Modeling and Implementation of LQR controller for Efficient EV Suspension Energy Harvesting

Abstract

Over the years, the global interest in the Electric Vehicle (EV) market has grown significantly. These vehicles are powered by electricity from off and on-vehicle sources. However, some of the challenges posed by most of these power sources are limited capacity, charging time constraints, availability of charging infrastructure, charger compatibility, etc. These consequently shortens the driving distance an EV can cover as long-distance trips will lead to more unwanted stops. In a bid to augment these sources, vibration energy from the vehicle suspension is harvested and converted to electricity for charging an onboard battery, consequently improving its mileage. In spite of this, a major issue with these vibration energy harvesters is that the device delivers weak output power when excited at frequencies outside their resonance frequencies. The motivation for this research stems from the need to model a low power consumption energy harvesting device that harvests energy rather wasted in the EV’s suspension. Also, to auto-tune its resonance frequency rapidly to coincide with the excitation frequency for maximum energy harvesting. This will be achieved by modeling an electromagnetic transducer which is controlled by a piezoelectric actuator. The spring stiffness will be altered by applying voltage to the piezoelectric actuator which will thereby widen the bandwidth of the energy harvester so as to ensure excitations below and above its natural resonance frequency. It is anticipated that the implementation will be carried out and the expected results should show optimized energy harvesting, improved tuning time and minimal energy consumption.