A wheel drive automobile electric wheel vertical load dynamic simulation device and use method

Abstract

This invention discloses a dynamic simulation device and method for vertical load on the electric wheel of a hub-driven automobile, belonging to the field of vehicle engineering technology. It solves the technical problem of inaccurate simulations caused by the lack of vertical loading in electric wheel test platforms, which do not accurately reflect actual vehicle conditions. The device includes: a test bench, an electric wheel-suspension-body assembly, a longitudinal load simulation device, a vertical load simulation device, a host computer, and a load controller. The load controller issues corresponding commands to the electric wheel-suspension-body assembly, the longitudinal load simulation device, and the vertical load simulation device, and provides feedback on the corresponding information from these devices. This invention compensates for the load transfer under actual vehicle operating conditions, making up for the lack of a dynamic vertical load adjustment device in the entire test platform, and facilitating research on vehicle dynamics performance control considering load transfer.

Description

Technical Field

[0001] This invention relates to the field of vehicle engineering technology, specifically to a load simulation test device and its usage method for a hub-driven automotive powertrain system. Background Technology

[0002] In-wheel drive vehicles offer advantages such as simple and diverse layouts and flexible and efficient control, providing more technical implementation paths for intelligent vehicle dynamics control and representing the most promising form of electric vehicle. However, the high integration and high speed of the electric wheels in in-wheel drive vehicles also present significant challenges to ride comfort and safety control. To overcome the technological bottlenecks in in-wheel drive vehicle applications, researchers have conducted extensive research on the control of the electric wheel's own dynamic characteristics, the control of active / semi-active suspension systems suitable for in-wheel drive, and the coordinated control of vehicle dynamics and drive systems.

[0003] In conducting the aforementioned research, a dedicated experimental platform for wheel-driven vehicles is an indispensable scientific experimental device. To save on the cost of scientific experimental equipment and improve experimental efficiency, with the rapid development of virtual simulation technology, researchers now mostly adopt a combined "virtual-real" approach to scientific research. The same applies to the wheel-driven vehicle experimental platform; that is, a combined "virtual-real" technique is used to build the experimental platform, with three-quarters of the vehicle model being virtual and one-quarter being physical. One of the key technologies regarding the physical part is the dynamic simulation of the load on the electric wheels.

[0004] Dynamic load simulation of electric wheels typically includes planar (lateral and longitudinal) dynamic loads and vertical dynamic loads. The applicant has already made breakthroughs in planar dynamic load simulation methods and has been granted a national invention patent. Regarding vertical dynamic loads, which reflect the load transfer during vehicle operation, the accuracy and real-time performance of vertical dynamic load simulation directly affect the drive control and driving stability control effects of hub-driven vehicles. Furthermore, previous research indicates that load transfer in hub-driven vehicles is more severe than in traditional drive vehicles. Research has revealed that existing vehicle vertical load simulation methods and devices fail to meet the requirements for collaborative control and "virtual-real" synchronization in terms of both simulation accuracy and real-time performance.

[0005] In the research and development of key vehicle technologies, test benches play a crucial role in advancing technological development. The main purpose of test benches is to realistically simulate the actual operating conditions of vehicles, allowing key technical methods and indicators to be reasonably verified under laboratory conditions. During actual vehicle operation, the electric wheels, as the primary power unit, require thorough simulation of their stress conditions, which is essential for the overall testing effectiveness of the test platform. Existing research largely focuses on simulating the planar loads (longitudinal and lateral loads) on the electric wheels, while neglecting the vertical loads.

[0006] Therefore, it is necessary to conduct in-depth research on the simulation methods and experimental devices for vertical dynamic loads of hub-driven vehicles in order to improve the accuracy and real-time performance of vertical dynamic load simulation, and thus provide important scientific research equipment for overcoming key technical bottlenecks in the application of hub-driven vehicles. Summary of the Invention

[0007] To address the problems existing in the prior art, the present invention provides a load simulation test device and method for wheel hub driven vehicle power system, the purpose of which is to make the operation state of the wheel hub driven vehicle dynamic performance test platform more realistic in the laboratory environment and the test data more reliable.

