Energy consumption to drive actuator is thought as a disadvantage of active vibration control. However, the actuator of the active vibration control system absorbs energy from vibrating structure to suppress the vibration. In other words, the actuator regenerates energy from the vibrating structure. Especially, piezoelectric actuator can regenerate energy effectively, because it has few internal energy loss. Recently, class D amplifier based on switching circuit has been utilized due to its high-efficiency. It can drive the actuator with few energy loss and regenerate energy from the actuator. Therefore, the energy regenerative active vibration control system can be realized by using the class D amplifier to drive the piezoelectric actuator. The validity of the system has been shown by numerical simulation. In this paper, the power consumption of the proposing energy regenerative active vibration control system is measured by electrical power meter to show the validity of the system and the power consumption is compared with power consumption of conventional active vibration control system using linear amplifier. The result shows the power consumption of the proposing system is negative and the power consumption of the conventional system is positive. In other words, the proposing system is regenerating vibration energy in contrast with the conventional system is consuming energy from external source.

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This paper deals with smart film sensors and actuators used with electrode patterning films. Almost all conventional distributed parameter sensors and actuators, PVDF film have to be shaped and attached on the substrate. To overcome handling ability and radical thickness, electrode patterning PVDF film using photoresist technique applies to distributed parameter modal sensor and actuator. First, this paper overviews the design process for modal filtering method and modal actuating method using two-dimensionally distributed modal sensor and actuator. And manufacture method for high-definition electrode patterning PVDF film is proposed. Furthermore, sensibility of the proposed films are experimentally measured in the case of one-dimensional structure. Then, efficient vibration-mode filtering and actuating used with electrode patterning film and effectiveness of proposed method are demonstrated by experimental results.

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Rotating machinery is widely used in the industrial plant, for example, power plant, chemical plant, mass-production plant and so on. In order to ensure safety operation of the rotating machinery, vibration condition monitoring of the machinery can play a crucial role. In this study, the vibration energy harvester of the piezoelectric bimorph cantilever type was proposed for vibration condition monitoring applications of rotating machinery. Proposed energy harvester consisted of Macro-Fiber Composite (MFC) actuator which is flexible and durable piezocomposite type actuator. This study evaluates the power generation performance of proposed energy harvester via both numerical simulation and experiment when subjected to sinusoidal mechanical vibration.

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This paper proposes a vibration testing and health monitoring system based on an impulse response excited by a laser ablation. In conventional vibration testing using an impulse hammer, the excitation force hardly includes high frequency element over tens of kilohertz. High power YAG pulse laser is used in this system for producing an ideal impulse force on structural surface. It is possible to measure high frequency FRF (Frequency Response Function) in this system. And water droplet overlay on the metal is used to adjust the force magnitude in laser excitation. A health monitoring system is constructed by this vibration testing system and damage detecting filter. A microscopic damage of structures can be extracted by detecting fluctuations of high frequency vibration response with this health monitoring system. The vibration testing system is validated by comparing an aluminum block's FRFs that are obtained by laser excitation, impulse hammer and FEM.

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A power assist system for automobile slide doors that can provide comfortable operational feelings has been developed. A VSS observer, that can consider the nonlinear characteristics of the plant, is applied to improve the estimation accuracy of the door speed. Tt is examined to improve the operational feelings using the VSS observer through simulations.

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In this paper, a search based MPC approach to the cold start control of SI engines is proposed. The combustion of SI engine is a complicated, nonlinear and hybrid process which has four strokes (events) in a cylinder cycle. Each event has different dyanmics. In particular, the control input of spark timing and fuel injection are discrete. For this system, we propose a model predictive control approach based on bisection search for the optimal determination of spark timing. To this end, the highly complicated dynamics is simplied first based on the property of engine combustion, from the view point of torque building. To ensure an effective search, the range of search is also determined based on the property of engine combustion. Application to the SICE engine benchmark shows that this approach works quite satisfactorily.

