UNIVERSITY COLLEGE OF ENGINEERING

(KAKATIYA UNIVERSITY)

A Report On

INTELLIGENT MINING SYSTEMS

SUBMITTED TO:

The Head Of The Department,

Department Of Mining Engineering,

UCE(KU), Kothagudem.

By:

V.GOUTHAM,

1709-2426,

B.Tech 4/4 (Mining).

UNIVERSITY COLLEGE OF ENGINEERING

(KAKATIYA UNIVERSITY)

A Report On

INTELLIGENT MINING SYSTEMS

SUBMITTED TO:

The Head Of The Department,

Department Of Mining Engineering,

UCE(KU), Kothagudem.

By:

V.SHIVANJANEYULU,

1709-2427,

B.Tech 4/4 (Mining).

INTELLIGENT MINING SYSTEMS

INTRODUCTION:

The path to intelligent mining systems follows the progression of mechanization, remote control, teleoperation, and robotics. The mining industry has adopted mechanized equipment to large extent .Remote-controlled equipment, where an opera-tor is stationed some distance from the machine but within line-of-sight, is found on some continuous mining machines in under-ground coal mines and some load-haul-dumps (LHDs) in under-ground metal mines. Teleoperated equipment, where operators can be stationed further away, beyond line-of-sight, is currently in the experimental stage. Research projects currently focus on robotics, the last stage of the progression. Robotics has been described as the intelligent connection between perception (the ability to understand the world around the robot) and action. It may provide the greatest benefits in productivity and safety.

MINING CLAIMS FOR ADVANCEMENT

Mining researchers must adapt these advances to the mining environment and develop additional technology for cost-effective application for the following reasons:

Mining equipment (like mobile haulage vehicles) can navigate from a map. Mining engineers can modify the layout to reduce the obstacle problems. Mining equipment must operate faster and more precisely than most of the present autonomous vehicles. Mining machines must have better on-board machine health monitoring and diagnostics. Excavation and drilling equipment require geo-sensing. Some of the autonomous vehicle techniques are not cost-effective for mining.

MINING ROBOTICS PROJECTS

Cost-effective application requires real-time sensing and reasoning at the same level as a highly experienced human operator. This is a very difficult and expensive development task; mining researches are focusing their efforts on the most promising.

VARIOUS PROJECTS:

1. Autonomous continuous mining

2. Tele operation

3. Computer-assisted Long wall Equipment

4. Semi-autonomous Load-Haul-Dump Machines

5. Computerized drills

1. AUTONOMOUS CONTINUOUS MINING

It develops enabling technology for computer-assisted control of mining equipment to improve worker safety and productivity. The work covers basic machine electrical, mechanical, and hydraulic components; sensors, algorithms, and languages for intelligent closed-loop control; obstacle detection; geo-sensing sensor; machine health sensors and knowledge-based systems; and path planning algorithms.

a) AUTONOMOUS CMR SENSORS

Sammarco (1988a) developed closed-loop control for all ma-chine functions except tramming using output from rotary variable differential transformers and hydraulic-pressure, temperature, and flow transducers He achieved closed-loop control for shearing, stab jack, and conveyor swing, based on the position of each component when operating in free space and cutting coalcrete. He controlled tram speed, direction, and pivoting an open loop (time clock limited) mode with the control safety relay, pump, gathering head/conveyor, and cutter motors latched. The system operated accurately in free space and when subjected to the vibration and stress of cutting coalcrete.

b) laser-based angular positioning system

Anderson (1989) developed the laser-based angular positioning system for precise, longer-range navigation guidance of the continuous miner in the face area. The positioning system reference is a mobile control structure, patterned after a mobile roof support that will follow the continuous miner along an entry. Surveyors or long-range automatic station will determine the precise coordinates of the mobile control structure after it is set at the face. During the excavation of each cut, the continuous miner will locate itself with a laser scanner mounted on the mobile control structure seeking retro reflective targets on the miner.

c) SENSORS ON THE MACHINE

Mowrey studied waveforms generated by accelerometers mounted on the machine and on the coal to develop algorithms that will automatically discriminate between vibrations resulting from cutting coal and rock. Natural gamma radiation had also been used successfully for cutting horizon definition. Infrared imaging is another technique under investigation because it discriminates between coal cutting and rock cutting by producing images of the higher-temperature areas that result when cutting rock (Mowrey , 1990b).

Hydraulic sensors: It is an expert system prototype to interrogate the various hydraulic sensors and report on machine health. The system will diagnose hydraulic problems based on sensor and user input. It will explain how it reached conclusions, and provide recommendations for repair. Mitchell used a hierarchy of rules to represent the knowledge of hydraulic diagnostic experts and backward chaining to diagnose the condition of the hydraulic system.

2. TELEOPERATIONSObjective: run existing equipment longer, faster, and cheaper. Applied to drilling equipment, Load-Haul-Dump (LHD) vehicles, and trucks.Examples: Inco’s Stobie mine in Canada, LKAB’s Kiruna mine in Sweden, and WMC Resources’ mine in Australia.

