33 results about "Error surface" patented technology

The invention discloses a correction method of an electronic compass in an underwater vehicle, which comprises the following steps of: inquiring magnetic declination, and carrying out corrected navigation on the water surface of the vehicle; recording navigation data by a navigation sensor; exporting correction navigation data from a communication module; searching a hard magnetic interference parameter, solving the error surface plot between a correction track and a reference track under the condition of (2N+1)<2> disperse hard magnetic interference parameters, wherein the minimum point corresponding to the surface plot is the search result; according to the set correction precision requirement, repeating and reducing the search range and grid, and re-searching to obtain a more precise hard magnetic interference parameter evaluation value; and finally, applying the searched magnetic parameter evaluation value in the navigation of the underwater vehicle. The method disclosed by the invention has the advantages that the operation is simple, the influence of the outer magnetic interference to the electronic compass in the underwater vehicle can be effectively eliminated and thus, the corrected electronic compass can return back to the corrected attitude angle.

A fast search algorithm for loop alignment of a feed forward amplifier is disclosed. The algorithm controls a processor that adjusts, digitally, the gain and phase of the loop alignment based on power measurements at the input and output of cancellation combiners, to find the optimal setting. A “non-collinear descent” algorithm is used to search, iteratively, for the minimum within an error surface. For loop alignment, the error surface is defined by the set of measurement points comprising the alignment settings and the associated cancellation residuals. For the case of first loop alignment, the cancellation residual is measured using the ratio of two power detectors located at the input and after the cancellation (error) combiner. For second loop alignment, cancellation is estimated using the residual pilot power detected at the output of the amplifier. The preferred alignment method uses three successive measurements to estimate the gradient direction with respect to gain and phase shifter settings. The actual descent direction is selected to be close to the gradient direction without being collinear with the most recent alignment adjustments. Quantization of the descent direction simplifies the implementation as well as the enforcement of the non-collinearity constraint on successive alignment settings. Two different step size selection approaches are disclosed, however, any standard step size selection approach may be employed.

The invention, which belongs to the field of the information technology, relates to an energy consumption prediction method for improving an energy utilization rate of an iron and steel enterprise. A neural network algorithm with error feedback correction learning is used for carrying out prediction. In order to solve a problem of slow convergence speed of the traditional learning method, a momentum is added into an adjusting formula of a weight value and a threshold value, thereby accelerating a training speed of a network. With an adaptive adjusting learning rate, a learning rate of training at an error curved surface flat area is increased; and a learning rate is reduced at a drastic error changing area. On the basis of time-varying-weight-based parameter combination optimization method, distribution of an initial weight value and an initial threshold value is optimized, and good searching space is localized in solution space to avoid a local minimal point. According to the energy consumption prediction method, characteristics of energy consumption of all procedures are taken into consideration; the energy utilization rate is improved; and the energy costs are reduced and thus total production cost is lowered.

The invention relates to a method for determining assembly-oriented rectangular plane shape error evaluation parameters and belongs to the field of error evaluation. The method comprises: generating a cutting surface by non-Gaussian plane simulation method, acquiring a shape error surface via wavelet filtering, and extracting characterization parameters of surface shape error distribution; subjecting the shape error surface to simulation assembly through contact algorithm, calculating assembly precision of spatial orientation changes of a second part after assembly, determining a relation between surface characterization parameters and post-assembly part assembly precision through correlation analysis, thereby determining shape error evaluation parameters and enabling quantitative description for the relation between the surface distribution characterization parameters and assembly precision. Plane characteristic parameters having important impact on assembly precision are obtained, and scientific basis is provided for improving machining quality of mating planes and optimizing assembly process to improve assembly precision.

A hypersonic vehicle attitude adaptive recursive control method and system, the steps are as follows: (1) Combining the control target, the aircraft re-entry attitude dynamics analysis and the unmodeled dynamics and disturbance analysis, an attitude error characteristic model with an expanded state is established , where the expanded state is used to describe the unmodeled dynamics and disturbances of the system; (2) construct a fuzzy neural network estimator to estimate the expanded state in the feature model, and combine the structure of the feature model to jointly design the parameters of the feature model and the automatic parameters of the neural network Adaptive law; (3) Based on the error surface, a recursive adaptive control law is designed to further improve the robustness of the control system. The method of the invention has better adaptability to uncertainty, has the advantages of strong robustness, high control precision, etc., and is suitable for accurate tracking of attitudes of hypersonic aircraft in complex unmodeled dynamics and strong interference environments.

The invention discloses a device and method of interferometry for a large-scale optical plane. Wherein, the interferometry device comprises an adjustment platform for the two-axis linear motion of an interferometer, a two-dimensional tilt adjustment platform for the measured plane mirror located at the front of the adjustment platform, a laser wave-front interferometer installed in the adjustmentplatform for the two-axis linear motion of an interferometer and a control computer contained the program of measured data processing algorithm, which is connected to the laser wave-front interferometer. With the device, a plurality of obtained error surface maps of partial region can be spliced to an error surface map containing medium-high frequency (MHF) band on the whole caliber according to the measured data processing algorithm through the control computer, which includes a method for determining the initial position, an algorithm for extracting data from the overlap region and an algorithm for splicing the area data. The invention is a device and method of interferometry for a large-scale optical plane with low cost, high precision and high efficiency.