Papers by somrak petchartee
Contact Identification using Tactile Arrays
Abstract This paper proposed a contact recognition algorithm capable of determining contact surfa... more Abstract This paper proposed a contact recognition algorithm capable of determining contact surfaces types by tactile sensor fusion. This algorithm can recognize grasped objects using a 2-fingered robot hand, on which tactile sensors are mounted. Experiments have ...
This dissertation describes a new type of tactile sensor and an improved version of the dynamic t... more This dissertation describes a new type of tactile sensor and an improved version of the dynamic tactile sensing approach that can provide a regularly updated and accurate estimate of minimum applied forces for use in the control of gripper manipulation. The pre-slip sensing algorithm is proposed and implemented into two-finger robot gripper. An algorithm that can discriminate between types of contact surface and recognize objects at the contact stage is also proposed. A technique for recognizing objects using tactile sensor arrays, and a method based on the quadric surface parameter for classifying grasped objects is described. Tactile arrays can recognize surface types on contact, making it possible for a tactile system to recognize translation, rotation, and scaling of an object independently.Diese Dissertation beschreibt eine neue Art von taktilen Sensoren und einen verbesserten Ansatz zur dynamischen Erfassung von taktilen daten, der in regelmäßigen Zeitabständen eine genaue Bew...
Slip Prediction through Tactile Sensing
Sensors & Transducers, 2008
This paper introduces a new way to predict contact slip using a resistive tactile sensor. The pro... more This paper introduces a new way to predict contact slip using a resistive tactile sensor. The prototype sensor can be used to provide intrinsic information relating to geometrical features situated on the surface of grasped objects. Information along the gripper finger surface is obtained with a measurement resolution dependant on the number of discrete tactile elements. The tactile sensor predicts the partial slip of a tactile surface by sensing micro vibrations in tangential forces which are caused by an expansion of the slip regions within the contact area. The location of the local slip is not specified but its occurrence can be predicted immediately following micro vibration detection. Predictive models have been used to develop a set of rules which predict the slip based on fluctuations in tactile signal data.
Real time kinect based robotic arm manipulation with five degree of freedom
2015 Asian Conference on Defence Technology (ACDT), 2015
We propose a real time, gesture based robotic arm manipulation using kinect sensor. This method u... more We propose a real time, gesture based robotic arm manipulation using kinect sensor. This method uses kinect depth data, skeletal data and joint orientation data for end effector movement including roll, pitch and pinch. For the initial data, we extracted skeletal of the person, hand position and hand state. In closed hand state condition, the position of the hand is extracted and the three dimension data is used for inverse kinematics of the joints of the robotic arm. In open hand state, tilting and rolling of hand is used for pitch and roll respectively. In lasso state, pinch of end effector is perceived. The robotic arm used for the experimentation is Scorbot ER III. The system shows promising results for non-invasive robotic arm manipulation.
Tactile Sensors for Force Control and Contact Recognition
The lack of suitable commercial tactile sensors has limited developments in the robotic handling ... more The lack of suitable commercial tactile sensors has limited developments in the robotic handling of fragile objects. An algorithm that can discriminate between types of contact surface and recognize objects at the contact stage is also proposed. A technique for recognizing objects using tactile sensor arrays, and a method based on the quadric surface parameter for classifying grasped objects is described. Tactile arrays can recognize surface types on contact, making it possible for a tactile system to recognize translation, rotation, and scaling of an object independently. In addition, the studies showing continuous adjustment of force to stabilize gripping, particularly during motion, have been reviewed. This prehension force adjustment occurs simultaneously with, or slightly ahead of, fluctuations in load forces. They may therefore be seen as anticipatory, and it is argued here that a key purpose of research in manipulation should be to understand the integration of sensory motor information in building an internal model of the object and the effector system in order to support such anticipation.
Liver elastometry and alcohol withdrawal: Median-term follow-up in a psychiatric unit
Alcohol, 2020
The measurement of liver stiffness (LS) show promise as a follow-up tool after alcohol withdrawal... more The measurement of liver stiffness (LS) show promise as a follow-up tool after alcohol withdrawal but has mainly been studied in the early phase or in patients with severe liver disease. A six-month ancillary study of a specific psychiatric cohort of alcoholic patients without known liver disease followed after withdrawal was conducted (Clinical Trial NCT01491347). Clinical and biological data and LS values were collected every two months. A total of 129 patients were included in the study, 93 had a LS assessment within the first seven days and 37 had all four LS measurements. Only seven (7.5%) patients had an initial LS > 12.1 kPa, the threshold used to define severe fibrosis. Abstinence was not associated with changes in LS at the various median-term follow-up periods. However, LS of abstinent subjects decreased significantly relative to that of non-abstinent subjects between M0 and M2. CAPTM values were not associated with abstinence. The systematical median-term follow-up of withdrawn patients does not appear to be contributory. However, LS could help to detect relapse in the first two months after withdrawal for subjects treated in a psychiatric hospital for dependence. It thus could serve as a motivation tool. Prospective studies with various and higher baseline LS values are warranted for simultaneous longitudinal assessment, including for very short- and long-term LS after withdrawal.
