Design Analysis, Motion Planning, and Development of an Inchworm-Inspired Biped Wall-Climbing Robot

This paper describes the design analysis, adhesion force measurement, motion control study, prototype fabrication, and testing of an inchworm-inspired wall-climbing robot (WCR) for ferrous surface use. An optimal adhesion force requirement for each gripper module has been evaluated using particle swarm optimization algorithm. The structure of the robot is designed and analyzed using SolidWorks modeling and finite element simulation software package for detailed design parameter evaluation. The design analysis for selecting suitable driving motors has been performed using dynamic formulation. Dynamic simulations for robot motion have been performed using MATLAB algorithm. Extensive trials to measure adhesion force of electromagnets have been carried out to understand the gripping power and payload capacity of WCR. The designed prototype of WCR is utilized for motion trials. The developed robot consists of an inchworm-like biped structure by connecting driving motors with brackets and attached to two gripping modules. Each gripping module integrates four electromagnets essential for generating the adhesion force requisite for vertical wall-climbing. For motion planning and control, the robot is actuated by three smart Dynamixel servo motors, which are controlled using an Open CM 9.04 microcontroller, whereas the adhesive force of the electromagnets is controlled by using a microcontroller unit (NodeMCU ESP 8266). A series of experiments were performed to evaluate the climbing performance using flip-over gait motion on horizontal and vertical surfaces and validated the carried design analysis.