CN103984375B - Temperature control system based on DSP and temperature sensor control and control method thereof - Google Patents

Abstract

The invention discloses a temperature control system and a control method based on DSP (digital signal processor) and temperature sensor control, belonging to the technical field of temperature control. When the system adopts isothermal heating control, it includes DSP, power supply, temperature sensor, control parameter input device and parameter output recording controller; when the system adopts heat flow heating control, a pulse width converter is added on the basis of the original system. The temperature control system not only has the input setting of temperature and heat flux density, but also has the functions of real-time monitoring and heating power recording of the temperature and heating heat flow of the controlled object.

Description

Temperature control system and control method based on DSP and temperature sensor control

technical field

The invention relates to a temperature control system and a control method based on DSP (digital signal processor) and temperature sensor control, belonging to the technical field of temperature control.

Background technique

Heating systems and their temperature control systems are widely used in a variety of different equipment. For example: heating and temperature control systems are required in single crystal furnaces, annealing furnaces, electric ovens, heat treatment furnaces and other equipment. The production and processing technology of the product requires that the temperature of the heating system be controlled within a certain range. Precise temperature control range ensures the pass rate of the product. The controlled heating equipment must not only be controlled during the temperature rise process, but also automatically feed back information to the heating equipment after reaching the set temperature value, so as to adjust the heating amount in time, so that the heating equipment can be controlled within a certain period of time. Keep the temperature constant, or automatically adjust within a certain range of temperature control accuracy. In addition, in addition to the demand for isothermal control of equipment or products, there is also the need for isothermal control, that is, within a certain period of time, the heating provided by the equipment is constant, and its technical difficulty is more complicated than that of isothermal heating. A new heating and control system that combines isothermal and isothermal flow heating and its control, and can be selected according to the needs of users will have a certain application market.

Contents of the invention

The invention provides a temperature control system and control method based on DSP and temperature sensor control.

The present invention adopts following technical scheme for solving its technical problem:

A temperature control system based on DSP and temperature sensor control, including DSP, power supply, temperature sensor, control parameter input device and parameter output recording controller, wherein the control parameter input device, DSP and parameter output recording controller are sequentially connected, DSP and The power supply is connected, the temperature sensor is arranged on the controlled object, the power supply is connected with the controlled object, and the temperature sensor on the controlled object is connected with the AD port of the DSP through a data line.

A temperature control system based on DSP and temperature sensor control, including DSP, power supply, control parameter input device, parameter output recording controller, temperature sensor and pulse width converter, the temperature sensor is arranged on the controlled object, and the control parameter input device , DSP and parameter output recording controller are connected sequentially, the PWM port of the DSP is connected to the pulse width converter, the temperature sensor on the controlled object is connected to the AD port of the DSP through the data line, and the pulse width converter is connected to the power supply to control Power supply, the power supply is connected with the controlled object.

The control method of the temperature control system based on DSP and temperature sensor control, is characterized in that, comprises the following steps:

(1) When isothermal heating control is used, firstly, the control parameter input device inputs the control temperature and temperature control accuracy value of the controlled object, and the power is turned on; the temperature sensor signal on the controlled object is collected, and the signal is passed through the AD module of the DSP The conversion is compared with the temperature value input by the control parameter input device, and a feedback signal is generated to the AC power supply;

(2) If the collected temperature value is higher than the sum of the control temperature of the controlled object and the temperature control accuracy, let the DSP issue an instruction to disconnect the power supply; if the collected temperature value is lower than the control temperature of the controlled object and the temperature control precision The difference in control accuracy allows the DSP to issue a command to turn on the power.

