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Variation minimization in tele-sandblasting system: The effect of human-arm movement error
(2018-08-14)
Jientrakul, Ranon
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Attavanish, Pornsak
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Chotiprayanakul, Pholchai
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Limnararat, Sunpasit
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Yuangyai, Chumpol
In tele-sandblasting task, human arm movement is a critical source of producing variation in position of sandblasting nozzle resulting in high operating cost and low productivity. Each operator behaves differently leading to unpredictable movements. Skilled operators are able to reduce the variation; however, developing skills requires a training period. In this paper, we proposed a new approach which is the use of a novel operator's arm movement pattern incorporated with a Kalman filter to reduce the effect of human-arm movement error. A virtual tele-sandblasting system is used to validate our approach. The experimental results verify that our proposed approach is able to significantly reduce the effect of human arm movement error. The approach helps operators to perform the task more comfortably and takes short training time.
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Investigating multiple human performance measures in teleoperation task: A translation task in a tele-sandblasting maintenance system
(2018-05-01)
Jientrakul, Ranon
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Yuangyai, Chumpol
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Cheng, Chen Yang
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Chotiprayanakul, Pholchai
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Limnararat, Sunpasit
In sandblasting tasks for complex steel structure maintenance, teleoperation is required to keep humans away from occupational risk and hazard. On the other hand, teleoperation typically degrades system-human performances, resulting in poor product quality and must be designed such that the performances remain as high as possible. However, designing the teleoperation system regarding to a single performance measure may lead to an improper design. In this article, we propose two novel loss-function-based human-performance measures to incorporate with a widely used performance measure, movement time, to thoroughly represent performance: unfinished surface and damaged surface. We aim to investigate the effects of two main design parameters, viewing distance and path width. The results show that only path width is significant for overall performances. Furthermore, the effect of gender is significant such that men outperform women in cleaning the surface. Finally, the optimal setting conditions are suggested to achieve their optimal performances.
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Decentralized control with neural network of cooperative robot manipulator for object balancing task on flat plate
(2017-12-13)
Jaisumroum, Nattapon
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Chotiprayanakul, Pholchai
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Limnararat, Sunpasit
In this paper, a decentralized framework for kinematic control of cooperative manipulators systems is developed. The motion of the robot system is specified at the object position, by adopting a task-oriented formulation for cooperative tasks. In the controller of robot computes, the end-effector motion of robots in a decentralized on the camera position frame of the knowledge of the assigned cooperative task. The motion of manipulator is reference computed by object and its neighbors. The joint motion of robots is reference corresponding from the end-effector. This study approach decentralized control of collaborative manipulators, tested in the simulation on MATLAB® software composed by neural network method. A neural network is used to approximate a decentralized control law designed by the back-propagation technique. The motion for each joint is controlled independently using local angular position and velocity measurements. Finally, the experiment shows the feasibility of the proposed control scheme using a robotics.
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The mediating role of innovative work behavior on the relationship between knowledge sharing behavior and innovation capability in Thailand private university
(2017-09-01)
Buranakul, Sorapol
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Limnararat, Sunpasit
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Pithuncharurnlap, Manat
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Sangmanee, Woranat
Amongst today turbulent business environment, innovation is considered as a main source of an organization competitive advantage. In higher education environment, especially in the private university, innovation has also received considerable concern as a major contributor in securing sustainable competitive edge in the marketplace. As a result, a number of factors have been introduced to enhance the organizational innovation capability. This research aims to examine the relationship between employees' knowledge sharing behavior, innovative work behavior and organizational innovation capability. The research surveyed a sample of 367 private university staffs in Thailand. Structural equation modeling was used to test the measurement model and path analysis was used to examine the comparative strength of direct and indirect relationships among variables. The analytical results revealed that knowledge sharing behavior showed a positive link to both innovation capability and innovative work behavior. In addition, innovative work behavior was found to be a partial mediator of the relationship between knowledge sharing behavior and innovation capability. This study provides some useful information for university administrators, and highlights management issues involving knowledge sharing behavior and understanding the influence of innovative work behavior on organizational innovation capability.
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The operational, economic and environmental benefits of returnable packaging under various reverse logistics arrangements
(2017-01-01)
Katephap, Nophanut
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Limnararat, Sunpasit
This research investigates the operational, economic and environmental advantages of the returnable packaging under various reverse logistics arrangements, in relation to the disposable packaging. The business under study is a Thai manufacturer and exporter of automotive parts with the trading partners in the Philippines and Vietnam. In the study, a switch was made from the currently disposable packaging to the standardized returnable packaging under three reverse logistics arrangements: the single-, round- and multi-trip arrangements. Due to the large initial investment associated with the returnable packaging, a mathematical model was proposed to calculate the total effective packaging cost. The research findings revealed that the multi-trip reverse logistics arrangement was most operationally and environmentally viable, with the largest total packaging cost reduction and packaging waste reduction of 61% and 68%, relative to the disposable packaging. Meanwhile, the single-trip reverse logistics arrangement was most favorable economically due to its shortest payback period of 0.33 year. Moreover, the life cycle assessment (LCA) was applied to the disposable and returnable packaging to evaluate the environmental impacts throughout their lifetime. The LCA results validate the more environmentally-friendly nature of the returnable packaging.
