Four-way vehicle based on WiFi and Lora network fusion and wireless communication method

Abstract

The invention provides a four-way vehicle based on WiFi and Lora network convergence and a wireless communication method. A first wireless communication module and a second communication unit which are complementary in performance are arranged in a four-way vehicle, and interactive communication is flexibly achieved through a base station or a gateway in a system by means of the two communication units according to the real-time communication quality in the warehousing system. According to the application, a WiFi + lora network fusion mode is adopted, so that on one hand, the defects of single network communication can be made up; the problem of WiFi signal shielding caused by cargo accumulation, the problem of incapability of roaming of a four-way vehicle caused by improper distance setting of a plurality of WiFi gateways, the problem of signal attenuation of a certain area caused by antenna angle change of the WiFi gateways, the problem of interference of other on-site WiFi networks on a four-way vehicle network, the problems of low transmission rate and low real-time performance of a Lora network, and the problems of small bandwidth and low real-time performance of the Lora network are solved. And the content of transmitted data is small. And on the other hand, the lora terminal can be matched with a GPIO switch on the main control power supply to remotely realize the on-off operation of the four-way vehicle.

Description

Technical Field

[0001] The present application relates to the technical field of intelligent warehousing systems, and more specifically to a four-way vehicle and a wireless communication method based on the fusion of WiFi and Lora networks. Background Art

[0002] Four-way carts are becoming more and more popular in the modern logistics and warehousing industry due to their high-density, high-flexibility and high-efficiency storage characteristics. Four-way carts are mostly used in stereoscopic warehouses. Stereoscopic warehouses have large site areas, many metal structures, and complex warehouse goods. Signal interference and signal attenuation are significant, so how to establish a stable wireless communication connection is particularly critical in four-way cart control technology.

[0003] There are many wireless communication methods on the market, each with its own advantages and disadvantages.

[0004] WiFi networks have the advantages of high flexibility, convenient installation (only one network cable is needed to connect to the transmitting gateway), fast transmission rate, multiple access devices, strong compatibility, etc. However, WiFi networks also have problems such as limited network coverage, communication blind spots, and communication interference.

[0005] The Lora network has the advantages of long transmission distance, strong penetration, low power consumption, and strong anti-interference ability, but at the same time, the Lora network also has its obvious shortcomings such as low transmission rate and high latency.

[0006] Existing four-way vehicles usually rely solely on WiFi network communication. This type of solution often performs well in experimental environments or empty warehouses, but in actual application scenarios, due to the large warehouse area and complex warehouse construction, a single wireless routing gateway often cannot meet the requirements. Multiple wireless routing gateways need to be laid to achieve full warehouse network coverage, which increases costs. In addition, since laying multiple wireless routing gateways requires requirements for the distance and antenna angle of each gateway, the level of professionalism is relatively high. When the network is not good in the later stage, special personnel are required to debug and maintain it, which increases labor costs. In addition, during the use of the warehouse, the situation of goods in the warehouse is random. If a large amount of goods are piled up or the goods themselves interfere with the WiFi signal, it is very easy to cause signal shielding problems in a certain area. Once the four-way vehicle enters it, it will lose connection. In severe cases, the warehouse may even be paralyzed. Generally, this situation cannot be recovered autonomously and must be restored manually, which greatly increases the operation and maintenance costs of the warehouse. Summary of the invention

[0007] In view of the shortcomings of the existing technology, this application provides a four-way vehicle and wireless communication method based on the integration of WiFi and Lora network. This application combines the advantages of the two communication technologies and can be adapted to equipment-intensive storage environments. While improving communication reliability, it also takes into account equipment power consumption and compensates for the delay and interference problems of a single communication method. This application specifically adopts the following technical solutions.

