ULD positioning management method and management system based on pallet truck

Abstract

The invention relates to the technical field of pallet truck-based ULD positioning management, in particular to a pallet truck-based ULD positioning management method and management system. According to the invention, the positioning device is directly installed on the pallet truck, and then the positioning device integrated with the laser sensor, the GPS module and the WiFi module is installed on the pallet truck; detecting the existence state of the ULD in real time by using a laser sensor; a GPS positioning mode or a WiFi positioning mode is automatically switched according to the environment; calculating an accurate position through a preset algorithm; and finally, comprehensive information is displayed on a user interface, seamless positioning switching of indoor and outdoor environments is realized, the positioning precision is improved, and the management efficiency and the automation level are greatly improved by establishing tight association between the ULD and the pallet truck.

Description

Technical Field

[0001] The present application relates to the technical field of ULD positioning management based on a pallet truck, and in particular to a ULD positioning management method and management system based on a pallet truck. Background Art

[0002] As a fast and efficient mode of transportation, air cargo plays an important role in international trade, high-tech products and fresh food distribution. With the continuous increase in global trade volume, how to efficiently manage and locate the unit load devices (ULD) used for cargo transportation has become a key issue in improving air cargo efficiency.

[0003] At present, the positioning technologies of ULD mainly include GPS positioning and WiFi positioning. GPS positioning technology can provide high-precision location information in outdoor environments, but the signal reception effect is poor in indoor environments. WiFi positioning technology calculates the location by measuring the signal strength between the device and multiple WiFi access points. It is suitable for indoor environments, but due to large signal fluctuations, the positioning accuracy is limited.

[0004] Existing positioning technologies have obvious limitations when switching between indoor and outdoor environments. For example, when a ULD moves from outdoor to indoor, the GPS signal will weaken or even be lost, and WiFi positioning has difficulty maintaining stable positioning accuracy in an environment with large signal fluctuations. In addition, any one positioning technology alone cannot fully cover indoor and outdoor environments, resulting in discontinuous positioning and unstable accuracy. More importantly, the existing technology manually searches for idle pallet trucks to load ULDs, which increases the workload and has low operating efficiency. This situation needs to be further improved. Summary of the invention

[0005] In order to solve the problems of poor positioning accuracy and low operating efficiency of the existing ULD positioning management method, the present application provides a ULD positioning management method and management system based on a pallet truck, which adopts the following technical solutions: In a first aspect, the present application provides a ULD positioning management method based on a pallet truck, comprising the following steps: Installing a positioning device on the pallet truck, wherein the positioning device includes a laser sensor, a GPS module and a WiFi module; The laser sensor detects in real time whether there is ULD covering the pallet truck, and obtains the loading status information of the pallet truck; Determining the current environment of the pallet truck; When the pallet truck is currently located in an outdoor environment, positioning data is acquired through a GPS module, and location information of the pallet truck is obtained according to the positioning data; When the pallet truck is currently located in an indoor environment, the pallet truck is connected to multiple WiFi access points in the indoor environment through a WiFi module, and the location information of the pallet truck is calculated using a preset positioning algorithm based on the information of the multiple WiFi access points; The loading status information and position information of the pallet truck are displayed through the user interface.

[0006] By adopting the above technical solution, in the traditional system, when the ULD enters the freight station from the outdoors, the GPS signal may be suddenly lost, resulting in positioning interruption; or in a busy freight area, it is difficult to accurately determine which ULD is associated with which pallet truck, which increases the difficulty of management; the present application installs the positioning device directly on the pallet truck, and then installs a positioning device integrating a laser sensor, a GPS module and a WiFi module on the pallet truck; uses a laser sensor to detect the presence status of the ULD in real time; automatically switches the GPS or WiFi positioning mode according to the environment; calculates the precise position through a preset algorithm; and finally displays comprehensive information on the user interface, thereby realizing seamless positioning switching between indoor and outdoor environments, improving positioning accuracy, and greatly improving management efficiency and automation level by establishing a close association between the ULD and the pallet truck.

