A restoring force of a repulsive-type passive magnetic bearing is essentially nonlinear. It may cause various kinds of vibrations in the rotating shaft supported by the repulsive magnetic bearing because the damping coefficient of the repulsive magnetic bearing is small. In this paper, the influences of both the length ratio and the axial displacement of the magnets on the restoring force characteristic of the repulsive magnetic bearing are investigated. As the result, followings are clarified : In the case that the length-difference of the inner and outer magnets is small, the system has the hard-spring nonlinear characteristic when the axial displacement is small, and it changes to the soft-spring nonlinear characteristic when the axial displacement increases. On the other hand, in the case that the length-difference of the inner and outer magnets is large, the system has the soft-spring nonlinear characteristic when the axial displacement is small, and it changes to the hard-spring nonlinear characteristic when the axial displacement increases. These results were validated experimentally. As a result, this paper clarified that the characteristics of both the linear and the nonlinear stiffness can be designed, and particulary the linear system can be realized, by adjusting both the axial displacement and the magnet lengths of inner and outer rings.

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The dominant mechanism involved in pattern formation phenomena in contact rotating systems is considered to be unstable vibrations generated in linear time-delay systems due to processes such as viscoelastic deformation, wear, cutting and grinding. A number of countermeasures have been proposed to prevent the occurrence of these phenomena. In a previous study, stabilization of the system using a dynamic absorber was suggested as an effective preventative measure, and the validity of this approach was confirmed by numerical analysis using a newly developed stability analysis method based on the existence condition of boundaries between stable and unstable regions. This analysis method can be carried out efficiently and accurately without the need to obtain characteristic roots. In this report, an experimental viscoelastic system was constructed in order to verify the effectiveness of a dynamic absorber and determine its optimum design using the new stability analysis method. The results for a single-degree-of-freedom system indicate that such a dynamic absorber is an effective means of preventing pattern formation phenomena from occurring.

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This paper describes a successful application of Magnetorheological (MR) grease to controllable dampers for general use. MR fluid is known to have a great potential as intelligent material to be applied to many devices such as dampers, clutches and engine mounts. However, ferromagnetic particles in MR fluid settle out of the suspension over time due to the density difference between the particles and their carrier fluid. Consequently, devices using MR fluid is difficult to achieve the desired performance. We have solved the problem by developing MR grease using grease as the carrier fluid which holds the particles in its thickener networks. The typical characteristics of MR grease have been measured by using a rotational rheometer specially designed for MR suspensions. The relationship of shear stress to shear rate and magnetic flux density in the MR grease is as same as MR fluid. The performance of a prototype controllable damper using the MR grease has been verified to be a wide dynamic force range and high time response. The ratio of maximum damping force in on-state to that in off-state is approximately 13. The time constant of damping force is 45 ms in off to on-state and 33 ms in on to off-state.

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This paper presents a new approach of an open-loop control for overhead cranes with load hoisting to suppress the sway motion after positioning, in which soft computing techniques are utilized. We apply a neural network to generate the desired trolley position. In order to obtain the trajectory of the trolley position to reduce the sway angle as much as possible, the neural network is trained by a particle swarm optimization (PSO). The suppression of the sway angle can be realized by moving the trolley along the obtained trajectory, that is, the open-loop control is established. By performing not only numerical simulations but also experiments, the effectiveness of the proposed method in suppressing the residual sway is demonstrated. In the present approach, it is a feature of the neural network trained by PSO that control systems can be constructed without any prior control knowledge if a mathematical model of a plant is given.

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This paper describes experimental study of nappe oscillation at a weir which is two meters high. Falling water sheet flowing over a weir sometimes oscillates at a low frequency. The water sheet oscillation causes low frequency sound problems. So far, spoilers are used to prevent from such vibrations. We develop the new equipment to suppress low frequency oscillation and investigate how to suppress low frequency sound from nappe oscillation. Its sound can be suppressed by setting equipment at the lower end of a falling water sheet. Experimental results show the characteristic of nappe oscillation and effectiveness of the equipment on low frequency sound.

