Higher harmonics are integer multiples of fundamental frequency. They have bad influence on various types of electric equipment. There are many studies of higher harmonics in both electrical and mechanical field. However, there are a few studies about control of higher harmonics.In this study, we investigate response of a cantilever beam excited by fundamental waveform with third harmonic frequency experimentally. The fundamental frequency equals to the second resonance frequency of the beam 40Hz, and the third harmonic frequency is 120Hz. Our experiments present that the control method of the waveform of the beam displacement at free end. Our control method changes the intensity and phase difference of third harmonic frequency of control signal.

In order to numerically simulate the formation of hologram appearing in the in-line holography method with high precision, improvement for FDTD (2,4) method was proposed. Examination about the effect of improvement showed that proposed improvement remarkably suppress the phase error of electro-magnetic wave to negligible level even in the case where large-scale calculation domain is ordered to treat multiple scattering problems, while the ordinal FDTD (2,4) method causes serious error in such cases. In addition, Conformal FDTD methods is combined with the above-mentioned FDTD (2,4) method with improvement in order to suppress the error associated with step-wise approximation of particle shape. At the next stage, examinations were carried out using the above-mentioned Conformal FDTD (2,4) method, about the influence of closeness between two particles on the location error of reconstructed image in the in-line holography method. Results of numerical simulation showed that reconstructed images of particles are deformed when the distance between two particles is shortened, and error appears in the evaluation of particle location. Location error is decreased with elongation of distance between two particles when they go away in the perpendicular direction to incident beam. On the other hand, contrary tendency partly appears when two particles go away in the parallel direction with incident beam. Additionally, it was considered that difference of plane of polarization.

A rational method of dimensional reduction is developed in order to analyze accurately a nonlinear vibration generated in a large-scale structure with locally strong nonlinearity, asymmetry and non-proportional damping. In the proposed method, the state variables of linear nodes are transformed into the modal coordinates by using the complex constrained modes that is obtained by fixing the nonlinear nodes, and a small number of modal coordinates that have a significant effect on the computational accuracy of the solution are selected and utilized in the analysis by combining them with the state variables of nonlinear nodes that are expressed in the physical coordinates. The remaining modes that have little effect on the computational accuracy are appropriately approximated and are eliminated from the system. From the reduced model constructed by these procedures, the steady state periodic solution and the stability, the transient solution and the quasi-periodic solution can be computed with a very high degree of computational accuracy and at a high computational speed. The effectiveness of the proposed method is verified by the computational results obtained for a straight-line beam structure modeled by FEM acting non-proportional damping with nonlinear supports.

In a rolling stock, acceleration force is transmitting to a car body from bogie by a single towing link which consists of rubber material for shock absorbing. Visual inspection and load test are carried out for the single towing link at regular maintenances. Recently, an alternative method is needed for the purpose of labor saving, because the maintenance requires heavy weight lifting and a lot of time. In this paper, impact tests were conducted for three types of towing link which had different backgrounds respectively. Then, we confirmed that an impact test was useful way to inspect the rubber conditions like the degradation changes or the presence of damage.

At present, approximately 60% of world's population lives in masonry structures. Some of these structures are found in developing countries experiencing frequent earthquakes. Strong earthquakes tend to collapse these brittle, “non-engineered” structures, causing great harm to humans when these are residential structures. The purpose of this study is to develop simple, low-cost sensor systems using piezoelectric films for structural health monitoring. We aim at applying the monitoring system to failure prediction system to prevent human suffering caused by earthquake-induced building collapses. As evaluation experiment of the sensors, we performed compression failure test of brick masonry specimens which were installed a sensor, and verified the availability of sensors from the test results. Furthermore, we simulated the destruction state of the specimen by finite element analysis. We verified the availability of the sensors by comparing finite element analysis results and the compression test results. Our novel sensors comprise a glass pipe or a metal holder with a glass pipe containing a piezoelectric film. Results of simulation under the same condition as actual test, cracks were visible on an analysis model of the specimen. For this reason, the consistency of the sensors is observed between the actual test using the sensors and the finite element analysis results, therefore, the availability of the sensors is shown.

