Research And Design Of A Capsule-Like Robot Wireless Powering System Based On Class-E Inverter

The power supply problem is one of the main problems facing the capsule-like robot technology. The normal wireless capsule-like robot relies on human intestinal peristalsis and powered by batteries. But to achieve accurate measurement and high quality pictures, take sample of the lesion and local operation treatment, the way to acquire electric energy is far inadequate, we must use a method which can provide adequate, stable power supply——In vitro wireless power supply. The present study for wireless power supply system for the capsule-like robot is still in the initial stage, there are many issues worthy of further exploration. Such as the transmitter power and efficiency is not high, the received power is low, the performance can be greatly reduced when increase the using frequency, the resonance between the stability problems, coil position stability problems, attitude stability problem. Aiming at these problems, this paper carried out the following research.Study on the method of improving the transmitter power, efficiency, operating frequency. Because of its special application, capsule-like robot wireless power supply system adopt coupling coil by big coil to small coil structure, is weak coupling power supply form. This system chooses the class-E inverter as the transmitter of the inverter, make optimization design and parametric modeling of class-E inverter from a new point of view. Analyze the transmitter circuit characteristics, parameters of actual circuit on the circuit performance, the properties of important electronic devices. Design and implement of the transmitter circuit of high frequency, high power, high efficiency of wireless power supply system, and the loop current with the input power supply voltage is in linear relation, the system has good repetition.Study on the emission coil structure model, make the magnetic field simulation analysis, and analyze the influence of coil parameters on the system, design the wireless power supply system coupling coil. The actual tests results show that, the coupling coil designed improved frequency effect, position stability, and attitude stability.In order to solve the problem of system resonance frequency offset, This system design a good stability, induction type current sensor which has small influence on the transmitter loop, and DC bias circuit, voltage comparator, PLL circuit and power. Finally design and implement frequency tracker, solves the problems such as the resonance point offset, enhance the stability of the system.Improved rectifying circuit structure, reduced the ripple, and improved the commutating performance. In different voltage and different load, this paper made receive power and stability testing of the wireless power supply system, test results show that, the wireless power supply system has high receiving power and output stability.