To overcome the influence of on-orbit extreme temperature environment on the tool pose(position and orientation) accuracy of a space robot,a new self-calibration method based on a measurement camera(hand-eye vision) a...
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To overcome the influence of on-orbit extreme temperature environment on the tool pose(position and orientation) accuracy of a space robot,a new self-calibration method based on a measurement camera(hand-eye vision) attached to its end-effector was *** the relative pose errors between the two adjacent calibration positions of the space robot,the cost function of the calibration was built,which was different from the conventional calibration *** particle swarm optimization algorithm(PSO) was used to optimize the function to realize the geometrical parameter identification of the space *** above calibration method was carried out through self-calibration simulation of a six-DOF space robot whose end-effector was equipped with hand-eye *** results showed that after calibration there was a significant improvement of tool pose accuracy in a set of independent reference positions,which verified the feasibility of the *** the same time,because it was unnecessary for this method to know the transformation matrix from the robot base to the calibration plate,it reduced the complexity of calibration model and shortened the error propagation chain,which benefited to improve the calibration accuracy.
An optimal measurement pose number searching method was designed to improve the pose selection *** optimal robot measurement configurations were added to an initial pre-selected optimal configuration set to establish ...
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An optimal measurement pose number searching method was designed to improve the pose selection *** optimal robot measurement configurations were added to an initial pre-selected optimal configuration set to establish a new configuration set for robot calibration one by *** root mean squares (RMS) of the errors of each end-effector poses after being calibrated by these configuration sets were *** optimal number of the configuration set corresponding to the least RMS of pose error was then *** based on those poses selected by this algorithm can get higher end-effector accuracy,meanwhile consumes less *** optimal pose set including optimal 25 measurement configurations is found during the *** errors after calibration by using these poses are 1.54,1.61 and 0.86 mm,and better than those before calibration which are 7.79,7.62 and 8.29 mm,even better than those calibrated by the random method which are 2.22,2.35 and 1.69 mm in directions X,Y and Z,respectively.
A spherical robot based on a novel double ballast masses principle is developed for military re-connaissance and unknown environment *** robot is driven by two DC motors,each of which drives one ballast mass,and the t...
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A spherical robot based on a novel double ballast masses principle is developed for military re-connaissance and unknown environment *** robot is driven by two DC motors,each of which drives one ballast mass,and the two ballast masses are placed symmnetrically on the major *** with the traditional ballast mass principle,the robot has featured high speed,the abil-ity of slope climbing and obstacle overcoming in linear *** robot has two inputs and three DOF,which is a nonholonomic and underactuated *** dynamic model of the robot is con-structed,and the linear motion performance of robot in theory is proved by Adams *** control system is briefly introduced,and the performance of the prototype is tested by experiments at last.
To overcome the shortcomings of the traditional artificial potential field method in mobile robot path planning, an improved artificial potential field model (IAPFM) was established, then a new path planning method ...
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To overcome the shortcomings of the traditional artificial potential field method in mobile robot path planning, an improved artificial potential field model (IAPFM) was established, then a new path planning method combining the IAPFM with optimization algorithm (trust region algorithm) is proposed. Attractive force between the robot and the target location, and repulsive force between the robot and the obstacles are both converted to the potential field intensity; and filled potential field is used to guide the robot to go out of the local minimum points ; on this basis, the effect of dynamic obstacles velocity and the robot's velocity is consid thers and the IAPFM is established, then both the expressions of the attractive potential field and the repulsive potential field are obtained. The trust region algorithm is used to search the minimum value of the sum of all the potential field inten- sities within the movement scope which the robot can arrive in a sampling period. Connecting of all the points which hare the minimum intensity in every sampling period constitutes the global optimization path. Experiment result shows that the method can meet the real-time requirement, and is able to execute the mobile robot path planning task effectively in the dynamic environment.
A general scheme for the automated classification of gait patterns based on time-frequency analysis was proposed to discriminate acceleration signals characterized by high dimension, non-linearity, strong coupling and...
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A general scheme for the automated classification of gait patterns based on time-frequency analysis was proposed to discriminate acceleration signals characterized by high dimension, non-linearity, strong coupling and high time-varying acquired under different terrains and motion patterns of lower limbs. A three-axis acceleration sensor was mounted on a crus to acquire acceleration signals in the sagittal, coronal and cross-sectional planes separately. By using a 5-order Daubechies wavelet base, the features were extracted from time-series acceleration signals and further dimensionally reduced by employing linear discrimination analysis (LDA). The reduced features were classified by the decision tree and the support vector machine (SVM). From experimental results, both classifiers can achieve the high classification accuracy ratio over 90% and for the specified gait the ratio can be up to 100%, indicating the rationality and effectiveness of the proposed methods for feature extraction and dimension reduction.
In response to the impossibility of directly using data of the actual road show experiment to the motion simulation of simulators, due to the limited work space of simulators, this paper begins with an attempt to extr...
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The forming technique of micro-punching is an important method for precision plastic machining of micro-parts, the micro-hole size must be sub-millimeter in two-dimension. To punch less than 200μm micro-holes on thin...
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The rapid development of the Integrated Circuit (IC) manufacturing equipment industry requires greater efficiency for wafer transfer. However, the faster wafer transfer robot moves, the bigger the force applied on its...
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During rover lunar exploration missions (such as China's "Chang'e"), rovers are required to move autonomously on the loose lunar soil. Control methods based on the rigidity hypothesis can hardly be e...
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In this paper, we take 6kg arc welding robot designed by our lab as research object and build a complex virtual prototype model. A fast, intuitive and effective dynamics method which is based on simulink and robotics ...
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