Patent Application
20070279203
One or more implementations of the invention will now be described with reference to the attached drawings. The invention relates to a monitoring system and associated method wherein tire data is acquired and transmitted from one or more sensor modules to a central control unit and/or an external monitoring unit in a reliable and efficient manner. In one particular embodiment the invention relates to a tire monitoring system and associated method.
The invention, in one embodiment, is directed to an improved system and method of collecting and transmitting data in a monitoring system, such as tire data in a tire monitoring system of a vehicle, e.g., an automobile, a truck, a bus, a van, a recreational vehicle, a motorcycle, a go-cart, a race car, an earth mover, a crane, a backhoe, a Humvee, a troop transport, a fire truck and the like. It is to be appreciated that although this disclosure applies to a vehicle employing rubber tires, it can equally apply to any system that remotely monitors temperature, pressure, etc., for example, a pressurized heating system in a remote location, a robotic manufacturing area, a locomotive, a track driven armored vehicle, etc.
In one embodiment, the invention relates to an improved tire monitoring system and design for determining tire conditions by employing contactless sensors in tire sensor modules configured with central control units and notifying the appropriate personnel if an unsafe condition occurs, utilizing an external control system. Contactless sensors are defined as devices that are not in contact with the surface on which the chosen parameter is being measured. A list of contactless sensors includes but is not limited to: anomorphic beam-conditioning optic sensors, angular sensors, barcode scanners, bifurcated optical fiber bundle sensors, capacitive angular-position sensors, charge-coupled device chemical sensors, chips, coupling linear movement sensors, depth mapping sensors, dimensional metrology sensors, displacement sensors, fringe projection sensors, gas detection sensor, high-resolution fiber optic sensors, holographic interferometry sensors, image sensors, inductive switches, inductive sensors, inductive switches, infrared sensors, iris scanning sensors, diodes, scanners, sensors, load sensors, optical encoders, magnetic strip sensors, piezoelectric effect sensors, photo sensors, photoelectronic sensors, pulse wire sensors, permanent magnet linear contact-less displacement (PLCD) sensors, pressure sensors, proximity sensors radio frequency sensors, reed switches, RFID sensors, shank-based system sensors, shearography sensors, sub-micron measurement sensors, surface wave sensors, 3D control sensors, temperature sensors, torsion sensors, and ultrasonic sensors.
The invention in this embodiment makes use of the contactless sensors to determine tire temperature, pressure, tire loading, tire symmetry, and/or other key tire characteristics, for example, flat spots, out-of-round conditions, tire re-tread de-lamination, tire wobble, tire defects, foreign objects in tires (e.g., a nail), tire failure, and the like. The invention in another embodiment also makes use of predictive analysis to determine or predict when an unsafe condition will occur, e.g., when the tires need replacing based on the tire history for a specific vehicle, when the tire treads will be out of spec., etc.
Another embodiment of the invention relates to a tire monitoring system design. The tire monitoring system employs and is associated with one or more contactless sensors operable within a tire sensor module. The tire sensor modules are associated with a tire and/or a tire location on a vehicle and configured to acquire tire data associated therewith. The tire monitoring system also employs a central control unit that is communicatedly coupled to the various tire sensor modules, and configured to transmit and receive data thereto. The central control unit is also configured in one embodiment to set a predetermined time interval at which the tire data is to be transferred, thereto. More particularly, the central control unit is operable to dictate predetermined time intervals for multiple tire sensor modules (when employed) such that the predetermined time intervals are unique and do not overlap one another in absolute time. Utilizing this approach, tire data collisions at the central control unit are eliminated.
In accordance with yet another embodiment of the invention, the tire monitoring system further comprises one or more external control units operably associated with the central control units of multiple vehicles and the associated tire sensor modules. In addition, the external control units can order decided time intervals, when the central control units and/or the tire sensor modules will communicate with the external control units, and determine whether a specific central control unit or tire monitoring system is authorized to communicate with the external control units. In this way, data collisions between the external control unit, the central control units and tire sensor modules are done away with. The external control unit in one embodiment of the invention has the highest level of authority in terms of communication with respect to the central control unit and the tire sensor module. The central control unit has the second highest level of communication authority and the tire sensor module the lowest level of authority.
