Implementation of a magnetorheological damper on a no-till seeding assembly for optimising seeding depth

摘要

No-till seeding requires a seeder that can effectively cope with the unfilled soil and place the seeds at an optimum depth in order to achieve a reliable germination and rapid plant emergence. This aim is more challenging due to the inappropriate response of the machine dynamics to harsh soil conditions, such as the compacted soil undulations and the presence of the stubble. In this paper, a seeder main frame carrying a seed dose mechanism and two no-till seeding assemblies was developed and designed with multiple sensors, to capture the dynamics of the assemblies together with the corresponding surface profile. A magnetorheological (MR) damper was implemented into one of the seeding assemblies to optimise its dynamics for better seed placement. A number of strain gauges were used to measure the dynamics of the seeding assemblies, like vertical and impact forces during seeding operation at a travelling speed of 10 km h(-1). The accuracy of the surface profile sensing system was validated by obtaining the profile of trapezoidal bumps with georeferenced dimensions resulting in a root mean squared error of 9.6 mm and 9.9 mm for the damped and undamped seeding assembly, respectively.