• Journal of Power System Engineering
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• v.13 no.2
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• pp.71-82
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• 2009

This paper presents a real-time haptic rendering method for a realistic force feedback in a remote environment with varying communication time-delay. The remote environment is assumed as a virtual environment based on a computer graphics, for example, on-line shopping mall, internet game and cyber-education. The properties of a virtual object such as stiffness and viscosity are assumed to be unknown because they are changed according to the contact position and/or a penetrated depth into the object. The DARMAX model based output estimator is proposed to trace the correct impedance of the virtual object in real-time. The output estimator is developed on the input-output relationship. It can trace the varying impedance in real-time by virtue of P-matrix resetting algorithm. And the estimator can trace the correct impedance by using a white noise that prevents the biased input-output information. Realistic output forces are generated in real-time, by using the inputs and the estimated impedance, even though the communication time delay and the impedance of the virtual object are unknown and changed. The generated forces trace the analytical forces computed from the virtual model of the remote environment. Performance is demonstrated by experiments with a 1-dof haptic device and a spring-damper-based virtual model.

• The Journal of Korea Robotics Society
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• v.8 no.3
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• pp.150-155
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• 2013

Vibrotactile actuators for small consumer electronic products, such as mobile devices, have been widely used for conveying haptic sensation to users. One of the most important things in vibrotactile actuators is to be developed in the form of thin actuator which can be easily embedded into mobile devices and to provide vibrotactile signals with wide frequency band to users. Thus, this paper proposes a thin film type haptic actuator with an aim to convey vibrotactile information with high frequency bandwidth to users in mobile devices. To this end, a vibrotactile actuator which creates haptic sensation is designed and constructed based on cellulose acetate material. A cellulose acetate material charged with an electric potential can generate vibration under the AC voltage input. It is found that the motion of the actuator can have concave or convex shape by controlling a polarity of both charged membranes and the actuator performance can be modulated by increasing level of biased electric potential. The experiment clearly shows that the proposed actuator creates enough output force to stimulate human skin with a large frequency bandwidth and to simulate various vibrotactile sensations to users.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1598-1602
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• 2003

The parallel-type mechanism provides more accurate and stiff motion than the serial-type mechanism. However, in case of using the haptic device, the performance of the force reflection can be deteriorated due to the singular points existing in workspace. In this paper, we propose a redundantly actuated parallel 3-DOF haptic device, which is singularity-free in the workspace and has an improved force reflection capability. In addition, we propose a new force distribution algorithm, which can reflect force of both high and low resolution, using two sets of actuator with different size. Redundant actuators are attached to the base frame in order to minimize the inertia of the system. Moreover, a wire and gear reduction system is employed to achieve high force reflection along with soft feeling. We confirm the performance of the force reflection capability throughout simulation.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1673-1678
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• 2005

This paper addresses both theoretical and experimental studies of the stability of haptic interfaces during the simulation of virtual Coulomb friction. The first objective of this paper is to present an analysis of how friction affects stability in terms of the describing function method and the absolute stability theory. Two different feedback methods are introduced and are used to evaluate the analysis: an active force feedback, using a motor, and a passive force feedback, using controllable brake. The second objective of this paper is to present a comparison of the theoretical and experimental results. The results indicate that the sustained oscillations due to the limit cycle occur when simulating friction with an active force feedback. In contrast, a passive force feedback can simulate virtual friction without the occurrence of instability. In conclusion, a hybrid active/passive force feedback is proposed to simulate a highly realistic friction display.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.119.1-119
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• 2001

Teleoperation enables an operator to manipulate remote objects. One of the main goals in teleoperation researches is to provide the operator with the feeling of the telepresence, being present at the remote site. For these purposes, a master robot must be designed as a bilateral control system that can transmit position/force information to a slave robot and feedback the interaction force. A newly proposed impedance algorithm is applied for the control of a haptic interface that was developed as a master robot. With the movements of the haptic interface for position/for co commands, impedance parameters are varying always. When the impedance parameters between an operator and ...

• Journal of the Korea Computer Graphics Society
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• v.26 no.1
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• pp.1-6
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• 2020

Patella surgery of small animal is an important veterinary surgery that the veterinarian should saw and drill the dislocated patella in order to fix the corrected position. However, the animal protection laws restrict the veterinarian students' chances for the practice and training of the patella surgery. This paper proposed a haptic based patella surgery simulator for veterinarian students. We modelled force feedback methods in order to provide best similar haptic feedbacks to the real drilling feedbacks in the patella surgery. The proposed patella drilling simulator provides haptic interface as a drill and a workbench in order to provide best surgery experiences. We conducted the performance evaluations in order to prove usability of the proposed patella surgery interface.

• Archives of design research
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• v.12 no.4
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• pp.221-229
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• 1999

There are not a few cases which we can handle more safely and conveniently in using the general goods if a haptic clue is offered to a user as a basis of an important judgment.The first purpose of this study is to embody how to study to understand the haptic discrimination element of the handling button in electronic product which can work as the essential elements in the product design and the physical interface. And the next purpose is to investigate basically the way of the adequate usage. We analyzed the basic materials through this study on the documents and planned the experiments with the analyses. We carried out planned experiments, analyzed, and integrated the experimental results. This means making the standard objectively in developing the shape which is an important element of the product design. And it also means the developing and extracting the way of objective information of the haptic intended.

• Journal of KIISE:Software and Applications
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• v.30 no.11
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• pp.1044-1053
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• 2003

A virtual science experience space(VSES) using virtual reality technology including haptic device is proposed to overcome limits which the existing science education has and to improve the effect of it. Four example scientific worlds such as Micro World, Friction World, Electromechanical World and Macro World are demonstrated by the developed VSES. Van der Waals forces in Micro World and Stick-Slip friction in Friction World, the principle of induction motor and power generator in Electromechanical World and Coriolis acceleration that is brought about by relative motion on the rotating coordinate are modeled mathematically based on physical principles. Emulation methods for haptic interface are suggested. The proposed VSES consists of haptic device, HMD or Crystal Eyes and a digital computer with stereoscopic graphics and GUI. The proposed system is believed to increase the realism and immersion for user.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2265-2267
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• 2003

In this paper, the virtual reality system is tried to developed, which controls not only the sense of sight and hearing but also the sense of touch, In order to develope the sense of touch in this study, the stable tactual transaction system, based on summing up the basic algorithm and theory is embodied. Especially, the graphic deformation algorithm is developed in realtime with using the deformed FEM. To apply the FEM, a deformed material model is produced and then the graphic deformation with this model is able to force. Finally, the graphic transaction algorithm is deduced by the realtime calculation and simplification because the purpose of this system is to transact in real time. The result of this study is that the proposed system is possible to deform the graphics and transact the haptic in real time in PC. The simulation program has been made to prove this result.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.202-208
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• 2016

The scope of activities of the visually impaired is increasing. But they are not easy to visit the destination safely because the building was complicated and larger than ever. There is a guide system for visually impaired such as GPS and Audio alerts, Braille guide block, Acoustic signaller, etc. But they are not suitable for indoor because most of them are the outdoor guide system. Therefore, in this paper, I propose a system that provides guidance information to the visually impaired using Voice Technology, TTS (Text to Speech) and Haptic Technology, Beacon based on the wireless sensor networks. It informed the visually impaired of guidance information about destination such as distance, height, and obstacle to the destination using the generalized smart phone. The user could be received guide info about searches for the optimal route to the destination using the TTS technology and Haptic technology in test result of the proposed system.