158 results about "Maintenance stage" patented technology

The invention discloses a routing method for the wireless sensor network with efficient energy, which is suitable for the layered sensor network structure. The routing method is composed of initialization, cluster building, adjacent clusters routing and routing maintenance, wherein, an initialization process of the protocol makes a Sink node obtain a topology and network average energy of the sensor network, and each node obtains hop counts from the node to the Sink node; in the stage of the cluster building, a repeated division method is used to divide sensor network clusters, the divided clusters are even, and a leader cluster node is undertaken by nodes with higher residual energy; the adjacent clusters routing uses an ant colony algorithm to determine the probability of using a link to send information according to the link pheromone concentration, and the link pheromone concentration is increased with the information transmission on the link and is reduced with the time going; and the routing maintenance stage is responsible for updating link pheromone concentration, and makes the nodes inside the cluster with higher residual energy undertake the leader cluster in turn. The routing method can reduce the consumption of the network total energy, can balance the consumption of the node energy and can prolong the network life cycle.

The invention discloses a coding-free integrated application platform system, which comprises a database, and an operation management platform and a development management platform, which are connected with and adapted to the database, wherein the operation management platform is butted with the database and comprises a Granite manager and a Granite service engine, which are matched with each other; the development management platform is butted with the database and comprises a Dasher parameter server, a Dasher console connected with the Dasher parameter server and a Mixer development tool; the database stores the parameter results configured by the development management platform for the application systems so that the operation management platform can call and use the parameter results; the system can fully cover the whole process of a software project, including demands, design, development, test, operation and maintenance stages, and in the whole process, programming is avoided, virtual computer-grade cluster mode and cloud computing virtual computing frame are supported, the functions are powerful and the maturity is high; and the system can be used as a software development platform and a business operation platform.

The invention discloses a design and configuration integrated system for an intelligent substation, which is technically convenient for information management for the intelligent substation in design, construction, operation and maintenance stages to reduce workload for checking staff. The design and configuration integrated system is arranged in a personal computer which is networked with switches of an electric power designing institute, an intelligent substation construction organization, an electricity authority, an intelligent substation operating maintenance department and a secondary equipment manufacturer. The system is provided with an intelligent substation design drawings module, a configuration management module, a model base module, a drawings management module, a retrieval module, a permission management module, a verification module, a database module and a version management module. Compared with the prior art, the design and configuration integrated system has the advantages that design and configuration are integrated, risks of errors of design and configuration are lowered, design and configuration efficiency of the intelligent substation is improved while an effective secondary data management tool is provided for operation and maintenance, repeated operations are avoided, and workload is greatly reduced for the checking staff.

An event interaction method based on a building information model (BIM) comprises the BIM. The BIM is respectively connected with a BIM library and an event triggering definition. The BIM is bound with an event correlation component self-defining model which is correlated with an event data information organization through a connector. The event data information organization comprises event information service and an event information database. The event interaction method has the advantages that by researching the event interaction technology and method in a BIM environment, application of the BIM at an operation and maintenance stage and even application of the BIM to intelligent buildings and intelligent cities are achieved, application range of the BIM is expanded, and the application depth of the BIM is extended.

The invention relates to a topology control method for wireless sensor network based on uneven cluster, belong to sensor technical field, comprising: during the topology generating stage, introducing an uneven minimum mean square subtraction clustering mechanism on a finished cluster in order to reduce energy consumption of in-cluster node; using a strategy based on cluster head energy consumption for setting cluster head changing time, in order to equalize energy consumption on each cluster head node in the network; establishing a cluster head-cluster head energy sensing route, in order to avoid remote wireless transmission; during topology maintenance stage, using a cluster head selection scheme based on node surplus energy and in-cluster node distribution, and using the same strategy to set cluster changing time. With the realization of the method, it can reduce total network energy consumption and equalize energy consumption on each node, in order to prolong cooperative working time of most nodes in the network.

An apparatus and method for processing food products is provided. The product conditioning system includes an inlet assembly, a pressurizeable tunnel and an outlet assembly. The inlet assembly and outlet assembly include a pair of vertically extending pressure vessels having entry and exit openings which are both sealable by doors to provide liquid and gaseous tight seals. The inlet and outlet assembly pressure vessels further include a pair of vertically extending parallel screws for transporting food products from one end of the pressure vessel to the other. The pressurizeable tunnel includes a heating stage having microwave sources for irradiating food products so as to pasteurize or sterilize prepackaged food. The pressurizeable tunnel further includes a heat maintenance stage and product cooling stage. Both the heat maintenance stage and product cooling stage include vertically extending pressure vessels. Within each pressure vessel, two pairs of parallel rotating screws are positioned for moving food products through a liquid environment at a desired temperature for continued pasteurization or sterilization in the heat maintenance stage, and product cooling within the cooling stage.

