5 research outputs found
Development and Optimisation of 3D Printed Compliant Joint Mechanisms for Hypermobile Robots
Hypermobile robots are an area of robotics that are often used as exploratory robots, but have facets that feature in other areas of the field. Hypermobile robots are robots that feature multiple body segments or modules, with joints between each. These robots are often used for exploratory purposes due to being able to maintain contact with the ground due to their flexible bodies. Wormbot was a hypermobile robot developed at the
University of Leeds, which used a locomotion gait based on that of a Caenorhabditis elegans nematode worm, otherwise known as C.elegans. This movement pattern is reliant on compliance; a mechanism where the joints are slightly sprung and comply to the environment.
The next iteration of Wormbot needs to be reduced in size, which would also require a new actuation and compliance system.
This thesis describes the process of investigating a method of compliance to be used in the next version of Wormbot, while utilising the multi-material 3D printing capabilities available at the University. 3D printing provides quick manufacturing, allowing for fast
changes to made to prototype components if required.
During the process of this research, two 3D printed compliant actuation systems were produced; a pneumatic bellow and a Series Elastic Element (SEE) to be used in tandem with a servo motor. Both methods were tested to analyse their performance. The bellow was produced to utilise the capabilities of multi-material printing to strengthening suspected weak areas of the actuator. However, the performance of the bellow was unsatisfactory, failing twice in two actuation tests tests due to the device breaking. The SEE on the other hand, designed with two stiffer plates and a rubber-like spring element in the middle, initially proved to be reliable and repeatable in performance, with potential to
behave linearly to a set spring constant. These results were acquired by performing rotational step response tests and fitting a spring-damper model to the results. However, issues with the plastic material were discovered when it was found to deform much more than anticipated, behaving in a similar manner to an additional spring element, complicating the model. Simulation work to explore the potential for using different spring constants of joint compliance in varying environments was also explored. This involved testing a virtual Wormbot in a range of environments while altering joint compliance. These simulations revealed that softer joints allow for favourable performance in constricting environments, while stiffer joints lend themselves more to quicker movement
The Architecture of Soft Machines
This thesis speculates about the possibility of softening architecture through machines. In deviating from traditional mechanical conceptions of machines based on autonomous, functional and purely operational notions, the thesis proposes to conceive of machines as corporeal media in co-constituting relationships with human bodies. As machines become corporeal (robots) and human bodies take on qualities of machines (cyborgs) the thesis investigates their relations to architecture through readings of William S. Burroughs’ proto-cyborgian novel The Soft Machine (1961) and Georges Teyssot’s essay ‘Hybrid Architecture: An Environment for the Prosthetic Body’ (2005) arguing for a revision of architecture’s anthropocentric mandate in favour of technologically co-constituting body ideas. The conceptual shift in man-machine relations is also demonstrated by discussion of two installations shown at the Venice Biennale, Daniel Libeskind’s mechanical Three Lessons in Architecture (1985) and Philip Beesely’s responsive Hylozoic Ground (2010). As the purely mechanical model has been superseded by a model that incorporates digital sensing and embedded actuation, as well as soft and compliant materiality, the promise of softer, more sensitive and corporeal conceptions of technology shines onto architecture. Following Nicholas Negroponte’s ambition for a ‘humanism through machines,’ stated in his groundbreaking work, Soft Architecture Machines (1975), and inspired by recent developments in the emerging field of soft robotics, I have developed a series of practical design experiments, ranging from soft mechanical hybrids to soft machines made entirely from silicone and actuated by embedded pneumatics, to speculate about architectural environments capable of interacting with humans. In a radical departure from traditional mechanical conceptions based on modalities of assembly, the design of these types of soft machines is derived from soft organisms such as molluscs (octopi, snails, jellyfish) in order to infuse them with notions of flexibility, compliance, sensitivity, passive dynamics and spatial variability. Challenging architecture’s alliance with notions of permanence and monumentality, the thesis finally formulates a critique of static typologisation of space with walls, floors, columns or windows. In proposing an embodied architecture the thesis concludes by speculating about architecture as a capacitated, sensitive and sensual body informed by reciprocal conditioning of constituent systems, materials, morphologies and behaviours
Bio-Inspired Robotics
Modern robotic technologies have enabled robots to operate in a variety of unstructured and dynamically-changing environments, in addition to traditional structured environments. Robots have, thus, become an important element in our everyday lives. One key approach to develop such intelligent and autonomous robots is to draw inspiration from biological systems. Biological structure, mechanisms, and underlying principles have the potential to provide new ideas to support the improvement of conventional robotic designs and control. Such biological principles usually originate from animal or even plant models, for robots, which can sense, think, walk, swim, crawl, jump or even fly. Thus, it is believed that these bio-inspired methods are becoming increasingly important in the face of complex applications. Bio-inspired robotics is leading to the study of innovative structures and computing with sensory–motor coordination and learning to achieve intelligence, flexibility, stability, and adaptation for emergent robotic applications, such as manipulation, learning, and control. This Special Issue invites original papers of innovative ideas and concepts, new discoveries and improvements, and novel applications and business models relevant to the selected topics of ``Bio-Inspired Robotics''. Bio-Inspired Robotics is a broad topic and an ongoing expanding field. This Special Issue collates 30 papers that address some of the important challenges and opportunities in this broad and expanding field