Suspension control system
First Claim
1. A suspension control system comprising:
- a shock absorber having adjustable damping characteristics, said shock absorber being interposed between a sprung member and an unsprung member of a vehicle;
a sprung mass vibration detecting device for detecting vibration of the sprung member of the vehicle;
a sprung mass absolute velocity detecting device for obtaining an absolute velocity of the vibration of the sprung member from a detected signal obtained from said sprung mass vibration detecting device;
a relative velocity estimation device for adjusting a phase of the detected signal obtained from said sprung mass vibration detecting device to use said detected signal as an estimated relative velocity between said sprung member and said unsprung member; and
a control unit for generating a control signal for controlling the damping characteristics of said shock absorber on a basis of the absolute velocity obtained from said sprung mass absolute velocity detecting device and the estimated relative velocity obtained from said relative velocity estimation device and for outputting said control signal to said shock absorber;
wherein said relative velocity estimation device adjusts the phase of said detected signal so that a phase difference of said detected signal with respect to an actual relative velocity is minimized in a sprung mass resonance frequency band.
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Accused Products
Abstract
By passing the vertical acceleration through a phase adjusting filter and a gain adjusting filter, the phase of the vertical acceleration is advanced by 49 degrees so that the phase difference with respect to the actual relative velocity becomes 180 degrees in the neighborhood of the vehicle body resonance point, thereby making the phase of the vertical acceleration, in effect, coincident with the phase of the relative velocity. In the neighborhood of the vehicle body resonance point (1 Hz), the gain of the estimated relative velocity takes a small value. In frequency regions other than the neighborhood of the vehicle body resonance point, the gain of the estimated relative velocity is increased. Consequently, the controlled variable in the neighborhood of the vehicle body resonance point increases, and the controlled variable in higher frequency regions decreases. Damping force is adjusted in correspondence to the controlled variable. Thus, it is possible to improve ride quality in the neighborhood of the vehicle body resonance point (1 Hz).
99 Citations
11 Claims
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1. A suspension control system comprising:
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a shock absorber having adjustable damping characteristics, said shock absorber being interposed between a sprung member and an unsprung member of a vehicle;
a sprung mass vibration detecting device for detecting vibration of the sprung member of the vehicle;
a sprung mass absolute velocity detecting device for obtaining an absolute velocity of the vibration of the sprung member from a detected signal obtained from said sprung mass vibration detecting device;
a relative velocity estimation device for adjusting a phase of the detected signal obtained from said sprung mass vibration detecting device to use said detected signal as an estimated relative velocity between said sprung member and said unsprung member; and
a control unit for generating a control signal for controlling the damping characteristics of said shock absorber on a basis of the absolute velocity obtained from said sprung mass absolute velocity detecting device and the estimated relative velocity obtained from said relative velocity estimation device and for outputting said control signal to said shock absorber;
wherein said relative velocity estimation device adjusts the phase of said detected signal so that a phase difference of said detected signal with respect to an actual relative velocity is minimized in a sprung mass resonance frequency band. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification