| The compound robot can replace human to complete some simple and repetitive chemical experiments,so as to achieve the goal of improving the efficiency of scientific research and speeding up the iteration of development.In the existing solution,the robot needs to complete the position calibration through the force feedback mechanism,and complete the action according to the preset position of the operating object.There is room for improvement in robustness and flexibility in this way of working.In addition,the functional equipment used by robot in this solution has the disadvantages of high research threshold,long research cycle and high cost,which is not conducive to popularization.Aiming at the above problems,a visual feedback compound robot and its control system are developed,and its robustness and flexibility optimization compared with the existing force feedback compound robots are studied.Taking the precise liquid dripping function as an example,a form of automation in chemical laboratories that is easy to replicate and popularize is explored.First,the hardware construction of the robot and its control system design are studied.According to the actual environment and task requirements of the laboratory,an automatic pipetting device is designed,and a prototype robot is built.The overall design of the robot control system based on visual feedback is proposed.Aiming at the shortcomings of the existing object recognition methods in the chemical laboratory automation scene,a target localization algorithm based on auxiliary signs and point cloud clustering is proposed to help the robot recognize the operating object.Then,the realization of the robot control system is studied.Based on the ROS(Robot Operating System)system,the robotic arm,target localization and control modules are implemented.Finally,the functional test of the robot control system is carried out.The accuracy of the robotic arm control and the effectiveness of the target localization module are verified,and the depthsensing camera intrinsic matrix and the robot hand-eye transformation matrix are obtained.Based on the above work,control the robot to carry out the experiment of transporting items and the experiment of liquid dripping.According to the analysis of the experimental results,the visual feedback compound robot and its control system have the following three advantages in the experimental operation.(1)Good accuracy,the placement error of the item is controlled within 3 cm,and the robot can accurately quantitatively transfer liquid between beakers with a diameter of 6 cm;(2)Strong flexibility,after the item is moved,it does not need to set its new position,and the robot can also accurately grasp the item;(3)Strong robustness,the actual position of the operating object is obtained by the visual sensor,rather than by pre-measurement,to avoid operation failure due to the discrepancy between the actual position and the preset position.The automatic pipetting device used by the robot has the characteristics of simple structure,high reliability and strong reproducibility,and is a precise liquid dripping method suitable for popular use. |
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