118results about How to "Solve the accuracy is not high" patented technology

The invention discloses a traffic condition prediction system fused with various transport data and a method. The traffic condition prediction system comprises a flow level detecting unit, a speed level detecting unit, a flow trafficability ratio level detecting unit, a flow occupancy level detecting unit, a speed occupancy level detecting unit, a saturation coefficient level detecting unit, a historical road level detecting unit and a road condition predicting unit, level numbers of parameters are obtained by the various level detecting units by means of measuring and computing, then the level numbers are multiplied by percentages of level numbers of the parameters preset in the road condition predicting unit, the sum of the products is computed to obtain road condition level numbers, and a road condition within future prediction time is obtained according to a road condition corresponding to preset road condition level numbers. The technical problem that a future road condition is predicted by means of combining a single road condition characteristic parameter with a historical road condition in the prior art. The traffic condition prediction system and the method are fused with various information of a current road condition.

The invention discloses a magnetic suspension rotor harmonic current suppression method based on a composite friction repetitive controller. Firstly, a magnetic suspension rotor dynamical model which comprises mass unbalance and sensor harmonic is established. Secondly, the composite friction repetitive controller is designed. The controller is obtained through parallelly connecting a double-mode friction repetitive controller and a phase shift notch filter. The double-mode friction repetitive controller comprises two branches, namely an odd-order harmonic suppression branch and an even-order harmonic suppression branch. The odd-order harmonic and the even-order harmonic can be suppressed in an enhanced manner through distributing the value of a control gain, and dynamic response performance is improved. A friction time delay link is replaced by a friction time delay filter, thereby improving harmonic current suppression precision. Furthermore the phase shift notch filter is introduced for performing additional suppression on fundamental frequency current, thereby reducing current overshoot and improving harmonic convergence speed. The magnetic suspension rotor harmonic current suppression method can realize harmonic current suppression in a fixed rotating speed and is suitable for magnetic suspension rotor harmonic current suppression in which mass unbalance and sensor harmonic exist.

The invention discloses a method for inhibiting radio frequency interference (RFI) of a synthetic aperture radar (SAR) on the basis of a neural network and belongs to the technical field of radar signal processing. Firstly, all global frequency domain characteristic values of an FRI signal are detected from frequency domain data of a SAR original echo; corresponding extended alternating projection neural network (EAPNN network) repository patterns are generated by the frequency domain characteristic values and are memoried into the EAPNN network one by one; then the RFI signal is associated from echo time domain data by utilizing an association function of the EAPNN network; and the echo time domain data is directly subtracted from the associated RFI signal so as to fulfill the aim of inhibiting the RFI. The EAPNN network combines the global characteristics and dynamic tracking characteristics, which are difficult to simultaneously consider in the existing method, and thus, on the premise of ensuring high inhibiting accuracy, a high processing speed can be obtained. The method can be widely used for the fields of the SAR, earth remote sensing and the like and is particularly suitable for places with high requirements on both the inhibiting accuracy and the processing speed and dense RFI.

The invention discloses a wearable device, which comprises a strip-shaped structure, a main body, a micro air pump, an airbag, a sensor and a driving control module, wherein the main body is connected to the outer surface of the strip-shaped structure and is provided with an accommodating space; the micro air pump is arranged in the accommodating space of the main body; the airbag, relative to the micro air pump, is arranged on the inner surface of the strip-shaped structure and communicates with the strip-shaped structure; the driving control module is arranged in the accommodating space of the main body; the sensor is arranged on the driving control module and is connected to the micro air pump, wherein the micro air pump acts under the control of the driving control module, so that gas is transmitted to the air pump from the micro air pump and the airbag, which gets expanded as being inflated, is fixed to special part of a wearing user; and physiological information of the wearing user is sensed by virtue of the sensor, and the physiological information is transmitted to the driving control module, so that the physiological information is recorded.

