Design And Development Of Soil Sample Automatic Collection System For Unmanned Driving Based On ROS

Soil nutrient content and soil heavy metal pollution have an important impact on the growth of crops.At present,most soil samples are collected manually.my country has a large area of farmland,so it is labor intensive to collect soil samples manually,and soil heavy metal pollutants can also cause harm to human health.For soil sample collection by domestic and foreign scholars,and the sampling operation can only be collected from the ground surface,the soil sample layering operation is complicated,the collection accuracy is low,and the information management is lacking.Therefore,in order to overcome the above problems and improve the technical level of soil sample collection in farmland,this paper designs an automatic soil sample collection system based on ROS for unmanned driving.In this paper,the mechanical structure design of the soil sample automatic collection system mainly includes the structure design of the unmanned sampling vehicle and the soil sample automatic collection device.The function of the unmanned sampling vehicle is to autonomously navigate according to the location information of the designated sampling point,and drive the automatic soil sample collection device to reach the target point to collect soil samples.This article mainly focuses on the design of the power system and steering system of the unmanned sampling vehicle,analyzes the kinematics characteristics of the sampling vehicle,and calculates the corresponding relationship between the steering rod steering system and the servo motor steering system(steering gear),which is the driving function of the unmanned sampling vehicle Provide theoretical basis.The main function of the soil sample automatic collection device is to automatically collect soil samples.Through the overall design of the lifting mechanism,the power of the lifting mechanism is calculated;the power of the borrowing mechanism is calculated through the overall design of the soil borrowing mechanism and the calculation of the bit parameters;The design of the sample organization realizes the functions of classified collection and information identification of the collected soil samples.In this paper,the design of the electrical control system of the soil sample automatic acquisition system includes the design of electrical control principles and the selection of corresponding electrical components.The industrial control computer is the core of the control system.It performs data processing on sensors such as lidar sensors,odometers,and IMUs.The controller completes the precise control of the servo drive motor,and provides a basis for the driving function of the driverless sampling vehicle and the device to collect soil samples.The output voltage of the motion controller is changed by the PWM DC speed regulation system to adjust the duty cycle,so as to realize the control of the driving speed of the unmanned sampling vehicle.The odometer,IMU and GPS modules are selected to provide fusion information for the fusion positioning of the unmanned sampling vehicle.The RFID reader can write the longitude and latitude information of the sampling point and the sampling depth information into the electronic tag in the process of collecting the soil sample,so as to realize the information management of the soil sample.This paper studies the software control system design and autonomous navigation content of the unmanned sampling vehicle.The system is based on the ROS system architecture.Based on the ROS system,this system develops the autonomous navigation and positioning functions of the unmanned sampling vehicle,and coordinates the navigation and positioning of the unmanned sampling vehicle through the master control node.This paper analyzes the Dijkstra algorithm and the dynamic window algorithm.The Dijkstra algorithm is used to achieve global path planning,and the dynamic window algorithm is used to achieve local path planning.In order to improve the positioning accuracy,this paper uses the extended Kalman filter algorithm to perform data fusion on the odometer information,IMU information and GPS information to improve the positioning accuracy.In order to verify the functions of the unmanned sampling vehicle and the automatic soil sample collection device and the actual operation effect,the system function verification was carried out through field trials.Through experiments on the collection device,it is concluded that the sampling accuracy and efficiency of the device are relatively high,and the sampling time error and soil sample quality error meet the design requirements.The automatic soil sample collection device can automatically layer and sample the soil in any depth range of 0-20 cm in the agricultural layer,and the whole process is automated.The operation of each mechanism is stable,and there is no phenomenon of sticking columnar soil on the drill bit.Through the test of the unmanned sampling vehicle,it is concluded that the sampling vehicle has good driving function and high positioning accuracy.In the static obstacle environment and the dynamic obstacle environment,the sampling vehicle can realize the obstacle avoidance function.The soil sample automatic collection system designed in this paper can significantly reduce labor costs,has a good soil sample collection effect,and can realize the automation and information management of soil sample collection.Therefore,this research can provide technical and equipment support for collecting soil samples.