A PID adjustment system and method

Abstract

The present invention provides a PID control system and method. The system includes a first calculation module, whose output end is respectively connected to the input ends of a proportional control module, an integral control module, and a differential control module, and its output end is also connected to the input end of a process control module. The output ends of the proportional control module, the integral control module, and the differential control module are respectively connected to the input end of a second calculation module. The output end of the second calculation module and the output end of the process control module are respectively connected to the input end of a third calculation module. The output end of the third calculation module is connected to the input end of an actuator. The output end of the actuator is respectively connected to the input end of the first calculation module and the control target. The output end of the control target is connected to the input end of the process control module. The method readjusts the parameters of the actuator by adjusting the proportional control parameter, the integral control parameter, the differential control parameter, and the process control parameter, ultimately reaching the parameter value set by the actuator, and obtaining a stable dynamic balance system.

Description

Technical Field

[0001] The present invention relates to the technical field of PID regulation, and in particular to a PID regulation system and method. Background Art

[0002] In process control, the PID controller that controls according to the deviation's proportional (P), integral (I) and differential (D) is the most widely used automatic controller. It has the advantages of simple principle, easy implementation, wide applicability, independent control parameters, and relatively simple parameter selection. The schematic diagram of the general PID control principle is as follows Figure 1 As shown, its time domain function is:

[0003]

[0004] Among them, U(t) is the output of the PID control system, e(t) is the input of the PID control system, K p 、T i and T d They are the three adjustment parameters P, I and D respectively. p The current deviation e(t) of the reaction system. A large coefficient can speed up the adjustment and reduce the error, but an excessively large ratio will reduce the stability of the system and even cause the system to be unstable. i The accumulated deviation of the reaction system eliminates the steady-state error and improves the degree of error-free. Because there is an error, the integral adjustment is carried out until there is no error. d The rate of change of the system deviation signal, e(t)-e(t-1), reflects the speed at which the system approaches the target value. This coefficient controls how quickly the system approaches the target value, creating a proactive control effect. Typical PID control systems use the P parameter to control response time, the I parameter to control the steady-state tolerance bandwidth, and the D parameter to control dynamic response. These three parameters collectively control the convergence of the output curve. Typical PID control systems suffer from slow output response, prone to overshoot, and steady-state errors. Therefore, developing a PID control method with fast response, short stabilization period, and minimal dynamic load fluctuation is an urgent problem to be solved. Summary of the Invention

[0005] In response to the shortcomings of the above problems, the present invention provides a PID control system, which includes a first calculation module, the output end of the first calculation module is respectively connected to the input end of the proportional control module, the integral control module and the differential control module, the output end of the first calculation module is also connected to the input end of the process control module, the output end of the proportional control module, the integral control module and the differential control module are respectively connected to the input end of the second calculation module, the output end of the second calculation module and the output end of the process control module are respectively connected to the input end of the third calculation module, the output end of the third calculation module is connected to the input end of the actuator, the output end of the actuator is respectively connected to the input end of the first calculation module and the control target, and the output end of the control target is connected to the input end of the process control module.

[0006] As a further improvement of the present invention, the first calculation module is used to calculate the deviation value e(t) between the preset setting value r(t) and the actual output value y(t) of the actuator; the proportional adjustment module, the integral adjustment module, the differential adjustment module and the process adjustment module are used to calculate the proportional adjustment parameter P[e(t)], the integral adjustment parameter I[e(t)], the differential adjustment parameter D[e(t)] and the process adjustment parameter D[z(t)] respectively; the second calculation module calculates the sum of the proportional adjustment parameter P[e(t)], the integral adjustment parameter I[e(t)] and the differential adjustment parameter D[e(t)]; the third calculation module calculates the sum of the proportional adjustment parameter P[e(t)], the integral adjustment parameter I[e(t)], the differential adjustment parameter D[e(t)], the process adjustment parameter D[z(t)] and the parameter value U(t-1) set by the actuator in the previous time period, where t is the time period value.