[0007] Optionally, determining the current environment of the pallet truck specifically includes the following steps: Detecting GPS signal strength of the surrounding environment of the pallet truck; It is determined whether the pallet truck is located in an indoor or outdoor environment based on the GPS signal strength.

[0008] By adopting the above technical solution, the signal strength in different environments is obviously different. In the outdoor environment, due to the open space, the signal strength is strong and stable; in the indoor environment, due to the obstruction and reflection of the building, the signal strength will be significantly weakened and more susceptible to interference. By detecting the signal strength, the environment in which the pallet truck is located can be preliminarily judged; at the same time, different wireless signal types also have significant differences in performance indoors and outdoors. The outdoor environment mainly relies on GPS signals, while the indoor environment mainly relies on WiFi signals. By detecting the signal type, the environment in which the pallet truck is located can be further confirmed and the corresponding positioning technology can be selected.

[0009] Optionally, the position information of the pallet truck is calculated using a preset positioning algorithm, which specifically includes the following steps: measuring the signal strength between the pallet truck and a plurality of WiFi access points; Allocate a weight corresponding to each WiFi access point according to the signal strength; The weighted centroid position is calculated according to the weights corresponding to the various WiFi access points to determine the position information of the pallet truck.

[0010] By adopting the above technical solution, the present application measures the signal strength between the pallet truck and multiple WiFi access points, and assigns weights according to the signal strength. The access point with stronger signal strength has a higher weight. This can ensure that the access point closer to the pallet truck has a greater impact on the positioning result. By calculating the weighted center of mass position, the location information of the pallet truck can be determined more accurately, making full use of the data of multiple access points to improve the reliability and accuracy of positioning.

[0011] Optionally, the method further comprises the following steps: When it is detected that the ULD covers the pallet truck, the ULD is automatically bound to the location information of the pallet truck; When the pallet truck enters a preset area, the ULD is automatically unbound from the location information of the pallet truck.

[0012] By adopting the above technical solution, in the traditional system, the staff needs to manually record or scan the association information between the ULD and the pallet truck, which is not only time-consuming and labor-intensive, but also prone to errors due to human negligence, especially in a busy airport environment. The present application utilizes the laser sensor on the pallet truck to automatically detect the presence of the ULD, and combines the preset area information to realize the intelligent binding and unbinding of the ULD and the pallet truck's location information, thereby reducing human errors and improving operational efficiency and data accuracy.

[0013] Optionally, the method further comprises the following steps: installing a vibration sensor on the pallet truck; Detecting the motion state of the pallet truck by means of the vibration sensor; The sending frequency of the position information is dynamically adjusted according to the motion state.

[0014] By adopting the above technical solution, in traditional systems, positioning devices often send position information at a fixed frequency, resulting in invalid data transmission in a stationary state, which not only wastes power but also increases the communication burden. The present application first installs a vibration sensor on the pallet truck; then continuously detects the motion state of the pallet truck through the vibration sensor; finally, according to the detected motion state, dynamically adjusts the sending frequency of the position information, increases the sending frequency when moving, and reduces the frequency when stationary; reduces the energy consumption and communication costs of the system, while ensuring the positioning accuracy and real-time performance at critical moments.

[0015] Optionally, the method further comprises the following steps: Install multiple WiFi signal receivers on the tray to form a receiver array; Utilizing the receiver array to receive WiFi signals from different directions; Calculating the location and orientation information of the pallet truck based on the strength and arrival time difference of the received WiFi signal; According to the position and orientation information of the pallet truck, combined with a pre-stored indoor environment map, obstacles and feasible paths around the pallet truck are identified; Obstacle avoidance and navigation instructions are sent to the pallet truck based on obstacles and feasible paths around the pallet truck.

