In Japan, various safety measures have been installed to assist visually impaired individuals in walking outdoors, including at railroad crossings. Specifically, even with the installation of Tactile Walking Surface Indicators (TWSI), which focus on preventing deviations toward the roadway or ballast, there is a risk of misidentification between the inside and outside of the crossing because the bar blocks inside the crossing have the same shape as those on the sidewalk. Furthermore, the walking characteristics of visually impaired individuals have not been sufficiently considered. In this study, we conducted an evaluation experiment at a railroad crossing near Okusawa Station to clarify issues related to the TWSI installed both inside and outside the crossing from the perspective of visually impaired individuals. In the experiment, two types of trials were conducted with visually impaired individuals: first trial involved the use of TWSI both inside and outside the crossing, while in the second trial, walls or fences were used in place of the TWSI outside the crossing. After the trials, participants were interviewed about their “level of confidence in determining the position of the crossing boundary” and “ease of understanding the boundaries between the inside and outside of the railroad crossing.” The results indicated that participants found it more difficult to understand the boundaries when exiting the crossing than when entering it. This suggests potential issues with the current TWSI installations at railroad crossings.

One of the problems with wheelchairs is that the vibrations generated during driving can cause users to experience motion sickness, discomfort, and annoyance. Wheelchair tire pressure is considered to be one of the factors that affects the ride comfort of a wheelchair. However, it is not yet known how much influence the tire pressure of a wheelchair has. One of the reasons for this is that it is not possible to accurately measure tire pressure with the English valve used in wheelchairs. Therefore, we created a tire pressure indicator to accurately measure the tire pressure of wheelchairs. The purpose of this study is to use the tire pressure display to evaluate the impact of changes in tire pressure on assistive wheelchairs on vibration. In addition, in this experiment, we created a device to push the assistive wheelchair using an electric wheelchair in order to make the assistive wheelchair move at a constant speed, aiming to improve the reliability of the data. In this paper, we examined the effects of different running speeds on ride comfort.In this study, we use a triaxial accelerometer to measure the vibration of the tire pressure of a manual attendant-controlled wheelchair in four patterns: 80kPa, 160kPa, 240kPa, and 320kPa. This measurement is performed at three different running speeds: low speed, medium speed, and high speed. FFT analysis is performed on the acceleration in three directions measured by the triaxial accelerometer, and the maximum power spectrum, frequency and integral value at the maximum power spectrum are determined. From these values, evaluate the trends caused by changes in tire air pressure. Verify the relationship with tire pressure. Riding comfort was evaluated using the SD method, and two types of evaluation were performed: stationary and running. The evaluation items consisted of three items, sitting comfort, sense of security, and sitting comfort of the buttocks, for both static and running conditions, and four items, including the strength of shaking while running. Responses were obtained on a five-point scale from 1 to 5. In this study, we verified the results of vibration measurements and sensory evaluations, and verified ride comfort due to differences in driving speed and tire air pressure.

In this study, we performed a demonstration experiment to determine a highly visible light emission pattern while feeling that the stimulus is suppressed using sensory evaluation. We performed sensory evaluation of stimulus intensity and visibility of simple blinking that repeats on and off and fade-in/fade-out blinking that gradually brightens and fades to investigate the trade-off relationship between stimulus adaptation and arousal. In the experiment, we compared the light-emitting blocks that are constantly lit, simple blinking, and fade-in/fade-out blinking and clarified the relationship of the blinking stimulus with visibility. In this experiment, subjects underwent the sensory evaluation for three types of environmental illuminance (20 lx, 50 lx, and 100 lx) and were asked to evaluate the strength of stimulation, visibility, and discomfort of each blinking pattern using normal light as a reference. When the surrounding illuminance was low (20 lx), the overall evaluation value was higher because the fade-in/fade-out flashing was less stimulating and easier to find. Conversely, when the ambient illuminance was high (50 lx), simple blinking was more stimulating and easier to find, and the overall evaluation value was higher. Although it was a simple blinking, it seemed that the visibility for the visually impaired had been secured. Moreover, in the case of 100 lx, the difference in the illuminance between the surroundings and the light-emitting block was small; therefore, finding the light-emitting block in both simple blinking and fade-in/fade-out blinking was difficult, and the overall evaluation value was very low. It was found that simple or fade-in/fade-out blinking is selected depending on the ambient illuminance. By installing light-emitting blocks that blink in an optimal blinking pattern at the entrance of a crosswalk, it is expected that the blinking will be effective in guiding the visually impaired while considering pedestrians and the surrounding environment.

