Enabling multi-point haptic grasping in virtual environments

Haptic interaction has received increasing research interest in recent years. Currently, most commercially available haptic devices provide the user with a single point of interaction. Multi-point haptic devices present a logical progression in device design and enable the operator to experience a far wider range of haptic interactions, particularly the ability to grasp via multiple fingers. This is highly desirable for various haptically enabled applications including virtual training, telesurgery and telemanipulation. This paper presents a gripper attachment which utilises two low-cost commercially available haptic devices to facilitate multi-point haptic grasping. It provides the ability to render forces to the user's fingers independently and using Phantom Omni haptic devices offers several benefits over more complex approaches such as low-cost, reliability, and ease of programming. The workspace of the gripper attachment is considered and in order to haptically render the desired forces to the user's fingers, kinematic analysis is discussed and necessary formulations presented. The integrated multi-point haptic platform is presented and exploration of a virtual environment using CHAI 3D is demonstrated.

A multi-point haptic platform for grasping and manipulating virtual objects

This work presents a multi-point haptic platform that employs two Phantom Omni haptic devices. A gripper attachment connects to both devices and enables multi-point haptic grasping in virtual environments. In contrast to more complex approaches, this setup benefits from low-cost, reliability, and ease of programming while being capable of independently rendering forces to each of the user’s fingertips. The ability to grasp with multiple points potentially lends itself to applications such as virtual training, telesurgery and telemanipulation.

Grasping virtual objects with multi-point haptics

The majority of commercially available haptic devices offer a single point of haptic interaction. These devices are limited when it is desirable to grasp with multiple fingers in applications including virtual training, telesurgery and telemanipulation. Multipoint haptic devices serve to facilitate a greater range of interactions. This paper presents a gripper attachment to enable multi-point haptic grasping in virtual environments. The approach employs two Phantom Omni haptic devices to independently render forces to the user's thumb and other fingers. Compared with more complex approaches to multi-point haptics, this approach provides a number of advantages including low-cost, reliability and ease of programming. The ability of the integrated multi-point haptic platform to interact within a CHAI 3D virtual environment is also presented.

Design, development, and evaluation of a pinch-grasp haptic interface

Interaction with virtual or teleoperated environments requires contact with objects on a multipoint level. We describe the design of a pinch--grasp hand interface device for use as a grasping mechanism to complement haptic interfaces. To preserve a suitable level of transparency for human--computer interaction, this novel interface is designed for high-resolution contact forces, while centered around a lightweight structure. This functionality renders the device scalable and adaptable to a wide range of haptic interface structures and force level requirements. We present an optimal configuration for a pinch--grasp interface, which produces bidirectional forces to an operator's fingers and a rotational force to the wrist through a cable drive system. The device is characterized for use on a commercial haptic interface through demonstration of sustained peak performance and also workspace utilization. The dynamic performance of the pinch--grasp interface is experimentally determined, and the frequency response is identified to illustrate its contact force resolution.

Extending haptic device capability for 3D virtual grasping

This paper presents an investigation into the workspace constraints observed through the use of multiple single point haptic interfaces, which lead to the design of a novel grasping device that improves upon current commercial haptic interfaces. The presented device is desktop based, and has been designed to maximise the haptic workspace while offering the ability to grasp and manipulate virtual objects, which is a function that current commercial interfaces are limited in providing. The performance of the commercial haptic interface in producing sustained effective operation and increased workspace with the attached haptic gripper is evaluated, and the improvement of both has been determined.

Multipoint haptic guidance for micrograsping systems

The ability to perform accurate micromanipulation offers wide-reaching benefits and is of increasing interest to researchers. Recent research into microgripper, microtweezer, and microforcep systems contributes toward accurate micrograsping and manipulation. Despite these efforts, achieving adequate operator control remains a distinct research challenge. Haptic interfaces interact with the human's haptic modality and offer the ability to enhance the operator's controllability of micromanipulation systems. Our previous work introduced single-point haptic guidance to assist the operator during intracellular microinjection. This paper extends the approach to propose multipoint haptic guidance for micrograsping tasks. Accurate micrograsping is valuable in many applications, including microassembly and biomanipulation. A multipoint haptic gripper facilitates haptic interaction, and haptic guidance assists the operator in controlling systems suitable for micrograsping. Force fields are used to guide the operator to suitable grasp points on micrometer-sized objects and consist of attractive and repulsive forces. The ability of the force field to effectively assist the operator in grasping the cell is evaluated using a virtual environment. Evaluation results demonstrate the ability of the approach to significantly reduce participants' average grasping error.

Soft tissue modelling for haptic rendering in virtual environments

This paper focuses on the development of a haptic recording and modelling system. Currently being evaluated for multiple uses in surgery and manufacturing, this recording system evaluates haptic data captured via a robotic ann coupled with real time high-resolution load cell. This data is then analysed and validated against previous samples and a generated model before being logged for playback during simulation and training of a human operator. 3D models of point force interactions are created allowing unique visuals to be presented to a user. Primarily designed for the medical field, recorded results of soft tissue cutting have been presented.

