259results about How to "Has engineering application value" patented technology

The invention relates to a tracking control method and especially relates to a distributed limited time tracking control method for formation-flying satellites. The invention aims at solving problems that the communication among formation-flying satellites is limited in a conventional formation-flying satellite control method, the control input upper limit information of a pilotage satellite is difficult to obtain, the inevitable perturbation of all satellites in a system cannot be considered, and the formation is longer in time. The method comprises the following steps: 1, building a double-satellite relative movement dynamic model; 2, building a relative dynamic model of the formation-flying satellites relative to a reference point; 3, designing a distributed limited time tracking control rule. The method solves a problem that the communication among formation-flying satellites is limited in the conventional satellite formation control method, considers the inevitable perturbation of all satellites in the system, and can complete the formation in a shorter time. The method can be used in the field of tracking control.

The invention discloses a modeling method for a third generation pressurized water reactor nuclear power generating unit. The modeling method comprises the following steps of: 1, decomposing a nuclear power generating unit system into a plurality of subsystem models; 2, establishing the subsystem models in the step 1 according to heat engineering and energy transfer and conversion rules; 3, combining the subsystem models obtained in the step 2 into a nuclear power generating unit full system model, and connecting the nuclear power generating unit full system model with a power system model toobtain a combined model of a nuclear power generating unit and the power system; and 4, establishing a customized model of the third generation pressurized water reactor nuclear power generating uniton the basis of the combined model of the nuclear power generating unit and the power system, and simulating the performance of the nuclear power generating unit and machine-grid interaction according to the customized model. The method effectively solves combined emulation of the nuclear power generating unit and a power unit, can be applied to machine-grid coordination analysis of a nuclear power plant and a power grid, and has high practicability.

The invention provides a method for converting cold wall heat flux into hot wall heat flux in an aerodynamic heat simulating test. The method comprises the following steps: firstly, calculating a temperature change curve for the surface of a thin metal plate according to a cold wall heat flux boundary condition; secondly, heating the thin metal plate test piece according to the calculated temperature curve, and recording a hot wall heat flux curve for the surface of a heat flux sensor in the same plane of the thin metal plate under the temperature condition, namely by a combined method of theoretical calculation and an experimental test, finally obtaining a hot wall heat flux boundary condition which corresponds to the cold wall heat flux boundary condition and is difficultly determined by a computer. The invention provides a practicable hot wall heat flux determining method for a radiant aerodynamic heat simulating test on a high-speed aircraft.

The invention discloses a heat-insulating and noise-reducing nonwoven composite material for automobile interior trim and a preparation method thereof. The composite material is prepared from certain proportions of PP (polypropylene) fiber, PET (polyester) fiber and hollow PET fiber, the mixed fiber is prepared into a composite felt by a certain acupuncture process, and an appropriate die pressing process is adopted to prepare a composite fiber felt. The composite material disclosed by the invention keeps lower surface density, good bending performance and good dimensional stability, can also meet the functional requirements for heat insulation and sound insulation, and can be used for preparing medium and high-grade automobile interior trim materials.

The invention provides a network-based AUV intelligent fault-tolerant integrated navigation simulation system which comprises a strap-down inertial navigation simulator, a GPS simulator, a DVL simulator, an AUV navigation terminal. A sub-navigation system is connected with the AUV navigation terminal through an IP network and transmits relevant navigation information to the AUV navigation terminal on a real-time basis, and fault detection and integrated navigation operation are finished in the AUV navigation terminal. Each sub-system has the characteristics of independent working, so that a plug-and-play AUV intelligent fault-tolerant integrated navigation simulation system is formed; the problem that the traditional navigation facility accesses to the integrated navigation terminal through an RS232 serial port and is limited to the number of serial ports is solved, thereby achieving the purpose of multiple accesses and representing a trend of equipment internet protocolization. Therefore, research cost is effectively reduced, and the invention has significant engineering application value for researching integrated navigation system and the design of communication for latter navigation system.

The invention discloses a method for simulating and predicting a transient thermoforming limit of ultra-high strength steel. The method comprises the steps as follows: a material constitutive model under a stable equilibrium condition is determined; a thermoforming limit model is determined on the basis of a localized instability theory of a material uneven groove hypothesis under a stable condition, wherein the material constitutive model determined under the stable equilibrium condition is adopted in the thermoforming limit model under the stable condition; and the thermoforming limit model is utilized to predict and simulate the thermoforming limit under a transient technological condition.

