Wyniki wyszukiwania - BazTech

1

Application of fractional calculus in iterative sliding mode synchronization control

Zhang Xin, Wen-Ru Lu, Zhang Liang, Xu Wen-Bo

Archives of Electrical Engineering

|

2020

|

Vol. 69, nr 3

499--519

EN

In order to control joints of manipulators with high precision, a position tracking control strategy combining fractional calculus with iterative learning control and sliding mode control is proposed for the control of a single joint of manipulators. Considering the coupling between joints of manipulators, a fractional-order iterative sliding mode crosscoupling control strategy is proposed and the theoretical proof of its progressive stability is given. The paper takes a two-joint manipulator as the research object to verify the control strategy of a single-joint manipulator. The results show that the control strategy proposed in this paper makes the two-joint mechanical arm chatter less and the tracking more accurate. The synchronous control of the manipulator is verified by a three-joint manipulator. The results show that the angular displacement adjustment times of the threejoint manipulator are 0.11 s, 0.31 s and 0.24 s, respectively. 3.25 s > 5 s, 3.15 s of a PD cross-coupling control strategy; 2.85 s, 2.32 s, 4.22 s of a PD iterative cross-coupling control strategy; 0.14 s, 0.33 s, 0.28 s of a fractional-order sliding mode cross-coupling control strategy. The root mean square error of the position error of the designed control strategy is 6.47 × 10−6 rad, 3.69 × 10−4 rad, 6.91 × 10−3 rad, respectively. The root mean square error of the synchronization error is 3.96×10−4 rad, 1.36×10−3 rad, 7.81×10−3 rad, superior to the other three control strategies. The results illustrate the effectiveness of the proposed control method.

2

Comparison of a Perpetual and PD Inventory Control System with Smith Predictor and Different Shipping Delays Using Bicriterial Optimization and SPEA2

Chołodowicz E., Orłowski P.

Pomiary Automatyka Robotyka

|

2016

|

R. 20, nr 3

5--12

EN

Inventory optimization is critical in inventory control systems. The complexity of real-world inventory systems results in a challenging optimization problem, too complicated to solve by conventional mathematical programing methods. The aim of this work is to confront: a perpetual inventory system found in the literature and inventory system with PD control and Smith predictor proposed by the authors. To be precise, the two control systems for inventory management are analyzed with different shipping delays and compared. With regard to complexity of the proposed control system, we use a SPEA2 algorithm to solve optimization task for assumed scenario of the market demand. The objective is to minimize the inventory holding cost while avoiding shortages. A discrete-time, dynamic model of inventory system is assumed for the analysis. In order to compare the results of systems, Pareto fronts and signal responses are generated.

PL

W pracy przyjęto dyskretny, stacjonarny, dynamiczny model systemu magazynowego ze stałym w czasie opóźnieniem dostaw. Głównym celem jest przeprowadzenie analizy porównawczej dwóch systemów automatycznego sterowania zamówieniami: ciągłego systemu sterowania magazynem z adaptacyjnym poziomem zamówienia (ang. Perpetual Inventory System with adaptive order level) oraz systemu sterowania magazynem z regulatorem proporcjonalno-różniczkującym oraz predyktorem Smitha z adaptacyjnym poziomem referencyjnym zapasów dla trzech różnych opóźnień dostaw. Optymalne nastawy układów regulacji zostały dobrane za pomocą algorytmu ewolucyjnego dla problemów optymalizacji wielokryterialnej: SPEA2 (ang. Strength Pareto Evolutionary Approach). W symulacji uwzględniono dwa kryteria minimalizacji: koszt utrzymania zapasów (ang. Holding Cost) oraz koszt niedoboru zapasu (ang. Shortage Cost). Wyniki badań symulacyjnych zaprezentowano za pomocą wykresów oraz tabel w środowisku MATLAB/Simulink.

3

Input Shaping and Feedback Control of a Single-Link Flexible Manipulator

Tokhi O. M., Mohamed Z.

Mechanika / Akademia Górniczo-Hutnicza im. St. Staszica

|

2003

|

T. 22, z. 3

447-454

EN

This paper presents investigations into the development of hybrid control schemes for input tracking and end-point vibration suppression of a single-link flexible manipulator system. A collocated proportional--derivative (PD) control scheme using hub angle and hub velocity feedback is initially developed for control of rigid body motion of the system. This is then extended to incorporate a noncollocated proportional-integral-derivative (PID) controller and input shaping techniques for control of vibration of the system. Simulation results of the response of the manipulator with the controllers are presented in time and frequency domains. The performances of the control schemes are assessed in terms of input tracking and level of vibration reduction in comparison to the PD control scheme.