[0016] By adopting the above technical solution, the present application first installs multiple WiFi signal receivers on the pallet truck to form a receiver array, and uses the array to receive WiFi signals from different directions; calculates the precise position and orientation of the pallet truck based on signal strength and arrival time difference; identifies surrounding obstacles and feasible paths in combination with a pre-stored indoor environment map; and finally sends obstacle avoidance and navigation instructions to the pallet truck based on this information; significantly improves the indoor positioning accuracy, realizes accurate identification of the orientation of the pallet truck, can provide intelligent obstacle avoidance and autonomous navigation capabilities, and greatly improves the automation and intelligence level of ULD management.

[0017] Optionally, the method further comprises the following steps: installing an inertial measurement unit on the pallet truck, and acquiring measurement data based on the inertial measurement unit; Calculate WiFi signal quality; When the WiFi signal quality is lower than a preset threshold, position estimation is performed based on the measurement data.

[0018] By adopting the above technical solution, when the pallet truck enters an area with weak WiFi signal (such as a storage area with dense metal structures), the positioning information may be suddenly lost or seriously deviated, affecting the continuity and reliability of ULD management. This application first installs an inertial measurement unit on the pallet truck to continuously obtain measurement data such as acceleration and angular velocity; at the same time, the WiFi signal quality is calculated in real time; when the WiFi signal quality is detected to be lower than the preset threshold, the system automatically switches to the position estimation mode based on IMU data to ensure the continuity of positioning; the robustness and reliability of the positioning system are improved, the positioning interruption problem in complex environments is effectively solved, and the continuity and accuracy of ULD management are guaranteed.

[0019] In a second aspect, the present application provides a ULD positioning management system based on a pallet truck, comprising: A plurality of pallet trucks, each of which is equipped with a positioning device, wherein the positioning device includes a laser sensor, a GPS module and a WiFi module; Multiple WiFi access points, distributed in the indoor environment; A central control server for receiving and processing data from the plurality of pallet trucks; Wherein, the central control server is configured to execute the above-mentioned ULD positioning management method based on the pallet truck.

[0020] Optionally, a plurality of WiFi signal receivers are installed on the pallet truck to form a receiver array; The central control server is also configured to: Utilizing the receiver array to receive WiFi signals from different directions; Calculating the location and orientation information of the pallet truck based on the strength and arrival time difference of the received WiFi signal; According to the position and orientation information of the pallet truck and in combination with a pre-stored indoor environment map, obstacles and feasible paths around the pallet truck are identified.

[0021] Optionally, the pallet truck is also equipped with an inertial measurement unit; The central control server is also configured to: acquiring measurement data based on the inertial measurement unit; Calculate WiFi signal quality; When the WiFi signal quality is lower than a preset threshold, position estimation is performed based on the measurement data.

[0022] In summary, the present application includes at least one of the following beneficial technical effects: In the traditional system, when the ULD enters the freight station from the outdoors, the GPS signal may be suddenly lost, resulting in interrupted positioning; or in a busy freight area, it is difficult to accurately determine which ULD is associated with which pallet truck, which increases the difficulty of management; this application installs the positioning device directly on the pallet truck, and then installs the positioning device integrating the laser sensor, GPS module and WiFi module on the pallet truck; uses the laser sensor to detect the existence status of the ULD in real time; automatically switches the GPS or WiFi positioning mode according to the environment; calculates the precise position through a preset algorithm; and finally displays the comprehensive information on the user interface, realizing seamless positioning switching between indoor and outdoor environments, improving positioning accuracy, and greatly improving management efficiency and automation level by establishing a close association between the ULD and the pallet truck; This application measures the signal strength between the pallet truck and multiple WiFi access points, and assigns weights according to the signal strength. The stronger the signal strength, the higher the weight of the access point. This ensures that the access point closer to the pallet truck has a greater impact on the positioning result. By calculating the weighted centroid position, the location information of the pallet truck can be determined more accurately, making full use of the data of multiple access points to improve the reliability and accuracy of positioning. In traditional systems, positioning devices often send location information at a fixed frequency, resulting in invalid data transmission in a stationary state, which not only wastes power but also increases the communication burden. The present application first installs a vibration sensor on the pallet truck; then continuously detects the motion state of the pallet truck through the vibration sensor; finally, according to the detected motion state, dynamically adjusts the sending frequency of the position information, increases the sending frequency when moving, and reduces the frequency when stationary; thus reducing the energy consumption and communication costs of the system, while ensuring the positioning accuracy and real-time performance at critical moments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of a ULD positioning management method based on a pallet truck according to an embodiment of the present application; Figure 2 It is a flow chart of location information binding in a ULD positioning management method based on a pallet truck in an embodiment of the present application; Figure 3 It is a flow chart of dynamically adjusting the sending frequency in a ULD positioning management method based on a pallet truck in an embodiment of the present application; Figure 4 It is a schematic diagram of a process of identifying obstacles in a ULD positioning management method based on a pallet truck according to an embodiment of the present application; Figure 5 It is a schematic diagram of a process of position estimation in a ULD positioning management method based on a pallet truck in an embodiment of the present application; Figure 6 It is a module schematic diagram of a ULD positioning management system based on a pallet truck according to an embodiment of the present application; Figure 7 It is a diagram of the internal structure of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] The terms used in the following embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to be used as limitations to the present application. As used in the specification and appended claims of the present application, the singular expressions "one", "a kind of", "said", "above", "the" and "this" are intended to also include plural expressions, unless there is a clear indication to the contrary in the context. It should also be understood that the term "and / or" used in the present application refers to any or all possible combinations comprising one or more listed items.

