JP3982830B2 - Remote tire pressure monitoring system - Google Patents

Description

Technical field
The present invention relates to a remote tire pressure monitoring system for a vehicle. The system provides a temperature compensated and, in one embodiment, altitude compensated tire pressure indication value via a radio frequency (RF) signal transmitted from a sensor attached to the tire to a central location of the vehicle. The system is also filed on March 11, 1993 and is related to a technology that allows the system to learn tire identification and position on a vehicle without interference from other nearby vehicles. Includes assignee technology as described in US93 / 01995. The disclosure of the co-pending application is hereby incorporated herein by reference.
Background art
Conventionally, many attempts have been made to monitor tire pressure in a vehicle. Many patents have also been issued that disclose various approaches. Early configurations tended to have electromechanical structures with large induction coil mechanisms attached to the wheels and brake drums. These systems continuously provided a high level of information regarding both tire pressure and tire temperature. However, due to its high cost and difficulty of installation, such a system has been unacceptable to major automobile manufacturers.
In recent years, low-cost systems have been developed that provide simple threshold pressure alarms using pressure switches, internal power supplies, and radio communication links from each wheel to instrument panel receivers and indicators. These systems are more attractive to automobile manufacturers because of their low cost and ease of installation. However, these systems have a number of problems including, among other things, the ability to provide a long-lasting and stable power source, the size and weight of the wheel unit, and the mounting of the unit inside the wheel. Furthermore, the information available for such systems has been limited to a single pressure threshold, typically 25 psi. In addition, this threshold value may or may not be compensated for a temperature change occurring inside the tire. Further, such systems that are not mounted inside the tire could not compensate for altitude changes that affect the performance of the tire pressure monitoring system.
In view of the foregoing, one object of the present invention is to provide a system that provides tire pressure information continuously in real time in the same way as a conventional coil type system. It is to provide using a communication system. As a result, the system of the present invention is attractive to automobile manufacturers because it provides a high level of information while maintaining low cost and adequate simplicity.
Disclosure of the invention
In one embodiment of the system of the present invention, each wheel unit is comprised of a low profile enclosure that is attached to the back of a conventional clamp-in tire valve located inside the wheel and tire. The enclosure contains an electronic unit consisting of a battery, a pressure sensor, a roll (operation) switch, control electronics, and a wireless transmitter. Further, the entire assembly is preferably fully fitted with the insulator to protect each electronic device from the environment. The overall dimensions and weight are kept to a minimum and the entire enclosure is positioned within the central recess of the wheel, thereby solving the problems associated with tire installation and removal.
The wheel unit measures tire pressure and reports information in the form of radio communication to the receiver on the instrument panel. To conserve battery power, the pressure is sampled periodically, typically every 10 seconds when the vehicle is running. Further, a radio frequency (RF) signal is transmitted periodically, typically once every minute when the vehicle is running, if the tire pressure does not change abruptly. If a rapid change in tire pressure is detected during pressure measurement (eg, 1 psi or more in 10 seconds), it is immediately reported to the instrument panel receiver in the form of an RF transmission. This rapid transmission informs the driver as soon as a dangerous pressure level occurs.
As described above, each wheel unit also preferably includes a roll switch or motion detection switch that detects vehicle movement to further save battery power. In general, while the vehicle is traveling at a speed of 16 km / h or more, the device obtains tire pressure samples and transmits them as described above. However, when the vehicle is parked, especially when the vehicle is housed overnight in the garage, the period of pressure sampling and RF transmission varies greatly. When a vehicle is parked for a long time, a pressure sample is typically taken once every 15 minutes rather than every 10 seconds. RF reports are sent only once per hour, not once a minute.
The approach of the present invention has the advantage of reducing the risk due to pressure drop and significantly reduces power consumption when the vehicle is stationary. However, since the receiver is always operating, the pressure value is displayed immediately when the automobile ignition is turned on. As a result, if a leak occurs while the car is parked overnight, a warning light or alarm will be activated as soon as the driver turns the key the next morning, and the tires will be under low pressure before the vehicle starts. Can inform the state.
Each wheel unit has a unique identification code that is programmed into the receiver during installation. Up to 2 million types of identification codes are available to prevent cross-vehicle interference and the reception of erroneous information associated therewith. Each RF transmission includes pressure information and identification information for a particular wheel, allowing the receiver to know which of the four wheels reported, and other systems with similar systems in close proximity. The receiver can reject all reports from the vehicle. Thus, the reception of erroneous pressure reports from nearby vehicles can be completely prevented by setting a unique identification code.
