A novel composite control method for actuated chamber air pressure of pneumatic microfluidic chip via a three-way electromagnetic microvalve is presented in this paper. The purpose of the control methods is to improve air pressure controlling precision for pneumatic control. By using the Bang-Bang (on-off) controller for pneumatic control, the step-response time, air pressure steady-state accuracy, and air pressure fluctuations are performed with different maximum thresholds and minimum thresholds. Moreover, by using the k (proportional ) plus PWM (Pulse-Width Modulation) control method for pneumatic control, the step-response time, air pressure steady-state accuracy, and air pressure fluctuations are performed with different carrier frequencies and carrier amplitudes. Both advantages and disadvantages of the two control methods are compared and analyzed based on the experimental data. According to the variable volume of the actuated chamber and the response characteristics of the three-way electromagnetic microvalve, the composite control method of the Bang-Bang plus k plus PWM is developed to control the actuated chamber air pressure. The experimental results show that when the absolute air pressure of the actuated chamber is set to 150kPa, the rising time is 69.3ms, which is about 8.0ms shorter than that of the k+PWM control method alone. The steady-state error is reduced from 0.90kPa to 0.65kPa, and the air pressure steady-state fluctuation is reduced from 1.60kPa to 0.90kPa, compared with the Bang-Bang control method alone.

本文提出了一种通过三通电磁微阀实现气动微流控芯片驱动腔气压的新型复合控制方法。控制方法的目的是提高气动控制的气压控制精度。通过使用 Bang-Bang（开关）控制器进行气动控制，在不同的最大阈值和最小阈值下执行阶跃响应时间、气压稳态精度和气压波动。此外，采用k（比例）加PWM（脉宽调制）控制方式进行气动控制，在不同载波频率和载波幅值下进行阶跃响应时间、气压稳态精度和气压波动。根据实验数据比较分析了两种控制方法的优缺点。根据作动腔的可变容积和三通电磁微阀的响应特性，开发了Bang-Bang+k+PWM的复合控制方法来控制作动腔气压。实验结果表明，当驱动室绝对气压设置为150kPa时，上升时间为69.3ms，比单独使用k+PWM控制方式缩短了约8.0ms。与单独的Bang-Bang控制方法相比，稳态误差从0.90kPa降低到0.65kPa，气压稳态波动从1.60kPa降低到0.90kPa。根据作动腔的可变容积和三通电磁微阀的响应特性，开发了Bang-Bang+k+PWM的复合控制方法来控制作动腔气压。实验结果表明，当驱动室绝对气压设置为150kPa时，上升时间为69.3ms，比单独使用k+PWM控制方式缩短了约8.0ms。与单独的Bang-Bang控制方法相比，稳态误差从0.90kPa降低到0.65kPa，气压稳态波动从1.60kPa降低到0.90kPa。根据作动腔的可变容积和三通电磁微阀的响应特性，开发了Bang-Bang+k+PWM的复合控制方法来控制作动腔气压。实验结果表明，当驱动室绝对气压设置为150kPa时，上升时间为69.3ms，比单独使用k+PWM控制方式缩短了约8.0ms。与单独的Bang-Bang控制方法相比，稳态误差从0.90kPa降低到0.65kPa，气压稳态波动从1.60kPa降低到0.90kPa。开发了Bang-Bang plus k plus PWM的复合控制方法来控制作动室气压。实验结果表明，当驱动室绝对气压设置为150kPa时，上升时间为69.3ms，比单独使用k+PWM控制方式缩短了约8.0ms。与单独的Bang-Bang控制方法相比，稳态误差从0.90kPa降低到0.65kPa，气压稳态波动从1.60kPa降低到0.90kPa。开发了Bang-Bang plus k plus PWM的复合控制方法来控制作动室气压。实验结果表明，当驱动室绝对气压设置为150kPa时，上升时间为69.3ms，比单独使用k+PWM控制方式缩短了约8.0ms。与单独的Bang-Bang控制方法相比，稳态误差从0.90kPa降低到0.65kPa，气压稳态波动从1.60kPa降低到0.90kPa。