SYSTEM FOR OBTAINING AND MANAGING TYRE INFORMATION
Field of the Invention The present invention relates to a system for obtaining and managing tyre information.
Background Art The following discussion of the background invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge of the person skilled in the art in any jurisdiction as at the priority date of the application. Tyres represent a significant economic expense to any company operating a commercial fleet . This expense arises in two contexts: • the cost of the tyres themselves; and • the reduced efficiency of commercial vehicles resulting from tyre-related factors, such as low-pressure In the case of mining companies, this expense can reach millions of dollars. As a means of monitoring and controlling such expense, some commercial fleets have implemented tyre management systems. Typically, these tyre management systems record information relevant to the tyre pursuant to a manual inspection of the tyre.
It would be advantageous to overcome, or at least ameliorate, some of the aforementioned problems of the prior art by providing a system.
Summary of the Invention In a first aspect, the present invention provides a system for obtaining and managing tyre information comprising: a tyre having a sensor embedded therein or positioned external thereto; a reader unit; and a central database, the sensor is arranged to take measurements of factors that influence tyre performance and is further arranged to communicate those measurements to the reader unit; and wherein the reader unit is operable to communicate the measurements to the central database for storage. The measurements taken by the sensor may include inherent factors such as tyre pressure. Alternatively, or additionally, the measurements may include measuring of environmental factors such as axle temperature, ambient air temperature and barometric pressure. The sensor may be provided in a package with a microprocessor. The package will hereinafter be referred to as a "microprocessor" . The tyre may form part of any commercial or passenger vehicle. The tyre may, amongst others, be part of an aircraft, a construction or other type of heavy vehicle, or a truck. The reader unit may be positioned at a location commonly frequented by the type of vehicle concerned. For instance: • in the case of a commercial vehicle, the reader unit may be located at a commercial refuelling station;
• in the case of a truck, the reader unit may be located at a truck stop; • in the case of heavy equipment, the reader unit may be located at the park up area; and • in the case of aircraft, the reader unit may be located at the airport terminal .
The automation of readings of all aspects of tyre and wheel management in accordance with an embodiment of the invention will reduce the risk of human error. The automation of retrieval of data in accordance with an embodiment of the invention will reduce the cost of collecting and transcribing data. A loyalty program may also be implemented to encourage the operator of the vehicle to attend premises where a reader unit is located. The means of communicating measurements between sensor and reader unit may be many and varied. For example, a synchronisation signal may be used by either the microprocessor or reader unit to inform the other component that transmission may occur. The method of communication may be by means of RFID or other form of wireless communication. The microprocessors may also implement a "store and forward" approach to ensure that measurement data over a predetermined time period is communicated to the reader unit rather than just measurement data taken while microprocessors are within the range of the reader unit . In addition to the measurement information, the sensor may also transmit identification information.
Similarly, the reader unit may transmit the measurement information and identification information relating to itself to the central database. With this level of
information it is possible to track the location of the vehicle (by means of the identification information of the reader unit) . It is also possible, by using analysis algorithms included as part of the system or implemented as part of a separate tyre management system, to determine exactly what tyre is presenting anomalous data representing a potential problem. The central database may be able to obtain information from more than one vehicle fleet and thereby present holistic data on tyre performance. This information may then be used by commercial fleet managers and/or tyre manufacturers, amongst others, for their own analysis purposes. A plurality of reader units maybe provided, each uploading information to the database. In a second aspect the present invention provides a method of obtaining and managing tyre information comprising the steps of: providing a. tyre having a sensor embedded therein or positioned external thereto; providing a reader unit; taking measurements of factors that influence tyre performance by way of the sensor; communicating those measurements to the reader unit; and wherein the reader unit communicates the measurements to a central database for storage . In a third aspect the present invention provides a method of controlling a vehicle wherein the vehicle is controlled based on measurements made of the tyres of the vehicle. In a fourth aspect the present invention provides a system for controlling a vehicle wherein the system is arranged to control the vehicle based on measurements made of the tyres of the vehicle.