[0025] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features, and in the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more.

[0026] The embodiments of the present application are further described in detail below in conjunction with the drawings in the specification.

[0027] In the first aspect, the present application provides a ULD positioning management method based on a pallet truck, referring to Figure 1 , including the following steps: S110: Install a positioning device on the pallet truck, wherein the positioning device includes a laser sensor, a GPS module, and a WiFi module.

[0028] Among them, pallet truck refers to a special vehicle used to transport ULD, usually used in airports or freight stations; positioning equipment refers to a comprehensive equipment installed on the pallet truck to determine the position and status; laser sensor is a sensor used to detect whether the ULD is covered on the pallet truck, usually installed above the pallet truck.

[0029] S120, using the laser sensor to detect in real time whether there is ULD covering the pallet truck, and obtain loading status information of the pallet truck.

[0030] In this step, ULD coverage refers to the state where the ULD is placed on the pallet truck, and loading status information refers to information on whether the pallet truck is loaded with the ULD, including two states: loaded and unloaded.

[0031] Specifically, the laser sensor continuously emits a laser beam to scan upward. The present application pre-sets a predetermined distance threshold, such as 2 meters. If the distance corresponding to the time when the laser is reflected back is less than the threshold, it is determined that there is ULD coverage. If the distance is greater than or equal to the threshold, it is determined that there is no ULD coverage. The detection result is then transmitted to the central control unit in real time to update the loading status information of the pallet truck. S130: Determine the current environment of the pallet truck.

[0032] Specifically, judging the current environment of the pallet truck refers to judging whether the pallet truck is located indoors or outdoors, which can be judged by WiFi signals, GPS signals, or other sensors such as light sensors, air pressure sensors, etc.

[0033] In this embodiment, determining the current environment of the pallet truck specifically includes: detecting the GPS signal strength of the environment surrounding the pallet truck; and determining whether the pallet truck is located in an indoor or outdoor environment according to the GPS signal strength.

[0034] S140: When the pallet truck is currently located in an outdoor environment, obtain positioning data through a GPS module, and obtain location information of the pallet truck according to the positioning data.

[0035] The GPS module receives signals from multiple satellites to calculate the precise location of the pallet truck, including longitude, latitude, altitude, and time information. GPS positioning technology can provide high-precision location information in outdoor environments, but the signal reception effect is poor in indoor environments.

[0036] S150: When the pallet truck is currently located in an indoor environment, the pallet truck is connected to multiple WiFi access points in the indoor environment through a WiFi module, and the location information of the pallet truck is calculated using a preset positioning algorithm based on information of the multiple WiFi access points.