The tire pressure of manual attendant-controlled wheelchairs was measured in four patterns of 80 kPa, 160 kPa, 240 kPa, and 320 kPa. The number of trials for each of the four patterns of tire pressure was 10 times for a total of 40 times. The maximum power spectrum, frequency at the maximum power spectrum, and integral value were obtained from the FFT analysis data for the acceleration in three directions measured using the triaxial accelerometer, and the trends due to changes in tire pressure were evaluated. Tire pressure indicators made for this study were attached to both rear wheels of the manual attendant-controlled wheelchairs, and a dummy weight of 50 kgf was placed on the seat. Acceleration in three directions, including up/down, front/back, and left/right directions, was measured using a three-axis accelerometer attached to a heavy object. The tire pressure of the manual wheelchair for assistance was measured in four patterns of 80 kPa, 160 kPa, 240 kPa, and 320 kPa. The number of trials for each of the four patterns of tire pressure was 10 times for a total of 40 times. FFT analysis was performed using numerical analysis software for acceleration in three directions measured using a triaxial accelerometer. The maximum power spectrum, frequency at the maximum power spectrum, and integral value were obtained from the FFT-analyzed data, and the relationship with tire pressure was verified. Riding comfort was evaluated using the SD method, and the following two types of evaluation were performed: stationary and running. For both static and running conditions, the evaluation consisted of three items, including sitting comfort, sense of security, and sitting comfort of the buttocks, and four items, including the strength of shaking while running. Responses were obtained on a five-point scale from 1 to 5. Consequently, in this study, an air pressure indicator for English valves was attached to manual attendant-controlled wheelchairs, and vibration measurements were performed under controlled conditions. As a result of experiments using the manufactured vibration measuring device, it was found that the vibration tends to increase as the tire pressure rises. Furthermore, it was found that the higher the tire pressure, the worse the ride comfort.

Vision is said to account for 80% of the information acquired of the five human senses. The presentation of light is an effective way to convey visual information. A blinking presentation especially attracts attention. A low-vision person acquires peripheral information through residual vision. In this case, light effectively supports the travel of low-vision persons. A blinking light stimulates more than a continuous light. However, a blinking light is not sufficiently compatible with the surrounding environment. This research investigates the effectiveness of blinking lights under different illuminance.

The progressive aging of society has increased expectations for the spread of nursing care robots to support long-term care and welfare services. This research had the goal of developing a communication system as one of the elemental technologies of nursing care robots, along with a method that allows care robots to consider a user’s emotions. The estimation of emotions based on a user’s electroencephalogram and heartbeat has attracted attention. However, users may experience stress when wearing the sensors needed for such measurements. To prevent this system from causing stress in users, we had the goal of developing an estimation model for emotions based on the pulse, which is relatively easy to measure. Various autonomic nervous activity indices (pNN50, RMSSD, LF, HF, LF/HF) were adopted for the estimation model, and transfer functions were established. These indices were considered in time domain and frequency domain analyses of the heart rate variability. The pulse was measured while the user was watching a video and converted into an accelerated plethysmogram using second order differentiation. Then, the autonomic nervous activity indices were calculated. The transfer function from the input to output was identified using these autonomic nervous activity indices as inputs and the responses to a questionnaire that was administered after watching the video as outputs.

A novel gaze-based user interface (UI) is proposed for the remote control of robots and electric wheelchairs. A task-based experiment showed that this UI is more suitable for remote control than a conventional interface. The UI was applied to the control of a commercially available low-cost electric wheelchair. By using a 360° camera and an eye tracker that can be used outdoors, the visibility of obstacles and the usability of the gaze-driven electric wheelchair were greatly improved. The gaze-driven electric wheelchair exhibited good performance in a task-based evaluation experiment.

