Does Just Noticeable Difference Depend on the Rate of Change of Kinesthetic Force Stimulus
24 Jun 2014-pp 40-47
TL;DR: This work designs an experimental set up where users are subjected to a continuous haptic force which starts increasing or decreasing from a fixed reference force value, and record the haptic responses and shows that the JND decreases for faster change in the stimulus.
Abstract: In all prior applications, it is assumed that the just noticeable difference (JND) for the kinesthetic force stimulus is independent of rate of change of the stimulus. In this work, we study how the JND is affected over the rate of change of the stimulus. This study has a possible application in better design of a haptic data compression algorithm. We design an experimental set up where users are subjected to a continuous haptic force which starts increasing or decreasing from a fixed reference force value, and record the haptic responses. A machine learning classifier- SVM is trained using the recorded haptic responses to estimate the best fit linear decision boundary between the JND and the rate of change of the stimulus. Our results show that the JND decreases for faster change in the stimulus. We also demonstrate an asymmetric behavior of perception between increasing and decreasing cases.
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01 Feb 2019
TL;DR: In this article, the authors present the fundamentals and state of the art in haptic codec design for the Tactile Internet and discuss how limitations of the human haptic perception system can be exploited for efficient perceptual coding of kinesthetic and tactile information.
Abstract: The Tactile Internet will enable users to physically explore remote environments and to make their skills available across distances. An important technological aspect in this context is the acquisition, compression, transmission, and display of haptic information. In this paper, we present the fundamentals and state of the art in haptic codec design for the Tactile Internet. The discussion covers both kinesthetic data reduction and tactile signal compression approaches. We put a special focus on how limitations of the human haptic perception system can be exploited for efficient perceptual coding of kinesthetic and tactile information. Further aspects addressed in this paper are the multiplexing of audio and video with haptic information and the quality evaluation of haptic communication solutions. Finally, we describe the current status of the ongoing IEEE standardization activity P1918.1.1 which has the ambition to standardize the first set of codecs for kinesthetic and tactile information exchange across communication networks.
104 citations
08 Dec 2014
TL;DR: This article identifies adaptive sampling strategies for haptic signals using classifiers based on level crossings and Weber’s law but also random forests using a variety of causal signal features and finds that the level crossing sampler is superior.
Abstract: In this article, we identify adaptive sampling strategies for haptic signals. Our approach relies on experiments wherein we record the response of several users to haptic stimuli. We then learn different classifiers to predict the user response based on a variety of causal signal features. The classifiers that have good prediction accuracy serve as candidates to be used in adaptive sampling. We compare the resultant adaptive samplers based on their rate-distortion tradeoff using synthetic as well as natural data. For our experiments, we use a haptic device with a maximum force level of 3 N and 10 users. Each user is subjected to several piecewise constant haptic signals and is required to click a button whenever he perceives a change in the signal. For classification, we not only use classifiers based on level crossings and Weber’s law but also random forests using a variety of causal signal features. The random forest typically yields the best prediction accuracy and a study of the importance of variables suggests that the level crossings and Weber’s classifier features are most dominant. The classifiers based on level crossings and Weber’s law have good accuracy (more than 90p) and are only marginally inferior to random forests. The level crossings classifier consistently outperforms the one based on Weber’s law even though the gap is small. Given their simple parametric form, the level crossings and Weber’s law--based classifiers are good candidates to be used for adaptive sampling. We study their rate-distortion performance and find that the level crossing sampler is superior. For example, for haptic signals obtained while exploring various rendered objects, for an average sampling rate of 10 samples per second, the level crossings adaptive sampler has a mean square error about 3dB less than the Weber sampler.
16 citations
29 Aug 2022
TL;DR: The results show that the generalized deadband do provide different increasing and decreasing JNDs, pointing towards asymmetry in force perception, but fails to improve the data reduction significantly as compared to the existing symmetric one.
Abstract: In the literature, perceptual deadband approach based on the Weber’s law of perception has been employed to reduce haptic data (i.e., force) rate for a typical teleoperation application. The approach selects only those samples for transmission which lie outside the perceptual deadband. The existing structure of the deadband has linear decision boundaries and assume that the just noticeable differences (JNDs) for increasing and decreasing change in a reference force stimulus are similar. This paper questions this assumption and searches for an asymmetric perceptual deadband using a data-driven approach. For the purpose, we design an experimental setup for collecting human haptic responses (perceived and non-perceived) of several users for a force range [3, 5] N. A machine learning classifier inspired from the Weber’s law is trained to predict the labels of the responses and define a generalized linear perceptual deadband for each user. The results show that the generalized deadband do provide different increasing and decreasing JND (i.e., pointing towards asymmetry in force perception), but fails to improve the data reduction significantly as compared to the existing symmetric one.
1 citations
29 Aug 2022
TL;DR: In this paper , a machine learning classifier inspired from the Weber's law is trained to predict the labels of the responses and define a generalized linear perceptual deadband for each user, and the results show that the generalized deadband do provide different increasing and decreasing JNDs, pointing towards asymmetry in force perception, but fails to improve the data reduction significantly as compared to the existing symmetric one.
