In the super aged society, it is expected that from now on the physical burden to caregivers will certainly increase. Transferring care-receivers between wheelchairs and beds is one of the heaviest physical labor to caregivers. To reduce the burden of the caregivers, we introduce Robot Suit HAL, which supports and expands the physical capability of humans during the daily activities. Particularly, in this paper we develop the upper half body of the HAL to support the wearer's force at upper limbs. We built a mechanism which locks the backdrivability of the power units of the HAL to assist the movement of the wearer's upper limbs. Through the demonstration of a transferring-care task with the HAL, we confirmed that the physical load on the upper limbs of the wearer was decreased and thus the wearer's trunk inclination angle was reduced, which contributes alleviating the physical load on around the lumber spine of the caregivers as well.

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The lateral vibration of a cantilevered flexible pipe with a spring supported end mass, which is self-excited by an internal fluid flow, is examiend theoretically and experimentally. It is well known that the velocity of the internal flow is near the critical value, above which the flutter-type instability occurs in the lateral vibration of the pipe. First, the complex amplitude equations are derived from the basic equation of the lateral pipe vibrations. The amplitudes of lateral pipe vibrations may undergo either a supercritical pitchfork bifurcation or a subcritical pitchfork bifurcation, depending on the spring constant of the spring support. Furthermore the displacements of the pipe were measured by the image processing system, which was based on the images from two CCD cameras. The typical feature of the self-excited pipe vibration, as predicted by the theory, was confirmed qualitatively.

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High productivity is commonly required in manufacturing processes. For this purpose, we need to run machines at high speed. However, high-speed motion usually generates vibration in positioning and then makes the settling time long. For this reason, various control strategies have been proposed for high-speed motion and vibration suppression at the same time. In this paper, we deal with a mechanical transfer system with a loading beam, which is widely used in manufacturing processes. We represent the system as composed of three rigid parts, that is, a driving unit, a hand, and a work. The driving unit and the hand are connected by an elastic timing belt. The work is loaded on a flexible beam which is connected rigidly to the hand. When the driving unit moves the hand, the work is vibrated not only in the translational motion but also in the bending motion because of the flexibility of the beam. We apply the idea of jerk reduction control to the hand for vibration suppression of the work and shortening the settling time in positioning. We show the effectiveness of jerk reduction of the hand by numerical simulations for a finite element model.

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Vibration control of a main system, which is modelized by two-degree-of-freedom spring-mass system, with two autoparametric vibration absorbers has been experimented and simulated. Every autoparametric vibration absorber consists of a pendulum and a torsion spring around its support point. Such a vibration absorber has no restriction on its vibration direction. The autoparametric resonance takes place at the first natural frequency of the main system in the only pendulum corresponding to the first mode and at the second natural frequency in another pendulum corresponding to the second mode. Then the resonance vibration of the main system is controlled by the autoparametric resonance of the pendulums. A vibration system with multi-resonances can be easily controlled by the autoparametric vibration absorbers because each of the vibration absorbers does not have influence on the others mutually. The effect of the pendulum damping on the autoparametric resonance is investigated by simulation and it is found that an optimal value of the pendulum damping exists for the vibration control over the resonance.

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Effect of base shape on damping characteristics of rocking of rigid body is presented. We pay attention to the fact that free vibraion amplitude of rigid body decrease rapidly without dampers or damping materials. We consider rocking of rigid body is very attractive as a low cost dynamic vibration absorber. At first, damping characteristics of rocking of typical rigid body with flat base shape is discussed theoretically. Next, we propose new type rigid body which base shape is polygon in order to design damping characteristics of rigid body in wide range. Theoretical method to calculate damping characteristics of rigid body is derived. Experiment of free vibration of the rigid body is carried out and the calculated results of the proposed method agree well with the experimental results. By calculating damping ratio of proposed rigid body using derived equations, it can be seen polygon base shape is very useful to design damping characteristics of rigid body.

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W-DLC coatings with various concentrations were prepared by chemical vapour deposition and DC magnetron co-sputtering of a tungsten metal target. Temperature dependence and strain dependence of electrical resistance was measured. Strain was applied to the sample by four-point bending configuration. The electrical resistance increased or decreased as increase or decrease in strain applied and the gauge factor varied according to metal concentration. TCR (temperature coefficient of resistance) varied according to metal concentration. Transmission electron microscope was employed for structure analyses. It was clarified that the structure of W-DLC is granular one. Variation of the resistance under the strain can be explained by the change in distance between the adjacent clusters. W-DLC coating indicated a potential for strain sensor.

