Test of proportional controller

比例控制器的测试
Test of proportional controller

比例控制放大器和比例电磁铁性能优劣直接影响比例阀的综合性能。对于单个部件如比例控制放大器和比例电磁铁都能达到设计要求，组成系统后不一定符合系统的要求，其原因是系统中存在各单元之间的参数匹配问题。
The performance of proportional control amplifier and proportional electromagnet directly affects the comprehensive performance of proportional valve. For single components, such as proportional control amplifier and proportional electromagnet, they can meet the design requirements. After the system is formed, it may not meet the requirements of the system. The reason is that there is a problem of parameter matching between each unit in the system.

对比例控制系统综合性能的测试，利用系统中各单元的可调部分，调整相应的参数，可以使系统达到最佳匹配。
For the test of the comprehensive performance of the proportional control system, using the adjustable parts of each unit in the system to adjust the corresponding parameters can make the system achieve the best match.

1．测试系统
1. Test system

测试系统设计目标是完成比例控制放大器性能测试，包括输出/输出特性、颤振信号（波形、幅值和频率）、斜波发生器性能测试；比例控制器的匹配测试（调试），主要包括电流一力特性、力一位移特性、力一输入信号变化阶跃响应、幅频特性、初始电流以及输出范围调试等。
The design goal of the test system is to complete the performance test of the proportional control amplifier, including the output / output characteristics, flutter signal (waveform, amplitude and frequency), and the performance test of the ramp generator; The matching test (debugging) of proportional controller mainly includes current force characteristic, force displacement characteristic, force input signal change step response, amplitude frequency characteristic, initial current and output range debugging, etc.

系统主要由控制柜、机械传动（支撑）系统、信号转接盒、PXI系统及其他部分组成。
The system is mainly composed of control cabinet, mechanical transmission (support) system, signal transfer box, PXI system and other parts.

机械传动系统主要为被测产品提供必要的支撑和相应的机械传动，主要包括力传感器变送器、位移传感变送器，其中直线步进电动机为比例控制器提供模拟负载。
The mechanical transmission system mainly provides necessary support and corresponding mechanical transmission for the tested product, mainly including force sensor transmitter and displacement sensor transmitter, in which the linear stepping motor provides analog load for the proportional controller.

控制系统包括系统电源控制、信号发生与采集、硬件驱动。控制系统是软件和硬件结合的枢纽，是PXI系统的一部分。
The control system includes system power control, signal generation and acquisition, and hardware drive. The control system is the hinge of the combination of software and hardware, and it is a part of PXI system.

数据采集及显示部分的功能是把控制信号、被测量以及其他辅助测试参数，通过软件转化为实时显示的数据，并对数据进行处理得到要测试的结果。
The function of data acquisition and display part is to convert the control signal, measured and other auxiliary test parameters into real-time displayed data through software, and process the data to get the test results.

测试系统软件开发平台是LabVIEW7.1。根据测试内容和测试步骤，软件的结构采用递进式结构，即：主程序层：由用户界面和测试执行部分构成；第二层是测试层，负责逻辑关系的验证及相关决策的制定；最低层是驱动层，负责与仪器、被测设备以及其他应用程序之间的通信。
The software development platform of the test system is LabView7.1. According to the test content and test steps, the software structure adopts a progressive structure, that is, the main program layer: composed of user interface and test execution part; The second layer is the testing layer, which is responsible for the verification of logical relations and the formulation of relevant decisions; The lowest layer is the driver layer, which is responsible for the communication with instruments, tested devices and other applications.

软件的主界面主要由波形图区、数据显示器区、数据输入框、操作按钮、指示灯等控件组成。
The main interface of the software is mainly composed of oscillogram area, data display area, data input box, operation button, indicator light and other controls.

