Case Study: Gray Bus Positioning System for Unmanned Stacker-Reclaimer & Belt Tripper Car Control

Project Snapshot

• Location: Hubei, China

• Industry: Coking / coal blending

• Scope: 2 stacker-reclaimers, 2 reversible belt tripper cars, 12 blending bins

• Objective: unmanned operation, remote centralized control, digital stockpile management

• Core technologies: 3D laser scanning, high-precision Gray bus positioning system, industrial wireless, video surveillance, PLC-based automation

Background

The coal yard originally relied on manual cab operation for stacker-reclaimers and local manual control for belt tripper cars. Real-time stockpile data, 3D models, and reliable video coverage were limited, which affected safety, efficiency, and coal blending accuracy.

Solution

1. Unmanned Stacker-Reclaimer System

The two stacker-reclaimers were upgraded with new electrical control systems, power and signal cables, local operation panels, and remote operator consoles in a ground central control room.

Key functions include:

• 3D laser scanning on both sides of the boom to scan the stockpile and generate a 3D model.

• A Gray bus positioning system for travel and slewing detection, plus encoder and inclinometer for pitch angle.

• Material flow monitoring and yard management for automatic stacking, reclaiming, and inventory checking.

• Video surveillance, anti-collision, and safety protection for remote monitoring and fault alarms.

• Industrial wireless communication for control and video signals, connected to the central control room by fiber.

• Manual backup in the driver’s cab for abnormal conditions.

The system supports one-key start/stop and fully automatic stacking and reclaiming with stable material flow and minimal manual intervention. It is a complete unmanned stacker-reclaimer operation solution for dusty and hazardous coal yards.

2. Automatic Belt Tripper Car Control System

The two reversible belt tripper cars above the blending bins were upgraded with:

• A high-precision Gray bus positioning system installed along the rail side, with ground decoders sending position data to the PLC.

• Radar level gauges for each bin to monitor real-time material level.

• Video monitoring, material flow detection, and blockage detection.

• PLC-based automatic bin switching and discharging.

• Industrial wireless communication to the ground network.

• Interlocking with the stacker-reclaimer system to prevent wrong coal retrieval and material mixing.

Here, Gray bus positioning technology provides reliable car position feedback. The system monitors coal type, belt status, bin status, and tripper car position. The car automatically travels to the target bin and discharges according to the coal blending plan. This automatic belt tripper car control system eliminates manual bin positioning and reduces the risk of wrong-bin discharge and material mixing.

Results

After the upgrade, the coal yard achieved:

• Remote centralized control and unmanned operation of stacker-reclaimers.

• Automatic stacking and reclaiming with stable, constant flow.

• Operators moved from dusty field conditions to a central control room.

• Real-time 3D stockpile visualization, including coordinates, quantity, and coal type.

• Digital stockyard management and inventory functions.

• Full-process tracking from coal yard to blending station.

• Interlocking between bin receiving and the stacker-reclaimer to avoid wrong coal and material mixing.

• Reduced on-site staffing, lower labor intensity, and improved safety and reliability.

Applicable Industries

• Steel plants and raw material yards

• Coking and coal blending plants

• Coal storage and transport facilities

• Ports and bulk cargo terminals

• Power plant coal yards

• Cement plants and raw material yards

• Mining and mineral processing

Typical Application Scenarios

A. Unmanned Stacker-Reclaimer System

• Fully automatic stacking and reclaiming in longitudinal stockyards, enclosed coal sheds, and circular stockyards.

• Remote centralized control rooms for steel plants, coking plants, power plants, and port coal yards.

• Multi-material, multi-pile stockyard management with 3D scanning and inventory.

• Constant-flow reclaiming and blending for stable downstream feeding.

• Anti-collision and safety interlocking between stacker-reclaimers and belt conveyor systems.

• Unmanned stacker-reclaimer operation in dusty, hazardous, and labor-intensive yards.

• Integration with belt conveyors, blending bins, and plant control systems.

B. Automatic Belt Tripper Car Control System

• Automatic bin switching and discharging above blending bins, batching bins, and coking coal bins.

• Coking coal blending, steel raw material batching, and power coal blending.

• Multi-bin, multi-coal-type applications requiring anti-mixing and anti-wrong-bin control.

• Bin level monitoring, blockage detection, and material flow detection.

• Remote central control and unmanned operation at the bin top.

• Process recording of coal type, bin number, and feeding time.

• Reversible belt tripper car, movable tripper car, and unloading car positioning.

• Interlocking with stacker-reclaimers and belt conveyor systems.