A fast food full-process unmanned automatic lunch box filling method and system

Abstract

This invention belongs to the field of lunchbox filling technology, specifically relating to a fully automated, unmanned lunchbox filling method and system for the entire fast food process. Through a controller coordinating a feeding robot, a conveyor system, multiple loading robots, a capping robot, and an unloading robot, it achieves complete automation from empty lunchbox loading, quantitative filling of multiple dishes, lid sealing, to finished product unloading. The conveyor system operates continuously, with each station positioned based on vision or sensors, and the loading robots completing the filling in a dynamic, synchronized manner. The entire process is automated, and the central control system allows for rapid switching of meal recipes and lunchbox specifications to adapt to various scenarios. It improves production efficiency and filling accuracy, reduces human intervention, ensures food safety and operational stability, and is suitable for automated fast food production lines.

Description

Technical Field

[0001] This invention belongs to the field of lunchbox filling technology, specifically relating to an unmanned automatic lunchbox filling method and system based on the entire fast food process. Background Technology

[0002] Against the backdrop of rapid industrialization and intelligent development in the catering industry, large-scale catering scenarios such as fast food, group meals, central kitchens, and pre-prepared meal delivery have placed higher demands on production efficiency and food safety control. The lunchbox filling process sequentially packs rice, meat dishes, vegetable dishes, and soup into multi-compartment lunchboxes, followed by subsequent processes such as lidding and stacking.

[0003] The fast food catering industry mostly uses manual box packing. The number of boxes that a single worker can pack per minute is limited. Long hours of repetitive work can easily lead to fatigue, resulting in large fluctuations in packing speed and unstable overall production capacity.

[0004] Catering companies using related technologies employ box-packing equipment. However, steps such as box positioning, food filling, and capping require machine downtime, and the coordination between these processes relies on manual assistance. This poor continuity of equipment operation not only reduces overall efficiency but also increases the frequency of manual intervention. Summary of the Invention

[0005] This invention provides an automated lunchbox filling method for the entire fast food process, integrating manual operations into a continuous and predictable mechanical cycle, enabling long-term operation. The entire process isolates human contact, meets food safety production standards, and adapts to the flexible production needs of large-scale meal preparation.

[0006] The methods include: S1: The controller controls the loading robot to grab empty lunch boxes from the loading position and place them at the starting end of the conveyor device. The conveyor device then arranges and positions them at a preset interval and transports them to the first loading station. S2: The first loading robot located at the first loading station grabs the first food from the first food supply container based on position awareness and quantitatively loads it into the first empty space area of ​​the lunch box; S3: The conveying device continues to transport the lunch box containing the first food to the front, and locates and transports it to the second loading station based on position perception; S4: The second loading robot, located at the second loading station, grabs the second food from the second food supply container based on position awareness and quantitatively loads it into the second empty space area of ​​the lunch box; S5: The conveying device continues to transport the lunch boxes to the subsequent loading stations in sequence. The corresponding loading robots at each station are guided by position perception to complete the quantitative filling of food in all subsequent empty areas in sequence. S6: The conveying device transports the filled lunchbox to the capping station and positions it. The controller controls the capping robot to pick up the lid and press it onto the lunchbox. S7: The conveying device transports the packaged finished lunch boxes to the unloading area and positions them, and the controller controls the unloading robot to move them out of the conveying device.

[0007] Preferably, in step S1, the controller controls the loading robot to grab empty lunch boxes from the loading position and place them at the starting end of the conveying device. The conveying device then arranges and positions the lunch boxes at a preset interval and transports them to the first loading station. This specifically includes the following steps: S11: Based on the inlet sensor, the actual distance between adjacent lunch boxes is measured, and the feeding rhythm or conveying speed is adjusted to make the lunch box queue enter the main conveying section at a preset distance. S12: Calculate and update the real-time position coordinates of each lunchbox on the main conveyor section using the trigger sequence of multiple positioning sensors on the main conveyor section and the known positions; S13: The first loading robot plans and executes a trajectory synchronized with the movement of the lunchbox based on the received real-time position coordinates of the lunchbox, and achieves speed and position alignment at the loading point to complete the loading.

[0008] Preferably, in step S2, the step of grabbing the first food from the first food supply container based on location awareness and quantitatively loading it into the first empty space area of ​​the lunchbox specifically includes the following steps: S21: Identify the material picking point and the center of the lunchbox empty space using a calibrated industrial camera, and calculate their three-dimensional coordinates in the robot coordinate system; S22: The robot moves to the grasping coordinate, and after confirming with the torque sensor that the gripper can reliably grasp the food, it lifts up. S23: During the robot's movement, the weighing sensor detects the weight in real time and adjusts it to the target value by replenishing or shaking it off; S24: The robot moves to the delivery coordinates, descends and opens its grippers to release the food, then lifts up and moves out along an inclined trajectory.

[0009] Preferably, in step S21, calculating the three-dimensional coordinates of both objects in the robot coordinate system specifically includes the following steps: S211: The controller triggers the industrial camera after the lunchbox is in place to capture two images: the material picking point and the empty space in the lunchbox. S212: The controller processes the image of the material picking point, identifies the preset position marker, and determines its two-dimensional pixel coordinates; S213: The controller calls the calibration parameters and calculates the three-dimensional grasping coordinates of the picking point into the robot coordinate system by combining the two-dimensional coordinates of the picking point with the known height; S214: The controller processes the image of the empty space in the lunchbox, identifies the center of the empty space and calculates it into three-dimensional projection coordinates, and then sends the two sets of coordinates to the robot.

[0010] Preferably, in step S22, the robot moves to the grasping coordinate, and after confirming with the torque sensor that the gripper has reliably grasped the food, it lifts the robot, specifically including the following steps: S221: The controller configures a spatial trajectory that includes safe lifting, horizontal movement, and vertical descent segments, with the target grasping coordinates and the current position as the starting and ending points. S222: The controller discretizes the spatial trajectory, solves it using inverse kinematics, and generates a sequence of position command sequences for the servo motors of each joint. S223: The controller sends joint position commands to the servo driver, which drives the joint motors to move, so that the robot end effector moves along the planned trajectory. S224: The controller calculates the actual coordinates of the end effector using feedback from the joint encoder and positive kinematics, and determines that the end effector is in position when the deviation from the target coordinates is less than a threshold.

[0011] Preferably, in step S3, the conveying device continues to transport the lunchbox already filled with the first food forward, and locates and transports it to the second loading station based on position sensing, specifically including the following steps: S31: After the position sensor is triggered by the lunchbox, the controller binds the event and records the encoder pulse value as the starting reference for position tracking; S32: The controller accumulates encoder pulses, calculates the difference from the initial reference, and multiplies it by the pulse equivalent to obtain the real-time movement distance of the lunchbox; S33: The second loading robot obtains the current position of the lunchbox, plans and executes a synchronous motion trajectory, and completes the food filling in a relatively static state.

[0012] Preferably, in step S33, the second loading robot acquiring the current position of the lunchbox specifically includes the following: S331: The controller writes the calculated lunchbox position and speed data into the transmission data area in each control cycle; S332: The controller encapsulates the data into message frames and sends them to the second loading robot controller in each communication cycle; S333: The second loading robot controller decodes the message frame, extracts the lunchbox position and speed data, and stores them in the variable area; S334: The second loading robot calculates motion instructions based on the read lunchbox data and drives the end effector to move to a state synchronized with the lunchbox.

[0013] Preferably, in S33, planning and executing a synchronous motion trajectory to complete the food filling in a relatively static state specifically includes the following: S3311: The second loading robot controller compares the real-time position of the lunchbox with the distance to the loading point, and generates a task start command when the distance is less than a preset threshold. S3312: Based on the state of the lunchbox at the time of triggering, the robot controller plans a sequence of operation trajectories that synchronize the speed of the end effector with that of the lunchbox at the filling point; S3313: When the robot executes its trajectory, it fine-tunes the end target command online based on the latest position data of the lunchbox to maintain alignment with the position of the lunchbox. S3314: Once the robot and the lunchbox reach a relatively stationary state, the robot will grasp the food and drop it down vertically.

[0014] Preferably, in step S6, the conveying device transports the filled lunchbox to the capping station and positions it, and the controller controls the capping robot to pick up the lid and press it onto the lunchbox. Specifically, this includes the following: S61: When the photoelectric sensor detects that the lunchbox has arrived at the lid-pressing station, the controller receives the positioning signal; S62: The controller drives the capping robot to pick up the caps from the cap warehouse, and the sensor confirms that the cap retrieval is complete; S63: The lid-pressing robot moves the lid above the lunchbox and uses sensors to adjust and align the two centers. S64: The lid-pressing robot presses the lid onto the lunchbox, and releases and resets the lid after reaching the preset pressure.

