1、附 录 附件 1：英文资料及中文翻译 英文资料 PID control algorithm 1, PID is a closed loop control algorithm. Therefore, to achieve the PID algorithm, you must have the hardware loop control, that is, must have feedback. Such as controlling a motor speed, you have to have a measurement of speed sensor, and the results f
2、ed back to the control line, the following will also be speed control, for example. 2, PID is the proportional (P), integral (I), Derivative (D) control algorithms. But not must have these three algorithms, it can be PD, PI, or even only the P-control algorithm. I used for closed-loop control of one
3、 of the most simple idea only P control, the current results fed back, and then subtract the target, is positive, then slow down, then it is negative acceleration. Now know that this is just the simplest closed-loop control algorithms. 3, the ratio (P), integral (I), differential (D) control algorit
4、hms have effect:?Proportion of the reaction system, the basic (current) deviation e (t), coefficient, can speed up the regulation, reduce errors, but the system is too large proportion decreased stability, or even cause system instability；?Integral, the cumulative deviation of the reaction system, a
5、llowing the system to eliminate the steady state error, no gradient to improve, because there is an error, integral control will be carried out until no error；?Differential, reflecting the rate of change of the system deviation signal e (t)-e (t-1), is foreseen to anticipate trends deviation generat
6、ed ahead of the control action, the deviation is not formed, has been the differential regulation of remove, so you can improve the dynamic performance. However, differential interference to noise amplification role in strengthening differential interference detrimental to the system.Integral and di
7、fferential can not work alone and must be proportional control cooperation. 4, the controller of the P, I, D item selection.The following rules will be used to control various control features briefly summarized here: 1, the proportional control law P: P control law used to quickly overcome the dist
8、urbances, which act on the output value of the fast, but not very stable at a desired value, compared with a negative result is to effectively overcome the disturbances, but more than a difference appears. It is suitable for the control channel lag is small, little change in the load control is less
9、 demanding, controlled parameters within a certain range to allow more than poor occasions. Such as: Jin Biao under the Ministry of Public Works pump house cold, heat pool water level control； pump room intermediate tank oil level control. 2, proportional integral control law (PI): in engineering pr
10、oportional integral control law is the most widely used control law. Points that can be eliminated on the basis of the proportion of residual error, which applies to the control channel lag is small, little change in load, was charged with parameters do not allow more than a poor occasions. Eg: In t
11、he main chamber kiln heavy commutation No. F1419 F1401 to heavy gun flow control system； pump room for the pipeline flow control system； annealing furnace temperature control system, etc. districts. 3, proportional and differential control law (PD): Differential effects has advanced, with capacity f
12、or hysteresis control channel, the introduction of differential involved in the control, the derivative term is set properly in the case, for improving the systems dynamic performance indicators, have a significant effect. Therefore, for the time constant of the control channel or capacity lags larg
13、er occasions, in order to improve the stability of the system, reducing the dynamic deviation proportional derivative control law can be used. Such as: heated temperature control, composition control. It should be noted that, for those pure lag larger area, the derivative term is powerless, and in t
14、he measured signal is noisy or periodic vibration system, you should not use derivative control. Such as: large kiln glass level control. 4, for example, integral derivative control laws (PID): PID control law is an ideal control law, it is based on the introduction of proportional integral, can eli
15、minate residual error, then add the derivative action, but also improve system stability. It is suitable for the control channel or capacity lag time constant is large, the control requirements of the occasion. Such as temperature control, composition control.?Given D role of the law, we must also u
16、nderstand the concept of time lag, the time lag including capacity lag and pure lag. Capacity in which they lag usually include: measurement and transmission lag lag. Measurement hysteresis is detecting element in the detection need to establish a balance, such as thermocouples, RTD, pressure, etc.
17、resulting from a slow response lag. The transmission lag is in the sensors, transmitters, actuators and other devices produce a control delay. Pure delay is measured relative lag in industry, most of the time delay caused due to material transport, such as: large kiln glass level, feeding maneuver d
18、one in the nuclear level gauge detection requires a very long period of time.?In short, the choice of control law according to the process characteristics and process requirements to select, and never say PID control law in any case, has better control performance, regardless of the occasion are use
19、d is unwise. If you do so, it will only add complexity to the other work and give parameter tuning difficult. When using PID controller has not yet reached technological requirements, you need to consider other control scheme. If cascade control, feedforward control, large hysteresis control. 5the p
20、roblem. Kp, Ti, Td setting the three parameters of the PID control algorithm key issues. Generally they can only be set when programming the approximate value and the system is running through repeated testing to determine the best value. Therefore, the program must apply for the commissioning phase
21、 and memory can be modified at any of these three parameters. 6 the parameter self-tuning. In some applications, such as generic instrumentation industry, systems work object is uncertain, different objects have different parameter values, can not set parameters for the user, on the introduction of the concept of self-tuning parameters . Essence is the first time, through the N measurements is looking for a new job object parameters, and
