Summer Blog 2024
Week 3
July 11: I went to the PRL to build a see-through acrylic tank for underwater testing.
July 9-10:
I worked with Hao on trying to get the code running for the Flexiv robot arm. This was challenging as we ran into a problem in achieving linear motion (trajectory for underwater testing): the arm would tend to jerk upwards before performing its linear travel. This was corrected by changing speed values and the home position coordinates. Though this solved the problem, when we reverted the code to the previous version, the problem was gone??
July 8:
I started this week off fixing the attachment I designed onto the Flexiv robot arm. This turned out well and there were no problems in the attachment process. After doing so, however, it was apparent that the attachment, made of PLA, was shaking and wobbling. This is a problem as it could add noise to the data collected by the whisker when testing in water. Therefore, I switched to using carbon fiber which was stiffer and decreased the wobbling.
Week 2
July 3:
After printing my first design on the Bambu printer in the lab, I realized there were a few design considerations which I had not taken into account and needed to address:
- Make screw holes more accessible for ease of attaching/detaching
- Make it narrower to easily fit into plastic tank for water testing
- Lose excess material
- Add bottom support mount to hold array in a stable position
And so, here is the updated version.
July 2:
My first task was to design an attachment to connect the robot arm that will be used for testing to the sensor array which houses the whiskers (optical fibers and FBG sensors).
Here is the design I came up with where the sensor array (shown above) would attach to the sides via screw holes.
July 1:
I talked with my PhD mentor, Hao Li, about the project I will be working on for the summer: whisker-inspired tactile sensing under deep water. The research involves developing highly flexible, curved, passive whiskers mounted along a robot arm to gather sensory data as they brush past objects during normal robot motion. The whiskers will be tested underwater and eventually mounted onto the OceanOneK robot. Over the next couple of weeks, I will be working on developing the apparatus for testing and reading fiber optic sensors in water.
- Lin, Michael A., et al. "Navigation and 3D Surface Reconstruction from Passive Whisker Sensing." arXiv preprint arXiv:2406.06038 (2024).
Week 1
June 27:
Today we had a Summer Retreat!!! Went hiking at Butano State Park, where I got to know my fellow lab members more. After a picnic, we all shared our summer goals. Here are mine! Afterwards, we went to Bean Hollow State Beach!
June 26:
I learned about the various applications of gecko-inspired adhesives including grasping onto objects in space. More specifically, I learned about the mechanism through which the adhesive functions via free-body diagrams. This involved the microwedges on the adhesive and how they activate when they slide against a flat surface, offering great resistance in shear, with the goal of trying to maximize the normal force before the adhesives fail. EmJ shared a paper which provides good background knowledge about the adhesives and their mechanism:
- Hawkes, Elliot W., Hao Jiang, and Mark R. Cutkosky. "Three-dimensional dynamic surface grasping with dry adhesion." The International Journal of Robotics Research 35.8 (2016): 943-958.
Afterwards, I spent some time doing the following:
- Went through tutorial for OnShape
- Started playing around with the software, making a few basic designs with Xitlali and Abby.
- Prototyping 2-tile designs for the adhesives
- While messing around with designs on OnShape, I was not aware of the importance of the line-of-action running from the string (tendon) attached to the tile running through to the center of the adhesive and the challenges of maintaining this line-of-action.
June 25:
Lab cleanup: organized lab hardware, materials, electronics
Intro to Gecko dry adhesives
June 24:
Starting off the Summer, we had an orientation, where we got safety training and an overview of ongoing work in the lab. I also created my own profile, here on the BDML website.
Afterwards, we had a SURI lunch and scavenger hunt around campus, which was a nice bonding event with other students doing exciting research in different labs.
Tadbot experiment intro tour: I got to see poison frogs at the Biology lab! I learned about the goal of creating realistic simulations of tadpoles in order to fool the parents into feeding the Tadbot to study frog behavior.