WO2006125256A1

WO2006125256A1 - Monitoring system for mechanically self-guided vehicle

Info

Publication number: WO2006125256A1
Application number: PCT/AU2006/000683
Authority: WO
Inventors: Christoper Robert Fairclough
Original assignee: Fairclough Corporation Pty Ltd
Priority date: 2005-05-23
Filing date: 2006-05-23
Publication date: 2006-11-30

Abstract

A monitoring system (30) for dynamically determining a current state of a mechanically self-guided vehicle (10) comprises sensors (32) for measuring either or both of: a vertical force on each of a plurality of wheels of the vehicle; and/or a lateral acceleration on each of a plurality of wheels of the vehicle, means (34) for processing the measurements from the sensors to determine the current state of the vehicle; and means (36) for acting on the determined state.

Description

MONITORING SYSTEM FOR MECHANICALLY SELF-GUIDED VEHICLE

FIELD OF INVENTION

The present invention relates to a method and system for dynamically determining a current state of a mechanically self-guided vehicle and producing an action based on the determined state.

BACKGROUND

Mechanically self-guiding vehicles include trains, trams, monorail trains, road-rail vehicles and track guided buses. These vehicles are guided by at least one track which is engaged by a number of wheels along the length of the vehicle.

Road-rail vehicles are road vehicles adapted for travel on rail in addition to road. A typical road-rail vehicle is a production road licensed, rubber tyred vehicle that is additionally equipped with one or more mechanical apparatus to lift, guide and/or propel the vehicle on any one of a multitude of rail systems and gauges . The attachment rail devices may typically comprise of independent suspension and guide wheels, full axle with independent rotating wheels or full axle - wheel set either with constant load or over centre carriers . The present invention is most suited for, but not limited to, higher speed lighter road-rail vehicles.

Such vehicles are generally tested and rated for certain speeds and loading under normal track operating conditions. Such tests may be empirically or theoretically determined over a restricted sample of conditions. The vehicle is then classified with a blanket rating for its permitted speed and loading.

However, in practice loading and speed need to adapt according to changing track conditions . Furthermore these vehicles are sometimes not loaded or driven according to the vehicle's rating or in a manner that suits the track conditions . For example the driver may exceed the track speed limit, or the vehicle's rated speed limit. However when track conditions are outside of the ideal operating window, for example when the track is wet or the rail has undergone movement or distortion, even driving at the correct speed limit or vehicle rated speed may not be appropriate .

The driver of these vehicles is not always aware of or able to react to changes in conditions or does not always comply with speed, loading or other requirements. As a result derailments occur. Derailments can be quite disastrous and result in very significant damage, injury and even death. Further they are costly in maintenance and consequential losses .

BRIEF SUMMARY OF THE INVENTION

The present invention seeks to provide an additional level of safety for mechanically self-guided vehicles.

According to first aspect of the present invention there is provided a monitoring system for dynamically determining a current state of a mechanically self-guided vehicle comprising: sensors for measuring either or both of : (i) a vertical force on each of a plurality of wheels of the vehicle; and/or (ii) a lateral acceleration on each of a plurality of wheels of the vehicle; means for processing the measurements from the sensors to determine the current state of the vehicle; and means for acting on the determined state.

Preferably the means for acting on the determined state is an alarm. Alternatively the means for acting on the determined state is an automatic control device for overriding control of the vehicle .

Preferably the sensors also measure wheel rotation velocity and/or vehicle velocity. Preferably the means for acting on the determined state comprises a means to determine whether the state falls outside one or more parameters and in that event said means acts on the state. Preferably the sensors measure the distance to the rail contact surface . In particular the sensors measure distance between the vertical contact surface of the track head and some reference point on the bogie assembly and also the inclined distance between the rail head corner (known as gauge corners in railway terminology) and some reference point on the bogie .

Preferably the means for acting on the determined state includes one or more of : issuing an audible and/or visual alert indication; means to reduce the application of vehicle acceleration; means to activate the vehicle brakes; or a speed limiting means .

Preferably the sensors further measure : dynamic load on each wheel; vertical acceleration; dynamic track gauge; track curvature; vehicle operating conditions; driver attentiveness/vigilance; driver door open; driver seat belt.

Preferably the states determined include: speeding; overloading, load imbalance, shifting load; hunting; rail wheel flange riding; derailment; derailment risk; roll over risk; poor tracking; poor track conditions; tyre deflation; poor mechanical reliability; driver presence.

Preferably the system further comprises recording means to record sensor measurements and/or the determined state in a log.

Preferably the measurements from the sensors are compared to a base line state recorded in a database storage means. Preferably the system further comprises means for comparing the measurements from the sensors to measurements stored in a database and in the event that the measurements fall outside of one or more tolerances from those in the database an alarm is triggered.

In some embodiments the vehicle is a road-rail vehicle.

Typically the means for acting on the determined state undertakes a dynamic action substantially immediately following determination of a state that requires action.

According to another aspect of the present invention there is provided a method of monitoring the state of a mechanically self-guided vehicle comprising: taking measurements from sensors that measure either or both of :

(i) vertical force on each of a plurality of wheels of the vehicle and the velocity of the vehicle; and/or

(ii) a lateral acceleration on each of a plurality of wheels of the vehicle; processing the measurements of the sensors to determine the current state of the vehicle; and acting on the determined state.

