CN114236466A - Fuzzy set-based discrete manufacturing workshop RFID and UWB fusion positioning system and method - Google Patents

Abstract

The invention discloses a fuzzy set-based RFID and UWB fusion positioning system and method for a discrete manufacturing workshop. When the method works, based on the fuzzy set theory and based on the RFID and UWB combined positioning method, the area position data acquired by the RFID and the UWB real-time position data are subjected to data fusion, accurate position information is provided for accurate management and control of a workshop on materials, the reliability of the workshop on positioning of production elements is improved, visual positioning tracking and real-time monitoring of the workshop are achieved, and real-time positioning, refinement and high-efficiency management of different production elements of a discrete manufacturing workshop are achieved.

Description

Fuzzy set-based discrete manufacturing workshop RFID and UWB fusion positioning system and method

Technical Field

The invention relates to the field of fusion of positioning data of a discrete manufacturing workshop, in particular to a fuzzy set-based RFID (radio frequency identification) and UWB (ultra wide band) fusion positioning system and method for the discrete manufacturing workshop.

Background

In the production process of the discrete manufacturing workshop, a production mode of 'multi-variety and small-batch' is mostly adopted, and for a large-scale, particularly ultra-large discrete manufacturing workshop, accurate real-time position information and state information are urgently needed to improve the management level and the production capacity of the workshop. In a traditional discrete manufacturing workshop, the position information is usually acquired by manually filling a production task list, the position information is delayed, the real-time performance is low, sufficient process information of production elements cannot be acquired, and the problems of missing filling and wrong filling of information exist. In this case, various techniques are used in the data acquisition and real-time localization of discrete manufacturing plants, including: bluetooth, Wi-Fi, infrared rays, RFID, UWB and the like, and the RFID technology has the advantages of non-contact reading and writing, large storage capacity, repeated use, high safety and the like; the UWB technology has the advantages of strong anti-interference capability, high positioning accuracy, low cost and the like; the two technologies get more and more attention, and with the progress of the technologies, however, data acquisition in the traditional discrete manufacturing workshop, single real-time positioning in the discrete manufacturing workshop by using the RFID technology or the UWB technology, and simple adoption of a fusion positioning mode fail to perform data fusion in combination with actual conditions of the workshop, and fail to satisfy the requirements of accurate acquisition of position data and efficient interaction of position information in the fusion positioning field, and have the following problems:

(1) data collection and management methods fall behind. In the discrete manufacturing workshop, manual recording and manual input modes are mostly adopted to collect data, and forms and cards are used to record and manage various general data in the production process, so that the recording is easy to be influenced by human factors, the recording is wrong, the actual condition of the workshop is inconsistent with the system data, and the accuracy of the positioning of production elements is influenced.

(2) The RFID sensing range has a 'jitter' phenomenon. The sensing range of the RFID antenna depends on the sensing range of a radio frequency field sent by a reader-writer, and the strength of a radio frequency field signal can be interfered by electromagnetic interference of workshop production equipment, so that the sensing range has a shaking phenomenon, and the accuracy of judging the material entering and exiting a station is influenced.

(3) UWB positioning data has a random "drift" phenomenon. UWB positioning relies on pulse signals, and the position of a tag is deduced through information such as signal transmission time, signal arrival angle and the like. The discrete manufacturing workshop area is big, the metal is densely covered, the environment is complicated, the positioning signal can be interfered by the dynamic movement of people and materials, the gradual change and the sudden change of the working condition of production equipment, the dynamic change of the production environment, heavy current, strong magnetic field and the like, so that the positioning data calculated by the positioning engine has larger noise.

(4) The traditional data fusion mode of fusion positioning is only to simply obtain data of various positioning technologies, and cannot perform positioning data fusion based on workshop reality.

Disclosure of Invention

The invention aims to solve the technical problem of providing a fuzzy set-based RFID and UWB fusion positioning system and method for a discrete manufacturing workshop.

