Robotic pipe crawling device

A robotic pipe crawling device comprises two three-wheel modules pivotally connected at their centers, each having one idler wheel and two driven wheels. Each module comprises an idler yoke and a driveline yoke chassis with parallel laterally spaced rectangular side plates, the idler side plates being pinned at one end to the chassis and the idler wheel mounted on the other end. The driveline side plates are pinned to the chassis and the drive wheels are rotatably mounted one at each end. A motor at each end of the chassis pivots the wheeled modules independently into and out of a wheel engaging position on the interior of the pipe and a drive motor carried by the driveline yoke drives the two drive wheels in opposite directions to propel the device. A motor mounted within each idler yoke allows them to pivot independently of the driveline yokes. A swivel joint in the chassis midsection allows each end to rotate relative to the other. The chassis may be extended with additional driveline yokes. In addition to a straight traverse, the device is capable of executing a "role sequence" to change its orientation about its longitudinal axis, and "L" , "T", and "Y" cornering sequences. Connected with a computer the device can "learn" a series of axis control sequences after being driven through the maneuvers manually.