Crank Shaft Torsional Vibration Analysis on the perspective of Improving the Crank Angle Measurement Accuracy for Closed-loop Combustion Control in ICES

2018 ◽  
Author(s):  
Xiaoguo Storm ◽  
Jari Hyvonen ◽  
Heikki J Salminen ◽  
Reino Virrankoski ◽  
Seppo Niemi
Keyword(s):  
Torsional Vibration ◽  
Vibration Analysis ◽  
Measurement Accuracy ◽  
Closed Loop ◽  
Angle Measurement ◽  
Combustion Control ◽  
Crank Angle

A Model-Based Methodology for Real-Time Estimation of Diesel Engine Cylinder Pressure

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Ahmed Al-Durra ◽  
Marcello Canova ◽  
Stephen Yurkovich
Keyword(s):  
Signal Processing ◽  
Diesel Engine ◽  
Real Time ◽  
Closed Loop ◽  
Operating Conditions ◽  
Recursive Least Squares ◽  
Cylinder Pressure ◽  
Combustion Control ◽  
Model Based ◽  
Crank Angle

Cylinder pressure is one of the most important parameters characterizing the combustion process in an internal combustion engine. The recent developments in engine control technologies suggest the use of cylinder pressure as a feedback signal for closed-loop combustion control. However, the sensors measuring in-cylinder pressure are typically subject to noise and offset issues, requiring signal processing methods to be applied to obtain a sufficiently accurate pressure trace. The signal conditioning implies a considerable computational burden, which ultimately limits the use of cylinder pressure sensing to laboratory testing, where the signal can be processed off-line. In order to enable closed-loop combustion control through cylinder pressure feedback, a real-time algorithm that extracts the pressure signal from the in-cylinder sensor is proposed in this study. The algorithm is based on a crank-angle based engine combustion of that predicts the in-cylinder pressure from the definition of a burn rate function. The model is then adapted to model-based estimation by applying an extended Kalman filter in conjunction with a recursive least-squares estimation scheme. The estimator is tested on a high-fidelity diesel engine simulator as well as on experimental data obtained at various operating conditions. The results obtained show the effectiveness of the estimator in reconstructing the cylinder pressure on a crank-angle basis and in rejecting measurement noise and modeling errors. Furthermore, a comparative study with a conventional signal processing method shows the advantage of using the derived estimator, especially in the presence of high signal noise (as frequently happens with low-cost sensors).

scholarly journals Modifying Kinect placement to improve upper limb joint angle measurement accuracy

2016 ◽  
Vol 29 (4) ◽  
pp. 465-473 ◽  
Author(s):  
Na Jin Seo ◽  
Mojtaba F. Fathi ◽  
Pilwon Hur ◽  
Vincent Crocher
Keyword(s):  
Upper Limb ◽  
Measurement Accuracy ◽  
Joint Angle ◽  
Angle Measurement

scholarly journals Effectiveness of Variable-Gain Kalman Filter Based on Angle Error Calculated from Acceleration Signals in Lower Limb Angle Measurement with Inertial Sensors

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Yuta Teruyama ◽  
Takashi Watanabe
Keyword(s):  
Kalman Filter ◽  
Lower Limb ◽  
Measurement Accuracy ◽  
Inertial Sensors ◽  
Angle Measurement ◽  
Angle Error ◽  
Variable Gain ◽  
Improve Measurement ◽  
Kalman Gain ◽  
Acceleration Signals

The wearable sensor system developed by our group, which measured lower limb angles using Kalman-filtering-based method, was suggested to be useful in evaluation of gait function for rehabilitation support. However, it was expected to reduce variations of measurement errors. In this paper, a variable-Kalman-gain method based on angle error that was calculated from acceleration signals was proposed to improve measurement accuracy. The proposed method was tested comparing to fixed-gain Kalman filter and a variable-Kalman-gain method that was based on acceleration magnitude used in previous studies. First, in angle measurement in treadmill walking, the proposed method measured lower limb angles with the highest measurement accuracy and improved significantly foot inclination angle measurement, while it improved slightly shank and thigh inclination angles. The variable-gain method based on acceleration magnitude was not effective for our Kalman filter system. Then, in angle measurement of a rigid body model, it was shown that the proposed method had measurement accuracy similar to or higher than results seen in other studies that used markers of camera-based motion measurement system fixing on a rigid plate together with a sensor or on the sensor directly. The proposed method was found to be effective in angle measurement with inertial sensors.

