US-OS characteristic control system for a vehicle responding to turning state quantity and the changing rate thereof

• US 5,013,062 A
• Filed: 12/29/1989
• Issued: 05/07/1991
• Est. Priority Date: 12/28/1988
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Sato, Kinihito, Buma, Shuuichi, Yonekawa, Takashi, Onuma, Toshio, Ikemoto, Hiroyuki, Ohashi, Kaoru, Aburaya, Toshio
• Primary Examiner(s): BERTSCH, RICHARD A
• Application Number:
  US07/459,325
• Time in Patent Office: 494 Days
• Field of Search: 280/707, 280/709, 280/714, 280/703, 280/91, 180/141, 180/79.1, 364/424.05
• US Class Current: 280/5.503
• CPC Class Codes: B60G 17/016 characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input B60G17/017 takes precedence
• CPC Class Codes: B60G 17/017 characterised by their use when the vehicle is stationary, e.g. during loading, engine start-up or switch-off
• CPC Class Codes: B60G 2202/15 Fluid spring
• CPC Class Codes: B60G 2204/80 Interactive suspensions; arrangement affecting more than one suspension unit
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2400/106 longitudinal with regard to vehicle, e.g. braking
• CPC Class Codes: B60G 2400/20 Speed
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2400/30 Propulsion unit conditions
• CPC Class Codes: B60G 2400/38 Speed of engine rotation
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2400/50 Pressure
• CPC Class Codes: B60G 2400/51 in suspension unit
• CPC Class Codes: B60G 2400/73 of other part than suspension unit
• CPC Class Codes: B60G 2500/10 Damping action or damper
• CPC Class Codes: B60G 2500/20 Spring action or springs
• CPC Class Codes: B60G 2500/30 Height or ground clearance
• CPC Class Codes: B60G 2600/04 Means for informing, instructing or displaying
• CPC Class Codes: B60G 2600/08 Failure or malfunction detecting means
• CPC Class Codes: B60G 2600/12 : Sampling or average detecting; Addition or substraction
• CPC Class Codes: B60G 2600/14 : Differentiating means, i.e. differential control
• CPC Class Codes: B60G 2600/16 : Integrating means, i.e. integral control
• CPC Class Codes: B60G 2600/20 : Manual control or setting means
• CPC Class Codes: B60G 2600/602 : high pass
• CPC Class Codes: B60G 2600/68 : Filtering means, e.g. fluid filters
• CPC Class Codes: B60G 2600/70 : Computer memory; Data storage, e.g. maps for adaptive control
• CPC Class Codes: B60G 2800/012 : Rolling condition
• CPC Class Codes: B60G 2800/014 : Pitch; Nose dive
• CPC Class Codes: B60G 2800/22 : Braking, stopping
• CPC Class Codes: B60G 2800/244 : Oversteer
• CPC Class Codes: B60G 2800/246 : Understeer

Abstract

In a system for controlling the US-OS characteristic of a vehicle having front and rear suspensions, a device for changing the US-OS characteristic is provided which is adapted to alter the roll stiffness distribution between the front and the rear suspensions. A turning state quantity is detected and the changing rate of a turning state quantity is determined. A control device is further provided which is adapted to respond to the turning state quantity and the changing rate of the turning state quantity, and to control the US-OS characteristic changing device so that the higher the changing rate of the turning state quantity is, the more the US-OS characteristic may be shifted toward higher over-steer, and for the same changing rate the higher the turning state quantity is, the more the US-OS characteristic may be shifted toward higher under-steer.

Claims

1. A control system for controlling the US-OS characteristic of a vehicle having suspension for the front and the rear vehicle wheels, comprising:

a means for changing the US-OS characteristic of the vehicle;

a means for detecting a turning state quantity;

a means for determining the changing rate of a turning state quantity;

a control means which, in response to the turning state quantity detected by said detecting means and the changing rate of the turning state quantity determined by said determining means, controls said US-OS characteristic changing means so that the higher the changing rate of the turning state quantity is, the more the US-OS characteristic may be shifted toward higher over-steer, and for the same changing rate the higher the turning state quantity is, the more the US-OS characteristic may be shifted toward higher under-steer.

2. A control system for controlling the US-OS characteristic of a vehicle according to claim 1, said means for changing the US-OS characteristic is adapted so as to alter the roll stiffness distribution between the front and the rear suspension.

3. A control system for controlling the US-OS characteristic of a vehicle according to claim 2, wherein said means for detecting a turning state quantity is adapted to detect a turning state quality selected from a group consisting of a lateral acceleration, the combination of a steering angle and a vehicle speed, and a yaw rate.

4. A control system for controlling the US-OS characteristic of a vehicle according to claim 2, wherein said means for determining the changing rate of a turning state quantity is adapted to determine the changing rate of said turning state quality selected from a group consisting of a lateral acceleration, a steering angle and a yaw rate.

5. A control system for controlling the US-OS characteristic of a vehicle according to claim 1, further comprising means for detecting the acceleration and the deceleration of said vehicle and said control means is adapted in response to said acceleration and deceleration detecting means to control said means for changing the US-OS characteristic so that for the same changing rate of a turning state quantity the higher the loaded weight of said front suspension is, the more the US-OS characteristic may be shifted toward higher under-steer, and the higher the loaded weight of said rear suspension is, the more the US-OS characteristic may be shifted toward higher over-steer.