[0008] The technical solution adopted in this invention is as follows:

[0009] A dynamic simulation device for vertical load on an electric wheel of a hub-driven vehicle is characterized by comprising: a test bench, an electric wheel-suspension-body assembly, a longitudinal load simulation device, a vertical load simulation device, a load controller, and a control terminal. The vertical load simulation device includes a vertical load loading device and a vertical load compensation device. The longitudinal load simulation device is longitudinally mounted on the test bench and is used to simulate the longitudinal load of the vehicle under actual operating conditions. The body portion of the electric wheel-suspension-body assembly is connected to the vertical load simulation device. The lower end face of the electric wheel portion of the electric wheel-suspension-body assembly contacts the sensor portion of the longitudinal load simulation device. The vertical load loading device is mounted on the test bench. The vertical load loading device is used to simulate the static vertical load of the vehicle under actual operating conditions. The vertical load compensation device is installed on the test bench and located below the electric wheel-suspension-body assembly. The upper end of the vertical load compensation device is connected to the lower end of the body part of the electric wheel-suspension-body assembly. The vertical load compensation device is used to simulate the dynamic vertical load of the vehicle under actual operating conditions. The load controller is used to issue corresponding commands to the electric wheel-suspension-body assembly, the longitudinal load simulation device, and the vertical load simulation device, and to provide feedback on the corresponding information of the electric wheel-suspension-body assembly, the longitudinal load simulation device, and the vertical load simulation device. The load controller is electrically connected to the control terminal.

[0010] Preferably, the vertical load compensation device adopts an integrated planetary roller screw electric cylinder, which is vertically mounted on the test bench, and the upper piston part of the electric cylinder is connected to the lower end of the body part of the electric wheel-suspension-body device.

[0011] Furthermore, the vertical load compensation device includes: a guide plate, a piston rod, a guide frame, a guide rod, a cylinder, a housing, a servo motor, an electric cylinder bracket, and a pressure sensor. The top of the electric cylinder bracket is connected to the outer side of the guide frame, and the bottom of the electric cylinder bracket is mounted on the test bench. The guide frame is connected to the upper flange of the cylinder. The piston rod, guide rod, cylinder, housing, and servo motor are connected sequentially from top to bottom to form an electric cylinder. The piston rod is connected to the lower end of the body part of the electric wheel-suspension-body device through the guide plate. The lower end face of the electric wheel part of the electric wheel-suspension-body device is in contact with the pressure sensor.

[0012] Preferably, the electric wheel-suspension-body assembly is a quarter-part electric wheel-suspension-body system of the original vehicle, including: an electric wheel drive system, a steering system, a braking system, a double wishbone suspension, and a body system. The electric wheel drive system is composed of wheel rims, tires, and a hub motor and its controller. The steering system is composed of a steering actuator and a steering controller. The braking system is a disc brake system, composed of friction pads, a brake pump, and its controller. The double wishbone suspension is composed of an upper control arm, a lower control arm, an electromagnetic valve-type shock absorber, and an air spring. The body system is a quarter-part body structure of the original vehicle. The electric wheel drive system, steering system, braking system, double wishbone suspension, and body system are connected and combined to form a quarter-part electric wheel-suspension-body system of the original vehicle.

[0013] Preferably, the longitudinal load simulation device includes: a dynamometer, a torque and speed sensor, a coupling, and a roller assembly. The dynamometer, torque and speed sensor, coupling, and roller assembly are connected sequentially from left to right to form the longitudinal load simulation device. The right side of the roller assembly is connected to the vertical load compensation device.

[0014] Preferably, the vertical load simulation device includes: a frame, a slide rail, a slide groove, and a vehicle frame. The frame is mounted on a test bench, the slide rail is vertically mounted on the frame, the slide groove is slidably connected to the slide rail, and the vehicle frame is connected to the slide groove.