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Conventionally, induction heating (IH) cooking heaters use thermisistors to measure the temperature of a cooking vessel during operation; however, this is an indirect measurement and is dependent on the transfer of heat through the glass plate. To overcome this problem, some attempts have been made to identify the boiling of water though audible sound waves, but this approach can not be applied to Teflon^[○!R]-coated cooking vessels, while the use of infra-red sensors are expensive. In this paper, we propose a novel method for boiling detection, utilizing the ultrasonic vibrations generated by the induction heating process. As the temperature of the water increases towards the boiling point, the amplitude of the ultrasonic vibration of the cooking vessel continuously changes due to reflection from the generated steam bubbles. The boiling point can be quickly identified by continuously monitoring the change in amplitude. As a results of this work, detection of the boiling point can be performed within 30 seconds, which is faster than that of the conventional thermistor approach.

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A side branch silencer which is one of reactive type silencer is effective for the reduction of the sound with periodicity. It is often used to reduce the noise due to the pulsation pressure etc. This is especially effective for the noise with single frequency. However, an effective frequency range is comparatively narrow. Moreover, the silencer is obliged to be large for countermeasure of the low frequency sound. And, that might cause the problem of the installation space. Then, in order to develop the side branch silencer which is effective for the low frequency range, the side branch with the finite impedance at the end of it was made and examined. As a result, it was clarified that this side branch was useful for the low frequency noise

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In this study, a portable type HMS (Health Monitoring System) device for the blood glucose level measurement is newly developed. It has features 1) puncturing a blood vessel by using a minimally invasive micro-needle, 2) extracting and transferring human blood and 3) measuring blood glucose level. This miniature SMBG (Self-Monitoring of Blood Glucose) device employs a syringe reciprocal blood extraction system equipped with an electro-mechanical control unit for accurate and steady operations. The device consists of a disposable syringe unit, a non-disposable body unit, and a glucose enzyme sensor. The experimental results using our miniature SMBG device was confirmed to output more than 90% volumetric efficiency under the driving speed of the piston, 1.0mm/s. In this condition, the extraction flow rates for the inner diameters of the micro-needle 80, 100 and 115μm are 3.6, 3.9 and 3.9μl/s. Further, the blood sugar level was measured successfully by using the glucose enzyme sensor.

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There have been some studies of exoskeletal robots to support upper limb motion. However, it is difficult to support internal/external rotation, one of 3 DOF in the shoulder joint. This is because the internal/external rotation is performed by the activities of the rotator cuff, which consists of deep layer muscles. In other words, it is difficult to recognize the surface electromyogram (SEMG) signals, which are generated at muscles far from the skin. In this paper, our aim is to quantify the different characteristics in the SEMG between the surface layer and deep layer muscles and apply different characteristics to the discrimination of the external rotation under the experimental evaluation with twelve young subjects. Three kinds of parameters, such as Zero Crossing, MPF and coefficient of the approximate function, were selected to express the characteristic of high frequency component in the EMG signal. Specifically, the classification was shown to be 97% successful by applying two features to Support Vector Machine (SVM). Hence, it is almost possible to assume that either the deep or the surface muscle is active and discriminate the motions which their muscles involve.

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This paper presents the Workspace-creation manipulator, a multi-DOF brain spatula type manipulator for minimally invasive neurosurgery. We show the mechanical design of the manipulator and evaluation of its function. The manipulator design specification is decided in consideration of newly operative procedure by using micromanipulator system through a 20mm diameter cranial hole and operating room constraints. The tip of the manipulator is 2mm thickness, 7mm width, 110mm length and has 10-DOF serial link manipulator which is able to be inserted from small cranial hole and follow the brain shape. The Positioning manipulator has an active prismatic joint and 5 passive joints with tendon length compensation method. Tendon length compensation method is based on three techniques, using rolling contact, parallel linkage, and moving pulleys, and we confirm the effectiveness of the tendon length compensation method through tendon tension force measurement experiment. To evaluate the mechanical design effectiveness, we execute an in vivo experiment using pig brain. We are easily able to set the system because of its lightness and compactness, and we insers it between the dura mater and cerebrum smoothly, and workspace in the brain is secured. We think this result shows the availableness of the mechanical design of the manipulator.

