生物质酶催化过程中pH值的非线性控制

为提高酶催化过程中pH值的控制精度,采用了具有参数自适应及Hammerstein模型2种相结合的控制策略方法,利用递推最小二乘进行参数估算,在控制器里颠倒静态非线性特性来对过程非线性部分进行补偿.此方式用于酶催化过程中的pH值过程控制,其试验结果不仅可使pH值高度非线性控制转换成一个近似的线性控制,并自动地改变控制器的整定参数,从而解决pH中和过程的高度非线性控制难点,还可达到提高酶催化过程中pH值的控制精度、提高酶的催化响应效果的目的.pH中和过程的计算机仿真结果表明,该控制算法比比例积分微分(proportion integral differential,PID)控制具有更好的控制品质.由于该控制主要是针对pH值的控制,有较强的通用性,具有典型应用价值和推广意义.

Nonlinear control of pH value in biomass catalytic process

Abstract: The pH neutralization process has the highly nonlinear characteristic, when you add neutralizer or interference, pH value near the neutralization point changes a lot, while the pH value in the else points are opposite. It is very difficult to control. According to the characteristics of the pH controls in enzyme catalysis, using a parameter adaptive state controller and Hammerstein model control strategies, employing recursive least squares parameter estimation, static nonlinear characteristics of the controller upside down process non-linear part of the compensation and Hammerstein model is used to design the nonlinear model predictive control algorithm. Compared with other controller state for a difficult to control process this has a very good effect. The system engages in uncertainties real-time compensation, so as to improve the enzyme catalytic process in the stability of the enzyme activity. When the temperature random variation occurred, we carried out various controls in the field experimental study, in the enzyme-catalyzed process in the pilot test. Due to the mutual coupling of the temperature and pH in the catalytic process. The enzyme catalysis in the process of test, and the reaction time of 30 minutes and the simple PID control of the pH value of the large fluctuation, resulting in a big decrease in enzyme activity. The model reference adaptive controller under the control of the pH value of the wave is small, thus leading to a small decline in the range of enzyme activity, so as to enhance the catalytic process of the stability of the enzyme activity. In this way, converted into an approximate linear control for the pH of the enzyme catalysis process control not only enables the pH value highly nonlinear control, and automatically changes the controller tuning parameters, and solves the high degree of pH neutralization process linear control difficulties, but also improves the accuracy of the pH control in the enzyme catalysis process. pH neutralization process computer simulation results show that the control algorithm has better control over the quality to PID control. The control method can also be used for zinc smelting, in the chemical industry and other areas of pH control. The result of the typical running status indicates that the derived equations according to the theory have a prominent application value and extended significance for popularization. The control technology can be used in all kinds of chemical industry, agriculture and other areas of pH control, and can reduce the pollution of the environment, and therefore has certain market prospects.