[0037] Among them, WiFi positioning technology uses the WiFi network infrastructure deployed indoors for positioning, without the need to install additional dedicated positioning equipment. It estimates the location by measuring the signal strength or arrival time difference between the pallet truck and multiple WiFi access points. It is suitable for indoor environments where GPS signals are weak or cannot be received.

[0038] Specifically, the WiFi module first scans the visible WiFi access points around and records the MAC address and signal strength (RSSI value) of each access point. The system then compares this data with the pre-established WiFi signal fingerprint database and uses a pattern matching algorithm to find the most similar reference point to determine the approximate location of the pallet truck. To improve positioning accuracy, information from multiple access points can be combined for trilateral measurement or weighted positioning calculation.

[0039] In this embodiment, a preset positioning algorithm is used to calculate the location information of the pallet truck, specifically including: measuring the signal strength between the pallet truck and multiple WiFi access points; allocating weights corresponding to each WiFi access point according to the signal strength; calculating the weighted center of mass position according to the weights corresponding to each WiFi access point to determine the location information of the pallet truck.

[0040] Furthermore, the navigation method corresponding to the project is determined. For example, if it is an overseas project, the longitude and latitude data are converted into the navigation format corresponding to Google Maps, and the location is displayed on Google Maps. If it is a domestic project, it is automatically converted into the target navigation such as the data format corresponding to Baidu Maps.

[0041] S160: Displaying the loading status information and location information of the pallet truck through a user interface.

[0042] Specifically, the present application also provides a user interface, which can be implemented in the form of a web page or a mobile application. The interface mainly includes two parts: a map display area and a status information area. The map area uses a vector map to display the real-time location of the pallet truck, and different colors or icons can be used to distinguish between loaded and unloaded states. The status information area displays detailed information about the pallet truck in a list format, including vehicle ID, current location coordinates, loading status, power, etc.

[0043] In the traditional system, the staff needs to manually record or scan the association information between the ULD and the pallet truck, which is not only time-consuming and labor-intensive, but also prone to errors due to human negligence, especially in a busy airport environment. Therefore, in one embodiment, referring to Figure 2 , the method further comprises the following steps: S210: When it is detected that the ULD covers the pallet truck, the ULD is automatically bound to the location information of the pallet truck.

[0044] In this embodiment, a sensor system installed on the pallet truck is used to monitor the presence of the ULD in real time. Once the ULD coverage is detected, the system immediately triggers a binding operation to associate the unique identifier of the ULD with the current location information of the pallet truck.

[0045] Specifically, when the laser sensor detects that the ULD covers the pallet truck, the system will immediately record the current timestamp and the exact location of the pallet truck. At the same time, the unique identifier of the ULD is obtained through the RFID reader or barcode scanner to create a binding record containing the ULD identification, pallet truck ID, binding time and location coordinates.

[0046] S220: When the pallet truck enters a preset area, the ULD is automatically unbound from the location information of the pallet truck.

[0047] The preset area in this embodiment generally refers to the unloading area or transfer area of ​​the ULD, such as the aircraft loading area, warehouse entrance, etc. The system tracks the position of the pallet truck in real time, and automatically triggers the unbinding process when it detects that the pallet truck enters these predefined areas.

[0048] Specifically, the system predefines and stores the geo-fence information of each unloading area. When the location reported by the GPS or indoor positioning system of the pallet truck matches these preset areas, the system automatically starts the unbinding procedure. The unbinding process includes recording the unbinding time and location, updating the status information of the ULD in the database, and releasing the association of the pallet truck. Furthermore, in order to increase reliability, the system can set a short delay (such as 30 seconds) to confirm that the pallet truck continues to stay in the preset area before performing the unbinding operation. In addition, the system can also reconfirm whether the ULD has been removed through the sensor on the pallet truck to further verify the correctness of the unbinding operation.

[0049] Through this, the present application utilizes the laser sensor on the pallet truck to automatically detect the presence of the ULD, and combines the preset area information to realize the intelligent binding and unbinding of the ULD and the pallet truck location information, thereby reducing human errors and improving operational efficiency and data accuracy.

