scholarly journals Eliminating Stick-Slip Vibrations in Drill-Strings with a Dual-Loop Control Strategy Optimised by the CRO-SL Algorithm

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1526
Author(s):  
Jorge Pérez-Aracil ◽  
Carlos Camacho-Gómez ◽  
Emiliano Pereira ◽  
Vahid Vaziri ◽  
Sumeet S. Aphale ◽  
...  
Keyword(s):  
Control Strategy ◽  
High Performance ◽  
Nonlinear Models ◽  
Drill String ◽  
Time Response ◽  
Fast Time ◽  
Parameter Uncertainties ◽  
Stick Slip ◽  
Loop Control ◽  
And Control

Friction-induced stick-slip vibrations are one of the major causes for down-hole drill-string failures. Consequently, several nonlinear models and control approaches have been proposed to solve this problem. This work proposes a dual-loop control strategy. The inner loop damps the vibration of the system, eliminating the limit cycle due to nonlinear friction. The outer loop achieves the desired velocity with a fast time response. The optimal tuning of the control parameters is carried out with a multi-method ensemble meta-heuristic, the Coral Reefs Optimisation algorithm with Substrate Layer (CRO-SL). It is an evolutionary-type algorithm that combines different search strategies within a single population, obtaining a robust, high-performance algorithm to tackle hard optimisation problems. An application example based on a real nonlinear dynamics model of a drill-string illustrates that the controller optimised by the CRO-SL achieves excellent performance in terms of stick-slip vibrations cancellation, fast time response, robustness to system parameter uncertainties and chattering phenomenon prevention.

scholarly journals Study on Topology and Control Strategy of High-Precision and Wide-Range Hybrid Converter for Photovoltaic Cell Simulator

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 39
Author(s):  
Jianfei Zhao ◽  
Minqi Hua ◽  
Tingzhang Liu ◽  
Tao Yu
Keyword(s):  
Control Strategy ◽  
Power Supply ◽  
High Performance ◽  
Photovoltaic Cell ◽  
Programmable Logic ◽  
Motor Simulation ◽  
Hybrid Topology ◽  
Wide Range ◽  
Cell Simulation ◽  
And Control

Aiming at the function and technical requirements of high-power photovoltaic cell simulation, high-performance programmable logic power supply and dc motor simulation, a high frequency isolation hybrid topology and control strategy based on current-source/voltage-source converter was studied and proposed. Firstly, according to the performance requirements of photovoltaic cell analog power supply, the control strategy requirements of the high-precision wide-range hybrid topology were proposed. Secondly, the working principle of the new hybrid topology was analyzed. At the same time, the equivalent model of the new hybrid topology was simplified and established, and the overall control strategy of the hybrid topology based on current compensation and sliding mode variable structure was proposed. Finally, simulation and experimental research on the hybrid topology was carried out, and the experimental test of photovoltaic cell simulation was completed. The simulation and experimental results show that the hybrid topology and control strategy proposed in this paper has the characteristics of wide-range output regulation, fast dynamic response, high efficiency and high power factor, and can be used for high performance photovoltaic cell simulation, programmable logic power supply and DC motor simulation.

scholarly journals Design and implementation of bi-directional converter with internet of things control based reading

2021 ◽  
Vol 23 (2) ◽  
pp. 938
Author(s):  
Wisam Dawood Abdullah ◽  
Raad Z. Homod ◽  
Abdulbasit H. Ahmed
Keyword(s):  
Internet Of Things ◽  
High Performance ◽  
Power Level ◽  
Loop Control ◽  
Current Voltage ◽  
Control Scheme ◽  
Performance Specifications ◽  
A New Technique ◽  
And Control ◽  
The Internet Of Things

In this paper, a new technique to monitor and control bidirectional DC-DC converter was designed and implemented precisely. A prototype of a complete system is verified with efficient communication capabilities. This system is realized by integrating the internet of things (IoT) operating system and the bidirectional DC-DC converter. The IoT communication facilities further develop and extend the platform for this system. The DC-DC converter with the soft switching technique will then convert the battery voltage to a high voltage of 380V inverter bus in emergencies via boost converter mode. High-frequency toroidal transformer has been used for power level shifting and isolation between the primary and secondary sides of the transformer. The closed-loop control scheme is implemented in software by using a high-performance 32-bit STM32 micro controller. IoT technique is used to find current, voltage and perform the communication smoothly through Wi-Fi sensors to complete the design of the system. The results of the proposed system prove the effectiveness of the proposed system with high-performance specifications.