[0008] First of all, to achieve the above-mentioned purpose, a four-way vehicle based on the fusion of WiFi and Lora network is proposed, which includes: a first wireless communication module, used for interactive communication with a base station in a warehousing system in a first frequency band; a second wireless communication module, used for interactive communication with a gateway in the warehousing system in a second frequency band, and can also be used to: respond to instructions from the warehousing system to trigger switching of the working state of the first wireless communication module in the four-way vehicle; wherein the specific frequency band used for interactive communication is selected by the warehousing system according to the communication quality of the four-way vehicle.

[0009] Optionally, a four-way vehicle based on the fusion of WiFi and Lora networks as described above, wherein the first wireless communication module is a WiFi terminal; the second wireless communication module is a LoRa terminal; the base stations in the warehousing system are networked with each other, and communication data is uploaded to the scheduling unit in the warehousing system according to the IP address and port number of the four-way vehicle; the gateways in the warehousing system are networked with each other, and communication data is uploaded to the scheduling unit in the warehousing system according to the frame header, frame tail and vehicle number of the four-way vehicle; the uploaded communication data at least partially includes the signal strength and / or packet loss rate of the WiFi terminal currently on the four-way vehicle; in the warehousing system, the scheduling unit determines the communication quality of the WiFi terminal based on the signal strength and / or packet loss rate of the WiFi terminal, and issues an instruction to trigger switching to interactive communication by the LoRa terminal when the communication quality does not meet the standard, and issues an instruction to trigger switching to interactive communication by the WiFi terminal when the communication quality meets the standard.

[0010] Optionally, in any of the above four-way vehicles based on the integration of WiFi and Lora networks, in which the four-way vehicle is also connected in series on its power control loop: a vehicle body hardware power switch and a GPIO switch; the control interface of the GPIO switch is connected to the LoRa terminal, and the GPIO switch is triggered by the LoRa terminal to switch its on and off state according to the received instruction to switch the working state of the first wireless communication module in the four-way vehicle. The first wireless communication module is powered by the power control loop.

[0011] Optionally, in the four-way vehicle based on the integration of WiFi and Lora networks as described above, the first wireless communication module is powered by a power control circuit in the four-way vehicle; and the second wireless communication module is powered separately.

[0012] Optionally, a four-way vehicle based on the fusion of WiFi and Lora networks as described above, wherein wireless data transmission is achieved between the WiFi terminal and the base station based on the TCP / IP protocol in the 4920-6100MHz wide frequency band; wireless data transmission is achieved between the LoRa terminal and the gateway through the Lora network transparent transmission in the 433 / 470 / 780 / 868 / 915 MHz frequency band based on the modbus_tcp protocol; the WiFi terminal uploads the signal strength and / or packet loss rate of the WiFi terminal to the base station in the warehousing system before interactive communication according to a preset period.

[0013] Optionally, in the above four-way vehicle, the WiFi terminal and the LoRa terminal can be set to keep only one of them working, and the other can be switched to standby or turned off accordingly.

[0014] Between each base station, each gateway and the dispatching unit in the storage system.

[0015] At the same time, in order to achieve the above-mentioned purpose, the present application also provides a wireless communication method for a storage system where any of the four-way vehicles as described above are located, which controls the scheduling unit in the storage system to perform the following steps: requesting the base station currently in working state to report the communication quality according to a preset period; based on the communication quality of each four-way vehicle obtained: sending instructions to the gateway corresponding to the four-way vehicle whose communication quality does not meet the standard to trigger the four-way vehicle to switch to interactive communication by the LoRa terminal, and sending instructions to the base station corresponding to the four-way vehicle whose communication quality meets the standard to trigger the four-way vehicle to switch to interactive communication by the WiFi terminal.

[0016] Optionally, in any of the wireless communication methods described above, when the signal strength of the WiFi terminal is lower than -75dBm and / or the packet loss rate reaches a preset threshold, it is determined that the communication quality does not meet the standard.

