BACKGROUND ART In the mining of ore, varying grades of ore are recovered, commonly after blasting operations. A geologist or similarly qualified person will often undertake an assessment of the grade, with or without metallurgical assay, and a decision reached as to the nature of further processing. In the case of economically viable ore, the ore (often of mixed grades and usually referred to as run-of-mine ore) is sent to plant for processing or to stockpile for eventual processing. Where the ore is not economically viable, it is dumped as waste at a different location, sometimes along with waste from processed ore.

Ore is usually transported around a minesite in dump trucks, with run-of-mine ore being transported from the point of extraction from the ground, to plant for processing or to stockpile for eventual processing; and ore that is not economically viable being dumped, as described above. Since all ore, viable or non-viable, originates from the same point, there is room for inadvertent error, whereby a driver can mistakenly dump a load worth several thousands of dollars with other waste.

This invention seeks to provide a system which will minimise the chance of such an error occurring.

Throughout the specification, unless the context requires otherwise, the word "comprise"or variations such as"comprises"or"comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

DISCLOSURE OF THE INVENTION The alarm/advisory system in accordance with the invention is achieved by providing a stationary unit for location alongside or near a transport pathway, and a mobile unit for installation in said vehicle; said mobile unit having a selector means to select a state corresponding to a path that said vehicle should or should not follow, and said stationary unit being allocated a pathway state; said stationary unit and said mobile unit including a transmitter and receiver pair, one of each pair being located in said mobile unit and said stationary unit, said transmitter and receiver pair having a reception range extending across said pathway to transfer between said mobile unit and said stationary unit an encrypted signal corresponding to state information, said alarm system including comparison means to compare said state with said pathway state, and actuator means to issue a control signal depending on correspondence between said state and said pathway state, said control signal being utilised for signaling and/or control purposes.

The control signal may be used for various purposes, including issuance of an alarm.

As will be understood, the alarm system functions by the comparison of the state selected by the selector means (which corresponds to the load type carried by the vehicle), with the pathway state allocated to the road (which corresponds to the destination that the road leads to). Thus if the vehicle is traveling along the incorrect road for its load type, an alarm or advisory signal can be issued. The alarm system can also be used to issue advisory information on approach of an intersection to the driver of the vehicle, to advise which way to turn at the intersection, depending upon the load type. Obviously, for the system to be fully effective, a mobile unit will be fitted in each vehicle to be monitored, and as many stationary units can be located at intervals along the road or location as required.

If the road has intersections, the pathway states allocated to the stationary units would relate to the destinations of the roads. There are two ways in which the alarm/advisory system may be impiemented, the first being with transmitter in the mobile unit and the receiver in the stationary unit, in which case the control signal (and hence alarm or other indication) is issued from the stationary unit. The second way in which the alarm system may be implemented is with the transmitter in the stationary unit, and the receiver in the mobile unit, in which case the control signal (and hence alarm or other indication) is issued from the mobile unit. Either implementation may include transceivers in both the mobile unit and the stationary unit, and data logging to a centralised location to gather data for statistical analysis. The three ways of implementation are described in the following descriptions of three aspects of the invention. While there are three aspects set out below, it should be appreciated that there are other implementations that will fall within the scope of the statements set out above.

In accordance with one aspect of the invention there is provided an alarm/advisory system for warning if a vehicle is proceeding along or incident in an incorrect path or location, the alarm system comprising a stationary unit for location alongside or near a transport pathway, and a mobile unit for installation in said vehicle, said mobile unit having a transmitter with a transmission range extending across said transport pathway sufficiently to reach said stationary unit when said vehicle is proximal thereto, said mobile unit having a selector means interfaced with said transmitter to select a state corresponding to a path that said vehicle should or should not follow, said transmitter being arranged to transmit an encrypted signal with encryption corresponding to said state, said stationary unit having a receiver sensitive to signals from said transmitter, whereby said stationary unit is cognisant of legal or illegal state values, and if said encrypted signal corresponds to an illegal value or a value which is not legal, output from said receiver triggers issuance of a stationary unit control signal for signaling and/or control purposes.

