Search

We propose a new technique that evaluates the structures of car interiors by the following two algorithms, based on visual processing in the brain. (1) Medial axes reveal the imaginary skeletal structures within objects. (2) Saliency maps identify the areas attracting attention in visual scenes. Integration of these techniques revealed hidden axes characterizing the global structures of car dashboards, which are possibly more alluring than explicit features. Furthermore, the variety of such hidden axes across different cars/brands can be summarized in reduced dimensional spaces. Because features revealed by this technique are consistent with the framework of universal rules for aesthetic experiences (e.g., symmetry and perceptual problem solving), this could be useful to evaluate some aspects of aesthetic values quantitatively in car interiors.

Background: Achieving clear visibility through a windshield is one of the crucial factors in manufacturing a safe and comfortable vehicle. The optic flow (OF) through the windshield has been reported to divert attention and could impair visibility. Although a growing number of behavioral and neuroimaging studies have assessed drivers' attention in various driving scenarios, there is still little evidence of a relationship between OF, windshield shape, and driver's attentional efficacy. The purpose of this research was to examine this relationship. Methods: First, we quantified the OF across the windshield in a simulated driving scenario with either of two types of the windshield (a tilted or vertical pillar) at different speeds (60 km/h or 160 km/h) and found more upward OF along the tilted pillar than along the vertical pillar. Therefore, we hypothesized that the predominance of upward OF around the windshield along a tilted pillar could distract a driver and that we could observe the corresponding neural activity. Magnetic resonance scans were then obtained while the subjects performed a visual detection task while watching the driving scene used in the OF analysis. The subjects were required to press a button as rapidly as possible when a target appeared at one of five positions (leftmost, left, center, right, and rightmost). Results: We found that the reaction time (RT) on exposure to a tilted pillar was longer than that on exposure to a vertical pillar in the leftmost and rightmost conditions. Furthermore, there was more brain activity in the precuneus when the pillar was tilted than when it was vertical in the rightmost condition near the pillar. In a separate analysis, activation in the precuneus was found to reflect relative changes in the amount of upward OF when the target was at the rightmost position. Conclusions: Overall, these observations suggest that activation in the precuneus may reflect extraneous cognitive load driven by upward OF along the pillar and could distract visual attention. The findings of this study highlight the value of a cognitive neuroscientific approach to research and development in the motor vehicle manufacturing industry.

Humans feel forces or weights while grasping and manipulating an object. There is a difference between the physical and perceived forces because the physical characteristics of an object and/or human psychophysical characteristics affect perceived force. Sense of effort plays an important role in deciding the movement made by humans. In this study, we propose a computational method to predict the perceived force by evaluating the muscle activity as a function of effort in the operation of a steering wheel based on a 3D-musculoskeletal model simulation. We found that the perceived-force characteristics depend on the driving posture, though the applied force is the same. We evaluated the results, and showed that the mean of the absolute error is 1.78 N for the experiments conducted on four different vehicles in commercially available.

The models of motion and perception characteristics of humans are helpful to evaluate subjective efforts associated with intuitive, safe, and easy-to-use products. Traditionally, the muscle activity and/or the joint torque estimated by using a musculoskeletal model have been evaluated, whereas there are few studies that consider human's perception characteristics. In this paper, the perception characteristics of force are investigated based on the estimation of the muscle activities. Experimental analysis of human force perception characteristics in a steering wheel operation has revealed that the perceived force depends on the angle of the steering wheel and the direction of the load. This paper proposes the estimation model of the force perceived by a subject that considers human's posture- and direction-dependent perception characteristics in the steering operation. We estimate the muscle activity during the steering wheel operation by using a three-dimensional musculoskeletal model, develops a perception conversion model that follows the Weber-Fechner law, and describes the experimental results that confirm the feasibility of the proposed force perception estimation.