WO2004032084A1

WO2004032084A1 - Dozer monitoring system and method

Info

Publication number: WO2004032084A1
Application number: PCT/AU2003/001311
Authority: WO
Inventors: Robert David Chatto
Original assignee: Bhp Billiton Innovation Pty Ltd
Priority date: 2002-10-04
Filing date: 2003-10-06
Publication date: 2004-04-15
Also published as: AU2002951862A0

Abstract

A system and method for monitoring an appliance working on a stockpile of coal in a thermal coal plant is described. The system and method include appliances in the form of dozers (30) which work on the stockpile and feeders (20) and a load-out conveyor (22) which convey coal from stockpile (14) to a train for transportation by the train. A control station (100) is provided and the dozers include a control system (50). A communication link (51) is established between the control system (50) and the central station (100) and in the event of a failure of the communication link, or upon manual control of the control system (50) by the operator of the dozer, an emergency alarm system is established and shutdown of the feeders (20) and load-out conveyor (22) occurs.

Description

DOZER MONITORING SYSTEM AMD METHOD

Field of the Invention

This invention relates to a system and method for monitoring an appliance, such as a dozer working on a stockpile, such as a stockpile of coal in a thermal coal plant .

Background Art In thermal coal plants, coal is delivered for transportation from a coal stockpile. The coal is delivered from the stockpile by a below ground load-out conveyor located beneath the stockpile. The stockpile is built up above ground level and coal effectively falls through in-ground feeders supported by a tunnel roof, so that the feeders can deliver the coal to the load-out conveyor for delivery to a train for transportation. In order to ensure a continuous supply of coal to the in- ground feeders, one or more dozers is utilised to keep the feeders supplied with coal from the stockpile by pushing coal in the stockpile towards the feeders so the coal can fall through the feeders onto the load-out conveyor.

As coal falls from the stockpile through the feeders, cavities can be created in the coal stockpile.

Furthermore, a crust can also build up on the stockpile which hides the cavities from view. Thus, an extremely dangerous condition can be created as coal is removed from the base of the stockpile, which is created by the formation of cavities below the surface area, which, if undetected, subject a dozer driver to the risk of being completely buried if the dozer breaks through the crust and falls into the cavity.

The feeders which are used to feed the coal to the load- out conveyor also represent a potential hazard to dozer operators. If a driver inadvertently places a machine in a feeder collection area, they can both be drawn into the stockpile as coal is removed. Once buried beyond the point where the machine can be driven out, both man and machine are likely to be buried.

Summary of the Invention

The object of the invention is to provide a method and system for monitoring of an appliance such as dozers working on a stockpile to minimise the risk of burying of a dozer and therefore serious injury to the dozer operator.

The invention may be said to reside in a system for monitoring an appliance working on a stockpile in a plant, including; a communication link between a control station and the appliance; a control system for mounting on the appliance; and a central station controller at the central station; wherein in the event of a failure of the communication link or upon manual control of the control system by an operator of the appliance, any one or more of the following conditions is implemented:

(a) actuation of an emergency alarm; and

(b) shutdown of the appliance.

Thus, according to the invention, should an appliance find itself in a dangerous situation which causes failure of the communication link, an alarm and/or shutdown of the appliance can occur and furthermore, should the operator of the appliance wish to initiate a shutdown, the appliance operator can do so by actuation of the control system on the appliance.

In the preferred embodiment of the invention, material from the stockpile is fed to a remote location by at least one underground feed system onto which material from the stockpile can drop, and wherein the failure of the communication link or actuation of the control system by the operator causes shutdown of the feed system.

Preferably the feed system includes a plurality of feeders and a load-out conveyor, and upon failure of the communication link, the control system causes shutdown of the feeders.

Preferably the feed system further includes a load-out conveyor for receiving material from the feeders and upon failure of the communication link or actuation of the control system by the operator, the control system also shuts down the load-out conveyor.

