This study presented the design of an electric-driven control system for the seed meter of a precision planter to avoid the issues of poor planting quality and low travel speed limitations associated with conventional ground wheel and chain driven planters. A closed-loop proportional-integral-derivative (PID) algorithm was deployed to control the seed plate rotation speed. The performance of three PID tuning methods (Ziegler-Nichols step response method (ZNM), Cohen-Coon method (CCM), and Chien-Hrone s-Reswick method (CHRM)) was compared by Matlab-Simulink simulation, and results testified that the CCM had a better performance with smallest rise time of 0.018 s, settling time of 0.082 s and maximum overshoot of 26.1%. Field experiments indicated that a four-row planter equipped with the developed electric-driven control system had significantly better quality of feed index (QFI), miss index (MI), and precision index (PREC) values compared with those of a ground wheel and chain driven planter under equivalent working conditions. For a travel speed of 8.6 km/h, the average values of the four rows for the QFI, MI, and the PREC were 98.62%, 1.29%, and 14.51%, respectively. For a high travel speed of 13.0 km/h, the average QFI still achieved a value of 97.09%. Most of the components employed in the system were made in China, and the overall system cost was much less than similar systems obtained from abroad. As such, the proposed system is accessible to precision planters in developing countries. (C) 2017 Elsevier B.V. All rights reserved.
