36 results about "Visual servoing system" patented technology

The embodiment of the invention discloses a joint automatic calibration method and device for a robot vision servo system, and the method comprises the steps: carrying out the camera calibration of the robot vision servo system, and determining the internal parameters and distortion parameters of a camera; performing line structured light plane calibration, and determining line structured light plane parameters; performing hand-eye calibration, and determining a coordinate conversion relation between a second robot end effector and a camera; performing positioning system calibration, and determining a transformation relation between a robot base coordinate system and an infrared laser positioning base station coordinate system; and determining a joint automatic calibration result of the robot vision servo system according to the camera internal parameters, the distortion parameters, the linear structure light plane parameters, the coordinate conversion relationship and the transformation relationship. Firstly, joint calibration of multiple sensing and positioning modes is realized, so that an industrial robot vision servo system is not limited to structured light vision sensing orbinocular vision sensing; secondly, the automation of the calibration process is realized, the manual operation is removed, and the working efficiency is improved.

The present invention belongs to the field of drawing platinum nozzle plate making technology, and is especially microscopic visual servo system and method for arc welding robot for making drawing platinum nozzle plate. The microscopic visual servo system consists of one visual light source, one microscopic lens, one imaging device, one video acquiring module and one video processing computer. The microscopic visual servo method realizes the precise location of the nozzle center, and the robot can adapt the heat deformation of the nozzle plate in the welding process and track the weld seam accurately. The method includes fast microscopic visual location of the nozzle center and visual servo. The fast microscopic visual location of the nozzle center is simple and fast and has high noise tolerance and capacity of providing the motion controlling system with real-time nozzle center information for precise servo location.

The invention relates to an operating object position and posture recognition method applicable to an industrial robot. The operating object position and posture recognition method applicable to the industrial robot can be applied to a visual servo system based on positions, timely provides positions and posture information of an operating object for the visual servo system, is short in operation time and high in precision, can adapt to different illumination conditions indoor and outdoor and the like, and provides technical support for usage of the industrial robot in unstructured environments. The operating object position and posture recognition method applicable to the industrial robot comprises the following steps: step1, an initialization operation, calibrating initialization of a left camera, a right camera and the operating object, and then using the left camera and the right camera to obtain image data; step2, following the moving operating object by using a front frame image and a back frame image in the process of image capture; step3, smoothing changes of an operating object following window of the front frame image and the back frame image through kalman filtering; step4, using an image data dimension reduction mode to reduce dimension of data processing; and step5, calculating three-dimensional positions and posture of the operating object, and feeding back data to a servo control system of the industrial robot so as to achieve servo control.

The invention discloses a fast focusing method for a robot visual servo system, which belongs to the field of image processing. The existing mechanical focusing technology has the problems of poor zoom ability and slow speed, and it is difficult to meet the real-time requirements of visual servoing. The method of the present invention installs a liquid lens for the camera at the end of the robotic arm of the robot; the current of the liquid lens when the image is obtained multiple times, and the distance data between the camera and the target object; determines the image with the maximum sharpness and the current of the corresponding liquid lens and The distance data between the camera and the target object; repeat the above content to obtain multiple sets of maximum sharpness current and distance data, establish the relationship model between the maximum sharpness current and distance, and obtain the model parameters through the system identification method; use the established The relationship model, combined with the distance information, obtains the current value required for the liquid lens to zoom, and then controls the liquid lens to zoom. The method of the invention ensures the fast focusing of the visual servo system and the imaging definition of the target object.

The invention discloses an intelligent trolley 2.5-dimensional visual servo control method based on nonlinear model prediction. The intelligent trolley 2.5-dimensional visual servo control method comprises the steps as follows: firstly, obtaining a current image and an expected image of a reference target respectively through a video camera at a current pose and an expected pose; secondly, extracting the characteristic points of the reference target and the pose information of the trolley, organically combining a two-dimensional image signal with a three-dimensional pose signal through coordinate conversion, and building a 2.5-dimensional visual error model; and lastly, aiming at the 2.5-dimensional visual error model, designing a multilevel visual predication controller by utilizing a nonlinear model prediction control method. According to the intelligent trolley 2.5-dimensional visual servo control method, the problem that velocity and torque constraint of a motion performing system and visibility constraint of the video camera cannot be processed by the conventional 2.5-dimensional visual servo control method is solved, the reference target can be guaranteed to remain visible all the time in the servo process, and the reliability and the safety of a visual servo system are greatly improved.

