Model Predictive Speed Control of a Digital Hydraulic Drive

Model Predictive Control (MPC) strategies have already been successfully studied for digital hydraulics, especially to control the torque of digital hydraulic drives and the pressure of digital hydraulic transmissions. A great improvement of the efficiency was appreciated, at the expense of a large computational time. This paper proposes a novel approach of the MPC which aims at controlling the rotational speed of a digital hydraulic motor. The new cost function that is introduced in this paper enables the motor performance to be balanced between precision and energetic efficiency. This algorithm is then compared to another control strategy which allows as well to regulate the rotational speed of the motor very accurately, using the torque as intermediate variable instead of the motor displacement. The performance of both control laws are illustrated in simulation.