[0007] As a further improvement of the present invention, the actuator is a temperature controller, and the control target is a temperature control target.

[0008] The present invention also provides a PID adjustment method, comprising:

[0009] Step 1: Get the preset set value r(t) and the actual output value y(t) of the actuator, and calculate the deviation value e(t) between r(t) and y(t), where t is the time period value;

[0010] Step 2: Adjust the constant K by proportionality p Adjust the response speed of the output parameter U(t) by K p To adjust the fast response capability, the proportional adjustment parameter P[e(t)] is obtained, where e(t) is the current deviation value and t is the time period value;

[0011] Step 3: Adjust the constant K by integration i Adjust the cumulative deviation to obtain the integral adjustment parameter I[e(t)];

[0012] Step 4: Adjust the constant K by differential d Adjust the rate of change of the deviation signal to obtain the differential adjustment parameter D[e(t)];

[0013] Step 5: Adjust the constant K through the process dz Adjust the relationship between the actual output value z(t) of the control target and the deviation value e(t) to obtain the process adjustment parameter D[z(t)];

[0014] Step 6: Re-adjust the parameters of the actuator using the adjusted proportional adjustment parameters, integral adjustment parameters, differential adjustment parameters and process adjustment parameters, and finally reach the parameter values ​​set by the actuator to obtain a stable dynamic balance system.

[0015] As a further improvement of the present invention, in step 2, the proportional adjustment parameter

[0016] As a further improvement of the present invention, in step 3, the integral adjustment parameter

[0017] As a further improvement of the present invention, in step 4, the differential adjustment parameter Where C1 is the debugging parameter.

[0018] As a further improvement of the present invention, in step 5, the process adjustment parameter Where C1 is the debugging parameter.

[0019] As a further improvement of the present invention, the parameter value set by the final actuator in step six is ​​U(t)=U(t-1)+D[z(t)]+D[e(t)]+I[e(t)]+P[e(t)], where U(t-1) is the parameter value set by the actuator in the previous time period.

[0020] As a further improvement of the present invention, in the PID adjustment method, the actuator is a temperature controller, and the control target is a temperature control target.

[0021] Compared with the prior art, the PID control system and method provided by the present invention have the advantages of fast response speed, short stabilization period and small dynamic load fluctuation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the control principle of a general PID regulation system;

[0023] Figure 2 A schematic diagram of the control principle of a PID adjustment method disclosed in one embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the control principle of a temperature control device using a PID adjustment method disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0026] The present invention is described in further detail below with reference to the accompanying drawings:

[0027] The present invention provides a PID regulation system, comprising a first calculation module, wherein the output end of the first calculation module is respectively connected to the input ends of a proportional regulation module, an integral regulation module and a differential regulation module, the output end of the first calculation module is also connected to the input end of a process regulation module, the output ends of the proportional regulation module, the integral regulation module and the differential regulation module are respectively connected to the input end of a second calculation module, the output end of the second calculation module and the output end of the process regulation module are respectively connected to the input end of a third calculation module, the output end of the third calculation module is connected to the input end of an actuator, the output end of the actuator is respectively connected to the input end of the first calculation module and the input end of a control target, and the output end of the control target is connected to the input end of the process regulation module. In this PID control system, the first calculation module is used to calculate the deviation value e(t) between the preset setting value r(t) and the actual output value y(t) of the actuator; the proportional control module, the integral control module, the differential control module and the process control module are used to calculate the proportional control parameter P[e(t)], the integral control parameter I[e(t)], the differential control parameter D[e(t)] and the process control parameter D[z(t)] respectively; the second calculation module calculates the sum of the proportional control parameter P[e(t)], the integral control parameter I[e(t)] and the differential control parameter D[e(t)]; the third calculation module calculates the sum of the proportional control parameter P[e(t)], the integral control parameter I[e(t)], the differential control parameter D[e(t)], the process control parameter D[z(t)] and the parameter value U(t-1) set by the actuator in the previous time period, where t is the time period value.

