When joint failure occurs in a redundant manipulator,it is required that the end-effector(EEF) continues the trajectory with a minimum velocity *** problem has been studied by the joint velocity redistribution method ...
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ISBN:
(纸本)9781509009107
When joint failure occurs in a redundant manipulator,it is required that the end-effector(EEF) continues the trajectory with a minimum velocity *** problem has been studied by the joint velocity redistribution method which means mapping the velocity of the faulty joint into healthy joints'.This method can tolerant joint fault successfully but may make joints out of their *** the gradient projection method(GPM) is adopted to avoid the redistributed joint limits in this *** regard to the selection of the scalar coefficient of GPM,an improved method called the coefficient matrix is *** only can this method avoid joint limits successfully but also reduce the unnecessary self-motion and control the self-motion of each joint *** last the coefficient matrix method is tested in a seven-degree-of-freedom(7-DOF) manipulator and the simulation results indicate the efficiency of this method.
When redundant manipulators work in a complex environment, many constraints need to be met. Gradient projection method (GPM) is a typical way to fulfil constraints that does not affect the main task. However it's ...
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Manipulator's obstacle avoidance is always a challenging topic in robotics. With the concern of the safety problems in human working environment, an improved obstacle avoidance method is proposed based on the gene...
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In this paper, we focus on the need for autonomous vehicles' path planning and decision making in the urban environment. In our modified method, traffic lanes, road edge and geographic information system(GIS) are ...
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ISBN:
(纸本)9781467365970
In this paper, we focus on the need for autonomous vehicles' path planning and decision making in the urban environment. In our modified method, traffic lanes, road edge and geographic information system(GIS) are integrated to generate three structured road models, which can be used to reduce car's lateral positioning error and guarantee car's driving stably without a precise pre-computed map for localization. Based on these models, car's position, attitude and speed are taken into account to find an optimal guided path and a suitable behavior strategy to keep our car obeying traffic rules. Thus, in the whole architecture, the instability of some modules' detection results and low positioning accuracy of GPS receiver is resolved. Applied to our autonomous vehicle - IN 2 BOT, which has taken part in "Chinese intelligent Vehicle Challenge" for many times, this method is proved more effective than our previous method after experiments under various conditions.
In this paper, a human robot shared control strategy is developed and tested on a Baxter robot. Using the proposed method, the human operator only needs to consider the motion of the end-effector of the manipulator, w...
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In this paper, a human robot shared control strategy is developed and tested on a Baxter robot. Using the proposed method, the human operator only needs to consider the motion of the end-effector of the manipulator, while the manipulator will avoid obstacle by itself without sacrificing the end effector motion performance. An improved obstacle avoidance strategy based on the joint space redundancy of the manipulator is designed. A dimension reduction method is presented to solve the over defined problem of avoiding velocity to achieve a more efficient use of the redundancy. By employment of an artificial parallel system of the teleoperate manipulator and the task switching weighting factor, the proposed control method enable the robot restoring back to the commanded pose smoothly when the obstacle is removed. By implementing the dimension reduction method, the trajectory of each joint of the manipulator can be controlled at the same time to achieve the restoring task. Thus, the proposed control method can eliminate the impact of the obstacle on the remaining task. Satisfactory experiment results demonstrate the effectiveness of the proposed methods.
An improved differential evolution algorithm was proposed for solving the online path planning problem of unmanned aerial vehicle (UAV) low-altitude penetration in partially known hostile environments. The algorithm a...
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An improved differential evolution algorithm was proposed for solving the online path planning problem of unmanned aerial vehicle (UAV) low-altitude penetration in partially known hostile environments. The algorithm adopts von Neumann topology and improves its structure to maintain the diversity of the population, prevent the population from falling into local optima in the early evolution and speed up the convergence rate in the later evolution as well. The mutation operator of differential evolution is improved to speed up the convergence rate of the algorithm, so that the optimal solution of the multi-objective optimization problem can be found quickly;the coding method combined the absolute Cartesian coordinates with the relative polar coordinates is used to improve the searching efficiency. The simulation experiment of online path planning for UAV low-altitude penetration shows that the proposed algorithm has a better performance than the unimproved differential evolution algorithm.
In this paper, a device for closed vessel's leaking localization is introduced based on infrared image processing. After the infrared thermography captured multi-frame infrared images of the closed vessel with coo...
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In this paper, a device for closed vessel's leaking localization is introduced based on infrared image processing. After the infrared thermography captured multi-frame infrared images of the closed vessel with cooling gas, each frame of the ROI region is processed by Gauss filtering. The suspected leak points are detected by hough circle detection method after their edges in the ROI are extracted by using canny edge operator. Finally, the appearance probability of the suspected leak point is used to determine a leaking point. Experiments show that the proposed method overcomes the disadvantage of infrared image's higher level noise effectively and is able to accurately localize the leak points.
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