Belt systems with flat belts and rollers have been widely used in power transmission and article transport mechanisms. In belt systems, the relative tilt of adjacent rollers, called misalignment, causes the flat belt to move in the width direction (lateral belt motion, also referred to as tracking). However, the mechanism of the lateral belt motion has not been precisely clarified. Understanding the mechanism of the lateral belt motion not only helps achieve the stable operation of the belt system but also is useful for web transportation, such as films and thin sheets. The lateral belt motion in the open-end belt system with in-plane misalignment was investigated using an experimental setup. The experiment shows that, in the open-end belt system, the lateral belt motion stays in equilibrium where the stream of the belt becomes perpendicular to the axis of the downstream roller. We, herein, proposed a formulation that predicts a lateral belt motion in the belt system using a relative displacement of the belt between rollers, distance between adjacent rollers and parameters of the crown roller. We observed that, in an open-end belt system, the lateral belt motion is influenced by the relative displacement of the belt between the rollers rather than the misalignment angle between rollers.

Descent deceleration using parachutes is widely used in the aerospace field for scenarios such as weather observation using the descent of high-altitude balloons (radiosondes), re-entry during space sample return, and emergency drone landings. These parachutes are used to protect the aircraft and samples, and to avoid hazards with objects and humans on the ground. However, it is difficult to control the dropping point using parachutes, and there have been concerns regarding accidents caused by insufficient deceleration and adverse environmental effects caused by the disposal of unrecovered objects. To solve these problems, we propose a control method for the aerial recovery of low-speed descent objects using fixed-wing unmanned aerial vehicles (UAVs). Our previous work has shown a flight trajectory generation method that employs updating final-state control (UFSC) to handle variations in the terminal target states until the object is recovered. The frequency-shaped optimal regulator control that enables a return to steady-state flight has also been used after UFSC. However, owing to the characteristics of each control method, the problem of sudden fluctuations in the control input before and after recovery of a descending object remained, and performing aerial recovery using an actual aircraft was predicted to be difficult. In this study, this problem is avoided by switching from UFSC to adaptive nonstationary control (ANC), which has proposed in previous studies. ANC can be applied when the aircraft approaches a descending object, and it can be confirmed that the control input is smooth in a series of trajectory designs until return to steady-state flight.

The infrastructure built in the 1950s has deteriorated beyond its service life. However, replacing all infrastructure is very difficult and involves huge replacement costs. To address this problem, the optimization of maintenance operations and participation of various stakeholders in the maintenance is required; however, maintenance technology and social cognition in terms of infrastructure deterioration remains insufficient. In this study, we perform research and development simultaneously to improve maintenance technology and social cognition. However, technological issues exist, such as lack of high-reliability diagnoses and optimized scheduling of maintenance, and optimized repair methods. In particular, this study focuses on high-reliability diagnosis. Next, communication of information between stakeholders and infrastructure is required to improve social cognition in terms of infrastructure deterioration. Particularly, in this study, the infrastructure with communication function between the residents and infrastructure is referred to as “future intelligent infrastructure.” We prototype a vibration-sensing-actuation device for a future intelligent infrastructure. In particular, we focus on the detection of the water main deterioration and estimation of the ground soil internal state. Then, the operation of the minimum valuable function is verified. The concept and fundamental functions of the vibration-sensing-actuation device are proposed. Moreover, a prototype device that functionally limits the active and dynamic sensing and simplifies autonomous discrimination is implemented for deterioration detection of the water main. Consequently, the fundamental operation of pipe-thinning detection is confirmed. Furthermore, an application for ground soil internal state estimation was considered. Consequently, the fundamental operation of detecting change in soil stiffness was confirmed.

A long flexible material called the web is converted into the final product through various processes such as printing, drying, coating, and laminating using a web handling system. The web is transported from an unwind roller to a rewind roller through some guide and drive rollers in the system. The servo motors control the rollers to regulate their rotation velocity or torque in the system, where web tension and transportation velocity controls play an important role in achieving the high quality of the web product. However, unacceptable variations, such as motor torque pulsation, roller misalignment, and roller eccentricity, cause tension/velocity control performance deterioration. These act on the tension/velocity control system as periodic ripple disturbances. This paper presents a control approach to regulate the web tension and transportation velocity at constant values in the web handling system. An iterative learning control system is designed to identify and suppress periodic ripple disturbances because these disturbances are repeated periodically during web transportation. The learning controller introduces a filter to stabilize the learning process. Furthermore, it is implemented as a zero-phase lowpass filter to improve the phase delay. The effectiveness of the proposed approach has been verified by conducting the experiment using a laboratory prototype of a web handling system.