[0015] A method for using a dynamic simulation device for vertical load on an electric wheel of a hub-driven automobile includes the following steps:

[0016] S1: Preparations before testing;

[0017] S2: Adjust the vehicle body mass using weights according to the vehicle body parameters to match the vehicle model;

[0018] S3: Set the vehicle model parameters and simulated operating conditions in the system, and send command signals to the hub motor controller, braking system controller and steering system controller through the load controller to send corresponding commands for driving, braking and steering conditions, and get feedback on the drive torque and speed information of the hub motor;

[0019] S4: The dynamometer controller calculates the simulated longitudinal load value and the expected simulated vertical load value of the vehicle based on the set vehicle parameters and simulated operating conditions.

[0020] S5: Start the test system. The torque and speed sensor detects the torque and speed on the roller, and the pressure sensor obtains the pressure signal at the roller. The torque, speed and pressure signals are then transmitted to the load controller. The pressure signal is converted into the actual vertical load on the electric wheel.

[0021] S6: The load controller compares the actual vertical load and actual longitudinal load simulation values ​​obtained in S5 with the vertical load simulation values ​​and longitudinal load simulation values ​​calculated in S4. Based on the comparison signal, the load controller combines the speed closed-loop control strategy to realize the dynamic simulation of the longitudinal load; the load controller also combines the thrust closed-loop control strategy to realize the dynamic simulation of the vertical load.

[0022] In summary, the beneficial effects of the present invention are as follows:

[0023] 1. This invention focuses on the application of vertical loads on a traditional hub-driven vehicle performance testing platform. By combining a variable-mass vehicle body and an electric cylinder and its control system, it achieves static and dynamic simulation of vertical loads on the electric wheels. An external vertical load dynamic simulation system is connected to the bottom of the chassis. The rotational motion of the servo motor output shaft is converted into linear motion through a ball screw and applied to the vehicle body. This further applies thrust to the electric wheels, compensating for the load transfer under actual vehicle operating conditions. This overcomes the deficiency of the entire testing platform lacking a dynamic vertical load adjustment device, facilitating research on vehicle dynamics performance control considering load transfer.

[0024] 2. This invention makes the vertical dynamic simulation more in line with the actual situation through vertical dynamic simulation compensation, thereby enabling the entire test system to achieve dynamic and accurate simulation in both longitudinal and vertical directions, thus better matching the load value of the vehicle under actual working conditions.

[0025] 3. This invention leverages the advantages of electric cylinders, such as high thrust, long stroke, small space occupancy, high control precision, and low cost. Through structural design, pressure sensors are placed at the bottom of the drum to accurately collect the actual vertical load value of the electric wheel. This value is then fed back to the control system to form a closed-loop control, which helps improve the accuracy and real-time performance of the vertical load dynamic simulation of the entire test platform, making the test results of wheel hub driven vehicle dynamics more realistic and reliable. Attached Figure Description

[0026] The present invention will be described by way of example and with reference to the accompanying drawings, wherein:

[0027] Figure 1 This is a schematic diagram of the overall structure of the simulation device in this invention;

[0028] Figure 2 This is a schematic diagram of the vertical load compensation device in this invention;

[0029] Figure 3 This is a schematic diagram of the load simulation control system structure in this invention;

[0030] Icons: 1-Frame, 2-Slide rail, 3-Slide groove, 4-Solenoid valve type shock absorber, 5-Upper swing arm, 6-Displacement sensor, 7-Steering system, 8-Lower swing arm, 9-Test bench, 10-Vertical load compensation device, 1001-Guide plate, 1002-Piston rod, 1003-Guide frame, 1004-Guide rod, 1005-Cylinder block, 1006-Housing, 1007-Servo motor, 1008-Electric cylinder bracket, 11-Pressure sensor, 12-Roller assembly, 13-Coupling, 14-Torque speed sensor, 15-Dynamometer, 16-Electric wheel drive system, 17-Brake system, 18-Air spring, 19-Frame, 20-Body system. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0032] In the description of the embodiments of this application, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] The following is combined Figures 1-3 The present invention will be described in detail below.

