A material conveying track control method for small batch manufacturing and related products

Abstract

The application provides a material conveying track control method for small-batch manufacturing and related products. The method includes obtaining physical attribute parameters and a process route of a current batch of to-be-conveyed material, determining material dynamics constraints of the to-be-conveyed material in a conveying process based on the physical attribute parameters, generating a material conveying track based on the material dynamics constraints and the process route, controlling a conveying device to convey the current batch of to-be-conveyed material based on the material conveying track, and performing real-time obstacle detection in the conveying process to determine an obstacle distance. When the obstacle distance is detected to be less than a preset distance threshold, the conveying device is controlled to perform deceleration, suspension, or detouring according to a preset obstacle avoidance route, and the conveying of the to-be-conveyed material continues based on the material conveying track after the obstacle disappears. The method can enhance the adaptive ability and dynamic environment response ability of the material conveying track in a small-batch manufacturing environment and improve the material transportation quality.

Description

Technical Field

[0001] This invention relates to the field of intelligent manufacturing technology, and in particular to a material conveying trajectory control method and related products for small-batch manufacturing. Background Technology

[0002] With the development of intelligent manufacturing, small-batch, multi-variety production models are gradually being applied to fields such as precision machining and equipment manufacturing. Unlike traditional large-scale production, production tasks change more frequently in small-batch manufacturing. The processing procedures, production cycles, and material types required for different batches of products may vary significantly, thus placing higher demands on the efficiency and reliability of material flow within the workshop.

[0003] Material handling in existing manufacturing workshops typically relies on fixed conveyor lines, manual handling, or pre-set operating rules. While these methods can meet basic conveying needs when production tasks are relatively stable, they struggle to adapt to changing production demands in scenarios with frequent batch changes. This can lead to problems such as inefficient conveyor path planning, reduced equipment utilization, and ultimately, a decline in material transport quality. Furthermore, the actual workshop environment is often highly uncertain. Factors such as equipment layout adjustments, personnel activities, and the operation of other logistics equipment can all cause changes in the conveying area. Existing conveying control methods often require manual intervention to adjust to sudden environmental changes, making it difficult to ensure continuous operation and safety during the conveying process. In addition, different materials vary in size, weight, and shape, resulting in different stability requirements during transport. Using a uniform conveying method may negatively impact material transport quality.

[0004] Therefore, how to improve the adaptability of material conveying processes in manufacturing workshops to different production tasks, and enhance the stability and safety of conveying processes in dynamic environments, has become a technical problem that urgently needs to be solved in the field of intelligent manufacturing logistics control. Summary of the Invention

[0005] This invention provides a material conveying trajectory control for small-batch manufacturing, which solves the problems of unreasonable path planning, inability to adapt to environmental changes and stability requirements in existing small-batch material transportation processes, resulting in poor material transportation quality.

[0006] In a first aspect, embodiments of this application provide a material conveying trajectory control method for small-batch manufacturing, including: Obtain the physical property parameters and process route of the current batch of materials to be transported; the physical property parameters are a set of data describing the physical properties of the materials to be transported; the process route describes the sequence of process nodes required for the current batch of materials to be transported to be processed or assembled in the workshop. The material dynamics constraints of the material to be transported during the transport process are determined based on the physical property parameters, and the material transport trajectory is generated based on the material dynamics constraints and the process route; the material dynamics constraints are the mechanical conditions that need to be met to ensure the stability and safety of the material to be transported. Based on the material conveying trajectory, the conveying equipment is controlled to convey the current batch of materials to be conveyed, and obstacle detection is performed in real time during the conveying process to determine the distance of obstacles; When an obstacle is detected to be less than a preset distance threshold, the control device will decelerate, pause, or detour along a preset obstacle avoidance route. After the obstacle is detected to have disappeared, the device will continue to transport the material to be transported based on the material transport trajectory.

[0007] In one embodiment, the physical property parameters include the size, weight, and center of gravity height of the material to be conveyed; based on the physical property parameters, the material dynamics constraints of the material to be conveyed during the conveying process are determined, and based on the material dynamics constraints and the process route, a material conveying trajectory is generated, including: Based on the process route, determine all conveying nodes for conveying the materials to be conveyed, and based on the sequence and position of all conveying nodes, plan the geometric path connecting each conveying node; Based on the size, weight and center of gravity height of the material to be conveyed, the material dynamics constraints of the conveying equipment when conveying the material to be conveyed are determined. The material dynamics constraints include at least the maximum speed and maximum acceleration when conveying the material to be conveyed. Based on the planned geometric path and material dynamics constraints, a material conveying trajectory with speed control parameters is generated.

[0008] In one embodiment, the maximum speed and maximum acceleration when conveying the material to be conveyed are determined as follows: Based on the size and center of gravity height of the material to be transported, determine the maximum acceleration at which the gravitational torque and inertial torque balance the material in the critical state of tipping over, and use it as the maximum acceleration to prevent tipping over. Based on the static friction coefficient between the material to be conveyed and the bearing surface of the conveying equipment, determine the maximum acceleration corresponding to the maximum static friction force of the material to be conveyed under the critical slip state, and use it as the maximum anti-slip acceleration; The minimum value between the maximum anti-tipping acceleration and the maximum anti-slip acceleration is taken as the maximum acceleration in the material dynamics constraint; Based on the minimum radius of curvature in the geometric path, and the minimum of the maximum anti-tipping acceleration and the maximum anti-slip acceleration, calculate the maximum bending speed of the material to be conveyed in the turning section without centrifugal slippage or centrifugal overturning. Determine the maximum travel speed of the material to be conveyed on the straight section based on the allowable vibration level of the material to be conveyed and the rated maximum speed of the conveying equipment. The minimum value among the maximum cornering speed, maximum driving speed, and preset safe speed is taken as the maximum speed in the material dynamics constraint.

[0009] In one embodiment, a material conveying trajectory with speed control parameters is generated based on the planned geometric path and material dynamics constraints, including: Based on the planned geometric path, an initial transport path that satisfies the motion continuity constraint is constructed in the state space composed of velocity variables, and a time parameter is introduced to transform the initial transport path into a three-dimensional motion trajectory with a timestamp. Based on material dynamics constraints and the kinematic limits of the conveying equipment, a state-space equation describing the evolution of the system state over time is constructed. The state-space equation includes the velocity variables, acceleration variables, and kinematic constraints of the conveying equipment. An objective function is constructed with conveying time and equipment energy consumption as optimization objectives. The state-space equation is used as a constraint condition to solve the three-dimensional motion trajectory in a rolling manner, generating a material conveying trajectory that satisfies the material dynamics constraints.

[0010] In one embodiment, based on the planned geometric path, an initial transport path satisfying motion continuity constraints is constructed within a state space composed of velocity variables, including: Discrete sampling is performed on the geometric path according to the preset sampling step size to obtain multiple continuous trajectory sampling points; Based on the maximum speed and maximum acceleration, each trajectory sampling point is assigned a corresponding running speed to generate an initial transport path containing three-dimensional spatial coordinates and running speed; Specifically, for the trajectory sampling points corresponding to the curves and start-stop sections in the geometric path, the assigned running speed is less than the preset transition speed; the preset transition speed is less than the maximum speed and is dynamically calculated based on the geometric position of the preceding and following trajectory sampling points and the curvature of the curve.

[0011] In one embodiment, the preset distance threshold includes a preset deceleration distance threshold and a preset stop distance threshold, wherein the preset deceleration distance threshold is greater than the preset stop distance threshold; When an obstacle is detected to be less than a preset distance threshold, the control of the conveyor equipment includes at least one of the following: deceleration, pausing, or detouring along a preset obstacle avoidance route: When the distance to an obstacle is detected to be less than the preset deceleration distance threshold and greater than or equal to the preset stopping distance threshold, the conveyor equipment is controlled to reduce its travel speed to the preset safe slow speed. When the distance to an obstacle is detected to be less than a preset stop distance threshold, the control system brakes the conveyor and stops it in place.

[0012] In one embodiment, after controlling the conveying equipment to brake and stop in place, the method includes: When the duration of the conveyor equipment's pause exceeds the preset timeout threshold and the detected obstacle has not disappeared, the pre-stored backup bypass path is retrieved as the preset obstacle avoidance route. The control conveyor switches to a preset obstacle avoidance route to bypass obstacles, and then switches back to the material conveying track to continue driving after bypassing the obstacles.