The damage identification analysis based on filtering theory has a potentially effectiveness as a global monitoring both for identifying the damage locations and for estimating the extent of damage. In the computation process, the natural frequencies are utilized as observation data, and then the inverse analysis are performed recurrently to obtain the estimate values of system parameters. However, it is difficult to experimentally measure a large number of natural frequencies accurately. The purpose of this study is to develop a ranking approach to estimating structural damages. In this method, it requires only a few lower natural frequencies which can be measured experimentally. Although the location and extent of damages cannot be determined, the damage potential rankings are obtained as minimum required information to detect damage locations. In this paper, for the multi damage estimation problem in a simple straight pipe structure, the validity of the developed algorithm is confirmed experimentally.

In recent years a study to move large number of joints in the robot of multi-degree-of-freedom. There is the modifying momentum trajectory generation method as a method to generate a motion trajectory from momentum. Reduction of the base reaction force is confirmed by simulation, but excessive torque is generated near the singularity. This paper propose a method to apply the singularity-consistent approach to the modifying momentum trajectory generation method. The validity of the proposed method was confirmed by trajectory generation simulation from the singularity.

This paper proposes the novel power assist suit for wall climbing, based on Universal Vacuum Gripper, in short UVG. UVG is the vacuum pad with the deformable skirt based on the jamming transition of the granular materials. It's capable to adhere uneven surfaces made of stiff materials. In order to climb the wall, two functions are required to the assist suit; lifting up the wearer's body, and gripping the wall surface. In this work, we employ McKibben artificial muscle to lift up the body, and UVG to grip the surface. We evaluated the proposed suit to grip uneven surfaces, and lift up the human subject.

In this paper, the robustness of a muscular internal force based position control method for a musculoskeletal system against an external disturbance force is validated experimentally. Up to now, we have proposed a combined control method that is composed of a muscular internal force based feed-forward control with an external sensing information. It is able to realize a PTP position regulation stably. It, however, has not discussed the robustness of the proposed controller against an external disturbance force. In order to validate it experimentally, firstly we perform experiments that the end-point is regulated to the desired position, and then an external disturbance force is added to the end-point using the proposed controller and the traditional P controller. By comparing their experimental results, the robustness of the proposed method is demonstrated.

In this study, the trajectory of a mobile robot is controlled by using a method based on the time state control form. It is possible to adjust the control parameters of this robot based on linear control theory. The distance to obstacles is measured by using a laser range finder. When the robot approaches to obstacles, the proposed controller switches the traveling direction and the control gain of the rotating motion. In the experiments, the robot avoided the obstacles and reached the target position, traveling back and forth automatically. Futhermore, the switching position and control parameters were searched by using a genetic algorithm. The parameters found by genetic algorithm made it possible for the robot to reach the target position in a short time.

This research is aimed at the ordinary family type cleaning robot to carry on the transformation. There are still a lot of problems with the common household cleaning robot. The biggest problem is that it can't clean the narrow area. This research is trying to solve this problem.

An expansion mechanism with convex tapes has been developed for a compact mobile robot. Algorithm of continuous posture control is developed by using the data of an acceleration sensor on a top plate. A span of the support rib is considered. A basic experiment of the improved control method has been confirmed. Next, smoother expansion control will be developed and the expansion mechanism will be mounted on a mobile robot to verify the effectiveness.

Various types of power assist systems are desired in the fields of manufacturing, farming, welfare, etc. In the direct handling which applies force directly to a heavy object, operating force is usually detected by using a force sensor. However, the force sensor is deficient in that, for example, it is sensitive to noise. In this paper, the authors propose a direct-handling enabled power assist system for handling heavy objects in the vertical direction. The system converts the operating force into the angular displacement using a coil spring as a passive element, and detects the direction of the converted force by using a displacement sensor. Any system which coexists and operates with humans is required to ensure high safety. In view of this, the authors will verify the operability of the proposed system, and demonstrate that the system has higher safety in comparison with the systems using a force sensor.