The control method of the temperature control system based on DSP and temperature sensor control, is characterized in that, comprises the following steps:

(1) When heat flow heating control is adopted, the control temperature, PID control law and temperature control accuracy value of the controlled object are first input by the control parameter input device; after the DSP receives the control input parameters, the PWM port of the DSP sends a signal to the pulse generator. wide converter, power on at 10% duty cycle;

(2) Collect the temperature sensor signal on the controlled object, convert the signal through the AD module of the DSP and compare it with the temperature value input by the control parameter input device, and generate a feedback signal to the DSP; (3) If the collected temperature value is higher than The sum of the control temperature of the controlled object and the temperature control accuracy will let the DSP issue a command to reduce the duty cycle, and the PWM port of the DSP will transmit it to the pulse width converter to adjust the duty cycle of the power supply; if the collected temperature value If it is lower than the difference between the control temperature of the controlled object and the temperature control accuracy, let the DSP issue an instruction to increase the duty cycle, and the PWM port of the DSP will transmit it to the pulse width converter to adjust the duty cycle of the power supply;

(4) When the temperature of the controlled object is controlled within the range of control accuracy input by the control parameter input device, the DSP sends an instruction and transmits it to the pulse width converter through the PWM port to lock the duty cycle of the power supply, and records this through the parameter output recording controller When the duty cycle information reaches the heat flow heating of the controlled object;

(5) Once the duty cycle of the power supply is locked, the controlled object enters the state of equal heat flow heating until the power supply is artificially cut off to stop heating.

The beneficial effects of the present invention are as follows:

The system does not have any device for adjusting voltage or current, which simplifies the control system and reduces the cost of system construction; the temperature signal fed back to the processor is obtained by multi-point acquisition, which avoids the temperature caused by the excessive error of the local temperature sensor. Misjudgment; the system has fast response and high sampling frequency, which can not only realize the constant control of heating temperature, but also the heating control of isothermal flow after the temperature reaches the set value; using the pulse width modulation (PWM) module of DSP processor and The proportional-integral-derivative (PID) control law can adjust and lock the duty cycle of the power input to realize the heating control of equal heat flow; the system not only has both temperature and heat flux input settings, but also controls the temperature and Real-time monitoring of heating heat flow, heating power recording function.

Description of drawings

Figure 1 is a schematic diagram of an isothermal control system based on DSP and temperature sensor control.

Figure 2 is a schematic diagram of the isothermal flow control system based on DSP and temperature sensor control.

Fig. 3 is a flowchart of an embodiment of the isothermal control of the present invention.

Fig. 4 is a flowchart of an embodiment of the isothermal flow control of the present invention.

detailed description

The invention will be described in further detail below in conjunction with the accompanying drawings.

With DSP TMS320 LF2407 as the microprocessor as the control core, multi-point temperature sensors are used to collect and average the feedback signal, and the feedback signal is compared with the user's preset control value, and the heating temperature or heating heat flow is controlled within a certain range of control accuracy. These two heating methods are automatically controlled, and have functions such as temperature and heat flux input setting, temperature and heat flux real-time monitoring, and heating power recording.

Isothermal control system: 220V AC power input is adopted, the AD (digital-analog) module port of the DSP processor processes the temperature signal collected by the temperature sensor, compares the temperature signal with the input value of the control parameter input device, and generates a feedback signal to the DSP to control the AC The switch of the power supply controls the temperature of the system by turning on and off the switch.

Isothermal flow control system: On the basis of the isothermal control system, the monitoring of the input voltage and current of the control system is added, and the PWM module of the DSP processor is used to realize the power input duty ratio locking after the control temperature reaches the set temperature, and realizes Heat flow heating control.

The specific way to implement isothermal control on the controlled object is shown in Figure 1. Input the control temperature of the controlled object and the control accuracy requirements of the controlled temperature into the control system through the control parameter input device; the K-type thermocouple temperature sensor transmits the temperature signal at the temperature sensor on the controlled object to the AD port of the DSP; The DSP compares the data collected by the AD port with the control parameters input to the DSP by the control parameter input device, and after judgment, issues power supply and power-off instructions to the power supply; in all control processes, the time of power supply and the temperature of the controlled object And other parameters can be recorded by the parameter output recording controller in real time. The specific control process of this embodiment is shown in Figure 3. T0 in the figure represents the control temperature of the controlled object, and ΔT is the control accuracy of the temperature. Both control quantities are input by the control parameter input device; The temperature of the controlled object measured by the thermocouple temperature sensor.