[0013] Secondly, embodiments of this application provide a material conveying trajectory control system for small-batch manufacturing, comprising at least a control device, the control device including: The acquisition module is used to acquire the physical property parameters and process route of the current batch of materials to be transported; the physical property parameters are a set of data describing the physical properties of the materials to be transported; the process route describes the sequence of process nodes required for the current batch of materials to be transported to be processed or assembled in the workshop. The generation module is used to determine the material dynamics constraints of the material to be transported during the transport process based on physical property parameters, and to generate the material transport trajectory based on the material dynamics constraints and the process route; the material dynamics constraints are the mechanical conditions that need to be met to ensure the stability and safety of the material to be transported. The control module is used to control the conveying equipment to convey the current batch of materials based on the material conveying trajectory; The detection module is used to detect obstacles in real time during the transportation process in order to determine the distance to obstacles; The control module is also used to control the conveying equipment to perform at least one of the following when the distance to the detected obstacle is less than a preset distance threshold: deceleration, pausing, or detouring according to a preset obstacle avoidance route, and to continue conveying the material to be conveyed based on the material conveying trajectory after the obstacle is detected to have disappeared.

[0014] Thirdly, embodiments of this application provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method described above.

[0015] Fourthly, embodiments of this application provide a readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0016] Fifthly, embodiments of this application provide a computer program product, which includes a computer program that implements the above-described method when executed by a processor.

[0017] In one solution provided by the aforementioned material conveying trajectory control method and related products for small-batch manufacturing, the physical property parameters and process route of the current batch of materials to be conveyed are obtained. Based on the physical property parameters, the material dynamics constraints of the materials to be conveyed during the conveying process are determined. A material conveying trajectory is generated based on the material dynamics constraints and the process route. Then, based on the material conveying trajectory, the conveying equipment is controlled to convey the current batch of materials. During the conveying process, obstacle detection is performed in real time to determine the distance to obstacles. When the detected obstacle distance is less than a preset distance threshold, the conveying equipment is controlled to perform at least one of the following: deceleration, pausing, or detouring according to a preset obstacle avoidance route. After the obstacle is detected to have disappeared, the conveying of materials to be conveyed continues based on the material conveying trajectory. Therefore, this solution can enhance the adaptability and dynamic environmental response capability of the material conveying trajectory in a small-batch manufacturing environment, improve the safety, stability, and reliability of the material conveying process, and thus improve the quality of material transportation. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the material conveying trajectory control system for small-batch manufacturing in one embodiment of the present invention; Figure 2 This is a flowchart illustrating a material conveying trajectory control method for small-batch manufacturing according to an embodiment of the present invention. Figure 3 yes Figure 2 A schematic diagram of the implementation process of step S10; Figure 4 yes Figure 2 A schematic diagram of the implementation process of step S20; Figure 5 yes Figure 2 A schematic diagram of the implementation process of step S30; Figure 6 yes Figure 1 A schematic diagram of the structure of the central control device; Figure 7 This is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. It should also be understood that, as used in this specification and the appended claims, the term "and / or" refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0022] Furthermore, in the description of this invention and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of the invention include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0024] To illustrate the technical solution of the present invention, specific embodiments are described below.

[0025] The material conveying trajectory control method for small-batch manufacturing provided in this invention can be applied to applications such as... Figure 1 The material handling trajectory control system (hereinafter referred to as the system) for small-batch manufacturing shown includes a data acquisition device, a transport device, and a control device. The data acquisition device communicates with the control device via a network or bus. The data acquisition device includes vision sensors, weighing sensors, and distance sensors, etc.

[0026] In practical applications, when the control device detects any material to be transported in the current batch in the loading area of ​​the transport equipment, the control device controls the data acquisition device to collect data on the material to be transported, in order to obtain the physical attribute parameters of the material to be transported in the current batch, and to obtain the pre-stored process route of the material to be transported in the current batch. Among them, the physical attribute parameters are a set of data describing the physical properties of the material to be transported itself; the process route is used to describe the sequence of process nodes required for the processing or assembly of the material to be transported in the workshop.

[0027] Then, based on the physical property parameters of the material to be transported, the control device determines the material dynamics constraints of the material during the transport process, and generates the material transport trajectory of the current batch of material based on the material dynamics constraints and the process route. The material dynamics constraints are the mechanical conditions that must be met to ensure the stability and safety of the material being transported.

[0028] Subsequently, the control device controls the conveying equipment to convey the current batch of materials based on the material conveying trajectory, and performs obstacle detection in real time during the conveying process to determine the distance of obstacles; when the distance of the detected obstacle is less than the preset distance threshold, the control device performs at least one of the following actions: deceleration, pausing, or detouring according to the preset obstacle avoidance route, and continues to convey the materials to be conveyed based on the material conveying trajectory after the obstacle is detected to have disappeared.

[0029] In this embodiment, by acquiring the physical property parameters of the current batch of materials to be transported and the corresponding process route, the material transport process can be specifically planned based on the characteristics of different batches of materials and production needs, improving the matching degree between transport tasks and production processes in small-batch manufacturing scenarios. Then, based on the material's own properties, motion constraints during the transport process are determined, and a corresponding transport trajectory is generated in conjunction with the process route, so that the transport path planning can simultaneously meet the requirements of the production process and the stability requirements of material transport, reducing the risk of attitude changes, impacts, or damages during transport due to material differences. At the same time, changes in the surrounding environment are continuously monitored during the transport process, and the operating status of the transport equipment is dynamically adjusted according to changes in the distance to obstacles, so that the transport process can respond promptly to emergencies in the workshop environment and avoid collisions or transport interruptions caused by path obstruction. When the impact of obstacles is eliminated, the transport task continues to be executed according to the predetermined transport trajectory, improving the continuity and stability of the material transport process.

[0030] Therefore, this solution can enhance the adaptive capability and dynamic environmental response capability of material conveying trajectory in small-batch manufacturing environment, improve the safety, reliability and production scheduling efficiency of material conveying process, solve the problem of poor conveying stability caused by the difficulty of adapting the conveying strategy to different material characteristics and production needs, and insufficient adjustment capability when facing dynamic obstacles in the existing technology, thereby improving the quality of material transportation.

[0031] The data acquisition device and control device can be devices installed in the transportation equipment; for example, the control device can be a controller within the transportation equipment. In other embodiments, the control device can be a terminal device, including but not limited to various personal computers, laptops, smartphones, tablets, and portable wearable devices. Furthermore, the control device can also be a server, which can be implemented using a standalone server or a server cluster consisting of multiple servers.

[0032] In one embodiment, such as Figure 2 As shown, a material conveying trajectory control method for small-batch manufacturing is provided, which is then applied to... Figure 1 Taking the control device in the middle as an example, the following steps are included: S10: The control device acquires the physical property parameters and process route of the materials to be transported in the current batch.

[0033] The control device can first communicate and interact with the workshop's manufacturing execution system or enterprise resource planning system to read the production task order for the current batch and extract the physical attribute parameters and process route of the materials to be transported from the production task order.

[0034] Among them, physical property parameters refer to the data set describing the physical properties of the material to be transported, including but not limited to the material's three-dimensional dimensions (length, width, height), weight, center of gravity height, material density, surface friction coefficient, etc. These parameters are used for subsequent dynamic calculations.

[0035] The process route refers to the sequence of process nodes required for the current batch of materials to be transported to be processed or assembled in the workshop. For example, the process route can be an ordered sequence of process nodes: loading area → rough machining center → fine machining center → inspection station → finished product buffer area.

[0036] The control device can receive the above information in JSON data format. For example, for a batch of aero-engine blades, the control device obtains from the MES system the blade's external dimensions of 0.6m×0.3m×0.2m and weight of 12kg, as well as the process route that needs to be processed in sequence, including milling, polishing, non-destructive testing, and finished product warehousing.

[0037] S20: Determine the material dynamics constraints of the material to be transported during the transport process based on the physical property parameters, and generate the material transport trajectory based on the material dynamics constraints and the process route.

