Mechanical Structure Design Of Medicine Taking Robot And Experimental Study On Its Gripping Mechanis

With the continuous progress of science and technology and the improvement of modern medical service level,various automated pharmacy systems are gradually entering major hospitals,and the realization of scientific,standardized and automated management of drugs has become the development trend of the pharmaceutical industry.Using robots to replace the traditional manual delivery of drugs can not only improve the efficiency of drug delivery,reduce the probability of drug delivery error,make full use of pharmacy space and other advantages,but also realize the objective needs of intelligent pharmacy management.Therefore,the development trend of automated pharmacy is studied.Based on the analysis of automated pharmacy system and product characteristics at home and abroad,this paper analyzes and demonstrates the structure,motion mechanism,end-effector and grasping target positioning of the pharmacy robot according to the working characteristics and technical requirements of the pharmacy.The main research work and achievements are as follows:(1)According to the characteristics of large motion range,fast speed and small load of the medicine fetching robot,cartesian coordinate type medicine fetching robot is designed.The overall mechanical structure of the robot was modeled and designed,and the load,motion characteristics and parameters of the motion mechanism were analyzed and calculated,and the driving motor was selected and checked.Through the finite element analysis of the key bearing parts,the strength and stiffness are verified to meet the requirements.(2)The clamping end-effector was designed in view of the flexible characteristics of drug packaging in various forms and sizes,including a telescopic mechanism pointing to the target drug box,a clamping mechanism and a dropping mechanism.The clamping mechanism adopts "two-way screw thread" design,compact structure,stable clamping.The actuator’s structure,motion mechanism,load bearing and driving motor selection are analyzed,calculated and checked.(3)Use binocular vision to detect the position of the drug box,effectively improve the accuracy of the "grasping" of the drug box by the clamping mechanism,and reduce the requirements on the movement and positioning accuracy of the robot mechanical system to a certain extent.According to the principle of geometric optical imaging,the camera imaging model was established,the coordinate transformation relationship of object image and the camera calibration method were theoretically analyzed,and the binocular measurement system calibration and drug box detection and positioning experiments were carried out with self-designed software,and the detection accuracy of the drug box distance was up to ±4mm.(4)The experimental device of clamping mechanism was made and the clamping experiment of drug box was carried out.The experimental results were basically consistent with the finite element analysis results of the clamping finger,which preliminatively verified the feasibility of the clamping mechanism of "two-way screw thread".