A vibration/noise control system controls vibrations and noises generated with a periodicity or a quasi-periodicity from a vibration/noise source having at least a rotating member. A self-expanding engine mount is arranged in at least one of vibration/noise transmission paths and is driven by a driving signal generated by the system. A vibration error sensor detects an error signal exhibiting a difference between the driving signal and the vibrations and noises. A reference sine wave is generated, which is superposed on a control signal for controlling the vibration/noise source, to thereby drive the self-expanding engine mount. A transfer characteristic of a portion of at least one of the vibration/noise transmission paths is identified based on the reference sine wave, a delayed sine wave delayed by a predetermined delay period M relative to the reference sine wave, and the error signal. The transfer characteristic stored is updated based on an identification signal output from an identifying filter formed by an adaptive digital filter having two taps. The predetermined delay period M is set relative to the repetition period of the reference sine wave in a range of 1/3.gtoreq.M.gtoreq.1/7, wherein M is a real number.

An apparatus (30) and a method for providing an output signal (28) indicative of a vehicle operating parameter. Preferably, the operating parameter is lateral acceleration of the vehicle. A lateral acceleration sensor (36) senses lateral acceleration and provides a first signal (38). A lateral acceleration estimator (40) estimates lateral acceleration and provides a second signal (42). The first signal (38) is passed through filters (44, 46) to provide first signal portions (38L, 38H). The second signal (42) is passed through filters (48, 50). The first signal (38) and the filtered second signal (42H) are provided to a fuzzy logic controller (56) for analysis. The fuzzy logic controller (56) provides two fuzzy variable values (K.sub.1, K.sub.2) based upon the analysis. The second signal portion (38H) and the filtered second signal (42H) are multiplied by the fuzzy variables, respectively. The results of the two multiplications and the first signal portion (38L) are summed together to provide the output signal (28). Preferably, the apparatus (30) is part of an active roll control suspension system (10) and the output signal (28) is provided to a controller (24) for use in controlling force to counteract the chassis roll force.

To provide a method of assisting in the design of a vehicular suspension by allowing definition points inherent in suspensions to be easily recognized regardless of the different types and mechanisms thereof, and allowing specification values to be simply entered at the definition points. A method of assisting in the design of a vehicular suspension to generate a simulation model for a suspension using a CAD system includes the steps of indicating a suspension to be designed, opening a specification value entering window for entering specification values inherent in the indicated suspension, entering specification values at definition points inherent in the indicated suspension in the specification value entering window, and generating a simulation model based on the specification values at the definition points.