Design And Control Of Picking Actuator Servoed By Monocular Vision Image

Pomelo is an important fresh fruit for medicine and food.It is also the raw material of deep processing products such as fruit tea and essential oil,which is widely planted in hilly and mountainous areas and mainly depends on manual picking.The loss of labor force and the increase of labor cost in the production area makes it necessary to develop mechanized and automatic picking of pomelo.In view of the complex calculation of the coordinate transformation of the target position in the process of picking by mechanical arms in mountainous orchards,a three-degree-of-freedom picking actuator based on monocular image visual servo was designed after analyzing the action requirements of pomelo picking.The whole machine construction was completed and debugged.The operation effect was verified.The specific research contents and results are as follows:(1)Overall function analysis and integral structure design of the picking actuator.Combined with the analysis of artificial picking action,the main tasks and required functions of the picking actuator were clarified,and the overall design scheme of the mechanism was determined.The three-dimensional modeling of the picking actuator was carried out by SOLIDWORKS software.The rationality of the structure was verified by the finite element simulation of the overall structure using ANSYS software.(2)Design of visual servo communication and debugging of picking actuator.It mainly included the control of MV-CE060-10 UM CMOS industrial camera and image transmission,the reception and application of image processing results,the determination and debugging of visual servo guidance method.The image data acquisition and preservation were realized based on MVS and Py Charm.The visual servo method based on image was determined.By using Visual Studio software for program design,the reading and sending of the centroid position information were completed.(3)Design and debugging of driving system of picking actuator.It mainly included the selection of motor,the design of driving circuit and the vibration analysis of the mechanism.The function of the driving system was explained,and the 86 stepper motor and the YKE2608 MH driver were chosen as the driving element.After determining the hardware composition of the drive system,the drive circuit was designed by using the common cathode connection method.Additionally,the modal analysis of the mechanism was carried out by ANSYS software,and the sixth-order natural frequency and vibration mode of the system were obtained.(4)Design of the control system of the picking actuator.It mainly included hardware design and software design.The hardware design included the selection of the required hardware and the design of the hardware platform circuit.The STM32 microcontroller was selected as the controller and the photoelectric sensor was chosen as the reset element.Moreover,the proximity switch and the pressure sensor were used to detect and sense the fruit.Besides,the composition of the system hardware platform was determined,and the design of the hardware circuit was completed.The software design included the communication between the upper computer and the lower computer,the transmission of data and the design of the control program and the human-machine interaction interface.The communication protocol between the upper computer and the lower computer was defined that the communication and data transmission between the upper computer and the lower computer were completed through the USB to serial port.The data reception and the writing of the control program were completed by using KEIL software,and the motion control of the actuator was realized.Based on the VS software,the design of humancomputer interaction interface was carried out.(5)Construction of the whole machine and function test of the picking actuator.It mainly included the construction of the whole machine and the hardware circuit connection,the determination of test materials and methods and the test of the whole machine operation effect.In order to explore whether the mechanism could complete the holding action of pomelo fruit in the visible range,the pomelo fruits with fruit diameter of 123-135 mm were selected as the experimental material,and 48 experiments were carried out in two groups.The test results showed that the success rate of the mechanism to complete the holding action was 87.5%,which could basically realize the holding action of the pomelo fruit within the visual range.In conclusion,the designed machine meets the expected function requirements and provides a technical basis for the subsequent development of mechanized pomelo picking equipment.