AU2004271220B2 - Heavy vehicle guidance system - Google Patents

Description

WO 2005/024536 PCT/AU2004/001201 HEAVY VEHICLE GUIDANCE SYSTEM FIELD OF THE INVENTION This invention relates to a heavy vehicle guidance system and has been devised particularly but not solely for the safe guidance of large haul trucks in mining situations. 5 BACKGROUND OF THE INVENTION In many forms of mining, typically in open cut mining, large (e.g. 300 tonne) haul trucks are used to transport the mined material from a loading location to a dumping location for further processing. These trucks often operate on rough haul road conditions in environments where 10 visibility may be substantially reduced, typically by dust, with resultant safety issues arising from potential collisions when haul trucks deviate from their intended route on the haul road. There is also a problem with vehicle operators becoming tired and falling asleep with resultant collisions. 15 Each year there are over 600 accidents involving powered haulage at mining resulting in more than 20 deaths. Some of these accidents involve collision of 300 tonne trucks with other truck or mine infrastructure due to operators becoming asleep. Although most operators involved in these accidents were experienced, trained and had excellent safety records many were working at the end of a night shift where micro 20 sleeping becomes a common manifestation of fatigue. The present invention aims to provide different levels of warning to alert the operator when the truck moves out of a valid corridor within the road. Previous approaches to address this problem consider: Absolute Position: These approaches measure the absolute position of the truck 25 using Global Positioning System (GPS) and compare it with a mine map. For this system to work the GPS needs to report position with less than a meter error and an updated map of the mine must be available. Only high quality differential or RTK GPS systems can provide this accuracy. The problem with this approach is that telemetry needs to be guaranteed to work everywhere in the mine to make the GPS corrections 30 available to the trucks. In addition enough number of satellites need to be seen at all time to get a position fix with required accuracy. This is not always possible in real life mining situations.

WO 2005/024536 PCT/AU2004/001201 -2 Wires buried in the road: These systems are designed to measure the distance from the truck to the wires. This approach has not been fully tested in mining environment and presents the inconvenience of making the road maintenance very hard and impossible in some mines. 5 Methods based on active detection of obstacles. There are a number of sensors and sensing systems that have been proposed to detect the proximity of obstacles to the truck. These are based on radar, cameras, ultrasonic etc. The most common implementation is based on Radio Frequency Identification Tags (RFID). These systems detect proximity to other equipment retrofitted with RFID. These systems are capable of 10 generating alarms when close to a recognizable object but can not in general present any information of the alignment of the truck within the road. It is desirable to provide a robust and reliable system for guiding haul trucks and other heavy vehicles in adverse situations in order to alert operators when the vehicle strays from a predetermined safe route. 15 SUMMARY OF THE INVENTION Accordingly the present invention provides a method of guiding the operator of a heavy vehicle along a predetermined route, including the steps of providing a plurality of markers at predetermined locations along the route, providing a scanning device on the vehicle capable of determining the location of the markers relative to the vehicle as the 20 vehicle proceeds along the route, and processing the information from the scanning device to provide a signal to alert the operator when the vehicle strays from the route. Preferably the plurality of markers include artificial infrastructure arranged to be a desired distance from the predetermined route. Preferably the markers are poles arrayed to one side of the predetermined route. 25 Preferably the markers are located at predetermined intervals calculated to be different from the intervals between any other similar devices along the route. Preferably the poles are formed from plastics pipe. Alternatively the artificial infrastructure is selected from the group comprising; earth bunds, excavated cutting walls, roadside buildings, roadside furniture, fencing and 30 screening. Alternatively the plurality of markers include natural infrastructure arranged to be a predetermined desired distance from the predetermined route.