[0017] Correspondingly, the present application also provides a wireless communication method for any of the four-way vehicles as described above, which controls each four-way vehicle to communicate according to the following steps: recording the signal strength and / or packet loss rate of the on-board WiFi terminal; uploading the signal strength and / or packet loss rate to the base station; responding to the gateway's instructions to trigger the four-way vehicle to switch to interactive communication through the LoRa terminal, or responding to the base station's instructions to trigger the four-way vehicle to switch to interactive communication through the WiFi terminal.

[0018] Optionally, a wireless communication method as described in any of the above, wherein, when a power-on and / or power-off command is received, the LoRa terminal triggers the GPIO switch in the power control circuit in the vehicle to turn on or off the power supply to the WiFi terminal accordingly; when triggering interactive communication through the WiFi terminal, the LoRa terminal in the vehicle can be synchronously triggered to switch to standby mode.

[0019] Optionally, a wireless communication method as described in any of the above, wherein the four-way in-vehicle WiFi terminal remains turned on by default for interactive communication, and the LoRa terminal remains on standby by default; the LoRa terminal is also used to receive a power-on or power-off command broadcast by a scheduling unit, and after receiving the power-on or power-off command, triggers the GPIO switch in the power control loop in the vehicle to turn on or off the power supply to the in-vehicle main control system and WiFi terminal. Beneficial Effects

[0020] The four-way vehicle and wireless communication method based on the fusion of WiFi and Lora network provided in the present application, by setting a first wireless communication module and a second communication unit with complementary performance in the four-way vehicle, using the two communication units to flexibly realize interactive communication through the base station or gateway in the system according to the real-time communication quality in the storage system. The present application adopts the WiFi+Lora network fusion method, on the one hand, it can make up for the shortcomings of single network communication, for example, the WiFi signal shielding problem caused by the accumulation of goods (especially when the goods are metal parts, the metal will obviously shield the WiFi signal), the problem that the four-way vehicle cannot roam due to improper distance setting of multiple WiFi gateways (the distance between the two gateways is too far, and the four-way vehicle cannot switch the gateway), the problem of signal attenuation in a certain area caused by the change of the WiFi gateway antenna angle, the problem of interference of other WiFi networks on the site to the four-way vehicle network, the problem of low transmission rate and low real-time performance of the Lora network, the problem of small bandwidth of the Lora network and small transmission data content; on the other hand, the switch operation of the four-way vehicle can be remotely realized according to the Lora terminal and the GPIO switch on the main control power supply.

[0021] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent from the description, or may be understood by practicing the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings: Figure 1 It is a schematic diagram of the step flow of the communication method provided in this application. DETAILED DESCRIPTION

[0023] In order to make the purpose and technical solution of the embodiment of the present application clearer, the technical solution of the embodiment of the present application will be clearly and completely described in conjunction with the drawings of the embodiment of the present application. Obviously, the described embodiment is a part of the embodiment of the present application, not all of the embodiments. Based on the described embodiment of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] 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 generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0025] The meaning of "and / or" described in this application means that the situations where each exists alone or both exist at the same time are included.

[0026] The term “connection” as used in this application may mean a direct connection between components or an indirect connection between components via other components.

[0027] The present application provides a four-way vehicle based on the integration of WiFi and Lora networks, wherein the first wireless communication module can be set as a vehicle-mounted WiFi terminal, which is used for interactive communication with a base station in a storage system in a first frequency band; the second wireless communication module can be set as a vehicle-mounted Lora terminal, which responds to the storage system and is used for interactive communication with a gateway in the storage system in a second frequency band, and triggers the four-way vehicle to switch the working state of the first wireless communication module according to the instruction of the storage system; In the storage system where the four-way vehicle is operated, the instructions are issued by the storage system according to the communication quality reported by the base station, and are used to switch the working status of the first wireless communication module and the second wireless communication module in each four-way vehicle. The switching rules can be set as follows: the dispatching system determines the current WIFI signal strength and packet loss rate, and determines that the communication quality does not meet the standard when the strength is lower than -75dBm and / or the packet loss rate reaches the preset threshold, and issues instructions through the Lora link to switch the communication status; after switching, continue to monitor the real-time signal strength and / or packet loss rate of the wireless communication module according to the preset period, and switch to restore the original default WIFI wireless communication module when the communication quality requirements can be met.