The invention adopts the following technical scheme for solving the technical problems:

the RFID and UWB fusion positioning system based on the fuzzy set comprises an RFID module, a UWB module, a control module, a storage module and a display module;

the RFID module comprises a plurality of electronic tags, a plurality of read-write units and an RFID middleware;

the electronic tags are attached to the production elements in a one-to-one correspondence manner and used for storing attribute data of the production elements attached to the electronic tags and serial numbers of the electronic tags; the production elements comprise equipment, materials, personnel, a goods shelf, a tool clamp and an AGV; the attribute data of the equipment comprises equipment name, equipment model, equipment spindle rotating speed, equipment outline dimension and equipment power; the attribute data of the material comprises a material code, a material figure number, a material type, a material name and a material specification model; the attribute data of the personnel comprises personnel names, personnel types, groups where the personnel are located and the on-duty state of the personnel; the attribute data of the goods shelf comprises the name of the goods shelf, the information of materials stored in the goods shelf and the model size of the goods shelf; the attribute data of the tool clamp comprises the name of the tool clamp, the model of the tool clamp and the specification of the tool clamp; the attribute data of the AGV comprise the name of the AGV, the model of the AGV, the maximum load capacity of the AGV and the maximum form speed of the AGV;

the plurality of reading and writing units are correspondingly arranged in the stations of each manufacturing workshop one by one and respectively comprise an RFID reader-writer and 2 RFID antennas connected with the RFID reader-writer, wherein one of the RFID antennas is arranged in an in-cache area of the station, and the other RFID antenna is arranged in an out-cache area of the station; the RFID reader-writer is used for reading the information in each electronic tag and the serial number of the RFID antenna corresponding to each electronic tag through 2 RFID antennas and transmitting the serial numbers to the RFID middleware;

the RFID middleware is electrically connected with the RFID reader-writer of each read-write unit and is used for acquiring the data read by each read-write unit and transmitting the data to the control module;

the UWB module comprises a plurality of UWB tags, a positioning engine and N UWB sensors, wherein N is a natural number more than or equal to 3;

the UWB tags are correspondingly attached to the production elements one by one, and the serial numbers of the UWB tags are stored in the UWB tags and used for the UWB sensor to acquire the position information of the production elements in real time;

the N UWB sensors are arranged in a manufacturing workshop and used for sensing the signal intensity of each UWB tag and transmitting the signal intensity to the positioning engine;

the positioning engine is used for calculating the position of each UWB tag relative to the positioning engine according to the received signal strength of each UWB tag to the N UWB sensors and the position information of the N UWB sensors, and transmitting the position of each UWB tag to the control module;

the storage module is used for storing map information of a manufacturing workshop, information of each production element, an electronic tag number corresponding to each production element, a UWB tag number corresponding to each production element, a station corresponding to each read-write unit and a station entering buffer zone or station exiting buffer zone corresponding to each RFID antenna number;

the control module is used for obtaining the area positioning information of each production element according to the information in each electronic tag read by the RFID middleware and the serial number of the RFID antenna corresponding to each electronic tag and the information in the storage module, obtaining the map coordinate of each production element according to the position of each UWB tag relative to the positioning engine measured by the UWB module and the information in the storage module, performing fusion positioning based on a fuzzy set according to the area positioning information and the map coordinate of each production element to obtain fused position information, and simultaneously controlling the display module to display the attribute data and the material circulation data of each production element on a workshop map in real time; the area positioning information of the production elements refers to the work station entering buffer area or the work station exiting buffer area corresponding to the production elements, and the material circulation data refers to the data of the material flowing and processing between the work stations of the manufacturing workshop from the entering workshop to the leaving workshop.

The invention also discloses a fusion positioning method of the fuzzy set-based discrete manufacturing workshop RFID and UWB fusion positioning system, which comprises the following steps:

step 1), when a production element passes through an RFID antenna of the production element, an RFID reader-writer reads the number of the electronic tag on the production element and the number of the corresponding RFID antenna according to the reading period of the production element and transmits the number to a control module through an RFID middleware, so that the number of times that the RFID reader-writer reads the number of the electronic tag on the production element is RN, and the number of the electronic tag is NU;

step 2), the positioning engine is used for calculating the position of each UWB tag relative to the positioning engine according to the received signal strength of each UWB tag to the N UWB sensors and the position information of the N UWB sensors, and transmitting the position information to the control module; the control module converts the position of each UWB tag relative to the positioning engine into a map coordinate of the UWB tag;