DESCRIPTION OF DIAGRAMS

In order to provide a better understanding of the present invention, some embodiments of the invention will now be described, in greater detail, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a side elevation of a road-rail system applied to a truck; Figure 2 is a front elevation of the road-rail system of

Figure 1 ;

Figure 3 is a side elevation of an alternative road-rail system applied to a truck;

Figure 4 is a schematic view of a system for dynamically determining a current state of a mechanically self-guided vehicle; and

Figures 5a to 5d are schematic information flow diagrams of a method of dynamically monitoring the current state of a mechanically self-guided vehicle and acting on the state, in which Figure 5a shows a sensor component, Figure

5b shows a database and input component, Figure 5c shows a processor component, and Figure 5d shows an output component . DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Road-rail vehicles are typically used to patrol and inspect the track, convey work gangs, personnel, assorted loads and construction equipment to worksites on rail networks . The road vehicles or construction vehicles are interfaced to rail using rail engaging bogeys, which are lifted from the ground during road travel, and are lowered to engage the track during rail travel. In some road-rail vehicles the road wheels carry a portion of the weight of the vehicle. The vehicle is guided along its course by the direction of travel of the truck and while the vehicle has its rail wheels engaged with the track it must follow that course .

Referring to Figures 1 and 2 there is shown a road-rail vehicle 10 which includes a road vehicle 12 guided by a rail 14 of a railway track. In this embodiment the vehicle 10 includes a front bogey 16 which is arranged to hydraulically descend to contact rail guide wheels (D) with the rail 14 thereby supporting the front of the vehicle so that front road engaging wheels 18 are raised from the ground. A rear bogey 20 is arranged to hydraulically descend rail wheels to engage with the rail 14. Rear road wheels 22 remain in contact with the rail surface. The bogeys 16 and 20 mechanically guide the vehicle along the railway track. The rear road engaging wheel 22 provides locomotive force to the vehicle thereby propelling it forwards or backwards.

In the embodiment shown in Figure 3 a road-rail vehicle 10' comprises a rear bogey 20' that supports the rear of the vehicle 10' such that the road engaging wheels 22 are above the ground. Either or both the bogeys 16 or 20 apply locomotive force to the rail 14 thereby propelling the road-rail vehicle 10' forwards or backwards.

Poor maintenance, accidental road tyre deflation, speed, poor loading and bad track conditions can cause the rail guide wheels on the vehicle to become unstable and therefore increase the risk of derailment.

At derailment the rail guidance system is no longer able to keep the vehicle self steering and in contact with the rail. When derailment occurs, at least one of the rail guide wheels loses correct contact with the rail track.

It will be appreciated that while certain examples of road-rail vehicles are described in this description the present invention has application for other mechanically self-guided vehicles.

Referring to Figure 4 a system 30 of the present invention is shown. The system 30 includes a plurality of sensors 32 which measure various physical properties 35 of the vehicle 10 and/or of the operating conditions (such as track condition) . The sensors 32 provide the measurements to a microprocessor 34 or some other data processor, programmable logic device, such as a Field-Programmable

Gate Array or a Programmable Logic Array, or other logical electronic circuitry. The microprocessor 34 interprets the measurements to determine the state of the vehicle according to the information provided by the sensors 32. The microprocessor 34 is connected to an output 36 which activates one or more alert/devices if the state of the vehicle falls outside one or more parameters.

The microprocessor 34 is connected to a storage means 38 for storing a database of information and for logging the measurements taken. The microprocessor 34 is also connected to a communications device 40 for receiving an update to one or more parameters stored in the database or for transmitting the measurements received from the sensors 32. The microprocessor 34 receives a clock input from clock circuit 42. The microprocessor 34 may also receive an input from the vehicle driver, via input means 86.

The microprocessor 34 determines a number of states of the vehicle, the different states being determined by different measurements from the sensors 32. The flow diagrams in Figures 5a to 5d show an embodiment of a method 50 of the present invention. The processor 34 is controlled by a computer program to perform the method 50. The sensor measurements are divided into a number of groups to determine related properties and thus states. This is done because it is possible to mathematically derive some measurable attributes from certain measurements, which in turn, means that not all of the possible sensors need to be used. For example: t = time x = dis tan ce v = velocity a = acceleration

v = ^ dt

_ dv_ ^{a ~} dt

x(t) = Jv + x(0) From the acceleration we can derive the displacement of the object. In this way we can substitute partially for missing direct sensor measurements by using derived results from other sensors with a corresponding change in accuracy.

The groups of measurements are processed by subsystems, which include a speed subsystem 52, a load sensor subsystem 54, a guidance subsystem 56 and a movement subsystem 58. The speed subsystem 52 uses measurements of speed, acceleration and direction. The load sensor subsystem 54 uses measurements of load per wheel and total load. The guidance subsystem 56 uses measurements of lateral displacement, lateral acceleration and lateral movement rate for each wheel. It also uses measurements of vertical displacement, vertical acceleration and vertical movement rate for each wheel .

