38results about How to "The derivation process is simple" patented technology

The invention relates to a sensor energy saving method of available Wi-Fi in an internet of things. The method is characterized in that a high-speed data transmission method is adopted for sensor equipment in an AP communication radius range. A deriving method of the sensor energy saving method of the available Wi-Fi in the internet of things comprises the steps of: firstly, analyzing system models in a typical Wi-Fi sensor network structure, then defining a plurality of different scenes, and researching the influences of all basic operations of the system models on aspects such as power consumption, interference or reliability and the communication radius in each scene. The sensor energy saving method of the available Wi-Fi in the internet of things has the advantages that the high-speed data transmission method is adopted for the sensor equipment in the AP communication radius range, the power consumption of a sensor is effectively lowered, and the service lifetime of a battery is prolonged.

The invention relates to the technical field of measurement, in particular to a remote elevation measuring method based on similar triangles. The remote elevation measuring method is characterized by comprising the following step: calculating the elevation of a point to be measured through a horizontal distance between a set site and a projection point of the point to be measured on an elevation level surface of the set site, a horizontal distance between the set site and the projection point of a second reference point on the elevation level surface of the set site, and space coordinates of the projection point of the second reference point on a connecting line of the set site and the point to be measured according to a geometrical relationship of the similar triangles. The remote elevation measuring method disclosed by the invention has the advantages that the formula derivation process is simple, the theory basis is reliable, the operation process is simple, and the elevation measurement precision is high.

The invention relates to a multi-step decision-making method for planning a trajectory around multiple no-fly zones. The method comprises the following steps of 1 impact point prediction calculation,2 boundary constraint handling scheme, 3 orientation adjustment scheme, 4 proportional navigation and 5 implementation of the method for planning the trajectory around multiple no-fly zones on the basis of a multi-step decision-making theory. Compared with an off-line planning method, the trajectory planning method has the advantages that the real-time performance is high, the on-line planning speed is high, and new avoiding instructions can be generated in real time according to the task and battlefield environment requirements; and compared with a traditional on-line planning method, the trajectory planning method has the advantages that the derivation process is simple, the condition of a large amount of randomly-distributed no-fly zones can be processed, and the trajectory planning method has the higher adaptability. According to the trajectory planning method, boundary constraints of the no-fly zones can be strictly guaranteed, a flying trajectory is smooth, the required overloadis small, and the trajectory planning method has the higher guidance precision.

The invention belongs to the technical field of water quality safety assessment, in particular to a pesticide freshwater aquatic organism water quality benchmark value derivation method and a water quality safety assessment method. The pesticide freshwater aquatic organism water quality benchmark value derivation method disclosed by the invention includes data collection, data screening evaluation, species screening, water quality benchmark derivation and benchmark value checking, when evaluating whether a certain water quality is safe or not, the water quality benchmark value for protecting aquatic organisms is obtained according to the aquatic organism water quality benchmark derivation procedure, and then the concentration value of such pollutants in the surface water source to be detected is detected. If the concentration value is lower than the water quality benchmark value, the water quality is safe, otherwise, the water quality is unsafe. The water quality benchmark derivation method provided by the invention has strong pertinence and wide applicability, and provides a theoretical basis for the environmental protection department to formulate the water quality standard of the pesticide surface water for protecting aquatic organisms in China.

The present invention discloses a three-phase full-bridge uninterruptible power supply control method with no need for a load current sensor. A three-phase uninterruptible power supply is widely applied to a distributed generation system, and is especially suitable for power supply of key loads such as the war industry, the medical treatment and advanced experiment devices, but the control methodmostly needs a load current sensor to ensure good robustness and control precision. An economical control strategy based on the Lyapunov large signal asymptotic stability principle is provided. Basedon the Lyapunov large signal asymptotic stability principle, an observer for real-time estimation of a load current and a corresponding control law are derived so as to omit three load current sensorsand greatly reduce the implementation cost. The zero steady-state error tracking control of a command voltage by the output voltage of the three-phase uninterruptible power supply is achieved, and good dynamic performances for various complex working conditions such as the resistance load jumping and non-linear load jumping are shown.

The invention discloses a harmonic quantitative calculation method for a three-phase two-level inverter based on a CBPWM technology. A harmonic calculation formula of the three-phase two-level inverter is deduced based on a fourier series analysis method; influence of a dead zone time to the output phase voltage waveform of the three-phase inverter is analyzed in detailed through a CBPWM modulation process to deduce a dead zone additional harmonic calculation formula; and influence of the dead zone to the harmonic amplitude value is analyzed in a quantitative manner so as to reveal a harmonicgeneration mechanism of a dead zone effect theoretically. The CBPWM three-phase two-level inverter harmonic quantitative analysis and calculation is proposed based on the fourier series analysis by considering that along with application of the PWM technology, the inverter easily causes harmonic pollution, harmonic resonance and the like, so that the inverter output phase voltage harmonic can be calculated quantitatively; and the requirements of simple deducing process, accurate calculation result and simple harmonic calculation expression can be satisfied.