In a fifth aspect the present invention provides a database compiled during use of a system according to the first aspect of the invention or through operation of a method according to the second aspect of the invention. In a sixth aspect the present invention provides a method of managing a fleet of vehicles, including the steps of utilising a system in accordance with the first aspect of the invention for a fleet of vehicles, each vehicle including tyres having sensors embedded therein or positioned external thereto for providing information to the system. The driver of a vehicle within the fleet may be alerted should information relating to that vehicle indicate that the vehicle requires attention. The method may further include the step of generating a report should information gathered on a vehicle indicate that the vehicle requires attention.
Brief Description of the Drawings
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic view of a system for obtaining and managing tyre information according to the present invention; Figure 2 is a schematic view of an alternative embodiment of the invention in a heavy vehicle configuration; Figure 3 is a flow chart illustrating the flow of information in the system of figure 2 ; Figure 4 is a tree diagram showing an embodiment of the system;
Figures 5 to 7 are flow charts illustrating the interactions of components in the system; and Figure 8 illustrates a display for a driver of a vehicle .
Detailed Description of the Invention
In accordance with a first embodiment of the invention there is a system 10 for obtaining and managing tyre information. The system comprises: • at least one microprocessor 12 embedded in a tyre 14 of a commercial vehicle 16; • A independent sensor attached to a rim emitting a digital code which specifically identifies the rim; • At least one receiver-network-computer-display in the vehicle; • at least one reader unit 18; • a central database 20.
Each microprocessor 12 is adapted to record measurements relating to the state of the tyre 14 and transmit the measurement and identification data to reader units 18. This measurement data is not limited to common "inherent" measures, such as tyre pressure, but extends to environmental factors including axle temperature, ambient air temperature and barometric pressure and includes data from an integrated GPS module (Global positioning system) . The microprocessors 12 may be based on the MPXY8020/8040 Pressure and Temperature sensor produced by Freescale Semiconductor, Inc and Motorola, but may be based on products from another manufacturer.
Each reader unit 18 comprises a receiving unit 22 and a communications unit 24. The receiving unit 22 is adapted to transmit a synchronisation pulse 26 and, in reply, receive a data packet 28 from any microprocessors 12 within the transmission radius. The communications unit 24 is adapted to communicate data with the central database 20. The system 10 will now be described in more detail in the context of its use . As mentioned above, a microprocessor 12 is installed in the tyres 14 of a commercial vehicle 16. Details of the position of each microprocessors 12, such as left front tyre, right rear tyre, etc, are recorded in the central database 20 and associated with details identifying the commercial vehicle 16 in which the microprocessor 12 has been installed. The commercial vehicle 16 is free to operate as normal. Hub, tyre, and wheel are separately identified in the database. A separate sensor may be attached to a rim to specifically identify the rim which will transmit independently to the receiver. A reader unit 18 is placed at a location frequented by the commercial vehicle 16 on a regular basis. In the example being described, the reader unit 18 is located at a commercial refuelling station 25 not operated by the operator of the commercial vehicle 16. The reader unit 18 constantly emits a synchronisation pulse 26. The vehicle operator may operate his/her own reader unit at any location at their option. As the commercial vehicle 12 pulls into the commercial refuelling station, each microprocessor 12 receives a synchronisation pulse 26. In response to the synchronisation pulse 26, the microprocessor 12 transmits
to the reader unit 18 that emitted the synchronisation pulse 26 a data packet 28 comprising: • identification data; and • measurement data. In the example described, the identification data comprises a first unique identifier. The measurement data comprises at least one measurement relating to the state of the tyre 14. The reader unit 18 then operates to transmit an additional data package 30 to the central database 20. The additional data package 30 comprises: • data packet 28; • identification data relating to the reader unit 18 (in the form of a second unique identifier) . The central database 20 operates to deconstruct the additional data package 30. The first unique identifier is used to identify the tyre 14 and commercial vehicle 16 to which the measurement data relates . The record of the central database 20 representative of that tyre