In accordance with another embodiment of the invention, a system for identifying a location of the various tire sensor modules associated with the vehicle is provided. The central control unit is physically located in the vehicle and receives data from the various tire sensor modules mounted on the vehicle frame. For example, the central control unit may receive infrared thermal data associated with each tire. By comparing a thermal signature from each of the tire sensor modules to the data stored in the central control unit, the central control unit is able to identify a location of the tire sensor modules and/or the tires by evaluating the thermal signature of the data received to the thermal signature stored in the central control unit's memory.
Turning to
In yet another embodiment, the tire sensor module 102 can also be operably coupled to the external control unit 108 and configured to transfer the acquired tire data to the external control unit 108 based on, for example, proximity of the tire sensor module 102, external control unit authorization, available storage memory 104, and the like. As will be further discussed in greater detail below, a clock circuit can operate to dictate a timing in which acquired tire data can be transmitted from a tire sensor module transceiver via an TSM antenna to the central control unit 106 mounted on the vehicle. In one embodiment of the invention, the TSM 102 transceiver and the central control unit 106 antenna can cooperatively operate to transmit tire data wirelessly at any suitable UHF frequency, for example, in one embodiment about 315 MHz.
In another embodiment of the invention, each tire sensor module 102 employed in the tire monitoring system 100 can be operable to enter a low power mode, wherein the power of the battery can be minimized and thus conserved. In one example, in the low power mode, all the components except for the clock circuit are switched off. The clock circuit, upon reaching a predetermined time interval (as will be discussed and more fully appreciated infra), can activate the other components, wherein, for example, the infrared sensor acquires, for example, tire temperature data, distance measurements, and the like, transferring such data to the central control unit transceiver via the tire sensor module controller. In one example, a contactless tire parameter sensor only acquires tire data during the respective predetermined time interval, however, in alternative embodiments the sensor may periodically activate, acquire data and save such data locally, either at the TSM 102 in the storage memory 104 or in the central control unit 106. Subsequently, during the predetermined time interval, multiple segments of tire data can be transmitted. It is to be appreciated, that although this disclosure refers to contactless sensors, the invention can make use of contact type sensors as well, for example, load cells, thermocouples, and the like.
In yet another embodiment of the invention, the predetermined time interval between measurements can be increased when it has been determined that the tire performance has degraded to a predetermined threshold level, for example, the tire tread has reached a given minimum thickness, the tire IR temperature reading indicates “hot spots”, and the like. In other words, when the likelihood of a tire failure has increased, the number of measurements per a given time can also be increased, so that the driver can be warned of a possible catastrophic failure (e.g., a tire blowout) prior to the occurrence of such an event. This can allow the tires to be changed out based upon scheduled maintenance rather than more costly unscheduled failures. Tire data or “data” can also include, but not be limited to the following: a properly inflated tire, an under-inflated tire, an over-inflated tire, a de-laminating tire re-tread, an unbalanced load in a vehicle, a tire that needs to be replaced, an unbalanced tire, exposed ply, tire bulge, a bald tire, insufficient treads, a foreign object embedded in tire, a tire out-of-round condition, an over heating tire, tire flat spots, tire overloading, tire structural defects, exceeding a tire's rated speed, tire installation errors, tire leaks, parking on too steep an incline, an incorrect tire or combinations therewith.
In one embodiment of the invention, the TSM 102 transceiver can contain a modulator/demodulator that can be configured to receive the tire data and modulate such data for UHF transmission. In one embodiment of the invention, tire data can be frequency modulated and converted for transmission to the central control unit 106.
