Research On Jam Fault Monitoring System For Combine Harvester Threshing Cylinder

Frequent jam fault of combine harvester threshing cylinder had influenced the work efficiency promoting of combine harvester for long time. The report of agriculture machinery fault rate in 2005, showed that the jam fault of threshing cylinder occupy the harvester jam fault about 30%, occupy the total fault about 10%. Threshing cylinder jam fault had evolved into main factor which restricted the efficiency of combine harvester, In order to reduce the combine harvester threshing cylinder jam fault when working in the field, we need cylinder can send warning or alarm signal before the occur the jam fault so that to guide the operator to make reasonable adjustments. So urgently need a can monitor real-time monitoring system of roller job status.In this paper, using electric thresher threshing soybean field experiments, effects of various parameters of the rotate speed of the roller in the process of threshing cylinder cap, related and measuring the thresher threshing process in blocking warning value and the lower limit value, provide a theoretical basis for the monitoring system designed in this system.The traditional roller jam fault monitoring system is using a single parameter as a judge the operation status of drum, for example, the speed of the drum and the drum shaft torque. The monitoring system structure is simple, but the accuracy of the early warning still not satisfactory, this is largely because, whether roller rotation speed and torque, in the process of harvesting operation need to do some adjustment according to actual condition. The warning system will likely misstatement or omission of the phenomenon such as lead to monitoring is not allowed. For the above reasons, this paper designed a kind of multiple parameters based on microcontroller multistage other combine threshing cylinder job status monitoring system, the threshing cylinder homework after the information fusion of the multiple parameter second-level evaluation drum operation standard, the first level is based on the sliding rate between the roller and the power output shaft as their roller job status criteria. So you can ensure that almost harvest machinery in the field operations will not delay because the clogging threshing device crop harvest time.The traditional drum jam fault monitoring system is useing single parameter evaluation roller operation state, such as the rotating speed and torque. This monitoring system has the advantages of simple structure, but its prediction accuracy are not satisfactory. This is mainly because both the roller speed or torque, do some adjustment according to the actual situation were needed in the harvesting process, then the early-warning system may mistake or omission phenomenon in. For the above reasons, this paper designed based on multi parameter design of multi level drum jam fault monitoring system. The multi parameters of threshing cylinder operation information as a level second standard cylinder operation state after fusion, the first level judgment standard is based on the slip speed between the roller and the size of the power output shaft to make decisions. This allows the monitoring system of early warning rule has high adaptability to the actual situation of harvesting time, prediction accuracy had been greatly improved.The monitoring system designed in this paper is based on MCU STC89C52 and wireless transceiver chip nRF905 for multi parameter online monitoring system. The calculation results and related parameters to judge the drum operation state, such as normal, warning, alarm state. Its basic principle is respectively monitor the drum speed and power output shaft speed using the hall speed sensor, the two speed signal to MCU and calculate the slip between the two axles, the numerical calculated slip size and standard model library in comparison. If the numerical slip is greater than the set, monitoring system warning or alarm signal; if slip size in the normal range, the monitoring system will need to be further extraction parameters of roller speed pulse sequences (first-order difference, relative ratio, differential accumulation and, two order difference), these parameters information fusion, according to the calculation result of the operation state of roller. Monitoring system is divided into the upper and lower machine, installed on the threshing cylinder internal computer, host computer installed in the cab. The machine will speed signal and warning signal is sent to the host computer through the wireless transmission module.In summary, this paper designs the cylinder working condition monitoring system based on microcontroller and wireless transceiver module. Received the related signal in the cab, determine the operation parameters might need to be adjusted by the machine operators combine harvester. With respect to the early warning rules of traditional single parameter prediction rules had improved a lot in terms of accuracy.