KC test loading method, system and equipment and computer readable storage medium

Abstract

Kamp; Kamp; the invention discloses a C test loading method, system and device and a computer readable storage medium. The C test loading method comprises the following steps: calculating tire force and vehicle body attitude parameters by using a vehicle dynamics simulation model based on vehicle transmission and control parameters, wheel center attitude and position, tire vertical force and steering wheel angle and torque parameters at the current moment; applying tire force to each tire by using the wheel platform, and applying vehicle body attitude parameters to the test vehicle by using the central platform; calculating the position and attitude of the wheel center and the vertical force of the tire at the next moment by using a wheel center position and attitude measurement system, and updating the position and attitude of the wheel center and the vertical force of the tire to the vehicle dynamics simulation model; and repeating the steps until the test reaches a preset end condition, and stopping the circulation. And the limitation of a traditional single-direction static working condition test is overcome.

Description

Technical Field

[0001] The present application relates to the field of K&C experiments of automotive chassis suspensions, and particularly relates to a K&C test loading method, system, device and computer-readable storage medium. Background Art

[0002] K&C (the initials of Kinematic and Compliance) characteristics describe the changes of the chassis (mainly the suspension + steering system) after receiving external inputs, mainly referring to the attitude changes of the wheels (tires). Since a vehicle can run on the ground entirely relying on the tires in contact with the ground, and the attitude of the tires has a great impact on the performance of the chassis. It is a direct influencer of vehicle handling stability, the soul of the suspension, and the DNA of the overall vehicle handling stability and comfort.

[0003] In related technologies, although traditional K&C tests can provide performance data of a vehicle under static conditions in a single direction, they cannot simulate the continuous dynamic response of the vehicle under the multi-directional coupling action of force and displacement during actual operation. Summary of the Invention

[0004] The present application provides a K&C test loading method, system, device and computer-readable storage medium, which can solve the technical problem in related technologies that although traditional K&C tests can provide performance data of a vehicle under static conditions in a single direction, they cannot simulate the continuous dynamic response of the vehicle under the multi-directional coupling action of force and displacement during actual operation.

[0005] In a first aspect, an embodiment of the present application provides a K&C test loading method, and the K&C test loading method includes:

[0006] Based on the vehicle transmission and control parameters, wheel center attitude and position, tire vertical force, and steering wheel angle and torque parameters at the current moment, calculate tire forces and vehicle body attitude parameters using a vehicle dynamics simulation model;

[0007] Apply the tire forces to each tire using a wheel platform, and apply the vehicle body attitude parameters to the test vehicle using a central platform;

[0008] Calculate the position and attitude of the wheel center and the tire vertical force at the next moment using a wheel center position and attitude measurement system, and update them to the vehicle dynamics simulation model;

[0009] Repeat the above steps in a loop until the test reaches a predetermined end condition and stops the loop.

[0010] In combination with the first aspect, in one embodiment, before calculating the tire forces and vehicle body attitude parameters by using a vehicle dynamics simulation model based on the vehicle transmission and control parameters, wheel center attitude and position, tire vertical force, and steering wheel angle and torque parameters at the current moment, the method further includes:

[0011] Calculating the vehicle transmission and control parameters at the current moment of the vehicle based on the current state of the vehicle and the set driving conditions.

[0012] In combination with the first aspect, in one embodiment, the current state of the vehicle includes tire pressure parameters, allowable error of load, load parameters, and suspension height parameters, and the set driving conditions include road conditions, target speed, target steering wheel angle, target trajectory, and target lateral acceleration.

[0013] In combination with the first aspect, in one embodiment, before calculating the tire forces and vehicle body attitude parameters by using a vehicle dynamics simulation model based on the vehicle transmission and control parameters, wheel center attitude and position, tire vertical force, and steering wheel angle and torque parameters at the current moment, the method further includes:

[0014] Importing the steering parameters into the steering wheel robot in the test bench, and using the wheel center position and attitude measurement system of the test bench to output the wheel center attitude and position, tire vertical force, and steering wheel angle and torque parameters at the current moment.

[0015] In combination with the first aspect, in one embodiment, the vehicle transmission and control parameters include steering, throttle, brake, clutch, and gearbox parameters.

[0016] In combination with the first aspect, in one embodiment, the tire force parameters include tire longitudinal force and tire lateral force parameters.

