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This paper presents a novel hybrid observer structure to estimate the lateral tire forces and road grip potential without using any tire-road friction model. The observer consists of an Extended Kalman Filter structure, which incorporates the available prior knowledge about the vehicle dynamics, a feedforward Neural Network structure, which is used to estimate the highly nonlinear tire behavior, and a Recursive Least Squares block, which predicts the road grip potential. The proposed observer was evaluated under a wide range of aggressive maneuvers and different road grip conditions using a validated vehicle model, validated tire model, and sensor models in the simulation environment IPG CarMaker®. The results confirm its good and robust performance. [ABSTRACT FROM AUTHOR]

In this paper, a new methodology for computing optimised obstacle avoidance steering manoeuvres for ground vehicles is presented and discussed. Most of the existing methods formulate the obstacle avoidance problem as an optimal control problem which is hard to solve or as a numerical optimisation problem with a large number of unknowns. This method is based on a reformulation of Pontryagin's Maximum Principle and leads to the solution of an adjustable time optimal controller. The control input is significantly simplified and permits its application in a sample and hold sense. Furthermore, with the proposed approach the maximum tyre forces exerted during the manoeuvre are minimised. In this study, it is shown how to ‘warm start’ the proposed algorithm and which constraints to ‘relax’. Numerical examples and benchmark tests illustrate the performance of the proposed controller and compare it with other standard controllers. A sensitivity analysis for different vehicle parameters is performed and finally conclusions are drawn. A significant advantage of the method is the small computational complexity. The overall simplicity of the controller makes it attractive for application on autonomous vehicles. [ABSTRACT FROM AUTHOR]

In this paper, a fully linear method for the kinetoelastodynamic analysis of mechanisms of engineering praxis, characterized by large displacements and rotations (rigid body motion) but small elastic displacements and strains, based on the standard Euler–Bernoulli finite elements is proposed and investigated. The method is a co-rotational approach and relies on the principle to decompose the motion of a mechanism in a series of successive time steps, so small that the linear finite element method can be applied within each step, adding a correction procedure in order to compensate errors resulting from not incorporating the exact (non-linear) beam theory. After presentation of the method, we apply it to test cases well known in the literature and discuss its characteristics. [ABSTRACT FROM AUTHOR]