Optimization Design Of Rear Wheel Suspension And Steering Mechanism Based On Space RSSR Mechanism

The FSAE event has been extensively exchanged and studied among the universities with its flexible design and independent manufacturing characteristics.The rear wheel can be rotated with the front wheel to improve the turning radius and stability of the car.The rules of the race promote the rear wheel steering and the rear wheel rotation can help the car achieve good results in the design and test items.At present,there are a few researches on the rear wheel steering mechanism of FSAE.The research focuses on the optimal design of the front wheel steering and suspension.The research on the rear wheel steering is also focused on the control theory method.The plane projection model is used in the research method.Spatial model,or in the simulation software modeling,can’t clearly explain the relationship between component parameters.In this paper,we will create a rear wheel suspension and steering rod system with steering characteristics composed of several spatial RSSR institutions.The mathematical model of the steering rod and rear wheel suspension is established by using the spatial RSSR mechanism.ADAMS modern design approach yields a reasonable structure.To this end,this paper has done the following aspects of the study:1)Based on the space rotation matrix method and the vector rotation method,the mathematical model of the integral steering trapezoid of the double RSSR mechanism is established.Taking the length of the trapezoidal bottom and the length of the trapezoidal arm as the design variable,the double Ackermann theorem is used as the objective function,The MATLAB toolbox completes the optimal design of the steering mechanism.In order to verify the correctness of the theoretical analysis,the rationality of the theoretical analysis in ADAMS is verified.2)In view of the superiority of the disengaged steering trapezoid and the analysis method of the spatial RSSR mechanism,by analyzing the reasonable arrangement of the rear wheel space of the car,the steering rod is replaced by the steering trapezoid,and the disengaged type trapezoidal steering rod is established and the mathematical model is established.In MATLAB,the input and output curves of the bars are obtained.In order to make the design more intuitive,establish the simulation model in ADAMS,according to the mathematical model of the model coordinate point parameterization,through the optimization of reasonable structure,and finally add the steering torque on the main pin,the mechanism of the largest force Rod,for its force and deformation analysis.3)The suspension with the steering characteristics needs to be redesigned.Based on the three-view method of the design of the car suspension,the telecom parameters are obtained according to the vehicle parameters and the roll center in the plane of the tire and the longitudinal center in the side view plane.The upper and lower control surface,by determining the length of the arm after the hard point of the suspension position,and finally the double wishbone suspension complex RSSR movement of the suspension of the suspension simulation,the parameters of the range of changes.4)According to the coordinates of the hard points of the suspension,the model of the double wishbone suspension is established in ADAMS.By changing the parameters of the suspension,the parameters of the parameters are obtained.Design variables,in Adams/Insight to complete the optimization of multi-objective function analysis,so that the parameters of the suspension changes within a reasonable range to achieve the optimal performance of the suspension.