The instrument panel receiver receives the RF transmission and decodes the digital information comprising the wheel identification code and the corresponding tire pressure information. The receiver is connected to a computer mounted on the vehicle and / or a display mounted on the instrument panel. The indicator may be a liquid crystal display (LCD), a light bulb, a buzzer, a voice synthesizer, or the like to warn the driver of abnormal pressure. During manufacturing, any threshold can be set with various alarm levels. Alternatively, the driver may be able to program the threshold value.
A receiver in an automobile instrument panel includes an RF receiving unit, a microcontroller unit, an output interface unit, and an atmospheric pressure measuring unit. An example of such a receiving unit is described in the aforementioned PCT application. Since the wheel unit is fully contained within the tire / wheel assembly, the pressure measurements made by the wheel unit are independent of the outside atmospheric pressure. Changes in weather and more significantly in altitudes cause large fluctuations in the surrounding atmospheric pressure. In particular, traveling at high altitudes changes the ambient atmosphere by several psi. For example, at an altitude of 12000 feet, the ambient atmosphere changes by about 6 psi.
In order to correct the wheel unit pressure measurement for changes in the outside ambient atmospheric pressure, a pressure sensor mounted in the receiver constantly monitors the ambient atmospheric pressure. This information is used to obtain the true “gauge” pressure of the tire pressure to be displayed. This approach allows a driver to read the tire pressure on the vehicle's instrument panel when four tire pressures are displayed on the vehicle's instrument panel, and these readings are simply attached to the tire valve. This is very advantageous because it can be correlated with the pressure value measured with a tire pressure gauge.
In accordance with the present invention, another option is available that is suitable for vehicle manufacturers who wish to provide a line along the threshold warning light system instead of an indicator that fully displays pressure. In this case, a wheel unit can be provided that indicates the temperature compensated pressure. When the automobile is traveling for a long time, the temperature of the tire rises remarkably depending on the vehicle speed, the road conditions, the amount of braking, and the like. Since the tire / wheel assembly constitutes a sealed pressure chamber, the tire pressure increases or decreases in direct proportion to the tire temperature.
As mentioned above, in certain cases it is desirable that pressure measurements are not affected by pressure changes caused by temperature, but only react to pressure changes caused by a decrease (or increase) in the air in the tire. Accordingly, the system of the present invention is set to provide such temperature compensated pressure values. Upon selection of the option, the pressure reported from each wheel is related to the standard temperature. For example, assuming that the tire pressure is 30 psi at an ambient temperature of 20 degrees Celsius and the automobile is running, the internal tire temperature rises to 40 degrees Celsius due to friction between the tire and the road surface. This temperature increase of 20 degrees Celsius increases the tire pressure proportionally in absolute conditions, so the pressure changes to about 33 psi. Normally, the system will report a pressure change and 33 psi will be displayed on the display. However, in the temperature compensation system, even if the true pressure increases, the displayed pressure remains at 30 psi. Thus, only expansion or contraction appears as a pressure change.
[Brief description of the drawings]
FIG. 1 is a block diagram of a circuit used for control of a tire pressure monitoring system according to a presently preferred embodiment of the present invention, and FIG. 2 is a flowchart showing an explanatory sequence of control operations according to the presently preferred embodiment. FIG. 3 is another flowchart showing another illustrative sequence of control operations according to the presently preferred embodiment.
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the other objects and features of the present invention will be described in detail with reference to the accompanying drawings. In FIG. 1, which is an electronic block diagram of the wheel unit, an application specific IC (ASIC) 100 is shown as being located in the center of the device. The application specific IC is illustrated as having six peripheral devices directly connected to it and a single cell lithium battery source 110. The six peripheral devices shown include a pressure sensor 120, four types of switches 130 to 160 (optional pressure switch 130, roll switch 140, tilt switch 150, and reed (magnetic) switch 160), and UHF (pole). Ultra-short wave) oscillation transmitter 170.
The entire circuit operates as follows. The application-specific IC 100 continuously monitors the state of the roll switch 140. Roll switch 140 indicates the vehicle speed. When the vehicle is stopped or at a speed of 16 km / h or less, the roll switch 140 is opened. However, when the speed of the vehicle exceeds 16 km / h, the roll switch 140 is closed. The application specific IC 100, which is a mixed (analog / digital) complementary metal oxide semiconductor (CMOS) custom integrated circuit, detects the closure of the roll switch 140.