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This paper presents injury protection control of the occupant's lower extremities in vehicle collision with an active seat belt and an active knee bolster. The seat belt force for his or her pelvis is controlled by the active seat belt. The contact force between his or her knees and the instrument panel is controlled by the active knee bolster. The control problem is formulated as an optimization problem and the control inputs are calculated to minimize the maximum load of his or her femurs under the constraint of the maximum seat belt force. Numerical simulations show that cooperative control of the active seat belt and the active knee bolster reduces the maximum load of the femurs and the maximum seat belt force at the same time.

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We propose a design method of an active front wheel steering controller that guarantees closed-loop stability under the rear tire side forces saturation. The proposed controller utilizes the information on the rear tire side forces to counteract the destabilizing effects caused by the rear tire side force saturation. The controller can suppress the magnitude of the slip angle while the rear tire side forces are saturated. The effectiveness of the proposed method is shown through numerical simulations.

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Automotive suspension consists of a suspension spring and a damper, and contributes to the performance of ride comfort and road-hugging property. Generally, it is well known that a trade-off exists between ride comfort and road-hugging property. In order to overcome this problem, respectively, damper has nonlinear characteristic that varies according to the relative velocity of suspension and controlled suspension systems are employed. However, there are few controller designs considering nonlinear damping characteristic depended on relative velocity of suspension. It needs the controller considering nonlinear characteristic of damper in order to adopt various road condition. Therefore we address the controller design considering nonlinear characteristic of damper. We proposed reasonable design of gain-scheduling controller adopting nonlinear characteristic of damper. In order to investigate effectiveness of proposed method, we carried out simulations assumed various road conditions. As a result, the proposed method demonstrated comprehensively good performance compared to the linear controller.

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Adaptive Cruise Control (ACC) is an in-vehicle convenience feature designed to maintain a set speed and, when necessary, adjust the speed to maintain an appropriate distance from a leading vehicle. This study aims at proposing a control method for ACC to improve not only following capability to a leading vehicle but also suppression of fuel consumption. It is said that low acceleration drive contributes suppression of fuel consumption, but excessive low acceleration causes worsening following capability. It is because there is trade-off between them and we have to consider both all together. We design a control system for ACC to balance the following capability and the suppression of fuel consumption using Linear Quadratic Integral control. It is demonstrated from some simulations that the control system is effective for suppression of fuel consumption.

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This paper describes an experiment for accelerated motion control for the Acrobot on the horizontal bar with compliance. Since the horizontal bar is bending during gymnastics, gymnasts seem to be demonstrating their abilities more effectively by utilizing this compliance. Similarly, there is possibility that the movement of the better performance that the robot originally has can be achieved by utilizing this compliance. Based on this presumption, a control law which achieves accelerated motion for the Acrobot is proposed. To confirm this discussion, simulation and experiment using the Acrobot are carried out, and the advantage and the disadvantage by using compliance are examined by comparing results of with and without compliance cases.

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In this paper, we describe a thennal control of a thermoelectric cooler / heater with Peltier device which is operated by the Peltier Effect. Generally, it is said that the thermal control with Peltier device is difficult because of its nonlineariry. In order to deal with the nonlinearity, we use nonlinear model predictive control for the thermal control of the device. A nonlinear model of the thermal system with Peltier device is derived. The validity of the model is evaluated by experimental results. Nonlinear model predictive control system is designed for the model. Recursive Kalman filter is used to estimate the unobservable state variables. The experimental results show the accurate control performance. The robustness against themal load is also verified by the experiments.

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This paper presents a design method of sliding mode controller for output tracking problems when the sensor measures only the tracking error. The proposed controller can be designed systematically so that the internal model principle should hold during the sliding mode. Since the discontinuous singnal in the sliding mode controller is naturally smoothened and the control input is contineous, the so called chattering problem does not happen.

