Research on Phase Synchronization Strategies for Diesel Engines to Startup Quickly

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Weijun Ren ◽  
Zifeng Wu ◽  
Rong Yang

Valid and quick phase synchronization is essential to diesel engine operation, with impacts on the starting time and emissions. This paper presents an innovative wheel shape of camshaft with four long teeth and four short teeth, which plays a fundamental role in the proposed phase synchronization strategies. A dynamic validity-check algorithm of camshaft and crankshaft sensor signals is developed as a premise. Specifically, the segment pattern matching method is used in the rapid phase synchronization strategy that is applicable given valid camshaft and crankshaft signals. A combination of trial injections and the pattern matching method is applied when either the camshaft or crankshaft sensor signal is missing in the limp home mode. Bench test results showed that phase synchronization could be realized within 180 crankshaft angles, and that the phase synchronization strategies in the limp home mode were feasible.

2021 ◽  
Vol 29 ◽  
pp. 115-124
Author(s):  
Xinlu Wang ◽  
Ahmed A.F. Saif ◽  
Dayou Liu ◽  
Yungang Zhu ◽  
Jon Atli Benediktsson

BACKGROUND: DNA sequence alignment is one of the most fundamental and important operation to identify which gene family may contain this sequence, pattern matching for DNA sequence has been a fundamental issue in biomedical engineering, biotechnology and health informatics. OBJECTIVE: To solve this problem, this study proposes an optimal multi pattern matching with wildcards for DNA sequence. METHODS: This proposed method packs the patterns and a sliding window of texts, and the window slides along the given packed text, matching against stored packed patterns. RESULTS: Three data sets are used to test the performance of the proposed algorithm, and the algorithm was seen to be more efficient than the competitors because its operation is close to machine language. CONCLUSIONS: Theoretical analysis and experimental results both demonstrate that the proposed method outperforms the state-of-the-art methods and is especially effective for the DNA sequence.


2019 ◽  
Vol 178 (3) ◽  
pp. 99-105
Author(s):  
Monika ANDRYCH-ZALEWSKA ◽  
Zdzisław CHŁOPEK ◽  
Jerzy MERKISZ ◽  
Jacek PIELECHA

The article presents the exhaust emission results from a diesel engine in dynamic states of engine operation in the driving tests: NEDC (New European Driving Cycle) and Malta test, developed at the Poznan University of Technology. The NEDC and Malta tests were carried out as simulations on the engine test bench mimicking the driving tests conditions. The test results of the emission of carbon monoxide, hydrocarbons and nitrogen oxides obtained in each of the tests were presented. The dynamic states have been classified de-pending on the time derivative value of the torque and engine rotational speed. Both the positive and negative as well as zero time deriv-ative values of torque and rotational speed were considered. Therefore, overall six types of dynamic states were analyzed. A high sensi-tivity of exhaust emission to various types of dynamic states was found. The exhaust emission sensitivity to dynamic states in the Malta test was found to be higher than for the NEDC test, although these tests have similar properties (average rotational speed and average torque). This is due to the fact that the NEDC test is created on the basis of the similarity of zero-dimensional characteristics of the cars speed characteristic, whereas the Malta test was designed in accordance with the principle of faithful representation in the time domain of the NEDC speed curve.


2012 ◽  
Vol 215-216 ◽  
pp. 160-167 ◽  
Author(s):  
Qing Long Li ◽  
Ji Yang Yu ◽  
Qiang Qiang Zhang ◽  
Jian Qun Yu ◽  
Hong Fu

A three-dimensional discrete element method analytic model of the corn seed metering device with combination inner-cell was established based on its 3D CAD model, and the three-dimensional particle model of corn seeds was built by using the method of combination spherical particle. The working process of the corn seed metering device was simulated and analyzed by self-developed three-dimensional CAE software. It was observed that the simulative results of the seeding performance, clearing angles and dropping angles of the corn seeds well agreed with the bench test results. A novel method for studying and designing of the corn seed metering device was put forward.


