Collision Avoidance System Presentation

Transcription

1 Collision Avoidance System Presentation to SACMA Regional Meeting 11 January 2006 Presentation by Johann du Plessis Manager Engineering, Xstrata Coal South Africa

2 A Business Case for an underground Collision Avoidance System We all have: Training for personnel Codes of Practice Standard Procedures Supervisory structures Aimed at preventing injury to people

3 A Business Case for an underground Collision Avoidance System In addition Xstrata Coal SA has Cardinal Rules A 3 Meter rule VVL Behaviorally Based Safety The intent of all is to ensure our personnel and visitors go home UNHARMED

4 A Business Case for an underground Collision Avoidance System So why, in spite of all the ingenious management systems, do people still get killed or seriously injured?

5 A Business Case for an underground Collision Avoidance System Our systems rely on human behavior Human behavior is fallible Unfortunately, in this case, when the behavior patterns fail, the potential for fatality is huge

6 A Business Case for an underground Collision Avoidance System The Collision Avoidance System: Does not replace any of the existing Soft Barriers Strives to provide an automated Hard Barrier between people and machines, Does not rely on human behavior

7 What is a Collision Avoidance System and how does it function? Take a machine and add a radio transmitter and receiver to it

8 What is a Collision Avoidance System and how does it function? Fit a radio transmitter and receiver to the cap lamps worn by personnel

9 What is a Collision Avoidance System and how does it function? The machine transmits a radio signal which is received by the cap lamp activating a flashing light or buzzer warning the person of the presence of a machine

10 What is a Collision Avoidance System and how does it function? The cap lamp transmits a radio signal which is received by the machine activating a flashing light or buzzer warning the machine operator of the presence of a pedestrian

11 What is a Collision Avoidance System and how does it function? Both the pedestrian and the machine operator are now aware of the other and can take evasive action. Quite simple and ingenious. There are numerous systems, from different suppliers, in operation around the world

12 What is a Collision Avoidance System and how does it function? Vehicle Transmitter Personnel Receiver and transmitter

13 What is a Collision Avoidance System and how does it function? Machine Mounted unit Detail Display Vehicle Count Personnel Count Buzzer ON/OFF Key Switch Power Indicator Buzzer Alarm System OK Indicator Tag Detected Antenna Connection 12v to 24V Power High bright Flashing Indicator

14 Some example of Collision Avoidance Systems in operation Pasminco Broken Hill Xstrata Alloys Rustenburg PT Freeport Indonesia Collahausi Mine Chile

15 Is it really that simple? The radio signal transmits omni-directional The signal maintains near constant strength over a 40 to 100 meters distance

16 Is it really that simple? Add four more machines in a confined environment like a production section

17 Add some more people Is it really that simple?

18 Is it really that simple? The signals get so cluttered and confusing that nobody reacts to any signal and we are back to where we started

19 What is the solution? A production section contains numerous machines and people in a relatively small area Continuous Miner Shuttle Car Roof Bolter Feeder Breaker LHD Person

20 What is the solution? The Collision Avoidance System must be able to determine the difference between a pedestrian in a safe position and a pedestrian in danger of being injured. Safe position for the moment Continuous Miner Shuttle Car Roof Bolter Feeder Breaker LHD Person Safe position for the moment

21 What is the solution? The system must measure the distance between machines and pedestrians. Unsafe position Continuous Miner Shuttle Car Roof Bolter Feeder Breaker LHD Person Unsafe position while Feeder Breaker is operating

22 What is the solution? The system must measure the distance between machines. Unsafe situation Shuttle Car is approaching Roof Bolter Roof Bolter is on Shuttle Car driver blind side Continuous Miner Shuttle Car Roof Bolter Feeder Breaker LHD Person

23 Distance measurement The system must determine the distance between the individual and the machine and create a Halo around the machine The Final Barrier around the machine defines the unsafe area 3 Meter Final Barrier 3 Meter 3 Meter Unsafe area 3 Meter More than 3 Meters = Safe Less than 3 meters = Unsafe

24 Hard Barrier The Final Barrier is a Hard Barrier At the Final Barrier we stop relying on human behavior Intrusion into the Final Barrier activates an automatic intervention in the machine control system Shuttle Car - The brakes are engaged Continuous Miner Cutter head and Tramming is disengaged Feeder Breaker The emergency stop is activated LHD The brakes are activated Final Barrier Unsafe area

25 System Logic The system operational logic defines under which circumstances a Final Barrier breach is allowed The system must differentiate between: The Shuttle Car driver approaching the CM operator at his CM on the right The Schuttle Car diver approaching the CM operator alone on the left The system must differentiate between: The Shuttle Car driver approaching the Feeder Breaker on his Schuttle Car on the right The Schuttle Car diver approaching the Feeder Breaker on foot on the left The system must differentiate between: The Artisan doing fault finding on the right The Artisan walking through the section on the left

26 System developments in progress Two systems are in the process of development for the coal mining industry: Becker Mining trial at the Xstrata Coal South Africa Group Training Center at Tavistock Colliery Mine Site Technologies development with the support of ACARP, Xstrata Coal and Centennial Coal.

27 System developments in progress Technical Challenges: Radio Frequency propagation in an underground environment is affected by antenna positioning, surrounding steel infrastructure, type of rock strata and tunnel dimensions. This results in a variance in the distance in which the tag is detected. Typically between 5-30 metres. (far field) To this end RF tags in isolation are not suitable for short range detection. (near field)

28 System developments in progress Technical Solution: By using ultrasonic transmitters and receivers a quick and accurate measurement can be achieved. Ultrasonic transducers have been successfully deployed in modern vehicles (PDC) Park Distance Control. The PDC system however does not discriminate between a sidewall, vehicle and person. By encoding and decoding the Ultrasonic pulses the system can identify the difference between Personnel, Vehicles and inanimate objects. Distance measurement is achieved by the processing the time difference between when the tag RF signal versus the tag ultrasonic signal is received.

