Limits...
Use of tactile feedback to control exploratory movements to characterize object compliance.

Su Z, Fishel JA, Yamamoto T, Loeb GE - Front Neurorobot (2012)

Bottom Line: Humans have been shown to be good at using active touch to perceive subtle differences in compliance.We developed similar exploratory and perceptual algorithms for a mechatronic robotic system (Barrett arm/hand system) equipped with liquid-filled, biomimetic tactile sensors (BioTac(®) from SynTouch LLC).These signals provided closed-loop control of exploratory movements, while the distribution of skin deformations, measured by more lateral electrodes and by the hydraulic pressure, were used to estimate material properties of objects.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Medical Device Development Facility, University of Southern California Los Angeles, CA, USA.

ABSTRACT
Humans have been shown to be good at using active touch to perceive subtle differences in compliance. They tend to use highly stereotypical exploratory strategies, such as applying normal force to a surface. We developed similar exploratory and perceptual algorithms for a mechatronic robotic system (Barrett arm/hand system) equipped with liquid-filled, biomimetic tactile sensors (BioTac(®) from SynTouch LLC). The distribution of force on the fingertip was measured by the electrical resistance of the conductive liquid trapped between the elastomeric skin and a cluster of four electrodes on the flat fingertip surface of the rigid core of the BioTac. These signals provided closed-loop control of exploratory movements, while the distribution of skin deformations, measured by more lateral electrodes and by the hydraulic pressure, were used to estimate material properties of objects. With this control algorithm, the robot plus tactile sensor was able to discriminate the relative compliance of various rubber samples.

No MeSH data available.


Related in: MedlinePlus

Coordinate frame of BioTAC: each impedance sensing electrode has a specific orientation in the BioTac coordinate frame.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3405524&req=5

Figure 3: Coordinate frame of BioTAC: each impedance sensing electrode has a specific orientation in the BioTac coordinate frame.

Mentions: The BioTac contains an array of 19 impedance sensing electrodes distributed over the surface of the core, which has a coordinate frame aligned with its long axis (Figure 3). Each impedance sensing electrode was determined to have the highest sensitivity to forces applied normally to its surface. The normal vectors to each of these electrodes in 3-axis coordinate space can be weighted with the change in impedance of these electrodes to determine an estimate of tri-axial force. We calculate the x, y and z force vectors from these electrodes with the following equation:[FxFyFz]=[Sx000Sy000Sz]×[N1, x⋯N19, xN1, y⋯N19, yN1, z⋯N19, z]×([E1⋯E19]−[E1, rest⋯E19, rest])Figure 3


Use of tactile feedback to control exploratory movements to characterize object compliance.

Su Z, Fishel JA, Yamamoto T, Loeb GE - Front Neurorobot (2012)

Coordinate frame of BioTAC: each impedance sensing electrode has a specific orientation in the BioTac coordinate frame.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3405524&req=5

Figure 3: Coordinate frame of BioTAC: each impedance sensing electrode has a specific orientation in the BioTac coordinate frame.
Mentions: The BioTac contains an array of 19 impedance sensing electrodes distributed over the surface of the core, which has a coordinate frame aligned with its long axis (Figure 3). Each impedance sensing electrode was determined to have the highest sensitivity to forces applied normally to its surface. The normal vectors to each of these electrodes in 3-axis coordinate space can be weighted with the change in impedance of these electrodes to determine an estimate of tri-axial force. We calculate the x, y and z force vectors from these electrodes with the following equation:[FxFyFz]=[Sx000Sy000Sz]×[N1, x⋯N19, xN1, y⋯N19, yN1, z⋯N19, z]×([E1⋯E19]−[E1, rest⋯E19, rest])Figure 3

Bottom Line: Humans have been shown to be good at using active touch to perceive subtle differences in compliance.We developed similar exploratory and perceptual algorithms for a mechatronic robotic system (Barrett arm/hand system) equipped with liquid-filled, biomimetic tactile sensors (BioTac(®) from SynTouch LLC).These signals provided closed-loop control of exploratory movements, while the distribution of skin deformations, measured by more lateral electrodes and by the hydraulic pressure, were used to estimate material properties of objects.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Medical Device Development Facility, University of Southern California Los Angeles, CA, USA.

ABSTRACT
Humans have been shown to be good at using active touch to perceive subtle differences in compliance. They tend to use highly stereotypical exploratory strategies, such as applying normal force to a surface. We developed similar exploratory and perceptual algorithms for a mechatronic robotic system (Barrett arm/hand system) equipped with liquid-filled, biomimetic tactile sensors (BioTac(®) from SynTouch LLC). The distribution of force on the fingertip was measured by the electrical resistance of the conductive liquid trapped between the elastomeric skin and a cluster of four electrodes on the flat fingertip surface of the rigid core of the BioTac. These signals provided closed-loop control of exploratory movements, while the distribution of skin deformations, measured by more lateral electrodes and by the hydraulic pressure, were used to estimate material properties of objects. With this control algorithm, the robot plus tactile sensor was able to discriminate the relative compliance of various rubber samples.

No MeSH data available.


Related in: MedlinePlus