The central control unit (central control unit) 106, in another embodiment of the invention, can comprise a transceiver that can be configured to receive transmitted tire data from various tire sensor modules 102 via an antenna. The central control unit 106 transceiver can contain a modulator/demodulator that, upon receipt of the tire data, demodulates the data and provides such demodulated data to a central control unit controller. The central control unit controller, in one embodiment, comprises a master clock, which may be called a real-time clock (RTC) that can be employed by the central control unit controller for synchronizing the clock circuits of the various tire sensor modules 102 thereto. The clocks can be synchronized to both the central control unit 106 and the various tire sensor modules 102 to operate synchronously with respect to the transmission and receipt of the tire data, as well as with respect to other information.
In yet anther embodiment of the invention, the central control unit controller 106 can be operably coupled to a vehicle bus interface that can be operably associated with the central control unit controller via a vehicle bus. For example, if the central control unit receives tire data from one or more of the tire sensor modules 102 that are outside a prescribed range, the controller may send an alarm or status message over the vehicle bus for communication of the status condition to a user, for example. Each of the central control unit components can be coupled to the vehicle battery via a voltage regulator in order to prevent voltage or current swings due to changed loading, etc.
In accordance with one embodiment of the invention, the central control unit 106 can be configured to assign unique predetermined time intervals to each of the tire sensor modules 102, wherein each of the predetermined time intervals are at different times and do not overlap one another in the time domain. Such time intervals can then be employed by each tire sensor module 102 to awaken from a low power mode, acquire tire data, and transmit such tire data back to the central control unit 106. By having each predetermined time interval unique, tire data collisions will not occur at the central control unit. Consequently, the invention eliminates the inefficient conventional anti-collision algorithms, wherein various modules send multiple blocks of redundant data, etc. In addition, since each block of data need only be sent once during a predetermined time interval, reduced electromagnetic transmissions occur, which may be advantageous in complying with various emission regulations in certain regulatory jurisdictions. Further, since each tire sensor module 102 has a predetermined time allocated thereto, the various components associated therewith can be switched off (except for the clock circuit), so that minimal current is drawn from the battery, thereby substantially improving the life of the various tire sensor modules 102.
In addition in an alternative embodiment of the invention, the external control unit 108 can be configured to be functionally connected to the vehicle bus interface that can be operably associated with the central control unit controller and a tire sensor module controller via the vehicle bus. For example, if the external control unit is within range of a CCU 106 on a vehicle, the ECU 108 can request to receive tire data from the central control unit 106 and/or one or more tire sensor modules 102. The central control unit 108 can be coupled to an external power source via a voltage regulator in order to prevent voltage or current swings due to, for example, vehicle startup, etc. The central control unit can transmit a signal at a predetermined time, for example, when the vehicle has returned to a rental location, the central control unit 108 can determine if the engine on that vehicle has been off for thirty minutes and if that condition has occurred, the CCU 108 can transmit a signal to determine if there is an external control unit 108 within range. If there is an external control unit 108 within range, the central control unit 106, for example, can initiate communication with it.
In yet another embodiment, numerous vehicles, for example, a fleet of rental cars can be returned to a single location where all vehicle central control units 106 (authorized to communicate with external control unit) can be queried by the external control unit 108 to, for example, either download and store data in an external database, wherein such data may be employed to determine those vehicles that require tire maintenance, for example, to identify those vehicles that should be scheduled for tire replacement in the near future based on predictive analysis, etc.
In accordance with yet another embodiment of the invention, the external control unit 108 can be configured to determine a unique predetermined vehicle number associated with each vehicle in a fleet. The external control unit 108 can then assign unique predetermined time intervals to each of the central control units 108 on each of the vehicles, wherein, in one example, each of the predetermined vehicle time intervals are at dissimilar times and are not overlapping each other in absolute time. Such time intervals can then be utilized by each central control unit 108 on each vehicle to transmit specific vehicle tire data to the external control unit 108, and the like. By each vehicle central control unit 106 having each predetermined time interval unique, central control unit tire sensor data transmission conflict will not occur between the various vehicles. As a consequence, the invention can more effectively provide data transmission, eliminate or reduce wasted transmission time, etc. An added advantage of the invention, whereas a single individual can often ignore a warning on the vehicle dashboard, e.g., regarding tire pressure, the pressure data will less likely be ignored if it is reported, at the fleet level, to numerous individuals responsible for vehicle maintenance, and the like.
