In this paper, a method to implement the input shaping control in Mechatrolink-III motion system is introduced. Firstly, the underdamped system is theoretically built by modeling. Then, the motion controller of Mechat...
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In this paper, a nonlinear adaptive control of a 3D overhead crane is investigated. A dynamic model of the overhead crane is developed, where the crane system is assumed as a lumped mass model. Under the mutual effect...
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For efficient and safe locomotion the gaits of legged robots should vary with the type of terrain. Hence, terrain surface classification is an important problem for this class of mobile robots. Prior research has deve...
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For efficient and safe locomotion the gaits of legged robots should vary with the type of terrain. Hence, terrain surface classification is an important problem for this class of mobile robots. Prior research has developed approaches to proprioceptive terrain classification for both wheeled and limbed robots that use sensor measurements dependent upon the dynamics of the robot, which ultimately requires the classification system to be trained at a large number of operating conditions (e.g., vehicle speeds and loads). This research develops an approach to terrain identification based on pressure images generated through direct surface contact using a robot skin constructed around a high-resolution pressure sensing array. Terrain signatures for classification are formulated from the magnitude frequency responses of the pressure images. The methodology is used to train and test a classifier using dynamically measured pressure images from a one-legged hopping robot. Experimental tests yield high classification accuracies, which are independent with respect to changing robot dynamics (i.e., different leg gaits). The findings of this paper suggest the methodology can be extended to autonomous field robots, providing the robot with crucial information about the environment that can be used to aid stability over rough terrains and enhance motion planning over varying terrains.
In this paper,we propose the analytical approach for adaptive decode-and-forward(ADF) relaying vehicle-toinfrastructure(V2I) schemes consisting of ND-symbol burst data transmission based on pilot symbol assisted-chann...
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In this paper,we propose the analytical approach for adaptive decode-and-forward(ADF) relaying vehicle-toinfrastructure(V2I) schemes consisting of ND-symbol burst data transmission based on pilot symbol assisted-channel estimation(PSA-CE) methods over quasi-static Rayleigh fading *** first,we focus on the error-event at relaying on board equipments(OBEs) for ND-symbol burst data transmission,whereas previous researches considered one data symbol transmission so that they showed the best performance *** considering ND-symbol burst for ADF relaying schemes,we derive an exact bit error rate(BER) expression which can be the performance of practical ***,the practical channel estimation(CE) process is considered by pilot symbols ***,we investigate the effects of both a CE error and an estimated noise variance,which can be obtained by pilot symbol assisted(PSA)-CE methods,on the received signal-to-noise ratio(SNR) and ***,the average BER is derived in approximated closed-form expression for an arbitrary link *** derived analytical approach is verified based on the number of relaying OBEs,pilots,and data *** accuracy is confirmed by comparison with simulation results.
In this paper,we derive the average symbol error rate(SER) for the ND-symbol burst hybrid adaptive decodeor-amplify-forward(HADF) relaying vehicle-to-infrastructure(V2I) communication systems over quasi-static indepen...
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In this paper,we derive the average symbol error rate(SER) for the ND-symbol burst hybrid adaptive decodeor-amplify-forward(HADF) relaying vehicle-to-infrastructure(V2I) communication systems over quasi-static independent and non-identical distributed(INID) Rayleigh fading *** proposed analytical approach includes channel estimation(CE)errors generated by practical pilot symbol assisted-CE(PSACE) ***,based on the error-events at relaying on board equipments(OBEs) for ND-symbol burst data transmission,the conditional SER expression has been derived as an exact ***,the approximated average SER(ASER)expressions are presented as the closed-forms and their accuracy is confirmed by the comparison with simulation ***,we can conclude that our analytical expressions are tractable forms,and can be used as a tool to verify effects of an erroneous detection and hybrid transmission at each relaying OBE on the combined signal-to-noise ratio(SNR) and ASER for cooperative HADF relaying communication systems.
