改进B样条插值法的焊接机器人关节轨迹优化

Research on the Trajectory Optimization of Welding Robot Based on Improved B-Spline Interpolation Method

为了提高汽车车身焊接过程中焊接机器臂轨迹的平稳性和精确度,在B样条插值法为基础上,建立三次B样条曲线数学模型,为使该曲线通过各焊点所对应的焊接机器臂关节空间位姿,反算曲线控制顶点,并对通过在控制顶点两侧添加辅助控制点的方法对机器人各关节进行轨迹优化,以提高机器人运动过程的平滑性。在MATLAB平台进行仿真实验并与三次样条插值法进行对比,优化结果表明,各关节在焊点附近的速度、加速度曲线变得更加平缓,验证了该方法的有效性。

In order to improve the stability and accuracy of the trajectory of the welding robot,a mathematical model of cubic Bspline curve is established on the basis of B-spline interpolation method.The control points of the curve are inversely calculated to make sure that the curve pass through the corresponding joint position and posture of the welding robot.Then,the method of adding auxiliary control points on both sides of the control points is used to optimize the trajectory of the robot.The trajectory optimization is carried out to improve the smoothness of the robot motion process.The simulation experiments on MATLAB platform are carried out and compared with the cubic spline interpolation method.The results show that the curves of velocity and acceleration of the joints near the spot joints become smoother,which verifies the effectiveness of the method.