The Development Of Flow Controller Based On Microcontroller ATmega16

The outputs of most sensors which are generally small voltage or current signals are nonlinear with the tested signals. So is the flow sensor in a gas flowmeter. We must scale the flowmeter before we use it. Here's a way of scaling a flowmeter. Firstly, we need to pick several flowrate samples among the range of the flowmeter to implement them one by one on the scaling platform; secondly, we record the corresponding voltage outputs of the flowmeter; finally, we make the piece-wise linearization to the outputs of the flowmeter based on its whole range and get a Flow-Voltage table, the scaling table. If we carry out a flow measurement with the flowmeter, the flowmeter will look up the scaling table according to its voltage output and get the flowrate magnitude. My work is the implementation of the selected flowrate in the air pipeline of the scaling platform through the adjustment of stepping motor and frequency-converter.The task used to be done by an operator before this design was accomplished. The operator uses the stepping motor to tune the valve and the frequency-converter to control the air speed in the pipeline so that he can adjust the flowrate to his destined magnitude. But there are some weaknesses in this scaling mode that the adjusting time is unbearable long and it takes the operator to do the repeated job if we need scale many flowmeters of the same type. So I designed a gas flowrate controller based on ATmegal6, a microcontroller produced by ATMEL co. of U.S.A. The controller can accept the flowrate inputs set by an operator, and then read the standard flowrate that could measure the current flowrate in a high degree of...