Design and validation of a complete haptic system for manipulative tasks

The present work deals with the design, implementation and assessment of a new haptic system specifically conceived for manipulative tasks in virtual environments. Such a system was designed by taking into account specific issues related to fine manipulation, such as multipoint haptics, coherence, transparency and physical representation. The haptic system described herein is integrated with a virtual environment engine for the simulation of multifinger manipulation. A preliminary evaluation of the system was conducted by comparing human performance in the manipulation of virtual objects with respect to real objects, according to the data available in the literature. The experiments confirm how the most relevant relationships among physiological and physical parameters involved in manipulation are also preserved during virtual manipulation. However, an in-depth analysis of the results shows that simulation parameters affect the level of force control during virtual manipulation and the quality of the perceived force feedback.     

Accurate force reflection method for a multi-d.o.f. haptic interface using instantaneous restriction space without a force sensor in an unstructured environment

This paper proposes an accurate force reflection method for a multi-d.o.f. haptic interface without a force sensor. Sensorless force reflection is possible using position–position (p–p) architecture. However, the conventional p–p architecture in the literature has limitations representing constraint space when it is applied to a multi-d.o.f. haptic interface in that it gives an inaccurate force direction. This paper demonstrates the limitation of the conventional p–p architecture through an example and proposes a novel force reflection method using the instantaneous restriction space (IRS) concept. The IRS can be calculated using the Jacobian and joint angle error of a slave manipulator. Since the proposed method has the form of an impedance two-port architecture in the sense of data flow, it can be easily combined with previous well-known results of two-port haptic display frameworks. The proposed method is especially useful when the slave manipulator collides with unexpected obstacles during motion, even though the slave does not have a force sensor. The performance of the proposed method is evaluated through experiments.     

Development of soft and distributed tactile sensors and the application to a humanoid robot

This paper describes a comprehensive tactile sensor system which can cover wide areas of full-body robots. Based on design criteria which are introduced from requirements, we develop two types of tactile sensor elements. One is a multi-valued touch sensor which has multi-level pressure thresholds. It is capable of covering wide areas of robot surfaces. The other is made of soft, conductive gel, which has the advantage of compliance compared with other sheet-type tactile sensors. With these two types sensors, we develop the tactile sensor system on the full-body robot 'H4'. Details of the sensor system on the robot and some experiments using tactile information are described.     

Tactile display and vibrotactile pattern recognition on the torso

A wirelessly controlled tactile display has been designed, fabricated and tested for use as a navigation aid. The display comprises a 4 × 4 array of vibrating motors that is mounted on a waist band and stimulates the skin across the lower back. Three types of electromechanical actuators were evaluated for use in the display; based on their mechanical performance and power requirements, two of these motors were then used to fabricate tactile displays. The performance of the displays and the wireless tactile control units was assessed experimentally by having subjects identify which of eight possible vibrotactile patterns was presented to the lower back. The results indicated that subjects could recognize the vibrotactile patterns with almost perfect accuracy and that there was no difference between the two types of motor used for the displays. Moreover, the ability to recognize the pattern of vibrotactile stimulation was superior on the back as compared to the forearm. A further experiment confirmed that the tactile display can be used as a navigation aid outdoors and that the vibrotactile patterns presented can be interpreted as directional or instructional cues with almost perfect accuracy.     

Development of a real-time visual and force environment for a haptic medical training simulator

In this article, a real-time, visual and force environment for a 5-dof haptic urological training simulator is presented that deals with a low-force, high-deformation environment. A real-time graphical representation of the male urethra during the insertion of an endoscope is developed. Smooth urethra deformations are produced by a mesh of piece-wise Bézier interpolations, while its inner wall is simulated by realistic tissue textures. Efficient real-time techniques are developed that introduce endoscope camera depth-of-field effects. A novel particle-based model computes in real-time the forces fed to the haptic device. A 13 fps refresh rate is achieved on a 2-GHz computer with the depth-of-field effect activated, while the rate is doubled to 26 fps with this feature disabled. It is expected that the simulator will contribute to ethical, efficient, and modern surgical training.     

Quantitative assessment of the effectiveness of using display techniques with a haptic device for manipulating 3D objects in virtual environments

Quantitative assessment is made of using two display techniques, providing two different levels of depth perception, in conjunction with a haptic device for manipulating 3D objects in virtual environments. The two display techniques are 2D display, and interactive 3D stereoscopic virtual holography display on a zSpace tablet. Experiments were conducted, by several users of different ages and computer training. The experiments involved selected pointing and manipulation tasks. The speed of performing the tasks using the two display techniques were recorded. Statistical analysis of the data is presented. As expected, the use of interactive 3D stereoscopic display resulted in faster performance of the tasks. The improvement in performance was particularly noticeable for the cases wherein the subjects needed to manipulate the haptic arm to reach objects/targets at different depths, and also when the objects/targets were occluded partially by the obstacles.     