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This paper presents a sliding mode controller of boat rudder angle servo systems. The integral sliding mode control theory is applied to the proposed controller so as to have high robustness against the normal pressure of the rudder, which is regarded as an unknown disturbance. With the twisting algorithm and the describing function method, a new switching input of the sliding mode controller is designed in order to lead the switching function to a limit cycle. As a result, the chattering could be improved by the relatively smooth control input.

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A rotating body with one input has been proven to be locally strongly reachable with some exceptions using a limited order of Lie brackets. This paper analyzes system behavior on the singular points using upto fourth degree of Lie brackets and discusses design strategy with respect to mass distribution.

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This paper describes the modeling of the Denguribot and the control experiment of rolling motion for the Denguribot. The Denguribot is the Acrobot composed of 2 links with the curved contour. The outer contour of links is shaped from the arc whose radius is different by the tip and the sidepiece of the link. It is difficult to control the whole motion via common control strategy since the model differs according to the contact between the Denguribot and the ground. Therefore, the control strategy is constructed for two phases, downward phase and upward phase. The rolling motion is realized by setting the output function that achieves the control objective for each phase and by applying Output Zeroing control. Finally, it is confirmed that the rolling motion control is realized through the control experiment, but the control experiment is not so easy. It is necessary to implement theoretical assumptions, such as perfectly inelastic collision and nonslip rolling motion. In this paper, the control experiments have been done with the Dengribot on a horizontal table with rubber shock absorber. The experimental results show validity of the proposed control strategy.

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This paper presents a traction control strategy for a vehicle robot comprising two modules: a normal vehicle with wheels and additional mass module to control the vehicle dynamics by changing the center of gravity. In order to obtain large traction force at slippery slopes, a simple nonlinear control law for the additional mass is proposed, which does not require estimation of the uncertain terrain conditions and measurement of the vehicle speed. The effectiveness is demonstrated through numerical simulations.

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In a car crush, in order to reduce a shock to a baby being laid in a child bed in a vehicle, it is necessary to control the impulsive force to be constant and under the allowable value. Therefore, it is proposed that an inverted pendulum style active child bed, which reduces the impulsive force affecting the bad in a car crush and is made the force to work perpendicularly with the bed. The effectiveness of the inverted pendulum style is confirmed by the simulation using the mechanism analysis software. As the result, it is clarified that the force affecting the bed is controlled to the constant desired value depending the collision velocity, and the maximum force can be reduced in comparison with the case in which the bed is being fixed at the sheet.

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This study, we proposed the motion control for omni four wheel independent steering/driving vehicle. This controller searches the optimal four driving forces and four side forces. Nevertheless solving the nonlinear motion equation is difficulty to search the these forces. So we solve the nonlinear motion equation by BFGS method of quasi-Newton's method. In addition, this motion control includes the Sliding mode control to improve the robustness. We verify the effectiveness of this robust motion control through the simulation.

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This paper presents an optimal control method which is based on a newly established framework of control problem. This framework is composed of obtaining the ideal characteristics of the system for a given criteria function and solving the equations of motion by using the inverse of ideal characteristics function as an optimal control law for given initial conditions. The criteria function is defined as the combination of the energy flow equation and performance measures. Minimization of the criteria function yields the ideal characteristics. In this paper, the necessary condition for optimality is given and the optimality is proven. Simulations carried out on an underactuated underwater vehicle with single actuator show the performance and feasibility of the control method.

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[in Japanese]

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[in Japanese]

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In this paper, fundamental tests were carried out using RFID tags with sensors and built-in memory in order to clarify the applicability of RFID tags with sensors to structural health monitoring systems. An alternative system was used because RFID tags with sensors and built-in memory are under development. This system has almost identical performance to that of RFID tags and data communication is performed by wireless LAN. Sensors such as acceleration sensors and wire strain gages are used for structural health monitoring systems. Fundamental performances of these sensors were clarified through shaking table tests using a two-story specimen. Furthermore, time historical displacement responses are estimated by using Fourier Integral and Butterworth Filter employed as a high-pass filter. Fundamental characteristics of the proposed system and used sensors, and the applicability of RFID tags with sensors to structural health monitoring systems are discussed and clarified based on results of shaking table tests and Fast Fourier Transform (FFT) analyses.

