scholarly journals Effect of EGR and Fuel Injection Strategies on the Heavy-Duty Diesel Engine Emission Performance under Transient Operation

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 566 ◽  
Author(s):  
Fangyuan Zhang ◽  
Zhongshu Wang ◽  
Jing Tian ◽  
Linlin Li ◽  
Kaibo Yu ◽  
...  
Keyword(s):  
Control Strategy ◽  
Fuel Injection ◽  
Open Loop ◽  
Point Load ◽  
Injection Timing ◽  
Open Loop Control ◽  
Loop Control ◽  
Smoke Opacity ◽  
Engine Emission ◽  
Close Loop Control

To reduce the smoke and nitrogen oxide (NOx) emissions; a detailed study concerned with exhaust gas recirculation (EGR) and diesel injection strategy was conducted on a two-stage series turbocharging diesel engine under transient operating condition. One transient process based on the constant speed of 1650 r/min and load increases linearly from 10% to 100% within 5 s was tested in this study. The effect of the EGR valve control strategy on engine transient performance was examined. The results show that better air-fuel mixing quality can be obtained with the optimized the EGR valve open loop control strategy and the smoke opacity peak decreased more than 64%. Under the EGR valve close loop control strategy; the smoke opacity peak was lower than with open loop control strategy; but higher than without EGR. The effect of fuel injection strategy on engine transient performance was examined with the EGR valve close loop control. The results show that sectional-stage rail pressure (SSRP) strategy (increasing injection pressure from a turning point load to 100% load) and optimizing fuel injection timing can improve the engine emission performance. The satisfactory results can be obtained with lower NOx (382 ppm) emissions and the smoke opacity peak (3.8%), when the turning point load is set to 60% with the injection timing delay 6° CA.

Responses and Optimization of a PID-Based Speed Regulating System of the Planetary Mixer

2011 ◽  
Vol 418-420 ◽  
pp. 1865-1868
Author(s):  
Ming Jin Yang ◽  
Xi Wen Li ◽  
Zhi Gang Wang ◽  
Tie Lin Shi
Keyword(s):  
Control System ◽  
Open Loop ◽  
Open Loop Control ◽  
Efficient Operation ◽  
Loop Control ◽  
Loop Control System ◽  
Response Optimization ◽  
Close Loop Control ◽  
Close Loop Control System

The performance of speed regulating is very important to the mixing process with safe, efficient operation and high quality of production. Strategies and practices of responses and optimization of a PID-based speed regulating system of a planetary mixer were presented in this paper. Research results show that: by means of the signal constraint function presented by Simulink Response Optimization, optimization PID parameters of the 2-DOF-PID controller can be obtained, and the response of close-loop control system has quite good performance of overshoot, response time, and stability compared with an open-loop control system.

Suppression of Instabilities in Gaseous Fuel High-Pressure Combustor Using Non-Coherent Oscillatory Fuel Injection

2003 ◽  
Author(s):  
D. Shcherbik ◽  
E. Lubarsky ◽  
Y. Neumeier ◽  
B. T. Zinn ◽  
K. McManus ◽  
...  
Keyword(s):  
High Pressure ◽  
Active Control ◽  
Fuel Injection ◽  
Injection Rate ◽  
Open Loop ◽  
Combustion Instabilities ◽  
Open Loop Control ◽  
Pressure Oscillations ◽  
Loop Control ◽  
Fuel Injection Rate

This paper describes the application of active, open loop, control in effective damping of severe combustion instabilities in a high pressure (i.e., around 520 psi) gas turbine combustor simulator. Active control was applied by harmonic modulation of the fuel injection rate into the combustor. The open-loop active control system consisted of a pressure sensor and a fast response actuating valve. To determine the dependence of the performance of the active control system upon the frequency, the fuel injection modulation frequency was varied between 300 and 420 Hz while the frequency of instability was around 375 Hz. These tests showed that the amplitude of the combustor pressure oscillations strongly depended upon the frequency of the open loop control. In fact, the amplitude of the combustor pressure oscillations varied ten fold over the range of investigated frequencies, indicating that applying the investigated open loop control approach at the appropriate frequency could effectively damp detrimental combustion instabilities. This was confirmed in subsequent tests in which initiation of open loop modulation of the fuel injection rate at a non resonant frequency of 300Hz during unstable operation with peak to peak instability amplitude of 114 psi and a frequency of 375Hz suppressed the instability to a level of 12 psi within approximately 0.2 sec (i.e., 75 periods). Analysis of the time dependence of the spectra of the pressure oscillations during suppression of the instability strongly suggested that the open loop fuel injection rate modulation effectively damped the instability by “breaking up” (or preventing the establishment of) the feedback loop between the reaction rate and combustor oscillations that drove the instability.