[0028] Specific reference Figure 1 The present application arranges two wireless communication systems in the body of the four-way vehicle and the storage space in which it operates to realize the transmission and reception of the WiFi network and the transmission and reception of the Lora network.

[0029] WiFi stands for Wireless Fidelity. It is the most widely used WLAN standard. It uses 2.4G and 5G spectrums. The transmission range is up to 300 meters without obstacles outdoors and up to 100 meters with obstacles indoors. It is the most commonly used transmission protocol. The essence of WiFi communication is that wireless devices transmit digital signals to each other through electromagnetic waves of different frequency bands. WiFi signals use public and universal wireless frequency bands, and there are no restrictions on the use of this frequency band. Therefore, all kinds of wireless products around the world can use this frequency band. However, this also makes 2.4G very crowded. Bluetooth, microwave ovens, zigbee (Internet of Things devices), amateur radio, etc. are all in this frequency band, which will cause serious interference to 2.4G WiFi. Relatively speaking, 5G works in the ultra-high frequency band, which belongs to the centimeter wave and is less interfered by daily life. However, when it is in the intelligent warehousing scene, various types of wireless RF modules, smart phones, positioning terminals, sensor devices in the warehousing system, especially radars, will cause a lot of interference to the 5G working frequency band of WiFi.

[0030] In addition, since a large number of metal structures such as shelves are required in the intelligent warehousing system, the WiFi wireless signal will be absorbed by different materials during the transmission process, resulting in signal attenuation. This is the main form of wireless attenuation. Generally speaking, the higher the density of the material and the more metal it contains, the stronger the absorption of the wireless signal. Because of the wave-particle duality of radio, wireless signal loss can also be caused by reflection, scattering, refraction, diffraction, etc., so the wireless signal we connect is the comprehensive result after these complex processes.

[0031] If LoRa (Long Range Communication) modulation signals are used for interaction with mobile devices such as four-way vehicles, although it can achieve a receiving sensitivity of -148 dBm, it can exchange a relatively small data rate for a higher communication distance (3km in the city, 15km in the suburbs) and low power consumption, enhance the signal's anti-interference ability, and ensure the reliable transmission of LoRa signals in noisy radio environments, but its data transmission rate is low and it is difficult to adapt to the diverse and complex transmission requirements of smart warehousing systems.

[0032] Although LoRa devices can detect extremely low-intensity signals, they can still communicate normally even under conditions of severe signal attenuation, which enables them to communicate over a large range. However, their transmission rate is not enough to meet the needs of smart warehousing systems. In the prior art, if the transmission channel in the smart warehousing system needs to be switched, data loss and asynchrony between the two communication systems will occur.

[0033] In order to overcome the above problems, the present application provides a wireless communication method for a storage system based on the integration of WiFi and Lora networks. It is arranged simultaneously in the four-way vehicle: the WiFi terminal is used to interact and communicate with the base station in the storage system in the first frequency band, and the LoRa terminal is used to interact and communicate with the gateway in the storage system in the second frequency band. The dispatching system can trigger switching according to the real-time communication quality of the four-way vehicle: when the dispatching system determines that any one of the current WIFI signal strength and packet loss rate exceeds the set disconnection threshold, it is considered that the WIFI is disconnected, and the dispatching system automatically switches to the lora mode to send instructions; if it is detected in the subsequent operation process that the WiFi signal strength or packet loss rate is restored, the four-way vehicle can be automatically switched to WiFi mode through the dispatching system. In each of the above-mentioned four-way vehicles, the LoRa terminal is independently powered, and its output end is connected to the GPIO switch connected in series with the power control circuit in the four-way vehicle, and the on-off control of the vehicle body power control circuit is realized through the GPIO switch.

