On robust estimation of the location parameter

The correct grasp of objects is a key aspect for the right fulfillment of a given task. Obtaining a good grasp requires algorithms to automatically determine proper contact points on the object as well as proper hand configurations, especially when dexterous manipulation is desired, and the quantification of a good grasp requires the definition of suitable grasp quality measures. This article reviews the quality measures proposed in the literature to evaluate grasp quality. The quality measures are classified into two groups according to the main aspect they evaluate: location of contact points on the object and hand configuration. The approaches that combine different measures from the two previous groups to obtain a global quality measure are also reviewed, as well as some measures related to human hand studies and grasp performance. Several examples are presented to illustrate and compare the performance of the reviewed measures.

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Grasp quality measures: review and performance

The development of a mobile robot to assist people in their home is a long term goal of Fraunhofer IPA. As a vision of a future household product, the latest prototype, Care-O-bot® 3, is equipped with the latest industrial state-of-the art hardware components and offers all modern multimedia and interaction equipment as well as most advanced sensors and control. Care-O-bot® 3 has been presented to the public on several occasions where it distributed drinks to the visitors of trade fairs and events. Current developments aim at applying the robot in an eldercare facility in order to support the personnel in their daily tasks.

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Robotic home assistant Care-O-bot ® 3 - product vision and innovation platform

Path planning and trajectory planning are crucial issues in the field of Robotics and, more generally, in the field of Automation. Indeed, the trend for robots and automatic machines is to operate at increasingly high speed, in order to achieve shorter production times. The high operating speed may hinder the accuracy and repeatability of the robot motion, since extreme performances are required from the actuators and the control system. Therefore, particular care should be put in generating a trajectory that could be executed at high speed, but at the same time harmless for the robot, in terms of avoiding excessive accelerations of the actuators and vibrations of the mechanical structure. Such a trajectory is defined as smooth. For such reasons, path planning and trajectory planning algorithms assume an increasing significance in robotics. Path planning algorithms generate a geometric path, from an initial to a final point, passing through pre-defined via-points, either in the joint space or in the operating space of the robot, while trajectory planning algorithms take a given geometric path and endow it with the time information. Trajectory planning algorithms are crucial in Robotics, because defining the times of passage at the via-points influences not only the kinematic properties of the motion, but also the dynamic ones. Namely, the inertial forces (and torques), to which the robot is subjected, depend on the accelerations along the trajectory, while the vibrations of its mechanical structure are basically determined by the values of the jerk (i.e. the derivative of the acceleration). Path planning algorithms are usually divided according to the methodologies used to generate the geometric path, namely:


roadmap techniques


cell decomposition algorithms


artificial potential methods.

Path Planning and Trajectory Planning Algorithms: A General Overview

Nowadays there are very little robot systems in operation in the field of medium to large-scale handling and assembly mostly due to lack of repetitive processes or shortcomings in programming and configuring such robots. In this paper we introduce a family of cable-driven parallel robot called IPAnema that are designed for industrial processes. We address the system architecture, key components such as winches and controller, as well as design tools. Furthermore, some experimental data from the evaluation are presented to illustrate the performance of cable robots.

IPAnema: A family of Cable-Driven Parallel Robots for Industrial Applications

This paper presents an algorithm to determine feasible force distributions for parallel wire robots in closed-form. The force distributions are continuous along trajectories and differentiable at most of the points. The computational efforts are strictly bounded and small even for large numbers of wires. The algorithm is compared to other approaches for calculation of force distribution in terms of the numerical effort and their applicability for control purposes.

Closed-form Force Distribution for Parallel Wire Robots

Welcome.- Motion Planning.- Force Distribution.- Application and Protoypes.- Design and Components.- Kinematics and Interval Methods.- Calibration und Identification.- Control.- Dynamics Modelling.

/pdf/cable-driven-parallel-robots-3hzt4mms8b.pdf

Cable-driven parallel robots

This paper introduces the CableRobot simulator, which was developed at the Max Planck Institute for Biological Cybernetics in cooperation with the Fraunhofer Institute for Manufacturing Engineering and Automation IPA. The simulator is a completely novel approach to the design of motion simulation platforms in so far as it uses cables and winches for actuation instead of rigid links known from hexapod simulators. This approach allows to reduce the actuated mass, scale up the workspace significantly, and provides great flexibility to switch between system configurations in which the robot can be operated. The simulator will be used for studies in the field of human perception research and virtual reality applications. The paper dicusses some of the issues arising from the usage of cables and provides a system overview regarding kinematics and system dynamics as well as giving a brief introduction into possible application use cases.

Andreas Pott

Papers

IPAnema: A family of Cable-Driven Parallel Robots for Industrial Applications

Closed-form Force Distribution for Parallel Wire Robots

Cable-driven parallel robots

The CableRobot simulator large scale motion platform based on cable robot technology

Cable-Driven Parallel Robots: Theory and Application