[0038] Among them, material dynamics constraints are the mechanical conditions that must be met to ensure the stability and safety of the material to be transported.

[0039] After obtaining the physical property parameters and process route, the control device first performs mechanical analysis based on the physical property parameters of the material (such as size, weight, and center of gravity height) to calculate the mechanical conditions that the material to be transported must meet to maintain a stable and safe posture during the transport process, namely material dynamic constraints. These material dynamic constraints include, but are not limited to, parameters such as maximum speed, maximum acceleration, and maximum turning speed, which are used to prevent the material from tipping over, slipping, or being damaged by vibration during the transport process.

[0040] Subsequently, the control device, in conjunction with the spatial layout of each process node in the process route, plans a geometric path connecting each node. Then, using material dynamics constraints as limitations, it performs speed planning and time parameterization on the geometric path, ultimately generating a complete material conveying trajectory that includes position coordinates, speed commands, and timestamps.

[0041] For example, for a precision instrument with a high center of gravity, the control device calculates its anti-tipping acceleration as 0.5 m / s² and its anti-slip acceleration as 0.8 m / s². Taking the minimum value of 0.5 m / s² as the maximum acceleration constraint, and combining it with the minimum radius of curvature of 5 m in the workshop path, the maximum speed of the curve is calculated to be 1.58 m / s. Finally, a complete conveying trajectory is generated that starts from point A, passes through the curve at a constant speed of 1.5 m / s, and decelerates smoothly to a stop at the end point.

[0042] S30: Based on the material conveying trajectory, control the conveying equipment to convey the current batch of materials to be conveyed, and perform obstacle detection in real time during the conveying process to determine the distance of obstacles.

[0043] The control device sends the material conveying trajectory generated in step S20 to the motion controller of the conveying equipment (such as an AGV, RGV, or conveyor belt robotic arm). The conveying equipment executes its movement according to the position coordinates and speed commands in the trajectory, carrying the material to be conveyed along the predetermined route. Simultaneously, various ranging sensors mounted on the conveying equipment (such as lidar and ultrasonic sensors) continuously emit detection signals forward, and calculate the relative straight-line distance to obstacles in real time by receiving reflected echoes; this distance is the obstacle distance. The control device reads sensor data at millisecond intervals, continuously monitoring the surrounding environment.

[0044] For example, when an AGV carrying materials travels along a track at 1.2 m / s, its front-end lidar scans 10 times per second, emitting a laser beam and receiving the reflected signal each time. Using the time-of-flight method, it calculates that there is a person 3.5 m ahead, and the control device obtains this distance information in real time.

[0045] S40: When the distance to an obstacle is detected to be less than a preset distance threshold, the control device shall perform at least one of the following actions: deceleration, pausing, or detouring according to a preset obstacle avoidance route, and continue to transport the material to be transported based on the material transport trajectory after the obstacle is detected to have disappeared.

[0046] The control device continuously compares the distances to obstacles with preset distance thresholds. When the obstacle distance is less than the preset threshold, a collision risk is determined, and the control device selects one or more of the following response strategies based on the current situation: reduce the travel speed, stop in place, or switch to a pre-stored backup obstacle avoidance route for detour. Once the sensor detects that the obstacle has moved out of the safe range (i.e., the obstacle has disappeared), the control device resumes execution of the material conveying trajectory, allowing the conveying equipment to continue traveling along the original trajectory.

[0047] For example, the preset deceleration distance threshold is set to 2.0m, and the preset stopping distance threshold is set to 0.5m. When the AGV detects a cargo box 1.2m ahead (less than 2.0m but greater than 0.5m), the control device issues a deceleration command, reducing the speed from 1.2m / s to a safe, slow speed of 0.3m / s before continuing to move forward. If the cargo box continues to approach, causing the distance to less than 0.5m, the control device issues an emergency braking command, stopping the AGV in place. After the cargo box is removed, the AGV accelerates back to the planned trajectory speed and continues moving.

[0048] In this embodiment, by acquiring the physical property parameters and corresponding process routes of the current batch of materials to be transported, the material transport process can be specifically planned in conjunction with the current production task requirements, avoiding the problem of insufficient adaptability to different materials or different production processes caused by using a fixed transport strategy. Furthermore, the motion constraints in the transport process are determined based on the material's own properties, and a corresponding transport trajectory is generated in conjunction with the production process flow. This ensures that the transport path not only meets the production process requirements but also meets the stability requirements of the material during transportation, reducing the risk of material deviation, overturning, or damage caused by mismatched motion modes. At the same time, the operating environment is monitored in real time during the transport process, and the operating status of the transport equipment is adjusted in a timely manner according to environmental changes, enabling the transport process to adapt to dynamic changes in the workshop and improving the safety response capability of the transport process. When an obstacle affecting transport safety is detected, the risk of collision is avoided by adjusting the transport speed, pausing operation, or changing the direction of operation, and the transport task continues after the environment recovers, improving the continuity and reliability of material transport. Therefore, this solution can improve the adaptability of material conveying trajectory planning, the stability of the conveying process, and the safety control capability in dynamic environments in small-batch manufacturing scenarios, and solve the problems of low conveying efficiency and poor safety caused by insufficient adaptation to material differences and untimely response to environmental changes in existing technologies.

[0049] In one embodiment, such as Figure 3 As shown, step S10, which involves obtaining the physical property parameters of the current batch of materials to be transported, specifically includes the following steps: S11: When any material to be conveyed in the current batch is detected in the feeding area of ​​the conveying equipment, the three-dimensional point cloud data of the material to be conveyed is collected through the vision sensors deployed around the feeding area.

[0050] Once the conveyor reaches the designated position in the loading area of ​​the workshop, the vision sensors (such as 3D structured light cameras or binocular stereo cameras) installed around the loading area are triggered. The vision sensors project coded structured light onto the material to be conveyed or use the principle of binocular parallax to capture an image of the material's surface. The three-dimensional spatial coordinates of each pixel on the material's surface are calculated using triangulation, thereby generating dense point cloud data containing hundreds of thousands of three-dimensional coordinate points, i.e., three-dimensional point cloud data. This data records the spatial position information of each point on the material's surface in the form of (x, y, z) coordinates.

[0051] For example, an Intel RealSense D455 depth camera is installed above the loading area. When the camera detects that the material has been placed on the loading platform, it automatically takes pictures and generates a three-dimensional coordinate point cloud containing all points on the upper surface of the material. The point cloud density is about 100 points per square centimeter, and the data volume is about 5MB.

[0052] S12: Extract the three-dimensional dimensions and centroid coordinates of the material to be transported from the three-dimensional point cloud data, and determine the height of the center of gravity of the material to be transported based on the three-dimensional dimensions and centroid coordinates.

[0053] The control device preprocesses the acquired 3D point cloud data, including filtering and noise reduction (removing outliers) and point cloud segmentation (separating the material point cloud from the background point cloud). Then, it extracts the minimum dimensions of the bounding box from the material point cloud, namely the length, width, and height of the material in the X, Y, and Z directions, as its 3D dimensions. Simultaneously, it calculates the arithmetic mean of all 3D coordinate points in the material point cloud to obtain the centroid coordinates of the material in 3D space (assuming the material is homogeneous). Finally, using the bearing surface of the conveyor as a reference plane, it calculates the vertical component of the centroid coordinates (Z-axis) to obtain the center of gravity height.

[0054] For example, for the aforementioned 0.6m×0.3m×0.2m blade, after point cloud processing, its length of 0.598m, width of 0.302m, and height of 0.201m can be accurately extracted, and its centroid coordinates are located at the geometric center of the material (0.299m, 0.151m, 0.1005m), and its centroid height is 0.1005m.

[0055] S13: The weight of the material to be conveyed is collected in real time by the weighing sensors deployed in the feeding area, and the three-dimensional dimensions, weight and center of gravity height are output as physical property parameters of the material to be conveyed.

[0056] A high-precision load cell (such as a strain gauge pressure sensor or a piezoelectric sensor) is installed below the loading platform in the feeding area. When the material to be conveyed is placed on the loading platform, the load cell detects the pressure applied to the material in real time, and outputs the weight data of the material through analog-to-digital conversion and calibration calculation. The control device combines the obtained three-dimensional dimensions and center of gravity height, as well as the weight data obtained in this step, into a complete data structure, which is then output as the physical property parameters of the material to be conveyed for use in subsequent steps.

