Patent ID: 9612600
Date: 2017-04-04
CPC Classifications: G02B,G05B,G05D,H02P

Claim:
1. A controller of a linear motion device including a magnet attached to a moving body and disposed adjacent to a driving coil, the controller comprising: a magnetic field sensor configured to detect a magnetic field generated by the magnet and output a detection position signal value corresponding to a value of the magnetic field; a calibration operation circuit configured to obtain the detection position signal value and generate a detection position operation signal value; a device position instruction signal generation circuit configured to output a target position signal value for instructing a target position to which the linear motion device is to move; a leak magnetic field correction circuit configured to correct the target position signal value and output a target correction position signal value; a PID control circuit configured to output a control signal based on the detection position operation signal value and the target correction position signal value; and an output driver configured to supply a driving current to the driving coil to move the moving body to the target position based on the control signal, wherein the leak magnetic field correction circuit is configured to correct the target position signal value based on the control signal and a value of a leak magnetic field caused by the driving coil, and the value of the leak magnetic is calculated based on a difference between the detection position signal value when an electric power is not supplied to the driving coil and the detection position signal value when the electric power is supplied to the driving coil.