Closed-Loop Control of SI-HCCI Mode Switch Using Fuel Injection Timing

2013 ◽  
Author(s):  
Nikhil Ravi ◽  
Michael Jagsch ◽  
Joel Oudart ◽  
Nalin Chaturvedi ◽  
David Cook ◽  
...  
Keyword(s):  
Control Strategy ◽  
Closed Loop ◽  
Fuel Injection ◽  
Combustion Model ◽  
Injection Timing ◽  
Mode Switch ◽  
Loop Control ◽  
Fuel Injection Timing ◽  
Smooth Transitions ◽  
Operating Points

Homogeneous charge compression ignition (HCCI) provides improved efficiency and emissions relative to current engine technologies. One of the barriers to implementing HCCI on production engines is the development of a robust control strategy to transition from traditional spark-ignition (SI) mode to HCCI mode and back. This paper presents such a strategy, based on the control of combustion phasing using fuel injection timing during the mode switch from SI to HCCI. The controller is based on a cycle-by-cycle combustion model developed in previous work. In order to obtain a state estimator for both modes, the model is linearized around operating points corresponding to the steady-states before (SI) and after (HCCI) the switch. The linearized HCCI model is used to synthesize a closed-loop controller to track a desired combustion phasing, with fuel injection timing as the controlled input. The control strategy is tested on a single-cylinder HCCI engine with direct injection. Experimental results at different operating points show that the controller is able to maintain a desirable phasing transient during the mode switch, prevent cycles with very early or late phasing and enable smooth transitions with minimal load fluctuations.

scholarly journals The research of the pulse oxygen supply based on the fuzzy control technology

2018 ◽  
Vol 189 ◽  
pp. 06012
Author(s):  
Faling Hu ◽  
Tongfeng Niu ◽  
Jun Yao ◽  
Bingyan Cui ◽  
Haoxing Xu ◽  
...  
Keyword(s):  
Control System ◽  
Fuzzy Control ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Fuzzy Control System ◽  
Loop Control System ◽  
Working Principle ◽  
The Stability ◽  
Close Loop Control

According to the working principle of pulse oxygen supplies, we analyze how to realize the control of the oxygen flow by double different valves. a two-dimensional fuzzy control system is proposed to solve the unstable problem, which is brought by the shortcomings of the open-loop control system. We add a new parameter, the rate of the differential pressure signal changes, which contributes to a close –loop control system and increases the stability of the system. The experiments and the data show that the fuzzy control system make the process of breathing much more comfortable and solve the hysteresis and overshoot caused by the open-loop control system. The product reliability has been greatly improved.

Control of a Digital Micromirror Device Using Input Shaping

2007 ◽  
Author(s):  
H. Jammoussi ◽  
S. Choura ◽  
E. M. Abdel-Rahman ◽  
H. Arafat ◽  
A. Nayfeh ◽  
...  
Keyword(s):  
Electrostatic Field ◽  
Control Strategy ◽  
Nonlinear Function ◽  
Input Voltage ◽  
Open Loop ◽  
Input Shaping ◽  
Control Law ◽  
Digital Micromirror Device ◽  
Open Loop Control ◽  
Loop Control

In this paper, an open-loop control strategy is proposed for maneuvering the angular motion of a Digital Micromirror Device (DMD). The control law is based on a micromirror model that accounts for both bending and torsion motions. The model characterizes two DMD configurations: with and without contact with the substrate. The device is actuated using an electrostatic field which is a nonlinear function of the states and input voltage. The proposed control strategy is a Zero Vibration (ZV) shaper. It overshoots the DMD to its desired final angle by appropriately varying two independent input voltages. Actuating voltages and switching times are determined to maneuver the DMD from −10° to +10° tilt angles while reducing the residual vibrations.

