Automatic truck tail loading method and system based on phased laser measurement

Abstract

The application relates to a truck tail automatic loading method and system based on staged laser measurement, wherein the method comprises the following steps: measuring a truck body to obtain a body measurement result, and binding and caching the body measurement result with a current parking space; making an automated guided vehicle carry a pallet to drive to an external path entry starting point; in response to a first section of the external path application, measuring the pallet in the carriage to obtain measured coordinates of a pallet center; performing coordinate compensation on the measured coordinates to obtain final coordinates of a pallet loading center, and updating an initial lateral coordinate of a carriage tail reference point to a lateral coordinate of the pallet loading center; generating a plurality of sections of the external path according to the external path entry starting point, the final coordinates of the carriage tail reference point and the final coordinates of the pallet loading center; and sequentially issuing the plurality of sections of the external path to the automated guided vehicle to complete the loading operation. The application avoids scratching and inaccurate loading caused by position deviation, and improves operation efficiency and safety.

Description

Technical Field

[0001] This application relates to the field of logistics automation technology, and in particular to an automatic loading method and system for the rear of a truck based on staged laser measurement. Background Technology

[0002] In warehousing and logistics platform loading operations, automated guided vehicles (AGVs) need to transport pallets to the cargo compartment of trucks parked at the platform and then reverse into the compartment to complete the unloading operation. Since there are unavoidable deviations in the truck's stopping position and posture each time, the gaps between the sides of the cargo compartment and the materials are usually very narrow. Therefore, accurately obtaining the reference point at the rear of the cargo compartment and the actual coordinates of the pallet unloading center becomes a crucial prerequisite for generating the AGV's entry path.

[0003] In existing technologies, after manual confirmation of truck parking compliance, the measuring equipment typically completes the measurement of the truck body and pallet in one go, immediately fixing the coordinates of the pallet placement point. Based on this, the entire loading path is then generated and issued, awaiting execution by the automated guided vehicle (AGV). However, from the completion of the measurement to the AGV actually arriving at the platform with the pallet and beginning loading, there are multiple stages, including task issuance, pallet retrieval, and transport to the platform, resulting in significant time delays. During this period, the relative positions of the truck body and pallet may change due to external factors such as slight vehicle movement or pallet stacking changes, causing the fixed placement point to fail to accurately reflect the actual working conditions at the moment the AGV enters the truck body. Especially when the gaps on both sides of the truck body are extremely small, if the path does not match the actual position when the AGV reverses into the truck body, lateral deviation is very likely to occur, causing problems such as scraping the truck body walls, material damage, and inaccurate placement, seriously affecting operational efficiency and safety. Therefore, ensuring that the timing of obtaining the pallet placement point is synchronized with the timing of the AGV's actual entry into the truck body, to provide a real-time and accurate basis for path generation, has become a key technical challenge for those skilled in the art. Summary of the Invention

[0004] The purpose of this application is to propose an automatic loading method and system for the rear of a truck based on phased laser measurement, which ensures that the timing of obtaining the pallet placement point is synchronized with the actual entry time of the automated guided vehicle, provides real-time and accurate path generation basis, avoids scratches and inaccurate placement caused by position deviation, and improves operational efficiency and safety.

[0005] To address the aforementioned technical problems, this application provides an automated loading method for the rear of a truck based on staged laser measurement, comprising: After confirming that the truck is parked properly, the truck body is measured using a laser measuring device to obtain the vehicle body measurement results. The vehicle body measurement results are then bound and cached with the current parking space. The vehicle body measurement results include the initial coordinates of the reference point at the rear of the truck bed, the truck parking tilt angle, and the measurement session identifier. A transport task is issued to the automated guided vehicle (AGV) so that the AGV carries the pallet and travels to the pre-marked external path to enter the starting point. Upon receiving the first external path request sent by the automated guided vehicle after arriving at the external path entry point, and in response to the first external path request, the laser measurement device is invoked to measure the pallet inside the vehicle according to the measurement session identifier, and the measured coordinates of the pallet center are obtained. Coordinate compensation is performed on the measured coordinates to obtain the final coordinates of the pallet placement center. In the world coordinate system, the initial lateral coordinates of the rear reference point of the truck bed are updated to the lateral coordinates of the pallet placement center so that the rear reference point of the truck bed and the pallet placement center satisfy the coaxial constraint, and the final coordinates of the rear reference point of the truck bed are obtained. Based on the final coordinates of the external path entry point, the rear reference point of the vehicle, and the final coordinates of the pallet unloading center, multiple external paths are generated, wherein the multiple external paths sequentially include an entry section, an unloading section, a departure section, and a return section. The multiple external paths are issued to the automated guided vehicle (AGV) segment by segment, so that the AGV executes the multiple external paths segment by segment to complete the loading operation.

[0006] To address the aforementioned technical problems, this application provides an automated truck tail loading system based on staged laser measurement, comprising: The vehicle body measurement module is used to measure the vehicle body of the truck using a laser measurement device after confirming that the truck is parked properly, obtain the vehicle body measurement results, and bind and cache the vehicle body measurement results with the current parking space. The vehicle body measurement results include the initial coordinates of the reference point at the rear of the truck bed, the truck parking tilt angle, and the measurement session identifier. The task assignment module is used to assign a task to the automated guided vehicle (AGV) so that the AGV carries the pallet and travels to the pre-marked external path to enter the starting point. The pallet center coordinate measurement module is used to receive the first external path application sent by the automated guided vehicle after it arrives at the external path entry point, and in response to the first external path application, call the laser measurement device to measure the pallet in the carriage according to the measurement session identifier to obtain the measured coordinates of the pallet center. The module for determining the coordinates of the rear reference point of the truck bed is used to perform coordinate compensation on the measured coordinates to obtain the final coordinates of the pallet placement center. In the world coordinate system, the initial lateral coordinates of the rear reference point of the truck bed are updated to the lateral coordinates of the pallet placement center so that the rear reference point of the truck bed and the pallet placement center satisfy the coaxial constraint, thereby obtaining the final coordinates of the rear reference point of the truck bed. The external path generation module is used to generate multiple external paths based on the final coordinates of the external path entry point, the final coordinates of the rear reference point of the carriage, and the final coordinates of the pallet placement center. The multiple external paths include, in sequence, an entry section, a placement section, a departure section, and a return section. The external path execution module is used to send the multiple external path segments to the automated guided vehicle segment by segment, so that the automated guided vehicle executes the multiple external path segments segment by segment to complete the loading operation.

[0007] This invention provides a method and system for automated loading at the rear of a truck based on phased laser measurement. By using phased laser measurement technology, the center coordinates of the pallet are acquired in real time after the automated guided vehicle (AGV) arrives at the starting point of the external path. This ensures that the path generation is synchronized with the actual loading time of the AGV, providing a real-time and accurate basis for path generation. It avoids problems such as scraping and inaccurate loading caused by positional deviations, thereby improving operational efficiency and safety. Attached Figure Description

[0008] To more clearly illustrate the solutions in this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0009] Figure 1 This is a flowchart illustrating the implementation of the automatic loading method for the rear of a truck based on staged laser measurement provided in this application embodiment; Figure 2 This is a flowchart illustrating the implementation of the first sub-process in the automatic loading method for the rear of a truck based on staged laser measurement provided in this application embodiment; Figure 3 This is a flowchart illustrating the implementation of an automated loading method for the rear of a truck based on staged laser measurement, provided in another embodiment of this application. Figure 4 This is a flowchart illustrating the implementation of the second sub-process in the automatic loading method for the rear of a truck based on staged laser measurement provided in this application embodiment. Figure 5 This is a flowchart illustrating the implementation of the third sub-process in the automatic loading method for the rear of a truck based on staged laser measurement provided in this application embodiment. Figure 6 This is a flowchart illustrating the implementation of the fourth sub-process in the automatic loading method for the rear of a truck based on staged laser measurement provided in this application embodiment. Figure 7This is a flowchart illustrating the implementation of the fifth sub-process in the automated loading method for the rear of a truck based on staged laser measurement provided in this application embodiment. Figure 8 This is a schematic diagram of an automated truck rear loading system based on staged laser measurement provided in an embodiment of this application. Detailed Implementation

[0010] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application, are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0011] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0012] In existing platform loading operations, after confirming that the truck is parked in compliance with regulations, the measuring equipment completes the measurement of the truck body and pallet in one go and fixes the loading point, and then generates the entry path. Because there is a time interval between the completion of the measurement and the actual arrival of the automated guided vehicle (AGV) at the platform, the relative state of the truck body and pallet may change during this period. The loading point fixed in one go cannot reflect the actual working conditions at the moment of entry, which causes lateral deviation when the AGV reverses into the truck body, and is prone to problems such as scraping the side wall of the truck body or inaccurate loading position.

