基于后推技术的绳驱动拟人肩关节动力学控制

Dynamic control of a cable-driven humanoid-shoulder joint based on backstepping technique

针对并联式绳驱动机器人建模困难、控制复杂等问题,采用拉格朗日动力学建模方法,推导得到便于控制器设计的标准动力学方程,考虑绳驱动的冗余特性和绳索的单方向受力性,提出基于最小预紧力的张力分配算法,求解出各绳索的驱动力.针对机器人轨迹跟踪控制问题,设计了基于后推技术的系统模型控制律.仿真结果表明:后推技术法在收敛速度方面明显优于计算力矩法,且各绳索的驱动力皆能满足其张紧所需的最小张力.

Aiming at the problems that cable-driven parallel manipulator is difficult to create model and control,the dynamic model of the humanoid-shoulder joint was built by using Lagrange dynamics method so as to obtain the standard form of dynamic equation.Taking into account the redundant actuation and single-direction force for the cable,tension distribution algorithm based on the minimum pre-tightening force was proposed to calculate driving force of each cable.Based on backstepping technique,the control law of the system model was designed for the robot trajectory tracking control problem.The results of simulation show backstepping-based control method is superior in convergence speed,and the driving force of each cable is more than the required minimum tension to keep the cable tensional.