Research On The Key Technology Of Sample Adding Manipulator For Thrombelastography

With the extensive application of thromboelastography in medical detection,it is urgent to develop a targeted automatic sampling system to eliminate the defects of manual operation error and low efficiency.However,due to the late start of research and development,lack of experience and technology,the current automatic sampling system has a series of problems,such as low efficiency,low precision,cross contamination and so on.As the core component of the automatic sampling system,the research and improvement of the manipulator is the most effective way to optimize the automatic sampling system.The main contributions of this thesis are as follows:(1)In order to solve the problem of low precision of repeated positioning of automatic sampling manipulator,a double line fitting spatial multipoint positioning algorithm based on laser sensor is proposed in this thesis.In this method,the laser sensor is fixed on the end manipulator.By controlling the manipulator to run in the two-dimensional plane,a series of mutation points are obtained by scanning and fixing the edge of the convex block of the test platform equipped with thrombus analyzer,and the plane linear equation is obtained by least square fitting,so as to calculate the reference point coordinates in the two-dimensional plane;Then,according to the principle of trigonometric function and the geometric relationship between the thrombometer and the test-bed,the relative coordinates of all points and reference points in the space are calculated,so as to achieve fast and accurate repeated positioning.The experimental results show that the positioning accuracy of this algorithm can reach0.5mm,which can meet the positioning requirements of the manipulator.(2)In order to solve the problem of liquid overflow caused by uneven distribution of velocity and acceleration in the process of liquid reagent grasping and transportation,an improved adaptive inertia weight particle swarm optimization(aiwcpso)algorithm is proposed for trajectory planning of each axis of the manipulator.In this thesis,firstly,the position and pose are planned,and the linear interpolation and circular interpolation are compared and analyzed;Then,for the speed curve planning,the trapezoidal speed planning and S-shaped speed planning are compared and analyzed.The smoother and more stable S-shaped speed curve is adopted.The parameters of S-shaped speed curve are planned by aiwcpso algorithm,and the optimal solution is obtained through multiple iterations.The experimental results show that the acceleration of the manipulator is obviously improved,which is better than the traditional trial and error method.(3)The software and hardware of the automatic sample adding system are designed,and the workflow and control mode of each part of the automatic sample adding system are introduced in detail.A three-level communication network from the upper computer to the lower computer and then to the sub controller is built to realize the normal and stable operation of the automatic sampling system.Experiments are carried out on this platform to verify the effectiveness of the algorithm.Experimental results show that the positioning algorithm and trajectory planning algorithm used in this thesis have certain advantages over the existing technology,and can solve some problems existing in the current automatic sampling system,which has practical significance.There are 53 figures,11 tables and 52 references in this thesis.