Referring now to
In accordance with yet another embodiment of the invention, the central control unit 204 can communicate with the tire sensor modules by employing, for example, wireless communication, etc. The tire sensor data can be shared employing a variety of mediums, the Internet, hard wiring, Blue-tooth, ultra-wide band, etc. The contactless sensors that can be utilized are, for example, infrared sensors, sensors, RFID, scanners, ultrasonic sensors, inductive sensors, photoelectronic sensors, pulse wire sensors, permanent magnet linear contact-less displacement (PLCD) sensor, proximity sensors, and the like.
In one embodiment of the invention, each tire of a vehicle 202 has a specific tire sensor module associated therewith, wherein the specific tire sensor module can be configured to acquire one or more tire parameters (e.g., a tire pressure), and transmit the tire data to the central control unit 204. In yet another example, if the right front tire 208 begins to fail, or shows indications that it may fail at some future time, the driver can be alerted with a dashboard signal that “Right Front Tire needs to be replaced”, for example. In another example if the right rear tire 210 has been replaced, the central control unit 204 can determine that the tire has been replaced, as discussed infra, and alert the service personnel that the tire was changed. In addition, the central control unit can determine that spare tire 214 is missing and inform the customer or maintenance personnel of that condition and/or alternatively, an alarm can be generated, a visual display can be presented, a voice message can be created, and the like.
Referring to
In one embodiment, the external control units 304 at each location can be operably coupled to an external power source, for example, 120 volts AC, 240 volt AC, and the like, and each external control unit 304 is configured to receive the tire data from all of the central control units 302 associated with the various vehicles at the first location that are authorized to communicate with the external control unit 304. The external control unit 304 can be designed so that it can determine what specific vehicles are on the lot at a given time based, for example, on a unique vehicle identifying number. The vehicle number can be read by the external control unit 304 utilizing, for example, RFID tags, barcode readers, magnetic strips, wireless communication and the like, associated with a specific vehicle and central control unit 302.
In one embodiment of the invention, an optimized vehicle algorithm can be employed to determine the optimum approach to downloading central control unit 302 tire data from the various vehicles, based on factors, e.g., priority, vehicles reserved by customers for the following day, vehicles associated with the central control units 302 that have lowest battery power, vehicles associated with the central control units 302 that have highest reported tire anomalies, etc. The external vehicle tire monitoring system 300 has benefits over conventional tire monitoring systems, as the tire data can be downloaded and reviewed by an organization rather than an individual and therefore can be less likely ignored if a hazardous condition is identified. In more detail, the external control unit 304 can operate on standard power as opposed to the battery power and therefore the data can be received and stored more reliably. Furthermore, in the event of a tire anomaly on a vehicle, the system has more communication paths available, for example, an alarm could be sounded, a blinking light could indicate the vehicle number and the tire(s) that need to be replaced, an e-mail could be sent to a manager, a report could be generated, a warning light could be activated in the vehicle when it is turned on, etc. In operation, the vehicle tire monitoring system 300 can help maintenance personnel to schedule and perform preventative maintenance on a vehicle rather than performing more expensive unscheduled maintenance.
In yet another embodiment of the invention, each tire sensor module 402 employed in the tire monitoring system 400 may be operable to go into a conservation power mode, wherein the power draw on the battery 410 is minimized and accordingly conserved. In one example, in the conservation power mode, all the components except for the TSM clock circuit 414 are switched off. The TSM clock circuit 414, upon reaching a predetermined time interval (as will be discussed and more fully appreciated infra), activates the other components, wherein, for example, the IR temperature sensor acquires tire temperature data and transfers such data to the TSM transceiver 412 via the tire sensor controller 408. In one example, the contactless tire sensor 418 can acquire tire data during the respective predetermined time interval, however, in alternative embodiments the sensor may occasionally turn on, obtain data and save such data locally. Subsequently, during the predetermined time interval, multiple segments of tire data and/or tire anomaly data may be transmitted to a local memory associated with the transceiver 412.