The invention discloses a coordination control method of a dissymmetric artery. Dissymmetric phases are designed according to a flow ratio of each strand traffic flow in the artery, the flow ratio of the traffic flow in the same phase is guaranteed to be close to the greatest extent, and waste of green time is reduced; in order to improve the utilization efficiency of the green time and guarantee the normal operation of each strand traffic flow at the same time, a computing method of each phase green time permitting intervals is set; a one-way coordination control best phase difference is put forward according to a gap of intersection, traffic flow travel speed and time needed by queued vehicle releasing of the coordination phase traffic flow in red time; at last the phase and phase sequence of the intersection, the coordination phase difference and the coordination green time are ensured according to each phase green time permitting intervals and the one-way best phase difference. The coordination control method can optimize a bi-directional coordination control effect when the artery traffic flow is in an unbalancing state, the phenomena that vehicles in the artery are delayed are reduced, and the utilization efficiency of a green light is improved. The coordination control method has practical engineering application value in an aspect of urban road traffic control management.

The invention discloses a method for correcting a synchronous phasor under the condition of frequency shift of voltage of a power grid, and a current signal. By a uniform approximation method in a fonctionelle, an expression is reasonably corrected, a formula is corrected by the same method in an amplitude-phase space, and a quantized correction expression is finally given. A calculated amount is greatly simplified by an amplitude-phase characteristic relation approximation ellipse. By the uniform approximation method, the correction formula of amplitude is solved, and a practical function expression of engineering is given. Compared with the conventional algorithm, the method mainly solves the problem of 0 / 0 data shift, which is caused by conventional amplitude correction and the problem of sudden change of phase angle, which is caused by discontinuity of a tan function. The research result has certain engineering application value.

The invention provides a guidance information extraction method of a strapdown homing seeker, which comprises the following steps that (1) a body line-of-sight azimuth angle and a body line-of-sight altitude angle of the seeker in an airborne coordinate system o-xbybzb are acquired; (2) measurement information of the strapdown homing seeker is processed; (3) a missile-target relative distance vector in the airborne coordinate system and a component of a movement velocity of a target relative to an aircraft in the airborne coordinate system are calculated; (4) an inertia line-of-sight azimuth angular rate of the aircraft at the current hour and an inertia line-of-sight altitude angle rate of the aircraft at the current hour in the airborne coordinate system are calculated; and (5) results obtained in Step (4) serve as guidance information and are sent to the strapdown homing seeker. To overcome the defects in the prior art, body line-of-sight angular measurement information and gyro angular velocity measurement information are used directly to extract an inertia line-of-sight angular velocity, so that the guidance precision is improved, the design difficulty of a guidance system is reduced, and the guidance information extraction method can be widely applied to various strapdown homing guidance weapons.

The invention discloses a prediction method of a thermal fatigue life of a BGA (Ball Grid Array) welding spot considering an influence of sequential temperature cycling load loading. The method comprises the steps of 1, analyzing the influence of the sequential temperature cycling load loading on the thermal fatigue life of the BGA welding spot, and a reason; 2, improving a Darveaux model according to the influence of the sequential temperature cycling load loading on the thermal fatigue life of the BGA welding spot and by reference to a Paris formula and building a prediction model of the thermal fatigue life of the BGA welding spot considering the influence of the sequential temperature cycling load loading; 3, determining a fit determination method of parameters in the prediction model of the thermal fatigue life of the BGA welding spot considering the influence of the sequential temperature cycling load loading; 4, performing analysis verification on the prediction model of the thermal fatigue life of the BGA welding spot considering the influence of the sequential temperature cycling load loading, and separately performing contrast analysis on fatigue life prediction results of the prediction model of the thermal fatigue life of the BGA welding spot considering the influence of the sequential temperature cycling load loading and the Darveaux model under a single temperature cycling load condition, and performing contrast analysis on fatigue life prediction results of the prediction model of the thermal fatigue life of the BGA welding spot considering the influence of the sequential temperature cycling load loading and the Miner theory under a sequential temperature cycling load loading condition; and 5, completing building of the prediction method.

