Attila Kis

Characterization of an Integrable Single-Crystalline 3-D Tactile Sensor

Porous-Si-micromachining technique was used for the formation of single-crystalline force-sensor elements, capable of resolving the three vector components of the loading force. Similar structures presented so far are created from deposited polycrystalline Si resistors embedded in multilayered SiO2/Si3N4 membranes, using surface micromachining technique for a cavity formation. In this paper, the authors implanted four piezoresistors in an n-type-perforated membrane, having their reference pairs on the substrate in order to form four half bridges for the transduction of the mechanical stress. They successfully combined the HF-based porous-Si process with conventional doping and Al metallization, thereby offering the possibility of integration with readout and amplifying electronics. The 300times300 mum2 membrane size allows for the formation of large tactile arrays using single-crystalline-sensing elements of superior mechanical properties. They used the finite-element method for modeling the stress distribution in the sensor, and verified the results with real measurements. Finally, they covered the sensors with different elastic silicon-rubber layers, and measured the sensors altered properties. They used continuum mechanics to describe the behavior of the rubber layer

3D tactile sensor array processed by CNN-UM : a fast method for detecting and identifying slippage and twisting motion

In this paper, we present a fast and efficient technique for detecting and identifying the slippage and twisting motion of touching objects. This kind of action cannot be detected with tactile sensors sensing only the normal (perpendicular) component of the forces acting between surfaces. Our approach utilizes an integrated sensing–processing–actuating system comprising: (1) A 2 × 2 taxel (tactile pixel) array mounted on a two-fingered robot hand, (2) a 64 × 64 CNN-UM (Cellular Neural Network-Universal machine), and (3) a closed-loop controller. This arrangement, along with the proper analogic algorithm, allows detection and the control of the tactile event. It is essential to know and comprehend the forces between contact surfaces and the related 3D pressure fields is essential in many robotic applications discussed in the paper. Copyright

Integrated tactile system for dynamic 3D contact force mapping

We present the first integrated tactile system that is based on dynamic, spatially distributed, three-axial contact force data. Compared to general pressure mapping systems, our devices measure not only one, but all three components of contact forces (normal and shear) with up to 64 independent micromachined force sensing elements integrated on a single chip. The spatially distributed shear force sensing adds new dimensions and directions to tactile data analysis, including pre-slip detection, enhanced robotic grasping or high quality tactile texture classification. In this paper we briefly describe the components of the novel system: the sensor arrays, the data acquisition methods and the data analysis software. We also present two example applications that exploit the advantages of real time three-dimensional contact force mapping.

Event detection with 3D tactile sensors

In this contribution we present a fast and efficient technique for detecting and identifying the tactile events. This kind of events cannot be detected with tactile sensors sensing only the normal (perpendicular) component of the forces acting between surfaces. Our approach utilizes an integrated sensing-processing-actuating system comprising: (1) A 8×8 taxel (tactile pixel) array mounted on a tri-fingered robot hand, (2) event detector central unit (3) a closed loop controller. This arrangement, along with the proper pattern recognition algorithm, allows the detection and the control of the tactile event. It is essential to know and comprehend the forces between contact surfaces and the related 3D pressure fields.

Developing system to detect and analyze spatio-temporal tactile events

This contribution presents a new developing system to test methods of tactile sensing and processing for dexterous telemanipulation, i.e., telemanipulation that involves imparting forces and motions with the fingertips.