The specific way of implementing isothermal flow control on the controlled object is shown in Figure 2. Input the control temperature of the controlled object and the control accuracy requirements of the controlled temperature into the control system through the control parameter input device; the K-type thermocouple temperature sensor transmits the temperature signal at the temperature sensor on the controlled object to the AD port of the DSP; The DSP compares the data collected by the AD port with the control parameters input to the DSP by the control parameter input device, and after judgment, uses the PWM port of the DSP combined with the pulse width converter to give the power supply an appropriate duty cycle until the control temperature and accuracy of the controlled object Reach the preset value; lock the duty cycle and run the whole system in the heating mode of equal heat flow until the control is artificially ended; Parameters such as heating capacity can be recorded by the parameter output recording controller in real time. The specific control flow of this embodiment is shown in Figure 4. T0 in the figure represents the control temperature of the controlled object, and ΔT is the control accuracy of the temperature. Both control quantities are input by the control parameter input device; The temperature of the controlled object measured by the thermocouple temperature sensor.

Claims (1)

1. A temperature control system based on DSP and temperature sensor control, is characterized in that comprising DSP, power supply, temperature sensor, control parameter input device and parameter output recording controller, wherein control parameter input device, DSP and parameter output recording controller Sequential connection, DSP and power supply connection, the temperature sensor is arranged on the controlled object, the power supply is connected to the controlled object, and the temperature sensor on the controlled object is connected to the AD port of the DSP through the data line; The isothermal heating control method of the temperature control system comprises the following steps: (1) First, input the control temperature and temperature control accuracy value of the controlled object through the control parameter input device, and turn on the power; collect the temperature sensor signal on the controlled object, and transmit the temperature signal to the AD port of the DSP; the DSP transfers the AD port The collected data is compared with the control parameters input to the DSP by the control parameter input device, and after judgment, the power supply and power-off instructions are sent to the power supply; (2) If the collected temperature value is higher than the sum of the control temperature and temperature control accuracy value of the controlled object, let the DSP issue an instruction to disconnect the power; if the collected temperature value is lower than the controlled object’s control temperature and temperature control The difference between the precision value, let the DSP issue a command to turn on the power; The isothermal flow heating control method of the temperature control system comprises the following steps: (1) First, the control temperature, PID control law and temperature control accuracy value of the controlled object are input by the control parameter input device; after the DSP receives the control parameters input by the control parameter input device, the PWM port of the DSP sends a signal to the pulse width conversion , turn on the power at a duty cycle of 10%; (2) Collect the temperature sensor signal on the controlled object, and transmit the temperature signal to the AD port of the DSP; the DSP compares and judges the data collected by the AD port with the control parameter input to the DSP by the control parameter input device; (3) If the collected temperature value is higher than the sum of the control temperature of the controlled object and the temperature control accuracy value, let the DSP issue a command to reduce the duty cycle, and the PWM port of the DSP will transmit it to the pulse width converter to adjust the power supply If the collected temperature value is lower than the difference between the control temperature of the controlled object and the temperature control accuracy value, let the DSP issue an instruction to increase the duty cycle, which is transmitted to the pulse width converter by the PWM port of the DSP to adjust The duty cycle of the power supply; (4) When the temperature of the controlled object is controlled within the range of control accuracy input by the control parameter input device, the DSP sends an instruction and transmits it to the pulse width converter through the PWM port to lock the duty cycle of the power supply, and records it through the parameter output record controller The duty cycle information at this time reaches the heat flow heating of the controlled object; (5) Once the duty cycle of the power supply is locked, the controlled object enters the state of equal heat flow heating until the power supply is artificially cut off to stop heating.