A real-time arc welding robot visual control system based on a local network with a multi-level hierarchy is developed in this paper. It consists of an intelligence and human-machine interface level, a motion planning...A real-time arc welding robot visual control system based on a local network with a multi-level hierarchy is developed in this paper. It consists of an intelligence and human-machine interface level, a motion planning level, a motion control level and a servo control level. The last three levels form a local real-time open robot controller, which realizes motion planning and motion control of a robot. A camera calibration method based on the relative movement of the end-effector connected to a robot is proposed and a method for tracking weld seam based on the structured light stereovision is provided. Combining the parameters of the cameras and laser plane, three groups of position values in Cartesian space are obtained for each feature point in a stripe projected on the weld seam. The accurate three-dimensional position of the edge points in the weld seam can be calculated from the obtained parameters with an information fusion algorithm. By calculating the weld seam parameter from position and image data, the movement parameters of the robot used for tracking can be determined. A swing welding experiment of type V groove weld is successfully conducted, the results of which show that the system has high resolution seam tracking in real-time, and works stably and efficiently.展开更多
A networked control and supervision system （NCSS） based on LonWorks fieldbus and lntranet/Intemet was designed, which was composed of the universal intelligent control nodes （ICNs）, the visual control and supervis...A networked control and supervision system （NCSS） based on LonWorks fieldbus and lntranet/Intemet was designed, which was composed of the universal intelligent control nodes （ICNs）, the visual control and supervision configuration platforms （VCCP and VSCP） and an Intranet/Internet-based remote supervision platform （RSP）. The ICNs were connected to field devices, such as sensors, actuators and controllers. The VCCP and VSCP were implemented by means of a graphical programming environment and network management so as to simplify the tasks of programming and maintaining the ICNs. The RSP was employed to perform the remote supervision function, which was based on a three-layer browser/server（B/S） structure mode. The validity of the NCSS was demonstrated by laboratory experiments.展开更多
A dual operational modes mobile robot system based on visual guiding and visual servo control is presented. This system consists of a mobile robot with a two-axis manipulator and a tele-operation station. In the visua...A dual operational modes mobile robot system based on visual guiding and visual servo control is presented. This system consists of a mobile robot with a two-axis manipulator and a tele-operation station. In the visual guiding mode, for the robot works in an open loop visual servo control mode, the manipulating burden of the operator is reduced largely. In the visual servo mode the robot can locate the position of the target assigned by the operator and pick it up by its manipulator. With the help of the operator, the diffieuh problems of finding and handling a target in a complicated environment by the robot can be solved easily.展开更多
In IBVS (image based visual servoing), the error signal in image space should be transformed into the control signal in the input space quickly. To avoid the iterative adjustment and complicated inverse solution of im...In IBVS (image based visual servoing), the error signal in image space should be transformed into the control signal in the input space quickly. To avoid the iterative adjustment and complicated inverse solution of image Jacobian, CMAC (cerebellar model articulation controller) neural network is inserted into visual servo control loop to implement the nonlinear mapping. Two control schemes are used. Simulation results on two schemes are provided, which show a better tracking precision and stability can be achieved using scheme 2.展开更多
To improve the accuracy and usability of the superconducting electron cyclotron resonance ion source with advanced design in Lanzhou(SECRAL), an upgraded version of the control system was designed and tested. This pap...To improve the accuracy and usability of the superconducting electron cyclotron resonance ion source with advanced design in Lanzhou(SECRAL), an upgraded version of the control system was designed and tested. This paper details the architecture of the optimized control system and presents the results of its use in the long-term operation of the accelerator. The control system software, based on Visual C++, was developed following the model-view-controller architecture design pattern. The data acquisition system was based on a field-programmable gate array integrated circuit. In addition, control strategies were optimized for higher operational stability. The upgraded control system was tested with a U^(33+) ion beam at SECRAL, where it provided a data acquisition time of less than 1 ms. The fast reaction time and highprecision data processing during beam tuning verified the stability and maintainability of the control system.展开更多
In this paper two methods for real-time debugging and testing of a control system are proposed. The basic instruments used are personal computers, a Visual C++ compiler and MATLAB including the GUI Design Environment,...In this paper two methods for real-time debugging and testing of a control system are proposed. The basic instruments used are personal computers, a Visual C++ compiler and MATLAB including the GUI Design Environment, Simulink, real-time workshop, xPC target, and some relevant hardware. For the first method, MATLAB functions are used to build a control system debugging and testing environment. This method is flexible and only one RS-232 serial cable is used. Limited programming is used for the second method and ready-made blocks in MATLAB/Simulink are used to build the simulation environment and communication channel. In both methods, the parameters of the emulation system can be modified online, important graphs can be drawn in real time and relevant data can be easily saved for the later analysis. As can be seen from the presented examples, both techniques are easily realized.展开更多
In order to further improve the efficiency of video compression, we introduce a perceptual characteristics of Human Visual System (HVS) to video coding, and propose a novel video coding rate control algorithm based on...In order to further improve the efficiency of video compression, we introduce a perceptual characteristics of Human Visual System (HVS) to video coding, and propose a novel video coding rate control algorithm based on human visual saliency model in H.264/AVC. Firstly, we modifie Itti's saliency model. Secondly, target bits of each frame are allocated through the correlation of saliency region between the current and previous frame, and the complexity of each MB is modified through the saliency value and its Mean Absolute Difference (MAD) value. Lastly, the algorithm was implemented in JVT JM12.2. Simulation results show that, comparing with traditional rate control algorithm, the proposed one can reduce the coding bit rate and improve the reconstructed video subjective quality, especially for visual saliency region. It is very suitable for wireless video transmission.展开更多
基金This work was supported by the National High Technology Research and Development Program of China under Grant 2002AA422160 by the National Key Fundamental Research and the Devel-opment Project of China (973) under Grant 2002CB312200.