step 3), the control module searches the production element MU corresponding to the electronic tag NU according to the data in the storage module, then searches the UWB tag UU corresponding to the production element MU according to the production element MU, and finally searches the electronic tag with the NU with the number of being the RN number when the electronic tag is read for the RN numberMap coordinate set U ═ U { U } where UU's UWB tags are located₁,u₂,u₃,…,u_i,…,u_nN is the number of times when the electronic tag with the NU number is read RN times and the UWB tag with the UU number is positioned by the positioning engine, u_iThe map coordinate of the positioned UWB label with the serial number of UU is, i is a natural number which is more than or equal to 1 and less than or equal to n;

step 4), calculating the distance from each map coordinate in the map coordinate set U to the map coordinate of the electronic tag with the number NU, comparing the distance with a preset RFID antenna sensing radius threshold value to obtain the number k of the map coordinates in the sensing range of the electronic tag with the number NU in the map coordinate set U, and obtaining the distribution rate UP (UP is more than or equal to 0 and less than or equal to 1) of the UWB positioning coordinates in the RFID antenna sensing range through k/n;

step 5), fuzzifying the RN and the UP, and establishing a fuzzy set RNU and a fuzzy set UPU of the RN, wherein the fuzzy set RNU comprises three fuzzy grades L, N, H and corresponding membership RN_L、RN_N、RN_HThe fuzzy set UPU includes three fuzzy levels L, N, H and their corresponding membership UP_L、UP_N、UP_H；

Step 6), adopting a trapezoidal membership function to define the membership functions of RN and UP, and calculating the membership RN of three fuzzy grades of RN relative to the fuzzy set RNU through the membership functions_L、RN_N、RN_HAnd degree of membership UP of UP to three fuzzy levels of fuzzy set UPU_L、UP_N、UP_H；

Step 7), defining a fuzzy rule base, wherein the fuzzy rule base comprises 9 rules, and the method specifically comprises the following steps:

the PDS is the satisfaction degree of the positioning data and comprises five levels;

step 8), RN_L、RN_N、RN_H、UP_L、UP_N、UP_HInputting according to 9 rules of a fuzzy rule base, and for each rule, taking the smaller value of two input variables as the membership degree of the PDS corresponding to the rule to obtain the PDS membership degree corresponding to the PDS grade of the 9 rules;

step 9), for the rules with the same PDS grade, taking the PDS membership degree of the rule with the maximum PDS membership degree as the PDS membership degree corresponding to the PDS grade to obtain the PDS membership degrees corresponding to five PDS grades;

step 10), defining an output membership function, and obtaining accurate positioning data satisfaction PDS according to the corresponding PDS membership of five grades of PDS by combining the membership function and adopting a gravity center method to defuzzify_N；

Step 11), mixing PDS_NAnd a preset positioning satisfaction threshold D_limitMaking a comparison when PDS_NIs less than D_limitJudging that the RN read data of the electronic tag with the NU number are misread data, and deleting the RN read data; when PDS is in process_NGreater than or equal to D_limitAnd judging that the data is normal, and taking the station in cache region or the station out cache region corresponding to the electronic tag with the NU as the region positioning information of the production element where the electronic tag with the NU is located.

Compared with the prior art, the invention adopting the technical scheme has the following technical effects:

the invention analyzes the production process information of data acquisition and real-time positioning of a discrete manufacturing workshop, provides a system framework of data acquisition, real-time positioning and data processing of production element information based on a fuzzy set, and improves the accuracy of data acquisition and positioning data. Based on a fuzzy set theory and a RFID and UWB combined positioning method, regional position data acquired by RFID and real-time position data of UWB are subjected to data fusion, accurate position information is provided for accurate management and control of a workshop on materials, reliability of the workshop on positioning of production elements is improved, visual positioning tracking and real-time monitoring of the workshop are achieved, and real-time positioning, refinement and high-efficiency management of different production elements of a discrete manufacturing workshop are achieved.

Drawings

FIG. 1 is a schematic illustration of a discrete manufacturing plant visualization interface of the present invention;

FIG. 2 is a schematic diagram of a real-time positioning platform according to the present invention;

FIG. 3 is a schematic flow diagram of the process of the present invention.

Detailed Description

The technical scheme of the invention is further explained in detail by combining the attached drawings:

the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, components are exaggerated for clarity.

