Muhammad Azmi Ayub

Determination of object stiffness control parameters in robot manipulation using a prototype optical three-axis tactile sensor

This paper presents experimental results to define suitable parameters in object stiffness control using a prototype optical three-axis tactile sensor mounted on robotic fingers. We have developed a novel optical three-axis tactile sensor system based on an optical waveguide transduction method applying image processing technique. We conducted a series of calibration experiments with soft and hard objects to define suitable parameters in object stiffness control. We analyzed normal and shearing forces data detected in the experiments and compiled suitable parameters in an algorithm inside the robot control system. Verification experiment using robotic fingers to manipulate soft object was conducted whose result revealed that the fingerpsilas system managed to recognize the stiffness and safely manipulate the object.

Roundness measurement of cylindrical part by machine vision

In this paper, a vision-based inspection system has been proposed for the roundness error measurement of a cylindrical part. Evaluation is based on minimum zone (MZC) circle method as to comply with the definition of roundness error given by Y14.5M-1994 and ISO 1001. New approach in the system set-up and image capturing technique has been performed to be in line with the measurement requirement of this form tolerance. The result shows that this system can be used and implemented in the evaluation of roundness error of a cylindrical part. The advantage of using machine vision is the non contact nature of the measurement process which can be implemented in-process of making the cylindrical part.

Non-contact approach to roundness measurement

In this paper, a non-contact approach to roundness measurement using machine vision is proposed. A test-rig and computer algorithm are developed to realised the approach. The computer algorithm employs minimum zone circle MZC technique to measure the roundness deviation. High contrast and good quality image segmentation is produced with the developed image processing algorithm technique. Camshaft profile is used to determine the effectiveness of the developed approach. Experimental results reveal that the developed computer algorithm coupled with minimum radial zone circle technique can be used as inspection tool for integrated in-process inspection of form tolerances.

Characteristic and sensitivity of Quantum Tunneling Composite (QTC) material for tactile device applications

This paper investigates the used of Quantum Tunneling Composite (QTC) Pill as a tactile sensor material for general tactile device application. The QTC Pill can be considered as soft, flexible material and has extraordinary electrical properties. It has capability of turning into a remarkable material for new era sensor. The piezoresistive experimental test of QTC Pill was performed to determine their resistivity characteristics and to evaluate the suitability of QTC Pills as tactile sensors. The experiments were conducted based on the sensitivity of the QTC Pill. The shows that, the QTC Pill was a perfect insulator as well as an extremely good conductor. This has been observed through resistance versus force (R vs F) investigation in which an exponential curve was obtained. This is coherent with the hypothesis of quantum tunneling charge transport within the polymer ‘assisted’ quantum tunneling. The hypothesis is further supported by comparing and contrasting current versus voltage (I vs V) curves. At intermediate pressure, QTC Pill exhibits a clearly not linear hysteric behaviour and current fluctuations. These characteristic features can be related to QTC Pill specific structure and electron quantum tunneling. Based on this investigation, QTC pill are suitable to be used as a material for general tactile device application and can be used as a guideline when designing a tactile sensor with this material.