This paper proposes a method of self-sensing and model-free vibration control based on DVFB (Direct Velocity Feedback). In general, model-based control theory is applied to design control system. In this case, an accurate vibration model of the system is required to achieve an adequate vibration control performance. However, making an accurate model and designing a control system increase the workload of engineers, and installing sensors to detect structural vibration obstructs a cost reduction of control system. In this study, we consider a self-sensing vibration control strategy using a single degree-of-freedom voice coil actuator without the model of target structures. First, the self-sensing is achieved by detecting the voltage and current of the voice coil and estimating the relative velocity of the actuator. Second, the state variables containing the velocity at the point on the target structure to which the actuator is connected are estimated by Kalman filter. Finally, an extended DVFB control law is applied to the actuator. In this paper, effectiveness of the proposed method is validated by simulation with the controlled systems of a two degree-of-freedom and FE (Finite Element) models.

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Particle damper is a passive vibration absorber which attenuates response of a vibrating structure using small particles within cavities embedded in the structure. The damper is promising especially for harsh environments, but the damping mechanism is very complicated and highly nonlinear, compared to the conventional damping techniques. In this paper, the approximate analytical model is developed for the vertical forced vibration of the damper. The granular particle bed in cavity is modeled as a single body with effective coefficient of restitution which can wrap all energy dissipation mechanism for reasonable bed/layer thickness. Numerical simulations and theoretical analysis based on this model yield results which are in accord with the experimental observations for the adequate mass ratios, bed/layer thickness, number of particles, and excitation levels. With this as a basis, numerical studies were carried to compare the results obtained by discrete elements method (DEM).

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Recently, many super high rise buildings are built in the rising nation. Elevator lateral vibration is one of the main problems affecting ride comfort in elevators. In the ultra-high-speed elevator, peculiar vibration is activated and it is difficult to maintain ride comfort by the conventional vibration suppression technique. We have developed an active cabin vibration control system to suppress the lateral vibration of ultra-high-speed elevators. In this research, the application of μ - synthesis to this system is dealt with, so that the performance to suppress vibration and the robustness about several parameter errors are investigated. In addition, we simplified the controller design and made implementation of the controller easy by simplifying μ - synthesis process. We manufactured the active cabin vibration control system and the experimental device to verify vibration reduction effect in ultra-high-speed elevators. Experimental results show that the active cabin vibration control system is capable of reducing the lateral vibration of ultra-high-speed elevators.

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The frictional behaviour is effective for dissipating seismic energy. Therefore, in recent years, the installation of a frictional isolator in industrial facilities has been investigated. However, the seismic response of the friction system is obtained only by non-linear time history analysis. A great deal of time is required for non-linear time history analysis. The present study deals with the easy estimation of seismic response for friction system. In the previous study, the authors proposed a response spectrum for 1-dof system with friction. This paper shows the validity of friction response spectrum by vibration test using the experimental model of 1-dof friction system. The difference of seismic response between numerical and experimental results is sufficiently small. Therefore, the seismic response of a 1-dof friction system can be simply estimated by friction response spectrum.

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We propose a method for path control in three-dimensional space which takes into consideration the error vector in path error plane. A search is performed for a desired point located at a minimum distance from the present position, and a straight line that connects the previous and subsequent points serves as a baseline. Considering multi-axial mechanical systems, the equations of motion in an orthogonal coordinate system are transformed into a rotating coordinate system. The transformed system can be decoupled and decomposed into a component in the movement direction and a component represented the plain containing the path error vector. Therefore, the direction of the error vector is controlled together with its magnitude. From a practical viewpoint, control of both the direction and magnitude of the error vector enables more efficient path control as compared with cases where only the magnitude of the error is controlled. Moreover, compensation for the desired moving signal is added to the component in the movement direction in order to compensate for delays in time response, and the compensation of the terms of second-order differential coefficients is also added by using disturbance observers. The effectiveness of the proposed method is confirmed experimentally by successfully applying it to a multi-axis linear motor table.

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Recently, servo presses driven by servo motors have become widely into use. In this research, we derive the optimal control inputs of the slide and die cushion and trajectory which fills the suitable index of formability and productivity using shock control. It aims to design the control system for securing the robustness for friction or a parameter error. The contact load of the slide and the die cushion, bottom dead point and its arrival time are used as the index. In derivation of the optimal control inputs and trajectory, we proposed method of applying final-state control by dividing from the collision of the slide and the die cushion until reaching the bottom dead point into two stages. In order to secure the robustness we propose the control system which changes control flexibility. By carrying out numerical simulations and experiments, it is verified that the control system has good performance.