The invention discloses a cell adhesion force measuring instrument and measuring method based on acoustic surface waves. The cell adhesion force measuring instrument comprises a lithium niobate crystal plate, a silver interdigitatal electrode annular array, a PDMS (polydimethylsiloxane) micro-channel and a micro-vision servo system, the micro-vision servo system comprises an upper computer system based on a PXI (peripheral component interconnect) bus, a multi-path signal generating system and a micro-vision monitoring system, the silver interdigitatal electrode annular array is arranged on the upper periphery of the lithium niobate crystal plate, the lithium niobate crystal plate and the silver interdigitatal electrode annular array form an interdigital transducer, and the silver interdigitatal electrode annular array is connected with the multi-path signal generating system. According to the measuring instrument, an expected sound field is synthesized in a PDMS micro-channel cavity by the aid of the interdigital transducer and the micro-vision servo system, cells are operated by the aid of radiation force of the acoustic surface waves, cell adhesion force is measured, and the measuring instrument has the advantages of simplicity and easiness in operation, fewer interference factors and the like.

The invention discloses a visual servo approaching method for a mobile columnar assembly. The method comprises the following steps: establishing a relationship among visual information of a columnar assembly target, target model parameters and an imaging model; extracting coordinates of at least four pixel points in an imaging visual angle range, and constructing a visual servo control input feature vector for the columnar assembly target and a Jacobi transformation matrix corresponding to the visual servo control input feature vector; in view angle constraint, performing adaptive recombination on the constructed control input feature vector and the reference feature vector, and obtaining a feature Jacobi conversion matrix corresponding thereto; and adjusting and compensating for the output of a visual servo controller, so that the visual servo system approaches the mobile columnar assembly target. In this way, redundant visual information of columnar assembly target imaging is fully utilized, the robustness of a servo system for image noise, the adaptability for view angle constraint and the applicability for columnar assembly movement can be improved, and global convergence of visual servo control for a moving target is promoted.

The invention relates to the field of visual servo systems, in particular to a PD-SMC control method of a visual servo system based on an eye-on-hand structure so as to solve the problems of uncertainty and large computation amount existing in an existing visual servo system control method. The method comprises the steps of (1) setting an expected image and collecting feature points of the expected image as an expected visual feature set; (2) conducting projection transformation on a target expected image with the current state of the relative poses of a camera and a target body to obtain a current image of the camera; (3) adopting the PD-SMC method for a visual servo controller part and adopting a proportional control method for a joint controller part; (4) extracting a visual feature setfrom the current image, computing a jacobian matrix of the image and then computing the controlled quantity u of the camera in a Cartesian space; and (5) computing the pose of the target body in a camera coordinate system, and repeating the operations with the pose as the current pose until the error is zero. The PD-SMC control method can be applied to target grabbing equipment.

The invention discloses a servo tracking acceleration convergence method for a robot visual feature planning trajectory, comprising the following steps: S101, establishing a visual feature trajectory planning model, and obtaining a specific planning trajectory; S102, evenly dividing parameter variables, and performing segmented visual servo tracking; S103, define the maximum displacement error and the maximum rotation error generated by tracking; S104, under the constraint of the maximum displacement error, minimize the total tracking convergence time. The present invention defines the tracking error, sets the trajectory interpolation, and performs multi-parameter optimization to achieve tight tracking and obtain global convergence, while reducing the tracking convergence time as much as possible, and improving the self-adaptive ability of the visual servo system in the face of dynamic targets and environments.

The invention provides a time-lag visual servo system optimal PI parameter optimization method and system. The method includes the steps: determining time lag of a visual servo system; performing kinematical modeling on the visual servo system according to the time lag; performing state space transformation on a kinematical model; calculating a state-transition matrix of a state space equation bya differential quadrature method; changing a parameter of a PI controller in the visual servo system, calculating a maximum value of modules of characteristic values under different parameters; makingthe maximum value of modules of characteristic values of the state-transition matrix to be 1, and calculating a stability boundary of the visual servo system in PI controller parameter space; optimally minimizing the maximum value of the modules of the characteristic values of the state-transition matrix in the stability boundary, and comparing the maximum values of the modules of the characteristic values of the state-transition matrix under different controller parameter conditions to obtain optimized PI controller parameter. According to the method, the response performance of the visual servo system is improved, and the application range of visual servo technologies is widened.