This paper concerns the problem of output feedback tracking (OFT) control with bounded torque inputs of robot manipulators

and proposes a novel saturated OFT controller based on fuzzy self-tuning proportional and derivative (PD) gains. First

aiming to accomplish the whole closed-loop control with only position measurements

a linear filter is involved to generate a pseudo velocity error signal. Second

different from previous strategies

the arctangent function with error-gain is applied to ensure the boundedness of the torque control input

and an explicit system stability proof is made by using the theory of singularly perturbed systems. Moreover

a fuzzy self-tuning PD regulator

which guarantees the continuous stability of the overall closed-loop system

is added to obtain an adaptive performance in tackling the disturbances during tracking control. Simulation showed that the proposed controller gains more satisfactory tracking results than the others

with a better dynamic response performance and stronger anti-disturbance capability.