The transient response of pneumatic transmission line, if the amplitude of it is greater than a certain value, is different from the one analyzed by the linear theory which is generally used. That shows the occurrence of nonlinear phenomenon. To investigate the nonlinear phenomenon of the transient response, firstly the boundary of an existence of it must be fixed, and so the precise analysis which include that of velocity fluctuation is needed, because of the transition to turbulence is considered to be the main factor of the nonlinear phenomenon.
In this study, high speed and accurate computing method for the transient response of very-small amplitude is developed, which is based on the linear thory and at the boundary condition of considering heat transfer through the line wall. Then the boundary of the validity of linear thoery is illustrated on basis of experimental and computed results. And it is concluded that the main factor of nonlinear phenomenon is the passing transition to turbulence of transient air flow in the line.

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In this paper, we propose a novel stress/strain sensing probe for tactile sensors, which observes the internal strain caused by touches through the resonance frequency shifts of a cavity. We form a spherical cavity below the touching surface and put a transmitter in it. Then we can observe strong resonance (Q∼100) at several frequencies. Since they are uniquely related with the shape, we can determine the deformation of the cavity from their frequency shifts. We formalize the relationship between the frequency shifts and the internal stress/strain. We also show an efficient manufacturing method of the sensor and several experimental results for determining contact style with a single receiver, and for obtaining direction information with triple receivers.

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In the previous paper, we extended the designing method proposed by Keel et al., which is originated from robust eigenvalue assignment, to a linear system subject to uncertainty which was expressed by the linear combination of time-varing parameters and time-invariant matrices characterizing (or restricting) the structure of uncertainty. In the expression, the uncertainty structure often tends to be considerably strong.
This paper presents a new design method to stabilize a linear system involving time-varying unceratinty in the state matrix by means of state feedback controller, in which the elements of uncertainty matrix are assumed to be continuous functions of time and to be individually limited in the variations. The expression of uncertainty is structually more relaxed than the preceding one. The proposed method is also based on eigenvalue assignment using Sylvester's equation. Moreover, Perron-weightings (positive real diagonal weightings) are utilized to reduce conservatism of the uncertainty tolerance. To demonstrate and estimate the effectiveness, designs of lateral missile autopilot are shown.

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For discrete-time plants with direct feedthrough terms, we consider a loop transfer recovery (LTR) technique based on the Riccati equation formalism. We find that the recovery procedure at the plant input side should utilize the correlation between a disturbance and an observation noise. The variance of the observation noise component independent of the disturbance is taken as a parameter for the recovery. It should be noted that most discrete-time models of practical interest are non-minimum phase. We show that, for non-minimum phase plants, the Riccati equation with the parameter being zero has multiple non-negative definite solutions one of which is stabilizing. The stabilizing solution is then used to obtain an explicit expression of the sensitivity matrix achieved by the recovery procedure. Using the expression, we discuss the meaning of the LTR for non-minimum phase plants with direct feedthrough terms.

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This paper is concerned with a design method of μ controllers. First, based on generalized strong positive real lemma, we derive a new LMI condition for uncertain systems to achieve μ<γ for all frequencies. Then we give a design method of μ suboptimal controllers in terms of BMI, and evaluate its effectiveness by simulation.

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Controllability and observability gramians are derived for input delay systems. The gramians are constructively given based on matrix Lyapunov equations and the corresponding eigenvalues/vectors are fairly characterized with the solutions to an transcendental equation. Then providing some interpretations for input delay systems, we elaborate the calculation method of balanced reduction and illustrate the prodedure with numerical examples.

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Quadratic stability analysis is one of the most effective technique to robust stability analysis for systems with parametric uncertainties. In ordinary quadratic stability analysis, quadratic stability of the system which consists of given system matrices (A-matrix), structure of parametric uncertainties, and a region of parametric uncertainties becomes a subject of discussion. In this paper, we evaluate the region of the parametric uncertainties for given system matrices and structure of parametric uncertainties, in which the system is quadratically stable. Though the evaluation is based on scaled H^∞ norm condition which is usually applied to quadratic stability analysis for parametric uncertain system, the evaluation dose not include scaling matrix.

