Digital Pan Coal System Implementation Deployment

1、Overview

The on-site coal bunker integrates coal storage and coal transfer functions, with a design capacity of 100,000 tons. The solution is based on the overall layout of the existing coal bunker equipment for transformation, using computerized automatic control and network information technology to laser scan the internal information of the bunker, combined with intelligent analysis and processing of the background data to establish a closed coal bunker digital intelligent inventory system.

The site is a strip-type closed coal bunker with an irregular shape. Three sets of laser scanners are arranged horizontally at the top of the coal shed along the centerline of the middle of the two belt conveyors.

Fig. 1 Schematic diagram of fixed installation scheme of closed coal bunker

The fixed 3D laser scanner installation solution for closed coal bunkers mainly contains two parts: dynamic measurement system and central control station. The functions that can be achieved are as follows：

1）The dynamic measurement system can automatically obtain the 3D coordinates of the coal field surface in real time and dynamically, and can complete the calculation, fusion and generation of a unified 3D model of the whole strip coal bunker within one minute from the scanned data. The data is fused with unified coordinate system and unified space-time, and the 3D model is realistic.

2）The software uses a fine-configuration network algorithm to reconstruct the triangular network from the 3D point cloud data on all sections, that is, the adjacent two sections are divided into many small triangles between them, and then the total volume is calculated by integrating each triangle. When the scanning unit enters the next scanning cycle, it is able to automatically update only the data of the changing part of the coal field, and the updated data need to change the 3D model timestamp after the update. The relative accuracy of the measurement reaches 0.5%.

3）The 3D coal field dynamic measurement and control system software can plan the coal field according to certain planning principles and establish a unified coordinate system according to the characteristics of incoming coal, and the scanned 3D model can automatically calculate the coal storage capacity of each subzone according to the planning principles. The scanned 3D model can automatically calculate the coal storage volume in each subzone according to the planning principle.

1、System content and functions

2、Dynamic measurement system solutions

According to the actual situation of coal yard, the dynamic measurement system consists of 3 sets of 3D laser scanners and other equipment installed on the top of the silo, three sets of laser scanners are arranged on the top of the coal shed, each set of laser scanners opens round holes on the concrete floor slab, during construction, according to the structure of the top slab, the round holes stagger the support beams and columns below, at the same time, the holes are of suitable size and will not affect the load bearing of the equipment above. Considering the dust environment in the warehouse, this plan sets laser dust cover, the front of the dust cover automatically opens when working for laser scanning, and closes the dust cover when the plate is not finished, this plan can effectively extend the maintenance cycle of the laser mirror caused by dust accumulation.

The 3 sets of laser scanning systems distributed on the top of coal bunkers can realize local and remote measurement by controlling the equipment in situ and connecting with the remote server through optical fiber. At the same time, all the measurement points deployed on site can be scanned and updated according to the set period or automatically triggered after the operation is completed. The scanned and updated point cloud data is transferred back to the database by itself through optical fiber, and the coal field data analysis, calculation and 3D coal field update are completed.

3、Dynamic measurement data fusion methods

The valid data collected by each scanner is part of the coalfield area, and these data need to be fused to build a unified 3D model. An example of data fusion is shown below.
A coal pile of known volume is scanned by three scanners installed at different points, and the data from each scan is calculated and modeled as follows：

The 3 data are combined and the 3D graph is as follows：

Data fusion of 3D coalfield dynamic measurement and control systems must achieve the following：

1）Unification of space and time

Establish the spatial datum of the system by scanning the empty bunkers of coal bunkers. The spatial position of each fixed installed laser scanner is determined by the base position measurement, and the coal field range 3D data control network is established. The temporal and spatial unification of the system is achieved by matching the time and spatial positions with high accuracy.

2）Distributed Fusion

Multiple laser scanners distributed in the coalfield area form a coal bin 3D data control network, and the local 3D data of the coalfield acquired by each control point has redundancy. The redundant data brings a large interference to the overall coal field original view 3D establishment. The system realizes the redundant data rejection and the optimal configuration of control range by high-precision filtering algorithm, which ensures the validity of measurement data and the timeliness of acquisition. The filtered local data are modeled in accordance with the coal bunker unified datum for conformation network, which ensures seamless connection between model units.

3）Central control station function

The central control station mainly consists of a data server, a monitoring terminal, and an external data control module.

1.The server is responsible for data acquisition, operation control, data calculation and output, and calculation result release of the 3D coalfield dynamic measurement and control system.

2.The monitoring terminal provides LCD monitors to monitor and control the work of each component of the 3D coal field dynamic measurement and control system distributed within the coal field.

3.The external data control module mainly processes and screens a large amount of fuel management link data called from external systems and is used to integrate with the original view data of the coal yard.

The central control station matches the incoming coal-related attributes (incoming coal point, incoming coal time, incoming coal weight, incoming coal quality, etc.) with the 3D data on the coal field surface acquired by real-time scanning, according to its different time and space characteristics, and the server correlates them according to the acquired 3D data on coal field morphological changes and pile pickup registration data to form a storage data unit for stratification and partitioning, and automatically updates the coal field 3D model, automatically renders different incoming coal with different colors to realize automatic stratification and partitioning of incoming coal.

4、Main equipment performance parameters