In order to accurately control the height of the suspension

a novel digital non-contact inductance sensor LDC1614 is adopted to detect the suspension clearance. LDC1614 is a four-channel

28 bits digital inductance sensor with inter-integrated circuit（IIC） interface. Digital quantity of 4 channels is tested by the four self-made inductance coils

evenly distributed on the same straight line. And corresponding suspension clearance is obtained by table look-up. It can ensure the rail gap will not appear infinite gap situation by adding numerical judgments in the software. At the same time

a temperature sensor is added to the circuit to achieve temperature compensation

and a repetitive calibration method is used to make the repeatability and precision of digital eddy current sensor meet the requirements.