WO 2005/024536 PCT/AU2004/001201 -3 Alternatively the natural infrastructure includes trees selectively felled to be at the desired distance from the predetermined route. Preferably the scanning device is a scanning laser. Alternatively the scanning device uses radar. 5 Alternatively the scanning device uses ultrasonic waves. Preferably the scanning device is mounted on the vehicle in a position where it can scan forwardly and rearwardly to one side of the vehicle. Preferably the markers are located a predetermined distance from a desired road centreline along the route and information from the scanning device is processed to 10 determine the distance of the vehicle from the road centreline. Preferably the distance of the vehicle from the road centreline is compared with two predetermined distances from the centreline defining a normal road corridor, and the operator of the vehicle alerted by way of visual and/or sound signals when the vehicle strays outside the normal road corridor. 15 Preferably the distance of the vehicle from the road centreline is also compared with other distances defining a valid operating road corridor wider than the normal road corridor, and the operator of the vehicle alerted by strident alarms when the vehicle strays outside the valid operating road corridor. Preferably the information from the scanning device is processed by a computer 20 within the vehicle, the computer also being programmed to recognise preset groupings of markers. Preferably preset groupings of markers are located at positions where it is desired to suppress or reactivate the alarm signals, and the computer programmed to suppress or reactivate the alarm signals accordingly. 25 In one form of the invention the vehicle is provided with Global Positioning System (GPS) equipment arranged to provide the location of the vehicle along the predetermined route. Preferably two or more vehicles are so equipped and the GPS signals in each are combined with the information from the scanning device to provide said location with an 30 enhanced degree of accuracy relative to the markers. Preferably the vehicles are equipped with communication equipment arranged to transmit their location information to one another, and each vehicle is provided with WO 2005/024536 PCT/AU2004/001201 -4 information processing equipment arranged to compare the location information from approaching vehicles and warn the operators of a potential collision. The present invention differs from previous approaches by constantly monitoring the Haul truck alignment within the road by using relative measurements to special 5 infrastructure in or alongside the road. It generates different levels of warning to alert the operator when it deviates from the normal preset corridor. The road is divided into areas of different risks allowing the system to generate the proper warning to the operator to react to the alarm well before the truck is in a collision area. This early warning normally allows gentle correction of the course of truck to avoid potential 10 collision expected from having the truck running outside a valid corridor. In its preferred embodiment, the system is based on relative measurement to PVC poles located at the side of the road. The accuracy is not degraded as long as the infrastructure is maintained. The system does not require any map or absolute position to work. 15 BRIEF DESCRIPTION OF THE DRAWINGS Notwithstanding any other forms that may fall within its scope, one preferred form of the invention will now be described by way of example only with reference to the accompanying drawings in which: Fig. 1 is a diagrammatic plan view of a road in a mining operation showing the 20 positioning of haul trucks in normal operating corridors on the road surface; Fig. 2 shows a typical extension of the system using a wireless link; Fig. 3 is a block diagram of the components located on or within the vehicle for operation of the system and method according to the invention; Fig. 4 is an example of a typical operator interface panel from the vehicle guidance 25 system; Fig. 5 is a diagrammatic view similar to Fig. 1 showing the distances used for calculation of a normal haul road corridor on the road surface; Fig. 6 is a similar view to Fig. 1 showing the calculation of a wider valid operating haul road corridor on the road surface; 30 Fig. 7 is a diagrammatic view of an ad-hoc radio network between vehicles; Fig. 8 is a diagrammatic plan view of a truck showing relative position and movement of proximity threats; and WO 2005/024536 PCT/AU2004/001201 -5 Fig. 9 is a block diagram showing the interaction between trucks and a base station. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION 5 The invention will be described in the context of the use of large haul trucks along a haul road in an open cut mining operation although it will be appreciated that the invention can be equally applied to any heavy vehicle operating environment where it is desired or necessary to alert the operator of the vehicle to deviations from an intended route. 10 The system used to implement the invention is based on a scanning laser sensor 9 that detects a row of markers or guide posts 1 (PVC Poles) located on the side of the haul road 2 as shown in Fig. 1. The guide posts are at a constant distance from the haul road centre line 6. The sensor determines the angle and distance to the guide posts. This information is processed in real time by an onboard CPU 10 (Fig. 3) to determine the 15 distance the vehicle 5 is from the row of guide posts 7 or 8, and thus the haul road centre line 6. Robust algorithms to detect and differentiate the poles from the background are used. This is essential to determine the orientation and location of a virtual wall formed by the Poles 1. This information is finally used to calculate the position of the truck 5. The haul road alignment is partitioned into normal and valid operating corridors 3 20 and 4 respectively. Heavy vehicles 5 spend most of their transit time within the normal haul road corridor. Once the vehicle is outside this corridor, visual alarms are initiated as a warning to other operators. The valid operating corridor is outside the normal corridor but can be utilised by a vehicle at a reduced speed, for example, when passing a grader. If the vehicle leaves the normal operating corridor and enters the valid operating corridor 25 at speed, or goes outside the valid operating corridor, the vehicle will be considered to be not in control and the operator will be notified via an audible alarm. Most of these parameters are configurable by the administrator of the system. A GPS (Global Positioning System) 11 is also incorporated to calculate vehicle speed. In the circumstances were the GPS can not generate vehicle speed, the scanning 30 laser sensor can still be used to calculate a speed. The distance from the haul road centre line and the vehicle speed is also used to generate a set of visual and audible alarms. The visual alarms are in the form of lights on the vehicle to inform other operators the status of the vehicle. The audible alarms are WO 2005/024536 PCT/AU2004/001201 -6 used to inform the operator of the truck that the vehicle is in a situation that may be hazardous to the operator or other operators. Special infrastructure e.g. preset groupings of markers in the form of three guide posts close together is used to trigger