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This paper presents a method to suppress the vertical bending vibration of electric railcar by using traction motor. Dynamics of the truck with parallel cardan drives can be controlled by torque of the traction motors. This paper proposes a control method to reduce vertical vibration of truck frame by the traction motor torques to reduce car-body vibration. The motor torques are added with the traction torques of the control scheme in reverse phase for two traction motors of a truck. Experimental result shows that the control method using traction motor torque can decrease the truck frame vibration.

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Directional response and directional stability of vehicle combinations are main research topics in vehicle safety. This paper analyzes the steering sensitivity in lane-change maneuvers of multi-articulated vehicles with multiple axles using simplified mathematical models. It also calculates the frequency response, pole, and zero in the transfer functions of each variable for two types of tractor-double-trailer, a tractor-semitrailer and a truck-full-trailer having multiple axles. The following conclusions are drawn. (1) The steering sensitivity of multi-articulated vehicles with multiple axles in lane-change maneuvers is composed of steering sensitivity in steady-state turns and the parameters of lane-change maneuvers. (2) The effect of the number of trailer axles on the damping ratio of zero is larger than that of the other parameters for multiple axles. (3) A large steering angle is necessary to change running lanes for multi-articulated vehicles with multiple axles that have low steering sensitivity in lane-change maneuvers; therefore, the rise time is short. Moreover, if the vehicle combination has a low damping ratio of oscillatory modes, the settling time is long, and the overshoot and maximum deviation are large.

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In recent years, huge earthquakes happen, for example, The South Hyogo prefecture Earthquake in 1995, The Mid Niigata Prefecture Earthquake in 2004, The Iwate-Miyagi Nairiku Earthquake in 2008. In The Niigataken Chuetsu-oki Earthquake in 2007, hundreds of drums fell down and water spilled out. A lot of studies about rocking behavior of rigid body had been performed from 1960's. However, these studies were only for a specific condition of the structure size or input vibration characteristics. Therefore, generalizes fall condition for earthquake is required. This paper deals with the analytical and the experimental study of the rocking vibration of 1-DOF rocking system, 2-DOF vibration-rocking system and 2-DOF rocking system under earthquakes. In this study, the equation of motion for each rocking systems are developed. The numerical model of 2-DOF rocking system is evaluated by free rocking experiment. In this paper, “Overturning Map” which can distinguish whether structures falls or not is proposed. The overturning map of each rocking systems excited by the artificial earthquake wave calculated from the design spectrum is shown. As the result, overturning condition of structures is clarified.

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Almost all of the equivalent circuit for ultrasonic motor is expressed as a one port circuit. However, an equivalent circuit with two-port pair is furthermore convenient, because both the phase and the voltage difference controls can be simulated. According to the research on literature, a parameter identification method was previously proposed for the two-port pair circuit. Identifying of circuit parameters is impossible. Then, in this paper, the matters that require attention are summarized and a revised method is proposed. Firstly, the practical equations to evaluate the parameters are derived. Next, we point out that the parallel supply test is unfit for the parameter identification, because the motor cannot rotate. To overcome this issue, the modified parallel supply test is proposed. Finally, it is shown that all circuit parameters are easily derived under the limited condition, i.e. the stator only and the USM without preload. While the parameter identification for the USM with preload is a failure.