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Direct Injection engines have strongly penetrated the gasoline engine market for their benefits of reduction in fuel consumption. A high-pressure gasoline pump is one of the important components of a DI engine. A recent trend for the pump is to increase the operating pressure. The challenge to increase the operating pressure withstands load design of sliding area. The purpose of this research was to provide a measurement method of contact force on sliding area for load design. We proposed an estimation method of contact force by measuring the strain of the plunger, and installed it into the pump. It was difficult to measure the strain because the plunger is in the engine oil and moves up and down very fast. In addition, we proposed a new design to reduce the contact force and tested its effect by using the measuring method.

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A new convergence calculation method of the Normal Distributions Transform (NDT) scan matching for high resolution of grid maps is proposed. NDT scan matching algorithm usually has a good effect on large grids, so it is difficult to generate the detailed map with small grids. The proposed method employs Interactive Closest Point(ICP) algorithm to find corresponding point, and it also enlarges the convergence area by modifying the eigenvalue of normal distribution so that the evaluation value is driven effectively for the pairing data. In addition, outlier elimination process is implemented to the scanning for sub-grid scale objects. The scanning data from Laser Range Finder(LRF) have error but its set of detected small objects can be clustered to determine the Center of Mass(CoM) and the outlier data. The outlier commonly locates behind true points and it can be eliminated when the robot observes from other points. Experimental result shows the effectiveness of the proposed convergence algorithm and the outlier elimination method.

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In this paper we study on the passivity of flexible master-slave manipulators using proposed modified symmetric bilateral control. First, we derive dynamic equations of flexible master-slave manipulators by means of the Hamilton's principle. Second, when applying the modified symmetric bilateral control to flexible master-slave manipulators, and we prove the passivity in the positioning operation and in the neighborhood of the desired state in the pushing operation to an environment by introducing a Lyapunov function related to the total energy. Finally, we show some results of numerical simulations in order to verify the usefulness of proposed controller.

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In this paper, a spring-parallel mechanism within high precision and wide working area, based on compliant mechanism, is presented. Spring-parallel mechanism is a parallel mechanism in which all of the joints are composed by elastic deformable joints. The presented mechanism is composed by circular spring joints that have been inspired by a plant “Drakaea”. From our analytical and experimental tests, it was revealed that the circular spring joint has desirable characteristics for composing a spring-parallel mechanism. From these primary experiments, we developed a 3 DOF spring-parallel mechanism, to be used for an optical component positioning machine. The prototype evaluation tests revealed the advantageous characteristics of the mechanism.

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The purpose of this paper is to develop a force haptic device “Parallel Glove” equipped with a 3-DOF parallel mechanism and to experimentally verify the effectiveness of a proposed motion control scheme using electromyogram signals. The proposed device is attached to an operator's wrist to display pseudo translational force to the operator's hand against rotational 2-DOF and translational 1-DOF movement of the operator's wrist. Control inputs of the motion control scheme of the haptic device are composed of actual forces applied from the operator and estimated forces computed from the electromyogram signals obtained from the operator's forearm muscles. To confirm the effectiveness of the proposed motion control scheme, experiments of displaying force information for human operators were carried out. In the experiment, the haptic device applies continuous force to the operator's wrist. The experimental results show that the magnitude of the applying force is approximately equal to that of perceptive force of the operator in the direction of the flexion-extension of the wrist. Therefore, the motion control scheme of the Parallel Glove is effective for displaying the force information for the human operator.

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A motion-planning scheme that enables robotic arms to avoid structural damage is developed by implementing risk determination and motion modification algorithms in a finite element code. The scheme searches safer motion of robotic arms when their structural risk determined by a function of sectional forces becomes higher than a threshold during their given tasks. The safer motion is achieved by decreasing the total strain energy stored in the structure of the robot. Some examples of motion modification are demonstrated by giving lift-up and lateral carrying tasks to a robotic arm, where the achieved motions are compared by varying the structural parameters. Furthermore, the proposed scheme is implemented in an interface of a robotic arm to verify its applicability and practicability in actual motion control.

