Suspension control system for automotive vehicle with feature of discrimination of vehicular driving condition on the basis of variation of lateral acceleration

• US 5,072,392 A
• Filed: 12/19/1989
• Issued: 12/10/1991
• Est. Priority Date: 12/20/1988
• Status: Expired due to Fees

• Current Assignee: Atsugi Unisia Corporation
• Original Assignee: Atsugi Unisia Corporation
• Inventors: Taniguchi, Minoru
• Primary Examiner(s): Black, Thomas G.
• Application Number:
  US07/452,590
• Time in Patent Office: 721 Days
• Field of Search: 364/424.05, 364/424.01, 280/707
• US Class Current: 701/38
• CPC Class Codes: B60G 17/018 characterised by the use of a specific signal treatment or control method
• CPC Class Codes: B60G 2202/152 Pneumatic spring
• CPC Class Codes: B60G 2202/41 Fluid actuator
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/51 in suspension unit
• CPC Class Codes: B60G 2400/91 Frequency
• CPC Class Codes: B60G 2500/10 Damping action or damper
• CPC Class Codes: B60G 2500/20 Spring action or springs
• CPC Class Codes: B60G 2500/22 Spring constant
• 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 2600/70 Computer memory; Data storage, e.g. maps for adaptive control
• CPC Class Codes: B60G 2600/90 other signal treatment means
• CPC Class Codes: B60G 2800/012 Rolling condition

Abstract

A suspension control system monitors a lateral acceleration exerted on a vehicular body. Based on the lateral acceleration, discrimination of mode of vibration of a vehicular body is performed by deriving variation rate of magnitude of lateral acceleration. The variation rate of lateral acceleration is then compared with a reference value so that suspension characteristics can be controlled on the basis of the variation rate of the lateral acceleration.

Claims

1. A suspension control system for an automotive vehicle comprising:

means for adjusting suspension characteristics of a suspension system disposed between a vehicle body and a suspension member on which a vehicular wheel is supported;

means for monitoring lateral acceleration exerted on the vehicular body and for producing a lateral acceleration indicative signal;

means for deriving a variation rate of lateral acceleration on the basis of said lateral acceleration indicative signal;

means for detecting a vibration mode of the vehicular body on the basis of the variation rate of lateral acceleration, for producing a suspension control signal representative of one of a plurality of suspension characteristics on the basis of the detected vibration mode of the vehicular body, for controlling said suspension characteristics adjusting means.

2. A suspension control system as set forth in claim 1, wherein said detecting means compares said variation rate of the lateral acceleration with a predetermined first threshold value representative of a criterion between vehicular bouncing and vehicular rolling for deriving suspension characteristics on the basis of the result of comparison.

3. A suspension control system as set forth in claim 2, wherein said detecting means further compares said variation rate of the lateral acceleration with a second threshold value representative of a criterion between vehicular rolling and steady traveling state so as to derive suspension characteristics on the basis of the result of comparison.

4. A suspension control system as set forth in claim 2, wherein said detecting means determines said control signal ordering a harder suspension characteristics when the vehicular vibration mode in rolling is detected.

5. A suspension control system as set forth in claim 2, wherein said variation rate deriving means derives a first variation rate over a first longer time interval and a second variation rate over a second shorter time interval, and said detecting means compares said first variation rate with said first threshold for discriminating vehicular vibration mode between bouncing mode and rolling mode.

6. A suspension control system as set forth in claim 5, wherein said detecting means compares said second variation rate with a second threshold defining a criterion between vehicular rolling mode and steady traveling state for discriminating rolling state and steady state.