The application of plastic mulch in the arid regions of northwest China has demonstrated significant advantages,making roller-type hole sowing on mulch a key agricultural trend.In order to enhance the performance of a...The application of plastic mulch in the arid regions of northwest China has demonstrated significant advantages,making roller-type hole sowing on mulch a key agricultural trend.In order to enhance the performance of a roller-type corn finger planter equipped with finger pickups.This study analyzed the motion patterns of corn seeds within the device and investigated the effects of control cam parameters,including pickup section,vibration section,pickup stroke angle,and torsion spring force,on seed-metering performance.Using DEM-MBD coupling technology,single-factor experiments and secondorder orthogonal rotational combination simulation experiments were conducted.The optimal parameter is that pickup section stroke angle is 78.98°,vibration section stroke angle is 20.07°,and a normal force is 2.99 N,which was validated through bench tests,achieving a seed-metering qualification rate of 93.86%,a missed seeding rate of 3.19%,and a reseeding rate of 2.95%.These results met the standards and agronomic requirements,demonstrating the effectiveness of the proposed optimization method.It provides a foundation for improving the precision and reliability of roller-type corn seed-metering devices.展开更多
Traditionally, in a cam mechanism, the cam is driven by an actuator at a constant speed. The motion characteristics of the follower are determined once the cam profile is designed. This paper presents a novel theory n...Traditionally, in a cam mechanism, the cam is driven by an actuator at a constant speed. The motion characteristics of the follower are determined once the cam profile is designed. This paper presents a novel theory named "integrated design of cam mechanisms and servo-control systems" whose basic idea is varying the input speed trajectory of the cam by a microcomputer-controlled servomotor to improve kinematic and dynamic characteristics of the follower system. The philosophy of the theory is developing superior machines by taking advantage of the flexibility of servo-control systems to compensate for disadvantages of rigid cam mechanisms. The systematic design criteria of the cam-servo-integrated system are developed and an approach based on optimal-control theory is presented for to select suitable cam speed functions, hence the basis of the theory is formed.展开更多
基金financially supported by the Fuxi Young Talent Cultivation Project of Gansu Agricultural University(Grant No.gaufx-05y02)National Natural Science Foundation of China(Grant No.52365030)The Science and Technology Innovation Fund of Gansu Agricultural University-Young Mentor Support Fund Project(Grant No.GAUQDFC-2024-06)。
文摘The application of plastic mulch in the arid regions of northwest China has demonstrated significant advantages,making roller-type hole sowing on mulch a key agricultural trend.In order to enhance the performance of a roller-type corn finger planter equipped with finger pickups.This study analyzed the motion patterns of corn seeds within the device and investigated the effects of control cam parameters,including pickup section,vibration section,pickup stroke angle,and torsion spring force,on seed-metering performance.Using DEM-MBD coupling technology,single-factor experiments and secondorder orthogonal rotational combination simulation experiments were conducted.The optimal parameter is that pickup section stroke angle is 78.98°,vibration section stroke angle is 20.07°,and a normal force is 2.99 N,which was validated through bench tests,achieving a seed-metering qualification rate of 93.86%,a missed seeding rate of 3.19%,and a reseeding rate of 2.95%.These results met the standards and agronomic requirements,demonstrating the effectiveness of the proposed optimization method.It provides a foundation for improving the precision and reliability of roller-type corn seed-metering devices.
文摘Traditionally, in a cam mechanism, the cam is driven by an actuator at a constant speed. The motion characteristics of the follower are determined once the cam profile is designed. This paper presents a novel theory named "integrated design of cam mechanisms and servo-control systems" whose basic idea is varying the input speed trajectory of the cam by a microcomputer-controlled servomotor to improve kinematic and dynamic characteristics of the follower system. The philosophy of the theory is developing superior machines by taking advantage of the flexibility of servo-control systems to compensate for disadvantages of rigid cam mechanisms. The systematic design criteria of the cam-servo-integrated system are developed and an approach based on optimal-control theory is presented for to select suitable cam speed functions, hence the basis of the theory is formed.