[0013] In response, this application proposes an automated loading method for the rear of a truck based on phased laser measurement, comprising: after confirming that the truck is parked correctly, measuring the truck body using a laser measurement device to obtain the vehicle body measurement results, and binding and caching the vehicle body measurement results with the current parking space, wherein the vehicle body measurement results include the initial coordinates of the reference point at the rear of the truck bed, the truck parking tilt angle, and the measurement session identifier; issuing a handling task to an automated guided vehicle (AGV) to enable the AAV to carry the pallet to a pre-marked external path entry point; receiving the first external path request sent by the AAV after arriving at the external path entry point, and responding to the first external path request by calling the laser measurement device to load the pallet inside the truck bed according to the measurement session identifier. Measurements are taken to obtain the measured coordinates of the pallet center. Coordinate compensation is performed on the measured coordinates to obtain the final coordinates of the pallet placement center. In the world coordinate system, the initial lateral coordinates of the rear reference point of the truck bed are updated to the lateral coordinates of the pallet placement center to ensure that the rear reference point of the truck bed and the pallet placement center satisfy the coaxial constraint, thus obtaining the final coordinates of the rear reference point of the truck bed. Based on the starting point of the external path, the final coordinates of the rear reference point of the truck bed, and the final coordinates of the pallet placement center, multiple external paths are generated. These external paths sequentially include an entry section, a placement section, a departure section, and a return section. The multiple external paths are then distributed to the automated guided vehicle (AGV) segment by segment so that the AGV executes each external path segment sequentially to complete the loading operation.

[0014] For ease of understanding, the following explains some key terms in this embodiment: Laser measuring equipment: A ranging sensing device that is configured at the loading platform to emit lasers into the car body and receive reflected signals in order to obtain information on the outline of the car body and the position of materials inside the car.

[0015] Measurement Session Identifier: A data code used to mark the laser measurement process within a single loading operation cycle, in order to associate data from different measurement stages at the same berth.

[0016] Rear reference point of the cargo compartment: The geometric location point at the opening at the rear of the cargo compartment, used as a path reference benchmark for the transition process of the automated guided vehicle entering and exiting the cargo compartment.

[0017] Coaxial constraint: refers to the geometric alignment relationship between the reference point at the rear of the carriage and the pallet placement center in the world coordinate system, so that the trajectory of the automated guided vehicle in the carriage is parallel to the longitudinal axis of the carriage.

[0018] External path: The running trajectory calculated and issued by the control system to the automated guided vehicle (AGV) for execution, used to guide the AGV from the platform area to the carriage to complete the loading.

[0019] This embodiment divides laser measurement into two stages: initial docking measurement and real-time measurement upon entering the compartment. The pallet center coordinates are acquired instantly when the automated guided vehicle (AGV) arrives at the entry point, eliminating state deviations caused by time delays during the handling process. By combining coaxial constraints with updates to the reference point coordinates at the rear of the compartment, the loading trajectory is precisely aligned with the compartment's axis, reducing the risk of lateral deviation of the AGV in the confined space of the compartment, preventing scraping, and ensuring loading alignment accuracy.

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0021] It should be noted that the automatic truck rear loading method based on staged laser measurement provided in this application is generally executed by a server, and correspondingly, the automatic truck rear loading system based on staged laser measurement is generally configured in a server.

[0022] Please see Figure 1 , Figure 1 This paper illustrates a specific implementation of an automated loading method for the rear of a truck based on staged laser measurement.

[0023] It should be noted that if substantially the same result is obtained, the method of this invention is not based on... Figure 1 Limited to the order of the processes shown, this method includes the following steps: S1: After confirming that the truck is parked properly, the truck body is measured using a laser measuring device to obtain the vehicle body measurement results. The vehicle body measurement results are then bound and cached with the current parking space. The vehicle body measurement results include the initial coordinates of the reference point at the rear of the truck body, the truck parking tilt angle, and the measurement session identifier.

[0024] Specifically, at the beginning of the loading operation, the truck stops at the loading berth. After confirming that the truck is parked correctly, the control system sends a measurement command to the laser measuring equipment installed at the berth. The laser measuring equipment performs a laser scan on the rear area of ​​the truck, extracts the edge contour of the rear of the truck bed, and calculates the initial coordinates of the reference point at the rear of the truck bed. At the same time, it fits the rear boundary to calculate the truck's parking tilt angle. The system generates a corresponding measurement session identifier and stores the initial coordinates of the reference point at the rear of the truck bed, the truck's parking tilt angle, and the measurement session identifier in the buffer of the current berth.

[0025] Please see Figure 2 , Figure 2 A specific implementation of step S1 is shown below: S11: After confirming the truck's parking is qualified, a start detection command is sent to the laser measuring device to receive a measurement response message returned by the laser measuring device after laser scanning the rear of the truck. The measurement response message includes a success code, coordinates of the center point of the truck's rear, the truck's parking angle, vehicle feature points, and the measurement session identifier. S12: The success code in the measurement response message is verified. If the success code indicates success and the measurement response message contains the vehicle feature points, the start detection is deemed successful. The initial coordinates of the truck's rear reference point, the truck's parking angle, and the measurement session identifier are cached to obtain the vehicle body measurement result. The vehicle body measurement result is then bound to the current parking space and cached. S13: If the success code indicates failure or the measurement response message lacks the vehicle feature points, the start detection is deemed unsuccessful, and the current measurement is terminated.

[0026] Specifically, the start detection command is used to actively trigger the working sequence of the laser measurement equipment, ensuring that the measurement action is initiated under control after the truck has been confirmed to be parked correctly. In practice, the system can send a command data packet containing the berth number and trigger parameters to the laser measurement equipment via industrial Ethernet, fieldbus, or wireless communication interface. After receiving the start detection command, the laser measurement equipment uses equipment such as a line laser scanner, area array lidar, or 3D laser measuring instrument to perform contour scanning and point cloud acquisition on the rear of the truck parked in the corresponding berth, completes local 3D modeling and feature extraction, and constructs a measurement response message for feedback.

[0027] The success code in the measurement response message is used to characterize the underlying hardware self-test status and point cloud algorithm processing status of the laser measurement equipment. It can be implemented through preset status enumeration values, error coding fields, or Boolean status flags. Vehicle feature points are key geometric features extracted from point cloud data by the algorithm to characterize the outer contour structure of the truck body. These may include, for example, the edge points of the left / right side panels of the truck body, the intersection points of the truck body floor, the feature points of the door lock bars, or the edge points of the vehicle body structure corresponding to the platform anti-collision buffer blocks. These feature points constitute the data basis for determining whether the measured object is a valid truck body geometry.

[0028] During data verification, the system executes dual verification logic. On one hand, it verifies whether the success code in the status field of the measurement response message matches the preset success identifier by parsing it. On the other hand, it confirms whether the message payload contains the extracted vehicle feature point data and its geometric confidence index through field parsing or data integrity verification. For data that passes verification, the system encapsulates the initial coordinates of the rear reference point of the truck bed, the truck parking tilt angle, and the measurement session identifier into the vehicle body measurement results, and binds them to the cache by establishing a key-value mapping relationship with the current parking space number as the primary key in the in-memory database or dedicated cache area. For cases where verification fails, the system directly blocks the subsequent data processing flow, terminates the current measurement operation, and can issue an alarm or record an anomaly log through the platform control terminal to prompt manual intervention or re-initiate parking and measurement.

