汽车matlab模型

1、Chapter 5 Vehicle Modeling in Matlab 施树明ContentsnModeling a Cruise Control SystemnModeling a Cruise Control System in Simulink nModeling a Bus Suspension System using Transfer Functions nBus Suspension Modeling in Simulink Modeling a Cruise Control SystemUsing Newtons law, modeling equations for thi

2、s system becomes:Physical setup and system equations Assumption: 1. the inertia of the wheels is neglected, 2. friction (which is proportional to the cars speed) is what is opposing the motion of the car (1) Design requirements nRise time 5 secnOvershoot 10%nSteady state error 2% nTo solve this prob

3、lem using MATLAB, copy the following commands into an new m-file: qm=1000; b=50; u=500; qnum=1; den=m b; qcruise=tf(num,den); MATLAB representation 1. Transfer FunctionModeling a Cruise Control SystemnOpen-loop response step(u*cruise)n2. State-Space nWe can rewrite the first-order modeling equation

4、(1) as the state-space model.nTo use MATLAB to solve this problem, create an new m-file and copy the following commands: m = 1000; b = 50; u = 500; A = -b/m; B = 1/m; C = 1; D = 0; cruise=ss(A,B,C,D); DuCxyBuAxxMATLAB representationModeling a Cruise Control SystemnOpen-loop response step(u*cruise) M

5、odeling a Cruise Control System in SimulinkUsing Newtons law, modeling equations for this system becomes: (1) Modeling a Cruise Control System in SimulinknBuilding the ModelnOpen-loop response 思考题n本节建立的汽车动力学模型有何问题？n如何改进？n请课后重新建模并编程分析。Modeling a Bus Suspension System using Transfer Functions * body m

6、ass (m1) = 2500 kg,* suspension mass (m2) = 320 kg,* spring constant of suspension system(k1) = 80,000 N/m,* spring constant of wheel and tire(k2) = 500,000 N/m,* damping constant of suspension system(b1) = 350 Ns/m.* damping constant of wheel and tire(b2) = 15,020 Ns/m.* road disturbance (W) * cont

7、rol force (u) = force from the controller we are going to design. Modeling a Bus Suspension System using Transfer FunctionsnPhysical setupnDesign requirementsnEquations of motionnTransfer function equationnEntering equations into MATLABnOpen-loop responseBus Suspension Modeling in SimulinknPhysical setupnBuilding the modelnOpen-loop responsea1v1x1a2v2x2WUSum5Sum4Sum3Sum2Sum1SumSpring 2k2Spring 1k1ScopeMass 2-K-Mass 1-K-Integrator 31sIntegrator 21sIntegrator 11sIntegrator1sDe