Deviation correction control system for express sorting machine

Abstract

The deviation correction control system is suitable for adjusting the position deviation of parcels in x / y / z three dimensions, a sorting machine main ring runs in the X direction, a tray unit is connected with a sorting machine main ring driving mechanism through a transmission chain, a tray belt is driven by a Y-axis two-way rotating mechanism, and the tray belt is driven by a Y-axis two-way rotating mechanism. The deviation rectification control system comprises a three-dimensional sensing module, an edge calculation unit, a dynamic control module, an execution mechanism and a power management unit. The package deviation correction control system for the express sorting machine, which integrates three-dimensional perception, dynamic compensation and high-precision execution, can adapt to high-speed variable-working-condition operation of the sorting machine, and can further improve deviation correction precision and response efficiency, so that the package deviation correction control system can adapt to express sorting machines under different working conditions.

Description

Technical Field

[0001] The present invention relates to the field of intelligent logistics equipment and control technology, and in particular to a deviation correction control system for an express sorting machine. Background Art

[0002] The deviation correction control of express sorting machines refers to the use of a series of technical means to ensure that objects (such as parcels, mail, etc.) in the sorting process can move accurately along the predetermined path and avoid deviation from the set track. The main purpose of the deviation correction control is to improve sorting efficiency and accuracy and reduce sorting errors caused by deviation from the path. The working principle of the deviation correction control mainly includes the following steps: detection, using photoelectric sensors, laser scanners and other equipment to detect whether the object has deviated from the predetermined path; signal processing, transmitting the detected signal to the control system for processing to determine whether the object has deviated; control execution, based on the signal processing results, the control system issues instructions to adjust the operating parameters of the sorting machine, such as speed, direction, etc., to return the object to the correct path; feedback adjustment, through continuous detection and adjustment, ensure that the object always moves along the predetermined path. Publication No. CN106054805B proposes a correction control system for a sorting machine. This system aims to overcome the shortcomings of the existing technology by automatically correcting and centering packages, flat items, and other objects that are not centered on the tray of the package sorting machine, thereby improving the accuracy of the objects falling into the grid. The technical solution adopted is two object offset value calculation methods: one based on a distance acquisition device and a laser distance measurement algorithm, and the other based on an image acquisition device and an image processing algorithm. This is to improve the accuracy of the objects falling into the grid. However, the correction control of existing express sorting machines still has some technical deficiencies. For example, the two-dimensional sensor cannot detect the Z-axis imbalance caused by the tilt of the package stack, and the goods are prone to collapse during high-speed sorting. The traditional PID control does not consider the control response lag caused by the dynamic coupling effect of the sorting machine's variable speed operation and the elastic deformation of the belt. Summary of the Invention

[0003] (1) Technical problems solved

[0004] In response to the shortcomings of the existing technology, the present invention adopts an express sorting machine package correction control system that integrates three-dimensional perception, dynamic compensation and high-precision execution. It can adapt to the high-speed and variable working conditions of the sorting machine and further improve the response efficiency.

[0005] (2) Technical solution

[0006] To achieve the above objectives, the present invention provides the following technical solution: a deviation correction control system for an express sorting machine, suitable for adjusting the position deviation of packages in the x / y / z dimensions. The sorting machine main ring runs along the X direction, the tray unit is connected to the sorting machine main ring drive mechanism via a transmission chain, and the tray belt is driven by a Y-axis bidirectional rotation mechanism. The deviation correction control system includes:

[0007] The 3D perception module, consisting of a circular array of laser radars and infrared vision sensors, covers the entire pallet operating area of the sorter's main ring track and collects the package's 3D profile, center of mass position, and surface texture data in real time.

[0008] The edge computing unit receives sensor data through a high-speed serial bus, performs point cloud noise reduction, coordinate system registration, and pose calculation, and outputs the X / Y offset, Z-axis inclination, and boundary features of the package in the pallet coordinate system.

[0009] The dynamic control module integrates the sorter operation status prediction model and the belt dynamics compensation algorithm to generate correction instructions including angle, acceleration and timing according to the offset, main loop speed and physical characteristics of the package;

[0010] The actuator, which includes a servo drive circuit, a reduction transmission component, and a displacement feedback unit, converts the correction instruction into a belt rotation action through three closed-loop control, and feeds back the execution status to the dynamic control module in real time;

[0011] The power management unit provides adaptive power distribution for each module and unit, including main power conversion, dynamic load adjustment and emergency energy storage sub-modules.

