PID, differential gain, differential time
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I searched the forum for many posts on differential action, but still didn’t understand the relationship between differential gain and differential time. Can it be understood in this way that the differential action is determined by the product of the differential gain and the differential time? Is the differential gain the amplification factor? In some PID parameter settings, there is only a derivative time, but no derivative gain – what’s the reason for that?
The derivative gain in a parallel PID is equal to the total gain in the ideal formula multiplied by the derivative time. Gain can be understood as the amplification factor; if it is not set, or is not available, it means the default value is 1!
Thank you for the explanation, teacher. I would like to ask further: since differential gain represents the amplification factor, it shouldn’t have any units? Can it be understood this way: if the differentiation time is 120 seconds when no differential gain is set, then with a differential gain of 2, the differentiation time should be set at 60 seconds?
Don’t call me teacher; I only know a little bit as well. Let’s all improve together – by helping you, I’m also reinforcing the knowledge I have! Correct me if I’m wrong: the differential gain can be 0, meaning that differentiation has no effect. As for the relationship between differential time and differential gain, you can refer to the explanation in the link below, as it is quite professional in nature. https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z0000019L5TSAU&l=zh-CN