1 research outputs found
Modular robots for sorting
Current industrial sorting systems allow for low error, high throughput sorts with tightly
constrained properties. These sorters, however, are often hardware limited to certain
items and criteria. There is a need for more adaptive sorting systems for processes that
involve a high throughput of heterogeneous items such as import testing by port authorities, warehouse sorting for online retailers, and sorting recycling. The variety of goods
that need to be sorted in these applications mean that existing sorting systems are unsuitable, and the objects often need to be sorted by hand. In this work I detail my design
and control of a modular, robotic sorting system using linear actuating robots to create
both low-frequency vibrations and peristaltic waves for sorting. The adaptability of
the system allows for multimodal sorting and can improve heterogeneous sorting systems.
I have designed a novel modular robot called the Linbot. These Linbots are based on
an actuator design utilising a voice coil for linear motion. I designed this actuator to be
part of a modular robot by adding on-board computation, sensing and communication. I
demonstrate the individual characteristics of these robots through a series of experiments
in order to give a comprehensive overview of their abilities. By combining multiple
Linbots in a collective I demonstrate their ability to move and sort objects using
cooperative peristaltic motion.
In order to allow for rapid optimisation of control schemes for Linbot collectives I
required a peristaltic table simulator. I designed and implemented a peristaltic table
simulator, called PeriSim, due to a lack of existing solutions. Controllers optimised in
simulation often suffer from a reduction in performance when moved to a real-world
system due to the inaccuracies in the simulation, this effect is called the reality gap. I
used a method for reducing the reality gap called the radical envelope of noise hypothesis,
whereby I only modelled the key aspects of peristalsis in PeriSim and then varied the
underlying physics of the simulation between runs. I used PeriSim to optimise controllers
in simulation that worked on a real-world system.
I demonstrate the how the Linbots and PeriSim can be used to build and control an
adaptive sorter. I built an adaptive sorter made of a 5x5 grid of Linbots with a soft
sheet covering them. I demonstrate that the sorter can grade produce and move objects
of varying shapes and sizes. My work can guide the future design of industrial adaptive
sorting systems