PLA 91550

Dalian, China

PLA 91550

Dalian, China
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Zhang Q.,PLA 91550 | Zhang Q.,Dalian University of Technology | Long W.,Dalian University of Technology | Tian J.,Dalian University of Technology
Neiranji Gongcheng/Chinese Internal Combustion Engine Engineering | Year: 2017

An experimental study on jet controlled compression ignition(JCCI) engine was conducted at all conditions on a prototype engine that was modified from a single cylinder diesel engine. The engine compression ratio was reduced to 12 to avoid auto-ignition of premixed diesel, and a small ignition chamber comprising a gas fuel injector and a spark plug was mounted on the cylinder head. Experiments were conducted at all loads to study the influences of ignition timing and load on the combustion controllability of a JCCI engine. The experimental results show that the combustion initial point θ10 and middle point θ10(referring to crank angles that correspond to 10% and 50% of total heat release) of premixed diesel change in one direction at most conditions. Its ignition delay is insensitive to load variation, indicating that a direct control of ignition timing for premixed combustion can be expected. However, the ignition delay starts to be reduced quickly at a point near full load due to an unexpected auto-ignition of premixed diesel. Therefore the effect of jet on the controllability of the ignition timing is weakened. The NOx and smoke are maintained at a low level at most conditions and they can be reduced greatly by advancing the spark timing due to their sensitivity to it. However, HC and CO are higher. © 2017, Chinese Society for Internal Combustion Engines(CSICE). All right reserved.

Zheng X.-B.,Tsinghua University | Dong J.-X.,Tsinghua University | Zhang Z.-G.,PLA 91550 | Meng L.-J.,PLA 91550
Zhongguo Guanxing Jishu Xuebao/Journal of Chinese Inertial Technology | Year: 2011

A target-firing simulation statistical method based on guidance instrument error was designed to acquire fall point dispersion evaluation of ballistic missile through Monte-Carlo before test. First, the error transfer equations from guidance instrument error to boost-phase end point error was founded, and the environment function matrix including 18 parameters was framed. Then, the elliptical orbit theory was applied to convert boost-phase end point error into fall point error. At last, a statistical test model was established for estimating fall point dispersion based on prior test information in range. A series of quasi-random numbers were generated and sampled, and their parameters, uniformity and randomicity were verified. The target-firing simulation test was carried out by using unit test data of range, and the estimation value and confidence interval of fall point CEP and dispersion was gained. The flight test results approve the feasibility of this method.

Zheng X.-B.,Tsinghua University | Dong J.-X.,Tsinghua University | Zhang Z.-G.,PLA 91550 | Meng L.-J.,PLA 91550
Zhongguo Guanxing Jishu Xuebao/Journal of Chinese Inertial Technology | Year: 2011

A comprehensive evaluation method for falling points' dispersion of ballistic missile is presented in order to improve precision-evaluation work for small-sample test. Firstly, the determination method for the minimal testing number is deduced starting from balancing producer's risk and consumer's risk. Then, a sequential test method is designed to discuss the possibility of gaining optimal testing number in the course of test. In order to solve the problem of dispersion evaluation in small-samples test, the applications of parametric Bootstrap and Bayes are respectively studied from simulation method and prior information utilization. Finally, the simulation is made which verify the effectiveness of the proposed approach.

Zheng X.-B.,Tsinghua University | Dong J.-X.,Tsinghua University | Meng L.-J.,PLA 91550 | Zhang Z.-G.,PLA 91550
Zhongguo Guanxing Jishu Xuebao/Journal of Chinese Inertial Technology | Year: 2012

Based on the assessment of missile's impact point dispersion, the Bootstrap method was applied to promote the evaluation accuracy of dispersion in small-sample test. The mathematic thought and application strategy of Bootstrap was introduced. Then theoretical and experimental investigations were implemented which proved that Bootstrap statistics created by parametric Bootstrap were distributed in a nearly normal fashion around classic evaluation and that estimation precision was not improved comparing with classic statistical methods. Based on analysis about the relationship between Bootstrap statistics distribution and estimation error distribution, it was proposed that in small sample case the difference of their approximation could not be ignored. At last it was proved that the application of random weighting method in dispersion assessment could not improve the accuracy similarly.