In yet an additional embodiment of the current invention, the TSM transceiver 412 can contain a modulator/demodulator that can be arranged to receive the tire data and modulate such data for UHF transmission. In a further embodiment of the invention, the tire data, for example, can be frequency modulated (or amplitude modulated, or both) and converted for communication to the central control unit 404.
In another embodiment, the central control unit (CCU) 404 can comprise a central control unit transceiver 422 that is configured to obtain transmitted tire data from the diverse tire sensor modules 402 via a central control unit antenna 420. The central control unit transceiver 422 can include a modulator/demodulator that, upon receipt of tire data, demodulates the data and provides such demodulated data to a central control unit controller 424. The central control unit controller 422, in one embodiment, comprises a central control unit master clock 426 (a real-time clock (RTC)), that can be engaged by the central control unit controller 424 for synchronizing the clock circuits of the various tire sensor modules 402, thereto. Since, in one example, such tire sensor module and central control unit clocks, 414 and 426, are synchronized, both the central control unit 404 and the various tire sensor modules 402 can operate in synch with respect to the transmission and receipt of data.
In yet another embodiment, the central control unit 404 can include a central control unit vehicle bus interface 428 that is operably associated with a central control unit controller via a central control unit vehicle bus 430. For example, if the central control unit controller 424 receives tire data from one or more tire sensor modules 402 that is outside a prescribed range, the controller 424 may send an update or warning alert over the central control unit vehicle bus 430 for communication of the status condition to a user, for example. Each of the central control unit components can be coupled to the vehicle battery via a voltage regulator 432 in order to prevent voltage or current spikes.
In another embodiment, the tire sensor modules 402 and/or the central control units 404 can be operably coupled to the external control unit(s) 406 that are within range of the at least one vehicle. A synchronization algorithm can, for example, be employed within an external control unit (ECU) controller 434 to synchronize an external control unit real time clock (RTC) 436 with the TSM clock 414 and/or the central control unit clock 426. By employing the synchronization algorithm the various clocks 414, 426 and 436 are synchronized which can allow, for example, the transmission, receipts, storage, etc., of data by the tire sensor modules 402, the various central control units 404 and the external control unit 406. In yet another embodiment, the external control unit 406 can identify and communicate with several vehicles when the vehicles are at a single location. As an example of this process, the external control unit 406 can receive AC power 438 at a rental car return location and can communicate with the vehicles transmitting and receiving tire data utilizing the external control unit transceiver 440 and the external control unit antenna 442. The tire data can be stored in the external control unit tire database 444, which, employing an algorithm can determine what action needs to be taken based on the tire data, for example, tires can be inspected, tires can be replaced, tire condition can be recorded, etc.
In yet another embodiment of the invention, the tire data collected can be analyzed using predictive analysis in order to optimize tire life. The data stored in the external control unit 406 can be employed with an analysis component to determine, for example, the optimum time to rotate tires, the number of warnings that have occurred with a specific tire, the tread life of a specific tire, etc. It is to be appreciated that, although a contactless sensor is disclosed herein, contact sensors can be used as well in combination with the contactless sensors or stand alone sensors.
Turning to
In one particular embodiment of the invention, the TSM modules 504 and 506 can employ contactless sensors, indicated by lines emanating from the TSM 504 and 506. These contactless sensors can include the following: IR sensors, inductive sensors, sensors, rotary sensors, position sensors, magnetic sensors, Hall effect sensors, chemical sensors, gas sensor arrays, ultrasonic sensors, microwave sensors, Doppler sensors, and the like. For example the sensors can be six Infrared sensors distributed equally, for example, among the tire sensor module 504 mounted within the tire 502 on the tire rim 508 and the tire sensor module 506 mounted on the vehicle frame. The TSM 506 mounted on the frame can be designed with a shield, in such a way to minimize road debris from interfering with the sensors. The three IR sensors of TSM 506, for example, can be directed at the inside edge, outside edge and center of the tire 502. The three external sensors can measure, for example, temperature, distance, etc., around 360° of the tire's circumference. This data can be utilized with an algorithm to determine: tire under-inflation, tire over-inflation, tire flat spots, tire anomalies, tire wear patterns, likelihood of tire blow out, vehicle load conditions, foreign objects embedded in the tire (e.g., a nail), tire tread remaining, tires out of balance, proper tire rotation, tires out of round, whether a tire retread is about to break away, and the like.
