Effects Of Single Drum Chassis Dynamometer System Error On Test Accuracy

In this paper, the topic from the National Natural Science Foundation of "Single DrumFree to Disassemble and Car Engine Output Measurement Method". Single drum chassisdynamometer testing equipment is a high-performance vehicle detection field. It can replacethe real road. It can transfer the car road test interior. And then, the test can be get rid of thelimit of the test site and weather conditions and other external factors with high precision,multi-function, and good test repeatability. Our country’s research on chassis dynamometerdeveloped later. Most products can not meet the test requirements. On this basis, in this paper,the causes of dynamometer system errors are analyzed and the error correction method ispresented. Aims to improve the precision of chassis dynamometer and provide a reference forsimilar products research and development.In this paper, the object of study is the type of AVL Roadsim48inches single drumchassis dynamometer. And it describes the various components constituting the chassisdynamometer. It detailedly describe the structure of the chassis dynamometer and explainedthe working mechanism of the chassis dynamometer systems. According to the workingprinciple of the structural characteristics of the chassis dynamometer test system and thedynamometer, the detection of vehicle test results to parameter errors are analyzed. Includingdynamometer drum geometry, runout drum circle, balancing features, speed sensors, forcesensors, control system response time, basic inertia dynamometer, dynamometer parasiticresistance and dynamometer simulation when traveling road load resistance load curve. And itanalyzed the effect of these parameters between each other.On the basis of the parameters that affect the performance of the dynamometer testsconducted analysis. These parameters are designed for the measurement method.Determination of the true value, comparison with the theoretical value, analysis of the testresults deviations due to the parameter errors this paper presents these parameters correctionmethod through a lot of testing and debugging. The test results show that, the dynamometerbased inertia value is1178kg, parasite load sliding friction values obtained in the methodused to measure the different load907kg,1178kg,2495kg with a time constant methodvalidation, the maximum deviation of only1.14N. The simulation curve of the road resistancecompared with the actual road resistance curve, also meet at the speed of less than36km/h.The maximum deviation is less than5%. The speed is greater than36km/h.The maximumdeviation is less than3%of the requirements. Calibration method is adopted in this paper. It make the chassis dynamometer test accuracy meet better.Finally, this paper contrast the road glide and the dynamometer slide.Based on the testresults, in the contrast of sliding time and coasting of power machine between pickup trucksand car. The maximum error is only1.09%and1.84%. It is proved that the proposed chassismeasurement and error correction method is feasible and effective for power factor. Aftercalibration of the chassis dynamometer the test has a good performance, the accuracy of thetest results meet the test requirements.