Computational Systems Design of Low-Cost Lightweight Robots

Abstract

With the increased demand for customisation, developing task-specific robots for industrial and personal applications has become essential. Collaborative robots are often preferred over conventional industrial robots in human-centred production environments. However, fixed architecture robots lack the ability to adapt to changing user demands, while modular, reconfigurable robots provide a quick and affordable alternative. Standardised robot modules often derive their characteristics from conventional industrial robots, making them expensive and bulky and potentially limiting their wider adoption. To address this issue, the current work proposes a top-down multidisciplinary computational design strategy emphasising the low cost and lightweight attributes of modular robots within two consecutive optimisation problems. The first step employs an informed search strategy to explore the design space of robot modules to identify a low-cost robot architecture and controller. The second step employs dynamics-informed structural optimisation to reduce the robot’s net weight. The proposed methodology is demonstrated on a set of example requirements, illustrating that (1) the robot modules allow exploring non-intuitive robot architectures, (2) the structural mass of the resulting robot is 16 % lower compared to a robot designed using conventional aluminium tubes, and (3) the designed modules ensure the physical feasibility of the robots produced.

Topology optimisation of multiple robot links considering screw connections

“…To enhance the performance of robotic arms, a new approach in topology optimisation was introduced to incorporate the interface connectors. In the current version (Sathuluri et al 2023a), so-called interface connectors to the attachment points are implemented as circular plates, contributing significantly to the mass of individual components, thereby limiting the efficiency of components concerning weight optimality. By including the interface connectors in the design space, additional potentials for mass reduction emerge.…”

“…In comparison to previous versions of the robot links, further minor adjustments have been made. Firstly, the cutouts addressed in Section 1 for cable routing have been significantly reduced compared to the results shown in Sathuluri et al 2023a. The optimisation results exclusively demonstrate hollow structures with lateral cutouts designed for screw access.…”

“…One application are robot manipulators which are applied in many fields and are often designed for high-precision motion with an end-effector load. Sathuluri et al 2023a draws attention to the growing need for cost-effective, lightweight, and reconfigurable robots in a world that is increasingly embracing mass customization and human-centric operations. When dealing with multi-component systems with high complexity, two problems emerge: First, the need for decomposition to reduce problem size and efficiently optimise the system (ElMaraghy et al 2012), and second the connection of the parts in the physical system has to be addressed (Rakotondrainibe et al 2020).…”