Ahmed Farooq

Delivering directional haptic cues through eyeglasses and a seat

Navigation systems usually require visual or auditory attention. Providing the user with haptic cues could potentially decrease cognitive demand in navigation. This study is investigating the use of haptic eyeglasses in navigation. We conducted an experiment comparing directional haptic cues to visual cueing in a car navigation task. Participants (N=12) drove the Lane Change Test simulator with visual text cues, haptic cues given by the eyeglasses and haptic cues given by a car seat. The participants were asked to confirm the recognition of a directional cue (left or right) by pressing an arrow on a tablet screen and by navigating to the corresponding lane. Reaction times and errors were measured. The participants filled in the NASA-TLX questionnaire and were also interviewed about the different cues. The results showed that in comparison to the visual text cues the haptic cues were reacted to significantly faster. Haptic cueing was also evaluated as less frustrating than visual cueing. The haptic eyeglasses fared slightly, although not significantly, better than the haptic seat in subjective and objective evaluations. The paper suggests that haptic eyeglasses can decrease cognitive demand in navigation and have many possible applications.

User experience and expectations of haptic feedback in in-car interaction

Haptic feedback based on the sense of touch and movement is a promising area of human-computer interaction in the car context. Most user studies on haptic feedback in the car have been controlled experiments of specific types of haptic stimuli. For the study presented in this paper, twelve participants tried novel haptic feedback prototypes and evaluated communication scenarios in the physical car context. Our aim was to understand user experiences and usage potential of haptic feedback in the car. The qualitative results show that haptic feedback may offer support for safety and social communication, but can be hard to interpret. We propose design considerations for in-car haptics such as simplicity, subtleness and directionality.

Touchscreen Overlay Augmented with the Stick-Slip Phenomenon to Generate Kinetic Energy

Kinesthetic feedback requires linkage-based high-powered multi-dimensional manipulators, which are currently not possible to integrate with mobile devices. To overcome this challenge, we developed a novel system that can utilize a wide range of actuation components and apply various techniques to optimize stick-slip motion of a tangible object on a display surface. The current setup demonstrates how it may be possible to generate directional forces on an interactive display in order to move a linkage-free stylus over a touchscreen in a fully controlled and efficient manner. The technology described in this research opens up new possibilities for interacting with displays and tangible surfaces such as continuously supervised learning; active feed-forward systems as well as dynamic gaming environments that predict user behavior and are able modify and physically react to human input at real-time.

Developing a stick-slip based kinesthetic touchscreen system for realtime stylus manipulation

Continuing our previous work on developing comprehensive haptic feedback mechanisms for touchscreen based devices, this research elaborates how it is possible to incorporate the stick-slip phenomenon onto a mobile touchscreen to provide kinesthetic feedback for multimodal user interaction. Research has already proven that kinesthetic feedback is greatly beneficial in a wide range of activities, especially within learning environments. Our research illustrates how we can develop kinesthetic feedback in real time haptic applications which use stylus based touchscreen interaction. Traditional kinesthetic feedback techniques require linkage-based high powered multi-dimensional manipulators (e.g. Phantom devices) which yet cannot be replicated on mobile devices. Prototypes discussed in this paper resolve the issue by expanding the approach introduced by Reznik and Canny in their “Universal Planar Manipulator” to generate kinesthetic afferentation on mobile touchscreens. Using this mechanism the authors were able to develop a series of prototypes and explore stick-slip effect to control directional forces on top of a Microsoft Surface Pro 3 tablet and manipulate the provided physical stylus according to its position in the virtual environment. Furthermore, the research also evaluated various actuator properties needed to provide an efficient and stable stick-slip touchscreen overlay for any touchscreen based system.

Haptic user interface enhancement system for touchscreen based interaction

Touchscreens are becoming a more attractive interaction technology in our daily lives and they are quickly replacing most of the conventional user interface controls. The ability to continuously modify and reconfigure screen contacts is a valuable feature in any device, especially in mobile devices like smartphones and tablets, where every inch matters. Perhaps the most inviting aspect of touchscreens is their ability to detect gestures and recognize human activities. Unlike externally static interfaces with a dedicated input device, such as a keypad with discrete well-defined keys; most touch sensitive displays are embodied as a flat, stiff and ridged screen surface. As a result, touch sensitive displays are breaking down and do not follow either ergonomic rules and standards nor physiological and psychological models/concepts of the afferent flow information processing. This, in turn, means that these systems diminish perceptual and intuitive haptic feedback which hinders and sometime limits user interaction.This paper defines a Haptic User Interface Enhancement System (UIES) that transforms the conventionally flat and stiff touchscreen surfaces intoa haptically adaptive interaction hub which is not only able to provide generic vibrotactile stimulation for conformational haptic feedback but is able to guide the user though onscreen User Interface controls via kinetic feedback cues which includes components of forces and torques applied dynamically in the place of contact to the fingertips.

