Design method of automobile rear wheel steering mechanism based on ADAMS
By applying genetic algorithms to optimize the design parameters of the rear wheel steering mechanism on the ADAMS platform, the problems of large parameter range and large calculation amount in the existing technology are solved, and the optimization design of the rear wheel steering mechanism is realized, which improves the vehicle's handling stability and steering response speed.
Patent Information
- Application Number
- CN202510407899.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-02
- Publication Date
- 2025-07-18
AI Technical Summary
In the prior art, in the optimization design of automotive rear wheel steering mechanisms based on ADAMS, it is difficult to coordinate the optimization of all parameters, the calculation amount is large, and the design parameter range value is large, resulting in poor optimization results.
Genetic algorithms are used to optimize the design parameters of the rear wheel steering system. By establishing a three-dimensional model, setting the design parameters, and using the objective function to calculate the fitness, selecting, crossing, and mutating operations, iterative optimization, and finally selecting the individual with the highest fitness as the optimization result.
It achieves the best value within the parameter value range, optimizes the design of the rear wheel steering mechanism, and improves the vehicle's handling stability, steering response speed and rollover resistance.
Smart Images
Figure CN120337402A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of vehicle design, and particularly to a design method for an automotive rear-wheel steering mechanism based on ADAMS. Background Technique
[0002] In recent years, the automotive rear-wheel steering mechanism based on ADAMS has become a research hotspot. As an important part of an automobile, the rear-wheel steering mechanism plays a crucial role in the overall vehicle design, and the optimal design of the rear-wheel steering mechanism is an important measure to improve the performance of the front-wheel steering system. In the existing steering system design, generally, the mutual interference between the vehicle and the automotive suspension system is checked by drawing curve graphs, mainly including the spatial method and the planar method.
[0003] When the traditional ADAMS-based optimization of the vehicle rear-wheel steering system is carried out, some steering system structure parameters need to be set according to experience first. These parameter range values are relatively large. When applying these parameters to the steering system structure, in order to ensure that the final design meets the usage requirements, corresponding parameters need to be selected within the range values of the corresponding parameters as design parameters. This step has a large amount of calculation and it is difficult to take into account the optimality of all parameters in an overall manner. Summary of the Invention
[0004] The purpose of the present invention is to provide a design method for an automotive rear-wheel steering mechanism based on ADAMS to solve the problems raised in the above background technique.
[0005] To achieve the above purpose, the present invention provides the following technical solution: A design method for an automotive rear-wheel steering mechanism based on ADAMS, including the following steps:
[0006] Model the rear-wheel steering mechanism using ADAMS software: Refer to the well-known automotive rear-wheel steering structure to establish a three-dimensional model;
[0007] Set the design parameters;
[0008] Optimize the design parameters using the genetic algorithm:
[0009] Convert the design parameters of the rear-wheel steering system into the coding form of individual chromosomes, and then initialize a group of individuals to form an initial population;
[0010] Calculation and evaluation of the objective function: For each individual in the population, calculate its fitness according to the objective function. After selection operation, crossover operation, mutation operation, fitness evaluation and selection, and iteration, output the optimal solution, and select the individual with the highest fitness as the result of the optimal design.
[0011] Preferably, when performing three-dimensional modeling on the rear-wheel steering mechanism, a beam is set on the frame of the rear axle to fix the driving device and the steering motor together. Then, determine the length of the vertical section and the starting swing angle. Finally, calculate the length of the front steering tie rod based on the length of the front axle and the position of the rear axle knuckle arm.
[0012] Preferably, setting the design parameters also includes setting kinematic pairs and constraints, setting the dynamic parameters of the kinetic parameters, and setting the minimum transmission angle.
[0013] Preferably, after the modeling is completed, verify the three-dimensional model. Compare the performance of the three-dimensional model with that of the actual vehicle under the same working conditions to verify the reliability of the model: including simulating the vehicle's motion trajectory, side slip angle, steering wheel angle, and the changes in the key tuning parameters of the steering tires during straight-line driving and turning, and comparing and analyzing with the measured data. Also, test the key performance indicators such as the vehicle's handling stability, rollover suppression ability, and steering response speed through simulating the rapid lane change process.