[0012] As a preferred solution, in the three-dimensional perception module, the lidar array consists of 6 groups of ToF sensors arranged in a circle at 60° intervals. The vertical field of view covers a pallet height range of 0-500mm. Each sensor has a built-in APD receiver with a sampling frequency of ≥200Hz; the infrared vision sensor is equipped with a polarizing filter and an 850nm fill light, which can still obtain clear images of the package edges in low-light environments.

[0013] As a preferred solution, the edge computing unit adopts a heterogeneous computing architecture, including:

[0014] FPGA chip, which realizes Gaussian filtering of point cloud data, background segmentation and pallet coordinate system conversion;

[0015] Multi-core CPU, running the improved ICP algorithm, matches the actual point cloud with the preset package template library, and calculates the pose offset and confidence index;

[0016] The data cache area uses DDR4 memory modules to store 10 seconds of continuous perception data for offline diagnosis and analysis.

[0017] As a preferred solution, the dynamic control module includes a multi-level compensation strategy, which is specifically implemented as follows:

[0018] The primary compensation layer generates the basic correction value based on the current X / Y offset through the PID controller. The PID parameters are dynamically adjusted according to the main loop speed.

[0019] The advanced compensation layer combines the package quality data provided by the sorter's central database, the friction coefficient measured by the thin film pressure sensor on the pallet surface, and the belt elastic deformation model to calculate the dynamic feedforward compensation amount;

[0020] The timing synchronization unit predicts the pallet position within the next 0.5 seconds based on the main ring encoder signal and generates the trigger timing for the correction action to ensure that the correction operation is accurately matched with the time when the pallet arrives at the target grid.

[0021] As a preferred solution, the friction coefficient is measured by the following process:

[0022] A1, a 16×16 array of thin film pressure sensors embedded on the surface of the tray, with a sampling frequency of 1kHz;

[0023] A2. The edge computing unit calculates the equivalent friction coefficient μ based on the pressure distribution data. The formula is: Among them F i is the pressure value of the i-th sensor, d i is the distance from the center of the pallet to the corresponding position, m is the mass of the package, and g is the acceleration due to gravity;

[0024] A3. The calculation results are transmitted to the dynamic control module via the I2C bus.

[0025] As a preferred solution, the servo drive circuit of the actuator includes:

[0026] Input-stage protection circuit, consisting of a π-type EMI filter, TVS diode, and resettable fuse, suppresses inrush current and voltage spikes;

[0027] The power amplifier module adopts IPM intelligent power module with built-in short-circuit protection and over-temperature shutdown functions;

[0028] The condition monitoring unit collects motor winding temperature, current harmonic distortion rate and vibration acceleration data in real time and feeds it back to the dynamic control module via the CAN bus;

[0029] Belt displacement feedback uses a magnetic scale to measure the actual belt displacement, and the data update cycle is ≤1ms.

[0030] As a preferred solution, the power management unit includes:

[0031] The main power conversion circuit uses a 24V DC input that is stepped down by the LM2596 chip to 12V for the actuator, and then converted by the TPS5430 to 5V for the 3D sensing module and 3.3V for the dynamic control module.

[0032] Dynamic load regulation circuit, based on the LT8705 Buck-Boost controller, automatically switches operating modes based on the servo motor load factor, enabling pulse frequency modulation to reduce power consumption under light load conditions.

[0033] The emergency energy storage module consists of four groups of 2.7V / 100F supercapacitors connected in series. It maintains the power supply of key modules for ≥200ms when the main power is interrupted, and manages the charge and discharge balance through the UCC39002 chip.

[0034] As a preferred solution, the correction control system further includes a redundant communication network, wherein the redundant communication network adopts a dual-ring topology structure, including:

[0035] Control command channel, based on EtherCAT protocol, used to send correction commands and receive displacement feedback;

[0036] Status monitoring channel, based on the Modbus-TCP protocol, used to report device temperature, fault codes, and performance statistics;

[0037] Failover mechanism: When the packet loss rate of the primary channel is detected to be greater than 0.1%, it automatically switches to the backup fiber channel.

[0038] As a preferred solution, the redundant communication network uses the Time Sensitive Network (TSN) protocol to connect the modules to ensure the real-time and reliability of the control instructions.