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Dual arm work machine that consists of hydraulic excavator is expected for transportation of long objects such as steel stocks and destruction of concrete walls by cooperating dual arm. However, cooperation of two or more arms generates overload in a work object and arms. Because the arms form closed-loop through the work object, refuge of internal force disappears. In this paper, a nondestructive dual manipulation technique for reducing working load is designed using indirect force control that applies in a part of one arm. Operator's positioning accuracy in transportation of long object is measured by a front structure of the hydraulic excavator. From the results, permissible positioning error in nondestructive dual manipulation is clarified. Moreover, load of working object is reduced by indirect force control by using hydraulic circuit with accumulator. Target mechanical impedance is maintained by combining hydraulic circuit with adaptive control in hydraulic system that changes the load characteristic while working. Transportation work experiment of long object is conducted by using the lifter that corresponds to positioning control manipulator and the hydraulic excavator that applies the force control system. Working load has decreased to 20% of maximum working load of the front structure of the construction machinery. Usable range of nondestructive manipulation is clarified by a chart that shows relations between expected load decrease and target mechanical impedance characteristic decided with the work object. Therefore, nondestructive dual arm manipulation of the construction machinery can be achieved by using the mechanical impedance adjustment with combination of the hydraulic circuit and the adaptive control.

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Backlash occurs in gear drive systems that are used with machine tools and transport mechanism. The problem with backlash is that it reduces positioning accuracy and tends to make vibrations worse, especially when the driving load is large and a large drive system is used. By using a system with a twin-motor drive, in this paper, a method that compensates for backlash is introduced mechanically. In this method, the phase of a slave motor is displaced depending on the phase of the main drive motor at the final position of the system. This method is suitable for applying to multiple motor drive system. When a pair of motor is driven by the same direction, a double thrust is obtained, of course. At final positioning of this method, the phase between main motor and slave motor is controlled to compensate the backlash. It is shown that this method is effective in increasing the stiffness of a gear drive system and improves the positioning accuracy of the system.

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In this study, we construct an impression evaluation model for button sounds generated when users press the buttons on car audio equipment using a neural network. The dynamic characteristics of 11 kinds of button sounds obtained by their wavelet transform frequencies and sound pressure values are fed into the network model inputs. The model responds with three factor scores, “esthetic”, “force” and “metallic”, and an evaluation value of “offensive - pleasant” as the outputs. By analyzing the synaptic weights of the neurons on the neural network after training, we confirmed the model acquired a mechanism that extracted four impression evaluation values from the sound characteristics. For example, about the "Force factor" and the "Metallic factor", the scores increased when the center frequency rose, and the sound pressure level of the frequencies between 0.0 and 0.040 seconds was hardly influenced, and so on. These results show that the model is able to attain automation of button sound design.

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Recently, touch-sensitive screen has been in widespread use as interface with high usability in public facilities. However, it is pointed out that installation height and screen tilt angle are not inequable for its user because there is a difference of the body type. In this study, for the purpose of taking the knowledge applicable to the design guide of touch-sensitive screen, we investigated the relationship between installation position of touch-sensitive screen and operability. Moreover, we measured maximum torque ratio of upper limb to examine the effect of installation position to arm burden. We asked examine to operate on touch-sensitive screen in nine conditions. Three conditions depend on the height of center of touch-sensitive screen (height of shoulder, elbow and lower back), and the other three conditions depend on the screen tilt angel (0°, 45°, 90°). The result showed that installation height and screen tilt angle of touch-sensitive screen have an influence on pointing time and arm burden. From this study, we suggest the installation positions that are easy to operate and lightly-loaded.

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Among the three components of electromagnetic field (radiated field, induced field and quasi electrostatic field (QEF)), the QEF has a characteristic of decaying proportional to cube of the distance. Regardless of the QEF's potential characteristics, QEF has been treated as unimportant in the past. In this paper, we developed a novel proximity sensing technology applying QEF. Noncontact and noninvasive object sensing is realized by using equilibrium of QEF distributions generated with the multiple electrodes structure. From results of electromagnetic simulation and experimental analysis, we clarified our method can improve the detection resolution of conventional proximity sensing method drastically, because the detection resolution in our method doesn't depend on QEF frequency generated by quadrupole electrodes, but depends on the parameter of the gap size between each electrode. Finally, we focused on human vein sensing, as one of the most important application example of our technique, which is well known as a biometrics technology. From the electromagnetic simulation, we confirmed our method is applicable to the vein sensor by using the matrix array structure of the fundamental element of quadrupole electrodes.

