共查询到10条相似文献,搜索用时 31 毫秒
1.
动态系统的自适应模糊神经网络控制 总被引:1,自引:0,他引:1
Aim To build an adaptive fuzzy neural controller and simulate
it. Methods Fuzzy logic and back propagation(BP) algorithm are combined
to utilize their advantages while avoiding the disadvantages. Results and
Conclusion Simulation results of the third-order plant with disturbances and dead
times show the validity of the presented controller. The presented controller can control
cases that preceding controllers were unable to control. 相似文献
2.
The controller designed according to classical or modern control theory will not satisfy the performance requirements when the controlled object in industrial field can not be described by exact mathematical model or the disturbance of the controlled system. In order to make the controlled system stable and having good performance, H∞ control theory was put forward to solve this practical problem. Taking the position of a rolling mill as the controlled object, it was rectified by optimal engineering way. Then, three different plans were put forward according to Bang-Bang control, LQ control and H∞ control, respectively. The result of the simulation shows that the controller designed according to H∞ method whose robust performance and ability to restrain colors disturbance is satisfactory. 相似文献
3.
Aim To assess simultaneously various risk states of a system. Methods
Using the catastrophe and fuzzy theory, the energy and uncertainty in a system are set as
two control variables and the function of the system is used as the state variable for
analysis. Results and Conclusion A risk analysis model named the cusp
model is presented. Various states regarding the safety of the system such as the accident
state, no-accident state and miss state can be represented at will on the cusp model. 相似文献
4.
Aim To study the relationship between the substrate
temperature and the morphology and properties of GaN. Methods Applying
the hydride chemical vapor deposition method, GaN films were deposited on different kinds
of substrates, including sapphire, Si(111),Si(100),GaAs and GaP(111) both on the P face
and the Ga face. The growth was performed at low temperatures of below 700℃. XRD, Hall measurement,
cathodoluminescence (CL) and atomic force microscopy (AFM) were used to characterise the
film properties. Results It was found that the temperature and the nature
of substrate materials influence the layer morphology. Conclusion The
analysis shows that no apparent relationship exists between the optical properties and
layer morphology. 相似文献
5.
Aim To present an ASIC design of DA-based 2-D IDCT. Methods
In the design of 1-D IDCT is utilized a Chen-based fast IDCT algorithm, and multiplier
accumulators based on distributed algorithm contributes in reducing the hardware amount
and in enhancing the speed performance. Results and Conclusion VHDL
simulation, synthesis and layout design of system are implemented. This 2-D IDCT ASIC
design owns best timing performance when compared with other better designs
internationally. Results of design prove to be excellent. 相似文献
6.
Aim To study the influence of restraint system performance
upon the occupant's response during impact, and provide a scientific base for occupant
restraint system design. Methods In the light of basic theory of
multibody system dynamics and impact dynamics on the basis of classical theory of impact,
R-W method is adopted to construct the vehicle-occupant system model consisting of
fourteen rigid bodies, thirty seven DOFs and slip joints for the simulation. A software
named SVC3D(3-dimensional simulation of vehicle crash) is developed in the FORTRAN
language. Results The results of simulation have a good coincidence with
those of tests and the restraint system with low elongation webbing and equipped with
pretensioner provides better restraint effect for the occupant. Conclusion The
model of vehicle-occupant multibody system and SVC3D are suitable for use. Occupant should
be belted with low elongation webbing to a certain degree and occupant restraint system
should be equipped with pretensioner. 相似文献
7.
节理岩体弹塑性动态有限元分析 总被引:1,自引:0,他引:1
Aim To study the elastic-plastic dynamical constitutive
relations about a jointed rock mass under explosion load and its computer simulation. Methods
Stress history is taken into account and stresses will follow changes in time during a
period of explosion load. According to the principle of static force balance, the
corresponding nodal concentrated force is calculated and the nodal displacement is
counted. The elastic-plastic dynamic finite element equations are thus obtained. Results
A finite element method is given for a jointed rock mass under explosion load. Conclusion
The problem of large plastic deformation for jointed rock mass on blasting was efficiently
resolved through dynamic finite element analysis and the range of damages by blasting
simulated, and this pushes forward the problem to engineering practice. 相似文献
8.
Aim To improve the efficiency of fatigue material tests and
relevant statistical treatment of test data. Methods Least square
approach and other special treatments were used. Results and Conclusion
The concepts of each phase in fatigue tests and statistical treatment are clarified. The
method proposed leads to three important properties. Reduced number of specimens brings to
the advantage of lowering test expenditures. The whole test procedure has more flexibility
for there is no need to conduct many tests at the same stress level as in traditional
cases. 相似文献
9.
Aim To determine the global optimal solution for a mine
ventilation network under given network topology and airway characteristics. Methods
The genetic algorithm was used to find the global optimal solution of the network. Results
A modified genetic algorithm is presented with its characteristics and principle. Instead
of working on the conventional bit by bit operation, both the crossover and mutation
operators are handled in real values by the proposed algorithms. To prevent the system
from turning into a premature problem, the elitists from two groups of possible solutions
are selected to reproduce the new populations. Conclusion The simulation
results show that the method outperforms the conventional nonlinear programming approach
whether from the viewpoint of the number of iterations required to find the optimum
solutions or from the final solutions obtained. 相似文献
10.
Aim To analyze the transient speciality of nonlinear,
anisotropic, AC+DC coupling electric field, and to compare the withstand-voltage strength
of different insulation structures. Methods The transient process of
polarity reversal is analyzed, considering the anisotropic property of oil-immersed
press-board, a new finite element model based on Galerkin method is presented and
verified. The model developed is applied to calculate the electric field distribution in
four typical winding end structures of the converter transformer. Results
The whole-ring structure possesses the best insulation characteristics. Conclusion
By introducing reasonable insulation components, insulation strength with the
same surrounding sizes can be improved more than 30%. 相似文献