This paper presents the design and implementation of a standing/sitting assist robot, helping elderly people support their balances in daily routines. Specifically, according to their standing and/or sitting behaviors, the height of the armrest in the assist robot is designed to be controlled. For this purpose, the location tracking model for the postural status of user's lower limbs when standing or sitting is proposed, to enable the robot to estimate and predict the knee locations. Based on the model, the proposed scheme can control the movement of the armrest corresponding to the user's behaviors. Details on the robot realization and its control scheme are explained, and its effectiveness is verified through experiments.

Many persons suffer from tremor in daily activities. Tremor suppression devises are expected to improve the quality of life for such persons. On the other hand, power-assist exoskeletons have been developed for many purposes up to the present. Some of them can be used to suppress the tremor motion. In this paper, an on-line tremor suppression method is proposed for the suppression of the essential tremor. In the proposed method, the tremor motion (involuntary motion) and the intended motion (voluntary motion) are separated by filters. Then, an artificial neural network which consists of sinusoidal activity functions is applied. The effectiveness of the proposed method was evaluated by performing the experiments.

Slips and falls during ordinary daily activities are a common cause of fractured bones and muscle injury. Several studies have analyzed the movements produced by artificially generated slip and fall stimulus, but few have investigated these stimuli. We analyzed lower-limb motion following a slip and fall stimulus produced using a pulled free-walking system consisting of a controllable split-belt treadmill, where a speed difference between the belts could be applied to produce a slipping motion.

Caging is a method to make an object inescapable from a closed region by rigid bodies such as robot hands. In this paper, we test achievement of 3D multifingered caging by exploring any regions completely closed by obstructions composed of robot bodies in six dimensional configuration space. Instead of mathematical description of the obstructions and the closed regions, voxelized configuration space and labeled connections of them are adopted for approximated exploration, to avoid huge computational costs. If there are any closed regions and the target object is present in one of them, caging constraint can seem to be achieved. As a result, our proposed exploration method successfully worked to examine achievement of caging in both 2D and 3D scenes. As for 3D caging, we proposed a method to test in six dimensional configuration space using uniformly-sampled quaternion for description of orientation of object. Finally, we showed a table of relationship between the number of posture and processing time.

Myoelectric prosthetic hands should be lighter in weight and maintainable, and able to exert large grip force to comfortably substitute the upper limb of amputees in daily life. This means it requires a lighter and simplified system whilst maintaining grip force. In this paper, we propose a five-fingered mechanical hand which each finger is comprised of three coupled four-bar mechanism. And three fingers of them is connected to a balance joint driven by a servo motor for adaptive grasping. We examined this mechanism's grip force and compliance performed by three small RC servo motors. The result shows that the hand can grasp several kinds of objects used in daily life weighing up to 2kg, in addition to being lightweight.

Caging-based grasping is a geometry-based method to grasp objects by robot hands with rigid links convered with soft skins. In this paper, we study 2D caging-based grasping, in which objects are held by caging-based grasping horizontally and by friction vertically. 2D caging-based grasping is easier to apply to pick-and-place of a class of objects than 3D caging-based grasping. Conditions of 2D caging-based grasping allow multiple grasping positions, and therefore we aim to decide a grasping position uniquely by optimization. We calculate optimal grasping positions of variously-shaped objects based on the margin of allowable finger positions. The calculated grasping positions are tested in pick-and-place experiments to validate our margin-based grasp synthesis.

It is important to eat some foods for a person. However, it is very difficult motion for people who have handicapped on their upper body. Therefore they need some supports around people. If robot brings meal to handicapped person's mouth, he will be able to eat something by himself. Current, robots have been developed to carry food to the mouth for meal support robot. It is not enough to support eating by autonomous robot. For example it is one of the eating tasks to wipe mouth after eating. Then, we propose the support system on the eating task. At first, it is to get the potion information of targets, mouth and a robot hand, by using KINECT v1. Next, the robot arm make the motion to wipe the mouth using the color and depth information and kinematics. In this paper, we show that switching control and the experiment result of wiping mouth by robot arm.

