Simulation and parameter optimisation of pickup device for full-feed peanut combine harvester

Abstract

To reduce the pickup and pod drop losses of peanut picking combine harvesters, and to improve the quality of pickup work, a peanut pickup device is designed and a kinematics simulation analysis is conducted using ADAMS software in this study. According to the simulation analysis of the different ratio (λ) of the rotary linear speed of the spring-finger end to the forward speed of the harvester, the motion trajectory diagram of the spring-finger end was obtained, and the reasonable value range for λ was λ > 1. Through the simulation analysis of the missed pickup zone for different spring-finger rows, six was determined as a reasonable number of spring-finger rows. On this basis, the multi-index field orthogonal tests were performed with the pickup and pod drop rate as the performance indexes. The forward speed of the harvester, rotary angular speed of the spring-finger, and bend angle of the spring-fingertip were considered as the test factors. The test results showed that the pickup rate was positively correlated with the value of λ. When λ ≤ 1, the pickup rate was<95 %; when λ > 1, the pickup rate increased gradually with the increase in λ and tended to be constant, which is consistent with the simulation analysis results. There was no positive correlation between the pod drop rate and λ value. A comprehensive scoring method was employed to evaluate and analyse the two performance indexes to determine the optimal parameter combination: when the harvester's forward speed was 1.0 m/s, with a rotary angular speed of 4 rad/s, and spring-fingertip bend angle at 150°, the comprehensive pickup performance was optimum (with a comprehensive test score of 0.106). This study can provide relevant technical references for the research of both peanut pickup combine harvesters and rape and forage pickup devices.