A real-time monitoring system for temperature and humidity of cold chain logistics based on active RFID technology
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1 Introduction
1.1 Document construction instructions
The purpose of this program is to let integrators, engineers and users understand the Internet of ThingsRFIDThe design concepts, principles, overall planning of technology in the field of cold chain logistics and transportation management, and how to play its huge role, and elaborate on the working principle, installation location and other information of related Internet of Things equipment, so that integrators, engineering companies, and users can correctly understand things. The revolutionary changes brought about by the Internet in the field of cold chain logistics have established a correct understanding of the Internet of Things in the field of cold chain logistics. If you encounter any confusion or confusion during the reading process, please contact the program writer.
Explanation of terms and abbreviations
RFIDRadio frequency identification is a communication technology that can identify specific targets and read and write related data through radio signals without the need to establish mechanical or optical contact between the identification system and specific targets
The high-precision temperature and humidity sensor tag is composed of an embedded processor and its software, a transmitting and receiving antenna in the card, a transceiver circuit, a high-energy battery, and a high-precision sensor for collecting temperature and humidity information. The special number is pre-stored in the microcontroller , Tags can collect temperature and humidity data in real time according to the set collection interval
The omnidirectional/directional reader is composed of information collection, processing, information transmission, and embedded software. Its main function is to complete real-time collection, processing and information transmission of the data actively sent by the tag.
The cold chain logistics temperature and humidity monitoring system receives the temperature and humidity information from the reader to display it in the monitoring system, set the temperature and humidity range, and give an early warning if the value exceeds the range for decision analysis
2. Project background
2.1 Status analysis
Cold chain logistics refers to a systematic project that temperature and humidity sensitive products are always in a pre-defined low temperature environment during production, storage, transportation, and sales to ensure the quality of goods and reduce logistics losses. It is generally divided into cold storage ( Frozen) processing, refrigerated (frozen) storage, refrigerated (frozen) transportation and distribution, and refrigerated (frozen) sales, among which refrigerated transportation and distribution are the weak links of cold chain logistics.
During the transportation of cold chain logistics, the temperature should be strictly controlled at (0℃~4℃), and the humidity should be strictly controlled at 85~90%. If you use traditional temperature and humidity monitoring methods, you can only monitor the end-to-end node temperature and humidity, but even if the node temperature and humidity are normal, it cannot guarantee that the temperature and humidity will always be normal during transportation. Using RFID technology, you can understand the cold chain logistics in transportation. Whether the temperature and humidity changes during the process and the quality changes that may be caused by it. RFID still has the cost advantage of large-scale application.
In response to this demand, the company launched a real-time monitoring system for temperature and humidity in cold chain logistics based on active RFID technology. Through the combination of advanced active RFID technology and wireless communication technology, the product quality of cold chain logistics transportation is managed in a detailed and real-time manner.
2.2 Significance of system construction
1. Real-time automatic detection and recording of temperature and humidity information during the cold chain transportation of products, effectively preventing various risks that may affect product quality and safety during storage and transportation, and ensuring product quality during storage and transportation.
2. Record the product temperature and humidity to facilitate timely query of data information, and provide the basis for data analysis and decision-making for the entire cold chain logistics
3. Establish a real-time monitoring system for the temperature and humidity of cold chain logistics, establish an early warning mechanism, set the upper and lower limits of the monitoring temperature and humidity, and alarm if the set value is exceeded to avoid risks.
3. System Overview
3.1 System design principles
The system development and construction follow the following principles:
Focus on overall planning
The temperature and humidity real-time monitoring system of cold chain logistics consists of three parts. First, the core hardware of the temperature and humidity real-time monitoring system (including: omnidirectional readers, high-precision temperature and humidity sensor tags). Second, the real-time monitoring of temperature and humidity in cold chain logistics. System platform; third, hardware middleware (including GPRS wireless modules, GPS modules, industrial switches, PCs, servers, uninterruptible power supplies, etc.);
Based on independent research and development
The core technology of the system construction adopts the standard 2.4G active microwave frequency band commonly used in the market. All the core equipment provided by the company has completely independent intellectual property rights, 2.4G micro-power technology, automatic identification and non-contact of cold chain logistics transportation vehicle products The collection and processing of sexual temperature and humidity information effectively integrates advanced information technology, data communication technology, electronic control technology and computer processing technology in the cold chain logistics temperature and humidity real-time monitoring management system, thus establishing a large-scale, all-round Play a role, and real-time, accurate and efficient temperature and humidity monitoring and management system.