[0034] Example 1

[0035] A dynamic simulation device for vertical load on an electric wheel of a hub-driven vehicle includes: a test bench 9, an electric wheel-suspension-body assembly, a longitudinal load simulation device, a vertical load simulation device, a vertical load compensation device 10, a host computer, and a load controller. The test bench 9 is placed horizontally, and the longitudinal load simulation device is mounted longitudinally on the test bench 9. The longitudinal load simulation device is used to simulate the longitudinal load of the vehicle under actual operating conditions. The body portion of the electric wheel-suspension-body assembly is connected to the vertical load simulation device, and the lower end face of the electric wheel portion of the electric wheel-suspension-body assembly contacts the sensor portion of the longitudinal load simulation device. The vertical load simulation device is mounted on the test bench and is used to simulate the static vertical load of the vehicle under actual operating conditions. The load compensation device 10 is installed on the test bench 9. The vertical load compensation device 10 is located below the electric wheel-suspension-body assembly. The upper end of the vertical load compensation device 10 is connected to the lower end of the body part of the electric wheel-suspension-body assembly. The vertical load compensation device 10 is used to simulate the dynamic vertical load of the vehicle under actual operating conditions. The host computer serves as a control terminal. The host computer sets the vehicle model parameters and simulated operating conditions. The load controller is electrically connected to the host computer. The load controller is used to issue corresponding commands to the electric wheel-suspension-body assembly, the longitudinal load simulation device, the vertical load simulation device, and the vertical load compensation device 10, and to provide feedback on the corresponding information of the electric wheel-suspension-body assembly, the longitudinal load simulation device, the vertical load simulation device, and the vertical load compensation device 10.

[0036] The vertical load compensation device 10 is an electric cylinder with an integral planetary roller screw. The electric cylinder is vertically mounted on the test bench 9, and the upper piston part of the electric cylinder is connected to the lower end of the body part of the electric wheel-suspension-body device.

[0037] The vertical load compensation device 10 includes: a guide plate 1001, a piston rod 1002, a guide frame 1003, a guide rod 1004, a cylinder body 1005, a housing 1006, a servo motor 1007, an electric cylinder bracket 1008, and a pressure sensor 11. The top of the electric cylinder bracket 1008 is connected to the outer side of the guide frame 1003, and the bottom of the electric cylinder bracket 1008 is mounted on the test bench 9. The guide frame 1003 is connected to the upper flange of the cylinder body 1005. The piston rod 1002, guide rod 1004, cylinder body 1005, housing 1006, and servo motor 1007 are connected sequentially from top to bottom to form an electric cylinder. The piston rod 1002 is connected to the lower end of the body part of the electric wheel-suspension-body device through the guide plate 1001. The lower end face of the electric wheel part of the electric wheel-suspension-body device is in contact with the pressure sensor 11.

[0038] The electric wheel-suspension-body assembly is a quarter-part electric wheel-suspension-body system of the original vehicle, including: an electric wheel drive system 16, a steering system 7, a braking system 17, a double wishbone suspension, and a body system 20. The electric wheel drive system 16 is composed of wheel rims, tires, and a hub motor and its controller. The steering system 7 is composed of a steering actuator and a steering controller. The braking system 17 is a disc brake system, composed of friction pads, a brake pump, and its controller. The double wishbone suspension is composed of an upper control arm 5, a lower control arm 8, an electromagnetic valve-type shock absorber 4, and an air spring 18. The body system 20 is a quarter-part body structure of the original vehicle. The electric wheel drive system 16, steering system 7, braking system 17, double wishbone suspension, and body system 20 are connected and combined to form the quarter-part electric wheel-suspension-body system of the original vehicle.

