The Optimization Simulation And Experimental Research On FSAE Race Car Controllability And Stability Based On Specific Racing Circuit

In the Formula Student China,all participating colleges and Universities focuse on how to utilize extremely limited time to develop,manufacture,test and tune a sufficient competitive racing car.Since there are different circuit layout plans for each dynamic project,FSAE racing car needs to be excellent in various performance,especially in handing stability of the limiting condition.In order to quickly and efficiently determine an optimal vehicle configuration that can complete the specific racing circuit in the shortest time,this thesis takes the 2017 racing car of Changsha university of science&technology as the research object,develop a set of simulation tool to compute lap minimum time and limiting handing stability of racing car.Firstly,according to the test data of the special tyres,we fit mechanical characteristic and identify parameters of the Magic Formula Pacejka2002 tire model with the I-M method of the unconditional constraint optimization algorithm.In Matlab/Simulink software,the article establishes the seven DOF modular vehicle model considering limited torque by using the derivation formulas of the mathematical model of the multi-friction plate type limited slip differential.Then,the accuracy of full vehicle model is verified by simulation in a variety of experimental conditions.Secondly,the thesis utilizes on-board measured vehicle data to reconstruct racing line on a specific circuit,and puts forward the "stretching" algorithm to correct the data the and computing model errors.Then,a complete driver model combined the vehicle model is built through path preview steer control scheme and speed control scheme,computing the required longitudinal and lateral control inputs following the giving driving line which are regard as lap minimum time optimization program.Thirdly,within the range of performance limits and road boundary constraints,the article uses the SQP method of nonlinear constrained optimization algorithm to iteratively adjust the driver control strategy matrix,finding out the minimum time and optimal driving line for special racing circuit.The influence of various parameters on lap minimum time for whole circuit is analyzed and summarized by developing the lap minimum time transient simulation tool,which provides guidance for the initial design of the racing car phase,the iterative development phase,testing phase and driving strategy.