[0029] This application's embodiments introduce a dual verification mechanism of active triggering and response messages during the initial vehicle body measurement phase. On one hand, the validity of the measurement equipment's own working status and algorithm parsing status is confirmed through success code verification. On the other hand, the completeness of vehicle feature points is strictly checked, verifying the authenticity of the measurement target and the reliability of its geometric structure from the data source. This effectively prevents erroneous measurement data caused by environmental photoelectric interference, obstruction by foreign objects, or non-standard parking of trucks from entering the control system. Simultaneously, the verified measurement data is strongly bound and cached with the current berth and measurement session identifier, ensuring the traceability and isolation of measurement data in a multi-berth parallel operation environment. This completely avoids subsequent path planning calls for incorrect or invalid data, thereby significantly improving the baseline reliability of the automated guided vehicle's entry path generation and the safety of automated operations.

[0030] Further, caching the initial coordinates of the rear reference point of the carriage includes: setting the initial lateral coordinates of the rear reference point of the carriage to the lateral coordinates of the midpoint coordinates of the rear of the carriage, and setting the initial longitudinal coordinates of the rear reference point of the carriage to a preset longitudinal depth reference value, wherein the preset longitudinal depth reference value is the longitudinal depth reference value of the world coordinate system calibrated for platform docking; when there is a conflict between the longitudinal coordinates of the midpoint coordinates of the rear of the carriage and the preset longitudinal depth reference value, the preset longitudinal depth reference value shall prevail.

[0031] Specifically, the lateral coordinates of the center point coordinates at the rear of the truck bed reflect the actual lateral offset of the truck within the parking space. Setting the initial lateral coordinates of the reference point at the rear of the truck bed directly as the lateral coordinates of the center point coordinates at the rear of the truck bed helps capture the actual lateral center features of the truck, thus providing a true lateral alignment basis for the vehicle entering the truck bed. In practice, this can be achieved by directly extracting the lateral coordinate components of the fitted center point from the point cloud returned by the laser measurement equipment, or by performing mean filtering on the lateral components obtained from multiple consecutive laser scans.

[0032] The preset longitudinal depth reference value is a one-dimensional reference parameter fixed in advance by geometrically calibrating the physical docking boundary of the platform in the world coordinate system. It represents the absolute longitudinal position that the rear of the freight car should be in under standard docking conditions. In specific implementation, this preset longitudinal depth reference value can be precisely measured and calibrated in the world coordinate system based on the physical installation position of the platform anti-collision limit block and stored in the system configuration database, or it can be fixed offline by statistically averaging multiple batches of docking history under qualified docking conditions.

[0033] During actual measurement, interference factors such as reflections from the rear structural components of the truck bed, local deformation, or obstructions from platform overhangs may cause the longitudinal measurement components resolved by laser scanning to drift, resulting in coordinate deviations or conflicts with the preset longitudinal depth reference value. When a conflict is determined, the system employs an arbitration mechanism based on the preset longitudinal depth reference value. Specifically, this conflict handling can be achieved by directly ignoring the measured longitudinal value in the measurement response message within the calculation logic, assigning the preset longitudinal depth reference value to the longitudinal coordinates; alternatively, it can be achieved by setting a deviation threshold, automatically triggering a reference value overriding strategy when the difference between the measured longitudinal coordinates and the preset longitudinal depth reference value exceeds a preset tolerance threshold.

[0034] This application embodiment assigns differentiated determination logic to the lateral and longitudinal coordinates of the reference point at the rear of the truck bed, achieving an organic combination of lateral dynamic adaptation and longitudinal static anchoring. Since the lateral coordinates strictly adopt the measured lateral component of the midpoint of the rear of the truck bed, they accurately reflect the true lateral attitude of the truck within the parking space, providing precise lateral input for subsequent coaxial constraints with the pallet center. Simultaneously, because the longitudinal coordinates are forcibly associated with the preset longitudinal depth reference value of the platform's physical docking calibration and use this reference in case of conflict, the rigid constraints of the platform hardware cleverly eliminate laser drift and environmental interference errors in longitudinal measurement, ensuring high stability and determinism of the truck bed's rear reference point in longitudinal space. This constructs a highly reliable geometric reference point for the subsequent generation of multiple external paths, effectively avoiding the problem of lateral or longitudinal positioning inaccuracies at the connection between the automated guided vehicle and the truck bed.

[0035] Please see Figure 3 , Figure 3 A specific implementation method prior to step S1 is shown below in detail: S101: Calculate the effective longitudinal length of the truck bed and obtain the lateral clearance of the truck bed, wherein the effective longitudinal length of the truck bed is equal to the truck length minus the longitudinal fixed compensation value and the distance from the truck head to the center of the pallet. S102: Calculate the tilt angle threshold based on the effective longitudinal length of the truck bed and the lateral clearance of the truck bed. S103: If the absolute value of the truck's parking tilt angle is less than or equal to the tilt angle threshold, the step of issuing the handling task to the automated guided vehicle is allowed to continue. S104: If the absolute value of the truck's parking tilt angle is greater than the tilt angle threshold, the step of issuing the handling task to the automated guided vehicle is prohibited, and a re-parking prompt message is generated.

[0036] Specifically, the effective longitudinal available length of the cargo compartment reflects the actual longitudinal space that the automated guided vehicle (AGV) can manage when operating within the compartment. Lateral clearance of the cargo compartment can be obtained either by scanning the inner wall of the cargo compartment with laser measuring equipment and calculating it in real time using the combined physical width of the AGV and its pallets, or by directly retrieving the nominal clearance parameters from the database based on the cargo model and pallet specifications pre-registered in the warehouse management system.

[0037] The tilt angle threshold is used to characterize the maximum permissible tilt angle that ensures the automated guided vehicle (AGV) safely enters the vehicle without scraping, given the current vehicle space margin. When calculating the tilt angle threshold based on the vehicle's effective longitudinal length and lateral clearance, the critical tilt angle value can be calculated in real time by establishing an inverse trigonometric function geometric constraint model based on the ratio of lateral clearance to effective longitudinal length. Alternatively, a tilt angle safety threshold lookup table corresponding to different combinations of effective longitudinal length and lateral clearance can be pre-constructed, and the matching tilt angle threshold can be quickly obtained through discrete lookup or linear interpolation.

[0038] In the judgment logic, when the absolute value of the truck's parking angle exceeds the calculated angle threshold, the system will conduct a safety interception at the source of the task. Methods for generating re-parking prompts include, but are not limited to, displaying re-parking prompts to truck drivers through on-site audible and visual alarm devices or parking space indicator screens at the platform, or pushing specific shunting guidance information to the corresponding driver's device through the fleet management terminal or mobile application to prompt the driver to readjust their parking posture.

[0039] This application's embodiments introduce a dynamic tilt angle safety verification mechanism based on the physical space geometric parameters of the vehicle compartment before the automated guided vehicle (AGV) handling task is issued. Since the tilt angle threshold integrates actual physical boundaries such as vehicle length, longitudinal fixed compensation, distance from the front of the vehicle to the center of the pallet, and lateral clearance, the verification standard can adapt to different loading depths and vehicle space. This allows for accurate prediction of the geometric feasibility of loading operations before the AGV departs, effectively intercepting collision risks at the front end of task execution. This avoids damage to the vehicle compartment walls, materials, or equipment caused by the AGV blindly executing tasks, significantly improving the safety and overall efficiency of automated loading operations at the platform rear.

[0040] S2: Issue a transport task to the automated guided vehicle (AGV) so that the AGV carrying the pallet travels to the pre-marked external path and enters the starting point.

[0041] Specifically, the control system generates material handling instructions and sends them to the automated guided vehicle (AGV). After receiving the instructions, the AGV picks up the target pallet and travels along the platform's preset path to the pre-marked external path to enter the starting point and wait.

[0042] S3: Receive the first external path request sent by the automated guided vehicle after it arrives at the external path entry point, and in response to the first external path request, call the laser measurement device to measure the pallet inside the vehicle according to the measurement session identifier to obtain the measured coordinates of the pallet center.

[0043] Specifically, when the automated guided vehicle (AGV) arrives at the starting point of the external path, it sends the first external path request to the control system via the wireless network. In response to this first external path request, the control system uses the previously cached measurement session identifier of the current berth index and calls the laser measurement equipment to scan the existing pallets in the vehicle compartment to obtain the measured coordinates of the center of the pallet in the current vehicle compartment.

