Study On The Monitoring System For Cleaning Loss Of The Grain Combine Harvester

Grain Combine Harvester is one of the important equipments in the process of modern agricultural production. However, with the combine harvester's using year growing and inpropriate repairing and adjustment, the loss during harvest has caused more and more attention. Currently, there is no relative cleaning-loss monitoring product matching with the combine harvesters. The popular calculation of cleaning-loss rate is to use bags during harvest or manual counting after harvest, which are inefficient and not monitored all the time. Aiming at the problem of high cleaning loss rate and non-timing detection in harvesting, this paper presents a intelligent monitoring system. When the loss rate exceeds the standard, it will warn the driver to take actions to monitor the situation just in time, and reduce the harvest loss.Based on the analysis of the reason of cleaning-loss and the cleaning-loss test methods of the in and out of China, designed a which can test the loss of grain kernels through counting the pulses generated by the grain impacting sensor. According to the sensor membrane's performance requirement within the grain combine harvester working environment and its working principle. At the same time, using the Pro/e and Auto-CAD, designed the three dimensional body models and the engineering drawings.Designed hardware of the monitor sydtem,which core part is STC89C52 MCU.The hardware is composed of power supply circuit, speed sensor, MCU and its peripheral circuits, the keyboard circuit, optical coupling circuit , logic circuits, LCD circuits, and alarm circuits etc. Select appropriate components and build the hardware circuit, and circuit debugging.Applying the modular programming ideas, developed monitoring system software by using C51 language, the software part is mostly composed of several modules, such as the initialization module, the keyboard module, interrupt module, LCD module and main program module and so on.By the combination of Keil and Proteus , the system software and hardware debugging and simulation.The simulation results indicate some conclusions: under the condition of manual setting grain production and thousand-seed-weight ,the system can collect the machines'forward speed, grain's lost weight, and calculate the loss rate and monitor it; meanwhile the system can start the auto alarm device when the loss rate exceed the standard. It works stably and safelym, which totally accords with the design requirement.