Design, Analysis, Simulation, and Performance of a Pneumatic Scrubbing Robot for Cleaning Assistance

This thesis investigates a cleaning robot arm for its efficiency in scrubbing tasks and its safety in operation around other human workers. We discuss the mechanisms of cleaning, the effect of automation on labor and socially cognizant design, and the current advancements in cleaning robot arm systems. We detail the design considerations for an underactuated two-link robot arm actuated at an “elbow” joint by a pneumatic transmission system. We describe the hardware that we utilize for the robot arm system, primarily being commercial-off-the-shelf parts. We derive a model of the pneumatic system and compare it to the performance of the experimental system. We take advantage of simulation tools in Simscape and Simscape Multibody to digitally reconstruct the robot arm and pneumatic system. We evaluate the performance of the simulation versus the experimental system, particularly in the force needed to move the end effector and the energy change in the pneumatic actuator as the end effector is moved. We discuss the scrubbing experiment procedures and the image processing pipeline for analyzing photos of stains before and after cleaning. Our results suggest that we achieve similar cleaning performance to prior works with similar normal force output. We see a median of at least 85% reduction in stain area across twelve tests. Additionally, we see good agreement in the actuator position and change in energy between a combined Simscape-Simscape Multibody simulation and experimental data. We quantify end effector stiffness between the simulated and experimental data and discuss the differences in the two settings. We discuss future work on this project, including adding more actuators for hybrid-force position control and advanced sensing and image processing capabilities for real-time stain monitoring and evaluation.