[0017] In a second aspect, an embodiment of the present application provides a K&C test specific condition loading system, and the K&C test specific condition loading system includes:

[0018] A tire force and vehicle body attitude calculation module, which is configured to calculate tire force and vehicle body attitude parameters by using a vehicle dynamics simulation model based on the vehicle transmission and control parameters, wheel center attitude and position, tire vertical force, and steering wheel angle and torque parameters at the current moment;

[0019] An execution module, which is configured to apply the tire forces to each tire by using a wheel platform, and apply the vehicle body attitude parameters to the test vehicle by using a central platform;

[0020] An update module, which is configured to calculate the position and attitude of the wheel center and the tire vertical force at the next moment by using the wheel center position and attitude measurement system, and update them to the vehicle dynamics simulation model;

[0021] A loop iteration module, which is used to repeat the above steps in a loop until the test reaches a predetermined end condition and then stops the loop.

[0022] Combined with the second aspect, in an embodiment, the K&C test specific working condition loading system includes: a vehicle transmission and control parameter calculation module, which is used to calculate the vehicle transmission and control parameters at the current moment of the vehicle based on the current state of the vehicle and the set driving working condition.

[0023] In a third aspect, an embodiment of the present application provides a K&C test specific working condition loading device, which includes a processor, a memory, and a K&C test specific working condition loading program stored on the memory and executable by the processor. When the K&C test specific working condition loading program is executed by the processor, the steps of the K&C test loading method described in some of the above embodiments are implemented.

[0024] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a K&C test specific working condition loading program is stored. When the K&C test specific working condition loading program is executed by a processor, the steps of the K&C test loading method described in some of the above embodiments are implemented.

[0025] The beneficial effects brought by the technical solutions provided by the embodiments of the present application include:

[0026] Determine the vehicle transmission and control parameters, wheel center attitude and position, tire vertical force, and steering wheel angle and torque parameters at the initial moment (T n ). Using the vehicle dynamics simulation model, calculate the tire force and vehicle body attitude parameters based on the parameters at the current moment. These parameters reflect the dynamic response of the vehicle under the current working condition; apply the tire force calculated by the simulation to each tire through the wheel platform to simulate the force condition of the tire during actual driving, and apply the vehicle body attitude parameters calculated by the simulation to the test vehicle through the central platform, so that the test vehicle can simulate the vehicle body attitude change similar to that during actual driving; use the wheel center position and attitude measurement system to measure and calculate in real time the parameters at the next moment (T n+1Parameters such as the wheel center position and attitude, and the vertical tire force; update the parameters at the next moment to the vehicle dynamics simulation model as the input for the next round of simulation. Iterate in a loop. When the test reaches the predetermined end condition (such as time, mileage, or a specific event), stop the loop, process and analyze the collected data, and evaluate the vehicle's performance under different working conditions. Through loop iteration and parameter update, the continuous dynamic response of the vehicle under different working conditions can be simulated, overcoming the limitations of traditional static tests in a single direction. Combining vehicle dynamics simulation and actual vehicle tests can more accurately reflect the combined dynamic performance of the vehicle under the multi-directional coupling of force and displacement during actual driving. Description of the Drawings

[0027] Figure 1 It is a schematic flow chart of an embodiment of the K&C test loading method of the present application;

[0028] Figure 2 It is a schematic hardware structure diagram of the K&C test specific working condition loading equipment involved in the embodiment of the present application;

[0029] Figure 3 It is a schematic structure diagram of the K&C test bench in the embodiment of the present application.

[0030] In the figure: 1. Central platform; 2. Wheel platform; 3. Wheel center position and attitude measurement system. Detailed Embodiment

[0031] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application.

[0032] First, some technical terms in the present application are explained to facilitate the understanding of the present application by those skilled in the art.

[0033] The K&C (the initials of Kinematic and Compliance respectively) characteristics describe the changes generated by the chassis (mainly the suspension + steering system) after receiving an external input, mainly referring to the attitude changes of the wheels (tires). Because a vehicle can run on the ground entirely relying on the tires in contact with the ground, and the attitude of the tires has a great impact on the performance of the chassis. It is a direct influencer of vehicle handling stability, the soul of the suspension, and the DNA of the overall vehicle handling stability and comfort.

[0034] K (Kinematic) characteristics - The kinematic characteristics of the suspension, which are the changes in the spatial position and attitude of the wheels caused by the input of the road surface and steering displacement (the up-and-down movement and left-and-right rotation of the wheels). It studies the geometric spatial position movement (determined by hard points) characteristics of the suspension and steering system, without considering the influence of mass and force.

[0035] C (Compliance) characteristics - The elastic kinematic characteristics of the suspension, which are the changes in the spatial position and attitude of the wheels caused by the deformation of the suspension due to the input of external forces (the forces and torques acting on the tire from the ground). It studies the deformation caused by the action of forces, such as the force-induced deformation of springs, bushings, stabilizer bars, and components.

