Develop a research question
Description
Team Response
Content
Introduction
Tractability
Novelty
Interesting
Open-Ended
Modular
Team Fit
Topic Fit
References
Introduction
Team 5 was given the general topic of “Navigating Tight Spaces with Foldable Robotics” and was tasked with researching a more specific question through a semester-long course. After half the semester, we had a major project change. We have shifted from tight space navigation to locomotion, and seek to answer the following question:
“How can foldable techniques translate a small number of actuators into unique locomotion?”
This paper will explain the aforementioned criteria and detail the thought process that was followed to meet those criteria with a more specific research question.
Tractability
The team has come across many ideas that would have been interesting to explore. However, due to the nature of the class for which this project will be carried out, there exist some constraints that will need to be met in order to make the project tractable/achievable. The main elements affecting the project scope are time and budget. Considering that the class mentioned above is a semester-long project class, the total time available to the team is about 15 weeks. With this in mind, the complexity we aim for will be kept to a minimum. Since this is a class environment, all of the team members are still learning. As such, keeping the scope of the project slim will ensure that we do not bite off more than we can chew in the allotted time. To further save time, the team will draw inspiration from already existing sources, particularly the tube foot (podia) of a starfish and similar bio inspired robots. We intend to focus most of our intention on locomotion and achieving interesting motion through a single ‘podia’ inspired leg. The last major way the team will attempt to cut down on time is through the choice of materials. Due to the nature of foldable techniques, structural components can be created with easily attainable materials such as paper, cardboard, or similar. Functional components also need to be considered. By minimizing the use of actuators, the team will be able to spend less time waiting for ordered parts and spend more time prototyping.
Both of the previous considerations also serve to keep the budget down to a minimum. Paper-like materials are inexpensive and easily found practically anywhere, and cutting down on actuators saves even more funds. Additionally, the team can make use of rapid prototyping techniques, particularly 3D printing and laser cutting, to achieve designs in a quick yet inexpensive way. The combination of all these constraints will allow for the completion of the project within the 15-week semester.
Novelty
Our question builds off of previous research projects that focus on podia-like designs to establish motion. The bio inspired design is a modular subject that has uses in fields of research pertaining to search and rescue, motion analysis, and, in general, soft robotics. To establish novelty, team 5 will focus on generating motion possible through a single actuator, out of a foldable-based robot crafted from cheap and easily accessible supplies. When searching for previous research, emphasis was placed on the following key words: starfish locomotion, podium/podia, tube feet, soft robotics movement There exists extensive research exploring bio-inspired starfish, all ranging from varying levels of complexity. However, much of the existing research does not focus on the podia for movement, but instead focuses on the arms of the starfish. Soft robotics, in particular, has been explored as a way to imitate the omnidirectional capabilities of starfish by controlling the gait of the arms, such as in a paper by Hu Jin et al., entitled “A starfish robot based on soft and smart modular structure (SMS) actuated by SMA wires.” [1] In said paper, the arms of the robot are made of a soft, composite structure, termed ‘smart modular structure’ or SMS. Another paper, “Geometric Gait Design for a Starfish-Inspired Robot Using a Planar Discrete Elastic Rod Model,” by W. L. Scot and D. A. Paley [2], has a very similar premise, except with a different structure for the arms. One particularly interesting paper, “Echinoderm-Inspired Tube Feet for Robust Robot Locomotion and Adhesion,” by Bell et al. [3], details the results of two robots, both of which base their motion on the extension and manipulation of tube feet, while also noting the prevalence of arm-based starfish robots. One bot is round and utilizes the podia, arranged radially about the center, to extend, adhere to a surface, and contract, pulling the bot into a roll in that direction. The other uses podia arranged on a plane with programmed deflection in order to move laterally. Hydraulic tubes were used to extend and contract the tube feet, which took advantage of an elastic dome shape, resulting in two stable rest states (in a similar manner to rubber popper toys commonly found in arcades and such). The next article of note is by T. Paschal et all. [4] Coincidentally, these authors also note the common focus on whole arm-scale motion of starfish from other previous works. This paper, however, looks to the sea urchin, another echinoderm aside from the starfish, for inspiration. The aspect of sea urchins that the authors find the most interesting is their unique anatomy, specifically the higher aspect ratio of the tube feet and spines. The difficulty in replicating such smooth motion through rigid robotics is acknowledged, and soft robotic actuators are brought into focus. The research resulted in a sea urchin robot that measured 500 times larger than the urchin after which it was modeled and could move at 0.027 body lengths per second, half that of adult sea urchins, and a tenth that of juveniles. However, The authors suggest that greater individual control of spines, among a few other ideal changes, would improve the prototype greatly. It is noted that two particularly useful applications of such a bio-inspired robot would be deep sea exploration and the monitoring of structures such as ship hulls. The four examples we discuss are all relevant to the project as they elaborate on research of starfish or echinoderm-inspired robots and reveal that the realm of foldable robotics has not yet been integrated by existing research, as far as we can see. The third and fourth papers mentioned are particularly interesting to us, as they focus not on the motion of the starfish’s arms, but on the individual podia, which is something the team would like to imitate through foldable-robotics techniques, seeing as they are almost a cross between rigid and soft robotics. Additionally, Team 5 proposes to make such a starfish-inspired robot that is capable of motion driven by a minimal amount of actuators, developed with inexpensive materials such as paper and elastic bands, and capable of being rapidly fabricated.
