Cigarettes Draw Resistance Measuring Instrument And Automatic Sorting Device Research

The present thesis designs the automatic sort device control system of cigarette draw resistance measuring instrument based on the DSP chip. It is focused on the following aspects such as the composition of the automatic sort device control system, the controlling method and strategy of electric motor, research and design of the controlling software and hardware as well as their theoretical analysis.This thesis first introduces the working principle of automatic sort device of cigarette draw resistance measuring instrument and structural features of each part. Then, DSP chip TMS320LF2407 of TI company is chosen as the CPU of control system, and the control system of the automatic sort device is designed. As this chip is specifically designed for the implementation of digital motor control, not only is it characterized by the high stability, precision and speed, but also it has integrated the auxiliary equipment of motor control, so that it greatly simplifies the hardware system, and lowers the cost.To drive motion components, the thesis examines the controlling principle of DC motor and the methods and circuits of using the DSP chip and DC motor control modules to realize the DC motor control. Based on the analysis of the principle of cigarette pushing system, this thesis creates a mathematical model, designs the double-close-loop control system of speed and current, chooses the PI-controller as the control strategy of speed and current, calculates the parameters of moderator, and designs the measurement system of current and speed as well as the control circuits of electric motor.The stepping motor which drives the cigarette bin can use the pulse signal to directly implement the open-cycle positioning control, with a certain precision, simple control circuits, convenience for use and reliability. This thesis analyzes the acceleration process of the stepping motor from the theoretical angle, and uses the ladder to fit the acceleration index curve of stepping motor. So this method is suitable to use DSP chips to implement the control of stepping motor.The automatic sort device control system of cigarette draw resistance measuring instrument can reduce the labor intensity of testing personnel, improve the sort accuracy, and enhance detection efficiency. Facts have proved that its development is of great significance.