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144 results about "Linear problem" patented technology

A linear problem is any problem which is solved by setting up only linear equations or linear systems of equations to solve. An expression in the variables x 1,...,x n is linear if it is of the form a 1x 1+...+a nx n+b. Here a 1,...a n and b are coefficients.

Motor position servo system self-adaptive control method based on interference observer

The invention discloses a motor position servo system self-adaptive control method based on an interference observer. The motor position servo system self-adaptive control method based on an interference observer includes the steps: establishing a mathematical model for a motor position servo system; constructing an interference observer and a self-adaptive controller based on the interference observer; and by means of a Liapunov stability theory, performing stability demonstration on the motor position servo system, and obtaining a global asymptotic stability result of the system by operatinga Barbalat lemma. The motor position servo system self-adaptive control method based on an interference observer is based on an integration series model and the interference observer of the motor position servo system, designs a non-linear control method based on the interference observer, integrates the non-linear control method with self-adaptive control, respectively estimates unmodeled interference and parameter nondeterminacy to enable the servo system to achieve the effect of global asymptotic stability when unmodeled interference is time-varying interference for the servo system, and solves the strong parameter nondeterminacy problem and the strong nondeterminacy non-linear problem of the system so as to enable the system to obtain better tracking performance.
Owner:NANJING UNIV OF SCI & TECH

Control method of driving system of permanent magnet synchronous motor of electrical automobile considering iron loss

InactiveCN103701371ASolve the problem of position tracking controlSolving Nonlinear Control ProblemsElectronic commutatorsBacksteppingSynchronous motor
The invention discloses a control method of a driving system of a permanent magnet synchronous motor of an electrical automobile considering iron loss, and provides a control method of a driving system of a permanent magnetic synchronous motor considering iron loss based on a self-adaptive fuzzy backstepping method, which solves the non-linear problem of the power driving and control system of the motor of the electrical automobile, enables the motor to quickly reach the stable running state and is more suitable for the control objects requiring quick dynamic response, such as the driving system of the electrical automobile. The control rules u[d] and u[q] only adopt one self-adaptive parameter theta, so as to reduce the calculation amount. The method has the advantages that the problem of position tracking and control of the permanent magnet synchronous motor considering the iron loss under the conditions of orienting to the site and having undetermined parameter and load torque disturbance is solved; the fuzzy logic system is used for approximating to the unknown non-linear item, and the self-adaptive fuzzy backstepping method is used for enabling the tracking error to approximate to 0; the more accurate control precision is reached, and the ideal position tracking and control effect is ensured.
Owner:QINGDAO UNIV

Thermal power generating unit operation optimization method and device based on consumption difference analysis

The invention provides a thermal power generating unit operation optimization method and device based on consumption difference analysis. The method comprises the following steps: a thermal power generating unit working process model is established based on an improved least square support vector machine algorithm; improved particle swarm optimization is adopted for optimizing parametric variables affecting the net coal consumption rate in the thermal power generating unit working process model, and a global optimum affecting the net coal consumption rate is output; operation of a thermal power generating unit is guided according to parametric variable data corresponding to the global optimum so as to make the thermal power generating unit operate at the optimal net coal consumption rate. According to the thermal power generating unit operation optimization method and device based on consumption difference analysis, the modeling method of the improved least square support vector machine algorithm is used for converting the nonlinear problem of steam working in the thermal power generating unit into the linear problem in a high-dimensional plane, an optimal decision variable is obtained finally, the optimal decision variable is used for guiding the operation of the thermal power generating unit to make the thermal power generating unit operate at the optimal net coal consumption rate, and therefore the energy utilization rate and economic benefit of the thermal power generating unit are increased.
Owner:STATE GRID CORP OF CHINA +1

Dispersion-shifted single-mode fiber having low dispersion slope for large capacity transmission