This paper presents the design of a new portable ophthalmic device, the so-called 3-in-1 device, that allows patients to self-examine their eyes. The device combines the three most essential ophthalmic examinations: slit lamp biomicroscopy to examine the anterior segment of the eye, visual acuity measurement to determine the quality of vision, and non-contact tonometry to assess the intraocular pressure of the eye. The aim of the device is to enable the patient to perform these standard examinations in the comfort of his home and to send the results via the internet to the ophthalmologist for further evaluation. Within the scope of this work, the first prototype of the 3-in-1 device was designed and manufactured. The slit lamp examination procedure can be recorded by a video camera and the footage can be used by an ophthalmologist to check for abnormalities in the anterior chamber of the eye. The visual acuity screener has been designed to be performed under the same conditions as a conventional visual acuity examination by an ophthalmologist. For this function an optical lens system was developed which projects the optotypes to a test distance of 6m. The non-contact tonometer evaluates the degree of deformation of the patient's cornea using machine learning algorithms to draw conclusions about the intraocular pressure. Ultimately, the goal of the device is to improve accessibility to ophthalmic care and the frequency with which examinations are performed in order to detect eye diseases and abnormalities earlier.

In this paper, we propose a fabrication method of a high temperature-resistant ultrasonic transducer for non-destructive tests. In typical pipe non-destructive wall thickness measurements, couplant material and backing material which do not have heat resistance are necessary. Therefore, there are restrictions for the practical online pipe thickness monitoring in chemical and power plants. To avoid a limitation of these non-heat-resistant material, we propose a couplant-less transducer fabrication method by attaching a piezoelectric film directly on the tested object with the spray coating method. Our method is based on the sol-gel spray technique to fabricate a piezoelectric ceramic film. With the sensor fabricated with this method, we measured the wall thickness under high temperature (100, 200, 300, 400, 500, 600°C) conditions. From the results of the high-temperature experiment, it was found that the sensitivity decrease due to temperature rise was limited to 3dB and the difference of frequency response was also limited to 2 MHz at the second peak frequency at the maximum. According to the results, the performance deterioration due to high temperature was within an acceptable range. Additionally, the wall thickness could be calculated from reflected pulse waves. We concluded that sufficient availability of the piezoelectric film under high temperature were confirmed. This paper describes the effectiveness of piezoelectric film attached directly on the tested object.

The ultrasonic scalpel used in the operation can perform coagulation hemostasis and tissue incision in the affected area. For coagulation, thermal denaturation must be completed before incision. Improvement of coagulation performance is required to shorten the operation time. The ultrasonic scalpels used were opposite-phase vibration modes with scissors like ultrasonic vibration modes proposed by our research group. Since the opposite-phase vibration vibrates in a direction vertical to an axis in addition to the longitudinal vibration of a normal ultrasonic scalpel, it is expected to improve coagulation performance due to heat generation by rubbing while pressing. In this research, a method for evaluating the coagulation performance of blood vessels that had been coagulated and incised with an ultrasonic scalpel was investigated. As a result, stress-strain curve results were obtained by using the experimental methods examined, and the strength of coagulation could be evaluated. In addition, characteristics of scalpel were evaluated by comparison of coagulation performance under different incision conditions.

This paper proposes a mobile robot navigation method based on augmented reality technique using not only AR markers’ patterns but their configurations. Mobile robot requires self-location to navigate toward destination. The authors propose a navigation system for wheelchairs that uses position and orientation of AR markers as well as information connoted in the AR marker patterns. AR technology is applied to estimate relative location of robot. The system consists of three elements: AR markers, a web camera, and a motor-driven wheelchair, WHILL Model CR. When the camera on the wheelchair recognizes an AR marker, it creates an action command according to both ID of the recognized AR pattern and arrangement of the AR marker. Identified position and posture of the AR markers are used to calculate the complement rotation angle to adjust the wheelchair to the planned route. The authors have designed the techniques to plan a path for a motorized nonholonomic wheelchair to enter a narrow corridor where nonholonomic robots cannot easily drive only by turning or circular routing. The techniques calculate the radius of the arc trajectory to enter a narrow corridor based on the recognized AR marker position and posture information. Experiments are conducted to guide a robot with a width of 0.55[m] by AR markers to enter a corridor with a width of 0.7[m]. The results confirm the effectiveness of our proposal because the error of the final arrival point is 5.7[mm] from the ideal position.

