ESTIMATION DEVICE FOR ESTIMATING FRICTION COEFFICIENT OF ROAD SURFACE AND STEERING DEVICE

An estimation device for estimating a friction coefficient of a road surface includes a sensor, a moment calculator, and a friction coefficient estimator. The sensor is configured to detect a force acting on a wheel. The moment calculator is configured to calculate a moment around a vertical axis at a center of a ground contact load of a tire of the wheel based on an output of the sensor. The friction coefficient estimator is configured to estimate the friction coefficient of the road surface with which the tire is in contact, based on the moment.