[0015] According to another embodiment of this application, an unmanned automatic lunchbox filling system based on the entire fast food process is provided. The system includes: a controller, a feeding robot, a conveying device, a first loading robot, a second loading robot, a capping robot, and a discharging robot. The controller controls the loading robot to grab empty lunch boxes from the loading position and place them at the starting end of the conveyor device. The conveyor device then arranges and positions them at a preset interval and transports them to the first loading station. The first loading robot, located at the first loading station, grabs the first food from the first food supply container based on position awareness and quantitatively loads it into the first empty space area of ​​the lunch box; The conveying device continues to transport the lunch box containing the first food ingredient forward, and locates and transports it to the second loading station based on position sensing; The second loading robot, located at the second loading station, grabs the second food from the second food supply container based on position awareness and quantitatively loads it into the second empty space area of ​​the lunch box; The control area controls the conveyor to continue transporting the lunch boxes to the subsequent loading stations in sequence. The corresponding loading robots at each station are guided by position perception to complete the quantitative filling of food in all subsequent empty areas in sequence. The control area controls the conveyor to transport the filled lunch boxes to the capping station and position them. The controller controls the capping robot to pick up the lids and press them onto the lunch boxes. It also transports the packaged finished lunch boxes to the unloading area, where the controller controls the unloading robot to remove them from the conveyor.

[0016] As can be seen from the above technical solutions, the present invention has the following advantages: This invention provides an automated, unmanned lunchbox filling method for the entire fast food process. A controller manages a feeding robot, a loading robot, a capping robot, an unloading robot, and a conveyor system working collaboratively. The conveyor system operates continuously, and each robot at each workstation completes its corresponding process synchronously based on feedback signals from sensors and position sensing technology, eliminating the need for downtime. This forms a continuous, uninterrupted lunchbox filling workflow, ensuring a stable production line pace and enabling 24 / 7 operation to handle large-volume orders. Each loading workstation is equipped with position sensing devices and weighing sensors to guide the robot in locating the food supply container and the empty space in the lunchbox. The weighing sensors provide real-time feedback on the weight of the food being grasped; once a preset value is reached, the robot stops grasping and performs the filling action. Robots replace manual labor in all aspects of lunchbox handling, including feeding, filling, capping, and unloading, operating in a fully closed system. This eliminates direct human contact with the food, improving hygiene standards. Position sensing technology tracks the lunchbox position in real time, and the controller pre-schedules the corresponding robot based on the lunchbox position signal. The robot and conveyor system move synchronously, enabling simultaneous conveying and operation. There is no need to stop and wait between each process, ensuring smooth transitions. The capping robot is equipped with a vacuum suction cup and a pressure sensor at its end. The vacuum suction cup precisely picks up the lid, while the pressure sensor provides real-time feedback on the capping force. The controller controls the capping action based on a preset pressure threshold. The capping force is uniform and consistent, resulting in a high degree of seal and preventing loosening or deformation of the lid. Attached Figure Description

[0017] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying 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.

[0018] Figure 1 Flowchart of an automated lunchbox filling method for the entire fast food process; Figure 2 This is a sequence diagram of an automated lunchbox filling method for the entire fast food process. Figure 3 This is a schematic diagram of an automated lunchbox filling system based on the unmanned operation of the entire fast food process. Detailed Implementation

[0019] The present invention provides an automated, unmanned lunchbox filling method for the entire fast food process, in which a controller controls robots and a conveying device to work together. Empty lunchboxes are placed onto the conveying device by a loading robot, arranged at fixed intervals using sensors or vision technology, and then delivered to the first loading station. At each station, robots, guided by vision or sensors, quantitatively grasp the corresponding food ingredients and fill them into designated areas of the lunchboxes. After filling multiple dishes, the lunchboxes are transported to the capping station, where a capping robot performs the sealing operation. Finally, the finished lunchboxes are removed from the conveying device by an unloading robot, all without human intervention. This method enables continuous operation for extended periods, maintains a stable filling rhythm, ensures precise food quantity, eliminates filling position deviations, and guarantees standardized meal production.

[0020] The following describes in detail the automated lunchbox filling method for the entire fast food process that pertains to this application. Specific details, such as particular system structures and technologies, are presented for illustrative purposes and not for limitation, to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application can also be implemented in other embodiments without these specific details.

[0021] It should be understood that, when used in this specification, the term "comprising" indicates the presence of the described feature, integral, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. The terms "comprising," "including," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0022] To facilitate a clear description of the technical solutions of this application, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that the terms "first" and "second" do not necessarily imply that they are different.

[0023] 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 embodiments of the present invention, and not all embodiments. 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.

[0024] Please see Figure 1 and Figure 2 The diagram shows a flowchart of a fully automated, unmanned fast food box filling method based on a specific embodiment. The method includes: S1: Empty lunchbox loading and positioning steps: The controller controls the loading robot to grab empty lunchboxes from the loading position and place them at the starting end of the conveyor device. The conveyor device then arranges and positions the lunchboxes at a preset interval and transports them to the first loading station. In some embodiments, the feeding robot uses a four-axis tandem robotic arm with flexible silicone grippers at its end. The grippers' opening stroke is adapted to the width of common fast food containers to avoid squeezing and deformation during gripping. The conveying device in this embodiment uses a stainless steel chain conveyor belt with anti-slip rubber pads attached to the surface to prevent slippage of the containers during transport.

[0025] As an embodiment of the present invention, S1 specifically includes the following steps: S11: In the entrance section of the conveying device, two photoelectric sensors with a fixed distance between them are installed side by side along the conveying direction to form a spacing measurement unit; when empty lunch boxes pass through these two sensors in sequence, the controller calculates the actual spacing between two adjacent lunch boxes based on the time difference between the triggering of the two sensors and the current running speed of the conveying device. Furthermore, the controller compares this actual spacing with the preset target spacing of lunch boxes, and dynamically adjusts the timing of the feeding robot releasing the next empty lunch box or fine-tunes the speed of the inlet section conveyor belt based on the deviation value, so that the subsequent lunch box queue entering the main conveyor line automatically forms and maintains the preset spacing.

[0026] In some embodiments, two sensors with a fixed spacing are used to non-contactly measure the distance between passing lunch boxes, specifically based on displacement calculations of speed and time difference.

[0027] The controller starts timing when the leading edge of the first lunchbox triggers sensor A; timing stops when the leading edge of the lunchbox triggers sensor B downstream.

[0028] Based on the known sensor spacing L and the passage time T1, the instantaneous velocity of the lunchbox at this moment can be calculated as V = L / T1.

[0029] When the second lunchbox triggers sensor A, the controller starts the second timing until sensor B is triggered, obtaining time T2, and thus its speed.

[0030] Furthermore, the controller records the time interval Δt between the first lunchbox leaving sensor A and the second lunchbox arriving at sensor A. Therefore, the actual distance Sactual between the two lunchboxes can be obtained using the formula Sactual = V * Δt. Δt can be estimated using the velocity V of the first lunchbox.

[0031] Furthermore, after obtaining Sactual, the controller compares it with the preset Starget.

[0032] If the spacing is too small, the controller can delay the instruction of the feeding robot to release the next lunchbox, or briefly reduce the speed of the inlet section conveyor belt to slow down the subsequent lunchboxes, thereby increasing the spacing.

[0033] If the spacing is too large, the opposite operation is performed. Through this feedforward or feedback adjustment, the lunch boxes are gradually adjusted into a uniformly spaced queue within the entrance section.

[0034] In this way, by pre-shaping, the flow of lunch boxes entering the main conveyor line is ensured to be stable and predictable. This provides a stable and periodic work rhythm for all downstream robots that need to work in sync with the lunch boxes, thereby improving the overall operational stability and rhythm of the line from the source.

[0035] S12: Several positioning sensors are installed at equal intervals along the length of the main conveying section of the conveying device; after each lunch box enters the main conveying section, whenever it triggers a precise positioning sensor, the controller records the unique identification number of the sensor and the trigger time; combined with the known sensor installation position coordinates and the constant running speed of the conveying device, the controller continuously calculates the real-time and absolute position coordinates of each lunch box on the main conveying section through linear interpolation.

[0036] In some embodiments, discrete absolute position reference points are combined with continuous interpolation calculations. Positioning sensors, which can be photoelectric or inductive, are installed at fixed intervals along the main conveyor section, and each sensor is assigned an address code in the controller.

[0037] As a lunchbox moves at a constant speed on the conveyor belt, it passes through these sensors in sequence. Each time a sensor is triggered, it's as if the lunchbox has learned a known absolute coordinate point.

[0038] The controller tracks which lunchbox, at what time, and which sensor was triggered by its ID or sequence. Since the conveyor operates at a constant speed V, the position of the lunchbox between the two sensors can be accurately calculated using a simple linear motion formula: Current position = absolute coordinates of the last triggered sensor + V * (current time - last trigger time).

[0039] In this way, the controller can know the precise location at any given time, even if the lunchbox is positioned between the two sensors. This real-time location data is continuously updated and broadcast as status information to all downstream devices that need it.

