Current Issue : October - December Volume : 2014 Issue Number : 4 Articles : 4 Articles
This paper proposed a method to improve thewalking behavior of bipedal robotwith adjustable step length. Objectives of this paper\nare threefold. (1) Genetic Algorithm Optimized Fourier Series Formulation (GAOFSF) is modified to improve its performance.\n(2) Self-adaptive Differential Evolutionary Algorithm (SaDE) is applied to search feasible walking gait. (3) An efficient method is\nproposed for adjusting step length based on themodified central pattern generator (CPG)model.TheGAOFSF ismodified to ensure\nthat trajectories generated are continuous in angular position, velocity, and acceleration. After formulation of the modified CPG\nmodel, SaDE is chosen to optimize walking gait (CPG model) due to its superior performance.Through simulation results, dynamic\nbalance of the robot with modified CPG model is better than the original one. In this paper, four adjustable factors (????hs,support,\nRhs,swing,Rks,support, and Rks,swing) are added to the joint trajectories.Through adjusting these four factors, joint trajectories are changed\nand hence the step length achieved by the robot. Finally, the relationship between (1) the desired step length and (2) an appropriate\nset of ????hs,support, Rhs,swing, Rks,support, and Rks,swing searched by SaDE is learnt by Fuzzy Inference System (FIS). Desired joint angles can\nbe found without the aid of inverse kinematic model....
We present insight into how contextual awareness can be derived from, and improve, a fusion algorithm combing a WSN and a\npassive RFID for autonomous mobile robot navigation. Contextual awareness of not where the robot is, but rather the context in\nwhich it exists in relation to the environment and human user serves to improve accuracy in navigation, alters the speed of the\nrobot, andmodifies its behavior. TheWSN system, using a virtual potential field, provides fast general navigation in open areas and\nthe RFID provides precision navigation near static obstacles and in narrow areas. We verified the effectiveness of our approaches\nthrough navigational and guidance experiments....
High efficiency in cruising is a determining factor in developing tuna-mimetic robots. So far, a number of tuna-like robots have\nbeen made. Nevertheless, the University of Canterbury has developed its own tuna-like robot called UC-Ika 1 to investigate and to\naccordingly improve the swimming performance of the biomimetic swimming robots. In order to do so, the propulsion system of\na tuna with respect to its thrust and resistive forces is studied. Following that, the fish robot is designed and fabricated considering\nthe tuna propulsion system. The robot is then tested several times to investigate its swimming performance. Comparison of the\nspeed and efficiency of UC-Ika 1 with those of other tuna-like robots shows a promising improvement of cruising performance of\nUC-Ika 1....
The field of teleoperation with force telepresence has expanded its scope to include manipulation at different scales and in virtual\nworlds, and the key component of which is force feedback hand controller. This paper presents a novel force feedback hand\ncontroller system, including a 3-dof translational and 3-dof rotational hand controllers, respectively, to implement position and\nposture teleoperation of the robot end effector. The 3-dof translational hand controller adopts innovative three-axes decoupling\nstructure based on the linear motor; the 3-dof rotational hand controller adopts serial mechanism based on three-axes intersecting\nat one point, improving its overall stiffness. Based on the kinematics, statics, and dynamics analyses for two platforms separately, the\nsystem applies big closed-loop force control method based on the zero force/torque, improving the feedback force/torque accuracy\neffectively. Experimental results show that self-developed 6-dof force feedback hand controller has good mechanical properties.\nThe translational hand controller has the following advantages: simple kinematics solver, fast dynamic response, and better than\n0.05mm accuracy of three-axis end positioning, while the advantages of the rotational hand controller are wide turning space,\nlarger than 1Nm feedback, greater than 180 degrees of operating space of three axes, respectively, and high operation precision....
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