For yet another embodiment, the tire sensor modules 504 and 506 can be employed to determine if a re-treaded truck tire is about to lose the tire re-tread. A central controller unit on the truck can compare (real time) temperatures from the IR sensors on the TSM 506 mounted outside the tire on the vehicle frame, for example, with the temperatures obtained from the IR sensors that are part of TSM 504 mounted inside the tire on the tire rim. If the tire re-tread is firmly attached to the base tire the temperature differential may remain steady due to a uniform conduction path. As the tire begins to delaminate a gap can be formed between the tire re-tread and the base tire, which can result in a greater temperature differential, indicating the tire re-tread is beginning to separate from the tire. The system can also determine how long the tire re-tread lasted, before delaminating, based on the time it was installed vs. the time it delaminated. It is to be appreciated that the sensors in the outer TSM 506 measure a parameter, e.g., distance to the tire, temperature of the tire surface, etc., circumferentially, in other words, 360° around the surface of the tire. Whereas, the sensors of the TSM 504 mounted to tire rim each measure one specific area on the inside of the tire. Sensors can be mounted in various locations in order to obtain the necessary and desired tire parameters.
In another embodiment, a or ultrasonic sensor can be employed in the inside tire sensor module 504 to determine if the tires are under-inflated, over-inflated or properly inflated. The sensor can be made to point directly at the center of the tire 502 that makes contact with the road. If the distance from the TSM 504 to the tire center increases (e.g., calibrated for the correct pressure) the tire can be over inflated, and if the distance is less that the calibrated distance the tire can be under inflated. It is to be appreciated that the tire 502 is a dynamic system and can change based on various conditions. The algorithm that is used to make the various calculations can compensate for those conditions, for example, vehicle loading, vehicle speed, ambient conditions (e.g., temperature, pressure, humidity, etc.), road conditions, bumps, uneven terrain, etc., by taking average or comparative readings.
In yet another embodiment, a gas analyzer sensor can be employed within the tire to determine tire pressure. A known quantity of a gas (to be detected) can be introduced into the tire and measured with the gas analyzer during a calibration phase. The tire sensor module 504 can then determine, for example, whether the tire is over-inflated (the gas analyzer sensor “sees” fewer gas molecules), the tire is under-inflated (the gas analyzer sensor “sees” more gas molecules), etc. It can thus be understood that any suitable manner of determining tire pressure, tire rotation speed, tire balance, and/or other tire parameters with contactless sensors and/or contact type sensors is contemplated and intended to fall under the scope of the hereto-appended claims.
In one particular embodiment, the over-the-road truck 602 can be outfitted with monitoring equipment that can communicate with the other trucks 604 tire sensors modules and/or central control units only if there is exists a hazardous tire condition that requires immediate attention, for example, a tire is about to burst, a re-tread is about to come off, the vehicle is overloaded, the wind conditions require that the truck come out of service, etc. All of the data retrieved in this manner can be e.g., stored, sorted, analyzed, etc., to determine effective tire pressures, proper loading conditions, etc., in order to improve highway driving safety.
In yet another embodiment, upon each tire sensor module 402 being identified, the tire monitoring system 400 exits the TSM learn mode 704 and enters a TSM program mode of operation 706, as illustrated in
It should be noted that although the transmission of data to a central controller may operate according to one predetermined or programmed schedule, the time(s) at which each TSM collects the data may operate according to a completely different schedule.