Disclosed are a device and a method for detecting elevator guide rail perpendicularity based on visual measurement. An elevator guide rail perpendicularity detecting robot is used for carrying a luminous ring perpendicularly mounted on the robot to travel on a guide rail, and a camera alignment ring is mounted at the bottom end of the guide rail to input camera images into a computer. Circle center coordinates of the luminous ring and the height of a corresponding luminous ring are precisely calculated, and then a change curve of the perpendicularity of an elevator to be measured is drawn and is displayed on a display screen of the computer in real time. By the aid of full-automatic intelligent detection, errors caused by laser imaging are avoided, and errors caused by manual intervention are decreased. Operation is convenient, detecting precision is high, and calculating speed is fast. The device and the method are applicable to various places, and can be applied to not only detecting the perpendicularity of the elevator at installation and maintenance stages, but also detecting torsion of the guide rail and detecting rails, circular parts and the like in other industries.

A device for realizing and maintaining shortcut nitrification in a continuous flow process is successively provided with a water inlet tank, an aeration system and a precipitation system, wherein the water inlet tank is communicated with a completely hybrid reaction tank through an intake pump and the completely hybrid reaction tank is communicated with a precipitation tank through a pipeline. The reaction tank is provided with a DO probe and a pH probe. Data is transmitted to a PLC control system through a DO\pH online detecting instrument and the PLC control system is connected with an air compressor. In an intermittent starting stage, the PLC control system can timely close a switch of the air compressor according to variation characteristics of DO and pH values. In a stable maintenance stage, the PLC control system can adjust an opening or a rotational speed of the air compressor in real time and control a DO concentration in the reaction tank within an optimized scope. This invention realizes rapid starting and stable maintenance of the shortcut nitrification and resolves a problem that starting of the shortcut nitrification in the continuous flow process is difficult in treating municipal sewage and the shortcut nitrification is difficult to be re-implemented. The invention is mainly used to realize the shortcut nitrification of the municipal sewage or wastewater containing high ammonia nitrogen in the continuous flow process, and saves the aeration energy consumption.

The invention relates to a clustering time synchronization method combining topological maintenance. The method comprises the steps that in the election stage, the system selects a node of the maximum connectivity to act as a network root node; in the clustering stage, network clustering is completed with the network root node acting as the start under the scene of network event asynchronization and equipping a directional antenna, and network initial synchronization is also completed; in the synchronization stage, the synchronization effect is stabilized through intra-cluster and inter-cluster synchronization; and in the maintenance stage, maintenance strategy analysis is performed on mobile network accessing and network withdrawing of the node. Compared with the methods in the prior art, the clustering time synchronization method has excellent synchronization performance and can greatly solve the problem of clustering synchronization based on a beam forming antenna, the synchronization efficiency can be effectively enhanced by adopting an inter-cluster synchronization priority policy, and the influence caused by dynamic network topology can be greatly adopted by combining topological maintenance.

The invention provides a carbon emission calculation method based on the entire life cycle of a building and relates to the technical field of carbon emission calculation. According to the features of carbon emission, carbon emission calculation is divided into four stages of building material production, building construction, operation maintenance and waste dismantlement. The method includes the steps that a carbon dioxide intensity value of building material production is determined; carbon emission coefficients in the material transportation and construction processes in the building construction stage are determined; carbon emission coefficients of consumed energy in the operation maintenance stage are determined; carbon emission coefficients of the construction technology and waste transportation in the waste dismantlement stage are determined; the total carbon emission amount of the building is calculated through collection; the unit area index and the per capita index are calculated, the indexes of the total carbon emission amount, the unit area carbon emission amount and the per capita carbon emission amount of the building in the entire life cycle are acquired, the carbon emission standard which the low-carbon building can reach is checked, assessment and affirmation are conducted, effective measures such as design, construction and operation are taken in each stage of the building, the carbon emission of the building is reduced, and the low-carbon level of the building is improved.