The movement subsystem 58 measures vertical displacement, vertical acceleration and vertical movement rates for and lateral displacement, lateral accelerations and lateral movement rates for each wheel.

Each of these measurements are transferred via an information highway to be stored 60 in the database of storage means 38, and are also used to calculate various derived conditions of the vehicle. At 62 the static and dynamic load and load variations are calculated. The results of these calculations can be subject to filtering and used to determine predictions and patterns . The stored measurements are transferred via information highway to calculation blocks, which perform calculations. Calculation block 64 calculates dynamic guidance variations and provides filtering, predictions and patterns. Calculation block 66 determines dynamic movement variations and also provides filtering, predictions and patterns. Calculation block 80 determines combined load, guidance and movement variations and provides filtering, predictions and patterns.

The database of storage means 38 may contain a set of safety parameters 68 (which may be input through the communications means 40) from a safety parameter storage facility 70. Each of the parameters 68 are compared with those measured and/or calculated at comparators 72, 74, 76 and 78.

The outcome of the comparison will result in a warning or alarm where for example the sensor measurement, derived measurement or calculated state is approaching or exceeds a safety parameter. A driver awareness subsystem 82 monitors the output of the comparators 72, 74, 76 and 78 to warn the driver. This occurs by a driver display and output system 84 causing an output through the output means 38. The driver awareness subsystem 82 may also prompt the vehicle diver to respond via driver input means 86 such as a keypad.

The type of alert generated may determine the type of output. The output may be provided in the form of an audible speaker system 84 which may drive a speaker 88 or it may in addition have an indicator light 87. It may also drive an alphanumeric display. Requiring feedback from the driver ensures that the driver is aware of the alert provided to them. In addition a log subsystem 90 logs the alerts given and the response thereto. The logged information is able to be output 92. A speed correction subsystem 94 receives a warning/alarm when the vehicle speed is approaching or exceeds a speed parameter. The parameter may be a maximum vehicle speed or may be dynamically calculated, based on track, and/or vehicle conditions. Upon detecting a warning/alarm the subsystem 94 will determine a control method, which may be one of issuing an instruction to the driver to slow down, or to take control of one or more aspect of the vehicles controls, such as acceleration and/or braking.

A detailed example of an embodiment of the present invention is described below.

Loading Static Loading

A vehicle with a non symmetrical lateral, transverse and/or longitudinal load will shift the centre of gravity of the vehicle from the centreline of the vehicle. Given unfavourable factors, the vehicle will have an increased risk to derail.

A vehicle that is overloaded has the centre of gravity shifted vertically upwards. This increases the rollover moment of the vehicle at speed and, as for unbalanced loads, the vehicle will have an increased risk of derailment .

By sensing (or deriving) the vertical force on each rail wheel the system 10 can determine the loading on the vehicle. Thus the system can detect an unbalanced or overloaded load by measuring or estimating the weights, directly or indirectly. The weight is estimated directly by measuring the load in the rail guidance system (RGS) with an appropriate device. An example of "indirectly" is by making an estimate by measuring the deflection or angular movement of an independent suspension component of a single wheel of a wheel set compared to a suitable location on the vehicle body.

Dynamic Loading

When a vehicle commences movement, the dynamic loading will change on each contact wheel.

If the dynamic loading value approaches near zero or negative for the RGS, the risk for derailment or accident greatly increases .

Guidance

Lateral Forces leading to derailment.

The vehicle can develop lateral RGS wheel movement that can lead to derailment because a lateral acceleration at the RGS wheel will generate enough force in certain conditions to allow the flange of the RGS wheel to climb over the rail gauge face whereupon the ability to guide is diminished or lost and derailment may occur.

Similarly, certain vertical RGS forces can generate enough vertical acceleration to permit the RGS wheel to leave contact with the rail. The likelihood of derailment from a purely vertical acceleration that causes loss of wheel contact is not sufficient in itself to be a problem. However, when combined with a minimal lateral force, the contactless wheel can be derailed with ease.

The system can determine two general parameters by measuring, via the sensors, the acceleration, and thus forces, particularly the patterns in time and space. The initial is the propensity and bias for lateral movement which is an indicator of vehicle maintenance and loading issues (and track maintenance in some situations) , an example is broaching. Secondly, the trending or prediction of the movement can lead to parameters that highlight approaching unstable conditions . Examples are cycling lateral impact conditions, called hunting.

The use of Nadal's formula on the lateral and vertical forces assists, but is not exclusively used, in the determination of the combination of safe lateral and vertical forces for these measurements. Nadal's formula is from APTA Passenger Rail Equipment Safety Standards Task Force Technical Bulletin 1998-1, Part 2 and is available at the following web site: http: //www. apta.com/about/committees/press/bulletin/1998- lb.cfm

Track Gauging

The track gauge has a direct bearing on the safe operation of the vehicle. If the gauge is too wide or too narrow relative to the gauge settings on the vehicle, then there is an increased risk of derailment. This is more so in track curves .

By measuring directly or indirectly the track gauge, to a suitable accuracy, or measuring the combined or singular vertical acceleration of a wheel or wheel sets, track gauge conditions that are approaching the safety limits of the vehicle in motion can be detected. The driver can be warned and alarms given to alter the vehicle's travelling speed or alternatively to stop the vehicle.

