Development of a 6 degree-of-freedom manipulator arm for use on an urban search and rescue robot

Includes abstract.Includes bibliographical references.This document reports on the design, construction and testing of the manipulator arm that is to be fitted to UCT's Urban Search and Rescue Robot (USRR), named the Ratel. The 6 degree-of-freedom manipulator arm is mounted on the crawler base. The USRR is designed to traverse difficult terrain in search of survivors. The base is therefore equipped with variable geometry tracks to enable it to traverse stairs and other tricky terrain. The sensor payload is equipped with life detection equipment and the manipulator arm enables the USRR to manipulate with its environment (opening doors etc.) and to interact with survivors, passing them water or food packs

Lunar vertical-shaft mining system

This report proposes a method that will allow lunar vertical-shaft mining. Lunar mining allows the exploitation of mineral resources imbedded within the surface. The proposed lunar vertical-shaft mining system is comprised of five subsystems: structure, materials handling, drilling, mining, and planning. The structure provides support for the exploration and mining equipment in the lunar environment. The materials handling subsystem moves mined material outside the structure and mining and drilling equipment inside the structure. The drilling process bores into the surface for the purpose of collecting soil samples, inserting transducer probes, or locating ore deposits. Once the ore deposits are discovered and pinpointed, mining operations bring the ore to the surface. The final subsystem is planning, which involves the construction of the mining structure

Piezomorphic materials

The development of stress-induced morphing materials which are described as piezomorphic materials is reported. The development of a piezomorphic material is achieved by introducing spatial dependency into the compliance matrix describing the elastic response of a material capable of undergoing large strain deformation. In other words, it is necessary to produce an elastically gradient material. This is achieved through modification of the microstructure of the compliant material to display gradient topology. Examples of polymeric (polyurethane) foam and microporous polymer (expanded polytetrafluoroethylene) piezomorphic materials are presented here. These materials open up new morphing applications where dramatic shape changes can be triggered by mechanical stress

Autonomous Space Processor for Orbital Debris (ASPOD)

A project in the Advanced Design Program at the University of Arizona is described. The project is named the Autonomous Space Processor for Orbital Debris (ASPOD) and is a Universities Space Research Association (USRA) sponsored design project. The development of ASPOD and the students' abilities in designing and building a prototype spacecraft are the ultimate goals of this project. This year's focus entailed the development of a secondary robotic arm and end-effector to work in tandem with an existent arm in the removal of orbital debris. The new arm features the introduction of composite materials and a linear drive system, thus producing a light-weight and more accurate prototype. The main characteristic of the end-effector design is that it incorporates all of the motors and gearing internally, thus not subjecting them to the harsh space environment. Furthermore, the arm and the end-effector are automated by a control system with positional feedback. This system is composed of magnetic and optical encoders connected to a 486 PC via two servo-motor controller cards. Programming a series of basic routines and sub-routines allowed the ASPOD prototype to become more autonomous. The new system is expected to perform specified tasks with a positional accuracy of 0.5 cm

Lunar deep drill apparatus

A self contained, mobile drilling and coring system was designed to operate on the Lunar surface and be controlled remotely from earth. The system uses SKITTER (Spatial Kinematic Inertial Translatory Tripod Extremity Robot) as its foundation and produces Lunar core samples two meters long and fifty millimeters in diameter. The drill bit used for this is composed of 30 per carat diamonds in a sintered tungsten carbide matrix. To drill up to 50 m depths, the bit assembly will be attached to a drill string made from 2 m rods which will be carried in racks on SKITTER. Rotary power for drilling will be supplied by a Curvo-Synchronous motor. SKITTER is to support this system through a hexagonal shaped structure which will contain the drill motor and the power supply. A micro-coring drill will be used to remove a preliminary sample 5 mm in diameter and 20 mm long from the side of the core. This whole system is to be controlled from earth. This is carried out by a continuously monitoring PLC onboard the drill rig. A touch screen control console allows the operator on earth to monitor the progress of the operation and intervene if necessary

Recent Developments in the Design, Capabilities and Autonomous Operations of a Lightweight Surface Manipulation System and Test-bed