[0057] For example, the three-dimensional dimensions of the blade [0.598, 0.302, 0.201] m, weight 12.05 kg, and center of gravity height 0.1005 m are encapsulated in JSON format {dimensions:[0.598,0.302, 0.201],weight:12.05,cogheight: 0.1005} and passed to the trajectory planning module.

[0058] In this embodiment, point cloud data is collected by a visual sensor and three-dimensional dimensions, centroid coordinates, and center of gravity height are automatically extracted. Combined with a weighing sensor to obtain weight in real time, automated and non-contact precise measurement of the physical property parameters of each batch of materials is achieved. This avoids errors that may occur due to manual input and provides an accurate data foundation for subsequent dynamic constraint calculations, thereby enabling the material conveying trajectory to be more accurately adapted to the physical characteristics of different materials.

[0059] In one embodiment, the physical property parameters of the material to be conveyed include the material's dimensions, weight, and center of gravity height. For example... Figure 4 As shown, step S20, which involves determining the material dynamics constraints of the material to be conveyed during the conveying process based on physical property parameters, and generating the material conveying trajectory based on the material dynamics constraints and the process route, specifically includes the following steps: S21: Determine all conveying nodes for transporting materials according to the process route, and plan the geometric path connecting each conveying node based on the sequence and position of all conveying nodes.

[0060] The control device analyzes the sequence of process nodes in the process route, queries the workshop map database for the specific spatial coordinates of each process node, such as the X and Y coordinates and orientation angle of the workstation, and arranges these process nodes according to the process sequence to obtain a list of conveyor nodes. Subsequently, based on a preset path planning algorithm, such as the A* algorithm, Dijkstra's algorithm, or RRT algorithm, a smooth geometric path is searched on the workshop grid map or topology map that can pass through all nodes in sequence and avoid fixed obstacles (such as columns and equipment). This geometric path is stored in the form of a series of coordinate sequences of continuous path points.

[0061] For example, the process route is loading area → rough processing → fine processing → inspection area, with corresponding coordinates of (0,0), (10,5), (18,8), and (25,3). The path planning algorithm finds the shortest unobstructed path that passes through these four points in sequence on the map, which is used as the geometric path. The point sequence of this geometric path is [(0,0), (3,2), (7,4), (10,5), (14,7), (18,8), (21,6), (25,3)].

[0062] S22: Based on the size, weight, and center of gravity height of the material to be conveyed, determine the material dynamics constraints of the conveying equipment when conveying the material.

[0063] Among them, material dynamics constraints include at least the maximum speed and maximum acceleration when conveying the material to be conveyed; the maximum speed refers to the highest operating speed that the conveying equipment is allowed to reach when conveying the material. Exceeding this speed may cause the material to tip over centrifugally or be damaged due to vibration when turning; the maximum acceleration refers to the maximum acceleration value that the conveying equipment is allowed to accelerate or decelerate. Exceeding this acceleration may cause the material to tip backward or slide forward.

[0064] For example, a preset safety state mapping table can be obtained. The construction process of the safety state mapping table is as follows: different material size, weight range, and material center of gravity height range are set. Based on the performance of the conveying equipment, different dynamic parameter constraints are set for different material size, weight range, and material center of gravity height range to form a safety state mapping table. The safety mapping table includes at least the maximum speed and maximum acceleration under different material size, weight, and material center of gravity height. The size, weight, and center of gravity height of the material to be conveyed are matched with the parameters in the safety state mapping table, and the matched dynamic parameter constraints are output as the material dynamic constraints when the material is to be conveyed.

[0065] For example, the control device accesses a preset safety status mapping table, which stores the corresponding maximum speed and maximum acceleration using size range, weight range, and center of gravity height range as indexes. For a material with dimensions of 0.6×0.3×0.2m, weight of 12kg, and center of gravity height of 0.1m, the table matches a maximum speed of 2.0m / s and a maximum acceleration of 0.8m / s².

[0066] S23: Generate a material conveying trajectory with speed control parameters based on the planned geometric path and material dynamics constraints.

[0067] The control device uses the planned geometric path as the spatial basis and the determined material dynamics constraints (including maximum speed and maximum acceleration) as the motion boundary conditions to perform velocity planning on the path.

[0068] Specifically, a reasonable speed value is assigned to each path point of the geometric path, such that the acceleration section does not exceed the maximum acceleration, the deceleration section is not lower than the braking distance requirement, and the curve section does not exceed the safe turning speed, thereby generating a material conveying trajectory with speed control parameters. This trajectory not only contains spatial location information, but also the target speed, acceleration, and even timestamp information corresponding to each location point.

[0069] For example, the total length of the geometric path is 30m. The control device sets the cruising speed to 2.0m / s on the straight section and reduces the speed to 1.2m / s at the curve (such as a curvature radius of 5m). The start and end sections use a trapezoidal speed curve to accelerate / decelerate, and finally generate a complete trajectory: speed 0m / s at position 0m → accelerate to 2.0m / s at position 5m → decelerate to 1.2m / s at the curve at position 15-20m → start decelerating at position 28m → speed 0m / s at position 30m.

[0070] In this embodiment, by transforming the process route into a geometric path and accurately calculating the dynamic constraints based on the material's size, weight, and center of gravity height, a complete conveying trajectory with speed control parameters is generated. This enables personalized customization of the material conveying trajectory, ensuring that different materials can run safely and efficiently on different road sections (such as straight sections, curves, and start-stop sections). This not only prevents damage to materials caused by dynamic instability but also maximizes conveying efficiency.

[0071] In one embodiment, in step S22, the maximum speed and maximum acceleration when conveying the material to be conveyed, i.e., the maximum speed and maximum acceleration in the material dynamics constraints, are determined as follows: S221: Based on the size and center of gravity height of the material to be transported, determine the maximum acceleration at which the gravitational torque and inertial torque balance the material under the critical tipping state, and use it as the maximum acceleration to prevent tipping.

[0072] The control device uses the center of gravity height h of the material to be conveyed and the bottom width d of the material in the conveying direction (this value is taken as the minimum side length of the material dimensions along the conveying direction) as input parameters to establish a tipping mechanics model.

[0073] When a material is about to tip over around its bottom edge, the restoring torque (mg·d / 2) caused by gravity and the tipping inertial torque (ma·h) caused by acceleration reach equilibrium. Based on this equilibrium, the formula for calculating the maximum anti-tipping acceleration is derived: atip=(d / 2h)×g, where g is the acceleration due to gravity (which can be 9.81m / s²). That is, the maximum acceleration that prevents the material from tipping over is directly proportional to the width of its bottom surface and inversely proportional to the height of its center of gravity.

[0074] For example, if the bottom width of the material is 0.3m and the center of gravity height is 0.1m, then atip = (0.3 / 0.2) × 9.81 ≈ 14.7m / s². For a tall and narrow material with a center of gravity height of 0.5m and a bottom width of 0.2m, atip = (0.2 / 1.0) × 9.81 = 1.962m / s², which is significantly lower than that of a material with a low center of gravity, indicating that tall and narrow materials are easier to tip over.

[0075] S222: Based on the static friction coefficient between the material to be conveyed and the bearing surface of the conveying equipment, determine the maximum acceleration corresponding to the maximum static friction force of the material to be conveyed under the critical slip state, and use it as the maximum anti-slip acceleration.

[0076] The control device obtains the static friction coefficient μ between the material to be conveyed and the AGV's bearing surface. This static friction coefficient can be obtained by querying a preset material friction database. For example, μ≈0.6 for metal and rubber contact surfaces, and μ≈0.3 for plastic and metal contact surfaces. At the critical state where the material is about to slip, the maximum static friction force fmax=μmg provides the inertial force ma required for the material's acceleration. From this, the formula for calculating the maximum anti-slip acceleration is derived: aslip=μ·g. For example, if the material is metal and the bearing surface is a rubber pad, with μ=0.6, then aslip = 0.6×9.81=5.886m / s².

[0077] S223: The minimum value between the maximum anti-tipping acceleration and the maximum anti-slip acceleration shall be used as the maximum acceleration in the material dynamics constraint.