In the present invention, the actual gauge for this vehicle type, weight and travelling conditions is measured. The official gauge measured by the railway companies is derived from more sophisticated track geometry measurement vehicles . The results can be different to the dynamic gauge measurement from this typically lighter road -rail vehicles. So predictions of vehicle operational safety from track problems using official track geometry data may sometimes have limited effect in vehicle safety compared to this dynamic measurement method.

Track Curvature

Track curvature is designed for safe operating speeds by designing and matching the rate of change of curvature, the radius and the entry and departure changes to the track curve cant to suit. When the vehicle has a speed significantly over the maximum allowable for the curve, and subject to the state of maintenance of the vehicle, the likelihood of derailment is significant.

An embodiment of the invention applies to curves of single cusp cross levels on curves, multiple down and out cusps, steady and dynamic curving.

By measuring the vehicle's speed, estimation of weight, estimations of the vehicle's mechanical properties (by modelling or field experiments or measurements) and/or measuring other dynamic parameters, an estimate for the probability of derailment can be determined. Static, workshop measurement of the rail wheel dimensions can provide a better model for derailment prediction which is stored in the database. Given other prior known track details by way of pre-programmed stored data, either by an online communications system or built in ^x flash' memory, the vehicle can be dynamically checked to determine the risk. The driver is then warned of the increased risk and the system may intervene in the control of the vehicle. Alternatively, the determination can be made dynamically when no such prior knowledge is available to the system. In this case, the Roll Over method may be used.

Roll Over

From the measurement of the lateral movement of the vehicle, an estimation of a roll over parameter can be made. In a similar fashion to the above, the safety parameters can be compared and appropriate driver awareness can be ensured. The Roll Over can be checked with more accuracy using a more direct form of measurement .

Movement

There are two components of interest. The rollover indicator and an alternative form of a lateral force indicator.

Rotation - Rollover

When a vehicle is moving there is a dynamic rotation (or moment) force acting laterally across the vehicle that will try to roll the vehicle when travelling around curves .

By measuring the acceleration of the lateral and vertical components of the forces acting on the vehicle, dangerous levels of forces can be predicted by knowing the vehicles load, balance, and speed (Load System) . Further, by supplementing the information with information from the other subsystems, for example, the Guidance System, a better prediction can be made. The calculation results are compared against the safety parameters set for the vehicle, so that the driver can be alerted to an increased risk of rolling and derailment.

Lateral Forces leading to derailment

Lateral acceleration of the vehicle can lead to derailment as described in the Guidance Section above.

In the absence of the Guidance System, making measurements of the vehicle's lateral forces can determine two general parameters. The initial parameter is the propensity and bias for lateral movement which is an indicator of vehicle maintenance and loading issues (and track maintenance in some situations) . Examples are hunting and broaching. Secondly, the trending or prediction of the movement can lead to parameters that highlight approaching unstable conditions. Examples are cycling impacts condition.

The character of the lateral force is different to those measured by the Guidance method. The vehicle has other elements that influence the calculation of the forces e.g. body Centre of Gravity and the suspension system.

Nevertheless, the lateral acceleration contains adequate information to enable a successful computation of the forces that can be compared against a safety parameter table .

When compared to the safety limits for the vehicle type and weight, warnings and alarms can be issued to the driver for action.

Safety Parameters .

The operational and dynamic limits of the vehicle can be stored onboard the vehicle in temporary or permanent, fixed or removable electronic computer memory. The parameters are derived by historical data, field experiments and standard models of vehicles. They may be in the form of lists, tables, arrays either in binary, text or encrypted for protection. The parameter storage and method may contain error checking and correction methods, for example LPC and CRC32, to ensure the integrity.

The parameters may be:

1. permanently installed at the time of the installation for the vehicle;

2. altered in the field by a programming device,-

3. downloaded at the time of installation from a centralised server;

4. downloaded dynamically as the vehicle is moving along the track or stationary; or

5. calculated and adjusted by internal algorithms to accommodate the vehicle and track nature, i.e. self learning within maximum and minimum overriding limits.

These parameters can act as thresholds to determine the permissible limit for the sensor measurement signals or derived results. They can be used in a vehicle static or dynamic mode of operation.

The parameters also contain calibration details for the sensors when required. Again, the calibration parameters have the same properties as all parameters. Calibration is important to maintain a standard throughout the rail company's fleet of vehicles or to allow adjustment of individual parameters to better discriminate unsafe and safe conditions . Types of Information Displayed and Safety Warnings

The information may be derived when the vehicle is in a stationery condition (Static) or when the vehicle is in a travelling condition (Dynamic) . Both static and dynamic operation are measured and displayed.

