The developed alternative solution for an active roll stabilization system in automobile application shows a high potential for system simplification compared to valve actuated systems. It also contributes to fuel savings because the main losses are at the pump and motor and it has the ability to recovery energy in certain cases. The assumed pump dynamics are sufficient for this actuator application. The required system responses, which are known from valve actuated system solutions, are mainly dependent on the valve dynamics of the pump control system. The pump control is considerably smaller than the valve used for the valve actuated system solutions. Therefore, higher dynamics can be achieved. For the controller design different control strategies have been presented and compared. Due to the fact that the fequency of the hydraulic system poles of the stabilizer system is considerably higher than the poles for the pump control system (the final control element) it is not possible to enhance the behaviour of a fixed gain angular position control concept in a cascade structure, which showed a steady-state error less than 0.5 percent in non-linear simulation. Measures to damp the hydraulic system poles by the use of pressure feedback or 2nd order compensator are not useful due to the dynamic limitation of the pump control system valve for this special application with the assumed valve dynamics. Simulation results for a typical driving situation (S-curve at 120 km/h) showed that the required power for the combustion engine to operate the active roll stabilization system is minimized, only covering the load dependent pressure losses of the hydraulic machines and also recovering energy in cases when the motor operates as a pump, which can be used to drive vehicle accessories.
Pump controlled active roll stabilizer
International Journal of Fluid Power ; 7 , 1 ; 27-40
2006
14 Seiten, 18 Bilder, 3 Tabellen, 18 Quellen
Article (Journal)
English