As shown in FIG. 1, the invention discloses a fuzzy set-based discrete manufacturing shop RFID and UWB fusion positioning system, which comprises an RFID module, a UWB module, a control module, a storage module and a display module;

the RFID module comprises a plurality of electronic tags, a plurality of read-write units and an RFID middleware;

the electronic tags are attached to the production elements in a one-to-one correspondence manner and used for storing attribute data of the production elements attached to the electronic tags and serial numbers of the electronic tags; the production elements comprise equipment, materials, personnel, a goods shelf, a tool clamp and an AGV; the attribute data of the equipment comprises equipment name, equipment model, equipment spindle rotating speed, equipment outline dimension and equipment power; the attribute data of the material comprises a material code, a material figure number, a material type, a material name and a material specification model; the attribute data of the personnel comprises personnel names, personnel types, groups where the personnel are located and the on-duty state of the personnel; the attribute data of the goods shelf comprises the name of the goods shelf, the information of materials stored in the goods shelf and the model size of the goods shelf; the attribute data of the tool clamp comprises the name of the tool clamp, the model of the tool clamp and the specification of the tool clamp; the attribute data of the AGV comprise the name of the AGV, the model of the AGV, the maximum load capacity of the AGV and the maximum form speed of the AGV;

the plurality of reading and writing units are correspondingly arranged in the stations of each manufacturing workshop one by one and respectively comprise an RFID reader-writer and 2 RFID antennas connected with the RFID reader-writer, wherein one of the RFID antennas is arranged in an in-cache area of the station, and the other RFID antenna is arranged in an out-cache area of the station; the RFID reader-writer is used for reading the information in each electronic tag and the serial number of the RFID antenna corresponding to each electronic tag through 2 RFID antennas and transmitting the serial numbers to the RFID middleware;

the RFID middleware is electrically connected with the RFID reader-writer of each read-write unit and is used for acquiring the data read by each read-write unit and transmitting the data to the control module;

the UWB module comprises a plurality of UWB tags, a positioning engine and N UWB sensors, wherein N is a natural number more than or equal to 3;

the UWB tags are correspondingly attached to the production elements one by one, and the serial numbers of the UWB tags are stored in the UWB tags and used for the UWB sensor to acquire the position information of the production elements in real time;

the N UWB sensors are arranged in a manufacturing workshop and used for sensing the signal intensity of each UWB tag and transmitting the signal intensity to the positioning engine;

the positioning engine is used for calculating the position of each UWB tag relative to the positioning engine according to the received signal strength of each UWB tag to the N UWB sensors and the position information of the N UWB sensors, and transmitting the position of each UWB tag to the control module;

the storage module is used for storing map information of a manufacturing workshop, information of each production element, an electronic tag number corresponding to each production element, a UWB tag number corresponding to each production element, a station corresponding to each read-write unit and a station entering buffer zone or station exiting buffer zone corresponding to each RFID antenna number;

the control module is used for obtaining the area positioning information of each production element according to the information in each electronic tag read by the RFID middleware and the serial number of the RFID antenna corresponding to each electronic tag and the information in the storage module, obtaining the map coordinate of each production element according to the position of each UWB tag relative to the positioning engine measured by the UWB module and the information in the storage module, performing fusion positioning based on a fuzzy set according to the area positioning information and the map coordinate of each production element to obtain fused position information, and simultaneously controlling the display module to display the attribute data and the material circulation data of each production element on a workshop map in real time; the area positioning information of the production elements refers to the work station entering buffer area or the work station exiting buffer area corresponding to the production elements, and the material circulation data refers to the data of the material flowing and processing between the work stations of the manufacturing workshop from the entering workshop to the leaving workshop.

Fig. 2 is a structural diagram of a real-time positioning platform of the embodiment, which mainly comprises an RFID area positioning module and a UWB accurate positioning module, and for production elements flowing between stations, such as tools and personnel, it is usually only necessary to provide area-level location information to quickly search for the production elements, and an RFID-based area positioning method can meet the positioning requirements; for production elements such as workshop material distribution vehicles, heavy parts and the like which need accurate guidance or accurate management, positioning coordinates and historical tracks are generally needed, and therefore an accurate positioning method based on UWB is adopted. For materials, the materials flow at each station in the production process, material information changes along with the production flow, RFID tags are required to record production data and station entering and exiting states of different stations, UWB accurate positioning is combined, and a data fusion method is adopted to obtain accurate data of the materials flowing at the stations in the station entering and exiting states and the data flowing at the stations in the historical state, so that the RFID tags and the UWB tags are bound to the materials at the same time.