[0050] In the above embodiment, the system can send the location information of the ULD and the pallet truck at a specified time interval, and reduce the load of the system by sending the positioning information regularly. In one embodiment, the system can also determine the positioning and sending frequency by detecting whether the pallet truck is in motion.

[0051] Reference Figure 3 , the method further comprises the following steps: S310: Install a vibration sensor on the pallet truck.

[0052] In this embodiment, a vibration sensor is installed on the pallet truck to detect minute vibrations and acceleration changes, thereby accurately determining whether the pallet truck is in different states such as stationary, moving or violently moving.

[0053] Specifically, a triaxial accelerometer can be used as a vibration sensor and installed on the chassis or frame of the pallet truck. The installation location of the sensor should avoid continuous vibration sources such as the engine to reduce interference. In addition, it is also possible to consider installing multiple sensors at different locations on the pallet truck to improve the reliability of detection through data fusion technology.

[0054] S320: Detect the motion state of the pallet truck by using the vibration sensor.

[0055] Specifically, the system can set a series of thresholds to distinguish different motion states. For example, when the vibration amplitude detected by the vibration sensor is lower than a preset threshold, it can be determined as a stationary state; when the vibration amplitude is in a medium range and the frequency is relatively stable, it can be determined as a uniform moving state; when high amplitude or high frequency vibration is detected, it can be determined as a violent motion state, such as acceleration, deceleration or driving on uneven roads.

[0056] S330: Dynamically adjust the frequency of sending the position information according to the motion state.

[0057] Specifically, the system pre-sets a base transmission frequency, such as sending location information once a minute. Then it adjusts according to different motion states: when it is detected that the stationary state lasts for more than 5 minutes, the transmission frequency can be reduced to once every 5 minutes; when it is in a uniform moving state, the base frequency remains unchanged; when it is detected that there is a violent movement state, the transmission frequency can be increased to once every 10 seconds. The system is also equipped with an adaptive adjustment mechanism. If the position does not change much for many consecutive times, the transmission frequency will be gradually reduced even in a moving state.

[0058] In one embodiment, referring to Figure 4 , the method further comprises the following steps: S410, installing multiple WiFi signal receivers on the tray to form a receiver array.

[0059] In this embodiment, a high-precision positioning system is constructed by installing multiple WiFi signal receivers on the pallet truck to capture WiFi signals from different directions.

[0060] Specifically, a WiFi signal receiver is installed at each of the four corners of the pallet truck to form a square array.

[0061] S420: Receive WiFi signals from different directions using the receiver array.

[0062] Specifically, each receiver is equipped with an independent signal processing unit that can record the received WiFi signal strength (RSSI), arrival time (ToA) and MAC address of the signal source in real time.

[0063] S430: Calculate the position and orientation information of the pallet truck based on the strength and arrival time difference of the received WiFi signal.

[0064] In this embodiment, the system first estimates the approximate distance between the pallet truck and each WiFi access point using RSSI information and a pre-established signal attenuation model. Then, the position of the pallet truck is preliminarily determined through a trilateration or multilateration algorithm. The signal differences between receivers at different positions in the receiver array are then analyzed, and the orientation angle is determined through vector analysis in combination with the known geometry of the pallet truck.

[0065] S440: Identify obstacles and feasible paths around the pallet truck based on the position and orientation information of the pallet truck and a pre-stored indoor environment map.

[0066] In this embodiment, the real-time position and orientation information of the pallet truck is matched with a pre-stored indoor environment map, thereby achieving accurate perception of the surrounding environment.

[0067] Specifically, the system first maps the location and orientation information of the pallet truck onto a pre-stored high-precision indoor map. Then, using a ray tracing algorithm, it projects virtual rays from the current position of the pallet truck in all directions, calculates the intersection of these rays with obstacles in the map, and thus determines the location and outline of surrounding obstacles.

[0068] S450: Send obstacle avoidance and navigation instructions to the pallet truck based on obstacles and feasible paths around the pallet truck.

