| As the promoter of the new cycle of information technology revolution,the Internet of Things（Io T）establishes valid data communication between humans and things,and between things and things by virtue of multi-mechanisms sensing,multi-channel communication and multi-modal intelligent processing,and realizes intelligent interconnection of all things.In China,the Io T industry has undergone multiple rounds of development and has already played an essential role in the fields of smart cities,industrial manufacturing and environmental monitoring,and will further develop in the future in combination with emerging technologies.Along with the restructuring of China’s energy source and the innovation of Io T technology,energy supply method of Io T is also facing the challenge of zero carbonization.Although distributed Io T sensing nodes provide wide coverage and massive sensing information,they are currently heavily dependent on batteries or urban power grids for power supply,which is not in accordance with the future development trend of environmentally friendly and zero-carbon energy supply for Io T systems.Due to the rapid advancement of electronic science and technology,self-powered systems that utilize energy from the surrounding environment for energy supply according to local conditions have been extensively studied,providing a feasible technical route for the development of distributed Io T systems.Aiming at the research of the methods of harvesting and utilizing the ambient energy in the self-powered system,this thesis realizes a forest environment monitoring self-powered system based on the electromagnetic-static hybrid energy harvesting technology,through the research and optimization of energy harvesters,the selection of energy transition circuit,the design and optimization of intelligent switch,the design and verification of wireless monitoring node and wireless receiving terminal,and completes the construction and research of the system.The main research of this thesis is as follows:Based on the principle of horizontal sliding contact electrostatic energy harvester,a positive-directional and rotary electrostatic energy harvester（PR-EEH）was designed by combining the structure of inner micro-beams and comb-shaped electrode pairs.After theoretical research and experimental analysis,the PR-EEH changes the characteristics of alternating current（AC）output of the conventional electrostatic energy harvester,and the positive electrical output simplifies the subsequent processing circuit and improves the energy utilization.In purpose of further enhancing the electrical output capability,an electromagnetic-electrostatic based rotary energy harvester（EE-REH）was designed and improved through a combination of electromagnetic energy harvesting technology.After structural improvement and targeted optimization,the EE-REH demonstrates outstanding electrical output capability and reliability,with a peak power density of195.2 m W/m~2 under matched load in the electrostatic section and a matched output power of 4.24 m W in the electromagnetic section,laying the foundation for the realization of a self-powered system.According to the energy supply characteristics of EE-REH,the comparison and fabrication of energy transition circuit,the design and optimization of intelligent switch circuit,the design and fabrication of wireless monitoring node and wireless receiving terminal were completed successively.Finally,the discrete devices such as EE-REH,energy transition circuit,intelligent switch circuit,wireless monitoring node and wireless receiving terminal were integrated to complete the construction and verification test of the self-powered system for forest environment monitoring,which proved the feasibility of realizing the self-powered system. |
