We conducted many research and development activities on functional fluid mechatronics, rehabilitation systems, and servo drive systems. In this review, studies on the development of magnetorheological fluid devices, electrorheological effects of liquid crystalline polymers on one-sided pattern electrodes, and vibration control using control theory and liquid crystalline polymer are introduced. In addition, applications of rehabilitation systems for upper and lower extremities employing functional fluids for individuals suffering from stroke, cerebellar ataxia, and Guillain-Barre syndrome are also introduced.

In robotics, a walking through motion is complex because of the presence of multipoint contact objects in the working environment of a robot. To simplify the walking through motion of a robot, a virtual impedance field is implemented to the contact points of the robot and an object so that the robot avoids the object passively. The traveling direction of the robot is altered by a virtual repulsive force obtained from the position of the estimated obstacle and the virtual impedance field. The resulting action depends on the parameter of virtual impedance coefficients. Because a combination of parameters includes many things, reinforcement learning is employed to obtain an optimal motion. The optimization of the multipoint contact walking through motion of a robot is finally achieved by evaluating the walking motion while encountering complex obstacles in a dynamic simulator. The motion is implemented on a hexapod robot, and the results demonstrate the effectiveness of the proposed method.

In recent years, global navigation satellite systems (GNSSs) have been widely used in intelligent transport systems (ITSs), and many countries have been rapidly improving the infrastructure of their satellite positioning systems. However, there is a serious problem involving the use of kinematic GNSS positioning in urban environments, which stems from significant positioning errors introduced by non-line-of-sight (NLOS) satellites blocked by obstacles. Therefore, we propose the method for positioning based on NLOS satellites detection using a fish-eye camera. In general, it is difficult to robustly extract an obstacle region from the fish-eye image because the image is affected by cloud cover, illumination conditions, and weather conditions. We extract the obstacle region from the image by tracking image feature points in sequential images. Because the obstacle region on the image moves larger than the sky region, the obstacle region can be determined by performing image segmentation and by using feature point tracking techniques. Finally, NLOS satellites can be identified using the obstacle region on the image. The evaluation results confirm the GNSS positioning accuracy without the NLOS satellites was improved compared with using all observed satellites, and confirm the effectiveness of the proposed technique and the feasibility of implementing its highly accurate positioning capabilities in urban environments.

We discuss novel approaches to the control of seaweed tangle formations in stirrer cultivation. Cultivating seaweed is one important way to avoid such formation. Because defining such formation is difficult based on human recognition alone, there is currently no quantitative evaluation criterion for formation. We develop physical simulation for analyzing formations in a water flow field and model three factors – physical, geometric and time – for characterizing formations. Our criterion is that formations are created by using these factors as input to a nonlinear support vector machine. To show the effectiveness of our simulation and criteria, we confirm the control effects of the water flow in simulation and the real world. Results show that our simulation model is useful for avoiding such formation in the real world.

Due to the complexity of designing mechatronic systems, providers of these systems need to precisely evaluate their products, design processes and projects all along the design phase and beyond. We propose a metrics generation process and then define related specifications to develop an evaluation tool to build customized metrics for the mechatronic industry with respect to its specific process and expectations. The proposed process has been experimented on the modularity measure of two generations of vacuum cleaner robots.

Reduction of burden of life support services has been studied for future ultra-aging society. However, highly advanced systems of the life support services often cause low accessibility. If the accessibility were low, service users would have difficulty in forecasting the system behavior and feel uneasy. In this paper, a cloud/crowd sensing system is proposed. Triggered by a monitoring result from sensors used in a life support service system, a character agent of the proposed system gives users dialogues and acquires information about their subjective views. A prototype of the cloud/crowd sensing system is described and evaluated in the paper. Anxiety of the users due to low accessibility could be removed by applying the proposed sensing system to the life support system.

