Automotive Ultrasonic Quality Sensor Strategy

Abstract

The invention discloses a vehicle-used ultrasonic quality sensor strategy, which is used to detect the concentration of urea in the urea tank of the vehicle. The urea quality sensor is arranged in the urea tank. The strategy includes the following steps: powering on the engine electronic control unit and initializing the report text signal, the ECU sends the vehicle condition signal to CAN through the post-processing of the message, the vehicle condition signal includes real-time vehicle speed and rotation speed information; the urea quality sensor recognizes that the vehicle is in the driving state or the parking non-stop state after receiving the real-time vehicle speed and rotation speed information; real-time detection obtains the urea concentration value, when the urea concentration value is greater than or equal to the first urea concentration threshold and less than or equal to the second urea concentration threshold, this concentration range is valid, and the previous effective urea concentration value is locked. The invention has the advantages of judging the real concentration of urea, fast detection, strong anti-interference ability and the like.

Description

technical field [0001] The invention relates to the technical field of engine accessory assembly, in particular to the strategy of ultrasonic quality sensors for vehicles. Background technique [0002] The urea tank is equipped with a urea quality sensor for monitoring the concentration of the urea aqueous solution in the urea tank. The urea quality sensor includes a sound wave transmitter, a sound wave receiver and a reflector for reflecting sound waves. When working, the sound wave transmitter, sound wave receiver and reflector The mirror is immersed in the urea aqueous solution, and the sound wave emitted by the acoustic wave transmitter propagates to the reflector in the urea aqueous solution, and the reflector reflects the sound wave, so that the returned sound wave is received by the acoustic wave receiver after reverse propagation in the urea aqueous solution. The speed of propagation in different concentrations of urea aqueous solution is different, so the density of...

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Problems solved by technology

[0004] There are still two deficiencies in the above disclosed urea concentration detection method, detection device and automobile patent technical scheme. One is that only the speed of the vehicle is used as the judgment condition for the rationality of the concentration. The bubbles generated by filling will make the concentration abnormal, and continue to drive again. If the bubbles do not dissipate, the latest abnormal concentration will be output as the locked value, causing OBD to alarm; The leakage of the urea tank causes the concentration of urea to be diluted, and the concentration will not be updated. Low-concentration urea will also cause excessive emissions during long-term driving

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