[0044] Please see Figure 4 , Figure 4 A specific implementation of step S3 is shown below: S31: Receive the initial external path request sent by the automated guided vehicle after it arrives at the external path entry point. S32: In response to the initial external path request, obtain the measurement session identifier based on the current berth, and send a pallet center measurement request carrying the measurement session identifier to the laser measurement device. S33: Receive the pallet center measurement result returned by the laser measurement device after laser scanning the pallet inside the vehicle compartment, wherein the pallet center measurement result includes the returned measurement session identifier. S34: Confirm that they belong to the same measurement session by comparing the returned measurement session identifier with the measurement session identifier carried in the pallet center measurement request. S35: When the pallet center measurement result verification passes, read the measured coordinates of the pallet center.

[0045] Specifically, the first external path request is a path request signal sent by the automated guided vehicle to the dispatch system when it is in a spatially ready position. It can be implemented by the automated guided vehicle actively sending a communication data packet to the dispatch server through a wireless local area network, industrial 5G network or ultra-wideband communication link, or by the automated guided vehicle triggering an onboard event notification message after recognizing the radio frequency identification tag or QR code landmark placed on the platform.

[0046] The measurement session identifier is a unique feature code used to identify the entire lifecycle of a single measurement interaction. Its specific generation and maintenance methods can be a unique hash character sequence generated based on the current berth number, timestamp, and random number, or a globally unique code string constructed by combining an incremental sequence number maintained by the system with a universally unique identifier.

[0047] The pallet center measurement request is a trigger command issued by the scheduling system or control node to the laser measurement equipment. Its communication implementation can be encapsulated and transmitted using the socket network communication format based on the TCP / IP protocol suite, or it can use industrial fieldbus protocol, RESTful interface or message queue mechanism for command issuance and parameter pass-through.

[0048] The pallet center measurement result is a structured message output by the laser measurement equipment after completing the laser point cloud scanning and algorithm feature fitting of the pallet in the compartment. In addition to the spatial position information calculated from the pallet features, it also includes the execution status code, data check bit, and measurement session identifier that is returned as is.

[0049] The comparison and verification process is a data consistency confirmation mechanism in the software logic layer. Specifically, it can be implemented by strictly matching the session identifier in the returned message with the session identifier in the request cache, determining the equality of the strings and values, and combining it with cyclic redundancy check codes or data packet integrity hash verification to confirm that the data source is legitimate and that no time sequence errors or communication packet fragmentation interference have occurred.

[0050] This application's embodiments achieve precise coordination and error prevention between the entire pallet measurement process and the automated guided vehicle's (AGV) operational status by introducing a closed-loop handshake and verification mechanism based on measurement session identifiers. On one hand, the measurement timing is determined by using the initial external path request triggered after the AGV arrives at the external path entry point, ensuring that the laser measurement action closely follows the actual moment the AGV enters the container and places the goods, effectively avoiding the problem of reduced data timeliness caused by premature measurement. On the other hand, by bidirectionally binding and comparing measurement session identifiers in request and result messages, the potential for data confusion and misalignment in multi-vehicle collaborative operations, multi-berth concurrent scheduling, or network retransmission environments is effectively eliminated. This ensures that the acquired pallet center coordinates strictly and uniquely correspond to the currently operating AGV and the target truck, providing highly reliable data support for subsequent accurate generation of the container entry path and eliminating the risk of path deviation and vehicle collisions caused by data disorder.

[0051] S4: Perform coordinate compensation on the measured coordinates to obtain the final coordinates of the pallet placement center. In the world coordinate system, update the initial lateral coordinates of the rear reference point of the truck bed to the lateral coordinates of the pallet placement center so that the rear reference point of the truck bed and the pallet placement center satisfy the coaxial constraint, and obtain the final coordinates of the rear reference point of the truck bed.

[0052] Specifically, the control system performs fixed-distance compensation on the acquired measured coordinates of the pallet center to obtain the final coordinates of the pallet placement center. At the same time, in the world coordinate system, the initial lateral coordinates of the rear reference point of the truck bed are modified to the lateral coordinates of the pallet placement center, while the longitudinal coordinates of the rear reference point of the truck bed remain at the baseline setting, so that the rear reference point of the truck bed and the pallet placement center are on the same straight line in the lateral direction, thereby satisfying the coaxial constraint and determining the final coordinates of the rear reference point of the truck bed.

[0053] Please see Figure 5 , Figure 5 A specific implementation of step S4 is shown below: S41: Set the final lateral coordinate to the measured lateral coordinate, and subtract a preset longitudinal fixed compensation value from the measured longitudinal coordinate to obtain the final longitudinal coordinate setting. S42: In the world coordinate system, set the initial lateral coordinate of the rear reference point of the cargo compartment to the final lateral coordinate, and keep the final longitudinal coordinate of the rear reference point of the cargo compartment unchanged by a preset longitudinal depth reference value, so that the rear reference point of the cargo compartment and the pallet loading center satisfy coaxial constraints, thus obtaining the final coordinates of the rear reference point of the cargo compartment. Through the coaxial constraints, the loading section and the departure section are made to be straight paths along the longitudinal direction in the world coordinate system.

[0054] Specifically, the final coordinates of the pallet placement center include the final lateral and longitudinal coordinates of the pallet placement center; the measured coordinates include the measured lateral and longitudinal coordinates. The measured lateral and longitudinal coordinates represent the spatial geometric center resolved by the laser measuring equipment based on the actual position of the pallet in the truck compartment at the measurement time. After obtaining the measured coordinates, the final longitudinal coordinate setting is generated by subtracting a preset longitudinal fixed compensation value from the measured longitudinal coordinates. This longitudinal fixed compensation value is specifically used to eliminate longitudinal positioning offsets caused by physical structures such as the pallet's own size specifications, the Automated Guided Vehicle (AGV) fork arm load-bearing depth margin, and stacking safety distance. In specific implementations, the longitudinal fixed compensation value can be matched and read from a preset configuration parameter table according to the pallet model of the goods loaded on the truck, or it can be specified in real time according to the AGV's vehicle model and structural parameters.

[0055] Meanwhile, coaxial constraint refers to forcibly ensuring that the lateral coordinates of the truck's rear reference point and the pallet placement center are completely consistent in the world coordinate system, thereby constructing a geometric baseline parallel to the truck's longitudinal axis in space. In specific implementation, the system can directly assign the lateral coordinates of the pallet placement center to the lateral coordinate field of the truck's rear reference point when updating the coordinate data structure, or introduce a collinear geometric constraint operator in the path generation algorithm to ensure that the truck's entrance control point and the internal target material drop point are absolutely aligned in the lateral dimension.

[0056] In addition, a preset longitudinal depth reference value is used as a physical constant of the world coordinate system for calibrating the platform docking boundary. This value remains constant throughout the entire coordinate update process to ensure that the longitudinal reference point at the rear of the car is always strictly aligned with the physical edge of the platform, thus avoiding longitudinal shifts in the initial docking point of the car due to longitudinal measurement fluctuations.

[0057] This application embodiment dynamically reconstructs the axial alignment between the car entrance and the target loading point inside the car in the world coordinate system by implementing longitudinal compensation of the measured coordinates and establishing a coaxial constraint mechanism between the reference point at the rear of the car and the pallet loading center. This design not only eliminates the interference of measurement deviation on the accuracy of loading point, but also enables the automated guided vehicle to strictly travel along a single longitudinal straight path during the reversing into the loading section and the forward exiting section. This completely eliminates the risk of lateral swaying or curve adjustment of the vehicle in the narrow space of the car, significantly improving the stability and safety of the automated guided vehicle in the compact car environment for loading and unloading operations.

[0058] S5: Generate multiple external paths based on the final coordinates of the external path entry point, the rear reference point of the carriage, and the final coordinates of the pallet placement center. The multiple external paths sequentially include an entry section, a placement section, a departure section, and a return section.

[0059] Specifically, the control system calculates the path based on the final coordinates of the starting point of the external path, the reference point at the rear of the carriage, and the final coordinates of the pallet unloading center, and sequentially generates multiple external paths connecting each coordinate point, including the entry section, unloading section, departure section, and return section.

