Scalable Low-Density Distributed Manipulation Using an Interconnected Actuator Array

TL;DR

This work tackles the challenge of manipulating small objects with distributed actuator systems while avoiding dense actuator layouts. It proposes a scalable surface formed by modular 3-DoF origami-inspired tiles interconnected with a compliant layer, enabling continuous contact and reduced actuator density. The authors analyze single-tile and shared workspaces, develop a region-based, state-machine controller, and validate the approach experimentally on a 2×2 prototype across multiple object geometries. The results demonstrate robust manipulation via two modes—tile-to-tile transfer and inter-tile surface manipulation—highlighting scalability potential and practical relevance for material transport and adaptive handling.

Abstract

Distributed Manipulator Systems, composed of arrays of robotic actuators necessitate dense actuator arrays to effectively manipulate small objects. This paper presents a system composed of modular 3-DoF robotic tiles interconnected by a compliant surface layer, forming a continuous, controllable manipulation surface. The compliant layer permits increased actuator spacing without compromising object manipulation capabilities, significantly reducing actuator density while maintaining robust control, even for smaller objects. We characterize the coupled workspace of the array and develop a manipulation strategy capable of translating objects to arbitrary positions within an N X N array. The approach is validated experimentally using a minimal 2 X 2 prototype, demonstrating the successful manipulation of objects with varied shapes and sizes.

Figures (11)

• Figure 1: A $2\times 2$ actuator array inter-connected by a flexible material to form a continuos manipulation surface
• Figure 2: Array hardware: (a) Robotic tile module comprising three origami-inspired legs, each actuated by a stepper motor and connected to a central end-effector with attachment points for the flexible surface. (b) Detailed view of a single leg assembly. (c) Visualization of the compliant surface layer showing regions of exposed rubber and bonded PVC film.
• Figure 3: Illustration of four modules modules in an array, connected by connective material. This shows motor angles $\theta_i$, which determine tile pose $(\delta^i, \phi^i, r^{i})$. Modules are at an inter-module distance, $D$, and are connected by a material of length $L$, with distances $\alpha$ and $\beta$ indicated.
• Figure 4: Visualization of the workspace of a single tile in red, and a radially symmetric subsection of that workspace in blue. Points show position of end-effector centre.
• Figure 5: Minimum material length to achieve all positions in single tile workspace when connected to a horizontally/ vertically adjacent tile ($\alpha_{max}$) and diagonally adjacent tile ($\beta_{max}$) for different inter-tile distances (D).