By the term"pathway", it should be understood that any place where a vehicle may access, including a depot, is intended.

The stationary unit control signal may be utilised to activate an alarm, which may be given as an audible signal or a visual signal. In one arrangement, the stationary unit may include display means to indicate a pathway that the vehicle should follow, depending upon the content of said transmitted signal. The stationary unit may also transmit data to a central office, to enable statistical logging or supervision.

Preferably in said mobile unit, said transmitter, said selector means, and said actuator are interfaced by processor means.

Preferably said selector means is able to select one or more of a plurality of states, each of which corresponds to a correct transport pathway or transport pathways for said vehicle.

Preferably said selector means is operable by remote control.

Preferably said mobile unit also includes a receiver and said stationary unit also includes a transmitter and processor means, whereby said stationary unit transmitter transmits a polling signal, and upon receipt of said polling signal by said mobile unit receiver, said mobile unit processor means operates to cause said mobile unit transmitter to transmit said encrypted signal ; whereby on receipt of said encrypted signal by said stationary unit receiver, said stationary unit processor means checks the encrypted signal and if said stationary unit processor means determines that said encrypted signal equates to an illegal value, said stationary unit processor means causes said stationary unit transmitter to transmit an actuation signal, whereby on receipt of said actuation signal by said mobile unit receiver and identification thereof by said mobile unit processor means, said mobile unit processor means triggers said actuator means.

Preferably said mobile unit processor means also causes said mobile unit actuator means to operate to disable one or more predetermined operational features of said vehicle, in response to said alarm signal being received by said mobile unit receiver. The disabling of one or more predetermined operational features of the vehicle may include the locking of a tailgate or tipping ram controller in a truck or trailer to prevent dumping of a load, or disabling of the vehicle from operating, by causing the brakes to be applied, or by cutting off the fuel supply, or by any other means known in the art by which a vehicle may be disabled.

Preferably said stationary unit includes alarm means, whereby when said stationary unit processor means detects an illegal value as described above, said stationary unit processor means also causes said alarm means to issue an alarm signal, giving a visual and/or audible alarm signal at said stationary unit. This signal may be relayed to a remote location for action by personnel if required.

In an alternative or additional arrangement, a said stationary unit includes display means interfaced therewith, and can be located alongside the roadway leading to an intersection from which two roads diverge, one leading to dumping sites for further processing of the ore (known as a rom pad), and the other leading to a waste dump, wherein upon receipt of said polling signal by said mobile unit receiver, said mobile unit processor means operates to cause said mobile unit transmitter to transmit said state encrypted signal ; whereby on receipt of said state encrypted signal by said stationary unit receiver means, said stationary unit processor means, checks the encrypted signal, and activates said display means to show the route corresponding to the state selected by said selector means. In this manner, the stationary unit is located before an intersection, and functions as a prompt to drivers of the vehicle, reminding the drivers of the correct route to take, dependent on the load being carried.

In accordance with a second aspect of the invention there is provided an alarm/advisory system for warning if a vehicle is proceeding along or incident in an incorrect path or location, the alarm system comprising a stationary unit for location alongside or near a transport pathway, and a mobile unit for installation in said vehicle, said stationary unit having a transmitter with a transmission range extending across said transport pathway and arranged to transmit a polling signal containing pathway state information, said mobile unit having a receiver capable of receiving said polling signal from said transmitter, a selector means interfaced with said receiver to select a state corresponding to a path that said vehicle should or should not follow, whereby when said state is selected, output from said receiver triggers actuator means in response to reception of said signal, said actuator means when triggered causing issuance of a control signal.

The polling signal is transmitted either continuously, or spaced apart at intervals sufficiently short so that a body cannot pass through the transmission range between successive polling signals. Thus, the maximum interval between successive transmission of the polling signals will be determined by the anticipated time that the body will be in proximity to the stationary unit. In practice the polling interval will be longer where it is required to minimise power demand, but where power demand is not critical, the polling can be continuous.