Information derived from the system can be used to warn the driver of :

• overloaded conditions ; • unbalanced load in the static and the dynamic condition;

• maintenance is due based on measured results, vehicle odometer for distance travelled, or time since last maintenance; • driver's hands on the steering wheel;

• steering wheel locked;

• steer forward only, bring steering to forward position;

• seat belt is not secured; • Wheel Slip braking and accelerating and fault conditions;

• door open;

• Disengage Park Brake,-

• speed restricted area (type can be shown) ; • over speed condition (dynamic only) ;

• Safety Lists - on tracking, operating, off tracking;

• poor vehicle tracking (type can be shown) ;

• poor track conditions (type can be shown) ; • dangerous track conditions (type can be shown) ;

• Rail (Guidance) Gear Malfunction (type can be shown) ;

• Rail (Guidance) Gear not locked (type can be shown) ; • communications drop out or weak area,- • road tire deflation;

• excessive or unusual vehicle travelling noise;

• excessive or unusual engine noise;

• vehicle general malfunction; • load shift (dynamic only) ;

• excessive vehicle hunting (dynamic only) ;

• Track Access Time Limit Warning; and/or

• Track Access Position or Distance Warning.

Implementation

With reference to figures 1 to 3, to implement this invention, in one embodiment a vehicle (A) is equipped with:

• front and / or rear guidance system (RGS) devices (B) ;

• a vehicle speed and distance travelled subsystem;

• a load measurement and/or load indication subsystem on each of the RGS or rail vehicle's devices (C) ; • a proximity linear distance sensing sensor subsystem for the rail gauge face and/or head (D);

• an acoustic noise measurements subsystem for vehicle and rail interface noise inside the vehicle or externally near the rail head;

• a movement subsystem of sensors for vertical and lateral motion detection (E) ;

• an electronic - computer device (F) having processor 34 to read the sensors and undertake computational algorithms, stores and reports dynamic and logged data;

• a light, display, audible, vibration warning system for the driver (G) ; • a driver's acknowledgment device (G) for the driver's use,- and

• a system to alert the driver of the state of the vehicle for action to bring it back into a recommended safe mode.

The implementation may be from a basic system with load monitoring for static use, through to a full equipped vehicle with all subsystems.

A speed and distance measurement sensor group may include, but are not limited to:

• a GPS system with or without inertial fibre optical gyro take over subsystems ; • a shaft encoder generating a number of pulses per unit of distance either by optical, magnetic (Hall Effect) , capacitive or inductive sensors installed on one or more rotating contact wheels;

• ultrasonic, infra red, Microwave or Laser sensors using Doppler methods either measuring the ground speed and/or the rotational speed of the contact wheels;

• optical CCD or similar photon to image linear and 2 dimension sensors with correlation computational electronics to determine speed and/or direction for either measuring the ground speed and/or the rotational speed of the contact wheels; and

• gyro subsystems giving direction and velocity information.

By integration of the pulses and using known calibration factors, the sensors generating pulses per unit distance can also give a distance travelled measurement. Distance travelled over a set time period yields the vehicle's speed.

Load measurement or load indication sensors may include, but are not limited to:

• angle measurement sensors of deflection of the load arms (torque arms) of which there maybe several and the most appropriate is selected;

• Strain Gauge measurement on the load arms; • piezoelectric stress sensors;

• ultrasonic sensors to determine ride heights at the corners or appropriate places of the vehicle;

• optical measurement sensors like laser range finding, triangulation, CCD linear or 2 dimensional image movement measurements, and fibre optical defection sensors,-

• inductive sensors determining proximity of the vertical position of the arms relative to some appropriate surface . For example the rail surface, road surface, vehicle body;

• capacitive sensors determining proximity of the vertical position of the arms relative to some appropriate surface. For example the rail surface, vehicle body,- and • linear distance measurement sensors such as linear potentiometer or LVDT sensors measuring the compression and/or expansion of the suspension device material or system between the wheel and vehicle.

Linear distance or indication measurement methods may include, but are not limited to:

• ultrasonic sensors; • optical measurement sensors like laser range finding, triangulation, CCD linear or 2 dimensional movement measurements;

• inductive or magnetic effect sensors; • capacitive sensors; and

• contact LVDT or resistive sensors, e.g. steering rod position measurement.

Motion detectors measurements or indicators may include, but are not limited to:

• ultrasonic, Microwave, Laser Doppler sensors,-

• Infra Red Detectors;

• optical measurement sensors like laser range finding, triangulation, CCD linear or 2 1 image movement detection and distance measurements.

• inductive or magnetic effect sensors;

• capacitive sensors;

• accelerometers;

• gyroscopes, either the traditional mechanical, accelerometer or the fibre optical and laser based; and

• GPS systems that determine absolute and relative motion.

Pressure sensors may include, but are not limited to:

• Conductive, or Carbon Impregnated polymers or rubber;

• PST Sensors;

• Polyvinylidene Fluoride (PVDF) materials; • Spring loaded contact switches; and

• Tape switch ribbon switch technology,

Other measurements are from those signals already provided in automotive road-rail vehicles or easily accessible with the inclusion of standard automotive sensor devices, e.g. pressure switches, temperature, voltage and current sensors .

Signals from the following sensors are measured by the system and used as required in the safe operating of the vehicle: Seat belt engaged / disengaged, engine on, engine running, reversing, braking, hydraulics operating, hydraulics at safe pressures, park brake engaged, gear position, clutch depressed.

Acoustic noise measurements are made by one of more microphones using capacitive, piezoelectric, dynamic or electrostatic techniques.