When the roll switch 140 is closed, the application specific IC 100 begins sampling the tire pressure detected by the pressure sensor 120 periodically, typically every 10 seconds. In one embodiment, the pressure sensor 120 is a micromachined piezoresistive silicon sensor, and in another embodiment, the pressure sensor 120 is a capacitive pressure sensor manufactured using a similar microfabrication technique. is there. During the measurement cycle, the application specific IC 100 increases the output of the pressure sensor 120 and monitors the output of the sensor 120 supplied to the application specific IC. The output of the sensor 120 is a voltage proportional to pressure (in the case of the piezoresistive pressure sensor embodiment) or a capacitance proportional to pressure (in the case of the capacitive pressure sensor embodiment). The sensor output is measured and pressure is calculated using calibration constants stored in an internal non-volatile memory (electrically erasable PROM (EEPROM)) of the application specific IC itself. These constants are automatically loaded into the application specific IC 100 during the initial calibration procedure performed during the manufacturing process. Since these procedures are known to those skilled in the art, a detailed description thereof is omitted here. Also, at this stage, temperature correction and compensation techniques are employed inside the application specific IC 100 to accurately measure pressure over a predetermined temperature range.
The pressure measurement or pressure sampling process takes approximately 100 microseconds, and at the end of the process, the application specific IC 100 reduces the output to a constant low power or “sleep” mode. During this time, the application-specific IC 100 keeps the clock counter running and monitors the inputs of the four switches. If roll switch 140 remains closed, application specific IC 100 will wake up from sleep mode after 10 seconds and repeat the pressure measurement process. In order to transmit pressure information to the instrument panel receiver mounted in the vehicle by wireless communication, the application-specific IC 100 excites the UHF transmitter 170 periodically during operation, typically every second.
The application specific IC 100 powers a UHF oscillator having a fundamental frequency of about 300 to 450 MHz. Furthermore, the application specific IC 100 supplies digital information to the UHF circuit 170 that modulates the basic oscillator. The UHF circuit 170 has an oscillator / amplifier configuration that is frequency controlled by a surface acoustic wave (SAW) resonator. This frequency control method ensures frequency stability and control over a wide operating temperature range. An example of a surface acoustic wave resonator is described in the previously mentioned PCT application.
The UHF circuit 170 has an integrated antenna, and the antenna is connected to a tire valve to which the entire housing of the electronic device is attached. The tire valve constitutes an antenna that protrudes to the outside of the tire and remarkably enhances RF (radio frequency) communication performance. The radio signal can be amplitude modulated (AM) or frequency modulated (FM) depending on the user's choice and other application reasons. In any case, the digital information to be transmitted is encoded to the fundamental frequency by the application specific IC 100 and then decoded by the receiver on the vehicle.
The digital information transmitted by the wheel unit consists of a wheel unit identification code. The length of the code can be up to 21 bits (thus allowing 2 million codes), allowing the transmission of 8 bits of pressure data and specific messages such as “Battery power down” Including various function bits. In addition, error check bits are included to assist in the decoding process, preventing incorrect data from being recorded or displayed.
One transmission is performed for one second in total. The individual transmissions that make up the “word” of information take a much shorter time, typically 20 microseconds. However, in order to ensure high performance and in particular to ensure that the receiver mounted in the vehicle can receive the information, the word is repeated several times at arbitrary intervals during the second. The Since the word interval is arbitrary, it is possible to simultaneously receive information from a plurality of transmitters even if the beginning of each information is completely synchronized. In addition to varying the spacing of transmitted words, the actual period of transmission varies from unit to unit in order to prevent all transmitters from synchronizing their information and consequently all wheels reporting completely simultaneously. ing. For example, when the vehicle travels, one of the transmitters may transmit every 60 seconds, and another transmitter may transmit every 63 seconds. By setting the transmission interval in this manner, even in the unlikely event that information from two or more transmitters are synchronized during a given transmission, those transmitters will be in the next transmission after one minute. The information from is no longer synchronized. This type of optional setting is also described in the aforementioned PCT application.
