CN205594335U - Developments assignment PID heating control system suitable for high vacuum environment - Google Patents

Abstract

The utility model discloses a dynamic assignment PID heating control system suitable for high vacuum environment, relates to the field of process control of material heating in high vacuum environment, and is designed to solve the problem of excessively high overshoot temperature in the heating process in high vacuum environment Proposed. In the traditional PID heating control system, a dynamic assignment operator is added to realize multiple and dynamic assignments to the PID controller. According to the feedback temperature of the current state and the set target temperature value, the assigned intermediate target temperature value is determined by Calculated by the assignment operation formula. The changing assigned temperature prompts the PID controller parameters to be adjusted quickly according to the dynamic intermediate target temperature, and the heating power is adjusted in time. When the feedback temperature is close to the set heating target temperature, the heating power can be promptly and quickly reduced, or even stop heating. , making full use of the thermal inertia of objects in a vacuum environment, and greatly reducing the overshoot temperature of the heating control process.

Description

Dynamic assignment PID heating control system suitable for high vacuum environment

technical field

The utility model relates to the technical field of object heating process control in a high vacuum environment.

Background technique

With the emergence of proportional-integration-differentiation (PID) control theory, PID controllers based on various algorithms have been widely used in many industries, especially in the field of temperature control, 90% of heating control The controller is designed based on the PID principle.

The traditional PID heating control system is shown in Figure 1. Its working principle is to compare the feedback temperature of the heating object with the given target temperature at time t , and take the current temperature error value as the input e ( t ) of the PID controller , by proportional coefficient kp , integral time constant TI ; differential time constant TD . Get the output u ( t ) of the PID controller

, (1)

The output u ( t ) of the PID controller controls the output power of the power regulator, changes the heating power of the heater, makes the temperature of the heating object rise, the feedback temperature value of the controller changes, and the temperature error value keeps decreasing until it reaches preset target temperature.

Usually, in order to prevent the high-temperature oxidation phenomenon in the atmospheric environment, the high-temperature test of the material must be carried out in a high-vacuum protective environment. Although, with the introduction of control principles such as fuzzy theory, neural network, and robust theory, many improved PID control algorithms have emerged to adapt to the complexity of the heating process and to meet the heating control in some special environments. However, in a high-vacuum environment, the thermal inertia of the object is large and the change law is complex. The traditional PID control method often causes excessive temperature overshoot, which is easy to damage the structure and performance of the test material.

Utility model content

In order to suppress the excessively high overshoot temperature generated during the heating process in a high-vacuum environment, the utility model proposes a PID heating control system with dynamic assignment. The control principle is based on the temperature difference between the current temperature feedback value and the target heating temperature value, Dynamically change the assigned temperature of the PID thermostat, and then control the power of the heater, and complete the PID control of the heating process of the heating object.

In order to achieve the above object, the utility model adopts the following technical scheme. The heating control system of the utility model includes a PID controller, a power regulator, a heater, a heating object and a temperature measuring piece, and the PID controller controls the temperature of the heater through the power regulator. Heating power, the heater directly heats the heating object, and the heating object is equipped with a temperature measuring part. The feedback temperature value of the object is fed back to the dynamic assignment operator, and the dynamic assignment operator is assigned to the PID controller after calculation and processing.

The heating control method of the present utility model is as follows: the target temperature value is first input into the dynamic assignment operator, and the intermediate target temperature value is calculated by the dynamic assignment operator according to the feedback temperature value of the current heating object, and then dynamically assigned to the PID controller, PID The controller adjusts the output power of the power regulator according to the dynamically changing intermediate target temperature value, changes the heating power of the heater, makes the temperature of the heating object rise, the feedback temperature value received by the dynamic assignment operator changes, and the temperature error value continues Decrease until the preset target temperature is reached.

Preferably, during the heating process, the dynamic assignment calculator performs multiple assignments of dynamic intermediate target temperature values to the PID controller.

Preferably, as the temperature of the heating object continues to rise, when the temperature difference between the feedback temperature value and the target temperature value is less than 1°C, the intermediate target temperature value output by the dynamic assignment operator is equal to the target temperature value, and the dynamic assignment operator The work stops, and the PID controller stabilizes the temperature of the heating object at the temperature of the target temperature value.

