Towards complex indoor environment, this paper proposed a fusion method of sequential Mb-ICP scan matching for mobile robot map building. We firstly introduce the classic ICP scan matching method and its limitations f...
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Electro-hydraulic shaking table(EHST) is a useful experimental apparatus to real-time replicate the desired acceleration vibration signal for evaluating the performance of the tested specimen structural systems. A thr...
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Electro-hydraulic shaking table(EHST) is a useful experimental apparatus to real-time replicate the desired acceleration vibration signal for evaluating the performance of the tested specimen structural systems. A three axis six degree-of-freedom(DOF) EHST system with eight hydraulic actuators is presented in the paper. A decouple control method is employed to lower the acceleration couple among the six DOF. The procedure of the decouple controller is programmed in MATLAB/Simulink, and then compiled to a realtime PC with Microsoft Visual *** for implementation. The experimental results demonstrate that a better tracking performance with the improved servo controller is achieved in experiments by using actual EHST.
Dominant plane detection is an essential task for an autonomous navigation of mobile robots equipped with a vision system, as we assume that robots move on the dominant plane. In this paper, based on optical flow, the...
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Dominant plane detection is an essential task for an autonomous navigation of mobile robots equipped with a vision system, as we assume that robots move on the dominant plane. In this paper, based on optical flow, the image motions of points which located in a plane were described by planar flow. After the parameters of planar flow are estimated, the distance error of image points can be used for detecting the plane region from monocular image sequence. The proposed method includes three steps. First, the robust optical flow is estimated between two consecutive images from the image sequence. Then a geometry constraint provided by planar flow is applied to detect the plane regions in optical flow. And finally, some iterative procedures can be used for improving the results. Compared with the feature point based method which sometimes is invalid because of the lacking of texture, the optical flow based method can detect the ground plane even if there are not much more image features in the plane region. Some experiments with outdoor images have been conducted.
Aiming at computing the force feel to be simulated at real time, thrust lever control loading system's simulation model is set by software called Sim Mechanics after its control mechanism being analyzed. The dynam...
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Aiming at computing the force feel to be simulated at real time, thrust lever control loading system's simulation model is set by software called Sim Mechanics after its control mechanism being analyzed. The dynamic characteristics of control systems and model torque are studied based on the simulation model. Then the counter potential, primary element to cause the surplus torque, is pointed out according to the dynamic characteristics of control. To make the loading system not only flow the model torque precisely but also retrain surplus torque effectively, the low frequency of the current loop is designed due to frequency spectrum of counter potential and follow-up component in model torque, while the medium frequency is on basis of the step component in model torque. Finally, the reasonableness of the designed current loop is verified by computer simulation of the torque output by motor and loading torque.
Toward the Internet-based robotic tasks, a state-guided teleoperation assistance method is presented. According to this method, the whole task can be identified into several states to direct the execution of teleopera...
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Toward the Internet-based robotic tasks, a state-guided teleoperation assistance method is presented. According to this method, the whole task can be identified into several states to direct the execution of teleoperation, through state definition, state recognition and state display. After building up an Internet-based teleoperation system centered on data fusion, the remote manipulations of medical treatment are accomplished finally. The experiment demonstrates that introduction of the assistance method alleviates the difficulties such as network time-delay effectively and operation efficiency, improving the global capacity of system.
Utilizing catheters with unchangeable distal tip, traditional endovascular minimally invasive surgery is manually performed by surgeons present in an operating room filled with X-ray radiation. It has many disadvantag...
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Utilizing catheters with unchangeable distal tip, traditional endovascular minimally invasive surgery is manually performed by surgeons present in an operating room filled with X-ray radiation. It has many disadvantages, such as poor maneuverability, radiation injury and undesirable interactivity. Thus it is difficult to guarantee the safety and efficiency. In order to improve these limitations, this paper develops a novel robotic catheter system with master-slave control, including the steerable catheter integrated with two magnetic tracking sensors, interventional mechanisms with force feedback and 3D guiding image with the collision test. The results demonstrate that the constructed system can reduce the usage of X-rays; surgeons can be located in the control room away from the operating room in the master-slave way; catheterization can be performed successfully and safely to the target point with high maneuverability.
Driving torques of a specific type of spot welding robot was simulated in RecurDyn, which provided useful information for motor selecting and gravity balancing. According to D-H parameters of the robot parts of th...
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Driving torques of a specific type of spot welding robot was simulated in RecurDyn, which provided useful information for motor selecting and gravity balancing. According to D-H parameters of the robot parts of the robot were modeled separately and then assembled to form the robot, in Pro/Engineer. Imported into RecurDyn and adding necessary constraints, the virtual prototype of the robot was constructed in RcurDyn for dynamic simulation. Time dependent torque variations of every joint were got by simulation, which facilitated motor selection. The spring for sustaining the gravity of robots links was also optimized through the simulation analysis of torques in Joint 2.
In order to obtain direct solutions of parallel manipulator without divergence in real time,a modified global Newton-Raphson(MGNR) algorithm was proposed for forward kinematics analysis of six-degree-of-freedom(DOF) p...
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In order to obtain direct solutions of parallel manipulator without divergence in real time,a modified global Newton-Raphson(MGNR) algorithm was proposed for forward kinematics analysis of six-degree-of-freedom(DOF) parallel *** on geometrical frame of parallel manipulator,the highly nonlinear equations of kinematics were derived using analytical *** MGNR algorithm was developed for the nonlinear equations based on Tailor expansion and Newton-Raphson *** procedure of MGNR algorithm was programmed in Matlab/Simulink and compiled to a real-time computer with Microsoft visual *** for *** performance of the MGNR algorithms for 6-DOF parallel manipulator was analyzed and *** the MGNR algorithm,the real generalized pose of moving platform is solved by using the set of given positions of *** theoretical analysis and numerical results indicate that the presented method can achieve the numerical convergent solution in less than 1 ms with high accuracy(1×10-9 m in linear motion and 1×10-9 rad in angular motion),even the initial guess value is far from the root.
The configuration design of in-pipe robot adapting mechanism has a significant impact on its motion performance. By analyzing the operation principle and structure composition of adapting mechanism, the four-bar linka...
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A novel untethered autonomous motor driven in-pipe robot inspecting system has been designed in order to solve the internal defect inspection for long-distance pipeLine. Which includes motor driven traction robot and ...
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