Study And Design Of Grain Suspending Speed Detecting System Based On The Single-chip Control

The quality of seed and food processing gets more and more attentions with the development of modern agriculture and human life. The pneumatic power technology has been used for a variety of agricultural equipments design such as precision pneumatic seeder, seed selecting machinery, threshing machinery, grain combine harvester and the grain-processing air selecting machinery, de-dust and other ventilation equipments. The speed of the suspended materials is an important characteristic and also a key factor to influence the processing effort of apparatus. So it is necessary to research the suspended speed of grains and the impurities. In order to further optimize the design of such farm machinery and equipment performance, the speed of the suspended materials must be studied.This paper briefly described the theoretical research as well as the development of speed detecting about the suspended materials and designed a smart suspending speed detecting system with single-chip control based on the traditional suspending speed mechanical detector. The main studies in this paper about this system are summarized below:1) The photoelectric TCD1001P linear array image sensor was used for the material suspension condition detecting and identifying through the output current from the photosensitive cells as an effective alternative to the complex digital image processing procedures, reducing the system's internal operations and accelerating the detecting speed of the system. The sensor-driven pulse timing characteristics, the output current amplification and AD conversion are mainly discussed and studied.2) The driving signals was outputted by PWM waveform generator instead of the motor control style realized by simulating PWM port through standard 8051 single-chip and look-up table method, the pre-described are based on the settings of built-in programmable timer / counter array (PCA) register of Cygnal C8051F000 single chip. With the application of this design, the system running efficiency was enhanced and the detecting accuracy was improved, the hardware design and the cost are also simplified and decreased respectively due to the driven pulse for the TCD sensor supplied by a high speed outputting style.3) The two-phase bipolar driver for the stepper motor was formed by L297/L298 driving chips and the stepper motor was droved through the distribution of PWM and power amplification.This smart device can not only widely used in food processing, grain selecting, de-dusting enterprises, but also can be used for the teaching and research activities of agricultural colleges and universities. Compared to the traditional grain suspension speed detecting devices, it possesses lots of merits such as wide detecting range, high-precision, short detecting time, simple operation and so on.