MPC-Based Vibration Control and Energy Harvesting using Stochastic Linearization for a New Energy Harvesting Shock Absorber

Existing Energy Harvesting Shock Absorbers (EHSAs) of vehicle suspensions are mainly designed based on the principle of linear resonance, thereby compromising suspension performance for high-efficiency energy harvesting and being only responsive to narrow-bandwidth vibrations. In this paper, we propose a new EHSA design - inerter pendulum vibration absorber (IPVA) - that integrates an electromagnetic rotary EHSA with a nonlinear pendulum vibration absorber. We show that this design simultaneously improves ride comfort and energy harvesting efficiency by virtue of the nonlinear effects of pendulum's inertia. To further improve the performance, model predictive control (MPC) is designed and evaluated in two cases. In the first case, we directly exploit the nonlinear dynamics of the proposed EHSA into a nonlinear MPC (NMPC) design. In the second case, we develop a novel stochastic linearization MPC (SL-MPC) in which we employ stochastic linearization to approximate the nonlinear dynamics of EHSA with superior accuracy compared to standard linearization. This leads to an MPC problem with bilinear dynamics, which is much more computationally efficient than the nonlinear MPC counterpart with no major performance degradation. Extensive simulations are performed to show the superiority of the proposed new nonlinear EHSA and to demonstrate the efficacy of the proposed SL-MPC.