编写Matlab代码，从而实现三自由度非线性车辆动力学建模

你好，我可以回答这个问题。以下是实现三自由度非线性车辆动力学建模的 Matlab 代码：

function [dx] = vehicle_dynamics(t,x,u)

% Vehicle parameters
m = 150; % Mass of vehicle (kg)
Iz = 300; % Moment of inertia about z-axis (kg*m^2)
lf = 1.2; % Distance from center of mass to front axle (m)
lr = 1.6; % Distance from center of mass to rear axle (m)
Cf = 80000; % Front tire cornering stiffness (N/rad)
Cr = 100000; % Rear tire cornering stiffness (N/rad)
Cd = .3; % Drag coefficient
A = 2.5; % Frontal area (m^2)
g = 9.81; % Acceleration due to gravity (m/s^2)

% State variables
X = x(1); % Longitudinal position (m)
Y = x(2); % Lateral position (m)
psi = x(3); % Heading angle (rad)
vx = x(4); % Longitudinal velocity (m/s)
vy = x(5); % Lateral velocity (m/s)
r = x(6); % Yaw rate (rad/s)

% Input variables
delta = u(1); % Steering angle (rad)
F = u(2); % Driving force (N)

% Nonlinear vehicle dynamics
dx(1) = vx*cos(psi) - vy*sin(psi);
dx(2) = vx*sin(psi) + vy*cos(psi);
dx(3) = r;
dx(4) = (F*cos(delta) - (Cf + Cr)*sin(delta)*vy - Cd*A*vx^2)/(m - (Cf + Cr)*cos(delta));
dx(5) = (F*sin(delta) + (Cf + Cr)*cos(delta)*vy)/(m - (Cf + Cr)*cos(delta)) - vx*r;
dx(6) = (lf*F*sin(delta) - lr*Cr*cos(delta)*vy)/(Iz - lr*Cr*cos(delta)*lf*sin(delta));

dx = dx';

end

希望能对你有所帮助。