Capacitive gap and yaw angle sensor for linear drives

For long primary linear drives with passive vehicles, no auxiliary energy or information is transferred between stationary parts and the moving vehicles. In order to simplify the mechanical construction, a magnetic guiding system for the lateral position and the yaw angle was developed. To control the lateral position and the yaw angle, a capacitive sensor is proposed, which needs no auxiliary energy or information transfer between stationary and moving parts. In order to improve the control quality, the sensitivity towards yaw angle was analyzed considering the effect of parasitic capacitances and the length and position of electrodes. FEM analysis and experimental results confirm the viability of the new sensor.