CAD Model of Soft Robot
The images correspond to 5 projects:
HyLo/StairBot, Quadrotor, RedBeest, Soft Robots, and Vibratron.
Here are the corresponding texts:
HyLo, short for Hybrid Locomotion, is a collaborative project fueled by Undergraduate Students at CMU.
The purpose of our work is to extend the capabilities of small robots beyond what has previously been tried or thought of on a robotic platform. The current team consists primarily of Mechanical and Electrical Engineering students as well as members studying Computer Science. We seek to make the dynamics of small robots work towards goals of effective locomotion over a very wide range of terrain.
Our current goals consist of creating a planar, three link robot capable of traversing a set of monkey bars typically found on a children’s playground. Eventually, we would like to apply the knowledge gained from the simple robot to a more sophisticated 4 limbed platform. This four limbed platform is intended to be used as a base for various research problems. One problem that was addressed in the previous year was traversing varied terrain that could be encountered in an urban environment. We tackled the problem by attaching powered wheels to the end of highly articulated legs. With the new platform, we are seeking to create a modular design that can accept a variety of end effectors, such as hooks or graspers to accomplish other tasks.
The end goal for this project is to have a robot capable of traversing a tight-rope and climbing a ladder.
The idea behind hybrid locomotion in robots is that a platform can transition between walking and rolling to fit terrain conditions. Rolling can be utilized in areas where doing so is feasible. However, obstacles larger than about half the diameter of a rolling robot’s wheels will stop an otherwise quick robot in its tracks. With suspension and an increase in wheel diameter, rolling robots can tackle larger obstacles, but a smaller legged robot would not struggle in the same situation. With the ability to simply step over an obstacle, walking robots are better suited to certain environments.
Legged robots are typically plagued by slowness compared to similar sized rolling robots. By combining the leg of a walking robot with the wheel of rolling robot, a robot using this platform gains utility while not necessarily encountering complexities foreign to either a rolling or walking robot. This is the premise of Stairbot, a hybrid locomotive robot platform.
Quadrotor is an autonomous and tele-operated aerial vehicle designed for completing vision based objectives.
The quadrotor helicopter, or quadrotor for short, is an especially fast and maneuverable aerial platform. Using a suite of sensors, our quadrotor will be able to perform GPS-guided position holding, path planning, and navigation with the aid of visual feedback. An end goal is to use the platform to map unstructured terrain, such as that present in the wilderness.
Our goal this year is to use the Microsoft Kinect sensor to navigate indoor environments. We use the MikroKopter platform for the quadrotor itself, and process video data from the Kinect on-board to navigate obstacles and create a map of the environment.
Your Take on Design
Using a computer as a conceptualization tool is invaluable for me in solving engineering and design problems. It is also a tool of creative expression. Computers have enabled me to recreate a design of Theo Jansen’s walking linkage in a new, digitally expandable form. I have kept the design as open and plain as possible given its complex mechanical nature, while being mindful of the placement of each component to ensure an aesthetically pleasing arrangement. Because of this, the concept is unusually organic for a mechanical creation and its walking capabilities are inspired by nature’s solutions.
The Walker concept is a creature that stands as high as dreams allow. In the attached images, the creature is only eight inches tall, but by design can be grown to over eight feet tall. This scalability is inherent in Theo Jansen’s linkage design. The linkage takes rotary motion and translates it into a walking gait, which I have applied to motivate the Walker. Jansen’s linkage is combined twelve times to create a beast that can walk in all directions. There are two distinct leg groups that comprise the left and right side, each with six legs. The left and right leg groups are independently driven, though the six legs that make up each group are linked together, 60º out of phase. This link is created through meshing gears. In practice, each of the leg groups will act as a wheel, having constant contact with the ground and ensuring stability as the Walker travels. When both leg groups are driven together at the same speed, the Walker travels in a straight line. However, when the leg groups are driven at different speeds, the Walker will turn towards the slower (or stopped) group of legs. These legs, a pair of motors, and a power source are the only components of the machine. This system can be realized as any tangible object ranging from a toy, to a transportation vehicle, to an extraterrestrial exploratory robot, or, as Jansen would have it, to a new form of life. The bare components are uncovered and unadorned, allowing onlookers to see exactly how the machine is working. The internal components make up the Walker’s lines and character, proudly striding without a shell or case. Mechanical design can always be beautiful.
