Acquiring Of Dynamic Load Spectrum About Automobile Transmission And Editing Of Load Spectrum For Test Bench

The dynamic load spectrum of automotive transmission is the indispensable data foundation for automotive transmission’s design, analysis and test. Because of the complexity of automobile driving diversities and load changing conditions, to obtain the dynamic load spectrum of automotive transmission accurately is a very important task for related design, research and using on the follow-up test bench. Domestic transmission data acquisition always uses the foreign standard without the consideration of inland road situation. At the same time, the acquisition of automotive transmission load spectrum is not comprehensive enough and also have a poor synchronization. It’s a bad impact on the subsequent use of automotive transmission load spectrum. In the test bench load spectrum compiling,the constant steady torque with constant speed spectrum or foreign standard spectrum is used frequently which poorly effect the actual loading of test bench. Acquiring and using of the real vehicle load spectrum poorly is an great obstacle of the research, development and test of the automotive transmission.First of all, this article builds up the complete synchronous data acquisition system of automotive transmission with the core component of the GIF wireless torque measuring device and HBM instrument of high performance data acquisition, considered design, test and analysis of automotive transmission and selected torque, speed, gear, brake pedal state, clutch pedal stroke state, temperature, strain, acceleration and other important parameters. Combined the characteristics of domestic road with the proving ground test specification, set the proving ground test scheme of dynamic load spectrum acquisition with a certain type of SUV transmission.Secondly, select the load data sample with 50% survival rate of the population based on the data processing and the key parts damage analysis. Extract the dynamic load spectrum of automotive transmission for each gear with the priming of speed ratio signal. Four point rain flow counting method is used to statistics of load frequency. According to the Epanechenikov kernel function theory and the rain-flow matrix extrapolation technique, extrapolate the load matrix to the target cycling mileage which containing the equivalent load cycles of the whole durability test in proving ground test.Finally, obtain the curves of accumulated more than cycle number and the four-level program load spectrum of bench test with the Miner fatigue cumulative damage theory and Goodman mean stress correction method. Through the damage verification of block spectrum and the proving ground test, the result shows the four-level program load spectrum with equivalent damage effect of the proving ground test. On the foundation of this process, the author have a study of the dynamic load spectrum preliminary.