Design And Optimization Of Wire-controlled Brake For Agricultural Unmanned Vehicle Based On Linear Moto

Mechanized and intelligent agricultural production has become an inevitable trend for future development,and unmanned vehicles for agriculture are an important part of future agricultural production,with safety issues worthy of attention.As the main system ensuring the safety of unmanned agricultural vehicles,the wire control braking system determines the safety of the entire vehicle.Currently,the electronic mechanical wire control actuator commonly used for braking systems adopts a combination of a rotating motor,a gear reduction mechanism,and a ball screw,resulting in a complex structure and difficulty in controlling the braking force.To effectively solve the problems of complex electronic mechanical braking structures and difficult braking force control,this paper proposes the use of a linear motor as the power driving part of the wire control actuator and provides a reliable vehicle testing platform for relevant performance experiments of the wire control braking system.The linear motor can directly generate linear motion without any intermediate conversion mechanism.The cylindrical linear motor has a simple structure,high utilization of permanent magnetic materials and coils,and convenient control of direction reversal.It also has advantages such as fast response speed and no tooth groove effect.Therefore,combined with the advantages of the structure and control aspects of the cylindrical linear motor,it is suitable for application as the power driving part of the wire control actuator for agricultural unmanned vehicles.However,the low thrust density of the linear motor has always been a problem that urgently needs to be solved.Therefore,by fully utilizing permanent magnetic materials and conducting reasonable structural design,the thrust of the motor can be increased without increasing the volume,which has important research value.This paper conducts research and experimental work mainly in the following aspects:(1)Introduce the basic electromagnetic theory of magnetic circuit and magnetic field and the working principle and classification of linear motors,and establish a mathematical model for the linear motor.According to the requirements of the wire control braking system for agricultural unmanned vehicles,the design indicators for the linear motor are proposed.Based on the characteristics of different types of linear motors and the design indicators for the motor,the linear motor is selected.(2)Analyze and select the materials for the linear motor,and design the structure.Use ANSYS Maxwell finite element electromagnetic simulation to simulate the structural parameters of the designed linear motor,and then use a thrust test platform to test the electromagnetic thrust of the linear motor.(3)In order to improve the electromagnetic thrust of the linear motor,DOE full factorial design is proposed for optimization analysis.Using Minitab software,the regression equation of the fitted model is obtained,and the optimal parameter combination for the key components of the linear motor is calculated through the optimization algorithm of the model.(4)A test platform for agricultural unmanned vehicles is designed as a wire control actuator based on the linear motor drive.ANSYS is used to perform finite element analysis on the skeleton of the wire control test platform,and the agricultural unmanned vehicle wire control test platform is manufactured.The braking performance of the agricultural unmanned vehicle with the wire control actuator based on the linear motor drive is tested under no load and load conditions,and the test results are analyzed.The wire control actuator based on the linear motor drive can meet the design requirements of the braking system for agricultural unmanned vehicles.