Preferably said control signal is issued when said vehicle is not intended to travel along said transport pathway and is within said transmission range, said control signal when issued being adapted to cause an alarm signal to be issued in response to said output.

By the term"pathway", it should be understood that any place where a vehicle may access, including a depot, is intended.

In its simplest form, the selector means would comprise a switch which is selected if the vehicle is an ore truck carrying a load of gold bearing ore (for example), and the stationary unit would be located alongside the roadway leading to a waste dump. Thus, the passing of the ore truck would cause the alarm signal to be issued. In this simples form of the invention, the actuator means would receive a signal from the receiver and set off an alarm in the truck.

Preferably said receiver, said selector means, and said actuator are interfaced by processor means.

Preferably said selector means is able to select one or more of a plurality of states, each of which corresponds to a correct transport pathway or transport pathways for said vehicle.

Preferably said selector means is operable by remote control.

In accordance with a third aspect of the invention there is provided an alarm/advisory system for warning if a vehicle is proceeding along or incident in an incorrect path or location, the alarm system comprising a stationary unit for location alongside or near a transport pathway, and a mobile unit for installation in said vehicle, said stationary unit having a transmitter with a transmission range extending across said transport pathway and arranged to transmit a polling signal, said mobile unit having a receiver capable of receiving said polling signal from said transmitter, a selector means interfaced with said receiver to select a state corresponding to a path that said vehicle should or should not follow, whereby when said state is selected, output from said receiver triggers actuator means in response to reception of said signal, said actuator means when triggered causing issuance of a control signal, wherein said mobile unit also includes a transmitter and said stationary unit also includes a receiver and processor means, whereby said stationary unit transmitter transmits said signal, and upon receipt of said signal by said mobile unit receiver, said mobile unit processor means operates to cause said mobile unit transmitter to transmit a further signal encrypted with information in accordance with said state selected by said selector means; whereby on receipt of said further signal by said stationary unit receiver means, said stationary unit processor means checks the encrypted signal and if said stationary unit processor means determines that said encrypted signal equates to an illegal value, said stationary unit processor means causes said stationary unit transmitter to transmit an actuation signal, whereby on receipt of said actuation signal by said mobile unit receiver and identification thereof by said mobile unit processor means, said mobile unit processor means triggers said actuator means.

The polling signal is transmitted either continuously, or spaced apart at intervals sufficiently short so that a body cannot pass through the transmission range between successive polling signals. Thus, the maximum interval between successive transmission of the polling signals will be determined by the anticipated time that the body will be in proximity to the stationary unit. In practice the polling interval will be longer where it is required to minimise power demand, but where power demand is not critical, the polling can be continuous.

Preferably said control signal is issued when said vehicle is not intended to travel along said transport pathway and is within said transmission range, said control signal when issued being adapted to cause an alarm signal to be issued in response to said output.

By the term"pathway", it should be understood that any place where a vehicle may access, including a depot, is intended.

Preferably said receiver, said selector means, and said actuator are interfaced by processor means.

Preferably said selector means is able to select one or more of a plurality of states, each of which corresponds to a correct transport pathway or transport pathways for said vehicle.

Preferably said selector means is operable by remote control.

Preferably said alarm signal is transmitted by said stationary unit transmitter to be received by said mobile unit receiver, whereby said mobile unit processor means causes said actuator means to cause said alarm signal to be issued.

Preferably said mobile unit processor means also causes said mobile unit actuator means to operate to disable one or more predetermined operational features of said vehicle, in response to said alarm signal being received by said mobile unit receiver. The disabling of one or more predetermined operational features of the vehicle may include the locking of a tailgate or tipping ram controller in a truck or trailer to prevent dumping of a load, or disabling of the vehicle from operating, by causing the brakes to be applied, or by cutting off the fuel supply, or by any other means known in the art by which a vehicle may be disabled.