scholarly journals RESEARCH ON THE ACCURACY OF ANGLE MEASUREMENT / KAMPŲ MATAVIMO TIKSLUMO TYRIMAS

2012 ◽  
Vol 3 (6) ◽  
pp. 15-18 ◽  
Author(s):  
Artūras Prielaidas ◽  
Rimas Lazdinas
Keyword(s):  
Main Part ◽  
Measurement Accuracy ◽  
Angle Measurement ◽  
Rotary Disk

Rotary encoders are the main devices in industrial angle measurement. Accuracy is very important and is assured by the technology of manufacture. The main part (rotary disk) is under examination, and therefore a number of its characteristics are established and a comparison with the assembled encoder is presented. In conclusion, an error in the angle of the rotary disk makes a possibility of forecasting an error in the assembled encoder angle. Santrauka Nagrinėjamas limbų paklaidų matavimas, jų vertinimas, fotoelektrinių matavimų keitiklių paklaidų matavimas, bandoma nustatyti keitiklio paklaidų priklausomybę nuo limbo paklaidų. Pateikta limbų, keitiklių apžvalga, analizė, pagrindinės schemos. Atlikta limbų ir keitiklių paklaidų aproksimacija parametrinėmis funkcijomis. Apibendrinti visų matavimų rezultatai – kas būdinga paklaidų kreivėms, kokie dydžiai, jų aproksimacijos parametrinėmis funkcijomis rezultatai, formulės, analizė. Atlikti koreliacijos tarp limbo ir matavimo keitiklio paklaidų tyrimai.

Real-time Closed-loop Active Surface Technology of a Large Radio Telescope

2022 ◽  
Vol 134 (1031) ◽  
pp. 015003
Author(s):  
Yong Zhang ◽  
Guoping Li ◽  
Guohua Zhou ◽  
Qishuai Lu ◽  
Heng Zuo ◽  
...  
Keyword(s):  
Real Time ◽  
Radio Telescope ◽  
Closed Loop ◽  
Preliminary Test ◽  
Active Surface ◽  
Angle Measurement ◽  
Quality Data ◽  
Surface Accuracy ◽  
Surface System ◽  
Reflector Surface

Abstract The surface accuracy of a large radio telescope’s primary reflector is easily affected by gravity and temperature change during observations. An active surface system is crucial to ensure the regular operation and high-quality data output of the radio telescope. We propose a real-time closed-loop active surface system including two components. The first component, a new type of photoelectric edge sensor, detects the angle change of the adjacent panels. The second component, the displacement actuator, adjusts the panels’ position and posture to compensate for the angle changes. So, over the entire observation, the closed-loop surface control system with these two components could actively maintain the primary reflector’s accuracy in real time. Using this approach, we constructed an experimental active surface system for the Xinjiang Qitai 110 m Radio Telescope (QTT) to test the maintenance of the surface accuracy. The angle measurement accuracy is better than 0.″2, and the positioning accuracy of the displacement actuator could achieve ±15 μm over the whole 50 mm stroke. The preliminary test results show that the accuracy requirements of the QTT’s primary reflector surface can be met using the active surface system we propose.

scholarly journals A Novel Vision-Based Pose Measurement Method Considering the Refraction of Light

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4348 ◽  
Author(s):  
Wei Liu ◽  
Xin Ma ◽  
Xiao Li ◽  
Yi Pan ◽  
Fuji Wang ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Measurement Accuracy ◽  
Performance Testing ◽  
Angle Measurement ◽  
Normal Vector ◽  
Calibration Model ◽  
Linear Calibration ◽  
Observation Window ◽  
Vision Measurement