Earthquakes are sudden natural disasters that endanger people’s lives and properties all around t... more Earthquakes are sudden natural disasters that endanger people’s lives and properties all around the world. Although much work has been done in the field of prevention of such damages via timely prediction the work needs to be tailored to the area-specific dataset for optimum accuracy. With the time series seismic event data of Chiang Mai for 4 years, we focus our study to provide a prediction of future earthquakes here by using z-normalization and a polynomial constraint in DTW on CUDA-enabled accelerators. By comparing polynomial constraint to Sakoe-Chiba Band as well as Itakura band, we have verified our work to have reduced the percentage of computational time and improved accuracy. The aim of this paper is to demonstrate a prediction accuracy of 0.95.
King Mongkut’s University of Technology North Bangkok International Journal of Applied Science and Technology, 2013
The authors have proposed a novel surface recognition algorithm capable of determining contact su... more The authors have proposed a novel surface recognition algorithm capable of determining contact surfaces types by means of tactile sensor fusion since 2008. With Quadric surface representing; the limiting procedures which relate various degenerate Cartesian coordinate systems play a crucial result in the classification of all such systems. In this paper, the renew recognition processes are described. The space transformations are technically reducing the complicated contact surface for classification refinement. The complete classification of these modifiable coordinate systems is provided by means of the corresponding space curvature. Information is obtained directly at the interface between the object and the sensing device and relates to three-dimensional. The technique called “eigenvalue trajectory analysis”, is introduced after and adopted for specifying the margin of classification. The authors demonstrate mathematically approach which offers significant computational advantage...
Abstract: The surface recognition algorithm that determines the types of contact surfaces by fusi... more Abstract: The surface recognition algorithm that determines the types of contact surfaces by fusing information collected by the tactile sensor system is proposed. The tactile system will be determined from the shape of the object image which can then be characterized using the mathematical properties of Quadric surface. This algorithm can recognize 3-D objects using a 2-fingered robot gripper, on which tactile sensors are mounted. Experiments have demonstrated the reliability of the surface classification method and the accuracy of transformations independent of an object’s shape, translation and rotation. Copyright 2007.
RCS measurements under GB-SAR environment
2015 IEEE Conference on Antenna Measurements & Applications (CAMA), 2015
New design wireless sensor network based TETRA DMO protocol
2015 Asian Conference on Defence Technology (ACDT), 2015
Adaptive learning of multi-finger motion and force control
2015 International Computer Science and Engineering Conference (ICSEC), 2015
IRIG S-band missile telemetry
2015 Asian Conference on Defence Technology (ACDT), 2015
The lack of suitable commercial tactile sensors has limited developments in the robotic handling ... more The lack of suitable commercial tactile sensors has limited developments in the robotic handling of fragile objects. An algorithm that can discriminate between types of contact surface and recognize objects at the contact stage is also proposed. A technique for recognizing objects using tactile sensor arrays, and a method based on the quadric surface parameter for classifying grasped objects is described. Tactile arrays can recognize surface types on contact, making it possible for a tactile system to recognize translation, rotation, and scaling of an object independently. In addition, the studies showing continuous adjustment of force to stabilize gripping, particularly during motion, have been reviewed. This prehension force adjustment occurs simultaneously with, or slightly ahead of, fluctuations in load forces. They may therefore be seen as anticipatory, and it is argued here that a key purpose of research in manipulation should be to understand the integration of sensory motor information in building an internal model of the object and the effector system in order to support such anticipation.
Contact Classification using Tactile Arrays
Intelligent Sensors, Sensor …, Jan 1, 2007
Abstract This paper proposed a contact recognition algorithm capable of determining contact surfa... more Abstract This paper proposed a contact recognition algorithm capable of determining contact surfaces types by tactile sensor fusion. This algorithm can recognize grasped objects using a 2-fingered robot hand, on which tactile sensors are mounted. Experiments have ...
ace.ucv.ro
The surface recognition algorithm that determines the types of contact surfaces by fusing informa... more The surface recognition algorithm that determines the types of contact surfaces by fusing information collected by the tactile sensor system is proposed. The tactile system will be determined from the shape of the object image which can then be characterized using the mathematical properties of Quadric surface. This algorithm can recognize 3-D objects using a 2-fingered robot gripper, on which tactile sensors are mounted. Experiments have demonstrated the reliability of the surface classification method and the accuracy of transformations independent of an object's shape, translation and rotation.
Extracting Composition Strain from Tactile Data Using Artificial Neural Networks for Six-Axis Force Sensing
Optimisation of prehension force through tactile sensing
Industrial Robot: An International …, Jan 1, 2008
PurposeThe purpose of this paper is to analyze surface deformations caused by shear and moment f... more PurposeThe purpose of this paper is to analyze surface deformations caused by shear and moment forces on tactile materials and present a method to detect and reduce the risk of slippage by controlling the normal force as measured by tactile sensor arrays. Design/ ...
Emerald Mobile
Industrial Robot: An International Journal
ace.ucv.ro
A method to detect pre-slip by controlling the normal force as measured by tactile sensor arrays ... more A method to detect pre-slip by controlling the normal force as measured by tactile sensor arrays has been developed. A predictive model has been proposed which uses a basic method adapted to real applications in grasp optimization. Prevention of premature release with minimum prehension force is addressed without the need to measure the coefficient of friction between object and robot gripper. Predictive models have been used to develop a set of rules which predict the preslip based on fluctuations in tactile signal data.
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Papers by somrak petchartee