Fig. 3 is a flow of a positioning data fusion method in the embodiment, and in order to meet the requirement of accurate management and control of a workshop on material entering and exiting stations, the invention adopts a positioning method combining data acquisition and regional positioning realized by an RFID technology and coordinate-level positioning realized by an UWB technology. The RFID reader-writer and the antenna are deployed at each station and the workshop entrance and exit of a workshop by taking the lowest deployment cost, the lowest reader-writer interference degree and the covering of each station and entrance and exit of the workshop as targets; the UWB positioning base station aims at the lowest deployment cost, the full coverage of a workshop range and the highest positioning precision, the UWB positioning base station is deployed on the wall of a workshop, and the RFID area positioning data and the UWB positioning data are fused on the basis of the fuzzy set theory, and the specific implementation method comprises the following steps:

step 1), when a production element passes through an RFID antenna of the production element, an RFID reader-writer reads the number of the electronic tag on the production element and the number of the corresponding RFID antenna according to the reading period of the production element and transmits the number to a control module through an RFID middleware, so that the number of times that the RFID reader-writer reads the number of the electronic tag on the production element is RN, and the number of the electronic tag is NU;

step 2), the positioning engine is used for calculating the position of each UWB tag relative to the positioning engine according to the received signal strength of each UWB tag to the N UWB sensors and the position information of the N UWB sensors, and transmitting the position information to the control module; the control module converts the position of each UWB tag relative to the positioning engine into a map coordinate of the UWB tag;

step 3), the control module searches the production element MU corresponding to the electronic tag NU according to the data in the storage module, then searches the UWB tag serial number UU corresponding to the production element MU according to the production element MU, and finally searches the map coordinate set U ═ U where the UWB tag with the serial number NU is positioned when the electronic tag with the serial number NU is read RN times₁,u₂,u₃,…,u_i,…,u_nN is the number of times when the electronic tag with the NU number is read RN times and the UWB tag with the UU number is positioned by the positioning engine, u_iThe map coordinate of the positioned UWB label with the serial number of UU is, i is a natural number which is more than or equal to 1 and less than or equal to n;

step 4), calculating the distance from each map coordinate in the map coordinate set U to the map coordinate of the electronic tag with the number NU, comparing the distance with a preset RFID antenna sensing radius threshold value to obtain the number k of the map coordinates in the sensing range of the electronic tag with the number NU in the map coordinate set U, and obtaining the distribution rate UP (UP is more than or equal to 0 and less than or equal to 1) of the UWB positioning coordinates in the RFID antenna sensing range through k/n;

step 5), fuzzifying the RN and the UP, and establishing a fuzzy set RNU and a fuzzy set UPU of the RN, wherein the fuzzy set RNU comprises three fuzzy grades L, N, H and corresponding membership RN_L、RN_N、RN_HThe fuzzy set UPU includes three fuzzy levels L, N, H and their corresponding membership UP_L、UP_N、UP_H；

Step 6), adopting a trapezoidal membership function to define the membership functions of RN and UP, and calculating the membership RN of three fuzzy grades of RN relative to the fuzzy set RNU through the membership functions_L、RN_N、RN_HAnd degree of membership UP of UP to three fuzzy levels of fuzzy set UPU_L、UP_N、UP_H；

Step 7), defining a fuzzy rule base, wherein the fuzzy rule base comprises 9 rules, and the method specifically comprises the following steps:

the PDS is the satisfaction degree of the positioning data and comprises five levels;

step 8), RN_L、RN_N、RN_H、UP_L、UP_N、UP_HInputting according to 9 rules of a fuzzy rule base, and for each rule, taking the smaller value of two input variables as the membership degree of the PDS corresponding to the rule to obtain the PDS membership degree corresponding to the PDS grade of the 9 rules;

step 9), for the rules with the same PDS grade, taking the PDS membership degree of the rule with the maximum PDS membership degree as the PDS membership degree corresponding to the PDS grade to obtain the PDS membership degrees corresponding to five PDS grades;

step 10), defining an output membership function, and obtaining accurate positioning data satisfaction PDS according to the corresponding PDS membership of five grades of PDS by combining the membership function and adopting a gravity center method to defuzzify_N；

