PREVIEW ROAD SURFACE DETECTOR, SUSPENSION CONTROLLER, AND PREVIEW ROAD SURFACE DETECTION METHOD

A preview road surface detector capable of discontinuing predictive control is provided, which suppresses the energy consumption required to determine whether predictive control should be discontinued. The preview road surface detector includes: a distance sensor provided on a vehicle body member, the distance sensor detecting a value related to a distance between the vehicle body member and a measurement point on a road surface ahead of a vehicle, the measurement point corresponding to at least part of a road surface contact portion of a wheel; and a distance calculator that calculates a road surface distance as the distance from the vehicle body member to the measurement point, based on a detection value detected by the distance sensor, in which the distance sensor is deactivated under a predetermined condition.