A keyboard or equivalent and touch sensitive input device is required to collect:

• the information about the driver for example, their license number, etc.;

• current vehicle status and conditions, for example odometer reading; and

• acknowledgements to warnings and alarms .

One or more electronic computing devices are required to:

• collect the signals, filter the signals as required, analyse the results to extract trends, peaks, cyclic variables, threshold violations and failures, present suitable graphic, textual, audible, audio or other warning and alarm information to the driver; • collect, store and communicate the operation and dynamic data (logging data) , safety parameters and other information as may be required, for example, new versions of the software; • interlink into the automotive CAN, VAN or similar bus streams to send and read data from other original vehicle computers and sensors;

• collect and analyse GPS data; and • interact with the driver.

The system of the present invention may be included in a vehicle control computer system by the vehicle manufacturer, added on and worked in conjunction with the original vehicle systems or as a separate, stand-alone device .

The system of the present invention may be included in driver vigilance systems, as an add on to work in conjunction with these systems or as a separate stand alone system.

Vehicle Check list safety and basic operation

When commencing use of vehicle with the system, the driver is required to complete a safety check list for the operational safety of the vehicle, the driver and the other occupants .

In some embodiments of the invention, the system will measure the state of the vehicle while in a static state and informs the driver of conditions exceeding the ability or predetermined operating permission for that vehicle and the driver. This is a check list of safety requirements. The system may permit the driver to operate the vehicle if programmed to do so or may inhibit the vehicle operation until the entire check list has been cleared and the static measurements are all within acceptable limits or condition for safe operation. Examples for the check lists are: seat belt on, hand brake on/off, rail gear locked, visual inspection check.

During operation, the driver may be required to attend to a track side inspection or temporary stop. The safety system will permit the driver to come to a full stop, make the vehicle safe and depart while still supervising the safe operation of the vehicle.

At the completion of travel, the driver must complete a closure check list to ensure the safe completion of use of the vehicle. The vehicle may then be transferred back to road use .

All actions of the driver' s interaction with the system are recorded for safety, driver education and system improvement measures .

The system provides an emergency override function in the event that urgent actions are required by the drive to make safe the vehicle, themselves or passengers.

Vehicle travelling safety

The position of the vehicle is monitored and compared to known track related information. Examples are switches, road crossings, curves, stations. At such locations as deemed necessary, the driver will be issued with a warning or advice instruction at a predetermined approach position. The instruction maybe for speed restrictions or specialise information concerning the safe operation of the vehicle in these areas.

In rail applications where the rail access is not protected and controlled by a signalling system, the vehicle must gain track access permission. The access will be granted with certain conditions. Namely, they may be a time limit before the vehicle must be cleared from track or permission to run to a distance limit or place limit then to clear the track.

In such applications, the system can provide the necessary facility to input the certain condition and monitor the progress of the vehicle against that condition. As the time limit is approached, appropriate advisory display will be issued. Similarly appropriate advisory displays will be issued for distance and position limits.

Raw Information Collection Process The system will collect signals from various sensors which may be filtered and amplified. These are then typically converted from analogue signals to a digital form (A to D) . Other signals, for example, hand brake engaged, are either a low (off) or high (on) voltage. These are converted directly to digital low or high for the computer system.

The system may be protected from dangerous analogue or power electrical spikes.

The speed, load, movement, guidance, status monitoring and acoustic subsystems will convert the raw signals into useful information. The subsystem may directly compute the outputs required or supply semi processed information for further processing by other computing elements in the invention.

The converted raw signals will be used to determine part output. The processes maybe singular or in combination of the following, as determined by the nature of the raw signal and the required output:

I. filtering the frequency by low, band or high pass techniques, digitally or in analogue form; 2. frequency measurements;

3. energy density per frequency band;

4. periodic repetition of the signal measurements;

5. periodic measurement of the extracted features;

6. burst, one off time and frequency content measurement;

7. thresholding the signal above or below the determined levels held in the parameter storage area;

8. thresholding with hysteresis for signals that do not follow the conventional monotonically increasing model;

9. noise or unwanted signal rejecting by background subtraction;

10. feature extraction to select only specific points and data of interest in the incoming raw stream;

II. correlation of the signal to calibration patterns held in the parameter storage.

Further, some sensors and their signals can be set to monitor the signal at a fixed distance or time intervals and record the results in the logged memory. This is to aid the analysis of the track maintenance and vehicle performance. The ability to control when this mode is turned on and off either manually or automatically (locally or remotely) is provided. Display and Alarm

The display and alarm subsystem combines one or more outputs from the Collection Systems and determine what action should be taken.

When the driver is issued with a display it may be necessary to seek their attention but without causing further safety concerns. Subject to the nature of the information to be acted on, i.e. its priority and safety level, the system will commence a sequence of events to raise the attention of the driver to the heightened safety issue of the vehicle.

This may be the following but not limited to the following.

Audible: Chimes and bell sounds, musical passage, verbal spoken instructions (prerecord or machine read from text files) by means of radio, computer, amplifier, vehicle horn. Other continuos or periodic sounds designed to be heard in the acoustic environment for the appropriate vehicle e.g. siren.

