Joshua Struble

A Robust Approach to High-Speed Navigation for Unrehearsed Desert Terrain

This article presents a robust approach to navigating at high-speed across desert terrain. A central theme of this approach is the combination of simple ideas and components to build a capable and robust system. A pair of robots were developed which completed a 212 kilometer Grand Challenge desert race in approximately seven hours. A path-centric navigation system uses a combination of LIDAR and RADAR based perception sensors to traverse trails and avoid obstacles at speeds up to 15m/s. The onboard navigation system leverages a human based pre-planning system to improve reliability and robustness. The robots have been extensively tested, traversing over 3500 kilometers of desert trails prior to completing the challenge. This article describes the mechanisms, algorithms and testing methods used to achieve this performance.

A Complete System for High-Speed Navigation of Prescribed Routes

This paper presents an approach that achieves robust high-speed navigation of prescribed routes. We present the mechatronic and software considerations that resulted in two robots that have completed over 4000 km of autonomous navigation of trails and off-road terrain at an average speed of approximately 30 km/h, with sustained top speeds of 55 km/h

Automated field testing of a track-type tractor

During the design process, earthmoving manufacturers routinely subject machines to rigorous, long-term tests to ensure quality. Automating portions of the testing process can potentially reduce the cost and time to complete these tests. We present a system that guides a 175 horsepower track-type tractor (Caterpillar Model D6R XL) along a prescribed route, allowing simple tasks to be completed by the automated machine while more complex tasks, such as site clean up, are handled by an operator. Additionally, the machine can be operated manually or via remote control and observed over the internet using a remote supervisor program. We envision that safety would be handled using work procedures, multiple over-ride methods and a GPS fence. The current system can follow turns within a half meter and straight sections within a quarter meter. The controller hardware and software are integrated with existing on-board electronic modules and allow for portability. The current system successfully handles the challenges of a clutch-brake drive train and has the potential to improve control over test variables, lower testing costs and enable testing at higher speeds allowing for higher impact tests than a human operator can tolerate.