Xuan Z.W.,PLA 91550 | Nie K.,PLA 91550
Applied Mechanics and Materials | Year: 2014

The sensor needs to maneuver to get better observability in Bearings-Only passive target tracking with single sensor which makes the observation time longer. Multisensor Bearings-Only passive target tracking can solve the problem using exchange data. So the constrained Least Square Estimation(CLSE) algorithm is proposed for Multisensor Bearings-Only passive target tracking. The constrained condition is introduced to the Least Square Estimation algorithm firstly. Then the eigenvector corresponding to the least eigenvalue of the matrix is used to overcome the shortcoming of Extend Kalman Filter algorithm which needs the initial value. Also the bias problem of Least Square Estimation is conquered. The simulation results show that the CLSE can gradually approach the Cramer-Rao Lower Bound and its precision is better than the Least Square Estimation algorithm. Finally the CLSE is proved to be a gradually, stable and almost unbiased estimation algorithm. © (2014) Trans Tech Publications, Switzerland.

Xiao Y.,Dalian University | Li Z.,PLA 91550
Key Engineering Materials | Year: 2011

Step-size is one of the important parameters which influence the performance of blind equalization, a variable step-size method control by attenuation function according to instantaneous gradient and iterative times is proposed in this paper. Initially, set larger step-size to obtain faster convergence, with iterative times increasing, step-size would decrease control by attenuation function for instantaneous gradient reducing. Step-size changes according to this method consistent with the demand variable step-size adaptive algorithm that can obtain combination of convergence rate and convergence precision to improve the performance of blind equalization. Simulations show that this method performs better than conventional blind equalization with constant step-size. © (2011) Trans Tech Publications.

Peng T.,PLA 91550 | Zhang Q.,PLA 91550 | Chen R.,Dalian Maritime University
Advanced Materials Research | Year: 2012

The main idea behind this paper is the use of cheap one-level pointer analysis information to achieve better results in the context of dependency-based program debugging. We model java programs by a points-to graph with annotations in the form of constraints, derive the inner logical representation deriving from this model, and use them to debug faults in input programs. Our analysis and the empirical results show that we can achieve better results in the context of dependency-based software debugging. © (2012) Trans Tech Publications, Switzerland.

Qian H.-Y.,PLA 91550 | Yang P.-Y.,PLA 91550 | Xu S.-L.,PLA 91550
Tuijin Jishu/Journal of Propulsion Technology | Year: 2012

The convergence of conventional solutions to nonlinear equation and component matching equations of aeroengine component model depends on the initial values. Based on the peculiarity of nonlinear equation of the model, a hybrid Particle Swarm Optimization (PSO) algorithm HPSO1 is proposed, which integrates constriction factor, passive congregation factor and adaptive inertia weight on the basis of neighbor PSO. As for component matching equations, another hybrid Particle Swarm Optimization (PSO) algorithm HPSO2 is proposed, which integrates constriction factor, passive congregation factor on the basis of basic PSO. The simulation results demonstrate that both HPSO1 and HPSO2 overcome the dependence on initial values and they are effective in obtaining solution of aeroengine component-level model.

Guo F.,PLA 91550 | Guo F.,Dalian University of Technology
Proceedings - 2015 International Conference on Computer Science and Mechanical Automation, CSMA 2015 | Year: 2015

Hereby a telemetry signal noise cancellation method which the reference noise is obtained by using the time series analysis was proposed. In flight test, the telemetry signal is usually single channel signal, and the noise cancellation method is lack of reference noise, thus the noise cancellation method cannot be used in the processing directly. By analyzing the time series of the flight test process, we can take the stationary stage signal as the reference noise, and use it to process the feature stage signal for noise cancellation. This method can use the noise cancellation method in the processing for telemetry signal, which can effectively improve the SNR (signal to noise ratio) to lay the foundation for the subsequent processing of the signal. Simulation signal and the high frequency vibration signal processing in the test of a flight test proves the validity of the proposed method. © 2015 IEEE.

The exterior ballistic measurement is the basis of the precision analysis for the vehicle experiment, and the distribution geometry of the velocity measurement system has important influence on the estimation precision of the exterior ballistic measurement data. This paper proposed an optimization method for distribution geometry of the velocity measurement device by PSO, and the optimized project under the unconstrained and constrained which the alternative sites have been given is obtained. The simulation results show the effectiveness of the optimization method for distribution geometry. © (2014) Trans Tech Publications, Switzerland.

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