Variable Topology Truss: Hardware Overview, Reconfiguration Planning and Locomotion

The variable topology truss (VTT) system is a new type of modular platform that enables control over both the shape and topology of a truss, bringing both the efficiency of variable geometry trusses and the flexibility of self-reconfigurable robots. A VTT has the capability to enter a disaster site and shore damaged structures to assist with rescue work. This paper presents a revised overview of the VTT hardware design, enhanced from our previous works. We propose an active VTT spherical joint, which can address the hardware-related issues and also simplify the VTT software. Additionally, reconfiguration and locomotion planning algorithms for VTT are presented. We propose a retraction-based RRT method especially suitable for VTT and show our algorithm is superior to basic RRT in a practical 21-member VTT scenario. The locomotion algorithm implements a rolling gait under kinematic constraints; simulation results for a 21-member VTT show our algorithm yields accurate trajectory tracking.