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We have formulated a new optimal control model of the human three-joint arm system characterized by a hand-joint's freezing mechanism. The new model possesses a freezing mechanism in its hand joint and optimizes its evaluation function composed of three kinds of energy terms and torque-change term. The freezing mechanism is a feedback controller to simulate the muscle dynamics contracting agonists and antagonists together. The following results were clarified: (1) the new model does not reproduce reaching movement characteristics for the human three-joint arm system by minimizing the torque-change term; (2) the new model reproduces them regardless of target positions by minimizing the energy terms. These results suggest that the new model with a freezing mechanism in its hand joint can be effective as a general and plausible model of the human three-joint arm control system and that energy optimizaion can involve the trajectory planning of human three-joint arm's reaching movements.

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We have developed a rehabilitation system for upper limbs, "PLEMO-P3", which utilizes ER brakes as torque generators and is one of the passive haptic devices. To detect abnormalities of patients, we developed a new sensing device and installed it on the grip of the PLEMO-P3. In this paper, we compare several kinds of information from the sensor system (grasping force, reaction force against a working plane, range of a wrist) and traditional assessment of stroke (BRS, FMA and STEF). We establish effective assessment and training methods with PLEMO-P3 system. We could found effect of training and strong correlation between them. We suggest a training method with PLEMO system depending on the results of clinical assessment. It was shown to be able to confirm the correlation of reaction force for working plane and wrist joint range of motion, and to detect synergy movement only with the wrist joint range of motion sensor. This correlation has been understood that it will equip it only with the wrist joint range of motion sensor, in practical use machine (PLEMO-P4).

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This paper discusses the grasp planning for a multifingered hand attached at the tip of a humanoid robot's arm. Different from previous methods on grasp planning, we use the reculangular convex models for both the object and the hand grasping region. By using these models, we provide heuristic methods for determining both a grasping style and nominal position/orientation of the palm. With this method, we can easily obtain the nominal position/orientation of the palm. The final grasping posture can be obtained by testing the force closure just around the nominal position/orientation of the palm. We will show the effectiveness of the proposed method by using several numerical examples. Also, by using the four-fingered hand and the stereo vision system both equipped with the humanoid robot HRP-3P, we will perform the experiment of grasping an object.

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In this paper, we analyze human eyeball movement through their avatars, by using an embodied virtual communication system with a line-of-sight measurement device. On the basis of this analysis, we propose an eyeball movement model, which consists of an eyeball delay movement model and a gaze withdrawal model. Then, we develop an advanced communication system in which the proposed eyeball movement model is applied to speech-driven embodied entrainment characters called InterActors. The communication system generates the eyeball movement on the basis of model, and it generates the head and body entrained motions of InterActors by using the speech input alone. The effectiveness of the proposed eyeball movement model and the developed communication system is demonstrated by means of sensory evaluations in an avatar mediated communication system.

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This paper presents a path following feedback control law with a variable velocity for a new type of undulatory locomotor, a trident steering walker. The feedback control law previously presented by one of the authors guarantees the asymptotical stability of all the state variables of the locomotor by feedback control except its position along a path under the precondition that its moving velocity along the path controlled by feedforward is non-zero constant. In order to make smooth start and stop, it is necessary for the locomotor to vary its moving velocity continuously. Especially, the slippage between the passive wheels of the locomotor and the floor causes its moving velocity along the path to be reduced so that it cannot move at the desired moving velocity along the path by feedforward control. Therefore, we modify the feedback control law previously presented. In the modified feedback control law, all the state variables of the locomotor are controlled by feedback and their asymptotical stability is guaranteed and furthermore, the deviation of its moving velocity from the desired velocity because of the slippage between the wheels of the locomotor and the floor is compensated and it is converged into zero by a new feedback control loop in which its moving velocity along the path is variable. We have developed an experimental apparatus of the locomotor and verified the validity of the feedback control law with a variable velocity experimentally.

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This paper presents construction of a simulation model of our developed flying robot (cyclogyro) with variable attack angle mechanism in order to rise the development efficienfy. A main feature of our robot is to be able to change angles of attack according to the wing positions (according to the rotational angles of the cyclogyro) without actuators. The constructed simulation model consists of three parts. The first part is the so-called attack angle model to compute the change of angle of attack. The second part is the so-called lift force model to compute lift force based on the computational result from the first part. The third part is the so-called power model to compute the electrical power of motors. The utility of the simulation model is verified by comparing simulation results with experimental results. As a result of optimizing design parameters through the simulation model, the double lift force generated from that of the flying robot optimized through some experiments.