Abstract: In the literature, perceptual deadband approach based on the Weber’s law of perception has been employed to reduce haptic data (i.e., force) rate for a typical teleoperation application. The approach selects only those samples for transmission which lie outside the perceptual deadband. The existing structure of the deadband has linear decision boundaries and assume that the just noticeable differences (JNDs) for increasing and decreasing change in a reference force stimulus are similar. This paper questions this assumption and searches for an asymmetric perceptual deadband using a data-driven approach. For the purpose, we design an experimental setup for collecting human haptic responses (perceived and non-perceived) of several users for a force range [3, 5] N. A machine learning classifier inspired from the Weber’s law is trained to predict the labels of the responses and define a generalized linear perceptual deadband for each user. The results show that the generalized deadband do provide different increasing and decreasing JND (i.e., pointing towards asymmetry in force perception), but fails to improve the data reduction significantly as compared to the existing symmetric one.
1 citations
DOI•
17 Sep 2015TL;DR: In this article, the authors investigated the effect of two top-down cues (perceived initiation of action and presence of action options) on sense of agency in haptic interfaces and investigated the consistency of the feeling of agency and answer the question whether consistent force feedback (bottom-up cue) is sufficient to grant stable experience of agency.
Abstract: The present study undertakes an ecological approach to haptic interfaces grounded in the sense of agency that accompanies human action. The study had two aims. The first aim was to investigate the effect of two top-down cues (perceived initiation of action and presence of action options) on sense of agency in haptic interfaces. The second aim was to investigate the consistency of the sense of agency and answer the question whether consistent force feedback (bottom-up cue) is sufficient to grant stable experience of agency. The results of the study suggest that while high number of action options can be associated with stronger agency, low numbers of action options are unlikely to produce such effect, and that the cue of task completion might be critical for the sense of agency. The study also showed that sense of agency was relatively inconsistent, with the main source of uncertainty being computer-attributed agency. The discussion addresses issues of joint human-computer agency and the contribution of multiple sources of information to agency experience.
Cites background from "Does Just Noticeable Difference Dep..."
..., differences in vibrotactile thresholds for wrist, elbow, and shoulder in [18]), rate of change of the stimulus [19], complexity of the generated movement [18], electrical and mechanical specifications of the device [20], and other factors....
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References
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TL;DR: This tutorial gives an overview of the basic ideas underlying Support Vector (SV) machines for function estimation, and includes a summary of currently used algorithms for training SV machines, covering both the quadratic programming part and advanced methods for dealing with large datasets.
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TL;DR: The experimental results show that the presented approach is able to reduce the packet rate between an operator and a teleoperator by up to 90% of the original rate without affecting the performance of the system.
Abstract: We present a novel approach for the transmission of haptic data in telepresence and teleaction systems. The goal of this work is to reduce the packet rate between an operator and a teleoperator without impairing the immersiveness of the system. Our approach exploits the properties of human haptic perception and is, more specifically, based on the concept of just noticeable differences. In our scheme, updates of the haptic amplitude values are signaled across the network only if the change of a haptic stimulus is detectable by the human operator. We investigate haptic data communication for a 1 degree-of-freedom (DoF) and a 3 DoF teleaction system. Our experimental results show that the presented approach is able to reduce the packet rate between the operator and teleoperator by up to 90% of the original rate without affecting the performance of the system.
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TL;DR: It is concluded that the rate of temperature change does not represent information about the rate constants of stimulation of warm and cool receptors but that its effect is by way of the rate at which thermal adaptation occurs.
Abstract: The variables which are said to affect human temperature sensitivity are the skin temperature, the area of thermal stimulation and the rate at which the temperature of the skin is changed. Of these, the last has been only partially described. Measurements of the warm and cool thresholds were made on two males, experienced in making threshold judgments, when the rate of stimulus temperature change was varied between 0.01–0.3° C/sec. Both the warm and cool thresholds remained constant at rates of 0.1° C/sec and above but increased rapidly when slower rates were used. The effect of slow rates of stimulus temperature change was greater on the warm threshold than upon the cool threshold. It is concluded that the rate of temperature change does not represent information about the rate constants of stimulation of warm and cool receptors but that its effect is by way of the rate at which thermal adaptation occurs
133 citations
25 Mar 2006
TL;DR: The presented approach reduces packet rates in haptic systems by up to 90% without any perceivable reduction of immersiveness, which is the first psychophysically motivated compression approach for multidimensional haptic data in literature.
Abstract: Haptic interaction with virtual as well as real environments is much more demanding to the underlying network than traditional audio/video communication. Because of very strict delay constraints imposed by the global control loop which is closed by the communication system very high packet rates are generated. Each packet typically carries a small amount of payload data leading to a significant packet header versus payload overhead. This paper presents a psychophysically motivated deadband transmission approach for multidimensional haptic data using the example of three dimensional haptic interaction. Packets are only generated and sent if the change in haptic variables exceeds the just noticeable difference of the human operator. The presented approach reduces packet rates in haptic systems by up to 90% without any perceivable reduction of immersiveness. To our knowledge the proposed approach is the first psychophysically motivated compression approach for multidimensional haptic data in literature.
52 citations
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TL;DR: A novel control scheme as well as a modification of the deadband approach is presented to take advantage of the stabilization ability of the wave variables while allowing perceptual coding on the communication channel.
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42 citations