[0028] The present invention provides a PID adjustment method, which includes:

[0029] Step 1: Get the preset set value r(t) and the actual output value y(t) of the actuator, and calculate the deviation value e(t) between r(t) and y(t), where t is the time period value;

[0030] Step 2: Adjust the constant K by proportionality p Adjust the response speed of the output parameter U(t) by K p To adjust the rapid response capability, we can get the proportional adjustment parameter P[e(t)], the proportional adjustment parameter Where e(t) is the current deviation value, and t is the time period value;

[0031] Step 3: Adjust the constant K by integration i Adjust the cumulative deviation to obtain the integral adjustment parameter I[e(t)], the integral adjustment parameter

[0032] Step 4: Adjust the constant K by differential d Adjust the rate of change of the deviation signal to obtain the differential adjustment parameter D[e(t)], the differential adjustment parameter Where C1 is the debugging parameter;

[0033] Step 5: Adjust the constant K through the process dz Adjust the relationship between the actual output value z(t) and the deviation value e(t) of the control target to obtain the process adjustment parameter D[z(t)], the process adjustment parameter Where C1 is the debugging parameter;

[0034] Step 6. Readjust the parameters of the actuator using the adjusted proportional adjustment parameters, integral adjustment parameters, differential adjustment parameters, and process adjustment parameters to ultimately reach the parameter value set by the actuator. The final parameter value set by the actuator is U(t) = U(t-1) + D[z(t)] + D[e(t)] + I[e(t)] + P[e(t)], obtaining a stable dynamic balance system.

[0035] The control principle of PID adjustment method:

[0036] like Figure 2As shown, the first acquisition module obtains the preset set value r(t), the second acquisition module obtains the actual output value y(t) of the actuator, and the third acquisition module obtains the actual output value z(t) of the control target. The process adjustment parameter D[z(t)] of z(t) is obtained by the process adjustment module. The deviation value e(t) between r(t) and y(t) is obtained by the first calculation module. The proportional adjustment parameter P[e(t)] of e(t) is obtained by the proportional adjustment module. The integral adjustment parameter I[e(t)] of e(t) is obtained by the integral adjustment module. The differential adjustment parameter The node parameters D[e(t)], P[e(t)], I[e(t)] and D[e(t)] are obtained through the second calculation module to obtain the sum of the three D[e(t)]+I[e(t)]+P[e(t)], D[e(t)]+I[e(t)]+P[e(t)], and then the sum is added through the third calculation module with the process adjustment parameter D[z(t)] and the parameter value U(t-1) set by the actuator in the previous time period to obtain the parameter value U(t) set by the actuator in the tth time period. U(t) is input into the actuator to obtain a stable dynamic balance system.

[0037] Example 1: Application of PID Adjustment Method in Temperature Control Device

[0038] like Figure 3 As shown, the first acquisition module obtains the preset temperature value r'(t), the second acquisition module obtains the actual output temperature value y'(t) of the temperature controller, and the third acquisition module obtains the actual output temperature value z'(t) of the temperature control target. The process adjustment parameter D[z'(t)] of z'(t) is obtained by the process adjustment module. The deviation temperature value e'(t) between r'(t) and y'(t) is obtained by the first calculation module. The proportional adjustment parameter P[e'(t)] of e'(t) is obtained by the proportional adjustment module. The integral adjustment parameter I[e'(t)] of e'(t) is obtained by the integral adjustment module. The differential adjustment parameter The node parameters D[e'(t)], P[e'(t)], I[e'(t)] and D[e'(t)] are obtained by the second calculation module to obtain the sum of the three D[e′(t)]+I[e′(t)]+P[e′(t)], D[e′(t)]+I[e′(t)]+P[e′(t)], and then the sum is added by the third calculation module with the process adjustment parameter D[z'(t)] and the temperature parameter value U′(t-1) set by the thermostat in the previous time period to obtain the temperature parameter value U′(t) set by the thermostat in the tth time period. U′(t) is input into the thermostat to obtain a stable dynamic equilibrium system.

