MINING is a primary industry that enables the growth of other industries such as construction, where its products are used in development projects.
For mining companies, regularly knowing the stockpile volume of their raw material accurately is very important. This allows them to effectively plan inventory activities.
Quarry company Pens Industries Sdn Bhd (PISB), which was established in 1986 as a wholly-owned subsidiary of the Perlis State Economic Development Corporation (PKENPs), used to face problems in keeping track of its inventory.
The company's core business is in limestone quarrying, with an extensive range of products like aggregates, premix and asphaltic concrete.
Its main issue was product volume calculation, of which the company management had no accurate records.
The amount of products produced were just estimated from the weight per lorry that the company sold.
This posed a problem as the company frequently could not reconcile the difference between total product produced and total product sold when performing an inventory check on their stockpile.
Then, help arrived in the form of drone technology from Universiti Malaysia Perlis' (UniMAP) Centre of Excellence for Unmanned Aerial Systems (COEUAS).
According to COEUAS director Professor Hazry Desa, aerial data from drones is revolutionising inventory management in the mining and aggregate industry.
"Site surveying is faster and safer with drones. Imagery analysis, cloud computing and machine learning technologies leverage drone aerial data to make inventory management efficient.
"It can save time and money, provide better accuracy and data confidence, improve financial forecasting, optimise supply chain management and improve production."
Hazry said traditionally, site managers will conduct surveys on the ground with a Global Navigation Satellite System (GNSS) receiver.
A GNSS receiver allows users to measure the precise location of any point on earth within centimetres.
"The surveyor is required to collect numerous measurement points around the base of the stockpile, and often has to climb onto the pile to take additional points.
"It is a time consuming and expensive process. In addition, there are inherent safety risks when climbing the stockpiles.
"Aerial surveying with drones, which is quicker and easier, enables surveyors to measure the stockpile with a dense point cloud using photogrammetry processes.
"The accuracy has been proven to about 98 to 99 per cent," he said.
By implementing drone technology, Hazry said site surveying becomes faster and safer.
"Inventory of the stockpile becomes efficient, financial forecasting is improved, and production and supply chain management is also better. This process can improve the validity of total products produced by PISB."
UniMAP has entered into a collaboration with PISB to support the mining company in conducting stockpile inventory on a quarterly and yearly basis for financial reporting of volume inventories and to monitor production.
COEUAS acted as the research team, PISB provided the funds, and the project was managed by Technopreneur @ UniMAP Sdn Bhd (TUSB) — a centre managing all contract research activities by the university.
The project kicked off in May last year and was scheduled to end in April.
But it has been extended since PISB requested for stockpile volume inspection to align with its audit schedule.
The stockpile volumes inventory process has to be executed in two stages — the first and second phase.
The first phase is on understanding the observation area and the establishment of Ground Control Points (GCP).
The point to locate a permanent GCP is marked and indicated by a cement base to stabilise the station.
Next, two observation methods are conducted, which are vertical control and GCP observations.
The second phase involves stockpile inspection and volume acquisition. The processes include flight planning, flight mapping, processing and stockpile volume calculation, and density and mass calculation.
"Before carrying out any photogrammetric measurement or data acquisition, the unmanned aerial vehicle (UAV) must be in good condition. The weather must be considered to avoid rain. Then, the flight plan is drawn," said Hazry.
The project area spans 42 hectares. All information about the flight path are obtained using the Mission Planner application.
After fight planning, the UAV is deployed to capture images.
"When flying this drone, the proper height ought to be maintained. The surrounding area needs to be considered since the survey area is hilly. Obstacles must be identified to avoid the drone from crashing into it."
Besides that, the surveyor must constantly observe the drone to avoid losing its signal.
After the study of the area has been photographed, the drone is taken to the office for data processing, said Hazry.
Drone technology helps to save time and reduce manpower in conducting surveys, besides providing better accuracy.
"Time savings are achieved as the drone can measure up to 100 hectares in half a day compared to traditional methods. Drones also can cut off survey time substantially.
"While reduced manpower and equipment is profitable, in the mining industry, the concern is more on safety.
"In conventional methods, numerous equipment are used to calculate production like lorries, weighbridges and backhoes.
"By using drone technology, the mining industry can improve the accuracy in calculating total stockpile product and visualise the project area in a 3D model," said Hazry.
In the aftermath of the project, COEUAS has been put in charge of stockpile volume acquisition for PISB.
"The management of PISB agreed to use our services continuously twice a year. COEUAS also acts as an adviser when PISB has any queries or thoughts on these technologies," Hazry said.
He said COEUAS has recruited a masters student under the research project, which indirectly creates room for journal publication.
"The centre received a lot of industrial engagement due to this project. Thus, it increased the network radius and created more opportunities to spread and share these technologies with others," he said.