Wearable Haptic Device for an IPT System Based on Pneumatic Muscles

2007 ◽  
Author(s):  
Mika Iltanen ◽  
Asko Ellman ◽  
Joonas Laitinen
Keyword(s):  
Fiber Optics ◽  
Motion Tracking ◽  
Force Feedback ◽  
Feedback System ◽  
Virtual Space ◽  
Human Interaction ◽  
Primary Input ◽  
Data Glove ◽  
Haptic System ◽  
Mckibben Actuators

The human haptic system has an important role to play in human interaction with Virtual Environments (VEs). Unlike the visual and auditory systems, the haptic sense is capable of both sensing and acting on the environment and is an indispensable part of many human activities. In order to provide the realism needed for effective and compelling applications, VEs need to provide inputs to, and mirror the outputs of, the haptic system. These characteristics are the most important issues in the design of confined spaces and mechanical constructions using 6 DOF input devices in Immersive Projection Technology (IPT) or Cave-like systems. Inputs to the haptic system are in the form of haptic displays and outputs are actuator action commands, where the primary input/output variables are displacements and forces. The idea of total free movement in the IPT system was one of the corner stones of the present study. Therefore the force feedback system should also be wearable. The observer is able to reach objects placed above and below, grip them, and move freely in virtual space. This paper discusses the hardware and software structure of the haptic force feedback system for an IPT system, the theoretical functionality of McKibben actuators and the measured performance of a glove. Force control is based on fast solenoid valves, PID controller and a developed pneumatic muscle model. Muscle actuators are attached to the forearm and control the electronics and valves to a wearable backpack. A developed sensing and force-reflecting exoskeleton applies force to all four fingers and also the thumb. The device has five active DOFs, one for each finger. An ascension motion tracking device is used to track the position and orientation of the forearm. A Fifth Dimensional Technologies fiber optics data glove is used to measure the position of the fingers and provides better information on finger movements. Virtools 4.0 software and VRPN interface was used to connect the data glove, feedback device and PC-cluster.

scholarly journals New Exoskeleton Arm Concept Design And Actuation For Haptic Interaction With Virtual Objects

2014 ◽  
Vol 44 (4) ◽  
pp. 3-14 ◽  
Author(s):  
D. Chakarov ◽  
I. Veneva ◽  
M. Tsveov ◽  
T. Tiankov
Keyword(s):  
Upper Limb ◽  
Motion Tracking ◽  
Force Feedback ◽  
Human Interaction ◽  
Joint Torque ◽  
Concept Design ◽  
Actuation System ◽  
Human Arm ◽  
Torque Regulation ◽  
Muscle Actuators

Abstract In the work presented in this paper the conceptual design and actuation of one new exoskeleton of the upper limb is presented. The device is designed for application where both motion tracking and force feedback are required, such as human interaction with virtual environment or rehabilitation tasks. The choice is presented of mechanical structure kinematical equivalent to the structure of the human arm. An actuation system is selected based on braided pneumatic muscle actuators. Antagonistic drive system for each joint is shown, using pulley and cable transmissions. Force/displacement diagrams are presented of two antagonistic acting muscles. Kinematics and dynamic estimations are performed of the system exoskeleton and upper limb. Selected parameters ensure in the antagonistic scheme joint torque regulation and human arm range of motion.

scholarly journals Development and Testing of a Methodology for the Assessment of Acceptability of LKA Systems

Machines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 47 ◽  
Author(s):  
Luca Salvati ◽  
Matteo d’Amore ◽  
Anita Fiorentino ◽  
Arcangelo Pellegrino ◽  
Pasquale Sena ◽  
...  
Keyword(s):  
Force Feedback ◽  
Feedback System ◽  
Operating Conditions ◽  
Experimental Methodology ◽  
Driving Safety ◽  
Steering Wheel ◽  
Human In The Loop ◽  
Automation Systems ◽  
Driving Stability ◽  
Lane Keeping

In recent years, driving simulators have been widely used by automotive manufacturers and researchers in human-in-the-loop experiments, because they can reduce time and prototyping costs, and provide unlimited parametrization, more safety, and higher repeatability. Simulators play an important role in studies about driver behavior in operating conditions or with unstable vehicles. The aim of the research is to study the effects that the force feedback (f.f.b.), provided to steering wheel by a lane-keeping-assist (LKA) system, has on a driver’s response in simulators. The steering’s force feedback system is tested by reproducing the conditions of criticality of the LKA system in order to minimize the distance required to recover the driving stability as a function of set f.f.b. intensity and speed. The results, obtained in three specific criticality conditions, show that the behaviour of the LKA system, reproduced in the simulator, is not immediately understood by the driver and, sometimes, it is in opposition with the interventions performed by the driver to ensure driving safety. The results also compare the performance of the subjects, either overall and classified into subgroups, with reference to the perception of the LKA system, evaluated by means of a questionnaire. The proposed experimental methodology is to be regarded as a contribution for the integration of acceptance tests in the evaluation of automation systems.

