Makoto Moriwaka

Applicability of location compatibility to the arrangement of display and control in human - vehicle systems: Comparison between young and older adults

The effects of age on applicability of the location compatibility principle to the design of display and control systems were discussed. A dual-task experiment was conducted, in which the primary task was first-order tracking. The secondary tasks included control of an air conditioner, the operation of a radio and the operation of a CD/MD, by means of either a steering wheel-mounted switch or a console-mounted switch. The display was arranged either in front of or on the left side of a participant. Performance of the young group did not completely follow predictions of the compatibility principle. In particular, the principle did not apply to the left-side display condition. The steering wheel-mounted switch was more effective than the left-side switch even for the left-side display. The compatibility principle was applicable to both front and left-side displays for the older adults. For the front display, the steering wheel-mounted switch was more effective. Such differences should be taken into account when designing display and control systems in man – vehicle systems.

Basic study on effectiveness of tactile interface for warning presentation in driving environment

The aim of this study was to get insight into the development of tactile interface for automobile warning system. In other words, it was investigated whether the important driving information in the right and left peripheral visual fields can be recognized faster using tactile warning system as compared with auditory warning system. The participants were required to simultaneously carry out a tracking task (main task), a switch pressing task such as selection of light-on function, and a judgment task of important information which randomly appeared to the right or left peripheral visual field. The tracking error, the number of lane deviation, the percentage correct of switch pressing, and the response time to right and left peripheral stimulus were measured. It was examined how age, the modality of alarm presentation (no alarm, auditory, and tactile), the addition of direction in alarm presentation, and the existence of disturbance sound, and the location of tactile sensor (steering or foot) affected the measures above. The young adults performed better than older adults. The response time was not affected by the modality of alarm presentation, and the disturbance sound. The addition of direction of alarm presentation affected the performance. The tactile sensor attached to the foot led to faster response than that attached to the steering wheel.

Proposal of automotive 8-directional warning system that makes use of tactile apparent movement

We proposed a tactile 8-directional warning system which informs drivers of hazardous traffic situations hidden in 8 directions via tactile apparent movement. The effectiveness of the proposed warning system was compared with that of a warning system by simultaneous two-point stimulation and a system without warning. As a result, the apparent lead to quick reaction and higher hit rate (higher accuracy of hazard perception and recognition) as compared with the simultaneous two-point stimulation. However, this was limited to the front and the rear hazard, and was not true for all directions. The vibrotactile warning system that can recognize hazards from all of eight directions should be developed in future research.

Study on character input methods using eye-gaze input interface

Four character input methods for eye-gaze input interface were compared from the viewpoints of input speed, input accuracy, and subjective rating on ease of input and fatigue. Four input methods included (1) I-QGSM (vertical), (2) I-QGSM (circle), (3) eye-fixation method, and (4) screen button. While the eye-fixation method (3) led to faster input, the I-QGSM (vertical) led to fewer errors. In conclusion, it is difficult to develop character input method that satisfies both speed and accuracy.

Anomaly in Safety Management: Is It Constantly Possible to Make Safety Compatible with Economy?

Although it is clear that we must satisfy both economy and safety, we sometimes place more emphasis on economy than safety, which leads to a critical disaster or crash. The reason must be identified for the further enhancement of safety. This study explored why one cannot satisfy both economy and safety. We attempted to explain the reason using the collapse model of proper balance between safety and economy (efficiency) induced by the following cognitive biases: (i) mental accounting, (ii) loss aversion, and (iii) discount of safety. The measure or remedy of this collapse of the proper balance between safety and economy (efficiency) was proposed as (a) disclosure system, (b) commitment approach to safety, and (c) mechanism design.

Multinomial Logistic Regression Model by Stepwise Method for Predicting Subjective Drowsiness Using Performance and Behavioral Measures

The aim of this study was to explore the effectiveness of physiological and behavioral evaluation measures for predicting a drivers’ subjective drowsiness based on a multinomial logistic regression model. The participants were required to steer a steering wheel and keep their vehicle to the centerline as much as they could, and to maintain the distance between their own car and a preceding car properly as much as possible using a brake or an accelerator. A number of measures were recorded during a simulated driving task, and the participants were required to report subjective drowsiness once every minute. EEG (electroencephalography), heart rate variability (RRV3), and blink frequency were the physiological measures recorded. Meanwhile, behavioral measures included neck bending angle (horizontal and vertical), back pressure, foot pressure, and tracking error in a driving simulator task. Drowsy states were predicted via a multinomial logistic regression model. Physiological and behavioral measures were independent variables in the regression model and equated to the dependent variable: subjective evaluation of drowsiness. The stepwise method was adopted for the estimation of parameters of multinomial logistic regression model. The interval used for attaining the highest prediction accuracy was a 100 s interval between 20 and 120 s before the prediction. This approach clarified that the parameters finally appeared in the multinomial logistic regression model were different among participants, which indicated that the optimal structure of the model for predicting subjective drowsiness should be different among participants.

