Cutting speed follow-up adjusting system of bidirectional electric drive side cutter for rape combine harvester

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 K(p) = 1.3, K(i) = 4.3, K(d) = 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.