It is a challenge to develop high spatial resolution texture display devices using electromagnetic-driven methods, as the magnetic driving force sharply decreases due to the small size of the actuators. To address this challenge, we report a high spatial resolution texture display device using a novel multi-coil superposition driving method, which consists of 25 tactile units arranged in a 5*5 matrix with a spatial resolution of 2.75mm. Using the vector superposition of magnetic fields, the driving force of the target tactile unit can be effectively enhanced through the joint driving of multiple electromagnetic coils. The experimental result indicates that the upward holding force of the target tactile unit using the proposed multi-coil superposition driving method increases by 36.2% compared to the traditional single-coil driving method.
Complex robotic tasks require human collaboration to benefit from their high dexterity. Frequent human-robot interaction is mentally demanding and time-consuming. Intuitive and easy-to-use robot control interfaces reduce the negative influence on workers, especially inexperienced users. In this paper, we present CobotTouch, a novel intuitive robot control interface with fingertip haptic feedback. The proposed interface consists of a projected Graphical User Interface (GUI) on the robotic arm to control the position of the robot end-effector based on gesture recognition and a wearable haptic interface to deliver tactile feedback on the user's fingertips. We evaluated the user's perception of the designed tactile patterns presented by the haptic interface and the intuitiveness of the proposed system for robot control in a case study. The results revealed a high average recognition rate of 75.25% for tactile patterns. The average NASA Task Load Index (TLX) indicated small mental and temporal demands, indicating a high level of intuitiveness of CobotTouch for interaction with collaborative robots.
The main application of virtual reality (VR) is to immerse users in the three-dimensional simulation environment and experience the virtual reality world. At present, VR products and content on the market have some problems to be solved, such as location information error, dizziness and discomfort, stereo vision error, sound mismatch and so on. Moreover, most VR applications use stereo vision perception, but that alone is not enough to fully immerse users in the VR environment. For a long time, the single way of information transmission makes people over rely on the visual channel, which leads to visual information overload. Compared with the receptive visual information obtained by a single channel, haptic interaction system is more bidirectional. The employment of tactile feedback technology in VR can provide better immersion and interaction, and expand the scope of user experience. Among the four main tactile stimuli-vibrant stimulus, pressure stimulus, electric stimulus and temperature stimulus, vibrant stimulus has higher comfort, consistency and better response speed and adjustable range. Therefore in this paper, combined with specific VR scene, external vibration was applied around the eyes to provide periocular stimulation, so as to explore the role of vibration in enhancing the immersion of VR equipments. A mathematical model of human visual-haptic interaction process is established, and it is verified that the artificial neural network model has good fitting effect in simulating human visual-haptic nervous system.
This paper presents a novel haptic device, named DeltaFinger, designed to deliver the force of interaction with virtual objects by guiding the user’s finger by a wearable delta mechanism. DeltaFinger delivers a 3D force vector to the fingertip of the index finger of the user, allowing complex rendering of various virtual reality (VR) environments. The developed device is able to render linear forces up to 1.8 N in vertical projection and 0.9 N in horizontal projection without restricting the motion freedom of the remaining fingers. The experimental results showed a sufficient precision in perception of force vector with DeltaFinger (mean angular error in the perceived force vector of 0.6 rad). The proposed device potentially can be applied to VR communications, medicine, and navigation for people with vision problems.
Aerial images that can interact with the hands and fingers inducing realistic tactile sensations and behave as though they are composed of physical substances are referred to as materialized graphics. Materialized graphics provides a natural interface that humans can handle and manipulate using skills that are inherent in any human. The technology also enables us to confirm and enjoy the tactile feeling and mediates human–human communication. This paper reports the ten-year progress of materialized graphics based on airborne ultrasound tactile displays. Early symbolic demonstrations of materialized graphics are presented, and the recent technological advances in haptic rendering that improve the realism are summarized. It explains the current non-contact display covers the sensations of static pressure and thermal interaction in addition to vibratory sensations.
