Hazardous materials emergency response mobile robot

A simple or unsophisticated robot incapable of effecting straight-line motion at the end of its arm inserts a key held in its end effector or hand into a door lock with nearly straight-line motion by gently thrusting its back heels downwardly so that it pivots forwardly on its front toes while holding its arm stationary. The relatively slight arc traveled by the robot's hand is compensated by a complaint tool with which the robot hand grips the door key. A visible beam is projected through the axis of the hand or gripper on the robot arm end at an angle to the general direction in which the robot thrusts the gripper forward. As the robot hand approaches a target surface, a video camera on the robot wrist watches the beam spot on the target surface fall from a height proportional to the distance between the robot hand and the target surface until the beam spot is nearly aligned with the top of the robot hand. Holes in the front face of the hand are connected through internal passages inside the arm to an on-board chemical sensor. Full rotation of the hand or gripper about the robot arm's wrist is made possible by slip rings in the wrist which permit passage of the gases taken in through the nose holes in the front of the hand through the wrist regardless of the rotational orientation of the wrist

Finding antipodal point grasps on irregularly shaped objects

Two-finger antipodal point grasping of arbitrarily shaped smooth 2-D and 3-D objects is considered. An object function is introduced that maps a finger contact space to the object surface. Conditions are developed to identify the feasible grasping region, F, in the finger contact space. A “grasping energy function”, E , is introduced which is proportional to the distance between two grasping points. The antipodal points correspond to critical points of E in F. Optimization and/or continuation techniques are used to find these critical points. In particular, global optimization techniques are applied to find the “maximal” or “minimal” grasp. Further, modeling techniques are introduced for representing 2-D and 3-D objects using B-spline curves and spherical product surfaces

Regrasp Planning using 10,000s of Grasps

This paper develops intelligent algorithms for robots to reorient objects. Given the initial and goal poses of an object, the proposed algorithms plan a sequence of robot poses and grasp configurations that reorient the object from its initial pose to the goal. While the topic has been studied extensively in previous work, this paper makes important improvements in grasp planning by using over-segmented meshes, in data storage by using relational database, and in regrasp planning by mixing real-world roadmaps. The improvements enable robots to do robust regrasp planning using 10,000s of grasps and their relationships in interactive time. The proposed algorithms are validated using various objects and robots

Automated Configuration of Gripper Fingers from a Construction Kit for Robotic Applications

Gripper finger design is a complex process that requires a lot of experience, time, and effort. For this reason, automating this design process is an important area of research that has the potential to improve the efficiency and effectiveness of robotic systems. The current approaches are aimed at the automated design of monolithic gripper fingers, which have to be manufactured additively or by machining. This paper describes a novel approach for the automated design of gripper fingers. The motivation for this work stems from the increasing demand for flexible, adaptable handling systems in various industries in response to the increasing individualization of products as well as the increasing volatility in the markets. Based on the CAD data of the handling objects, the most suitable configuration of gripper fingers can be determined from the existing modules of a construction kit for the respective handling object, which can significantly reduce the provisioning time for new gripper fingers. It can be shown that gripper fingers can be effectively configured for a variety of objects and two different grippers, increasing flexibility in industrial handling processes

The Effect of Constructional Features on the Tensile Strength of Woven Structures

The main field of enquiry included the effect of interlacing on the tensile strength and the influence of changes in weft particulars on the strength of the warp. The result in all cases are expressed in terms of fabric assistance ratios which are of greater interest when dealing with the influence of component yarns on the fabric than direct strength values. Behaviour of continous filement yarns and cotton yarns in woven constructions was investigated and considerable differences in the basic pattern were discovered between the different materials. In addition to the sett and the weave structure it was found that the crimp factor exerted a distinct influence on the ultimate strength value. In this connection it was postulated that of considerable importance in the standard method of tensile strength was the ratio of crimp between longitudinal and transverse components of a fabric. A trellis type of jaw was constructed to test fabrics under conditions of homogeneous strain with the elimination of "waist" effects and comparisons were made between the two methods of test using identical specimens

Reliability Test Fixture for Flexible Hybrid Electronics

During the 2016-2017 school year, the Cal Poly NextFlex Group, in conjuncture with the Cal Poly Industrial and Manufacturing Engineering Department, was comprised of professors, undergraduate students, and graduate students all working towards the manufacturing of flexible hybrid electronics (FHEs). FHEs, which are comprised of a flexible plastic substrate (thermoplastic polyurethane), screen-printed silver ink, and a thin silicon wafer, have a wide range of potential applications. At the time of this project, FHEs and other flexible electronics did not have a set of test standards to characterize their mechanical and electrical properties. The Cal Poly NextFlex Group recruited three Cal Poly Mechanical Engineering students (known as the BendatroniX Team) from the Fall 2016 Senior Project class to create a Reliability Test Fixture to test the FHEs that they were manufacturing. Over the course of three quarters, the team designed, built, and validated a reliability test fixture that characterized the electrical integrity of the FHEs as a function of mechanical strain. The fixture was comprised of four clamps that mated with an Instron tensile testing machine. One of the clamps had a unique pogo pin housing that monitored the electrical resistance across the FHEs while it was stretched. Upon the conclusion of the project, the BendatroniX Team trained Cal Poly NextFlex students on how to use the fixture so that they could continue to test and characterize the tensile properties of different FHE configurations. The following report details the design, build, and test process that the BendatroniX Team performed to create the Reliability Test Fixture for FHEs

Application of image analysis techniques to determine strain distribution in leather

The optimum cutting of various parts of a shoe, prior to shoe manufacture requires knowledge of the topographical variation of what are termed “lines of tightness”. Currently the cutting operation for shoe parts is guided by a general assumption about the pattern of the lines of tightness. There is a need to have available a system which can determine, in a non-destructive way, the lines of tightness in an indvidual piece of leather. Initially an image analysis system was developed to investigate the uni-axial deformation behaviour of leather. This technique provided more information about the stress-strain behaviour of a leather sample along the gauge length than a conventional mechanical test and it was possible to accurately measure the strain distribution along the gauge length. A system was developed which could determine the relative displacement of marked spots along the gauge length of the sample using images captured during a uni-axial, bi-axial or multi-axial tensile test. The separation of the marked spots along the direction of applied stroke allowed the determination of longitudinal strain while contraction across the width was also measured in some cases, which was useful in calculating the Poisson’s ratio of leather for which a great variation was observed between different locations (Butt, Belly, Neck etc). Various approaches were investigated to determine the lines of tightness. Firstly, the local Poisson’s ratio was observed since a higher value of this parameter was associated with these lines of tightness. Secondly, biaxial stretching of leather by a series of actuators for each axis indicated the lines of tightness along the actuator with lower strain values. Thirdly, the strain was measured when the leather was stretched along number of known axes. This latter technique appeared to be the best approach and mathematical modeling was investigated to provide further refinement. A mechatronics-based device by industrial application of the third approach was also proposed. The software was written using a graphical programming system (LabVJ EW