Step 11), mixing PDS_NAnd a preset positioning satisfaction threshold D_limitMaking a comparison when PDS_NIs less than D_limitJudging that the RN read data of the electronic tag with the NU number are misread data, and deleting the RN read data; when PDS is in process_NGreater than or equal to D_limitWhen the data is normal, the data is judged to be normalAnd taking the station in cache region or the station out cache region corresponding to the electronic tag with the NU number as the region positioning information of the production element where the electronic tag with the NU number is located.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only illustrative of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (2)

1. The fuzzy set-based discrete manufacturing workshop RFID and UWB fusion positioning system is characterized by comprising an RFID module, a UWB module, a control module, a storage module and a display module;

the RFID module comprises a plurality of electronic tags, a plurality of read-write units and an RFID middleware;

the electronic tags are attached to the production elements in a one-to-one correspondence manner and used for storing attribute data of the production elements attached to the electronic tags and serial numbers of the electronic tags; the production elements comprise equipment, materials, personnel, a goods shelf, a tool clamp and an AGV; the attribute data of the equipment comprises equipment name, equipment model, equipment spindle rotating speed, equipment outline dimension and equipment power; the attribute data of the material comprises a material code, a material figure number, a material type, a material name and a material specification model; the attribute data of the personnel comprises personnel names, personnel types, groups where the personnel are located and the on-duty state of the personnel; the attribute data of the goods shelf comprises the name of the goods shelf, the information of materials stored in the goods shelf and the model size of the goods shelf; the attribute data of the tool clamp comprises the name of the tool clamp, the model of the tool clamp and the specification of the tool clamp; the attribute data of the AGV comprise the name of the AGV, the model of the AGV, the maximum load capacity of the AGV and the maximum form speed of the AGV;

the plurality of reading and writing units are correspondingly arranged in the stations of each manufacturing workshop one by one and respectively comprise an RFID reader-writer and 2 RFID antennas connected with the RFID reader-writer, wherein one of the RFID antennas is arranged in an in-cache area of the station, and the other RFID antenna is arranged in an out-cache area of the station; the RFID reader-writer is used for reading the information in each electronic tag and the serial number of the RFID antenna corresponding to each electronic tag through 2 RFID antennas and transmitting the serial numbers to the RFID middleware;

the RFID middleware is electrically connected with the RFID reader-writer of each read-write unit and is used for acquiring the data read by each read-write unit and transmitting the data to the control module;

the UWB module comprises a plurality of UWB tags, a positioning engine and N UWB sensors, wherein N is a natural number more than or equal to 3;

the UWB tags are correspondingly attached to the production elements one by one, and the serial numbers of the UWB tags are stored in the UWB tags and used for the UWB sensor to acquire the position information of the production elements in real time;

the N UWB sensors are arranged in a manufacturing workshop and used for sensing the signal intensity of each UWB tag and transmitting the signal intensity to the positioning engine;

the positioning engine is used for calculating the position of each UWB tag relative to the positioning engine according to the received signal strength of each UWB tag to the N UWB sensors and the position information of the N UWB sensors, and transmitting the position of each UWB tag to the control module;

the storage module is used for storing map information of a manufacturing workshop, information of each production element, an electronic tag number corresponding to each production element, a UWB tag number corresponding to each production element, a station corresponding to each read-write unit and a station entering buffer zone or station exiting buffer zone corresponding to each RFID antenna number;

the control module is used for obtaining the area positioning information of each production element according to the information in each electronic tag read by the RFID middleware and the serial number of the RFID antenna corresponding to each electronic tag and the information in the storage module, obtaining the map coordinate of each production element according to the position of each UWB tag relative to the positioning engine measured by the UWB module and the information in the storage module, performing fusion positioning based on a fuzzy set according to the area positioning information and the map coordinate of each production element to obtain fused position information, and simultaneously controlling the display module to display the attribute data and the material circulation data of each production element on a workshop map in real time; the area positioning information of the production elements refers to the work station entering buffer area or the work station exiting buffer area corresponding to the production elements, and the material circulation data refers to the data of the material flowing and processing between the work stations of the manufacturing workshop from the entering workshop to the leaving workshop.

