Finger design automation for industrial robot grippers: A review <s> Re-configurable Design <s> Modular fixturing kits are sets of components used for flexible, rapid construction of fixtures. A modular vise is a parallel-jaw vise, each jaw of which is a modular fixture plate with a regular grid of precisely positioned holes. To fixture a part, one places pins in some of the holes so that when the vise is closed, the part is reliably located and completely constrained. The modular vise concept can be adapted easily to the design of modular parallel-jaw grippers for robots. By attaching a grid-plate to each jaw of a parallel-jaw gripper we gain the ability to easily construct high-quality grasps for a wide variety of parts from a standard set of hardware. Wallack and Canny (1994) developed an algorithm for planning planar grasp configurations for the modular vise. We expand this work to produce a 3D fixture/gripper design tool. We describe several analyses we have added to the planar algorithm, including a 3D grasp quality metric based on force information, 3D geometric loading analysis, and inter-gripper interference analysis. Finally, we describe two applications of our code. One of these is an internal application at Sandia, while the other shows a potential use of our code for designing part of an agile assembly line. <s> BIB001 </s> Finger design automation for industrial robot grippers: A review <s> Re-configurable Design <s> This paper presents an implemented algorithm that automatically designs fixtures and assembly pallets to hold three-dimensional parts. All fixtures generated by the algorithm employ round side locators, a side clamp, and cylindrical supports; depending on the value of an input control flag, the fixture may also include swing-arm top clamps. Using these modular elements, the algorithm designs fixtures that rigidly constrain and locate the part, obey task constraints, are robust to part shape variations, are easy to load, and are economical to produce. For the class of fixtures that are considered, the algorithm is guaranteed to find the global optimum design that satisfies these and other pragmatic conditions. The authors present the results of the algorithm applied to several practical manufacturing problems. For these complex problems the algorithm typically returns initial high-quality fixture designs in less than a minute, and identifies the global optimum design in just over an hour. The algorithm is also capable of solving difficult design problems where a single fixture is desired that can hold either of two parts. <s> BIB002 </s> Finger design automation for industrial robot grippers: A review <s> Re-configurable Design <s> An algorithm for automatically generating a common jaw design and planning grasps for a given set of polyhedral objects is presented. The algorithm is suitable for a parallel-jaw gripper equipped with three cylindrical fingers. The common jaw design eliminates the need for custom made grippers and tool changing. The proposed jaw configuration and planning approach reduces the search associated with locating the finger contacts from six degrees-of-freedom to one degree-of-freedom. Closed-form algorithms for checking force closure and for predicting jamming are developed. Three quality metrics are introduced to improve the quality of the planned grasps. The first is a measure of the sensitivity of the grasp to errors between the actual and planned finger locations. The second is a measure of the efficiency of the grasp in terms of the contact forces. The third is a measure of the dependence of force closure on friction. These quality metrics are not restricted to cylindrical fingers and can be applied to n finger grasps. Running on a standard PC, the algorithm generated a solution in less than five minutes for a set of five objects with a total of 456 triangular facets. © 2003 Wiley Periodicals, Inc. <s> BIB003
Some researchers BIB001 BIB002 BIB003 approach gripper designs with the possibility of reconfiguring fingers (pins) locations. The work of BIB003 is focused on three-finger parallel jaw grippers. The fingers configuration is defined to have two fixed cylindrical fingers in one jaw and the third finger is fixed on the perpendicular bisector of the centerline on the other fingers. The pair of fingers on the same jaw are the variables for changing configuration and the single finger is constantly fixed. The developed algorithm automatically obtains the fingers configurations. Pros: These approaches provide quick and simple solutions for industrial applications. Cons: The proposed algorithms require many technical inputs which cause only experts in this area be able to use the methods.