New PID controllers for step response of robot manipulators with an uncertain Jacobian matrix

In framework of PID controllers, there is only three parameters available to tune, as a result, performance of the resulting system is always limited. As for cartesian regulation of robot manipulators with uncertain Jacobian matrix, a new scheme of PID controllers is proposed to improve performance for step response. Compare with the traditional PID controllers, a time-dependent integration is employ in this proposed controller to improve performance.