Closed loop system is stable if the gains are positive and in addition, .This follows from Routh's stability criterion.

Strategy simple to implement.

PID control is good for slow point-to-point motions of robot.

Steady state error is eliminated.

Lower gains à Saturation of actuators can be avoided.

Fast motion with high performance cannot be possible .

PD and PID control algorithms are for point-to-point motion.

Strategy ideal for robots – With high gear reduction at joints – Carrying out slow speed tasks, material transfer tasks, teach and playback mode, etc.

No need for nonlinear kinematics or dynamics computation in control implementation .