Earticle

경로 추종 알고리즘은 행성 탐사, 무인 배송, 자율 주행 등의 다양한 모바일 플랫폼에 대하여 많은 연구가 수행되었다. 하지만, 환경에 존재하는 불확실성으로 인해 실제 응용 분야에서 높은 정확도를 보장하기 어렵다. 본 논문에서는 pure pursuit 알고리즘으로 제어되는 모바일 로봇의 경로 추종 성능을 분석함으로써 알고리즘 설계 및 구현에 대한 지침을 도출하는 것을 목표한다. 이를 위해, 전방 주시 거리(look ahead distance)를 설정하고 오류가 있는 액추에이터를 장착할 때, pure pursuit 알고리즘의 추종 정확도를 전산 실험을 통해 평가한다.

Path following algorithms have been intensively studied for various mobile platforms such as planetary exploration, unmanned delivery, and autonomous driving. However, ensuring high accuracy in practical applications is challenging due to enormous uncertainty inherent in real environment. In this paper, we aim to reveal the guideline for the design and implementation by investigating the path following performance of mobile robot controlled by the pure pursuit algorithm. To this end, we evaluate the accuracy of the pure pursuit algorithm when tuning the look ahead distance and deploying erroneous actuator.

In the path traveling of differential-drive robots, the steering controller plays an important role in determining the path-following performance. When a robot with a pure-pursuit algorithm is used to continuously drive a right-angled driving path in an unstructured environment without turning in place, the robot cannot accurately follow the right-angled path and stops driving due to the ground and motor load caused by turning. In the case of pure-pursuit, only the current robot position and the steering angle to the current target path point are generated, and the steering component does not reflect the speed plan, which requires improvement for precise path following. In this study, we propose a driving algorithm for differentially driven robots that enables precise path following by planning the driving speed using the radius of curvature and fusing the planned speed with the steering angle of the existing pure-pursuit controller, similar to the Model Predict Control control that reflects speed planning. When speed planning is applied, the robot slows down before entering a right-angle path and returns to the input speed when leaving the right-angle path. The pure-pursuit controller then fuses the steering angle calculated at each path point with the accelerated and decelerated velocity to achieve more precise following of the orthogonal path.