[0069] Specifically, the system calculates the safe driving area based on the identified obstacle locations. Then, it selects the best route among the feasible paths and generates a series of waypoint coordinates based on the selected route as the navigation target for the pallet truck. For each section of the path, it calculates the appropriate driving speed and automatically reduces the speed when approaching obstacles or turning.

[0070] In one embodiment, referring to Figure 5 , the method further comprises the following steps: S510: Install an inertial measurement unit on the pallet truck, and acquire measurement data based on the inertial measurement unit.

[0071] In this embodiment, an inertial measurement unit is installed on the pallet truck to achieve real-time monitoring of the motion state of the pallet truck. An IMU usually includes an accelerometer, a gyroscope, and a magnetometer, and can provide key data such as the acceleration, angular velocity, and direction of the pallet truck.

[0072] Specifically, a 9-axis IMU module that integrates a three-axis accelerometer, a three-axis gyroscope, and a three-axis magnetometer can be selected and firmly installed in the center of the pallet truck to obtain the most accurate measurement results.

[0073] S520: Calculate WiFi signal quality.

[0074] S530: When the WiFi signal quality is lower than a preset threshold, perform position estimation based on the measurement data.

[0075] In this embodiment, when it is detected that the WiFi signal quality drops below a preset threshold, the system automatically starts position calculation based on IMU data.

[0076] Specifically, the system first sets a WiFi signal quality threshold, for example, triggering a switch when the signal quality score is less than 60 points. When switching to IMU extrapolation, the system uses dead reckoning technology to estimate the position change of the pallet truck by integrating the acceleration and angular velocity data provided by the IMU.

[0077] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0078] In the second aspect, the present application provides a ULD positioning management system based on a pallet truck. The ULD positioning management system based on a pallet truck of the present application is described below in combination with the above-mentioned ULD positioning management method based on a pallet truck.

[0079] Reference Figure 6 , a ULD positioning management system based on a pallet truck, comprising: include: A plurality of pallet trucks, each of which is equipped with a positioning device, wherein the positioning device includes a laser sensor, a GPS module and a WiFi module; Multiple WiFi access points, distributed in the indoor environment; A central control server for receiving and processing data from the plurality of pallet trucks; Wherein, the central control server is configured to execute the above-mentioned ULD positioning management method based on the pallet truck.

[0080] In one embodiment, a plurality of WiFi signal receivers are installed on the pallet truck to form a receiver array; The central control server is also configured to: Utilizing the receiver array to receive WiFi signals from different directions; Calculating the location and orientation information of the pallet truck based on the strength and arrival time difference of the received WiFi signal; According to the position and orientation information of the pallet truck and in combination with a pre-stored indoor environment map, obstacles and feasible paths around the pallet truck are identified.

[0081] In one embodiment, the pallet truck is also equipped with an inertial measurement unit; The central control server is also configured to: acquiring measurement data based on the inertial measurement unit; Calculate WiFi signal quality; When the WiFi signal quality is lower than a preset threshold, position estimation is performed based on the measurement data.

[0082] In one embodiment, the present application provides an electronic device, which may be a server, and its internal structure diagram may be as follows: Figure 7 As shown. The electronic device includes a processor, a memory and a network interface connected through a system bus. Among them, the processor of the electronic device is used to provide computing and control capabilities. The memory of the electronic device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the electronic device is used to store data. The network interface of the electronic device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a ULD positioning management method based on a pallet truck is implemented.

[0083] Those skilled in the art will understand that Figure 7 The structure shown in the figure is merely a block diagram of a partial structure related to the scheme of the present application, and does not constitute a limitation on the electronic device to which the scheme of the present application is applied. The specific electronic device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0084] In one embodiment, an electronic device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

[0085] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the above-mentioned computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0086] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A ULD positioning management method based on a pallet truck, characterized in that: The steps include: Installing a positioning device on the pallet truck, wherein the positioning device includes a laser sensor, a GPS module and a WiFi module; The laser sensor detects in real time whether there is ULD covering the pallet truck, and obtains the loading status information of the pallet truck; Determining the current environment of the pallet truck; When the pallet truck is currently located in an outdoor environment, positioning data is acquired through a GPS module, and location information of the pallet truck is obtained according to the positioning data; When the pallet truck is currently located in an indoor environment, the pallet truck is connected to multiple WiFi access points in the indoor environment through a WiFi module, and the location information of the pallet truck is calculated using a preset positioning algorithm based on the information of the multiple WiFi access points; The loading status information and position information of the pallet truck are displayed through the user interface.

