Autonomous systems have not become mainstream because of the shortcomings in the sensing of the environment and the required intelligence to react to it appropriately. Another hindrance to its maturity is the lack of a standard. Great innovations have been made in isolated applications for both sensing and intelligence, but it has been difficult to leverage them in other systems. Autonomous Solutions Inc. has built a development platform with the JPO JAUGS standard enabling rapid development of compliant hardware and software modules.
The Center for Self-Organizing and Intelligent Systems has built several vehicles with ultra-maneuverable steering capability. Each drive wheel on the vehicle can be independently set at any angle with respect to the vehicle body and the vehicles can rotate or translate in any direction. The vehicles are expected to operate on a wide range of terrain surfaces and problems arise in effectively controlling changes in wheel steering angles as the vehicle transitions from one extreme running surface to another. Controllers developed for smooth surfaces may not perform well on rough or 'sticky' surfaces and vice versa. The approach presented involves the development of a model of the steering motor with the static and viscous friction of the steering motor load included. The model parameters are then identified through a series of environmental tests using a vehicle wheel assembly and the model thus obtained is used for control law development. Four different robust controllers were developed and evaluated through simulation and vehicle testing. The findings of this development will be presented.
KEYWORDS: Optical filters, Cameras, Intelligence systems, Fuzzy logic, Sensors, 3D scanning, CCD cameras, Data processing, Global Positioning System, System integration
The Center for Self-Organizing and Intelligent Systems at Utah State University has been developing laser-based obstacle detection and avoidance during the past four years. The JPL initially encouraged us down this path to provide an optional software upgrade for its Rocky Rover. The USU system was based on a unique combination of fuzzy logic and a decision tree behavioral technique, and this system provided the Rocky Rover the option of venturing independently beyond the observance of the base station. Shortcomings in the data collection prompted a redesign that included more sophisticated line tracing and filtering methods to locate and track the actual laser lines. The signal to noise ratio problems combined with platform changes lead to the choice of a commercial range finder. The design challenge then became one of system integration including the meting of real time constraints on the current processor platform, and obstacle characterization and avoidance.
Conference Committee Involvement (6)
Unmanned Systems Technology X
17 March 2008 | Orlando, Florida, United States
Unmanned Systems Technology IX
9 April 2007 | Orlando, Florida, United States
Unmanned Systems Technology VIII
17 April 2006 | Orlando (Kissimmee), Florida, United States
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