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This paper proposes a novel visual odometry method by tracking feature points on floor surfaces. In floors, there are many shadows by some objects and image changes in tracking region when a view point moves. It is necessary for robust tracking to extract stably feature points on the floor in intensity change. The proposal method extracts the feature points by using various differential filters which output constant values in intensity change. We normalize the filters in intensity change for robust tracking. Generally, template matching is used in tracking methods for visual odometry. Measuring resolution and limitation of the methods depends on the number of templates. Robots' motions are constrained by the resolution and limitation constrain. In order to reduce the constraint, the proposal method measures motion by using the least-square method of estimation motion errors from a large number of tracking points on motions. The experimental results show that the proposal method by using normalized filters can track stably the feature points in intensity change and can measure a round path repeatedly by practicable accuracy.

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In recent years, it is reported that passenger's dynamics and sensibility are different from a driver. However, there are few researches about a suspension control which considers the dynamics of human body, and a sitting position. In this paper, an active suspension control method is developed to reduce a passenger's vibration and motion. First, a vehicle and passenger model including the dynamics of human body and the sitting position is constructed. Second, robust control system design method which uses the vertical acceleration of a passenger's head as one of evaluation functions, is proposed. In order to verify the effectiveness of the proposed control method, the simulation is carried out by using the full vehicle model which has an active suspension system. From the results, it was confirmed that in nearly the resonance frequency of vertical direction of the passenger's head, the proposed control method can reduce the passenger's vibration better than general control methods which use a vertical acceleration of the vehicle body as the evaluation function.

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This paper discusses a steer-by-wire system (SWS), which has both of faults detected only by demands and commission faults. Firstly, a single-channel SWS is modeled by use of a statetransition diagram and the relationship between system characteristics and the malfunctioning-event rate is analyzed. This SWS is known as poor for a single failure. Next, functional safety analysis of a fault tolerant SWS, which has a backup channel, is carried out in a similar manner. As a result how the malfunctioning-event rate depends on the failure rate of the main channel, the detection rate of main channel failures, switching time and margin time is explored. Thus, it is concluded that the approach presented by this paper is useful for the functional safety assessment of SWS.

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Railway companies in Japan are required to formulate further efficient passenger transportation and to reduce relevant costs because of competition against other transportations (air, bus, truck) and a decline in passenger. A railway rolling stock planning is one of the important scheduling in railway transport, which assigns physical train units to given time table services and determines a roster of the train units. This planning is usually designed with an expert's hand calculation. Therefore, an effective algorithm for the rolling stock planning has been developed. This paper proposes a novel approach based on Ant Colony Optimization to solve the planning. The proposed method can not only minimize the number of train units and deadheads, but also can consider a periodical inspection for the train units. The effectiveness of the proposed method is demonstrated through numerical experiments with instance problems made from real railway lines.

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In Japan, snow removal requires a detailed understanding of the particular type of climates, the road configuration, and road surface condition on sidewalk. The sidewalk is always changed by unexpected several operation condition, such as road condition and movement of several maneuver obstacles. Snow removing operation on sidewalk depends on operator's experience and physical ability. The goal of this research is mainly to clarify a strategy for designing the operation assistance system to improve safety and task performance by analyzing information processing ability of each operator during operation. This paper proposes a quantitative evaluation method of operator's information processing ability during operation actions and verifies the effectiveness of the method by using simulator.

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This paper presents a method of increasing the load capacity of magnetic suspension systems. The limits of coil current and suspension gap determine the load capacity. In the PID-controlled system, the displacement is kept zero and the coil current increases when load is added to the floator. In contrast the current is kept zero and the gap decreases in the zero-power controlled system. As a result the load capacity is determined by the current limit in the former and the gap limit in the latter. It can be increased by switching them each other. The switching stiffness control is applied for this purpose in this paper. Experimental results demonstrate the operating range is extended almost twice.

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A wet blast technique has high potential for precision surface processing when tiny particles can be used. In this study, the effect of particle size on the wet processing properties of monocrystalline silicon wafer was investigated, i.e. a fundamental study of the wet blast processing for brittle materials such as semiconductors and MEMS was conducted. Pure water, containing angular alumina particles whose sizes ranged from 1.2μm (WA#8000) to 8.3μm (WA#2000) at the concentration of 0.05 to 3mass% was impacted at an impingement angle of 90 degree by using a micro slurryjet erosion (MSE) apparatus. The depths of surface removal and the surface roughness were measured by a stylus profilometer. The removal rates and maximum roughness (Rz) increased with particle size, but the degree of these increases was much smaller in the range of WA#8000-6000 (1.2-2.4μm) than in the range of WA#4000-2000 (3.7-8.3μm). The critical particle size for smooth processing at shallow blasting depth was about 3μm in this experiment. This behaviors and its mechanism were also discussed by SEM observations of the blasted surfaces.