The invention relates to a method for acquiring absolute open flow of a shale gas layer based on a gas productivity index. The method comprises the following steps of: acquiring shale gas layer parameters of a tested well in a work area, acquiring shale gas layer fracturing parameters of the tested well, and acquiring open flow of the shale gas layer of the tested well by virtue of tested productivity data; sequentially calculating a gas bearing index, a fracturing transformation index and a gas production index of a tested well gas layer by virtue of the acquired parameters, and determining the model coefficient of a model AOFg=A*eB*IPG by virtue of a gas productivity index IPG calculated in a corresponding tested well by utilizing a least square method; and acquiring to-be-predicted well shale gas layer parameters in the work area, acquiring to-be-predicted well shale gas layer fracturing parameters, sequentially calculating a fracturing transformation index, a gas bearing factor and a gas production index of the to-be-predicted well gas layer according to a formula by virtue of the acquired parameters, introducing the gas productivity index into a model AOFg1=A*eB*IPG1, calculating the open flow of the to-be-predicted well shale gas layer, and outputting the calculation result. The method disclosed by the invention is adopted in 30 predicted wells of a certain shale gas field, and the average error does not exceed 20%.

The invention provides an information processing method and device based on vehicle clustering. The method comprises: a requestor vehicle sends a first cooperation sensing request to a cluster head vehicle, wherein the first cooperation sensing request includes first location information where the requestor vehicle is located and an identifier of the requestor vehicle and is used for making a request of road environment information of the first location information; the requestor vehicle receives a first cooperation sensing response sent by a responder vehicle, wherein the first cooperation sensing response includes the road environment information of the first location information, the road environment information is obtained by the responder vehicle based on a second cooperation sensing request sent by the cluster head vehicle, and the second cooperation sensing request includes the first location information and the identifier of the requestor vehicle; and according to the first cooperation sensing response, control information of an autonomous vehicle is generated.

The invention discloses a powder pressing formation device and belongs to the technical field of powder pressing formation. The powder pressing formation device is characterized in that a rotary workbench with inner teeth formed in the periphery of a center hole is supported on a machine base, formation lower die grooves are formed in the workbench face of the rotary workbench at the equal intervals of 120 degrees, and a funnel-shaped hopper, a quantization device, a formation upper die column connected with a piston rod and a finished product ejection and collection device are arranged at the upper positions corresponding to the formation lower die grooves respectively. The powder pressing formation device has the advantages that the formation lower die grooves at the trisection positions of the rotary workbench correspond to three working procedures of quantized loading, pressing formation and finished product collection to work simultaneously, the working efficiency is improved, product quality is improved through quantized loading and pressing formation, and automatic production is achieved through continuous work.

The invention discloses a double-vector predicted flux linkage control method for a permanent magnet synchronous motor. The method comprises the steps of firstly converting a torque increment into a load angle increment and unifying control objectives as a stator flux linkage vector; calculating and obtaining a reference voltage vector according to a dead-beat idea, selecting a I vector through interval positions of the reference vector and selecting a II vector through subinterval positions of the reference vector; dividing a control period into two parts through optimizing a duty ratio of the voltage vector, making the I vector act on one part of the control period and selecting the II vector or a zero vector in the remaining time; and finally carrying out loop optimization calculation on the selected voltage vectors and the duty ratio to obtain an optimal voltage vector and conveying the optimal voltage vector to the permanent magnet synchronous motor. According to the double-vectorpredicted flux linkage control method for the permanent magnet synchronous motor, torque and flux linkage ripples of a system are reduced while the calculating time of a processor is shortened, and the reliability and the steady-state performance of the system are improved.

The invention discloses an inter-partition dual-vector model predictive control method for a parallel PWM rectifier. The method comprises the steps that voltage vector inter-partition calculation is introduced into model predictive control, and a vector duty cycle modulation method is combined, so that the reduction of zero sequence circulating current and the decrease of processor computation time can be effectively achieved; the influence of different voltage vector combinations on circulating current in a control system is directly analyzed, then 36 voltage vector combinations are divided into 4 partitions, so that the zero sequence circulating current and processor computation burden are reduced; by optimizing effective vector duty cycles of a selected partition, a control cycle is divided into two parts, effective vectors only act on a part of the control cycle, and the remaining time selects zero vectors to further improve the system circulating current suppression precision; andfinally, cyclic optimizing computation is carried out on voltage vectors in the selected partition. The problem of uneven current and waveform distortion caused by the circulating current can be solved without additional hardware devices, and the reliability and efficiency of the system are improved.