The invention belongs to the technical field of unmanned aerial vehicles and discloses an ellipsoid fitting-based unmanned aerial vehicle magnetic sensor calibrating method and an unmanned aerial vehicle. The method divides unmanned aerial vehicle postures into six types comprising a vertical upward direction along X axis, a vertical downward direction along X axis, a vertical upward direction along y axis, a vertical downward direction along Y axis, a vertical upward direction along Z axis and a vertical downward direction along Z axis. The method comprises rotating an unmanned aerial vehiclein each posture position, acquiring a series of output values of a magnetic sensor under different postures, fitting an ellipsoidal curved surface through the output values of the magnetic sensor, calculating a calibrating coefficient through the ellipsoidal curved surface, and compensating output of the unmanned aerial vehicle sensor through the calibration coefficient and calibration model. Themethod does not depend on external equipment, is easy to operate, has high calibration accuracy, can be flexibly used in any field, can calibrate six factors such as scale factors and zero point drifts and can improve the measurement accuracy of the magnetic sensor.

The invention discloses a testing method and system of a generator power transmitter with consideration of synchronous phasor measurement. The method comprises: a synchronous phasor measurement unit (PMU) is set at one side of a generator, wherein the PMU is used for obtaining a dynamic characteristic signal of a power transmitter of the generator; a PMU signal receiving device is arranged and isused for receiving the dynamic characteristic signal, obtained by the PMU, of the a power transmitter of the generator and transmitting the signal to a real-time digital simulation system (RTDS); a generator simulation model is established in a simulation interface of the RTDS; control information of the generator is transmitted to the generator simulation model to simulate the actual operation state of the generator; and on the basis of the actual operation state result of the simulated generator, dynamic characteristics of the power transmitter are checked. The testing method and system havethe following beneficial effects: when a fault occurs at a power system, information of voltage fluctuation and system oscillation and the like is recorded, so that the stability margin of the systemis determined in advance.

The invention discloses an aircraft winglet expansion amount optimization method based on a Gaussian pseudo-spectrum method, which comprises the following steps of: establishing constraint conditionsof a winglet expansion track of a climbing section of a near-space variable-wing aircraft, including boundary constraint, path constraint, state variable and control variable constraint; establishinga performance index function of the small wing telescopic track of the climbing section of the near-space variable-wing aircraft, wherein the performance index function is established according to a target with the most fuel-saving effect; discretizing the established continuous optimization control problem by adopting a Gaussian pseudo-spectrum method so as to convert the discretized continuous optimization control problem into a nonlinear programming problem, and solving the nonlinear programming problem to obtain an optimal near-space variable-wing aircraft climbing section winglet telescopic track. According to the method, the expansion amount of the winglet of the climbing section of the near-space variable-wing aircraft can be optimized within a short time, and the control target ofthe minimum fuel consumption is achieved.

The invention discloses a single-side high-temperature testing device of a hypersonic aircraft material in an 1800-degree aerobic environment. The testing device comprises a silicon-molybdenum heater array, a high-temperature ceramic support, a heat insulation base, a high-temperature ceramic flat plate, a hypersonic aircraft plane testing part material, a high-temperature heat insulation material, a thermocouple temperature sensor and a computer. According to the device, when a radiation heating experimental research of the hypersonic aircraft material is conducted, a single-side flight thermal environment for a high-mach number aircraft in an aerobic environment is achieved, heat insulation characteristic parameters of the hypersonic aircraft material in an extreme, aerobic and high-temperature environment are measured, and important extreme thermal environment testing methods are provided for high-speed spacecraft and aircraft production.

The invention discloses a high-pressure nuclear magnetic resonance CO2 geological storage model test system. A load control system is connected with a sample visualization observation system through a pipeline. A fluid control system is connected with a core holding unit in the sample visualization observation system through a fluid injection pipeline. An axial pressure sensor and a confining pressure sensor in a data collecting and processing system are installed on a pipeline connecting an axial pressure pump in the load control system with the core holding unit and a pipeline connecting a confining pressure pump in the load control system with the core holding unit respectively. A left water pressure sensor and a right water pressure sensor in the data collecting and processing system are installed on a pipeline connecting a left salt water injection pump in the fluid control system with the core holding unit and a pipeline connecting a right salt water injection pump in the fluid control system with the core holding unit respectively. An injection air pressure sensor and a flow meter in the data collecting and processing system are installed on a pipeline connecting a CO2 injection pump in the fluid control system with the core holding unit. By means of the high-pressure nuclear magnetic resonance CO2 geological storage model test system, the transport law of CO2 in reservoirs and cap rock on the conditions of different temperatures, different vertical stresses and different horizontal stresses and the deformation and fracture law of the reservoirs and the cap rock are researched.

