Universal Trajectory Optimization Framework for Differential Drive Robot Class

TL;DR

This paper presents a universal trajectory optimization framework for various differential drive robots, enabling efficient, high-quality path planning adaptable to different mechanisms and validated through extensive simulations and real-world tests.

Contribution

The paper introduces a novel polynomial-based trajectory representation and a comprehensive optimization framework applicable to multiple differential drive robot types.

Findings

Effective trajectory generation for different robot types

Validated robustness in crowded environments

Achieved high-quality paths within limited computation time

Abstract

Differential drive robots are widely used in various scenarios thanks to their straightforward principle, from household service robots to disaster response field robots. There are several types of driving mechanisms for real-world applications, including two-wheeled, four-wheeled skid-steering, tracked robots, and so on. The differences in the driving mechanisms usually require specific kinematic modeling when precise control is desired. Furthermore, the nonholonomic dynamics and possible lateral slip lead to different degrees of difficulty in getting feasible and high-quality trajectories. Therefore, a comprehensive trajectory optimization framework to compute trajectories efficiently for various kinds of differential drive robots is highly desirable. In this paper, we propose a universal trajectory optimization framework that can be applied to differential drive robots, enabling the generation of high-quality trajectories within a restricted computational timeframe. We introduce a novel trajectory representation based on polynomial parameterization of motion states or their integrals, such as angular and linear velocities, which inherently matches the robots' motion to the control principle. The trajectory optimization problem is formulated to minimize complexity while prioritizing safety and operational efficiency. We then build a full-stack autonomous planning and control system to demonstrate its feasibility and robustness. We conduct extensive simulations and real-world testing in crowded environments with three kinds of differential drive robots to validate the effectiveness of our approach.