One of the indicators that affects the comfort of a wheelchair is tire pressure. However, since the English valve which is most frequently used for a wheelchair has a structure that it can not put out air even if it can be arbitrarily inserted, how much the tire pressure of the wheelchair will affect the vibration Has not been revealed yet. The purpose of this study was to measure the vibration generated in the wheelchair due to the difference in tire pressure using the pneumatic pressure indicator dedicated to the English valve and the influence of the road surface and vibration of the manual attendant-controlled wheelchairs.

A Micro Electro-Mechanical System (MEMS) is a micro-sized mechatronic device based on semiconductor integrated-circuit manufacturing technology. MEMS technology is inherently a very powerful tool for researchers to manipulate and measure the microscopic biological components of biological tissues since their basic constituent units, cells and intracellular microstructures, are also micron or even submicron in size. MEMS technology applied to medicine and life sciences is called Bio-MEMS. Many Bio-MEMS devices and technologies have been developed in recent years, including microfluidic devices for cell culture, manipulation, and measurement, as well as lab-on-a-chip devices for chemical reactions and analyses on MEMS devices. This special issue consists of 13 papers: 1 review article, 1 letter, and 11 research papers. These papers include studies on mechanical stress on cells using MEMS devices, the control of cell functions through microfabrication techniques, cell measurement and in vivo microenvironment simulation using microfluidic devices, and basic research on wearable devices and self-assembling microstructures using MEMS technologies. The editorial committee members are confident that this special issue will make a significant contribution to the further development of Bio-MEMS. We sincerely appreciate the excellent contributions of the authors and the time and effort of the reviewers. We would also like to thank the editorial board of the Journal of Robotics and Mechatronics for their support of this special issue.

In today’s super-aging society, it is essential to maintain and improve the quality of life of the elderly and to counter the shortage of young workers. Such problems are becoming evident in several areas, not just in the manufacturing sector but also in the fields of transport/mobility and healthcare/welfare. In these fields, there is an abundance of situations that cannot be solved simply by replacing human workers with robots. In the manufacturing sector, for instance, the transmission of skills and knowledge is threatened as the members of the baby boomer generation, who have both knowledge and experience, have reached retirement age at a time when the younger population is declining. Another example is the provision of care with human warmth at nursing sites. As we evolve toward Society 5.0, which is represented by a digital transformation and which encompasses elements such as digital twins, it will be critical to pioneer robotic technologies that allow robots to work with humans to achieve a prosperous coexistence and create an affluent society. For this special issue, which features humancentric robotic systems coexisting and working together with humans, we invited researchers to submit papers covering a wide range of topics, including element technologies as well as operating and evaluation methods. This special issue on Humancentric Robotic Technology and its Applications for Coexistence with Humans includes two review papers, 29 regular papers, and two development reports that cover the following topics. • Research on rehabilitation equipment and training systems • Research on power assist and support actuators • Research on human-robot interaction systems • Research on motor characteristics and the musculoskeletal system • Research on the utilization and development of vital signs and sensors • Research on IoT technology and smart technologies We thank all authors and reviewers of the papers, as well as the Editorial Board of the Journal of Robotics and Mechatronics, for their help with this special issue.

Along with the assisted wheelchair, a self-propelled wheelchair is also used as an assisted wheelchair by a caregiver; however, the problem with wheelchairs is that the vibration during driving causes motion sickness, discomfort, and annoyance for users. The tire pressure of the wheelchair is considered an influencing factor affecting the ride quality of the wheelchair; however, the extent of the effects of tire pressure on the wheelchair remains unknown. Therefore, this study aimed to evaluate the factors influencing the tire pressure changes of the self-propelled wheelchair on the vibration using the tire pressure indicator. Furthermore, this experiment aimed to improve data reliability by manufacturing a device that pushes out a self-propelled wheelchair using an electric wheelchair to run the self-propelled wheelchair at a constant speed. A dummy heavy object was placed on the seat of the self-propelled wheelchair of the vibration measuring device manufactured in this experiment, and a triaxial accelerometer was mounted on it. Moreover, an electric wheelchair is used to drive the uneven road surface at a constant speed at regular intervals. The tire pressure display manufactured in this study was attached to both sides of the rear wheel of the self-propelled wheelchair, and a dummy weight of 50 kg was placed on the seat. Then, acceleration in the vertical direction is measured by a three-axis accelerometer mounted on a heavy object. In this study, the effects of tire pressure on ride quality were considered by looking at the correlation between ride quality by sensory evaluation and vibration analysis.

