Trajectory Generation using Sharpness Continuous Dubins-like Paths with Applications in Control of Heavy Duty Vehicles

TL;DR

This paper introduces a novel trajectory generation method for heavy-duty vehicle control that accounts for steering actuator constraints, using Sharpness Continuous curves to produce smooth, feasible, and passenger-comfort-enhancing paths.

Contribution

It proposes Sharpness Continuous curves for trajectory planning, directly incorporating steering rate and torque limits, improving control smoothness and computational efficiency.

Findings

Trajectories are smooth and continuously differentiable.

Method improves tracking and passenger comfort.

Real-time computation demonstrated in simulations.

Abstract

We present a trajectory generation framework for control of wheeled vehicles under steering actuator constraints. The motivation is smooth autonomous driving of heavy vehicles. The key idea is to take into account rate, and additionally, torque limitations of the steering actuator directly. Previous methods only take into account curvature rate limitations, which deal indirectly with steering rate limitations. We propose the new concept of Sharpness Continuous curves, which uses cubic and sigmoid curvature trajectories together with circular arcs to steer the vehicle. The obtained trajectories are characterized by a smooth and continuously differentiable steering angle profile. These trajectories provide low-level controllers with reference signals which are easier to track, resulting in improved performance. The smoothness of the obtained steering profiles also results in increased passenger comfort. The method is characterized by a fast computation time, which can be further speeded up through the use of simple pre-computations. We detail possible path planning applications of the method, and conduct simulations that show its advantages and real time capabilities.