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We suggest rapid motion generation methods against unexpected structure changes for service robots. Service robots for a therapy need to be compact, lightweight and inexpensive. It is considered for these robots that unexpected structure changes have occurred with users accidental operations such as falling by their mistakes. Because robot users have no knowledge and cannot repair their robots, it is desired to recover the motions autonomously without repair. On trajectory control, the original motions can be realized by recovering the positions of end-effector. Conventionally search methods needs huge amounts of explorations to obtain adaptable end-effector points on the target trajectory, and conventionally adaptable methods are not intended for structure changes especially discontinuous changes. In order to reduce the costs of exploration, we suggest motion mapping methods by which robots learn the differences of joint angles between prepared robot model and changed robot structure based on position observation of the end-effector. The mapping is executed within real time scale because new motions are estimated from the low amount of position observation data which is gathered along with a motion execution. By learning the differences iteratively, the generated new motions will converge at the adapted motions achieving the desired trajectories without unnecessary explorations. In simulation, the adapted motions are generated autonomously against discontinuous changes with low number of position observations.

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We introduce the wireless remote controlled unmanned small scout robot. The robot is aimed to scout and work in dangerous area for example the area of the crime or the terrorism and in the poisonous gas atmosphere. It can move around mainly artificial place like in the building with many stairs and can be operated by wireless system from out-of-sight area. And it can be carried to anywhere by one man's shouldering. The robot can start from the base floor to other floor by stairs inclination up to 40 degrees, and scouts with multi camera system and works with a manipulator around the troubled area. After the mission, it returns to the start point on the base floor. All operation and monitoring can be held at the start point. We report that we tested and evaluated the operation and some semiautomatic assist systems for driving about the robot.

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Power assist systems have been introduced to reduce workers' load in industrial production. The authors' research group has studied on control systems for realizing power assist systems for conveying flexible structures, and proposed a control system consisting of an impedance controller, the disturbance accommodating optimal controller, a disturbance observer and a reaction force controller. However, power assist control based on unintentional input force may cause reckless motion and severe accident in actual uses. In industrial uses, enable switches are often applied to prevent such a problem. However, the spread of various kinds of power assist systems requires another safety measure. Therefore, this note presents a controller design method taking account of the influence to conveyed objects by unintentional input force. Concretely, the conveyed objects are set on the active table on the assist system. The table is controlled by the frequency-shaped disturbance accommodating optimal control theory. Abrupt motion of the assist system based on the unintentional input force is prevented by the frequency-shaping characteristic. The effectiveness of the proposed method is verified by simulations and experiments for a power assist cart with a linear motor table.

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The oblique impact of a golf ball with a rigid steel target was studied using a high-speed video camera. The video images during the impact were employed to measure the compressional displacement of the ball normal to the target and to determine the normal velocity and acceleration of the ball as a function of time. The rotation angle of the ball was also measured to evaluate the angular velocity during the impact. The results showed that the angular velocity increased and then decreased during the impact. To study the velocity change, we introduced an analytical model and suggested that the ball deformation can play an important role to understand the friction effect during the impact.

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In V-shaped process of model-based development, methods of product information model decomposition from upper processes to lower processes have not yet been established. In this paper, we defined the diagrams, diagram elements and the design operations that are necessary to support the refinement and V&V process of the product information model in two Layers, based on stepwise methods for refining function structures, product behaviors, constraints, and required specifications. It is shown that design results are reflected and managed by expressing the model information data and design operations in DSM. It is proposed that iterative design processes using the matrices supports the effective refinement process, and stepwise V&V is supported effectively using the DSM in cooperation with product information models by demonstrating verification as a method of verifying the design on the model in the lower Layer, and validation as a method of evaluating the design in the lower Layer for requirements in the upper Layer.

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In recent years, efficient production by use of CAD/CAM systems draws attention due to the demand of high-variety low-volume. Semi-finishing by square end mill has some problem than finish cutting by ball end mill. However five-axis controll machining with square end mill is more difficult due to the various cusp height and the possibility of the tool gouging. This study aim at proposing a tool path generation method for five-axis controll semi-finishing with square end mill. The method can decide the position and the posture of square end mill without the interference and generate the tool path, which enables to decrease the machining time in consideration of the cusp height.

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Recently, industrial dual-arm robots have gained attention as new tools in the field of new automation. We therefore focus on them to flexibly control both the linear motion and the rotational motion of a working plate. However, one problem has been that it is difficult to measure the synchronous accuracy of two rotary axes without high accuracy gyro sensor. Thus, we proposed a novel method to measure the synchronous accuracy of two rotary axes of working plate with a ball, which keeps a ball rolling around a circular path on it by dual-arm cooperative control, and demonstrated this method made it feasible to estimate the synchronous accuracy of two rotary axes of it. In the present report, we investigated an influence of used ball and the offset error of plate rotary motion on estimating accuracy.

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