The book is very application-oriented and provides the reader with detailed working procedures and hints for implementation routines and software tools.
Hydraulic Servo-systems will interest scientists and qualified engineers involved in the analysis and design of hydraulic control systems, especially in advanced hydraulic industries, the aeronautical and space, and automotive industries. Altogether the book gives a comprehensive survey of physical modelling, conventional and modern control stategies for hydraulic drives and can be recommended to engineers and scientists who are working in this field.
Help Centre. Track My Order. My Wishlist Sign In Join. Be the first to write a review. Add to Wishlist. Ships in 15 business days. Link Either by signing into your account or linking your membership details before your order is placed. Description Table of Contents Product Details Click on the cover image above to read some pages of this book! Featuring: - theoretical physically based modelling of hydraulic servo-systems; - experimental modelling system identification ; - control strategies for hydraulic servo-systems; - case studies and experimental results. Industry Reviews From the reviews: Altogether the book gives a comprehensive survey of physical modelling, conventional and modern control stategies for hydraulic drives and can be recommended to engineers and scientists who are working in this field.
All Rights Reserved. Lego Gadgets Klutz. The reshaped imaginary reference input makes the mold properly follow the original reference input. Furthermore, a velocity feedforward control algorithm is proposed for the non-sinusoidal mold oscillation. Because the mold velocity is closely connected to the valve input, the proposed velocity feedforward control algorithm with appropriate gain is effective for the non-sinusoidal oscillation. The test results showed that the mold adequately follows the original reference input for both the sinusoidal and non-sinusoidal oscillations of various input parameters.
In this paper, a mold oscillator based on a hydraulic servo system with dual cylinders is targeted. The basic configuration of a mold oscillator is shown in Fig. System configuration for mold oscillator with dual cylinder.
A typical closed-loop output trajectory is shown in Fig. Zadeh and C. In the reactor, an irreversible exothermic reaction takes place. In addition to the traditional function of course control, the ship rudder makes increasing demands on the rudder roll stabilization in its own scope of application [ 1 ], aiming to steadily, rapidly, and accurately track the rudder angle commands [ 2 ]. If the flow controlled by the pump and valve is assigned reasonably in the valve-pump parallel system, effective energy saving will be obtained. A scheme of a packed countercurrent absorption column.
Jelali and A. In this chapter, the feedforward control algorithms for mold oscillation are proposed. The feedforward control algorithm is composed of two separate algorithms; an input shape control algorithm and a velocity feedforward control algorithm. The overall control is a combined structure of a conventional feedback and proposed feedforward control algorithms as shown in Fig.
Overall diagram for mold oscillator control algorithm. In other words, the input shape control algorithm is split into the phase and amplitude adjustment algorithms.
First, the idea behind the phase adjustment is to shift the reference input so that it is in the reverse direction of the phase lead-lag relationship. To achieve this, the following index is introduced:. Curves for two sinusoidal waves with same amplitude and different phases. Online version in color. Similar to the phase adjustment, the amplitude of the reference input is adjusted using the feedback information returned from the mold position. However, as opposed to the phase adjustment case in which the mold position is used directly, the index for amplitude adjustment is derived from the maxima and minima of the mold position in each period.
The basic idea is to scale up or down the maxima and minima of the reference input by comparing those of the mold position with reference values. To achieve this, the following indices are introduced:.
Examples of original reference input and imaginary reshaped reference input. Recently, the continuous casting process requires a fast-speed operation to increase production. Because powder consumption rate is reduced and friction is increased as a result of increased casting speeds, more effective lubrication is required.
Among the various parameters that affect slab quality, a sinusoidal wave with an asymmetric modification to sinusoidal wave has a more significant effect. This paper focuses on a proportional relationship between the valve input and cylinder velocity. This means that the cylinder velocity basically has the same waveform as that of the valve input without the scale difference.
Further, the non-sinusoidal wave and its derivative have different waveforms and are given as. This difference in non-sinusoidal oscillation has a clear effect on the control performance of the mold oscillator.
Hydraulic Servo-systems details the basic concepts of many recent developments of nonlinear identification and nonlinear control and their application to hydraulic servo-systems: developments such as Advances in Industrial Control. Hydraulic Servo-systems details the basic concepts of many recent developments of nonlinear identification and nonlinear control and their application to.
With previous feedback control algorithms, the control reference did not have a wide enough positive and narrow enough negative peaks as compared to those of non-sinusoidal waves Fig. Curves for control references a without the velocity feedforward control algorithm; b with the velocity feedforward control algorithm. A more reasonable solution is to generate the control reference using the velocity of the non-sinusoidal wave. The ratio between the velocity feedforward and feedback control references is an important factor. Furthermore, the ratio is decided by the feedforward velocity gain of the non-sinusoidal wave.
Including the velocity feedforward control, the total control reference is thus given as. The proposed feedforward control algorithm was tested on a Matlab Simulink model and a scaled specimen of a typical mold oscillator used in industry. The Simulink model was derived from the mathematical model described in Section 2. First, the proposed feedforward control algorithm was tested on the Simulink model. Four cases were tested: a sinusoidal oscillation with only feedback control b sinusoidal oscillation with proposed input shape control c non-sinusoidal oscillation with input shape control and without velocity feedforward control d non-sinusoidal oscillation with velocity feedforward control.
This model-based test was done to demonstrate the behavior of the proposed algorithm. Following this, the performance analysis was carried out on the specimen.
In Fig. Curves for the reference input and corresponding mold position Simulink test a with only the feedback control b with input shape control c with input shape control and without velocity feedforward control d with velocity feedforward control algorithm. Following the Simulink simulation, the algorithm was then tested on the specimen. Curves for the comparison of plant algorithm and proposed algorithm Specimen test : increases of a averaged downward velocity b positive strip time.
In this study, a feedforward control algorithm has been developed for both sinusoidal and non-sinusoidal mold oscillations.
The proposed feedforward control algorithm consists of two components: an input shape control algorithm and a velocity feedforward control algorithm. The input shape control algorithm compensates for the phase delay and amplitude reduction of the mold position by generating an imaginary reshaped input reference. To handle the non-sinusoidal oscillation, a velocity feedforward control algorithm was introduced based on the relationship between the valve input and mold velocities.
For various input parameters including frequency, amplitude, and asymmetry, the mold position accurately followed the input reference using the proposed feedforward control algorithm. Already have an account? Login in here. ISIJ International. Journal home Advance online publication Journal issue About the journal. Regular Article. Keywords: continuous casting process , mold oscillator , non-sinusoidal oscillation , slab quality , hydraulic servo system. Model Description.
Feedforward Control Algorithms. Experimental Results.