scholarly journals Sliding Mode Control with Dynamical Correction for Time-Delay Piezoelectric Actuator Systems

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 132 ◽  
Author(s):  
Javier Velasco ◽  
Oscar Barambones ◽  
Isidro Calvo ◽  
Joseba Zubia ◽  
Idurre Saez de Ocariz ◽  
...  
Keyword(s):  
Time Delay ◽  
Sliding Mode Control ◽  
Control Strategy ◽  
Sliding Mode ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Mode Control ◽  
Control Response ◽  
Dynamical Correction

In piezoelectric actuators (PEAs), which suffer from inherent nonlinearities, sliding mode control (SMC) has proven to be a successful control strategy. Nonetheless, in micropositioning systems with time delay, integral proportional control (PI), and SMC, feedback control schemes have a tendency to overcompensate and, consequently, high controller gains must be rejected. This may produce a slow and inaccurate response. This paper presents a novel control strategy that deals with time-delay micropositioning systems aimed at achieving precise positioning by combining an open-loop control with a modified SMC scheme. The proposed SMC with dynamical correction (SMC-WDC) uses the dynamical system model to adapt the SMC inputs and avoid undesirable control response caused by delays. In order to develop the SMC-WDC scheme, an exhaustive analysis on the micropositioning system was first performed. Then, a mixed control strategy, combining inverse open-loop control and SMC-WDC, was developed. The performance of the presented control scheme was analyzed and compared experimentally with other control strategies (i.e., PI and SMC with saturation and hyperbolic functions) using different reference signals. It was found that the SMC-WDC strategy presents the best performance, that is, the fastest response and highest accuracy, especially against sudden changes of reference setpoints (frequencies >10 Hz). Additionally, if the setpoint reference frequencies are higher than 10 Hz, high integral gains are counterproductive (since the control response increases the delay), although if frequencies are below 1 Hz the integral control delay does not affect the system’s accuracy. The SMC-WDC proved to be an effective strategy for micropositioning systems, dealing with time delay and other uncertainties to achieve the setpoint command fast and precisely without chattering.

Synthesis of Robust Gain Matrices for Adaptive Rotor Vibration Control

1997 ◽  
Vol 119 (2) ◽  
pp. 298-300 ◽  
Author(s):  
C. R. Knospe ◽  
S. M. Tamer ◽  
S. J. Fedigan
Keyword(s):  
Steady State ◽  
Control Strategy ◽  
Synthesis Method ◽  
Open Loop ◽  
Active Magnetic Bearings ◽  
Open Loop Control ◽  
Rotor Vibration ◽  
Loop Control ◽  
Structured Uncertainty ◽  
Steady State Performance

Experimental results have recently demonstrated that an adaptive open-loop control strategy can be highly effective in the suppression of the unbalance induced vibration of rotors supported in active magnetic bearings. A synthesis method is presented for determining the adaptive law’s gain matrix such that the adaptation’s stability and steady-state performance are robust with respect to structured uncertainty.

LIM Control Strategy Supported by Genetic Algorithm with Unbalanced AC Source

2018 ◽  
Vol 19 (4) ◽  
Author(s):  
Matheus Garcia Soares ◽  
Afonso Bernardino Almeida Junior ◽  
Thiago Berger Canuto Alves ◽  
Luciano Martins Neto
Keyword(s):  
Computational Model ◽  
Control Strategy ◽  
Induction Motors ◽  
Linear Motor ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Linear Motors ◽  
Low Speeds ◽  
Supply Voltages

AbstractThis work presents the improvement of an open loop control strategy for linear induction motors operating at low speeds. The improvement is provided through the application of genetic algorithms in determining unbalance factors of the supply voltages of the linear motor. For this, a computational model of the linear motor was used as the evaluation function. The computational model was developed based on the equations of the linearized induction motor. The proposed methodology is validated through the comparison between computational results and experimental data performed in a linear motor prototype. This methodology allows to evaluate the influence of the unbalance of the supply voltages for linear motors working at low speeds.

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