Nowadays, due to the advantages of non-contact and high-speed, vision-based pose measurements have been widely used for aircraft performance testing in a wind tunnel. However, usually glass ports are used to protect cameras against the high-speed airflow influence, which will lead to a big measurement error. In this paper, to further improve the vision-based pose measurement accuracy, an imaging model which considers the refraction light of the observation window was proposed. In this method, a nonlinear camera calibration model considering the refraction brought by the wind tunnel observation window, was established first. What’s more, a new method for the linear calibration of the normal vector of the glass observation window was presented. Then, combining with the proposed matching method based on coplanarity constraint, the six pose parameters of the falling target could be calculated. Finally, the experimental setup was established to conduct the pose measurement study in the laboratory, and the results satisfied the application requirements. Besides, experiments for verifying the vision measurement accuracy were also performed, and the results indicated that the displacement and angle measurement accuracy approximately increased by 57% and 33.6%, respectively, which showed the high accuracy of the proposed method.

Heat Release Experimental Analysis for RCCI Combustion Optimization

2018 ◽  
Author(s):  
V. Ravaglioli ◽  
F. Ponti ◽  
F. Carra ◽  
M. De Cesare
Keyword(s):  
Low Temperature ◽  
Experimental Analysis ◽  
Closed Loop ◽  
Combustion Stability ◽  
Closed Loop Control ◽  
Combustion Control ◽  
Transient Conditions ◽  
Feed Forward ◽  
Loop Control ◽  
Injection Parameters

Over the past years, the increasingly stringent emission regulations for Internal Combustion Engines (ICE) spawned a great amount of research in the field of combustion control optimization. Nowadays, optimal combustion control has become crucial, especially to properly manage innovative Low Temperature Combustion (LTC) strategies, usually characterized by high instability, cycle-to-cycle variability and sensitivity to slight variations of injection parameters and thermal conditions. Many works demonstrate that stability and maximum efficiency of LTC strategies can be guaranteed using closed-loop control strategies that vary the standard injection parameters (mapped during the base calibration activity) to keep engine torque and center of combustion (CA50) approximately equal to their target values. However, the combination of standard base calibration and closed-loop control is usually not sufficient to accurately control Low Temperature Combustions in transient conditions. As a matter of fact, to properly manage LTC strategies in transient conditions it is usually necessary to investigate the combustion methodology of interest and implement specific functions that provide an accurate feed-forward contribution to the closed-loop controller. This work presents the experimental analysis performed running a light-duty compression ignited engine in dual-fuel RCCI mode, the goal being to highlight the way injection parameters and charge temperature affect combustion stability and ignition delay. Finally, the paper describes how the obtained results can be used to define the optimal injections strategy in the analyzed operating points, i.e. the combination of injection parameters to be used as a feed-forward for a closed-loop combustion control strategy.

scholarly journals Development of methods for equalizing level networks

2020 ◽  
Vol 21 (1) ◽  
pp. 58-65
Author(s):  
Ekaterina N. Esina ◽  
Vladislava V. Likhodeevskaya
Keyword(s):  
Measurement Accuracy ◽  
Closed Loop ◽  
Mutual Influence ◽  
Parametric Method ◽  
Network Configuration ◽  
Nodal Points ◽  
True Values ◽  
Intensive Development ◽  
Method Of Adjustment

The article is devoted to comparison of methods of calculating the approximate elevations of nodal points when adjusting leveling networks by strict and non-strict methods. Ensuring geomechanical monitoring of the mutual influence of constructed and operated objects is important in the intensive development of underground space of megacities, the construction of unique objects and structures. In the course of the research, mathematical models of level networks were developed and presented in the form of a closed loop and a set of open polygons. Analysis of modeling allows to determine the feasibility of applying the knot method by Professor V.V. Popov instead of the parametric method of adjustment. It is established that the quality of the results of strict equalization depends entirely on the quality of measurements, since deviations from the true values do not exceed the measurement error. The research has shown that it is possible to simplify the processing of monitoring data and evaluation of various configuration options for leveling networks, using algorithms for calculating approximate marks of nodal points. This makes it easier to process monitoring results and evaluate various network configuration options while ensuring the required level of measurement accuracy.

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