The invention discloses a magnetic suspended rotor harmonic current inhibiting method based on MQRSC (multiple quasi-resonant control with phase-shift). Firstly, a magnetic suspended rotor kinetic model containing mass unbalance and sensor harmonic is established, and then, the magnetic suspended rotor harmonic current inhibiting method based on an MQRSC controller is adopted, wherein MARSC consists of multiple quasi-resonant controllers, and each quasi-resonant controller corresponds to a harmonic current component in each frequency doubling position in a rotor system. By means of the controlmethod, the stability of the system and the dynamic property for current inhibition can be improved. The quasi-resonant controllers have simple and fixed mathematical forms and are very convenient inactual application. The harmonic component of magnetic bearing coil current in a magnetic suspended rotor can be inhibited, and the method is applicable to harmonic current inhibition of the magneticsuspended rotor system with mass unbalance and sensor harmonic.

The invention relates to a method for determining wind power curtailment at a wind farm based on anemometer data of an anemometer tower. The method includes the following steps: based on the anemometer data of the anemometer tower, taking factors such as terrains, land forms and wake flow of wind generation sets, into consideration, calculating the wind speeds at the highest positions of the wheel hubs of the wind generation sets, and in accordance with the power curve, obtaining theoretical power of the wind generation sets, calculating the sum of the theoretical power of all wind generation sets at the wind farm and obtaining theoretical power at the wind farm, finally respectively integrating the theoretical power at the wind farm and actual power over time, obtaining a theoretical quantity of electricity and an actual quantity of electricity, and obtaining the wind power curtailment by subtracting the theoretical quantity of electricity from the actual quantity of electricity, thus achieving an accurate calculation of the wind power curtailment at the wind farm. The method is generally applicable to all types of wind farms, and successively addresses the problem of inaccuracy of calculating wind power curtailment by using a template machine method.

The invention relates to a global seamless locating method based on a GPS, a fourth-generation mobile communication network and a WiFi. Target location is conducted by automatically selecting one of a GPS locating method, a GPS and fourth-generation mobile communication network combined locating method, a fourth-generation mobile communication network locating method, a fourth-generation mobile communication network and WiFi network combined locating method and a WiFi wireless network locating method, so that the effect of the optimal locating precision is achieved. Signal intensity of a receiver is ensured through the combination of the GPS locating, the fourth-generation communication network base station locating and the WiFi wireless network locating, accordingly, the global seamless locating is achieved, the problem that locating can not be conducted by the GPS under the severe environment is solved, and the problem that the GPSONE indoor locating precision is not high is solved at the same time.

The invention relates to a compression molding technique for a tungsten alloy holding-up hammer, and relates to a device for realizing the technique. The innovation points are as follows: the tungsten alloy holding-up hammer provided by the invention is molded through compression by adopting an automatic molding device for the tungsten alloy holding-up hammer; the automatic molding device for the tungsten alloy holding-up hammer comprises a female mold, an upper punch and a lower punch; the technique comprises the following steps: (S1) powder is added; (S2) staging compression is performed for 5 times; the upper punch is used for enabling the female mold to downwards move so as to realize floating compression through the indirect effect of the powder body on the female mold; (S3) after the compression is completed, the pressure maintaining is performed for 56-67 S, and the pressure is relieved; (S4) demolding is carried out. The automatic molding technique and device have the following advantages: as the tungsten alloy holding-up hammer is produced by adopting the powder metallurgy technology, the utilization rate of raw materials is high, and the production cost is low; through the multi-grading compression is combined with the floating compression, the density consistency of products is largely improved, the reject number is decreased, and the processing efficiency is improved.

A wearable measurement device for blood pressure comprises a watchband, a valve piece, a gas collecting seat, a gas conveying device, an elastic medium and a pressure sensor, wherein the watchband isprovided with an embedding region, the embedding region is provided with a first containing groove, a second containing groove, a gas collecting through hole and a pressure relief through hole, the gas collecting through hole is communicated between the first containing groove and the second containing groove, and the pressure relief through hole is communicated between the first containing grooveand the exterior of the watchband; the valve piece is overlapped in the first containing groove and provided with a valve hole corresponding to the gas collecting through hole; the gas collecting seat is arranged in the first containing groove, overlapped on the valve piece and provided with multiple holes; the gas conveying device is assembled and seals the gas collecting seat; the elastic medium seals the second containing grooves for inflation elastic displacement; the pressure sensor is arranged on the elastic medium. In this way, guided and conveyed gas is transmitted into the elastic medium, and the elastic medium is inflated with gas to expand to push the pressure sensor to abut against the measurement position of a user so that a blood pressure numerical value can be measured.