[0039] The longitudinal load simulation device includes: a dynamometer 15, a torque and speed sensor 14, a coupling 13, and a roller device 12. The dynamometer 15, the torque and speed sensor 14, the coupling 13, and the roller device 12 are connected in sequence from left to right to form the longitudinal load simulation device. The right side of the roller device 12 is connected to the vertical load compensation device 10.

[0040] The vertical load simulation device includes: a frame 1, a slide rail 2, a slide groove 3, and a vehicle frame 19. The frame 1 is mounted on a test bench 9, the slide rail 2 is vertically mounted on the frame 1, the slide groove 3 is slidably connected to the slide rail 2, and the vehicle frame 19 is connected to the slide groove 3.

[0041] A method for using a dynamic simulation device for vertical load on an electric wheel of a hub-driven automobile includes the following steps:

[0042] S1: Connect the host computer and each controller to the power supply. After verifying that the power supply is matched correctly, turn on the main switch. At this time, the entire system enters the running mode.

[0043] S2: Adjust the vehicle body mass using weights according to the vehicle body parameters to match the vehicle model;

[0044] S3: Set the vehicle model parameters and simulated operating conditions in the system, and send corresponding commands for driving, braking and steering conditions to the hub motor controller, braking system controller and steering system controller in the form of CAN signals through the load controller, and get the drive torque and speed information of the hub motor back.

[0045] S4: The dynamometer controller calculates the simulated longitudinal load value and the expected simulated vertical load value of the vehicle based on the set vehicle parameters and simulated operating conditions.

[0046] S5: Start the test system. The torque and speed sensor detects the torque and speed on the roller, and the pressure sensor obtains the pressure signal at the roller. The torque, speed and pressure signals are transmitted to the load controller through the I / O interface. The pressure signal is converted into the actual vertical load on the electric wheel.

[0047] S6: The load controller compares the actual vertical load and actual longitudinal load simulation values ​​obtained in S5 with the vertical load simulation values ​​and longitudinal load simulation values ​​calculated in S4. Based on the comparison signal, the load controller combines the speed closed-loop control strategy to realize the dynamic simulation of the longitudinal load; the load controller also combines the thrust closed-loop control strategy to realize the dynamic simulation of the vertical load.

[0048] Example 2

[0049] Based on the original "electric wheel-suspension-body" system [1] of the whole vehicle, this invention improves and designs a set of vertical load dynamic simulation device for testing the dynamic performance of wheel hub driven vehicles. The overall hardware structure layout is as follows: Figure 1As shown. The main function of this system is to provide real-time vertical load excitation for the "electric wheel-suspension-body" system based on the vehicle's quarter section. In the vehicle's quarter section, the wheel rim tires and the wheel hub motor and its controller together form the electric wheel drive system 16; the steering actuator and steering controller together form the steering system 7; the braking system 17 adopts a disc brake system, which consists of friction pads, brake pumps (upper pump and lower pump) and their controllers; the suspension adopts a double wishbone suspension (upper control arm 5, lower control arm 8), equipped with electromagnetic valve type shock absorbers 4 and air springs 18; the body system 20 changes the body mass by stacking mass blocks. One end of the hub motor is bolted to the wheel rim, while the other end is secured to restrict the circumferential and axial movement of the hub motor stator via a key and nut. The steering knuckle is connected to the upper and lower control arms 5 and 8 via T-shaped hinges, and the other end of the double wishbone suspension is fitted with a bushing and connected to the frame via bolts and control arm mounting brackets. A slider is fixed on the frame and slides up and down on the side of the base 1 via a guide rail. In addition, a height sensor 6 is installed between the lower control arm 8 and the frame, and an acceleration sensor is attached to the frame 19. The frame 1 is bolted to the slide rail 2 and the test bench 9, and the cooperation of the slide groove 3 and the slide rail 2 gives the body system 20 and the frame 19 vertical freedom. To fully simulate the actual vehicle operating environment in the laboratory, the load simulation system includes two modules: a longitudinal load simulation module consisting of a dynamometer 15, a torque and speed sensor 14, a coupling 13, and a roller device 12; and a vertical load simulation system consisting of a linear motor module 10 and a pressure sensor 11.