[0039] in conclusion:

[0040] The PID control system and method provided by the present invention have the advantages of fast response speed, short stabilization period and small dynamic load fluctuation.

[0041] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A PID control system for a temperature control device, comprising a first calculation module, wherein the output end of the first calculation module is connected to the input ends of a proportional control module, an integral control module, and a differential control module, respectively, and characterized in that: The output end of the first calculation module is also connected to the input end of the process regulation module, the output ends of the proportional regulation module, the integral regulation module and the differential regulation module are respectively connected to the input end of the second calculation module, the output end of the second calculation module and the output end of the process regulation module are respectively connected to the input end of the third calculation module, the output end of the third calculation module is connected to the input end of the temperature controller, the output end of the temperature controller is respectively connected to the input end of the first calculation module and the temperature control target, the output end of the temperature control target is connected to the input end of the process regulation module; wherein, the process regulation module is used to calculate the process regulation parameter D[z(t)], the process regulation parameter Among them, C1 is the debugging parameter, K dz is the process adjustment constant, z(t) is the actual output temperature of the temperature control target, and e(t) is the deviation between the set value and the actual output value of the temperature controller.

2. The PID control system according to claim 1, characterized in that: The first calculation module is used to calculate the deviation value e(t) between the preset temperature value r(t) and the actual output value y(t) of the temperature controller. The proportional adjustment module, the integral adjustment module and the differential adjustment module are used to calculate the proportional adjustment parameter P[e(t)], the integral adjustment parameter I[e(t)] and the differential adjustment parameter D[e(t)] respectively. The second calculation module calculates the sum of the proportional adjustment parameter P[e(t)], the integral adjustment parameter I[e(t)] and the differential adjustment parameter D[e(t)]. The third calculation module calculates the sum of the proportional adjustment parameter P[e(t)], the integral adjustment parameter I[e(t)], the differential adjustment parameter D[e(t)], the process adjustment parameter D[z(t)] and the temperature parameter value U(t-1) set by the thermostat in the previous time period, where t is the time period value.

3. A PID adjustment method applied to a temperature control device, characterized in that: include: Step 1: Get the preset temperature value r(t) and the actual output value y(t) of the temperature controller, and calculate the deviation value e(t) between r(t) and y(t), where t is the time period value; Step 2: Adjust the constant K by proportionality p Adjust the response speed of the output parameter U(t) by K p To adjust the fast response capability and obtain the proportional adjustment parameter P[e(t)]; Step 3: Adjust the constant K by integration i Adjust the cumulative deviation to obtain the integral adjustment parameter I[e(t)]; Step 4: Adjust the constant K by differential d Adjust the rate of change of the deviation signal to obtain the differential adjustment parameter D[e(t)]; Step 5: Adjust the constant K through the process dz Adjust the relationship between the actual output value z(t) of the temperature control target and the deviation value e(t) to obtain the process adjustment parameter D[z(t)]; among them, the process adjustment parameter Where C1 is the debugging parameter; Step 6: Re-adjust the parameters of the thermostat using the adjusted proportional adjustment parameters, integral adjustment parameters, differential adjustment parameters and process adjustment parameters, and finally reach the temperature parameter value set by the thermostat to obtain a stable dynamic balance system.

4. The PID adjustment method according to claim 3, characterized in that: In the step 2, the proportional adjustment parameter 5. The PID adjustment method according to claim 3, characterized in that: In step 3, the integral adjustment parameter 6. The PID adjustment method according to claim 3, characterized in that: In step 4, the differential adjustment parameter Where C1 is the debugging parameter.

7. The PID adjustment method according to claim 3, characterized in that: The temperature parameter value set by the final thermostat in step 6 is U(t)=U(t-1)+D[z(t)]+D[e(t)]+I[e(t)]+P[e(t)], where U(t-1) is the temperature parameter value set by the thermostat in the previous time period.

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