Multi-sensor data fusion theory and methods have been widely applied to many fields. Multi-sensor data fusion and information redundancy technology are adopted to achieve target characters synthetically judgment.. The...
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Data process of large rotating machinery is in line with basic features of information fusion. The fault deterioration is extracted from the pattern spectrum as the fault feature , and its trend is predicted by the in...
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The reliable characters of grounding grid influence the safe and steady operations of the power system, but the grounding grid are mostly buried under the earth. It is very difficult to diagnose the fault of the groun...
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Camshaft is the key component of automobile engine valve timing mechanism, whose machining precision will affect overall performance of automobile engine. This paper presents a kind of camshaft journals multi-paramete...
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Camshaft is the key component of automobile engine valve timing mechanism, whose machining precision will affect overall performance of automobile engine. This paper presents a kind of camshaft journals multi-parameters measuring instrument based on the actual requirement of camshaft production. The camshaft measuring instrument was auto measuring instrument composed of pneumatic control system, precision measurement system and computer-aided measurement system, which was developed for measuring journal diameter, roundness, conicity, journal radial runout relative to center holes connection, and number 2, 3, 4 journal radial runout relative to number 1 and 5 journal center connection, etc. The measurement repetition and stability were perfect, it was fit for high precision and fast measurement at production site.
Attitude determination with navigation satellites is a key technology in aviation, marine and land navigation. In the method based on carrier phase difference, the double difference integer ambiguity solving is import...
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The principle of Phase-Inversion Symmetric method (PISM ) in time-domain based on noise correlation is presented, and its anti-narrowband noise interference ability is analyzed. The simulation models of PISM in time-d...
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The principle of Phase-Inversion Symmetric method (PISM ) in time-domain based on noise correlation is presented, and its anti-narrowband noise interference ability is analyzed. The simulation models of PISM in time-domain and narrowband noise interference are designed. The band-limited Gaussian white noise and narrowband noise interference model is applied to PISM in time-domain to study anti-interference ability of this method. Simulation results show that the bit error rate (BER) of PISM in time-domain in band-limited Gaussian white channel is close to zero, and the bit error rate of this method in narrowband noise interference is very low, and prove the Phase-Inversion Symmetric method in time-domain has good ability against narrowband noise interference.
The ability to maintain a constant lift force on a low aspect ratio semi circular wing using pulsed blowing active flow control is experimentally investigated. Dynamic models of the wing's response to pressure (pu...
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The lift response of the separated flow over a wing to different actuator input disturbances is used to obtain linear models useful for closed-loop control design. The wing has a small aspect ratio, a semi-circular pl...
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ISBN:
(纸本)9781600867392
The lift response of the separated flow over a wing to different actuator input disturbances is used to obtain linear models useful for closed-loop control design. The wing has a small aspect ratio, a semi-circular planform, and is fully stalled at a 20° angle of attack. Individual pulse-like disturbances and step-input disturbances with randomized frequency were inputs to the actuator, and the lift coefficient increments were output signals. The "prediction error method" system identification technique was used to obtain two linear models of the separated flow. A 4th order model reproduced the non-minimum phase behavior of the pulse input, but did not work well for control purposes. The second model identified was limited to first order. The first order model proved to be useful for designing a proportional-integral feedback controller capable of suppressing lift oscillations in unsteady flows. Good suppression of lift oscillations was observed in the experiment after a step change in wind tunnel flow speed occurred. When the control system was tested with a randomized freestream velocity, it reduced the root-mean-square lift oscillation by 50 percent relative to the uncontrolled case. 2010 by David R. Williams. Published by the American institute of Aeronautics and Astronautics, Inc.
Based on the harsh underground environment and complex monitoring data, some sensors that have different purposes need to be set up, a routing algorithm(LEACH-N)suitable for underground heterogeneous wireless sensor n...
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Based on parameterized algebraical method, the non-prefect reconstruction (NPR) biorthogonal wavelet is presented. According to the particularity of image edge detection process, the perfect construction condition is ...
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Based on parameterized algebraical method, the non-prefect reconstruction (NPR) biorthogonal wavelet is presented. According to the particularity of image edge detection process, the perfect construction condition is relaxed. The low pass decomposition filter of non-prefect reconstruction biorthogonal wavelet is even symmetry about zero location, so that the edge position is more accuracy in multi-scale decomposition. The high pass decomposition filter is odd symmetry about 1/2 location and the sign is monotonic. The wavelet with above properties can ensure the validity of edge detection.
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