The invention belongs to the technical field of water quality safety evaluation and particularly relates to a water quality criterion derivation method for human health protection and a safety evaluation method of water quality of a drinking water source region. When whether certain water quality is safe is evaluated, the carcinogenic effect acting mode of a pollutant is judged firstly, water quality criterion values for human health protection are calculated by use of corresponding derivation formulas according to the carcinogenic effect acting mode, then, the concentration value of pollution matter of the to-be-detected drinking water source region is detected, if the concentration value is lower than the water quality criterion value, the quality of drinking water is safe, and otherwise, the quality is not safe. The provided water quality criterion derivation method is simple, the derivation result error is small, the pertinence is high, and a theoretical basis is provided for the environmental protection department to set the water quality standard of drinking water for human health protection.

The invention discloses a transformer distribution parameter based LCC resonant type electrostatic precipitator high-frequency high-voltage power supply. The power supply comprises a three-phase rectifier bridge, an input filter capacitor, a full-bridge inversion circuit, an LCC serial-parallel resonant circuit, a high-frequency boosting transformer and a high-voltage silicon stack rectifier bridge which are connected in sequence; the three-phase rectifier bridge is electrically connected with three-phase alternating current; and the high-voltage silicon stack rectifier bridge is connected with a load. According to the power supply, the influence on a circuit from the high-frequency transformer distribution parameters is taken into full consideration; the LCC serial-parallel resonant circuit is designed by a fundamental wave analyzing method; the switch-on and switch-off of the zero voltage and zero current of a switch tube can be realized, so that the power switching tube is protected, the EMI noise is lowered, the switch loss is reduced, the switch frequency is improved, and the size of the power supply is reduced; meanwhile, the system is subjected to intermittent power supply control, so that sparks and back corona are effectively prevented; and in addition, the power supply is low in switch loss, relatively smaller in size, low in electromagnetic interference, and high in transmission efficiency.

The invention discloses an elastic torque control device. The device comprises an angle sensor, a connecting plate, a shell and an input motor. A servo coder is arranged on the input motor, and the connecting plate is fixedly connected with the shell. The angle sensor is rotationally connected with the connecting plate; one end of a middle connecting piece is connected with the angle sensor, and the other end of the middle connecting piece is connected to a rotating shaft of the input motor. An inner ring of a bearing is coaxially and rotatably connected with the middle connecting piece, and an outer ring is connected with the shell. A plurality of extension springs are further arranged at the side, away from the angle sensor, of the shell. One end of each tension spring is fixedly connected with the shell, and the other end of each tension spring is fixedly connected with the middle connecting piece. The common extension springs are adopted as the elastomers, and the mathematical model derivation is simple. The permissible torque is controlled and output through the servo motor, and the servo motor control method is mature, and the control precision is high. The device is simple in structure and low in cost, and the extension springs can be replaced at any time to change the rigidity of the elastomers. The device is high in universality, and the output actual torque can be accurately controlled through simple calculation.

The invention belongs to the technical field of aircraft structural strength design load analysis, and particularly provides a method for quickly analyzing landing load of a support arm type undercarriage. According to the method, a large-side-angle support arm type undercarriage structure is simplified into a mass-spring system on the basis of the energy conservation principle, in the system, theweight of an airplane is simplified and concentrated to be M, the large-side-angle support arm type structure is simplified into a spring model, tires are simplified into a spring model, and connection of support arms and the tires is simplified into series connection of two springs; an energy equation for simplifying the large-side-angle support arm type structure into the spring model is solved, and an energy equation for simplifying the tires into the spring model is solved; and then, the obtained energy equation is substituted into an energy conservation equation, the maximum vertical load of the landing load of the undercarriage is solved, and the loads in the lateral direction and the heading direction on the undercarriage during landing is calculated. According to the method provided by the invention, a complex calculation model does not need to be established, the derivation process is simple, the obtained landing load is effective and reliable, and the requirements of engineering design can be met.

The invention relates to a method for designing a low-field nuclear magnetic resonance biplanar gradient coil. The method is improved by a classic target field method. The current density distributionis limited in a limited surface, Fourier expansion is directly carried out on the current density, then a gradient coil design problem is attributed to solving of a matrix equation problem, the matrix equation is solved, a biplanar current density coefficient can be obtained, and a wiring track of a gradient coil is drawn by utilizing an isoline diagram of a flow function. Compared with a traditional design method, the method has the advantages that the limited-size coil problem is solved, derivation is simpler, and the method is more suitable for numerical calculation on a computer.