The invention discloses a video abnormal behavior discrimination method based on non-local network deep learning, and belongs to the field of computer vision, intelligence and multimedia signal processing. A training set is constructed by using a multi-example learning idea, and positive and negative packages and examples of video data are defined and labeled. A non-local network is adopted for feature extraction of a video sample, an I3D network of a residual structure serves as a convolution filter for extracting space-time information, and a non-local network block fuses long-distance dependence information so as to meet the time sequence and space requirements of video feature extraction. After the features are obtained, a regression task is established through a weakly supervised learning method, and a model is trained. According to the method, unlabeled categories can be judged, and the method is suitable for the conditions that positive samples of abnormal detection tasks are rare and the diversity in the categories is high. The method meets the recall rate requirement of an abnormal scene and has engineering application value.

The invention belongs to the field of array signal processing, and particularly relates to a sparse direction of arrival angle estimation method based on a multiple-input multiple-output array. The method comprises the following steps of s1, establishing a signal model; S2, estimating and vectorizing a signal covariance matrix; S3, expanding the spatial degree of freedom by using a co-prime matrixprocessing method; S4, obtaining target direction of arrival estimation by adopting a neighbor operator method; and S5, determining a target direction of arrival and number. The method disclosed by the invention has the following beneficial effects that the multi-target angle estimation precision under the conditions of low signal-to-noise ratio and small samples can be improved, and method for estimating the target angle is fast in iterative rate of convergence, and high in operation efficiency, can be applied to a real-time multi-target angle estimation system, and has important engineeringapplication value.

The invention discloses a power transmission line single-ended fault location method based on a variable traveling wave recognition time window. According to the method, through online estimation of opposite-end system impedance and establishment of an improved distribution parameter method, the irregularity of error distribution of a conventional method is effectively improved, and the feasibility of establishing a combined location algorithm according to power frequency quantity location error is promoted. A variable fault distance window is calculated according to different fault conditions and error rules, the corresponding time area of fault reflected traveling waves is targeted, and thus the variable reflected traveling wave recognition time window is defined. Based on the variable time window, the bus wiring mode of the local end and the opposite end of measurement, influences of adjacent bus reflected waves and other factors are comprehensively considered, and a reflected wave recognition method and a location method in the variable time window are established through the traveling wave method. Simulation verification results show that the reliability level of the combined location method is improved through the method, and the method has high fault location precision and certain engineering application value.

The invention discloses a multi-type signal-based power system low-frequency oscillation analysis method, and belongs to the field of analyzing the stability of the power system. The method mainly comprises the steps of analyzing internal physical contact among multi-type curves of sets; formulating amplitude deviation and phase deviation evaluation indexes based on the contact, and evaluating the accuracy degree of extracting oscillation mode by the Prony algorithm; in order to avoid the signal in some type from being covered caused by over large amplitude difference of the curves in different types, performing translation processing on the amplitude of the signals in different types; giving a dominant oscillation mode identifying method, establishing a comprehensive evaluation index of a multicomputer signal, and reflecting the reliability of the Prony algorithm. The index system provided by the invention has engineering application value; according to the system, the reliability of extracting the oscillation mode information can be reflected; the appropriate Prony algorithm order can be selected according to the comprehensive index.

The invention discloses a harmonic wave measurement method based on spectral energy interpolation. According to ten cyclic wave detection environments meeting the IEC standard, concrete parameters of a certain component are detected out accurately, and an IEC method only can roughly detect out the amplitude of signals within the certain frequency band; from the point of view of spectral energy in a signal frequency domain for the first time, transformation and interpolation of an energy spectrum are carried out by multiplying the frequency spectrum by a rotation phase factor, influence of overlaid leakage of sidelobes of the frequency spectrum is eliminated by mutual offset of energy of interference components, and the detection precision of the frequency, the amplitude and the phase position is improved; when the components in signals are likely submerged in noise signals, main signals are highlighted through transformation of the spectrum energy, and therefore usable signals are extracted from the noise signals effectively. The method is based on a DFT / FFT algorithm recommended by the IEC standard, the principle is simple, the effect and stability are good, and the method has certain engineering application value and good application prospects.