2015 ◽  
Vol 68 (5) ◽  
pp. 937-950 ◽  
Author(s):  
Lin Wu ◽  
Hubiao Wang ◽  
Hua Chai ◽  
Houtse Hsu ◽  
Yong Wang

A Relative Positions-Constrained pattern Matching (RPCM) method for underwater gravity-aided inertial navigation is presented in this paper. In this method the gravity patterns are constructed based on the relative positions of points in a trajectory, which are calculated by Inertial Navigation System (INS) indications. In these patterns the accumulated errors of INS indicated positions are cancelled and removed. Thus the new constructed gravity patterns are more accurate and reliable while the process of matching can be constrained, and the probability of mismatching also can be reduced. Two gravity anomaly maps in the South China Sea were chosen to construct a simulation test. Simulation results show that with this RPCM method, the shape of the trajectory in gravity-aided navigation is not as restricted as that in traditional Terrain Contour Matching (TERCOM) algorithms. Moreover, the performance included matching success rates and position accuracies are highly improved in the RPCM method, especially for the trajectories that are not in straight lines. Thus the proposed method is effective and suitable for practical navigation.


2018 ◽  
Vol 26 (4) ◽  
pp. 54-58
Author(s):  
С. А. Кудринский ◽  
Г. Л. Поздеев ◽  
Л. В. Муравлева ◽  
Т. В. Гуназа

The paper discusses the issues for neutralization of solid waste – sorbent saturated with vapors of highboiling propellants (dinitrogen tetraoxide – oxidizer, nonsymmetrical dymethylhydrazine – fuel). The original methods of neutralizing the sorbent, contaminated with vapors of propellants, have been developed and the known methods have been experimentally checked. The neutralization methods bench test results have been presented.


2016 ◽  
Vol 12 (4) ◽  
pp. 21-44 ◽  
Author(s):  
R. Hema ◽  
T. V. Geetha

The two main challenges in chemical entity recognition are: (i) New chemical compounds are constantly being synthesized infinitely. (ii) High ambiguity in chemical representation in which a chemical entity is being described by different nomenclatures. Therefore, the identification and maintenance of chemical terminologies is a tough task. Since most of the existing text mining methods followed the term-based approaches, the problems of polysemy and synonymy came into the picture. So, a Named Entity Recognition (NER) system based on pattern matching in chemical domain is developed to extract the chemical entities from chemical documents. The Tf-idf and PMI association measures are used to filter out the non-chemical terms. The F-score of 92.19% is achieved for chemical NER. This proposed method is compared with the baseline method and other existing approaches. As the final step, the filtered chemical entities are classified into sixteen functional groups. The classification is done using SVM One against All multiclass classification approach and achieved the accuracy of 87%. One-way ANOVA is used to test the quality of pattern matching method with the other existing chemical NER methods.


2003 ◽  
Vol 24 (2) ◽  
pp. 449-466 ◽  
Author(s):  
Guoya Dong ◽  
Richard H Bayford ◽  
Shangkai Gao ◽  
Yoshifuru Saito ◽  
Rebecca Yerworth ◽  
...  

2012 ◽  
Vol 472-475 ◽  
pp. 2760-2765
Author(s):  
Hao Bin Jiang ◽  
Ying Jun Du ◽  
Shen Chen Ye

The design scheme of a new type strut was put forward, whose stiffness characteristics can undertake linkage control. The structure and basic principle of this new suspension component were introduced. According to fluid mechanics and thermodynamics, a mathematical model for the stroke dependent stiffness characteristics of the strut was established, and the stiffness characteristics were analyzed by using software SIMULINK. Then the stiffness performance bench test of the strut specimen was carried out for verification. Results show that the test results agree well with the simulation results. It is verified that the established mathematical model is correct and the stiffness of this strut shows nonlinear changes vary with the displacement of piston. When the suspension is largely impacted, the stiffness of this strut increases quickly which could restrain the wheel bouncing, body roll and vertical vibration.


Sign in / Sign up

Export Citation Format

Share Document