The invention provides a control method of an electric pressure cooker, a control device of the electric pressure cooker, and the electric pressure cooker. The control method of the electric pressure cooker comprises the steps that when an instruction of high flames for concentration is received, a heating device of the electric pressure cooker is controlled to carry out heating in a first heating mode; the interior state of the electric pressure cooker is detected, and whether the interior state of the electric pressure cooker meets the conditions of a maintenance stage or not is judged; when it is determined that the interior state of the electric pressure cooker meets conditions of the maintenance stage, the heating device is controlled to carry out heating in a second heating mode, so that the temperature of a cooker body of the electric pressure cooker is kept within a preset temperature range; when the time length of the situation that the temperature of the cooker body of the electric pressure cooker is kept within the preset temperature range reaches a preset time length, the heating device is controlled to stop heating. According to the technical scheme of the control method of the electric pressure cooker, the control device of the electric pressure cooker, and the electric pressure cooker, the temperature of food in the cooker can be kept above the boiling point so as to achieve the effect of sufficient boiling, the taste of soup in the electric pressure cooker can be rich, and the requirements of users for cooking are met.

The invention discloses an operation control method of an urban rail transit train. The operation control method comprises the steps: (1) a resultant force model of the single train under three working conditions of traction, braking and coasting is established, and thus a single-train motion model based on dynamics is constructed; (2) an operation simulation model of the single train is established and comprises the train starting stage, the acceleration stage, the coasting stage, the pull-in braking stage, the stopping stage and the pull-back stage; and (3) a train group tracking operation simulation model based on a train operation plan is established and comprises the train interval tracking interval maintenance stage, the train station interval maintenance stage, the rush-hour train increasing stage and the flat-peak-stage train return stage. The complete operation process such as train starting, traction, coasting and braking condition conversion is considered, and the train interval operation time division, the whole process operation time, the operation chart period, the interval instant speed, the technical speed, the travel speed, the average operation speed, and even train energy consumption and manipulation data can be analyzed, measured and calculated according to the track, train and passenger capacity conditions.

The invention discloses a PWM control method for increasing the response speed of a high-speed on-off solenoid valve. The PWM control method is characterized in that when the high-speed on-off solenoid valve is used as a switch, the on-off control process of the high-speed on-off solenoid valve is set to have three stages; at the first stage, the high-speed on-off solenoid valve is in an open state to a full open state; at the second stage, the high-speed on-off solenoid valve is in the full open state; at the third stage, the high-speed on-off solenoid valve is in the full open state to a closed state; and different frequencies and duty ratios of PWM control signals are set at the different stages. By means of the PWM control method, the open time delay and the closed time delay of the high-speed on-off solenoid valve can be effectively reduced, the response speed of the high-speed on-off solenoid valve is increased, the current of the high-speed on-off solenoid valve at the maintenance stage is reduced, and power consumption of the high-speed on-off solenoid valve is reduced.

The invention relates to a rice cooker and a porridge cooking heating control method thereof. The rice cooker comprises a cooker body (1), an inner container (2), an upper cover device (3) and a heating device (4), wherein the heating device (4) is used for heating the inner container. A bottom temperature detecting device (5) for detecting the temperature of the inner container is arranged at the outer side of the bottom of the inner container (2). The upper cover device (3) is provided with a cover temperature detecting device (6) for detecting the temperature of the upper cover, and a control device (7) for controlling rice cooking. The control device (7) comprises a main controller (8), a timer (9) and a memory, wherein the timer (9) and the memory are respectively connected with the main controller (8). The output ends of the bottom temperature detecting device (5) and the cover temperature detecting device (6) are connected with the input end of the main controller (8), and the output end of the main controller (8) is electrically connected with the heat device (8). The invention can quickly and uniformly transfer heat, can avoid the problem of insufficient boiling and heating when temperature rises abnormally and boiling maintenance stage is ended in advance because of the factors of processing technology deflection of the inner container and the like, and avoid the abnormal phenomenon of overflow of fluid foods of porridge, gruel and the like in cooking. The porridge cooking heating control method is simple and convenient to control.