[0039] (3) Beneficial effects

[0040] Compared with the prior art, the present invention provides a deviation correction control system for express sorting machines, which has the following beneficial effects:

[0041] 1. The correction control system of the present invention includes a three-dimensional perception module, an edge computing unit, a dynamic control module, and an actuator, among other components. It comprises three core modules: multi-sensor fusion perception, adaptive decision-making control, and high-precision execution. The system uses a circular laser radar array and infrared vision sensors to capture the three-dimensional position data of packages in real time. The edge computing unit integrates the operating status parameters of the sorting machine to generate dynamic correction instructions. The servo drive mechanism precisely adjusts the rotation of the pallet belt using a three-loop control system combining current, speed, and position. The system integrates fault prediction, dynamic power management, and redundant communication mechanisms to further improve correction accuracy and response efficiency, enabling it to adapt to express sorting machines in different operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic diagram of the control system architecture of the present invention;

[0043] Figure 2 This is a schematic diagram of the control system and the main ring transmission principle of the sorting machine of the present invention. DETAILED DESCRIPTION

[0044] In order to better understand the purpose, structure and function of the present invention, the correction control system for an express sorting machine of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0045] Example 1

[0046] refer to Figure 1-2 The present invention provides a deviation correction control system for an express sorting machine, which is suitable for adjusting the position deviation of packages in the three dimensions of x, y, and z. The main ring of the sorting machine runs along the X direction, and the tray unit is connected to the main ring drive mechanism of the sorting machine through a transmission chain. The tray belt is driven by a Y-axis bidirectional rotation mechanism. The deviation correction control system includes:

[0047] The 3D perception module, consisting of a circular array of laser radars and infrared vision sensors, covers the entire pallet operating area of the sorter's main ring track and collects the package's 3D profile, center of mass position, and surface texture data in real time.

[0048] The edge computing unit receives sensor data through a high-speed serial bus, performs point cloud noise reduction, coordinate system registration, and pose calculation, and outputs the X / Y offset, Z-axis inclination, and boundary features of the package in the pallet coordinate system.

[0049] The dynamic control module integrates the sorter operation status prediction model and the belt dynamics compensation algorithm to generate correction instructions including angle, acceleration and timing according to the offset, main loop speed and physical characteristics of the package;

[0050] The actuator, which includes a servo drive circuit, a reduction transmission component, and a displacement feedback unit, converts the correction instruction into a belt rotation action through three closed-loop control, and feeds back the execution status to the dynamic control module in real time;

[0051] The power management unit provides adaptive power distribution for each module and unit, including main power conversion, dynamic load adjustment and emergency energy storage sub-modules.

[0052] Specifically, this system is deployed at a circular express sorting facility. The main ring track utilizes a high-strength aluminum alloy frame to form a circular guideway. The 18m diameter circular track is coated with a low-friction ceramic coating. Pallet units are evenly spaced along the track's circumference, and a non-slip silicone coating is applied to the surface of standard 400mm x 600mm pallets. The 3D perception module features a lidar array consisting of six ToF sensors arranged in a circular pattern at 60° intervals, covering a vertical field of view of pallets from 0 to 500mm in height. Each sensor incorporates an APD receiver with a sampling frequency of ≥200Hz. The infrared vision sensor is equipped with a polarizing filter and an 850nm fill light, enabling clear images of package edges even in low-light environments. The 3D perception module is mounted at the entrance of the sorting ring via a column bracket. Six symmetrically distributed optical components are positioned 1.2m above the pallet's operating plane, with the cameras mounted at a 30° angle to cover the front and rear edges of the pallet.

[0053] Specifically, the edge computing unit adopts a heterogeneous computing architecture, including:

[0054] FPGA chip, which realizes Gaussian filtering of point cloud data, background segmentation and pallet coordinate system conversion;

[0055] Multi-core CPU, running the improved ICP algorithm, matches the actual point cloud with the preset package template library, and calculates the pose offset and confidence index;

[0056] The data cache area uses DDR4 memory modules to store 10 seconds of continuous perception data for offline diagnosis and analysis.

[0057] Its dynamic control module includes a multi-level compensation strategy, which is specifically implemented as follows:

[0058] The primary compensation layer generates the basic correction value based on the current X / Y offset through the PID controller. The PID parameters are dynamically adjusted according to the main loop speed.

[0059] The advanced compensation layer combines the package quality data provided by the sorter's central database, the friction coefficient measured by the thin film pressure sensor on the pallet surface, and the belt elastic deformation model to calculate the dynamic feedforward compensation amount;

[0060] The timing synchronization unit predicts the pallet position within the next 0.5 seconds based on the main ring encoder signal and generates the trigger timing for the correction action to ensure that the correction operation is accurately matched with the time when the pallet arrives at the target grid.

[0061] Furthermore, the edge computing unit and dynamic control module are housed in the sorter control cabinet, maintaining an operating temperature below 45°C through industrial-grade cooling ducts. The communication bus utilizes a dual-mode optical / electrical transmission mechanism, and the EtherCAT backbone network cabling follows a star-ring hybrid topology. All cables maintain an IP67 protection rating.

