The implementation of tracking controls for an automobile robot based on wire magnetic induction

Navigation to follow special trajectories or move within working boundaries is very essential for automobile robots, especially for mission-oriented service robots. For example, a kind of auto-mower is one with the capability of cutting grass automatically within the area with the wired boundary surroundings. While weakened power status is happening, it can trace the boundary wire back to the charging port to charge electric power. Therefore, based on the measurement of magnetic induction sensing, a navigation system and the tracking controls for an automobile robot are implemented in this paper. The navigation system includes a magnetic field detecting sensor designed to sense the magnetic induction on an armature sensor and an AC signal excited in the boundary wire, so as to the armature sensor can be induced a voltage change which is proportional to the distance between the boundary wire and the armature sensor. Considering commercial applications, the signal transformation is designed further, and the control algorithms are designed by VHDL and implemented by a FPGA. For validations, the excellent results of the tracking controls for an automobile robot to follow a boundary wire are shown in the paper.