The present invention relates to the technical field of constructional engineering, and particularly to a BIM-based constructional engineering operation and maintenance management constructing method and system. An operation and maintenance stage model is constructed, and all components in the operation and maintenance stage model are encoded sequentially to form a first code; according to a demand of operation and maintenance in a later phase, devices and accessories that need to be managed by one-to-one correspondence are encoded disorderly to form a second code, and the second code is attached to a corresponding device or accessory of a corresponding CAD drawing; the operation and maintenance stage model is reduced in weight and the operation and maintenance stage model reduced in weight is stored in a database of an operation and maintenance management platform; and an electronic file that is generated during design and construction and can be used for operation and maintenance in the later phase is imported into the database of the operation and maintenance platform. The model file in the construction stage is effectively used, and the mode is used as a carrier to carry materials during design and construction, so as to avoid information islands and overcome the previous difficulty of referring to piles of paper materials.

Therapeutic methods includes several stages, including a modified fasting and low calorie stages, with low impact, moderate exercise, a sliming stage, and a maintenance stage. Nutritional therapeutics are also consumed during each phase, which support a plurality of metabolic and physiological functions.

The invention relates to a drying and corrosion prevention method of a main cable of a suspension bridge. The main cable of the suspension bridge is placed in a closed tubular jacket layer to ensure that the main cable of the suspension bridge is isolated with outside moist air. In an initial operation stage, a main cable dehumidification system is in a dehumidification stage; at the moment, vent valves on the lower part of a vent clamp of the main cable jacket layer of the suspension bridge are opened, and a larger flow of dry air is sent into the jacket layer from an air inlet clamp of the main cable jacket layer and then exhausted from a vent port of the vent clamp through gaps of main cable steel wires so that water in the main cable is drained as soon as possible; after the water in the main cable is exhausted, the main cable dehumidification system enters a maintenance stage; in the maintenance stage, all the vent valves on the vent clamp of the main cable jacket layer are closed to ensure that the main cable jacket layer forms a closed space; Through detecting the pressure of the vent clamp and controlling a dehumidification device and a blowing-in device, a small amount of dry air is sent to ensure that the pressure of the vent port of the main cable jacket layer of the suspension bridge is in a state of slightly exceeding the atmospheric pressure so as to maintain the main cable to be dry.

The invention relates to a structural deformation observation and data processing method at the operation and maintenance stage of a high-speed train. Though a structural deformation observation and data processing at a construction period can predict under-track settlement, the method has adaptability-related problems in the structural deformation monitoring at an operation period. The method comprises the steps of: laying reference points, deformation monitoring points and characteristic section points at two levels; conducting rigorous constraint adjustment to calculate the heights of the reference points, the deformation monitoring points and the characteristic section points; under the situation that the deformation monitoring points are broken or lost, conducting broken height repair to actually measured height difference to eliminate high-difference mutation errors caused by broken height; and calculating actually measured height difference between two adjacent monitoring points, directly adopting the actually measured height difference to conduct differential deformation analysis to the adjacent deformation monitoring points and calculating current additional gradients, accumulated additional gradients, gradient difference and accumulated gradient difference of a line. The structural deformation observation and data processing method at the operation and maintenance stage of the high-speed train has the advantages that the field observation workload is reduced, the differential deformation is accurately and intuitively reflected and comprehensive suggestions are made for the safe operation of railways.

The invention discloses a method for electromagnetic valve frequency conversion and current control of an automatic transmission. The method comprises control at a clutch / brake oil-way pressure regulation stage and control at a clutch / brake oil-way pressure maintenance stage, wherein an electromagnetic valve carrier valve control technology is adopted for the clutch / brake oil-way pressure regulation stage and current control is adopted for the pressure maintenance stage, and whole-course frequency conversion control of the electromagnetic valve is realized; the electromagnetic valve carrier valve control technology is adopted for the clutch / brake oil-way pressure regulation stage so that the response speed and the response precision of the electromagnetic valve are improved; the current control is adopted for the clutch / brake oil-way pressure maintenance stage, so that current change, caused by circuit voltage change, is avoided, and self-adaptive control of current is realized; besides, the current control is adopted for the clutch / brake oil-way pressure maintenance stage, so that extra heating or electromagnetic force reduction, caused by current change, of the electromagnetic valve is avoided, and the reliability of the electromagnetic valve during working is improved.