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The contour control of industrial mechatronics servo system have been implimented in cutting process, sealing, polishing and boundeering. In recent years, the control performance with high precision is requied from working environments and quality improvement. A method for precise contour control of mechatronic servo system with master-slave axes was proposed by use of the synchronous position control technique. Robustness of the proposed method for the modelling error was analysed theoretically. The proposed method was evaluated by use an experiment of XY table and showed satisfactory contour control performances.

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In this paper, we propose two sensor-based deadlock-free navigation algorithms in a 2D uncertain world. In almost all previous algorithms, a mobile robot comes close to its goal monotonously after avoiding an interfered obstacle. Consequently at worst, there is no obstacle where a mobile robot can hit in a 2D uncertain world and the robot arrives at the goal surely. We call this deadlock-free property, i.e., the convergence of a mobile robot to its goal, as the metric property. In this paper, we propose a new type of two sensorbased navigation algorithms whose deadlock-free characteristics are ensured by obstacle geometry. By using the geometric characteristic, a mobile robot never joins any deadlock, i.e., periodic cycle, and consequently arrives at its goal in an unknown 2D world.

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Characteristics of control system design using Universal Learning Network (U.L.N.) are such that a system to be controlled and a controller are both constructed by U.L.N. and that the controller is best tuned through learning. U.L.N. has the same generalization ability as N.N.. So the controller constructed by U.L.N. is able to control the system in a favorable way under the condition different from the condition at learning stage. But stability can not be realized sufficiently.
In this paper, we propose a robust control method using U.L.N. and second order derivative of U.L.N.. The proposed method can realize more robustness than the commonly used Neural Network. Robust control considered here is defined as follows. Even though the system parameter variables in a nonlinear function of the system at control stage change from those at learning, the control system is able to reduce its influence to the system and can control the system in a preferable way as in the case of no variation. In order to realize such robust control, a new term concerning the variation is added to a usual criterion function. And control parameter variables are adjusted so as to minimize the above mentioned criterion function using the second order derivative of the criterion function with respect to the parameters. Finally it is shown that the controller constructed by the proposed method works in an effective way through a simulation study of a nonlinear crane system.

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This paper presents a revised genetic algorithm (RGA) for parameter adjustment of nonlinear controllers. The RGA is based on the principle of selecting stabilizable chromosomes. The quadratic stabilization technique is used to realize the principle, i.e., to check stabilizability of the chromosomes which describes the parameters of nonlinear controller in the form of binary notation. In addition, the RGA has an index parameter of the robustness for control systems. It is, therefore, possible to design robust controllers by appropriately selecting a value of the index parameter. This simulation results show that the RGA can realize avoidance of instability phenomenon, fast parameter adjustment and robust controller design.

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The calibration accuracy of four type R thermocouples was evaluated from a series of deviations between measured values which were corrected with a SPRT and interpolating thermo-EMFs concerning the JIS for thermocouples. The mean deviation of each thermocouple is found to be about -0.15°C∼+0.10°C with the standard deviation of less than ±0.05°C in the temperature range of 50°C∼950°C.

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A new image velocimetry which measures velocity distributions from dynamic image of visualized flow field was utilized by applying a genetic algorithm to a velocimetry based on a tracking of particles image pattern. It was demonstrated by measuring velocity vectors around a circular cylinder that the new image velocimetry was effective.

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This paper deals with a positive realness problem raised in the discrete repetitive control. It is shown that the sufficient conditon of the repetitive control stability can be satisfied through constructing a discrete positive real transfer function using some phase-lead compensation.

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This paper disscusses open loop system identification method from impulse response of closed loop system using ERA. Some experimental demonstration using Engineering Test Satellite-VI (ETS-VI) is shown to verify the validity of the algorithm.

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A simple rotary testing equipment is needed to measure directly angular acceleration. In this paper a simple biaxial rotary equipment is set up by using one motor, a rotating shaft having inclined surface and a table having pivots as a gyroscope, reduding vibratory noise to a certain extent. Secondly, a biaxial angular acceleration sensor is set up using accelerometer of a monolithic IC type. It was cleared that the equipment can be a good excitor for low frequency range.

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