Experimental analysis of vibration control algorithms applied for an off-road vehicle with magnetorheological dampers

Abstract

The paper presents an experimental analysis of the selected feedback vibration control schemes dedicated to magnetorheological dampers, related to ride comfort and road holding. They were applied in a complex vibration control system installed in a commercially available off-road vehicle. Original shock-absorbers of the vehicle were replaced with magnetorheological dampers. The control system takes advantage of numerous sensors installed in the vehicle tracking its motion, i.e. accelerometers, suspension deflection sensors (linear variable differential transformer) and IMU module. Vibration control algorithms: Skyhook, PI, and Groundhook were tested experimentally using mechanical exciters adapted for diagnosis of a vehicle suspension system. Since the presented semi-active vibration control requires the magnetorheological damper inverse model to be applied, accurate operation of this model significantly influences the quality of vibration control. Therefore, additional analysis was related to application of measurements from accelerometers or suspension deflection sensors in the inverse model. Presented variants of control algorithms were compared by means of transmissibility characteristics evaluated in the frequency domain as well as using ride-comfort-and drivingsafety-related quality indices. It was confirmed that the Skyhook control as well as PI improved ride comfort, whereas Groundhook control improved road holding and decreases vibration of the wheels. Furthermore, it was shown that both approaches to the relative velocity estimation, based on accelerometers and linear variable differential transformers, can be used in this application. However, the first solution gives better results in the case of the Skyhook and PI control, whereas application of LVDT sensors is better for the Groundhook algorithm.

Research on Ride Comfort and Driving Safety under Hybrid Damping Extension Control for Suspension Systems

“…The frequency response of suspension dynamic displacement is illustrated in Figure 3b. The performance of hybrid control is better than the sky-hook control under high vibration (5)(6)(7)(8)(9)(10)(11)(12), although hybrid control is still at a disadvantage to the passive suspension. Meanwhile, the ground-hook control performs best of all under high frequency (5)(6)(7)(8)(9)(10)(11)(12), worst under low frequency (0-5 Hz).…”

“…The performance of hybrid control is better than the sky-hook control under high vibration (5)(6)(7)(8)(9)(10)(11)(12), although hybrid control is still at a disadvantage to the passive suspension. Meanwhile, the ground-hook control performs best of all under high frequency (5)(6)(7)(8)(9)(10)(11)(12), worst under low frequency (0-5 Hz). Figure 3c illustrates that the tire dynamic deformation gain of hybrid control is slightly higher than passive suspension under high frequency (5)(6)(7)(8)(9)(10)(11)(12).…”

“…Meanwhile, the ground-hook control performs best of all under high frequency (5)(6)(7)(8)(9)(10)(11)(12), worst under low frequency (0-5 Hz). Figure 3c illustrates that the tire dynamic deformation gain of hybrid control is slightly higher than passive suspension under high frequency (5)(6)(7)(8)(9)(10)(11)(12). However, compared with the sky-hook control, it has a significant decrease.…”

“…Because of the simpler algorithm and better reliability, sky-hook control has been widely used in various vehicles. However, the ride comfort performance and the driving safety performance of the vehicle under sky-hook control is conflicting that the better ride comfort leads to the worse driving safety [6]. Therefore, in the light of vehicle state, intelligently restraining sprung mass and unsprung mass vibration at the same time is key to improving the comprehensive performance of the suspension system.…”

A High-Resolution Measurement System Designed for Semiconductor Microcalorimetry Sensors

“…Most of the quantities that are measured in science and industry are non-electrical and, most often, they are converted into electrical quantities using specialised sensors and electronic devices. In the literature, one can find many examples from medicine [1], analyses of drive failures [2], audio signal processing [3], vibration analyses [4,5], noise reduction [6,7], astronomical aspects [8,9], frequency measurement [10] and many more. A very important issue when measuring non-electrical quantities is the method of data acquisition.…”