The invention discloses a method for metering carbon emission of roads in the whole life cycle. The carbon emission of the roads in the whole life cycle relates to carbon emission directly related to construction and use of road engineering in the whole life cycle in the carbon emission caused by social activities, and the whole life cycle includes the early building stage, the construction stage, the operation stage, the maintenance stage and the dismantling stage. The results of multiple embodiments of the method indicate that carbon emission of the roads is effectively evaluated, and the method for building of load-carbon model roads provides reference for further construction of low-carbon roads. In view of realizing low-carbon emission, a basis system of carbon metering and evaluating for the roads is established, research and construction progress of the low-carbon roads is boosted greatly, deterioration of the environment due to carbon emission of the social activities is alleviated, and the method has great contribution for realizing low-carbon emission and emission reduction.

The invention discloses a method for detecting consistency of intelligent electronic equipment loop information and SCD file loop information. The method starts with practical run loop information of the intelligent transformer station secondary equipment and the loop information in an engineering offline SCD file based on IEC61850 standards. According to the method, firstly, the engineering offline SCD file is analyzed, and the intelligent secondary equipment is taken as an object to form specific loop information of target equipment; then through access of an application network analyzer to a transformer station practical network, real-time monitoring, grasping, judgment and analysis of communication packets are realized to form real loop information of the target equipment; and finally, the two sets of the loop information are automatically compared to verify the consistency of the information, so as to ensure that an intelligent transformer station secondary loop runs in accordance with design requirements. The method is suitable for consistency detection of the intelligent device loop information and the SCD file loop model information based on the network analyzer in the capital construction, operation and maintenance stages of an intelligent transformer station.

The invention provides a smart parking lot based on a parking AGV. The smart parking lot comprises a main building, a computer module, a gate vehicle-blocking module, an AGVS and supporting module, ahuman-computer interaction module, a positioning AP module, an exit and entrance lifting module, a charging module, a vehicle washing module, a maintenance module, an emergency firefighting module, and a green energy source module; the smart parking lot is provided with five layers, and parking areas, AGV charging areas, AGV maintenance areas, monitoring areas, vehicle washing areas, emergency exits, intelligent firefighting areas are arranged in the layers; and lifting vertical ladders are arranged on the two sides of the smart parking lot, the top layer is covered with solar power generationfacilities, and emergency auxiliary ramps are arranged between all layers. The smart parking lot adopts a BIM technology in the design, construction and operation and maintenance stages to form a BIMdatabase.

The invention belongs to an open type abrasive belt steel rail grinding device in the maintenance machinery steel rail grinding field. The open type abrasive belt steel rail grinding device is composed of a traction device, a lifting device, a walking mechanism, an abrasive belt transmission mechanism, and an abrasive belt and steel rail contacting and pressing part, wherein the traction device, the lifting device and the walking mechanism are connected with an external grinding trolley, the walking mechanism is connected with the traction device and the lifting device, and the abrasive belt transmission mechanism makes contact with a trolley steel rail through the abrasive belt and steel rail contacting and pressing part. The open type abrasive belt steel rail grinding device has the advantages that abrasive belts make elastic contact with the steel rail, rigid collision between grinding wheels and the steel rail is avoided, and the abrasive belts belong to coating and grinding tools and can be effectively used in the grinding process; grinding units are simplified, the requirement for the control technology is lowered, and maintenance cost is reduced; the heat dissipation performance of the abrasive belts is good, the noise is low, the surface of the steel rail can not be burnt in the grinding process, the grinding tools can not be damaged in the grinding process, the grinding belts replace grinding wheels to conduct grinding in the maintenance stage of part of paths, and the open type abrasive belt steel rail grinding device is popularized to preventive grinding of an existing path.

In random access state, terminals decide the transmit power in UpPTS in open loop mode, by using the broadcast information and the DwPTS power measured. In the communication maintenance stage, the base station informs the terminals what is the received power needed by the base station. The terminal calculates the power value in open loop mode by using the DwPTS power measured as the threshold andreference of the transmitting power in up channel. The invention utilizes the same transmission condition in up and down links of TDD duplex mode and exerts the advantages of the simple and accurate of the open loop power control as far as possible so as to raise the accuracy of the power measurement. That is to say the accuracy of the power control is raised.

The invention provides a key downloading method of a POS terminal. The method comprises the following steps: at a production or maintenance stage of the POS terminal, setting an equipment authentication key pair and an equipment encryption key pair in the POS terminal; performing mutual authentication on the POS terminal and a remote key server according to a remote authentication key pair set by the remote key server and the equipment authentication key pair in the POS terminal, and binding a certificate of the remote key server in the POS terminal equipment after the authentication is passed; and downloading a main key by the POS terminal from the remote key server according to the equipment authentication key pair and a temporary transmission key. By adoption of the method, the main key can be downloaded by a network beyond a security center, the security is high, the transport cost can be saved, and the efficiency is high.

