| With the rapid development of mechanical,hydraulic and electronic control technologies,modern plant protection machinery is developing towards high efficiency,intelligence and versatility.This paper has carried out the design and research of the steering and leveling control system for the highland gap plant protection machine in the southern paddy field.Through extensive reading of research status at home and abroad,the paper analyzes and determines the high-altitude plant protection machine plan suitable for the southern hilly area,and determines the steering mode of the plant protection machine according to the actual requirements of the operation,and selects the hardware selection of the steering and leveling control system of the whole machine.Type and installation,software design related design and research.The two-wheel steering and four-wheel steering for the high-altitude plant protection machine must meet the Ackerman steering principle,carry out theoretical analysis,and establish a mathematical model of the angle control of the steering system to determine the minimum turning radius and four-wheel independent steering for multiple modes.Software flow chart for analysis.In order to better complete the ground clearance adjustment and leveling control of the high ground clearance plant protection machine chassis,this paper designs a chassis automatic leveling control strategy and hardware system.The STM32F103VET6 microcontroller is used as the main control chip,and the system detects four legs in real time.The inclination angle and the horizontal inclination of the chassis are processed by Kalman filtering algorithm.For the ground clearance and leveling control of the high ground clearance plant protection chassis,the system is prone to overshoot due to load asymmetry.The parameter adaptive PID algorithm of fuzzy control theory controls the hydraulic cylinder displacement.In order to verify the effectiveness and reliability of the algorithm for hydraulic cylinder displacement control,the single-legged valve-controlled hydraulic cylinder system is modeled and analyzed,and the Simulink toolbox under Matlab software is used to establish conventional PID control,conventional fuzzy control and self-adaptation.Fuzzy PID control three control algorithms simulate the system.The results show that the adaptive fuzzy PID algorithm has small overshoot,fast convergence and rapid response.At the same time,the hydraulic schematic of the system is established in AMESim software.The adaptive PID algorithm is used to simulate the displacement of the hydraulic cylinder under different loads.It shows that the hydraulic cylinder can complete the displacement simulation well,there is almost no overshoot,the static error is small,and it has good working stability and reliability.A leveling control strategy based on position error control method and angle error control method is proposed.It is proved by experiments that the automatic leveling system can complete the ground clearance adjustment and chassis leveling,the response time is 0.45 s,and the static average level error is ≤ 0.25.°,the maximum error is 0.45 °,The root mean square error is ≤ 0.27°;The dynamic average horizontal error is ≤ 0.64°,the maximum error is 0.81°,and the root mean square error is ≤ 0.34°.The system runs stably and is responsive,meeting the operational requirements of the plant protection machine. |