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The mediating effect of knowledge-sharing behaviour on total quality management and organisational innovation capability
(2017-01-01)
Buranakul, Sorapol
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Limnararat, Sunpasit
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Pithuncharurnlap, Manat
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Sangmanee, Woranat
Ever since innovation was recognised as a key contributor to securing competitive advantage in the higher education arena, many factors have been introduced to enhance innovation capability. The purpose of this study is to examine the relationship between total quality management (TQM) and organisational innovation capability (OIC), as well as investigate the role of knowledge-sharing behaviour (KSB) in mediating this relationship. A survey was conducted on 367 academic staff and support staff from private universities in Thailand. The analytical results suggest that TQM is positively linked to OIC and KSB, in which the KSB plays a partial mediating role between TQM and OIC. The findings should benefit university administrators to improve innovation capability in addition to implementing TQM to develop appropriate strategies for maintaining a knowledge-sharing environment, leading to the kind of tacit knowledge that can successfully raise the innovation capability of private universities.
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A conceptual framework of decentralized learning neural network control approach for multi-robot cooperation in an object balancing task
(2016-12-27)
Jaisumroum, Nattapon
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Chotiprayanakul, Pholchai
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Limnararat, Sunpasit
This paper presents a conceptual framework of a neural network control approach for robot manipulator cooperative, which is based on decentralized learning. Back propagation neural network is used for learning procedure to adapt and adjust the neuron-controller's parameters which depend on the approximated error. Dynamic model of two cooperating 3-DOF robot manipulators are defined and implement with neural network control. Visual feedback enables two robots to correct and calibrate their movement to compensate their object balancing task whereas both robots hold a flat plate balancing a round object on it. This conceptual framework of the decentralized learning procedure will be verified by a simulation and experiments in near future.
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Self-tuning control with neural network for robot manipulator
(2016-01-24)
Jaisumroum, Nattapon
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Chotiprayanakul, Pholchai
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Limnararat, Sunpasit
This paper presents an approach of the self-tuning control with neural network for robot manipulator in an object balancing task. A 3DOF robot arm (Novint Falcon 3D haptic) is used to hold a flat plate balancing a cylindrical object put on. Since a neural network algorithm were presented earlier in [1], [2] in order to learn and control the posture of the robot, we now employ the visual feedback into neural network to enable the robot arm learn to move its end effector. A webcam is used to determine position of a cylinder object rolling on a flat plate that the robot is holing. The images are processed to the object position by neural network. The output of the neural network is the height of the robot's end-effector that the robot has to lift the plate. The neural network must learn and self-calibrate by some repeating trail movements until the virtual feedback enable the robot arm adopts recalibrating parameters to stabilize the rolling task. The results of experiments show the learning procedure of the neural network is succeed in self-tuning control.
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Effect of mixed filler on thermal properties of foodstuff conveyor belts compound using an industrial microwave pre-heating
(2016-01-01)
Limhengha, Suphatchakorn
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Limnararat, Sunpasit
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Sriseubsai, Wipoo
This study presented the utilization of microwave power for heating of epoxidized natural rubber-50 compounding (ENR50c) with and without mixed filler in which the sulfur contents were 1.0, 1.5 and 2.0 parts per hundred parts of dried rubber by weight basis, respectively. The microwave power used was varied in a range of 340-1,700 W with a constant frequency of 2.45 GHz. The mixed filler significantly affected the relative dielectric constant, relative loss factor and loss tangent coefficient. The microwave power and time strongly influenced the temperature of the specimen. The longer time and higher microwave power resulted in higher temperature of the specimen. On the contrary, the thickness of specimen inversely affected the temperature of the specimen. The lower temperature was obtained from the thicker specimen.
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Effect of ENR50/STR5L blends on properties of foodstuff conveyor belts compound
(2016-01-01)
Limhengha, Suphatchakorn
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Limnararat, Sunpasit
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Sriseubsai, Wipoo
Natural rubber blending with nitrile rubber is the important raw material employed for the foodstuff conveyor belts formulation. This research involves the replacement of nitrile rubber with epoxidised natural rubber (ENR) aiming for food safety precaution and cost saving on the materials. This work included the investigation on the ratio of ENR with 50% epoxidation (ENR50) and natural rubber (Standard Thai Rubber 5L,STR5L). The ratios of ENR50:STR5L were 100:0, 75:25, 50:50, 25:75 and 0:100. The effect of fillers, i.e. silica (SiO<inf>2</inf>) and magnesium carbonate (MgCO<inf>3</inf>) on the properties of rubber blends was also investigated. The vulcanizing system was semi-efficient vulcanization (Semi-EV). The study was further focused on the morphological characterization and mechanical properties. It was found that increasing the proportion of ENR50 and STR5L at 50% produced better mechanical property, however, the elongation at break increased once the ENR50 was down at 25%. Thus, this enhanced the property of the foodstuff conveyor belts compound.

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