29 System developments in progress System Principle: The Tag and ultrasonic ID is transmitted simultaneously. Distance measurement is accomplished by measuring the difference in time between the reception of the Ultrasonic ID and the Radio ID.. Ultrasonic Transmitter T1 = Time for Ultrasonic Code to be received (dependant on distance) Ultrasonic Receiver RF Tag Transmitter T2 = Time for RF Tag be received Light = Fixed) (Speed of RF Tag Receiver

30 System developments in progress The system will discriminate between near and far presence of pedestrians and machines. Far Field 5-30m Near Field 0-5m

31 System developments in progress As the system is dependant on line-of site, antennas /ultrasonic receivers will be placed on the 4 corners of machines thus ensuring complete coverage. Personnel & Ultrasonic Transmitter DPOD Receiver 1 CAS Controller Personnel & Ultrasonic Transmitter DPOD Receiver 2 Multiple antennas (DPOD S) are connected to the CAS Controller via RS485 serial connection. The CAS displays the tags within the danger zones. RS 485 Bus DPOD Receiver 4 DPOD Receiver 3 Personnel & Ultrasonic Transmitter Personnel & Ultrasonic Transmitter

32 System developments in progress

33 System developments in progress Tavistock trial progress An LHD was fitted with the CAS Cap Lamps were equipped with the RF tags and ultrasonic transmitters The ultrasonic RF combination has demonstrated the capability of measuring distance with extreme accuracy To date the system has not demonstrated the ability to create an effective Final Barrier around the machine The trial is continuing Definitive results are not expected before May 2007

34 System developments in progress Background Mine Site Technologies with the support of ACARP, Xstrata Coal and Centennial Coal is currently undertaking a Project to develop a Proximity Detection system aimed at developing technology to help avoid people/vehicle and vehicle/vehicle collisions in a mining environment.

35 System developments in progress The technology under development basically consists of: People and vehicles carry active tags with a range of more than 50m. A Tag Reader is fitted on the vehicle. When the receiver on the vehicle receives a tag signal it gives a medium-level alarm to indicate that a person/vehicle is around. A magnetic field antenna (a so called Exciter ) is fitted on the vehicle. This antenna transmits its own ID using a magnetic field, the size of this magnetic field can be adjusted relatively accurately. When a tag on a person/vehicle receives this magnetic signal it sends out an alarm message to indicate that it is within dangerous range of a magnetic antenna. When the receiver on the vehicle receives this alarm tag signal it gives a high-level alarm.

36 System developments in progress Tag Receiver Exciter

37 System developments in progress Two types of active tags are currently being used: TRACKER UHF Tags have: A 433MHz transmitter; These Tags are already in use at mines that have installed the TRACKER Tagging System, and are already proven in use and approved Intrinsically Safe in Australia, USA and China. TRACKER UHF Tag Already in use at mines and IS Approved

38 Two types of active tags are currently being used: b Tags have: A 2.4 GHz transmitter, and also include a magnetic receiver capable of receiving the Exciter s signal; The version of these Tags that fit into the ICCL (Integrated Communications Cap Lamp) are currently going through approval for coal mine use in the USA and Australia. System developments in progress ICCL a cap Lamp that can include UHF or b RFID Tag

39 System developments in progress An Exciter is also being investigated to determine its use in providing a second inner zone warning: Exciter units from Mine Site produce a constant low-frequency (125kHz) magnetic field around them. The size of this field can be adjusted in increments of 50cm via a TCP/IP interface. The current units have a range limit of 6m. One of the on-going areas of development is to increase this range to 10 or 20m to make it viable as an inner, higher danger zone.

40 System developments in progress TRACKER and (WLAN) tests The underground survey results confirmed very good signal coverage up to 80 m from vehicle mounted Reader. Straight down the roadways the signal did not fall below the threshold, there is continuous coverage. Though the signal decays quickly around corners there is still limited coverage.

41 System developments in progress Reception around corners (both TRACKER and WLAN tags) It is essential that the Proximity detection system can detect tags that are around a corner, so that the system is not surprised by a tag suddenly coming into radio view around a corner.

42 System developments in progress Tag Test Conclusion Both the TRACKER and WLAN Tags have reliable reception and sufficient range to be used in this application. Further definition of guaranteed read range will be required to define system specifications and confirm they meet application expectations.

43 System developments in progress Exciter Range and Stability Tests Minimum/Maximum Range: Exciter mounted on top of vehicle

44 System developments in progress Minimum/Maximum Range: Underground test, Exciter mounted on top of vehicle

45 System developments in progress Exciter Test Conclusion A decision needs to be made whether the Exciter s range is accurate enough for Proximity detection. The Exciter s range is unlikely to be sufficient, it needs to be increased to at least 10-20m to provide the level of protection required for the inner zone. These tests have to be repeated after increasing the Exciter s range.

46 System developments in progress Project Time Table The next series of trials is planned for early These will test the pre-production prototype, which will give design confirmation and form the basis for the final commercialisation phase. It is anticipated production system will be released in early 2008.

47 Conclusion There is no proven Collision Avoidance System suitable for use in underground coal mines available at present. Indications are good that the first commercial systems which will provide a barrier, not reliant on human behavior, will be available in 2008.