I. Project Background and Core Objectives

The outdoor storage area of the steel plant is characterized by numerous steel batches, wide stacking ranges, and harsh environments (high temperature, rain, vibration). The existing system can only manage basic steel information and cannot associate physical locations, requiring manual area-by-area searches during retrieval. The average retrieval time severely impacts production continuity efficiency and customer pickup speed.

The ZigBee semi-active system positioning technology aims for "precise positioning, rapid retrieval, and integration with the source system". Through the collaboration of tags and base stations, it achieves real-time location awareness for each batch of outdoor steel, while enabling data interoperability with the source system. This builds an integrated management system of "information - location", reducing the single retrieval time to within 2 minutes.

II. Basis for Technology Selection: Why Choose ZigBee Semi-Active System Positioning Technology

Addressing the requirements of the outdoor steel plant scenario, ZigBee semi-active system positioning technology holds significant advantages compared to other positioning technologies, with a specific comparison as follows:

III. Overall System Architecture Design

(I) Perception Layer: Core Hardware Deployment (Matching Requirement List)

ZigBee Semi-Active System Light-emitting Tag (Bound to Steel)

• Core Parameters: Semi-active communication mode, supports ZigBee protocol + low frequency 125K; Protection rating IP67 (rainproof, dustproof); High-temperature resistance -20℃~70℃ (adapts to summer exposure and winter low temperatures in steel plants); Impact resistance rating IK08 (withstands steel stacking vibrations); Built-in unique ID (one-to-one binding with steel batch number); Equipped with LED light-emitting function (illuminates during close-range retrieval for quick target steel identification); Battery life 2-5 years (low-power design, reduces replacement frequency).

• Installation Method: Uses strong magnetic adsorption, screw fixation, zip tie binding, double-sided adhesive pasting (attached to the side of steel bundles to prevent falling off during hoisting).

ZigBee Semi-Active System Reader Base Station (Covers Storage Area)

• Core Parameters: Supports reading ZigBee semi-active system tags (range 10-100 meters, adjustable power to adapt to different stacking densities); Built-in 4G full-network module (supports long connection to external network servers for real-time data transmission and remote control); Protection rating IP67 (outdoor rainproof, corrosion resistant); Supports DC 12-24V dual power supply or solar + lithium battery (adapts to outdoor wiring scenarios); Possesses low-frequency 125K activation function (assists close-range positioning); Built-in signal enhancement antenna (optimizes signal penetration in metal environments).

• Deployment Principle: Installed corresponding to steel stacking areas, deploying one base station per storage area to ensure no signal blind spots; Installation height above 2 meters (avoids steel hoisting paths while ensuring coverage), preferably fixed on storage area columns or fences.

(II) Transmission Layer: Data Transmission Channel Construction

• Core Transmission Link: Base stations establish long connections with external network servers via the 4G module, using TCP/IP protocol for encrypted transmission (prevents data leakage), uploading tag location data every 30 seconds (frequency adjustable on demand, balancing real-time performance and traffic cost).

• Edge Computing Optimization: Base stations have built-in simple data processing units capable of filtering invalid data (e.g., tag signal jitter) before uploading valid data, reducing server computational load.

(III) Platform Layer: Data Hub and Source System Collaboration

Core Functional Modules

• Data Reception and Parsing: Receives tag ID, signal strength, timestamp, and other data uploaded by base stations in real-time, associates it with steel batch information after parsing.

• Location Calculation Engine: Based on "point-to-point beacon positioning", calculates the specific coordinates of the steel (e.g., "Storage Area A - Row 3 - Pile 5").

• Source System Data Interface: Develops standardized API interfaces for bidirectional data synchronization with the existing source system — retrieves steel batch number, specifications, storage time, etc., from the source system, and pushes real-time steel location data to the source system, ensuring perfect matching of "source system information - location".

• Database Design: Uses MySQL database, storing three types of core data: ① Steel basic information table (batch number, specifications, source system code); ② Tag association table (tag ID – steel batch number binding relationship); ③ Location record table (steel real-time location, historical location轨迹/trajectory).

(IV) Application Layer: Retrieval Function Implementation (For Different User Roles)

Web Management Platform (Suitable for Office Administrators)

• Real-time Location Monitoring: Displays steel distribution in all storage areas in map form; clicking a steel batch shows detailed information (location, specifications, storage time); supports filtering and locating by "batch number, specifications, source system code".

• Retrieval Task Initiation: After synchronizing pickup demands from the source system, retrieval tasks can be initiated directly; the system automatically generates "target location".

• (3) Data Statistical Reports: Automatically generates reports such as "Retrieval Time Statistics", "Steel Turnover Rate", "Base Station Online Rate", etc., supporting Excel export to assist management decisions.

PDA Mobile Terminal (Suitable for On-site Operators)

• Quick Goods Search: Quickly locates and finds target goods based on the map position located by the system.

• Quick Binding and Unbinding of Semi-Active Tags

IV. Project Benefit Analysis

Efficiency Improvement: Single retrieval time reduced from 1 hour to within 5 minutes, daily retrieval time reduced by 4-6 hours, pickup efficiency improved by over