the audible alarm. This infrastructure is positioned 5 at the entry to all intersections, entry to dump points and entry to load points. Its function is to make sure the operator is alert when entering these areas. Another set of special infrastructure is used to suspend the system operation (no visual or audible alarms). Similar infrastructure enable the system when in suspend mode. The system includes an Operator Interface Box with an operating panel such as 10 shown in Fig. 4, that informs the operator the status of the system. At a quick glance the operator knows if the system is functioning correctly, and if it is not, what could be the cause. The Operator Interface Box also houses a button 12 to allow the operator to cancel any audible alarms. The system can be fitted with IEEE 802.1 lb wireless capabilities shown at 13 to 15 download the logged data and potentially report information such as GPS position and infrastructure state. This will enable almost real time capability of fleet monitoring capabilities with appropriate installation of wireless download stations, as shown in Fig. 2. The wireless capability 13 can also be used in combination with the GPS 11 to 20 provide an enhanced proximity detection system as between vehicles. Normally, determining position of a vehicle using GPS alone results in an area of uncertainty which is typically circular in nature with the truck or other vehicle at the centre. Due to the difficulty of using GPS in a mining situation as referred to on page 1, the area of uncertainty can cause problems when two trucks are about to pass each other in the 25 situation shown in Fig. 1 as the areas of uncertainty can overlap, causing a proximity alarm to be activated even where each truck is safely within the normal corridor. By combining the location information from the scanning device with the information from the GPS signal it is possible to obtain an enhanced degree of accuracy relative to the markers. 30 The end of this is to reduce the area of uncertainty of position of the truck from the GPS to an ellipse of the type shown at 27 in Fig. 1 which will allow two trucks to pass safely within the normal corridor without the respective areas of uncertainty 27 overlapping. The position of the truck along the road is still able to be accurately WO 2005/024536 PCT/AU2004/001201 -7 determined using the GPS system and the alarm to be triggered when a dangerous object comes within the envelope surrounding the truck. This process is generated according to a set of rules that also considers direction of travel as shown in the example of Figure 8. In this example, the operator of the truck 28 is provided with information 5 regarding the presence of a typical intruder 29 that may pose a collision risk with the truck. As the intruder 29 enters the warning area 30 an alarm is sounded and information provided to the operator of the truck that identifies not only the presence of the intruder but their relative direction of travel and speed as shown by vectors 31. The proximity system can then generate a different type of alarm according to the threat 10 level, e.g. "truck approaching in front", "vehicle behind" etc. The transmission of proximity data between vehicles is normally directly to the truck in question 28 (Fig. 7) by way of direct ad-hoc wireless network transmissions from e.g. other trucks 32, personnel 33 or light vehicles 34. The invention also envisages the downloading of equipment recorded in the 15 computer in each truck to a base station as can be seen in Fig. 9. In this example each truck 35, 36 downloads recorded data from its system computer via wireless links 37 to a base station 38 typically located at the crusher which is periodically visited by each truck. The information from the base station 38 may then be transmitted via internet links 39 to management terminals 40, 41 to be logged and analysed to manage operator 20 fatigue issues and other data from the system. The invention uses relative information to obtain the position of the truck within the road and the algorithms to generate the position information. This is based on range and bearing information obtained from a sensor mounted on the truck and looking at a special infrastructure located at known distance from the center of the road and 25 sophisticated feature extraction and data association algorithms. The system is autonomous to the vehicle, except for a single 24 V DC (<6A) power input into the main box, as shown in Fig. 3. The main system sensor is an outdoor scanning laser 9 such as those manufactured by Erwin Sick. The model used is typically the LMS221. This laser has a maximum 30 scanning angle of 1800. The laser is mounted on shock absorbers in a steel housing at the front of the vehicle. The laser mounting is designed such that the laser will be subjected to less than the manufactures recommended vibration levels. The laser is approximately 2.8 meters WO 2005/024536 PCT/AU2004/001201 -8 from the road surface as the heavy equipment can negotiate water crossings up to 2 meters in depth. At this height the laser will detect the 3.5 meter high guide posts. The laser is mounted on the left hand side of the vehicle, parallel to the side of the vehicle to allow the laser to side scan in front and behind the vehicle. 5 Although the system used to implement the invention has been described so far using a laser scanner to detect a row of guide posts, the system is equally applicable to using other scanning devices such as radar or ultra-sonic scanners to measure relative distance from either natural or artificial infrastructure known to be at a certain distance from the centre of the road.. 10 The artificial infrastructure could include continuous roadside features such as earth bunds or excavated cutting walls and could also be devices such as roadside buildings placed at the desired spacing of the centreline of the road, roadside furniture such as signs or guardrails, and various forms of fencing or screening placed alongside the road. Various combinations of these devices can also be used such as fencing or 15 guardrails in between groups of buildings to provide the desired reference datum for the scanning device. The nature of the scanning device may depend partly on the environment in which it is used and also on the nature of the infrastructure being scanned. For example, where the infrastructure is relatively constant in nature such as an earth bund or excavator 20 cutting wall, radar sensing technology may be more appropriate, particularly in dusty or bad visibility conditions. It is also possible to use natural infrastructure to form the markers arranged at a predetermined desired distance from the predetermined route. The natural infrastructure may for example include a row of trees which is already in place, or trees which have 25 been selectively felled to leave a defined row or edge to a plantation in the desired location. The processing apparatus is located within the operator's cabin in the form of a box housing a PC-104 type Microcomputer 13, an A12 GPS 11 OEM board and power adapters, signal distribution hardware and interfaces, as shown in Fig. 3. 30 The operator interface box 14 is located within the operator's cabin at a location to allow easy visual and physical access by the operator. The purpose of the operator interface box is to: 1. Notify the operator that the system is in operation.