There is provided a system for tagging information in a virtual server environment based on a systems model. The system comprises a systems model arranged to provide configuration data for tags. The tags are associated with configurable items of the systems model in the virtual server environment. The system further comprises an evaluation rules engine arranged to evaluate data in the virtual server environment based on a set of predetermined evaluation rules and the provided configuration data, and to generate a new tag, remove an existing tag, or update an existing tag based on the evaluation.

The invention belongs to the technical field of water quality safety assessment, in particular to a deducing method for aquatic biological water quality standard of a pyrethroid pesticide and a waterquality safety assessment method. When evaluating whether a certain water quality is safe or not, the water quality benchmark value for protecting aquatic organisms is obtained according to the aquatic organism water quality benchmark derivation procedure, and then the concentration value of such pollutants in the surface water source to be detected is detected. If the concentration value is lowerthan the water quality benchmark value, the water quality is safe, otherwise, the water quality is unsafe. The water quality reference derivation method provided by the invention is simple and has strong pertinence, and provides a theoretical basis for the environmental protection department to formulate the surface water quality standard for protecting pyrethroid pesticides.

The invention discloses an SCR system urea injection control method based on an H infinite feedback gain pulse spectrum table, which belongs to the technical field of diesel engine urea SCR discharge post-processing system control. According to the invention, linear system H infinite state feedback and the multi-operating point gain pulse spectrum table are combined; the control demand of a nonlinear system in real industry is met; and the design advantages of an H infinite state feedback control theory is used. The existing LMI toolbox is reasonably used to solve an optimization problem offline. The calculation amount of an online control system can be reduced. The method has the advantages of simple derivation process and high practicality, and can provide a way for the design of a vehicle-mounted control system.

Devices and methods for Intra prediction are provided. The method includes: obtaining a value of an indication information of a current block. When the value of the indication information indicates the intra prediction mode of the current block is not comprised in the set of most probable modes, deriving the intra prediction mode IntraPredModeY [xCb] [yCb] of the current block by the following ordered steps: i. IntraPredModeY [xCb] [yCb] is set equal to intra_luma_mpm_remainder [xCb] [yCb], ii. The value of IntraPredModeY [xCb] [yCb] is incremented by one. The method can improve the efficiency to determine the intra prediction mode of the current block.

The invention discloses an elastic torque control device. The device comprises an angle sensor, a connecting plate, a shell and an input motor. A servo coder is arranged on the input motor, and the connecting plate is fixedly connected with the shell. The angle sensor is rotationally connected with the connecting plate; one end of a middle connecting piece is connected with the angle sensor, and the other end of the middle connecting piece is connected to a rotating shaft of the input motor. An inner ring of a bearing is coaxially and rotatably connected with the middle connecting piece, and an outer ring is connected with the shell. A plurality of extension springs are further arranged at the side, away from the angle sensor, of the shell. One end of each tension spring is fixedly connected with the shell, and the other end of each tension spring is fixedly connected with the middle connecting piece. The common extension springs are adopted as the elastomers, and the mathematical model derivation is simple. The permissible torque is controlled and output through the servo motor, and the servo motor control method is mature, and the control precision is high. The device is simple in structure and low in cost, and the extension springs can be replaced at any time to change the rigidity of the elastomers. The device is high in universality, and the output actual torque can be accurately controlled through simple calculation.

The normal-incidence Fresnel optical characterization method for two-dimensional materials provided by the present invention adopts the traditional basic theory of optical thin films-conduction matrix method, introduces the concept of optical admittance, and deduces the absorption, The simple calculation formulas of reflectivity and transmittance, and the derivation process are simple, which is conducive to the application of two-dimensional materials in the field of optoelectronics.

The invention relates to a calibration device (1110) for a direct digital modulator (direct digital modulator, DDM) (1120), wherein said DDM (1120) comprises a plurality of elements (1121) to be based on a pair of Modulation of an input signal (1122) generates an output signal (1124), said calibration apparatus (1110) comprising a calibration controller (1111) for providing a stimulus (1113) to at least one (1121a) of said elements (1121) ); and a measurement device (1112) for measuring a DDM (1120) output signal (1124) in response to said stimulus (1113) provided to said at least one element (1121a), wherein said calibration controller (1111 ) for providing said excitation (1113) based on an oscillating signal applied to an input of said DDM (1120) and an antiphase oscillating signal applied to an error compensation path of said DDM (1120).

The decoupling method of the independent inverse system of the bearingless asynchronous motor, the original model of the independent torque system and the original model of the independent magnetic levitation system constructed according to the working principle of the bearingless asynchronous motor, respectively establish the no-load torque variable T L The inverse model of the independent torque system and the α and β axis components of the air gap flux linkage of the independent torque system observed by the independent observer of the air gap flux linkage ψ 1α and ψ 1β The inverse model of the independent maglev system, the cross-coupling item in the dynamic change process of the torque winding stator current has been decoupled by the inverse system method, so the current closed loop in the independent torque original system can be omitted, and the inverse system model does not contain difficult The predicted load torque variable can save the torque online identification link in the system implementation, which can effectively simplify the complexity of the overall control system structure of the bearingless asynchronous motor; using the independent inverse system decoupling method in this paper, the independent torque system inverse The model and the inverse model of the independent maglev system and their derivation process are relatively simple, which is convenient for engineering and technical realization.

