• Journal of Institute of Control, Robotics and Systems
• /
• v.7 no.2
• /
• pp.160-167
• /
• 2001

This paper presents control and evaluation of a new haptic device with a 6-DOF parallel mechanism for interfacing with virtual reality. This haptic device has low inertial, high bandwidth compactness, and high output force capability mainly due to of base-fixed motors. It has also wider orientation workspace mainly due to a RRR type spherical joint. A control method is presented with gravity compensation and with force feedback by an F/T sensor to compensate for the effects of unmodeled dynamics such as friction and inertia. Also, dynamic performance has been evaluated by experiments. for force characteristics such as maximum applicable force, static-friction force, minimum controllable force, and force bandwidth Virtual wall simulation with the developed haptic device has been demonstrated.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.8
• /
• pp.807-814
• /
• 2014

In this paper, we proposed a haptic navigation system which used the tactile data for the user guides of the mobile robot to the reference point via tele-operation in unknown blind environment. This navigation system can enable a mobile robot to avoid obstacles and move to the reference point, according to the direction provided by the device guides through a haptic device consisting of a vibration motor in a blind environment. There are a great deal of obstacles in real environments, and so mobile robots can avoid obstacles by recognizing the exact position of each obstacle through the superposition of an ultrasonic sensor. The navigation system determines the direction of obstacle avoidance through an avoidance algorithm that uses virtual impedance, and lets users know the position of obstacles and the direction of the avoidance through the haptic device consisting of 5 vibration motors. By letting users know intuitionally, it lets the mobile robot precisely reach the reference point in unknown blind environment. This haptic device can implement a haptic navigation system through the tactile sensor data.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.1559-1564
• /
• 2003

In this paper, a control method is presented to improve performance of haptic display on a passive haptic device equipped with passive actuators. In displaying a virtual wall with the passive haptic device, an unstable behavior occurs with excessive actions of brakes due to the time delay mainly arising from the update rate of the virtual environment and force approximation originated from the characteristics of the passive actuators. The previous T.D.P.C. (Time Domain Passivity Control) method was not suitable for the passive haptic device, since a programmable damper used in the previously introduced T.D.P.C. method easily leads to undesirable behaviors. A new passivity control method is evaluated with considering characteristics of the passive device. First, we propose a control method which is designed under the analysis of the passive FME (Force Manipulability Ellipsoid). And then a passivity control scheme is applied to the proposed control method. Various experiments have been conducted to verify the proposed method with a 2-link mechanism.

• The Journal of Korea Robotics Society
• /
• v.1 no.2
• /
• pp.135-141
• /
• 2006

This paper presents offline estimation of equivalent physical damping parameter in haptic interaction systems where damping is the most important parameter for stability. Based on the previous energy bounding algorithm, an offline procedure is developed in order to estimate the physical damping parameter of a haptic device by measuring energy flow-in to the haptic device. The proposed method does not use force/torque sensor at the handgrip. Numerical simulation and experiments verified effectiveness of the proposed method.

• Journal of Institute of Control, Robotics and Systems
• /
• v.11 no.7
• /
• pp.602-608
• /
• 2005

In the virtual environment, force feedback to the human operator makes virtual experiences more realistic. To ensure the safe operation and enhance the haptic feeling, stability should be guaranteed. Both motors and brakes are commonly used for haptic devices. Motors can generate a torque in any direction, but they can make the system active during operation, thus leading to instability. Brakes can generate a torque only against their rotation, but they dissipate energy during operation, which makes the system intrinsically stable. Consequently, motors and brakes are complementing each other. In this research, a two degree-of-freedom (DOF) haptic device equipped with motors and brakes has been developed to provide better haptic effects. Each DOF is actuated by a pair of motor and brake. Modeling of the environment and the control method are needed to utilize both actuators. Among various haptic effects, contact with the virtual wall, representation of friction and representation of plastic deformation have been investigated extensively in this paper. It is shown that the hybrid haptic device is more suited to some applications than the motor-based haptic device.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.23 no.2
• /
• pp.160-166
• /
• 2013

