Touching creativity; a review and early pilot test of haptic tooling to support design practice, within a distance learning curriculum

Machine haptics has been shown to assist and enhance human–computer interactions. Research from previous studies in the field of haptics has focused on developing a user’s sense of realism of touch when using a haptic device. This paper examines the use of haptics for education, specifically for creative online education. The paper is presented in two parts. First, a review of literature was conducted and used to aid the rationale and underpin the design of a pilot test. Second, a pilot test was designed using a single-point kinaesthetic haptic device with a haptic rendered interface, to support the assembly of a virtual design prototype. The pilot test proved to be extremely valuable in creating and developing a rich virtual environment for non-sighted and sighted participants to use. The results from the initial pilot test showed that although users were positive about their experience of using the haptic device, there were improvements to be made to the interface to enhance the user experience in the next phase of testing

Haptic Zoom: An Interaction Model for Desktop Haptic Devices with Limited Workspace

[EN] Haptic devices can be used to feel through the sense of touch what the user is watching in a virtual scene. Force feedback devices provide kinesthetic information enabling the user to touch virtual objects. However, the most reasonably priced devices of this type are the desktop ones, which have a limited workspace that does not allow a natural and convenient interaction with virtual scenes due to the difference in size between them and the workspace. In this paper, a brand-new interaction model addressing this problem is proposed. It is called Haptic Zoom and it is based on performing visual and haptic amplifications of regions of interest. These amplifications allow the user to decide whether s/he wants more freedom in movements or an accurate interaction with a specific element inside the scene. An evaluation has been carried out comparing this technique and two well-known desktop haptic device techniques. Preliminary results showed that haptic zoom can be more useful than other techniques at accuracy tasks.SIA. G. acknowledges a FPU fellowship provided by the Ministerio de Educación, Cultura y Deporte of Spain

Virtual reality for assembly methods prototyping: a review

Assembly planning and evaluation is an important component of the product design process in which details about how parts of a new product will be put together are formalized. A well designed assembly process should take into account various factors such as optimum assembly time and sequence, tooling and fixture requirements, ergonomics, operator safety, and accessibility, among others. Existing computer-based tools to support virtual assembly either concentrate solely on representation of the geometry of parts and fixtures and evaluation of clearances and tolerances or use simulated human mannequins to approximate human interaction in the assembly process. Virtual reality technology has the potential to support integration of natural human motions into the computer aided assembly planning environment (Ritchie et al. in Proc I MECH E Part B J Eng 213(5):461–474, 1999). This would allow evaluations of an assembler’s ability to manipulate and assemble parts and result in reduced time and cost for product design. This paper provides a review of the research in virtual assembly and categorizes the different approaches. Finally, critical requirements and directions for future research are presented

Improving user comfort in haptic virtual environments through gravity compensation

Our experience with a Haptic Workstation™ has shown that this device is uncomfortable to use during long sessions. The main reason is the uncomfortable posture of the arms, which must be kept outstretched horizontally while supporting the weight of an exoskeleton. We describe Zero-G, a real-time weight compensation system aimed at improving user comfort by compensating for the weight of both the exoskeleton and arms (zero gravity illusion). We present experimental results complemented with electro myography measures (EMG) as an indicator of muscular activity/fatigue. Our tests show how Zero-G exerts a positive influence on the reduction of muscular fatigue when using a Haptic Workstation

Position-Based Control of Under-Constrained Haptics: A System for the Dexmo Glove

The Dexmo glove is a haptic exoskeleton that provides kinesthetic feedback in virtual reality. Unlike many other gloves based on string–pulleys, the Dexmo uses a free-hinged link-bar to transfer forces from a crank to the fingertips. It also uses an admittance-based controller parameterized by position, as opposed to an impedance-based controller parameterized by force. When setting the controller’s target position, developers must use its native angular coordinate system. The Dexmo has a number of uninstrumented degrees of freedom. Mature forward models can reliably predict the hand pose, even with these unknowns. When it comes to computing angular controller parameters from a target pose in Cartesian space however, things become more difficult. Complex models that provide attractive visuals from a small number of sensors can be non-trivial or even impossible to invert. In this letter, we suggest side-stepping this issue. We sample the forward model in order to build a lookup table. This is embedded in three-dimensional space as a curve, on which traditional queries against world geometry can be performed. Controller parameters are stored as attributes of the sample points. To compute the driver parameters for a target position, the application constrains the position to the geometry, and interpolates them. This technique is generalizable, stable, simple, and fast. We validate our approach by implementing it in Unity 2017.3 and integrating it with a Dexmo glove

