A Study of Cutaneous Perception Parameters for Designing Haptic Symbols towards Information Transfer

Vibrotactile displays can substitute for sensory channels of individuals experiencing temporary or permanent impairments in balance, vision, or hearing, and can enhance the user experience in professional or entertainment situations. This massive range of potential uses necessitates primary research on human vibrotactile perception. One leading aspect to consider when developing such displays is how to develop haptic patterns or symbols to represent a concept. In most settings, individual patterns are sorted as alphabets of haptic symbols which formulate tactons. Tactons are structured and perceivable tactile patterns (i.e., messages) that transfer information to users by employing the sense of touch. Hence, haptic patterns are critical when designing vibrotactile displays, as they not only affect the rate of information transfer but also determine the design of the displays (e.g., the number and the placement of tactors engaged) and how the information is encoded to achieve separability. Due to this significance, this paper presents an overview study on the cutaneous perception parameters (i.e., intensity, loci, frequency, duration, illusions, and combinations of these) for designing haptic symbols to identify mutual best-practices and knowledge gaps for future work. The study also provides developers from different scientific backgrounds with access to complex notions when engaging this specialized topic (i.e., the use of cutaneous perception parameters towards information transfer). Finally, it offers recommendations on defining which parameters to engage for a specific task or pattern.

Comparison of Usability between Gear Shifters with Varied Visual and Haptic Patterns and Complexities

Shift-by-wire technology enables more options concerning the design, placement and functions of gear shifters compared to traditional gear shifters with manual transmission. These variations can impact usability and driver performance. There is a lack of research regarding the potential advantages and disadvantages of different types of gear shifters. The purpose of this study was to investigate the efficiency and subjective ease-of-use of mono- and polystable joystick gear shifter types at different complexity levels and with full or limited visibility. An experimental study with 36 participants was conducted. The results showed that monostable joysticks, especially those with an I/J-shape, were overall less efficient and easy to use than polystable joysticks. The highest complexity level clearly affected the efficiency for the monostable joystick with an I/J-shape (mono I/J) compared with the other gear shifter types. The monostable joystick with an I/J-shape (mono I/J) was also most affected by reduced visibility at the highest level of complexity, indicating that it was more prone to causing users to take their eyes off the road.

The Advanced Control Approach based on SMC Design for the High-Fidelity Haptic Power Lever of a Small Hybrid Electric Aircraft

In the serial hybrid electric propulsion system of a small propeller aircraft the battery state of charge is fluctuating due to the diversity of possible power flows. Overwhelming visual information on the cockpit displays, besides requiring visual pilot attention, increases pilot workload, which is undesirable, especially in risky flight situations. Haptic interfaces, on the other hand, can provide intuitive cues that can be applied to enhance and simplify the cockpit. In this paper, we deal with an enhanced power lever stick, which can provide feedback force feel with haptic cues for enhanced information flow between the pilot and the powertrain system. We present selected haptic patterns for specific information related to the fluctuating battery state of charge. The haptic patterns were designed to reduce pilot workload, and for easy use, safe and energy-efficient control of the hybrid electric powertrain system. We focus on the advanced control design for high-performance force feedback required for rendering fine haptic signals, which stimulates the sensitive haptics of a pilot’s hand-arm system. The presented control algorithm has been designed by the sliding mode control (SMC) approach in order to provide disturbance rejection and high-fidelity haptic rendering. The proposed control design has been validated on an experimental prototype system.