Kinematic analysis of rotary harrows

  • Terenziano Raparelli Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy.
  • Gabriella Eula | Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy.
  • Alexandre Ivanov Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy.
  • Giuseppe Pepe Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy.


This article presents the kinematic analysis of the tine motion of a rotary harrow. In particular, it analyses the trajectories that the tines describe when they are pulled by the motion of the tractor and rotated by the rotors. This analysis, has led to the identification of the parameters that influence the motion of the tines and how these parameters intervene in the secondary tillage. The interaction between the tines and the soil is evaluated considering a plastic soil, i.e. without any cleavage and its propagation. With this hypothesis, the dimensions of the soil clods created by the passage of the tines in the soil have been analysed. The trajectories described by the tines of the machine, and therefore the dimensions of the portions of worked or unworked soil, are influenced by the operating parameters of the soil tillage process, such as the tractor speed and the angular speed of the tines themselves. Furthermore, a contribution is also given by the geometric parameters of the machine, such as the rotor radius and the geometric configuration of the rotary harrow in terms of rotor arrangement. This study is based on the creation of a mathematical model of the trajectories of the tines of a rotary harrow during soil tillage. The model is parametric and makes it possible to simulate and optimise the tillage process. The approach adopted also makes it possible to visualise the trajectories in graphic form for an easy visual interpretation of the results.



PlumX Metrics


Download data is not yet available.


Ahmadi I, 2017. A torque calculator for rotary tiller using the laws of classical mechanics. Soil and Tillage Research. 165:137-43 DOI:

Cavazza L, 1981. Fisica del terreno agrario. UTET, Torino, Italy

Chan C W, Wood R K, Holmes R G. 1993. Powered harrow operating parameters: effects on soil physical properties. Transactions of the ASAE. 36(5):1279-1285. DOI:

Destain M F, Houmy K. 1990. Effects of design and kinematic parameters of rotary cultivators on soil structure. Soil and Tillage Research. 17:291-301. DOI:

Godwin R J, 2007. A review of the effect of implement geometry on soil failure and implement forces. Soil and Tillage Research. 97:331-40 DOI:

Hirasawa K, Kataoka T, Kubo T, 2013. Prediction and evaluation for leveling performance in rotary tiller. Proc. 4th IFAC Conference on Modelling and Control in Agriculture, Horticulture and Post Harvest Industry, Espoo, Finland, 46: 315-20 DOI:

O'Callaghan J R, McCullen P J, 1965. Cleavage of soil by inclined and wedge-shaped tines. J. agric. Engng Res. 10:248-54. DOI:

Piccarolo P, 1976. Analisi comparativa del comportamento cinematico e dinamico di due erpici azionati dalla p.d.p. della trattrice. St.Sass III Agr. XXIV

Raparelli T, Eula G, Ivanov A, Pepe G, 2018. Analisi della catena cinematica per la trasmissione del moto dal trattore a un erpice rotativo. Organi di trasmissione. Novembre:76-81

Raparelli T, Eula G, Ivanov A, Pepe G, Ricauda Aimonino D. 2019. Preliminary analysis of interaction among gears, tines and soil in a rotary harrow. International Journal of Mechanics and Control. International Journal of Mechanics and Control. 20(1):81-91.

Stafford J V, 1979. The performance of a rigid tine in relation to soil properties and speed. J. Agric. Engineering Res. 24:41-56. DOI:

Swick W C, Perumpral JV, 1988. A model for predicting soil-tool interaction. Journal of Terramechanics 25:43-56. DOI:

Original Articles
Kinematic analysis, rotary harrow, soil tillage.
  • Abstract views: 536

  • PDF: 248
  • HTML: 1
How to Cite
Raparelli, T., Eula, G., Ivanov, A., & Pepe, G. (2019). Kinematic analysis of rotary harrows. Journal of Agricultural Engineering, 51(1), 9-14.

Most read articles by the same author(s)