[0078] The control device compares the two calculated acceleration values ​​and takes the smaller one as the final allowable maximum acceleration to simultaneously meet both anti-tipping and anti-slip safety requirements. For example, if atip is 14.7 m / s² and aslip is 5.886 m / s², the minimum value of 5.886 m / s² is taken as the maximum acceleration.

[0079] S224: Based on the minimum radius of curvature in the geometric path, and the minimum of the maximum anti-tipping acceleration and the maximum anti-slip acceleration, calculate the maximum bending speed at which the material to be conveyed will not experience centrifugal slippage or centrifugal overturning in the turning section.

[0080] The control device extracts the minimum radius of curvature for each bend in the geometric path generated in step S21. At the bend, the material is subjected to centrifugal force, the magnitude of which is mv² / R. This centrifugal force may cause centrifugal sideslip (e.g., the material slides laterally relative to the bearing surface) or centrifugal rollover (e.g., the material overturns around the outer edge). To prevent sideslip, mv² / R ≤ μmg; to prevent rollover, mv² / R × h ≤ mg·d / 2; the smaller of the two values ​​is taken as the maximum bend speed. h is the height of the center of gravity.

[0081] S225: Determine the maximum travel speed of the material to be conveyed on the straight section based on the allowable vibration level of the material to be conveyed and the rated maximum speed of the conveying equipment.

[0082] The control device queries the allowable vibration level of the material, which is the upper limit of vibration acceleration that the material can withstand during transportation, expressed in m / s² or G value. Precision instruments have lower allowable vibration levels. Simultaneously, it obtains the rated maximum speed of the conveying equipment, i.e., the maximum speed allowed by the equipment's motor and transmission system. In straight sections, the main factors limiting speed are vibration sensitivity and equipment limits. Using a vibration dynamics model and considering road surface unevenness parameters, the maximum travel speed corresponding to the allowable vibration level is calculated. Then, the smaller value between this maximum travel speed and the rated maximum speed of the conveying equipment is taken as the maximum travel speed in the straight section. For example, an allowable vibration level of 0.5G (approximately 4.9 m / s²) corresponds to a maximum travel speed of 2.0 m / s; since the rated maximum speed of the conveying equipment is 3.0 m / s, the minimum value of 2.0 m / s is taken as the maximum travel speed in the straight section.

[0083] S226: The minimum value among the maximum curve speed, maximum travel speed, and preset safe speed shall be used as the maximum speed in the material dynamics constraint.

[0084] The control device compares the calculated maximum speed on curves, the maximum speed on straight sections, and the preset global safe speed, and takes the minimum value as the maximum speed in the final material dynamics constraint.

[0085] For example, the maximum speed on a curve is 3.43 m / s, the maximum speed on a straight section is 2.0 m / s, and the maximum speed limit specified in the workshop safety regulations is 2.5 m / s. The minimum value of 2.0 m / s is taken as the maximum speed in the material dynamics constraints.

[0086] In this embodiment, a mechanical model based on material size, center of gravity height, and static friction coefficient is established to calculate anti-tipping acceleration, anti-slip acceleration, curve safety speed, and straight-line vibration speed limit, and the minimum value is taken at each level as the final dynamic constraint. This comprehensively ensures the safety and stability of the material throughout the entire conveying process from multiple dimensions, ensuring that the material will not tip over, slip, or be damaged by vibration, whether it is accelerating in a straight line, turning in a curve, or braking in an emergency, while also taking into account the limitations of the equipment hardware capabilities.

[0087] In one embodiment, step S23, namely generating a material conveying trajectory with speed control parameters based on the planned geometric path and material dynamics constraints, specifically includes the following steps: S231: Based on the planned geometric path, an initial transport path that satisfies the motion continuity constraint is constructed in the state space composed of velocity variables, and a time parameter is introduced to transform the initial transport path into a three-dimensional motion trajectory with a timestamp.

[0088] Based on the planned geometric path, the control device constructs a state space with path arc length as the independent variable and velocity as the dependent variable. In this state space, the control device first assigns an initial velocity value to each path point, ensuring that the velocity change between adjacent path points satisfies the motion continuity constraint, i.e., the rate of velocity change does not exceed the maximum acceleration, thus forming an initial transport path represented by (path arc length, velocity). Subsequently, a time parameter t is introduced, and the path arc length s is correlated with time t through the integral relationship t = ∫(1 / v(s))ds, transforming the initial transport path into a three-dimensional motion trajectory with timestamps, expressed in the form (x(t), y(t), z(t), v(t)).

[0089] For example, the geometric path has 100 discrete points, each spaced 0.1m apart. The speed of each point in the initial transport path starts from 0, accelerates from 0.5m / s² to 2.0m / s, and then decelerates back to 0. After time integration, a timestamped trajectory with a total time of approximately 18s is obtained.

[0090] S232: Based on the material dynamics constraints and the kinematic limits of the conveying equipment, construct a state-space equation describing the evolution of the system state over time; the state-space equation includes the velocity variables, acceleration variables, and motion constraints of the conveying equipment.

[0091] The control device combines material dynamics constraints, such as maximum speed vmax and maximum acceleration amax, with the kinematic limits of the conveying equipment itself, such as maximum torque of the drive motor and response delay of the braking system, to establish the state-space equation of the system.

[0092] The state-space equations use the position p(t) and velocity v(t) of the conveying equipment as state variables, and the acceleration a(t) as control input. They are in the form: dp / dt = v(t), dv / dt = a(t), with additional constraints: 0 ≤ v(t) ≤ vmax, |a(t)| ≤ amax. These state-space equations fully describe the dynamic evolution of the system's state (position and velocity) over time t.

[0093] S233: Construct an objective function with conveying time and equipment energy consumption as optimization objectives, use state-space equations as constraints, and perform rolling solution on the three-dimensional motion trajectory to generate a material conveying trajectory that satisfies material dynamics constraints.

[0094] The control device constructs a multi-objective optimization function, weighting and summing the total conveying time (reflecting production efficiency) and equipment energy consumption (reflecting operating costs) as two optimization indicators. Using the established state-space equation as the core constraint, and incorporating material dynamics constraints as additional constraints, a model predictive control algorithm is employed to perform rolling optimization of the trajectory within each control cycle. In each cycle, the algorithm predicts the optimal motion sequence for a future time domain based on the current state, executes only the first control command, and repeats this process in the next cycle, ultimately generating a material conveying trajectory that satisfies all dynamic constraints and achieves an optimal balance between conveying time and energy consumption.

[0095] For example, the multi-objective optimization function can be: J = w1·T_total + w2·Σa²(k)·Δt, where w1=0.7 and w2=0.3. The MPC algorithm predicts the time domain 2s forward in each 50ms control cycle, solves for the acceleration sequence that minimizes J, and generates a smooth and efficient complete trajectory.

[0096] In this embodiment, the path planning problem is transformed into a constrained state-space optimization problem. The solution is rolled over with the dual optimization objectives of transport time and energy consumption, generating an optimal transport trajectory that satisfies both material dynamics safety constraints and production efficiency and energy economy. This achieves efficient, energy-saving, and safe transport of different materials in small-batch production scenarios, significantly improving the flexibility and intelligence of the production line.

[0097] In one embodiment, step S231, namely, constructing an initial transport path that satisfies motion continuity constraints within the state space composed of velocity variables based on the planned geometric path, specifically includes the following steps: S2311: Discretely sample the geometric path according to the preset sampling step size to obtain multiple continuous trajectory sampling points.

[0098] The control device performs equidistant divergence processing on the generated geometric path at fixed arc length intervals, i.e., a preset sampling step size, such as 0.05m or 0.1m. Starting from the path's origin, it samples a location point every step, ultimately obtaining a sequence of N trajectory sampling points. Each sampling point contains its coordinate position information (xi, yi, zi) in two-dimensional or three-dimensional space, as well as the path curvature ki at that point. The selection of the sampling step size requires a trade-off between trajectory smoothness and computational efficiency; a smaller step size results in a more refined trajectory but also increases the computational load.

[0099] For example, for a geometric path with a total length of 30m, the path is discretized with a sampling step size of 0.1m to obtain 300 trajectory sampling points, and the coordinates and curvature values ​​of each point are recorded.

