Projection mapping (PM) is useful in the product design process, since it seamlessly bridges a physical mockup and its digital twin by allowing designers to interactively explore new textures, colors, and shapes without the need to create new physical mockups. While PM has proven effective for car interior design, previous research focused solely on supporting the design of dashboards and instrument panels, neglecting evaluation in realistic driving scenarios. This paper introduces a self-contained car interior design support system that extends beyond the dashboard to include the A-pillars. Additionally, to enable designers to evaluate their designs in authentic driving conditions, we integrate a driving simulator, complete with a motion platform, into the PM system. Through the construction of a prototype, we demonstrate the feasibility of our proposed system. Finally, through user studies, we derive guidelines for PM-based car interior design to optimize the user experience.

With the recent diversification of operating devices, the demand for input operations that require confirmation of the effect of differences in display response on operability has increased. Regarding display response, previous studies have investigated the threshold time and sense of agency for a delayed response during device operation. However, these studies only focused on subjective evaluations. Therefore, this study aims to clarify the human motor characteristics and activated brain regions based on the differences in display response time during device operation. The target motion is the rotational operation of the cylindrical rotary controller using the index finger and thumb. The experimental conditions involve four types of display response times (the duration from the operation to the indicated response). We measured the brain activity using near-infrared spectroscopy, the muscle activity from a surface myoelectric potential measurement device, and the force data of the index finger and thumb tip obtained from two independent six-axis force/torque sensors. Although the experimental results showed no significant difference in the muscle activity and gripping force, a significant difference was observed in the brain activity and the questionnaire survey by the difference in display response time. This investigation reveals that the difference in display response time affects brain activity and subjective information, clarifying the relationship between brain activity and subjective information.

This study aim to confirm the effect of viscosity characteristics differences on the rotational manipulation of a cylindrical rotary controller with the index finger and thumb through a quantitative analysis and evaluation of muscle and brain activations. The target motion was a rotary manipulation with the index finger and thumb of a cylindrical rotary controller with a 50 mm diameter. The rotary motion of the controller produces a click sensation at every 12 degrees in the rotation. The experimental conditions were three conditions with different viscosity characteristics related to the rotary motion of the controller. The subjects were six right-handed healthy males with a mean age of 21.7 (S. D.: 1.03) years. We analyzed the brain activity from a near- infrared spectroscopy measurement system, the muscles activity using a surface myoelectric potential measurement device, the force data at the index finger and thumb tip using two independent six-axis force/torque sensors, and the position data using a 3D position measurement device. The experimental results showed that there was no significant difference in the questionnaire survey, muscle activity, and grasping force, respectively; however, a significant difference in brain activity was observed with increased controller viscosity. Therefore, it became clear that there was a change in the brain activity when rotating the cylindrical rotary controller with the viscosity characteristics related to the rotary motion.

This study aims for the new driving skill improvement support system based on driving skill evaluation. We try to define driving skill in terms of "spatial perception" and "prediction". This research can be roughly divided into two steps. The first step is to establish an objective skill evaluation model. The second step is to verify effects of the support system for driving skill improvement. In this paper, we describe that we evaluated driving skill based on parking performance, operational behavior like steering and cognitive behavior like head motion and gazing points. We conducted driving behavior measurement experiment by using a real vehicle to get operational and cognitive data during driving. In consequence, we confirmed that driving skill could be defined by spatial perception and operational behavior of drivers in approaching to an obstacle.

Car interior design, such as dashboard, broadly consists of two parts. One is shape design, where the processes of 2D drawing, 3D modeling and evaluation with full-scale mockups are iterated, which takes a massive amount of time and cost. The other is material design such as surface property tuning, where designers compare material samples. This way, however, has a limitation on the number of material samples to compare and does not allow applying of the samples of interest to the whole mockups in early phases. In this paper, we apply projection mapping technique to boost the design process by altering the appearance of the surface of projected objects and enabling various shape and material evaluations in early phases. Our proposed system uses multiple projectors, one of which is 4K projector to reproduce fine leather surface. Utilizing physiological and psychological depth cues, the system allows the user to perceive the projected mockup as deformed. Psychological experiments confirm that users perceive deformation and have controlled impression on leather reproduced with certain parameters. In addition, we discuss the usability of the proposed system as a support system of car interior design.