Preferably, assuming that the feedback temperature value of the currently heated object is used as the input T _i of the dynamic assignment operator, and the target heating temperature T _S , the intermediate target temperature value is determined by the assignment operation formula in the dynamic assignment operator Calculated, where N is the number of assignments of the dynamic assignment operator, N =0,1,2....

Beneficial effects of the utility model:

Different from the traditional PID heating control method, the utility model adds a dynamic assignment calculator to the heating control system, realizing multiple and dynamic assignments to the PID controller, according to the feedback temperature of the current state and the set target temperature Value, the assigned intermediate target temperature value is calculated by the assignment calculation formula. The changing assigned temperature prompts the PID controller parameters to be adjusted quickly according to the dynamic intermediate target temperature value, and the heating power is adjusted in time. When the feedback temperature is close to the set value When the heating target temperature is reached, the heating power can be reduced in time and quickly, or even the heating can be stopped, making full use of the thermal inertia of the object in the vacuum environment, and greatly reducing the overshoot temperature of the heating control process.

Description of drawings

Fig. 1 is prior art PID heating control system diagram;

Fig. 2 is a dynamic assignment PID heating control system diagram of the present utility model;

1-target temperature value, 2-dynamic assignment calculator, 3-PID controller, 4-power regulator, 5-heater, 6-heating object, 7-temperature measuring piece.

detailed description

Below in conjunction with accompanying drawing 2 the utility model is done further technical description:

As shown in Figure 2, the utility model comprises a PID controller 3, a power regulator 4, a heater 5, a heating object 6 and a temperature measuring part 7, the PID controller 3 controls the heating power of the heater 5 through the power regulator 4, The heater 5 directly heats the heating object 6, and the heating object 6 is provided with a temperature measuring part 7, and also includes a dynamic assignment calculator 2, the preset target temperature value 1 in the dynamic assignment calculator 2, and the temperature measuring part 7 will heat The feedback temperature value of the object 6 is fed back to the dynamic assignment calculator 2 , and the dynamic assignment calculator 2 is assigned to the PID controller 3 after calculation and processing.

The utility model reads the feedback temperature value of the currently heated object and compares it with the set target temperature value, and when the feedback temperature value is less than the target temperature value, the dynamic assignment operator starts.

The working principle of the dynamic assignment operator is as follows: Let the feedback temperature of the currently heated object be the input T _i of the dynamic assignment operator, and according to the target heating temperature T _S , the output T _i+1 of the dynamic assignment operator is:

, (2)

In the formula, N is the number of assignments of the dynamic assignment operator, N =0,1,2....

The T _i+1 calculated by the assignment calculation formula (2) is input to the PID controller as the intermediate target temperature value to adjust the heating power of the heating object; as the temperature of the heating object rises, the feedback temperature is continuously measured. When the feedback temperature T _Fn is equal to the intermediate target temperature T _i+1 in the current state, and enters the next dynamic assignment process.

With the increase of assignment times i , the temperature of the heating object gradually increases, gradually approaching the heating target temperature, and the incremental temperature value of the intermediate target temperature value is getting closer to 0. When the feedback temperature value is equal to the target temperature value, then The dynamic assignment operator stops working, and at this time, the assignment temperature of the PID controller is the target temperature value of heating.

The dynamic assignment PID heating method proposed by the utility model promotes the PID adjustment parameters in the PID controller to be quickly adjusted according to the dynamically changing intermediate target temperature through multiple dynamic assignments to the PID controller, and the heating power of the heater is adjusted in time. When the feedback temperature value is close to the set target temperature value, the heating power can be reduced in time and quickly, or even stop heating, making full use of the thermal inertia of the object in the vacuum environment, so that the heating object gradually reaches the set target heating temperature, effectively avoiding Excessive temperature overshoot.

The utility model is not limited to the above-mentioned preferred embodiments, and any technical solutions that are the same as or similar to the utility model all belong to the protection scope of the utility model.

Claims (1)

1. Dynamically assigned PID heating control system suitable for high vacuum environment, including PID controller, power regulator, heater, heating object and temperature measuring piece, PID controller controls the heating power of the heater through the power regulator, and the heater The heating object is directly heated, and the heating object is equipped with a temperature measuring part, which is characterized in that it also includes a dynamic assignment operator, the target temperature value is preset in the dynamic assignment operator, and the temperature measuring part feeds back the feedback temperature value of the heating object For the dynamic assignment operator, the dynamic assignment operator is assigned to the PID controller after calculation and processing.