No abstract

This article proposes a new, efficient path-planning algorithm for articulated steering vehicles operating in semistructured environments, in which obstacles are detected online by the vehicle's sensors. The first step of the algorithm is offline and computes a finite set of feasible motions that connect discrete robot states in order to construct a search space. The motion primitives are parameterized using Bézier curves and optimized as a nonlinear programming problem (NLP) equivalent to the constrained path planning problem. Applying the A * search algorithm to the search space produces the shortest paths as a sequence of these primitives. The sequence is drivable and suboptimal, but it can cause unnatural swerves. Therefore, online path smoothing, which uses a gradient-based method, is applied in order to solve another NLP. Numerical simulations demonstrate that performance of the proposed algorithm is significantly better than that of existing methods when determining constrained path optimization. Also, field experimental results demonstrate the successful generation of fast, safe trajectories for real-time autonomous driving.

Abstract-In this paper, a computationally effective trajectory generation algorithm of omnidirectional mobile robots is proposed. The algorithm plans a reference path based on Bézier curves, which meets obstacle avoidance. Then the algorithm solves the problem of motion planning for the robot to track the path in short travel time while satisfying dynamic constraints and robustness to noise. Accelerations of the robot are computed and refined such that they satisfy the time optimal condition for each sample time interval. The numerical simulation demonstrates the improvement of trajectory generation in terms of travel time, satisfaction of dynamic constraint and smooth motion control compared to a previous research.

Abstract-We present a practical path planning algorithm based on Bézier curves for autonomous vehicles operating under waypoints and corridor constraints. Bézier curves have useful properties for the trajectory generation problem. This paper describes how the algorithm apply these properties to generate the reference trajectory for vehicles to satisfy the path constraints. The algorithm generates the piecewise-Bézier-curves path such that the curves segments are joined smoothly with C 2 constraint which leads to continuous curvature along the path. The degree of the curves are minimized to prevent them from being numerically unstable. Additionally, we discuss the constrained optimization problem that optimizes the resulting path for a user-defined cost function.

In this paper a computationally effective trajectory generation algorithm of mobile robots is proposed. The algorithm plans a reference path based on Voronoi diagram and Bézier curves, that meet obstacle avoidance criteria. Bézier curves defining the path are created such that the circumference convex polygon of their control points miss all obstacles. To give smoothness, they are connected under C 1 continuity constraint. In addition, the first Bézier curve is created to satisfy the initial heading constraint and to minimize the maximum curvature of the curve. For the mission, this paper analyzes the algebraic condition of control points of a quadratic Bézier curve to minimize the maximum curvature. The numerical simulations demonstrate smooth trajectory generation with satisfaction of obstacle avoidance in an unknown environment by applying the proposed algorithm in a receding horizon fashion.