CONTROL METHOD FOR HYDRAULIC RETARDER, AND CONTROL SYSTEM

Disclosed are a control method for a hydraulic retarder, and a control system. The method includes: acquiring a slope of a downhill road segment ahead of a vehicle; determining whether an absolute value of the slope is greater than an absolute value of a slope for which a braking force is not required; if so, predicting a required braking force and oil amount for the vehicle at a steady speed; predicting, according to the oil amount, oil filling time and a distance between the vehicle and an origin of the above road segment at the start time of oil filling of the hydraulic retarder; in the case that the actual distance of the vehicle is equal to a predicted distance, starting oil filling; and upon the vehicle reaching the origin of the road segment, starting braking. The present disclosure can lower wear of brake pads and reduce vehicle running costs.