Structure Design And Intelligent Control Of Integrated Wheelchair Bed Robot

With the increase of the proportion of the middle-aged and the elderly in China's population structure,the nursing problem of the disabled elderly is becoming increasingly prominent.There is a huge manpower gap in the medical industry.The employment cost of family care workers has also become a long-term high cost for families.In order to solve the problem of expensive and cumbersome nursing,this paper designs a bed chair integrated robot that can be used in hospitals,homes and other places,and studies its structure,function,software and hardware control in detail.The specific contents are as follows.Firstly,the functional indexes of the bed chair integrated robot are determined according to the purpose.Starting from ergonomics,this paper introduces the basic size parameters of human body,and further designs the main structural dimensions of wheelchair unit and bed unit.The wheelchair chassis part can realize omni-directional automatic walking,posture transformation of wheelchair sitting and lying posture,docking between wheelchair and toilet,toilet and bed.The specific mechanical structure of each function is described in detail,including the type of chassis and the motion principle of mcnamu wheel chassis,and the selection of servo motor,reducer and power supply;The design of toilet structure mainly includes the selection of steering gear and the installation of slide rail.Secondly,the kinematics and dynamics of the key mechanism are analyzed.Use Adams and MATLAB software to simulate the kinematics of the back push rod mechanism and the leg push rod mechanism,and then use the experimental design method to carry out parametric modeling of the connecting rod mechanism with the push rod as the power of the back and leg,and optimize the parameters such as the driving force of the push rod and the angular velocity of the back and leg,so as to reduce the required driving force.The dynamic analysis of strength and stiffness of key parts is carried out in ABAQUS software.Then,the control mode is generally introduced,and the CAN bus communication mode is selected to analyze the message transmission mode and communication performance of CAN communication.Finally,the c470 controller of Hesheng is selected as the main controller to complete the control of electrical components,and the CAN bus is used to complete the communication between man-machine interface and controller.This paper introduces the working mode of omnidirectional mobile chassis motor driver,the working principle of electric push rod and PWM speed regulation drive,the control mode of high-voltage controller and low-voltage steering gear based on optocoupler,and the working principle of sensor for bed and chair docking,and draws the wiring diagram of the above components.Finally,the software level and touch interface of the control system are designed.A man-machine interface is designed by using HMI editor interface editing software.The man-machine interface is mainly composed of three modules: chassis control interface,attitude change control interface and toilet control interface.The chassis control interface is divided into speed selection and direction control buttons;Separate movement buttons for back and legs on the attitude change control interface;Two groups of steering gear control and push rod control buttons on the toilet control interface.The switching logic of different interfaces and the interlocking logic inside a single interface are also designed.Based on the known human-computer interaction interface,the core control program is written with Co De Sys software,the work flow chart of each module is drawn,and the specific control programs of chassis motion module,attitude change module,toilet module and bed chair docking module are developed with ST language to show the overall function of bed chair integrated robot.