Virtual Reality (VR) in Pediatrics: Innovative Perspectives With Special Reference To Clinical Applications and Pediatric Rehabilitation

2021 ◽  
Author(s):  
Stefan Bittmann
Keyword(s):  
Virtual Reality ◽  
Virtual Environment ◽  
Virtual Worlds ◽  
Virtual World ◽  
Mixed Reality ◽  
Clinical Applications ◽  
Virtual Space ◽  
Data Glove ◽  
Input Devices ◽  
Head Mounted Displays

Virtual reality (VR) is the term used to describe representation and perception in a computer-generated, virtual environment. The term was coined by author Damien Broderick in his 1982 novel “The Judas Mandala". The term "Mixed Reality" describes the mixing of virtual reality with pure reality. The term "hyper-reality" is also used. Immersion plays a major role here. Immersion describes the embedding of the user in the virtual world. A virtual world is considered plausible if the interaction is logical in itself. This interactivity creates the illusion that what seems to be happening is actually happening. A common problem with VR is "motion sickness." To create a sense of immersion, special output devices are needed to display virtual worlds. Here, "head-mounted displays", CAVE and shutter glasses are mainly used. Input devices are needed for interaction: 3D mouse, data glove, flystick as well as the omnidirectional treadmill, with which walking in virtual space is controlled by real walking movements, play a role here.

Evidence of positive force feedback among hindlimb extensors in the intact standing cat

1995 ◽  
Vol 73 (6) ◽  
pp. 2578-2583 ◽  
Author(s):  
C. A. Pratt
Keyword(s):  
Force Feedback ◽  
Functional Organization ◽  
Force Plate ◽  
Feedback System ◽  
Implanted Electrodes ◽  
Golgi Tendon Organs ◽  
Ia Afferents ◽  
Extensor Muscles ◽  
Stimulation Of ◽  
Positive Force

1. The functional organization of heterogenic reflexes produced by activation of extensor force receptors (Golgi tendon organs) was studied in intact cats during stationary stance. Intramuscular stimulation (200 Hz, 20 ms) of hindlimb extensor muscles via chronically implanted electrodes was used to evoke weak muscle contractions and naturally activate Golgi tendon organ Ib afferents while cats stood unrestrained with each paw on a moveable triaxial force plate. 2. Intramuscular stimulation of every hindlimb extensor muscle tested in this study evoked excitatory responses that were widely distributed among hindlimb extensor muscles. Source and target specializations in the functional organization of this positive force feedback system were also observed. For example, stimulation of ankle extensors typically excited extensors and flexors at the ankle and hip (but not knee), whereas stimulation of hip extensors typically excited only extensors at all three joints. In addition, intramuscular stimulation of either lateral (LG) or medial (MG) gastrocnemius consistently inhibited soleus while exciting other extensors at the ankle and more proximal joints. 3. The electromyographic (EMG) reflex responses described above are attributed to the natural (via muscle contraction) activation of extensor group Ib afferents. Direct activation of intramuscular afferents by the stimulus was unlikely because there was no evidence that Ia afferents, which have the lowest electrical thresholds, were activated. Both the observed inhibition of the synergist, soleus, and the excitation of the antagonist, tibialis anterior, produced by gastrocnemius stimulation are opposite to the reflex effects that would be produced at the ankle by activation of gastrocnemius Ia afferents.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Method for the Detection of Tumor Blood Vessels in Neurosurgery Using a Gripping Force Feedback System

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5157
Author(s):  
Hiroki Yokota ◽  
Takeshi Yoneyama ◽  
Tetsuyou Watanabe ◽  
Yasuo Sasagawa ◽  
Mitsutoshi Nakada
Keyword(s):  
Blood Vessel ◽  
Blood Vessels ◽  
Force Feedback ◽  
Correlation Coefficients ◽  
Feedback System ◽  
Force Sensor ◽  
Robot System ◽  
Blood Vessel Detection ◽  
Operating Space ◽  
Gripping Force

Avoiding unnecessary bleeding during neuroendoscopic surgeries is crucial because achieving hemostasis in a narrow operating space is challenging. However, when the location of a blood vessel in a tumor cannot be visually confirmed, unintentional damage to the vessel and subsequent bleeding may occur. This study proposes a method for tumor blood vessel detection using a master–slave surgical robot system equipped with a force sensor in the slave gripper. Using this method, blood pulsation inside a tumor was detected, displayed as a gripping force wave, via the slave force sensor. The characteristics of gripping force due to blood pulsation were extracted by measuring the fluctuation of the force in real time. The presence or absence of blood vessels was determined on the basis of cross-correlation coefficients between the gripping force fluctuation waveform due to blood pulsation and model fluctuation waveform. Experimental validation using two types of simulated tumors (soft: E = 6 kPa; hard: E = 38 kPa) and a simulated blood vessel (E = 1.9 MPa, radius = 0.5 mm, thickness = 0.1 mm) revealed that the presence of blood vessels could be detected while gripping at a constant angle and during transient gripping.

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