Design and Analysis of a Four-Track-Based Mobile Robot With Novel Tracker–Bogie Mechanism

Robots working in environments that are hazardous to human beings must have high mobility to perform multiple tasks. This study presents a robot platform called sinuous quad-tracker-bogie (SQuaT), which exhibits high mobility and robustness. SQuaT employs the tracker–bogie mechanism, which utilizes a half rocker–bogie and track mechanisms with an adaptable tensioner. The linkage interface is used along with the tracker–bogie to enhance its stability and overcome its limitations. The shape of the tracker–bogie has been optimized from the perspective of the force transmission ratio and accessible design area for the tensioner deformation. A simple simulation was performed in a 3-D environment using the simple SQuaT schematic dummy model and two previously reported models. An experiment was carried out with SQuaT placed on an outdoor step obstacle. The simulation results indicate that SQuaT exhibits the best terrainability owing to its low friction and energy requirement because of the effect of force transition by the tracker–bogie. The experimental results indicate that SQuaT can reduce the maximum acceleration magnitude compared with the all-joint-fixed reference model when the SQuaT climbs the square bump. For the other experimental cases, a boulder, stepping stones, and square wood rods were conducted and verified. In future works, we aim to adopt an optimal controller for the SQuaT platform to avoid fluctuations while overcoming obstacles.