Bucyrus signed a technology licensing agreement with CSIRO to access LASC technology in July 2009 and still has equipment in use at the LASC R&D Broadmeadow and Grasstree sites, while the Beltana example will operate until the end of this year.
Working on its own hardware and software automation equipment since 1992, the OEM has developed automation systems involving roof supports, shearers, computer simulation technology (CST) and UEL overload protection drive systems.
The development of a control system that treats the entire longwall as a single integrated machine has resulted in the Programmable Mining Control (PMC) family, a follow on from the PM4.
The PMC family provides controls and sensors for all components of the longwall system, eliminating interfacing problems. The system offers a tailored control unit for each of the various longwall functions, with the PMC-R for roof support systems, PMC-D for drive control, PMC-V for visualisation and parameter setup of the drive system and PMC-P node computer to act as an interface between the Bucyrus controller network, third-party systems and the mine computer.
PMC-R units have the know-how to control the entire longwall, including all external factors such as position and speed of the plow or shearer, conveyor speed, and chain tension. Each PMC-R installs itself 'independently' in the longwall and can communicate with external computers. This means that an operator can control the entire longwall from any roof support.
The PMC-R electro-hydraulic longwall face control system facilitates full automation, monitoring and remote diagnostic capabilities for all face equipment. Information can be transferred in “real time” to the surface to provide data to operating and management personnel to maximise longwall system performance.
A spokesman for Bucyrus tells Mining Magazine: “In the PMC system, a PMC-R is typically mounted on each roof support in keeping with our ‘intelligence in each shield’ philosophy. Each PMC-R is equipped with the face operating program, creating a network of independent logical controls, allowing multiple face operations to be performed simultaneously. Faults are easily diagnosed and repaired because each PMC-R can interrogate its neighbours to quickly determine the source of the problem. The PMC-P coordinates elements of the longwall, for example, if the shearer is cutting large quantities of coal, it must either speed up the conveyor drives or, if that is not possible, slow down the shearer.
It also passes shearer position data to drive controllers so that they can fold in the roof support flipper at the appropriate time to prevent collision. Data transmission to the surface via optical fibre, modem or copper wire is also implemented by the PMC-P.”
The Visualisation Control Unit (VCU) allows data on all components of the longwall to be collected and analysed by a central computer, and controlled as required.
Programmes include VPlow, showing a plow system with solenoid switches and setting of the parameters of the UEL drive controllers; VShearer, which allows setting and visualisation of operational parameters and the status of the shearer; and VDrive, showing the conveyor gearbox controllers. A range of sensor values can be displayed graphically and all parameters can be changed.
The VCU can be installed in a longwall control centre underground, in the vicinity of the longwall, or in a surface control room.
Xstrata’s Newlands Northern mine in the Bowen Basin provides an example of an aging longwall mine updated with Bucyrus automated longwall equipment.
The mine set a new Australian annual production record in May 2009, when it extracted 961,891t in a month, beating Beltana’s previous record of 955,049t set in November 2005. Machinery used included an EL3000 shearer working off a Jumbotrack 2000 rackbar haulage system with 181 two-leg roof supports, automated with Bucyrus’s PM4 electro-hydraulic control system.
Eickhoff’s previous investigations into longwall automation led to the development of EiControl, featuring automated ranging arm control, automated direction and speed control, AFC overload protection and an anti-collision system regarding AFC face end equipment.
Continued work on the EiControl package led to the launch of EiControlPLUS, which also offers anti-collision support by means of radar technology and video surveillance of the cutting drums and the areas in front of and behind the shearer.
The latest software development EiControlSB is an absolute flexible automation environment which provides easy customising of pre-defined sequences and the implementation of tailor-made cutting cycles.
Uwe Marewski, sales director for Eickhoff tells Mining Magazine: “EiControlSB and LASC fit perfectly together, but this is only one option for automated longwall systems. Eickhoff shearer automation systems will also interface with any other longwall automation technology.”
Over 90% of all Eickhoff shearers currently in operation globally are equipped with EiControl. Two SL750 machines using the advanced EiControlPLUS system are going through the final tests at RAG’s Auguste-Victoria Mine in Germany. Since 2009, EiControlSB (integrated in an SL 1000) has been successfully applied at Vale’s Carborough Downs coal mine, where the system has performed well.
Joy Mining Machinery
Joy Mining Machinery, Bucyrus and Eickhoff were the only three OEMs involved during the R&D phase of the LASC technology.
However, Joy was the first to sign an agreement to take CSIRO’s longwall automation system commercial in October 2008, and quoting the first Joy INS for a longwall system in Australia.
Anglo Coal’s Moranbah North mine was the first customer to receive the commercial LASC system, which also ordered 151 1750t yield rating, 2m-wide Joy roof supports and two Joy 7LS6 shearers.
Joy now provides roof support automation through a new generation of electronic control systems, RS20s. A follow on from the earlier RS20, the RS20s system supplies a complete automation library of over 100 face cutting sequences, consisting of a Mimic (the man to machine interface), Micro (Control Unit) and a STU (Solenoid Transducer Unit), which controls the hydraulic functions of the support.
Using shearer initiation with gate-end automation, Joy claims no operators need to be specifically deployed for shield operation. The majority of RS20s installations are using full gate end automation.
Part three will be published Monday.