WO 2005/024536 PCT/AU2004/001201 -9 2. Notify the operator that the system requires attention. 3. Allow the operator to cancel any audible alarms. 4. Allow the operator to adjust the brightness of any lights on the box. During normal operation, the green 'System Tracking' light 15 (Fig. 4) will be 5 illuminated. This will indicate that the system is detecting the row of guide posts down the side of the haul road and the system can determine the truck's position on the haul road. If the system can not detect the guide posts, the 'System NOT Tracking' light 16 will illuminate indicating that the system is still operational, however, the truck's position can not be determined. Only one of these LEDs will be illuminated at any one 10 time. If none of these LEDs are illuminated, another light on the operator interface box will indicate the reason why the truck's position can not be calculated. The scanning laser has an automatic pollution detection system. If the window of the sensor becomes dirty, the yellow 'Laser requires cleaning' light 17 will be illuminated. The laser will still be operable but requires cleaning at the next possible 15 opportunity. If the laser becomes very dirty or malfunctions, the red 'Laser inoperable' light 18 will be illuminated. If this occurs, the laser window should be cleaned. If this light remains on, the system should be checked by maintenance. If the system has a hardware malfunction, the red 'System Malfunction' light 19 20 will be illuminated. In this case the system should be checked by maintenance. The patterns to identify the faults are as follows: 1. System malfunction LED ON only: GPS Fault. 2. System Malfunction and laser Inoperable LEDs ON: Laser Polluted or not working. 25 There are also two visual warning lights, each a different colour, on the top of each vehicle. An amber light is used to indicate to all other operators in proximity that the vehicle has moved to the left of the normal haul road corridor. This light is only a warning and that vehicle collision is unlikely. A red light is used to indicate that the vehicle has moved to the right of the normal haul road corridor and other operators 30 should monitor the vehicles location. A GPS aerial will be mounted on the vehicle to receive satellite information to determine vehicle speed (used for alarm generation) and location (used in data logging). The audible alarm generated will have two levels.