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In this paper, the authors aim at developing a wearable power assist wear for lower limb The system requires compact size and lightweight to achieve a practical application, therefore we discuss its effective structure using biarticular muscle. At first, two model of targeting at support device for human lower limb is described, followed by showing each alignment of rubber artificial muscles. Next, construction force generated by rubber artificial muscles to achieve static balance is calculated. At the end, Experiment apparatus is designed from calculation and experimental results is showed.

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In order to investigate the human characteristic on length perception between the thumb and four fingers, we developed a four-degree-of-freedom (4DOF) length display device which can adjust each four distances respectively. The 4DOF device was proofed by length perception experiment. The placement of 4 units of the 4DOF device arranges from fingertip trajectory experimental data. The position of 4 fingers basing on the thumb is changed by stepping motor. The experiment is that each length between the thumb and other four fingers is same length. The results suggested that the same trend of perceptual length by thumb and any other finger is underestimation. In addition, perceptual error around 70mm was the biggest.

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A wiring task such as laying LAN cable under the roof by worker is a dangerous and an inefficient work. To improve the safety and the efficiency of the work, authors have proposed a remote controlled mobile robot for the wiring task with flexible spoke type wheels. The work space under the roof has obstacles including metal fixtures, suspending bolts and some electronic appliances. Thus the traverse ability of the mobile robot for the obstacles is very important. The spoke wheel of the mobile robot has advantage on the traverse ability comparing with normal wheels. The traverse ability of the spoke wheel depends on the number of the spokes and flexibility of the wheel. The paper discusses the traverse ability for the design of flexible spoke wheel of the remote controlled wiring mobile robot under the roof.

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Fish robots that swim with the tail fin do not give the caution to underwater creatures. Therefore, they become useful for the investigation of ecosystem in water and the usage of the environmental surveillance and so on. However, the propulsive velocity of fish robots is extremely slower than that of live fishes. It is necessary to examine the difference of how to swim between live fishes and fish robots in order to put the robots to practical use. In this study, the modification has been added to the CFD code that had been developed up to now, so as to clarify the relation between tail fin's flexibility and the propulsive performance of the fish robot. The new code can calculate fluid-structure interaction analysis considering elastic deformation of tail fin. By using the modified CFD code, effects of tail fin flexibility on propulsive velocity and flow pattern of water around the fish robot have been examined.

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In this paper, a master-slave surgical robot system with heartbeat synchronization mechanism for off-pump CABG suturing operation is developed. This robot system is composed of a master manipulator, a slave manipulator, a heartbeat sensing system and a compact flexible endoscope system. The heartbeat sensing system measures 6 DOF heartbeat motion in real-time. The position of the slave manipulator is controlled as synchronizing with heartbeat. The compact flexible endoscope is fixed to a heart using a soft coupling which is used in medical case, so that the relative position between a heart and the compact flexible endoscope is maintained constant. Moreover, the surgical robot system is controlled in master-slave control method for surgeon's tele-operation. Therefore this system is able to perform surgical procedure while the system synchronizes with the heartbeat. In order to evaluate the performance of the system, the synchronization ability test, the master-slave operation test in vivo, and the performance of suturing operation under synchronization were conducted. In the result of the first test, it was showed that the maximum error between desired position and experimental position in the synchronization control was less than 1mm. In the second test, it was confirmed that the system was able to suture a pericardia, which was not beating. In the third test, it became clear that the maximum error between the desired position and experimental position was less than 1.24 to 2mm and the system was able to suture an isolated tissue which was driven by a robotic heartbeat phantom in 1Hz.