Use of microprocessors for the determination of electrochromic display device characteristics

This paper describes a system using microprocessors to store optical data obtained during coloration and bleaching of WO₃ thin films and to restitute them after treatment. Such a device gives us the ability quickly to determine the characteristics of an electrochromic display device as a function of many parameters. Experimental curves will be presented. A cycling system with adjustable parameters to test the lifetime of the electrochromic cells is also described. Results obtained are given with a scanning electron microscope picture of the film after a cycling test.     

Proposal of a SkilMate Hand and its component technologies for extravehicular activity gloves

In this study, we propose a SkilMate Hand for space extravehicular activity gloves which is equipped with devices of both a power assist and a tactile media. The paper focuses on development of component technologies for constructing a SkilMate Hand, which is proposed for recovering deteriorated haptic sensation in human hands. First, we manufacture a power assist device which compensates the bending moment exerted at a human finger joint utilizing a standing-wave-type ultrasonic motor. We plot the examined characteristics, propose a control policy of the actuators and show some control perforce in Bode plots. Second, we produce a tactile media device which is composed of a vibrotactile sensor element on the outer side and a vibrotactile display element on the inner side at the fingertips of the SkilMate Hand. Piezo-rubber is chosen to be used as a vibrotactile sensing transducer whose sensing performance is examined in the extremely high/low-temperature regions. We locate SkilMate in a wider framework of wearable intelligent machines which assist in affording such working surroundings that they can exhibit their skills in spite of their necessity for wearing special suits typical in hazardous environments. A proposal of a wearable intelligent machine such as that of a SkilMate with its concept has not been made before.     

A pointer device for TFT display screens that determines position by detecting colours on the display using a colour sensor and an Artificial Neural Network

Thin Film Transistor (TFT) screens are replacing traditional Cathode Ray Tube (CRT) screens and are becoming more common in the workplace. Traditional light sensing pens do not work effectively on a TFT screen, as the TFT screen does not generate a scan-line. A novel prototype computer system has been created that depicts where a user is pointing. The new sensor may replace the need for a touch-screen, mouse or keyboard. The system flashes a kaleidoscope of colours onto a TFT screen. A tri-colour photodiode detects these colours. A problem with this solution was the limited number of colours that could reliably be detected by the photodiodes and the time that the colours needed to remain on the screen. This paper describes a new system that includes an Artificial Neural Network (ANN) to predict the future position of the colour sensor on a computer screen. This information was used to place the optimum colours closest to the sensor in order to increase the accuracy of the reported position.     

A comparison of tactile,auditory, and visual feedback in a pointing task using a mouse-type device

A mouse was modified to add tactile feedback via a solenoid-driven pin projecting through a hole in the left mouse button. An experiment is described using a target selection task under five different sensory feedback conditions (‘normal’, auditory, colour, tactile, and combined). No differences were found in overall response times, error rates, or bandwidths; however, significant differences were found in the final positioning times (from the cursor entering the target to selecting the target). For the latter, tactile feedback was the quickest, normal feedback was the slowest. An examination of the spatial distributions in responses showed a peaked, narrow distribution for the normal condition, and a flat, wide distribution for the tactile (and combined) conditions. It is argued that tactile feedback allows subjects to use a wider area of the target and to select targets more quickly once the cursor is inside the target. Design considerations for human-computer interfaces are discussed.     

User interface and interactivity display for converging PC,IPTV, and mobile device in a video sharing service

This paper proposes a user interface and interactivity adaptor for PCs, Internet protocol televisions (IPTVs), and mobile devices. The adaptor accounts for the screen limitations for display of mobile devices and the remote control limitations for the interactivity of IPTVs. A framework for convergence of these client‐side devices is also proposed as a basis for a video sharing service. In‐depth verification and evaluation demonstrate the robustness of the proposed adaptor.     

The effects of simulated fog and motion on simulator sickness in a driving simulator and the duration of after-effects

In the study, we checked: 1) how the simulator test conditions affect the severity of simulator sickness symptoms; 2) how the severity of simulator sickness symptoms changes over time; and 3) whether the conditions of the simulator test affect the severity of these symptoms in different ways, depending on the time that has elapsed since the performance of the task in the simulator.     

