scholarly journals Fractional Modeling and Characteristic Analysis of Hydro-Pneumatic Suspension for Construction Vehicles

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1414
Author(s):  
Huilai Sun ◽  
Ruichuan Li ◽  
Jikang Xu ◽  
Funing Xu ◽  
Bo Zhang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Fractional Order ◽  
Vibration Characteristics ◽  
Suspension System ◽  
Ratio Test ◽  
Characteristic Analysis ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Fractional Modeling ◽  
Pneumatic Suspension

The motion differential equation of hydro-pneumatic suspension is established to describe the vibration characteristics for a certain type of construction vehicle. The output force was deduced from the suspension parameters. Based on the suspension characteristics of a multi-phase medium, fractional calculus theory was introduced, and its fractional Bagley–Torvik equation was formed. The numerical computation by a low-pass filter of the Oustaloup algorithm was performed. The numerical solution of a nonlinear fractional equation was obtained to investigate the vibration characteristics of the suspension fractional system. Through the building of an equal-ratio test platform and simulation model, the fractional- integer-order model simulation and experimental data were compared. When the fractional order is 0.9, it better describes the motion characteristics of suspension system. The experiments show that the experimental data can fit the fractional-order system model well, and thereby prove the model on a hydro-pneumatic suspension system.

An experimental analog circuit realization of Matsuda’s approximate fractional-order integral operators for industrial electronics

2021 ◽  
Author(s):  
Murat Koseoglu ◽  
Furkan Nur Deniz ◽  
Baris Baykant Alagoz ◽  
Ali Yuce ◽  
Nusret Tan
Keyword(s):  
Fractional Order ◽  
Analog Circuit ◽  
Low Cost ◽  
Electric Circuit ◽  
Partial Fraction ◽  
Circuit Realization ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Performance Improvements ◽  
Low Pass

Abstract Analog circuit realization of fractional order (FO) elements is a significant step for the industrialization of FO control systems because of enabling a low-cost, electric circuit realization by means of standard industrial electronics components. This study demonstrates an effective operational amplifier-based analog circuit realization of approximate FO integral elements for industrial electronics. To this end, approximate transfer function models of FO integral elements, which are calculated by using Matsuda’s approximation method, are decomposed into the sum of low-pass filter forms according to the partial fraction expansion. Each partial fraction term is implemented by using low-pass filters and amplifier circuits, and these circuits are combined with a summing amplifier to compose the approximate FO integral circuits. Widely used low-cost industrial electronics components, which are LF347N opamps, resistor and capacitor components, are used to achieve a discrete, easy-to-build analog realization of the approximate FO integral elements. The performance of designed circuit is compared with performance of Krishna’s FO circuit design and performance improvements are shown. The study presents design, performance validation and experimental verification of this straightforward approximate FO integral realization method.

scholarly journals DEVELOPMENT OF A CONTROL ALGORITHM DEVICE LOAD BALANCING DEVICE

2021 ◽  
pp. 47-55
Author(s):  
Sergei V. Volkov ◽  
Ilsur Kh. Garipov ◽  
Aleksandr I. Orlov ◽  
Aleksei A. Savelyev
Keyword(s):  
Experimental Data ◽  
Load Balancing ◽  
Control Algorithm ◽  
Position Control ◽  
Filter Design ◽  
Nodal Point ◽  
Electrical Network ◽  
Primary Data ◽  
Pass Filter ◽  
Low Pass Filter

The work is devoted to improving the control algorithm of the load balancing device for 0.4 kV electrical mains that are in pilot operation. The action of the device is aimed at balancing the load at the nodal point of the electrical network, where several 3-phase outgoing lines are connected, by changing the connection diagram of the phases of one of them. The device is capable of realizing 6 combinations obtained by circular permutation and changing the phase rotation. The classification of analogs of the device according to the type of connection to the network is proposed. The technique of collection and processing of experimental data on the operation of the device is presented. Analysis of primary data shows that among the consumers there are powerful energy receivers with automatic two-position control. As a criterion for the expediency of one or another method of connecting the phases of the outgoing line to the phases of the source, the coefficient of non-uniformity of conductivities is taken. Strict observance of the condition of the minimum coefficient of unevenness is impossible in practice with the existing nature of the load due to the need for too frequent operation of the device. This and other limitations given in the work are the reason for the systematization of requirements for the device control algorithm, one of which is the need to filter the initial data before executing the main algorithm. The paper provides a rationale for the use of a digital IIR low-pass filter. Based on the frequency analysis of the curves of the conductivity unevenness coefficients, the filter design was carried out and the digital transfer function coefficients were calculated. A difference equation is determined that is suitable for implementation in the program for the control microcontroller of the device. The developed filter is universal and suitable for use in the control algorithm of a load balancing device of any power and for any type of load. The results of modeling the proposed filter are presented using the example of experimental data. The prospect of the research is the collection of statistics on various types of consumers, analysis of practical situations, in order to further refine the algorithm.

scholarly journals Fractional-order low-pass filter with electronic tunability of its order and pole frequency

2018 ◽  
Vol 69 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Lukas Langhammer ◽  
Jan Dvorak ◽  
Jan Jerabek ◽  
Jaroslav Koton ◽  
Roman Sotner
Keyword(s):  
Fractional Order ◽  
Current Mode ◽  
Proper Function ◽  
Electronic Control ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Internal Parameters ◽  
Current Follower ◽  
Low Pass ◽  
Experimental Laboratory

Abstract This paper presents novel solution of a fractional-order low-pass filter (FLPF). The proposed filter operates in the current mode and it is designed using third-order inverse follow-the-leader feedback topology and operational transconductance amplifiers (OTAs), adjustable current amplifiers (ACAs), auxiliary multiple-output current follower (MO-CF) as simple active elements. The filter offers the beneficial ability of the electronic control of its order and also the pole frequency thanks to electronically controlled internal parameters of OTAs and ACAs. As an example, five particular values of fractional order of the FLPF were chosen and parameters of the filter were calculated. Similarly, also electronic control of the pole frequency of the filter was studied. The design correctness and proper function of the filter are supported by simulations with CMOS models and also by experimental laboratory measurements. Comparison of the simulation results of the proposed filter for two different approximations of the parameter sα is also included.

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