[0040] S13: The first loading robot, set up at the first loading station, receives the current position coordinates of the target lunchbox from the controller in real time through the control network; the motion planner of the first loading robot calculates in advance the robot trajectory required to synchronize with the lunchbox based on the position coordinates and the constant speed of the conveying device.

[0041] When the lunchbox enters the robot's working range, the robot drives its end effector to start and move along the calculated trajectory. When the lunchbox reaches the preset filling point, the end effector achieves speed synchronization and position alignment with the lunchbox in the horizontal direction, thereby completing the grabbing and delivery of the first food while the two are relatively stationary.

[0042] In some embodiments, the first loading robot does not wait for the lunchbox to come to a stop, but rather the controller obtains the real-time location data stream of the target lunchbox from step S12.

[0043] Furthermore, the robot's motion planner performs calculations in advance: assuming the lunchbox moves along a straight line at a constant speed Vtray, its future arrival time at the robot's work point, Tmeet, is predictable.

[0044] Furthermore, the controller generates a spatial trajectory so that the robot's end effector, such as a gripper or spoon, also moves to the work point at time Tmeet, and its horizontal movement speed at that point is equal in magnitude and direction to the lunchbox speed V_tray.

[0045] In this embodiment, the trajectory is planned as a smooth spatial curve. The robot accelerates from its standby position, meets the lunchbox at the work point, and maintains relative stillness with the lunchbox for a short time window near the meeting point. During this brief period of stillness relative to the ground, the robot performs a precise delivery maneuver. After completing the maneuver, the robot decelerates along the planned trajectory and returns to the standby point to prepare for the next lunchbox. Throughout the entire process, both the conveyor belt and the lunchbox maintain a constant speed without any pauses.

[0046] Step S2: The first loading robot, positioned at the first loading station, grasps the first food from the first food supply container based on the guidance of the first loading position visual perception technology or the first loading position sensor, and quantitatively loads the first food into the first empty space area of ​​the lunchbox located at the first loading station.

[0047] In some embodiments, a CMOS camera is provided at the first loading station, with a field of view covering the discharge port of the first food supply container and the first empty space area of ​​the lunch box.

[0048] Furthermore, a laser displacement sensor is installed next to the camera to detect the position of the lunchbox. The end effector of the first loading robot is selected according to the form of the first food: a multi-claw silicone gripper is used for solid granular food, and a drip-proof vacuum suction cup is used for liquid food.

[0049] The first loading robot's actuator integrates a weighing sensor. During operation, an industrial camera captures images and identifies the center coordinates of the first empty space area. A laser displacement sensor corrects positional deviations, and the controller converts the coordinate data into robot joint movement commands. The robot drives the actuator to grasp the food, and the weighing sensor provides real-time weight feedback. When the weight reaches a preset threshold, the grasping stops, and the food is then precisely delivered into the first empty space area of ​​the lunchbox.

[0050] As can be seen, accurate target position data is obtained through visual recognition of industrial cameras and deviation compensation of laser displacement sensors; the controller converts the position data into motion parameters that the robot can execute, and combines it with the real-time weight feedback of the weighing sensor to form a closed-loop control, thereby realizing quantitative grasping and filling of food.

[0051] S3: Transmission and positioning step, the transmission device continues to transport the lunch box containing the first food forward, and positions and transports it to the second loading station based on position perception.

[0052] In some embodiments, a rotary encoder is coaxially mounted on the output shaft of the drive motor of the conveying device, and the encoder signal terminal is connected to the counting unit of the controller.

[0053] Furthermore, when the lunchbox that has completed the first feeding leaves the first loading station, the photoelectric sensor at the end of the station triggers the controller, which records the cumulative pulse value of the encoder at this moment as the initial reference value. The controller collects the encoder pulse signal in real time through the high-speed counting unit, continuously calculates the difference between the current cumulative pulse value and the initial reference value, and calculates the real-time moving distance of the lunchbox; when the distance display shows that the lunchbox is a certain distance away from the second loading station, the controller sends a pre-start signal to the second loading robot.

[0054] As can be seen, the incremental rotary encoder converts the mechanical rotational displacement of the conveying device into electrical pulse signals. The controller tracks the movement of the lunchbox in real time by counting pulses and converting pulse equivalents, triggering the downstream workstation robot to start in advance, shortening the operation waiting time, and improving the overall production line cycle time.

[0055] S4: The second loading robot, positioned at the second loading station, grasps the second food from the second food supply container and quantitatively loads the second food into the second empty space area of ​​the lunchbox located at the second loading station, guided by the second loading position visual perception technology or the second loading position sensor.

[0056] In some embodiments, the detection angle of the laser displacement sensor at the second loading station is adjusted to 30° with the conveying plane to ensure that the detection light is not blocked by the first loaded food. The second loading robot uses a six-axis serial robotic arm, and the end effector adopts a quick-change structure, equipped with grippers with scraping structures for sticky foods.

[0057] Furthermore, the weighing sensor integrated into the actuator of the second loading robot is preset with a weight threshold that matches the second food item. During operation, the position sensing system obtains the coordinates of the outlet of the second food item supply container and the second empty space area of ​​the lunch box. The controller drives the robot to grab the food item, and after the weight reaches the threshold, it adjusts the actuator posture to avoid the first food item and loads the second food item into the corresponding empty space area.

[0058] Furthermore, based on visual recognition with added polarization filters and laser positioning after angle adjustment, the target position is obtained without interference; the controller drives the six-axis robot to move along the planned trajectory, and combined with weighing closed-loop control, the second food is quantitatively filled, while avoiding already filled food.

[0059] S5: The conveying device continues to transport the lunch boxes to at least one subsequent loading station in sequence, and positions them based on the visual perception technology or the sensor sensing of the conveying position. The corresponding loading robots set up at each of the subsequent loading stations then grab food from the corresponding food supply containers in sequence and quantitatively load the food into the corresponding empty space area of ​​the lunch box until all empty spaces in the lunch box are filled with food.

[0060] In some embodiments, each subsequent loading station adopts a modular design, with the position sensing system and robot configuration of each station being consistent with the second loading station, and the camera parameters, actuator type and weighing threshold being adjusted only according to the characteristics of the corresponding food.

[0061] Furthermore, the controller pre-stores filling parameters for different meal recipes, including the quantitative values ​​of each ingredient, the coordinates of the corresponding empty areas, and the operation sequence. The lunchboxes pass through each subsequent workstation in sequence with the conveyor device. When the photoelectric sensor at each workstation detects the arrival of the lunchbox, it triggers the controller to call up the corresponding recipe parameters, driving the robot at that workstation to complete the grasping, quantitative, and filling actions according to the preset sequence, until all empty areas of the lunchbox are filled with food.

[0062] S6: The conveying device transports the lunch box with the food filling completed to the capping station and positions it based on the capping position visual perception technology or the capping position sensor; the controller responds to the positioning signal of the capping station, controls the capping robot set at the capping station to pick up the lid and transport the lid to the top of the lunch box located at the capping station to perform the capping operation.

[0063] In some embodiments, a diffuse reflection photoelectric sensor is installed on the side of the capping station to identify whether the lunchbox has arrived at the work area. An inclined lid holder is set up next to the station, using gravity to automatically fit the lid onto the holder's outlet. A miniature photoelectric sensor is installed at the holder's outlet to detect whether the lid is in place.

[0064] Furthermore, a silicone vacuum suction cup is installed at the end of the capping robot, and the suction cup base integrates a pressure sensor.

[0065] During operation, once the sensor detects that the lunchbox is in place, the controller drives the robot to move to the lid storage compartment. The vacuum generator is activated to create negative pressure to suck up the lid. After the sensor at the outlet of the compartment confirms that the lid has been successfully retrieved, the robot carries the lid and moves it above the lunchbox.

[0066] After visual positioning confirms that the lid is aligned with the lunchbox, the robot lowers the lid at a constant speed. The pressure sensor provides feedback on the pressing force, and the robot holds the pressure for a certain period of time after reaching the preset value. Then, the vacuum generator stops working, and the robot resets.

[0067] Step S7: The conveying device transports the finished lunch box after the capping is completed to the unloading area and positions it based on visual perception technology or unloading position sensor. The controller responds to the positioning signal of the unloading area and controls the unloading robot set in the unloading area to grab the finished lunch box and move the finished lunch box out of the conveying device to complete the unloading.

[0068] In some embodiments, a diffuse reflection photoelectric sensor is installed in the unloading area to detect whether the finished lunch box has reached the unloading position. The unloading robot uses a four-axis robotic arm with anti-slip and anti-scratch rubber grippers at the end, and the opening and closing stroke of the grippers is adapted to the width of the finished lunch box.

[0069] Furthermore, the controller pre-stores the coordinate parameters of the feeding position and the finished product storage area. When the sensor detects that the finished lunch box is in place, the controller drives the robot to move above the lunch box, and the gripper grabs the lunch box with a preset clamping force to avoid clamping too tightly and damaging the seal.

