Mechatronic Design, Dynamic Modeling, and Real-Time Control of a Movable Scaffold

TL;DR

The paper addresses the challenge of flexible exterior scaffolding by introducing a cable-driven movable scaffold with a 3-DOF planar platform actuated by four corner motors. It develops a dynamic framework and kinematic relations for the system, implements a real-time PI control scheme, and validates the design through both simulations and a low-budget laboratory prototype. Results show sub-millimeter cord-length tracking, millimeter-scale platform positioning accuracy, and manageable power requirements, demonstrating the feasibility of precise vertical-plane positioning. The work offers a scalable, modular solution for exterior surface operations with potential applications in cleaning, painting, plastering, and pick-and-place tasks on buildings and large structures.

Abstract

This study presents mechatronic design, dynamic modeling, simulations and real-time control experiments of a new movable scaffolding system. The proposed system consists of a 3 degrees-of-freedom movable platform, which can be positioned on the outer surface of buildings. The platform is supported and driven by cords that are wound on pulleys and coupled to servo controlled dc-motors located at four corners of the building surface. A mathematical model considering the actuator dynamics for this cable-driven mechanism is obtained and its simulation results are presented. Design, manufacture and real-time control tests of a prototype has been done. Both numerical simulations and experiments provide good positioning performance of the proposed cable-driven mechanism.

Figures (12)

• Figure 1: Prototype of the system
• Figure 2: Schematic diagram of the electrical components
• Figure 3: Blockdiagram of the real-time microcontroller code
• Figure 4: Schematic diagram and parameters of the movable scaffold
• Figure 5: Simulation results