This paper proposes an optimum picking position for flexible pouched object using adhesion robotic hand. The bin picking problem for flexible and multiple stacked objects is a challenging one. A combination method of model based estimation of the objects and a stochastic planning based Bayes' estimation is proposed. The method is verified for bin picking of multiple deformable food pouches.

In the current agricultural and food industry, automation of various works by robots is very popular. Robots are required to grasp objects when automating the works that harvesting crops or selecting and packaging merchandises. So far mechanical hands or suction hands have been mainly used for grasping. However, they cannot grasp tender objects that are uneven in their size and shape without damage. SUNBIT Inc. succeeded in grasping Momen-Dofu by using their original control method of hand and passively deformable soft fingers which were proposed by Yamamoto et al. However, the hand cannot hold the object when it moves rapidly because the control method is not considered the dynamic influences. This paper proposes the control method of hand which makes holding the objects possible by considering the dynamic influences of the fingers and the object. To confirm the effect, the results of experiments applying the control method to the hand are shown.

This research aims at realizing a high altitude wind power generation system, we have proposed a kite-based tethered flying robot.In order to lift up heavy wind power generator and monitoring sensors with the robot, we have also proposed that the kite is lifted up first to acquire enough lifting power, and then, the wind power generator and monitoring sensors are lifted along the tether line later. In this paper, we report the improved wind power generation system by lifting up wind power generator using kite-based tethered flying robot with lifting mount.

This paper introduces practical design and hardware implementation issues of a sensor positioner composed of a pair of rotation joints for an unmanned aerial vehicle (UAV) like a drone. Through the proposed sensor positioner, we aim at enabling UAV to recognize the geometric surfaces of various objects by enlarging its field of view (FoV). For the purpose, an observation motion scheme based on the positioner is developed to enhance the object shape recognition capability. This paper provides a detailed presentation on 1) how to realize the sensor positioner and integrate it with a UAV robot and 2) how to enlarge its FoV in order to identify their geometric shapes. The observation functionality of the sensor positioner mounted under the robot and the effectiveness of the observation scheme are verified through extensive experiments.

Snake-like robot is a hyper-redundant mobile robot with an articulated body composed of serially-connected modules driven by actuators. Recently several hyper-redundant mobile robots have been developed in hope of the versatility brought from its simple form. Snake-like robots have been developed aiming at its applications to operations dangerous to man: the in-pipe inspection at chemical or nuclear energy plants and the rescue of victims under collapsed buildings by making use of its flexible and slender shape, and the mine detection by distributing its own weight on the ground and so on. In this paper, the novel mechanical design is proposed to enhance the mobility for various environments, and a prototype model is composed of serially-connected modules with suctions. The performance of the prototype model is described.

In this paper, a new type bipedal robot which has soft hemispheric feet is proposed. It is able to realize an efficient bipedal locomotion by utilizing a rolling motion of hemispheric feet effectively. Furthermore, each hemispheric foot has an active torsional joint. Thus it is able to move as a wheeled vehicle using an infinite rolling motion by the torsional joint. It, however, is difficult to keep its balance more proper than a humanoid robot having normal flat feet. Therefore, firstly a balance control and gait generation method which consider the rolling effect of feet are proposed. After that, several numerical simulations are conducted to demonstrate the effectiveness of the proposed balance control and gait generation method.

Recently, the autonomous robot is desired in spread versatile area to support the human society, This paper presents the first step of the authors plan to realize human-robot synchro- nized walking. Walk control of quasi- passive four-legged robot is carried out with phase oscillator. The walk pitch of quadruped robot is decided with oscillating cycle of neural oscillator. Vision subsystem extracts man's walk pitch by tracking man's heel. The extracted walk pitch data is sent to phase oscillator. Phase oscillator is entrained by the extracted pitch.

