Review on Gravity Compensation by Mechanism Synthesis

An articulated robot spends a very high amount of energy carrying the weight of its own arm while working against gravity, which results in an increase in size actuators, which also increases the expense and weight of the system. Thus, a high amount of actuated power is utilized to compensate for the gravitational torques. Gravitational Torques are generated due to the mass of the robot arm and inertia of the payload. This torques severely affect the dynamic performance of the robot and the ability to withstand external forces. The presented review paper gives a detailed idea on various methods to compensate the gravitational torque, in which the gravity effect is compensated fully by a mechanical structure that reduces the actuator size.