Optical: LED lighting positioned for the driver, indirect display lighting, indirect LED or other lighting (eg vehicle cab lights), dashboard symbols, projected displays on the surrounding dash, windscreen or driver visible object in the direction of the outlook of the driver, computer screen displays .

Vibration: Seat vibration devices, steering wheel vibration devices .

When the safety warnings have not been acknowledged and/or the probability of risk of derailment or accident has increased above a threshold, the system optionally may commence procedures to bring the vehicle back into a safe mode. Examples of intervention may be one or more of the following: • the application of brakes;

• reduction or cancelling of the accelerator;

• cutting the power to the fuel supply system;

• overriding the vehicle computer's accelerator demand; and/or • selecting a lower gear (when the vehicle has electrical control of the gear selection) .

Logging and remote access

All information that is of significance to the driver and the vehicle owner/operators is captured in an electronic memory device, be it flash style, disk or other.

All events that require driver acknowledgement or action are also logged.

The system may be equipped with a telecommunications device. The logged information can be accessed and sent to remote computer storage for later processing.

The advantages of this are:

• the information is available for improving the safety of the driver;

• training information;

• QA of results; • maintenance data is provided; and

• post accident information can assist finding the cause of the problem to improve future safety procedures or training. The logged information can be transmitted in real time to allow real time remote reporting and analysis if required.

Remote access can be via standard speed modem, Bluetooth wireless, LAN wireless, satellite, hardwired or GSM facilities. The information in real time will permit the latest safety parameters, instructions and track information details to be sent to the system rather than the preloaded information. Thus the system will always have the latest information to guide the driver and minimise derailment and accident risks.

Post processing

Information captured from the logging process can be post processed to reveal trends and extract track and truck maintenance information.

Examples of track related information relate to the track geometry measurements. For typical examples, but not limited to these are:

1. curves with excessive throw on the entry or exit;

2. curves with narrow gauge;

3. irregular curve transitions;

4. vertical curve irregularities; 5. corrugations of long, medium and short wavelength;

6. rail sections prone to cause vehicle hunting and broaching;

7. collapsing ballast and track structure; 8. excessive wear in points and switch running surfaces;

9. excessive head gauge wear;

10. road crossings with irregular ride;

11. areas of poor ride quality. This data can be calculated by the statistical or other processing methods from the logged data over numerous vehicles and daily operational patterns.

A particular advantage is that each vehicle is collecting the information on a daily bases rather than the infrequent bi-yearly, but more detailed measurements made by specialised track geometry measurement vehicles. Thus problems can be attended to before they become of significance and cause rail and wheel wear, further track degradation, track access problems, increased risk of track downtime and increased derailment risks.

Vehicle maintenance problems can be located statistically or with other mathematical techniques. Such, typical examples, but not limited to these are:

1. bent and misaligned frames,-

2. excessive back to back gauge of the wheel sets,- 3. excessive flange wear;

4. defective braking components;

5. wheel flats;

6. bearing problems ;

7. recalls for standard vehicle maintenance based on distance and time.

Advantages and Benefits

Loading Operational Safety Benefits

By determining a representative and/or static loaded arrangement of the vehicle then comparing against known input, permissible values for the road rail vehicle, the driver, will be issued with:

• safety warnings;

• advised of the maximum speed limit; • requirement to redistribute or reduce the loads;

• other maintenance requirements; and

• permission to proceed.

By determining the representative and/or actual dynamic loading applied to the rail system from the vehicle movement caused typically by, but not limited to: track - vehicle interaction, speed, and other causes, then measuring and computing time and spatial load variant changes then comparing against known, input, permissible values for the road rail vehicle, the driver will be issued with:

• safety warnings;

• updated speed restrictions; • load position changes ;and

• vehicle maintenance issues.

Vehicle Guidance Operational Safety Benefits

By determining the representative and/or actual lateral movement of the vehicle's rail guide wheels relative to the gauge face of the rail head, caused typically by but not limited to:

• the track - vehicle interaction;

• track conditions; • speed; and

• other causes e.g. steering incorrectly, then measuring and computing time and spatial position variant changes and comparing against known, input, permissible safety values for the road rail vehicle, the driver will be issued with:

• safety warnings ;

• track conditions;

• updated speed restrictions;

• urgent braking updates . By determining the representative and/or actual vertical movement of the vehicle's RGS wheels relative to the top surface of the rail head and the RGS lateral acceleration, caused by:

• the track - vehicle interaction;

• track conditions;

• speed; and

• other causes, then measuring and computing

• time and spatial position functions and comparing against known, input, permissible safety values for the vehicle, the driver will be issued with;

• safety warnings; • track conditions;

• updated speed restrictions;

• urgent braking updates .

Such variables that can be determined are yaw, pitch, roll (upper and lower body) , bounce, track gauge narrowing, vehicle resonance.

The derivation of the output from the guidance subsystem is not limited to just this subsystem. Other subsystems of the invention can also compute similar information. The outputs may the combination of one or more subsystem processes mathematically combined to yield a more significant and probable conclusion.