In one embodiment, each of the tire sensor modules 402 then enter the TSM low power mode 708, wherein, in one example, all of the components except for the clock circuit 414 are switched off in order to reduce current draw on the tire sensor module battery 410. Then, based on the arrival of the predetermined time interval, each of the tire sensor modules 402 can selectively enter the send mode 710. That is, if the first tire sensor module received time/date data for a first time period, when that first time period arrives, it awakens into the TSM send mode while the other tire sensor modules remain in the low power mode 708. In the TSM send mode 710, the selected tire sensor module 402 activates or turns on its various components, acquires tire data via the contactless tire parameter sensor 418 (e.g., tire temperatures, pressures, positions, velocities, accelerations, torques, angles, barcode information, depths, gas properties, chemicals, forces, moments, magnetic fields, ultrasonic measurements, strains, etc.), and transmits such data to the central control unit 404 via the transceiver. In one example, the acquired tire data is frequency modulated and up-converted in the TSM transceiver 412 and transmitted via the TSM antenna 416. Upon transmission being completed, the selected tire sensor module 402 returns to the TSM low power mode 708 and awaits its next predetermined time interval.
In accordance with another embodiment of the invention, during the TSM send mode 710, after the tire data has been received at the central control unit 404, the central control unit transmits back updated time/date information that dictates the next predetermined time interval. In one example, the next predetermined time interval is the same type of interval as used previously, wherein a frequency at which the data is collected from the tire sensor modules 402 remains relatively constant. In another example, the predetermined time interval changes, for example, based on one or more characteristics associated with the vehicle in which the tire monitoring system 402 resides. For example, the central control unit 404 may receive updated vehicle speed information via the vehicle bus 430, wherein at low speeds (or in a parked condition), the frequency at which tire data is acquired and transmitted may be reduced substantially (e.g., about once per hour), while at vehicle speeds above a given threshold the tire data may be acquired and transmitted at a substantially higher frequency (e.g., about once per minute). By sending the new time/date information based on one or more vehicle characteristics, the central control unit dynamically varies the next predetermined time intervals to collect the needed data while concurrently reducing the power drawn from the various tire sensor modules 402 when such high frequency tire data collection is not needed.
In yet another alternative embodiment of the invention, when the system is acquiring tire data infrequently (e.g., once per hour), the system may account for potential changes during the TSM low power mode time frame by periodically awakening and checking if the vehicle condition (e.g., speed) has changed. If not, the tire sensor modules 402 do not see a general awaken command from the central control unit, and they then return to their low power mode 708. The periodic wake-up and check for a change in vehicle conditions may be performed at any predetermined time interval (e.g., every five (5) minutes).
Turning now to
In another embodiment, upon central control unit 404 and vehicle identification, the central control unit 404 can exit the central control unit transmit mode 804 and enters a central control unit program mode of operation 806, as illustrated in
In accordance with another embodiment of the invention, during the central control unit 404 send mode 810, after the tire data has been received at the external control unit 406, the external control unit 406 can transmit back updated time/date information that dictates the next predetermined time interval. Alternatively, the central control unit 404 can transmit data to the external control unit 406 based on priority, for example, the central control unit 404 then can enter the low power mode 808, wherein, in one example, all of the components except for the central control unit clock circuit 426 are switched off in order to reduce current draw on a vehicle battery. Then, based on the arrival of the predetermined time interval, each of the tire sensor modules 402 can selectively enter the send mode 810. That is, if the first central control unit 404 received time/date data for a first time period, when that first time period arrives, it awakens into the send mode while the other tire sensor modules remain in the low power mode 708. In the send mode 810, the selected central control unit 404 activates or turns on its various components and transmits such data to the external control unit 406 via the central control unit transceiver 422. In one example, the acquired tire data is frequency modulated and up-converted in the central control unit transceiver 422 and transmitted via the central control unit antenna 420. Upon transmission being completed, the selected central control unit 404 can return to the low power mode 808 and awaits its next predetermined time interval if the vehicle remains stationary.