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This paper proposes the rapid damage detection system utilizing the dsPIC micro-controller and the short time period fast Fourier transform (SFFT). The proposed damage detection system has the two types of the sensors. One is the accelerometer for detecting the damage. The other is the vibration switch for using the trigger system.The proposed damage detection system can automatically provide information about the safety of the structure under an earthquake in real time. The proposed damage detection methodology also provides useful information for implementing the advanced structural health monitoring system. First of all, the capability of the vibration switch, accelerometer and dsPlC micro-controller are experimentally investigated. Then, the validity of the proposed methodology is demonstrated by conducting computer simulations and small scale model experiments.

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The Connected Control Method (CCM) has attracted attention as a new control method for vibration of high-rise buildings. The effectiveness of CCM has already been established in previous studies. However, the level of control force required to CCM often excess the allowable stress of structures. In this study, to alleviate the effect of concentrated control force, distributed CCMs connecting structures at multiple levels is introduced. In this paper, the effectiveness of distributed CCMs is investigated through computer simulations and experiments using earthquake excitation records. The influence of numbers and locations of actuators on control performance is examined and the advantage of distributed CCMs to reduce stress is confirmed.

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An Elastic wedge is a plate whose thickness decreases smoothly to zero. Several authors presented results on Elastic wedges as new passive method for damping of structural vibrations. They proved that vibration energy in Elastic wedges accumulates in the thin edge theoretically and experimentally. As a result, small amounts of damping material added to that edge are enough to dissipate large amount of energy. Previous papers showed experimental results using a second-power law function for the thickness variation. This paper farther investigated the efficiency of Elastic wedges and presents experimental results using first (linear), second and third power laws. Experiments were carried out by inputting a vibration signal in the wedges and measuring accelerations at a number of locations. Then, the response of each Elastic wedge was evaluated with and without damping material. The results showed that all these Elastic wedges can achieve important damping levels, most especially at high frequency ranges.

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This study proposes a load combination method considering the correlation coefficient among support excitations for response analysis of multi-supported piping system. The traditional combination methods can lead to large errors depending on the combination of inputs because of neglecting the correlation among inputs. However, because this proposed method should lead to small errors regardless the combination of inputs, it is expected that designing comes more rational. In the simulation of single- degree-of-freedom system, the comparison of results of this method and traditional methods showed us the availability of this method. And, the simulation of two-degree-of-freedom system showed us the availability of using the combination method considering the correlation among modes in addition to this method.

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There are some nonlinear control methods for vibration control of the pendulum model. We proposed a nonlinear control method based on Jacobian elliptic functions in previous studies. The control method aims to reduce the mechanical energy of a pendulum by the motion of the actuator synchronized with the pendulum. In this report, we apply the method to a cart-type serial double pendulum system. In the double pendulum model, it can deprive the first pendulum connected to the cart of the mechanical energy. Then, the second pendulum in the edge is controlled indirectly. The effectiveness of the method is verified by numerical simulations with the object of power from cart to pendulum. In addition, we clarify that the performance of vibration control depends on the system parameters.

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The design ground motions are usually defined to be compatible with the given response spectrum which is a useful measure of the linear dynamic response of the structure. Recently, a new synthesis method was proposed by Masuda et al. that can make artificial ground motions compatible with the given time-frequency characteristics as well as the given response spectra. Because the maximum elasto-plastic deformation level depends on the nonstationary load history applied to the structure, the structural response to the ground motions designed by that method are expected to be less-variable even in the elasto-plastic region. In this paper, a number of artificial ground motions are synthesized, and elasto-plastic response analyses are carried out to examine the variance of the structural response in the elasto-plastic region. It is revealed that the variance of the structural response to the ground motions designed by Masuda's method is less than one to the ground motions by the conventional design method.