[0014] Preferably, when setting the dynamic parameters of the kinetic parameters, consider the actual working conditions and performance indicators of the whole vehicle. According to the initially set parameters, simulate and analyze to observe the dynamic response characteristics of the vehicle under different working conditions, and make fine adjustments to the key kinetic parameters.
[0015] Preferably, the minimum transmission angle is not less than 40°.
[0016] Preferably, the steering tie rod is curved.
[0017] Preferably, the objective function is the goal that needs to be optimized to achieve maximization or minimization. Specifically, determine the expression of the objective function according to the design requirements. Each individual has an objective function representing that individual. Input the solution of each individual into the objective function, and the objective function returns a value as the objective function value of that individual. Convert the objective function value into fitness through the fitness function. In the maximization problem, the fitness is the objective function value itself. In the minimization problem, the fitness is the reciprocal of the objective function. For each individual, calculate its fitness value and store it.
[0018] Preferably, the steps for calculating fitness also include using ADAMS software to conduct simulation experiments, including operability simulation experiments, stability simulation experiments, and bilateral tire steering parallel simulation experiments.
[0019] Preferably, during the bilateral tire steering parallel simulation experiment, when the vehicle steers, the vertical and horizontal parallel jump ranges of the centers of the two tires are between -65 and 135 mm.
[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention introduces a genetic algorithm, and uses the characteristics of the genetic algorithm to process the value ranges of all parameters, ensuring that the optimal values of these parameters are obtained within the value ranges, and then selecting the optimal values of all parameters to achieve the optimization of the optimization effect. Description of the Drawings
[0021] Figure 1 Schematic diagram of setting a beam on the rear axle frame when modeling the present invention;
[0022] Figure 2 Schematic diagram of the force curve of the crossbar;
[0023] Figure 3 Schematic diagram of the wheel bounce curve in the vehicle straight-ahead state;
[0024] Figure 4 Schematic diagram of the deviation curve when the right rear wheel turns left by 15°;
[0025] Figure 5 Schematic diagram of the deviation curve when the right rear wheel turns left by 25°;
[0026] Figure 6 Schematic diagram of the comparison before and after optimization of the flat jump steering condition;
[0027] Figure 7 Schematic diagram of the comparison before and after optimization of the flat jump camber condition;
[0028] Figure 8 Schematic diagram of the degree of wheel center retraction during flat jump;
[0029] Figure 9 Schematic diagram of the comparison before and after optimization under the forward tilt steering condition. Detailed Embodiment
[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0031] The present invention provides a technical solution: A design method for an automotive rear-wheel steering mechanism based on ADAMS, including the following steps:
[0032] Model the rear-wheel steering mechanism using ADAMS software: Refer to the well-known automotive rear-wheel steering structure to establish a three-dimensional model;
[0033] Refer to the determined rear-wheel steering structure of the vehicle, establish the relevant 3D model, and establish the geometric model of the rear-wheel steering mechanism. To ensure the authenticity and accuracy of the model, industry standard data should be referred to, such as the length of the steering arm and the angle of the steering knuckle. Due to the differences in the space of the vehicle body chassis, the configuration methods of the rear wheels and the front wheels are different. First, set a beam on the frame of the rear axle to fix the drive device (steering motor) together, and then determine the length of the vertical rod and the starting swing angle. The length of the vertical section is determined according to the length of the upper knuckle arm on the rear axle. Generally, it is considered that the ratio of the length of the upper knuckle arm on the rear axle to the length of the vertical axis is between 0.8 and 1.2. When determining the initial swing angle of the vertical arm, it should be ensured that it is in a neutral state during the distribution process. Finally, calculate the length of the front steering tie rod according to the length of the front axle and the position of the rear axle knuckle arm. Since the vehicle bounce and the position of the beam need to be considered, the steering tie rod is made into a curved shape.
[0034] Introduce the dynamic parameters of the real vehicle to further improve the simulation accuracy of the model. After the modeling is completed, the model should be strictly verified. Compare the performance of the simulation model with that of the real vehicle under the same working conditions to verify the reliability of the model. For example, simulate the changes of key parameters such as the vehicle motion trajectory, side slip angle, steering wheel angle, and tuning of the steering tires during straight driving and turning, and compare them with the measured data for analysis. Test the key performance indicators such as the vehicle handling stability, rollover suppression ability, and steering response speed through simulating the rapid lane change process.