14/commercial vehicle 16 combination is then updated to include the transmitted measurement data. The record of the central database 20 representative of the commercial vehicle 16 is also updated to include the second unique identifier in a field representing the last known location of the commercial vehicle 16. As the commercial vehicle's 16 purpose for pulling into the commercial refuelling station 25 is most likely to obtain goods and/or services, the system 10 is integrated with a loyalty program. The loyalty program requires : • the operator of the commercial refuelling station 25 to purchase, install and maintain at
least one reader unit 18 at the commercial refuelling station 25; and • to provide economic benefits to the operator of the commercial vehicle 16 on attainment of certain targets (such as accumulation of a predetermined number of points) . In return, the operator of the commercial refuelling station 25 can seek to maintain, or increase, patronage by commercial vehicle 16 and other vehicles operated by the same party as operates commercial vehicle 16. As should be apparent to the person skilled in the art, the information recorded by the system 10 can be used in a variety of manners by various parties. To elaborate, operators of commercial vehicles 16 can use the information stored in respect of each commercial vehicle 16 to: • determine whether any tyre 14 of the commercial vehicle 16 is recording measurements outside of pre-set tolerance levels; • determine the approximate position of a commercial vehicle 16 and its whereabouts over a period of time; • analyse the measurement data on a collective basis to quantify economic benefits provided by maintaining tyres 14 within the pre-set tolerance levels; • determine objective criteria for tyre comparisons to determine the "best fit" tyre for the operator of the commercial vehicle's 16 commercial activities. On a holistic basis, the central database, when used to store information from more than one operator of a fleet of commercial vehicles 16, can also provide useful
data to tyre manufacturers as to the performance of their tyres 14 in "real-world" conditions. Thus, the information can be used to direct the research, manufacturing and/or marketing activities of tyre manufacturers . In either the case, the means of accessing the data stored in the central database 20 is as would be known to the person skilled in the art. It should be appreciated by the person skilled in the art that the above invention is not limited to the embodiments described. In particular: • The system 10 may be adapted to provide real-time tyre information to the operator of the commercial vehicle 16. This information may be displayed via an add-on unit or incorporated as part of the instrumentation panel located in the dashboard. • The central database 20 can be a simple data repository operable to interact with a tyre management system for the required analysis. Alternatively, the central database 20 could form part of a modified tyre management system. • The central database 20 can be integrated into a reader unit 18, with "slave" reader units 18 operating to transmit data to the integrated reader unit 18. • The method of communication between reader unit 18 and central database 20 can be by wired or wireless transmission. Further, no part of the invention is limited to any particular data transmission protocol. • The microprocessor 12 may transmit measurement data taken over an immediately preceding period of operator-specified duration.
• Alternatively, the microprocessor 12 may transmit measurement data recorded since the last transmission occurred. In this arrangement, it is also preferable for the receiving unit 22 to provide an acknowledgment to the microprocessor 12 on a successful transmission of data packet 28. In this manner, the microprocessor 12 can operate to delete, or overwrite, recorded measurements that have been successfully transmitted to the receiving unit 22. • In a similar manner, it is preferable for the central database 20 to provide an acknowledgment to the reader unit 18 on successful transmission of data package 30. If no such acknowledgment is provided, the reader unit 18 can then operate to store the data package 30 for later transmission and delete the data package 30 following successful transfer.
• The microprocessor 12 and reader unit 18 may be adapted to provide full identification details as part of data packet 28 and data package 30, rather than unique identifiers.
• The synchronisation process described above may be reversed. In such an arrangement the microprocessor 12 sends the synchronisation pulse and waits for a response from a reader unit 18. • The reader unit 18 may be placed at other locations. For example, a reader unit 18 may be placed at a direct supplier's premises. Alternatively, the reader unit 18 may be placed at an indirect supplier's premises, such as a truck-stop eatery. • The central database 20 may be adapted to record location data for a commercial vehicle 16 over a period of time. This then allows the operator of the commercial vehicle 16 to determine, as best as
- Im possible, the route a commercial vehicle 16 has taken during that time period. • The invention is not limited to the loyalty program described above . Any loyalty program may be implemented that provides some incentive to the operator of the commercial vehicle 16 (and/or its driver) to attend premises where a reader unit 18 is located. Further, the operator of the commercial vehicle may undertake to pay for, or reimburse some of the expense involved in purchasing, installing and maintaining the reader unit 18.
