Design and experimental research on the rocker arm walking mechanism of the wheeled inspection robot for the main transportation roadway of coal mines

Currently, inspection robots for main transport roadway belt conveyors primarily employ a suspended track-based inspection method. However, this approach cannot inspect equipment located in lower or obstructed positions, making it difficult to meet the comprehensive inspection requirements for underground roadways and equipment. A rocker arm walking mechanism for a wheeled inspection robot was designed to complement track-based inspection robots, fulfilling the need for comprehensive inspections. The system structure of the wheeled inspection robot was determined, with a focus on analyzing its walking system. Quantitative models for three walking mechanisms—crawler, wheeled-crawler, and rocker arm—were established. The Delphi method and network analysis were employed for a comprehensive performance evaluation of the walking mechanisms. The results demonstrated that the robot’s mobile chassis, based on the rocker arm walking mechanism, had the best adaptability for walking in the underground roadway environment. Static performance analysis of the key component, the inverted V-link, in the rocker arm walking mechanism revealed that the inverted V-link met the strength and stiffness requirements for three typical working conditions in coal mines: full-load ramp, emergency turning, and emergency braking. Considering the terrain features of the main transport roadway and the environment of the transport equipment in coal mines, simulated inspection experiments were conducted in a laboratory roadway. The results showed that the rocker arm wheeled inspection robot exhibited excellent environmental adaptability during walking tests on ramps, steps, and channels, fulfilling the inspection needs for underground roadways and their main equipment in coal mines.