Focus on future development
In the overall system architecture, service equipment selection, activeelectronic labelIn terms of function selection, basic data collection, etc., fully consider the realization of subsequent functions, taking into account the compatibility of the equipment, the scalability of the system, the scalability of functions and the diversity of applications;
Strengthen system specifications
System development and resource construction conform to a unified technical specification and characterization system, pay attention to the continuity and sharing of development work, and pay attention to leaving standardized data and control interfaces for subsequent system development and promotion. Unified development of technical indicators such as application technology, data storage format, signal transmission system, and interconnection interface mode;
Utilize construction benefits
The development and construction of the system should combine the actual conditions of the traffic area, and further strengthen the management of the traffic on the basis of the existing system; follow the overall planning, construction while using, and gradually improve the construction ideas to give full play to the construction benefits;
3.2 The working principle of the system
First, the high-precision temperature and humidity sensor tags will be loaded on the container or the target item (box), and after the shipment has started, it will continue to record the temperature and humidity of the environment where the item is located. There are generally two application modes. One is to upload the temperature and humidity curve at each intermediate site or destination at one time, and the logistics management platform integrates all uploaded data to monitor the quality of items in different links; the other is to set up on the transport vehicle/ship GPRS real-time transmission equipment, the logistics management platform can continuously monitor the target items in real time. The only difference between the two modes is that the latter mode, the real-time mode, can be used to rescue some valuables, and not just like the former mode can only identify whether the item is damaged. Of course, the active tag is to identify a certain packaging box (cabinet), and different packaging units in the same container can be monitored by installing multiple active tags.
The monitoring equipment can also be equipped with a GPS module. Through GPS and GIS technology, the monitoring center can locate and dispatch the geographic location of container vehicles.
If the temperature and humidity changes beyond a preset range, such as 20°C to 30°C, the system will automatically give an early warning. If there is a record in the middle of the curve that is significantly lower than 20°C, you can query the corresponding location and external environment based on this time, so as to explore the corresponding temperature and humidity changes.
Information collection of vehicles in transit: RFID reader reads the RFID high-precision temperature and humidity sensor electronic tags in the refrigerated compartment through wireless means, and transmits them to the GPS vehicle terminal device through the data line, and the GPS vehicle terminal device receives GPS positioning through an external antenna Satellite positioning information.
Information transmission of vehicles in transit: GPS vehicle terminal equipment obtains temperature and humidity information and GPS positioning information and sends it to the communication data center through the GPRS wireless network. The communication data center then sends the encrypted data to the GPS communication gateway through the router through the APN special tunnel, and finally transmits it to the database server.
3.3 Schematic diagram of overall system design
3.4 System function introduction
RFID function. Support the application of RFID equipment in the logistics process, including the temperature and humidity monitoring in the car, etc. GPS/GIS monitoring. Through the integration of GPS, GPRS and GIS, the transportation vehicles can be monitored in real time. Business process synchronization. Apply workflow management concepts to achieve a high degree of coordination of internal business processes. Cryogenic equipment management. Support the daily management and maintenance of cryogenic equipment. Temperature and humidity monitoring. Real-time monitoring of the humidity, temperature and humidity that affect the quality of goods in the logistics process, and setting up an early warning mechanism. Quick storage function. Provide quick warehousing function for special goods. Prompt and event management. Provide system users with prompt and event management functions. Fleet optimization. Improve the management and control of the transportation fleet. Transport plan execution management. Manage the implementation of the transportation plan throughout the process. policy support. Apply statistical analysis methods to achieve support for business decision-making.Cold storage temperature and humidity monitoring
3.5 System software introduction
The cold chain logistics temperature and humidity real-time monitoring system with active RFID technology detects and records in real time, and can collect and process records. The monitoring terminal with alarm function can collect the temperature and humidity of the surrounding environment in real time, and can transmit and alarm. The temperature and humidity real-time monitoring system of cold chain logistics automatically continuously monitors and records the temperature and humidity environment during product storage and transportation. The system should update the temperature and humidity data at the measuring point at least once every 1 minute, and automatically record real-time temperature and humidity data at least every 30 minutes during storage, and automatically record real-time temperature data at least every 5 minutes during transportation. When the monitored temperature and humidity exceed the specified range, the system should record real-time temperature and humidity data at least once every 1 minute. When the monitored temperature and humidity data reaches the set critical value or exceeds the specified range, and the battery voltage in the temperature and humidity sensor tag is lower than the set value or the system is interrupted in power supply, it can be alarmed by the buzzer and LED light. Can send out wireless alarm information at the same time.
