Study On The Motion Control System Of Transplanting Mechanism For Vegetable Transplanter

At present,the main methods of transplanting vegetables in our country are artificial transplanting and semi-automatization transplanting,its labor intensity and low production efficiency have been restricting the development of vegetable industry in china.It is significant to improve the automation degree of vegetable trans-planter for increasing the output of vegetable industry,liberating the labor force and improving the production efficiency.The key technology of vegetable trans-planter automation is the automation of the seedling taking and the automation of the seedling collection is divided into three processes: the location of the seedling,the holding of the seedling and the final seeding.A series of studies were carried out in order to find the location of the seedling in this paper which was based on the existing seedling transplanting device.And a set of control system based on single neuron PID algorithm was designed to locate the seedling location.The mathematical model of the actuator and sensor was set up aimed at the actual situation of the device,and the executing mechanism of the device included a step motor rotating the device and a double cylinder for driving device to reach seedling point;the sensor of the device included an angle sensor for measuring the rotation angle of the stepping motor and a displacement sensor for measuring the automatic extraction of the double shaft cylinder.The mathematical model for the controlled object of stepping motor and angle sensor was established according to the function of the actuator and the sensor,and also the model of the controlled object with double shaft cylinder and displacement sensor.The movement process of the device was analyzed to obtain the mathematical model of the rotation angle of the stepping motor and the automatic extraction of the double shaft cylinder,according to the movement of the disk transmission device and the seedling taking device.Single neuron PID control algorithm was designed in this paper aimed at the control of the stepping motor and the biaxial cylinder in the seedling collecting device.The control system composing of different actuators and sensors was simulated and analyzed,and compared with the traditional PID control algorithm in the Simulink.The simulation results showed that the single neuron PID control algorithm was superior to the traditional PID control algorithm with higher precision,smaller overshoot and better system performance.STM32F103C8T6 was took as the core of control system,and combined with the single neuron PID control algorithm.Then the hardware and software platform of the control system was built to carry out the test,record and analyze the test data.The final results showed that in the control of single neuron PID control algorithm for picking seedling fetching device positioning process,the maximum absolute error of stepper motor angle was less than 3%,and the maximum absolute error of the biaxial cylinder displacement pick-up was less than 5%.In addition,the three axis sensor measured that the vibration was reduced obviously and the stability of the system was improved,which could meet the actual demand in the course of the actual movement.At the same time,it was also showed practical to use the single neuron PID control algorithm on the platform of seedling transplanting device.