软件主要功能如下；
The main functions of the software are as follows;

(1)数据显示与处理。所采集的有关数据主要用图和数字框实时显示，便于测试人员观察数据的变化。测试结束后，提示测试人员输入有关的参数，根据定义得到比例控制器性能的测试结果。
(1) Data display and processing. The collected relevant data is mainly displayed in real time with graphs and digital boxes, which is convenient for testers to observe the changes of data. After the test, prompt the tester to input relevant parameters and get the test results of the performance of the proportional controller according to the definition.

(2)数据保存与读取。所测试的数据以LabVIEW提供的格式保存在本地硬盘，需要读取数据时，选择相应的文件，即可在测试环境里再现测试曲线。

(3)报告生成。被测试参数（曲线）以图片的格式在MSWORD中显示，其他测试信息和结果也一并导人文档，便于文档的保存和管理，具有一定的通用性。

2．测试系统工作原理

以电流力特性测试为例，根据比例电磁铁的性能，调整比例控制放大器的可调整参数。由直线步进电动机往复移动找到比例电磁铁的工作行程区，步进电动机上电固定不动。输入比例控制放大器控制信号电压，由PXI系统信号发生器生成递增（递减信号），由DMM记录比例电磁铁的电流（横坐标），AI采集卡记录力传感变送器信号（纵坐标），自动完成控制信号从小大小循环过程的电流力变化曲线。为了得到该特性的有关参数，上述过程重复3次，最后得到3组（条）数据（曲线）。输人有关数据处理的参数，即可得到该比例控制器的滞环、重复精度和线性度等测试结果。

比例控制器的力、位移特性测试时，由步进电动机往复移动作为比例电磁铁的模拟负载，自动记录比例控制器的位移变化对应比例电磁铁力输出的变化，输入相应初始值，同样可以计算出力滞环等参数。瞬态特性的测试与电流力变化特性测试类似，只是控制信号不同。
When testing the force and displacement characteristics of the proportional controller, the reciprocating motion of the stepping motor is used as the simulated load of the proportional electromagnet, and the displacement change of the proportional controller corresponding to the change of the proportional electromagnet force output is automatically recorded. The corresponding initial value is input, and the output hysteresis and other parameters can also be calculated. The transient characteristic test is similar to the current force change characteristic test, but the control signal is different.

3．技术特点
3. Technical features

测试系统可以精确记录比例控制器参数变化值，可方便准确地计算出有关结果，这是传统比例电磁铁测试方法（比如用X-Y记录仪）所不易完成的。
The test system can accurately record the parameter changes of the proportional controller and calculate the relevant results conveniently and accurately, which is not easy to complete by the traditional proportional electromagnet test method (such as using X-Y recorder).

模拟负载采用步进电动机，有利于位置的精确控制，保证负载的平稳性，避免测试过程中干扰，有利保证测试精度。另外，具有净化测试系统环境，系统维护方便等优点。
The simulated load adopts stepping motor, which is conducive to the accurate control of position, ensuring the stability of load, avoiding interference in the test process, and ensuring the test accuracy. In addition, it has the advantages of purifying the testing system environment and convenient system maintenance.

比例控制器元件制造的个别差异可以在该测试系统中进行初始状态调试，达到比例控制放大器和比例电磁铁的最佳匹配，保证比例控制器在一定范围内互换而不影响比例阀的主要特性。在开发新产品阶段，对于电液比例阀性能分析有很大的帮助作用。
Individual differences in the manufacturing of proportional controller components can be debugged in the initial state of the test system to achieve the best match between the proportional control amplifier and the proportional electromagnet, so as to ensure that the proportional controller can be interchanged within a certain range without affecting the main characteristics of the proportional valve. In the stage of developing new products, it is very helpful for the performance analysis of electrohydraulic proportional valve.
Individual differences in the manufacturing of proportional controller components can be debugged in the initial state of the test system to achieve the best match between the proportional control amplifier and the proportional electromagnet, so as to ensure that the proportional controller can be interchanged within a certain range without affecting the main characteristics of the proportional valve. In the stage of developing new products, it is very helpful for the performance analysis of electrohydraulic proportional valve.