[0070] The robot moves the lunchboxes out of the conveyor according to the planned trajectory and places them in the finished product storage area. After completion, it resets to the standby position to wait for the next finished lunchbox.

[0071] In this embodiment, the anti-slip and anti-scratch grippers can protect the appearance and sealing of the finished lunch box, preventing leakage during transportation; the precise material placement ensures that the finished lunch boxes are stored in an orderly manner, without any stacking or disorder.

[0072] In one embodiment of the present invention, S2, guided by a first loading position visual perception technology or a first loading position sensor, the process of grabbing the first food from the first food supply container and quantitatively loading the first food into the first empty space area of ​​the lunchbox located at the first loading station specifically includes the following steps: S21: An industrial camera is fixedly installed above the first loading station. The field of view of the industrial camera simultaneously covers the discharge area of ​​the first food supply container and the filling area of ​​the lunch box located at the first loading station. Before the system is started, the industrial camera is calibrated to establish a mapping relationship between the camera image coordinate system and the coordinate system of the first loading robot base; Before each loading operation, the industrial camera takes pictures of the designated picking point of the first food supply container and the center position of the first empty space in the lunch box. The two-dimensional pixel coordinates of the two are identified by the visual processing algorithm. Then, the corresponding three-dimensional spatial coordinates in the coordinate system of the first loading robot base are calculated according to the calibration mapping relationship, which are used as the target grasping coordinates and target delivery coordinates of the robot.

[0073] In some embodiments, an industrial camera installed in a fixed position undergoes a calibration process, during which its internal parameters and external parameters relative to the robot base are obtained, thereby constructing a transformation matrix from camera pixel coordinates (u,v) to robot world coordinates (X,Y,Z).

[0074] During operation, the camera takes pictures of the material collection point and the empty space in the lunchbox. The visual processing algorithm first extracts features from the image of the material collection point, such as identifying the container edge or preset marker points, and determines the pixel position of the material collection center through template matching or feature point detection.

[0075] Furthermore, for the image of the lunchbox, the algorithm identifies the outline of the lunchbox through edge detection, and then calculates the pixel position of the geometric center of the specified first empty space region in the image based on the pre-stored CAD model or size parameters of the lunchbox.

[0076] These two pixel coordinates are calculated separately using the same transformation matrix to obtain three-dimensional spatial coordinates that the robot can directly use. This ensures that regardless of slight shifts in the food container position due to refilling or deviations in the lunchbox's positioning on the conveyor belt, the robot can find the accurate operating position based on real-time visual information. This method solves the positioning problem for grasping and delivery with a single vision system, requiring only one system calibration. It also improves the system's adaptability to the positions of different batches of lunchboxes and food containers.

[0077] S22: A servo motor-driven parallel gripper is installed on the end flange of the first loading robot, and a food-grade silicone pad is attached to the inside of the gripper. The controller sends a motion command to the first loading robot, driving the robot's end effector to move above the target grasping coordinates calculated in step S21, and controls the servo motor to drive the parallel gripper to close with a preset gripping force, grasping a portion of the first food from the first food supply container. During the gripper closure process, a torque sensor installed on the gripper drive shaft monitors the gripping torque in real time. When the torque reaches the set threshold, the controller determines that the gripping is reliable and then controls the robot to lift the end effector.

[0078] In some embodiments, after the robot receives the target coordinates, its motion controller plans a smooth trajectory and drives the servo motors of each joint to make the end gripper move precisely above the picking point.

[0079] Furthermore, the servo motor of the parallel gripper closes according to a preset speed and acceleration curve, and the control method is force-position hybrid control. The controller monitors the closed position of the gripper; it also reads the torque value of the drive shaft in real time through a torque sensor, which is proportional to the clamping force.

[0080] The torque value begins to rise when the grippers contact the food and begin to apply pressure. The controller sets a torque threshold as a criterion for securing the food.

[0081] Furthermore, during the closing process, if the gripper displacement has reached the preset fully closed position but the torque has not reached the threshold, the controller will determine that the gripping has failed. If the gripper fails to grasp or slips, an alarm may be triggered or a retry may be initiated. Only when the torque reaches the threshold will the controller confirm successful gripping and instruct the robot to perform the lifting action.

[0082] Furthermore, the food-grade silicone pad increases friction, and its elastic deformation can adapt to different shapes of food, such as meat chunks and vegetables, providing sufficient clamping force while avoiding crushing the food.

[0083] S23: A weighing sensor is installed in series between the end effector of the first loading robot and the flange of the robot's sixth axis; during the process of the robot carrying the first food to be grasped and moving towards the lunch box, the weighing sensor measures the weight of the end load in real time; the controller reads the weight value and compares it with the preset target weight of the food; if the measured weight is lower than the target weight, the controller generates a replenishment signal and controls the robot to return to the food supply container to replenish a small amount again until the total weight enters the target error range.

[0084] If the measured weight is higher than the target weight, the robot's end effector is controlled to move above a vibrating feeding tray located above the food supply container, and the gripper is driven to shake slightly to shake off the excess food into the feeding tray until the weight meets the requirements.

[0085] In some embodiments, a weighing sensor installed at the end of the robot converts the total weight of the end effector, gripper, and the grasped object into an electrical signal in real time. After the robot grasps the foodstuff and leaves the container, the controller starts a weight sampling cycle. The system presets a target weight value Wtarget and an allowable error band. The controller compares the real-time weight Wreal read back by the sensor with Wtarget. If Wreal falls within the error band, it is considered qualified and the next step can be directly carried out.

[0086] If Wreal is insufficient, the controller defines a return path, controls the robot to approach the foodstuff surface again, performs a small-stroke replenishment grasping action, and then weighs again. This process can be quickly iterated until it meets the standard. If Wreal is overweight, the robot moves above the vibrating material leveling tray, and the controller sends a pulse signal with a preset frequency and amplitude to drive the servo motor of the gripper to generate reciprocating jitter, shaking off the excess foodstuff.

[0087] Furthermore, the material leveling tray is used to承接抖落的食料,防止污染并便于回收。此过程同样伴随着实时称重,直到重量达标。整个称重与修正过程在机器人从取料点到投放点的移动路径中完成。

[0088] S24: After completing the quantification, the first loading robot moves above the target placement coordinate calculated by step S21, and the coordinate is at a certain height directly above the center of the first blank area of the lunch box; The end of the robot descends along a vertical trajectory. When it reaches a preset height from the bottom of the lunch box, the servo motor is controlled to drive the parallel gripper to fully open, so that the foodstuff falls into the lunch box under the action of gravity; After the gripper is opened, the end effector of the robot lifts and moves out of the lunch box area along a preset inclined trajectory. The purpose of this trajectory is to utilize the gravitational inertia of the foodstuff itself to further promote the separation of the residues attached to the gripper or the foodstuff from the end effector, ensuring that the foodstuff completely falls into the lunch box.

[0089] In some embodiments, when the robot carrying the qualified foodstuff moves above the target placement point, the release methods are as follows: Vertical placement: The end of the robot descends linearly along the Z axis to a pre-calculated safe height, which ensures that the foodstuff can freely fall when the gripper is opened, preventing collision with the items already placed in the lunch box or the box wall. After reaching the specified height, the controller commands the gripper servo motor to quickly open, and the foodstuff basically falls into the lunch box under the action of gravity.

[0090] It also involves inclined lifting and material cleaning: After the gripper is opened, the controller does not immediately control the robot to lift vertically, but controls the gripper to move along a diagonal trajectory at a certain angle to the vertical direction. The kinematic principle of designing this trajectory is inertial separation.

[0091] Note: There is an unclear part in the original text for item which is "承接抖落的食料,防止污染并便于回收" and needs to be further clarified in the source text for a more accurate translation. The above translation is based on the existing text as much as possible.Furthermore, as the robot's end effector accelerates along an oblique line, any small amount of soup or debris adhering to the inner wall of the grippers or the surface of the food will experience an inertial force opposite to the direction of motion. This inertial force, combined with gravity, will generate a resultant force that causes the residue to separate from the actuator surface and fall. Since the actuator is now away from directly above the lunchbox, the residue will fall into the collection trough next to the lunchbox or the waste tray below the conveyor belt, without contaminating other compartments of the lunchbox or the outside of the machine. This trajectory is planned using forward kinematics and dynamics subroutines to ensure smoothness and efficiency.

[0092] In one embodiment of the present invention, step S21, calculating the three-dimensional coordinates of the two objects in the robot coordinate system, specifically includes the following steps: S211: At the start of each loading cycle, after receiving the lunchbox positioning signal from the conveying device or position sensor, the controller sends a synchronization trigger command to the industrial camera fixedly installed above the first loading station. The industrial camera responds to the command and captures two digital images from the preset shooting angles of the first material picking point and the first lunchbox empty space. The acquisition of the two images is completed by the same camera by rotating and switching the viewing angle through the pan-tilt unit, or by two fixed cameras with their viewing angles aimed at the target area, either synchronously or sequentially.