[0060] Please see Figure 6 , Figure 6 A specific implementation of step S5 is shown below: S51: Based on the final coordinates of the external path entry point, the rear reference point of the carriage, and the final coordinates of the pallet placement center, generate the following segments: entry segment from the external path entry point to the rear reference point of the carriage, placement segment from the rear reference point of the carriage to the pallet placement center, departure segment from the pallet placement center to the rear reference point of the carriage, and return segment from the rear reference point of the carriage to the external path entry point.

[0061] Wherein, the end point of the entry section, the start point of the unloading section, the end point of the departure section, and the start point of the return section are all the final coordinates of the rear reference point of the carriage; the end point of the unloading section and the start point of the departure section are both the final coordinates of the pallet unloading center; the end point of the return section is the entry point of the external path; The heading angles of the multiple external paths are all pre-calibrated angles for each segment; the driving direction of the entry segment and the unloading segment is reverse, while the driving direction of the departure segment and the return segment is forward.

[0062] Specifically, the multiple external paths are smooth spatial trajectories generated based on the aforementioned key coordinate points using a preset path interpolation algorithm (such as Bézier curve interpolation algorithm, cubic B-spline curve interpolation algorithm, or polynomial curve fitting algorithm), thereby ensuring that the movement trajectory of the automated guided vehicle between the platform area and the interior of the carriage has spatial continuity and curvature smoothness.

[0063] The pre-calibration angle of a road segment refers to the target heading reference value pre-configured for each path segment during the system initialization or site calibration stage, in combination with the platform berth direction and the car axis orientation. Alternatively, it can be the attitude angle value calculated and fixed in the path point attributes based on the tangent direction at the beginning and end of each path segment during path planning. It is used to constrain the vehicle body attitude orientation when the automated guided vehicle travels along the corresponding path, and to prevent the vehicle body from swaying.

[0064] The setting of the driving direction clarifies the motion mode of the automated guided vehicle (AGV) in different operation stages. The entry and unloading sections are set to reverse direction to meet the process requirement of sending palletized materials deep into the car body first. The departure and return sections are set to forward direction so that the AGV can drive directly out of the narrow car body and return to the initial position on the platform after unloading the pallet.

[0065] This application embodiment strictly decouples the entire automated loading operation process and divides it into four standardized logical segments: loading into the compartment, unloading, departure, and return. The reference point at the rear of the compartment and the pallet unloading center are used as closed-loop anchoring nodes to ensure seamless connection between the beginning and end of each path segment, eliminating trajectory gaps caused by discrete programming. At the same time, coaxial constraints and pre-calibrated angles of road segments are used to strongly constrain the vehicle's attitude, making the reversing trajectory during loading into and unloading highly consistent with the centerline of the compartment, and the forward departure and return processes smooth and stable. This not only effectively prevents the risk of scraping and collision of the automated guided vehicle in the narrow compartment, but also significantly improves the smoothness of connection and execution reliability of multi-task continuous operation.

[0066] Furthermore, the inbound section and the return section are curved paths, generated using a first control point strategy; the outbound section and the departure section are straight paths, generated using a second control point strategy; the first control point strategy has more control points than the second control point strategy.

[0067] Specifically, the curve path refers to the curved travel trajectory of the automated guided vehicle (AGV) as it turns and changes direction between the area outside the platform and the rear of the freight car. The first control point strategy used for the entry and return sections refers to setting a relatively dense number of geometric control points or shape points in the path generation algorithm to constrain the curve shape. This can be implemented using a high-order Bézier curve control point generation strategy, a cubic B-spline curve interpolation generation strategy, or a multi-control point discretization generation strategy based on fitting multiple spiral curves and circular arcs. By configuring a large number of control points, the rate of curvature change and heading angle transition of the curve path can be finely constrained, thereby meeting the nonholonomic constraints and kinematic smoothness requirements of the AGV during large-angle turns.

[0068] Correspondingly, a straight path refers to the linear trajectory of the automated guided vehicle (AGV) as it moves inside the cargo compartment along the longitudinal axis of the freight car to either load or unload cargo. The second control point strategy employed for the loading and unloading sections refers to a strategy that uses only the simplest geometric constraints to generate a straight trajectory in the path generation algorithm. This can be implemented as a two-point line segment control strategy containing only the start and end points, or a simplified control point interpolation strategy containing only the start, geometric midpoint, and end point. By significantly reducing the number of control points, the small computational disturbances or local curve deformations introduced by redundant intermediate control points are avoided, thus ensuring that the path exhibits a strictly absolute straight-line shape at the geometric level.

[0069] This application implements differentiated path planning designs based on the geometric and motion characteristics of different driving sections. During the process of the automated guided vehicle (AGV) entering the platform from the external path towards the rear of the carriage (entry section) and leaving the platform after completing its work (return section), the first control point strategy utilizes more control points to achieve a smooth and refined fit to complex curved trajectories, effectively eliminating abrupt changes in path curvature. This ensures that the AGV's posture is smoothly aligned before entering the narrow carriage, avoiding the risk of carriage wall collisions caused by trajectory jitter and excessive lateral sway during turning. During the process of the AGV entering the carriage to unload goods (unloading section) and returning to the rear of the carriage after unloading (departure section), the second control point strategy, by reducing the number of control points, constructs a strictly longitudinally distributed straight path. This not only greatly reduces the computational complexity of path planning but also ensures that the AGV maintains a stable longitudinal straight-line posture within the extremely limited space of the carriage, maximizing the high precision of pallet alignment and placement and operational safety.

[0070] S6: The multiple external paths are sent to the automated guided vehicle segment by segment, so that the automated guided vehicle executes the multiple external paths segment by segment to complete the loading operation.

[0071] Specifically, the control system sends the generated external paths to the automated guided vehicle (AGV) in sequence. The AGV then executes the entry section, unloading section, departure section, and return section in sequence. At the end of the unloading section, the pallet is unloaded and the vehicle exits the car along the subsequent path, completing the automated loading operation.

[0072] Please see Figure 7 , Figure 7 A specific implementation of step S6 is shown below: S61: Issue the current segment's travel path to the automated guided vehicle (AGV). S62: Receive the next segment's path request sent by the AGV after the onboard controller determines that the current segment has ended. S63: In response to the next segment's path request, issue the next segment's travel path to the AGV, and sequentially issue the multiple external paths segment by segment until the return segment is completed, then receive the unloading completion information reported by the AGV.

[0073] Specifically, issuing the current segment's travel path to the automated guided vehicle (AGV) means that the dispatching system, based on the current operational status, only sends path planning data matching the current execution phase to the AGV. In practice, wireless transmission protocols such as industrial wireless LAN, 5G communication, or ultra-wideband communication can be used to encapsulate parameters such as the coordinates of discrete control points on the current segment's path, preset travel speed, travel direction commands, and end-point tolerance into a travel command data packet and send it to the AGV. Alternatively, the ground dispatching system can push the trajectory equation parameters and motion control constraint commands for the current segment in real time via a message queue protocol to ensure that the AGV has clearly defined and definite local motion commands within a specific phase.

[0074] The vehicle controller's determination of the end of the current segment refers to the vehicle control unit's real-time comparison of the vehicle's actual pose with the pose at the end of the current segment during the execution of the current driving path. Specifically, the vehicle controller can use a fusion positioning algorithm combining laser natural contour positioning, inertial navigation, and wheel odometer to calculate the vehicle's center coordinates and heading angle in real time. When the deviations of this pose from the target coordinates and heading angle at the end of the current segment both fall within a preset tolerance threshold, it is determined that the vehicle has reached the end of the segment. Alternatively, the vehicle controller can, based on the fusion positioning, perform secondary verification of preset reference features at the end of the segment using vehicle-mounted LiDAR, ultrasonic ranging sensors, or visual sensors. After confirming stable parking, it outputs a signal indicating that the vehicle has reached the end of the segment, thereby triggering the vehicle communication module to send a request to the ground dispatch system containing confirmation of the current status and a request for the next segment's route.

