High-energy orbit sliding mode control for nonlinear energy harvesting

Abstract

Vibration energy harvesting has extensive application prospects in many significant occasions, such as mechanical structure health monitoring, vehicle tire pressure monitoring, IoT devices and human health monitoring. The nonlinearity is an effective method to improve the energy harvesting efficiency where there are low-and high-energy orbits in the multi-solution region of the system. The harvested power will be increased significantly when the system is guided from the low-energy orbit to the high-energy orbit. However, previous research mainly focuses on the theoretical and numerical investigation of controlling strategy, but the feasibility of control methods has not been verified experimentally. This paper proposes a high-energy sliding mode control method through rotatable magnets actuated by micro-motor. The electromechanical model of mono-stable and bi-stable systems with the identified nonlinear restoring force is established to design a sliding mode control algorithm for enhancing the energy 2 harvesting performance. Simulation and experiment results demonstrate that the rotatable magnets with sliding mode control have a positive influence on reaching the high-energy orbit for both mono-stable and bi-stable systems within the multisolution region. Moreover, the rotatable magnets method with a sliding mode control actuates the small magnets in the system for a short time with little consumption of energy. This research has provided a practical application of highenergy orbit control for improvement of the energy harvesting.

Modeling and analysis of magnetically coupled piezoelectric dual-beam with an annular potential energy function for broadband vibration energy harvesting

“…Here repulsive force between the two magnets is chosen for generating a two-dimensional interaction between the two cantilevers. Indeed, similar configurations were analyzed previously [28,[35][36][37][38][39][40][41][42]. On the other hand, these researches focused on one-dimensional features of adjustable potential wells or multiple directional harvesting.…”

“…It is also worth mentioning that the bistable PEHs with dynamic potential wells [35][36][37][38][39][40][41][42] may have similar potential functions in two-dimensional space. On the other hand, the cantilevers in the abovementioned reseraches have large or different stiffnesses.…”

“…For another example, potential well with multiple stable states would also enable large amplitude motion [25,26]. Inter-well modulation is used to reduce the barrier height and make inter-well oscillation easier to achieve [35][36][37][38][39][40][41][42]. In addition, it was demonstrated that an external impact force can trigger a jump phenomenon between two potential wells under small amplitude excitations [27].…”

Adaptive tracking control of a new nonlinear energy harvester system based on the cantilever beam structure

“…The signal y r is the desired output signal to harvest the desired energy in an uncertain excitation. While in Zhang et al (2021), the desired output is the desired trajectory of high-energy orbit in the certain excitation. Now, the adaptive DSC procedure is implemented in two steps, which is presented below.…”

“…In order to harness most energy from the ambient vibrations, a disturbance observer-based sliding mode control with input saturation is designed in Yousefpour et al (2020) to push the system from low-energy periodic and chaotic attractors to high-energy periodic attractors. In Zhang et al (2021), an implement method is presented by adjusting rotatable external magnets based on sliding mode control.…”