Current Issue : October - December Volume : 2016 Issue Number : 4 Articles : 5 Articles
Human-robot interaction (HRI) plays an important role in future planetary exploration mission, where astronauts with\nextravehicular activities (EVA) have to communicate with robot assistants by speech-type or gesture-type user interfaces embedded\nin their space suits. This paper presents an interactive astronaut-robot system integrating a data-glove with a space suit for the\nastronaut to use hand gestures to control a snake-like robot. Support vector machine (SVM) is employed to recognize hand\ngestures and particle swarm optimization (PSO) algorithm is used to optimize the parameters of SVM to further improve its\nrecognition accuracy. Various hand gestures from American Sign Language (ASL) have been selected and used to test and validate\nthe performance of the proposed system....
Technology has recently been developed which offers an excellent opportunity to design systems with the ability to help people\nin their own houses. In particular, assisting elderly people in their environments is something that can significantly improve their\nquality of life. However, helping elderly people outside their usual environment is also necessary, to help them to carry out daily\ntasks like shopping. In this paper we present a person-following shopping cart assistance robot, capable of helping elderly people\nto carry products in a supermarket. First of all, the paper presents a survey of related systems that perform this task, using different\napproaches, such as attachable modules and computer vision. After that, the paper describes in detail the proposed system and its\nmain features. The cart uses ultrasonic sensors and radio signals to provide a simple and effective person localization and following\nmethod.Moreover, the cart can be connected to a portable device like a smartphone or tablet, thus providing ease of use to the end\nuser.The prototype has been tested in a grocery store, while simulations have been done to analyse its scalability in larger spaces\nwhere multiple robots could coexist....
The torque sensor is used to measure the joint torque of a robot manipulator. Previous\nresearch showed that the sensitivity and the stiffness of torque sensors have trade-off characteristics.\nStiffness has to be sacrificed to increase the sensitivity of the sensor. In this research, a new torque\nsensor with high sensitivity (TSHS) is proposed in order to resolve this problem. The key idea of\nthe TSHS comes from its 4-bar linkage shape in which the angular displacement of a short link is\nlarger than that of a long link. The sensitivity of the torque sensor with a 4-bar link shape is improved\nwithout decreasing stiffness. Optimization techniques are applied to maximize the sensitivity of the\nsensor. An actual TSHS is constructed to verify the validity of the proposed mechanism. Experimental\nresults show that the sensitivity of TSHS can be increased 3.5 times without sacrificing stiffness....
Parallel kinematic machines (PKMs) are commonly used for tasks that require high precision and stiffness. In this sense, the\nrigidity of the drive system of the robot, which is composed of actuators and transmissions, plays a fundamental role. In this\npaper, ball-screw drive actuators are considered and a 6-degree of freedom (DoF) parallel robot with prismatic actuated joints is\nused as application case. A mathematical model of the ball-screw drive is proposed considering the most influencing sources of\nnonlinearity: sliding-dependent flexibility, backlash, and friction.Using this model, the most critical poses of the robot with respect\nto the kinematic mapping of the error from the joint- to the task-space are systematically investigated to obtain the workspace\npositional and rotational resolution, apart from control issues. Finally, a nonlinear adaptive-robust control algorithm for trajectory\ntracking, based on the minimization of the tracking error, is described and simulated....
This study describes a trajectory planning method based on execution time, acceleration, and jerk to ensure that a glass-handing\nrobot runs smoothly at execution time. The minimised objective function consists of the weighted sum of the square of the\nintegral of the execution time, the integral of the acceleration, and the integral of the jerk, all of which are obtained through the\nweighted coefficientmethod.Athree-dimensional kinematics model of the glass-handing robot is then established and nonuniform\nfifth-order ...
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