In the preferred embodiment of the invention, the control system also provides for restart of the feed system upon operator input to the control system.

In the preferred embodiment of the invention, the plant includes a stacker conveyor for delivering coal to the stockpile and the control system causes shutdown of the stacker conveyor upon failure of the communication link or actuation of the control system by the operator to prevent material from being deposited from the stacker conveyor onto the appliance.

Preferably the control system for mounting on the appliance comprises monitoring means for monitoring the status of the communication link, means for shutting down the appliance in the event of a failure of the communication link, and means for manually overriding the appliance shutdown in order to restart the appliance if required by the operator. Preferably the control system further includes means for stopping the feed system upon input from an operator regardless of the status of the communication link, and means for activating the emergency alarm regardless of the status of the communication link.

Preferably the control system includes an arm switch to arm the control system and the appliance to thereby include the appliance within the monitoring system.

Preferably the control system includes a radio system for establishing the communication link, and the monitoring system includes signal processing means for monitoring and processing signals to determine the status of the communication link, and operator indicators and controls so the operator can observe the status of the control system and also input commands into the control system.

Preferably the central station controller includes monitoring means for monitoring the communication link between the central station and the or each appliance, means for causing shutdown of the feed system in the event of failure of the communication link between the central system and the or any one of the appliances, and means for generating an alarm upon failure of the communication link between the central station and the or any one of the appliance .

Preferably the central station controller includes a radio system for establishing the radio link between the central station and the or each appliance, processing means associated with the monitoring means for processing signals indicative of the status of the communication link.

The invention in a second aspect may also be said to reside in a system for monitoring an appliance working on a stockpile in a plant which includes a feed system for transporting material in the stockpile to a remote location, including: a communication link between a control station and the appliance; monitoring means for monitoring the communication link; and shutdown means for shutting down the feed system should the monitoring means determine a failure of the communication link between the control station and the appliance.

Thus, according to this aspect of the invention, if the communication link fails indicative of the appliance finding itself in a dangerous situation, the shutdown of the feed system reduces the likelihood of injury to the appliance and the operator of the appliance, which may otherwise called if the feed system is operating and the feed system draws the appliance and the operator into the stockpile.

Preferably the system also includes an appliance shutdown means and the monitoring means is coupled to the appliance shutdown means to cause shutdown of the appliance in the event of a failure of the communication link.

Preferably the monitoring means is also coupled to an alarm system for activating the alarm system in the event of failure of the communication link.

Preferably the monitoring means includes a control system for mounting on the appliance and a central station controller at the central station, and wherein an operator by manual control of the control system is also able to cause shutdown of the feed system, activation of the alarm and shutdown of the appliance, regardless of the state of the communication link. Preferably the feed system includes a plurality of feeders and at least one load-out conveyor, and the shutdown means shuts down the feeders.

Preferably the shutdown means also shuts down the load-out conveyor.

Preferably the feed system further includes a stacker conveyor and the shutdown means also shuts down the stacker conveyor.

The invention may be said to reside in a method of monitoring an appliance working on a stockpile, including: establishing a communication link between a control station and the appliance; providing a control system on the appliance; and providing a central station controller at the central station; wherein in the event of a failure of the communication link or upon manual control of the control system by an operator of the appliance, any one or more of the following conditions is implemented:

(a) actuation of an emergency alarm; and (b) shutdown of the appliance.

Preferably the feed system includes a plurality of feeders and a load-out conveyor.

Preferably the shutdown means shuts down at least the feeders of the feed system.

Preferably the shutdown means shuts down the load-out conveyor as well as the feeders.

Preferably the control system monitors the status of the communication link, shuts down the appliance in the event of a failure of the communication link, and allows manual overriding of the appliance shutdown in order to restart the appliance if required by the operator.

Preferably the control system stops the feed system upon input from an operator regardless of the status of the communication link, and activates the emergency alarm upon input from the operator regardless of the status of the communication link.

