What is PID? What is KD? Please give me some advice, heroes?

PID pipeline professional refers to "processing & instrument drawing" processing & instrument drawing. Automatic control professional PID refers to the acronym of proportion, integral and differential. In biology, KD is a unit of molecular mass. KD in automatic control seems to refer to differential control.

PID is the abbreviation of Proportion, Integral and Differential.: It responds to the deviation of the system in proportion. Once a deviation occurs in the system, the proportional adjustment immediately produces an adjustment effect to reduce the deviation. A large proportional effect can speed up adjustment and reduce errors, but an excessively large proportion will reduce the stability of the system and even cause instability in the system.: It is to eliminate the steady-state error of the system and improve the indifference. Because there is an error, the integral adjustment is carried out until there is no difference, the integral adjustment stops, and the integral adjustment output is a constant value. The strength of the integral effect depends on the integration time constant Ti. The smaller Ti, the stronger the integral effect. On the contrary, if Ti is large, the integral effect is weak. Adding integral adjustment can reduce the stability of the system and slow down the dynamic response. The integral effect is often combined with the other two adjustment laws to form the differential adjustment effect of a PI regulator or a PID regulator.: The differential effect reflects the rate of change of the system deviation signal and is foreseeable. It can predict the trend of deviation changes, so it can produce advanced control effects. Before the deviation is formed, it has been eliminated by the differential adjustment effect. Therefore, the dynamic performance of the system can be improved. When the differential time is appropriately selected, overshoot can be reduced and the adjustment time can be reduced. The differential effect amplifies noise interference, so excessive differential adjustment is detrimental to the system's anti-interference. In addition, the differential response is the rate of change, and when the input does not change, the output of the differential action is zero. The differential effect cannot be used alone and needs to be combined with the other two regulating laws to form a PD or PID controller. What picture is the KD you mentioned shown on? I didn’t find it, but I saw many instrument models represented by KD.