A system and method for time-domain conversion of internal-combustion engine cylinder pressure signal to angle domain

Abstract

The invention discloses a system and a method for a time domain and a rotation angle domain of an in-cylinder pressure signal of an internal combustion engine, a cylinder pressure measurement device and a pulse signal measurement device. The cylinder pressure measurement device and the pulse signal measurement device measure the collected in-cylinder pressure signal and the The pulse signal corresponding to the flywheel ring gear is transmitted to the internal clock acquisition system, and the internal clock acquisition system further transmits the received data to the processor for processing; the precise zero-crossing point of the pulse signal is determined by an interpolation algorithm, and on this basis, the in-cylinder The pressure signal is converted from the time domain to the angle domain; this method effectively avoids the problem of false triggering due to the loss or interference of the encoder signal in the traditional test method, and effectively improves the reliability of the data acquisition process.

Description

technical field [0001] The invention relates to a test method for a pressure signal in a cylinder of an internal combustion engine, in particular to a system and a method for converting the pressure signal in a cylinder of an internal combustion engine from a time domain to an angle domain based on an interpolation algorithm. Background technique [0002] The internal combustion engine cylinder pressure signal contains a wealth of information about the combustion process in the cylinder, which can provide important references for the development and performance improvement of internal combustion engines. Every 720-degree crankshaft angle of the internal combustion engine is a working cycle, and the collection and analysis of the pressure signal in the cylinder is based on the crankshaft angle. For this reason, the existing in-cylinder pressure signal testing systems mostly use external clock sampling to test the in-cylinder pressure. This test method requires the use of an ...

AI Technical Summary

Problems solved by technology

The encoder shaft and the crankshaft rotate synchronously, requiring high concentricity between the two. If there is a deviation between the centers of the two, it is easy to cause the loss of the encoder output signal, or even the breakage of the encoder shaft, which will adversely affect the reliable operation of the entire test system.

In addition, the output of the encoder is a high-frequency pulse signal, which is sent to the test system for shaping and processing to trigger sampling. There are various interferences such as dynamometers at the engine test site, which may easily lead to false sampling by the test system

[0004] According to the above-mentioned analysis of the existing in-cylinder pressure signal test methods, it can be seen that the existing methods have problems such as inconvenient installation of the sensor, and are easily affected by interference; and because the encoder is difficult to install, the current method can only be applied to laboratory testing occasions , for vehicle engines, due to the limited space at the free end of the engine, it is difficult to test the in-cylinder pressure

Images