Preferably said stationary unit includes alarm means, whereby when said stationary unit processor means detects an illegal value as described above, said stationary unit processor means also causes said alarm means to issue an alarm signal, giving a visual and/or audible alarm signal at said stationary unit. This signal may be relayed to a remote location for action by personnel if required.

In an alternative or additional arrangement, a said stationary unit includes display means interfaced therewith, and can be located alongside the roadway leading to an intersection from which two roads diverge, one leading to dumping sites for further processing of the ore (known as a rom pad), and the other leading to a waste dump, wherein upon receipt of said signal by said mobile unit receiver, said mobile unit processor means operates to cause said mobile unit transmitter to transmit a further signal encrypted with information in accordance with said state selected by said selector means; whereby on receipt of said further signal by said stationary unit receiver means, said stationary unit processor means, cecks the encrypted signal, and activates said display means to show the route corresponding to the state selected by said selector means. In this manner, the stationary unit functions as a prompt to drivers of the vehicle, reminding the drivers of the correct route to take, dependent on the load being carried.

BRIEF DESCRIPTION OF THE DRAWINGS Two preferred embodiments of the invention, both being an ore load tracker system, will now be described in the following description, made with reference to the drawings in which: Figure 1 is a block diagram of circuitry for a stationary unit or stationary transceiver according to the first and second embodiment; Figure 2 is a block diagram of circuitry for a mobile unit or vehicle transceiver according to the first embodiment; Figure 3 is a map or plan of a minesite where the first embodiment may be employed ; Figure 4 is a block diagram of circuitry for a stationary unit or stationary transceiver according to the second embodiment; Figure 5 is a block diagram of circuitry for a mobile unit or vehicle transceiver according to the second embodiment; and Figure 6 is a map or plan of a minesite where the second embodiment may be employed.

BEST MODE (S) FOR CARRYING OUT THE INVENTION The primary purpose of the ore load tracker system is to help prevent ore, from a mining truck, being dumped in the wrong place. This is accomplished by way of very short range radio transmissions covering access roads to the dumping sites, and in the second embodiment covering the dumping sites themselves, and radio receivers mounted in ore carrying trucks.

In the first embodiment, the ore tracker system comprises at least one stationary unit in the form of a stationary transceiver 3, as shown in figure 1; and mounted in each mining truck which is used to transport ore or waste, a mobile unit in the form of a vehicle transceiver, as shown in figure 2. A stationary tranceiver 3 is located alongside each road 5 leading to dumping sites at the mine. The dumping sites may typically be sites for dumping run-of-mine ore, which may comprise several sites 7 for different grades of ore which require different processing steps, and a dump 9 for ore containing uneconomic levels of mineral values. The dumping sites 7 may be in separate locations, but are more commonly located as feedstock bins in a single location.

Referring to figure 1, the stationary transceiver 3 has a transmitter 11 which is controlled by a processor means in the form of a microprocessor 13 to transmit an encrypted"polling"radio signal. The encrypted"polling"radio signal is repeated at 0.5 second intervals, in effect to poll for proximal vehicle transceivers. The radio signal is encrypted so that it can be distinguished from other radio signals that may be present on a mine site. The polling interval can be varied, dependent on expected traffic speed, by decreasing the polling interval so that a vehicle transceiver is not missed, for example due to the vehicle passing the stationary unit too quickly, or by increasing the polling interval to decrease power demand in situations when traffic speeds are low.

