A Suspension Control System Adaptive To Detected And Estimated Road Profiles
Publication Date: 2004-Jun-15
The IP.com Prior Art Database
In a semi-active or an active suspension system, both vehicle body and wheels are needed to be controlled for achieving the so-called ride comfort performance (body performance) and handling performance (wheel performance). Due to the inherent performance limitation, the suspension controls need to balance the body performance (usually at around 1 Hz frequency range) and wheel performance (usually at around 10 Hz frequency range), and those two performances are in conflict with each other. A method is proposed here to use suspension height sensor signals to estimate and detect the road disturbance (the road vertical profiles) and vehicle body and wheel states, and based on the frequency content of the road disturbance to adjust the suspension actuation command so as to achieve body performance (from 1 Hz up to the middle frequency range of about 4 Hz), on-demand wheel performance. If the detected and estimated road profile includes frequency contents higher than the so-called harshness frequency (for example, above 12 Hz), the suspension control is turned off such that the body performance is not worse than the performance of the passive suspensions.