[0093] In some embodiments, the actions of the vision system are closely synchronized with the mechanical process to ensure that the target state at the moment of operation is captured. When using a single-camera gimbal solution, the gimbal is an electromechanical device that connects to the camera and allows for programmable control of its rotation angle.

[0094] The controller first drives the gimbal to rotate to angle A, aligning the camera with the designated feeding area on the food container and taking a picture. Then, it drives the gimbal to rotate to a preset angle B, aligning the camera with the food container's filling area and taking another picture. When using a dual-camera setup, the two cameras are fixedly mounted. The controller uses hardware trigger lines or software commands to cause the two cameras to expose sequentially or simultaneously within a short period. This ensures that the two acquired images represent almost the same scene at the same time, and that the perspective is pre-calibrated, covering the two key positions the robot needs to operate on. Compared to continuous camera shooting with software filtering of valid frames, this embodiment requires less data computation and has a more predictable response.

[0095] S212: The controller processes the acquired image of the first feeding point and identifies and locates the preset position mark feature on the first food supply container in the image through a preset image processing algorithm. The position mark feature is a one-dimensional barcode, a two-dimensional barcode, or a specific shape of identification block pasted at a specified position on the container. By calculating the center pixel coordinates of the position mark feature in the image, it is determined to be the two-dimensional coordinates of the first target grabbing point in the image coordinate system.

[0096] In some embodiments, image localization is based on pre-set contrast markers. The controller runs an image processing program to preprocess the pick-up point image, such as filtering for noise reduction and contrast enhancement. Features matching a pre-stored template are searched in the image. If a barcode / QR code is used, the decoding algorithm can directly calculate the precise pixel coordinates of its four corner points or center point in the image.

[0097] If a specific shape of marker block is used, such as a circular or cross-shaped calibration plate, its center coordinates are determined by contour extraction, ellipse fitting, or calculation of the intersection of straight lines.

[0098] This location marker is pre-attached or engraved on the food supply container at a position with a fixed geometric relationship to the dispensing point.

[0099] For example, the marker might be affixed to the edge of the container, and the pick-up point is defined as the location where the center of the marker is offset into the container by a fixed distance. Once the marker is identified in the image, its center pixel coordinates (umark, vmark) are obtained.

[0100] Based on the known fixed positional relationship between the marker and the picking point, the pixel coordinates (ugrab, vgrab) of the target picking point can be derived in the image coordinate system through simple coordinate translation. This method does not directly identify the food itself, but rather identifies a reference object, ensuring that the starting reference point of each picking action is consistent.

[0101] S213: The controller calls the pre-calibrated and stored camera intrinsic and extrinsic parameter matrix and hand-eye transformation matrix; for the target coordinates of the first picking point, the two-dimensional pixel coordinates obtained in step S212 are combined with the known fixed height value of the position mark feature in the robot base coordinate system, and the three-dimensional spatial coordinates (Xgrab, Ygrab, Zgrab) of the target picking point in the robot base coordinate system are calculated by the inverse operation of perspective projection transformation.

[0102] In some embodiments, the two-dimensional image coordinates are mapped to the three-dimensional robot space using the camera's geometric imaging model and the rigid transformation relationship between the coordinate systems. This embodiment is based on two key mathematical models that have been pre-calibrated.

[0103] The first is the camera's intrinsic parameter matrix K, which contains parameters such as focal length and principal point coordinates, describing the camera's own imaging geometry.

[0104] The second is the hand-eye transformation matrix [H] from the camera coordinate system to the robot base coordinate system. This is a 4x4 homogeneous matrix consisting of a 3x3 rotation matrix R and a 3x1 translation vector T, which was determined through hand-eye calibration experiments. The coordinate calculation is performed in two steps.

[0105] Furthermore, a back projection from the 2D image to the 3D camera coordinates is performed. The actual height Zworld of the position marker corresponding to the target grasping point, the Z value in the robot coordinate system (a known fixed value determined during mechanical design and installation), and the pixel coordinates (u,v) of that point in the image are known.

[0106] Furthermore, given the pixel coordinates (u,v) and corresponding depth Zc on the image plane, K is set as the camera intrinsic parameter matrix: using the camera's pinhole imaging model, through the formula... The coordinates of the point in the camera coordinate system can be solved. .

[0107] Since Zworld is known and is related to the camera coordinates Zc through hand-eye transformation, Xc and Yc can be directly solved by establishing a system of equations in actual calculations.

[0108] Furthermore, a coordinate transformation is performed from the camera coordinate system to the robot coordinate system. The homogeneous transformation matrix is ​​obtained through hand-eye calibration. Points in the camera coordinate system can be transformed to the robot base coordinate system: Through matrix multiplication This gives us the final three-dimensional coordinates (Xgrab, Ygrab, Zgrab) of the target grasping point in the robot's base coordinate system. (Xr, Yr, Zr)T represents the three-dimensional coordinates of the point in the robot's base coordinate system.

[0109] Furthermore, Zgrab is usually equal to the known marker height Zworld.

[0110] This embodiment allows the robot's operational target to no longer be a preset, fixed mechanical coordinate, but rather coordinates calculated in real-time based on the actual scene and provided by the vision system. This enables the system to tolerate mechanical installation errors, minor deformations after long-term operation, and positional deviations caused by changing food containers, achieving adaptive positioning.

[0111] S214: The controller processes the acquired image of the first empty space in the lunchbox, identifies the outline of the internal partition of the lunchbox using an edge detection algorithm, and locates the two-dimensional pixel coordinates of the geometric center of the first empty space in the image according to the preset lunchbox partition model. Using the same coordinate calculation method as in step S213, the known height value is replaced with the calibrated height value of the lunchbox on the upper surface of the loading station, and the three-dimensional spatial coordinates (Xplace, Yplace, Zplace) of the target placement point in the robot base coordinate system are calculated. The controller sends the calculated three-dimensional coordinates (Xgrab, Ygrab, Zgrab) and (Xplace, Yplace, Zplace) to the first loading robot as the absolute position command for this operation cycle.

[0112] In some embodiments, image processing, known models, and coordinate transformations are combined to locate specific areas within the lunchbox. Unlike step S212, step S214 identifies the positional structure of the lunchbox. The controller processes the image of the empty space in the lunchbox and uses an edge detection operator (Canny operator) to extract all obvious line contours in the image.

[0113] Furthermore, based on the pre-defined lunchbox CAD drawing or dimensional parameter-defined lunchbox compartment model, combinations that conform to the geometric features of the model are searched among the extracted contours.

[0114] For example, for a rectangular lunchbox with four compartments, the model is defined as an image that should have a rectangular outline, with three mutually perpendicular line segments dividing it into four sub-rectangles.

[0115] These contours were identified using Hough transform, line segment detection, and parallelism, perpendicularity, and length ratio checks, and four sub-regions were determined. Based on the requirement of serving the first dish, the model indicated that the first empty space region was the upper left sub-rectangle. The minimum bounding rectangle of this identified sub-rectangle contour was calculated, or the centroids of all its pixels were directly calculated to obtain the pixel coordinates (uplace, vplace) of the center of this empty space region in the image.

[0116] Furthermore, the coordinate calculation process is completely consistent with step S213, and the height value Zworld is replaced with the calibrated height of the upper surface of the lunchbox when it is in the loading station.

[0117] Through the same back projection and coordinate transformation, the robot coordinates (Xplace, Yplace, Zplace) of the target delivery point are obtained. Finally, the controller packages the calculated gripping and delivery point coordinates and sends them to the robot controller via a communication protocol. The robot controller uses these coordinates as the absolute target point for this motion command. In this way, by combining the known lunchbox model, the correct compartments can be robustly identified from the image. Ultimately, the robot obtains a delivery point based on the actual position of the current lunchbox, ensuring that food is accurately placed in the center of the designated compartment, achieving multi-item packaging without cross-contamination.

[0118] In one embodiment of the present invention, step S22, in which the robot moves to the grasping coordinate and lifts the food after confirming by the torque sensor that the gripper has reliably grasped the food, specifically includes the following steps: S221: Based on the target grasping coordinates obtained in step S21 and the current coordinates of the robot's end effector, the controller plans a spatial motion trajectory consisting of five segments in the robot's base coordinate system. The spatial motion trajectory includes three main stages: lifting from the current position to the safe plane, moving horizontally within the safe plane to directly above the target point, and descending vertically to the grasping preparation height. An arc transition segment is inserted at the stage transition to avoid sudden changes in velocity direction.

[0119] In some embodiments, trajectory planning and geometric path construction are based on coordinate space. The controller uses the robot's base coordinate system as a reference and decomposes the robot's movement task into several key waypoints.

