The following two pictures separately using two groups of Kp, Ki, Kd parameters, the input signal for the step function, get the response of the
Figure in the red line is the system output under the PID control, the blue line is the step signal input, intuitive as you can see, compared with the above, below response is slow, and big overshoot, so PID parameter is superior to the chart above,
Figure such have obvious difference in the circumstances, can be intuitive conclusion, but in the process of a fine parameter adjustment, the response of the two sets of parameters, there would be little difference, the human eye is difficult to directly make good judgment, the group that won't be able to select the optimal parameters, is I think of the solution to obtain the different time, the system response (red line) and the error between the system input (blue line), which USES the shaded area in the graph system response and the deviation of the input signal, the area is smaller, the system response is more close to the input signal, then the PID parameters is the best,
For half a day on the Internet, found that automatic control theory doesn't seem to be involved in the problem, also didn't see anyone to discuss this problem, many articles about method of parameter setting, are not clear is pointed out that the criterion of evaluating parameters, I this judgment method for? In the, hope to discuss, thank you very much!