Levels Of Force Feedback Research Articles

May the force be with you: exploring force discrimination in chimpanzees using the force-feedback device.

While force-feedback devices have been developed in areas such as virtual reality, there have been very few comparative cognitive studies in nonhuman animals using these devices. In addition, although cross-modal perception between vision and touch has been actively studied in nonhuman primates for several decades, there have been no studies of their active haptic perception. In this study, we attempted to train force discrimination in chimpanzees using a force-feedback device modified from a trackball. Chimpanzees were given different levels of force feedback (8.0 vs. 0.5N) when moving the on-screen cursor to the target area by manipulating the trackball and were required to select one of two choice stimuli based on the force cue. The experiment was conducted using a trial-block procedure in which the same force stimulus was presented for a fixed number of trials, and the force stimulus was changed between blocks. The block size was progressively reduced from ten trials. Four chimpanzees were trained, but none reached the learning criterion (80% or more correct responses under the condition that the force stimuli were presented randomly). However, a detailed analysis of the chimpanzees' performance before and after the trial-block switching revealed that their choice behavior could not be explained by a simple win-stay/lose-shift strategy, suggesting that the switching of the force stimuli affected the chimpanzees' choice behavior. It was also found that the chimpanzees performed better when switching from small to large force stimuli than when switching from large to small force stimuli. Although none of the chimpanzees in this study acquired force discrimination, future studies using such force-feedback devices will provide new insights for understanding haptic cognition in nonhuman primates from a comparative cognitive perspective.

Development and Testing of a Wearable Vibrotactile Haptic Feedback System for Proprioceptive Rehabilitation

The human sense of touch is an integral part of daily life. For tasks involving grasping and manipulation of objects, force feedback is a key requirement. Most of the systems give contact point or complete grasping force feedback; for precision grasping and other physical interactions, finger awareness and force feedback from independent fingers is essential. In this study a novel, wearable proprioceptive rehabilitation system is designed which restores the ability of identifying and distinguishing between individual fingers of a prosthetic hand or an exoskeleton in a non-invasive manner. Moreover, it provides different levels of force feedback from every finger as well, which enables the user to distinguish and control force in precision grasping activities. For testing the system accuracy, classical psychophysical methods were used on a group of 14 voluntary disabled subjects. The tests were conducted in both, ideal and real-world conditions i.e. without and with distractions and accuracies were calculated accordingly. A p-test was also conducted to observe significance between the samples of with and without distraction datasets. The system performed with an overall accuracy of 82.04% which was well above the min. performance measure of 60%. Vi-HaB is standalone system and can be mounted on any upper limb rehabilitation (prosthesis, exoskeleton) system for finger awareness and force feedback.

The Effect of Variations in Force Feedback in a Virtual Reality Environment on the Performance and Satisfaction of Dental Students.

The aim of this study was to investigate the transfer of skills between various levels of force feedback (FFB) using the Simodont dental trainer (Moog, Nieuw-Vennep, the Netherlands). Students practiced a manual dexterity exercise in a virtual reality environment at a standard level of FFB and then were tested at the standard and an altered level of FFB. In addition, the students' satisfaction with the training exercise was evaluated. One hundred twenty-six first-year dental students were randomly distributed into four groups and underwent a manual dexterity test in the virtual reality environment with automatic assessment after a 3-month period of practicing with standard FFB. The test consisted of drilling with the standard FFB and an altered level of FFB to evaluate the effect on performance. After the test, the participants completed a questionnaire. The results showed that 74% of the students who passed completed between one of three and three of three successful attempts at FFB levels at which they had not previously practiced. The results of this study imply that if students practice a sufficient amount of time at one level of FFB, a skill is transferable from one level of FFB to another.

Effects of Force Feedback and Distractor Location on a CDTI Target Selection Task

New flight deck technologies need to be implemented in order to support the projected rises in traffic levels. Future cockpit displays of traffic information (CDTIs) shall accommodate the altered responsibilities of pilots by facilitating more efficient routes and minimizing conflicts. However, the unstable nature of the cockpit may present challenges when precise inputs are required. The present study investigated the effects of force feedback and distractors on point-and-click movement times in a CDTI environment. Participants performed target selection tasks with multiple levels of force feedback and distractor location. Results implied that force feedback failed to benefit movement times relative to the standard computer mouse. However, substantial interactions between distractor effects, force levels, and other target characteristics are explored.

Effects of Type and Strength of Force Feedback on Movement Time in a Target Selection Task

Future cockpits will likely include new onboard technologies, such as cockpit displays of traffic information, to help support future flight deck roles and responsibilities. These new technologies may benefit from multimodal feedback to aid pilot information processing. The current study investigated the effects of multiple levels of force feedback on operator performance in an aviation task. Participants were presented with two different types of force feedback (gravitational and spring force feedback) for a discrete targeting task, with multiple levels of gain examined for each force feedback type. Approach time and time in target were recorded. Results suggested that the two highest levels of gravitational force significantly reduced approach times relative to the lowest level of gravitational force. Spring force level only affected time in target.

Clean Diesel Technologies reports 2Q 2003 results

New flight deck technologies need to be implemented in order to support the projected rises in traffic levels. Future cockpit displays of traffic information (CDTIs) shall accommodate the altered responsibilities of pilots by facilitating more efficient routes and minimizing conflicts. However, the unstable nature of the cockpit may present challenges when precise inputs are required. The present study investigated the effects of force feedback and distractors on point-and-click movement times in a CDTI environment. Participants performed target selection tasks with multiple levels of force feedback and distractor location. Results implied that force feedback failed to benefit movement times relative to the standard computer mouse. However, substantial interactions between distractor effects, force levels, and other target characteristics are explored.

The effect of force saturation on the haptic perception of detail

This paper presents a quantitative study of the effects of maximum capable force magnitude of a haptic interface on the haptic perception of detail. Specifically, the haptic perception of detail is characterized by identification, detection, and discrimination of round and square cross-section ridges, in addition to corner detection tests. Test results indicate that performance, measured as a percent correct score in the perception experiments, improves in a nonlinear fashion as the maximum allowable level of force in the simulation increases. Further, all test subjects appeared to reach a limit in their perception capabilities at maximum-force output levels of 3-4 N, while the hardware was capable of 10 N of maximum continuous force output. These results indicate that haptic interface hardware may be able to convey sufficient perceptual information to the user with relatively low levels of force feedback. The data is compiled to aid those who wish to design a stylus-type haptic interface to meet certain requirements for the display of physical detail within a haptic simulation.

Operator workload and system performance under different conditions of force feedback in a telemanipulation task

Recent developments in the design of teleoperators have produced various functions aimed at reducing the physical workload of the human operator. The effects of modifying force feedback and of suppressing the vertical force component of the manipulated object on task performance and subject workload have been studied. A pick and place task was carried out on a horizontal or vertical work surface using an MA 23 computer-aided telemanipulator. Subjects manipulated standard sized objects of two weights under two conditions of force feedback either with or without the vertical force component acting on the object. Task performance was measured in terms of movement times and pointing accuracy on the target. Subject workload was evaluated using surface EMG recordings of muscle activity from selected muscles of the upper arm and shoulder. The results showed that movement direction had the greatest influence on performance. Improvements in performance were noted when the overall forces required to carry out the movement were reduced. For the range of conditions tested, few significant differences were found for individual factors, that is between the two levels of force feedback or the presence/absence of the vertical force component