We make a thorough kinematic comparison of forward and backward swimming and maneuvering on a self-propelled robot platform that uses sub-carangifbrm swimming as the primary propulsor. An improved Central Pattern Gene...
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We make a thorough kinematic comparison of forward and backward swimming and maneuvering on a self-propelled robot platform that uses sub-carangifbrm swimming as the primary propulsor. An improved Central Pattern Generator (CPG) model allowing free adjustment of phase relationship and directional bias is employed to achieve flexible swimming and smooth transition. Considering the characteristics of forward swimming in carangiform fish and backward swimming in anguilliform fish, various backward swimming patterns for the sub-carangiform robotic fish are suitably created by reversing the direction of propagating propulsive waves. Through a combined use of the CPG control and closed-loop swimming direction control strategy, flexible and precise turning maneuvers in both forward and backward swimming are implemented and compared. By contrast with forward swimming, backward swimming requires a higher frequency or an increased lateral displacement to reach the same relative swimming speed. Noticeably, the phase difference shows a greater impact on forward swimming than on backward swimming. Our observations also indicate that the robotic fish achieves a larger turning rate in forward maneuvering than in backward maneuvering, yet these two maneuvers display comparable turning precision.
The delta parallel mechanism has proven to be a very successful parallel robot design and a number of variants have been proposed in the literature. Taking advantage of its simple construction and the intrinsic featur...
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ISBN:
(纸本)9781467391054
The delta parallel mechanism has proven to be a very successful parallel robot design and a number of variants have been proposed in the literature. Taking advantage of its simple construction and the intrinsic features such as high stiffness and accuracy, delta robots play an important role both in the fields of industrial robots and academical fields. In this paper, dynamic modeling and control simulation of a cable-driven modified delta manipulator for haptic interface are discussed. For the parallel mechanism is highly coupled and nonlinear, the dynamic model is of great importance for model-based controller to achieve a satisfactory performance. Based on the principle of virtual work, the dynamic equations of this manipulator are established. The proportional-derivative (PD) computed torque control scheme is proposed for trajectory tracking. With the help of the virtual prototype builded in ADAMS software and used in MATLAB software, the co-simulation is accomplished and the results validate the performance of the controller proposed in this paper.
In this paper,we propose a clique-based sparse reinforcement learning(RL) algorithm for solving cooperative *** aim is to accelerate the learning speed of the original sparse RL algorithm and to make it applicable for...
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In this paper,we propose a clique-based sparse reinforcement learning(RL) algorithm for solving cooperative *** aim is to accelerate the learning speed of the original sparse RL algorithm and to make it applicable for tasks decomposed in a more general ***,a transition function is estimated and used to update the Q-value function,which greatly reduces the learning ***,it is more reasonable to divide agents into cliques,each of which is only responsible for a specific *** this way,the global Q-value function is decomposed into the sum of several simpler local Q-value *** decomposition is expressed by a factor graph and exploited by the general maxplus algorithm to obtain the greedy joint *** results show that the proposed approach outperforms others with better performance.
It has been recognized by many researchers that accurate bus travel time prediction is critical for successful deployment of traffic signal priority (TSP) systems. Although there exist a lot of studies on travel time ...
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It has been recognized by many researchers that accurate bus travel time prediction is critical for successful deployment of traffic signal priority (TSP) systems. Although there exist a lot of studies on travel time prediction for Advanced Traveler Information systems (ATIS), this problem for TSP purpose is a little different and the amount of literature is limited. This paper proposes a deep learning based approach for continuous travel time prediction problem. Parameters of the deep network are fine-tuned following a layer-by-layer pre-training procedure on a dataset generated by traffic simulations. Variables that may affect continuous travel time are selected carefully. Experiments are conducted to validate the performance of the proposed model. The results indicate that the proposed model produces prediction with mean absolute error less than 4 seconds, which is accurate enough for TSP operations. This paper also reveals that, except for obvious factors like speed, travel distance and traffic density, the signal time when the prediction is made is also an important factor affecting travel time.
The results of traditional traffic status analysis are mostly single values, whose accuracy can't be determined;fuzzy c-means clustering (FCM) algorithm based on fuzzy theory can calculate the clustering center of...
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Differential spatial modulation (DSM) is a newly proposed differential modulation technique tailored to spatial modulation (SM), which requires no channel state information (CSI) at the receiver. DSM can offer flexibl...
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ISBN:
(纸本)9781467364300
Differential spatial modulation (DSM) is a newly proposed differential modulation technique tailored to spatial modulation (SM), which requires no channel state information (CSI) at the receiver. DSM can offer flexible tradeoff between the reception reliability and the systemcomplexity. In this paper, we are the first to study the adoption of DSM in a dual-hop amplify-and-forward (AF) relaying system, which consists of a two-antenna source, a single-antenna relay, and a single-antenna destination, so as to reduce the burden of channel tracking on both the relay and the destination. We derive a general upper bound on the average bit error probability (ABEP) achieved by the system. Moreover, an exact closed-form ABEP expression and the asymptotic result are provided for BPSK signaling in Rayleigh fading environment. The same system setup with the adoption of SM at the source is chosen as a benchmark for performance comparisons. Simulation results validate the analysis and reveal a 3dB signal-to-noise power ratio (SNR) penalty of the considered system compared with the benchmark.
Radio Environment Map(REM)is a map that indicates the radio signal strength(RSS)over a finite geographical *** enables cognitive radio(CR)users to opportunistically access to the spectrum unoccupied by the primary use...
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ISBN:
(纸本)9789881563842
Radio Environment Map(REM)is a map that indicates the radio signal strength(RSS)over a finite geographical *** enables cognitive radio(CR)users to opportunistically access to the spectrum unoccupied by the primary users(PUs)who are licensed to use specific *** this paper,a basis expansion based scheme is presented to estimate *** take the sparsity of preselected basis functions and the inherent time-varying spectrum usage of primary users into account such that the RSS estimation is formulated as a recursive least squares(RLS)problem with an l1norm constraint.A distributed algorithm is presented to solve the RLS *** SU only need to exchange information with its one-hop neighbours to sketch the REM with radio signal ***,simulation studies are presented to validate the performance of the proposed method.
Pose variation is a major challenge in face recognition. In this paper, we propose a novel cross-pose face recognition method by learning associate appearance manifolds to model the connection of faces under different...
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In the Still-to-Video (S2V) face recognition, each subject is enrolled with only few high resolution images, while the probe is video clips of complex variations. As faces present distinct characteristics under differ...
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Robust scene-text-extraction system can be used in lots of areas. In this work, we propose to learn co-occurrence of local strokes for robust character recognition by using a spatiality embedded dictionary (SED). Diff...
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