Optimal design of an onion planting mechanism based on a denatured Pascal limacon gear

Liu, Yongping (author), Wang, Jianli (author), Dong, Changbin (author)

Mechanized onion planting is crucial for improving efficiency and reducing labor costs. However, traditional elliptical gear-driven planting mechanisms often exhibit issues such as unstable trajectories and excessively high velocities and accelerations. To address this, this paper proposes a parallelogram planting mechanism based on a denatured Pascal limacon gear drive. By analyzing the mechanism’s operating principle and the transmission characteristics of the denatured Pascal limacon gear, a kinematic model was established. The effects of parameters such as gear denaturation coefficient, drive speed, and link dimensions on the planting point trajectory and motion velocity were investigated. Results indicate that the denaturation coefficient, crank length, and initial mounting angle significantly influence the mechanism’s performance. Based on these findings, multi-objective optimization using a genetic algorithm was conducted to meet agronomic requirements. The optimized mechanism achieves a planting depth of 27 mm at a forward speed of 0.3 m/s and a gear angular velocity of 2π rad/s. Horizontal velocities at soil entry and exit approach zero, acceleration changes gradually during the planting phase, and operational stability is significantly enhanced. Compared to the elliptical gear drive configuration, it demonstrates superior overall performance.

• Language: English
• Keywords: denatured Pascal limacon gear, onion transplanting, non-circular gear, asymmetric transmission, optimization algorithm
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: Str. 72-83
• Numbering: Vol. 72, no. 3/4
• PID: 20.500.12556/RUL-182483
• UDC: 621.833: 519.16
• ISSN on article: 0039-2480
• DOI: 10.5545/sv-jme.2025.1517
• COBISS.SI-ID: 278033411
• Publication date in RUL: 13.05.2026

Record is a part of a journal

• Title: Strojniški vestnik
• Shortened title: Stroj. vestn.
• Publisher: Zveza strojnih inženirjev in tehnikov Slovenije [etc.], = Association of Mechanical Engineers and Technicians of Slovenia [etc.
• ISSN: 0039-2480
• COBISS.SI-ID: 762116

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Title: Optimalna zasnova mehanizma za sajenje čebule na osnovi zobnika v obliki deformiranega Pascalovega polža

Abstract

Mehanizirano sajenje čebule je ključno za izboljšanje učinkovitosti in zmanjšanje stroškov dela. Vendar pa tradicionalni sadilni mehanizmi, gnani z eliptičnimi zobniki, pogosto izkazujejo težave, kot so nestabilne trajektorije ter previsoke hitrosti in pospeški. Za odpravo teh pomanjkljivosti članek predlaga paralelogramski sadilni mehanizem, ki temelji na pogonu z zobnikom v okliki deformiranega Pascalovega polža. Z analizo principa delovanja mehanizma in prenosnih značilnosti zobnika je bil vzpostavljen kinematični model. Preučeni so bili vplivi parametrov, kot so koeficient deformacije zobnika, pogonska hitrost in dimenzije členov, na trajektorijo sadilne točke ter hitrost gibanja. Rezultati kažejo, da koeficient deformacije, dolžina ročice in začetni montažni kot bistveno vplivajo na delovanje mehanizma. Na podlagi teh ugotovitev je bila izvedena večkriterijska optimizacija z uporabo genetskega algoritma, da bi zadostili agronomskim zahtevam. Optimiziran mehanizem doseže globino sajenja 27 mm pri napredovalni hitrosti 0,3 m/s in kotni hitrosti zobnika 2π rad/s. Horizontalni hitrosti ob vstopu in izstopu iz tal se približata vrednosti nič, spremembe pospeška med fazo sajenja so postopne, operativna stabilnost pa je bistveno izboljšana. V primerjavi s konfiguracijo z eliptičnim zobnikom izkazuje boljše celotne zmogljivosti.

• Keywords: zobnik v obliki deformiranega Pascalovega polža, presajanje čebule, nekrožni zobnik, asimetrični prenos, optimizacijski algoritem