Research On Virtual Force Feedback Control Based On Visual Servo For Telerobotic

The tele-robotics played an important role with the rational development ofhuman undersea, underground resources and outer space. Robots are in the directionof intelligence. Due to limited development levels of control, sensors and artificialintelligence, current researches should be focused on interactive technologies ratherthan fully intelligent robot technologies.During the control of master-slave robot, the operator could not perceive realworking sites and just depends on the feedback of images, sounds, forces etc. tocomplete operation tasks due to the far distance from the robot. Therefore, the currentmaster-slave robot system exists problems of low efficiency, overburden, safety andoperability. In addition, since the image features are incomplete and task objects arenot visible in the image, the traditional visual servo control method will inevitablyoccur the phenomenon that task objects are away from the camera field of view.In order to solve this problem, this paper presents a virtual force feedback controlmethod based on visual servo for telerobotic, makes full use of the advantages of astrong local stability and high robustness on traditional visual servo control methods,introduces the concept of virtual image guiding force, fuses the robotic localautonomous with advanced intelligence of the operator, real time adjusts the pose ofthe robot to ensure that the image is always the camera field of view and avoids theoccurrence of misoperation effectively. This paper introduces visual servo control intoteleoperation, using the traditional visual servo control principle, and on the basis ofartificial potential field theory, builds a virtual image force and supplies the operatorwith a sense of guding force. This paper is based on National Natural Science Fund Project “Research onshared control strategies for robot system based on kinesthetic and force guidingmethod” and key scientific research projects of Jilin province “Kinesthetic guidingshared control for robot system”. Relying on the robot, binocular camera and joysticksin the Department of Mechanical and Electronic Engineering, Jilin University, thispaper builds a virtual image force feedback control experimental platform. To buildthe virtual image force, this paper introduces the robot kinematics and dynamics,feature extraction of task objects, analysis of composite image Jacobian matrix andvirtual force model etc.. In this paper, the main tasks are as follows:1. Use HSI (Hue Saturation Intensity) image segmentation algorithm, imagedilation and erosion algorithms and contour polygon fitting algorithm toachieve feature extraction of task objects.2. Adopt methods of homogeneous coordinate transformation to establish robotkinematics equations, use Lagrangian method to build dynamics equations.3. Introduce visual servo into tele-operation. Use RLS (Recursive Least Square)algorithm to estimate the composite image Jacobian matrix online. Based onthe artificial potential field theory, build the virtual image forces.4. Build the virtual force feedback control experimental platform, use VisualStudio2008to develop a teleoperation virtual force feedback control systemsoftware, carry out the virtual image force feedback control experiment toverify the feasibility and effectiveness.