The Implementation in VISSIM REALTIME of an Active Electromagnetic Damper Controller for Lightweight Electric Vehicles

Abstract

The use of linear electromagnetic active damper units in the suspension system of a lightweight electric vehicle offers many advantages over conventional passive, semi-active and active hydraulic dampers. While full active hydraulic systems have been commercially available in automobiles for many years, the linear electromagnetic active damper offers a lower weight system with a much reduced power demand. However an active system requires the use of a controller to adjust the power output to the damper unit. This unit must process signal inputs and provide an output solution within a short time period, often 5 milliseconds or less. By using VISSIM REALTIME, a controller was built that controlled a scale linear electromagnetic damper using Karnopp’s Skyhook algorithm. This had to deal with issues such as accelerometer drift and signal to noise ratio. These required simple but fast techniques to provide useful information to the damper in a useful timeframe. This controller-damper combination proved effective in reducing the vibration experienced by the sprung mass and was more effective than an ideal passive damper at all frequencies tested by at least a factor of three.