Experimental attenuation and evaluation of whole body vibration for an off-road vehicle with magnetorheological dampers

Abstract

The paper presents an analysis of vehicle vibration, ride comfort and handling which have a decisive influence on health and safety of a driver. Experiments were carried out for a commercially available experimental all-terrain vehicle in the field in hard conditions with retaining the sufficient repeatability. The vehicle is equipped with a complex vibration control system, taking advantage of four automotive magnetorheological dampers. Numerous sensors, which measure acceleration in four points of the vehicle body, near the driver's seat, feet and hands, body orientation in space and speed of vehicle wheels, are available in the vehicle. They were used for evaluation of magnetorheological dampers' control signals and analysis of vibration affecting the driver. Constant values of magnetorheological damper control current were used for emulation of different settings of passive suspension. The analysis performed in frequency domain showed how vibration propagates in a medium-sized all-terrain vehicle and indicated that driver's hands are mostly affected by the road-induced vibration. It was also confirmed that the greatest improvement of ride comfort can be obtained for the soft suspension, i.e. uncontrolled magnetorheological dampers. Furthermore, the Skyhook algorithm was implemented, including the proportional control of the magnetorheological damper force and the inverse Tanh model of the magnetorheological damper. It was validated for the wideband road-induced excitation contrary to the experiments commonly presented in the literature, which are performed only for harmonic excitation. It was shown that the properly tuned Skyhook algorithm enables improving vehicle handling compared to the passive suspension and simultaneously it can maintain the similar or even better results of ride comfort.

Driving Safety Improved with Control of Magnetorheological Dampers in Vehicle Suspension

“…The vehicle model that is presented in Section 2 was tested in simulation experiments. The model was subjected to the rough road profile of class F according to the ISO8608 in order to refer to tests that were performed on a real vehicle in terrain [8]. Additionally, vehicle longitudinal velocity during a constant speed phase was related to the previous experiments when the vehicle was driving at a longitudinal velocity v sx = 5 ms −1 due to significant irregularities of the terrain.…”

“…The application of MR dampers in vehicle suspension allows for changing the suspension settings from soft to hard during the drive. However, the Skyhook algorithm that is presented in [17] is considered as one of the first semi-active control algorithms, simultaneously robust and widely tested, e.g., in [8] for an all-terrain vehicle (ATV). It also serves as a reference for other algorithms.…”

“…Consequently, pitch angle can also be used for the assessment of ride performance and steering stability as it was stated in [7]. Further, the approach of assessing vehicle handling on the pitch and roll rates was also applied in [8], presenting an analysis of whole body vibration for an off-road vehicle with magnetorheological (MR) dampers.…”

The Assessment of the Technical Condition of Complex Fatigued Load-Carrying Structures

“…Such activities may lead to modernization; an example is the bucket wheel [12]. The methods of extending the service of technical objects include efficiency improvements [24], reduction in the dynamic loads' impact [25,26], and work safety improvements [27][28][29].…”

Chladni Figures in Modal Analysis of a Double-Panel Structure

“…Low-frequency vibration, specific to the machine operator’s profession, is especially harmful and causes decrease of work efficiency [ 2 ]. Vibrations in the form of shocks have dangerous impact on humans in vehicles, as resonant frequencies of the human body may be excited [ 3 ]. The aim of contemporary researchers is to minimize noise and vibration pollution in the human environment by improvement of the materials and methods.…”