[17] Real-time Locomotion Control by Sensing Gloves (Komura & Lam – 2006)

Current Mood: studious

Blogs I Commented On:

• Josh Johnston
• Pankaj Rajan
• Aaron Wolin

Summary:
This is a paper that describes a system which uses sensing gloves as an input device potentially for virtual 3D games. The sensing gloves used in this paper were the P5 and Cyberglove. Their method consists of a calibration stage and a control stage for employing the sensing gloves. In the calibration stage, some mapping function is created that converts hand motion to human body motion by mimicking the character motion appearing on a graphical display using the hand. The control stage involves performing a new hand movement, and then the corresponding motion of the computer character is generated by the mapping function and displayed in real-time. Construction of the mapping function first involves topological matching of the human body and fingers by comparing the motion of the fingers to that of the character. This is estimated by first calculating the DOF and then the autocorrelation of the trajectories. The authors determined the autocorrelation value to be 50 cycles, and joints are classified as either being a full cycle,, half cycle, or exceptional. After classifying the joints into one of the three categories, the hand’s generalized coordinates are matched to the character using the 3D velocity of the user’s fingers and the character’s body segments. This is done by first calculating the relative velocity of the character’s end effectors comparative to the root of the body, and then the relative velocities of the tip of the fingers comparative to the wrist of the hand. Lastly, all the end effectors of the character are matched to the finger of the user. Sometimes there is a phase shift between the user’s fingers and the character’s joints, which is remedied by keeping the ratio of the phase shift and the period the same when the user controls the character. In cases when the user suddenly extends or flexes the fingers, causing the system to not cover the range of the new finger motion, the system does extrapolation based on the tangent of the mapping function at the end of the original domain. Upper and lower joint angle boundaries are additional used by keeping the joint angles the same when those boundaries are exceeded until the mapping function comes back to within the valid domain. A virtual 3D environment with walls and obstacles were prepared to test their system on users using the Cyberglove, where users controlled the computer character with the index and middle finger to emulate walking, compared to keyboard input for the same task. The authors discovered that the average time to complete the task was shorter with the keyboard, but collisions were smaller with the glove.

Discussion:
I found this paper as an interesting application paper using glove devices for input, and also thought that it did a good job in covering the details behind their the method and their motivation behind their design choices. My gripe is more on the reasoning behind their application, primarily because I’m not a fan of using gloves to mimic locomotion of computer characters. The Iba paper was the only paper that came in mind that also focused on using gloves to achieve this feat, and I preferred the Iba paper because it felt more intuitive to use fingers to dictate motion as opposed to emulate motion.