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The center of gravity of a moving train differs time to time due to variety of number of passengers on board. There can be significant difference of 3D-locations of the center of gravity on the same train between at rush hour time and at off peak one. It is essential to detect the location for preventing rollover accidents of trains on which the critical speed of rollover for them depends. In this respect, this paper applies the innovative new theory of detecting 3D-locations of the center of gravity of a moving object for trains, which was invented by the second author of this paper and abbreviated as D3DCG⁽¹⁾. D3DCG was created by the concept of motion dynamics of a ship floating on water. This paper assumes that similar condition can occur while a train is moving straight at constant speed. Based on this assumption, the authors measured the vertical acceleration and the roll rate of moving trains, which were to be applied to D3DCG for trains, and were successfully able to detect 3D-locations of the center of gravity on trains by D3DCG.

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To clarify the overturning possibility of trains exposed to strong cross wind, several experiments were done to study the affect of the wind velocity and wind direction on the axle load changing. In this paper, the results of the experiment in the Japan Sea Coast Main Line, where the seasonal wind swept bitterly in winter, are described. Various kinds of trains, such as limited express, fright, commuter and local, were operated on the sites. To eliminate the turbulence of the wind on the sites, the 3 wind sensors were installed parallel with the track at regular intervals. As the results of the experiments, the author found that the ratio of wheel unloading caused by the wind could be more accurately expressed by the “Detailed equation” than the Kunieda's equation which was conventionally used to decide the regulation standard to prevent the train overturning by the strong cross wind in Japanese railways. Mesurement data also show that consideration of relative wind velocity and relative wind direction is important for running vehicle.

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This study develops a mixing machine driven by a spherical motor that can rotate around any axis. The developed mixing machine is composed of a rotor, a stator, a control PC, an electro-magnet excitation circuit, and a power supply. The rotor that its outer diameter is 200 [mm] is composed of double spherical shells in order to contain liquid in its inner spherical shell. Totally 91 permanent magnets are arranged in almost spherical symmetry on the inner surface of the outer spherical shell. On the other hand, 80 electro-magnets are arranged on the stator of a semi-spherical shell. The applicability of the mixing machine to material production under the condition of small influence of gravitational force is evaluated by mixing experiments to dissolve salt of 50 [g] in water of 200 [g]. The mixing performance is compared for five mixing methods. The results show that the mixing performance of the method to change randomly the rotation direction is only slightly lower than that of the method of rotating continuously around a horizontal axis that exhibits the highest mixing performance.

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While the product family design has been recognized as an effective concept for flexibly meeting with various customer's needs with less cost, its contents depend on kinds of products, business categories, etc. This paper explores its possibility for designing a family of engineering products, such as turbine, pump, the performance of which is pursued for each specification individually. In this paper, their design and development process is recognized as the chain of three phases; product architecture design, anticipatory platform design and scale-based customization for shortening its longer lead time even under smaller total number of production units. A design methodology, which is composed of three procedures; strategic identification of common subsystems and adjustable subsystems, anticipatory design of the former subsystems prior to individual orders, and adjustment design of a latter subsystem for each order, is proposed. Further, an optimization-based design method for the second phase, which is essentially important but complicated among them, is mathematically formulated and proposed. Finally it is applied to a design problem of centrifugal compressors for showing its effectiveness.

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An external load applied to a rolling bearing is distributed among the rolling elements. The conventional calculation of load distribution among rolling elements already established assumes that the bearing races, shaft and housing are rigid except for elastic deformations at the individual contacts between rolling elements and raceways. In many applications, the bearing rings as well as the supporting structures can not be considered rigid, so that the actual load distribution is different from that predicted on the above assumption. Several experimental methods to determine the load distribution of rolling bearings have been proposed so far. Their methods, however, can not provide dynamic load distributions while rolling elements make one revolution along the raceway. The objective of this study is to establish a more direct method than the other ones for determining rolling element load distributions not only statically but also dynamically. In the method herein proposed, the strains of rollers developed under an applied load are measured by using an optical fiber strain sensor mounted on a roller of a measuring cylindrical roller bearing. The obtained strain data provides rolling element load distributions. This paper presents the method for determination of dynamic load distributions, and shows examples of dynamic measurements using the method. The dynamic behaviors of the load distributions and the correspondence of the experimental results to the conventional theory have been investigated. In addition, the comparison of the dynamic load distributions obtained here and the static ones presented in Part I of this study has been made.