[0050] The vertical load simulation system employs an integral planetary roller screw electric cylinder, a system with linear motion, as the load actuation device. For example... Figure 3As shown, the electric cylinder mainly consists of a servo motor 1007, a coupling and its housing 1006, and a cylinder body 1005. The electric cylinder uses electricity as its direct power source. The servo motor 1007 drives the nut inside the cylinder body 1005 to rotate, and the helical motion between components is converted into linear motion of the lead screw (located inside the cylinder body). The lead screw then drives the piston rod 1002 to perform reciprocating linear motion. Its performance is similar to that of a hydraulic cylinder. Compared to a hydraulic cylinder, the electric cylinder has a simpler structure, lower cost, smaller space occupation, and is easier to install. It also has advantages such as high thrust and large stroke. Furthermore, by controlling the rotational motion of the servo motor to control the linear motion, the control method is more convenient, accurate, and has better real-time performance. The guide frame 1003 of the guide bracket assembly is connected to the front flange on the cylinder body 1005. The guide plate 1001 is bolted to the frame 19 and the guide rod 1004, and threaded to the piston rod 1002. The electric cylinder bracket 1008 is L-shaped, with its two outer planes connected to the guide bracket 1003 and the slotted test bench 9 respectively via bolts. Utilizing the above-mentioned electric cylinder's motion principle and actual structural arrangement, the thrust of the electric cylinder is applied to the frame 19, and further amplified to the electric wheel via the frame-suspension-electric wheel 1 / 4 structural section, thus compensating for the electric wheel's vertical load. The actual magnitude of the vertical load is obtained through the pressure sensor 11 and sent to the host computer to form a closed-loop control, making the simulation of the vertical load more closely resemble the vehicle's actual motion.

[0051] By integrating the vertical load dynamic simulation system into the entire measurement and control platform, the following results were obtained: Figure 3 The diagram shows a load simulation control system. The entire load simulation control system is divided into two parts: a vertical control module and a longitudinal control module.

[0052] In the longitudinal load simulation control module, combined with Figure 2 As can be seen from the longitudinal load simulation device, a torque and speed sensor is installed between the output shaft of the electric dynamometer and the drive shaft of the drum; the dynamometer controller and the hub motor controller are both connected to the load controller via a CAN bus; the torque and speed sensor transmits the analog signal to the load controller through the I / O interface; the load controller and the host computer interact via a LIN connection.

[0053] In the vertical load simulation control module, combined with Figure 3 As shown in the vertical complex simulation device, the power supply provides power to the electric cylinder servo motor driver. The servo motor driver and the electric cylinder servo motor are connected via three-phase AC power, and the load controller exchanges signals via a CAN bus. The electric cylinder thrust output shaft is connected to the vehicle frame, enabling the load compensation (force) to act on the electric wheel through the transmission path of the vehicle body-suspension-electric wheel.

[0054] The method for using the wheel hub drive vehicle powertrain load simulation test system includes the following steps:

[0055] S1: Connect the host computer and each controller to the power supply. After verifying that the power supply is matched correctly, turn on the main switch. At this time, the entire system enters the running mode.

[0056] S2: Adjust the vehicle body mass using weights according to the vehicle body parameters to match the vehicle model;

[0057] S3: Set the vehicle model parameters and simulated operating conditions in the system, and send corresponding commands for driving, braking and steering conditions to the hub motor controller, braking system controller and steering system controller in the form of CAN signals through the load controller, and get the drive torque and speed information of the hub motor back.

[0058] S4: The dynamometer controller calculates the simulated longitudinal load value and the expected simulated vertical load value of the vehicle based on the set vehicle parameters and simulated operating conditions.