Interesting
Some of the goals for the projects in this class include concepts that are interesting, timely, and relevant. Part of what Team 5 believes will be the most important effect of our project on others is the application of our concepts to other future robots. Developing techniques to minimize actuator usage is something that can reduce costs for any actuated robot, especially considering that actuators are one of the primary components in terms of both cost and space. Increasing the usage of foldable techniques also has a side effect of opening up new ways to utilize additive manufacturing, which has been a rapidly improving technology recently. The use of laminate materials, paired with the layer-by-layer deposition of 3D printing allows for complex structures to be rapidly prototyped that may have been difficult or impossible without such a technique. Another area that could be improved is that of soft robotics; the origami-inspired techniques used in foldable robotics have potential to be applied in a field where soft/compliant materials are used. One of the potential expansion paths from this project, which will be discussed in more detail in a later section, is the use of cheap and biodegradable materials. If it becomes viable to create small robots that are quick and inexpensive to manufacture and leave a small footprint in nature, then this project could be relevant to fields like exploration or search/rescue. The scaling of such a project could positively impact these fields by reducing the manpower needed to accomplish these tasks and, in turn, providing a safer alternative.
Open-Ended
Our question is quite open ended, as it leaves a lot of room for improvements and could be adapted in various areas of study. Our research question, as it stands, focuses on creating motion with a minimal amount of actuators, which is a goal that could benefit robotics used in many fields of study. One direction that our research question could be taken is adapting our project in the field of soft-robot technology. Soft robotics is an ever growing field that takes inspirations from various fields and areas of engineering, so our research question could prove to be beneficial to soft-robot technology. Lastly, the most relevant area where our research question could be expanded is with several different areas of study where there is a need to navigate through small, hard-to-reach spaces with accuracy. As a side result of this scaling down, ;ess materials would also be used, improving the carbon footprint. Our question is broad enough to where areas such as medical, mining, rescue, etc. could benefit from our research.
Modular
Modular: Is your question modular? How does it fit with other complementary research thrusts?
Our research focus adds on to over a decade of work being conducted in the area of miniature robots with reduced number of actuation that can perform some specific tasks such as data acquisition in petroleum reservoirs, or navigating rough terrains. Our research seeks to build upon and contribute to this broader research thrust of promoting single-actuation of bio-inspired miniature robots. Locomotion of such robots is one step in reaching the goal of having robots navigate through areas that humans cannot get to due to size and danger - from oil exploration to complex medical surgeries. In the long run, such low-cost robots could, for instance, be fitted with cameras for taking pictures of these spaces or, in the case of surgery could be used in drug delivery or even controlled venous surgery (such as declogging cholesterol from arteries). Our research hence presents one module of the overarching goal of having tiny robots perform tasks that human beings may be unable to perform.
Team Fit
Generally, the team consists of members with an interest and some experience in the kinematics and control of robots. This comes in very handy given that our research focuses heavily on locomotion in miniature sized robots. In addition a number of the members on the team have experience with prototyping skills from Computer Aided Designing, to 3D printing and laser cutting. This wide range of rapid prototyping skills give us the advantage of being able to physically model our robot within the time frame of the academic semester. Members of the team also have considerable experience in scripting languages such as MATLAB and Python as well as a substantial skillset in electronics. These meet the need to script any commands as well as build and power our robot. Being graduate students, the team members have experience with conducting research and will be able to leverage said research skills into learning about and completing our given research project.
Topic Fit
Our research question has the potential to use multiple aspects of foldable robotics techniques to answer it. One of the foldable robotic techniques that would be used to answer our research question is that of using folding techniques to create or improve motion. As seen in the pop-up book assignment, there are a plethora of folding techniques, and many of them can be used to create unique motions. The combination of folding techniques paired with an actuator to create motion fits perfectly within the scope of the class. Not only can the folding techniques be used to create motion, but the folding techniques could also be used for the structural component of our project. Lastly, we want to show that we can optimize the movement of our robot through the use of only one actuator, so we will need to rely heavily on folding techniques to carry out the motion for the actuator.
References
[1] H. Jin et al 2016 Bioinspir. Biomim. 11 056012
[2] W.L. Scott, D. A. Paley. “Geometric Gait Design for a Starfish‐Inspired Robot Using a Planar Discrete Elastic Rod Model.” Advanced Intelligent Systems, vol. 2, no. 6, Wiley, 2020, p. 1900186–n/a, doi:10.1002/aisy.201900186.
[3] M.A. Bell, et al. “Echinoderm-Inspired Tube Feet for Robust Robot Locomotion and Adhesion.” IEEE Robotics and Automation Letters, vol. 3, no. 3, IEEE, 2018, pp. 2222–28, doi:10.1109/LRA.2018.2810949
[4] T. Paschal, et al. “Design, Fabrication, and Characterization of an Untethered Amphibious Sea Urchin-Inspired Robot.” IEEE Robotics and Automation Letters, vol. 4, no. 4, IEEE, 2019, pp. 3348–54, doi:10.1109/LRA.2019.2926683.