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Products formed by metal spinning have been inherently limited to straight-axis and circular-sectional shapes. In this study, we succeeded in making curved-axis and non-axisymmetric shells by synchronizing the roller motion in the axial and radial direction with the rotation of the spindle axis, and without using forming dies. A hemi-spherical head tool and straight/inclined-shape mandrels are designed for a use of general purpose. A numerically-controlled spinning machine moves the tool along a spiral trajectory on the surface of the product. The trajectory is calculated from the desired shape considering contact with the tool. Curved cones up to 60 degree bended and curved non-axisymmetric shapes are experimentally formed from aluminum sheet. An equation is proposed to estimate the wall thickness of products, based on curved shear deformation model. It is verified that the model nearly coincides with measured thicknesses of products. Twisting distortion of the product shape is suppressed by switching direction of the spindle rotation alternately.

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Spontaneous magnetization of a WC-Co cemented carbide tool was measured before and after machining to evaluate the stress distribution on the ferromagnetic Co binder. After machining the pre-demagnetized tool, residual magnetic density flux, perpendicular to the flank and cutting surface, were observed. Because of the negative magnetostrictive coefficient of Co, the magnetic-flux direction indicates the residual stress from the spring back of plastic deformation during machining, The observed spontaneous magnetization can be explained from an asymptotic approach to the ferromagnetic anhysteresis curve under external stress. This method can be applied for the evaluation of residual stress on cemented carbide cutting tools.

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This study aims to develop novel cutting tools that have either microscale or nanoscale textures on their surfaces. Texturing microscale or nanoscale features on a solid surface allowed us to control the tribological characteristics of the tool. In this report, the textures were applied to drills with the diameter of 0.5mm and drilling experiments of aluminum alloy were performed to evaluate the developed tools. The texture decreased thrust and its fluctuation range under the high feed rate conditions. This effect depended on the direction of the texture and lower thrust was observed when the texture was perpendicular to the chip flow direction rather than the parallel. The breakage resistance could be improved utilizing this phenomenon. These results indicate that the developed tool is effective as a drill for small holes.

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In order to reduce the costs in wheel manufacturing and on usage of the wheels, we investigated the method of adjusting the sharpness of grinding wheels by using heat treatment and UV treatment. At first it was confirmed that heat treatment of phenol resin grinding wheels for aluminum in a furnace enabled to improve the grindability of stainless steel and to prevent swarf loading. Next it was made clear that surface treatment of grinding wheels by using UV irradiation and hot air blowing had the similar effect with the heat treatment in a furnace. These treatments reduced the force ratio in surface grinding. In these cases the affected layer was limited to the wheel surface though heat treatment in a furnace affected the whole wheel. The thickness of the layer varied with the UV irradiation time. At last we applied this technique to other resinbond wheels and the same effect was obtained for the wheels with polyester bond. However heat treatment did not improve the grindability of epoxy bond wheels with high heat resistance. In such case UV treatment was an effective method to activate flow-out of swarf.

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In this paper, the method of extracting true abnormal information from the statistics analysis of the occurrence probability of a binary output of an abnormality diagnosis system is examined. In general, since a fluctuation occurs in a sensor measuring quantity in the normal state by various factors, such as a noise and environment, an incorrect diagnostics arises in the abnormality diagnosis system which use threshold value. Therefore, abnormal detection will detect more than the actually caused abnormalities significantly. In this case, the judgement to all the abnormal information is required, the treatment to an individual phenomenon becomes shortly, and it causes hindrance of accurate judgment. Such a situation causes a delay of the detection of the true accident and this delay also causes a delay of a maintenance. And at the worst case, it may also causes a further accident. Therefore, for quick action and the maintenance, reduction of the incorrect information is desired. Then, in this paper, the method of extracting true abnormal information from the statistics analysis of the occurrence probability of a binary output of an abnormality diagnosis system is examined. By the abnormality diagnosis system, exis ence or not of an abnormality is shown by the binary parameter (1 and 0, for example.). In this research, a diagnostics is performed from parameters, such as duration and interval of the alarm. By using these parameters, threshold value between the normal and the abnormal condition is decided from the approximation of occurrence probability of the parameters using exponential distribution. Finally, this method was applied to the actual rail crossing abnormality diagnosis system, and it succeeded in reducing almost 98% of incorrect information using the duration of the alarm and reducing almost 94% using the interval of the alarm.

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