Rear wheel steering method

Abstract

Abstract PURPOSE:To improve turning-roundability at the early stage of high speed turning and at the same time obtain adequate steering stability as a 4WS by steering rear wheels so that the larger a vehicle speed or the larger front wheel steering angles, the larger the toe-in amount of the rear wheels becomes, at a high speed time when the vehicle speed is above a predetermined value. CONSTITUTION:In a 4WS which controls the rear wheel steering angles of a vehicle according to a vehicle speed and front wheel steering angles thetaf, the rear wheels 18L, 18R of the vehicle are controlled respectively to the toe-ins of steering angles thetarl, thetarr at a high speed time when the vehicle speed is above a predetermined value. The larger the vehicle speed or the larger front wheel steering angles, the larger the toe-in amount is made to become. At the early stage of turning, the cornering force due to each rear wheel of the toe-in is mutually canceled, and the same turning-roundability as in a 2WS may be obtained. While turning, at the later stage, a load is on a rear wheels' turning outer wheel, and functioning as a customary 4WS which makes the front and rear wheels the same phase is done, and adequate steering stability may be obtained.

Inventors

• 👤 Mizuho Sugiyama
• 👤 杉山　瑞穂

Bibliographic Details