Abstract: As for Cartesian regulation of robot manipulators with uncertain Jacobian matrix, an anti-windup scheme of robust nonlinear PID (RN-PID) controllers is proposed to solve the practical problems arising from integral action and integrator windup in PID-like control systems. Asymptotic stability is guaranteed while position and joint velocity measurements are only required; robustness of the resulting closed-loop system is also guaranteed due to the constraints acting on integral action. Especially, compared with other anti-windup approachs, the proposed algorithm is simpler and more effective for anti-windup design.