Predictive-based sliding mode control for mitigating torsional vibration of drill string in the presence of input delay and external disturbance

2020 ◽  
pp. 107754632096099
Author(s):  
Roya Sadeghimehr ◽  
Amirhossein Nikoofard ◽  
Ali Khaki Sedigh
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
External Disturbance ◽  
Drill String ◽  
Smith Predictor ◽  
Input Delay ◽  
Drilling Process ◽  
Parameter Uncertainties ◽  
Stick Slip ◽  
Mode Control

Dealing with torsional vibrations and stick–slip oscillations of a drill string system is a challenging engineering task in the oil drilling process because of the harmful and costly consequences of such vibrations. In this article, the drill string system is modeled using a lumped-parameter model with four degrees of freedom, and the bit–rock contact is represented by a nonlinear function of a bit velocity. Also, tracking the desired velocity of a drill string system with known constant input delay is addressed in the presence of external disturbance and parameter uncertainties by applying the Smith predictor–based sliding mode control method. The performance of the smith predictor–based sliding mode control with input delay and disturbance in tracking the desired velocity and controlling the stick–slip oscillations is compared with the sliding mode control with/without input delay. The system output’s sensitivity to the delay parameter is also investigated, indicating how the bit velocity changes concerning the delay parameter. The proper choice of adaptation gain is determinative in the performance of the controller, and its impact is investigated. Moreover, the robustness of the smith predictor–based sliding mode control is shown by changing the weight on the bit parameter. Simulation results demonstrate the effectiveness of the proposed method.

scholarly journals Suppression of drill-string stick–slip vibration by sliding mode control: Numerical and experimental studies

2018 ◽  
Vol 29 (5) ◽  
pp. 805-825 ◽  
Author(s):  
VAHID VAZIRI ◽  
MARCIN KAPITANIAK ◽  
MARIAN WIERCIGROCH
Keyword(s):  
Mathematical Model ◽  
Sliding Mode Control ◽  
Close Agreement ◽  
Sliding Mode ◽  
Drill String ◽  
Numerical Results ◽  
Physical Parameters ◽  
Parameter Uncertainties ◽  
Stick Slip ◽  
Mode Control

We investigate experimentally and numerically suppression of drill-string torsional vibration while drilling by using a sliding mode control. The experiments are conducted on the novel experimental drill-string dynamics rig developed at the University of Aberdeen (Wiercigroch, M., 2010, Modelling and Analysis of BHA and Drill-string Vibrations) and using commercial Polycrystalline Diamond Compact (PDC) drill-bits and rock-samples. A mathematical model of the experimental setup, which takes into account the dynamics of the drill-string and the driving motor, is constructed. Physical parameters of the experimental rig are identified in order to calibrate the mathematical model and consequently to ensure robust predictions and a close agreement between experimental and numerical results for stick–slip vibration is shown. Then, a sliding mode control method is employed to suppress stick–slip vibration. A special attention is paid to prove the Lyapunov stability of the controller in presence of model parameter uncertainties by defining a robust Lyapunov function. Again experimental and numerical results for the control cases are in a close agreement. Stick–slip vibration is eliminated and a significant reduction in vibration amplitude has been observed when using the sliding controller.

Dynamic and Control Modeling and Simulation of High Speed Precision Positioning XY Table

2011 ◽  
Vol 467-469 ◽  
pp. 978-983
Author(s):  
Zhi Peng Ma ◽  
Xing Yu Zhao ◽  
Fu Jun Wang ◽  
Da Wei Zhang
Keyword(s):  
Control Strategy ◽  
High Speed ◽  
Closed Loop ◽  
Dynamic Performance ◽  
Matching Law ◽  
Closed Loop Control ◽  
Precision Positioning ◽  
Loop Control ◽  
Decoupling Mechanism ◽  
And Control

To study the dynamic performance and control strategy of a kind of high speed precision positioning XY table with a new kind of decoupling mechanism, the electromechanical co-simulation model with three closed-loop control system using proportional–integral–derivative controller (PID controller) is constructed. By use of finite element analysis (FEA) and co-simulation method, the preloaded spring as the key component in the decoupling mechanism is optimized. The matching law of the spring stiffness and preload is presented. The decoupling mechanism influence on the dynamic performance of the XY table during the movement is fully discussed. Based on the electromechanical model, a three closed-loop control scheme with disturbance observer and feed-forward controller is proposed. Co-simulation results demonstrate the validity of the control strategy.

Research on Modeling and Control Strategy of Electric Power Steering

2011 ◽  
Vol 97-98 ◽  
pp. 677-680
Author(s):  
Chang Shu Zhan ◽  
Ning Xu ◽  
Zhen Jiang Ma
Keyword(s):  
Electric Power ◽  
Control Strategy ◽  
Tracking Error ◽  
Equation Model ◽  
Electric Power Steering ◽  
Loop Control ◽  
Modeling And Control ◽  
Response Characteristics ◽  
Power Steering ◽  
And Control

This paper establishes the differential equation model and simulink simulation model of Electric Power Steering (EPS). After determining the structure of the control system, closed-loop control of given signal filtering and steering dish corner feedback signals was used respectively. The simulation shows that control strategy reduced the tracking error and the system dynamic response characteristics were good.

Modeling and Control of Drill-String System With Stick-Slip Vibrations Using LPV Technique

2020 ◽  
pp. 1-13
Author(s):  
Jun Cheng ◽  
Min Wu ◽  
Fen Wu ◽  
Chengda Lu ◽  
Xin Chen ◽  
...  
Keyword(s):  
Drill String ◽  
Stick Slip ◽  
Modeling And Control ◽  
And Control
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