| The automatic operation technology of agricultural machinery is currently the research hotspot of precision agriculture at home and abroad,and it is also the core technology to realize the intelligent operation of agricultural machinery equipment.The automatic operation technology of the rice transplanter not only can alleviate the driver's fatigue problem in the process of the traditional rice transplanter operation,but also can effectively improve the production efficiency and land utilization rate.In this article,the Kubota SPU-68 C high-speed rice transplanter is used as the test platform to study the automatic operation control system of the rice transplanter.Aiming at the influence of lateral deviation and heading deviation on the driving speed during the automatic operation of the rice transplanter,a self-adjusting fuzzy control algorithm was researched.The lateral deviation and heading deviation were used as input variables,and the driving speed was used as the output control variable.Then,the look-ahead distance is adaptively adjusted in conjunction with the relationship between driving speed and look-ahead distance,and the desired front-wheel turning angle is further obtained through a pure tracking model.Finally,the algorithm and control system are verified through the automatic operation control simulation and environment.Based on the vehicle motion information and the changes of each deviation,the automatic adjustment of the driving speed is realized.The robustness and adaptability of the rice transplanter working in a complex paddy field environment are improved,and a good theoretical and technical foundation is laid for the automation of the rice transplantation operation.The main research work of this article includes the following parts:1.In this article,the vehicle motion perception system is designed,including GPS positioning system,integrated inertial navigation system,angle / speed sensor and other equipment.We use RTK-GPS technology,inertial navigation technology,sensor technology,etc.to provide real-time motion information and position information of rice transplanter feedback.In the end,the motion sensing system of the rice transplanter was successfully built to obtain real-time position information,actual front wheel rotation angle and driving speed of the vehicle during the automatic operation process.Finally,the accuracy test and calibration test of each sensor were carried out.2.The movement characteristics and automatic operation technical requirements of the rice transplanter were studied and analyzed,and analyze the working characteristics of the operating components such as the steering wheel,the main shift handle,the transplanting clutch handle,the brake pedal.The automatic operation control system of the rice transplanter have been designed and researched;the data processing controller and driving unit were designed and installed.The platform construction of the execution mechanism,data processing and hardware drive of the automatic operation control system were completed,and the automatic steering,automatic speed regulation,automatic transplanting and automatic braking operations of the rice transplanter were realized.3.The three control processes of the lateral control,longitudinal control and automatic transplanting control of the automatic operation control system of the rice transplanter have been explained,and the basic principles of the automatic navigation control,speed self-adjusting control and automatic transplanting control of the rice transplanter were introduced.The rice transplanter was simplified into a two-wheeled vehicle model,and it was combined with a pure tracking model to derive the kinematics model of the vehicle.The relationship between the driving speed and the look-ahead distance was constructed to obtain the corresponding look-ahead distance according to the driving speed,derive the desired front wheel angle.4.The fuzzy control method were integrated to design the speed self-adjusting fuzzy control algorithm,set the controller input as the lateral deviation and heading deviation,and the output as the driving speed.Then,the look-ahead distance is calculated according to the relationship between the driving speed and the look-ahead distance,and the expected front-wheel turning angle is further obtained.Finally,a Simulink simulation model is established to conduct a simulation experimental study and verify the effectiveness of the speed self-adjusting fuzzy control algorithm.The simulation results show that the deviation of the straight line segment is small during the operation of the rice transplanter,and the maximum lateral deviation of the turning section is less than 0.08 m.The driving speed follows the deviation and changes regularly,and the process of automatic speed adjustment is relatively stable.It can be seen from this that the speed self-adjusting fuzzy control algorithm has better path tracking correction and speed self-adjusting capabilities.5.A field experiment of the rice transplanter automatic operation control system was designed to verify it.Firstly,the experimental platform of the automatic operation control system of the rice transplanter was built.Secondly,three ground experimental schemes of a straight line path without deviation,a straight line path with 0.3m deviation and a S-shaped path were designed for verification.The experimental results show that the average deviation of the lateral deviation of the straight path section during the running of the rice transplanter is about 0.05 m,and the maximum value is about 0.08m;the deviation of the deviation of the turning path section is large,and the maximum lateral deviation is 0.157m;the effect of automatic speed adjustment is better,it complies with the law of speed self-adjusting fuzzy control algorithm basically,and the acceleration/deceleration phase is relatively stable,without large fluctuations.The designed automatic operation control system of the rice transplanter basically meets the agronomic requirements of the rice transplanter. |
PDF Full Text Request