[0075] Responding to the next route request and sequentially issuing multiple external route segments until the return segment is completed refers to the event-triggered step-by-step interactive control mechanism established between the ground dispatch system and the automated guided vehicle (AGV). In specific implementation, the dispatch system can use a preset state machine model, sequentially changing the operation state according to the received route request events. During each state transition, it retrieves the corresponding next route segment data from the route buffer and issues it to the vehicle, forming a chain-like closed loop of "execution-arrival determination-request-reissue." Alternatively, after receiving the request, the dispatch system can perform dynamic access verification by combining the real-time safety interlock status and equipment operating status at the berth. After confirming no environmental interference, it issues the next route segment. Once the AGV completes the return segment and the onboard sensors confirm that the pallet has been completely detached and the vehicle body has been reset to the external starting point, it receives the unloading completion status message reported by the AGV, thus terminating the current loading operation process.

[0076] This application embodiment breaks down the overall operation path, including the entry section, unloading section, departure section, and return section, into a multi-stage sequence composed of local instructions. A refined closed-loop interactive control mode is formed by relying on the on-board controller's end-of-section arrival determination and the on-demand issuance of instructions by the scheduling system. Since the flow of each stage of the path is strictly bound to the actual physical arrival status of the vehicle at the key connection points at the end of each section, the mechanism eliminates the potential for cumulative positioning error propagation and premature instruction execution caused by issuing instructions all at once. Simultaneously, this segment-by-segment confirmation mechanism closely coordinates with the coaxial straight-line entry and exit constraints within the narrow and confined space of the vehicle compartment, ensuring the attitude alignment and smooth action switching of the automated guided vehicle at key turning points such as the rear of the compartment and the unloading center. This significantly improves the path tracking accuracy, action continuity, and overall operational safety of automated loading operations in narrow and long compartment environments.

[0077] The above technical solution will be explained in more detail through a more specific example: Taking the loading operation at the rear of a truck at berth A as an example, the loading control process includes the parking calibration stage, the material positioning stage, the real-time trigger measurement and coordinate update stage, and the path planning and segmented execution stage.

[0078] During the docking calibration phase, after the truck docks at berth A, the system sends a start detection command to the laser measurement equipment deployed on the platform. The laser measurement equipment performs an initial laser scan of the truck's rear and returns a measurement response message containing a success code, the coordinates of the truck's rear midpoint, the truck's docking tilt angle, vehicle feature points, and a measurement session identifier. The system verifies the integrity of the success code and feature points. If the verification passes, the system determines the lateral coordinates of the truck's rear midpoint as the initial lateral coordinates of the truck's rear reference point and uses the preset longitudinal depth reference value in the world coordinate system as the initial longitudinal coordinates of the truck's rear reference point. This forms the initial coordinates of the truck's rear reference point, and the initial coordinates, truck docking tilt angle, and measurement session identifier are bound to berth A and cached in the system. In this phase, the system calculates the effective usable longitudinal length of the truck body based on the vehicle length minus the longitudinal fixed compensation value and the distance from the truck's front to the pallet center, and calculates the tilt angle threshold based on the lateral clearance of the truck body. When the absolute value of the truck's docking tilt angle is within the tilt angle threshold range, the docking is deemed compliant, and the system is allowed to proceed to the next phase.

[0079] During the material placement phase, the system issues a pallet handling task to the automated guided vehicle (AGV). After retrieving the goods, the AGV carries the pallet to berth A until it reaches the pre-marked external path and enters the starting point. During the AGV's movement, the system does not pre-fix the pallet placement positions inside the vehicle compartment to avoid state deviations due to the initial time span.

[0080] During the real-time trigger measurement and coordinate update phase, the automated guided vehicle (AGV) arrives at the external path entry point, triggers, and sends the first external path request to the system. In response to the first external path request, the system retrieves the previously cached measurement session identifier based on berth A and sends a pallet center measurement request carrying the measurement session identifier to the laser measurement device. Upon receiving the request, the laser measurement device immediately performs a laser scan of the pallet in the vehicle compartment and returns the pallet center measurement result containing the measurement session identifier. After verifying the session identifier, the system reads the measured lateral and longitudinal coordinates of the pallet center. Subsequently, the system uses the measured lateral coordinates as the final lateral coordinates of the pallet placement center and subtracts a preset longitudinal fixed compensation value from the measured longitudinal coordinates to obtain the final longitudinal coordinates, completing coordinate compensation. Simultaneously, in the world coordinate system, the system directly updates the initial lateral coordinates of the vehicle compartment's rear reference point to the final lateral coordinates of the pallet placement center, while maintaining the preset longitudinal depth reference value for the longitudinal coordinates, ensuring that the vehicle compartment's rear reference point and the pallet placement center form a coaxial constraint in the world coordinate system, thus obtaining the final coordinates of the vehicle compartment's rear reference point.

[0081] During the path planning and segmented execution phase, the system generates a multi-segment continuous path based on the final coordinates of the external path entry point, the rear reference point of the vehicle, and the final coordinates of the pallet unloading center. This path consists of an entry segment, an unloading segment, a departure segment, and a return segment. The entry and return segments are curved paths, generated using a first control point strategy with a larger number of control points. The unloading and departure segments, due to coaxial constraints, form a straight path along the longitudinal direction in the world coordinate system, generated using a second control point strategy with a smaller number of control points. The entry and unloading segments are set to reverse mode, while the departure and return segments are set to forward mode. The system first sends the entry segment path downwards. The automated guided vehicle (AGV) reverses along the entry segment to the rear reference point of the vehicle. Upon arrival, the onboard controller requests the next path segment from the system. The system then sequentially sends the unloading, departure, and return segments. The AGV completes unloading at the end of the unloading segment and reports unloading completion information after returning to the external path entry point along the return segment.

[0082] Compared to the technology that measures and fixes the loading path once at the initial stage of the truck's parking, the above solution postpones the pallet measurement process until the moment when the automated guided vehicle actually arrives at the starting point of the external path. It achieves data coordination of phased measurements through measurement session identifiers and uses the coaxial constraint of the lateral coordinate to eliminate the lateral deviation of the reversing path inside the truck compartment, thus eliminating the impact of the task handling time interval on the accuracy of the loading operation.

[0083] Please refer to Figure 8 As a response to the above Figure 1 The implementation of the method shown in this application provides an embodiment of an automated truck tail loading system based on staged laser measurement. This device embodiment is similar to... Figure 1The method embodiments shown correspond to those described.

[0084] like Figure 8 As shown, the automated truck rear loading system based on phased laser measurement in this embodiment includes: a vehicle body measurement module 71, a handling task issuing module 72, a pallet center coordinate measurement module 73, a truck rear reference point coordinate determination module 74, an external path generation module 75, and an external path execution module 76, wherein: The vehicle body measurement module 71 is used to measure the vehicle body of the truck through a laser measurement device after confirming that the truck is parked in a qualified manner, obtain the vehicle body measurement result, and bind and cache the vehicle body measurement result with the current parking space. The vehicle body measurement result includes the initial coordinates of the reference point at the rear of the truck body, the truck parking tilt angle, and the measurement session identifier. The transport task issuing module 72 is used to issue transport tasks to the automated guided vehicle so that the automated guided vehicle carries the pallet and travels to the pre-marked external path to enter the starting point. The pallet center coordinate measurement module 73 is used to receive the first external path application sent by the automated guided vehicle after it arrives at the external path entry point, and in response to the first external path application, call the laser measurement device to measure the pallet in the carriage according to the measurement session identifier to obtain the measured coordinates of the pallet center. The reference point coordinate determination module 74 at the rear of the carriage is used to perform coordinate compensation on the measured coordinates to obtain the final coordinates of the pallet placement center. In the world coordinate system, the initial lateral coordinates of the reference point at the rear of the carriage are updated to the lateral coordinates of the pallet placement center so that the reference point at the rear of the carriage and the pallet placement center satisfy the coaxial constraint, and the final coordinates of the reference point at the rear of the carriage are obtained. The external path generation module 75 is used to generate multiple external paths based on the final coordinates of the external path entry point, the rear reference point of the carriage, and the final coordinates of the pallet placement center. The multiple external paths include, in sequence, an entry section, a placement section, a departure section, and a return section. The external path execution module 76 is used to send the multiple external path segments to the automated guided vehicle segment by segment, so that the automated guided vehicle executes the multiple external path segments segment by segment to complete the loading operation.