Vehicle Movement Operational Safety Benefits

By determining the representative and/or actual vertical and/or lateral and/or combined movement of the vehicle's RGS, caused by:

• the track - vehicle interaction; • track conditions;

• speed; and

• other causes . then measuring and computing time and spatial position functions and comparing the results against known, input, permissible safety values for the vehicle, the driver will be issued with:

• safety warnings;

• track conditions; • updated speed restrictions;

• urgent braking updates .

The derivation of the output from the movement subsystem is not limited to just this subsystem. Other subsystems of the invention can also compute similar information. The outputs may the combination of one or more subsystem processes mathematically combined to yield a more significant and probable conclusion.

Vehicle Tracking Safety Benefits

There is other information that reveals vehicle tracking issues over and above those described above .

By determining the acoustic emissions and vibrations from the rail interface on the vehicle of one, or more contact wheels, rubber or conventional rail wheels, which may be caused typically by, but not limited to:

• scuffing;

• flanging (rail wheel flange is in contact with the side of the head of the rail and is attempting to climb over the rail head to derail) ; • wheel flats (caused by the steel wheels skidding on the rail head and melting flat spots on the running surface) ;

• corrugation of the rail surface; • deflated or damaged road tyres, then measuring and computing time, spatial position and frequency functions and comparing the results against known, input, permissible safety values for the vehicle, the driver will be issued with: • safety warnings;

• track conditions alerts;

• updated speed restrictions;

• urgent braking updates;

• maintenance issues .

The acoustic and vibration devices are not limited to the rail interface area but may also reside in other areas in and/or on the vehicle.

The derivation of corrugation, scuffing, flanging and wheel flats is not limited to just this subsystem. Other subsystems of the invention can also compute similar information. The outputs may the combination of one or more subsystem processes mathematically combined to yield a more significant and probable conclusion.

Vehicle Brake Control System Benefits

By providing wheel speed and/or rotational speed of the contact wheels, either the road rail wheels or the tired wheels and measuring the relative ground speed, the slippage of the braking wheels can be determined.

With the provision of hydraulic disk or drum braking with electric activation and control, the wheel slip can be reduced by reducing the braking pressure on the wheel to regain rotation.

Modifications and variation may be made to the presenting invention without departing form the basic inventive concept. Such modifications and variations are intended to fall within the scope of the present invention.

Claims

1. A monitoring system for dynamically determining a current state of a mechanically self-guided vehicle comprising: sensors for measuring either or both of :

(iii) a vertical force on each of a plurality of wheels of the vehicle; and/or

(iv) a lateral acceleration on each of a plurality of wheels of the vehicle; means for processing the measurements from the sensors to determine the current state of the vehicle; and means for acting on the determined state .

2. A system as claimed in claim 1, wherein the sensors also measure wheel rotation velocity and/or vehicle velocity.

3. A system as claimed in claim 1, wherein the sensors measure the distance to the rail contact surface.

4. A system as claimed in claim 3, wherein the sensors measure the distance between the vertical contact surface of the track head and a reference point on the bogie assembly and the inclined distance between the rail head corner and the same or another reference point on the bogie.

5. A system as claimed in claim 1, wherein the sensors further measure: dynamic load on each wheel; vertical acceleration; dynamic track gauge; track curvature; vehicle operating conditions; driver attentiveness/vigilance; driver door open; driver seat belt .

6. A system as claimed in claim 1, wherein the means for acting on the determined state is an alarm.

7. A system as claimed in claim 1, wherein the means for acting on the determined state is an automatic control device for overriding control of the vehicle.

8. A system as claimed in claim 1, wherein the means for acting on the determined state comprises a means to determine whether the state falls outside one or more parameters and in that event said means acts on the state .

9. A system as claimed in claim 1, wherein the means for acting on the determined state includes one or more of: issuing an audible and/or visual alert indication; means to reduce the application of vehicle acceleration; means to activate the vehicle brakes; or a speed limiting means .

10. A system as claimed in claim 1, wherein the states determined include: speeding; overloading, load imbalance, shifting load; hunting; rail wheel flange riding; derailment; derailment risk; roll over risk; poor tracking; poor track conditions; tyre deflation; poor mechanical reliability; driver presence.

11. A system as claimed in claim 1, wherein the system further comprises recording means to record sensor measurements and/or the determined state in a log.

12. A system as claimed in claim 1, wherein the measurements from the sensors are compared to a base line state recorded in a database storage means.

13. A system as claimed in claim 1, wherein the system further comprises means for comparing the measurements from the sensors to measurements stored in a database and in the event that the measurements fall outside of one or more tolerances from those in the database an alarm is triggered.

14. A system as claimed in claim 1, wherein the vehicle is a road-rail vehicle.

15. A system as claimed in claim 1, wherein the means for acting on the determined state undertakes a dynamic action substantially immediately following determination of a state that requires action.

16. A method of monitoring the state of a mechanically self-guided vehicle comprising: taking measurements from sensors that measure either or both of : (iii) vertical force on each of a plurality of wheels of the vehicle and the velocity of the vehicle; and/or (iv) a lateral acceleration on each of a plurality of wheels of the vehicle; processing the measurements of the sensors to determine the current state of the vehicle; and acting on the determined state .