DESIGN AND ANALYSIS OF A WIRELESS POWER TRANSMITTING SYSTEM FOR CAPSULE ROBOT USING TWO-DIMENSIONAL COMBINED SOLENOID COILS

摘要

Wireless power transmission system (WPTS) based on electromagnetic induction is a promising way to power a gastrointestinal capsule robot (CR) for wireless diagnosis, which typically consists of a one-dimensional (1-D) power transmitting coil (PTC) to excite an alternating magnetic field and a three-dimensional (3-D) power receiving coil (PRC) to induce signal. However, it is difficult to apply a 3-D PRC to practical medical applications since the oversize bodily form of the mounting receiver brings the extra challenge of design for microCR. This paper proposes a novel WPTS with a space-saving architecture by combining a two-dimensional (2-D) PTC outside the human and 1-D PRC onboard the CR, which can permit CR to accomplish the mission of exploring the intestinal space with wireless energy supplying owing to small size related to 1-D PTC. The analytical expressions of the magnetic flux density, magnetic field orientation, and uniform magnetic field excited by the designed PTC are derived. Simulated and experimental outcomes are implemented to achieve the desired magnetic field strength and direction by changing the transmission current of PTC, which verifies the feasibility and effectiveness of developed methods. And the magnetic field uniformity is greater than 44%. It can basically cover the 20 cm 20 cm area of the human abdomen at all times, which can permit the operational requirements of the CR in the practical case.