[0035] Set the kinematic pairs and constraints: The kinematic pair is the core component of the vehicle rear-wheel steering system. Use the hinge pair to simulate the rotational connection between the joint and the vehicle body. The accurate setting of its rotation axis is directly related to the flexibility and accuracy of steering. Using ADAMS software, it is convenient to set the rotation center, rotation range, and starting angle of the hinge pair, so that the model can truly reflect the real working state.
[0036] Set the dynamic parameters of the kinetic parameters: When inputting the kinetic parameters, the actual working conditions and performance indicators of the whole vehicle should be fully considered to ensure that each parameter can truly reflect the dynamic characteristics of the whole vehicle. During the dynamic parameter adjustment stage, according to the initially set parameters, simulate and analyze to observe the dynamic response characteristics of the vehicle under different working conditions, and make fine adjustments to the key kinetic parameters. For example, when the vehicle has excessive rollover during high-speed turning, the suspension damping coefficient can be appropriately increased and the tire cornering stiffness can be adjusted to improve the anti-rollover performance of the vehicle. The input and adjustment of the kinetic parameters need to fully consider the mutual influence and restriction among the parameters. For example, parameters such as the stiffness and damping coefficient of the suspension system are not only related to the handling performance of the vehicle, but also related to the ride comfort and fuel economy of the vehicle. Therefore, when adjusting these parameters, it is necessary to comprehensively consider, weigh the pros and cons, and seek the optimal balance.
[0037] Relationship between steering performance and minimum transmission angle: The minimum transmission angle is the smallest angle between the trapezoidal steering arm and the tie rod. If this angle is too small, the force on the strut will be small, and excessive force will also cause the strut to tend to rotate at the "dead point", thus affecting its normal operation. During mechanical transmission, its transmission angle is variable. In design, to ensure better transmission performance of the mechanism, it is generally required that the minimum transmission angle is not less than 40°. Therefore, the limitation of the minimum transmission angle should be considered in the transmission mechanism.
[0038] When inputting dynamic parameters, the actual working conditions and performance indicators of the whole vehicle should be fully considered to ensure that the parameters can truly reflect the dynamic characteristics of the whole vehicle. During the dynamic parameter adjustment stage, according to the initially set parameters, simulate and analyze to observe the dynamic response characteristics of the vehicle under different working conditions, and make fine adjustments to the key dynamic parameters. For example, when the vehicle has excessive roll during high-speed turning, the suspension damping coefficient can be appropriately increased and the tire cornering stiffness can be adjusted to improve the anti-roll performance of the vehicle. The input and adjustment of dynamic parameters need to fully consider the mutual influence and restriction among the parameters. For example, parameters such as the stiffness and damping coefficient of the suspension system are related not only to the handling performance of the vehicle, but also to the ride comfort and fuel economy of the vehicle. Therefore, when adjusting these parameters, it is necessary to comprehensively consider, weigh the pros and cons, and seek the optimal balance.
[0039] For the ADAMS application software system 2 described, the relationship between steering performance and minimum transmission angle
[0040] The minimum transmission angle is the smallest angle between the trapezoidal steering arm and the tie rod. If this angle is too small, the force on the strut will be small, and excessive force will also cause the strut to tend to rotate at the "dead point", thus affecting its normal operation. During mechanical transmission, its transmission angle is variable. In design, to ensure better transmission performance of the mechanism, it is generally required that the minimum transmission angle is not less than 40°. Therefore, the limitation of the minimum transmission angle should be considered in the transmission mechanism.
[0041] Refer to Figure 2 , curves (from top to bottom) 1, 2, 4 are the force curves at a length of 400 mm with trapezoidal base angles of 65°, 70°, 75°, and curve 3 is the force curve of the tie rod with a trapezoidal base angle of 70° and a steering arm length of 700 mm. The minimum transmission angles corresponding to curves 1, 2, 3, 4 are 22°, 29°, 23°, 35°. As the transmission angle increases, the force on the tie rod decreases significantly. On the contrary, when the trapezoidal base angle is constant, increasing the length of the guiding trapezoidal arm, although it reduces the minimum transmission angle, under the combined influence of the above two factors, when the steering trapezoidal arm length is 400 mm and the trapezoidal base angle is 75°, its value is still relatively large. Therefore, designing a larger minimum transmission angle effectively reduces its force state and improves its handling stability.