The invention belongs to the field of high-temperature alloys, and particularly relates to a gamma' phase reinforced cobalt-based high-temperature alloy with high-stability structure and good oxidation resistance. The gamma' phase reinforced cobalt-based high-temperature alloy comprise the following chemical components of, by weight, 2.5-4% of Al, 3-10% of W, 0.5-5% of Ti, 1.5-6% of Ta, 18-35% ofNi, 10-14% of Cr, 0-4.5% of Nb, 0-0.5% of Hf, 0-0.1% of C, 0-0.1% of B, 0-0.1% of Zr, 0-0.5% of Si, and the balance Co, and the contents of Al plus Cr is more than or equal to 13.5%, the Al plus the Ti plus the Ta plus the Nb are more than or equal to 9.5%, and the W plus the Ta is less than or equal to 12.5%; and a vacuum arc furnace is adopted for smelting, then solid solution is carried out atthe temperature of 1200-1250 DEG C, and aging heat treatment is carried out at the temperature of 700-900 DEG C. The gamma / gamma' two-phase structure stably exists at the temperature of 700-900 DEG C,and the gamma' strengthening phase volume fraction is larger than 40%; and meanwhile, the alloy has good oxidation resistance, large hot working window and low alloy density, and is an alternative material of a high-temperature disc piece of an aero-engine and an industrial gas turbine.

The invention provides a method for forming a Ti3Al-based alloy thin-wall barrel. The method comprises the following steps of: (1) preparing a barrel blank by using a Ti3Al-based alloy plate with the thickness of between 1.5 and 4 millimeters at the temperature of between 650 and 700 DEG C by a hot rolling and bending method; (2) penetrating and welding a weld in the bus direction of the barrel blank by continuously inputting laser through CO2 so as to obtain a thin-wall barrel; (3) preserving the heat of the thin-wall barrel at the temperature of between 950 and 1,000 DEG C for 1 to 3 hours and cooling the thin-wall barrel along with a furnace; (4) calibrating the thin-wall barrel at the temperature of between 600 and 650 DEG C; and (5) preserving the heat of the thin-wall barrel at the temperature of between 900 and 1,000 DEG C in vacuum for 1 to 2 hours and cooling in the air. Due to the adoption of the method, cracks are effectively prevented in a forming process and deformation resistance is reduced; particularly, the intensity of the weld and a parent metal is lowered by thermal treatment after welding, plasticity is enhanced, and calibration after welding is facilitated and can be performed at a relatively low temperature; simultaneously, the intensity of the barrel is enhanced integrally through final thermal treatment.

The invention belongs to the field of array signal processing, and in particular relates to a fast target angle estimation method based on sparse Bayesian learning. The method comprises the followingsteps of S1, performing initialization on the parameters to be estimated of gammaj and sigma0, wherein j is equal to 1,2 to N; S2, quickly obtaining signal posterior probability density functions at each moment by using the AMP algorithm; S3, updating values of the parameters to be estimated of gammaj and sigma0 by using the EM algorithm, wherein j is equal to 1,2 to N; and S4, determining whetherthe update iterative process of the parameters to be estimated converges, returning to the S2 to re-iterate if not, and if so, jumping out of the loop and determining the direction and quantity of the target incoming waves. The method provided by the invention can improve the low signal-to-noise ratio and the multi-objective angle estimation accuracy under small sample conditions, and has the advantages of fast iterative convergence speed and high computational efficiency for estimating the target angle, which can be applied to the real-time multi-objective angle estimation system and has important engineering application value.

The invention discloses a duplication eliminating method based on a multidimensional lattice data spatial model. The method includes following steps: loading local cache data and building the multidimensional lattice data spatial model; transferring the data into customized data format and cutting the data into data points; searching the data one by one, positioning coordinates of each data point on dimensions corresponding to the data model, searching each data point from a first digit down digit by digit, characterizing each data point if the same does not exist in the data model, and marking the data as absence; and traversing the data points of the data, outputting the cache if the data is marked as absence, and searching next data until all the data is searched. The duplication eliminating method based on the multidimensional lattice data spatial model is suitable for filtration and duplication eliminating of various data, high in duplication eliminating efficiency and has fine application value in engineering. In addition, by the method, the problem of severe resource consumption caused by length difference of the data is solved.