The invention discloses a filling body-pillar system mechanical effect mechanism test method. The method comprises the steps of: processing and preparing a pillar test piece and a homemade elasticity module, and subjecting a resistance strain gauge to paste, waterproof and moistureproof treatment; pasting the pillar test piece with the strain gauge, conducting waterproof treatment, placing the pillar test piece in a middle position of a square lateral confinement steel mold; filling the steel mold with a prepared filling slurry; embedding an resistance strain gauge module treated in advance and matching with the ratio of the filling slurry; after full filling of the filling slurry in the steel mold, flattening the surface; leading and marking a wire connected to the strain gauge; taking out the filling body after certain maintenance stage; according to the testing requirements, connecting the connected wire of the embedded strain gauge with a strain gauge outside the device and carrying out a load test as required. The invention analyzes and researches on the relationship characteristic of deformation rules, rock pillar destroy characteristic and compression time of the filling body in the loading process.

The invention discloses an aviation self-organized network routing method. The method comprises three stages: at a routing establishment stage, a source node queries whether the routing to a destination node is existent from the own recorded routing table, and initiates a routing request RREQ if the routing to the destination node is inexistent, when the RREQ is transmitted to the destination node, the destination node immediately produces routing reply RREP, and transmits back the RREP along the path of transmitting the RREQ, and the source node finishes the routing establishment after receiving the RREP; at a routing selection stage: an intermediate node records the information of a surrounding neighbor node transmitting the RREQ to the self in the RREQ table, wherein the information contains the minimum hop to the source node from the neighbor node; at a routing maintenance stage, the data is transmitted to some neighbor node when a data link of some node is broken, and the data iscontinuously transmitted on a standby path located by the neighbor node. The aviation self-organized network routing method disclosed by the invention can adapt to the aviation self-organized networkfeature, the network data transmission delay, the data packet arrival rate and like performances are obviously improved.

The invention discloses a method of operation and maintenance emergency alarm and quick response based on a 3DGIS+BIM technology and artificial intelligence. In order to improve the treatment efficiency of a disastrous event at the operation and maintenance stage, based on the 3DGIS+BIM technology and real-time monitoring data, combined with a fussy gray clustering algorithm, automatic assessment and judgment are conducted on the disaster grade. According to the method, a fire disaster is taken as an example, judgment results of artificial intelligence are integrated, and relevant information of the occurrence location and the surroundings of the fire disaster is quickly acquired in a 3DGIS+BIM system platform, so that a fire disaster emergency response scheme is provided with decision support.

The invention provides a method for improving the activity of nitrification function microbiology in activated sludge through directly feeding Fe ions, which comprises a cultivation stage of the nitrification function microbiology and a long-time running activity maintenance stage. In a saprobiont denitrification system, ferric salt chemical agent with Fe <2+> or Fe<3+> is directly fed into an activated sludge mixture of an aerobic pond of a biology denitrification system, and basic compounds are also fed simultaneously; and in the long-time running activity maintenance stage of nitrificationfunction microbiology, the feeding amount of the ferric salt chemical agent with the Fe <2+> or the Fe<3+> is gradually reduced, and the fed ferric salt chemical agent with the Fe <2+> or the Fe<3+> is only used for replenishing loss amount of the Fe<3+> or the Fe <2+>. According to the method, the biochemical reaction metabolic activity of the nitrification function microbiology can be effectively improved, the breeding of the nitrification function microbiology and the secretion of endoenzyme of microbial cell are promoted, the applicability of saprobiont denitrification technology is improved, the bottleneck problems existing in the saprobiont denitrification system are solved, and the low temperature resistant capacity of the system is obviously improved.

The invention discloses a wireless mesh safety hierarchical transmission method based on an SDN. The method includes: a strategy generation stage, a strategy distribution / maintenance stage, a strategy update / loading stage and a strategy execution stage. According to the method, transmission requirements of data flows with different safety demands can be flexibly met based on an SDN architecture, problems of poor flexibility of the network function and high update cost are solved, the method is in accordance with safety hierarchical transmission of the conventional network protocol, safety hierarchical transmission of wireless data messages is guaranteed, and better protection is provided for the data messages with high safety level.