[0034] Correspondingly, in the warehousing system, the base stations and gateways are networked with each other, and each base station uploads communication data to the dispatching unit in the warehousing system according to the IP address and port number of the four-way vehicle, and each gateway exchanges communication data with the dispatching unit in the warehousing system according to the frame header, frame tail and vehicle number of the four-way vehicle. In the warehousing system, the dispatching unit of the four-way vehicle determines the communication quality of the WiFi terminal according to the signal strength and / or packet loss rate of the WiFi terminal, and issues instructions to trigger switching to interactive communication by the LoRa terminal when the communication quality does not meet the standards, and issues instructions to trigger switching to interactive communication by the WiFi terminal when the communication quality meets the standards.

[0035] In the above system, the vehicle-mounted WiFi terminal and the various base stations arranged inside the storage system constitute the WiFi network transmission and receiving equipment, which is usually composed of an industrial-grade integrated wireless base station (AP) and an industrial-grade airborne wireless terminal (CPE). The WiFi protocol adopts the international standard VDA5050 communication protocol. The VDA5050 protocol is a standard interface for mobile robot (AGV / AMR) communication jointly developed by the German Association of the Automotive Industry (VDA) and the Material Handling and Internal Logistics Association (VDMA), and the communication interaction process is realized through the MQTT standard message protocol. Through VDA5050, the central control system can dispatch multiple four-way vehicles in real time, optimize the material handling path, and improve the efficiency of warehouse operations. The whole set of AP supports 4920-6100MHz wide frequency band selection, and the terminal CPE supports 2.4G and 5G dual-mode synchronous reception. By receiving different frequency bands, the problem of interference to the four-way vehicle network caused by other WiFi networks or signals in the same frequency band on site can be solved. The antenna uses the standard 802.11a / n protocol to ensure that terminal devices can quickly access the network, and ensure timely and efficient communication through 300Mbps transmission bandwidth and 1000mW transmission power.

[0036] The vehicle-mounted LoRa terminal and the gateways arranged in the storage system constitute a set of LoRa network transmitting and receiving equipment. The IoT wireless communication router (gateway) and LoRa data transmission terminal (terminal) support 433 / 470 / 780 / 868 / 915 MHz frequency band selection to ensure that the on-site LoRa working frequency band is not interfered with. The communication protocol format under the LoRa network adopts the modbus free protocol, and the content mainly includes fixed frame headers and frame tails, four-way vehicle numbers, data length, data content and CRC checksum. The frame header and frame tail ensure the integrity of each frame of data, and the CRC checksum ensures the correctness of each frame of data. The maximum communication rate can reach 62.5kbps, and the high rate ensures the timeliness and efficiency of communication. The transmission power can reach 30dBm, and the indoor transmission distance is 2km, ensuring full coverage of the LoRa network warehouse.

