动压反馈伺服阀的反馈性能测试方法

Test Method for Dynamic Pressure Feedback Servo Valve

为准确测量动压反馈伺服阀的反馈网络时间常数τ,提出一种用频率扫描法来测量时间常数的方法。建立了动压反馈伺服阀的反馈压差与加载压差的传递函数,该传递函数是关于τ的表达式。据此,只要能获取该传递函数,就可以计算出时间常数的值。为此,设计了专门的测试装置,通过试验法获取该传递函数的幅频特性,从而间接计算出τ。测试装置由一个加载伺服阀为被测伺服阀提供幅值恒定、频率递增的交变负载,通过一个数字控制器实现加载压力幅值的恒定控制。试验测试表明,测试过程可行,结果准确可靠,能够满足实际要求。

In order to test the time constant value τ of dynamic pressure feedback servo valves,an approach based on frequency sweep is presented.The transfer function is established between the load differential pressure and feedback differential pressure.The transfer function is an expression about τ.So the time constant value can be calculated through the transfer function.A testing equipment is designed,and the amplitude frequency characteristic of the transfer function can be acquired through it.In this equipment, an alternating load with constant amplitude and incremental frequency is generated through a load servo valve. A digital controller is designed to realize the load amplitude value control. The test result shows that the test procedure is feasible, and the data obtained is accurate and reliable. The test method designed in this article can meet engineering requirements.