Touch and design: novel haptic interfaces for the generation of high quality surfaces for industrial design

This paper presents the results of a research project aimed at developing haptic tools for virtual shape modelling resembling real tools like rakes and sandpaper used by modelers and designers in the real workshop. The developed system consists of a CAD (computer aided design) system enhanced with intuitive designer-oriented interaction tools and modalities. The system requirements have been defined on the basis of the observation of designers during their daily work, and translating the way they model shapes using hands and craft tools into specifications for the modelling system based on haptic tools.     

Plug and play perimetry: Evaluating the use of a self-calibrating digital display for screen-based threshold perimetry

This study evaluated the feasibility of using a ‘self-calibrating’ display (EIZO CG277) to perform screen-based threshold perimetry. Such displays incorporate their own integrated photometer, so could potentially be used ‘straight out of the box’, without the need for time-consuming and costly luminance calibration by skilled experts. Concerns remain, however, due to the fact that the internal calibration of such devices is imperfect, and lingering doubts regarding the accuracy of screen-based perimetry in general. To evaluate such a system, automated static threshold perimetry was performed in thirty-two normal-sighted adults. In one condition, participants performed a novel screen-based perimetry test, for which the screen was calibrated extensively using traditional photometric techniques/equipment. In a second condition, the same test was performed, but the display was calibrated using only the screen’s integrated photometer (and assuming uniformity across the display). For reference, participants also completed a traditional visual-field assessment using a Humphrey Field Analyzer (HFA). All three tests were performed twice to assess test-retest repeatability (six tests total). The results showed no differences when comparing screen-based perimetric measurements made with internal self-calibration vs full manual calibration (either in terms of mean sensitivity, pointwise sensitivity, test-retest repeatability, or test duration). Furthermore, the accuracy and precision of both were indistinguishable from the current gold standard (HFA), although the HFA was approximately two minutes (~30%) faster. These results indicate that self-calibrating commercial monitors can be used to perform screen-based perimetry almost as well as current clinical devices, and without the need for any specialized knowledge or equipment to setup or maintain. This could facilitate perimetric testing in currently hard-to-reach settings, such as community centers, stroke wards, homes, rural locations, or developing countries.     

Spatial stimulus response compatibility for a horizontal visual display with hand and foot controls

In this study, two experiments were conducted to examine spatial stimulus–response compatibility (SRC) effects for a horizontal visual display with hand and foot controls. In experiment 1, the hand and foot controls were in a hands above and feet below vertical plane, such that the display and controls were orthogonal to each other. In experiment 2, the foot pedals were moved forward and placed directly underneath the front row of signals, resulting in an additional horizontal display and control relationship. The results of experiment 1 revealed a strong orthogonal SRC effect, such that the best performance was for the front signals with hand controls and rear signals with foot pedals, which was not altered with the presence of horizontal location mappings in experiment 2. These findings indicate that the front-hand/rear-foot mapping relationship was quite robust with regard to changes in the relative locations of the hand and foot response devices.

Statement of Relevance: The results of this study provide useful ergonomics recommendations for designing control consoles with visual signals presented in a horizontal plane and control devices operated by hands and feet. They are helpful for improving efficiency and overall system performance in person–machine systems.     

用于测量体温的无线实时监测系统的设计与实现

介绍了一种基于无线数字传输芯片和单片机构成的病人体温监护系统的设计，讨论了系统的硬件电路设计和软件设计。在该系统中，单片机对温度传感器进行控制和数据传输，借助串行通信实现了人机交互控制。运行表明，该系统控制方便、工作稳定．能实现可靠的无线数据传输。     

基于Web的风粉在线网络实时监测系统的设计与研究

本文针对已开发完成的电厂风粉在线实时监测系统，提出了一基于Web的对该系统的运行状态和主要运行参数进行实时自动监测及信息发布的可行方案，并对系统的总体结构及系统实现的关键技术进行了研究。     

分布式电网暂态稳定实时监控系统中实时通信的设计与实现

文章首先介绍了分布式电网暂态稳定实时监控系统的研发和应用背景,论证了在Windows2000平台下采用TCP/IP协议实现在该系统中进行强实时通信的可能性,并提供了实时通信的设计与实现方法,最后用实验数据证明了采用文中介绍的设计和实现方法,通信可以达到实时性的要求。     

A tissue P system and a DNA microfluidic device for solving the shortest common superstring problem

This paper describes a tissue P system for solving the Shortest Common Superstring Problem in linear time. This tissue P system is well suited for parallel and distributed implementation using a microfluidic device working with DNA strands. The approach is not based on the usual brute force generate/test technique applied in DNA computing, but it builds the space solution gradually. The possible solutions/superstrings are build step by step through the parallel distributed combination of strings using the overlapping concatenation operation. Moreover, the DNA microfluidic device solves the problem autonomously, without the need of external control or manipulation.An erratum to this article can be found at