Autonomous Positioning of a Mobile Robot for Wireless Charging Using Computer Vision and Misalignment-Sensing Coils

摘要

Mobile robots have been the subject of research and experimentation for several decades. They combine mobility, sensor feedback, and smart control to achieve specific tasks-many times autonomously. One such task is autonomous charging. In this paper, the autonomous positioning of a differential-drive mobile robot above an inductive wireless charger is tested. Wireless charging is an increasingly popular technology for contactless power transfer, but it usually requires precise positioning of the receiver above the charger for effective charging to take place. The experimental mobile robot in this paper uses a camera sensor and computer-vison algorithm to approach a color target that marks the charger location. Then, the mobile robot uses misalignment-sensing coils to detect and correct small lateral misalignments with the charger. Measurements from the encoders on the robot wheels are used in a dual-loop controller featuring a linear quadratic regulator (LQR) to achieve the robot control objectives. The robot is successful in approaching and positioning itself within ±5 mm of the wireless charger center in several experimental trials. The hardware and control methods used in this experiment can be applied to similar systems to achieve autonomous wireless charging.