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Sliding tests at 800°C in air of 25Cr-20Ni stainless steel (heat-resistant steel) and high silicon content stainless steel (high Si content steel) clarified that the high Si content steel has better tribological characteristics. Since work hardening and crystal refinement were shown on the glaze oxide layer of high Si content steel, same mechanism as the previous report of Ni-Cr cast alloy, the layer contributes to good tribological characteristics. On the other hand, hard oxides on the surface layer of heat-resistant steel cause the abrasive wear against the soft area formed by wear particle of base material on the surface layer. In this reason, surface layer was removed and sliding surface got rough.

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In this study, seizing was considered as the state when the sliding surface became severe wear according to Nakahara's model. The aim of this research was to evaluate the seizing of cast iron from the viewpoints of temperature rise, coefficient of friction, wear volume and surface state, under two different conditions, and the mechanism of seizing was discussed. Two kinds of seizing were observed, “macro-seizing” and “micro-seizing”. Moreover, a model of the seizing concerning micro and macro-seizing was proposed. When the disturbance like an abrupt increase in load is given in a stable sliding condition, the seizure occurs, followed by plastic flows and an increase in contact area. The contact pressure keeps lower than the critical pressure, the surface becomes smooth and stable sliding is recovered due to the formation of a surface film in the micro-seizing. It seems that the predominant film formed is of graphite at low velocity and oxide at high velocity for cast iron. When the contact pressure becomes greater than critical pressure, the macro-seizing occurs. The apparent critical pressure is 20 MPa at 4.8 m/s for cast iron.

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Currently, equipments using paper feeding mechanism such as copy-machine and printer are required higher paper feeding velocity. It is necessary to reveal the impact of paper feeding velocity on the characteristics of paper feeding mechanism. In this paper, high speed paper feeding experiment was firstly performed. And the characteristics of paper feeding mechanism dependences on paper feeding velocity were verified. Next, the effects of rubber viscoelasticity, dynamic friction coefficient of rubber dependences on slipping velocity and dynamic friction coefficient of paper dependences on slipping velocity were shown with experiments and two dimensional analyses. It is found that the characteristics of paper feeding mechanism dependences on paper feeding velocity are mainly caused by dynamic friction coefficient of paper dependences on slipping velocity.

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In this paper, friction characteristics of the linear motion rolling bearing are analyzed with a locomotive multi-bristle model. The contact surface between the race and the ball are modeled with multi-bristle. Each bristles in the contact surface represents the stick and slip characteristics of the friction. The bristles locomote as the ball rotates and the state of the contact surface is updated. In the calculation of friction force, the contact surface is divided into stripes where slipping velocities between the race and the ball are constant. Firstly, distribution of the slipping velocity on the contact surface is calculated. Then, the friction forces in the each stripe are calculated with Soda's tangential force models of the contact surface. Finally, the friction force of the whole contact surface is obtained by summing the friction force of all stripes. With the suggested method, a hysterisis characteristic of the friction in the contact surface is simulated. When differential slipping is existing in the contact surface, the friction characteristics have a extreme value after the moving direction is changed. In addition, the saturation value of the friction force becomes smaller compared with the case without the differential slipping.

