The Research For Dynamic Level Measuring System Under Special Working Condition

In the industrial procedure,solid or liquid level should often be measured accurately to implement the automatic monitoring and unwatched management of enterprise production.The traditional level measuring methods cann't meet our demand because the subjective investigated is in such a poor systemic condition that the temperature is a little high and there's so many mill dust and steam there.In this article we perform systemic discuss and research against the dynamic level measuring method under special working condition on the basis of analyzing kinds of level measuring technique in and abroad.First we establish the pressure distribution mathematic model in storage bin and then deduce the mathematic relation between level height and the uniform stress on the bottom of the bin and designed a resistance compressive stress sensor used for the special condition and put forward a resoivement according to its zero excursion existing in practical use. In order to reach the requirement of applying for the multi-objective and multi-parameter measuring,we adopt the distributing computer controlling system which the AT89C52 single chip was used as core in the system,also the circuit of signal conditioning and data acquisition and processing are all integrated in the system. We use nixie tube to fullfill the displaying function and adopt high-capacity memory to record the data of production process. In order to transmit the data collected to the upper control center,the RS485 network bus technique has been employed in the monitoring system to complete the function of communication between the microcontrollers and upper PC computer.In order to implement the automation of production process,we use fuzzy control algorithm routine in the single chip.lt can adjust the opening angle of electric valves with corresponding voltage according to the real-time material level that measured and so the automation control of material level was implemented. In design of programming,we use modularization design method and adopted the actual prevalent Keil C51 compiler to write the code of single chip controller. As regards of upper PC computer,we adopted Borland C++ language to design the program interface and implement the function of control system,what's more several key component such as the implementation of serial port class and the creation of multi-thread were also introduced here.