Autonomous Navigation for Forest Machines

5 Executive summary This document is a pre-study for the project Autonomous Navigation for Forest Machines. The project is part of a long-term vision, of developing an unmanned vehicle that transports timber from the area of felling to the main roads for further transportation. The main goal of the project is to present a working solution for autonomous path tracking navigation, to be implemented in a vehicle for operation in forest terrains. The Autonomous Ground Vehicle (AGV) should operate in two modes: Path Recording, and Path Tracking. In the Path Recording mode, a human driver drives along the chosen path, recorded in the computer memory. In the Path Tracking mode, the computer assumes control over propulsion and steering. The vehicle then automatically travels along a memorized path. The operation has to account for unplanned deviations from the path, caused by imperfect sensing of position, and also by the vehicle sliding and jumping along the path. Another important part involves detection of new obstacles appearing on the path. In some cases the system should stop the vehicle and alert the human operator, who should be given the option of manually correcting the vehicle position, or giving the system the green light to go ahead along the original path. The software and hardware will be installed in a standard forest machine, selected and prepared in collaboration with the manufacturer. A first version of the system will be installed and demonstrated on a smaller-sized robot, specifically purchased for this project. This robot will also be important for speeding up and simplifying the development. Construction of Autonomous Ground Vehicles has been an intense research area for the last decade. A number of successful applications in agriculture and the mining industry, albeit not commercial, have been demonstrated. It is reasonable to believe that similar solutions are relevant for a forest-based AGV. However, the forest environments have enough peculiarities to make the proposed development project highly advanced, and full of challenging tasks for research. The research work will deal with obstacle detection problems, where cameras, infra-red detectors, and other sensors are utilized to detect objects close to the vehicle. Another area of research is Path Tracking and control algorithms that take into account the specific problems involved in controlling a huge forest machine in a forest environment. The suggested hardware solution will involve two computers connected by a high-speed radio-based network. One computer onboard the vehicle …