[0062] The friction coefficient is measured by the following process:

[0063] A1, a 16×16 array of thin film pressure sensors embedded on the surface of the tray, with a sampling frequency of 1kHz;

[0064] A2. The edge computing unit calculates the equivalent friction coefficient μ based on the pressure distribution data. The formula is: Where is the pressure value of the i-th sensor, is the distance from the corresponding position to the center of the pallet, m is the mass of the package, and g is the acceleration due to gravity;

[0065] A3. The calculation results are transmitted to the dynamic control module via the I2C bus.

[0066] Example 2

[0067] The present invention provides a deviation correction control system for an express sorting machine, further comprising an actuator. Specifically, the servo drive circuit of the actuator in this embodiment comprises:

[0068] Input-stage protection circuit, consisting of a π-type EMI filter, TVS diode, and resettable fuse, suppresses inrush current and voltage spikes;

[0069] The power amplifier module adopts IPM intelligent power module with built-in short-circuit protection and over-temperature shutdown functions;

[0070] The condition monitoring unit collects motor winding temperature, current harmonic distortion rate and vibration acceleration data in real time and feeds it back to the dynamic control module via the CAN bus;

[0071] Belt displacement feedback uses a magnetic scale to measure the actual belt displacement, and the data update cycle is ≤1ms.

[0072] Specifically, its 3D positioning process is as follows: when a package passes through the scanning area: the lidar array generates point cloud data at 100,000 points per second; the FPGA performs background segmentation (RANSAC algorithm); the CPU performs 3D registration (ICP matching with the standard package template; extracts the package center of mass coordinates (x, y, z, θx, θy, θz); and outputs a pose error value δx = ±50mm (calibrable range).

[0073] Furthermore, the correction control system of the present invention also includes a redundant communication network, wherein the redundant communication network adopts a dual-ring topology structure and includes:

[0074] Control command channel, based on EtherCAT protocol, used to send correction commands and receive displacement feedback;

[0075] Status monitoring channel, based on the Modbus-TCP protocol, used to report device temperature, fault codes, and performance statistics;

[0076] Failover mechanism: When the packet loss rate of the primary channel is detected to be greater than 0.1%, it automatically switches to the backup fiber channel.

[0077] As a preferred solution, the redundant communication network uses the Time Sensitive Network (TSN) protocol to connect the modules to ensure the real-time and reliability of the control instructions.

[0078] The power management unit of the present invention comprises:

[0079] The main power conversion circuit uses a 24V DC input that is stepped down by the LM2596 chip to 12V for the actuator, and then converted by the TPS5430 to 5V for the 3D sensing module and 3.3V for the dynamic control module.

[0080] Dynamic load regulation circuit, based on the LT8705 Buck-Boost controller, automatically switches operating modes based on the servo motor load factor, enabling pulse frequency modulation to reduce power consumption under light load conditions.

[0081] The emergency energy storage module consists of four groups of 2.7V / 100F supercapacitors connected in series. It maintains the power supply of key modules for ≥200ms when the main power is interrupted, and manages the charge and discharge balance through the UCC39002 chip.

[0082] The present invention adopts a package deviation correction control system for express sorting machines that integrates three-dimensional perception, dynamic compensation and high-precision execution. The main ring track of the sorting machine extends along the X direction, and the tray unit is connected to the main ring drive motor through a transmission chain. The tray belt is driven by a Y-axis servo motor to achieve bidirectional rotation. It can adapt to the high-speed and variable working conditions of the sorting machine, further improving the response efficiency.

[0083] It will be understood that the present invention is described by way of some embodiments, and it will be appreciated by those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. A deviation correction control system for express sorting machines, suitable for adjusting package position deviation in the x / y / z dimensions. The sorting machine main ring runs in the x-direction, and the tray units are connected to the sorting machine main ring drive mechanism via a transmission chain. The tray belt is driven by a Y-axis bidirectional rotation mechanism. The characteristics are: The correction control system includes: The 3D perception module, consisting of a circular array of laser radars and infrared vision sensors, covers the entire pallet operating area of the sorter's main ring track and collects the package's 3D profile, center of mass position, and surface texture data in real time. The edge computing unit receives sensor data through a high-speed serial bus, performs point cloud noise reduction, coordinate system registration, and pose calculation, and outputs the X / Y offset, Z-axis inclination, and boundary features of the package in the pallet coordinate system. The dynamic control module integrates the sorter operation status prediction model and the belt dynamics compensation algorithm to generate correction instructions including angle, acceleration and timing according to the offset, main loop speed and physical characteristics of the package; The actuator, which includes a servo drive circuit, a reduction transmission component, and a displacement feedback unit, converts the correction instruction into a belt rotation action through three closed-loop control, and feeds back the execution status to the dynamic control module in real time; The power management unit provides adaptive power distribution for each module and unit, including main power conversion, dynamic load adjustment and emergency energy storage sub-modules.

