Jaeha Kim

Stable bilateral teleoperation using the energy-bounding algorithm: Basic idea and feasibility tests

This paper presents basic idea and feasibility test results of the energy-bounding algorithm (EBA) for bilateral teleoperation. Various test results for free, contact, and abrupt motions show that the EBA can ensure stable bilateral teleoperation for the fairy large constant/variable time delays (2.5 sec for free motion and 300 msec for contact motion). In addition, the EBA with holding previous data strategy can achieve stable teleoperation when some packet drop is occurred during the data transmission.

Construction of a haptic-enabled broadcasting system based on the MPEG-V standard

With rapid developments in communications technology and digital multimedia, there has been increasing demand in recent years for realistic broadcasting technology beyond conventional audio-visual media. In response to this demand, this paper presents an example of the construction of a haptic-enabled broadcasting system based on the MPEG-V standard that was established recently. The construction processes of the proposed haptic-enabled broadcasting system include various types of media acquisition, haptic content creation by modeling and authoring, transmission, rendering, and interaction. This paper illustrates the data flow within the system, from the creation of haptic contents to the rendering of these contents to the end user, and explains a method of building the system with the MPEG-V standard. The constructed haptic-enabled broadcasting system allows users to have more immersive interaction with the synthesized haptic multimedia, which is closely synchronized with audio-visual data.

A Survey of Haptic Control Technology

Haptics technology allows one to interact with virtual environments, augmented environments, and real environments providing tactual sensory information. Science and technology of haptics can in general be classified into three groups: machine haptics, computer haptics, and human haptics. This paper surveys the state-of-the-art of haptic control technology for virtual environments and teleoperation (real environments) and then proposes possible future research directions in the following areas: haptic stability control, bilateral teleoperation control, and stability enhancement control.

Accurate and efficient cpu/gpu-based 3-dof haptic rendering of complex static virtual environments

This paper proposes a novel, accurate, and efficient hybrid CPU/GPU-based 3-DOF haptic rendering algorithm for highly complex and large-scale virtual environments (VEs) that may simultaneously contain different types of object data representations. In a slower rendering process on the GPU, local geometry near the haptic interaction point (HIP) is obtained in the form of six directional depth maps from virtual cameras adaptively located around the object to be touched. In a faster rendering process on the CPU, collision detection and response computations are performed using the directional depth maps without the need for any complex data hierarchy of virtual objects, or data conversion of multiple data formats. To efficiently find an ideal HIP (IHIP), the proposed algorithm uses a new abstract local occupancy map instance (LOMI) and the nearest neighbor search algorithm, which does not require physical memory for storing voxel types during online voxelization and reduces the search time by a factor of about 10. Finally, in order to achieve accurate haptic interaction, sub-voxelization of a voxel in LOMI is proposed. The effectiveness of the proposed algorithm is subsequently demonstrated with several benchmark examples.

Six degree-of-freedom energy bounding algorithm for stable and directionally transparent haptic interaction

This paper proposes a 6-DOF energy bounding algorithm (EBA) for stable and directionally transparent 6-DOF haptic interaction. The proposed 6-DOF algorithm can solve the problem that the direction of the force vector can be distorted if the original EBA shortens the magnitude of each component of force vector for guaranteeing stability in some directions. The proposed solution is based on guaranteeing passivity on each direction and projecting the direction of the resultant force vector on its original direction as had been proposed by Preusche et al. [5] for PO/PC algorithm [3]. The preliminary validity of the proposed algorithm is shown by some experiments.

Enhancing rate-hardness of energy-bounding algorithm by considering Coulomb friction of haptic interface

In haptics, both transparency and stability are major requirements for providing realistic feeling of virtual objects. The crisp contact feeling at the instant of touch with high impedance walls is necessary especially for proper identification and manipulation of virtual objects. This paper presents a new passivity condition that explicitly includes Coulomb friction effects. Moreover, the energy bounding algorithm incorporating Coulomb friction effects shows that the viscous damping of the haptic device affects the maximum displayable stiffness in steady-state and that the Coulomb friction of the device contributes to temporarily enhance rate-hardness in initial transient responses. Experimental results are presented for showing effectiveness of the proposed derivation and control law.

An energy bounding approach for directional transparency in multiple degree-of-freedom haptic interaction

This paper presents an energy bounding approach (EBA) to enhance directional transparency while guaranteeing stability for multiple degree-of-freedom (DOF) haptic interaction. It was observed that the passivity condition for multiple ports may lead to some oscillations in some coordinate directions even though total energy is positive. The passivity condition, therefore, needs to be applied to each orthogonal coordinate. For guaranteeing stability in each orthogonal coordinate, the EBA is applied. For multiple-dof haptic interaction, however, the EBA in each coordinate may cause a problem that the direction of the rendered force vector is distorted. This problem can easily be solved by projecting the direction of the rendered force vector on its original direction. The validity of the proposed algorithm is shown by some experiments.

MPEG-V standardization for haptically interacting with virtual worlds

With rapid developments in virtual reality (VR), haptics, communications technology and digital multimedia, there has been increasing demand for creation and widespread development of more realistic or immersive display systems. Consumers are eager to experience engrossing contents capable of providing presence, beyond traditional audio-visual media. In response to this demand, tactile and haptic interaction is also becoming increasingly important. Recently, MPEG-V standard (ISO/IEC 23005) has been published. The MPEG-V provides architecture and metadata for interaction and interoperability between virtual worlds and real worlds through various sensors and actuators. The aim of this paper is to provide an overview of MPEG-V standard, particularly regarding haptic and tactile interactions.

Energy-bounding algorithm for stable haptic interaction and bilateral teleoperation

This demonstration shows the effectiveness of the energy-bounding algorithm (EBA) for stable haptic interaction and bilateral teleoperation. The EBA proposed for stable haptic interaction based on the passivity theory and extended to stabilize the bilateral teleoperation system that has the time delay in communication channel. In this demo, a virtual wall test for haptic interaction and bilateral teleoperation through internet connection between USA to Korea will be demonstrated.