[0085] Furthermore, the vehicle body measurement module 71 includes: The detection command sending unit is used to send a detection start command to the laser measuring device after confirming that the truck is parked in a qualified manner, so as to receive the measurement response message returned by the laser measuring device after performing laser scanning on the rear of the truck. The measurement response message includes a success code, the coordinates of the center point of the rear of the truck, the truck parking tilt angle, vehicle feature points and the measurement session identifier. The success code verification unit is used to verify the success code in the measurement response message. When the success code indicates success and the measurement response message contains the vehicle feature point, the start detection is determined to be successful. The initial coordinates of the rear reference point of the cargo box, the parking tilt angle of the truck, and the measurement session identifier are cached to obtain the vehicle body measurement result. The vehicle body measurement result is then bound to the current parking space and cached. The failure verification unit is used to determine that the start detection has failed and terminate the current measurement when the success code indicates failure or the vehicle feature point is missing in the measurement response message.

[0086] The success code verification unit includes a coordinate caching unit, which is used to cache the initial coordinates of the reference point at the rear of the carriage.

[0087] Furthermore, the coordinate buffer unit includes: The coordinate setting subunit is used to set the initial lateral coordinate of the rear reference point of the carriage to the lateral coordinate of the midpoint coordinate of the rear of the carriage, and to set the initial longitudinal coordinate of the rear reference point of the carriage to a preset longitudinal depth reference value, wherein the preset longitudinal depth reference value is the longitudinal depth reference of the world coordinate system calibrated for platform docking. The reference value determination subunit is used to determine the preset longitudinal depth reference value when there is a conflict between the longitudinal coordinate in the coordinates of the midpoint of the rear of the carriage and the preset longitudinal depth reference value.

[0088] Furthermore, the vehicle body measurement module 71 also includes: The available length calculation module is used to calculate the effective longitudinal available length of the carriage and obtain the lateral clearance of the carriage, wherein the effective longitudinal available length of the carriage is equal to the length of the carriage minus the longitudinal fixed compensation value and the distance from the front of the carriage to the center of the pallet; The tilt angle threshold calculation module is used to calculate the tilt angle threshold based on the effective usable longitudinal length of the carriage and the lateral clearance of the carriage; The first execution module is configured to allow the step of issuing the handling task to the automated guided vehicle to continue if the absolute value of the parking angle of the truck is less than or equal to the angle threshold. The second execution module is used to prevent the execution of the transport task issued to the automated guided vehicle and generate a re-parking prompt message if the absolute value of the parking angle of the truck is greater than the tilt angle threshold.

[0089] Furthermore, the pallet center coordinate measurement module 73 includes: The path request receiving unit is used to receive the first external path request sent by the automated guided vehicle after it arrives at the external path entry point; The application response unit is used to respond to the first external path application, obtain the measurement session identifier according to the current berth, and send a pallet center measurement request carrying the measurement session identifier to the laser measurement equipment; The measurement result receiving unit is used to receive the pallet center measurement result returned by the laser measuring device after performing laser scanning on the pallet inside the carriage, wherein the pallet center measurement result includes the returned measurement session identifier; The measurement session unit is used to confirm that the measurement session belongs to the same measurement session by comparing the measurement session identifier returned with the measurement session identifier carried in the pallet center measurement request. The coordinate reading unit is used to read the measured coordinates of the pallet center when the measurement result of the pallet center passes the verification.

[0090] Furthermore, the final coordinates of the pallet placement center include the final lateral coordinates and the final longitudinal coordinates of the pallet placement center; the measured coordinates include the measured lateral coordinates and the measured longitudinal coordinates. The module 74 for determining the coordinates of the reference point at the rear of the carriage includes: The coordinate compensation unit is used to set the final lateral coordinate to the measured lateral coordinate and to subtract a preset fixed longitudinal compensation value from the measured longitudinal coordinate to obtain the final longitudinal coordinate setting. The final coordinate determination unit is used to set the initial lateral coordinate of the rear reference point of the carriage to the final lateral coordinate in the world coordinate system, and to keep the final longitudinal coordinate of the rear reference point of the carriage unchanged by a preset longitudinal depth reference value, so that the rear reference point of the carriage and the pallet loading center satisfy the coaxial constraint, thereby obtaining the final coordinate of the rear reference point of the carriage. The coaxial constraint makes the loading section and the departure section a straight path along the longitudinal direction in the world coordinate system.

[0091] Furthermore, the external path generation module 75 includes: The final coordinate generation unit is used to generate, based on the final coordinates of the external path entry point, the rear reference point of the carriage, and the final coordinates of the pallet loading center, an entry segment from the external path entry point to the rear reference point of the carriage, a loading segment from the rear reference point of the carriage to the pallet loading center, a departure segment from the pallet loading center to the rear reference point of the carriage, and a return segment from the rear reference point of the carriage to the external path entry point; Wherein, the end point of the entry section, the start point of the unloading section, the end point of the departure section, and the start point of the return section are all the final coordinates of the rear reference point of the carriage; the end point of the unloading section and the start point of the departure section are both the final coordinates of the pallet unloading center; the end point of the return section is the entry point of the external path; The heading angles of the multiple external paths are all pre-calibrated angles for each segment; the driving direction of the entry segment and the unloading segment is reverse, while the driving direction of the departure segment and the return segment is forward.

[0092] Furthermore, the inbound section and the return section are curved paths, generated using a first control point strategy; the outbound section and the departure section are straight paths, generated using a second control point strategy; the first control point strategy has more control points than the second control point strategy.

[0093] Furthermore, the external path execution module 76 includes: The route distribution unit is used to distribute the current segment's travel route to the automated guided vehicle; The path request sending unit is used to receive the next path request sent by the on-board controller after the automated guided vehicle has arrived at the end of the current segment; The external path issuing unit is used to issue the next segment of the driving path to the automated guided vehicle in response to the next segment path request, and to issue the multiple external path segments one by one in sequence until the return segment is completed, and to receive the unloading completion information reported by the automated guided vehicle.

[0094] Obviously, the embodiments described above are merely some embodiments of this application, not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the scope of this application. This application can be implemented in many different forms; rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this application's specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of protection of this application.

Claims

1. A method for automatic loading at the rear of a truck based on staged laser measurement, characterized in that, include: After confirming that the truck is parked properly, the truck body is measured using a laser measuring device to obtain the vehicle body measurement results. The vehicle body measurement results are then bound and cached with the current parking space. The vehicle body measurement results include the initial coordinates of the reference point at the rear of the truck bed, the truck parking tilt angle, and the measurement session identifier. A transport task is issued to the automated guided vehicle (AGV) so that the AGV carries the pallet and travels to the pre-marked external path to enter the starting point. Upon receiving the first external path request sent by the automated guided vehicle after arriving at the external path entry point, and in response to the first external path request, the laser measurement device is invoked to measure the pallet inside the vehicle according to the measurement session identifier, and the measured coordinates of the pallet center are obtained. Coordinate compensation is performed on the measured coordinates to obtain the final coordinates of the pallet placement center. In the world coordinate system, the initial lateral coordinates of the rear reference point of the truck bed are updated to the lateral coordinates of the pallet placement center so that the rear reference point of the truck bed and the pallet placement center satisfy the coaxial constraint, and the final coordinates of the rear reference point of the truck bed are obtained. Based on the final coordinates of the external path entry point, the rear reference point of the vehicle, and the final coordinates of the pallet unloading center, multiple external paths are generated, wherein the multiple external paths sequentially include an entry section, an unloading section, a departure section, and a return section. The multiple external paths are issued to the automated guided vehicle (AGV) segment by segment, so that the AGV executes the multiple external paths segment by segment to complete the loading operation.

2. The automatic loading method for the rear of a truck based on staged laser measurement according to claim 1, characterized in that, After confirming that the truck is parked properly, the truck body is measured using a laser measuring device to obtain the measurement results, and these results are then cached and bound to the current parking space. This includes: After confirming that the truck is parked properly, a start detection command is sent to the laser measuring device to receive a measurement response message returned by the laser measuring device after performing a laser scan on the rear of the truck. The measurement response message includes a success code, coordinates of the center point of the rear of the truck bed, the truck parking tilt angle, vehicle feature points, and the measurement session identifier. The success code in the measurement response message is verified. When the success code indicates success and the measurement response message contains the vehicle feature point, the start detection is determined to be successful. The initial coordinates of the rear reference point of the cargo box, the parking tilt angle of the truck, and the measurement session identifier are cached to obtain the vehicle body measurement result. The vehicle body measurement result is then bound to the current parking space and cached. If the success code indicates failure or the vehicle feature point is missing in the measurement response message, the start detection is determined to have failed, and the current measurement is terminated.

