (5) and the data acquisition device (6). The industrial control computer (3) calculates the wheel speed of each wheel, the deceleration of the whole vehicle, the vehicle posture information and the transmission output shaft speed based on the received pressure signal and the current actual torque of the hydraulic retarder system (2) obtained through CAN1, and solves the road model to obtain the wheel speed of each wheel, the deceleration of the whole vehicle, the vehicle posture information and the transmission output shaft speed; The digital signal of each wheel speed is simulated by the front and rear axle wheel speed integration system, and the wheel speed signal is transmitted to the EBS system (1) through an electrical signal to calculate the tire status and vehicle speed. At the same time, the industrial control computer (3) controls the motor to simulate the current retarder input speed, and inputs it into the hydraulic retarder system (2) through the deceleration mechanism and mechanical connection. The hydraulic retarder system (2) responds according to the current input shaft speed and the braking torque request from the EBS system (1), and outputs the real-time braking torque. The real-time braking torque is transmitted to the EBS system (1) and the industrial control computer (3) through CAN1 for braking torque feedback, and the braking torque feedback result is obtained, thereby completing the hardware-in-the-loop simulation of the combined braking of the EBS system (1) and the hydraulic retarder system (2).

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