This paper presents the service robot system based on informationally structured environment named ROS-TMS that supports a robot to provide services to human. The development of the system was started in 2005 in the project named Robot Town Project, and recently we launched a new version named ROS-TMS4.0, which enables to utilize the high scalability and a plenty of resources of ROS. In this paper, we introduce the newly implemented extensions in ROS-TMS4.0 and the service provide experiments using the proposed system.

Recently, there has been a great demand for operating robots at disaster sites to prevent human damage. Many rescue robots acted and gained various achievements in hazardous condition during the Great East Japan Earthquake. However, owing to the drawback of remote robots that become uncontrollable when wired or wireless communication is ceased, their working area and condition have been limited. To solve the problem, the remote robots must determine their action and perform their work autonomously. Generally, an autonomous mobile robot estimates a self-location via GPS, however, the effective area is limited when overhead obstacles, such as large buildings or trees, are spotted. In this paper, we propose a self-location estimation method using radio wave makers and a directional reception antenna. In this method, a remote robot with the directional reception antenna measures the radio wave arrival angles by catching radio wave emitted by the makers located at known points, thus the robot position is able to be estimated by calculation. We conducted an experiment and investigated the accuracy of our method.

A lot of crawler mechanism is used for a mobile robot such as the anti-disaster robot. However, there are few candidates of the camera mounting location of the robot. Our research purpose is camera system construction for crawler mechanism by mounted cameras inside the crawler. Because the camera images are shredded through crawler shoes gap, the images must be combined for remote control.We have proposed some complement shredded image patching methods by using two camera's image, past image using and mechanical information. This paper discusses the methods for image complement for tele-operation.

The sand erosion damage has occurred on the blade of wind power generation of the land. In the case of the blade of the offshore wind power generation, the rain erosion damage supposed to be occurred. In many cases, blades of wind power generation are made of GFRP (Glass Fiber Reinforced Plastics). In this study, we made a rain erosion tester, and erosion experiments were performed on GFRP. Considering the actual environment, experiments were also performed by the irradiation of ultraviolet. Moreover, the rain erosion behavior was discussed by the surface observation of the test pieces. As a result, it was found that there are differences with the erosion rate by the effect of ultraviolet.

The stress intensity factor for branched cracks formed in a PMMA plate under the influence of a static load was investigated using caustics method. Branched cracks with various shapes whose lengths were from 1 to 10 mm, were produced by applying a static load along different directions. The stress intensity factor for the cracks was experimentally evaluated, and the results proved that the caustic shadow pattern was mixed mode and that the stress intensity factor was independent of crack length under static loading conditions.

The outdoor structures such as the infrastructures are indispensable to human life. Periodical of the inspection is necessary to prevent those failures. However, those numbers are enormous. Therefore, the adjustment of the inspection interval is necessary by a probability of failure evaluation. Since the qualitative visual inspection is mainly used as the inspection method for the infrastructure, quantitative evaluation of probability of failure is difficult. Then, in this research, quantitative evaluation method of probability of failure from quantitative inspection result using Bayesian theorem is proposed.

A flow channel instrument as a structurally simple and easy-to-use viscometer which is used for evaluation of the viscosity of liquid foods was operationally modified with an opening-variable gate in the channel path functioning as a valve for flow control. In the modified instrument, Newtonian and non-Newtonian test liquids were employed for flow experiments. The former liquid was purely viscous and the latter liquids were both of elasticities higher and lower relative to viscosity. The related flows were examined to assess the effect of the gate on the flow in consideration of the process swallowing liquid foods. The functional channel instrument revealed that the flow behavior differed depending on the relative elasticity of the liquid.

A flow channel instrument as a structurally simple and easy-to-use viscometer which is used for evaluation of the viscosity of liquid foods was structurally modified with a circularly-cylindrical obstruction to the flow being fixed to the channel path. In the modified instrument, Newtonian and non-Newtonian test liquids were employed for flow experiments. The former liquid was purely viscous and the latter liquids were both of elasticities higher and lower relative to viscosity. The related flows were examined to assess the effect of the circular cylinder on the flow in consideration of the process swallowing liquid foods. The obstructed channel instrument revealed that the flow behavior differed depending on the relative elasticity of the liquid.

