What are the core technologies of intelligent logistics sorting line?

The core technology of intelligent logistics sorting line is built around the four core objectives of "accurate identification, efficient sorting, intelligent scheduling and stable operation", covering five technical dimensions of perception, control, execution, software and data, and is a deep integration of mechanical design, electronic engineering, artificial intelligence and Internet of Things. Starting from eight core technology modules, combined with technical principles, application scenarios and industry benchmark cases, this paper systematically analyzes their core values and implementation paths:

I. Perception and identification technology of cargo information (sorting "eyes")

Core function: Accurately collect information such as identity, size, weight and shape of goods, and provide data basis for sorting decision.

Key technologies and applications:

Bar code/RFID identification technology

Technical principle: the core data such as order number, destination and cargo type can be quickly obtained by reading the single-dimensional code/QR code on the surface with a barcode scanner (laser/image type) or reading the electronic chip information in the cargo label with an RFID reader.

Technical highlights: the recognition distance of laser scanning gun can reach 0.5-3 meters, and the image scanning gun supports tilt, fold and fuzzy bar code recognition (accuracy ≥ 99.8%); RFID technology supports non-contact identification (the distance is less than or equal to 10m), can penetrate the package and read, and is suitable for high-speed sorting scenes (the identification speed is less than or equal to 0.1s/piece).

Application scenarios: e-commerce express parcel sorting, manufacturing parts traceability, tobacco and cigarette sorting. For example, ZF transshipment center adopts Zebra image scanning gun to realize 100% rapid identification of parcel bar codes.

OCR optical character recognition technology

Technical principle: The image of the cargo manifest is collected by a high-definition camera, and the text information (such as the receiving address, name and telephone number) on the manifest is recognized by using image processing algorithms (such as edge detection and character segmentation) and deep learning models (such as CNN convolutional neural network).

Technical highlights: Support multi-language recognition (Chinese, English, Japanese, Korean, etc.) and handwriting recognition, adapt to irregular face sheets (inclined, blocked, folded), and the recognition accuracy is ≥99.5%, which can make up for the limitations of barcode recognition.

Application scenario: cross-border e-commerce international parcel sorting (multi-language single-face) and special-shaped parts sorting (no bar code or bar code damage). For example, Jingdong Logistics "Asia No.1" adopts self-developed OCR identification system to handle complex single-face parcels.

Volume and weight measurement technology

Technical principle: Using laser ranging, 3D visual imaging or infrared sensing technology, the length × width× height (accuracy 1 mm) of goods can be measured quickly, and the weight data can be obtained by combining with the weighing sensor (accuracy ±0.1g) to calculate the volume and weight of goods (for logistics billing and space allocation).

Technical highlights: the measuring speed is ≤0.3 seconds/piece, which supports the measurement of irregular goods, and can be integrated at the front end of the sorting line to realize the integrated processing of "identification+measurement+weighing".

Application scenarios: express billing sorting, cross-border e-commerce customs clearance sorting (volume and weight need to be declared), and storage space optimization, such as the rookie network "intelligent weighing and volume measurement integrated machine", which is suitable for the whole scene measurement of power distributors' packages.

AI visual recognition technology

Technical principle: Based on deep learning models (such as YOLO, SSD), real-time images of goods are collected by industrial cameras, and goods shape (regular/irregular), packaging type (carton/envelope/plastic bag), damage and even the category of unlabeled goods are identified.

Technical Highlights: Support dynamic identification (moving speed of goods ≤3m/s), simultaneous identification of multiple targets, adaptability to different lighting and background environments, and recognition accuracy ≥99.9%.

Application scenarios: special-shaped parts sorting (such as cylindrical and triangular packages), damaged parts detection, and unlabeled goods sorting. For example, Amazon Logistics adopts AI visual recognition system to automatically sort irregular household items.

Second, the sorting actuator technology (sorting "arm")

Core function: according to the sorting decision, the goods are accurately transported to the target channel, which is the core execution unit to realize physical sorting.

Key technologies and applications:

Cross belt sorter technology

Technical principle: It consists of a main drive belt conveyor and a loading trolley (with a small belt conveyor). The loading trolley runs along the main track, and the goods are pushed to the target sorting crossing laterally through the cross movement of the trolley belt and the main track.

Technical highlights: the sorting efficiency is 8000-20000 pieces/hour, and it can handle goods of 0.1-30kg, 50mm×30mm×10mm to 600mm×500mm×300mm, and the breakage rate is ≤0.01%, which is suitable for multi-category parcel sorting.

Core components: high-precision synchronous belt (positioning accuracy ±2mm), servo drive system (response speed ≤ 0.05s), light-weight loading trolley (reducing energy consumption).

Application scenario: e-commerce express transshipment center and cross-border e-commerce bonded warehouse. For example, Zhongtong "Longxing" transshipment center adopts high-speed cross-belt sorting machine, and the sorting volume per day exceeds one million pieces.

