根据文档中的意思帮我生成对应的MATLAB代码

根据文档内容，您需要使用标准的D-H法和改进的D-H法对SCARA机器人进行建模、仿真，并求解其正、逆运动学。以下是相应的MATLAB代码示例：

### 标准的D-H法

#### 1. 公式求解
首先定义SCARA机器人的D-H参数表：

% D-H参数表 (单位: 米, 弧度)
a = [0, 0.35, 0.35, 0]; % 连杆长度
alpha = [pi/2, 0, 0, 0]; % 连杆扭角
d = [0.15, 0, 0, 0]; % 偏距
theta = sym('theta', [1 4]); % 关节角度

#### 2. 推导齐次变换矩阵
使用D-H参数表推导每个关节的齐次变换矩阵：

syms theta1 theta2 theta3 theta4
T1 = dh_matrix(a(1), alpha(1), d(1), theta(1));
T2 = dh_matrix(a(2), alpha(2), d(2), theta(2));
T3 = dh_matrix(a(3), alpha(3), d(3), theta(3));
T4 = dh_matrix(a(4), alpha(4), d(4), theta(4));

% 总的齐次变换矩阵
T_total = T1 * T2 * T3 * T4;

function T = dh_matrix(a, alpha, d, theta)
    T = [cos(theta) -sin(theta)*cos(alpha) sin(theta)*sin(alpha) a*cos(theta);
         sin(theta) cos(theta)*cos(alpha) -cos(theta)*sin(alpha) a*sin(theta);
         0          sin(alpha)             cos(alpha)            d;
         0          0                      0                     1];
end

#### 3. 仿真图形
绘制SCARA机器人的结构图并进行仿真：

% 定义关节角度
joint_angles = [0, pi/4, -pi/4, 0];

% 计算总的齐次变换矩阵
T_total_val = subs(T_total, {theta1, theta2, theta3, theta4}, joint_angles);

% 提取机器人末端位置
position = double([T_total_val(1,4); T_total_val(2,4); T_total_val(3,4)]);

% 绘制机器人结构图
figure;
hold on;
plot3([0, position(1)], [0, position(2)], [0, position(3)], 'r-o');
axis equal;
grid on;
xlabel('X-axis');
ylabel('Y-axis');
zlabel('Z-axis');
title('SCARA Robot Structure');

% 调用teach函数驱动机器人
robot = robotics.RigidBodyTree('DataFormat', 'column');
addRobot(robot, 'scara_robot.urdf'); % 假设您有一个URDF文件描述SCARA机器人
setJointPositions(robot, joint_angles);
show(robot);

#### 4. 求解仿真结果
输出机器人末端的位置和姿态：

% 输出机器人末端位置
disp(['机器人末端位置: X = ', num2str(position(1)), ', Y = ', num2str(position(2)), ', Z = ', num2str(position(3))]);

% 计算机器人姿态
R = T_total_val(1:3, 1:3);
[Rx, Ry, Rz] = rotm2eul(R, 'ZYX');
disp(['机器人姿态: Roll = ', num2str(Rx), ', Pitch = ', num2str(Ry), ', Yaw = ', num2str(Rz)]);

### 改进的D-H法

#### 1. 公式求解
改进的D-H法通常涉及不同的参数定义方式，假设我们使用以下参数：

% 改进的D-H参数表 (单位: 米, 弧度)
a_improved = [0, 0.35, 0.35, 0]; % 连杆长度
alpha_improved = [pi/2, 0, 0, 0]; % 连杆扭角
d_improved = [0.15, 0, 0, 0]; % 偏距
theta_improved = sym('theta_improved', [1 4]); % 关节角度

#### 2. 推导齐次变换矩阵
使用改进的D-H参数表推导每个关节的齐次变换矩阵：

syms theta1_improved theta2_improved theta3_improved theta4_improved
T1_improved = dh_matrix_improved(a_improved(1), alpha_improved(1), d_improved(1), theta_improved(1));
T2_improved = dh_matrix_improved(a_improved(2), alpha_improved(2), d_improved(2), theta_improved(2));
T3_improved = dh_matrix_improved(a_improved(3), alpha_improved(3), d_improved(3), theta_improved(3));
T4_improved = dh_matrix_improved(a_improved(4), alpha_improved(4), d_improved(4), theta_improved(4));

% 总的齐次变换矩阵
T_total_improved = T1_improved * T2_improved * T3_improved * T4_improved;

function T = dh_matrix_improved(a, alpha, d, theta)
    T = [cos(theta) -sin(theta)*cos(alpha) sin(theta)*sin(alpha) a*cos(theta);
         sin(theta) cos(theta)*cos(alpha) -cos(theta)*sin(alpha) a*sin(theta);
         0          sin(alpha)             cos(alpha)            d;
         0          0                      0                     1];
end

#### 3. 仿真图形
绘制SCARA机器人的结构图并进行仿真：

% 定义关节角度
joint_angles_improved = [0, pi/4, -pi/4, 0];

% 计算总的齐次变换矩阵
T_total_val_improved = subs(T_total_improved, {theta1_improved, theta2_improved, theta3_improved, theta4_improved}, joint_angles_improved);

% 提取机器人末端位置
position_improved = double([T_total_val_improved(1,4); T_total_val_improved(2,4); T_total_val_improved(3,4)]);

% 绘制机器人结构图
figure;
hold on;
plot3([0, position_improved(1)], [0, position_improved(2)], [0, position_improved(3)], 'b-o');
axis equal;
grid on;
xlabel('X-axis');
ylabel('Y-axis');
zlabel('Z-axis');
title('SCARA Robot Structure (Improved DH)');

% 调用teach函数驱动机器人
robot_improved = robotics.RigidBodyTree('DataFormat', 'column');
addRobot(robot_improved, 'scara_robot_improved.urdf'); % 假设您有一个URDF文件描述改进后的SCARA机器人
setJointPositions(robot_improved, joint_angles_improved);
show(robot_improved);

#### 4. 求解仿真结果
输出机器人末端的位置和姿态：

% 输出机器人末端位置
disp(['机器人末端位置 (改进): X = ', num2str(position_improved(1)), ', Y = ', num2str(position_improved(2)), ', Z = ', num2str(position_improved(3))]);

% 计算机器人姿态
R_improved = T_total_val_improved(1:3, 1:3);
[Rx_improved, Ry_improved, Rz_improved] = rotm2eul(R_improved, 'ZYX');
disp(['机器人姿态 (改进): Roll = ', num2str(Rx_improved), ', Pitch = ', num2str(Ry_improved), ', Yaw = ', num2str(Rz_improved)]);

以上代码涵盖了标准的D-H法和改进的D-H法对SCARA机器人的建模、仿真及结果求解。您可以根据实际需求调整参数和代码细节。