Design and control of a linear electromagnetic actuation system for active vehicle suspensions

Traditionally, automotive suspension designs have been a compromise between the three conflicting criteria of road holding, load carrying and passenger comfort. The Linear Electromagnetic Actuation System (LEA) design presented here offers an active solution with the potential to meet the requirements of all three conditions. Using a tubular permanent magnet brushless AC machine with rare earth magnets, thrust densities of over 6 x 105 N/m3 can be achieved with a power requirement of around 50W RMS, much less than equivalent hydraulic systems. The paper examines the performance of the system for both the quarter car and full vehicle simulation, considering high level control of vehicle ride and chassis roll, with the vehicle model being parameterized for a target Jaguar XJ test vehicle. Results demonstrate the ability for 100% roll cancellation with significant improvements in ride quality over the passive Jaguar system.