[0036] The static condition in a single direction refers to the static (i.e., non-dynamic, not changing with time) state of the vehicle in a specific direction (for example, only considering the forward or backward direction of the vehicle, or only considering the roll direction of the vehicle) during vehicle performance testing.

[0037] As Figure 3 shown, the K&C test bench mainly includes a central platform 1, four wheel platforms 2, and four wheel center position and attitude measurement systems 3. Among them, the vehicle body is fixedly connected to the central platform 1, which can simulate the vertical movement, roll, and pitch movements of the vehicle body. The wheel platform 2 can only rotate and translate in a plane parallel to the ground plane, and can measure the forces and torques acting on the tire at the same time. Its surface friction coefficient is relatively high, and it can apply forces and torques to the wheels by moving, simulating the forces and torques acting on the wheels when the actual vehicle is driving on the road surface. The wheel center position and attitude measurement system 3 has a six-degree-of-freedom encoder link structure, and can obtain the position and attitude at the wheel center through the readings of six encoders. The wheel center position and attitude measurement system 3 can collect the force conditions of the tire during the test process.

[0038] To make the objectives, technical solutions, and advantages of this application clearer, the following will further describe the embodiments of this application in detail with reference to the accompanying drawings.

[0039] In the first aspect, referring to Figure 1 , Figure 1 is a schematic flowchart of an embodiment of the K&C test loading method of this application. As Figure 1 shown, the K&C test loading method includes:

[0040] S100: Based on the vehicle transmission and control parameters, wheel center attitude and position, tire vertical force, and steering wheel angle and torque parameters at the current moment, use the vehicle dynamics simulation model to calculate the tire force and vehicle body attitude parameters;

[0041] S200: Use the wheel platform to apply the tire force to each tire, and use the central platform to apply the vehicle body attitude parameters to the test vehicle;

[0042] S300: Calculate the position, attitude, and vertical tire force of the wheel center at the next moment using the wheel center position and attitude measurement system, and update them to the vehicle dynamics simulation model;

[0043] S400: Repeat the above steps in a loop until the test reaches the predetermined end condition and then stop the loop.

[0044] In this embodiment, S100 calculates the tire force and vehicle body attitude parameters using the vehicle dynamics simulation model based on the vehicle transmission and control parameters, wheel center attitude and position, vertical tire force, and steering wheel angle and torque parameters at the current moment. This step is the core of the simulation. It predicts the changes in tire force and vehicle body attitude through the vehicle dynamics simulation model according to the current vehicle state parameters, which is the basis for simulating real driving conditions; S200 applies the tire force to each tire using the wheel platform and applies the vehicle body attitude parameters to the test vehicle using the central platform. This step is the key step to convert the simulation results into actual physical effects. By the wheel platform and the central platform, the calculated tire force and vehicle body attitude parameters are applied to the test vehicle to simulate real driving conditions; S300 calculates the position, attitude, and vertical tire force of the wheel center at the next moment using the wheel center position and attitude measurement system, and updates them to the vehicle dynamics simulation model. This step is a measurement and feedback process. Through the wheel center position and attitude measurement system, the actual wheel center position, attitude, and vertical tire force of the test vehicle at the current moment (T n+1 ) are obtained, and these data are updated into the vehicle dynamics simulation model for the next round of simulation calculation; S400 repeats the above steps in a loop until the test reaches the predetermined end condition and then stops the loop. This step is the loop part of the entire test loading method. By continuously repeating the steps of S100 to S300, the dynamic response of the vehicle over continuous time can be simulated. When the test reaches the predetermined end condition (such as time, mileage, specific events, etc.), the loop stops, and the collected data is processed and analyzed to evaluate the performance of the vehicle under different working conditions. Through loop iteration and parameter update, the continuous dynamic response of the vehicle under different working conditions can be simulated, overcoming the limitations of traditional static tests in a single direction. Combining vehicle dynamics simulation and actual vehicle tests can more accurately reflect the combined dynamic performance of the vehicle under the multi-directional coupling of force and displacement during actual driving.

