This paper mainly discusses the pursuit-evasion games, in which a team of autonomous mobile robots act as pursuers to pursue multiple moving targets cooperatively. In order to reduce the communication load during the ...
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This paper mainly discusses the pursuit-evasion games, in which a team of autonomous mobile robots act as pursuers to pursue multiple moving targets cooperatively. In order to reduce the communication load during the task negotiation process, the auction mechanism in Economics was introduced,and an improved task negotiation process based on Multi-Unit Combinatorial Auction was proposed. It allocated task dynamically through capability classification and independent competition. A kind of multi-robot cooperative pursuit algorithm that allows dynamic alliance is proposed. Simulation results show the feasibility and validity ofthe given algorithm.
In order to searching the best threshold of Otsu rule rapidly, a modified strategy to the inertia weight in Particle Swarm Optimization (PSO) is introduced. The strategy correlates the inertia weight in PSO with the g...
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In order to searching the best threshold of Otsu rule rapidly, a modified strategy to the inertia weight in Particle Swarm Optimization (PSO) is introduced. The strategy correlates the inertia weight in PSO with the globally best position and the individual best position in particle swarm and modifies the inertial weight by the distance between the best individual position and the globally best position. With the reduction of the distance between the globally best position and the individual best position, the inertia weight of the individual particle will be reduced, vice versa. The experimental results indicate that this algorithm decreases computational work and improves average convergence rate by 21.0726% as compared with that of traditional methods. It can speed up on-line image segmentation using this method.
By combination of parallelogram link and gear, a new type of exoskeleton mechanism is developed. As placed on the back of extra vehicular activity (EVA) glove in an external way, this mechanism is able to drive the EV...
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By combination of parallelogram link and gear, a new type of exoskeleton mechanism is developed. As placed on the back of extra vehicular activity (EVA) glove in an external way, this mechanism is able to drive the EVA glove finger to extent or flex like human finger grasp *** force sensor located at the tip of exoskeleton mechanism measures the EVA glove damping force during flexion or extension. The force reaches even to 10 N and the hysteresis of the force approaches to 31%.To predict the force which corresponds to an angular displacement of EVA glove and simulate the human factors performance metrics of extra vehicular activity, an unified Preisach numerical calculating strategy is presented by recording the number of vertices of the interface line in discrete Preisach plane and getting a series of first order reversal curves. A distance-weighted interpolation is chosen to evaluate at the points belonging to the Preisach plane except the discrete grid points. The proposed method is validated by the experiments.
A two-stage subsurface-flow constructed wetland (SSFCW);combined with horizontal flow constructed wetland (HFCW) and vertical flow constructed wetland (VFCW) was established to investigate nutrients transfer in the ca...
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After analyzing the reasons related to the pixel nonuniformity in details, an algorithm based on least square method is presented to correct the pixel nonuniformity of a CCD. The grey level datum sets of each pixel ar...
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After analyzing the reasons related to the pixel nonuniformity in details, an algorithm based on least square method is presented to correct the pixel nonuniformity of a CCD. The grey level datum sets of each pixel are acquired on the cases of different irradiances, then a least square method is used to estimate the relation between irradiance and desired grey level data. The correct parameters of each pixel are computed, and the correct matrix is established. Finally, the pixel response uniformity is achieved by using the matrix to correct the grey level data of each pixel. The maximum deviation is 76.5 before correcting, while correcting by the proposed method, the maximum deviation is only 0.00108. The experimental results indicate that the method is effective to correct CCD nonuniformity.
Aiming at the problem that the present wave variable method can not satisfy the requirement of medical bone-setting in time delay condition, the system stability and the master-slave track precision were obtained by i...
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Aiming at the problem that the present wave variable method can not satisfy the requirement of medical bone-setting in time delay condition, the system stability and the master-slave track precision were obtained by introducing prediction techniques in wave domain. In order to use this method in different initial conditions, and keep it robust in slave model mismatch and round off error, the modified Smith prediction method was used in the scheme. It employed a state observer combined with a time forward observer to estimate the output of slave part, then an energy regulation algorithm was used in the conjunction of a prediction algorithm to ensure the system passivity. The proposed wave prediction method can ensure the system stability under varying time delay environments in most cases, but varying time delay and round off error can lead to the position shift error-between master and slave part. Thus an error correction method was designed to regulate the wave domain energy to correct the shift in master-slave position.
In order to analyze the performance of lunar rover, drawbar pull and motion resistance are analyzed in this paper based on terramechanics. The relationships between configuration parameters (like wheel width, wheel ba...
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ISBN:
(纸本)9781424424948
In order to analyze the performance of lunar rover, drawbar pull and motion resistance are analyzed in this paper based on terramechanics. The relationships between configuration parameters (like wheel width, wheel bases et al.) and mobility performance parameters are obtained from the analysis. Meanwhile, the sensitive factors of the motion resistance are found. Then main performance evaluation metrics and indexes of mobility performance are presented, based on which performance comparison of LER-1 and ALR (a new configuration lunar rover) locomotion systems is performed. The method of evaluating mobility performance of lunar rover by simulation is introduced. The analysis results indicate that the new locomotion system configuration ALR has good mobility performance. The study results can apply to the design of planetary exploration rovers for reference.
In this paper, an improved algorithm to measure China's EMU spacesuit joint damping parameters for the old passive robot system is presented. The measuring principle is based on robot kinematics and dynamics. Firs...
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In this paper, an improved algorithm to measure China's EMU spacesuit joint damping parameters for the old passive robot system is presented. The measuring principle is based on robot kinematics and dynamics. Firstly, a kinematic model of the passive robot and the EMU spacesuit's arm is built according to the special mechanical structure. Secondly, improved methods of solving the inverse kinematics of the EMU spacesuit arm including flexible joints are proposed. And finally, a new algorithm that eliminates the gravity effect is implemented to calculate the damping torques of the EMU spacesuit joints. Experimental results and verification on SGI workstation proved the correctness and effectiveness of the proposed measuring method.
To meet the requests of miniaturization and high precision of nano-positioning X-Y stage, a novel 2-DOF single crystal silicon (SCS) nano-positioning micro X-Y stage with the function of displacement detection was suc...
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To meet the requests of miniaturization and high precision of nano-positioning X-Y stage, a novel 2-DOF single crystal silicon (SCS) nano-positioning micro X-Y stage with the function of displacement detection was successfully developed using silicon bulk machining, and its principle was introduced in this paper. Based on the combination of theoretical analysis and finite element simulation, a sidewall piezoresistor in plane technique was proposed to fabricate piezoresistor sensor in the micro X-Y stage. The experimental results verify the reasonable ness of micro X-Y stage design. Under the driving voltage of 23.68 V, the maximal displacement of X-Y stage is 10 μm in each of the four directions, with the positioning precision of better than 20 nm. The piezoresistor sensor of 4.2 k is tested using semi-automatic probe stage and its breakdown voltage is 75 V. The sensitivity of the fabricated piezoresistor, namely, the relative changes in resistance, is 3.6 × 10-5 under the displacement of 10 nm, which fully meets the design requirements.
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