Design of a Pneumatic drive train with regenerative braking

In automobiles, Regenerative Braking (RB) / Acceleration Assist (AA) System captures a portion of the Kinetic Energy (KE) dissipated during braking and stores it in a reusable form to assist the subsequent acceleration of the vehicle. This improves the energy efficiency and reduces vehicle emissions. Electric hybrid cars employing regenerative braking systems are popular, but they are expensive and cannot capture energy at low speeds. Heavy trucks employ Hydraulic Regenerative Braking, which uses a hydraulic pump to pressurize hydraulic oil and stores the energy in a high pressure accumulator for reuse. They are heavy, bulky and expensive to be used in Light Motor Vehicles (LMVs). Hence there is a need for a low cost alternative to capture energy at low speeds. In an unconventional and unique attempt, we employ fluid power (Pneumatics) to build a Parallel RB/AA prototype for LMVs. Modeling, design, development and fabrication of a Parallel Pneumatic drive train with Regenerative Braking and Acceleration Assist (PPRB/AA) system has been attempted. Physical models were built and validated through simulation and experiments. A functional prototype of RB/AA system has been successfully built, mounted on a Go-kart and tested. Results show that even at very low velocities, energy lost during braking can be captured, stored and reused gainfully. Hence Parallel Pneumatic RB/AA system is a green and feasible alternative for LMVs operating at low urban velocities.