Case Study of Energy Optimal and Energy Near-optimal Control Algorithms for the Drives with Constant, Linear and Quadratic Frictions

Design, description and verification of two energy saving position control strategies as case study of their effect on energy consumption for the drives loaded with combined constant, linear and quadratic frictions or load torques is the main contribution of this paper. To decrease energy demands the energy optimal control strategy based on overall losses minimization is compared with the energy near-optimal one based on symmetrical trapezoidal speed-profile for pre-planned rest-to-rest position maneuver. Both control strategies respect prescribed maneuver time and have defined acceleration profile to achieve the demanded position. Overall control system consists of energy saving profile generator, pre-compensator and position control system based on forced dynamics control capable of precise tracking of prescribed state-variables. Energy demands of both control algorithms are verified and compared via simulations results of which confirmed possibility of achieving energy savings.