Controlling chemical dosing for sulfide mitigation in sewer networks using a hybrid automata control strategy

2013 ◽  
Vol 68 (12) ◽  
pp. 2584-2590 ◽  
Author(s):  
Yiqi Liu ◽  
Ramon Ganigué ◽  
Keshab Sharma ◽  
Zhiguo Yuan
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Biological Processes ◽  
Control Performance ◽  
Hybrid Automata ◽  
Sewer Pipe ◽  
Physical Chemical ◽  
Iron Salts ◽  
Pumping Stations ◽  
Sewer Networks

Chemicals such as magnesium hydroxide (Mg(OH)2) and iron salts are widely used to control sulfide-induced corrosion in sewer networks composed of interconnected sewer pipe lines and pumping stations. Chemical dosing control is usually non-automatic and based on experience, thus often resulting in sewage reaching the discharge point receiving inadequate or even no chemical dosing. Moreover, intermittent operation of pumping stations makes traditional control theory inadequate. A hybrid automata-based (HA-based) control method is proposed in this paper to coordinate sewage pumping station operations by considering their states, thereby ensuring suitable chemical concentrations in the network discharge. The performance of the proposed control method was validated through a simulation study of a real sewer network using real sewage flow data. The physical, chemical and biological processes were simulated using the well-established SeweX model. The results suggested that the HA-based control strategy significantly improved chemical dosing control performance and sulfide mitigation in sewer networks, compared to the current common practice.

Following Straightly Control Strategy and Testing for Split Platform in Roadway

2012 ◽  
Vol 619 ◽  
pp. 34-38
Author(s):  
Jing Yi Zhao ◽  
Feng Lei Chen ◽  
Rui Guo
Keyword(s):  
Field Test ◽  
Control Strategy ◽  
Control Method ◽  
Kinematic Model ◽  
Control Performance ◽  
Test Verification

On the basis of two pilots operating the split truck in the roadway, study control strategy of the single-pilot operating powering vehicle and flatbed walking and following straight; establish the kinematic model of the control method and field test verification; detect angles of the rod and powering vehicle、flatbed vehicle; improve the control performance of the truck, supply the theoretical and practical basis for similar products, and further corner’s following.

scholarly journals Disturbance Rejection Control Method for Isolated Three-Port Converter with Virtual Damping

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3204 ◽  
Author(s):  
Jiang You ◽  
Mengyan Liao ◽  
Hailong Chen ◽  
Negareh Ghasemi ◽  
Mahinda Vilathgamuwa
Keyword(s):  
Power Density ◽  
Control Strategy ◽  
Disturbance Rejection ◽  
Control Method ◽  
Damping Ratio ◽  
Current Control ◽  
Resonant Peak ◽  
Model Parameters ◽  
Control Performance ◽  
Disturbance Rejection Control

The high-power density and capability of three-port converters (TPCs) in generating demanded power synchronously using flexible control strategy make them potential candidates for renewable energy applications to enhance efficiency and power density. The control performance of isolated TPCs can be degraded due to the coupling and interaction of power transmission among different ports, variations of model parameters caused by the changes of the operation point and resonant peak of LC circuit. To address these issues, a linear active disturbance rejection control (LADRC) system is developed in this paper for controlling the utilized TPC. A virtual damping based method is proposed to increase damping ratio of current control subsystem of TPC which is beneficial in further improving dynamic control performance. The simulation and experimental results show that compared to the traditional frequency control strategy, the control performance of isolated TPC can be improved by using the proposed method.

scholarly journals An improved negative zero vibration anti-swing control strategy for grab ship unloader based on elastic wire rope model

2021 ◽  
Vol 22 ◽  
pp. 45
Author(s):  
Xiaohua Cao ◽  
Chao Meng ◽  
Yong Zhou ◽  
Meng Zhu
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Operation Time ◽  
Wire Rope ◽  
Control Performance ◽  
Control Effect ◽  
Swing Angle ◽  
Working Cycle ◽  
Bridge Type ◽  
The Wire

A dynamic model of swing system of bridge-type ship unloader is established by considering the elastic factor of wire rope in this paper. Based on this model, an improved Negative Zero Vibration (NZV) shaper with optimal control parameters of variable rope length system is proposed to restrain the swing of grab. Then the control effects, influence of elasticity factor and parameter sensitivities are analyzed based on numerical simulation. The results show that the proposed control strategy can reduce the working cycle time of the grab ship unloader about 11% when considering the elastic factor of the wire rope, and the grab's maximum residual swing angle decreases by 67% when discharging at full load, and decreases by 79% when taking the cargos at empty load. This implies that the improved NZV control method provides better swing angle control performance and shorter operation time compared with the Zero Vibration (ZV) and Zero Vibration and Derivative (ZVD) methods. Moreover, elastic rope model can improve the swing angle control effect of grab based on the proposed control strategy compared with rigid rope model. The parameter sensitivity analysis displays that the grab's maximum residual swing angle by using the improved NZV method is sensitive to the change of the grab's center of gravity, and this angle is more sensitive to the wire rope diameter deviation compared with the elastic modulus deviation.

