152 lines
5.5 KiB
Python
152 lines
5.5 KiB
Python
import math
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import numpy as np
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import matplotlib.pyplot as plt
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from mpl_toolkits.mplot3d import Axes3D
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from matplotlib.widgets import Slider
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# 设置中文字体
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plt.rcParams['font.sans-serif'] = ['SimHei', 'Arial Unicode MS', 'DejaVu Sans']
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plt.rcParams['axes.unicode_minus'] = False
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class SpatialTwoLinkArm:
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def __init__(self, l1=1.0, l2=1.0):
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self.l1 = l1
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self.l2 = l2
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self.theta1 = 0.0 # 绕Z轴旋转（偏航，Yaw）
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self.theta2 = 0.0 # 绕Y轴旋转（俯仰，Pitch）
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# 创建3D图形
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self.fig = plt.figure(figsize=(10, 8))
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self.ax = self.fig.add_subplot(111, projection='3d')
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self.ax.set_xlim(-2, 2)
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self.ax.set_ylim(-2, 2)
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self.ax.set_zlim(0, 2)
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self.ax.set_xlabel("X")
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self.ax.set_ylabel("Y")
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self.ax.set_zlabel("Z")
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self.ax.set_title("空间两自由度机械臂（绕Z轴 + 绕Y轴俯仰）")
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self.ax.grid(True)
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# 绘制机械臂
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self.line_link1, = self.ax.plot([], [], [], 'b-', linewidth=4, label='连杆1')
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self.line_link2, = self.ax.plot([], [], [], 'r-', linewidth=4, label='连杆2')
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self.joint_point, = self.ax.plot([], [], [], 'go', markersize=8, label='关节2')
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self.end_point, = self.ax.plot([], [], [], 'mo', markersize=8, label='末端执行器')
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self.base_point, = self.ax.plot([0], [0], [0], 'ko', markersize=10, label='基座')
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self.ax.legend()
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# 添加角度显示文本
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self.angle_text = self.ax.text2D(
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0.02, 0.95, '', transform=self.ax.transAxes,
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fontsize=10, bbox=dict(boxstyle="round", facecolor="wheat")
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)
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# 添加滑块控制
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self.slider_ax_theta1 = plt.axes([0.2, 0.1, 0.5, 0.03])
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self.slider_ax_theta2 = plt.axes([0.2, 0.05, 0.5, 0.03])
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self.slider_theta1 = Slider(self.slider_ax_theta1, 'θ1(绕Z轴)', -np.pi, np.pi, valinit=0, valfmt="%.2f rad")
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self.slider_theta2 = Slider(self.slider_ax_theta2, 'θ2(俯仰角)', -np.pi/2, np.pi/2, valinit=0, valfmt="%.2f rad")
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self.slider_theta1.on_changed(self.on_slider_change)
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self.slider_theta2.on_changed(self.on_slider_change)
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# 初始绘制
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self.update_plot()
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def rotation_matrix_z(self, theta):
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"""绕Z轴旋转矩阵"""
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return np.array([
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[np.cos(theta), -np.sin(theta), 0],
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[np.sin(theta), np.cos(theta), 0],
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[0, 0, 1]
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])
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def rotation_matrix_y(self, theta):
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"""绕Y轴旋转矩阵"""
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return np.array([
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[np.cos(theta), 0, np.sin(theta)],
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[0, 1, 0],
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[-np.sin(theta), 0, np.cos(theta)]
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])
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def fk(self, theta1, theta2):
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"""正向运动学：返回关节1和末端的位置"""
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# 关节1位置（绕Z旋转后）
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joint1 = np.array([self.l1, 0, 0])
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joint1 = self.rotation_matrix_z(theta1) @ joint1
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# 连杆2的方向：初始沿X轴，先绕Y转θ2，再绕Z转θ1
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link2_dir = np.array([self.l2, 0, 0])
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link2_dir = self.rotation_matrix_z(theta1) @ (self.rotation_matrix_y(theta2) @ link2_dir)
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end_effector = joint1 + link2_dir
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return joint1, end_effector
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def ik(self, x, y, z):
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"""逆向运动学：给定末端位置(x,y,z)，求θ1和θ2"""
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# θ1 由 x,y 决定（绕Z轴）
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theta1 = math.atan2(y, x)
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# 在局部坐标系中，x' = sqrt(x^2 + y^2), z' = z
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x_prime = math.sqrt(x*x + y*y)
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z_prime = z
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# 现在是2D平面问题：连杆1长度l1，连杆2长度l2，目标(x_prime, z_prime)
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d_sq = x_prime*x_prime + z_prime*z_prime
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cos_theta2_numerator = d_sq - self.l1**2 - self.l2**2
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denominator = 2 * self.l1 * self.l2
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if abs(cos_theta2_numerator) > abs(denominator):
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return None # 不可达
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cos_theta2 = np.clip(cos_theta2_numerator / denominator, -1.0, 1.0)
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theta2 = math.acos(cos_theta2)
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# 修正方向：确保z方向正确
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# 注意：这里假设θ2是向上为正（z>0）
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# 可扩展为elbow_up/down选择
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return theta1, theta2
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def update_plot(self):
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"""更新3D图像"""
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joint1, end_effector = self.fk(self.theta1, self.theta2)
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# 确保使用numpy数组以避免shape属性问题
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joint1_np = np.array(joint1)
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end_effector_np = np.array(end_effector)
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# 更新线条
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self.line_link1.set_data_3d([0, joint1_np[0]], [0, joint1_np[1]], [0, joint1_np[2]])
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self.line_link2.set_data_3d([joint1_np[0], end_effector_np[0]], [joint1_np[1], end_effector_np[1]],
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[joint1_np[2], end_effector_np[2]])
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self.joint_point.set_data_3d([joint1_np[0]], [joint1_np[1]], [joint1_np[2]])
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self.end_point.set_data_3d([end_effector_np[0]], [end_effector_np[1]], [end_effector_np[2]])
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# 更新角度显示
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angle_str = f"θ1 = {self.theta1:+.3f} rad\nθ2= {self.theta2:+.3f} rad"
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self.angle_text.set_text(angle_str)
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self.fig.canvas.draw_idle()
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def on_slider_change(self, val):
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"""滑块变化时更新角度"""
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self.theta1 = self.slider_theta1.val
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self.theta2 = self.slider_theta2.val
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self.update_plot()
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def show(self):
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plt.show()
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# ========================
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# 主程序
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# ========================
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if __name__ == "__main__":
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print("使用滑块控制空间两自由度机械臂！")
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arm = SpatialTwoLinkArm(l1=1.0, l2=1.0)
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arm.show() |