WO 2005/024536 PCT/AU2004/001201 - 10 The first level is to indicate to an alert operator that the vehicle is in an alarm situation. In this case the alarm volume and frequency will be sufficient that it will be identified by the operator as an alarm from this system and that it can be manually cancelled using the 'Cancel audible alarm' button on the Operator Interface Box. 5 The second level of alarm should be at a level of volume and frequency that the alarm would 'wake the dead'. The transition from the first to second levels should be executed within a short period of time. If the alarm reaches the second level, it will be logged so the data can be used for monitoring the performance of any systems to minimise driver fatigue. 10 The system requires a normal operating haul road corridor to be defined. When a vehicle is within this corridor, no visual or audible alarms will be generated. The normal operating haul road corridor will be defined by two distances from the haul road centre line. Distance 21 will be from the haul road centre line to the right of the corridor and distance 22 from the haul road centre line to the left of the corridor. 15 The poles are typically placed at 20 meters distance apart, avoiding 20 meters distance from other poles 26 which may already be in place. This is important since the system looks for poles separated at 20 meters to form a wall and measure distance to this wall. The system also requires a valid operating haul road corridor to be defined. The 20 valid operating corridor is used to control the type of alarms generated. In general, a vehicle that is travelling at speed and tracking and is outside the valid operating corridor will be considered to be not in control. The same as the normal operating haul road corridor, the valid operating haul road corridor is defined by two distances from the haul road centre line. Distance 23 will be 25 from the haul road centre line to the right of the corridor and distance 24 from the left of the corridor. Distance 25 is the distance from the haul road centre line to the system detection guide posts. Distances 23, 24 and 25 are system parameters predetermined by operating conditions. 30 The system can also log two sets of data that can be downloaded onto a laptop or hand-held PC when required. The first will be when the audible alarm has reached level 2 alarm volume. When ever this occurs, the following will be logged: WO 2005/024536 PCT/AU2004/001201 - 11 1. Current date and time. 2. Vehicle identification If tracking guide posts 3. Vehicle position from side line guide posts 5 Else 3. A large negative number (i.e. -999) 4. Vehicle speed 5. Vehicle approximate GPS location This data will be used to monitor the performance of any systems to minimise 10 driver fatigue. The second set of data to be logged will be the last hour of operation of the vehicle. The interval between logging will be <=1 second. The data logged will be: 1. GPS Data. 2. Laser Data. 15 This information is can be downloaded at any time through the use of wireless IEEE 802.11b.

