Control system for automotive vehicle suspension having variable damping characteristics with anti-dive control during deceleration

A suspension control system for an automotive vehicle comprising:

• a suspension system with damping characteristics variable at least between a first harder suspension mode and a second softer suspension mode;
• a first sensor for detecting application of vehicular brakes and producing a first sensor signal indicative thereof;
• a second sensor for monitoring vehicle height relative to a road surface and producing a second sensor signal indicative of the vehicle height;
• a timer responsive to said first sensor signal to measure elapsed time and produce a timer signal indicative thereof;
• a controller responsive to said first sensor signal to derive a first reference value on the basis of an instantaneous value of said second sensor signal at the time of occurrence of said first sensor signal, comparing subsequently received second sensor signal values with said first reference value so as to detect when said second sensor signal value drops below said first reference value to indicate a predetermined displacement in vehicle height, latching said timer signal value in response to said second sensor signal value dropping below said first reference value, comparing said latched timer signal value with a predetermined second reference value, and producing a control signal for operating said vehicular suspension system in said first harder suspension mode when said timer signal value is less than said second reference value thus indicating that said predetermined displacement in vehicle height occurred within a predetermined time period.

In an automotive suspension system with damping characteristics variable at least between a first harder suspension mode and a second softer suspension mode, a method for anti-dive controlling the suspension comprising the steps of:

• detecting vehicular braking;
• monitoring vehicular height relative to a read surface;
• detecting, in response to vehicular bracking, when the change in the vehicle height exceeds a given first threshold to indicate a predetermined displacement in vehicle height;
• detecting, in response to vehicular braking and a change in the vehicle height in excess of said first threshold, when the rate of change of the vehicle height through said predetermined displacement exceeds a given second threshold;
• and
• operating said suspension system in said first harder suspension mode when said change in said vehicle height exceeds said first given threshold and said rate of change of said vehicle height exceeding said second given threshold are 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 which detects vehicular braking and produces a first sensor signal indicative thereof;
• a second sensor for monitoring vertical height of a body of said vehicle and producing a second sensor signal indicative thereof;
• and
• a controller responsive to said first sensor signal to derive the magnitude of change and rate of change of said second sensor signal, comparing the derived magnitude of change of said second sensor signal with a first reference value and comparing the derived rate of change of said second sensor signal with a second reference value, and operating said vehicular suspension system in said first harder suspension mode when said magnitude of change of said second sensor signal is greater than said first reference value and said rate of change of said second sensor signal is higher than said second reference value, and in said second softer suspension mode otherwise.

A suspension control system for an automotive vehicle comprising:

• a suspension system with damping characteristics variable at least between a first harder suspension mode and a second softer suspension mode;
• a first sensor for detecting application of vehicular brakes and producing a first sensor signal indicative thereof;
• a second sensor for monitoring vertical height of a body of said vehicle and producing a second sensor signal indicative thereof;
• a timer responsive to said first sensor signal to measure elapsed time from the application of said vehicle brakes and produce a timer signal indicative thereof;
• and
• a contrller responsive to said first sensor signal to derive a first reference value on the basis of the instantaneous vlaue of said second sensor signal at the time of occurrence of said first sensor signal, comparing subsequently received second sensor signal values with said first reference value so as to detect when said second sensor signal value drops below said first reference value, latching said timer signal value in response to said second sensor signal value dropping below said first reference value, comparing said latched timer signal value with a predetermined second reference value, and operating said vehicular suspension system in said first harder suspension mode when said timer signal value is less than said second reference value, and in said second softer suspension mode otherwise.

In a automotive suspension system with damping characteristics variable at least between a first harder suspension mode and a second softer suspension mode, a method for anti-dive controlling the suspension comprising the steps of:

• detecting vehicular braking;
• monitoring vertical height of a body of said vehicle;
• detecting, in response to vehicular braking, when the change in the vehicle height exceeds a given first threshold to indicate a predetermined vertical displacement of said vehicle body;
• detecting, in response to vehicular braking and a change in the vehicle height in excess of said first threshold, whether the rate of change of the vehicle height through said vertical displacement exceeds a given second threshold;
• and
• operating said suspension system in said first harder suspension mode when said change in said vehicle height exceeds said first given threshold and said rate of change of said vehicle height exceeding said second given threshold are 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 an a second softer suspension mode;
• a first sensor which detects vehicular braking and produces a first sensor signal indicative thereof;
• a second sensor for monitoring vehicle height relative to a road surface and producing a second sensor signal indicative of the vehicle height;
• and
• a controller responsive to said first sensor signal to derive magnitude and rate of change of said second sensor signal, comparing the derived magnitude of change of said second sensor signal with a first reference value which is representative of a vehicle height change dependent harder suspension criterion, and comparing the derived rate of change of said second sensor signal with a second reference value which is representative of a rate of height change dependent harder suspension mode criterion, wherein said controller normally produces a control signal for operating said suspension system in said second softer suspension mode and produces a control signal for operating said vehicular suspension system in said first harder suspension mode when both conditions that said magnitude of change of said second sensor signal is greater than said first reference value and said rate of change of said second sensor signal value is higher than said second reference value are satisfied.

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 detector which produces a first detector signal indicative of the beginning of a vehicle deceleration period;
• a second detector means responsive to said first detector signal for detecting magnitude of vertical displacement of the vehicle body relative to the road surface to produce a second detector signal when the detected magnitude of vertical displacement is greater than a first reference value which represents a displacement magnitude dependent harder suspension criterion;
• a third detector means for detecting speed of vertical displacement of the vehicle body relative to the road surface to produce a third detector signal when the detected speed of vertical displacement is higher than a second reference value which represents a displacement speed dependent harder suspension criterion;
• and
• a controller which normally produces a control signal for operating said suspension system in said second softer suspension mode and produces a control signal for operating said vehicular suspension system in said first harder suspension mode when said second and third detector signals are produced.