Introduction
The excavator can be seen at any construction site in the city. One driver can handle a conventional excavator. It does not require a complex automation system to control it.
But if an excavator is many times larger than usual and reaches the height of a five-story building, can a Land Cruiser be placed in its bucket, and the “stuffing” consists of electric motors, cables and gears, the size of a car? And he works in coal and mining quarries, 24 hours a day / 7 days a week for 30-40 years in a row?
Such an excavator is an industrial system, the maintenance of which is very expensive.
Automation of technological processes reduces the cost of operating an industrial system. An automated process control system is called - APCS. An excavator like the one described is no exception.
So what is an excavator? What process control system does it use?
What excavators are we talking about?
We are talking about mining excavators. On such machines, mining and coal quarries are being developed.
Dimensions: mining excavators reach the height of a five-story building.
Movement: the excavator is moved by means of a caterpillar undercarriage. The trolley consists of:
- caterpillar frames;
- caterpillars;
- travel drives;
- undercarriage lubrication circuit.
Digging: for digging, mining excavators use the "Shovel" mechanism. The mechanism consists of a bucket, a handle and an arrow. The bucket is attached to the handle. The handle is designed to give the bucket translational movement. It is located transverse to the arrow. A pressure mechanism is installed on the boom, which carries out the pressure and return movement of the handle with the bucket. A complex system of ropes sets this mechanism in motion.
Device (composition): The excavator consists of three enlarged units:
- working equipment;
- turntable with mechanisms;
- running cart.
The working equipment was described above - this is exactly the “Straight Shovel” mechanism.
Mining excavators perform many operations: digging, turning the machine body, moving, etc. Each operation has a separate engine. To perform all these operations requires a huge number of systems. All systems and mechanisms, as expected, are in the "machine room".
The “machine room” of the excavator is a turntable. It contains a bucket lifting mechanism, a rotary mechanism, excavator electrical equipment with a control and monitoring system, auxiliary mechanisms, a pneumatic system, and a centralized automatic lubrication system.
Working conditions and service life: mining excavators operate 24/7, and the service life is really 30-40 years.
Power / fuel: Mining excavators run on electricity. Each mountain section of the cut receives electricity from a 35/6 kV substation.
What kind of automation do excavators have on board
The mining excavator is an industrial system. The tasks of operating an excavator are similar to the tasks of operating an industrial facility:
- control of parameters of the movement system;
- equipment wear monitoring;
- protection of equipment from external and internal threats: overloads, short circuits, etc.;
- energy accounting;
- excavator position control;
- inspection of equipment during operation;
- control of "blind zones";
- monitoring of indicators of work of the excavator;
- event logging;
- data transfer for centralized accounting.
All these tasks are handled by one operator. This is possible through automation.
ACS TP "on board" the excavator includes the following systems:
To monitor movement parameters controllers are installed. The operator monitors the following parameters: the operation of drive control systems, the heating temperature of the system nodes, the pressure in the pneumatic system, and thick lubrication.
To account for consumed and delivered active and reactive electrical energy an electricity meter is installed.
Blind spots, mechanical equipment operation and working face displayed on the operator's screen. For this, video cameras are installed.
For calculation and accounting excavator performance controller data is used. The indicators are calculated for a certain time interval: per shift, per month, by teams.
All events are saved in the event log and the required time interval is stored.
How is data transfer organized?
As mentioned above, the excavator consists of a undercarriage and a turntable.
The turntable can freely rotate 360 degrees relative to the undercarriage. It is very problematic to use wires to transfer data between these two parts. They wear out very quickly.
Data between parts of the excavator is transmitted via Wi-Fi. Wi-Fi WLAN 5100 functional modules from together with special cables and omnidirectional antennas . In total, 3 antennas are installed on the excavator for stable communication.
Also installed on the excavator with omnidirectional antenna and surge protection device .
Structural diagram of the information system of a mining excavator
Installation of antennas on the excavator EKG-20
What does the operator's cab look like?
The end result of automation for the operator looks like this:
Source: habr.com