Panpan Yuan

Bus-voltage fluctuations of unstabilized PTO-driven generators, together with pneumatic load variations, cause negative-pressure instability in electric-driven air-suction seeding fans, degrading seeding quality. This paper proposes a cascaded composite control strategy combining model reference adaptive control (MRAC) with voltage feedforward. Based on time-scale separation, the inner loop uses a PI controller with voltage feedforward for millisecond-level compensation of bus-voltage disturbances, while the outer loop employs output-feedback MRAC against time-varying chamber dynamics. The strategy was compared with PID, fuzzy PID, and cascaded MRAC without feedforward (CMRAC-NFF) through nonlinear simulations, bench tests, and cotton field trials. In nonlinear simulations, a 72-to-65 V voltage step induced a maximum negative-pressure deviation of −0.48 kPa with a 1.08 s recovery time; under combined voltage and seed-suction load disturbances in the simulation environment, the error standard deviation was 0.07 kPa. In bench tests, the mean absolute steady-state deviation remained within 0.12–0.16 kPa across the 7.0–10.0 kPa setpoints. In field tests, the proportion of time outside the ±0.3 kPa tolerance was reduced to 3.84%, with a qualified seeding rate of 96.24%. With feedforward rejecting supply disturbances and MRAC absorbing model uncertainty, the scheme sustained agronomic-grade pressure stability on a 12-row cotton seeder across tested 7.0–10.0 kPa setpoints.

To avoid the issues of seeds lying atop straw, where the seeds cannot germinate, during no-till maize seeding, a seed furrow cleaning device is proposed. The device uses rotating spring teeth and a curved sliding shovel to clear the straw from the seed furrow to the outside. The critical components of the side throwing mechanism, rotary disc and spring teeth design are analyzed, and the value range of the installation inclination angle, rotating speed and bending angle of spring teeth are determined. The force on the straw at the moment of starting to touch and throw it is analyzed theoretically in the three installation directions of forward inclination, radial and backward inclination on the rotary disc, and the backward inclination of the spring teeth is determined. A simulation model of the seed furrow cleaning device is established by using the discrete element method simulation software; the forwarding speed, rotating speed, installation inclination angle, and bending angle of spring teeth are used as influencing factors to carry out single-factor experiments. The influence characteristics of different parameters on seed ditch cleaning effect are analyzed from the aspects of straw cleaning quantity and soil disturbance. A field validation experiment is carried out, and the results show that when rotating speed is 180 r/min, installation inclination angle of spring teeth is 40°, and bending angle is 30°, the straw cleaning rate is 82.26%. The research could provide references to develop the no-till seeder for maize seeding.