Referring to Figure 3 , it can be seen that the data relating to the tyre is stored in Maintenance Database 29. The information in Maintenance Database 29 may be combined with tyre, rim and hub inventory information and cost information in General Ledger 31. The General Ledger allows management to manage a fleet of vehicles by planning future decisions.
The following features are also implemented:
- interrelationships with other chassis systems (Advanced
Driver Assistance Systems -ADAS) 32.
- Chassis integration - linking the braking, steering and suspension systems to form a single unified network that coordinates the functioning of each system. The system interfaces are intricately integrated through an internal network and each processor, and take inputs from existing vehicle management systems VMS 34 and ADAS 32.
The data the wheel-tyre monitoring capabilities deliver which are useful for chassis integration include
forces whilst cornering to adjust braking, suspension and stability and drive transmission. This data assists, depending on momentary driving situations at interrelated modules. The benefits, in terms of driveability, safety, comfort etc. are to improve drive chain transfer of energy, braking efficiency, engine performance, adjust all interrelated components of the tree dynamically. The tyres telling the suspension system when the vehicle is going around curves enabling it to jack up the suspension at the outside wheels, or when it is braking to jack it up in the front .
The Λ System' for obtaining and managing tyre information measures the changes in pressure and temperature for each individual tyre as the vehicle moves along. One example where such changes in Pressure will occur is cornering, where the outer wheels are experiencing pressure increase, whilst the inner wheels are subject to a corresponding pressure decrease. These changes in pressure can be used as additional data input to aid chassis integration as follows:
• Changes in tyre pressure and therefore force on tyres • Determining the dynamic delta or changes in pressure that occur between a unilateral bank of tyres and or the pressure changes that occur whilst cornering • Determining the dynamic delta • monitoring the delta or discrepancy between one bank of tyres versus the contralateral or opposite bank
• using wheel position through the steering column in the case of front wheel steering to provide feedback • providing feedback to the ABS system, to adjust forces during brake application and reduce the risk of loss of traction and wheel spin • optimise braking forces whilst cornering by increasing forces to improve traction on the inside tyres • supply positive effects of feedback control FB to the suspension system to keep the tray level and have input into the body module • Increase torque to the outside tyre through the drive train
Giving input during braking according to wheel load so that the ABS 36 can be optimised in terms of brake pressure for each individual wheel . Similarly to cornering, pressure differentials emerge when a vehicle is braking. The front wheels are experiencing additional load, hence increased pressure. During braking the rear wheels register a reduced load, hence reduced pressure. ABS 36 (Automated Braking Systems) receive sensor inputs from wheel spin sensors to compare wheel spin rates during braking with the actual speed of a vehicle. If there is a significant difference between what the spin rate of the wheel should be (angular velocity) according to speed and what it is, the wheel's brake will be released until its speed is back in spec or to its predicted speed or angular velocity. If the ABS 36 can additionally gain information such as a pressure gradient change between the opposing wheels and the actual pressures from wheels, it is able to
anticipate changes in wheel spin before they actually occur, which is a significant improvement for the working algorithms of such systems . Giving feedback to the suspension system regarding the roughness or otherwise of the road surface so that ride height can be adjusted as required. As the vehicle travels, it will encounter undulations in the road's surface. These undulations affect the pressure within the tyre 14; hence, they can be picked up by the 'System' . The pressure variations are more pronounced as the road surface gets rougher, but they will also be affected by the vehicle's speed. These variations register as superimposed over 'slow' changes like those caused by braking or cornering. The 'System' has the ability to gain speed input from other vehicle systems and is able, through these 'fast' pressure variations as described, to calculate the roughness of the road surface. If the vehicle is equipped with ABC (Active Body Control) or ESP (Electronic Stability Program) systems, input from the
'System' could further improve the reaction of chassis components like adjustable dampers to the road encountered, hence automatically adjust ride height, for example . For the 'System' to know other conditions of the road surface, it can have "Telematics" enabled, i.e. it receives information about the prevailing road condition, based on vehicle position known through GPS 38 (for example) , and from information service providers outside the vehicle. Other advance driver warning systems which can be provided by the system include • vehicle to vehicle anti collision
• Road weather management systems • Traffic Incident management systems • Arterial operations and traffic control systems • Highway-rail intersection systems • Emergency management and public safety systems • Traveller information systems • 3 dimensional road maps linked to GPS enabled systems The engine/driveline module also benefits as follows: - Interaction with the engine/driveline module - giving useful data to help smooth power output when the going gets rough, to prevent wheel spin when there are significant variations of maximum transmissible torque due to undulations.
