| Seeder was a core component of precision sowing technical, its work performance directly affected the sowing accuracy, seed space uniformity and emergence rate. Vacuum-vibration seeder has become the major development trend of precision seeder because of its advantages including lower requirement of seeds size, lower harmful to seeds, higher universality and better versatility. The working performance of the seeder was majorly determined by the seeds motion states in vibration plate. This paper takes the new designed Multi-DOF vibration plate as test object, through the mechanisms, experiment optimization method and combined the EDEM simulation to analyze the seed movement law in the Multi-DOF vibration plate and real-time monitor the seeds distribution during the process of seeding. The main work includes the following aspects:1. Design the structure of Multi-DOF vibration plate. Tests revealed that seeds was flowing when the vertical vibration plate was working. This phenomenon lead to uneven seeds distribute in vibration plate. A 3-DOF vibration plate which can realize horizontal rotation and vertical vibration was designed. And through Adams simulation to verify the feasibility of the correcting element.2. Monitoring method of rice seeds mass in vibrating plate. A monitoring regional whose size was 60×60mm was marked off to install the cantilever force sensor. The impact signal of seeds was measured by cantilever force sensor. Two processing circuit was designed through analyzing the characteristics of the sensor output signal. And the linear relationship between seeds quality and output voltage was obtained by calibration test with the final processing signal.3. The flow regulation of seeds in the Multi-DOF vibration plate. Due to the impact of external interference and other factors, the plate has a small tilt angle during vibration. This lead to seeds flow in the plate. This paper used EDEM simulation to study the seeds flowing movement law in various vibration frequency, amplitude and tilt angle of vibrating plate. Experimental results show that the speed of seeds flowing decreased with the increasing of seeds thickness and increased with the increasing of vibration frequency, amplitude and tilt angle. Test the seeds’ s flow movement in the Multi-DOF vibration plate, the results shows that the flow movement of seeds was consistent with the simulation results.4. Discrete movement regulation of seeds in vibration plate. The results of EDEM simulation shows that within a certain range, the discrete degree of seeds increased with the increasing of vibration frequency, amplitude, but the stability of motion decreased; when the seeds layer was 10 to 25 mm, the discrete degree of seeds was closer. When the seeds layer reached to 30 mm, the discrete degree of seeds was low, but the stability of the movement was better.5. The distribution of seeds in the Multi-DOF vibration plate. According t o the movement of seeds in Multi-DOF vibration plate, a method was propose d to monitor the distribution of seeds. This method mainly uses 4 groups cantil ever force sensor to monitor the seeds mass in the monitoring regional. The re sults of seeds discrete simulation at different seeds thickness and tilt angle sho ws that the relative average error between efficiency and actual value was less than5%. Then the feasibility of monitoring method was verified by bench test. |