[0045] Among them, when conducting vehicle dynamic response simulation tests, for the determination of the three end conditions of "time", "mileage", and "specific events", the following methods and principles are usually followed. Time, as a condition for ending the test, is usually a fixed value or range preset before the test starts. During the test, the system will record the duration of the test in real time and compare it with the preset time condition. When the test time reaches or exceeds the preset time condition, the system will automatically stop the test and save the relevant data. Mileage, as another condition for ending the test, is also preset according to the test requirements. The system will record the driving mileage of the vehicle in real time through an odometer or similar sensor installed on the vehicle. When the driving mileage reaches or exceeds the preset mileage condition, the test will also automatically stop, and data collection and processing will be carried out. Specific events refer to certain specific situations or states that may occur during the test and are directly related to vehicle performance or safety. These events can be that the vehicle reaches a certain specific speed, acceleration, temperature and other parameter thresholds, or the vehicle has a certain failure or abnormal state, such as battery power depletion, motor overheating, etc.

[0046] Further, in one embodiment, before S100, the following steps are further included:

[0047] S001: Calculate the vehicle transmission and control parameters at the current moment of the vehicle based on the current state of the vehicle and the set driving conditions.

[0048] In this embodiment, in the K&C test loading method, step S001 (calculate the vehicle transmission and control parameters at the current moment of the vehicle based on the current state of the vehicle and the set driving conditions) is added, which further improves the entire simulation process and enhances the accuracy and practicality of the simulation; based on the current state of the vehicle and the set driving conditions, the transmission and control parameters of the vehicle at the current moment can be calculated. These parameters are important inputs for the vehicle dynamics simulation model and determine the behavior of the model during the simulation. By adding step S001, the K&C test loading method can more accurately simulate the continuous dynamic response of the vehicle under different working conditions. First, it ensures the accuracy and timeliness of the vehicle transmission and control parameters, making the simulation results closer to the actual driving situation. Second, it improves the flexibility and scalability of the simulation because the transmission and control parameters can be adjusted according to different driving conditions and vehicle states, thus simulating more types of driving scenarios.

[0049] Further, in one embodiment, in S001, the current state of the vehicle includes tire pressure parameters, load allowance error, load parameters, and suspension height parameters, and the set driving conditions include road conditions, target speed, target steering wheel angle, target trajectory, and target lateral acceleration.

[0050] In this embodiment, the tire pressure parameter refers to the current air pressure value of the vehicle tires, which is crucial for the driving stability and safety of the vehicle; the load tolerance refers to the allowable deviation range between the actual load and the set load when the vehicle is loaded with goods or passengers; the load parameter is the total weight currently borne by the vehicle, including the vehicle's own weight, the weight of passengers, and the weight of goods, etc.; the suspension height parameter refers to the current height of the vehicle suspension system, which affects the driving stability and passability of the vehicle; the road condition describes the type of road on which the vehicle will travel, the road surface condition (such as straight, curved, ramp, bumpy, etc.), and the road environment (such as weather, visibility, etc.); the target speed is the driving speed that the vehicle plans to reach or maintain; the target steering wheel angle is the angle by which the steering wheel needs to be turned when the vehicle is performing a specific driving task; the target trajectory is the route or trajectory that the vehicle plans to travel; the target lateral acceleration is the value of the lateral acceleration that the vehicle expects to reach when turning or changing lanes. These parameters together constitute a detailed description of the current state of the vehicle and the set driving conditions in step S001, providing basic data support for the subsequent calculation of vehicle transmission and control parameters and the implementation of the entire K&C test loading method.

[0051] Further, in one embodiment, before S100, the following steps are further included:

[0052] S002: Import the steering parameters into the steering wheel robot in the test bench, and use the wheel center position and attitude measurement system of the test bench to output the wheel center attitude and position, tire vertical force, and steering wheel angle and torque parameters at the current moment.

[0053] In this embodiment, S002 imports the steering parameters into the steering wheel robot in the test bench, and uses the wheel center position and attitude measurement system of the test bench to output the wheel center attitude and position, tire vertical force, steering wheel angle and torque parameters at the current moment. First, the pre-set steering parameters (such as steering wheel angle, steering speed, etc.) are imported into the steering wheel robot in the test bench. These parameters are determined based on simulated driving conditions and vehicle characteristics, aiming to ensure that the steering operation during the test process is consistent with the actual situation. Next, the wheel center position and attitude measurement system of the test bench is used to capture and output the wheel center attitude and position at the current moment (i.e., a specific time point) in real time. This data is crucial for analyzing the kinematic characteristics of the suspension under dynamic loading. At the same time, the system also measures and outputs the tire vertical force, which is an important indicator for evaluating the elastic characteristics (C characteristics) of the suspension. The change in the tire vertical force reflects the elastic deformation of the suspension when it is stressed. In addition, the steering wheel angle and torque parameters will also be measured and output. These parameters are of great significance for understanding the influence of the steering system on the K&C characteristics of the suspension, especially when conducting a steering test. The implementation of step S002 ensures that the K&C test can capture the key kinematic and dynamic characteristics of the suspension under dynamic loading while accurately simulating driving conditions. These data provide a solid foundation for subsequent analysis and optimization.