[0042] ByFigure 2 It can be seen that between 65° and 75°, for every 1° change in the trapezoidal base angle, there is an average 5% impact on the force on the tie rod. However, the impact on the stepped base angle is not significant. For a range from 100 mm to 200 mm, it only has the same impact as when the trapezoidal base angle changes by 1°.
[0043] The above parameters are all taken as a range value according to requirements. The genetic algorithm is used to optimize the rear-wheel steering system, and appropriate design parameters are selected within the range value:
[0044] Individual coding and initialization: First, the design parameters of the rear-wheel steering system (such as bogie angle, connecting rod length, wheel offset, etc.) need to be converted into the coding form of individual chromosomes. Common coding methods include binary coding, real number coding, etc. Then, initialize a group of individuals (i.e., design schemes) to form an initial population.
[0045] Calculation and evaluation of the objective function: For each individual in the population, calculate its fitness according to the objective function. The objective function is the goal that needs to be optimized to achieve maximization or minimization. Specifically, determine the expression of the objective function according to the design requirements. Each individual has an objective function representing that individual. Take the solution of each individual as the input and pass it into the objective function. The objective function returns a value as the objective function value of that individual. Convert the objective function value into fitness through the fitness function. In a maximization problem, the fitness is the objective function value itself. In a minimization problem, the fitness is the reciprocal of the objective function or its transformed form. For each individual, calculate its fitness value and store it. For example, calculate indicators such as the steering angle range, steering torque, and stability of the design scheme, and convert these indicators into fitness values. The higher the fitness value, the better the design scheme. For example, to minimize the movement trajectory deviation of the connection point between the upper arm and the steering tie rod on the rear steering wheel under different motion conditions, convert this indicator into a fitness value. The smaller the fitness value, the better the design scheme. Specifically, when calculating the sensitivity of the hard points of the steering system model of the prototype vehicle to the Bump steer curve, the optimization objective function can be defined as where f(x) is the optimization objective function, μ is a coefficient taken as 0.01, qmax and qmin are the upper and lower bounce ranges of the front wheels, taken as ±20 mm respectively, F1(q) is the Bump steer curve function of the reference prototype vehicle during the wheel bounce process, and F2(q) is the Bump steer curve function of the model to be optimized. It is necessary to take the minimum value of the objective function. The determined steering system structure parameters make the Bump steer curve as close as possible to the ideal curve, thereby enabling the steering system to obtain better performance.
[0046] Selection operation: Use methods such as fitness proportionate selection and tournament selection to select excellent individuals from the current population so that they can be used as parents to participate in subsequent crossover and mutation operations.
[0047] Crossover operation: The crossover operation simulates the gene recombination process in biological inheritance. Through the crossover operation, some design parameters of two parent individuals are exchanged to generate a new generation of individuals. The crossover operation helps to explore new design spaces.
[0048] Mutation operation: The mutation operation is used to introduce diversity and prevent the optimization process from falling into a local optimum. Through the mutation operation, a part of the design parameters of an individual is randomly changed to increase the breadth of the search.
[0049] Fitness evaluation and selection: Evaluate the fitness of the new generation of individuals generated after crossover and mutation, and select the most excellent individuals according to the fitness to form a new generation of population.
[0050] Iteration: Repeat the above process until the stop condition is met (such as reaching the maximum number of iterations or the fitness value reaches a predetermined threshold).
[0051] Output the optimal solution: Finally, select the individual with the highest fitness as the optimization result, that is, the optimal design scheme of the rear-wheel steering system.
[0052] The operator first selects some setting parameter range values for optimization. After determining this part of the parameter range, optimize its parameter range values. After determining the air pressure parameter range values, adjust the first set of parameter range values and optimize again. Through secondary optimization, the optimization time is saved and over-optimization is avoided.
[0053] Finally, conduct three aspects of analysis:
[0054] Ride and handling simulation test, stability simulation test, bilateral tire steering parallel simulation test to ensure the actual performance of the evaluation and optimization results and meet all design requirements.
