Skid Pad Simple

Maneuver in circles of a nonlinear simple vehicle with Pacejka tire model.

Contents

Code start

clear ; close all ; clc

import VehicleDynamicsLateral.*

Model and parameters

Simulation

T       = 10;                 % Total simulation time [s]
resol   = 100;                % Resolution
TSPAN   = 0:T/resol:T;        % Time span [s]

Tire (default)

TireModel = TirePacejka();

Vehicle

System = VehicleSimpleNonlinear();

% Defining vehicle parameters
System.mF0      = 700;
System.mR0      = 600;
System.IT       = 10000;
System.lT       = 3.5;
System.nF       = 2;
System.nR       = 2;
System.wT       = 2;
System.muy      = 0.8;
System.deltaf   = 20*pi/180;
System.Fxf      = 0;
System.Fxr      = @VelControl; % To keep longitudinal speed.

Simulation

System.tire     = TireModel;
simulator       = Simulator(System, TSPAN);
simulator.V0    = 8.333;

simulator.Simulate();

Results

% Retrieving states
XT      = simulator.XT;
YT      = simulator.YT;
PSI     = simulator.PSI;
VEL     = simulator.VEL;
ALPHAT  = simulator.ALPHAT;
dPSI    = simulator.dPSI;

figure(1)
hold on ; grid on ; box on
plot(TSPAN,XT)
xlabel('time [s]')
ylabel('Distance in the x direction [m]')

figure(2)
hold on ; grid on ; box on
plot(TSPAN,YT)
xlabel('time [s]')
ylabel('Distance in the y direction [m]')

figure(3)
hold on ; grid on ; box on
plot(TSPAN,PSI)
xlabel('time [s]')
ylabel('Yaw angle [rad]')

figure(4)
hold on ; grid on ; box on
plot(TSPAN,VEL)
xlabel('time [s]')
ylabel('Velocity [m/s]')

figure(5)
hold on ; grid on ; box on
plot(TSPAN,ALPHAT)
xlabel('time [s]')
ylabel('Vehicle slip angle [rad/s]')

figure(6)
hold on ; grid on ; box on
plot(TSPAN,dPSI)
xlabel('time [s]')
ylabel('Yaw rate [rad/s]')

Graphics

Frame and animation

g = Graphics(simulator);
g.TractorColor = 'c';

g.Frame();

angulo = 0:0.01:2*pi;

[R,XC,YC] = circfit(XT(40:end),YT(40:end));

XX = XC + R*cos(angulo);
YY = YC + R*sin(angulo);

hold on
plot(XX,YY,'k')

g.Animation();
% g.Animation('html/SkidPadSimple');       % Uncomment to save animation gif

Maneuver radius

disp(num2str(R))

10.7397

See Also

Home | SkidPad Simple 4DOF

Published with MATLAB® R2019b