[0054] Furthermore, in one embodiment, in S100, the vehicle transmission and control parameters include steering, throttle, brake, clutch, and gearbox parameters.

[0055] In this embodiment, the steering parameters mainly involve the steering angle of the steering wheel, the steering speed, and the steering torque, etc. These parameters determine the change of the vehicle's driving direction and are one of the most direct control inputs during driving. By adjusting the steering parameters, precise steering and stable driving of the vehicle can be achieved; the throttle parameter mainly refers to the opening of the throttle or the stroke of the accelerator pedal, which directly controls the output power and speed of the engine, thereby affecting the acceleration performance and driving speed of the vehicle. Precise control of the throttle parameter is crucial for achieving smooth acceleration and fuel-efficient driving of the vehicle; the braking parameters include the stroke of the brake pedal, the braking pressure, and the braking torque of the brake, etc. These parameters determine the braking performance and parking stability of the vehicle. By reasonably adjusting the braking parameters, smooth braking of the vehicle and rapid response during emergency braking can be achieved; the clutch parameters mainly involve the engagement and disengagement states of the clutch, as well as the transmitted torque of the clutch, etc. The clutch is an important component connecting the engine and the transmission, and precise control of its parameters is crucial for achieving smooth starting and shifting of the vehicle; the transmission parameters include the gear position of the transmission, the shifting timing, and the shifting smoothness, etc. The transmission is an important part of the vehicle's drive system. By adjusting the transmission parameters, the best power transmission and fuel economy of the vehicle under different working conditions can be achieved. To sum up, the steering, throttle, braking, clutch, and transmission parameters in the vehicle drive and control parameters together constitute the basis of the vehicle's dynamic performance and driving control. By precisely controlling and adjusting these parameters, driving requirements such as stable driving, smooth acceleration, rapid braking, and efficient shifting of the vehicle can be achieved.

[0056] Further, in one embodiment, in S100, the tire force parameters include tire longitudinal force and tire lateral force parameters.

[0057] In this embodiment, the tire longitudinal force refers to the force generated by the tire in the vehicle's driving direction, which directly affects the acceleration and braking performance of the vehicle. When the vehicle accelerates, the tire generates a forward longitudinal force to push the vehicle forward; when the vehicle brakes, the tire generates a backward longitudinal force to decelerate or stop the vehicle; the magnitude of this parameter is closely related to the tire grip, the vehicle weight, and the intensity of acceleration or braking. The tire lateral force refers to the force generated by the tire in the direction perpendicular to the vehicle's driving direction, which is crucial for the steering stability of the vehicle and for resisting external forces such as lateral wind. When the vehicle turns, the tire generates a lateral force to enable the vehicle to travel along the curve without deviating from the track. In addition, when affected by external forces such as lateral wind, the tire lateral force can also help the vehicle maintain stability and prevent rollover or loss of control. The magnitude of the tire lateral force is related to factors such as the tire side slip characteristics, the vehicle weight, and the steering angle. To sum up, the tire longitudinal force and tire lateral force parameters are indispensable tire force parameters in step S001, and they jointly determine the dynamic performance and handling stability of the vehicle.

[0058] Further, in one embodiment, before S100, it further includes:

[0059] S000: Prepare the K&C test bench and the vehicle.

[0060] Specifically, first, calibrate the tire pressure to ensure that the difference between the actual tire pressure and the required tire pressure is within ±10 kPa. Record the results in the table shown in Table 1 below.

[0061]

[0062]

[0063] Table 1

[0064] Second, adjust the axle load of the vehicle to the design value or the state required by the manufacturer. The error shall be executed according to Table 2. The difference between the actual axle load and the required axle load is within ±10 kg, the difference between the left and right wheel axle loads is within ±5 kg, and the difference between the actual total weight and the required total weight is within ±20 kg. Record the results in the table shown in Table 3 below.

[0065]

[0066] Table 2

[0067]

[0068] Table 3

[0069] Third, for the air spring suspension, after the vehicle is parked on a horizontal ground, switch the suspension attitude to the design value or the state required by the manufacturer. After waiting for the adjustment to complete, turn off the air spring height adjustment function and record the height of each suspension.

[0070]

[0071]

[0072] Table 4

[0073] Fourth, perform parameter positioning measurement according to the load state required by the manufacturer. Measure the four-wheel alignment parameters of the vehicle and make appropriate adjustments to keep them within the required range. Record the values before and after the adjustment in the table shown in Table 5 below.