[0037] The system detects the communication quality of the four-way car, and the dispatch terminal flexibly switches back and forth between the two communication systems according to the real-time communication status of each four-way car. Specifically, the WiFi signal strength and packet loss rate information are only included in the first wireless communication module (WiFi communication), and not in the second wireless communication (Lora communication). Before issuing instructions, the dispatch system will query the WiFi signal strength and packet loss rate under the WiFi network. When the WiFi signal meets the requirements, the dispatch instruction is issued by WiFi. When the WiFi signal does not meet the requirements, the dispatch instruction is sent by Lora. In Lora mode, the WiFi strength and packet loss rate will still be queried once under the WiFi network before the next instruction is issued. In this way, the WiFi network can be used in the use of our four-way car, mainly responsible for the normal communication needs of the car (stable WiFi signal strength, no disconnection scenario), and the Lora network can be used to deal with the scene of poor WiFi signal or WiFi signal disconnection. Therefore, by utilizing the characteristics of fast access to the WiFi network, only the corresponding four-way car IP address and port number need to be provided to realize the needs of fast configuration access of multiple cars. Based on the TCP / IP protocol, a client is established in the dispatching system, and a server is established in the four-way vehicle terminal to realize wireless data transmission. The roaming function of the four-way vehicle is realized by using multiple AP networking to ensure that the four-way vehicle can automatically switch to the best AP in the network during high-speed movement in the warehouse, and ensure that the WiFi signal strength is stable and does not drop. The high-bandwidth transmission characteristics of the WiFi network are used to ensure the efficiency and timeliness of data transmission between the dispatching system and the four-way vehicle. At the same time, when the four-way vehicle runs to an area with more blocked and unstable signals, it can dynamically switch to the Lora network through the real-time status of the packet loss rate or signal strength. When the dispatching system detects that the WiFi signal strength of the four-way vehicle is less than -75dBm or the packet loss rate of the WiFi network is greater than the preset range, the dispatching system sends a switching instruction to the four-way vehicle to switch its communication network to Lora communication. After waiting for the WiFi signal strength of the four-way vehicle to be greater than -75dBm again or the packet loss rate of the network node is less than the preset range, the dispatching system can normally dispatch the four-way vehicle through the WiFi network.

[0038] During the specific transmission process, the modbus_tcp protocol is used between the lora gateway and the four-way vehicle dispatching system. A tcp_client is established in the four-way vehicle dispatching system, and a tcp_server is established in the Lora gateway to realize data transmission between the dispatching system and the gateway.

[0039] The Lora gateway and the Lora terminal use the Lora network transparent transmission method to realize the data transmission between the gateway and the four-way car terminal. When the Lora network communication is enabled, the dispatching system first broadcasts and sends the query command of the four-way car status. After the four-way car compares the frame header, frame tail, and car number, it packages the four-way car status and sends it to the dispatching system. After the dispatching system receives the four-way car status, it considers that the Lora network connection is successful, and then sends the movement command to the four-way car to realize the car position scheduling.

[0040] Based on the low power consumption characteristics of the Lora terminal, this application can also power it separately, and use its output to control the GPIO switch in the power control loop, so as to realize the remote power on and off of the four-way car through the Lora network: when the four-way car is not used for a long time or needs to be powered off and restarted, the dispatching system can directly send a shutdown command through Lora to cut off the power supply of the main control system of the corresponding four-way car. At this time, only the low power consumption of the Lora terminal module is retained through an independent power supply, and the low power consumption characteristics of Lora can be used to achieve a long standby time for the car. In specific implementation, it is generally necessary to adopt a dual switch form for the power control loop of the four-way car, and set a car body hardware power switch and a Lora terminal GPIO switch at the same time. The two switches are connected in series to jointly control the power supply of the main control system of the four-way car. The car body hardware power switch has been in the on state since the first power-on. The dispatching system controls the Lora terminal GPIO level to high or low by sending the switch to realize the remote power on and off function of the four-way car.

[0041] When the above-mentioned converged communication system is specifically arranged, wireless base stations (APs) are arranged around the three-dimensional warehouse. After a single AP is deployed, the distance between the remaining APs and the antenna angle need to be determined according to the signal strength received by the CPE terminal of the four-way vehicle. The specific deployment method principle is: the four-way vehicle performs a signal strength test in the warehouse, and the signal strength received by the CPE terminal of the four-way vehicle meets the requirement of greater than -75dBm. If the signal strength in a certain area does not meet the requirement, it can be improved by reducing the distance between two APs or increasing the number of APs.

[0042] Similarly, Lora gateways are arranged around the stereoscopic warehouse. After deploying a single gateway, the layout principle of the remaining gateways is as follows: the four-way vehicle performs a signal strength test in the warehouse, the Lora gateway broadcasts and sends data at regular intervals, and the four-way vehicle can receive data at the four extreme positions of the stereoscopic warehouse.

