Design and implementation of a magnetic levitation control system for robotically actuated capsule endoscopes

In this paper, a new and simple actuation system based on a magnetic levitation is proposed to move a small permanent magnet embedded in a Wireless Capsule Endoscope (WCE) for inspection of the colon. This study focuses on the design of a PID linear controller to hold the WCE and maintain it at a desired position relative to the robotic movable frame so that it can navigate the bowel by moving this frame and/or the patient. The controller output in the form of pulse width modulation (PWM) is based on position feedback from magnetic sensors. A realistic simulation model is designed and implemented in Matlab/Simulink to validate the proposed controller. To verify the effectiveness of the proposed system, the controller is implemented, based on the TMS320F2812 digital signal processor (DSP). The real-time tracking performance of the control system is evaluated based on step and square reference trajectories. Simulation and experimental results are included showing the performance of the proposed controller for capsule actuation.