Abstract: An energy-based hybrid reentry methodology was developed for hypersonic vehicles. The three-degree-of-freedom reentry kinematic equations was conducted based on energy, and typical inequality constraints was converted to the constraints of bank-angle by using quasi-equilibrium glide condition (QEGC)...
Abstract: To eliminate singularity in robots' kinematics calibration, identifiable parameters in distance square difference model were confirmed. Robot's link structure was expressed by modified Denavit-Hartenberg (DH) model, while the transformation between last joint and tool frame by six parameters. The li...
Abstract: To investigate flight performance of the signal main rotor helicopters with different aerodynamic configurations based on helicopter nonlinear flight dynamic model, trim calculation of main rotor required power in case of level flight, steady-climb and descent, and steady coordinated-turn under base...
Abstract: For the fiber-optic gyroscope (FOG) was easily influenced by the ambient temperature resulting Shupe bias, the thermoelectric analogy method was applied to do the thermal analysis of different structural fiber optic ring (FOR) modules. The principle that the parallel heat capacity and series resista...
Abstract: To conquer the question of uncertain factors in the remaining useful life (RUL) prediction of airborne equipment, a RUL model was presented based on the conditional probability distribution of states. Firstly, the conditional probability vector of states was introduced to improve the ability of hidd...
Abstract: 18% Ni ultra-high strength steel C250 was employed to investigate the effect of single shot peening (SSP) with cast-iron bead and double shot peening (DSP) with cast-iron bead and glass bead on surface topography, micro-structure and low-cycle fatigue (LCF). The results show that the low-cycle fatig...
Abstract: Roe's flux difference splitting (FDS), a widely used scheme today, encounters shock inability that needs to be avoided in hypersonic flows. Moreover, it can't preserve the total enthalpy while in steady inviscid flows' simulations. To get over the defects above, schemes called RoeMW1, RoeMW2 that ar...
Abstract: A static balance testing system for coordinator gyro rotation axis was desired to do a test about the static unbalance value and distributed position angle. In this system, the measured axis of the coordinator gyro was mounted parallel with the horizontal turntable axis by the direction of the fixtu...
Abstract: During lunar exploration program, the dust on the lunar surface has a severe impact on the energy utilization efficiency of photoelectric devices, such as solar panels. Based on the model of adherence dust, the effect of levitation dust was analyzed from the view of stereo space. The model of levita...
Abstract: Reentry trajectory optimization with multiple constraints on g-load, dynamic pressure, heat flux on stagnation point of craft and parachute deployment position was studied for low-lift-to-drag lunar return vehicle, and a novel coevolutionary algorithm was presented to solve the parameters optimizati...
Abstract: Thermal cycling tests were performed to determine the phase change temperature shift of pure barium hydroxide octahydrate (Ba(OH)2·8H2O) phase change material (PCM) with respect to 150 accelerated thermal cycles. The results show a slightly phase change temperature shift and a severe supercooling ph...
Abstract: Contact-type conduction electric heater was developed for testing high-temperature material under both heat and pressure. For this heater, temperature control under high heating rate was studied. The specificity of the mathematical mode of general heaters under high heating rate was analyzed, theref...
Abstract: Compared to the traditional Earth observation satellites, the agile satellites have more degrees of freedom for attitude maneuver and complex observation modes. An agile satellite attitude strategy based on time-ordered directed acyclic graph was proposed for the one-orbit strips-jointed and multi-s...
Abstract: For the problem of reentry vehicle (RV) tracking, adaptive piecewise constant Jerk model and tracking algorithm were proposed based on kinetics acceleration model and stochastic model approximation. Recursive model of target acceleration was induced by introducing kinetics Jerk model and assumption ...
Abstract: Different structure crack initiation position may affect the performance of the structural safety in structures containing multiple site damage. Considering that, a method to analyze the sensitivity of failure probability with respect to the stress and crack initiation life on each site was proposed...
Abstract: According to the proposed new principle of directly-driven hydraulic serve pump, a novel short stroke permanent magnet linear oscillating motor (LOM) was designed. The LOM working principle based on minimum reluctance rule was elaborated, and a special hollow mover design structure employing Halbach...
Abstract: Tightly correlative structures are widely used in aircraft manufacturing tooling, elements which constitute them have rigorous correlations in the spatial orientation and structural dimensions, but sometimes they do not constitute a complete assembly as independent part of the overall structure atta...
Abstract: To investigate the receptivity characteristic of hypersonic flow under the action of free stream pulse wave, a high-order finite difference method was used to do numerical simulation of hypersonic unsteady flow over a blunt wedge with slow acoustic wave in free stream. The evolution of disturbance w...
Abstract: To reduce the image matching errors caused by local structure similarity and other factors, a matching judgment method based on support description was proposed. An initial matching set was obtained by scale invariant feature transform(SIFT) algorithm, from which the more stable feature points were ...
Abstract: The components characteristic modification technology was studied. A model optimization algorithm based on changed fitness function was proposed to reduce the modeling error and improve the model accuracy. Based on the static model, characteristic correction coefficients of every component, air-entr...
Abstract: Flying wing configuration eliminates conventional vertical tail and rudder, thus existing severe problem on yawing control. To make the configuration into practical use, it is necessary to gain an extensive understanding on the collocation features and control characteristics of yawing control devic...
Abstract: The rotation number range was expanded significantly through increasing the absolute pressure of the channel to about 5 atm. Experiments were carried out to investigate heat transfers in a smooth square two-pass channel under large rotation numbers. In current study, Reynolds and rotation number ran...
Abstract: The parametric model of the lunar lander based on multi-body dynamics was established for improving landing performances of the lunar lander. With the model, an optimal Latin hypercube experimental design for a typical failure case was carried out to find out the key factors. The sample points were ...
Abstract: Based on hybrid ultrahigh frequency pulse variable polarity gas tungsten arc welding (HPVP-GTAW) surfacing process for 2219-T87 high strength aluminum alloy, the effect of pulse current parameters on weld appearance was analyzed. Experimental results show that the weld penetration and weld depth to ...
Abstract: Repeated use of eutectic AgCu28 solder can cause performance degradation in the base material due to grain boundary penetration. To gain further understanding of this phenomenon, thus providing comprehensive data and technical guidance for greater reliability during production of vacuum devices, the...
Founded: 1956 (
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Sponsor: Ministry of Industry and Information Technology of the People's Republic of China
Sponsored by: Beijing University of Aeronautics and Astronautics