[0059] S5: Start the test system. The torque and speed sensor detects the torque and speed on the roller, and the pressure sensor obtains the pressure signal at the roller. The torque, speed and pressure signals are transmitted to the load controller through the I / O interface. The pressure signal is converted into the actual vertical load on the electric wheel.

[0060] S6: The load controller compares the actual vertical load and actual longitudinal load simulation values ​​obtained in S5 with the vertical load simulation values ​​and longitudinal load simulation values ​​calculated in S4. Based on the comparison signal, the load controller combines the speed closed-loop control strategy to realize the dynamic simulation of the longitudinal load; the load controller also combines the thrust closed-loop control strategy to realize the dynamic simulation of the vertical load.

[0061] During actual vehicle operation, varying operating conditions, especially during acceleration, deceleration, and braking, result in different degrees of load transfer. This load transfer further affects the adhesion between the electric wheel and the road surface, impacting vehicle dynamics performance testing and control research to varying degrees. This invention compensates for the load transfer under actual vehicle operating conditions by connecting a vertical load dynamic simulation system externally to the bottom of the chassis. This overcomes the lack of vertical load compensation control in the entire test platform, facilitating research on vehicle dynamics performance control that considers load transfer.

[0062] In load simulation systems, real-time performance and model complexity are contradictory. Higher model complexity leads to lower simulation feasibility, and dynamic load simulation devices should be designed with maximum integration to reduce force transmission lag. Therefore, this invention proposes using an electric cylinder as the actuator in a vertical load simulation device. The rotational motion of the servo motor output shaft is converted into linear motion through a ball screw and applied to the vehicle body. This further compensates for the force in the vertical direction of the electric wheel. By strategically arranging pressure sensors, the actual vertical load on the electric wheel is collected and monitored in real time, and feedback is sent to the controller to form a closed-loop control, thus solving the problem of real-time compensation control of the vertical load on the electric wheel.

[0063] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

Claims

1. A vertical load dynamic simulation device for an electric wheel of a wheel-hub drive vehicle, characterized by, include: The test bench (9), electric wheel-suspension-body assembly, longitudinal load simulation device, vertical load simulation device, load controller, and control terminal are included. The vertical load simulation device includes a vertical load loading device and a vertical load compensation device (10). The longitudinal load simulation device is longitudinally mounted on the test bench (9) and is used to simulate the longitudinal load of the vehicle under actual operating conditions. The body part of the electric wheel-suspension-body assembly is connected to the vertical load simulation device. The lower end face of the electric wheel part of the electric wheel-suspension-body assembly is in contact with the sensor part of the longitudinal load simulation device. The vertical load loading device is mounted on the test bench and is used to simulate the longitudinal load of the vehicle under actual operating conditions. The static vertical load under operating conditions, the vertical load compensation device (10) is installed on the test bench (9), the vertical load compensation device (10) is located below the electric wheel-suspension-body device, the upper end of the vertical load compensation device (10) is connected to the lower end of the body part of the electric wheel-suspension-body device, the vertical load compensation device (10) is used to simulate the dynamic vertical load of the vehicle under actual operating conditions, the load controller is used to issue corresponding commands to the electric wheel-suspension-body device, the longitudinal load simulation device, and the vertical load simulation device, and to feed back the corresponding information of the electric wheel-suspension-body device, the longitudinal load simulation device, and the vertical load simulation device, the load controller is electrically connected to the control terminal; The vertical load compensation device (10) adopts an electric cylinder with an integral planetary roller screw. The electric cylinder is vertically installed on the test bench (9). The upper piston part of the electric cylinder is connected to the lower end of the body part of the electric wheel-suspension-body device. The vertical load compensation device (10) includes: a guide plate (1001), a piston rod (1002), a guide frame (1003), a guide rod (1004), a cylinder body (1005), a housing (1006), a servo motor (1007), an electric cylinder bracket (1008), and a pressure sensor (11). The top of the electric cylinder bracket (1008) is connected to the outside of the guide frame (1003), and the bottom of the electric cylinder bracket (1008) is mounted on the test bench (9). The piston rod (1002), guide rod (1004), cylinder (1005), housing (1006), and servo motor (1007) are connected to the upper flange of the cylinder body (1005) in sequence from top to bottom to form an electric cylinder. The piston rod (1002) is connected to the lower end of the body part of the electric wheel-suspension body device through the guide plate (1001). The lower end face of the electric wheel part of the electric wheel-suspension-body device is in contact with the pressure sensor (11). The pressure sensor (11) is arranged at the bottom of the roller.

