Generation of Turning Motion for Tracked Vehicles Using Reaction Force of Stairs’ Handrail

Inspections by mobile robots are required in chemical and steel plants. The robots are required to ascend and descend stairs because equipment components are installed on different-level floors. This paper proposes turning motion for tracked vehicles on stairs. A characteristic of the proposed turning motion is that it is generated using the reaction force from the safety wall of the stairs’ handrail. The safety wall is commonly used in plants because it prevents objects from dropping down and damaging equipments. Proper turning motion is generated based on the motion model of the tracked vehicle. Experimental results show that the proposed turning motion can change the heading direction on the stairs. In addition, the proposed turning motion enables the vehicle to run with less slippage, as compared to other turning motions. The proposed method can reduce slippage by 88% while climbing up the stairs and by 44% while climbing down the stairs. The proposed method is more effective on the upward stairs than on the downward stairs. An autonomous turning motion control is implemented on the tracked vehicle, and it is evaluated on the upward stairs.