On Modular Design of Field Robotic Systems

Robots are needed to perform important field tasks such as hazardous material clean-up, nuclear site inspection, and space exploration. Unfortunately their use is not widespread due to their long development times and high costs. To make them practical, a modular design approach is proposed. Prefabricated modules are rapidly assembled to give a low-cost system for a specific task. This paper described the modular design problem for field robots and the application of a hierarchical selection process to solve this problem. Theoretical analysis and an example case study are presented. The theoretical analysis of the modular design problem revealed the large size of the search space. It showed the advantages of approaching the design on various levels. The hierarchical selection process applies physical rules to reduce the search space to a computationally feasible size and a genetic algorithm performs the final search in a greatly reduced space. This process is based on the observation that simple physically based rules can eliminate large sections of the design space to greatly simplify the search. The design process is applied to a duct inspection task. Five candidate robots were developed. Two of these robots are evaluated using detailed physical simulation. It is shown that the more obvious solution is not able to complete the task, while the non-obvious asymmetric design develop by the process is successful.

The NEBLINE, October 1998

Contents: Character Counts! for everyone Growing hardy bulbs Tree planting snafus Timely care of hardy chrysantheums Mole, mole, go away Termite control options: baits vs. barriers? Celebrate America Recycles Day Household hazardous waste collection: November 7 It's time for your annual “pest-proof” check-up Removing skunk odor Temporary/emergency grain storage options Control leafy spurge Fall clean-up of warm-season grasses The first frost, the last hurrah Pasture weed control What is this thing called winter desiccation? Dormant planting grasses and legumes Finding facts about vegetables and fruits Healthy Eating: No-Crust Pumpkin Pie Focus on Food Preparing for the winter food olympics! Family & Community Education News FCE: Jean's Journal Household Hints Furniture workshop AARP offers 55 Alive—Mature Driver Course Caring for athletic uniforms Halloween safety 4-H Bulletin Board Character Counts! Super Day Camps 4-H CAN Fight Hunger Food Campaign 4-H Shooting Sports meeting Holiday gifts needed 4-H Volunteer Forum Make a Difference Day Engineering and Technology 4-H Club Put us to work, please! Lancaster County Born and Raised beef SERIES fun America Recycles Day Livestock judging teams excel at state Lemke and Nisley place University of Nebraska Speakers Bureau announced Public notice Community Resource Directory available E.N. Thompson Forum on World Issues

Risk-based Modeling to Develop Zoning Criteria for Land-use Near Canadian Airports

Land development in the vicinity of airports often leads to land-use that can attract birds that are hazardous to aviation operations. For this reason, certain forms of land-use have traditionally been discouraged within prescribed distances of Canadian airports. However, this often leads to an unrealistic prohibition of land-use in the vicinity of airports located in urban settings. Furthermore, it is often unclear that the desired safety goals have been achieved. This paper describes a model that was created to assist in the development of zoning regulations for a future airport site in Canada. The framework links land-use to bird-related safety-risks and aircraft operations by categorizing the predictable relationships between: (i) different land uses found in urbanized and urbanizing settings near airports; (ii) bird species; and (iii) the different safety-risks to aircraft during various phases of flight. The latter is assessed relative to the runway approach and departure paths. Bird species are ranked to reflect the potential severity of an impact with an aircraft (using bird weight, flocking characteristics, and flight behaviours). These criteria are then employed to chart bird-related safety-risks relative to runway reference points. Each form of land-use is categorized to reflect the degree to which it attracts hazardous bird species. From this information, hazard and risk matrices have been developed and applied to the future airport setting, thereby providing risk-based guidance on appropriate land-uses that range from prohibited to acceptable. The framework has subsequently been applied to an existing Canadian airport, and is currently being adapted for national application. The framework provides a risk-based and science-based approach that offers municipalities and property owner’s flexibility in managing the risks to aviation related to their land use.