Preferably the method includes the step of arming the control system and the appliance to thereby include the appliance within the monitoring system.

Preferably the central station monitors the communication link between the central station and the or each appliance, and causes shutdown of the feed system in the event of failure of the communication link between the central system and the or any one of the appliances, and generates an alarm upon failure of the communication link between the central station and the or any one of the appliances.

The invention in a second aspect may also be said to reside in a method of monitoring an appliance working on a stockpile in a plant which includes a feed system for transporting material in the stockpile to a remote location, including: establishing a communication link between a control station and the appliance; monitoring the communication link; and shutting down the feed system should the monitoring means determine a failure of the communication link between the control station and the appliance.

Preferably the method also includes the step of shutting down of the appliance in the event of a failure of the communication link.

Preferably the monitoring means activates the alarm system in the event of failure of the communication link.

Preferably the feed system includes a plurality of feeders and at least one load-out conveyor, and the method shuts down at least the feeders.

Preferably the method also shuts down the load-out conveyor.

Preferably the feed system further includes a stacker conveyor and the method shuts down the stacker conveyor.

Brief Description of the Drawings

A preferred embodiment of the invention will be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a schematic plan view of a thermal coal plant with which the system and method of the preferred embodiment is used; Figure 2 is a cross-sectional view along the line

A-A of Figure 1;

Figure 2A is a detailed view of part of Figures 1 and 2;

Figure 3 is a schematic block diagram of a control system to be mounted on a dozer working on a stockpile in the plant of Figure 1; and

Figure 4 is a schematic block diagram of a central control station of the thermal coal plant.

Detailed Description of the Preferred Embodiment

Figures 1 and 2 are a plan view and cross-sectional view of a thermal coal plant.

With reference to these figures, the plant includes a stacking conveyor 12 which is pivotally moveable in the arc illustrated by double-headed arrow A so that coal can be stockpiled at various locations within the plant. A stockpile 14 of coal is shown in Figure 2.

The stockpile 14 is built up over a tunnel 16 which has a roof 18. The roof 18 includes a plurality of feeders 20 which are supported by the roof and project down into the tunnel 16 so that coal can be delivered from the stockpile 14 through the feeders 20. A load-out conveyor 22 is located in the tunnel for conveying coal to a bin 24 from which the coal is deposited onto a train (not shown) .

One or more dozers 30 are used to push coal towards the feeders 20 so that the feeders 20 are always supplied with coal from the stockpile so that coal is delivered to the load-out conveyor for transportation to the train. Figure 2A shows schematically one type of feeder which may be used in the preferred embodiment. The feeder 20 includes a motor and vibrator 23 which facilitates disturbance of the stockpile 14 so that material from the stockpile 14 will fall into the feeder 20 and be discharged from the feeder 20 onto the load-out conveyor 22. The feeder 20 may also include a control gate 26.

As coal drops from the stockpile 14 through the feeders 20 onto the conveyor 22, cavities can form in the stockpile

14 which can be undetected by the operator of the dozer 30 with the result that the dozer can drive into the stockpile and fall into the cavity and become buried by coal in the stockpile.

The present invention relates to a system and method for monitoring the dozers in the plant so that appropriate action can be taken if the dozers become involved in a hazardous situation.

Figure 3 is a schematic block diagram of the control system mounted on each of the dozers 30 shown in Figure 1. The control system 50 of Figure 2 enables a two-way radio communication link to be established between the control system 50 of each dozer and the central station controller (100 shown in Figure 4) of the thermal coal plant.

In order for the dozer with which each control system 50 is associated to be within the monitoring system, the control system and dozer 30 must be armed by an operator. This can be done by way of a key maintained by the operator and which simply switches the control system 50 on to enable a communication link to be established.

