Research On Path Tracking System And Control System Design Of Transfer Robot

With the increasingly serious problem of population aging and the disabled population with a large base,it is impossible to assist patients in daily movement and travel through wheelchair movement controlled by limbs.The automatic omnidirectional transfer robot combined with EEGBCI(electroencephalogram brain computer interface)system can effectively improve the autonomous mobility of disabled people,and puts forward a good solution to solve this pain point problem.The purpose of this project is to design a transfer robot chassis with good omnidirectional mobility and safety,and deeply study its path tracking algorithm and control system.The specific contents are as follows:(1)The main functional requirements and performance indexes of the transfer robot was analyzed.Then,the driving and layout scheme of the chassis gear train of the transfer robot was determined,the navigation and positioning scheme of the transfer chassis,the hardware and software scheme of the control system,including communication and EEG trigger mode,etc were determined.Finally,the design and selection of hardware,software and navigation and positioning scheme of the transfer robot were completed.(2)According to the motion analysis of the chassis of the transfer robot,the forward and inverse kinematics models of the mobile chassis were established and simulated.Combined with the kinematics model,the iterative formula for updating the position and attitude deviation was established.Aiming at the problems of difficult calculation and complex use of the path tracking controller using the optimal control principle,a multi-step predictive path tracking algorithm based on the optimal control theory was designed to ensure the correction accuracy and realize the synchronous elimination of angle deviation and position deviation at the same time.Then,the different sign deviation controller was optimized according to the two evaluation indexes of deviation correction time and maximum overshoot of position deviation.The simulation results show that the combination of the two path tracking algorithms can effectively reduce the time of deviation correction and greatly reduce the maximum overshoot of position deviation,so as to verify the correctness and effectiveness of the algorithm.(3)Combined with the actual application scenario of the robot,the host computer operating system developed by visual studio 2017 was determined.The hierarchical architecture of the host computer software was analyzed with the top-down design idea.The software design of initialization,safety monitoring and processing,path tracking,EEG acquisition and analysis,serial communication and database access was introduced in detail,Finally,the patient transfer function with the EEG typing result as the target location input was realized.(4)The physical prototype of the transfer robot chassis was assembled,and a high-precision measurement system using Faro laser tracker was built.The speed performance test and circular motion performance test of the physical prototype were performed to verify the correctness of the kinematic model and omni-directional mobility.Then,the path tracking accuracy tests were carried out to verify the correctness and effectiveness of the proposed algorithm.The test results show that the chassis of the transfer robot meets the performance design requirements of each system,which lays a foundation for the patient’s autonomous transfer.