Claims (21)

1. A method of guiding the operator of a heavy vehicle over a predetermined route along a roadway, including the steps of providing a plurality of markers elevated above the roadway and offset to one side of the roadway at predetermined locations along the 5 route, providing a scanning device on the vehicle arranged to transmit a signal toward the markers adjacent the vehicle and to receive a modified signal reflected from the markers usable to determine the location of the markers relative to the vehicle as the vehicle proceeds along the route, and processing the information from the scanning device to provide a signal to alert the operator when the vehicle strays from the route. io

2. A method as claimed in claim 1, wherein the plurality of markers include artificial infrastructure arranged to be a desired distance from the predetermined route.

3. A method as claimed in either claim I or claim 2, wherein the markers are poles arrayed to one side of the predetermined route.

4. A method as claimed in claim 3, wherein the poles are formed from plastics pipe. 15

5. A method as claimed in any one of the preceding claims, wherein the markers are located at predetermined intervals calculated to be different from the intervals between any other similar devices along the route.

6. A method as claimed in claim 2, wherein the artificial infrastructure is selected from the group comprising; earth bunds, excavated cutting walls, roadside buildings, 20 roadside furniture, fencing and screening.

7. A method as claimed in claim 1, wherein the plurality of markers include natural infrastructure arranged to be a predetermined desired distance from the predetermined route.

8. A method as claimed in claim 7, wherein the natural infrastructure includes trees 25 selectively felled to be at the desired distance from the predetermined route.

9. A method as claimed in any one of the preceding claims, wherein the scanning device is a scanning laser.

10 A method as claimed in any one of claims I to 8, wherein the scanning device uses radar. 30

11. A method as claimed in any one of claims I to 8, wherein the scanning device uses ultrasonic waves. - 13

12. A method as claimed in any one of the preceding claims, wherein the scanning device is mounted on the vehicle in a position where it can scan forwardly and rearwardly to one side of the vehicle.

S3. A method as claimed in any one of the preceding claims wherein the markers are 5 located a predetermined distance from a desired road centreline along the route and information from the scanning device is processed to determine the distance of the vehicle from the road centreline.

14. A method as claimed in claim 13, wherein the distance of the vehicle from the road centreline is compared with two predetermined distances from the centreline 10 defining a normal road corridor, and the operator of the vehicle alerted by way of visual and/or sound signals when the vehicle strays outside the normal road corridor.

15. A method as claimed in claim 14, wherein the distance of the vehicle from the road centreline is also compared with other distances defining a valid operating road corridor wider than the normal road corridor, and the operator of the vehicle alerted by 15 strident alarms when the vehicle strays outside the valid operating road corridor.

16. A method as claimed in any one of the preceding claims, wherein the information from the scanning device is processed by a computer within the vehicle, the computer also being programmed to recognise preset groupings of markers.

17. A method as claimed in claim 16, wherein preset groupings of markers are 20 located at positions where it is desired to suppress or reactivate the alarm signals, and the computer programmed to suppress or reactivate the alarm signals accordingly, and/or to sound an alarm.

18. A method as claimed in any one of the preceding claims, wherein the vehicle is provided with Global Positioning System (GPS) equipment arranged to provide the 25 location of the vehicle along the predetermined route.

1 9. A method as claimed in claim 18, wherein two or more vehicles are so equipped and the GPS signals in each are combined with the information from the scanning device to provide said location with an enhanced degree of accuracy relative to the markers.

20. A method as claimed in claim 19 wherein the vehicles are equipped with 30 communication equipment arranged to transmit their location information to one another, and each vehicle is provided with information processing equipment arranged to - 14 compare the location information from approaching vehicles and warn the operators of a potential collision.

21. A method as claimed in any one of the preceding claims, wherein processed information is periodically downloaded to a base station and analysed to identify 5 operator fatigue patterns.