The invention relates to a low dispersion slope dispersion-shifted single-mode fiber for large capacity transmission comprising a core and a cladding. Said fiber is characterized in that said core has three to five core segments having different refractive index profiles, and said cladding has four to six cladding segments. The total dispersion slope of said fiber at 1550 nm is less than 0.060 ps/nm2·km, the zero dispersion wavelength is less than 1420 nm, the effective area ranges from 55 μm2 to 65 μm2, and the dispersion in the region of 1530 nm˜1565 nm ranges from 5.0 ps/nm2·km to 12.0 ps/nm2·km. The fiber has low dispersion slope, moderate dispersion, low attenuation, and excellent bend resistance performance. It is suitable for a high-speed (10 Gbits/s and 40 Gbits/s), large capacity, and long distance DWDM system. Therefore, not only the non-linear problem that fazes high-speed communication is solved effectively, but also the DWDM transmission at 10 Gbits/s can be realized within a wider wavelength range. In addition, low dispersion slope is advantageous for comprehensive management of dispersion, so that the requirement for long distance non-electric relay can be fulfilled.
Owner:YANGTZE OPTICAL FIBRE & CABLE CO LTD

Bituminous pavement structural analysis and increment method based on modulus stress and strain dependence model of pavement materials

The invention relates to a bituminous pavement structural analysis and increment method based on a modulus stress and strain dependence model of pavement materials. The method includes the steps of according to the structural pattern and material type of a bituminous pavement in a simulation analysis, determining the thickness and Poisson's ratio of each layer and the modulus stress and strain dependence model of the pavement materials, adopting the modulus stress and strain dependence model of the pavement materials to represent the modulus of each layer of a bituminous pavement structure, combining calculation load with interlayer combination conditions to create a calculation analysis system, using an increment method as an analysis basis, obtaining a modulus matrix of each point of theinteriors of pavement structural layers through finite element software numerical calculation, and based on the steps above, calculating the stress, strain and displacement of an arbitrary point in the bituminous pavement structure according to an elastic layered system theory. According to the method, influences caused by non-linear problems of materials on pavement mechanical calculation are taken into account to make the force analysis of the bituminous pavement structure more reasonable and complete.
Owner:RES INST OF HIGHWAY MINIST OF TRANSPORT

Two-time scanning-based high-resolution optical scanning holographic section imaging method

The invention discloses a two-time scanning-based high high-resolution optical scanning holographic section imaging method, belongs to the field of optical scanning and mainly overcomes the defect that larger defocus noise exists in the prior art when any two-dimensional sliced image is reconstructed. The two-time scanning-based high high-resolution optical scanning holographic section imaging method comprises the following steps of carrying out two-dimensional scanning on an object on a two-dimensional scanning mirror for the first time, moving the object towards the direction of the two-dimensional scanning mirror by a distance deltaZ after a first matrix equation containing section information is obtained and carrying out scanning on the object for the second time to obtain a second matrix equation containing the section information; and then integrating the first matrix equation and the second matrix equation into a minimum linear equation, converting the solution of a linear problem into a minimum problem and realizing section imaging through introducing a conjugate gradient algorithm. Through the technical scheme, the two-time scanning-based high high-resolution optical scanning holographic section imaging method has the beneficial effects that the high-precision section imaging is realized, and the defocus noise is greatly reduced. The two-time scanning-based high high-resolution optical scanning holographic section imaging method is suitable for various fields.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Resistance-changing-type single-fault-source diagnosing method for mine ventilation system based on air volume characteristics

The invention discloses a resistance-changing-type single-fault-source diagnosing method for a mine ventilation system based on air volume characteristics. A training sample of the fault and air volume relation is generated through a mine ventilation simulating system (MVSS), a classification model and a regression model based on a support vector machine (SVM) are built, and the fault position andequivalent air resistance are diagnosed. The topology structure of a ventilation system network is complex, change of the air resistance of one of branches of the ventilation system network gives rise to change of the air volume of the branch and the ventilation network of a partial area, the air volume serves as a vector mode so as to distinguish the topology position where a resistance-changing-type fault occurs, and the single-fault-source SVM diagnosing method is put forward to diagnose the resistance-changing-type single fault source position and fault degree of the mine ventilation system; a final decision model is built according to the method, the method is simple, human interference is less, connection between data is objectively reflected, and the method is suitable for solvingthe essential non-linear problem; and the model is determined by a support vector, data dimension disaster is avoided, and good robustness is achieved.
Owner:LIAONING TECHNICAL UNIVERSITY
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