Haplink
Haplink is an open-source, kinesthetic haptic device that derives from the 1-DOF Hapkit, but has been designed to function as either a 1- or 2-DOF device. Haplink is not meant to replace Hapkit, but to be used as a platform to explore more advanced concepts. We propose that students could benefit from learning concepts incrementally and develop on them in parallel with their device. One could learn basic concepts in one degree of freedom, then transform the device to a 2-DOF device and learn concepts in two degrees of freedom.
Haplink combines two rotational joints in a serial linkage to become a 2-DOF device while keeping both of its motors grounded in order to maintain the cost of the device low. Without the grounding of both motors, one motor would have to rotate significantly more inertia as it would have to support the other motor.
Haplink is made from 3D printed structural components that allow for student's customization of their devices.
In the Fall quarter of 2017, Haplink was used in an introduction to Haptics class for freshmen undergraduate students at Stanford University who are considering engineering as a mayor.
The course is taught in a classroom with big lab benches which creates a very collaborative environment. About half of the time is spent listening to lectures and about half building devices and doing experiments with them.
In the course, the students started by learning an introduction to mechatronics and kinematics in order to understand how Haplink (in the 1-DOF version) works. Then they built Haplink as a 1-DOF device and rendered several virtual environments such as a spring, a wall, a texture and a damper.
In previous versions of the class. The instructor just taught rendering in 1 DOF, however with Haplink, after working with the 1-DOF device, the instructor then introduced 2-DOF kinematics– She started by refreshing the students on the 1-DOF kinematics of their device, and then showed how the 2-DOF kinematics of Haplink resulted from combining two 1-DOF devices.
After this, the students then learned how to render 2-DOF virtual environments and rendered inside of a box and circle, outside of a circle as well as others that they made up themselves.
The final two weeks of the class were spent working on a project in which students were tasked with creating a novel haptic application. Students formed teams of 2 to 3 people and together combined their 1-DOF, 2-DOF devices with tactile haptic rendering and other sensors to create new haptic devices.
Some students chose to further customize their Haplinks to create their application.
Publications
- M. Orta Martinez, J. Campion, T. Gholami, M. K. Rittikaidachar, A.C. Barron, and A.M. Okamura. Open-Source, Modular, Customizable, 3-D Printed Kinesthetic Haptic Devices. IEEE World Haptics, 2017.
- M. Orta Martinez, K. Gee, and A.M. Okamura. Design and Analysis of a Modular, Open-Source, 2-DOF, Kinesthetic Haptic Device for Educational Applications. Journal paper in preparation.
Conference Demonstrations
- M. Orta Martinez, K. Gee, T. S. Cloyd, M P. Hernandez, T. Hsieh, B. Immel, M. Steimle, J.A. Sosa, T. Sun, and A. M. Okamura. Haplink Customizations. Presented at IEEE Haptics Symposium, 2018.
- M. Orta Martinez, M. Rittikaidachar, and A. M. Okamura. Haplink: A low cost, open source, two-degree-of-freedom, 3-D printed haptic kit. Presented at IEEE World Haptics, 2017.