[0100] S2312: Based on the maximum speed and maximum acceleration, assign corresponding running speeds to each trajectory sampling point to generate an initial transport path containing three-dimensional spatial coordinates and running speeds.

[0101] Specifically, for the trajectory sampling points corresponding to the curves and start-stop sections in the geometric path, the assigned running speed is less than the preset transition speed; the preset transition speed is less than the maximum speed and is dynamically calculated based on the geometric position of the preceding and following trajectory sampling points and the curvature of the curve.

[0102] The control device uses the maximum speed and maximum acceleration in the material dynamics constraints as boundary conditions to assign a reasonable operating speed value to each trajectory sampling point. The specific allocation strategy can be as follows: for curved sections in the path (sampling points with curvature greater than a threshold), a safe curved speed less than the maximum speed is assigned to the point based on the curvature radius and the calculation method in step S224; for start-stop sections of the path (i.e., near the start and end points), the speed gradually accelerates or decelerates from zero to cruising speed; and for transition sections of the path (such as the area connecting curves and straight sections), the control device dynamically calculates a preset transition speed based on the geometric positional relationship of adjacent points before and after the current sampling point and the curvature change trend of the curve. This speed is between the curve speed and the cruising speed on the straight section, ensuring the smoothness of speed changes. Finally, after assigning a speed to each sampling point, the generated initial conveying path is a dataset containing three-dimensional spatial coordinates and corresponding operating speeds.

[0103] For example, on a straight section (curvature ≈ 0), a speed of 2.0 m / s is assigned; on a curved section (curvature 0.2 m / s),... - ¹, i.e., R=5m), is given a speed of 1.2m / s; in the transition section before entering the curve from the straight section, the control device dynamically calculates the transition speed as 1.6m / s→1.4m / s→1.2m / s smoothly decreasing based on the curvature of adjacent points gradually changing from 0 to 0.2.

[0104] In this embodiment, by performing discrete sampling of the geometric path at equal steps and combining the transition speed with the curve curvature to accurately allocate the running speed to each sampling point, an initial conveying path that satisfies both material dynamics constraints and has smooth speed transition characteristics is constructed. This effectively avoids the impact and material instability caused by sudden speed changes at the junction of curves and straight sections, providing a good initial solution for subsequent trajectory optimization.

[0105] In one embodiment, step S233 involves constructing an objective function with conveying time and equipment energy consumption as optimization objectives, using the state-space equation as a constraint condition, and performing a rolling solution on the three-dimensional motion trajectory to generate a material conveying trajectory that satisfies the material dynamics constraints. Specifically, this includes the following steps: S2331: The total transport time is estimated based on the transport distance, and the total transport time is divided into prediction time domains to obtain multiple prediction sampling points.

[0106] The control device first estimates the theoretical minimum total conveying time for transporting the material based on the total length of the geometric path and the maximum speed in the material dynamics constraints. This estimated time will be slightly longer than the actual conveying time due to acceleration and deceleration. Subsequently, within the model predictive control framework, a prediction time domain (e.g., 3s) is set, and this prediction time domain is divided into equal intervals according to the control period (e.g., 50ms) to obtain multiple prediction sampling points. Each prediction sampling point corresponds to a future discrete time moment.

[0107] For example, the total path length is 30m, the maximum speed is 2.0m / s, the estimated total transport time is 15s; the prediction time domain is 2s, the control period Δt=0.05s, and 40 prediction sampling points are obtained.

[0108] S2332: At each predicted sampling point, calculate the square of the position deviation between the predicted position of the conveying equipment and the corresponding position on the reference geometric path, as a position deviation penalty term, and calculate the square of the predicted acceleration at each predicted sampling point, as a penalty term for equipment energy consumption and smoothness.

[0109] At each predicted sampling point k, the control device acquires two values: the expected position of the device's future position on the reference geometric path, predicted based on the current state using the state-space equations, and the position deviation between these two values ​​at the predicted time; the square of this deviation is used as a position deviation penalty term, reflecting the trajectory tracking accuracy. Simultaneously, the predicted acceleration at this sampling point is acquired, and its square is used as a penalty term for device energy consumption and smoothness; a larger acceleration indicates higher energy consumption and poorer operational smoothness.

[0110] S2333: The objective function is constructed by weighting and summing the position deviation penalty term, equipment energy consumption and smoothness penalty term, and the total transport time estimated based on the transport distance at each predicted sampling point.

[0111] The control device assigns weight coefficients w1, w2, and w3 to the position deviation penalty, energy consumption and smoothness penalty, and total transport time, respectively, constructing the objective function J = w1·Σe(k)² + w2·Σa(k)² + w3·Ttotal, where the first two terms are summed over all predicted sampling points in the prediction time domain, and the third term is the total transport time of the entire path. The setting of the weight coefficients reflects the emphasis on different optimization objectives: if w1 is larger, trajectory tracking accuracy is prioritized; if w2 is larger, energy saving and smoothness are prioritized; if w3 is larger, transport efficiency is prioritized.

[0112] S2334: In each control cycle, the actual position and speed of the conveying equipment at the current sampling time are used as the initial state, and the objective function is optimized and solved using the state space equation, maximum speed and maximum acceleration as constraints to obtain the optimal control input sequence in the prediction time domain.

[0113] At the beginning of each control cycle, the control device acquires the current actual position and speed of the conveying equipment as the initial state of the optimization problem. Using the established state-space equations as dynamic constraints, the maximum speed and maximum acceleration from the material dynamics constraints as inequality constraints, and the constructed objective function as the optimization objective, optimization algorithms such as quadratic programming or sequential quadratic programming are employed to solve for an optimal sequence of speed commands in the prediction time domain. This sequence of speed commands minimizes the objective function.

[0114] S2335: Extract the first control command from the optimal control input sequence and send it to the conveying equipment for execution. Then, in the next control cycle, roll forward the prediction time domain and repeat the solution to generate a continuous and smooth material conveying trajectory.

[0115] The control device extracts only the first control command from the optimal control input sequence obtained from the solution, and sends it as the execution command for the current cycle. This command is then sent to the drive controller of the conveying equipment via the communication interface. The drive controller then controls the motor to run according to this acceleration command. Upon entering the next control cycle, the control device rolls the overall prediction time domain forward by one sampling step, using the latest actual position and speed of the conveying equipment as the initial state. It repeats the optimization process of step S2333, extracting and executing the new first command again. This process is repeated continuously, with each cycle performing local optimization based on the latest state and executing one command, ultimately generating a continuous, smooth material conveying trajectory that satisfies all constraints.

[0116] For example, in the first cycle, a*(1) = 0.5 m / s² is sent, and the AGV's actual response speed is accelerated to 0.125 m / s; in the second cycle, the speed is re-optimized based on the new position and speed, and a*(1) = 0.48 m / s² is sent, and so on until the material is transported to its destination.

[0117] In this embodiment, a rolling optimization strategy based on model predictive control is adopted. The conveying time, tracking accuracy, and energy consumption are incorporated into a unified objective function for online solution. The trajectory is continuously updated through rolling execution and feedback correction, realizing real-time optimal control of the material conveying process. This effectively addresses model errors and external disturbances that may occur in actual operation, ensuring that the conveying trajectory maintains both global optimality and local robustness. This significantly improves the adaptability, smoothness, and economy of material conveying in small-batch manufacturing.

[0118] In one embodiment, such as Figure 5As shown, step S30, which involves real-time obstacle detection during the transport process to determine the distance to obstacles, specifically includes the following steps: S31: During the material conveying process, the distance sensor mounted at the front end of the conveying equipment transmits a detection signal to the forward direction and receives the reflected signal of the detection signal.

[0119] The ranging sensor includes at least one of lidar, ultrasonic sensors, or millimeter-wave radar. As the conveyor travels along the material transport path, the ranging sensor installed at the front end of the conveyor continuously operates. This type of sensor measures distance by actively emitting electromagnetic or acoustic signals and receiving the reflected signals after encountering an obstacle. Lidar emits a laser beam and uses the pulse-time-of-flight method for ranging, offering high accuracy and good angular resolution; ultrasonic sensors emit ultrasonic waves, suitable for short-range detection and unaffected by light; millimeter-wave radar emits electromagnetic waves in the millimeter-wave frequency band, offering strong anti-interference capabilities and long detection range. The sensor calculates the straight-line distance from the obstacle by multiplying the time difference between the emitted and received reflected signals by the signal propagation speed and then dividing by 2.

