Research On Computer Control System For Dyeing Temperature

In the staining technique, it has a strict requirement for the dye liquor temperature of the dyed object. Generally speaking, when dyeing for the specific dyed object, the temperature variation curve of dye liquor is relatively fixed. When dying for different dyed objects, the required temperature curves are also different. Whether the dye liquor temperature can accurately operate in accordance with the required temperature curve will seriously impact on the dyeing quality of the dyed object.To ensure the accuracy of the temperature curve of dye liquor and improve the dyeing quality, this thesis designs a distributed control system that are able to accurately control the temperature of dye liquor of many dyeing machines by using an industrial personal computer to control many lower computers. Each lower computer can control a dyeing machine. The lower computer uses the enhancement type single chip microcomputer STC12C5A60S2, the inside of which integrates with ADC, PWM module, etc and has relatively strong anti-interference capability and control performance. It selects platinum resistor PT100as temperature sensor. The sensor is applicable to liquid measured medium and has the advantage of large scope measuring temperature, high-precision measuring temperature and quick response, etc. The signal captured by the sensor needs to go through remote transmission. The integrated ADC of lower computer carries out the analog-to-digital conversion and gets the real-time temperature value. The temperature data obtained by the lower computer will communicate with the upper computer through RS485bus. RS485bus has the advantage of long distance transmission and strong ant-inference capability, etc.The upper computer uses Visual Basic6.0to write the human-computer interface. It can call the standardized temperature curve to operate or input a new curve and then call it to operate. The parameter of a new curve can be modified and saved. When the system is running, the upper computer can display the real-time temperature value and can also dynamically display the temperature curve. The system can give an alarm under the abnormal condition. The change of dye liquor is achieved by the injected steam flow which flows through the pipe. Use the electric control valve as an actuator to control stream flow. The size of valve opening controls the flow of injected stream in the pipe, which finally realizes the purpose of controlling the temperature. The system employs the self-adaption PID to precisely control the temperature, which achieves a good control effect. After many experiments and data analysis, it proves that the system achieves a perfect control purpose.