Taghizadeh Mostafa, Ghaffari Ali, Najafi Farid
Mechanical Eng. Department, KNToosi University of Technology, Tehran, Iran.
ISA Trans. 2009 Oct;48(4):512-8. doi: 10.1016/j.isatra.2009.05.001. Epub 2009 May 29.
In this paper, the effect of pneumatic circuit design on the input-output behavior of PWM-driven servo-pneumatic systems is investigated and their control performances are improved using linear controllers instead of complex and costly nonlinear ones. Generally, servo-pneumatic systems are well known for their nonlinear behavior. However, PWM-driven servo-pneumatic systems have the advantage of flexibility in the design of pneumatic circuits which affects the input-output linearity of the whole system. A simple pneumatic circuit with only one fast switching valve is designed which leads to a quasi-linear input-output relation. The quasi-linear behavior of the proposed circuit is verified both experimentally and by simulations. Closed loop position control experiments are then carried out using linear P- and PD-controllers. Since the output position is noisy and cannot be directly differentiated, a Kalman filter is designed to estimate the velocity of the cylinder. Highly improved tracking performances are obtained using these linear controllers, compared to previous works with nonlinear controllers.
本文研究了气动回路设计对脉宽调制（PWM）驱动的伺服气动系统输入输出行为的影响，并使用线性控制器而非复杂且昂贵的非线性控制器来改善其控制性能。一般来说，伺服气动系统以其非线性行为而闻名。然而，PWM驱动的伺服气动系统在气动回路设计方面具有灵活性优势，这会影响整个系统的输入输出线性度。设计了一种仅带有一个快速切换阀的简单气动回路，该回路可实现准线性输入输出关系。所提出回路的准线性行为通过实验和仿真均得到了验证。然后使用线性P控制器和PD控制器进行闭环位置控制实验。由于输出位置存在噪声且无法直接求导，设计了卡尔曼滤波器来估计气缸的速度。与先前使用非线性控制器的工作相比，使用这些线性控制器可获得显著改善的跟踪性能。