Slider sorting machine technology

Technical principle: slider devices are installed on both sides of the main conveying roller line, and the slider is driven by a cam or a chain, and the slider moves laterally along the guide rail to push the goods from the main conveying line to the target crossing, which is suitable for sorting large and heavy goods.

Technical highlights: The sorting efficiency is 5000-12000 pieces/hour, and it can handle goods with weight ≤50kg and size ≤800mm×600mm×500mm. It has firm structure and low maintenance cost, and supports inclined layout (saving space).

Core components: wear-resistant slider (made of polyurethane, with service life ≥ 1 million times), high-strength guide rail (bearing ≥100 kg/m) and frequency conversion drive system.

Application scenarios: sorting of finished products in home appliance manufacturing industry, sorting of large items for express delivery, and sorting of container goods in ports. For example, Midea's home appliance warehouse uses a slider sorting machine to sort large items such as refrigerators and washing machines.

Robot sorting technology

Technical principle: With AGV/AMR robot and mechanical arm as the core, combined with visual recognition technology, the integrated operation of grabbing, handling and sorting goods is realized, which is divided into two modes: "goods arrive to people" and "people arrive".

Technical highlights:

Mechanical arm sorting: cooperative robot (load 3-50kg) is adopted, equipped with vacuum sucker or gripper (adaptive to goods with different shapes), and the sorting accuracy is 1 mm, which is suitable for small batch and multi-category sorting;

AGV robot sorting: Kiva robot, for example, can move goods shelves to the sorting station through two-dimensional code navigation, or directly sort individual packages to the target area, which supports flexible layout (no fixed track is needed).

Application scenario: 3C electronic manufacturing parts sorting, e-commerce small package sorting, fresh e-commerce pre-warehouse sorting, such as Amazon "Kiva robot" system, to achieve full automation of warehouse sorting.

Inclined sorter technology

Technical principle: It is composed of inclined belts or rollers. By adjusting the inclination angle of belts/rollers (15-30), automatic sorting can be realized by using the gravity of goods. It is suitable for goods with regular shape and medium weight.

Technical highlights: simple structure, low energy consumption (no additional pushing device), sorting efficiency of 3000-6000 pieces/hour, suitable for regular goods such as cartons and plastic boxes.

Application scenario: Shangchao distribution center and finished goods sorting in manufacturing industry. For example, Wal-Mart distribution center uses inclined roller sorting machine to sort daily necessities cartons.

3. Motion control and driving technology (sorting "brain nerves")

Core function: control the movement precision, speed and coordination of the sorting actuator, and ensure the quick, accurate and stable sorting action.

Key technologies and applications:

PLC programmable logic control technology

Technical principle: PLC controllers (such as Siemens S7-1500 and Mitsubishi FX5U) write control programs, receive signals from the sensing system, and output instructions to control the motor, cylinder, solenoid valve and other executive components of the sorting machine, so as to realize the automatic operation of the sorting process.

Technical highlights: fast response speed (scanning period ≤1ms), strong anti-interference ability (adapting to industrial environment), flexible programming (supporting ladder diagram, function block diagram and other languages), and realizing multi-equipment collaborative control (such as linkage between sorter, conveyor and detection equipment).

Application scenario: The core control units of all intelligent sorting lines, such as SF cross-belt sorting line, adopt Siemens PLC to realize the cooperative control of sorting machine, scanning gun and crossing device.

Servo drive technology

Technical principle: It is composed of servo controller, servo motor and encoder, which receives the instructions from PLC, accurately controls the speed, position and torque of the motor, and realizes the high-precision movement of the sorting actuator (such as the positioning of the cross-belt trolley and the grasping action of the mechanical arm).

Technical highlights: positioning accuracy ≤±0.01mm, rotational speed response time ≤0.02 seconds, support for high-speed start-stop (adapting to the processing speed of sorting line above 8000 pieces/hour), and remarkable energy saving effect (30% lower than that of ordinary motors).

Application scenarios: cross-belt sorter trolley drive, manipulator joint control, slider type sorter slider drive, such as ABB servo system used in Jingdong Logistics manipulator sorting line.

Frequency conversion speed regulation technology

Technical principle: adjust the power supply frequency of the motor through frequency converters (such as Schneider ATV320 and Fuji FRN) to realize stepless adjustment of the motor speed and adapt to different sorting scenes (such as speeding up when the flow of parts is dense and slowing down when it is sparse).

Technical highlights: soft start (avoiding motor starting shock), overload protection, energy consumption optimization, and closed-loop control (automatically adjusting speed according to component flow density) can be realized by linkage with PLC.

Application scenario: motor control of main conveying line and speed adjustment of sorter. For example, the rookie network sorting line adopts frequency conversion speed regulation technology to realize stepless adjustment of sorting speed from 0 to 3 m/s.

Multi-axis collaborative control technology

Technical principle: The synchronous control of multiple servo motors is realized through the motion controller (such as Befu CX2020), so as to ensure the cooperative action of the sorting executive mechanism (such as the speed matching between the main track and the trolley belt in the cross belt sorter and the cooperative sorting of multiple mechanical arms).

