Research On Omni-directional Wheel Navigation Control System Of Elderly Care Nursing Robot

With the increasing ageing of the population in today's society,the use of elderly care holding robots in the field of medical care can greatly relieve the pressure in the field of medical care.This paper designs an omnidirectional mobile platform with three-dimensional perception function for the elderly care holding and lifting robot.Aiming at the complexity of the structure of the nursing robot and the diversity of the indoor environment,a layered environment perception technology of the nursing robot is proposed.After using the lidar to perform multi-level environmental perception on the robot,the grid map is constructed on each level to improve the traditional A* navigation algorithm.The improved A* algorithm is used to plan the path of the elderly care holding robot and conduct simulation experiments on it.First,design an omnidirectional mobile platform for the elderly care holding and lifting robot.Comprehensively consider the needs of omnidirectional movement,stability,shock absorption and anti-dumping of the omnidirectional mobile platform of the nursing care lifting robot,and design the omnidirectional mobile platform.In order to meet the actual needs of the elderly care holding and lifting robot for holding and moving in an indoor environment,the power calculation and selection of the omnidirectional wheel drive motor are carried out.Complete the hardware connection of the omnidirectional mobile platform controller,driver,motor,etc.The PC software of the Beckhoff controller communicates the motion control signals with the four drives through the module EL2521 and the coupler EK1100 to send pulse commands,and the drives control the operation of the servo motor.After the driver parameter setting is completed,the physical axis setting,NC axis control and PLC programming of the motor are carried out through the Beckhoff controller upper computer software TwinCAT3.Secondly,analyze the evenly distributed layout of the four-wheeled nursing care lifting robot,analyze the rank of the Jacobian matrix of various arrangements,and select the best arrangement.According to the structure layout of the omnidirectional mobile platform of the nursing care lifting robot,the robot kinematics model is established.The movement speed of the main wheels driven by four Swiss wheel motors can be obtained from the overall moving speed of the nursing care lifting robot.Finally,the motion path of the elderly care holding and lifting robot is planned.Use lidar to sense obstacles and indoor integrated environment.In order to ensure the best imaging effect when the nursing robot is working,the laser radar is selected to perform imaging tests at different distances.Considering that the overall structure of the nursing robot is complexand the body is large,in view of the problem that the A* algorithm can not choose the robot volume,the edge obstacle compensation method is proposed.Improve the traditional A*algorithm to estimate the cost function to reduce the turning point of the planned path.In view of the huge gap in the profile of the elderly care holding and lifting robot,different obstacle edges are compensated on the plane grid map of each level.By superimposing the grid maps after different obstacles compensation at each level,the multi-level integrated navigation can take into account the structural differences of the robot to a large extent.Design a simulation experiment environment,install a radar on the bottom omnidirectional wheel mobile platform and the waist of the nursing robot to perceive the indoor environment at different levels.