Control method for output signal of automobile urea quality sensor

Abstract

The invention relates to an automobile urea quality sensor output signal control method, which comprises the following steps that a urea quality sensor is arranged in a urea box, and a certain amount of urea solution is filled in the urea box; a power supply of the urea quality sensor is switched on, and the urea quality sensor works normally and records voltage energy signals converted from five continuous ultrasonic echo signals; if the number of the energy signals higher than the threshold value line in the five signals recorded continuously is larger than or equal to 3, it is judged that the output signals of the sensor are reliable, and the ECU outputs the actually-calculated urea concentration value, and if the number of the energy signals higher than the threshold value line in the five signals recorded continuously is smaller than or equal to 2, it is judged that the output signals of the sensor are not reliable, and the sensor outputs invalid signal codes; and the electronic control unit ECU outputs the reliable signal which is output last time as a replacement signal. According to the method, the sensor signal judgment logic is optimized, so that the sensor output value is more reliable, and the system robustness and the customer driving experience are improved.

Description

technical field [0001] The invention relates to the technical field of automotive aftertreatment systems, in particular to a control method for an output signal of an automotive urea quality sensor. Background technique [0002] As an important part of the driver induction restriction system, the vehicle urea quality sensor is also one of the most noteworthy new components in the national VI after-treatment injection system. Its main function is to monitor the quality of urea. Once the sensor detects the customer Adding unqualified urea solution, the driver induction system will trigger a prompt and limit the normal driving of the vehicle after a period of time, forcing the customer to re-add qualified urea. [0003] The most widely used type of urea quality sensor in the industry is ultrasonic sensor, which has many advantages such as strong anti-interference, high precision and low cost, so it is widely sought after by major sensor manufacturers. But such sensors also hav...

AI Technical Summary

Problems solved by technology

This processing method is logically simple, but it is easy to misjudge and trigger the induction system to turn on the fault light, which will affect the driving experience of customers.

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