Trackless Greenhouse Transportation Tracking System Based On Ultrasonic Distance Measurement

China,as a major agricultural country,relies on greenhouses for the modernization of rural agriculture,particularly for the production of high-quality off-season vegetables using natural winter light.However,the automation level of transportation tools within existing greenhouse systems is relatively low,hindering the development of greenhouse agriculture.Therefore,this study focuses on improving the automation level of greenhouse transportation tools by developing a trackless transportation tracking system.The system utilizes an ultrasonic ranging algorithm and combines it with an ant colony optimization PID control algorithm to enhance motor speed control.The research involves theoretical analysis,physical model production,and simulation experiments to develop a trackless transportation tracking system based on.The main research content and conclusions are as follows:1.Overall design scheme of the trackless following system: Analyzes the functional requirements of the greenhouse transportation tracking system,determines performance indicators and module device models,provides an overall design scheme,and determines relevant module models.Designs an ultrasonic ranging module with separate transmitter and receiver,incorporates temperature compensation for ranging,and improves the trilateral positioning algorithm to enable positioning under the working conditions of two sensors.2.Software and hardware implementation: Designs the system’s module hardware and provides a detailed description for the production of a system prototype.Designs an automatic following algorithm for customizable following distance and utilizes Keil5 for software programming.Adds mobile app interaction to enable multiple control methods.3.Implementation of control algorithms: Utilizes the PID control algorithm to provide real-time feedback on the deviation of the transportation following system for adaptive adjustment.To address steady-state error and static error problems in the PID control algorithm,susceptible to integral calculation and overflow effects,a new parameter optimization of the ant colony optimization algorithm is employed to improve motor speed control.Matlab is used for software programming,and simulation experiments are conducted to verify the effectiveness.Joint simulation using Carsim and Simulink builds a steering following model for simulation experiments,demonstrating good directional following performance at low and medium speeds.4.Experimental verification: Conducts following experiments on three road conditions(slate road,asphalt road,and grassland)using a prototype machine.Parameters such as deviation angle and amount of the moving target and the following system are used to assess the following effect.The maximum error is observed under grassland road conditions,with relatively high stability when the following distance is less than 250 cm.Load following experiments are conducted on grassland road conditions,revealing that the error increases with larger loads.When carrying a 5KG load,the maximum deviation angle is 12.1 °,and the maximum deviation is 12.8cm.