The invention provides a smart jamming noise signal design method based on velocity pull-off and relates to the smart jamming noise signal design method. The smart jamming noise signal design method based on the velocity pull-off is put forward to solve the problem that false target track is easy to be cancelled by radar anti-interference when uncorrelated, so that the effect of suppression jamming cannot be achieved, and the effect of anti-jamming measures, such as echo sidelobe cancellation, is not good enough. The method is realized through the following steps: 1) calculating time delay tau; 2) calculating Doppler frequency shift fd obtained after an electromagnetic signal is reflected back to a radar antenna through secondary scattering of a target; 3) calculating the amplitude value At of a target echo signal at the time t after the electromagnetic signal is reflected back to the radar antenna through secondary scattering of the target; 4) calculating the target echo signal sr(t); and 5) increasing offset of the Doppler frequency shift fd. The method is applied to the smart jamming noise signal design field.

The invention discloses a method for calculating the crack width of a reinforcing steel bar-steel fiber concrete shield duct piece. The method comprises: S1, carrying out loading testing on a reinforcing steel bar-steel fiber concrete beam; S2, carrying out calculation based on loading test data to obtain a crack width influence coefficient; S3, determining a corresponding pre-crack width according to the crack width influence coefficient; S4, carrying out calculation based on loading test data to obtain a tensile strength influence coefficient; S5, determining a corresponding crack bending moment based on the tensile strength influence coefficient; and S6, carrying out correction based on the calculation formula of the pre-crack width and acquiring a corresponding crack width according tothe corrected calculation formula. The calculation result is more accurate and close to the actually measured result. The method is easy to apply directly in the engineering practice and the reference is provided for the tunnel duct piece design. The method has the important engineering application value. An assessment basis is provided for evaluating the durability of the high-strength reinforcing steel bar-steel fiber concrete shield duct piece.

The invention discloses a ship type optimization method based on a multi-objective particle swarm optimization algorithm. The method comprises the following steps: generating a group of particle swarmdesign variables according to the multi-objective particle swarm optimization algorithm, wherein each design variable particle corresponds to a group of ship type modification parameters; establishing a ship body new geometry corresponding to the ship type modification parameter by adopting an arbitrary curved surface deformation technology; calculating hydrodynamic performance by adopting a deepbelief network algorithm; and inputting a target function into the multi-objective particle swarm algorithm, generating a group of new particle swarm design variables according to the transformationrule of the multi-objective particle swarm algorithm, returning to step 2 to continue the next optimization until the multi-objective particle swarm algorithm reaches the maximum iteration times, andoutputting the hull geometry corresponding to the optimal particle. The hydrodynamic performance of the ship in waves is predicted by adopting a deep belief network algorithm, and global optimizationis performed by adopting the multi-objective particle swarm algorithm, so that the accuracy and the practicability of ship type design are ensured while the ship type optimization efficiency can be effectively improved.

The invention relates to a method for determining and controlling a high-precision gesture of a space-based telescope. As a telescope for optical detection is combined with a star sensor for data measurement, in combination with velocity information measured by a gyroscope, high-precision measurement of a gesture is realized; gesture measurement data is delivered to a Kalman filter, to realize high-precision estimation of the gesture; and a controller provides a control law for a maglev mechanism and a flywheel, so as to realize high-precision control of the gesture. According to the method disclosed by the invention, determination and control in the high-precision gesture of the space-based telescope can be realized, and therefore imaging quality of the space-based telescope is improved; and the method disclosed by the invention has an engineering application value.

The invention belongs to the field of brushless direct-current motor control, and particularly relates to a method for acquiring compensating voltage restraining a commutation torque pulsation device of a brushless direct-current motor. In a non-commutation period, a first switch T1 is switched off, a second switch T2 is switched up, a power supply charges a boosting capacitor to enable the compensating voltage Uc=Ubus-Udc, and when charging is over, the second switch T2 is switched off, when commutation starts, the first switch T1 is switched on, a diode is switched off, the power supply and the capacitor are connected serially so as to supply power to the brushless direct-current motor until commutation is over, and when voltage of the capacitor drops and commutation is cover, bus voltage is equal to four times of a counter electromotive force amplitude, namely Ubus=4E. In a commutation period, a phase power device can be switched on without modulating the bus voltage by chopping, so that generation of direct-current bus voltage fluctuation caused by reverse bus current is avoided, switch loss and switch interference are reduced. The method for acquiring the compensating voltage restraining the commutation torque pulsation device of the brushless direct-current motor is low in data acquisition amount and has a certain engineering application value.