Authorship：Lead author   Language：English  

DOI： 10.24462/jnse.11.0_76

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Fuji Technology Press Ltd.   Participation form：Joint(The main charge)  

Numerous training simulators have been developed using virtual reality (VR) owing to their various advantages. Systems for training machine operations with physical movements face differences in the operational feel between actual and virtual machines. Moreover, virtual training is problematic in safety education because trainees in safe virtual environments can exhibit unsafe behavior in reality. To solve these problems, a previous study developed a virtual reality (VR) system to train a lathe operation with mixed reality using a motion capture system. This study included a function to teach the procedure and safety precautions for straight turning operations using a lathe. To evaluate the training effectiveness of this system, an experiment was conducted to compare learning using a video. Testees were divided into a simulator group, who learned with the system, and a video group, who learned with the video material. Work on the actual lathe by each testee after learning, was evaluated. Consequently, the actual work by the testees who used this system had fewer errors and shorter standstill times in which they attempted to recollect the next phase task. Although the number of trainees was small, this relationship had a statistical advantage. In the actual work, all the testees in the video group entered the danger area; however, only half of the testees in the simulator group entered the danger area. Therefore, a trainee using a simulator can remember the work process more reliably and accurately and perform it safely. Moreover, trainees who have undergone training several times should be able to perform actual work without making operational errors or engaging in unsafe behaviors.

DOI： 10.20965/jrm.2023.p0145

Language：English   Publishing type：Research paper (international conference proceedings)  

Manufacturers can reduce environmental impact and costs by introducing remanufacturing. In remanufacturing, inventory control of remanufactured and newly manufactured products should be considered for production planning. It is indispensable for predicting the demand quantity of products and the collecting quantity of used products to minimize the total cost incurred by remanufacturing and newly manufacturing. The prediction varies depending on the product characteristics and the time elapsed since shipment. In this paper, we study a remanufacturing system minimizing the total cost by a life-cycle simulation method. In the flow of products, there are two types of inventory: one is a remanufactured and newly manufactured product inventory before shipment to the market, and the other is a collected product inventory for used products. Depending on the time elapsed since launch, products pass through an introductory stage, a growth stage, a maturity stage, and a decline stage in a usual manner. We analyze the impact on the total cost of the prediction accuracy of the product demand and the collected used products to each stage. When the ratio of an ordering cost for newly manufactured products to an inventory holding cost for the finished products has a significant value, or as the life-cycle stage is approaching the decline stage, the predicting accuracy of collection of the used products and the product demand has a high impact on the total cost.

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japan Society for Precision Engineering   Participation form：Joint(The main charge)  

Training systems for manual machine tools using virtual reality have been developed for high safety and economy. Using these systems, a trainee can safely work on virtual machines to manipulate input interfaces modeled after devices in real-world machines. However, a trainee cannot completely learn how to use the target machine because the interface lacks all the necessary devices. Because safety is ensured even if the trainee performs dangerous actions, these virtual systems cannot teach safety measure. Therefore, after training with these systems, a trainee needs instructors when operating actual machines. This study describes a training system that does not require instructors. By training with the proposed system, a trainee can safely work on virtual machines as the input interface to manipulate the actual lathe. This system constantly monitors the position of all operating devices, handles and levers on the actual lathe, and the user's body parts (the head, both hands and upper body of the trainee) by motion capture. The behavior of the virtual lathe and the cutting of the virtual workpiece are simulated from the manipulated variables. This system can detect whether the trainee is in danger from the movement of his body parts.

Language：English   Publishing type：Research paper (international conference proceedings)   Participation form：Joint(The main charge)  

Training systems for manual machine tools using virtual reality have been developed for high safety and economy. Using these systems, a trainee can safely work on virtual machines to manipulate input interfaces modeled after devices on real-world machines. However, a trainee cannot completely learn how to use the target machine because the interface lacks all the necessary devices. Because safety is ensured even if the trainee performs dangerous actions, these systems cannot teach safety. Therefore, after training with these systems, a trainee needs instructors when operating actual machines. To this end, this study describes a training system that does not require instructors. By training with the system, a trainee can safely work on virtual machines as the input interface to manipulate the actual lathe. This system constantly monitors the position of all operating devices, handles, and levers on the actual lathe and the user's body parts—the head and both hands—of the trainee by motion capture. The behavior of the virtual lathe and the cutting of the virtual workpiece are simulated from the manipulated variables. This system can detect whether the trainee is in danger from the movement of his or her body parts.

Language：Japanese   Publishing type：Rapid communication, short report, research note, etc. (scientific journal)   Participation form：Joint(The main charge)  

Language：Japanese   Publisher：THE VIRTUAL REALITY SOCIETY OF JAPAN  

Dental calculus, hardened plaque on the teeth, is a cause of periodontitis, or gum diseases in mouth. For dentists and dental hygienists, it is an important task to remove the calculi of patients. The task is called "tooth scaling" and the calculi just beside the gum and between the tooth and gum are always removed away by using a hand scaler. Since the scaling by a hand scaler requires skill, apprentice dentists and dental hygienists must be trained to get the skill. Unfortunately in the training environment, however, there are several problems such as difficulty in collecting teeth on which various type calculi are stuck, lack of cooperative patients, and so on. Then, the authors have been newly developed a simulator for the training by using a PHANToM and a video-see-through HMD. The training effectiveness has been evaluated by artificial calculus removal on model teeth. The experimental result shows the developed simulator is more effective than the conventional paint removing method.

DOI： 10.18974/tvrsj.11.4_453

CiNii Books

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

A simulator for training manual arc welding operation by means of mixed reality technique was proposed and discussed in the previous paper. According to the experimental training results with the simulator in it, most trainees could not gain the skill of electrode tip positioning so well, though they could gain the skill of moving speed and angle control of the electrode. In this research, the authors investigate the reason for the less effectiveness and the solutions. As the results, it is found that in the conventional system, the trainees have difficulty in perception of electrode tip position, because of its inaccurate drawing in the real environmental image and two dimensional visual displaying. To improve the drawing accuracy, the camera for video-see-through HMD is replaced with high resolution ones and the multimarker position detection system is adopted. In addition, a stereo vision HMD with an easy vergence angle adjustment function is adopted to give the trainees three dimensional image. The experiments with the improved simulator show apparent reduction of the position-perception error of electrode tip and effective training.

DOI： 10.2493/jspe.72.249

CiNii Books

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Other Link： https://jlc.jst.go.jp/DN/JALC/00386430873?from=CiNii

Language：Japanese   Publisher：THE VIRTUAL REALITY SOCIETY OF JAPAN  

Machine tool operations such as small-diameter-deep-hole drilling and boring are well known as skilled tasks because of low stiffness of the cutting tools. Artificial reality technique is useful to develop the simulator for skill training of the machine tool operations. In the present paper, the simulation of the boring operation with a lathe has been investigated. Since the size, shape and tactile feeling of the tool feed handle of the lathe are important in the skill training, an actual handle should be used in the simulation. In addition, operator's head movement during the operation should be taken into consideration. So, the authors have adopted the mixed reality technique to realize the simulator. Simplified dynamical and geometrical models have been introduced and their parameters have been identified by an optimization method from experimental data of the actual lathe operation.

DOI： 10.18974/tvrsj.4.4_685

CiNii Books

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Event date： 2023.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：西日本総合展示場新館  

Event date： 2023.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：西日本総合展示場新館  

Event date： 2023.9

Language：Japanese  

Venue：福岡工業大学  

Event date： 2023.8 - 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北海道科学大学  

Event date： 2023.8 - 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北海道科学大学