My motivation as a designer stems from objects that hold promise for beautiful and tangible creation, but whose design is executed in an unsatisfactory manor. I am annoyed with art, sculpture, and toys that are meant to appear functional, but are limited or immutable. These objects just don’t work the way you want. There are exceptions to my issue with falsity- for example, in fantasy. Digital animation that visualizes the currently impossible is an amazing treat. Visuals such as those present in recent science fiction films like Transformers and Iron Man can’t be physically manufactured today, but the concepts are almost realizable. The audience of these films can accept that details are in place so that the mechanical devices in action on screen could exist in the real world eventually. There are many gaps in detail that we are currently filling with ‘Hollywood Magic,’ which is appropriate for movies, but not for today’s objects. In some cases design is moving in the more open, understandable direction. The ElectroLux vacuum cleaner of the 1930’s sought to hide its workings, enclosing the magic, but the Dyson vacuums of today fall within my principles by making its workings visible and clean.
Design of an object should not only follow the function of an object, but also how that object accomplishes that function. Often, a designer detaches their work from the means by which a task is completed. Dogs, for example, walk effortlessly, without regard to which muscle to tense at any given point to propel themselves forward. To many designers, making a walking creature involves merely attaching legs, allowing the underlying mechanism to work itself out. It is easy for design to abstract these types of problems, it takes effort to make an object work, and in the minds of many, effort to make the object appeal. My principle of design is that an object that works is appealing, be it conceptually, visually or physically.
Like Jansen, I believe that the aesthetics of an object come about due to natural application constraints. The form of his ‘beests’ came to be out of necessity. The proportions of the mechanism that I have borrowed from Jansen in the concept make for a visually pleasing object, perhaps only by coincidence. By following natural solutions to engineering problems, beautifying and ornamenting objects becomes superfluous. Jansen frees himself and his work of excess, focusing on efficiency and self-sustainability, brought about by deterministic solutions.
Theo Jansen’s vision expands beyond engineering and art. He uses technology to enable his ideas, a process ideology that I increasingly employ. Software facilitates the design of complex mechanical systems that mimic nature in its beauty and effectiveness. It allows systems to come together as a whole, as demonstrated in the concept images. The design of this object and its visual appeal are merely a side effect of its purpose- to walk.
There is a growing need for robots that can function in close proximity to human beings and also physically interact with them safely. This calls for a paradigm shift in the way robots are designed. We believe inherent safety is extremely important for robots in human environments. Towards this end, we propose the use of inflatable robot links instead of traditional rigid links, to improve safety in physical human robot interac- tion (pHRI). Robots with inflatable structural components offer the possibility of an extremely light weight structure and passive compliance along with a high payload to weight ratio, which are all highly desirable features in a robot expected to closely interact with humans. This paper builds upon prior work by our group in the development of a single link inflatable robotic system to design and develop a multiple DoF inflatable arm. The paper describes the development of a 2 DoF prototype inflatable arm; the link structure, joint design, kinematics and other features of the system are discussed. Preliminary trials utilizing the system for sponge bathing a human mannequin are presented. Experiments that demonstrate the inherent safety of the system under unexpected collisions are also shown.
Vibratron is one of the main RobOrchestra projects for the 2010-2011 year. After receiving $1000 in grant money from the Undergraduate Research Office in the form of a SURG and a donated vibraphone from a former member, the team began designing a robotic Vibraphone.
The overall vision for the project involves laying out the 30 vibraphone keys in a circular array and dropping steel ball bearings onto the keys in order to create music. While other more direct methods might have been more effective, the group opted to create a more unique piece of art.
The project is currently in the prototype stage, but the general layout has been designed. The robot will be composed of three main systems. One of the systems will dispense the balls onto the keys, one will collect the used balls and recycle them to be used again on a different note, and the third system will be the structure of the robot that hold the keys and all other systems together.
The ball dispensing mechanism has been through two complete designs. The initial design used a rotating notched wheel attached to a stepper motor to dispense balls one at a time. The second design used a solenoid as a gate to block and release balls from a queue. Both designs were prototyped, and the solenoid design was chosen because of its greater speed and reliability over the wheel design. Each of the 30 gate mechanisms will cost less than $5.00, and will be capable of dispensing over 14 balls per second. There are renders and photographs of the gate below.
The recirculation mechanism is basically an Archimedes Screw that brings balls from a lower hopper to an upper hopper. Once in the upper hopper, a paintball-style system will be used to spread the ball bearings into the 30 individual tubes, each of which routes to a separate gate.
The structure of the system will not be designed in any detail until the kinks have been worked out of the other two systems. However, a conceptual render of the desired circular layout of the Vibratron is below.
An Arduino Mega will be used to control the robot. A MIDI shield will allow the Arduino to read standard MIDI signals from any controller, and software will decode the MIDI commands into notes.
Each of the 30 gates will have a small custom printed circuit board (PCB) with a MOSFET and LED. This circuit board receives a digital signal from the Arduino and uses that signal to turn on the solenoid for a certain amount of time.