http://hdl.handle.net/10016/11852 2013-06-19T06:40:39Z 2013-06-19T06:40:39Z Bensalah, Choukri Abderrahim, Mohamed González Gómez, Juan http://hdl.handle.net/10016/14116 2012-06-08T10:42:06Z 2010-12-31T23:00:00Z

Title: A new finger inverse kinematics method for an anthropomorphic hand Author(s): Bensalah, Choukri; Abderrahim, Mohamed; González Gómez, Juan Abstract: In this paper, a new method for solving the inverse kinematics of the fingers of an anthropomorphic hand is proposed. Our approach combines a Modified Selectively Damped Least Squares (MSDLS) and Jacobian Transpose (JT) methods. The main advantages of this method with respect to the ordinary SDLS are: optimal Cartesian increment, shorter computation time and better response near singularity configurations. The original JT method exhibits a strong shattering with small magnitudes which occurs near the goal position or in the case of unreachable positions. Like in the SDLS, a damping factor was applied to each input singular vector to filter the undesirable behavior. A comparative study between the MSDLS applied to the inverse Jacobian and JT matrix is developed to investigate manipulator performance in critical end-point positions of the index finger of a commercial anthropomorphic robotic hand and also to evaluate the impact of the increment length on computation time. Description: Proceedings of: 2011 IEEE International Conference on Robotics and Biomimetics (ROBIO), December 7-11, 2011, Phuket (Thailand)

2010-12-31T23:00:00Z Klimentjew, Denis Zhang, Jianwei http://hdl.handle.net/10016/14114 2012-06-08T09:30:46Z 2010-12-31T23:00:00Z

Title: Adaptive sensor-fusion of depth and color information for cognitive robotics Author(s): Klimentjew, Denis; Zhang, Jianwei Abstract: The presented work goes one step further than only combining data from different sensors. The corresponding points of an image and a 3D point cloud are determined through calibration. Color information is thereby assigned to every voxel in the overlapping area of a stereo camera system and a laser range finder. Then we analyze the image and search for the locations, which are especially susceptible to errors by both sensors. Depending on the ascertained situation, we try to correct or minimize errors. By analyzing and interpreting the images as well as removing errors we create an adaptive tool which improves multi-sensor fusion. This allows us to correct the fused data and to perfect the multi-modal sensor fusion or to predict the locations where the sensor information is vague or defective. The presented results demonstrate a clear improvement over standard procedures and show that other progress based on our work is possible. Description: Proceedings of: 2011 IEEE International Conference on Robotics and Biomimetics (ROBIO), December 7-11, 2011, Phuket (Thailand)

2010-12-31T23:00:00Z Palm, Rainer Iliev, Boyko http://hdl.handle.net/10016/13982 2012-06-11T07:43:47Z 2011-06-30T22:00:00Z

Title: Programming-by-demonstration and adaptation of robot skills by fuzzy-time-modeling Author(s): Palm, Rainer; Iliev, Boyko Abstract: Complex robot tasks can be partitioned into motion primitives or robot skills that can directly be learned and recognized through Programming-by-Demonstration (PbD) by a human operator who demonstrates a set of reference skills. Robot motions are recorded by a data-capturing system and modeled by a specific fuzzy clustering and modeling technique where skill models use time instants as inputs and operator actions as outputs. In the recognition phase the robot identifies the skill shown by the operator in a novel test demonstration. Skill models are updated online during the execution of skills using the Broyden update formula. This method is extended for fuzzy models especially for time cluster models. The updated model is used for further executions of the same skill. Description: Proceedings of: 2011 IEEE Workshop on Robotic Intelligence in Informationally Structured Space (RiiS 2011 MDCM), April 11-15, 2011, Paris (France)

2011-06-30T22:00:00Z Nguyen, Kien-Cuong Perdereau, Véronique http://hdl.handle.net/10016/13963 2012-06-08T09:34:36Z 2011-11-30T23:00:00Z

Title: Arm-hand movement: imitation of human natural gestures with tenodesis effect Author(s): Nguyen, Kien-Cuong; Perdereau, Véronique Abstract: For an anthropomorphic arm-hand robot, grasping and in-hand manipulating an object can be realized with numerous approach trajectories and grasping configurations. The redundancy at this level of the tasks is due to a large number of degrees-of-freedom (DOFs) of the arm-hand system. This redundancy constitutes a big challenge to the planning and control tasks of the robot. For this kind of tasks, human has his own choices privileging certain configurations over the others. These choices come from a long learning process which implicitly takes into account the mechanical constraints of the system. In this work, we concentrate our effort on deciphering certain mechanical constraints, ”tenodesis” phenomenon in particular, in order to solve the redundancy and imitate the human natural gestures in the tasks of grasping or in-hand manipulation. Description: Proceedings of: 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS '11), September 25-30, 2011, San Francisco, USA

2011-11-30T23:00:00Z