[0043] The dispatching unit in the system usually works on the WiFi network. The dispatching system regularly queries the WiFi signal strength and network packet loss rate of the four-way vehicle. When the WiFi signal strength is greater than -75dBm or the network packet loss rate is less than the preset value, the WiFi network is used to dispatch the four-way vehicle. When the WiFi signal strength is less than -75dBm or the network packet loss rate is greater than the preset value, the Lora network is used to dispatch the four-way vehicle: When the Lora network communication is enabled, the dispatching system first broadcasts and sends a command to query the status of the four-way car. After the four-way car compares the frame header, frame tail, and car number, it packages the status of the four-way car and sends it to the dispatching system. After the dispatching system receives the status of the four-way car, it considers that the Lora network connection is successful, and then sends a moving command to the four-way car to realize the movement of the car in the three-dimensional warehouse. When the four-way vehicle moves out of the network shielding area, the dispatching system can query the WiFi signal strength and network packet loss rate of the four-way vehicle again. When the WiFi signal strength of the four-way vehicle is greater than -75dBm or the network packet loss rate is less than the preset value, the four-way vehicle will be triggered to switch to the WiFi network for dispatching the four-way vehicle. When the WiFi signal strength is still less than -75dBm or the network packet loss rate is still greater than the preset value, the Lora network will continue to be used to dispatch the four-way vehicle.

[0044] In this process, the base station relies on the TCP / IP protocol to interact with the dispatching system, and the gateway relies on modbus_TCP to interact with the dispatching system. Modbus TCP is a specific implementation based on the TCP / IP protocol, which also uses the network communication capabilities of TCP / IP. Therefore, these two communication methods are essentially based on the TCP / IP protocol, so they will not affect the system communication performance.

[0045] When the four-way car is powered on normally, both the WiFi module and the Lora module are in working state. The only difference is whether the dispatch system sends instructions through the WiFi network or the Lora network. The four-way car does not need to switch the working state of the communication unit, but only cooperates with the dispatch system to exchange data through the corresponding base station or gateway.

[0046] When the four-way car needs to be turned on or off remotely, the dispatch system sends the corresponding command through the Lora gateway, and remotely turns on or off the Lora terminal GPIO port to realize the remote on / off function of the four-way car. When the four-way car is on standby, only Lora is powered, so the dispatch system can only send a power-on command to the four-way car through Lora, wait for the four-way car to start up, and then send a WiFi query command to determine whether to use the WiFi network or the Lora network.

[0047] In the above-mentioned four-way vehicle communication system, the dispatching unit is deployed on the server of the intelligent warehousing site, which is generally set as an independent computer on site and is responsible for dispatching all the vehicles on site.

[0048] In summary, this application uses a four-way car wireless communication method that integrates WiFi+Lora network, and switches between WiFi and Lora networks. When the four-way car WiFi signal is greater than -75dBm and the network packet loss rate is less than a preset value, WiFi connection is used, and when the WiFi signal is less than -75dBm or the network packet loss rate is greater than a preset value, Lora connection is used. When the goods are concentrated in the stereoscopic warehouse, the density increases, the signal attenuates, and the four-way car enters it and loses connection, the dispatching system can use the Lora network dispatching system to get out of the signal shielding area, so that the four-way car will never lose connection.

[0049] The above is only an implementation method of the present application, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present application. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application.

Claims

1. A four-way vehicle based on the integration of WiFi and Lora network, characterized in that: include: A first wireless communication module, used for interactive communication with a base station in the storage system in a first frequency band; A second wireless communication module, used for interactive communication with a gateway in the storage system in a second frequency band; Among them, the specific frequency band used for interactive communication is selected by the warehouse system according to the communication quality of the four-way vehicles.

