Abstract
With the depletion of global energy resources, saving energy has become an important aspect in design of energy consuming equipment. Hence, this paper deals with an optimal time of operation of a manipulator which minimizes the energy dissipated in the actuators. When the manipulator is operated in a vertical plane, the system is highly non-linear due to gravity and an analytical solution can not be found. Therefore, the system is first linearized around various equilibrium points and the existence of an optimal time is investigated theoretically. The theoretical results resemble the simulation of the non-linear system except for a slight difference in the optimal time. The theoretical results and simulations show that an optimal operating time exists when the first link of the manipulator traverses the stable equilibrium point and that it does not exist when the first link traverses the unstable equilibrium point. Finally, a non-linear optimization method is applied to ascertain the accurate optimal time of operation.
