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The assimilation of path planning and motion control is a crucial capability for autonomous vehicles. Pure pursuit controllers are a prevalent class of path tracking algorithms for front wheel steering cars. Nonetheless, their performance is rather limited to relatively low speeds. In this paper, we propose a model predictive active yaw control implementation of pure pursuit path tracking that accommodates the vehicle’s steady state lateral dynamics to improve tracking performance at high speeds. A comparative numerical analysis was under taken between the proposed strategy and the traditional pure pursuit controller scheme. Tests were conducted for three different paths at iteratively increasing speeds from 1 m/s up to 20 m/s. The traditional pure pursuit controller was incapable of maintaining the vehicle stable at speeds upwards of 5m/s. The results show that implementing receding horizon strategy for pure pursuit tracking improves their performance. The contribution is apparent by preserving a relatively constant controller effort and consequently maintaining vehicle stability for speeds up to 100Km/h in different scenarios. A Matlab implementation of the proposed controller and datasets of the experimental paths are provided to supplement this work. [ABSTRACT FROM AUTHOR]

This paper describes a novel manoeuvre planning method to attenuate disturbances acting on occupants of autonomous cars as a result of driving behaviour. New research findings suggested that the passengers in autonomous cars might be more prone to motion sickness and thus overall discomfort. The proposed approach is based on a recently developed novel continuous B-spline path smoothing algorithm for car-like steered robots. Two algorithms are designed for urban driving scenarios and steering between two predefined poses. The resulting paths avoid abrupt changes in steering and longitudinal velocity, by maintaining curvature and its high order continuity. We show that this lead to reduced high frequency disturbances in steering and resulting load disturbances on passengers. The presented novel B-spline manoeuvres outperform other planning methods by reducing lateral acceleration and yaw disturbances. New approach was verified by rigorous simulations, numerical and field experimentation. Tests were repeated for a number of different paths and velocities. The reported results are the first spline based parameterisation methods practically applied for autonomous cars planning and re-planning, then validated using both noisy actuation simulations and field experiments. [ABSTRACT FROM AUTHOR]

This paper presents the dynamic behavior of microcantilever-based microresonators and compares their steady state behavior for polarized and nonpolarized systems at different levels of nonlinearities. A microcantilever, equipped with a time-varying capacitor, makes the microresonator system. The capacitor is activated by a constant polarization voltage, and an alternative actuating voltage. The partial differential equation of motion of the vibrating electrode can be reduced to a highly nonlinear parametric second order ordinary differential equation. The steady state behavior of the microresonator has been analyzed with and without polarization voltage. The main characteristic of the non-polarized model is explained by the stability of the system in parameter plane. A set of stability chart is provided to predict the boundary between the stable and unstable domains. Furthermore, the main characteristic of the polarized model is determination by the period-amplitude relationship of the system. Applying perturbation methods, analytical equations are derived to describe the frequency response of the system, which are suitable to be utilized in parameter study and design. [ABSTRACT FROM AUTHOR]