Updates that are frequently made every minute are for management purposes only. When the vehicle is traveling (that is, traveling at 16 km / h or more), the receiver schedules each wheel to transmit every minute. The identification code and pressure data contained in each piece of information is first, by the receiver, to identify that the information is from a wheel belonging to the vehicle, and secondly which wheel position. Third, it is used to identify the actual tire pressure in order to identify whether information is coming from (eg left front wheel).
For example, when there is a rapid pressure fluctuation such as occurs when a leak occurs, the application-specific IC 100 immediately starts transmission as shown in FIG. 2 when detecting a significant pressure fluctuation. For example, assuming that a pressure sample taken every 10 seconds shows a constant pressure value of 33 psi at a given wheel, the corresponding wheel unit sends a pressure value of 33 psi with its respective identification code to the instrument panel every minute. To do. After 10 seconds, if the pressure fluctuates by 1 psi or more in the next pressure sample (in this example, the pressure drops to 32 psi or less), the application-specific IC 100 detects this change. First, the application-specific IC 100 re-samples the pressure sensor after 1 second to check the pressure fluctuation, and immediately transmits new information. Thus, as soon as significant pressure fluctuations are detected, the immediately transmitted information is added and the management reports per minute increase. With this immediate update, the driver is notified of abnormal pressure fluctuations as soon as such fluctuations occur.
While the vehicle is traveling, the processing sequence described above is continuously repeated. When the vehicle stops or when the vehicle speed drops below 16 km, the roll switch 140 is opened. Upon detecting the opening of the roll switch 140, the application specific IC 100 starts a counter / timer. After a predetermined time has passed in consideration of stop signs, traffic signals, traffic jams, etc. (in one embodiment, after 5 minutes), that is, stop signs, traffic signals, traffic jams, etc. Since there is usually no special purpose IC 100, a longer vehicle stop is interpreted as a parked vehicle.
In the parking mode, the application specific IC 100 can be programmed to perform two functions. In one embodiment, the application specific IC 100 completely stops monitoring tire pressure and does not transmit. In this state, the application specific IC 100 is in a complete power saving mode and consumes very little power. In this mode, the receiver can also be completely shut off when the vehicle ignition is turned off. In another embodiment, during the parking period, the wheel unit remains operational and continues to sample the output of the pressure sensor 120 and performs RF transmission as described above. Here, however, the sampling period is significantly extended to 10 seconds, typically 15 minutes. Furthermore, the period of management RF transmission increases from one minute to typically once an hour. Thus, for example, if the ignition is turned off overnight and the receiver in the vehicle is in operation, the wheel unit will still monitor and report the tire pressure. Thus, the next morning when the driver turns the key to ignite, all four wheel tire pressures are displayed and, if necessary, a warning is issued before the driver leaves the garage or private road. While parking, the number of pressure samples and RF reports is significantly reduced to save battery power, but the driver can still receive tire pressure reports on the spot. The above is summarized in FIG.
Hereinafter, the functions of the other three switches shown in FIG. 1 will be described. A magnetically actuated reed switch 160 included in the wheel unit is connected to the application specific IC 100. The reed switch 160 is operated via a small magnet attached in the vicinity of the valve shaft on the edge of the wheel rim outside the tire. Whenever the magnet is held in that position, the reed switch is closed. The application-specific IC 100 detects this closure and continuously transmits a specific “learning sequence” as described in the above-mentioned co-pending PCT application after a confirmation period of 2 seconds. When the magnet leaves the wheel, the reed switch 160 opens and transmission stops immediately. This operation is used when the system is installed in a vehicle, and is also useful when exchanging or recombining tires as described in the PCT application mentioned above.
When attaching transmitters with different unknown identification codes to all wheels, the following method was developed to “learn” the vehicle's unique wheel identification code to the system receiver. That is, by first programming the receiver by programming a receiver with a simple switch located on the outside of the receiver or via a digital communication unit on the receiver that can be connected to a computer mounted on the vehicle. Switch to a specific “learning mode”. In “learning mode”, the receiver expects to receive four different pieces of information (in the case of four-wheel drive), one from each wheel (for vehicles with more wheels, the sequence is different and extended) Sometimes). An operator who installs the system walks around the vehicle in a predetermined order with a magnet (which may be attached to a rod so that the operator does not have to bend it close to the wheels), A learning transmission is performed from each wheel using a magnet (this procedure can also be automatically performed using a robot control magnet on an automobile production line). The receiver receives the different information and loads the received identification code into a non-volatile memory (electrically erasable PROM).