Input of further information enhances the performance of the whole chassis/driveline setup. Interaction with the body module via telematics enablement and utilisation of data regarding location, prevailing road surface condition (dry, wet, icy etc.). Information regarding the road surface condition is obtained via data input.
The system can determine changes in gradient along the route. Again, similarly to cornering and braking, there are changes in tyre pressure when a vehicle encounters a slope. If going uphill, pressure in rear wheels increases with a corresponding decrease in front wheels; going downhill, the reverse occurs. The 'System' is able to recognise these changes. In correlation with speed information, the 'System' is able to determine whether it deals with acceleration or going uphill (which may read the same in terms of pressure) ; likewise, it is
able to distinguish between downhill and braking. Alternatively, an inclinometer can be used to measure gradient . Location-based information (if the system is Telematics-enabled) can further improve security on these determinations. The road surface and gradient will be assisted through external input obtained via data input from third party providers . Information like this can enhance the performance of systems like cruise control or its more sophisticated permutations, like adaptive cruise control through feedback to provide intuitive responses. The wheel monitoring system uses this information acquired via the body module to further enhance the interaction with engine/transmission regarding torque output, and with the integrated chassis function to optimise the seamless performance of the whole setup. Chassis integration relies on 'sensor fusion', i.e. the evaluation of many sensor signal inputs to optimise a total system performance. The 'System' optimises the seamless performance of the whole system because it is able to contribute valuable sensor input for a variety of vehicle dynamics parameters. There may be automatic input into other vehicle systems, information flow to the operator driving the vehicle and/or a remote control centre/vehicle fleet manager or similar.
External forces
There is a relationship between the pressure and force (i.e. weight) transferred from the truck through the tray to the wheel and thence the ground. The weight of the
vehicle rests on its tyres, resulting in pressure changes. This pressure is modulated by vehicle dynamics as described above. This is only static. Once the vehicle is moving, then there are lateral, longitudinal & downward forces generated by the vehicle movement, its acceleration/deceleration etc. and all this is superimposed by the undulations in the road surface. It is possible to determine the total load of a vehicle and the proportional distribution of a load through the medium which is on contact with the road. It is also possible to ascertain differential load management for load that are distributed evenly or homogenous loads and unevenly distributed loads or non homogenous loads. There may be an impact reflecting in increased road maintenance due to unevenly distributed loads, and the impact may be reduced by improving the distribution of the load. Calibration of differential load management device would occur at required regulatory truck stops for mandatory weigh data acquisition. Traditional load management devices require vehicles to drive over a large scale called a weigh- bridge or WIM (Weigh in motion device) . These devices are reference devices. The present system can be used to determine the load balance on the vehicle when stationary, i.e. whether the load is evenly distributed. The system assists in allowing each wheel to take an equal load by helping to determine the position of a load on a vehicles tray. Again, this can be determined via pressure differentials between the wheels or pneumatic tyres. This is a valuable capability to have to support asset tracking applications, as loading and unloading of vehicles can be monitored. Telematics enhancement enables determination of the locations where the change in load occurs.