Cantilever vibration in an optical lever AFM is theoretically analyzed considering the effect of surface force and ambient fluid. The surface force between the tip and the sample is modeled using a cantilever with a spring and damping added to the tip, and the effect of ambient fluid on the cantilever vibration is analyzed using the bead model. The amplitude ratios of the forced vibration were derived by solving the equation of motion. There are discrepancies between the amplitude ratio derived from bending vibration theory and that obtained through the optical lever method. The amplitude ratio from bending vibration theory reveals that the effect of surface force dominates primarily below the second resonant frequency. The tip-added spring affects the resonant frequency shift and amplitude ratio, while the tip-added damping mainly affects the amplitude ratio at the resonant frequency. In contrast, the amplitude ratio considering the optical lever method reveals that anti-resonance occurs when the tip-added spring constant is positive, which is not observed in bending vibration theory. The amplitude ratio of the cantilever is modified by introducing a correction factor. The correction factor decreases with excitation frequency except for the frequency where the anti-resonance occurs. The correction factor becomes small when the ambient fluid has high density and viscosity.

The objective of this paper is to develop a method for visualizing the onset of skin layer formation at the gas-liquid interface during the evaporation of a water-based pigment ink filled in a narrow space such as the nozzle of an inkjet printhead. We developed two methods to visualize the surface and depth-wise distributions of the diffusion coefficient near the edge of a glass capillary filled with aqueous colloidal solution by using measurements based on the dynamic light scattering method. One method generates laser speckles at the gas-liquid interface of the ink, which are analyzed to determine the temporal changes in the surface distribution of particle diffusion coefficients. Another method uses an optical coherence tomography method to acquire cross-sectional images of the ink in the depth-wise direction, and analyzes the speckles that appear on the images to determine the temporal change in the depth distribution of the particle diffusion coefficient. It was observed that, depending on the type of hardly volatile solvent in ink, there are cases where the diffusion coefficient changes while remaining spatially uniform, and other cases where the diffusion coefficient differs remarkably near the gas-liquid interface. Since the motion of particles in the ink can be visualized in three dimensions, although pseudo-lightly, it has been possible to detect signs of skin layer formation.

With its low birthrate, Japan currently faces an aging issue. As the senior population gradually increases, applying moderate daily exercise has been widely accepted as a key to ease the incidence of life-related diseases, such as cerebrovascular disease that leads to severe aftermath by causing unhealthy gait posture. An already productized active assistive device named RE-Gait^® uses a motor and pressure sensors to detect the force varying from forefoot to heel in walking, thereby aiding both plantarflexion and dorsiflexion for people who are unable to freely control their lower limbs. Corresponding torque output depending on individual physical conditions can be customized from physiotherapist’s site. By contrast, considering a larger torque production with short delay time and less weight, replacing the motor with springs is appropriate. Furthermore, given that the target user includes senior and able-bodied people who possess muscle functionalities, the proposed device reduces the amount of time spent on learning to maneuver the battery-powered type and allows them to walk freely with less concerns on adjusting parameters and battery level. Therefore, the full mechanical types appear to be appropriate. By implementing the ratchet–pawl combination, the necessary energy source used for driving the assistance can be obtained from the body weight. With the pair of mechanical pressure sensors that can store and release the body weight energy, assistance on the foot can be enhanced at each anticipated stage. Four sets of experiments, including Motion Capture to verify the ankle angle variation and electromyography (EMG) to muscle activities, are used to verify the effectiveness of the mechanical walking assistive device. Results show that the device effectively offers assistance to both plantarflexion and dorsiflexion. Comparison with and without attaching the device and trajectories from Motion Capture are all increased. Furthermore, compared with the percentage of maximum voluntary contraction (%MVC) for muscle acquired by EMG, the muscle activities clearly decline. The device effectively provide assistance to foot flexions.