In normal operation of the system, for each piece of information received, the received identification code is compared with the identification code in the memory. If the codes match, the receiver processes the pressure data and updates the display or issues a warning if necessary. However, if the received identification code does not match any of the identification codes stored in the memory, the entire information is from another vehicle with a similar system, or from other sources It is regarded as Neuss and rejected.
The other two switches shown in FIG. 1 are optional and are installed according to specific user requirements. The pressure switch 130 is a mechanical diaphragm type pressure switch, which is pressurized from the inside or is vacuum-filled and switched at a predetermined threshold pressure. Application specific IC 100 can be programmed at the factory to allow three options for the use of a pressure switch, such as switch 130. According to the first option of using only the pressure switch to monitor the tire pressure, a simple detection by the pressure switch takes place instead of sampling by the pressure sensor and subsequent pressure calculation. When the tire pressure exceeds the switch threshold point, the pressure switch closes and the wheel unit transmits a “normal” or “good” pressure signal as part of its transmission sequence. When the tire pressure falls below the switch threshold, the pressure switch opens. This is immediately detected by the application specific IC 100 and an “abnormal” or “low” pressure signal is transmitted. In this case, the receiver emits a warning sound or turns on a warning light.
According to a second option, both a pressure switch and a pressure sensor are used. At high and normal pressures when the pressure switch closes, the pressure sensor is not sampled every 10 seconds and occasionally rechecks the switch state, for example every hour. When the pressure switch 130 is opened due to the pressure drop, the pressure sensor sampling measurement is started, and the accurate value of the low pressure state is transmitted, so that the abnormal tire pressure can be closely monitored. Thus, when tire pressure is normal, power consumption is typically significantly reduced to over 95%, and the closed pressure switch 130 prevents unnecessary pressure sampling during this period. .
According to a third option for using the pressure switch, the pressure is monitored while the vehicle is parked, and the pressure sensor 120 is used for pressure monitoring while the vehicle is traveling. That is, when the roll switch 140 is opened to indicate that the vehicle is parked, the pressure sensor sampling is all finished, and the application-specific IC 100 switches only the state of the pressure switch. As a result, battery power is significantly saved since pressure sampling is not performed while the vehicle is parked throughout the life of the vehicle.
The tilt switch 150 shown in FIG. 1 is used to indicate that the wheel is tilted from a normal vertical position by a certain angle, typically 30 degrees. Thus, the switch 150 can detect that the wheel is detached from the vehicle, for example, when the wheel is stolen. When the vehicle alarm device is installed, when the tilt switch 150 is closed, the wheel unit outputs certain defense information and can emit an automobile alarm sound. With this structure, it is possible to constitute a defense against wheel theft.
The receiver of the low pressure tire warning system has a conventional configuration. Depending on the modulation type and data rate required for a particular application, a superheterodyne or super regenerative RF front end can be selected. The microcontroller-based decoding unit includes a non-volatile memory for storing the addresses of the four wheels loaded during the “learning mode” sequence at installation. Also, an analog circuit including a pressure sensor is used to measure the ambient atmospheric pressure and correct the input wheel pressure due to the gauge display frequency. Furthermore, an output exciter block is provided to provide sufficient buffering and excitation performance depending on the chosen interconnection and display / warning type.
The receiver software embedded in the microcontroller has the ability to execute a “learning mode” sequence, can reconfigure the tire position using external programming, and can adjust the threshold. , Provides diagnostic information for each part of the system, ie all four transmitters and the RF part of the receiver. Some of these details are described in the above-mentioned PCT application, and others are obvious to those skilled in the art, so a detailed description is omitted here.
The receiver can also be configured to receive other information on similar fundamental frequencies to extend the control function. For example, the “remote keyless entry” system currently being developed for vehicles is configured using the receiver of the low pressure tire warning system, and the low pressure tire warning system and the keyless entry system are integrated into one common receiver unit. By doing so, significant cost savings can be achieved.
Although the present invention has been described based on the preferred embodiments, various modifications will be apparent to those skilled in the art. Accordingly, it is to be understood that the invention is limited only by the appended claims.

