Views: 0 Author: Site Editor Publish Time: 2026-07-20 Origin: Site
A large steel sintering plant operates a C‑type raw material yard of approximately 180m × 68m for storing iron concentrate. The yard is equipped with 2 heavy‑duty stackers (tipper cars) for stacking and 2 semi‑portal scraper reclaimers for reclaiming, forming the core link for material storage and supply.
Before the upgrade, each machine required on‑board operators working in a dusty environment with high labour intensity. Operational efficiency was also limited by human response. The client aimed to achieve remote automated operation to improve working conditions and enhance yard management.
Wuhan Forward Technology designed and delivered a complete unmanned system for the stackers and reclaimers, covering hardware deployment and software platform development, with all integration and commissioning carried out by our company.
Travel positioning uses Gray code (absolute position) technology combined with built‑in encoders, achieving continuous accuracy of ±1 mm with 0.1 mm resolution and no signal jumping.
Luffing angle is measured by inclinometers with an accuracy better than ±0.1°, ensuring precise knowledge of each machine’s position and attitude at all times.
A total of 8 laser scanners are installed on the stackers and reclaimers (one per stacker, two per reclaimer). They continuously scan the stockpile surface, capture 3D point cloud data, and reconstruct real‑time 3D models.
The system automatically calculates stockpile volume and weight for inventory, and extracts key parameters such as boundaries, height and width to support automated operations.
Radar level sensors mounted on both sides of each stacker monitor stacking height in real time, ensuring even and controlled pile shapes.
Upon receiving incoming material information, the system automatically generates a stacking plan. Using the 3D model, it calculates the start/end positions and target height, then sends control commands to the stacker PLC. During stacking, radar sensors continuously monitor height; when the set height is reached, the system moves the stacker to the next point, achieving continuous and uniform layering.
Based on downstream demand (e.g., bin levels), the system automatically creates a reclaiming plan. The 3D model calculates the cut‑in point and layer length for each pass, and the reclaimer follows a stratified layered reclaiming process. A flow meter at the discharge outlet monitors material flow in real time and automatically adjusts travel speed and luffing angle to maintain a constant feed rate, preventing belt overloading or starvation.
The control network uses a dual‑path parallel design with fibre optics and wireless APs, supporting the PRP redundancy protocol. If one link fails, the other takes over seamlessly with zero packet loss and no interruption. Control signals, video streams and point cloud data are transmitted on separate networks to avoid interference.
Ultrasonic anti‑collision sensors are fitted on the reclaimers.
Laser ranging devices are installed between the two stackers that run on the same track.
Combined with PLC‑based software logic, the system provides two‑stage alarms (warning) and a final stage forcing an emergency stop, ensuring safe operation.
Our independently developed control platform is deployed in the central control room, offering:
3D digital twin interface – real‑time display of yard models and machine status.
Task management – automatic generation of stacking plans from incoming material signals, and reclaiming plans from bin demand.
Process monitoring – live parameters, alarms and progress.
Data management – automatic recording of operation logs, alarm history and statistical reports.
Inventory management – automatic stocktaking based on laser scanning data, with weight calculation for each pile.
The platform supports three control modes: fully automatic, semi‑automatic (manual positioning + automatic execution), and remote manual (emergency). Operators can switch flexibly as needed.
After commissioning, all 2 stackers and 2 reclaimers now operate without on‑board personnel. All operators work from the central control room. The equipment automatically performs positioning, stacking, reclaiming, layer changing, and pile switching according to system commands. Only 1‑2 operators are needed for monitoring and exception handling. Yard inventory data is available in real time, operation records are automatically archived, and management efficiency has been significantly improved.