scholarly journals Torque Ripple Suppression of PMSM Based on Robust Two Degrees-of-Freedom Resonant Controller

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1015
Author(s):  
Mingfei Huang ◽  
Yongting Deng ◽  
Hongwen Li ◽  
Jing Liu ◽  
Meng Shao ◽  
...  
Keyword(s):  
Control Strategy ◽  
Measurement Errors ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Torque Ripple ◽  
Current Loop ◽  
Two Degrees Of Freedom ◽  
Robust Stability Analysis ◽  
Resonant Controller ◽  
Testing Environments

This paper concentrates on a robust resonant control strategy of a permanent magnet synchronous motor (PMSM) for electric drivers with model uncertainties and external disturbances to improve the control performance of the current loop. Firstly, to reduce the torque ripple of PMSM, the resonant controller with fractional order (FO) calculus is introduced. Then, a robust two degrees-of-freedom (Robust-TDOF) control strategy was designed based on the modified resonant controller. Finally, by combining the two control methods, this study proposes an enhanced Robust-TDOF regulation method, named as the robust two degrees-of-freedom resonant controller (Robust-TDOFR), to guarantee the robustness of model uncertainty and to further improve the performance with minimized periodic torque ripples. Meanwhile, a tuning method was constructed followed by stability and robust stability analysis. Furthermore, the proposed Robust-TDOFR control method was applied in the current loop of a PMSM to suppress the periodic current harmonics caused by non-ideal factors of inverter and current measurement errors. Finally, simulations and experiments were performed to validate our control strategy. The simulation and experimental results showed that the THDs (total harmonic distortion) of phase current decreased to a level of 0.69% and 5.79% in the two testing environments.

scholarly journals Electromagnetic Actuator System Using Witty Control System

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 65
Author(s):  
Der-Fa Chen ◽  
Shen-Pao-Chi Chiu ◽  
An-Bang Cheng ◽  
Jung-Chu Ting
Keyword(s):  
Control System ◽  
Control Method ◽  
Search Algorithm ◽  
Electromagnetic Actuator ◽  
Control Performance ◽  
Learning Capability ◽  
Learning Rates ◽  
Agricultural Applications ◽  
Actuator System ◽  
Rice Milling

Electromagnetic actuator systems composed of an induction servo motor (ISM) drive system and a rice milling machine system have widely been used in agricultural applications. In order to achieve a finer control performance, a witty control system using a revised recurrent Jacobi polynomial neural network (RRJPNN) control and two remunerated controls with an altered bat search algorithm (ABSA) method is proposed to control electromagnetic actuator systems. The witty control system with finer learning capability can fulfill the RRJPNN control, which involves an attunement law, two remunerated controls, which have two evaluation laws, and a dominator control. Based on the Lyapunov stability principle, the attunement law in the RRJPNN control and two evaluation laws in the two remunerated controls are derived. Moreover, the ABSA method can acquire the adjustable learning rates to quicken convergence of weights. Finally, the proposed control method exhibits a finer control performance that is confirmed by experimental results.

Performance Improvement of SVPWM-Based Three-Phase Grid-Connected Inverters

2013 ◽  
Vol 732-733 ◽  
pp. 1261-1264
Author(s):  
Zhi Lei Yao ◽  
Lan Xiao ◽  
Jing Xu
Keyword(s):  
Dynamic Response ◽  
Control Strategy ◽  
Pulse Width Modulation ◽  
Control Method ◽  
Grid Current ◽  
Current Controller ◽  
Three Phase ◽  
Reference Grid ◽  
Grid Connected Inverter

An improved control strategy for three-phase grid-connected inverters with space vector pulse width modulation (SVPWM) is proposed. When the grid current contains harmonics, the d-and q-axes grid currents is interacted in the traditional control method, and the waveform quality of the grid current is poor. As the reference output voltage cannot directly reflect the change of the reference grid current with the traditional control strategy, the dynamic response of the grid-connected inverter is slow. In order to solve the aforementioned problems, the d-and q-axes grid currents in the decoupled components of the grid current controller are substituted by the d-and q-axes reference grid currents, respectively. The operating principles of the traditional and proposed control methods are illustrated. Experimental results show that the grid-connected inverter with the improved control strategy has high waveform quality of the grid current and fast dynamic response.