2. A deviation correction control system for an express sorting machine according to claim 1, characterized in that: In the three-dimensional perception module, the lidar array consists of 6 groups of ToF sensors arranged in a circle at 60° intervals. The vertical field of view covers a pallet height range of 0-500mm. Each sensor has a built-in APD receiver with a sampling frequency of ≥200Hz. The infrared vision sensor is equipped with a polarization filter and an 850nm fill light, which can still obtain clear images of the package edges in low-light environments.

3. The deviation correction control system for express sorting machines according to claim 1, characterized in that: The edge computing unit adopts a heterogeneous computing architecture, including: FPGA chip, which realizes Gaussian filtering of point cloud data, background segmentation and pallet coordinate system conversion; Multi-core CPU, running the improved ICP algorithm, matches the actual point cloud with the preset package template library, and calculates the pose offset and confidence index; The data cache area uses DDR4 memory modules to store 10 seconds of continuous perception data for offline diagnosis and analysis.

4. The deviation correction control system for express sorting machines according to claim 1, characterized in that: The dynamic control module includes a multi-level compensation strategy, which is specifically implemented as follows: The primary compensation layer generates the basic correction value based on the current X / Y offset through the PID controller. The PID parameters are dynamically adjusted according to the main loop speed. The advanced compensation layer combines the package quality data provided by the sorter's central database, the friction coefficient measured by the thin film pressure sensor on the pallet surface, and the belt elastic deformation model to calculate the dynamic feedforward compensation amount; The timing synchronization unit predicts the pallet position within the next 0.5 seconds based on the main ring encoder signal and generates the trigger timing for the correction action to ensure that the correction operation is accurately matched with the time when the pallet arrives at the target grid.

5. The deviation correction control system for express sorting machines according to claim 4, characterized in that: The friction coefficient is measured by the following process: A1, a 16×16 array of thin film pressure sensors embedded on the surface of the tray, with a sampling frequency of 1kHz; A2. The edge computing unit calculates the equivalent friction coefficient μ based on the pressure distribution data. The formula is: Among them F i is the pressure value of the i-th sensor, d i is the distance from the center of the pallet to the corresponding position, m is the mass of the package, and g is the acceleration due to gravity; A3. The calculation results are transmitted to the dynamic control module via the I2C bus.

6. The deviation correction control system for express sorting machines according to claim 1, characterized in that: The servo drive circuit of the actuator comprises: Input-stage protection circuit, consisting of a π-type EMI filter, TVS diode, and resettable fuse, suppresses inrush current and voltage spikes; The power amplifier module adopts IPM intelligent power module with built-in short-circuit protection and over-temperature shutdown functions; The condition monitoring unit collects motor winding temperature, current harmonic distortion rate and vibration acceleration data in real time and feeds it back to the dynamic control module via the CAN bus; Belt displacement feedback uses a magnetic scale to measure the actual belt displacement, and the data update cycle is ≤1ms.

7. The deviation correction control system for express sorting machine according to claim 1, characterized in that: The power management unit comprises: The main power conversion circuit uses a 24V DC input that is stepped down by the LM2596 chip to 12V for the actuator, and then converted to 5V by the TPS5430 for the 3D sensing module and 3.3V for the dynamic control module. Dynamic load regulation circuit, based on the LT8705 Buck-Boost controller, automatically switches operating modes based on the servo motor load factor, enabling pulse frequency modulation to reduce power consumption under light load conditions. The emergency energy storage module consists of four groups of 2.7V / 100F supercapacitors connected in series. It maintains the power supply of key modules for ≥200ms when the main power is interrupted, and manages the charge and discharge balance through the UCC39002 chip.

8. The deviation correction control system for express sorting machines according to claim 1, characterized in that: The correction control system also includes a redundant communication network, which adopts a dual-ring topology structure and includes: Control command channel, based on EtherCAT protocol, used to send correction commands and receive displacement feedback; Status monitoring channel, based on the Modbus-TCP protocol, used to report device temperature, fault codes, and performance statistics; Failover mechanism: When the packet loss rate of the primary channel is detected to be greater than 0.1%, it automatically switches to the backup fiber channel.

9. The deviation correction control system for express sorting machines according to claim 8, characterized in that: The redundant communication network uses the Time Sensitive Network (TSN) protocol to connect the modules to ensure the real-time and reliability of the control instructions.

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