[0055] The handling simulation test is an important step to evaluate the correctness of the design scheme. Among them, the turning radius and response speed are important indicators to measure the handling performance of the vehicle, which directly affect the driving stability of the vehicle and the driving experience of the driver. Using ADAMS software can accurately simulate the rear-wheel turning radius under various working conditions, achieving the purpose of optimizing the mechanism design, reducing the turning radius, and improving the maneuverability. In the simulation test, typical driving scenarios such as emergency obstacle avoidance and narrow-road turning are set, and by changing the rear-wheel steering angle and vehicle speed, the change of the turning radius is observed. The results show that the optimized rear-wheel steering mechanism can effectively reduce the turning radius, not only improving the passing ability of the vehicle, but also enhancing the driving safety. The ADAMS software is used to simulate and analyze the actual response time and steering angle after the driver inputs the steering command, and it is found that the response speed of the optimized rear-wheel steering mechanism is significantly improved, and the driver's ability to quickly respond to the steering command is significantly enhanced.
[0056] The stability simulation of the vehicle's rear-wheel steering system includes roll suppression and trajectory keeping of the vehicle. Using ADAMS, a detailed dynamic model is established to deeply simulate the rollover characteristics of the vehicle under various working conditions. The optimized rear-wheel steering mechanism can effectively reduce the body roll angle during large turns and can effectively improve the driving stability and ride comfort of the vehicle.
[0057] To make the results of the simulation calculation closer to the actual objective situation, the simulation of the parallel steering of both-side tires of the model is carried out. During the simulation process, when the vehicle steers, the vertical and horizontal parallel jump ranges of the centers of the two-side tires are from -65 to 135 mm. The results show that in the improved rear-wheel steering mechanism, the initial rotation angle of the vertical rod is 1.5°, and the initial rotation angle of the knuckle rod is 10.8°. And the misalignment degrees of the steering rods and suspension systems before and after optimization are calculated. Through the analysis of the calculation results, the fitting curve is as Figure 3 .
[0058] Because the above simulations are all for the wheel rotation angle of 0°, that is, the simulation results in the straight-ahead state, it is necessary to calculate the wheel rotation offset under different angle conditions to verify the rationality of the optimization algorithm. Through on-vehicle measurement, when the right rear wheel steers to the left, the following results are obtained, as Figure 4 and Figure 5 shown.
[0059] At the present stage, the existing design mechanism has controlled its displacement error within 5 mm, but in actual application, the maximum deviation value is relatively large. This is because in the design process, the position of the steering mechanism and the symmetry of the front and rear swing angles of the pitman arm need to be considered, rather than simply the displacement deviation. But overall, the optimization effectively reduces the mutual interference between the rear wheel and the leaf spring suspension.
[0060] To make the results of the simulation closer to the actual objective situation, the following is a comparative analysis of various K characteristic indicators before and after optimization. In the wheel bounce condition, the vertical bounce stroke of the wheel is in the common range of ±50 mm; in the roll condition, the roll angle of the vehicle is ±4.1°. The optimization of the suspension hard points is a process of continuous trade-offs, which may make some index parameters better or some index parameters worse. It is necessary to ensure that there are no serious problems with some key index parameters of the vehicle. The following curves are in red before optimization and in blue after optimization.
[0061] As Figure 6 , in this condition, the red curve is before optimization and the blue curve is after optimization. It can be seen from the curve change that the change of the front wheel alignment angle after optimization is smaller, and the change rate decreases from 0.0037 to 0.0027, which is beneficial to improving the stability of the vehicle during driving.
[0062] As Figure 7 , in this condition, by comparing the curves before and after optimization, it can be seen that the change of the suspension hard points has little effect on the change of this parameter, and the change rate changes from 0.028 to 0.029.
[0063] As Figure 8 , in this condition, the longitudinal retraction degree of the wheel center during the bounce process is reduced, which is beneficial to the vehicle's ability to resist impact and reduce abnormal wear of the tires.
[0064] As Figure 9 As shown, in this condition, the change range of the front wheel alignment angle of the tire in the roll condition is reduced, which is beneficial to improving the straight-line driving stability of the vehicle during rolling.
