修焊机器人非线性关节系统建模与控制算法

Modeling and control of the nonlinear joints system of mobile repair welding robot

针对所研制修焊机器人关节存在死区、间隙等高度非线性环节,影响系统动态响应性能与作业路径精度的问题,采用粒子群优化的方法辨识了含间隙非线性环节的机器人主动关节模型,结合辨识结果采用间隙补偿切换控制算法,并综合采用基于速度逆运动学的前馈反馈复合控制,提高了主动关节的角度跟踪控制精度.控制算法的实际试验结果显示,机器人各主动关节联动控制下的机器人末端作业单元直线路径的平均误差0.2 mm.结果表明,所采用软件算法有效弥补了低精密度减速器的不足,降低硬件成本.

Highly nonlinear units such as deadzone and backlash exist in the joints of mobile repair welding robot,which have negative effects on control accuracy. To improve the path control accuracy of the end effector,Particle swarm optimization algorithm is used to identify the model of the nonlinear joints system. Then switching compensation control method referring the identified model is applied to the joint controlling system,combined with feedfoward-feedback control based on inverse kinematics,the hybrid control method realize considerable path accuracy. Experiments show that the average path error of designed welding robot's end effector is less than 0. 2 mm with this control method,and the shortcomings of low precision reducer are compensated.