[0074]

[0075] Table 5

[0076] Fifth, check the steering system, suspension system, and tire treads, and make adjustments, tightenings, and lubrications according to the regulations. Only when it is determined that the vehicle meets the specified technical conditions can the test be carried out.

[0077] Sixthly, clean the vehicle. Mainly clean the chassis and tires of the vehicle. Prevent sand grains from falling on the guide rails during K&C measurement. Sand grains are likely to damage the guide rails and affect the system performance. After the vehicle is cleaned, wait for the vehicle to dry before installing it on the measurement bench.

[0078] Seventhly, confirm the clamping position of the vehicle body. The clamping points on the body skirt need to meet two requirements: A. There are no obstacles interfering with the fixture near the clamping points. B. The clamped part of the vehicle body needs to have sufficient strength, with a height ≥ 16 mm, a length ≥ 150 mm, a thickness ≥ 2.5 mm, and a flat surface. If the clamping position does not meet the above requirements, appropriate treatment should be carried out according to the characteristics of the vehicle skirt, or a special adapter fixture should be processed. The clamping point should be as close as possible to the outer end in the Y direction and as close as possible to the wheel end in the X direction. At the same time, calculate and confirm the clamping reliability to ensure that it cannot be disengaged during loading. For vehicles without skirts, auxiliary fixtures should be considered for processing or welding (riveting) extension plates for the jaws to clamp. Necessary calculations should be carried out before designing, processing auxiliary fixtures or welding (riveting) extension plates, leaving a margin to ensure that it cannot be disengaged during loading.

[0079] Eighthly, align the vehicle as much as possible with the center of the platform. After the wheels fall on the exact center of the wheel platform, clamp the vehicle and fix the vehicle body on the central platform.

[0080] Ninthly, install the brake robot to ensure that the KC test bench can control the brake robot to step on or release the brake pedal; install the steering robot to ensure that the KC test bench can control the steering robot to operate the steering wheel at a specified angle or specified torque; install the wheel center position measurement system so that the KC test bench can measure the linear displacement and angular displacement of the vehicle wheel center at any time.

[0081] Tenthly, set up limit protection for the system to prevent over-range of displacement, force and torque, which may damage the measurement system or the vehicle.

[0082] Further, in one embodiment, before S100, it further includes:

[0083] S000: Establish a vehicle dynamics simulation model.

[0084] Specifically, firstly, establish a vehicle dynamics simulation model without suspension and steering, mainly including a body model, a tire mathematical model, an aerodynamic model, a braking model, a power system model, an electronic control system model, a sensor model, and a driver model.

[0085] Secondly, the vehicle dynamics simulation model should include all masses, such as the chassis, engine, payload, unsprung mass, etc. Mass values, centroid positions, torques, and products of inertia are the basic characteristics of the vehicle in the tests covered by this application.

[0086] Thirdly, vehicles with significant frame-twisting characteristics require more detailed modeling, including the frame-twisting effects that occur during extreme maneuvers. The modal neutral file (mnf) of the frame can be calculated using finite element software with the modal superposition method to characterize the flexible deformation of the vehicle.

[0087] Fourthly, the vertical, lateral, and longitudinal forces, as well as the alignment and overturning moments, when each tire contacts the ground, play a major role in the vehicle. The fidelity of vehicle motion prediction depends on the fidelity of the calculated tire forces and moments. When modeling the tire mathematical model, at least it is necessary to ensure that the forces and moments obtained from the tire mathematical model and the forces and moments obtained from actual tire tests meet the requirements of Table 6 below.

[0088] Serial number Operating condition Accuracy requirement (%) 1 Pure longitudinal slip test Pure Brake / Drive 95 2 Pure cornering test condition Pure Cornering 95 3 Pure Mz condition 80 4 Combined slip test condition Combined Slip 90

[0089] Table 6

[0090] Accuracy calculation formula:

[0091]

[0092] In the formula, F measured is the actually measured tire force, and F model is the tire force predicted or calculated by the model.

[0093] Fifthly, the maximum vehicle speed applicable to the vehicle's aerodynamic model should be greater than or equal to the maximum vehicle speed during subsequent real vehicle simulation tests.

[0094] Sixthly, if the brake is not in operation during the test, a brake system model is not required; however, if the active controller uses the brake to control the vehicle's operation during the test, the vehicle requires a brake system model.

[0095] Seventhly, the powertrain model should at least simulate factors such as engine power, the dynamic response of the throttle, shift characteristics, and clutch characteristics.

[0096] Eighthly, any electronic control system of the vehicle should be included in the vehicle model, and the electronic control system model should include transmission delay and control logic.