The invention discloses a technical field of a RFID (radio frequency identification device), and discloses an automatic elimination method of RFID receiving circuit carrier and a circuit thereof, and a reader circuit. Through a directional coupler, an inhibiting carrier signal source with the same frequency and signal as a carrier signal input from an emitting end is obtained from an emitting chain; the inhibiting carrier signal source performs a power scaling so that its power is equal to the power of a leakage carrier signal of a receiving end; through a phase adjusting, the phase difference between the inhibiting carrier signal source and the input carrier signal is 180 degrees, and a reverse carrier signal is obtained; and then the reverse carrier signal is coupled to a receiving chain through the directional coupler, and thereby the leakage carrier in a receiving circuit is eliminated. The automatic carrier elimination method is easy to realize, and the best effect of carrier inhibition-30 dbc can be reached.

The invention discloses a meat cutter with a good meat cutting effect. The meat cutter comprises a workbench. The top of the workbench is fixedly connected with a protection box. The tops of the two sides of an inner cavity of the protection box are fixedly connected with supporting tables correspondingly. The tops of the two supporting tables are fixedly connected with motors correspondingly. The output end of each motor is movably connected with a first bevel gear. The sides, away from the output ends of the motors, of the first bevel gears are engaged with second bevel gears correspondingly. According to the meat cutter provided by the invention, by arranging the workbench, supporting posts, the protection box, the supporting tables, the motors, the first bevel gears, threaded rods, a cover plate, a supporting plate, the second bevel gears, sleeves, limiting blocks, a cutting tool, a holding table, telescopic rods, springs and a fixing plate which are in cooperative use, the meat cutting effect is better in this way, the problems that when an existing meat cutter is in use, the cutting force is difficult to control, and consequentially cut materials are insufficient in precision are solved, using by a user is facilitated in this way, and the practicability of the meat cutter is improved.

The invention discloses a DC biasing digital inhibition system and method based on a bidirectional full-bridge converter. A power phase shift angle is removed from a traditional phase shift control algorithm, a new control variable is introduced, the control variable is the modulation phase shift angle of an advance arm and a lagging arm of a bridge B1, the control variable is introduced to realize a ZVS soft switch in the given power range, and in the working process of the converter, the control variable changes with change of the phase shift angle. Due to the fact that stray parameters of a switch tube and a parasitic capacitor cannot be absolutely consistent in four switch tubes and a winding technology of a transformer has problems, biasing in the transformer cannot be avoided, and biasing inhibition is a necessary function of the full-ridge converter.

The invention discloses an intelligent prediction method of a user satisfaction in an IPTV video business, and is used for solving the shortages such as the user satisfaction needs to be measured by subjective scoring, the internal relevancy modeling between the user satisfaction and influence factors thereof is not accurate and reasonable enough, and the like in existing user satisfaction prediction methods. An implementation process of the invention is as follows: first of all, determining factors which affect the user satisfaction and thereafter measuring the user satisfaction objectively by employing a duration that a user uses the service; then, establishing a CART tree model via training, and partitioning to-be-predicted data to related areas by employing the CART tree model; and searching in the areas by employing KNN, and at last taking a distance weighted average as a prediction result. By adopting the method disclosed by the invention, the computation burden in the prediction process can be effectively reduced, and the prediction accuracy is greatly improved.

The invention discloses an automatic driving vehicle path planning system and method based on a V2I technology, and relates to the technical field of automatic driving. According to the invention, a vehicle-mounted sensor of an automatic driving vehicle, an electronic high-definition map system and the V2I technology are combined; the vehicle position is mapped to MAP data broadcasted by RSU equipment on a roadside by utilizing data acquired by the vehicle-mounted sensor; related information of a signal lamp phase which should be concerned by a current lane and a connection mode of the currentlane in a road network can be obtained by combining SPAT data broadcasted by RSU equipment; therefore, a basis is provided for path planning and speed planning of the automatic driving vehicle, accurate driving of the automatic driving vehicle can be achieved, the electronic high-definition map system and MAP data are tightly combined, and the problem that the electronic high-definition map system is insufficient in accuracy is solved.