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In this paper we discuss a method of the giant swing motion of a 2-DOF link horizontal bar mechanism using Delayed Feedback Control. Firstly we define a kind of Poincare section to regard the system as a discrete-time system for evaluating its stability. On the other hand, a way to calculate numerically the transitional error matrix is shown. Secondly, we investigate how we can obtain the gain of feedback on the basis of analysis about the stabilization of system under the control of delayed feedback. Finally, we present a simulation result to show the effectiveness of this method.

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Recently, automatic digging and remote control hydraulic excavator has been often studied from an productivity and safety standpoint. The productivity for the automatic digging algorithm is a moot point. The ultimate goal of this study is to figure out the digging performance by the simulation for the automatic digging process. Authors define the soil volume per the applied energy as productivity in this paper. At first, a miniature test device was developed to simulate the digging by the pre-programmed bucket tip trace. Besides, digging simulation model by two dimensional distinct element methods (2D-DEM) was developed. The simulation is validated by comparing with the digging test results of the miniature. As the result, it is obtained that the time histories of the reaction forces from the soil and the soil volume for several tip traces. Finally, it is quantitatively clarified that the productivity due to the tip trace.

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In most studies on flexible robot arm, the controller is designed in joint space, besides the task for robot arm is described in reference coordinate frame. In this paper, basic research of end point position control for two links flexible robot arm is dealt with. The nonlinearity of the arm is canceled by using a nonlinear compensator designed by a dissolve motion acceleration control (DMAC). The linearlized model is controlled by a PID controller. The robustness of the obtained controller are verified by the simulation and the control experiment.

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A surveillance system is required to gather the suffering information in the stricken area safely after large- scale disasters. An autonomous blimp is the best option for this purpose. This paper proposes a control design method for automatic landing of outdoor blimp robots with lateral slip. The landing method consists of stabilizing control in horizontal plane and longitudinal control for letdown-velocity and pitching motion of the blimp. A stabilizing controller considering wind is designed by inverse opimal control. Some simulations are performed to confirm the usefulness of the proposed method.

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In this paper, guidance control of small electric helicopter with low cost GPS is presented. In the case of small helicopter, the payload limitation is tight by comparison with larger one. So, we should use light weight, low cost and low accuracy GPS. At first, we combine the low cost GPS and a inertial navigation system(INS) with low accuracy inertia sensor, and INS/GPS composition navigation system is designed. And next, horizontal velocity and position model of small helicopter is derived, and then, guidance controller for small unmanned helicopter are designed by using model base control method. Finally, a flight control experiment with INS/GPS system is carried out, and the experimental results show the effectiveness of suggested navigation system and controller.

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In this paper, we propose an autonomous hovering control of hobby class small scale unmanned helicopter by using model based control method. Firstly, we make the model of small-scale unmanned helicopter analythically.Secondly, we designed control system with kalman filter based LQI control method. The control system consists of the attitude controller and the velocity controller. And we connect these two controllers to series. Finally, the hovering control experiment is carried out, and experiment result shows that analytic modeling method and model based control design are very useful for autonomous control for small scale unmanned helicopter.

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The accuracy of small and low cost GPS is insufficient for precise landing of MAV. This study aims to land on an MAV size landing target by using outer sensors. This paper describes about proposed mobile outer sensors which consist of IR rangeflnders, servo motors and ultrasonic sensor for measuring outer environment and an algorithm for position measurement. Additionally, by using proposed sensor system, an experiment of autonomous hovering over the 52cm × 52cm table and autonomous landing was carried out in indoor environment. As a result of experiment, MAV was succeeded to hover keeping 17.9cm horizontal accuracy, and succeeded to land on the table from 50cm height.