Referring to figure 2 the vehicle transceiver of the first embodiment has a receiver 15 which is interfaced with processor means in the form of a microprocessor 17, and interfaced with selector means in the form of a set of switches 19. The set of switches 19 comprises four individual switches 21 which are interlockingly arranged so that only one switch at a time may be selected. The set of switches 19 are housed in a console 23, together with four indicator lamps 25, one associated with each switch 21. The indicator lamps 25 are repeated by a set of four further indicator lamps 27 which are mounted externally on the mining truck so as to be visible to personnel at the mine site. The console 23 is located inside the cabin of the truck for operation by the driver, under instruction from the mine geologist, depending upon the grade of ore being carried. The indicator lamps 25 and further indicator lamps are coloured, with red corresponding to high ore grade, yellow corresponding to lower ore grade, blue corresponding to sub grade, and white corresponding to"undetermined". The mine geologist will instruct the driver to operate the appropriate switch 21 depending upon the load being transported, which will result in the appropriate lamp of those comprising indicator lamps 25 and 27 being illuminated. The operation of any one of the switches 21 is detected by the microprocessor 17, which enables the receiver 15. The microprocessor is programmed to be cognisant of which particular switch 21 is operated, and allocates a code for each switch, the code corresponding to the type of load being carried by the mining truck. It should be understood that while there are four switches and four lamps in these embodiments, some mines may operate with more or less than three viable ore grades, and hence may require more or less switches and lamps, corresponding to the number of different grades of ore (plus one for the waste dump).

The vehicle transceiver also contains transmitter 29 which is interfaced to the microprocessor 17, and actuator means 31 also interfaced to the microprocessor 17.

Referring back to figure 1, the stationary transceiver 3 has a receiver 33 interfaced to the microprocessor 13, and alarm means in the form of a flashing light 35 and also optional alarm transmitter 37 and optional radio modem 39.

Operation of the ore tracker system will now be described. When the mining truck carrying the load approaches the stationary transceiver 3, it will come into the range of transmission of the transmitter, and the encrypted"polling"radio signal.

When the receiver 15 of the vehicle transceiver receives the encrypted"hello" radio signal, the microprocessor 17 causes the transmitter 29 to transmit a signal encrypted with the code relating to the switch 21 selected by the driver, and hence to the load (the code encrypted signal).

This code encrypted signal is received by the receiver 33 in the stationary transceiver 3, and the code contained in the code encrypted signal is compared with the code (s) stored for the route along which the stationary transceiver 3 is located, by the microprocessor 13. If the code contained in the encrypted signal is an illegal value (ie not correct for the route the mining truck is taking), the microprocessor 13 over-rides transmission of the encrypted"polling"radio signal, and causes the transmitter 11 to transmit an actuation signal. The actuation signal is encrypted with the same code that was transmitted as the code encrypted signal from the vehicle transceiver. The microprocessor 13 also activates the flashing light 35, and also optional alarm transmitter 37 and optional radio modem 39 if employed. As soon as the actuation signal has been transmitted, the stationary transceiver reverts to sending the encrypted"polling" radio signal as described above, but the alarm means in the stationary unit will require manual resetting. This ensures that the stationary transceiver unit can continue to cause alarm signals to be given in further mining trucks carrying an incorrect load.

When the microprocessor 17 of the vehicle transceiver detects the actuation signal is encrypted with the same code as set by the set of switches 19, the microprocessor 17 activates actuator means 31, which sets off audio and visual alarms in the cab of the mining truck, and also activates a tail gate lock to prevent the load from being dumped. Sending back of the code encryption by the stationary transceiver ensures that if two or more mining trucks are present within receiving range, an alarm will be given in only those with the wrong switch settings as present in the mining truck initially detected. It will be appreciated that other encoding techniques may be employed, such as a unique code for each vehicle transceiver, which would be transmitted between the stationary transceiver and the vehicle transceiver.

Once the microprocessor 17 has activated actuator means 31, the receiver 15 is disabled, so that the ore tracker system can continue to monitor other mining trucks without receiving further transmissions from the mining truck in which the actuation means has activated.

In the event that the code contained in the encrypted signal is a legal value (ie correct for the route the mining truck is taking), the microprocessor 13 continues transmission of the encrypted"polling"radio signal by the transmitter 11.

The stationary transceiver shown in figure 1 also contains a real time clock 41 interfaced with the microprocessor, so that data-logging 43, if employed, can be cognisant of the time. A printer 45 can also be connected, so that logged events can be printed, if required. Power is derived from a rechargable battery 47, which has its power derived from solar cells 49, although in the unlikely event it is more convenient, the power may be derived from mine site generators or normal electrical grid power, if available.