In this paper we study learning in cooperative object pushing systems. The proposed approach is based on the idea of learning individual skills and then mapping the required cooperative behaviors on the learned skills...
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In this paper we study learning in cooperative object pushing systems. The proposed approach is based on the idea of learning individual skills and then mapping the required cooperative behaviors on the learned skills. The control point for each individual robot is chosen so as to simplify the design of the reinforcement signal and reduce the role of delayed reward on individual learning in addition to make cooperative protocol simpler. A fuzzy Q-learning system for learning individual object pushing is proposed, together with a method for coordination among the robots to push the object cooperatively. The coordination method takes into account the dynamics of the object and the learned individual skills. The idea of the coordination protocol is based on the notion of ability and active regions defined in this paper. In effect, the cooperation protocol is mapped to a Q-value based policy. Simulation results supportively show that the robots learn individual and cooperative object pushing efficiently
This paper is concerned with the derivation of the kinematics model of the University of Tehran-Pole Climbing Robot (UT-PCR). As the first step, an appropriate set of coordinates is selected and used to describe the s...
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This paper is concerned with the derivation of the kinematics model of the University of Tehran-Pole Climbing Robot (UT-PCR). As the first step, an appropriate set of coordinates is selected and used to describe the state of the robot. Nonholonomic constraints imposed by the wheels are then expressed as a set of differential equations. By describing these equations in terms of the state of the robot an underactuated driftless nonlinear controlsystem with affine inputs that governs the motion of the robot is derived. A set of experimental results are also given to show the capability of the UT-PCR in climbing a stepped pole.
Despite that omni-directional mobile robots have been employed popularly in several application areas, effort on optimal design of such mobile robots has been few in literature. Thus, this paper investigates the optim...
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ISBN:
(纸本)0780372727
Despite that omni-directional mobile robots have been employed popularly in several application areas, effort on optimal design of such mobile robots has been few in literature. Thus, this paper investigates the optimal design of omni-directional mobile robots. Particularly, optimal design parameters such as one or double offset distance of wheel mechanism and the wheel radius are identifed with respect to isotropic characteristic of mobile robots. In addition, the force transmission characteristics and actuator-sizing problem of mobile robots are investigated Analysis has been performed for three actuation sets. It is shown that the redundantly acruated mobile robot with three active caster wheels represents the best performance among them.
This paper focuses on distributed fault recovery in agent-based systems by providing help for faulty members. In the presented method, if one faulty agent requests for help or agents are informed of fault in one of th...
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This paper focuses on distributed fault recovery in agent-based systems by providing help for faulty members. In the presented method, if one faulty agent requests for help or agents are informed of fault in one of their teammates, they first decide if they are able to help or not. In the case that they are able to help and several help requests exist, helper agents specify a sequence of help actions through another distributed decision-making phase. The introduced fault clearing method is totally distributed in the sense that each helper agent makes its decisions by itself and no central or special agent exists in the system. In fact, the decision making process and the required information are designed such that the agents cooperate implicitly to prevent the system performance loss. The developed ideas are implemented in a simulated distributed controlsystem. As it is shown, the proposed distributed fault-clearing method through reconfiguring the agents' roles is very effective.
A kinematic modeling method is proposed which uses augmenting variables to match the dimensions of the input vector and output vector of each serial subchain of the mobile robots. Firstly, kinematic models of various ...
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ISBN:
(纸本)0780365763
A kinematic modeling method is proposed which uses augmenting variables to match the dimensions of the input vector and output vector of each serial subchain of the mobile robots. Firstly, kinematic models of various type of wheels are derived including skidding and sliding velocities. Then the method of augmented generalized coordinates is applied to obtain inverse and forward kinematic models. The kinematic models derived by the direct inverse of the augmented matrices provide an accurate solution, which was not achievable by the modeling method based on the pseudo-inverse method which provides an approximate solution. Lastly, two kinematic models for typical, differential-driven mobile robots are presented to show the effectiveness of the proposed modeling method.
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