4. Overall system construction plan
4.1 RFID cold chain logistics temperature and humidity real-time monitoring system
The temperature and humidity label will be loaded on the container or the target item (box), and after the shipment has started, the temperature and humidity of the environment where the item is located will be continuously recorded. There are generally two application modes. One is to upload the temperature and humidity curve at each intermediate site or destination at one time, and the logistics management platform integrates all uploaded data to monitor the quality of items in different links; the other is to set up on the transport vehicle/ship GPRS real-time transmission equipment, logistics management platform can continuously monitor target items. The only difference between the two modes is that the latter, the real-time mode, can be used to rescue some valuables, not just the former mode can only identify whether the items are damaged. Of course, the active label identifies a certain packaging box (cabinet), and different packaging units in the same container can be monitored by installing multiple active labels.
4.1.1 Hardware composition
1) RFID base station type omnidirectional reader, installed on the cold chain logistics vehicle, read the temperature and humidity information of the temperature and humidity sensor tags loaded on the product in the vehicle, and send the data to the background prison system in real time via the GPRS wireless network
2) High-precision temperature and humidity sensor electronic tags, installed on products that need to collect temperature and humidity information in real time
3) GPRS wireless module, the GPRS module sends data to the background through the wireless network
4.1.2 Precautions for hardware installation
1) RFID base station type omnidirectional reader, need to pay attention to the installation position, height, 2.4G antenna of the omnidirectional reader, in order to better receive the data of the temperature and humidity sensor tag, it needs to be placed in the cold chain logistics compartment
2) The high-precision temperature and humidity sensor label is attached to the product, and the installation method can be pasted with 3M glue or fixed with screws
3) GPRS wireless module In order to send data better, the GRPS antenna should be installed outside the car body;
5. Introduction of hardware equipment
5.1 RW-R801 base station type omnidirectional reader
Product technical characteristics
Recognition distance: 0～100m radius
Recognition speed: 200 km/h
Recognition ability: Recognize more than 500 labels at the same time
Recognition angle: omnidirectional
Polarization mode: vertical polarization or dual polarization
Gain: 5dBi, 32 levels adjustable for receiving, 4 levels adjustable for transmitting
Working frequency band: 2.4 GHz ~ 2.4835 GHz
Power consumption standard: working power is milliwatt
Communication mechanism: Based on HDLC time division multiple access and synchronous communication mechanism
Anti-interference: channel isolation technology, multiple devices do not interfere with each other
Security: Encrypted calculation and security authentication to prevent link detection
Interface standard: RS232, RS485, Wiegand26, RJ45, TTL, WiFi, etc. optional
Expansion I/O: 2 channels of switch signal input and output (optional)
Power standard: DC 7.5～12V 500～1000mA
Package characteristics: Aluminum alloy shell package
Reliability: Thunderproof, waterproof and shockproof, meeting the requirements of industrial environment
Size: 180×135×60 mm (without antenna)
Weight: 0.58kg
Installation method: U-shaped, L-shaped special metal installation kit
5.2 RW-T601 high-precision temperature and humidity sensor label
Product technical characteristics
Launch distance: 0～100 meters
Collection interval: 1s～1800s/time, can be set
Working mode: RFID or Bluetooth mode, omnidirectional sending and receiving
Working frequency band: 2.4 GHz ~ 2.4835GHz
Communication rate: 250Kb/s, 1Mb/s, 2Mb/s
Reading ability: When working in RFID mode, it has 100 sheets per second to be read and anti-collision performance
Sensor: Adopt a new generation of digital high-precision temperature and humidity sensor SHT21 or SHT20 imported from Switzerland, with lower power consumption and higher reliability
Collection range: temperature -40～+85 ℃, humidity 0～100%RH
Temperature measurement accuracy: ± 0.3 ℃, temperature measurement resolution 0.01 ℃
Humidity accuracy: ± 2%, humidity measurement resolution 0.04%RH
User memory: standard 4K, can be expanded on demand
Real-time clock: RTC real-time clock chip
Recording capacity: 32M memory chip can be expanded as needed, and up to 3 million sets of temperature and humidity records with time can be stored
Anti-demolition function: anti-demolition device can be added as needed
Anti-interference: The channel can be moved, and multiple devices will not interfere with each other
Power consumption standard: The average working power is microwatts
Battery configuration: 1~4 3V cylindrical lithium batteries can be configured, the maximum capacity of 4 batteries can reach 3800mAh
Service life: 1~5 years, when the voltage is low, you can wirelessly prompt to replace the battery
Packaging characteristics: ABS+PC engineering plastics
Reliability: Anti-soaking, anti-impact, meeting the requirements of industrial environment
Appearance: round cake type, OEM customized service can be provided
Size: Φ84 mm, thickness 25 mm
Dead weight: 112g
Installation method: paste, magnetic buckle adsorption, screw fastening
6. Project implementation
6.1 Project implementation process
Project implementation process
6.2 Project after-sales service
As far as sales are concerned, service must come
7χ24 hours professional guarantee;
Arrive at the maintenance site quickly within 4 hours.
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