The mobile transceiver has its power derived from the DC supply available in the truck, using a voltage regulator and on-board filtering to remove any electrical interference which may be present. A backup battery may be incorporated if required.

In summary, in operation, the driver must activate one of the lamps (using a switch inside the cab), to activate the system. Once the system has been activated the driver is allowed to move off. If the driver moves onto a road that is "covered"by the stationary transceiver, the driver is alerted to the"wrong turn", by way of a buzzer and/or a flashing light in the cab. The stationary transceiver also flashes a warning beacon. The system can be extended to lock the dumping system in the vehicle if it has passed into a no-go area, the stationary transceiver can also be set up so the area is"only go", ie the dumper can only be activated if in the (short) range of the stationary transceiver.

Further enhancements couid include individual ID codes for each vehicle, and data logging capabilities for the stationary transceivers. This would be able to monitor each vehicle that passes into the range of the system, storing date and time. This can be downloaded into a computer for print-out, or a printer can be fitted to the equipment for immediate reports.

The range of the transmitter can be set to suit the situation. A directional antenna could be used to"aim"the signal across the road, or around the dumping area, as required. The transmission frequency will be chosen so as to avoid interference, although it is expected that the band around 433MHz would be most appropriate.

The stationary unit could also have the facility to transmit the alarm signal to an office (up to 500 meters away), and also have the ability to remotely download the data from the logger, via the radio modem.

As an alternative to requiring manual reset, the stationary unit could have auto resets when vehicle passes out of field, or could be reset manually by the radio modem.

Also as an alternative to the driver manually setting the ore type by using switches in the cabin, the geologist may set the ore type by remote control.

Many of the foregoing alternatives are embodied in the second embodiment, which referring to figure 6 incorporates the same stationary units 3 as in the first embodiment, but also does so proximal to dumping sites 7 in the form of ore bins on a rom pad 51.

In addition, prior to the intersection 53 leading from the pit 55 is located an advisory unit in the form of a roadside reminder unit 57, the block diagram for which is shown in figure 4. The roadside reminder unit 57 differs from the stationary units 3 insofar as the flashing light 35 and alarm transmitter are not present, and instead a display panel 59 having illuminated arrows 61 is interfaced with the microprocessor 13 thereof. The code encrypted signal is received by the receiver 33 and the code contained therein decoded therefrom. The microprocessor 13 checks the codes in a look-up table, and compares the received code therewith, and then actuates the appropriate arrow 61 to indicate to the driver of the vehicle which road should be taken at the intersection.

The vehicle transceiver of the second embodiment differs from the first embodiment in that the unit with the further external indicator lamps 27 incorporates a receiver 63 sensitive to a transmitter in a transmitter unit 65 which is operated by the mine geologist to allocate the load destination dependent on the load being transported. The transmitter unit 65 has five switches, four of which correspond to the three ore grades and waste site at a mine, and one of which is used to reset the current assignment. While the driver has access to switches to assign a load, in this embodiment, the driver cannot reset the current assignment.

It should be understood that either embodiment is equally suitable for use at either type of minesite illustrated here in figures 3 and 6. The primary consideration in determining which embodiment to use is likely to be one of cost of implementation. A further embodiment is envisaged based on the second embodiment, whereby to reduce cost of implementation further, the stationary units 3 located proximal to dumping sites 7 on the rom pad 51 may be omitted ; however, then the onus will be on personnel to ensure a load is dumped in the correct location, or loaded into the correct ore bin by front end loader, after being dumped. However, with this arrangement, in common with both embodiments described here, the primary objective of preventing economic grade ore being dumped to waste can be achieved.

It will be readily understood that the invention could be utilised to monitor traffic comprising persons in secure buildings such as in military installations, research institutions, penal institutions and the like. In this regard, in this specification, the term"vehicle"includes within its scope people and personnel.

It should be appreciated that the scope of the invention is not limited to any particular embodiment described herein.