Investigations into Alternative Suspensions for Commercial Vehicles

The ride dynamics of articulated heavy trucks were studied to assess the benefits of applying electronically controlled suspension elements. Computer simulations were used to compare passive, two-state and continuous semi-active, and fully active suspensions. These results prompted further work to develop a prototype active suspension, operating according to a limited bandwidth strategy, which was tested on a full size, single-wheel-station vibration rig. With the active prototype, root mean square body vertical acceleration was 30% lower than with a production air suspension, during a test simulating travel over a very good road profile. RMS dynamic tyre forces, generated by the active prototype were similarly 20% lower. Mean power consumption during this test was 1.2kW. Further consideration of the limited bandwidth active suspension led to the invention of a substantially passive equivalent. This passive equivalent was also tested and gave results indistinguishable from those of the active prototype.