Nonlinear adaptive backstepping control design of flexible-joint robotic manipulators

In this paper, a nonlinear adaptive backstepping design control scheme is proposed for the trajectory tracking control of flexible-joint robotic manipulators. The difference between flexible-joint and common robotic manipulators is the occurrence of angular errors between motor rotation and link movement In many cases, the end of the link is required to move from one place to another and follows various desired trajectories. In addition, the load conditions and stiffness coefficients are probably unknown, so flexible-joint robotic manipulators with parameter uncertainties would be considered in the design of our nonlinear adaptive backstepping control algorithm. Furthermore, some simulation results are given to illustrate the excellent performance of the nonlinear adaptive backstepping control applied to a two-link flexible joint manipulator.