Technical highlights: It supports pulse command and EtherCAT bus control, and the synchronization accuracy is ≤±0.1ms, which can realize complex trajectory planning (such as circular motion of manipulator and linear interpolation).

Application scenario: high-speed cross-belt sorting machine and multi-robot cooperative sorting line, such as Amazon robot sorting system adopts multi-axis cooperative control to realize path avoidance and cooperative operation of multi-Kiva robots.

Four, software system and intelligent scheduling technology (sorting "brain")

Core role: It is the core command center of sorting line to realize intelligent decision-making, scheduling, monitoring and management of sorting process.

Key technologies and applications:

WMS/WCS warehousing and control system

Technical principle:

WMS (Warehouse Management System): responsible for order management, inventory management, sorting task allocation and generating sorting instructions (such as "sorting by destination city" and "sorting by order priority");

WCS (Warehouse Control System): receives the instructions from WMS, converts them into control signals recognizable by PLC, coordinates the operation of sorters, conveyors and detection equipment, and realizes the automatic control of the whole process.

Technical highlights: Support multi-rule sorting (by region, order, weight, aging, etc.), dynamic task allocation and real-time monitoring of equipment status, which can be seamlessly connected with e-commerce platform and TMS (Transportation Management System).

Application scenario: E-commerce warehouse distribution center and manufacturing finished product warehouse, such as SAP WMS system, are used in Huawei mobile phone finished product sorting line to realize the integrated management of order and sorting.

AI intelligent scheduling algorithm

Technical principle: Based on the model of machine learning and operational research, the sorting task is optimized and scheduled, including path planning (such as the optimal driving path of the cross-belt sorter car), crossing assignment (such as assigning high-frequency destinations to near crossings) and resource scheduling (such as adjusting the running number of sorting lines according to the piece flow prediction).

Technical highlights: real-time response (algorithm decision time ≤0.5 seconds), self-learning optimization (adjusting algorithm parameters according to historical data), and anti-interference (dealing with unexpected situations such as component flow fluctuation and equipment failure).

Application scenario: peak sorting scheduling and multi-sorting line collaborative operation are greatly promoted. For example, Jingdong Logistics "Qinglong System" adopts AI scheduling algorithm to realize the optimal sorting path planning of millions of packages during double 11.

Data visualization and MES system

Technical principle: MES (Manufacturing Execution System) collects real-time data of sorting line (sorting quantity, accuracy, equipment running status, fault information, etc.) and displays them through visual interfaces (such as Dashboard and digital twin model) to support managers to monitor and make decisions in real time.

Technical highlights: the data update frequency is ≤1 second, which supports multi-terminal access (computer, mobile phone, tablet), and can generate reports (such as daily/weekly/monthly sorting efficiency reports) and fault warning (such as motor overheating warning).

Application scenario: sorting line operation management and equipment maintenance. For example, the rookie network "Smart Logistics Brain" simulates the running state of sorting line in real time through digital twinning technology to realize remote monitoring and fault diagnosis.

System integration and interface technology

Technical principle: Standardized communication protocols (such as EtherNet/IP, Profinet, MQTT) are adopted to realize data interaction and seamless docking between the sorting line and the upstream and downstream systems (e-commerce platform, TMS, ERP, customs declaration system) to ensure real-time synchronization of information.

Technical highlights: support cross-platform integration (Windows, Linux, Android), data encryption transmission (conforming to ISO27001 security standard), and extensible interface (adapting to new systems).

Application scenarios: cross-border e-commerce sorting (docking with customs system) and e-commerce express sorting (docking with Taobao/JD.COM platform). For example, DHL International Sorting Center adopts MQTT protocol to realize real-time synchronization of sorting data with global logistics network.

5. Sensor and Internet of Things (IoT) technology (sorting "nerve endings")

Core function: real-time collection of data such as equipment status, goods location and environmental parameters of sorting line, so as to realize the whole process perception of equipment and goods.

Key technologies and applications:

Position sensor technology

Technical principle: photoelectric sensors, proximity switches, encoders, etc. are used to detect the position of goods on the sorting line (such as whether it reaches the sorting crossing or not, whether it is congested) and the movement position of equipment parts (such as the track position of the cross-belt car).

Technical highlights: fast response speed (≤10μs), high positioning accuracy (±0.1mm), wear resistance (industrial protection grade IP67), adapting to the high-speed operation environment of sorting line.

Application scenario: goods in place detection, equipment positioning control, for example, the slider sorter uses photoelectric sensors to detect whether the goods reach the push position.

Force/torque sensor technology

Technical principle: It is installed on the gripper of the mechanical arm and the pushing device of the sorter to detect the grasping force and pushing force, so as to prevent the goods from being damaged due to too much force or falling off due to too little force.

Technical highlights: the measurement accuracy is ±0.5% FS, the response time is ≤0.01 second, and the force feedback control is supported (the force is automatically adjusted according to the weight of the goods).

Application scenario: mechanical arm sorting and fragile goods sorting. For example, the SF cold chain sorting line uses force sensors to automatically adjust the grasping strength when sorting fresh products.