[0120] For example, the front end of the conveying equipment is equipped with a single-line lidar and two ultrasonic sensors, which alternately emit laser pulses and ultrasonic pulses at a frequency of 20Hz to collect reflected signals from the environment in front in real time.

[0121] S32: Based on the received reflected signal, calculate the straight-line relative distance between the conveying equipment and the obstacle in front in real time, and use it as the obstacle distance.

[0122] The control device processes the received reflected signals: first, it filters out noise and interference signals, such as multipath reflection and ambient light interference; then, it extracts the effective reflected echoes; and based on the time difference between signal transmission and reception, it calculates the straight-line distance between the sensor and the obstacle, which is the obstacle distance.

[0123] For lidar, scanning angle data can be combined to obtain obstacle location information and generate a two-dimensional or three-dimensional obstacle distribution map of the environment ahead. The control device compares this distance data with a preset distance threshold in real time to determine whether there is a risk of collision.

[0124] For example, in a certain scan, the lidar receives the reflected signal 0.02μs (i.e., 20ns) after emitting a pulse, and calculates the distance d = 3 × 10 8 ×20×10 -9 / 2=3.0m. At the same time, based on the scanning angle of the laser beam (0° directly in front), it is determined that there is an obstacle 3.0m directly in front. The ultrasonic sensor receives the echo 12ms after it emits at another moment, and calculates d=340×0.012 / 2=2.04m. After the two data are fused and verified, the final output obstacle distance is 3.0m. The control device compares this value with the preset deceleration threshold of 2.5m and determines that no deceleration is required.

[0125] This embodiment uses a combination of various ranging sensors to achieve real-time and accurate detection of obstacles in front of the conveying equipment. It can adapt to different environmental conditions such as lighting, temperature, and humidity, providing reliable sensing data support for subsequent obstacle avoidance control and effectively ensuring the safety of material conveying.

[0126] In one embodiment, the preset distance threshold includes a preset deceleration distance threshold and a preset stop distance threshold, wherein the preset deceleration distance threshold is greater than the preset stop distance threshold. Specifically, step S40, where the conveying device is controlled to decelerate, pause, or detour along a preset obstacle avoidance route when the detected obstacle distance is less than the preset distance threshold, includes the following steps: S41: When the distance to the detected obstacle is less than the preset deceleration distance threshold and greater than or equal to the preset stopping distance threshold, control the conveyor to reduce its travel speed to the preset safe slow speed.

[0127] The control device continuously compares the obstacle distances it acquires with preset distance thresholds. The preset deceleration distance threshold is the critical distance at which deceleration is triggered (e.g., 2.5m), while the preset stopping distance threshold is the critical distance at which emergency braking is triggered (e.g., 0.5m), with the former being greater than the latter. When the obstacle distance is less than the preset deceleration distance threshold but greater than or equal to the preset stopping distance threshold, the control device determines there is a moderate collision risk and sends a deceleration command to the drive controller of the conveyor equipment. By adjusting the PWM duty cycle of the drive motor or reducing the speed command value, the current travel speed is reduced from the normal cruising speed (e.g., 2.0m / s) to a preset safe slow speed (e.g., 0.3m / s), allowing the equipment to slowly approach the obstacle at this low speed. This ensures rapid resumption of travel if the obstacle suddenly disappears, or timely braking if the obstacle approaches further.

[0128] For example, when the conveyor is traveling at 2.0 m / s, the lidar detects a placed parts box 1.8 m ahead (meeting 0.5 m ≤ 1.8 m < 2.5 m). The control device immediately sends a deceleration command to the motor driver, setting the target speed to 0.3 m / s. The AGV decelerates to 0.3 m / s with a maximum acceleration of 0.8 m / s² and then moves forward slowly at a constant speed.

[0129] S42: When the distance to the detected obstacle is less than the preset stop distance threshold, control the conveyor to brake and stop in place.

[0130] When the distance d from the obstacle further decreases to less than the preset stopping distance threshold (e.g., 0.5m), the control device determines that there is an emergency collision risk and immediately sends an emergency stop command to the braking system of the conveyor equipment. For conveyor equipment driven by a motor, the control device sends a zero-speed command to the driver and activates regenerative braking or electromagnetic braking to quickly stop the drive motor. For equipment equipped with a mechanical brake, the brake is triggered simultaneously to bring the equipment to a complete stop within the shortest distance, maintaining it in a stationary state. During this period, the control device continuously monitors sensor data to determine whether the obstacle has moved or disappeared.

[0131] S43: When the duration of the in-place pause of the conveying equipment exceeds the preset timeout waiting threshold and the obstacle is not detected to have disappeared, retrieve the pre-stored backup bypass path as the preset obstacle avoidance route.

[0132] After the equipment enters a stationary pause state, the control device starts a timer to record the duration of the pause. A preset timeout threshold (e.g., 30 seconds) is the maximum waiting time set by the system. When the timer shows that the waiting time exceeds this threshold, and the sensor still detects that the obstacle's distance is less than the stop threshold (i.e., the obstacle has not disappeared), the control device determines that the obstacle is a static obstacle (such as temporarily stored materials, equipment under maintenance, etc.), and waiting will not solve the problem. At this time, the control device retrieves a pre-planned alternative bypass path for the current conveying task from local storage or the server database. This path is an alternative route that bypasses the obstacle area and may intersect with the original geometric path after bypassing the obstacle.

[0133] S44: Control the conveying equipment to switch to a preset obstacle avoidance route to bypass obstacles, and switch back to the material conveying track to continue driving after bypassing the obstacles.

[0134] The control unit switches the navigation target of the conveyor to the backup bypass path, sends a new path command sequence to the drive controller, and starts the equipment from the paused position to travel along the backup bypass path. The speed constraints of the backup route also follow material dynamics constraints to ensure safety during the bypass process.

[0135] When the equipment travels along the bypass path to the intersection with the original material conveying trajectory (i.e., the recovery point after bypassing the obstacle), the control device automatically switches the navigation target back to the remaining part of the original material conveying trajectory, and the equipment resumes traveling along the original planned trajectory towards the target node.

[0136] For example, the conveyor starts from the paused position, turns right along the bypass path to bypass the parts box, passes through the backup path points [(0.2, 1.5), (2.0, 1.5), (2.0, 0.0)] in sequence, and reaches the intersection point (2.0, 0.0) with the original trajectory. Then, the control device switches the navigation back to the remaining part of the original trajectory, and the AGV accelerates again to 2.0m / s to move to the next process node.

[0137] In this embodiment, differentiated responses are achieved when obstacles are at different distances by setting graded distance thresholds: actively decelerating to maintain safety when at a long distance, and braking urgently to avoid collision when at a close distance. After a long wait, the system automatically switches to a backup bypass path to bypass static obstacles. This minimizes the impact of interruptions on the conveying task while ensuring safety, avoids production line stagnation caused by the inability to recover after simple braking, and significantly improves the robustness and automation level of the material conveying system in a small-batch manufacturing environment.

[0138] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0139] In one embodiment, a control device is provided, which corresponds one-to-one with the material conveying trajectory control method for small-batch manufacturing described in the above embodiments. For example... Figure 6 As shown, the functional modules in this control device are described in detail below: The acquisition module 601 is used to acquire the physical property parameters and process route of the current batch of materials to be transported; the physical property parameters are a set of data describing the physical properties of the materials to be transported; the process route is used to describe the sequence of process nodes required for the current batch of materials to be transported to be processed or assembled in the workshop. The generation module 602 is used to determine the material dynamics constraints of the material to be transported during the transport process based on physical property parameters, and to generate the material transport trajectory based on the material dynamics constraints and the process route; the material dynamics constraints are the mechanical conditions that need to be met to ensure the stability and safety of the material to be transported. The control module 603 is used to control the conveying equipment to convey the current batch of materials based on the material conveying trajectory. The detection module 604 is used to perform obstacle detection in real time during the conveying process in order to determine the distance to the obstacle; The control module 603 is also used to control the conveying equipment to perform at least one of the following when the distance to the detected obstacle is less than a preset distance threshold: deceleration, pausing, or detouring according to a preset obstacle avoidance route, and to continue conveying the material to be conveyed based on the material conveying trajectory after the obstacle is detected to have disappeared.

