基于电磁振动的玉米粒群定向整列系统的参数优化与试验

为提高玉米粒群定向整列系统性能及精度,分析电磁振动系统设计参数对定向整列性能的影响.首先,通过分析系统的工作原理,构建了籽粒的滑移模型;其次,开展了系统动力学分析及定向阶段籽粒的受力分析,探讨了籽粒定向整列过程与系统设计参数之间的关系,选取出对系统作业性能有显著影响的参数,得到满足要求的设计参数临界条件;最后,搭建定向整列试验平台,通过三因素二次正交旋转设计试验,进一步优化设计参数,建立因素与试验指标(定向成功率、整列成功率)的回归方程.经优化计算得出:最佳设计参数范围为振动方向角32°~35°、振幅为0.1~0.15 mm、振动频率为51.5~52 Hz,相对应的试验指标定向成功率范围为63.8%~67.4%,整列成功率范围为95.8%~96.3%,其中最优参数组合为:振动方向角34.42°、振幅为0.14 mm、振动频率51.77 Hz;将系统置于最优参数组合进行验证试验,同时借助高速摄像系统对籽粒定向整列过程实时记录和分析,在无机械机构辅助的情况下,平均定向成功率为66.2%,整列成功率为97.4%.该研究可为玉米籽粒定向种植、定向育苗等相关装备的研制提供参考.

Parameters optimization and experiment of oriented alignment system for maize seed group based on electromagnetic vibration

Abstract: The study of corn mechanization planting orientation is still in the primary stage. Design of relevant institutions is mostly based on conceptual design of ideal grain shape, and the study on the basic characteristics and basic theory on corn particle swarm oriented alignment technology is lack. The motion state is more complex and affects the oriented alignment effects of maize grain seriously in electromagnetic vibration modes on maize grain in line in the process of conveying and sorting grain. Understanding of mechanical properties and optimization of vibration source parameters are the premise and key to get better oriented alignment effect of maize grain in the study of maize grain in vibration field. At first, this paper established the model of maize grain sliding motion through the force analysis of corn grain in the electromagnetic vibration system, and also obtained the minimum amplitude of the system of 0.05 mm which was the critical condition of contacts between the kernel and platform. Secondly, considering the special physical characteristics of corn grain, 1000 grains for each kind among 5 different kinds of corn with high quality in directional cultivation conditions were selected, and the instruments were adopted, such as the electronic balance with precision electronic scale of 0.01 g, the BPG-9.30AH electric thermostat blast drying box and MXD-01 friction coefficient instrument. For the different types of maize grains, the measured water content is in the range of 13.88%-14.53%, the density range is 1.13-1.19 g/cm3, and the sliding friction coefficient range between corn and hard rubber is 0.58-0.79. The corn planting orientation still relies on artificial pendulum, lacking mechanized corn directional seeding device. In order to make corn group oriented alignment system achieve directional cultivation, directional seeding accuracy requirements, and design parameters of the electromagnetic vibration system for corn particle swarm oriented alignment performance, were analyzed, as well as kinematics and dynamics of the system. The relationship between seed oriented alignment process and design parameters of system was explored in order to satisfy critical conditions requirements; the selected parameters had significant influence on the working performance of the system, and the main parameters affecting the performance of oriented alignment were the direction angle of vibration, vibration amplitude and frequency. On the corn particle swarm oriented alignment test platform, through the 2 orthogonal rotation design tests with 3 factors, the design parameters were optimized, and the factor and test index (directional success rate, the success rate of the entire column) regression equation was established. The optimal design parameters range was as follows: Vibrating direction angle was 32°-35°, amplitude was 0.1-0.15 mm, and vibration frequency was 51.5-52 Hz; corresponding to the test index, directional success rate was in the range of 63.8%-67.4%, the success rate of entire column was 95.8%-96.3%; the optimal combination of design parameters was the vibration direction angle of 34.42°, the amplitude of 0.14 mm and the vibration frequency of 51.77 Hz. The best combination of parameters was used in system verification test, with the high speed camera system implementation of recording and analysis on grain oriented alignment process, and in the absence of mechanical assisted mechanism, the average success rate of the orientation reached 66.2%, the success rate of entire column was 97.4%. The research can provide reference for the directional planting of maize grain and the development of directional seedling-raising equipment.