The system of Figure 3 includes a radio receiver transmitter for receiving and transmitting the radio signal to and from the central control station 100. When the control system 50 is armed, a processing section 52 monitors the communication link. The communication link may include a signal which includes a specific code identifying the control system 50, and therefore the dozer 30 with which the control system 50 is associated.

If the monitoring and processing section 52 detects a failure of the communication link 51, the section 52 can commence automatic engine shutdown of the dozer with which the control system 50 is associated. A shutdown timer 53 is provided and is initiated. by the section 52 upon establishment of the failure of the communication link 51. If the time set by the timer 53 expires, the processing section 52 shuts down the dozer engine 54. The timer set by the shutdown timer 53 is adjustable in a fixed range and may, for example, be 60 seconds or less.

The system 50 also includes a manual override 55 of the engine shutdown capability which can be actuated by the operator of the dozer to prevent automatic shutdown of the engine, provided that the operator actuates the override before the time set by the shutdown timer 53 expires. Thus, assuming that the shutdown time set by the timer is 60 seconds, if the operator initiates the manual override 55 before the 60 seconds expires, then the engine of the dozer will not be shutdown. This enables the operator of the dozer 30 to attempt to drive out of the hazardous situation should the operator so desire.

If the dozer is removed from the hazardous situation and the communication link 51 re-established, the shutdown timer 53 is automatically reset to commence a new count if the control system 50 again determines that the communication link 51 has failed.

The control system 50 at each dozer also, upon the detection of failure of the communication link 51, cause crash stop of the stacker conveyor 12 and the load-out conveyor 22 and also shuts off the feeders 20 so the feeders 20 do not draw more coal from the stockpile 14.

The system 50 may also include appropriate controls for input by the operator and indicators such as lights which indicate the function or status of the system.

Once an operator has armed a dozer and control system 50 by the operator key, and the radio link 51 has been established, an indicator will illuminate to indicate that the system is operational. The dozer operator is able to operate the dozer without arming the system, and therefore without including the dozer within the monitoring system should the operator so desire.

The system 50 also includes a manual input 56 for manually stopping the feeders 20 and allowing restart control of the feeders 20, regardless of the status of the communication link 51, as well as a system 57 for manually initiating an emergency alarm and also initiating crash stop of the conveyers 12 and 22.

If the communication system 51 is lost, a monitor failure warning light can be displayed in the system 50 indicating to the operator that the link has been lost. f the communication link is re-established before the time of 53 counts down and shuts off the dozer engine, the monitor failure warning light will extinguish and revert to a status showing that the monitoring system is operational and that the communication link 51 is in place and the shutdown timer 53 will be reset.

If the control system 50 is armed, and the control link 51 is lost during dozer operation, this will assumed to be an emergency condition, for example, that the dozer has become buried. On loss of the communication link 51, the central control station 100 will operate as follows.

The control system 50 also enables the dozer which initiated a shut-down of the feed system to restart the feed system. To prevent a potentially hazardous situation, only the control system associated with the dozer that initiated the stop command is capable of restarting the feed system comprised of the stacker conveyor 12, the feeders 20 and the load-out conveyor 22.

With reference to Figure 4, the central station controller 100, which is usually located at the thermal coal plant sub-station, also includes a radio transmitter receiver for establishing the link 51.

When a dozer is armed as previously described, a monitoring section 102 will monitor the communication link 51 to that dozer. The monitoring section 102 will activate a local audible and visible alarm system 103 which may comprise a local siren and strobe light and will also start an emergency site alarm timer 104, which will commence a countdown to set off a site emergency alarm 105. The time set within the timer 104 may be, for example, 3 minutes to allow some time for the dozer operator to recover from the incident and re-establish the communication link 51 before a complete site emergency is declared. If the 3 minute time period expires without re- establishment of the link 51, then the site emergency alarm 105 is activated, initiating a full emergency response procedure, as shown by reference 106.

If the link 51 is re-established within a three minute period, the site emergency alarm timer 104 is reset, as shown by reference 107.