[0097] Ninthly, the sensor model in the vehicle model is used to extract signals from the operation process of the model for interaction with the bench test and for viewing and analyzing the results after the test is completed.

[0098] Tenthly, the driver model in the vehicle model should be able to control steering (since the vehicle model does not have a steering model and directly controls the steering of the bench test), throttle, brake, gear, etc. according to the requirements of the test method set by the user for open-loop tests, and can also perform closed-loop control of the vehicle according to the route, speed, lateral acceleration, longitudinal acceleration, etc. set by the user.

[0099] Further, in one embodiment, before S100, it further includes:

[0100] S000: Information interaction between the vehicle dynamics simulation model and the test bench.

[0101] Specifically, define the input and output interfaces of the bench test and the input and output interfaces of the vehicle dynamics digital model as shown in Table 7 below.

[0102]

[0103]

[0104] Table 7

[0105] In a second aspect, an embodiment of the present application further provides a K&C test specific condition loading system. The K&C test specific condition loading system includes: a tire force and vehicle body attitude calculation module, which is used to calculate tire force and vehicle body attitude parameters by using a vehicle dynamics simulation model based on vehicle transmission and control parameters, wheel center attitude and position, tire vertical force, and steering wheel angle and torque parameters at the current moment; an execution module, which is used to apply the tire force to each tire by using a wheel platform and apply the vehicle body attitude parameters to the test vehicle by using a central platform; an update module, which is used to calculate the position and attitude of the wheel center and the tire vertical force at the next moment by using a wheel center position and attitude measurement system and update them to the vehicle dynamics simulation model; a loop iteration module, which is used to repeat the above steps in a loop until the test reaches a predetermined end condition and then stops the loop.

[0106] Further, in one embodiment, the K&C test specific condition loading system further includes a vehicle transmission and control parameter calculation module, which is used to calculate the vehicle transmission and control parameters at the current moment of the vehicle based on the current state of the vehicle and the set driving conditions.

[0107] Among them, the function implementation of each module in the above K&C test specific condition loading system corresponds to each step in the above K&C test loading method embodiment, and its function and implementation process will not be elaborated here one by one.

[0108] In a third aspect, an embodiment of the present application provides a loading device for specific working conditions of K&C tests. The loading device for specific working conditions of K&C tests can be a device with data processing functions such as a personal computer (PC), a laptop computer, a server, etc.

[0109] Referring to Figure 2 , Figure 2 FIG. is a schematic diagram of the hardware structure of the loading device for specific working conditions of K&C tests involved in the solution of the embodiment of the present application. In the embodiment of the present application, the loading device for specific working conditions of K&C tests may include a processor, a memory, a communication interface, and a communication bus.

[0110] Among them, the communication bus can be of any type and is used to interconnect the processor, the memory, and the communication interface.

[0111] The communication interface includes interfaces such as input / output (I / O) interfaces, physical interfaces, and logical interfaces for interconnecting components inside the loading device for specific working conditions of K&C tests, as well as interfaces for interconnecting the loading device for specific working conditions of K&C tests with other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, a fiber optic interface, an ATM interface, etc.; the user device can be a display screen (Display), a keyboard (Keyboard), etc.

[0112] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical memory, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0113] The processor can be a general-purpose processor, and the general-purpose processor can call the K&C test specific working condition loading program stored in the memory and execute the K&C test loading method provided by the embodiment of the present application. For example, the general-purpose processor can be a central processing unit (CPU). Among them, the method executed when the K&C test specific working condition loading program is called can refer to the various embodiments of the K&C test loading method of the present application, which will not be elaborated here.

[0114] Those skilled in the art can understand, Figure 2The hardware structure shown does not constitute a limitation on this application. It may include more or fewer components than those shown, or combine certain components, or have different component arrangements.

[0115] Fourthly, an embodiment of this application also provides a readable storage medium.

[0116] A K&C test specific condition loading program is stored on the readable storage medium of this application. When the K&C test specific condition loading program is executed by a processor, the steps of the K&C test loading method as described above are implemented.

[0117] Among them, the method implemented when the K&C test specific condition loading program is executed can refer to the various embodiments of the K&C test loading method of this application, which will not be elaborated here.

[0118] It should be noted that the serial numbers of the above embodiments of this application are only for description and do not represent the superiority or inferiority of the embodiments.

[0119] The terms "including" and "having" in the description of the specification, claims and the above drawings of this application, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices. The descriptions of terms such as "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit that "first", "second" and "third" are different types.

