Design and experimental evaluations on energy efficient control allocation methods for overactuated electric vehicles: Longitudinal motion case

The energy-efficient control allocation (EECA) scheme was previously proposed to distribute control efforts for overactuated systems by explicitly incorporating efficiency functions and working modes of redundant actuators. In this paper, three different real-time EECA schemes, namely adaptive EECA (A-EECA), KKT-based, and rule-based EECA, are proposed and compared for longitudinal speed tracking control of an electric ground vehicle (EGV) with two pairs of in-wheel motors. Two additional power resistor packs inserted in the dc circuits are applied to modify the operating efficiencies of two rear in-wheel motors, which are calibrated for experimental validations of the three EECA designs on a prototype EGV. In terms of the vehicle speed tracking performances, actuator dynamic responses, and total energy consumptions, both simulation and experimental results are evaluated and compared for the three distinct EECA methods. For the same EGV speed tracking effects, both simulation and experimental results indicate different power consumption savings are achieved by three EECA designs with different dynamic responses.