数据采集与变频调速在插销裂纹试验机上的应用

Application of data-acquisition and frequency-converter technology to an implant cracking test machine

针对插销裂纹试验机加载过程波动大,影响试验结果的问题,利用数据采集技术记录插销所经历的热循环和载荷历程,通过采集卡的数字输出通道控制继电器的通断,从而改变变频器的输出电压相位,达到控制插销试验机电机转向的目的;对于试验过程中给定的载荷设定值,系统根据等比关系将其模糊化成几个区间,并确定当前采集到的载荷的所在区间,根据区间的不同,赋予采集卡的模拟输出通道一变化电压值,将其输出到变频器,最终控制电动机的转速。试验结果表明,加载过程实现了自动化和平稳化,并且在载荷设定值处没有超调量。

The paper illustrates the application of frequency-converter and data acquisition card to implant cracking test machine. The loading history and temperature in the test are recorded using a data acquisition card. The digital output channel of the data acquisition card is connected with the switches which are used to control the frequency converter. When the state of the switch changes, the phase of the frequency converter output voltage also changes. So the direction of the motor can be controlled. At the same time, the setting load is divided into 5 intervals by the system according to the ratio of equality, and the interval in which the currently-acquired load stays can be fixed as well. With the change of the interval, analog output channel outputs a variant voltage to frequency converter that controls the speed of the motor. The experimental results indicate that the new loading process is smooth and stable, without overshoot.