| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1994: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1993: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Research Abstract |
1. We designed and developed a hydrawlic powered prototype vehicle to overcome rough terrains or obstacles. The vehicle has four sets of small type crawler as running device, whose housing rotates by itself at the same time the crawler moves for running, and each housing shafts are connected to two sets of front and rear differential gear. The prototype showed many benefits such as : 1)the whole four sets of crawler can always stay in touch with terrain regardless of its bumpy figure, 2) the two sets of differential gear can work normally without having rolling motion of the vehicle as long as the level of the terrain is the same between right and left side (eg. overriding on the ditch or hedge), 3) the control system to keep maintaining the vehicle chassis horizontal can be simplified. However, the vehicle tend to induce its rolling motion on certain figure of the terrain because the ground contact loads between the right and left crawlers, in general, are different. To avoid rolling, at least one housing shaft out of four should be controlled in accordance with figure of the terrain.
2. Some particular crawler's shapes were discussed and designed to avoid the rolling motion of vehicle. By using these crawlers, the difference of the ground contact forces between the right and left crawlers can be decreased to about 2/3-1/2 compared with the traditional shape of crawler.
3. We designed and developed a model vehicle equipped with four sets of running device with a tire, whose housing shaft was constituted with two linear bearings so that the moment exerted to the right and left housing shafts stayd the same. Two housing shafts of the device were connected to a set of differential gears, and the ground contact forces of the tires became equal, being the fact that the moments at the housing shafts were the same. A bench test with various terrain shape showed desired performance, although at least one of the housing should be controlled as above.
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