DVP-ES3 Series Programming Manual Suggestions 1. Since you can use the 32-bit instruction in a lot of controlled environments, you must choose the appropriate control function. For example, to prevent improper control, do not use PID_MODE in the motor controlled environment when it is set to 1. 2. When you tune the parameters Kc_Kp , Ti_Ki , and Td_Kd (PID_MODE is set to 0), you must tune KP first (based on experience), and then set Ti_Ki and Td_Kd to 0. When you can handle the control, you can increase Ti_Ki and Td_Kd . When Kc_Kp is 1, it means that the proportional gain is 100%. That is, the error value is increased by a factor of one.
When the proportional gain is less than 100%, the error value is decreased. When the proportional gain is larger than 100%, the error value is increased. 3. To prevent the parameters that have been tuned automatically from disappearing after a loss of power, you must store the parameters in the latched data registers when PID_MODE is set to 1. The parameters that have been automatically tuned are not necessarily suitable for every controlled environment. Therefore, you can modify the automatically tuned parameters; however, it is suggested that you only modify the Ti_Ki and the Td_Kd. 4.
You can use this instruction with many parameters, but to prevent improper control, do not set the parameters randomly. Example 2: Tuning the parameters used with the PID instruction _6 Suppose that the transfer function of the plant is the first-order function ( ) a + s b = s G , the SV is 1, the sampling time Ts is 10 milliseconds. It is suggested that you follow these steps when tuning the parameters. Step 1: First, set the K I and the K D to 0. Next, set the K P to 5, 10, 20 and 40 successively, and record the target values and the process values. The results are shown in the following diagram.
1.5 K =40 P K =20 P K =10 P SV=1 1 K =5 P 0.5 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Time (sec) 6-210