Haptic handwriting aid for training and rehabilitation

This paper reports a method of controlling a user's hand through the process of writing. Developed predominantly for enabling users to re-learn the skill of writing after a stroke, the process could also be used for teaching children hand/eye coordination, motor skills, movement and position awareness in writing. Utilising low cost haptic technology and custom control software, the system has the potential to increase writing skills in stroke sufferers in the privacy and comfort of their own home.

Haptic control of multi-axis robotic systems

Control of tele-operated remote robot’s is nothing new; the public was introduced to this 'new' field in 1986 when the Chernobyl cleanup began. Pictures of weird and wonderful robotic workers pouring concrete or moving rubble flooded the world. Integration of force feedback or 'haptics' to remote robot's is a new development and one that is likely to make a big difference in man-machine interaction. Development of haptic capable tele-operation schema is a challenge. Often platform specific software is developed for one off tasks. This research focussed on the development of an open software platform for haptic control of multiple remote robotic platforms. The software utilises efficient server/client architecture for low data latency, while efficiently performing required kinematic transforms and data manipulation in real time. A description of the algorithm, software interface and hardware is presented in this paper. Preliminary results are encouraging as haptic control has been shown to greatly enhances remote positioning tasks.

Fuzzy haptic augmentation for telerobotic stair climbing

Teleoperated robotic systems provide a valuable solution for the exploration of hazardous environments. The ability to explore dangerous environments from the safety of a remote location represents an important progression towards the preservation of human safety in the inevitable response to such a threat. While the benefits of removing physical human presence are clear, challenges associated with remote operation of a robotic system need to be addressed. Removing direct human presence from the robot's operating environment introduces telepresence as an important consideration in achieving the desired objective. The introduction of the haptic modality represents one approach towards improving operator performance subject to reduced telepresence. When operating in an urban environment, teleoperative stair climbing is not an uncommon scenario. This work investigates the operation of an articulated track mobile robot designed for ascending stairs under teleoperative control. In order to assist the teleoperator in improved navigational capabilities, a fuzzy expert system is utilised to provide the teleoperator with intelligent haptic augmentation with the aim of improving task performance.

Bilateral haptic teleoperation of an articulated track mobile robot

Teleoperation has been used in many applications, allowing a human operator to remotely control a robotic system in order to perform a particular task. Recently haptic teleoperation has focused mainly on improving performance in remote manipulation tasks, however the haptic approach offers similar advantages for teleoperative control of the motion of a mobile robot. This paper describes a prototype system designed to facilitate haptic teleoperation of an all-terrain, articulated track mobile robot. This system utilizes a multi-modal user interface intended to improve operator immersion, reduce operator overload and improve teleoperative task performance. The system architecture facilitates implementation of an application-specific haptic augmentation algorithm in order to improve operator performance in challenging real-world tasks. The contributions of this work can be categorized as the custom mobile platform, teleoperator interface and haptic augmentation strategy.

OzBot TM - Haptic augmentation of a teleoperated robotic platform for search and rescue operations

A continued increase in computing power, sensor capability, software functionality, immersive interfaces and hardware modularity has given robot designers seemingly endless potential in the area of mobile robotics.  While some mobile robotic system designers are focusing on expensive, full-featured platforms, developers are realising the advantages of emerging technology in providing small, low-cost mobile reconnaissance vehicles as expendable teleoperated robotic systems.  The OzBot^TM mobile reconnaissance platform presents one such system.  The design objectives of the OzBot^TM platform focus on the development of inexpensive, lightweight carry-case sized robots for search and rescue operations, law enforcement scenarios and hazardous environment inspection.  The incorporation of Haptic augmentation provides the teleoperator with improved task immersion for an outdoor search and rescue scenario.  Achieved in cooperation with law enforcement agencies within Australia, this paper discusses the performance of the first four revisions of the OzBot^TM platform.

Artificial hand - from a robotic perspective

The human hand provides proof that the anthropomorphic configuration, properly controlled, is successful and gives a target to aim at for artificial hand/robot hand researchers. In this paper we discuss the human hand physiology and grasp capabilities. We then provide design on a double thumb, two finger robotic hand. Architecture of the hand, fingers and their dynamic modelling is discussed. Finally, results are reported on the performance of a finger in the hand.

3D haptic needle insertion simulator utilising an agent based spherical voxel model

This paper describes a technique for the real-time modeling of deformable tissue. Specifically geared towards needle insertion simulation, the low computational requirements of the model enable highly accurate haptic feedback to a user without introducing noticeable time delay or buzzing generally associated with haptic surgery simulation. Using a spherical voxel array combined with aspects of computational geometry and agent communication and interaction principals, the model is capable of providing haptic update rates of over 1000Hz with real-time visual feedback. Iterating through over 1000 voxels per millisecond to determine collision and haptic response while making use of Vieta’s Theorem for extraneous force culling.