We consider the harmonic control for 2 robot arms that provide 2 links. This dynamics of two link robot arms are expressed by non-linear differential equations. In this presentation, we linearize the non-linear differential equation using non-linear feedback and make control inputs for the linearized system by using the Genetic Algorithm (GA). When we apply the control inputs made for the linearized system to the original non-linear system, control performance is affected by parameters of stabilizing feedback. Then, we make optimal parameters of stabilizing feed back by using GA.

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Continuous-time sliding mode control is realized by a simple control algorithm and is evaluated as a very effective control method. However, the control input can be changed at only sampling instants when the continuous-time sliding mode control is implemented. We investigate what happens due to the implementation and how the control algorithm should be modified.

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In the reference [1], Oueini et al proposed a nonlinear absorber for the vibration of flexible structure, i.e. a cantilever beam. The absorber is composed of controllers each of which corresponds to a mode and utilizes the parametrically excited oscillation of the Mathieu equation. They showed the effectiveness of the absorber through the experiments and numerical simulation for the first mode of the beam. In this paper, we explain their analysis and present the results of the numerical simulation for the case where the vibrations of the first and second modes of the beam are excited simultaneouly. It is shown that the nonlinear absorber works well.

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Observers for tire/road friction and road conditions are relevant to optimization of ABS, TCS, etc. In the reference [1], Canudas de Wit et al designed these observers with LuGre model. In this paper, following the procedure of Canudas de Wit et al, we design observers and examined their behaviors under various conditions by means of numerical simulations, which are satisfactory.

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Ortega studied the output feedback stabilization of food-chain systems using the passivity of the port-controlled Hamiltonian systems and presented a procedure to determine the feedback control law for the case of simplified cofficients. In this paper, we applied his procedure to the general food-chain systems and obtained an output feedback stabiliting control law. The numerical simulation shows the satisfactory results.

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We study the design of PI controller for the linear system with structured uncertainties. PI controller is usually designed by the ultimate sensitivity method. We derive the interval of K_P and T_I in the closed loop system, where all poles lie in the desired root region in left-half plane. Our design method is application of Kharitonov’s theorem with concept of monotonicity.

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Sliding-mode control is investigated for a discrete-time system with slowly varying disturbance and uncertaities. We first show the narrowest neighborhood of the sliding surface in which the state can remain and next propose a sliding mode control algorithm that keeps the state in there without requiring an enormous input. Under the presence of system parameter variations, it is then shown that the condition for x=0 to be the stable equilibrium point. To reduce the narrowest range, disturbance is estimated and approximately canceled. Finally, we show some simulation results to confirm the effectiveness of the theoretical results and the proposed control algorithm.

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The Liner Quadratic Gaussian Poisson(LQGP) problem denotes an optimal control problem with linear dynamics and quadratic costs with Gaussian and Poisson noise disturbances. This paper applies risk-sensitive control to LQGP problem in order to consider influence of large noise(amplitude). The problem is examined with an application to a single stage manufacturing system in an uncertain environment.

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In the past, we presented the tracking system with one sampling delay. In this paper, at first we propose a tracking system with N-th sampling delay, in the case where an input-output pulse transfer function of a plant is Z^-N. Secondly we propose a system converting an input-output pulse transfer function of a plant to Z^-N with the inverse system of the plant.

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It’s necessary that robots in human living space and their motion are designed so as not to give mental stress to human. To design such motion, we propose to express the mental stress by motion feature quantity, representing the feature of the robot motion. In this paper, we choose subjectivity evaluation reported by subjects watching the motion of a manipulator as the mental stress index. We define motion feature quantity by linear combination of mean magnitude of joint angular velocities of the manipulator, and approximate it to the mental stress index by means of the least squares method. As a result of investigating the correlation between the motion feature quantity and the mental stress, it turns out that the mental stress can be feasibly expressed by motion feature quantity to some degree.

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In the disturbance suppression control method for car-mounted and portable optical disk drive proposed by Yokoyama and others, the use of actuator position sensor is always necessary. In this paper, an improved method, in which the expensive actuator position sensor is useless, is proposed for the same purpose.

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We consider the stability analysis method for the linear digital control system with structured uncertainties. Our necessary and sufficient stability conditions are obtained by using Jury-Pavlidis’s theorem. Since derived conditions should be ascertained on the whole parameter region, we apply the notion of monotonicity to check the stability conditions at endpoints of parameter region. However, there are some cases where the monotonicity conditions do not hold. In such case, we apply monotonization method. Although the stability conditions become sufficient by applying the monotonization method, it can be checked analytically at endpoints of parameter region.

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In this paper a new indirect robust self-tuning regulator is proposed including an inverse system of a plant and a robust compensator which is obtained by solving the mixed H^∞ sensitivity problems. The influence of the error of the identification and external disturbance can be cleared up mostly.

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