# Thread: Regenrative Suspension System for HGVs

1. ## Regenrative Suspension System for HGVs

Ok, so im having some trouble modelling a problem mathematically.

I am designing a suspension system for a truck. It will consist of a variable rate spring and a double sided rack and two pinions on roller clutches either side of the rack. The rack and pinion setup will drive a flywheel which will drive a generator. The double sided rack and pinions on roller clutches will make it possible to achieve a uni-directional motion of the flywheel irregardless of there being a positive or negative displacement of the rack. The rack will be attached directly to the axle and it is hoped that the rack and pinion driving a generator will act as the damping for the system.

I am having trouble modelling the system mathematically. I have decided to input a road profile as a sine wave and chose a pinion radius. Mapping the displacement of the rack from its zero position allows me to calculate the rpm of the pinion but I am unsure of how to map the varying torques being transferred to the system from the rack. Here is my initial calculations on excel. These are rough obviously just so i can begin sizing parts.

Any help would be much appreciated, completing this for my final year project and my supervisor is useless.
Best Regards, George