[0140] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0141] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0142] This application also provides an electronic device, such as... Figure 7 As shown, the electronic device includes: at least one processor, a memory, and a computer program stored in the memory and executable on the at least one processor. When the processor executes the computer program, it implements the steps in any of the above method embodiments, or when the processor executes the computer program, it implements the functions of each module / unit in the above device embodiments.

[0143] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete this application. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the electronic device.

[0144] Those skilled in the art will understand that Figure 7 The electronic device described is merely an example and does not constitute a limitation on the electronic device. It may include more or fewer components than shown, or combine certain components, or different components. For example, the electronic device may also include input / output devices, network access devices, buses, etc.

[0145] The processor mentioned above can be a central processing unit, or it can be other general-purpose processors, digital signal processors, application-specific integrated circuits, field-programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0146] The memory can be an internal storage unit of the electronic device, such as a hard drive or RAM. The memory can also be an external storage device of the electronic device, such as a plug-in hard drive, smart memory card, secure digital card, flash memory card, etc. Furthermore, the memory can include both internal and external storage units of the electronic device.

[0147] This application also provides a readable storage medium storing a computer program that, when executed by a processor, implements the steps described in the various method embodiments above.

[0148] This application provides a computer program product that, when run on an electronic device, enables the electronic device to perform the steps described in the various method embodiments above.

[0149] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying the computer program code to a photographic device / terminal device, a recording medium, a computer memory, a read-only memory, a random access memory, an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.

[0150] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0151] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0152] In the embodiments provided in this application, it should be understood that the disclosed apparatus / devices and methods can be implemented in other ways. For example, the apparatus / device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0153] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0154] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A material conveying trajectory control method for small-batch manufacturing, characterized in that, include: Obtain the physical property parameters and process route of the materials to be transported in the current batch; the physical property parameters are a set of data describing the physical properties of the materials to be transported. The process route is used to describe the sequence of process nodes required for the current batch of materials to be transported to be processed or assembled in the workshop. The material dynamics constraints of the material to be transported during the transport process are determined based on the physical property parameters, and the material transport trajectory is generated based on the material dynamics constraints and the process route; the material dynamics constraints are the mechanical conditions that need to be met to ensure the stability and safety of the material to be transported. Based on the material conveying trajectory, the conveying equipment is controlled to convey the current batch of materials to be conveyed, and obstacle detection is performed in real time during the conveying process to determine the distance of obstacles; When the distance to the obstacle is detected to be less than a preset distance threshold, the conveying equipment is controlled to perform at least one of the following: deceleration, pausing, or detouring according to a preset obstacle avoidance route. After the obstacle is detected to have disappeared, the conveying equipment continues to transport the material to be transported based on the material conveying trajectory.

2. The method as described in claim 1, characterized in that, The physical property parameters include the size, weight, and center of gravity height of the material to be transported; the process of determining the material dynamics constraints of the material to be transported during the transport process based on the physical property parameters, and generating a material transport trajectory based on the material dynamics constraints and the process route, includes: Based on the process route, determine all conveying nodes for conveying the material to be conveyed, and based on the order and position of all the conveying nodes, plan the geometric path connecting each of the conveying nodes; Based on the size, weight and center of gravity height of the material to be conveyed, the material dynamics constraints of the conveying equipment when conveying the material to be conveyed are determined. The material dynamics constraints include at least the maximum speed and maximum acceleration when conveying the material to be conveyed. Based on the planned geometric path and the material dynamics constraints, the material conveying trajectory with speed control parameters is generated.

3. The method as described in claim 2, characterized in that, The process of generating the material conveying trajectory with speed control parameters based on the planned geometric path and the material dynamics constraints includes: Based on the planned geometric path, an initial transport path that satisfies motion continuity constraints is constructed in the state space composed of velocity variables, and a time parameter is introduced to transform the initial transport path into a three-dimensional motion trajectory with a timestamp. Based on the material dynamics constraints and the kinematic limits of the conveying equipment, a state-space equation describing the evolution of the system state over time is constructed; the state-space equation includes the velocity variables, acceleration variables, and motion constraints of the conveying equipment. An objective function is constructed with conveying time and equipment energy consumption as optimization objectives. The state-space equation is used as a constraint condition to solve the three-dimensional motion trajectory in a rolling manner, thereby generating a material conveying trajectory that satisfies the material dynamics constraints.

4. The method as described in claim 3, characterized in that, The initial transport path, based on the planned geometric path, is constructed within a state space composed of velocity variables, satisfying motion continuity constraints. This includes: The geometric path is discretely sampled according to a preset sampling step size to obtain multiple continuous trajectory sampling points; Based on the maximum speed and the maximum acceleration, a corresponding running speed is assigned to each of the trajectory sampling points to generate the initial transport path containing three-dimensional spatial coordinates and running speed; Specifically, for the trajectory sampling points corresponding to the curves and start-stop sections in the geometric path, the assigned running speed is less than a preset transition speed; the preset transition speed is less than the maximum speed and is dynamically calculated based on the geometric positions of the preceding and following trajectory sampling points and the curvature of the curves.

5. The method according to any one of claims 1-4, characterized in that, The process of obtaining the physical property parameters of the current batch of materials to be transported includes: When any of the materials to be conveyed in the current batch is detected in the feeding area of ​​the conveying equipment, the three-dimensional point cloud data of the materials to be conveyed is collected by visual sensors deployed around the feeding area. The three-dimensional dimensions and centroid coordinates of the material to be transported are extracted from the three-dimensional point cloud data, and the height of the center of gravity of the material to be transported is determined based on the three-dimensional dimensions and centroid coordinates. The weight of the material to be transported is collected in real time by weighing sensors deployed in the feeding area, and the three-dimensional dimensions, weight and center of gravity height are output as physical property parameters of the material to be transported.

6. The method according to any one of claims 1-5, characterized in that, The preset distance threshold includes a preset deceleration distance threshold and a preset stop distance threshold, wherein the preset deceleration distance threshold is greater than the preset stop distance threshold; Wherein, when the distance to the detected obstacle is less than a preset distance threshold, controlling the conveying device to perform at least one of deceleration, pausing, or detouring according to a preset obstacle avoidance route includes: When the distance to the obstacle is detected to be less than the preset deceleration distance threshold and greater than or equal to the preset stopping distance threshold, the conveying equipment is controlled to reduce its travel speed to a preset safe slow speed. When the distance to the obstacle is detected to be less than the preset stop distance threshold, the conveying equipment is controlled to brake and stop in place.

7. A material conveying trajectory control system for small-batch manufacturing, characterized in that, Includes a control device, the control device comprising: The acquisition module is used to acquire the physical property parameters and process route of the materials to be transported in the current batch; the physical property parameters are a set of data describing the physical properties of the materials to be transported; the process route is used to describe the sequence of process nodes required for the processing or assembly of the materials to be transported in the current batch in the workshop. The generation module is used to determine the material dynamics constraints of the material to be transported during the transport process based on the physical property parameters, and to generate the material transport trajectory based on the material dynamics constraints and the process route; the material dynamics constraints are the mechanical conditions that need to be met to ensure the stability and safety of the posture of the material to be transported. The control module is used to control the conveying equipment to convey the current batch of materials to be conveyed based on the material conveying trajectory. The detection module is used to detect obstacles in real time during the transportation process in order to determine the distance to obstacles; The control module is also used to control the conveying device to perform at least one of the following when the distance to the obstacle is detected to be less than a preset distance threshold: deceleration, pausing, or detouring according to a preset obstacle avoidance route, and to continue conveying the material to be conveyed based on the material conveying trajectory after the obstacle is detected to have disappeared.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the material transport trajectory control method for small-batch manufacturing as described in any one of claims 1 to 6.

9. A readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the material transport trajectory control method for small-batch manufacturing as described in any one of claims 1 to 6.

10. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the material transport trajectory control method for small-batch manufacturing as described in any one of claims 1 to 6.

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