The disclosure relates to a calibration device (1110) for a direct digital modulator (DDM) (1120), wherein the DDM (1120) comprises a plurality of elements (1121) to generate an output signal (1124) based on a modulation of an input signal (1122) according to a predetermined constellation, the calibration device (1110) comprising: a calibration controller (1111) configured to provide a stimulus (1113) to at least one (1121a) of the elements (1121); and a measurement device (1112) configured to measure an output signal (1124) of the DDM (1120) responsive to the stimulus (1113) provided to the at least one element (1121a), wherein the calibration controller (1111) is configured to provide the stimulus (1113) based on an oscillation signal applied to the input of the DDM (1120) and an anti-phase oscillation signal applied to an error compensation path of the DDM (1120).

The invention belongs to the field of fracture mechanics, and discloses a multi-mode failure judgment method suitable for transverse isotropic carbon fibers, which comprises the following steps: (1) judging the failure form of the transverse isotropic fibers; (2) constructing a fiber shearing and bending failure stress criterion basic model; (3) judging the sign of the normal stress of the failure surface; (4) solving an undetermined coefficient in the basic form by considering a normal stress symbol of a failure surface under fiber shearing and bending failure states respectively; and (5) establishing a finite element model to verify the accuracy of the model. According to the method disclosed by the invention, the axial / transverse performance difference of the fiber and the influence of the normal stress sign of the failure surface on the shearing and bending failure stress state are considered for the first time, so that the failure of the carbon fiber in various loading processes can be accurately judged. The derivation process is simple, program codes are conveniently generated, and the application of the method is beneficial for further improving the prediction precision of the design performance of the composite material component.

The invention discloses a linear / nonlinear double-layer insulation dielectric interface polarization characteristic analysis method, and belongs to the technical field of insulation dielectric. For solving the problems that in the prior art, the theoretical derivation process is complicated and is difficult to obtain an analytical solution, the method comprises a linear insulation dielectric layer and a nonlinear insulation dielectric layer, wherein the linear insulation dielectric layer and the nonlinear insulation dielectric layer are connected in series, the linear insulation dielectric layer is connected with a first electrode lead, the nonlinear insulation dielectric layer is connected with a second electrode lead, and a direct current high voltage U0 is formed between the first electrode lead and the second electrode lead; and the linear / nonlinear double-layer insulation dielectric is represented by a first volt-ampere special effect curve and a second volt-ampere characteristic curve correspondingly, a linear / nonlinear double-layer insulation dielectric is described by an equivalent circuit model, and the voltage value of the linear insulation dielectric layer, a voltagevalue of the nonlinear insulation dielectric layer, a total polarization current value and a time constant value of the linear / nonlinear double-layer insulation dielectric are obtained, and the technical problem that the interface polarization characteristic derivation process of the double-layer insulation dielectric is complicated is solved.

The invention discloses a fast modeling and simulation method for natural vibration characteristics of a wind turbine flexible tower system comprising the following steps: reasonably simplifying a wind turbine flexible tower system, and dispersing the system into multi-body dynamic elements; based on a multi-body system transfer matrix method, deducing a tower tube beam transfer matrix considering the gravity effect; determining a transfer matrix of other multi-body dynamic elements; determining boundary conditions, and establishing a total transfer equation of the flexible tower system; and solving the total transfer equation to obtain the vibration characteristics of the flexible tower system. According to the method, the structural details of the wind turbine flexible tower system are fully considered, the calculation efficiency is high, the simulation precision is high, rapid modeling and natural vibration characteristic analysis of the wind turbine flexible tower system can be achieved, and meanwhile, and a reference is provided for dynamic modeling and vibration characteristic analysis of a slender flexible body system similar to a flexible tower structure in engineering.

The invention relates to the technical field of measurement, in particular to a remote elevation measuring method based on similar triangles. The remote elevation measuring method is characterized by comprising the following step: calculating the elevation of a point to be measured through a horizontal distance between a set site and a projection point of the point to be measured on an elevation level surface of the set site, a horizontal distance between the set site and the projection point of a second reference point on the elevation level surface of the set site, and space coordinates of the projection point of the second reference point on a connecting line of the set site and the point to be measured according to a geometrical relationship of the similar triangles. The remote elevation measuring method disclosed by the invention has the advantages that the formula derivation process is simple, the theory basis is reliable, the operation process is simple, and the elevation measurement precision is high.