2. The four-way vehicle based on the fusion of WiFi and Lora network as claimed in claim 1, characterized in that: The first wireless communication module is a WiFi terminal; The second wireless communication module is a LoRa terminal; The base stations in the storage system are networked with each other, and the communication data is uploaded to the dispatching unit in the storage system according to the IP address and port number of the four-way vehicle; The gateways in the storage system are networked with each other, and the communication data is uploaded to the dispatching unit in the storage system according to the frame header, frame tail and vehicle number of the four-way vehicle; The uploaded communication data at least partially includes the signal strength and / or packet loss rate of the WiFi terminal on the current four-way vehicle; In the warehousing system, the scheduling unit determines the communication quality of the WiFi terminal according to the signal strength and / or packet loss rate of the WiFi terminal, and issues instructions to trigger switching to interactive communication by the LoRa terminal when the communication quality does not meet the standards, and issues instructions to trigger switching to interactive communication by the WiFi terminal when the communication quality meets the standards.

3. The four-way vehicle based on the fusion of WiFi and Lora network as claimed in claim 2, characterized in that: In the four-way vehicle, the power control circuit is also connected in series with: a vehicle body hardware power switch and a GPIO switch; The control interface of the GPIO switch is connected to the LoRa terminal, and the GPIO switch is triggered by the LoRa terminal to switch its on and off state according to the received instruction to switch the working state of the first wireless communication module in the four-way car.

4. The four-way vehicle based on the fusion of WiFi and Lora network as claimed in claim 3, characterized in that: The first wireless communication module is powered by a four-way in-vehicle power control circuit; The second wireless communication module is powered independently.

5. The four-way vehicle based on the integration of WiFi and Lora network as claimed in claim 2, characterized in that: Wireless data transmission between WiFi terminals and base stations is realized based on TCP / IP protocol in the 4920-6100MHz wide frequency band; The LoRa terminal and the gateway realize wireless data transmission through the LoRa network transparent transmission in the 433 / 470 / 780 / 868 / 915 MHz frequency band based on the modbus_tcp protocol; The WiFi terminal uploads the signal strength and / or packet loss rate of the WiFi terminal to the base station in the storage system before interactive communication according to a preset period.

6. A wireless communication method for a storage system where the four-way vehicle described in claims 1-5 is located, characterized in that: The dispatch unit in the warehousing system performs the following steps: Requesting the base station currently in working state to report the communication quality according to a preset period; According to the communication quality of each four-way vehicle obtained: an instruction is sent to the gateway corresponding to the four-way vehicle whose communication quality does not meet the standard to trigger the four-way vehicle to switch to interactive communication by the LoRa terminal, and an instruction is sent to the base station corresponding to the four-way vehicle whose communication quality meets the standard to trigger the four-way vehicle to switch to interactive communication by the WiFi terminal.

7. The wireless communication method according to claim 8, characterized in that: When the signal strength of the WiFi terminal is lower than -75dBm and / or the packet loss rate reaches a preset threshold, it is determined that the communication quality does not meet the standard.

8. The wireless communication method for the four-way vehicle according to claims 1-5, characterized in that: Each four-way vehicle communicates according to the following steps: Record the signal strength and / or packet loss rate of the vehicle-mounted WiFi terminal; Uploading the signal strength and / or packet loss rate to a base station; The four-way vehicle is triggered to switch to interactive communication through the LoRa terminal in response to the instruction of the gateway, or the four-way vehicle is triggered to switch to interactive communication through the WiFi terminal in response to the instruction of the base station.

9. The wireless communication method according to claim 8, characterized in that: When receiving a power-on and / or power-off command, the LoRa terminal triggers the GPIO switch in the power control loop in the vehicle to correspondingly turn on or off the power supply to the WiFi terminal.

10. The wireless communication method according to claims 8-9, characterized in that: The WiFi terminal in the four-way car is kept turned on by default for interactive communication, and the LoRa terminal is kept on standby by default; The LoRa terminal is also used to receive the power-on or power-off command broadcasted by the scheduling unit, and after receiving the power-on or power-off command, trigger the GPIO switch in the power control loop in the vehicle to turn on or off the power supply to the main control system and WiFi terminal in the vehicle.

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