Performance Evaluation of an Electromechanical Linear Actuator with Optimal Trajectories

Emission reduction targets in both highway trucks and off-road vehicles have turned the electrification focus into vehicle mountable equipment such as loader cranes and tail lifts. Nowadays, these devices are powered by hydraulic linear actuators, which provide cost-efficient and robust solutions that also fulfill lifting device safety standards. However, lifting device electrification has the potential to offer several advances, such as efficient utilization of on-board battery with fewer components and energy conversions. In order to contribute to the electrification trend, different aspects of substituting those conventional actuators with the almost new electromechanical linear actuators (EMLA) technology need to be investigated. This paper studies the different energy conversion processes in the EMLA for a heavy-duty mechanism and estimates the loss in each component. The investigation of energy conversion processes in EMLA paves the way for obtaining the efficiency map of the system and its power flow with the purpose of performance analysis. To this end, all the mentioned energy conversions are categorized into desirable and power loss categories. Subsequently, the dynamic model of one degree of freedom (DOF) parallel-serial mechanism is exerted in a trajectory optimization framework. Objectives such as minimum effort, energy expenditure, and delivered power are selected to generate optimal trajectories that feed the efficiency algorithms and examine the EMLA performance. The results show the efficacy of the above-mentioned trajectories concerning the criteria costs, total time, and efficiency of the whole system.