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It is extremely important to evaluate the rolling deformation and large strain distribution conditions in the surface of the processed materials after machining. On the other hand, the sub-pixel digital image correlation (Sub-DIC) method enables to measure the full-field strain distribution only using the photographs taken by the commercially available digital camera. This study aims to develop the rolling deformation and the large strain distribution conditions using the Sub-DIC method. Here, it is well known that the measurement accuracy deteriorates in large strain conditions when the conventional Sub-DIC method is used. In this paper, we proposed the facility technique for measuring the large strain distribution by the Sub-DIC method in which the sub-set area are applied to the strain regarding the reduction in thickness of rolling processing. And, we demonstrated the measurement characteristics using the facility Sub-DIC method through a series of experiments from the viewpoint of changes in the test piece surface strain distribution conditions. Moreover, we evaluated the curve of test piece after rolling processing with a radius of curvature. Finally, we discussed measurement characteristics of the steady/ unsteady conditions in the rolling processing using the facility Sub-DIC method.

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Drive recorders have been used more frequently in Japan on the transportation vehicle such as taxicabs, buses and trucks than before. The drive recorders can record the driving data including motion pictures in the traffic accidents and near-accidents, which are considered as “dangerous data”. Analysis and application of safety education using the “dangerous data” are useful to prevent traffic accidents. The drive recorder, however, can record a large number of “not dangerous data” which are not derived from the accident or near-accident data when the car passes the undulation or bumps on the road. The current useful method to extract the “dangerous data” exactly from all the raw data is the human observation and classification of the data while some automatic methods have been developed, which are not very exact to classify the data. The authors show a new method of automatic classification of the drive recorder data into more than two categories including “accidents”, “near-accidents” and “bound” etc., by using the waveforms of the acceleration data. The method is much more effective and reliable than the current automatic methods and it enables to build an automatic processing system for mass data from drive recorders to be classified exactly.

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A new numerical analysis method for elastic adhesive contact mechanics between a sphere and a flat with a sub-nanometer roughness is presented by taking account of Lennard-Jones (LJ) surface forces. In contrast to conventional theories, the LJ forces of contacting asperities and all noncontacting rough surfaces are taken into account. Elastic deformation of mean height surfaces is also taken into account. Convergent solutions obtained by a simple under-relaxation iteration method are shown for two contact models: 2-mm radius glass slider and magnetic disk with relatively large roughness, and 20-mm radius head model contacting with a magnetic disk with low roughness. Comparison of this new theory with previous theory considering LJ surface forces of mean height surfaces and modified Chang-Etsion-Bogy theory with and without deformation of mean height surfaces are presented. It is found that the present theory gives the largest external adhesion force and that this theory tends to approach the mean height surface theory as roughness height decreases to zero.

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A rotational parallel mechanism is proposed that can perform rotational output motion around two axes and fine translational motion to compensate for position error of a target point, the center of rotation of the output link. This mechanism is composed of three connecting chains: one is a constraint chain without actuation and two are actuation chains, each with two actuators. The structures of the constraint and actuation chains were synthesized so that the mechanism can perform fine translational motion for position compensation while achieving a rotational output motion within a large workspace. Dimensional synthesis was carried out taking into account singularity with respect to actuation torque and output velocity, and rotational output motion coupled with translational compensation motion for position error. Based on the synthesis results, a prototype mechanism was designed and built. Experimental results regarding compensation for position error of the target point are shown to support our structural and dimensional syntheses.

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To improve strength and vibration and noise, it is important to remove the burrs and pits generated at the edges of gear teeth during the gear cutting process. However, as the tooth groove of the small gears in compact geared motors is small, removal of such burrs and pits is difficult due to space constraints. To address this, a gear-shaped tool composed of glass fiber-reinforced plastic (GFRP) has previously been proposed and the effectiveness of the removal process using it has been confirmed. However, in some cases, the method does leave burrs and pits in the position on the pitch circle. Herein, to address this issue, an improved method is proposed which introduces oscillation to the GFRP gear-shaped tool. A theoretical analysis of the sliding velocity at the tool/work-piece interface is also presented. The apparatus for the process was constructed and used to validate the proposed method experimentally.

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