Approximately 80% of people with visual impairment have residual visual acuity. As such, the authors have developed a light-emitting block that is placed at the entrance of a pedestrian crossing to support those with visual impairment at night. A blinking light has generally been used for selectively distinguishing the target light source from the surrounding light source. However, this type of blinking (i.e., simple blinking) can be stimulating, making it suitable for night-time road construction sites but not for normal road environments. Therefore, the authors have focused on phase-in-phase-out blinking, which gradually brightens and darkens with each blink, thereby suppressing stimulation. This blinking pattern has been considered to reduce visibility just by suppressing the stimulus. However, focusing on the human sensory characteristics of adaptation and arousal, evidence has suggested the existence of a blinking cycle and pattern that awakens while suppressing stimuli.Therefore, the current study sought to identify blinking cycles and patterns that awaken while suppressing light stimulation. The intensity of light stimulation is evaluated via sensory evaluation. Based on the intensity of the stimulus and degree of arousal, we searched for the optimum blinking cycle that promotes adaptation, a human sensory characteristic, and arousal from the blinking pattern and verified the visibility of the obtained blinking pattern in individuals with visual impairment and healthy subjects. Previously, we had conducted an experiment in a region with a period of 4–7 s. This time, however, we conducted an experiment in a region with a period of 2– 3.5 s. This study verified that phase-in-phase-out blinking is effective for pedestrians while considering the surroundings.The purpose of this experiment was to determine the optimal blinking method for supporting people with visual impairment. Although it is desirable to provide support for people with visual impairment by promoting stronger visibility, introducing flashing blinks in public facilities may cause discomfort to healthy people around them. For instance, introducing a blinking light of approximately 1 Hz, which has a fast blinking cycle, at the entrance of a pedestrian crossing can enter the driver's field of vision, causing discomfort and making the driver look away, thereby leading to accidents. The ideal blinking light for support is that which limits arousal to some extent and does not induce discomfort. Based on the blinking patterns used in this experiment under the aforementioned condition, we believe that a fade-in-fade-out type pattern with a blinking cycle of 2 s and a lighting time of 2 and 3 s would be effective. The reason for this is that the intensity of the stimulus obtained from the sensory evaluation of healthy subject and those with visual impairment is suppressed, visibility is secured to some extent, and the blinking method does not induce discomfort. Thus, the fade-in-fade-out blinking method can be expected to suppress discomfort.

We are developing devices that apply a linear equation mechanism in which three joints are coupled with a differential mechanism through continuously variable transmissions (CVTs). One of these devices is an adjustable lift cart in which three joints are connected to two axes of the left and right wheels of the cart and to one axis that lifts the cart's loading platform. The adjustable lift cart can lift the loading platform up or down to a desired height while it is moved horizontally by human power. The cart's loading platform moves forward and upward (or downward) as if it is on a virtual guiding surface. Until now, the virtual guiding surface generated by the linear equation mechanism has been a flat surface defined by a single normal vector. In this work, we show that not only flat but also curved surfaces can be generated by setting the normal vector as a function of the displacement or velocity of the cart.

Approximately 80% of the visually impaired are composed of individuals with low vision. As people with low vision have residual visual acuity, light guidance has been deemed effective. Thus, the authors have developed a light-emitting block that is placed at the entrance to a pedestrian crosswalk to support the visually impaired at night. Generally, blinking light is accepted as a method to selectively distinguish a target light source from an ambient light source. However, on/off blinking lights, such as those used at a road construction site at night, are unsuitable for normal road environments. Therefore, the authors focused on fade-in/fade-out blinking, which gradually brightened and darkened, suppressing inappropriate visual stimulation. Therefore, this study aimed to search for blinking cycles and patterns that ensured visibility while suppressing light stimulation and reducing discomfort.

Expectations for care robots are increasing owing to the aging of society with a declining birthrate and shortage of manpower in the care field. However, the use of care robots has not yet become widespread. In this study, we explained the artificial intelligence (AI) technology to care staff and conducted a questionnaire survey to understand their needs. Then, we began to develop a care robot that was required in the care field. In this paper, we report an overview and the current status of the study.