[0120] Furthermore, a plane height is defined to ensure that the robot does not interfere with the edges of containers or lunchboxes in the work area when moving horizontally.

[0121] The starting point of the trajectory is the current position of the actuator, and the ending point is the point directly above the target's grasping coordinates. The X and Y coordinates are the same, and the Z coordinate is the grasping preparation height.

[0122] Furthermore, the controller inserts three necessary intermediate points between the start and end points: a safety point directly above the current position, a safety point directly above the target point, and the final grab preparation point. Connecting these points forms three straight path segments.

[0123] To prevent the robot from dropping to zero and restarting at straight corners, the controller calculates and inserts a tangent circular arc at the junction of every two straight path segments. This allows the robot's end effector to pass through corners with a smooth and continuous velocity vector, resulting in a geometrically continuous and first-order differentiable trajectory. The entire trajectory is planned to avoid all pre-defined obstacle areas in the database.

[0124] S222: The controller discretizes the planned spatial trajectory according to the preset interpolation period and calculates the target angle of each joint axis of the robot in each interpolation period. The calculation process is based on the inverse kinematics model of the robot and takes into account the velocity and acceleration constraints of each joint to generate a segmented position command sequence for each joint servo motor.

[0125] In some embodiments, the robot controller samples the continuous spatial path planned in step S221 at a fixed cycle. For each sampling point, the controller needs to call an inverse kinematics algorithm. The algorithm establishes a mathematical model based on the robot's arm length, joint offsets, and other geometric parameters, and calculates the angle values ​​that each of the six joints needs to rotate to reach the end effector pose. This process maps Cartesian space coordinates to joint space coordinates.

[0126] Furthermore, to ensure smooth motion, the controller also needs to perform look-ahead processing. Path points for a future time period are pre-read, and based on the maximum speed, acceleration, and jerk limits of each joint motor, a series of generated joint angle values ​​are smoothed and filtered to plan the position curve of each joint motor over time. The final output is a sequence of precise angle command values ​​that each joint servo motor needs to achieve within each interpolation cycle.

[0127] S223: The controller periodically sends the joint position command sequence to the robot's multi-axis servo driver via a real-time fieldbus; each driver drives the corresponding joint's servo motor to rotate according to the received command, and forms a closed-loop position control through feedback from a high-resolution photoelectric encoder connected coaxially to the motor, so that the robot's end effector moves along the planned trajectory.

[0128] In some embodiments, the controller is connected to multiple joint servo drives of the robot. In each control cycle, the controller packages the target position commands for each joint calculated in step S222 into data frames and broadcasts them to all drives.

[0129] Each driver controls one articulated motor. The driver integrates a three-loop control algorithm: current loop, speed loop, and position loop. The received position command serves as the setpoint for the position loop.

[0130] The driver drives the motor to rotate, and the encoder on the motor shaft feeds back the actual position signal to the driver in real time.

[0131] The driver compares the actual position with the target position, calculates the control quantity based on control algorithms such as PID, and adjusts the current output to the motor to correct the motor's position error.

[0132] S224: During the movement of the robot's end effector, the controller reads the feedback position of each joint encoder in real time and continuously calculates the actual three-dimensional coordinates of the end effector flange center through the forward kinematics model. When the deviation between the calculated actual coordinates and the target grasping coordinates in the X, Y, and Z directions is less than the preset position tolerance threshold, the controller determines that the robot has moved above the target grasping coordinates and issues a position completion signal.

[0133] In some embodiments, during robot motion, feedback values ​​from the encoders of each joint are transmitted back to the controller in real time. The controller uses these fed-out joint angle values ​​to invoke a forward kinematics algorithm. Based on the same robot geometry model, the forward kinematics algorithm calculates, in reverse, the actual three-dimensional coordinates (Xact, Yact, Zact) of the robot's end flange center point relative to the base coordinate system at the current joint angle.

[0134] As the robot approaches the target point, the controller begins comparing the actual coordinates with the target coordinates, calculating the absolute values ​​of the deviations in the X, Y, and Z directions. The controller only determines the robot is in position when all three deviation values ​​are simultaneously less than a pre-set tolerance threshold. This determination is based on an AND condition. Once the condition is met, the controller sets a position completion flag and sends this status to the gripper control module via a digital output signal or internal variable. If the condition is not met for an extended period, a timeout alarm is triggered. This addition of real-time position detection and confirmation enhances the system's reliability and robustness.

[0135] In one embodiment of the present invention, in step S3, the conveying device continues to transport the lunchbox already filled with the first food ingredient forward, and positions and transports it to the second loading station based on location perception, specifically including the following steps: S31: A position sensor is installed on the side of the conveyor between the first loading station and the second loading station. The position sensor is a through-beam photoelectric sensor. When the lunchbox that has completed the first feeding leaves the first loading station and enters the transportation zone between the two stations along the continuously operating conveyor, the side wall of the lunchbox will block the beam of the through-beam photoelectric sensor, generating a level transition signal. The controller receives the level transition signal, binds the level transition signal event with the lunchbox currently being transported, marks that the lunchbox has entered the process of heading to the second loading station, and records the real-time cumulative pulse value of the incremental rotary encoder on the drive shaft of the conveyor at this moment, as the starting pulse reference value for tracking the position of this lunchbox.

[0136] S32: During the continuous operation of the conveying device, the counting unit of the controller continuously receives and accumulates the pulse signals emitted by the incremental rotary encoder; the controller obtains a relative pulse difference by subtracting the initial pulse reference value of the lunchbox recorded in step S31 from the current total accumulated encoder pulse value; the pulse difference is multiplied by a pre-calibrated pulse equivalent to calculate the straight-line distance moved by the lunchbox after triggering the position sensor in real time, thereby realizing continuous and real-time tracking of the position of the lunchbox during movement.

[0137] In some embodiments, a ranging method based on a displacement-pulse linear mapping relationship is used to achieve real-time, non-contact position feedback of a moving target. An incremental rotary encoder is coaxially connected to the drive roller; for every minute the drive roller rotates, the encoder generates a set of square wave pulses. The controller's counting unit counts and accumulates these pulse edges.

[0138] Mark the conveyor belt and run it for a known length L. Record the total number of pulses M emitted by the encoder during this process. Then, the pulse equivalent δ = L / M. During operation, for the lunchbox marked in step S31, the controller performs a calculation once in each control cycle: The current position S = (current cumulative pulse count Pnow - initial pulse reference value Pstart) * δ. This calculation is continuous, so the value of S is a variable that increases smoothly over time, reflecting in real time the distance the lunchbox has traveled since the trigger point.

[0139] S33: At the second loading station, the second loading robot controller obtains the current position information of the target lunchbox in real time through the communication network. When the calculated position shows that the lunchbox is about to enter the working space of the second loading robot, the second loading robot starts to move in advance. Its end effector plans and executes a motion trajectory synchronized with the conveying device, so that the end effector remains relatively stationary with the lunchbox when it arrives at the filling point. In this relatively stationary state, the second loading robot performs the grabbing of the second food and simultaneously loads the food into the second empty space area of ​​the moving lunchbox in a measured amount. After the filling is completed, the robot end effector desynchronizes along the planned trajectory and returns to the standby position to prepare to serve the next lunchbox.

[0140] In some embodiments, the robot's end effector is made to maintain the same speed and direction as the moving conveyor belt and the lunchboxes on it for a period of time, thereby completing the operation during the period when both are relatively stationary.

[0141] Furthermore, the controller of the second loading robot receives the real-time position S of the target lunchbox from the controller. The controller has pre-stored the mapping range of the robot's workspace on the conveyor belt coordinate axis.

[0142] When the calculation detects that the S-value enters the preset robot start window, the robot immediately begins to move. Based on the current lunchbox speed and its own dynamic model, the robot motion controller plans a complex spatial trajectory in Cartesian space. The starting point of this trajectory is the robot's standby point; the middle section requires smooth acceleration until the robot's end effector meets the lunchbox at a convergence point above and to the side of the lunchbox. At this point, the horizontal component of the robot's end effector's linear velocity is equal in magnitude and direction to the conveyor belt speed.

[0143] Based on relatively static operation: After merging, the robot's end effector locks horizontally with the lunchbox, and both move together at a constant speed. The robot immediately executes a series of pre-planned sub-actions: grabbing food from a food container fixed to the ground and accurately placing the grabbed food into a designated compartment in the moving lunchbox below. The delivery action itself is also completed in a relatively static state, ensuring accuracy.

[0144] After the loading action is completed, the robot controls the end effector to decelerate and lift along a smooth curve, dissynchronize with the lunchbox, and quickly return to the standby position to prepare for the next lunchbox.

[0145] Furthermore, in step S33: at the second loading station, the second loading robot controller obtains the current position information of the target lunchbox, calculated by the controller, in real time through the communication network. This specifically includes the following: S331: The controller communicates with the second loading robot controller; within each fixed control cycle, the controller writes the current position and speed data of the target lunchbox, which is calculated in real time in step S32, into the pre-allocated transmission data area in its protocol stack.