This study aims to investigate the behavior of a person who teaches a robot, and the behavior required for the robot to learn from such a person. A robot used for education needs to have a pedagogical relationship, namely, to understand the roles of teacher and learner, and recognize user behavior. In order for a robot to establish a pedagogical relationship with people, it has to understand the characteristic behavior of the person teaching it. Moreover, the robot needs to demonstrate to its “teacher” the characteristic behavior learned from this person. For this purpose, we observe and analyze through case studies the characteristic behavior of a human teacher and the effectiveness of the behavior designed for the robot. The results of the observation and analysis of a situation where a person teaches a robot a game on a tablet device show that, as the robot attempted through trial-and-error to perform the actions learned from the human teacher, the latter became more careful when teaching, and attempted to verify what the robot expressed to show its human teacher how much it understood.

The seat is an important interface between many types of machines and their users, able-bodied and disabled users alike. In this work, new seating system with adjustable sheets and body surface measurement is developed to improve the sitting postures and pressure distributions for patients with deformed backbones. A basic structure and adjustment method for the adjustable sheet is proposed. In addition, a way of using a Microsoft Kinect sensor to measure lengths is also developed and utilized to adjust the seating system. Evaluation tests are conducted on a healthy subject with different mock spinal deformations, and pressure distributions and postures of the subject are evaluated. The proposed method successfully averages pressure on the model and also adjusts his posture, simultaneously reducing pressure and increasing the contact area of the back.

We developed a virtual mooring buoy, called an autonomous buoy “ABA” for AUV, which navigates the sea using thrusters in 2014. Its purpose was to deploy autonomous underwater vehicles (AUVs) effectively in seafloor exploration. The ABA tracks and positions AUVs operating underwater using onboard acoustic positioning. We have deployed the ABA with two type AUVs in seafloor exploration. That conducted in February 2015 used the ABA with one AUV to survey and inventory mineral deposits, demonstrating the ABA’s capability of positioning an AUV navigating at 1,370–1,550 m depths at a standard deviation of 100 m or less and tracking it while maintaining a horizontal distance of 50 m or less. The ABA navigated the AUV within a position error of about 10 m.

In order to effectively investigate the distribution and amount of cobalt-rich manganese crust (CRC), an autonomous underwater vehicle BOSS-A equipped with visual and acoustic instruments were developed. BOSS-A observes the seafloor along preset waypoints at a constant speed and altitude. Detailed 3D seafloor images can be obtained from the visual instrument, which employs a sheet laser and a camera. In addition, an acoustic instrument measures the CRC thickness beneath BOSS-A. The CRC at Katayama seamount was surveyed in February. The results visually presented the state and distribution of the CRC in this site and clarified the amount of the CRC. In the future, the authors will develop a more reliable thickness measurement method.

This paper reports on a hydraulic dual arm robot developed as a rapid prototype for our hydraulic humanoid robot. The lightweight arms (4 kg each) have three joints driven by hydraulic linear servo actuators that can achieve higher torque and speed than human arms. A double four-bar linkage provides a wide range of motion (210°) to the shoulder joint. Each joint has torque controllability that is fully utilized for compliant whole-body motion control tasks. Based on singular perturbation analysis, we discuss how damping on the joints is actively modulated by hydraulic force feedback control, which is then utilized in our passivity-based task-space force control scheme. The effectiveness of the proposed system is experimentally evaluated through zero-force tracking gravity compensation with a 10 kg payload and object manipulation tasks.

A super-aging society must implement assistive technology and develop welfare equipment to enhance quality of life and enable senior citizens to operate independently in society. Devices such as walkers help support them in daily life. To aid senior citizens, we developed an electric cart to assist in walking.

We developed robovie-mR2, a desktop-sized communication robot, in which we incorporated a “Kawaii” design to create a familiar appearance because it is an important acceptance factor for both researchers and users. It can interact with people using multiple sensors, including a camera and microphones, expressive gestures, and an information display. We believe that robovie-mR2 will become a useful robot platform to advance the research of human-robot interaction. We also give examples of human-robot interaction research works that use robovie-mR2.