Tire pressure monitoring system
The invention relates to a tire pressure monitoring system with a wheel electronic to be installed in a pneumatic tire, comprising a battery as power source, a pressure sensor for measuring of tire pressure or pressure change, and a transmitter for transmitting pressure data, a receiver to be mounted either in or at the vehicle for receiving pressure data, a control unit for evaluating of pressure data, and a serial bus system via which, during operation, the control unit interrogates the receiver and receives subsequently pressure data from the receiver. In accordance with the invention it is provided that additionally to the serial bus system the receiver is also connected with the control unit via a data transfer line that is separate from the serial bus system, wherein the receiver notifies the control unit of critical pressure data via the data transfer line in an unrequested manner.
1. A tire pressure monitoring system comprising:
a wheel electronic installable in a pneumatic tire, the wheel electronic comprising a battery as power source, a pressure sensor for measuring of tire pressure or pressure change, and a transmitter for transmitting non-critical pressure data and critical pressure data, wherein the critical pressure data is a rapid pressure drop indicating a blowout of the pneumatic tire;
a receiver for receiving the non-critical pressure data and the critical pressure data;
a control unit for evaluating the non-critical pressure data and the critical pressure data;
a serial bus system interconnecting the control unit and the receiver for enabling the control unit to interrogate the receiver and receive the non-critical pressure data from the receiver, wherein the serial bus system is a master-slave bus system; and
a data transfer line, separate from the serial bus system, for connecting the receiver with the control unit, the receiver being configured for sending to the control unit the critical pressure data via the data transfer line in an unrequested manner;
wherein the receiver, the control unit, the serial bus system and the data transfer line are mounted either in or at a vehicle of the pneumatic tire;
wherein the wheel electronic comprises an evaluation unit for gathering, from signals of the pressure sensor, the non-critical pressure data and the critical pressure data to be transmitted, the evaluation unit determining according to a stored criteria whether the data is non-critical pressure data or critical pressure data, the evaluation unit including a special identifier associated only with the critical pressure data, wherein the special identifier comprises a bit or a bit string;
wherein the wheel electronic transmits the critical pressure data with the special identifier, enabling the receiver to recognize that the critical pressure data is to be sent by the data transfer line;
wherein via the serial bus system the receiver sends the non-critical pressure data to the control unit only upon request of the control unit, and wherein via the data transfer line the receiver sends the critical pressure data within a few milliseconds to the control unit only upon recognizing the special identifier.
2. The tire pressure monitoring system according to claim 1 , wherein the evaluation unit, when detecting the critical pressure data, increases the transmission rate at which the pressure data are sent.
3. The tire pressure monitoring system according to claim 1 , wherein the receiver is a central receiver for receiving the non-critical pressure data and the critical pressure data from several wheel electronics.
4. The tire pressure monitoring system according to claim 1 , further comprising a vehicle bus and the control unit includes a connector for outputting processed pressure data to the vehicle bus.
5. The tire pressure monitoring system according to claim 4 , wherein the control unit provides a vehicle safety system with information regarding a critical pressure drop via the vehicle bus.
6. The tire pressure monitoring system according to claim 5 , wherein an anti-lock braking system of the vehicle is controlled with consideration of information about a critical pressure drop provided by the control unit via the vehicle bus.
7. The tire pressure monitoring system according to claim 6 , wherein the anti-lock braking system is controlled by an electronic stability control system using information provided by the control unit via the vehicle bus.