Switching vibration control between dynamic absorber and active control has been proposed for the dual structural vibration device on the basis of the kinetic energy as the threshold. For the active control with a fixed feedback gain, the threshold of switching should be set conservative and the effect of the active control was not enough. Therefore, a variable feedback gain control is introduced, which is assumed the mechanical energy as an indicator. It is expected that the actuator moves in a stroke range as possible and the performance will be better than the conventional switching control. In this paper, the effective variable feedback and switching control on the basis of mechanical energy as the two threshold are considered by experimental results.

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This paper proposes an active control type of momentum exchange impact damper (AMEID) and its application to reducing shock vibration of the floor. The floor is modeled as a one-degree-of-freedom system. The active component of AMEID is realized by using a linear motor. The controller design of AMEID is based on the LQR optimal control theory. The simulation results show that the performance of AMEID is not affected by the mass ratio. In addition, the performance of AMEID is compared with the conventional passive momentum exchange impact damper (PMEID), the active mass damper (AMD) and the conventional active control method in reducing the floor shock vibration. It is shown that the shock reduction performance obtained by AMEID is larger than that obtained by PMEID. The power consumption and the stroke of the actuator for AMEID are lower than those of AMD. Furthermore, the transmitted force obtained by AMEID is smaller than that of the conventional active control.

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This paper treats the control of a pneumatic servo table combining the air cylinders and sliding guides embedded with aerostatic bearing. Since compressed air flows into the small gap between the bearing and the sliding guide, the cylinder floats around the air film and on the guide surface of the table. The friction forces of the pneumatic servo table are measured, and the relation of frictional force and speed is plotted. The hybrid self-tuning fuzzy controller with the velocity compensators and dead-zone are proposed in this paper. From the experimental results, in case of different position, the positioning accuracy can reach the 0.04μm.

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In regard to the nonminimum phase MIMO discrete time systems, a method using estimation method in designing an observer-based output tracking controller is proposed in this paper. Provided the variation of the disturbance in the two consecutive sampling instances is not changed significantly, both the system state and the unknown disturbance can be simultaneously estimated by our proposed observer algorithm with the estimation error being constrained in a small bounded region of the order of O (T). The control law including a feedforward term and a feedback input can cause the tracking error to be bounded in a small region with the guarantied system stability. A numerical example is presented to demonstrate the applicability of the proposed control scheme.

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This paper describes an improved solution to the simultaneous localization and mapping (SLAM) problem based on pseudolinear models. Accurate estimation of vehicle and landmark states is one of the key issues for successful mobile robot navigation if the configuration of the environment and initial robot location are unknown. A state estimator which can be designed to use the nonlinearity as it is coming from the original model has always been invaluable in which high accuracy is expected. Thus to accomplish the above highlighted point, pseudolinear model based Kalman filter (PLKF) state estimator is introduced. A less error prone vehicle process model is proposed to improve the accuracy and the faster convergence of state estimation. Evolution of vehicle motion is modeled using vehicle frame translation derived from successive dead reckoned poses as a control input. A measurement model with two sensor frames is proposed to improve the data association. The PLKF-based SLAM algorithm is simulated using Matlab for vehicle-landmarks system and results show that the proposed approach performs much accurately compared to the well known extended Kalman filter (EKF).

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An investigation was made of a method for designing adaptive cruise control (ACC) so as to achieve a headway distance response that feels natural to the driver while at the same time obtaining high levels of both string stability and ride comfort. With this design method, the H_∞ norm is adopted as the index of string stability. Additionally, two norms are introduced for evaluating ride comfort and natural vehicle behavior. The relationship between these three norms and headway distance response characteristics was analyzed, and an evaluation method was established for achieving high levels of the various performance characteristics required of ACC. An ACC system designed with this method was evaluated in driving tests conducted on a proving ground course, and the results confirmed that it achieved the targeted levels of string stability, ride comfort and natural vehicle behavior.

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As people grow older, the ability to walk becomes ever more important to live an independent life. A simple system that is useful for evaluation and analysis of gait is necessary. Our goal is to design a wearable gait analyzer. In this study, we estimated the floor reaction force vector using an ultra-thin pair of wearable sensor pads. The floor reaction force vector, when someone is walking, is in the direction of the body's center of gravity. The gap separating the floor reaction force vector and the body's center of gravity generates a rotation moment, which is what we used to create this equation. Our evaluation method will be useful for future development of sensor systems.

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The subject of this paper is the estimation of damping coefficients for an air motor rotation experiment. This paper studies three methods for the calculation of damping coefficients under the air motor rotation experiment, including the proposed inverse model, finite difference model and the application of Laplace transform method to deduce an equation for calculation of damping coefficient. In the air motor rotation experiment, the data of experimental angular velocity and experimental torque can be employed to calculate the damping coefficients by using the inverse model proposed by this paper. The advantage of the inverse model is that the damping coefficients, the angular velocity and the angular displacement for air motor rotation experiment can be obtained at the same time. But the finite difference method and the Laplace transform method can not do that. Synthesizing the analytic results, the inverse model proposed by this paper can reasonably calculate the damping coefficients for air motor rotation experiment.

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A number of different structures in industrial facilities are installed on supports. There is the case that the damage occurs by the coupled vibration. The response magnification is obtained from the modal natural frequency and the modal damping ratio of the coupled system in the seismic design. Therefore, the modal natural frequency and the modal damping ratio of the coupled system are required. The natural frequency and the damping ratio of the support and the structure are obtained during the initial design process or by a shaking test. However, the modal natural frequency and the modal damping ratio of the coupled system are not easily obtained. The modal natural frequency of the coupled system can be calculated from theoretical equation, but the modal damping ratio cannot be easily calculated. In the present study, an equation to calculate the modal damping ratio of the coupled system with classic damping is presented. In addition, a simple equation to calculate the modal damping ratio with a non-classic damping system is proposed. This equation is evaluated both theoretically and experimentally. The proposed equation is useful for obtaining the modal damping ratio without performing eigenvalue analysis or a shaking test.

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A novel symbolic formulation is presented to model dynamics of large-scale open-loop holonomic multibody systems, by using absolute joint coordinates and via matrix transformation, instead of solving constraint equations. The resulting minimal set of second-order linear ordinary differential equations (ODEs) can be used for linear vibration analysis and control directly. The ODEs are generated in three steps. Firstly, a set of linearized ODEs are formulated in terms of absolute coordinates without considering any constraint. Secondly, an overall transform matrix representing constraint topology for the entire constrained system is generated. Finally, matrices for a minimal set of ODEs for the open-loop holonomic multibody system are obtained via matrix transformation. The correctness and efficiency of the presented algorithm are verified by numerical experiments on various cases of holonomic multibody systems with different open-loop topologies, including chain topology and tree topology. It is indicated that the proposed method can significantly improve efficiency without losing computational accuracy.

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This paper proposes an impact control method for a forging machine using a momentum exchange impact damper. This method is based on momentum conservation of two colliding bodies. A conventional added mass control method fails to suppress the acceleration and force transmission simultaneously. By using the momentum exchange impact damper, it is shown that the bed acceleration and the transmitted force to the floor are reduced. This paper presents a theoretical analysis of an impact damper and an optimum condition that leads to a minimization of the energy of a forging machine. An experimental analysis is shown to validate the simulation results.

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