[0146] S332: At the beginning of each communication cycle, a periodic data interaction is initiated; during the data interaction, the controller sends the position and speed data of the lunchbox in the data area, which is encapsulated into a message frame and sent to the second loading robot controller.

[0147] Step S333: After receiving the data message frame, the second loading robot controller decodes it, extracts the real-time position S and real-time speed V of the lunchbox, and stores them in the specified variable area; the second loading robot controller reads the specified variable area in each servo cycle and uses it as input conditions.

[0148] S334: Based on the real-time position S and velocity V of the lunchbox, combined with the current position of the end effector of the second loading robot, the motion commands required for each joint of the second loading robot are calculated in real time; the robot end effector is driven to accelerate from the standby point until it meets the moving lunchbox in space at the preset synchronization start point, and obtains the same moving speed V as the lunchbox in the horizontal direction, thereby entering a relatively static synchronization state with the lunchbox.

[0149] The starting point here is the current position of the robot's end effector, and the ending point is the relatively stationary state relative to the moving lunchbox. A spline curve interpolation algorithm is used. An interception point is calculated, and a path is planned so that when the second loading robot encounters the lunchbox at this point, the horizontal velocity component of the center point of its end effector is exactly equal to the conveyor belt speed V, and its position is aligned with the loading point on the lunchbox. During the movement, the robot's inverse kinematics solver calculates the theoretical angles for each of the six joint motors in each servo cycle based on the planned end effector target pose. The servo drivers of each joint receive these angle commands and, through built-in PID control and filtering algorithms, drive the motors to approximate these angles with minimal tracking error. When entering the relatively stationary synchronization window, the robot's end effector has no relative movement to the lunchbox in the horizontal direction. At this time, the robot can perform operations such as grasping and placing, and the operations are no different from when the lunchbox is stationary. After completing the operation, the planner generates another departure trajectory, allowing the robot to smoothly decelerate and return to the standby point.

[0150] Further, step S33: When the calculated position indicates that the lunchbox is about to enter the working space of the second loading robot, the second loading robot starts moving in advance. Its end effector plans and executes a motion trajectory synchronized with the conveying device, so that the end effector remains relatively stationary with the lunchbox when it arrives at the filling point. In this relatively stationary state, the second loading robot performs the grasping of the second food and simultaneously loads the food into the second empty space area of ​​the mobile lunchbox. Specifically, this includes the following: S3311: The second loading robot controller has a preset distance threshold, which is determined based on the achievable working range and acceleration capability of the second loading robot; the controller continuously compares the real-time position of the lunchbox with the fixed coordinates of the loading point of the second loading station and calculates the straight-line distance between the two. When the calculated distance is less than or equal to the preset distance threshold for the first time, the controller determines that the lunchbox has entered the workable space, generates a task start command, and triggers the subsequent trajectory planning and motion control module.

[0151] S3312: The second loading robot controller calls the trajectory interpolator based on the real-time position and speed of the lunchbox and the target coordinates of the loading point when triggered in step S3311. The trajectory interpolator uses the zero relative speed between the end of the second loading robot and the lunchbox at the loading point as a constraint to calculate the start-up time, acceleration curve and constant speed segment parameters required for each joint of the second loading robot to start moving from the current position. It generates a synchronous straight line trajectory segment in the base coordinate system of the second loading robot, which is parallel to the direction of movement of the conveying device and has the same speed. The trajectory segment is then connected in space and time with the grasping action trajectory and the delivery action trajectory of the second loading robot to form a sequence of work task trajectories.

[0152] In some embodiments, inverse time parameterized trajectory planning based on kinematic constraints is employed. When the trigger signal arrives, the robot controller knows several key pieces of information: the current pose of the robot's end effector at point A, the current position and velocity of the lunchbox, and the target pose of the loading point at point B, which is located above the conveyor belt. The goal of the planning is to ensure that the end effector of the second loading robot meets the lunchbox at point B, at which point their relative velocity is zero. It is determined that the end effector of the second loading robot must move at the exact same speed as the conveyor belt at point B. Based on the acceleration limits of each joint of the second loading robot, the time required to decelerate from the velocity state at point B back to the velocity state at the robot's starting point A is calculated in reverse.

[0153] S3313: The second loading robot controller converts the generated task trajectory sequence into servo control commands for each joint motor, driving the robot to start moving; during the second loading robot's movement toward the synchronization point and the synchronization movement phase, the second loading robot continuously receives the latest position data of the lunchbox, and uses this data as a reference to fine-tune the pre-generated target trajectory of the second loading robot's end effector online; the fine-tuning algorithm corrects the target position command of the second loading robot's end effector in the synchronization movement phase in real time according to the deviation between the actual position and the predicted position of the lunchbox, ensuring that the second loading robot and the lunchbox are always aligned in space.

[0154] S3314: When the end effector of the second loading robot moves to a predetermined relative position with the lunchbox, and the relative speed between the two in the conveying direction is lower than a preset threshold, the controller of the second loading robot determines that a relative stationary state has been reached; in this state, the controller sends a gripping command to the end gripper to complete the gripping of the second food; while maintaining synchronous movement, the controller controls the end effector of the second loading robot to descend to the placement height in a direction perpendicular to the conveyor belt, and performs the action of opening the gripper to put the food into the second empty space area of ​​the lunchbox.

[0155] In one embodiment of the present invention, in step S6, the conveying device transports the filled lunchbox to the capping station and positions it, and the controller controls the capping robot to pick up the lid and press it onto the lunchbox. Specifically, this includes the following: S61: A diffuse reflection photoelectric sensor is installed on the side of the conveyor at the capping station and is connected to the controller. When the lunch box that has been filled with food arrives at the preset area of ​​the capping station with the conveyor, it blocks the detection light path of the diffuse reflection photoelectric sensor, triggers an effective positioning signal and transmits it to the controller.

[0156] S62: A lid storage room is set up next to the capping station. The lids are placed in the lid storage room in a stacked manner. A lid positioning sensor is installed on the side of the lid storage room. After the controller receives a valid positioning signal, it sends a lid picking command to the capping robot, drives the robotic arm to move above the lid storage room, controls the vacuum generator to start to generate negative pressure, and picks up a single lid through a suction cup. After the lid positioning sensor detects that the suction cup has picked up the lid, it sends a lid picking completion signal to the controller.

[0157] S63: After receiving the lid-removal completion signal, the controller calls the robot trajectory planning unit to generate an arc-shaped motion trajectory from the lid storage to the lid-pressing station; it drives the robotic arm to move the suction cup holding the lid along the planned trajectory. When it approaches the top of the lunchbox, the laser displacement sensor at the end of the robot detects the distance between the lid and the top of the lunchbox and adjusts the posture of the robotic arm in real time to align the center of the lid with the center of the lunchbox opening.

[0158] S64: After the lid is aligned with the lunchbox, the controller controls the robotic arm to lower the lid at a constant speed. When the lid contacts the edge of the lunchbox opening, the lid-pressing servo motor is activated to apply axial pressure according to the preset pressure value. During the lid-pressing process, the pressure sensor in the suction cup seat provides real-time feedback of pressure data. When the pressure reaches the preset threshold, the controller controls the vacuum generator to stop working, releasing the negative pressure. The robotic arm then drives the suction cup to rise and reset, completing the lid-pressing operation.

[0159] 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.

[0160] The following are embodiments of the fully automated, unmanned lunchbox filling system for the fast food industry provided in this disclosure. This system and the fully automated, unmanned lunchbox filling method for the fast food industry in the above embodiments belong to the same inventive concept. For details not described in detail in the embodiments of the fully automated, unmanned lunchbox filling system for the fast food industry, please refer to the embodiments of the fully automated, unmanned lunchbox filling method for the fast food industry described above.

[0161] like Figure 3 As shown, the system includes: a controller, a loading robot, a conveying device, a first loading robot, a second loading robot, a capping robot, and an unloading robot; The controller controls the loading robot to grab empty lunch boxes from the loading position and place them at the starting end of the conveyor device. The conveyor device then arranges and positions them at a preset interval and transports them to the first loading station. The first loading robot, located at the first loading station, grabs the first food from the first food supply container based on position awareness and quantitatively loads it into the first empty space area of ​​the lunch box; The conveying device continues to transport the lunch box containing the first food ingredient forward, and locates and transports it to the second loading station based on position sensing; The second loading robot, located at the second loading station, grabs the second food from the second food supply container based on position awareness and quantitatively loads it into the second empty space area of ​​the lunch box; The control area controls the conveyor to continue transporting the lunch boxes to the subsequent loading stations in sequence. The corresponding loading robots at each station are guided by position perception to complete the quantitative filling of food in all subsequent empty areas in sequence. The control area controls the conveyor to transport the filled lunch boxes to the capping station and position them. The controller controls the capping robot to pick up the lids and press them onto the lunch boxes. It also transports the packaged finished lunch boxes to the unloading area, where the controller controls the unloading robot to remove them from the conveyor.