The invention discloses a synchronous machining locating clamp and a machining method of a moving scroll plate and a static scroll plate. The clamp comprises a bottom plate, the static plate and themoving plate, wherein the static plate and the moving disc are located on the bottom plate. An annular static plate locating seat and an annular moving plate locating seat are arranged on the bottom plate. At least three press cylinders are arranged at the position, in the circumferential direction of each of the static plate locating seat and the moving plate locating seat, of the bottom plate inan annular array manner. Press blocks used for pressing the corresponding scroll plates are arranged on pistons of the press cylinders. The two ends of the bottom plate are rotationally connected with a fixed seat and a drive seat used for driving the bottom plate to turn over. Avoiding holes are formed in the bottom plate, the static plate locating seat and the moving plate locating seat in thevertical direction in a penetrating manner. In the machining method, two cutters are adopted for achieving synchronous machining with completely-communicating parameters. According to the synchronousmachining and locating clamp and the machining method, clamping efficiency is improved, operation is simple and convenient, manpower is saved, secondary clamping is avoided, machining efficiency and position precision are improved, procedures are reduced, and products keep consistent through synchronous machining.

The invention discloses a method for restricting rotation of a rotary machinery rotor. The method comprises the following steps: firstly determining the maximum rotation position of a rotor in a small rotary machinery rotor system; subsequently fixing a magneto-rheological elastomer dynamic vibration absorber on the rotor system so as to perform the operation for restricting the vibration, wherein the magneto-rheological elastomer dynamic vibration absorber is used according to the following steps: fixing the magneto-rheological elastomer dynamic vibration absorber at the maximum rotation position of the rotor, and starting the system of the magneto-rheological elastomer dynamic vibration absorber to reduce vibration amplitude of the rotor and restrict the vibration, wherein the value of rigidity ka of the magneto-rheological elastomer dynamic vibration absorber is regulated by specifically utilizing the characteristic that the rigidity of a magneto-rheological elastomer is controllable, so that the inherent frequency is nearly equal to the vibration frequency of the rotary machinery rotor system. According to the method disclosed by the invention, the equipment is good in controllability and low in fault rate; the system is good in operation stability; the method can be used for restricting the vibration of the rotary machinery rotor system.

The invention discloses a K clustering intelligent selection microwave signal multipath interference suppression method, and relates to an interference suppression method. The method comprises the following steps: 1) establishing and training a multipath interference suppression model; 2) setting test conditions of the antenna in the anechoic chamber; 3) adding reflection plate interference sources of different materials or shapes to establish an interference model; 4) dividing the difficulty condition of the interference degree; and 5) correspondingly and respectively selecting proper algorithms according to interference degree classification to complete K-clustering intelligently-selected microwave signal multipath interference suppression. When the multipath interference mode is simple,a polynomial regression algorithm is used, a gradient descent method is used to train the model until the error converges, the current optimal multipath interference suppression model is stored, theoperation is simple, and the precision is improved. And when the multipath interference mode is medium, multipath interference suppression under the condition of three interference paths is realized by adopting a random forest. When the multipath interference mode is difficult, the neural network is adopted to realize multipath interference suppression under the condition of five interference paths, and finally, the optimization efficiency of the antenna is improved.

The invention discloses a wearable measurement device for blood pressure. The wearable measurement device comprises a strip-shaped structure, a miniature gas pump, an elastic medium and a pressure sensor; the strip-shaped structure is worn by a user; the miniature gas pump is arranged on the strip-shaped structure; the pressure sensor is combined on the miniature gas pump through the elastic medium to be arranged on the inner surface of the strip-shaped structure so as to make contact with the skin of the user to monitor blood pressure, wherein the miniature gas pump operates to drive gas to be conveyed into the elastic medium, the elastic medium is inflated to expand to push the pressure sensor to abut against the skin of the user so that scanning can be realized through flattening to measure the blood pressure numerical value of a target artery.

A light-transmitting mold structure having a mold pattern corresponding to a portion to form a pattern by nanoimprint and a conductive film pattern corresponding to a portion to form a pattern by nonadiabatic near-field exposure is used to irradiate UV light from a back surface of the mold structure and to perform nonadiabatic near-field light exposure in an imprint process so that all patterns having various sizes for simulating various designs can be faithfully transferred by a single imprint process (imprint & UV exposure).