[0065] In summary, with the progress of driverless technology, the rear-wheel steering mechanism, as a key component to improve the handling performance of vehicles, will play an increasingly prominent role. Taking the rear-wheel steering mechanism as the research object, through the modeling of the automotive rear-wheel steering mechanism, the objective function is established, and it is dynamically optimized to obtain the optimal layout plan. Using the method of combining theoretical analysis and numerical simulation, the relationship between the wheel force and the wheel side displacement is analyzed, and the proposed theoretical model is verified through the test of the force at the joint of the wheel and the vertical arm, and the proposed algorithm is also verified, so as to provide a theoretical basis for the design of the wheel steering mechanism.
[0066] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it is understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A design method for the rear-wheel steering mechanism of an automobile based on ADAMS, characterized in that: It includes the following steps: Model the rear-wheel steering mechanism using ADAMS software: Refer to the well-known rear-wheel steering structure of an automobile to establish a 3D model; Set the design parameters; Optimize the design parameters using the genetic algorithm: Convert the design parameters of the rear-wheel steering system into the coding form of individual chromosomes, and then initialize a group of individuals to form an initial population; Calculation and evaluation of the objective function: For each individual in the population, calculate its fitness according to the objective function. After selection operation, crossover operation, mutation operation, fitness evaluation and selection, and iteration, output the optimal solution, and select the individual with the highest fitness as the result of the optimized design.
2. The design method of an automotive rear-wheel steering mechanism based on ADAMS according to claim 1, characterized in that: When performing 3D modeling of the rear-wheel steering mechanism, set a beam on the frame of the rear axle to fix the driving device and the steering motor together, then determine the length of the vertical section and the starting swing angle, and finally calculate the length of the front steering tie rod according to the length of the front axle and the position of the rear axle knuckle arm.
3. A design method for an automotive rear-wheel steering mechanism based on ADAMS according to claim 1, characterized in that: Setting the design parameters also includes setting kinematic pairs and constraints, setting the dynamic parameters of the dynamic parameters, and setting the minimum transmission angle.
4. A design method of an automotive rear-wheel steering mechanism based on ADAMS according to claim 2, characterized in that: After the modeling is completed, verify the 3D model. Compare the performance of the 3D model with that of the actual vehicle under the same working conditions to verify the reliability of the model: including simulating the vehicle's motion trajectory, sideslip angle, steering wheel angle, and changes in the key tuning parameters of the steering tires during straight-line driving and turning, and comparing and analyzing with the measured data. Also, test the key performance indicators such as vehicle handling stability, rollover suppression ability, and steering response speed through simulating the rapid lane change process.
5. The design method of an automotive rear-wheel steering mechanism based on ADAMS according to claim 3, characterized in that: When setting the dynamic parameters of the dynamic parameters, consider the actual working conditions and performance indicators of the whole vehicle, and simulate and analyze the dynamic response characteristics of the vehicle under different working states according to the initially set parameters, and make fine adjustments to the key dynamic parameters.
6. The design method of an automotive rear-wheel steering mechanism based on ADAMS according to claim 3, characterized in that: The minimum transmission angle is not less than 40°.
7. A design method of an automotive rear-wheel steering mechanism based on ADAMS according to claim 2, characterized in that: The steering tie rod is curve-shaped.
8. A design method for an automotive rear-wheel steering mechanism based on ADAMS according to claim 1, characterized in that: The objective function is the target that needs to be optimized to achieve maximization or minimization. Specifically, determine the expression of the objective function according to the design requirements. Each individual has an objective function representing the individual. Take the solution of each individual as the input and pass it into the objective function. The objective function returns a value as the objective function value of the individual. Convert the objective function value into fitness through the fitness function. In the maximization problem, the fitness is the objective function value itself. In the minimization problem, the fitness is the reciprocal of the objective function. Calculate the fitness value of each individual and store it.
9. The design method of an automotive rear-wheel steering mechanism based on ADAMS according to claim 6, characterized in that: Steps for calculating fitness: It also includes performing simulation experiments using ADAMS software, including operational simulation experiments, stability simulation experiments, and bilateral tire steering parallel simulation experiments.
10. A design method of an automotive rear-wheel steering mechanism based on ADAMS according to claim 1, characterized in that: During the bilateral tire steering parallel simulation experiment, when the vehicle steers, the vertical and horizontal parallel jumping ranges of the centers of the two tires are in the range of -65 to 135 mm.