[0162] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for automated, unmanned lunchbox filling throughout the entire fast food process, characterized in that the method... include: S1: The controller controls the loading robot to grab empty lunch boxes from the loading position and place them at the starting end of the conveyor device. The conveyor device then arranges and positions them at a preset interval and transports them to the first loading station. S2: The first loading robot located at the first loading station grabs the first food from the first food supply container based on position awareness and quantitatively loads it into the first empty space area of ​​the lunch box; S3: The conveying device continues to transport the lunch box containing the first food to the front, and locates and transports it to the second loading station based on position perception; S4: The second loading robot, located at the second loading station, grabs the second food from the second food supply container based on position awareness and quantitatively loads it into the second empty space area of ​​the lunch box; S5: The conveying device continues to transport the lunch boxes to the subsequent loading stations in sequence. The corresponding loading robots at each station are guided by position perception to complete the quantitative filling of food in all subsequent empty areas in sequence. S6: The conveying device transports the filled lunchbox to the capping station and positions it. The controller controls the capping robot to pick up the lid and press it onto the lunchbox. S7: The conveying device transports the packaged finished lunch boxes to the unloading area and positions them, and the controller controls the unloading robot to move them out of the conveying device.

2. The automatic lunchbox filling method based on unmanned operation of the entire fast food process according to claim 1, characterized in that, In S1, the controller controls the loading robot to grab empty lunch boxes from the loading position and place them at the starting end of the conveyor device. The conveyor device then arranges and positions the lunch boxes at a preset interval and transports them to the first loading station. The specific steps include the following: S11: Based on the inlet sensor, the actual distance between adjacent lunch boxes is measured, and the feeding rhythm or conveying speed is adjusted to make the lunch box queue enter the main conveying section at a preset distance. S12: Calculate and update the real-time position coordinates of each lunchbox on the main conveyor section using the trigger sequence of multiple positioning sensors on the main conveyor section and the known positions; S13: The first loading robot plans and executes a trajectory synchronized with the movement of the lunchbox based on the received real-time position coordinates of the lunchbox, and achieves speed and position alignment at the loading point to complete the loading.

3. The automatic lunchbox filling method based on unmanned operation of the entire fast food process according to claim 1, characterized in that, In S2, the process of grabbing the first food from the first food supply container based on location awareness and quantitatively loading it into the first empty area of ​​the lunchbox specifically includes the following steps: S21: Identify the material picking point and the center of the lunchbox empty space using a calibrated industrial camera, and calculate their three-dimensional coordinates in the robot coordinate system; S22: The robot moves to the grasping coordinate, and after confirming with the torque sensor that the gripper can reliably grasp the food, it lifts up. S23: During the robot's movement, the weighing sensor detects the weight in real time and adjusts it to the target value by replenishing or shaking it off; S24: The robot moves to the delivery coordinates, descends and opens its grippers to release the food, then lifts up and moves out along an inclined trajectory.

4. The automatic lunchbox filling method based on unmanned operation of the entire fast food process according to claim 3, characterized in that, Step S21, calculating the three-dimensional coordinates of both objects in the robot coordinate system, specifically includes the following steps: S211: The controller triggers the industrial camera after the lunchbox is in place to capture two images: the material picking point and the empty space in the lunchbox. S212: The controller processes the image of the material picking point, identifies the preset position marker, and determines its two-dimensional pixel coordinates; S213: The controller calls the calibration parameters and calculates the three-dimensional grasping coordinates of the picking point into the robot coordinate system by combining the two-dimensional coordinates of the picking point with the known height; S214: The controller processes the image of the empty space in the lunchbox, identifies the center of the empty space and calculates it into three-dimensional projection coordinates, and then sends the two sets of coordinates to the robot.

5. The automatic lunchbox filling method based on unmanned operation of the entire fast food process according to claim 4, characterized in that, In step S22, the robot moves to the grasping coordinate, and after confirming with the torque sensor that the gripper has reliably grasped the food, it lifts up. The specific steps include the following: S221: The controller configures a spatial trajectory that includes safe lifting, horizontal movement, and vertical descent segments, with the target grab coordinates and the current position as the start and end points. S222: The controller discretizes the spatial trajectory, solves it using inverse kinematics, and generates a sequence of position command sequences for the servo motors of each joint. S223: The controller sends joint position commands to the servo driver, which drives the joint motors to move, so that the robot end effector moves along the planned trajectory. S224: The controller calculates the actual coordinates of the end effector using feedback from the joint encoder and positive kinematics, and determines that the end effector is in position when the deviation from the target coordinates is less than a threshold.

6. The automatic lunchbox filling method based on unmanned operation of the entire fast food process according to claim 1, characterized in that, In S3, the conveyor continues to transport the lunchbox already filled with the first food ingredient forward, and based on position sensing, locates and transports it to the second loading station. Specifically, this includes the following steps: S31: After the position sensor is triggered by the lunchbox, the controller binds the event and records the encoder pulse value as the starting reference for position tracking; S32: The controller accumulates encoder pulses, calculates the difference from the initial reference, and multiplies it by the pulse equivalent to obtain the real-time movement distance of the lunchbox; S33: The second loading robot obtains the current position of the lunchbox, plans and executes a synchronous motion trajectory, and completes the food filling in a relatively static state.

7. The automatic lunchbox filling method based on unmanned operation of the entire fast food process according to claim 6, characterized in that, In S33, the second loading robot obtains the current position of the lunchbox, specifically including the following: S331: The controller writes the calculated lunchbox position and speed data into the transmission data area in each control cycle; S332: The controller encapsulates the data into message frames and sends them to the second loading robot controller in each communication cycle; S333: The second loading robot controller decodes the message frame, extracts the position and speed data of the lunchbox, and stores it in the variable area; S334: The second loading robot calculates motion instructions based on the read lunchbox data and drives the end effector to move to a state synchronized with the lunchbox.

8. The automatic lunchbox filling method based on unmanned operation of the entire fast food process according to claim 6, characterized in that, In S33, planning and executing a synchronous motion trajectory to complete the food loading process while in a relatively static state specifically includes the following: S3311: The second loading robot controller compares the real-time position of the lunchbox with the distance to the loading point, and generates a task start command when the distance is less than a preset threshold. S3312: Based on the state of the lunchbox at the time of triggering, the robot controller plans a sequence of operation trajectories that synchronize the speed of the end effector with that of the lunchbox at the filling point; S3313: When the robot executes its trajectory, it fine-tunes the end target command online based on the latest position data of the lunchbox to maintain alignment with the position of the lunchbox. S3314: Once the robot and the lunchbox reach a relatively stationary state, the robot will grasp the food and drop it down vertically.

9. The automatic lunchbox filling method based on unmanned operation of the entire fast food process according to claim 1, characterized in that, In S6, the conveyor transports the filled lunchboxes to the capping station and positions them. The controller then controls the capping robot to pick up the lids and press them onto the lunchboxes. Specifically, this includes the following: S61: When the photoelectric sensor detects that the lunchbox has arrived at the lid-pressing station, the controller receives the positioning signal; S62: The controller drives the capping robot to pick up the caps from the cap warehouse, and the sensor confirms that the cap retrieval is complete; S63: The lid-pressing robot moves the lid above the lunchbox and uses sensors to adjust and align the two centers. S64: The lid-pressing robot presses the lid onto the lunchbox, and releases and resets the lid after reaching the preset pressure.

10. A fully automated, unmanned lunchbox filling system based on the entire fast food process, characterized in that: The system is used to implement the unmanned automatic lunchbox filling method based on the entire fast food process as described in any one of claims 1 to 9; The system includes: a controller, a loading robot, a conveying device, a first loading robot, a second loading robot, a capping robot, and an unloading robot; The controller controls the loading robot to grab empty lunch boxes from the loading position and place them at the starting end of the conveyor device. The conveyor device then arranges and positions them at a preset interval and transports them to the first loading station. The first loading robot, located at the first loading station, grabs the first food from the first food supply container based on position awareness and quantitatively loads it into the first empty space area of ​​the lunch box; The conveying device continues to transport the lunch box containing the first food ingredient forward, and locates and transports it to the second loading station based on position sensing; The second loading robot, located at the second loading station, grabs the second food from the second food supply container based on position awareness and quantitatively loads it into the second empty space area of ​​the lunch box; The control area controls the conveyor to continue transporting the lunch boxes to the subsequent loading stations in sequence. The corresponding loading robots at each station are guided by position perception to complete the quantitative filling of food in all subsequent empty areas in sequence. The control area controls the conveyor to transport the filled lunch boxes to the capping station and position them. The controller controls the capping robot to pick up the lids and press them onto the lunch boxes. It also transports the packaged finished lunch boxes to the unloading area, where the controller controls the unloading robot to remove them from the conveyor.

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