Closed Loop Control of Spark Advance Using a Cylinder Pressure Sensor

1976 ◽  
Vol 98 (4) ◽  
pp. 414-420 ◽  
Author(s):  
M. Hubbard ◽  
P. D. Dobson ◽  
J. D. Powell

The objective of the spark advance control technique discussed in this paper is to provide a schedule which is optimum in the presence of changing engine and environmental conditions. The paper shows the benefits of adaptable spark control, describes the ability of a cylinder pressure based system to adapt to optimum spark on a single cylinder laboratory engine and describes the transient performance of a controller mechanized in the laboratory. Averaged over the entire engine speed-load operating regime, the closed loop system yields average brake horsepower within 0.1 percent of optimum based solely on the cylinder pressure information. The system has demonstrated a transient settling time of 0.1 second.

2016 ◽  
Vol 49 (11) ◽  
pp. 202-209 ◽  
Author(s):  
Yaodong Hu ◽  
Tianyuan Zhou ◽  
Changsheng Yao ◽  
Fuyuan Yang ◽  
Jinli Wang ◽  
...  

Author(s):  
R Whalley ◽  
M Ebrahimi

The regulation of linearized multivariable system models, following input set point and load disturbance changes, is considered. An inner and outer closed-loop control strategy is outlined, enabling targeted recovery rates, offset attenuation and low steady state interaction to be achieved. Proportional control and passive network compensation alone are employed. Gain ratio selection and outer loop tuning are exercised, ensuring thereby the confinement of output perturbations to low-frequency load disturbances and reference input changes. Application studies are presented for purposes of comparison.


2009 ◽  
Vol 628-629 ◽  
pp. 257-262 ◽  
Author(s):  
Tong Xing

The cutter head drive hydraulic system of φ1.8m simulate shield machine is introduced in this article, which has the variable speed pump control technique and the closed loop control method. The AMESim simulation model of the hydraulic system is built up, and the efficiency of the hydraulic system, speed control performance by open loop and closed loop control are analyzed. The result of the simulation shows that the variable speed pump control system has higher efficiency than the variable displacement pump control system about 4%-26% in the same condition when the cutter head speed is at the range of 0.5-4r/min, and the hydraulic system has good dynamic characteristics in closed-loop PID control.


Author(s):  
V Rouillard ◽  
G T Lleonart

Computer software was developed to control an electromechanical wave generator to accurately simulate random wave fields derived from mathematical spectral models. The software algorithm makes use of a spectral feedback control technique to improve accuracy and reliability in the continuous generation of random waves in the laboratory. Experiments were conducted to investigate the advantages of this closed-loop control technique over more commonly used open-loop random wave generation methods. The results show a decided advantage in using closed-loop control for the generation of random waves, especially for double-peak wave spectra and model testing purposes.


2021 ◽  
Author(s):  
Gustavo Sanchez

<div>A method to assess the performance of closed loop control loops, based on closed-loop system identification. This method allows to take into account the trade-off between process variable and manipulated variable energy, thus overcoming one of the most important criticisms to Harris' index. </div>


Author(s):  
Leah M. Wilson ◽  
Peter G. Jacobs ◽  
Katrina L. Ramsey ◽  
Navid Resalat ◽  
Ravi Reddy ◽  
...  

<b>Objective: </b>To assess the efficacy and feasibility of a dual-hormone closed loop system with insulin and a novel liquid stable glucagon formulation compared with an insulin-only closed loop system and a predictive low glucose suspend system. <p><b>Research Design and Methods:</b> In a 76-hour, randomized, crossover, outpatient study, 23 participants with type 1 diabetes used three modes of the Oregon Artificial Pancreas system: (1) dual-hormone (DH) closed loop control, (2) insulin-only single-hormone (SH) closed loop control and (3) predictive low glucose suspend (PLGS). The primary endpoint was percent time in hypoglycemia (<70 mg/dL) from start of in-clinic aerobic exercise (45mins at 60% VO<sub>2max</sub>) to 4 hours after.</p> <p><b>Results:</b> DH reduced hypoglycemia compared with SH during and after exercise (DH 0.0% [0.0-4.2], SH 8.3% [0.0-12.5], p=0.025). There was an increased time in hyperglycemia (>180mg/dL) during and after exercise for DH vs SH (20.8% DH vs. 6.3% SH, p=0.038). Mean glucose during the entire study duration was: DH 159.2, SH 151.6, PLGS 163.6 mg/dL. Across the entire study duration, DH resulted in 7.5% more time in target range (70-180 mg/dL) compared with the PLGS system (71.0% vs. 63.4%, p=0.044). For the entire study duration, DH had 28.2% time in hyperglycemia versus 25.1% for SH (p=0.044) and 34.7% for PLGS (p=0.140). Four participants experienced nausea related to glucagon leading 3 to withdraw from the study. </p> <p><b>Conclusions:</b> The glucagon formulation demonstrated feasibility in a closed loop system. The dual-hormone system reduced hypoglycemia during and after exercise with some increase in hyperglycemia.</p>


2018 ◽  
Vol 8 (9) ◽  
pp. 1463 ◽  
Author(s):  
Xianghua Ma ◽  
Hanqiu Bao

The payload swing of an overhead crane needs to be controlled properly to improve efficiency and avoid accidents. However, the swing angle is usually very difficult to control to zero degrees or for it to even remain within an acceptable range because the overhead crane is a complex nonlinear underactuated system, especially when the actual working environment is accompanied by strong disturbances and great uncertainty. To resolve this, a real-time anti-swing closed-loop control strategy is proposed that considers external disturbances. The swing angle is measured in time and it functions with the load displacement as feedback inputs of the closed-loop system. The nonlinear model of the crane is simplified by a linear system with virtual disturbances, which are estimated by the equivalent input disturbance (EID) method. Both simulation and experimental results for a 2-D overhead crane system are investigated to illustrate the validity of the proposed method.


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