Research On The Control Module Of Human Digestive Tract Inspection Micro-Robot

The research on human digestive tract inspection micro-robot is helpful to break the bottleneck of the traditional capsule endoscope. The control module of human digestive tract inspection micro-robot is discussed in this paper. An effective and robust overall system design is detailed, which is constituted by an internal micro-robot module, a main-control board and a remote PC. We focus on the micro-robot module design with several novel ideas. More specifically, brushless DC motor and shape memory alloy (SMA) are both deployed to the micro-robot’s motion part. Then, an appropriate microcontroller and other hardware components are employed. The key point of our hardware design is concentrated on the overall functions, physical size shrink, and to lower the system power consumption.The brushless DC motor control algorithm is presented. In this algorithm, the motor’s phase-switch progress is realized by back electromotive force signal detection rather than the position sensors. A brushless DC motor simulation model is built in MATLAB simulink, which shows the sensorless control and PID speed control process. And then, the SMA is driven by current heating and natural cooling. Furthermore, the SMA temperature simulation model is applied, which shows all the heating, cooling and holding state of SMA temperature. Simulation results show that the control algorithm can implement the control requirements of brushless DC motor and SMA.The software system is also designed based on polling and interrupt. To achieve multi-task real time response, the task flags are cyclic queried and then execute corresponding software operation. In additional, the high priority tasks can be carried on first by interrupt. The CPU time can be shared segmented to get better real-time achievement.To get better low power consumption performance, both the power management and the software optimization are taken into account. In the power management, we chose appropriate supply mode, according to characteristics of control chip, to optimize the circuit power consumption. In the software design, we allocate exact system state to adequately conserve energy and extend the working hours.