Research On The Test System Of Shaft Power Based On Strain Gauge

Testing of vehicle shaft power is mainly carried out in the study of the efficiency of power transmission. Power transmission system is an important part of power plant. The shaft power parameters provide an important design requirements basis for power test. Therefore, improve measuring accuracy of the shaft power transmission has great practical significance on vehicle power drive systemCurrently, foreign domestic the main measurement for shaft power is by measuring the speed and strain of the shaft torsional, then change to power and the torque conversion methods available. Speed measurement technology is relatively mature, testing precision has been met requirements Therefore, torque measurement accuracy is the top priority in shaft power test. There are three test methods for torque measurement as follows: magnetic elastic type, phase type and strain type. Based on analyzing and comparing the advantages and disadvantages of various types of torque testing methods, the topic uses strain gauge torque measurement method. The test method has a wide range, high measurement accuracy, and simple structure, so it is not only suitable for static measurements but dynamic measurements.The vehicle drive shaft exist torque and additional torque caused by bending moment and torsional vibration, which have a great impact on the measuring accuracy of the shaft power. So the topic develops a vehicle shaft power test system which has simple structure and high reliability, starting from torque testing theory and analyzing the shaft bending moment, torsional vibration, developed a simple structure, high reliability of the drive shaft power.First, based on the test principle of strain gauge torque, the topic completed the strain gauges of the paste, group bridge, protection, and designed the torque signal conditioning circuit. According to the system requirements, completed the design of the speed measurement circuit, A / D circuit, LPC2129 control circuit, data transfer circuit implements the PCB design. The topic transplants the real time operating system ofμC/OS-Ⅱand programs the code. Finally, the topic analyzes the bending moment and torsional vibration of vehicle drive shaft, proposed to eliminate influence on the torque test measures and completed a static calibration test system which gives the system measurement errors.In this paper, the vehicle shaft power test system through the laboratory test is verified to the feasibility and correctness.