2. The fuzzy set based fusion positioning method of the discrete manufacturing shop RFID and UWB fusion positioning system based on claim 1, characterized by comprising the following steps:

step 1), when a production element passes through an RFID antenna of the production element, an RFID reader-writer reads the number of the electronic tag on the production element and the number of the corresponding RFID antenna according to the reading period of the production element and transmits the number to a control module through an RFID middleware, so that the number of times that the RFID reader-writer reads the number of the electronic tag on the production element is RN, and the number of the electronic tag is NU;

step 2), the positioning engine is used for calculating the position of each UWB tag relative to the positioning engine according to the received signal strength of each UWB tag to the N UWB sensors and the position information of the N UWB sensors, and transmitting the position information to the control module; the control module converts the position of each UWB tag relative to the positioning engine into a map coordinate of the UWB tag;

step 3), the control module searches the production element MU corresponding to the electronic tag NU according to the data in the storage module, then searches the UWB tag UU corresponding to the production element MU according to the production element MU, and finally searches the electronic tag with the NU with the number of being the RN number when the electronic tag is read for the RN numberMap coordinate set U ═ U { U } where UU's UWB tags are located₁,u₂,u₃,…,u_i,…,u_nN is the number of times when the electronic tag with the NU number is read RN times and the UWB tag with the UU number is positioned by the positioning engine, u_iThe map coordinate of the positioned UWB label with the serial number of UU is, i is a natural number which is more than or equal to 1 and less than or equal to n;

step 4), calculating the distance from each map coordinate in the map coordinate set U to the map coordinate of the electronic tag with the number NU, comparing the distance with a preset RFID antenna sensing radius threshold value to obtain the number k of the map coordinates in the sensing range of the electronic tag with the number NU in the map coordinate set U, and obtaining the distribution rate UP (UP is more than or equal to 0 and less than or equal to 1) of the UWB positioning coordinates in the RFID antenna sensing range through k/n;

step 5), fuzzifying the RN and the UP, and establishing a fuzzy set RNU and a fuzzy set UPU of the RN, wherein the fuzzy set RNU comprises three fuzzy grades L, N, H and corresponding membership RN_L、RN_N、RN_HThe fuzzy set UPU includes three fuzzy levels L, N, H and their corresponding membership UP_L、UP_N、UP_H；

Step 6), adopting a trapezoidal membership function to define the membership functions of RN and UP, and calculating the membership RN of three fuzzy grades of RN relative to the fuzzy set RNU through the membership functions_L、RN_N、RN_HAnd degree of membership UP of UP to three fuzzy levels of fuzzy set UPU_L、UP_N、UP_H；

Step 7), defining a fuzzy rule base, wherein the fuzzy rule base comprises 9 rules, and the method specifically comprises the following steps:

the PDS is the satisfaction degree of the positioning data and comprises five levels;

step 8), RN_L、RN_N、RN_H、UP_L、UP_N、UP_HInputting according to 9 rules of a fuzzy rule base, and for each rule, taking the smaller value of two input variables as the membership degree of the PDS corresponding to the rule to obtain the PDS membership degree corresponding to the PDS grade of the 9 rules;

step 9), for the rules with the same PDS grade, taking the PDS membership degree of the rule with the maximum PDS membership degree as the PDS membership degree corresponding to the PDS grade to obtain the PDS membership degrees corresponding to five PDS grades;

step 10), defining an output membership function, and obtaining accurate positioning data satisfaction PDS according to the corresponding PDS membership of five grades of PDS by combining the membership function and adopting a gravity center method to defuzzify_N；

Step 11), mixing PDS_NAnd a preset positioning satisfaction threshold D_limitMaking a comparison when PDS_NIs less than D_limitJudging that the RN read data of the electronic tag with the NU number are misread data, and deleting the RN read data; when PDS is in process_NGreater than or equal to D_limitAnd judging that the data is normal, and taking the station in cache region or the station out cache region corresponding to the electronic tag with the NU as the region positioning information of the production element where the electronic tag with the NU is located.

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