Effects of directional haptic and non-speech audio cues in a cognitively demanding navigation task

Existing car navigation systems require visual or auditory attention. Providing the driver with directional cues could potentially increase safety. We conducted an experiment comparing directional haptic and non-speech audio cues to visual cueing in a navigation task. Participants (N=16) drove the Lane Change Test simulator with different navigational cues. The participants were to recognize the directional cue (left or right) by responding as fast as possible using a tablet. Reaction times and errors were measured. The participants were also interviewed about the different cues and filled up the NASA-TLX questionnaire. The results showed that in comparison to visual cues all the other cues were reacted to significantly faster. Haptic only cueing resulted in the most errors, but it was evaluated as the most pleasant and the least physically demanding. The results suggest that non-visual cueing could improve safety.

Actuators for touchscreen tactile overlay

This paper evaluates the most promising innovative actuators and transducers, both off-the-self and prototypes in advanced stages of development, utilized to provide haptic feedback for direct touch interaction, with touchscreen mobile devices. Most of commercially available actuators / transducers are specific to the medium of interaction, while the skin contact constraints are often underestimated. Therefore, tactile information delivered to the skin contact can be distorted and incorrect for interpretation. This research tries to identify the reasons behind the loss / decay of signals between the transducer and skin contact, by measuring distortion and integration of vibration signals propagating through the contact medium. The research postulates that the parameters of the haptic signals cannot be referred to specification of the individual components (actuators/transducers) but require of an assessment of a variety of constraints which need to be considered and compensated for to ensure their effective use.

Evaluating transparent liquid screen overlay as a haptic conductor: Method of enhancing touchscreen based user interaction by a transparent deformable liquid screen overlay

In line with our previous work, this research focuses on a method for attenuating acoustic components (noise) while providing enhanced vibrotactile feedback signals on mobile devices using, deformable touchscreen overlays. Traditional mechanism of providing tactile feedback to the fingertip via a flat rigid touchscreen is limited due to the dampening of the mechanoreceptors which are sensitive to static deformation and lie at the tips of the intermediate ridges in the epidermal-dermal junction. This tactile mechanism becomes useless when the fingertip acts against a ridged surface (chemically strengthened alkali-aluminosilicate glass). Furthermore, the actuation provided by most devices is indirect with little or no mediation mechanism, which results in filtering various signal frequencies, loss of signal intensity as well as creating acoustic noise. The resulting haptic signal is considerably inefficient and incongruent to the applied signal, which was designed to stimulate user skin contact. To resolve these issues we developed a unique transparent screen overlay conductor which contains an oil based composition (a low viscosity inert nonconductive liquid), that acts as a soft deformable interaction point, enhancing the ratio between tactile signals and the acoustic components, provided by haptic actuators. Using surface mounted and embedded actuators to the overlay, while being attached to an ExoPC Slate, we measured haptic signal to noise correlation, as well as signal efficiency and strength over multiple frequencies and concluded that the haptic conductor was able to limit auditory noise and mediate tactile signals more efficiently than traditional rigid glass based surfaces.

Developing actuation mechanism for stick-slip based intelligent mobile displays

In line with our previous work, this research focuses on enhancing touchscreen based interaction through stick-slip phenomena. By balancing inertial and frictional forces on a transparent screen overlay, we can control the resulting directional forces specific to multiple objects on a touchscreen surface. Using “stick-slip” phenomenon, we can associate tangible objects in relation to their virtual environment and adjust their behavior in real time without any stiff mechanical linkages. Our previous research shows the possible advantages of such a system (Stick-Slip Kinesthetic Display Surface) for a wide range of applications, such as continuous supervised input as well as novel applications with cross-environment interaction, where real-world physical objects can interact with their virtual counterparts and vice versa. However, to ensure that the directional forces are sufficient for these and other types of applications to serve as the system output, the mechanical actuation mechanism needs to be specifically designed for the particular novel use case. This research utilizes an electromagnetic setup to develop custom designed linear actuator which can increase the efficiency of the stick-slip based system. Our testing shows that the custom actuator is stable and more efficient at generating directional forces in the smart kinesthetic display surfaces (SKDS) as compared to actuators designed for conventional vibrotactile feedback.

Using Skin Micro-Displacements to Create Vibrotactile Signals for Mobile Touchscreen Displays

This paper investigates the possibility of providing one-directional micro-displacement-based tactile feedback for touchscreen displays on mobile devices, utilizing the existing haptic actuators and transducers. Most existing systems use a generic vibration signal, transmitted throughout the entire device, irrespective of the point of interaction. This low-resolution generic haptic feedback mechanism also does not account for variations caused during signal propagation through various density components and ignores specific skin-receptor constraints. Therefore, tactile information delivered to the point of contact is usually distorted and inconsistent with reference to the original signal and its meaning, creating phase shifts and signal integration as well as dead zones, throughout the device. This research tries to redefine vibrotactile feedback by utilizing the micro-displacements of a screen overlay on top of the touchscreen as the core haptic feedback mechanism. To achieve this, we have developed a custom setup to test and deliver one-directional micro-displacements on a mobile device (Nokia Lumia 710) with the help of a transparent 100-μm-thick PET film overlay. Utilizing four generic vibrotactile actuators, to generate skin micro-displacements, at various frequencies, we have measured each actuators ability to create one-directional displacement of the screen overlay and concluded that it is indeed possible to evolve from an inefficient, entire-device-based vibration haptic system, to a simple screen overlay micro-displacement mechanism for delivering onscreen tactile feedback utilizing the existing actuators. Furthermore, we also specify additional parameters that need to be considered in designing any touchscreen-based haptic system.