Ocular Movement Characteristics to LED Lights with High Luminous Intensity

The ocular movement characteristics to LED lights with high luminous intensity were explored when viewing such LED lights using a belt conveyer equipped with such LED light with high luminous intensity. The ocular movement characteristics such as blink duration, blink frequency, and PERCLOS70 were investigated as a function of LED color and luminous intensity. The blink duration consistently tended to increase with the increase of luminous intensity for all colors of LED. The blink frequency tended to increase under the high luminous intensity for both red and white LED which have higher wavelength. As for green LED, the blink frequency was not affected by the luminous intensity. Contrary to the case of red and white LED, the blink frequency of blue LED tended to decrease under the high luminous intensity. PERCLOS70 of red, white, and green LEDs tended to increase with the increase of luminous intensity. In this manner, the ocular movement characteristics of blue LED could be indicated.

Preventive safety by auditory-vibrotactile automotive warning system-Effectiveness of auditory-tactile automotive warning that makes the most of advantages of auditory and tactile modalities

The aim of this study was to identify a more effective condition when providing warning with drivers. The type of auditory stimulus and the type of tactile stimulus were within-subject experimental variables. The auditory stimuli were looming sound, pure tone, and car horn. The tactile stimuli were simultaneous two-point stimulation, stimulation by apparent movement, and two-stimulation by apparent movement. The participants were required to carry out a simulated driving task, speed keeping operation by adjusting a foot pedal, and a judgmental task of hazardous situation from four directions (front, rear, left, and right). No significant differences of reaction time were detected among three types of auditory stimuli, and among three types of tactile stimuli. As for the false reaction to the catch trial, the combination of the looming sound and the 2-stimulation by apparent movement led to fewer false reactions than other combinations, which suggested the effectiveness of the combination of the looming sound and the 2-stimulation by apparent movement.

Effects of Luminous Intensity and Color of LED Light on Ocular Movement Characteristics

The aim of present study was to explore the effects of luminous intensity and color of LED light on the ocular movement characteristics experimentally. The experimental factors were the color of LED (red, green, blue, and white) and the luminous intensity of LED (low: about 3500 lx, high: about 17500 lx). The participants required to stand in front of the conveyer, to gaze at the center on the surface of the conveyor, and not to move during the measurement. The measured ocular movement parameters were: the blink duration, the blink frequency, PERCLOS70. As a result, the blink duration tended to increase under blue LED condition independent of luminous intensity. The blink frequency tended to increase under the high luminous intensity condition for blue LED. Because PERCLOS70 was low in all condition (less than 10%), these ocular movement characteristics was not caused as the result of low arousal level.

Effectiveness of Eye-Gaze Input Method: Comparison of Speed and Accuracy Among Three Eye-Gaze Input Method

Effectiveness of eye-gaze input methods was examined in click, drag, and menu selection tasks. In a click task, three eye-gaze methods were (c)-(i) eye-gaze input with fixation, (c)-(ii) eye-gaze input with pressing BS key, and (c)-(iii) eye-gaze input with voice (voice1). Method (d)-(i) eye-gaze input with pressing BS key and (d)-(ii) eye-gaze input with voice (voice1) were compared for the drag task. In the menus selection task, the performance was compared between Method (m)-(i) eye-gaze input with voice (voice1) and (m)-(ii) eye-gaze input with voice (voice2: uttering one of the following menu items: “save”, “print”, “cut”, “copy”, and “paste”). The pointing time in the click task increased according to the following order: (c)-(i) eye-gaze input with fixation, (c)-(ii) eye-gaze input with pressing BS key, and (c)-(iii) eye-gaze input with voice (voice1). The pointing accuracy of (c)-(i) was nearly equal to 100% and by far better than that of Method (c)-(ii) and (c)-(iii). Concerning the drag, Method (d)-(i) tended to be faster than Method (d)-(ii). However, the pointing accuracy of both methods was not satisfactory and ranged from 70% to 80%. This indicated that Method (d)-(i) and (d)-(ii) must be further improved when used for the drag task. The pointing time in the menu selection task did not differ significantly between Method (m)-(i) and (m)-(ii). The pointing accuracy of Method (m)-(ii) was by far higher than that of Method (m)-(i) when the target size was small. The larger target size tended to lead to faster and accurate pointing for all three tasks. It seems that the better pointing method differs according to the eye-gaze method. Other than the click task, the pointing accuracy was at most 90%. Therefore, future research should propose an effective method to increase the prediction accuracy for both drag and menu selection tasks.