Yoshihiro Matsui

Plant model analysis based on closed-loop step response data

In this paper, a simple scheme to estimate frequency responses of linear time-invariant single-input single-output (SISO) systems based on closed-loop step response data is investigated. The method uses only a single set of step response data of plants under closed-loop operating conditions. The input and output of a plant are filtered by a simple bandpass filter, and the frequency response of the plant is obtained with the Discrete Fourier Transforms (DFTs) of the filtered input and output signals. The validity of the proposed method is illustrated through simulations and experiments.

Virtual reference feedback tuning using closed-loop step response data in frequency domain

The paper gives a controller tuning method using a Virtual Feedback Tuning (VRFT) approach in the frequency domain. While the original VRFT uses a data-driven performance index based on input/output data directly, the proposed one derives a frequency domain performance index based on the Fourier transformation of one-shot experimental input-output data. The frequency domain performance index makes the optimal pre-filter be straightforwardly designed without using the spectral density of the collected input signal. Hence, the proposed ones outperforms the original ones when the input and output data is collected from the closed loop step response. The effectiveness of the proposed method is illustrated through a numerical example.

A Direct PID Gain Tuning Based on FRIT Method Using Optimal Filter in the Frequency Domain

Abstract The paper gives a PID gain tuning method using a Fictitious Reference Iterative Tuning (FRIT) approaches in the frequency domain. The proposed method obtains the PID gains that optimize a performance index, which evaluates the difference between the closed loop output and the reference model output in the frequency domain. The performance index is calculated using the Fourier transformation of one-shot experimental input-output data. The paper shows that a bandpath filter plays an important role in the Fourier transformation of the one-shot input-output data, and the optimal pre-filter, which well approximates the performance index to the original performance index, can be easily calculated in the frequency domain, and contributes to deriving a better PID gains improving the closed loop response through numerical examples.

A controller design for nonlinear systems with time-delay using closed-loop step response data

This paper proposes a controller design method for the Hammerstein models which are linear models with static input nonlinearities and are a kind of nonlinear systems. The method requires only closed-loop step response data for controller design. The information in time domain of the data is used to estimate the plant model, and that in frequency domain is used to confirm the validity of the linear part of the plant model. Since the method estimates the plant model and compensates the nonlinearity of the plant, the controller for the linearized plant can be designed in consideration of the trade-off between the closed-loop bandwidth and the stability margin by a model-based approach.

Fictitious Reference Tuning Using Information in Frequency Domain

Abstract In this paper, an application method of Fictitious Reference Iterative Tuning (FRIT), which has been developed for controller gain tuning for single-input single-output systems, to state feedback gain tuning for single-input multivariable systems is proposed. Transient response data of a single-input multivariable plant obtained under closed-loop operation is used for model matching by the FRIT in time domain. The data is also used in frequency domain to estimate the stability and to improve the control performance of the closed-loop system with the state feedback gain tuned by the method. The method is applied to a state feedback control system for an inverted pendulum with an inertia rotor and its usefulness is illustrated through experiments.

Design of fixed-order controller for traveling crane

Manually operated traveling cranes are used in many industrial plants. One of the most difficult operations of such crane is the load swing suppression. This paper proposes an anti swing controller for traveling cranes. The traveling crane model was linearized to design the controller. The controllers are designed based on LMI. Simulations confirm that the controllers are able to suppress the load swing.

Speed Control of Three-inertia Systems by Full-order Controllers

This paper proposes a design method of controllers for three-inertia systems. The controllers designed by the method are compared to the PID controllers. The validity of the method is confirmed by the simulations