Monday, April 13, 2009

Quanser Active Suspension

Quanser Active Suspension is a bench-scale plant to emulate a quarter-car model controlled by an Active Suspension mechanism.

The plant consists of three floors/plates on top of each other. The top floor resembles the vehicle body and is suspended over the middle plate with two springs and a tunable damper. A capstan drive high quality DC motor is also standing between the top and middle plates to emulate an active suspension mechanism. The top floor is instrumented with an accelerometer to measure the acceleration of the vehicle body relative to the plant ground. The middle plate is in contact with the bottom plate, i.e. the road, through a spring and a damper and constitutes the tire in the quarter-car model. The bottom floor provides the road excitation in the system. It is connected to a fast response DC motor so that the designer can simulate different road profiles.

When the road simulation motor turns, the torque created at the output shaft is translated, through the lead screw and gearing mechanism, to a linear force which results in the bottom plate's motion. The structure is made of steel and the three plates can smoothly slide along a stainless steel shaft using linear bearings. The motion of the two bottom plates is tracked directly by two high resolution optical encoders while a third encoder measures the motion of the top plate relative to the middle one. Such a scaled quarter-car structure has been designed to study critical aspects of Active Suspension control implementations.

Below, is a demo video of Quanser Active Suspension System in which the road simulator is coupled with a virtual terrain. Driving with and without haptic feedback is demonstrated in this video. Finally the demo is concluded with an open-loop vs. closed-loop response of the system to road disturbances.

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