Current robots are primarily rigid machines that exist in highly constrained or open environments such as factory floors, warehouses, or fields. There is an increasing demand for more adaptable, mobile, and flexible robots that can manipulate or move through complex environments. This problem is currently being addressed in two complementary ways: (i) learning and controls algorithms to enable the robot to better sense and adapt to the surrounding environment and (ii) embedded intelligence in mechanical structures.
Here are some of our projects to address these challenges:
Robots that assist humans in everyday environments will need to perform manipulations with high levels of dexterity, robustness, and safety. For example, to be able to assist a human in taking their medication, a robot manipulator must be able to open a pill bottle, grasp a small pill, and gently feed that pill to the human. These tasks require sophisticated manipulation capabilities, enabled by human fingers and fingertips.
To address these challenges, it is crucial to develop compliant (defined as inverse of stiffness) mechanisms that have the correct precision and force profiles to act as fingers but also have sufficient flexibility to enable human interaction. Our early work has focused on characterizing the linkages of the delta mechanism to determine the optimum stiffness ratio between the links and the joints . For other results, please visit our dedicated page for compliant parallel robots (in construction).
PHYSICALLY COUPLING ROBOTS
Collaborative swarm behaviors have been widely observed in nature, particularly among insects . Robots in unstructured environments may face similar challenges (e.g., uneven terrain, gaps, etc.). For instance, search-and-rescue robots have to operate in cluttered, dynamic environments. Utilizing swarm techniques such as robust coupling and decoupling will enable these robots to work under different force conditions and in unpredictable terrain.
We work on developing novel coupling mechanisms that have low energy consumption for small scale robotic modules. To make these robotic modules low-cost and easy-to-build, we use off-the-shelf components and 3D printing. Our first experiments presented an increased gap-crossing ability, the robot can cross gaps that are half as wide as the length of the connected modules . We also studied the effects of environmental parameters such as the height difference between two sides of the gap.
Origami-inspired printable robotics provides a novel and efficient approach to fabricating lightweight, low-cost, fully functional 3D robots using 2D sheet materials and planar . Last step in the manufacturing origami-inspired mechanisms is folding the 2D sheets into 3D structures. For more complex origami-inspired mechanisms, assembly through manual folding becomes extremely challenging.
Our primary focus is on automating the sequential folding process. We are developing a method to incorporate friction latches and thus actively control the timing of the folds in the origami manufacturing process without manual interruption. In addition to our experiments, we are developing an analytical model and validating our results with experiments. This model will generate a framework to design self-folding structures with simple timing control.
FACILITIES AND LAB EQUIPMENT
We currently have 2 FDM printers: Ultimaker S5 and Prusa i3. We use this for manufacturing compliant parallel robots and physically coupling robots (e.g., PuzzleBots)
In addition, we have Form3 SLA 3D printer. Stay tuned for results of our research that uses this machine!
LPKF U4 LASER
We use this micromachining system to cut or etch different materials and build circuits, that we use to build our robots and robotic systems. The laser focus with a diameter of 20 micrometers allows us to machine incredibly tiny features (e.g., circuitry running in our puzzle-bots)
For more information on the equipment, please see LPKF's website.
UNIVERSAL LASER SYSTEM VLS 3.60
This laser uses CO2 source, allowing us to cut wide range of materials, including paper, wood, polyester, fabric, etc. We use this for manufacturing dynamic origami 2D sheets.