Claims (7)

A remote tire pressure monitoring system in a vehicle having at least two wheels to which a tire is attached, the pressure sensor for detecting the tire pressure for each of the tires and providing a tire pressure measurement accordingly And a wireless transmitter for transmitting the tire pressure measurement value by wireless transmission, and connected to the pressure sensor and the wireless transmitter to control the periodicity of operation of the pressure sensor and the wireless transmitter. A control circuit for controlling the operation of the pressure sensor and the wireless transmitter, and a magnetic actuation switch connected to the control circuit and placed in a first state in response to the presence of a magnetic field, In response to the first state of the activation switch, the control circuit causes the wireless transmitter to transmit an identification signal that individually identifies the tire. An operation switch; a power source for continuously supplying power to the control circuit; and at least first and second states connected to the control circuit, the first and second running states of the vehicle A roll switch for monitoring the pressure sensor and the wireless transmitter in response to the first state of the roll switch associated with the first running state of the vehicle. In response to the second state of the roll switch associated with the second running state of the vehicle, the control circuit causes the pressure sensor and the wireless transmitter to operate in the first cycle. A roll switch configured to operate in a shorter second cycle, and a tilt switch connected to the control circuit and having at least a first state and a second state, for monitoring the mounting state of the tire, , In accordance with one of the first and second states of the tilt switch, the control circuit includes a tilt switch configured to cause the wireless transmitter to output an alarm indicating an insufficient mounting state of the tire. A remote tire pressure monitoring system characterized by that. The first cycle is 15 minutes for the pressure sensor, 1 hour for the wireless transmitter, the second cycle is 10 seconds for the pressure sensor, and the wireless transmitter. The remote tire pressure monitoring system according to claim 1, wherein is one minute. 2. The remote tire pressure monitoring system according to claim 1, wherein the control circuit causes the wireless transmitter to output a digital signal composed of a predetermined number of bits in response to the tire pressure measurement value. 4. The remote tire pressure monitoring system according to claim 3, wherein the predetermined number of bits includes a first number of bits for individually identifying the tires. A remote tire pressure monitoring system in a vehicle having at least two wheels to which a tire is attached, the pressure sensor for detecting the tire pressure for each of the tires and providing a tire pressure measurement accordingly And a wireless transmitter for transmitting the tire pressure measurement value by wireless transmission, and connected to the pressure sensor and the wireless transmitter to control the periodicity of operation of the pressure sensor and the wireless transmitter. Including a control circuit for controlling the operation of the pressure sensor and the wireless transmitter, and at least first and second states connected to the control circuit, the first and second running states of the vehicle A roll switch for monitoring the vehicle and a power source for continuously supplying power to the control circuit, the low switch related to the first running state of the vehicle. In response to the first state of the switch, the control circuit operates the pressure sensor and the wireless transmitter in a first period, and the first of the roll switch associated with the second travel state of the vehicle. In response to the second state, the control circuit operates the pressure sensor and the wireless transmitter in a second cycle shorter than the first cycle, and is connected to the control circuit and is connected to at least the first and A tilt switch for monitoring a mounting angle of the tire having a second state, and the control circuit according to one of the first and second states of the tilt switch; the remote tire pressure monitoring system characterized by outputting the alarm indicating that the tire is in a poor attachment state. A remote tire pressure monitoring system in a vehicle having at least two wheels to which a tire is attached, the pressure sensor for detecting the tire pressure for each of the tires and providing a tire pressure measurement accordingly And a wireless transmitter for transmitting the tire pressure measurement value by wireless transmission, and connected to the pressure sensor and the wireless transmitter to control the periodicity of operation of the pressure sensor and the wireless transmitter. A control circuit for controlling the operation of the pressure sensor and the wireless transmitter, and a tilt connected to the control circuit and having at least first and second states and for monitoring the mounting state of the tire A switch and a power supply for continuously supplying power to the control circuit, and depending on one of the first and second states of the tilt switch , Wherein the control circuit, the alarm indicating an insufficient attachment state of the tire, the value is output wireless transmitter, further, connected to said control circuit having at least first and second states, said vehicle A roll switch for monitoring the first and second traveling states of the vehicle, and the control circuit is configured to control the pressure according to the first state of the roll switch related to the first traveling state of the vehicle. In response to the second state of the roll switch associated with the second running state of the vehicle, the control circuit is configured to operate the sensor and the wireless transmitter in a first period, A remote tire pressure monitoring system, wherein the transmitter is operated in a second period shorter than the first period. The first cycle is 15 minutes for the pressure sensor, 1 hour for the wireless transmitter, the second cycle is 10 seconds for the pressure sensor, and the wireless transmitter. 7. The remote tire pressure monitoring system according to claim 6 , wherein is one minute.

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