The arming of the dozer 50 also enables dozer emergency controls 108 which are connected to the thermal coal plant and motor control centre 120 which supplies power to the plant and, in particular, to the stacker conveyor 12 and 22 schematically shown in Figure .

The dozer emergency controls 108 are initiated by the control system 50 on the dozer as previously described, in the event of failure of the communication link 51 or by manual shutdown by the dozer operator as represented by references 109 and 110 in Figure 4.

In order for the dozer emergency controls 108 to operate to shutdown the conveyors 12 and 22, the dozer 30 must be armed as previously described. If the dozer is disarmed, then the emergency controller 108 is disabled thereby preventing the control system 50 from performing emergency stop of the conveyors 12 and 22.

If the system is disarmed as shown by reference 113, the alarm 103 is also reset so that the alarm can effectively be extinguished after the emergency situation is identified and an appropriate response has commenced.

If site emergency alarm 105 is activated, indicators on the site and rescue station emergency mimic panels 111 will announce a dozer emergency at the thermal coal plant, and the alarms will also be annunciated on the Citeσt systems 112 which may be coupled to the controller 100 by a microwave link 113. The Citect system 112 is the existing computer based operator control station at the plant and train load out control rooms. The principle function of this system is to log alarms and events determined by the central station 100.

The local audible and visual alarms which are activated immediately upon failure of the link 51 can be cancelled by operating the unique dozer key switch at the controller 100 to disarm the particular dozer, or operating a master disarmer control as shown by reference 113 at the station 100. The master disarm control 113 can only be activated by authorised persons or the site emergency rescue team, and the means to do so could be by a ^smashed glass" type operation, or through the use of a common key currently carried by the emergency rescue team.

Since modifications within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiment described by way of example hereinabove.

Claims

1. A system for monitoring an appliance working on a stockpile in a plant, including: a communication link between a control station and the appliance; a control system for mounting on the appliance; and a central station controller at the central station; wherein in the event of a failure of the communication link or upon manual control of the control system by an operator of the appliance, any one or more of the following conditions is implemented: (a) actuation of an emergency alarm; and

(b) shutdown of the appliance.

2. The system of claim 1 wherein material from the stockpile is fed to a remote location by at least one underground feed system onto which material from the stockpile can drop, and wherein the failure of the communication link or actuation of the control system by the operator causes shutdown of the feed system.

3. The system of claim 1 wherein the feed system includes a plurality of feeders and a load-out conveyor, and upon failure of the communication link, the control system causes shutdown of the feeders.

4. The system of claim 1 wherein the feed system further includes a load-out conveyor for receiving material from the feeders and upon failure of the communication link or actuation of the control system by the operator, the control system also shuts down the load- out conveyor.

5. The system of claim 1 wherein the control system also provides for restart of the feed system upon operator- input to the control system.

6. The system of claim 1 wherein the plant includes a stacker conveyor for delivering coal to the stockpile and the control system causes shutdown of the stacker conveyor upon failure of the communication link or actuation of the control system by the operator to prevent material from being deposited from the stacker conveyor onto the appliance.

7. The system of claim 1 wherein the control system for mounting on the appliance comprises monitoring means for monitoring the status of the communication link, means for shutting down the appliance in the event of a failure of the communication link, and means for manually overriding the appliance shutdown in order to restart the appliance if required by the operator.

8. The system of claim 7 wherein the control system further includes means for stopping the feed system upon input from an operator regardless of the status of the communication link, and means for activating the emergency alarm regardless of the status of the communication link.

9. The system of claim 8 wherein the control system includes an arm switch to arm the control system and the appliance to thereby include the appliance within the monitoring system.

10. The system of claim 1 wherein the control system includes a radio system for establishing the communication link, and the monitoring system includes signal processing means for monitoring and processing signals to determine the status of the communication link, and operator indicators and controls so the operator can observe the status of the control system and also input commands into the control system.

