Tire air pressure monitoring apparatus and method
First Claim
1. A tire air pressure monitoring apparatus having a transmitter for wirelessly transmitting data concerning the internal pressure of a tire on a vehicle and a receiver for receiving the data, the apparatus comprising:
- generation means, provided in the transmitter, for assigning a value to a variable according to a predetermined sequence every time the transmitter sends data, wherein the transmitted data includes a current value of the variable; and
determination means, provided in the receiver, for determining whether there has been a communication failure based on the value of the variable in the received data.
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Accused Products
Abstract
Each transmitter installed in tires on a vehicle generates a variable value, which is updated according to a predetermined sequence every time it sends data. The current value of the variable is transmitted to a receiver regularly along with other the information. The receiver determines whether any receptions have been skipped prior to the current reception based on whether or not the variable value included in the received data has been updated according to the sequence. The receiver judges that there is a communication failure when the number of skipped receptions is equal to or greater than an upper limit value and judges that there is no communication failure when the skipped reception number is less than the upper limit value. This permits easy and reliable detection of communication failures.
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Citations
15 Claims
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1. A tire air pressure monitoring apparatus having a transmitter for wirelessly transmitting data concerning the internal pressure of a tire on a vehicle and a receiver for receiving the data, the apparatus comprising:
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generation means, provided in the transmitter, for assigning a value to a variable according to a predetermined sequence every time the transmitter sends data, wherein the transmitted data includes a current value of the variable; and
determination means, provided in the receiver, for determining whether there has been a communication failure based on the value of the variable in the received data. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of monitoring a communication state between a transmitter and a receiver, the method comprising:
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assigning a value to a variable in accordance with a predetermined sequence every time the transmitter sends data, wherein the transmitted da-a represents at least a physical status and the current value of the variable;
receiving data with the receiver; and
determining whether there has been a communication failure based on the value of the variable in the received data. - View Dependent Claims (9, 10, 11, 12)
finding a number of skipped receptions between the previous data reception and the current data reception based on the variable values of the previous and current data; and
judging that a communication failure has occurred when the number of skipped receptions is equal to or greater than a predetermined upper limit value.
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12. The method according to claim 8, further comprising the step of displaying the result of the determination.
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13. A method of monitoring communication states among a plurality of transmitters and a receiver, the method comprising:
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assigning, for each transmitter, a value to a variable in accordance with a predetermined sequence every time each transmitter sends data, wherein the transmitted data represents at least a physical status and the current value of the variable;
receiving data with the receiver;
finding a number of skipped receptions between the previous data reception and the current data reception for each transmitter based on the variable values in the associated data; and
determining whether each transmitter is malfunctioning by analyzing the numbers of skipped receptions for all of the transmitters. - View Dependent Claims (14, 15)
selecting a maximum value and a minimum value from the numbers of skipped receptions; and
judging that the transmitter associated with the maximum value is malfunctioning when the difference between the maximum value and the minimum value is equal to or greater than a predetermined value.
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15. The method according to claim 13, further comprising the step of displaying a result of the determination.
Specification