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Real-time information on the wheel static and dynamic normal reaction on various road and terrain conditions is extremely important for agile tyre dynamics to improve vehicle mobility. This article proposes a novel approach for reliable and real-time estimation of the dynamic normal reaction of an open-link locomotion module, as an essential constituent of electric vehicles. Nonlinear normal dynamics, including stochastic behaviour of suspension and nonlinearity of damping force caused by the terrain profile and damper design is considered. Robustness performance of the proposed approach is proved based on input-to-state stability theory. As demonstrated, the proposed approach is robust against model parameter uncertainties, and can keep the estimation error within the assigned boundaries. The proposed approach is indifferent to variation of the stiffness and damping coefficients of the tyre-surface patch and thus is applicable to different terrains. The approach was implemented in a new design of a sliding mode observer. A design method of the observer gains is also presented and numerical values of the gains are determined with application to the locomotion module. The estimation accuracy of the wheel normal reaction on different terrains and the robustness against parameter uncertainties are validated. Computational results confirm the real-time performance and effectiveness of the proposed observer design. [ABSTRACT FROM AUTHOR]

Byline: Vladimir V. Vantsevich, Gennady Lomako, Alexandre Opeiko Today's studies in Vehicle Dynamics are becoming increasingly isolated from one another. They relate to different systems of a vehicle and do not demonstrate an interconnection between these systems. For example, mechatronic systems to control the circumferential wheel forces of vehicles can be divided into two groups: systems of the first group act through the brake system and throttle, and the second group's systems act through the drivetrain. Systems of both groups are not interconnected with one another. This approach is not conducive to moving ahead in the development of novel systems, such as autonomous vehicles. A new approach has been proposed to overcome these difficulties. The proposed approach in vehicle dynamics is aimed at the control of the vehicle properties. Developing of a new direction in vehicle dynamics requires a mathematical model, which would allow design engineers to control the interaction between a wheel and road surface in three dimensions the normal, longitudinal, and lateral ones. However, the interaction in the real-life system is so complex that a model would be equally complex and thus unmanageable or prohibitively expensive. The development of such a model that would include a certain minimal set of the system's characteristics so that the model approximates the real system yet remains cost-effective and manageable and meets engineering needs, is the aim of this paper.

Byline: Vladimir V. Vantsevich, Mikhail S. Vysotski, Gemunu S. Happawana, Osita D.I. Nwokah Solving the first dynamics problem - determination of a vehicle movement with known forces acting upon the vehicle - allows us to answer the question, 'How do the vehicle running abilities vary while changing vehicle parameters and operational factors?' Thus, by solving the first dynamics problem, nobody can declare that the chosen parameters and characteristics of a vehicle and its systems are the best. In such conditions, researchers and designers have to rely on their own experience. Therefore, the problems connected with the development of advanced vehicles require another approach to study their running abilities. To overcome this situation, a new approach to the development of vehicle dynamics is proposed. The approach can be defined as 'Second Dynamics Problem' - given the motion of a vehicle, calculate the total sum of forces acting on the vehicle. Here the vehicle forces are taken in aggregate with given kinematics, making the basis for synthesising control laws for vehicle units and systems, namely, what parameters and characteristics of a vehicle have to be maintained for best transport efficiency in various road conditions? The proposed trend is focused not only on analysis of an influence of the vehicle parameters and operational factors on the vehicle performance but also to search for the parameters and characteristics which provide a vehicle with the desired properties. In other words, we can say that the trend is based on synthesis of technical systems as a research method.