This study proposes a multi-mode switching control strategy based on
electromagnetic damper suspension (EMDS) to address the different performance
requirements of suspension systems on variable road surfaces. The working modes
of EMDS are divided into semi-active damping mode and energy harvest mode, and
the proposed mode switching threshold is the weighted root mean square value of
acceleration. For the semi-active damping mode, a controller based on LQR(Linear
Quadratic Regulator) was designed, and a variable resistance circuit was also
designed to meet the requirements of the semi-active mode, which optimized the
damping effect relative to passive suspension. For the energy harvest mode, an
energy harvest circuit was designed to recover vibration energy. In order to
reduce the deterioration of suspension performance caused by frequent mode
switching in the mode switching strategy, as frequent system switching can lead
to system disorder, deterioration of damping effect, and reduction of energy
harvest efficiency, two switching conditions are introduced to increase system
stability, namely mode switching judgment frequency and sampling interval time.
The setting of mode switching judgment frequency is to avoid sudden and
occasional switching, while the setting of sampling interval time is to obtain a
more reasonable weighted acceleration root mean square value. By selecting these
two parameters reasonably, the stability and effect of mode switching can be
optimized. The results indicate that the multi-mode switching control strategy
can achieve reasonable switching of electromagnetic suspension in two modes,
achieving good vibration reduction effect and certain energy harvest
capability.