The invention relates to the field of building component intelligent logistics positioning and BIM model visual application, in particular to a component intelligent logistics positioning method and system based on a BIM model plug-in. The method comprises the following steps of step 1, performing data extraction and model conversion on an uploaded model by utilizing a BIM plug-in, and storing information into a cloud database; wherein the BIM model is used for displaying visual logistics traceability of the component, and the extracted component data information is used for component logistics positioning traceability; step 2, collecting logistics state information of the component in various modes, including multiple terminals and multiple devices; step 3, judging logistics state information acquired by the component, judging an acquisition mode according to the transmitted component information set, performing displacement operation by utilizing a component intelligent displacementalgorithm, and storing final data; step 4, rendering and displaying the collected component positioning information in the BIM in real time.

A charge-redistribution successive approximation ADC includes: a comparator, generating a comparison result; a register, storing a digital output code, determining a bit value of the digital output code according to the comparison value; a control unit, generating a control signal according to the digital output code; a plurality of first capacitors, each including a first end and a second end, the first end coupled to a first input end of the comparator; at least one second capacitor, including a third end and a fourth end, the third end coupled to the first input end of the comparator. Before the voltages of the second end of each first capacitor and the fourth end of the second capacitor are switched, the second end is coupled to a first voltage and the fourth end is coupled to a second voltage different from the first voltage.

A packaging unit and a method for wrapping flat articles which are arranged in particular in an on-edge position is provided. The packaging unit comprises a feeding region, in particular a feeding table, and a dispensing unit for packet-type arrangements of flat articles, and furthermore comprises a stock of wrapping material present in tape form, such as, for example, bands. An articulated arm forms a processing plane in which the wrapping material is fixed, and the articulated arm guides the wrapping material around the item to be packaged, in particular flat articles.

The invention relates to the field of unmanned aerial vehicle examinations, and provides an unmanned aerial vehicle examination evaluation method and system for the problem of poor teaching effect ofan unmanned aerial vehicle, and the method comprises the steps: receiving a practical operation evaluation instruction, calling practical operation evaluation information according to the practical operation evaluation instruction, and sending the practical operation evaluation information to a first user side for practical operation flight evaluation; receiving assessment flight state informationof the first user side practical operation flight assessment, generating practical operation assessment result information according to the assessment flight state information, and sending the practical operation assessment result information to a second user side for display, wherein the practical operation evaluation instruction comprises a simulated practical operation evaluation instruction and a field practical operation evaluation instruction, when a simulated practical operation evaluation instruction is received, simulated practical operation evaluation information is called, and whenan on-site practical operation evaluation instruction is received, on-site practical operation evaluation information is called. The problem that the teaching effect of offline education of the unmanned aerial vehicle is poor can be solved. The invention also discloses an unmanned aerial vehicle examination evaluation system.

The invention relates to a data analysis technology, and discloses a user intention analysis method, which comprises the following steps of: obtaining an input text of a user, and converting the inputtext into a semantic vector; performing intention prediction on the semantic vector to obtain a prediction intention label of the input text; performing feature extraction on the prediction intentionlabel by using a feature extraction network, and generating a plurality of target intentions according to the extracted features; calculating the priority of each target intention in the plurality oftarget intentions; and selecting a preset number of target intentions from the plurality of target intentions as user intentions according to the priority. In addition, the invention also relates toa blockchain technology, and the seal record can be stored in a node of the blockchain. The invention further provides a user intention analysis device, electronic equipment and a computer readable storage medium. The accuracy of identifying the user intention can be improved.

The invention relates to an electro-hydraulic servo valve with the acceleration bias drift inhibition function. The electro-hydraulic servo valve comprises an electro-hydraulic servo valve body, an accelerometer arranged in the electro-hydraulic servo valve body and used for detecting the axial acceleration of a main valve element in the electro-hydraulic servo valve body and converting the acceleration into measuring current and a current amplifier which is arranged in the electro-hydraulic servo valve body and connected with the accelerometer and used for amplifying the measuring current toobtain feedback current, and overlapping the feedback current to the control current of a control coil of the electro-hydraulic servo valve body so as to achieve inhibition of the acceleration bias drift of the electro-hydraulic servo valve body. Compared with the prior art, the valve has the beneficial effects that the inhibition of the acceleration bias drift can be effectively achieved, the valve is simple, the application range is wide, and the implementation cost is low.