2. The ULD positioning management method based on a pallet truck according to claim 1 is characterized in that: Determining the current environment of the pallet truck specifically includes the following steps: Detecting GPS signal strength of the pallet truck's surroundings; It is determined whether the pallet truck is located in an indoor or outdoor environment based on the GPS signal strength.

3. The ULD positioning management method based on a pallet truck according to claim 1 is characterized in that: The position information of the pallet truck is calculated using a preset positioning algorithm, which specifically includes the following steps: measuring the signal strength between the pallet truck and a plurality of WiFi access points; Allocate a weight corresponding to each WiFi access point according to the signal strength; The weighted centroid position is calculated according to the weights corresponding to the various WiFi access points to determine the position information of the pallet truck.

4. The ULD positioning management method based on a pallet truck according to claim 3 is characterized in that: The method further comprises the steps of: When it is detected that the ULD covers the pallet truck, the ULD is automatically bound to the location information of the pallet truck; When the pallet truck enters a preset area, the ULD is automatically unbound from the location information of the pallet truck.

5. The ULD positioning management method based on a pallet truck according to claim 4 is characterized in that: The method further comprises the steps of: installing a vibration sensor on the pallet truck; Detecting the motion state of the pallet truck by means of the vibration sensor; The sending frequency of the position information is dynamically adjusted according to the motion state.

6. The ULD positioning management method based on a pallet truck according to claim 1, characterized in that: The method further comprises the steps of: Install multiple WiFi signal receivers on the tray to form a receiver array; Utilizing the receiver array to receive WiFi signals from different directions; Calculating the location and orientation information of the pallet truck based on the strength and arrival time difference of the received WiFi signal; According to the position and orientation information of the pallet truck, combined with a pre-stored indoor environment map, obstacles and feasible paths around the pallet truck are identified; Obstacle avoidance and navigation instructions are sent to the pallet truck based on obstacles and feasible paths around the pallet truck.

7. The ULD positioning management method based on a pallet truck according to claim 6 is characterized in that: The method further comprises the steps of: installing an inertial measurement unit on the pallet truck, and acquiring measurement data based on the inertial measurement unit; Calculate WiFi signal quality; When the WiFi signal quality is lower than a preset threshold, position estimation is performed based on the measurement data.

8. A ULD positioning management system based on a pallet truck, characterized in that: include: A plurality of pallet trucks, each of which is equipped with a positioning device, wherein the positioning device includes a laser sensor, a GPS module and a WiFi module; Multiple WiFi access points, distributed in the indoor environment; A central control server for receiving and processing data from the plurality of pallet trucks; Wherein, the central control server is configured to execute the ULD positioning management method based on a pallet truck as described in any one of claims 1-5.

9. The ULD positioning management system based on a pallet truck according to claim 8, characterized in that: The pallet truck is equipped with a plurality of WiFi signal receivers to form a receiver array; The central control server is also configured to: Utilizing the receiver array to receive WiFi signals from different directions; Calculating the location and orientation information of the pallet truck based on the strength and arrival time difference of the received WiFi signal; According to the position and orientation information of the pallet truck and in combination with a pre-stored indoor environment map, obstacles and feasible paths around the pallet truck are identified.

10. The ULD positioning management system based on a pallet truck according to claim 9, characterized in that: The pallet truck is also equipped with an inertial measurement unit; The central control server is also configured to: acquiring measurement data based on the inertial measurement unit; Calculate WiFi signal quality; When the WiFi signal quality is lower than a preset threshold, position estimation is performed based on the measurement data.

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