Automotive suspension system with variable damping characteristics

In an automotive suspension system with damping characteristics variable at least between a first harder suspension mode and a second softer suspension mode, a process for suppressing vibration of a vehicle body comprising the steps of:

• detecting the vertical speed of said vehicle body;
• detecting the relative speed between said vehicle body and a vehicular wheel assembly;
• predicting the effect of damping force produced by said suspension system based on said vehicle body speed and said relative speed from between a first condition in which damping characteristics act to amplify vehicle body vibrations, and a second condition in which damping characteristics of the suspension system act to absorb vehicle body vibrations;
• and
• causing said vehicular suspension system to assume said second softer suspension mode when said first condition is detected, and to assume said first harder suspension mode when said second condition is detected.

A suspension control system for an automotive vehicle comprising:

• a vehicular suspension system with damping characteristics variable at least between a first harder suspension mode and a second softer suspension mode;
• a first sensor means for monitoring vertical displacement direction and speed of a vehicle body within a gravity field and producing a first sensor signal indicative of the direction of motion of the vehicle body in bounding and rebounding directions, and further indicative of the vertical speed of said vehicle body;
• a second sensor means for monitoring relative direction of relative motion, and relative speed of motion between the vehicle body and a vehicular wheel assembly and producing a second sensor signal indicative of the direction of relative motion between the vehicle body and the vehicular wheel in bounding or rebounding directions, and the relative speed of motion between said vehicle body and said wheel assembly;
• a controller responsive to said first and second sensor signals for predicting the effect of damping characteristics of the suspension system depending on the direction of motion of said vehicle body and the direction of relative motion of said vehicle body and said vehicular wheels from between a first condition in which said damping characteristics of the suspension system act to absorb vehicle body vibrations and a second condition in which said damping characteristics of the suspension system act to absorb vehicle body vibrations, said controller causing said vehicular suspension system to assume said second softer suspension mode when said first condition is predicted and to assume said first harder suspension mode when said second condition is predicted.

In an automotive suspension system with damping characteristics variable at least between a first harder suspension mode and a second softer suspension mode, a process for suppressing vibration of a vehicle body comprising the steps of:

• detecting direction and speed of vertical motion of said vehicle body and producing a first signal indicative of the direction and speed of said vertical motion;
• detecting direction of relative motion and speed of relative motion between said vehicle body and a vehicular wheel assembly and producing a second signal indicative of the direction of relative motion and speed of relative motion between said vehicle body and said vehicular wheel assembly;
• predicting the effect of damping force produced by said suspension system based on said vehicle body speed and said relative speed by comparing the direction of said detected vertical motion of said vehicle body and the direction of said relative motion between said vehicle body and said vehicular wheel from between a first condition in which damping characteristics act to amplify vehicle body vibrations, and a second condition in which damping characteristics of the suspension system act to absorb vehicle body vibrations;
• and
• causing said vehicular suspension system to assume said second softer suspension mode when said first condition is detected, and to assume said first harder suspension mode when said second condition is detected.