<div class="section abstract"><div class="htmlview paragraph">Electromagnetic suspension systems have increasingly gained widespread attention
due to their superiority in improving ride comfort while providing fast
response, excellent controllability and high mechanical efficiency, but their
applications are limited due to the accuracy of the underlying control actuation
tracking. For addressing this problem, this study presents a novel hierarchical
control strategy for an electromagnetic active suspension (EMAS) system equipped
with an electromagnetic actuator (EMA) structure. The structure of the EMA
device and the working principle of the motion conversion model are introduced
in detail first, and the motion conversion equation is derived based on the
force-torque relationship. Based on this, a linear quadratic regulator (LQR)
control method is proposed to be applied to a half-vehicle suspension system to
improve the vibration isolation performance of the vehicle and ensure the ride
comfort. Then, the underlying layer control of the permanent magnet synchronous
motor (PMSM) based on field-oriented control (FOC) is adopted to tracking the
active control forces generated by the upper LQR controller. Immediately
afterwards, the EMA converts the torque generated by the motor into vertical
forces acting on the suspension through rational synergies between the upper LQR
controller and the underlying motor controller, which ultimately achieves active
control of the vehicle suspension system. The simulations are carried out from
the perspective of the half-vehicle integrated with the EMA, which demonstrate
that the proposed EMAS system has greatly reduced vehicle vertical and pitch
accelerations compared to the conventional passive suspension, significantly
improving the ride comfort and vibration isolation effect on external
excitation.</div></div>