2. The vertical load dynamic simulation device for electric wheel of hub-driven automobile according to claim 1, characterized in that, The electric wheel-suspension-body assembly is the electric wheel-suspension-body system of the original vehicle 1 / 4 part, including: electric wheel drive system (16), steering system (7), braking system (17), double wishbone suspension, and body system (20). The electric wheel drive system (16) is composed of wheel rim tires and wheel hub motor and its controller. The steering system (7) is composed of steering actuator and steering controller. The braking system (17) is a disc brake system, composed of friction pads, brake pump and its controller. The double wishbone suspension is composed of upper control arm (5), lower control arm (8), electromagnetic valve type shock absorber (4) and air spring (18). The body system (20) is the original vehicle 1 / 4 body structure. The electric wheel drive system (16), steering system (7), braking system (17), double wishbone suspension and body system (20) are connected and combined to form the electric wheel-suspension-body system of the original vehicle 1 / 4 part.

3. The vertical load dynamic simulation device for electric wheel of hub-driven automobile according to claim 1, characterized in that, The longitudinal load simulation device includes: a dynamometer (15), a torque and speed sensor (14), a coupling (13), and a roller device (12). The dynamometer (15), the torque and speed sensor (14), the coupling (13), and the roller device (12) are connected in sequence from left to right to form the longitudinal load simulation device. The right side of the roller device (12) is connected to the vertical load compensation device (10).

4. The vertical load dynamic simulation device for electric wheel of hub-driven automobile according to claim 1, characterized in that, The vertical load simulation device includes: a frame (1), a slide rail (2), a slide groove (3), and a vehicle frame (19). The frame (1) is installed on the test bench (9), the slide rail (2) is installed vertically on the frame (1), the slide groove (3) is slidably connected to the slide rail (2), and the vehicle frame (19) is connected to the slide groove (3).

5. The device for dynamic simulation of vertical load on the electric wheel of a hub-driven automobile according to claim 1, characterized in that, It also includes a host computer, and the control terminal is a host computer.

6. A method of using the dynamic simulation device for vertical load on the electric wheel of a hub-driven automobile according to any one of claims 1-5, characterized in that, Includes the following steps: S1: Preparations before testing; S2: Adjust the vehicle body mass using weights according to the vehicle body parameters to match the vehicle model; S3: Set the vehicle model parameters and simulated operating conditions in the system, and send command signals to the hub motor controller, braking system controller and steering system controller through the load controller to send corresponding commands for driving, braking and steering conditions, and get feedback on the drive torque and speed information of the hub motor; S4: The dynamometer controller calculates the simulated longitudinal load value and the expected simulated vertical load value of the vehicle based on the set vehicle parameters and simulated operating conditions. S5: Start the test system. The torque and speed sensor detects the torque and speed on the roller, and the pressure sensor obtains the pressure signal at the roller. The torque, speed and pressure signals are then transmitted to the load controller. The pressure signal is converted into the actual vertical load on the electric wheel. S6: The load controller compares the actual vertical load and actual longitudinal load simulation values ​​obtained in S5 with the vertical load simulation values ​​and longitudinal load simulation values ​​calculated in S4. Based on the comparison signal, the load controller combines the speed closed-loop control strategy to realize the dynamic simulation of the longitudinal load; the load controller also combines the thrust closed-loop control strategy to realize the dynamic simulation of the vertical load.

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