In accordance with another embodiment of the invention, during the send mode 810, after the tire data has been received at the external control unit 406, the central control unit transmits back updated time/date information that dictates the next predetermined time interval if the vehicle will be in the external control unit's location at that time. In one example, the next predetermined time interval is the same type of interval as used previously, wherein a frequency at which the data is transmitted from the central control unit 404 remains relatively constant.
As alluded to above, the tire monitoring systems 100 and 500 and the methods 700 and 800 of the invention each contemplate an identification of tire anomalies in the vehicle.
The method 900 begins at 902, wherein a tire sensor module 506 is located outside the tire, for example, on the vehicle frame and a tire sensor module 504 is mounted inside the tire on the tire rim. It is to be appreciated, that although the TSM 504 is shown mounted in a single location, the TSM 504, for example, can be mounted on a linear track, mounted on a circumferential track, a moveable platform, etc., so that the TSM 504 can “look” at any location of the tire. In another example, the sensors within the TSM 504 can be e.g., three contactless sensors and may be directed to sense the distance from the sensor to the tire's inside left edge, center and right edge. It is to be appreciated that although the sensors in this example are contactless, other sensors, for example, sensors in direct contact with the tire are contemplated. The method 900 then continues at 904, wherein each of the tires 502 is adjusted to the correct manufactures pressure (e.g., given the associated ambient conditions) and the sensors in the tire sensor modules 504 and 506 are calibrated for the calibrated pressure. In one example, each sensor in the tire sensor module 504 measures the average distance from the sensor to the tire surface being measured, however, other measurements may be employed and are contemplated as falling within the scope of the invention. Infrared sensors in the TSM 506 can be directed at the outer surface of the tire as shown in
The method 900 continues at 906, wherein the tire sensor modules 504 and 506 can transmit the various tire data to the central control unit 516 at periodic intervals, discussed supra. At 908 the algorithm of the central control unit 516 can compare the real-time average distance determined by the sensors to the inner tire surface with the calibrated average distance, on a periodic basis. For example at 910, if the average distance of the center has decreased beyond a predetermined average distance and the edge average distances increase beyond a given average distance the algorithm can determine that an over-inflation has occurred and at 916 a hazard light could be switched on in the vehicle's dashboard, directing the driver to check the front right wheel's tire pressure. The central control unit algorithm can also evaluate at 912 the tire pressure based on the IR sensors within the TSM 504. The central control unit algorithm can determine at 914 based on the average temperature profile map or matrix obtained for each IR sensor that the data indicates the various tires are under-inflated or over-inflated with respect to the readings obtained during the calibration time period 902. If the temperature readings are outside a predetermined range at 916 again a hazard light can be lit indicating a tire pressure problem. In addition the central control unit algorithm can determine whether there is a tire pressure problem based on reading from a combination of sensors, for example. In either case, the sensor measurements and/or the IR sensor measurements can determine the tire pressure is within an acceptable range. Of course, those skilled in the art will recognize many modifications may be made to this configuration, without departing from the scope or spirit of what is described herein.
Turning specifically to
At 1004, integers N and M can be set equal to one (1). At 1006 the central control unit algorithm can associate each tire sensor module 506 (TSM (M)), with a specific tire location (TIRE (N)). For example, considering a left front tire 206, it is associated with the left front TSM (not shown in
It is to be understood that this process can include the spare tire as well, in the event that all of the tires do not match up as a pair. This process can also be expanded to include vehicles have more than four tires, for example, school busses, hauling trucks, OHV earth movers, and the like.
Although the invention has been illustrated and described with respect to one or more implementations, alterations and/or modifications may be made to the illustrated examples without departing from the spirit and scope of the appended claims. In particular regard to the various functions performed by the above described components or structures (assemblies, devices, circuits, systems, etc.), the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component or structure which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated implementations of the invention. In addition, while a particular feature of the invention may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. Furthermore, to the extent that the terms “including”, “includes”, “having”, “has”, “with”, or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term “comprising”.
