Vehicle condition information acquisition system for vehicle NVH evaluation and test

Abstract

The invention discloses a vehicle condition information acquisition system for vehicle NVH evaluation and test. The system comprises a serial port unit, a CAN unit, a central processing unit, an RPM pulse output unit, a Speed pulse output unit and a display unit; the output end of the CAN unit is connected with the input end of the central processing unit, and the output end of the central processing unit is connected with the input ends of the serial port unit, the RPM pulse output unit, the Speed pulse output unit and the display unit. The system has the advantages that a CAN bus test mode of the system adopts a monitoring mode, non-interference of engine operation is realized, and a CAN bus test mode based on real-time inquiry is effectively overcome; in addition, the system can achievethe data updating speed of 100 Hz, effectively solves a problem that the inherent time resolution of a rotating speed signal and a vehicle speed signal obtained directly through an ISO15765 protocolis poor and usually does not exceed 20 Hz, and completely meets the requirements of an NVH test for the precision of the rotating speed and the precision of the vehicle speed.

Description

technical field [0001] The invention belongs to the technical field of vehicle condition information collection, and in particular relates to a vehicle condition information collection system for automobile NVH evaluation and testing. Background technique [0002] At present, about 1 / 3 of the failure problems of automobiles are related to NVH, and nearly 20% of the research and development costs of major companies are spent on solving the NVH problems of vehicles. During the research and development period of mid-to-high-end cars, the amount of experiments related to NVH is the largest, so Automotive NVH testing plays a pivotal role in vehicle development. Car NVH test obtains car status information through a series of test methods, including: speed, vehicle speed, pedal depth, throttle opening, output torque, intake manifold pressure, actual gear position of automatic transmission, clutch status of automatic transmission, compressor status , catalytic converter heating sta...

AI Technical Summary

Problems solved by technology

[0004] (2) Gear position information. For manual transmission cars, we can easily know which gear the car is in, but for automatic gear vehicles, it is difficult to obtain the gear position information in real time.

[0008] 1) Difficult to install, small space for fixed position, difficult to fix;

[0009] 2) Unstable, because the engine keeps oscillating while running

[0012] 1) Instability, electromagnetic pulse instability;

[0013] 2) Limitation, the diesel engine cannot clamp the cylinder line

[0018] 1) The transmission ratio of each engine is inconsistent. For the case where the ripple frequency is different, it needs to be calibrated before testing;

[0019] 2) In some cases, the generator does not generate electricity, or the ripple signal is too weak, resulting in unstable signal, unable to prepare to obtain the speed information

[0022] 1) Based on the standard protocol, there is a problem of poor time resolution and certain limitations;

[0023] 2) Interrogate the CAN bus in real time to interfere with engine work

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