A variety of airplane in the functional surface is also different of the safety. Airplane than the safety of the principle is impossible to stop the operation to be landing and take off once. This study was discussed crisis avoidance of aircraft trim from the safety point of view.

The case flammable gas has been compressed in some industrial products or in some manufacturing processes is on the increase. However, unexpected troubles such as an explosion accident could be held if oxidizer was accidentally entrained and mixed under high pressure condition. We have been studied the ignition and the building up to explosion of flammable gas in the high pressure vessel with consideration that risk assessment and the prevention are important. In that study, a safe and convenient technique to ignite gas in high pressure with a fuse explosion is required. The device that can explodes the fuse metal in high pressure gas successively was proposed and the performance was observed. Here metal balls were adopted as the fuse for the benefit of the recycle use of them and the exchangeability. Preliminary test results showed the almost same flashing performance with that of a exhaustible copper wire used to use so far. And the copper ball also performed as the ignitor of butane gas mixture. It is concluded that we might get an convenient and safe ignitor.

Captive balloon is sometimes used for weather observation. But at the time of strong wind, the stability of the balloon is reduced, and various risks of balloon (disconnection, collision of buildings, fall of measuring equipment) are increased. Therefore, we aim to develop of safe captive balloon against the wind force. In order to that, we perform four of change. Firstly, we provide an angle of attack to the balloon. Secondly, we provide a tail and introduce ACS (Attack Angle Control) system. Thirdly, the way to keep the balloon is changed from Kapton to net. Finally, the introduction of the tension control device. The result of the change, stability and safety of the balloon improves.

At the time of the Great East Japan Earthquake, many socio-technical systems experienced significant damages from the earthquake and tsunami far beyond the preparedness for disasters. Therefore, necessity of Business Continuity Plan (BCP) has been recognized irrespective of domains. Case studies of various on-site responses related to this disaster were analyzed to extract lessons from BCP that is common to various systems. Specifically, in reference to the concept of Resilience Engineering that is focused for enhancing resilience of organizations (i.e. resilience and flexibility) in recent years, analysis was conducted with attention to the cases in which the concerned systems could restore or ensured the safety from disturbance. Lessons useful for disaster prevention and mitigation have been extracted successfully from activities conducted for preparing and responding to the earthquake-driven disturbances.

In recent years, hydrogen fueling stations are being constructed to expand the hydrogen society. Risk assessment is required for safer hydrogen fueling stations. There are several types of hydrogen fueling stations, such as on-site type stations and off-site type stations. The target of risk assessment in this study is the on-site hydrogen station using an organic chemical hydride method. The purpose of this study is to reveal unique serious incident scenarios in the station and propose new safety measures. As a result, a serious incident scenario that a rupture of hydrogen tank may occur due to pool-fire at an organic hydride system was revealed. For preventing the scenario, hydrogen in storage tank must be released quickly and safety into atmosphere from a vent system. We verified the safety of existing vent systems, and suggested new vent systems using physical modeling software (SimulationX) to reduce the risk of the serious incident scenario.

This paper presents the analysis method for accidents caused by human error. Recently, accidents caused by human error have occurred in a variety of fields such as nuclear power, chemical, aviation, and maritime. However, the analysis method for these accidents has not been established yet. On the other hand, PRA (Probabilistic Risk Assessment) is a technique for evaluating the safety of nuclear power plants. In the PRA, HRA (Human Reliability Analysis) is used to quantitatively evaluate the human error. The purpose of this paper is to present the accident analysis technique that incorporate the procedure of the PRA. The proposed method is three steps (1. Identification of an accident scenario, 2. Quantitative evaluation, 3. Risk assessment). The first step is carried out the identification of an accident scenario with top-down and bottom-up analysis method. The second step is a quantitative evaluation using the THERP. The third step is to extracting the accident factor using importance measures. Moreover, step 1 of the proposed method was applied to the titanic accident.

It would result in the application of the stop safety production line as well as discuss the " Stop risk", the risk is, on what kind of effect on the production line, be considered from the side of safety.