Robust Control Method Based on Machine Learning for Boiler Combustion System

2014 ◽  
Vol 685 ◽  
pp. 368-372 ◽  
Author(s):  
Hao Zhang ◽  
Ya Jie Zhang ◽  
Yan Gu Zhang
Keyword(s):  
Robust Control ◽  
Intelligent Control ◽  
Pid Control ◽  
Control Algorithm ◽  
Control Method ◽  
Support Vector ◽  
Control Performance ◽  
Fuzzy Pid Control ◽  
On Line ◽  
Control Output

In this study, we presented a boiler combustion robust control method under load changes based on the least squares support vector machine, PID parameters are on-line adjusted and identified by LSSVM, optimum control output is obtained. The simulation result shows control performance of the intelligent control algorithm is superior to traditional control algorithm and fuzzy PID control algorithm, the study provides a new control method for strong non-linear boiler combustion control system.

Optimized Non-Dead-Time Control of Inverter with Two-Phase Modulated SVPWM

2012 ◽  
Vol 562-564 ◽  
pp. 1531-1536
Author(s):  
Ming Xing Zhu ◽  
Jing Bo Shi
Keyword(s):  
Control Strategy ◽  
Pulse Width Modulation ◽  
Dead Time ◽  
Control Method ◽  
Short Circuit ◽  
Two Phase ◽  
Zero Crossing ◽  
Time Control ◽  
Bus Voltage ◽  
Current Zero

In the inverter control system, two-phase modulated space vector pulse width modulation (SVPWM) algorithm has the advantages of minimum switch loss and higher utilization of direct current (DC) bus voltage. Non-dead-time control strategy can eliminate the problems of the dead time effects. But the traditional non-dead-time control strategy heavily depends on the current zero-crossing detection, which may cause the output voltage distortion or even a short circuit. Based on the analysis of the reason for the distortion, a new optimized non-dead-time control method is proposed. Two methods for the detection of the overlapping area are enumerated. The conclusions are confirmed by the simulation results with MATLAB/ SIMULINK.

Time-Optimal Coordination Control for the Gear-Shifting Process in Electric-Driven Mechanical Transmission (Dog Clutch) without Impacts

2020 ◽  
Vol 9 (2) ◽  
pp. 155-168
Author(s):  
Ziwang Lu ◽  
◽  
Guangyu Tian ◽  
Keyword(s):  
Control Strategy ◽  
Position Control ◽  
Control Method ◽  
Synchronization Control ◽  
Mechanical Transmission ◽  
Coordination Control ◽  
Optimal Position ◽  
Drive Motor ◽  
Time Optimal ◽  
Optimal Coordination

Torque interruption and shift jerk are the two main issues that occur during the gear-shifting process of electric-driven mechanical transmission. Herein, a time-optimal coordination control strategy between the the drive motor and the shift motor is proposed to eliminate the impacts between the sleeve and the gear ring. To determine the optimal control law, first, a gear-shifting dynamic model is constructed to capture the drive motor and shift motor dynamics. Next, the time-optimal dual synchronization control for the drive motor and the time-optimal position control for the shift motor are designed. Moreover, a switched control for the shift motor between a bang-off-bang control and a receding horizon control (RHC) law is derived to match the time-optimal dual synchronization control strategy of the drive motor. Finally, two case studies are conducted to validate the bang-off-bang control and RHC. In addition, the method to obtain the appropriate parameters of the drive motor and shift motor is analyzed according to the coordination control method.

Constant force control for aluminum wheel hub grinding based on ESO + backstepping

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shijie Dai ◽  
Yufeng Zhao ◽  
Wenbin Ji ◽  
Jiaheng Mu ◽  
Fengbao Hu
Keyword(s):  
Control Strategy ◽  
Force Control ◽  
Control Method ◽  
Response Speed ◽  
Backstepping Control ◽  
Constant Force ◽  
Content Type ◽  
Disturbance Rejection Control ◽  
The Stability ◽  
Differential Control

Purpose This paper aims to present a control method to realize the constant force grinding of automobile wheel hub. Design/methodology/approach A constant force control strategy combined by extended state observer (ESO) and backstepping control is proposed. ESO is used to estimate the total disturbance to improve the anti-interference and stability of the system and Backstepping control is used to improve the response speed of the system. Findings The simulation and grinding experimental results show that, compared with the proportional integral differential control and active disturbance rejection control, the designed controller can improve the dynamic response performance and anti-interference ability of the system and can quickly track the expected force and improve the grinding quality of the hub surface. Originality/value The main contribution of this paper lies in the proposed of a new constant force control strategy, which significantly improved the stability and precision of grinding force.

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