This paper proposes a driver supportive device with haptic cue function which can be applicable for vehicles adopting manual transmission system to transmit gear-shifting information to a driver by kinesthetic forces. This haptic cue function is implemented on accelerator pedal by utilizing magnetorheological(MR) fluid and clutch mechanism. In order to achieve this goal, an MR clutch mechanism is devised to be capable of rotary motion of accelerator pedal. The proposed MR clutch is then optimally designed and manufactured under consideration of spatial limitation of vehicles. After transmission torque is experimentally evaluated according to field intensity. The manufactured MR clutch is integrated with accelerator pedal and electric motor to establish the haptic cue device. Control performances are experimentally evaluated via a simple feed-forward control algorithm.

• Proceedings of the KIEE Conference
• /
• 2006.04a
• /
• pp.78-80
• /
• 2006

Mouse is widely used in multimedia education. However, using mouse is not easy for user to get exact three dimentional (3D) user input and to manipulate delicately as the user can not know the surface information of virtual objects, which are typical drawbacks of using mouse in multimedia education, especially in 3D multimedia contents authoring. In this paper, haptic device is introduced to the 3D multimedia education. The haptic device provides 3D user's input information as well as haptic information of virtual objects such as surface textures, collisions and etc. which thus allow to enhance the task efficiency in multimedia education. Simple experiment results are presented to show the positive results of using the haptic device in multimedia education.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.312-316
• /
• 2004

In this study, a spatial 3-dof haptic mechanism is implemented. The implemented mechanism does not employ the gear transmissions as velocity reducers for all three joints but uses wire-based transmissions, thereby it is able to minimize the frictions significantly. Also, by employing the structure of the four-bar mechanism to drive third joint from close to the base, the mechanism is able to minimize the inertia effect from the third actuator very effectively. Its kinematic analysis such as position and velocity analyses are performed first. Then, its operating software development, hardware implementation, and the related interfaces between a PC and the implemented Haptic device are completed. To evaluate its potential and its performance as a haptic device, a experiment generating a virtual constraint in a operational task space is conducted and preliminary results are discussed.

• Journal of the Korea Convergence Society
• /
• v.8 no.12
• /
• pp.291-298
• /
• 2017

In recent years, the increase of secondary controls within vehicles requires a mechanism to integrate various controls into a single device. This paper presents control performance of an integrated magnetorheological (MR) haptic device which can adjust various in-vehicle comfort instruments. As a first step, the MR fluid-based haptic device capable of both rotary and push motions within a single device is devised as an integrated multi-functional instrument control device. Under consideration of the torque and force model of the proposed device, a magnetic circuit is designed. The proposed MR haptic device is then manufactured and its field-dependent torque and force are experimentally evaluated. Furthermore, an inverse model compensator is synthesized under basis of the Bingham model of the MR fluid and torque/force model of the device. Subsequently, haptic force-feedback maps considering in-vehicle comfort functions are constructed and interacts with the compensator to achieve a desired force-feedback. Control performances such as reflection force are experimentally evaluated for two specific comfort functions.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1662-1667
• /
• 2005

In this paper, analysis, design, control and prototype construction of a wearable wire-driven haptic interface called HapticPen is discussed. This device can be considered as a wire driven parallel mechanism which three wires are attached to a pen-tip. Wire tensions are provided utilizing three DC servo motors which are attached to a solid frame on the user's body. This device is designed as input as well as output device for a wearable PC. User can write letters or figures on a virtual plate in space. Pen-tip trajectory in space is calculated using motor encoders and force feedback resulting from contact between pen and virtual plate is provided for constraining the pen-tip motion onto the virtual plane that can be easily setup by arbitrary non-collinear three points in space. In this paper kinematic model, workspace analysis, application analysis, control and prototype construction of this device are presented. Preliminary experiments on handwriting in space show feasibility of the proposed device in wearable environments.