文摘A real-time arc welding robot visual control system based on a local network with a multi-level hierarchy is developed in this paper. It consists of an intelligence and human-machine interface level, a motion planning level, a motion control level and a servo control level. The last three levels form a local real-time open robot controller, which realizes motion planning and motion control of a robot. A camera calibration method based on the relative movement of the end-effector connected to a robot is proposed and a method for tracking weld seam based on the structured light stereovision is provided. Combining the parameters of the cameras and laser plane, three groups of position values in Cartesian space are obtained for each feature point in a stripe projected on the weld seam. The accurate three-dimensional position of the edge points in the weld seam can be calculated from the obtained parameters with an information fusion algorithm. By calculating the weld seam parameter from position and image data, the movement parameters of the robot used for tracking can be determined. A swing welding experiment of type V groove weld is successfully conducted, the results of which show that the system has high resolution seam tracking in real-time, and works stably and efficiently.
基金Project (60425310) supported by the National Natural Science Foundation of ChinaProject(2006AA04Z172) supported by the High-TechResearch and Development Program of China
文摘A networked control and supervision system （NCSS） based on LonWorks fieldbus and lntranet/Intemet was designed, which was composed of the universal intelligent control nodes （ICNs）, the visual control and supervision configuration platforms （VCCP and VSCP） and an Intranet/Internet-based remote supervision platform （RSP）. The ICNs were connected to field devices, such as sensors, actuators and controllers. The VCCP and VSCP were implemented by means of a graphical programming environment and network management so as to simplify the tasks of programming and maintaining the ICNs. The RSP was employed to perform the remote supervision function, which was based on a three-layer browser/server（B/S） structure mode. The validity of the NCSS was demonstrated by laboratory experiments.
基金Supported by the National High Technology Research and Development Program of China （No. 2003AA421030） and the National Science Foundation of China （No. 60375026）.
文摘A dual operational modes mobile robot system based on visual guiding and visual servo control is presented. This system consists of a mobile robot with a two-axis manipulator and a tele-operation station. In the visual guiding mode, for the robot works in an open loop visual servo control mode, the manipulating burden of the operator is reduced largely. In the visual servo mode the robot can locate the position of the target assigned by the operator and pick it up by its manipulator. With the help of the operator, the diffieuh problems of finding and handling a target in a complicated environment by the robot can be solved easily.
基金This project is supported by National Natural Science Foundation of China (No.59990470).
文摘In IBVS (image based visual servoing), the error signal in image space should be transformed into the control signal in the input space quickly. To avoid the iterative adjustment and complicated inverse solution of image Jacobian, CMAC (cerebellar model articulation controller) neural network is inserted into visual servo control loop to implement the nonlinear mapping. Two control schemes are used. Simulation results on two schemes are provided, which show a better tracking precision and stability can be achieved using scheme 2.
基金supported by the National Natural Science Foundation of China(No.u1232123)
文摘To improve the accuracy and usability of the superconducting electron cyclotron resonance ion source with advanced design in Lanzhou(SECRAL), an upgraded version of the control system was designed and tested. This paper details the architecture of the optimized control system and presents the results of its use in the long-term operation of the accelerator. The control system software, based on Visual C++, was developed following the model-view-controller architecture design pattern. The data acquisition system was based on a field-programmable gate array integrated circuit. In addition, control strategies were optimized for higher operational stability. The upgraded control system was tested with a U^(33+) ion beam at SECRAL, where it provided a data acquisition time of less than 1 ms. The fast reaction time and highprecision data processing during beam tuning verified the stability and maintainability of the control system.
文摘In this paper two methods for real-time debugging and testing of a control system are proposed. The basic instruments used are personal computers, a Visual C++ compiler and MATLAB including the GUI Design Environment, Simulink, real-time workshop, xPC target, and some relevant hardware. For the first method, MATLAB functions are used to build a control system debugging and testing environment. This method is flexible and only one RS-232 serial cable is used. Limited programming is used for the second method and ready-made blocks in MATLAB/Simulink are used to build the simulation environment and communication channel. In both methods, the parameters of the emulation system can be modified online, important graphs can be drawn in real time and relevant data can be easily saved for the later analysis. As can be seen from the presented examples, both techniques are easily realized.
基金supported by National Natural Science Foundation of China under Grant No.610700800973 Sub-Program Projects under Grant No.2009CB320906+3 种基金National Science and Technology of Major Special Projects under Grant No.2010ZX03004-003S&T Planning Project of Hubei Provincial Department of Education under Grant No. Q20112805H&SPlanning Project of Hubei Provincial Department of Education under Grant No.2011jyte142Science Foundation of HubeiProvincial under Grant No.2010CDB05103
文摘In order to further improve the efficiency of video compression, we introduce a perceptual characteristics of Human Visual System (HVS) to video coding, and propose a novel video coding rate control algorithm based on human visual saliency model in H.264/AVC. Firstly, we modifie Itti's saliency model. Secondly, target bits of each frame are allocated through the correlation of saliency region between the current and previous frame, and the complexity of each MB is modified through the saliency value and its Mean Absolute Difference (MAD) value. Lastly, the algorithm was implemented in JVT JM12.2. Simulation results show that, comparing with traditional rate control algorithm, the proposed one can reduce the coding bit rate and improve the reconstructed video subjective quality, especially for visual saliency region. It is very suitable for wireless video transmission.