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In late years, automatic running of the vehicle robots is studied actively. There are various kinds of methods; visual feedback control is one of them. In our laboratory, ten cameras setting below the ceiling capture vehicle states; then each image are processed by host computer and vehicles are controlled. This experimental system includes time delay, for example, transmission time of captured image to host computer from cameras, communication time between host computers and processing time of image. These time delays degrade accuracy of control. In addition, for large delay, this system might become unstable. In this paper, influence of time delay on vehicle motion control is studied. We computed stability margin using Nyquist plot and verified it through experiment.

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Wheel drive is widely used for mobile robots because of its high mobility and efficiency. Since it is necessary to set wheel position apart from others to keep enough stability, the size of robot tends to become larger. So it gets to be difficult to operate in crowded space. To resolve this problem, we propose wheel position optimization using receding horizon control for leg/wheel robots. Wheel position is optimized for each wheels independently to balance stability with mobility. In this paper, we show how to compute optimal wheel position by receding horizon control. Then, we verified our method through simlations and confirmed its effictiveness.

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This paper proposes a competition of inverted pendulum type two-wheeled robot vehicle on MCR(Micom car rally) course. The control theory of inverted pendulum type vehicle is already established. But the control technology like this system is not extended in education among university students. Proposed competition is able to participate by using commercially developed small and low cost robotic vehicle, and is expecting to bring highly educated engineers.

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In order to achieve a skillful handling like a human hand, it is necessary that a hand has a capability to manipulate tools. One important problem of tool handling with a multifingered hand is that relative positions among a robot hand, a tool and a handled object change during the handling. For this reason, it is necessary to measure the relative positions in realtime, and to control a hand so as to cancel the changes. In our research, we have resolved this problem by using a high speed visual servoing and a passive joint model. Using the passive joint model, dexterous and flexible tool handling is achieved. In this paper, as an example, a tweezers is handled by a multifingered hand. A new method to control tools and some experiment results are shown.

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This paper deals with cooperative Target-enclosing problem by swarms of vehicles. First, we introduce Closed-Loop Inverse Kinematics(CLIK) which is utilized for control law. Second, we define two control objectives. One is to enclose a target in regular polygon and the other is to close up the traveling direction of a moving target. To achieve control objectives, we design several tasks and they are connected by Null-Space-based Behavioral(NSB) control. Then, we analyze the convergence of Target-enclosing behavior by Lyapunov Stability Theorem. Finally, simulation and experimental results show our effectiveness of the proposed method.

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This paper deals with a passive-decomposition based control a bilateral teleoperation between a single master robot and multiple cooperative slave robots with time varying delay At first. we decompose the dynamics of multiple slave robots into two decoupled dynamics by using passive-decomposition: the Shape-system describing dynamics of the cooperative works, and the Locked-system representing overall behavior of the multiple slave robots. Second, we propose the PD control method for bilateral teleoperation to guarantee the asymptotical stability of the system for time varying delay. Finally experimental results show the effectiveness of the proposed teleoperation.

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This paper deals with the Simultaneous Localization and Mapping (SLAM) problem using Extended Kalman Filter. We analyze the convergence of the error covariance matrix of SLAM problems via EKF for the two cases. One is a stationary robot case and the other is a moving robot case. In simulation results evaluate the correctness of derived theorems for the convergence properties of the error covariance matrices. In experimental results, robot's state and environment information can be precisely estimated. Finally, the effectiveness of EKF-SLAM was shown.

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In this paper, an adaptive control method for target-enclosing strategies is considered. The proposed enclosing control laws achieve enclosing configurations based on virtual structures. We assume that there exit an uncertainty in the information exchange between an agent and all of its neighbors on the network.We regard that the uncertainty in the information exchange can be described by the perturbation of the elements of adjacent matrix. Our proposed method can estimate the perturbation of the elements in the notion of adaptive control strategy.

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