It is much more than a person working pedals and a joystick. Objective is to shape specific behaviors with artificial intelligence, increase autonomy. Each teleoperator controls an increasing number of machines

Various Teleoperations:

Granholm et al. studied and tested LHD guidance systems. In one of their tests, they teleported an LHD with a TV camera. In another test, the operator drove the LHD using a TV and monitor placed inside a cab with the windows covered. Nantel et al. installed a video camera on a LHD and transmitted the image 75 ft (23 m) to a remote operator in the Noranda Lyon Lake mine. The purpose was to help the operator load the bucket fully when operating by remote control in a production draw-point below a bulk mining stops. Kallio reported on similar teleoperation work with cameras mounted on the machine and on the rib. LHD operators expressed that teleoperation was easier than remote control. Kal-lio’s paper also described a computerized equipment control and monitoring system (CECAM), that is a microcomputer-based production and condition data acquisition and storage system.

Advantages

Teleoperation reduces machine down time caused by worker transit time into and out of the mine. More machine time = more throughput. It reduces wear and tear on machines when artificial intelligence programs shape optimal behaviors. It increases worker safety.

Disadvantages

It does not help much if it does not free up a bottleneck. Many bottlenecks are related to such factors as frequent blasting schedules or maintenance breakdowns that may be out of the reach of current

robotic technology. It does not solve organizational problems if a company suffers from poor leadership and general inefficiency to begin with.

3. COMPUTER ASSISSTED LONGWALL EQUIPMENT

Recent work has focused on coal interface detection, automatic shield advancement (shearer initiation), and system monitoring. Researchers recently applied results of the inter-face detection research to measure boundary, coal thickness. Their evaluation revealed that a natural gamma background sensor was most appropriate, and they installed one with various instruments aided shearer operators to consistently leave 6 to 8 in. of roof coal in one mine. They successfully modified the sensor for more rugged mounting in shield toes for floor.

Software of NCB

The NCB developed systems that collect data from in-mine transducers and transmit them to a surface computer for analysis and reporting. The software is divided into modules: a basic operating system, data transmission and interface, and tables of colliery characteristics. The sensor covers haulage and loading equipment and shearers and plows. The surface computer console operator gathers data about delay causes by calling the face whenever the display screen shows production interruptions.

4. SEMI AUTONOMOUS LHD MACHINES

Mobile fragmentation machines are difficult to control autonomously because the level of sensing and intelligence to handle exceptions in the highly variable geology is underdeveloped. Controlling the direction of cutting or drilling and determining the proper force to use in rock masses with different properties are difficult. EX: At the AMAX Henderson mine, LHDs load molybdenum ore from draw points, tram to an ore pass, dump, and return or switch to another draw point.

Henderson LHD fleet

An autonomous LHD at Henderson senses vehicle position along the route. It relates sensor data to stored map to determine location. It must follow drift centerlines. It plans paths between dump points and ore passes. It must compare sensed position with planned position. It must sense vehicle operating status and health. It acts as a key on features or targets for special tasks like high-speed turns. It performs loading and dumping. It detects and avoids obstacles.

5. COMPUTERIZED DRILLS

Recent advances have made drills autonomous, which will improve their output, reduce labor cost, but increase their purchase price.

However, robotic technology is appealing since drilling is an inherent element in most mines’ production cycle. Underground and surface metal, nonmetal, and coal mines all employ drills to penetrate rock for

exploration, blasting, and ground support. These developments are driven by the fact that human operators are not capable of obtaining maximum equipment productivity.

Computerized Zumbo

To reposition drills fast enough to keep up with the fast penetration-rate capability of hydraulic drills.To accurately position drills as quickly as computer control. A basic computerized jumbo that contains a microprocessor; a control console; angle transducers at boom joints; linear transducers for extension, feed, and crowd; hydraulic sensors; and electro-hydraulic valves. The operator can modify and store drill patterns with a portable computer to avoid collaring in holes left from the previous round.

OPERATION:

Input a reference into the computer such as the relation between the tunnel axis and a fixed laser beam. Then the drill is manually trammed to the face, and a drill rod is aligned with the laser. The operator presses the navigate button, and the jumbo drills the round. The video display graphs penetration rates for each drill to help the operator when to change bits and changes in geological conditions.

Use of Sensors

The sensors monitored rotary speed, torque, thrust, air-flushing pressure, and penetration rate with a microprocessor on a surface blast-hole rig. Then relationships between the changes in these data and rock mass properties are developed.

ADVANTAGES

1. Supervised autonomy can reduce the number of operating units by increasing operating time per shift since computer-controlled machines can operate during lunch and between shifts and reduce operator errors.

2. Inexpensive, robust sensors requiring minimal processing are a key to cost-effective implementation, so ultrasonic ranging is a good candidate.

3. It is appropriate for underground mines because the equipment travels in well-known areas, and the ultrasonic ranger can locate the machine relative to features in an on-board map.

DISADVANTAGES

This technique attempts to solve the problem with an array of sensors, fusing with other sensor types, horns to reduce the field of view, and building maps from multiple range readings from different robot locations are not appropriate for mining. This technique is not appropriate for a vehicle trying to accomplish an industrial task where it has to reach an objective quickly.

SUMMARY

Most of the present work in mining robotics focuses on individual machines. Some researchers integrate them into systems and develop new systems. Integrated approaches are necessary to develop intelligent mining systems.