Research On Safety Control System Of Human-Machine Cooperative Robot

After more than half a century of development and application,industrial robots have gradually replaced manpower in the production process in various fields,and various technologies have gradually matured,significantly improving production efficiency and product quality.However,traditional industrial robots can only work in unmanned environments.A fence is required to isolate the robot from the operator.The robot cannot get rid of the restrictions on the working range of the safety fence,which affects the ability of the robot to complete various tasks with the workers.With the transformation and upgrading of the manufacturing industry,humans and machines are now required to complete work together,and the flexibility and safety requirements of robots are becoming higher and higher.Therefore,in this paper,the safety control system of human-robot collaboration robots is designed and built.It conducts safety research on both front and rear safety,and conducts control system construction,kinematic analysis,human detection,and motion planning.And safety experiments:(1)The hardware architecture of the robot control system is designed,and the control scheme of the robot PC+motion control card is given.The software system is divided into functional modules.Based on ROS,the upper computer software system of the robot and the lower computer motion control card are designed,and establish communication between upper and lower computers;use D-H parameter method to perform kinematics analysis of the robotic arm,establish the kinematics equation and velocity Jacobian matrix of the robotic arm;analyze the task and safety requirements of the robot,and give the overall hybrid control method of the robot control system.(2)The components of the robot vision system are introduced from hardware and software respectively;Kinect is used to collect human skeleton data and extract the specified joint point position data;ROS calibration function package is used to calibrate the camera's internal parameters,and the least square method is used to calibrate the Principle,design and complete the camera hand-eye calibration experiment,and obtain the transformation matrix;in the robot coordinate system,a human-centered risk field is established to describe the risk index of a point in space.(3)Contrast the rapidly-exploring random tree method(RRT)and its improved algorithm.Set the planning scene under ROS to realize the motion planning of Cartesian space;write the nodes of each functional module and establish the communication relationship between the nodes.The motion planning of the robotic arm,and sending the planning results to the lower computer to realize the motion control of the robot.(4)A human-robot collaborative robot experiment platform was set up,and a safety-level monitoring stop experiment based on Kinect was designed for ex-ante safety control design;an airbag-based safety collision experiment was designed for ex-post safety control to verify the safety of human-robot collaboration.