Absrtact: The control mechanism of Dahlin controller is reinterpreted.
The incident angle of the root locus of the Dahlin controller is calculated by using the vector analysis method. The relationship between the pole radius and the pole radius of the Dahlin controller and the angle between the positive and real axes is studied.
A computer plotting method for root locus of Dahlin controller is presented. In addition, the position of the complex poles of the Dahlin controller can be determined by drawing. The Dahlin controller [1] is used to control the first-order time-delay process and has good control effect. The Dahlin controller is simple to use and the expected closed-loop time constant is its only setting parameter. Document [2] studies the root locus of Dahlin controller, thermostatic element which takes the expected closed-loop time constant as the parameter. By using the root locus property of Dahlin controller, the paper draws the following conclusion: for any order Dahlin controller, the output of the controller may produce ringing phenomenon when there is model mismatch and the expected closed-loop time constant is small; the ringing phenomenon can be suppressed by increasing the expected closed-loop time constant. In reference [5], the robust stability of Dahlin control systems with gain mismatch, time constant mismatch and delay mismatch is studied.
The internal model structure of Dahlin control system is studied in reference [6].
In this paper, the control mechanism of Dahlin controller is redefined according to the existing root locus properties.
The incident angle of the root locus of the Dahlin controller is calculated by using the vector analysis method. The relationship between the pole radius and the pole radius of the Dahlin controller and the angle between the positive and real axes is studied. The computer plotting method of root locus of Dahlin controller is given.
In addition, the position of the complex poles of the Dahlin controller can be determined by drawing.