11. The system of claim 1 wherein the central station controller includes monitoring means for monitoring the communication link between the central station and the or each appliance, means for causing shutdown of the feed system in the event of failure of the communication link between the central system and the or any one of the appliances, and means for generating an alarm upon failure of the communication link between the central station and the or any one of the appliances.

12. The system of claim 11 wherein the central station controller includes a radio system for establishing the radio link between the central station and the or each appliance, processing means associated with the monitoring means for processing signals indicative of the status of the communication link.

13. A system for monitoring an appliance working on a stockpile in a plant which includes a feed system for transporting material in the stockpile to a remote location, including: a communication link between a control station and the appliance; monitoring means for monitoring the communication link; and shutdown means for shutting down the feed system should the monitoring means determine a failure of the communication link between the control station and the appliance.

1 . The system of claim 13 wherein the system also includes an appliance shutdown means and the monitoring means is coupled to the appliance shutdown means to cause shutdown of the appliance in the event of a failure of the communication link.

15. The system of claim 14 wherein the monitoring means is also coupled to an alarm system for activating the alarm system in the event of failure of the communication link.

16. The system of claim 13 wherein the monitoring means includes a control system for mounting on the appliance and a central station controller at the central station, and wherein an operator by manual control of the control system is also able to cause shutdown of the feed system, activation of the alarm and shutdown of the appliance, regardless of the state of the communication link.

17. The system of claim 13 wherein the feed system includes a plurality of feeders and at least one load-out conveyor, and the shutdown means shuts down the feeders.

18. The system of claim 17 wherein the shutdown means also shuts down the load-out conveyor.

19. The system of claim 13 wherein the feed system further includes a stacker conveyor and the shutdown means also shuts down the stacker conveyor.

20. A method of monitoring an appliance working on a stockpile, including: establishing a communication link between a control station and the appliance; providing a control system on the appliance; and providing a central station controller at the central station; wherein in the event of a failure of the communication link or upon manual control of the control system by an operator of the appliance, any one or more of the following conditions is implemented: (a) actuation of an emergency alarm; and

(b) shutdown of the appliance.

21. The method of claim 20 wherein material from the stockpile is ,fed to a remote location by at least one underground feed system onto which material from the stockpile can drop, and wherein the failure of the communication link or actuation of the control system by the operator causes shutdown of the feed system.

22. The method of claim 21 wherein the feed system includes a plurality of feeders and a load-out conveyor, and the method includes shutdown of at least the feeders of the feed system.

23. The method of claim 22 wherein the method also shuts down the load-out conveyor as well as the feeders.

24. The method of claim 23 wherein the method stops the feed system upon input from an operator regardless of the status of the communication link, and activates the emergency alarm upon input from the operator regardless of the status of the communication link.

25. The method of claim 20 wherein the method includes the step of arming the control system and the appliance to thereby include the appliance within the monitoring system.

26. The method of claim 20 wherein the method monitors the communication link between the central station and the or each appliance, and causes shutdown of the feed system in the event of failure of the communication link between the central system and the or any one of the appliances, and generates an alarm upon failure of the communication link between the central station and the or any one of the appliances.

27. a method of monitoring an appliance working on a stockpile in a plant which includes a feed system for transporting material in the stockpile to a remote location, including: establishing a communication link between a control station and the appliance; monitoring the communication link; and shutting down the feed system should the monitoring means determine a failure of the communication link between the control station and the appliance.

28. The method of claim 27 wherein the method also includes the step of shutting down of the appliance in the event of a failure of the communication link.

29. The method of claim 27 wherein the method activates the alarm system in the event of failure of the communication link.

30. The method of claim 27 wherein the feed system includes a plurality of feeders and at least one load-out conveyor, and the method shuts down at least the feeders.

31. The method of claim 30 wherein the method also shuts down the load-out conveyor.

32. The method of claim 31 wherein the feed system further includes a stacker conveyor and the method shuts down the stacker conveyor.