China has the world's largest planting area of paddy rice, but large quantities of paddy rice fall to the ground and are lost during harvesting with a combine harvester. Reducing grain loss is an effective way to increase production and revenue. In this study, a monitoring system was developed to monitor the grain loss of the paddy rice and this approach was tested on the test bench for verifying the precision. The development of the monitoring system for grain loss included two stages: the first stage was to collect impact signals using a piezoelectric film, extract the four features of Root Mean Square, Peak number, Frequency and Amplitude (fundamental component), and identify the kernel impact signals using the J48 (C4.5) Decision Tree algorithm. In the second stage, the precision of the monitoring system was tested for the paddy rice at three different moisture contents (10.4%, 19.6%, and 30.4%) and five different grain/impurity ratios (1/0.5, 1/1, 1/1.5, 1/2, and 1/2.5). According to the results, the highest monitoring accuracy was 99.3% (moisture content 30.8% and grain/impurity ratio 1/2.5), the average accuracy of the monitoring tests was 92.6%, and monitoring of grain/impurity ratios between 1/1 and 1/1.5 (>95.4%) had higher accuracy than monitoring the other grain/impurity ratios. Monitoring accuracy decreased as impurities increased. The lowest accuracy for grain loss monitoring was obtained when the grain/impurity ratio was 1/2.5, with monitoring accuracies of 88.2%, 75.7% and 78.8% at moisture contents of 10.4%, 19.6% and 30.4%.
In rape combine harvester, side cutter must be equipped to cut off tangled rapeseed twigs. Inappropriate cutting speed would increase the repeated cutting and missing cutting of side cutter, which lead to serious header loss. In allusion to the problems mentioned above, bidirectional electric drive side cutter and a cutting speed follow-up adjusting system were proposed. The kinematic law of side cutter blades was analyzed. The trajectory, velocity, and acceleration of the two blades were the same, but the phase difference is π. Numerical simulation of cutting areas at different cutting speed ratios was carried out and the best cutting speed ratio was determined to be 1.1. Cutting speed follow-up adjusting system was designed based on matching relationship between combine harvester forward speed and side cutter cutting speed. Cutting speed follow-up adjusting system was designed with proportional–integral–derivative (PID) algorithm. The control parameters were determined to be Kp = 1.3, Ki = 4.3, Kd = 0.007. Simulation showed that the maximum overshoot of the system was 4.3%, steady-state error was 0.24%, and the rise time was 0.036 s. The cutting speed follow-up adjusting system was applied to the 4LZ-6T-type rape combine harvester. Experimental results showed that the side cutter cutting speed error was within 1.5%. When forward speed changed, the cutting speed response delay time was 1.5 s. The rape combine harvester header average loss was 2.96% and side cutter average loss was 0.81%. Compared to the fixed speed cutting, header loss was reduced by 14.05% and side cutter loss was reduced by 34.76%. The research can reduce the loss of rapeseed combine harvester and provide theoretical basis for the design of rapeseed combine harvester.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.