[0120] In the description of the embodiments of this application, "exemplary", "for example" or "for instance" etc. are used to indicate examples, illustrations or explanations. Any embodiment or design solution described as "exemplary", "for example" or "for instance" in the embodiments of this application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly speaking, using words such as "exemplary", "for example" or "for instance" is intended to present relevant concepts in a specific way.

[0121] In the description of the embodiments of this application, unless otherwise specified, " / " means "or". For example, A / B can mean A or B; "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "a plurality of" means two or more than two.

[0122] In some processes described in the embodiments of the present application, there are multiple operations or steps that appear in a specific order. However, it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or may be executed in parallel. The serial numbers of the operations are only used to distinguish different operations, and the serial numbers themselves do not represent any execution order. Additionally, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0123] Through the description of the above embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present application, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium as described above (such as ROM / RAM, magnetic disk, optical disc) and includes several instructions for causing a terminal device to execute the methods described in the various embodiments of the present application.

[0124] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A K&C test loading method, characterized in that, The K&C test loading method includes: Based on the vehicle transmission and control parameters, wheel center attitude and position, tire vertical force, and steering wheel angle and torque parameters at the current moment, using a vehicle dynamics simulation model to calculate the tire force and vehicle body attitude parameters; Using a wheel platform to apply the tire force to each tire, and using a central platform to apply the vehicle body attitude parameters to the test vehicle; Using a wheel center position and attitude measurement system to calculate the position and attitude of the wheel center and the tire vertical force at the next moment, and updating them to the vehicle dynamics simulation model; Repeating the above steps in a loop until the test reaches a predetermined end condition and stops the loop.

2. The K&C test loading method according to claim 1, characterized in that Before calculating the tire force and vehicle body attitude parameters based on the vehicle transmission and control parameters, wheel center attitude and position, tire vertical force, and steering wheel angle and torque parameters at the current moment using a vehicle dynamics simulation model, it further includes: Calculating the vehicle transmission and control parameters at the current moment of the vehicle based on the current state of the vehicle and the set driving conditions.

3. The K&C test loading method according to claim 2, characterized in that The current state of the vehicle includes tire pressure parameters, allowable loading error, load parameters, and suspension height parameters, and the set driving conditions include road conditions, target speed, target steering wheel angle, target trajectory, and target lateral acceleration.

4. The K&C test loading method according to claim 1, characterized in that Before calculating the tire force and vehicle body attitude parameters based on the vehicle transmission and control parameters, wheel center attitude and position, tire vertical force, and steering wheel angle and torque parameters at the current moment using a vehicle dynamics simulation model, it further includes: Importing the steering parameters into the steering wheel robot in the test bench, and using the wheel center position and attitude measurement system of the test bench to output the wheel center attitude and position, tire vertical force, and steering wheel angle and torque parameters at the current moment.

5. The K&C test loading method according to claim 1, characterized in that The vehicle transmission and control parameters include steering, throttle, brake, clutch, and transmission parameters.

6. The K&C test loading method according to claim 1, characterized in that The tire force parameters include tire longitudinal force and tire lateral force parameters.

7. A loading system for specific working conditions of K&C test, characterized in that, The K&C test specific condition loading system includes: A tire force and vehicle body attitude calculation module, which is used to calculate the tire force and vehicle body attitude parameters based on the vehicle transmission and control parameters, wheel center attitude and position, tire vertical force, and steering wheel angle and torque parameters at the current moment using a vehicle dynamics simulation model; An execution module, which is used to apply the tire force to each tire using a wheel platform and apply the vehicle body attitude parameters to the test vehicle using a central platform; An update module, which is used to calculate the position and attitude of the wheel center and the tire vertical force at the next moment using a wheel center position and attitude measurement system, and update them to the vehicle dynamics simulation model; A loop iteration module, which is used to repeat the above steps in a loop until the test reaches a predetermined end condition and stops the loop.

8. The K&C test specific condition loading system according to claim 7, wherein The K&C test specific condition loading system includes: A vehicle transmission and control parameter calculation module, which is used to calculate the vehicle transmission and control parameters at the current moment of the vehicle based on the current state of the vehicle and the set driving conditions.

9. A loading device for specific working conditions of K&C test, characterized in that The K&C test specific condition loading device includes a processor, a memory, and a K&C test specific condition loading program stored on the memory and executable by the processor. When the K&C test specific condition loading program is executed by the processor, the steps of the K&C test loading method according to any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium, characterized in that, A K&C test specific condition loading program is stored on the computer-readable storage medium. When the K&C test specific condition loading program is executed by a processor, the steps of the K&C test loading method according to any one of claims 1 to 6 are implemented.

Images