3. The automatic loading method for the rear of a truck based on staged laser measurement according to claim 2, characterized in that, The initial coordinates of the reference point at the rear of the carriage are cached, including: The initial lateral coordinate of the rear reference point of the carriage is set to the lateral coordinate of the midpoint coordinate of the rear of the carriage, and the initial longitudinal coordinate of the rear reference point of the carriage is set to a preset longitudinal depth reference value, wherein the preset longitudinal depth reference value is the longitudinal depth reference of the world coordinate system calibrated for platform docking. When there is a conflict between the longitudinal coordinate of the midpoint coordinate of the rear of the carriage and the preset longitudinal depth reference value, the preset longitudinal depth reference value shall prevail.

4. The automatic loading method for the rear of a truck based on staged laser measurement according to claim 1, characterized in that, After confirming that the truck is parked properly, the truck body is measured using a laser measuring device to obtain the measurement results. These results are then bound and cached with the current parking space. Before issuing a transport task to the automated guided vehicle (AGV) to carry the pallet and travel along a pre-defined external path to the starting point, the method further includes: Calculate the effective longitudinal usable length of the car body and obtain the lateral clearance of the car body, wherein the effective longitudinal usable length of the car body is equal to the length of the car body minus the longitudinal fixed compensation value and the distance from the front of the car body to the center of the pallet; The tilt angle threshold is calculated based on the effective usable longitudinal length of the carriage and the lateral clearance of the carriage; If the absolute value of the truck parking angle is less than or equal to the angle threshold, then the step of issuing the handling task to the automated guided vehicle is allowed to continue. If the absolute value of the parking angle of the truck is greater than the tilt angle threshold, the execution of the transport task to the automated guided vehicle is prohibited, and a re-parking prompt message is generated.

5. The automatic loading method for the rear of a truck based on staged laser measurement according to claim 1, characterized in that, The process of receiving the first external path request sent by the automated guided vehicle after it arrives at the external path entry point, responding to the first external path request, and calling the laser measurement device to measure the pallet inside the vehicle according to the measurement session identifier to obtain the measured coordinates of the pallet center includes: Receive the first external path request sent by the automated guided vehicle after it arrives at the external path entry point; In response to the first external path request, the measurement session identifier is obtained based on the current berth, and a pallet center measurement request carrying the measurement session identifier is sent to the laser measurement equipment; The system receives the pallet center measurement result returned by the laser measuring device after performing a laser scan on the pallet inside the carriage, wherein the pallet center measurement result includes the returned measurement session identifier; By comparing the measurement session identifier returned with the measurement session identifier carried in the pallet center measurement request, it is confirmed that they belong to the same measurement session; When the measurement result of the pallet center passes the verification, the measured coordinates of the pallet center are read.

6. The automatic loading method for the rear of a truck based on staged laser measurement according to claim 1, characterized in that, The final coordinates of the pallet placement center include the final horizontal coordinates and the final vertical coordinates of the pallet placement center; the measured coordinates include the measured horizontal coordinates and the measured vertical coordinates. The process involves performing coordinate compensation on the measured coordinates to obtain the final coordinates of the pallet placement center, and updating the initial lateral coordinates of the rear reference point of the truck bed to the lateral coordinates of the pallet placement center in the world coordinate system, so that the rear reference point of the truck bed and the pallet placement center satisfy the coaxial constraint. This process, along with obtaining the final coordinates of the rear reference point of the truck bed, includes: The final lateral coordinate is set to the measured lateral coordinate, and the measured longitudinal coordinate is subtracted from the preset longitudinal fixed compensation value to obtain the final longitudinal coordinate setting. In the world coordinate system, the initial lateral coordinate of the rear reference point of the cargo compartment is set as the final lateral coordinate, and the final longitudinal coordinate of the rear reference point of the cargo compartment is kept unchanged by a preset longitudinal depth reference value, so that the rear reference point of the cargo compartment and the pallet loading center satisfy the coaxial constraint, and the final coordinate of the rear reference point of the cargo compartment is obtained. In this way, the loading section and the departure section are straight paths along the longitudinal direction in the world coordinate system through the coaxial constraint.

7. The automatic loading method for the rear of a truck based on staged laser measurement according to claim 1, characterized in that, The process generates multiple external paths based on the final coordinates of the external path entry point, the reference point at the rear of the vehicle, and the final coordinates of the pallet placement center, including: Based on the final coordinates of the external path entry point, the rear reference point of the carriage, and the final coordinates of the pallet unloading center, an entry segment from the external path entry point to the rear reference point of the carriage, a unloading segment from the rear reference point of the carriage to the pallet unloading center, a departure segment from the pallet unloading center to the rear reference point of the carriage, and a return segment from the rear reference point of the carriage to the external path entry point are generated. Wherein, the end point of the entry section, the start point of the unloading section, the end point of the departure section, and the start point of the return section are all the final coordinates of the rear reference point of the carriage; the end point of the unloading section and the start point of the departure section are both the final coordinates of the pallet unloading center; the end point of the return section is the entry point of the external path; The heading angles of the multiple external paths are all pre-calibrated angles for each segment; the driving direction of the entry segment and the unloading segment is reverse, while the driving direction of the departure segment and the return segment is forward.

8. The automatic loading method for the rear of a truck based on staged laser measurement according to claim 7, characterized in that, The inbound and return sections are curved paths, generated using a first control point strategy; the outbound and departure sections are straight paths, generated using a second control point strategy; the first control point strategy has more control points than the second control point strategy.

9. The automatic loading method for the rear of a truck based on staged laser measurement according to any one of claims 1 to 8, characterized in that, The step of issuing the multiple external paths segment by segment to the automated guided vehicle (AGV) so that the AGV executes the multiple external paths segment by segment to complete the loading operation includes: The current travel path is sent to the automated guided vehicle; The system receives the next route request sent by the onboard controller after the automated guided vehicle arrives at the end of the current segment and determines that the vehicle has reached the end of the current segment. In response to the request for the next route segment, the system issues the next travel route segment to the automated guided vehicle (AGV), and then issues the multiple external routes segment by segment until the return segment is completed. Finally, the system receives the unloading completion information reported by the AGV.

10. An automated truck rear loading system based on staged laser measurement, characterized in that, include: The vehicle body measurement module is used to measure the vehicle body of the truck using a laser measurement device after confirming that the truck is parked properly, obtain the vehicle body measurement results, and bind and cache the vehicle body measurement results with the current parking space. The vehicle body measurement results include the initial coordinates of the reference point at the rear of the truck bed, the truck parking tilt angle, and the measurement session identifier. The task assignment module is used to assign a task to the automated guided vehicle (AGV) so that the AGV carries the pallet and travels to the pre-marked external path to enter the starting point. The pallet center coordinate measurement module is used to receive the first external path application sent by the automated guided vehicle after it arrives at the external path entry point, and in response to the first external path application, call the laser measurement device to measure the pallet in the carriage according to the measurement session identifier to obtain the measured coordinates of the pallet center. The module for determining the coordinates of the rear reference point of the truck bed is used to perform coordinate compensation on the measured coordinates to obtain the final coordinates of the pallet placement center. In the world coordinate system, the initial lateral coordinates of the rear reference point of the truck bed are updated to the lateral coordinates of the pallet placement center so that the rear reference point of the truck bed and the pallet placement center satisfy the coaxial constraint, thereby obtaining the final coordinates of the rear reference point of the truck bed. The external path generation module is used to generate multiple external paths based on the final coordinates of the external path entry point, the final coordinates of the rear reference point of the carriage, and the final coordinates of the pallet placement center. The multiple external paths include, in sequence, an entry section, a placement section, a departure section, and a return section. The external path execution module is used to send the multiple external path segments to the automated guided vehicle segment by segment, so that the automated guided vehicle executes the multiple external path segments segment by segment to complete the loading operation.

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