Expanding the usable workspace of a haptic device by placing it on a moving base

The goal of this research is to expand the reachable workspace of a haptic device when used in a projection screen virtual environment. The proposed method includes supplementing the haptic device with a redundant degree of freedom to provide motion of the base. The key research challenge is to develop controls for the mobile base that will keep the haptic end-effector in the usable haptic workspace at all times. An experimental set up consisting of an Omni haptic device and a XY motorized table was used in the development of the control algorithms. Tests were conducted which demonstrate that the force felt by the user when touching a virtual wall remains constant even when the mobile base is moving to re-center the haptic device in the usable haptic workspace

Capturing tactile properties of real surfaces for haptic reproduction

Tactile feedback of an object’s surface enables us to discern its material properties and affordances. This understanding is used in digital fabrication processes by creating objects with high-resolution surface variations to influence a user’s tactile perception. As the design of such surface haptics commonly relies on knowledge from real-life experiences, it is unclear how to adapt this information for digital design methods. In this work, we investigate replicating the haptics of real materials. Using an existing process for capturing an object’s microgeometry, we digitize and reproduce the stable surface information of a set of 15 fabric samples. In a psychophysical experiment, we evaluate the tactile qualities of our set of original samples and their replicas. From our results, we see that direct reproduction of surface variations is able to influence different psychophysical dimensions of the tactile perception of surface textures. While the fabrication process did not preserve all properties, our approach underlines that replication of surface microgeometries benefits fabrication methods in terms of haptic perception by covering a large range of tactile variations. Moreover, by changing the surface structure of a single fabricated material, its material perception can be influenced. We conclude by proposing strategies for capturing and reproducing digitized textures to better resemble the perceived haptics of the originals

Development of a Tactile Thimble for Augmented and Virtual Reality Applications

The technologies that have gained a renewed interest during the recent years are Virtual Reality (VR) and Augmented Reality (AR), as they become more accessible and affordable for mass-production. The input device which allows us to interact with the virtual environment is a very crucial aspect. One of the main barriers to immerse ourselves in virtual reality is the lack of realistic feedback. The user has to almost rely entirely on visual feedback without any haptic feedback, and this increases the user's workload and decreases the performance. In this thesis, a functional demonstrator of a tactile feedback device which conveys compelling interactions with not just VR, but also AR is presented. The device is designed such that there is realistic feedback for virtual touches and least obstruction during contact of a real object in AR applications. New design principle of introducing small actuators allows the device to be compact and increases its portability. In contrast to actuators that are placed on the finger pad in most of the available input devices for VR, a tactile device with two actuators that are arranged laterally on the finger, so that the underside of the fingertip is free is proposed. The output from these actuators generate a tactile stimulus by stimulating a sense of touch, which helps the user to manipulate virtual objects. The actuators are designed to independently generate vibrations and this coupled tactile feedback enhances the stimulation resulting in a wide variety of stimulation patterns for the sense of touch. Preliminary experimental evaluation for design and location of actuators has been carried out to measure the vibration intensity. In addition, user experiments for design evaluation of the two actuators based on different vibration patterns have also been conducted

A hybrid method for haptic feedback to support manual virtual product assembly

The purpose of this research is to develop methods to support manual virtual assembly using haptic (force) feedback in a virtual environment. The results of this research will be used in an engineering framework for assembly simulation, training, and maintenance. The key research challenge is to advance the ability of users to assemble complex, low clearance CAD parts as they exist digitally without the need to create expensive physical prototypes. The proposed method consists of a Virtual Reality (VR) system that combines voxel collision detection and boundary representation methods into a hybrid algorithm containing the necessary information for both force feedback and constraint recognition. The key to this approach will be successfully developing the data structure and logic needed to switch between collision detection and constraint recognition while maintaining a haptic refresh rate of 1000 Hz. VR is a set of unique technologies that support human-centered computer interaction. Experience with current VR systems that simulate low clearance assembly operations with haptic feedback indicate that such systems are highly desirable tools in the evaluation of preliminary designs, as well as virtual training and maintenance processes. This work will result in a novel interface for assembly methods prototyping, and an interface that will allow intuitive interaction with parts based on a powerful combination of analytical, visual and haptic tools