Load can also be monitored specifically at locations where excessive load may have environmental impact such as loading docks, wharf facilities, in timber haulage vehicles, dangerous terrain and heavy earth moving vehicles to optimise vehicle management and reduce environmental impact such as road wear. The Tyre Pressure Monitoring System (TPMS) allows the vehicle to measure the difference in pressure and therefore weight pre and post loading. It measures the weight of the load using the change in tyre pressure, the use of gas laws and integrating tyre specific data. This data is specific to manufacturer and category of the make and model of a particular tyre. The inventory management system provides automatic identification of a tyre through database access. Regarding the distribution of load, it is measured by comparing the absolute weight over the combined unit to that from the banks of wheels and tyres. Reference is made to the preloading pressure from when every thing is ideal, i.e. when cold and when moving very slowly and when they are stationary. This is done by measuring the change before and after loading of a particular tyre or group of tyres on an axle, relative to other tyres to determine how the load is distributed. Tread thickness may be measured by high frequency ultrasound, a conduction medium and interpreted through a mathematical algorithm. It may be contained in a hand held device. It may be contained on the wheel bay to automate tread depth management and integrated with the wheel management system and the data stored in a mass data storage system and transmitted to a distal location and the cabin of a vehicle. This data may be transmitted to a
web enabled fleet management system for commercial vehicles
A reader for inventory management may be incorporated into the fleet management system which operates to gather data from the tyre sensor independent of the rim sensor and the hub sensor. It may be installed into a fixed location in a wheel arch within the confines of a vehicle. Fixed points may be located at depots where vehicle drive over a fixed point and simultaneously download inventory management data and tread depth measurements Fixation points could also be located at weigh bridges and suited to calibrate.
A temperature measurement device 40 may be provided which measures temperature of a remote surface by infra red spectroscopy. It may be inserted through a rim inspection port. It may be permanently installed. It may have a cylindrical housing. It operates to measure internal rubber temperature surface and is integrated with data transmission to central processing unit 42.
Data stored on a Mass storage device may be transmitted to a distal location for review by fleet managers . Data is acquired for review by fleet managers or by third party for data analysis.
A self mapping feature may be provided using an existing active neural net incorporated into each sensor device. Each chip spatially configures themselves into a network. Independent of a fixed rim hub and tyre con iguration each individual component self maps.
Addition trailers and or a bogey will self map on installation each component for inventory management and wheel and pressure management. The self mapping feature can be achieved using the ZigBee Wireless Network protocol (IEEE802.15.4) . ZigBee chips talk to each other. They are low cost and low battery output. They develop an active neural network and have the ability to create a spatial configuration and do not require formal programming or hardwiring of a location. Rim and Hubs if linked with
ZigBee have inherent inventory identifiers and are able to spatially configure themselves on a map of a vehicle together with a tyre. These specific digital codes also facilitate security.
Data acquisition entails load management systems.
Inventory management for a rim is independent of tyre management as each unit may be separated. At least one sensor is required per wheel for pressure and temperature monitoring. Each sensor has a digital identifier which is transmitted with every signal . Further sensors may be added to provide system integrity checks . Further additional identification chips may be inserted onto the rim and placed within the tyre itself. They can be used to track a wheel assembly, rim, hub or tyre throughout the life of the component and will facilitate regulatory management of Rims. This will automate the retrieval of data and enhance vehicle safety. These identification codes or serial numbers encoded into the sensor, track and monitor the component through out its useful life.
Additional sensors may read existing Tyre Manufacturers RFID tags and can be incorporated into the system. These signals from these devices support inventory management and security functions. RFID technology as developed by Sokymat and Dunlop, for instance, allows these implanted Inventory devices to be very robust and therefore reliable even during vulcanisation and retreading. The principal sensor measures the pressure (changes) within the tyre and transmits those remotely to a chassis- fixed receiver. A combination of sensors, receivers (depending on vehicle configuration) and one CPU makes up the 'System' .
System integration
The vehicle data is integrated into a fleet management system. This allows for a combination of fleet management system and tyre analysis including rim management and tyre management . The system is intuitive and warns the driver of exception reports when, for whatever reason, transmission of data is not possible due to environmental issues, proximity to GPRS/CDMA networks or an inability to transmit to a satellite. This requires load parameters which are derived to be calculated in the vehicle.
The control Module Environmental temperature and pressure readings are used to correct for the variations in the transwall pressure due to changes in temperature and pressure which affect the internal pressure and temperature of a tyre which inturn affect the volume of this vessel .
It should also be appreciated by the person skilled in the art that features described above, not being alternatives or substitutes, can be combined to form additional embodiments that fall within the scope of the present invention. In this 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 .