Japan’s population is aging at a speed unprecedented in the world, and its shortage of caregivers has become a major issue. At the same time, the Internet of Things (IoT) is expected to create unprecedented new value by connecting all people and things, allowing them to share various kinds of knowledge and information. In addition, as artificial intelligence (AI) and big data are undergoing a transformation that is changing the value of human labor, robots incorporating these innovative technologies are expected to solve the problems of the aging society. On the other hand, in the field of nursing care, the relationship between the caregiver and the care-receiver is basically a person-to-person connection. There is a question of how people and technology can coexist and produce new creations in such fields. This special issue on Nursing Robots and Support Systems for Welfare Sites includes one review paper and 23 other interesting papers that cover the following topics: ı Research on independence support and systems to watch over the elderly. ı Research on support systems for diet, recreation, medication, etc. for people with dementia. ı Research on control and sensor systems for vital signs and excretion. ı Research on rehabilitation equipment for the physically handicapped. ı Research on assistive technologies for mobility support. ı Research on upper and lower limb power assistance devices and robots. We thank all authors and reviewers of the papers as well as the Editorial Board of the Journal of Robotics and Mechatronics for their help with this special issue.

One of the indicators that affects the comfort of a wheelchair is tire pressure. The purpose of this study was to measure the vibration generated in the wheelchair due to the difference in tire pressure using the pneumatic pressure indicator dedicated to the English valve and the influence of the road surface and vibration of the manually self-propelled wheelchairs.

Wheelchairs are very convenient for the elderly who cannot walk, but the vibration generated during use can cause discomfort to the rider and can have consequences, such as convulsions. Tire pressure is one of the factors that affects the ride quality of wheelchairs. Wheelchairs are often used indoors, in which case they travel on hard flooring or on carpet. The purpose of this study was to investigate how the road surface on which the wheelchair travels and the tire pressure of the wheelchair contribute to the vibration experienced by the rider, and the influence of the vibration on the human body. We used an air pressure indicator that measured an English valve. The vibration generated was measured and the sensory perception of comfort and security were evaluated on hard and soft surfaces at different tire pressures. The vibration test revealed that vibration tends to increase as tire pressure increases and that ride comfort decreases as tire pressure increases.

Brain machine/computer interface (BMI/BCI) technologies are based on analyzing brain activity to control machines and support the communication of commands and messages. To sense brain activities, a functional NIRS and electroencephalogram (EEG) that has been developed for that purpose is often employed. Analysis techniques and algorithms for the NIRS and EEG signals have also been created, and human support systems in the form of BMI/BCI applications have been developed. In the field of rehabilitation, BMI/BCI is used to control environment control systems and electric wheelchairs. In medicine, BMI/BCI is used to assist in communications for patient support. In industry, BMI/BCI is used to analyze sensibility and develop novel games. This special issue on Brain Machine/Computer Interface and its Application includes six interesting papers that cover the following topics: an EEG analysis method for human-wants detection, cognitive function using EEG analysis, auditory P300 detection, a wheelchair control BCI using SSVEP, a drone control BMI based on SSVEP that uses deep learning, and an improved CMAC model. We thank all authors and reviewers of the papers and the Editorial Board of Journal of Robotics and Mechatronics for its help with this special issue.

Neural networks (NNs) are effective for the learning of nonlinear systems, and thus they achieve satisfactory results in various fields. However, they require significant amount of training data and learning time. Notably, the cerebellar model articulation controller (CMAC), which is modeled after the cerebellar neural transmission system, proposed by Albus can effectively reduce learning time, compared with NNs. The CMAC model is often used to learn nonlinear systems that have continuously changing outputs, i.e., regression problems. However, the structure of the CMAC model must be expanded to apply it to classification problems as well. Additionally, the CMAC model finds it difficult to simultaneously classify categories and estimate their proportional linear measure because designated learning algorithms are required for both regression and classification problems. Therefore, we aim to build a composite-type CMAC model that combines classification and regression algorithms to simultaneously classify categories and estimate their proportional linear measures.