The first generation of a versatile high performance device for performing payload handling and assembly operations on planetary surfaces, the Lightweight Surface Manipulation System (LSMS), has been designed and built. Over the course of its development, conventional crane type payload handling configurations and operations have been successfully demonstrated and the range of motion, types of operations and the versatility greatly expanded. This enhanced set of 1st generation LSMS hardware is now serving as a laboratory test-bed allowing the continuing development of end effectors, operational techniques and remotely controlled and automated operations. This paper describes the most recent LSMS and test-bed development activities, that have focused on two major efforts. The first effort was to complete a preliminary design of the 2nd generation LSMS that has the capability for limited mobility and can reposition itself between lander decks, mobility chassis, and fixed base locations. A major portion of this effort involved conducting a study to establish the feasibility of, and define, the specifications for a lightweight cable-drive waist joint. The second effort was to continue expanding the versatility and autonomy of large planetary surface manipulators using the 1st generation LSMS as a test-bed. This has been accomplished by increasing manipulator capabilities and efficiencies through both design changes and tool and end effector development. A software development effort has expanded the operational capabilities of the LSMS test-bed to include; autonomous operations based on stored paths, use of a vision system for target acquisition and tracking, and remote command and control over a communications bridge

Tool flow management in batch manufacturing systems for cylindrical components

The objective of the research is to study the design of and operating strategies for advanced tool flow systems in highly automated turning systems. A prototype workstation has been built to aid this process. The thesis consists of three main parts. In the first part the current flexible manufacturing technology is reviewed with emphasis laid on tool flow and production scheduling problems. The 'State-of-the-Art' turning systems are studied, to highlight the requirement of the computer modelling of tool flow systems. In the second part, the design of a computer model using fast modelling algorithms is reported. The model design has concentrated on the tool flow system performance forecasting and improving. Attention has been given to the full representation of highly automatic features evident in turning systems. A number of contemporary production scheduling rules have been incorporated into the computer model structure, with the objectives of providing a frontend to the tool flow model, and to examine the tool flow problems interactively with the production scheduling rules. The user-interface of the model employs conversational type screens for tool flow network specification and data handling, which enhances its user friendliness greatly. An effective, fast, and easy to handle data base management system for tool, part, machine data entries has been· built up to facilitate the model performance. The third part of the thesis is concerned with the validation and application of the model with industry supplied data to examine system performance, and to evaluate alternative strategies. Conclusions drawn from this research and the recommendations for further work are finally indicated

The 31st Aerospace Mechanisms Symposium

The proceedings of the 31st Aerospace Mechanisms Symposium are reported. Topics covered include: robotics, deployment mechanisms, bearings, actuators, scanners, boom and antenna release, and test equipment. A major focus is the reporting of problems and solutions associated with the development and flight certification of new mechanisms

Design, development and testing of miniature instruments for flexible endoscopy

This thesis describes the design and development of single-stitch and chain-stitch endoscopic sewing machines for flexible endoscopy as well as devices and methods for tying knots and cutting thread at flexible endoscopy. The work also includes a comparative study of clipping methods for endoscopic haemostasis and a feasibility study of a wireless endoscope that might allow images to be transmitted from sites in the gastrointestinal tract without wires, cables or fibre optic bundles. The development and testing of simple prototypes of such an endoscope are reported. Chapter 1 reviews the surgical instruments and methods used for tissue approximation in general surgery, laparoscopic surgery and flexible endoscopic surgery. The design of existing, conventional sewing machines and the ways in which they form stitches are also considered. In Chapter 2, a comparative study of clipping methods for endoscopic haemostasis is reported. In Chapter 3, the design and development of new single-stitch endoscopic sewing machines are described, together with data on the clinical use of one of these machines. In Chapter 4, studies of ways of improving endoscopic vision during endoscopic sewing and the effects of needle size and the size and shape of the suction cavity are reported. In Chapter 5, the design and development of novel chain-stitch endoscopic sewing machines are reported. These make use of two new catch mechanisms. In Chapter 6, knot tying at flexible endoscopy is considered, and a number of new devices and methods are described and clinical results reported. In Chapter 7, cutting thread at flexible endoscopy is described. Several new endoscopic thread cutting devices and methods together with results are presented. In Chapter 8, a feasibility study of wireless endoscopy is reported. The study includes tests of the concept of wireless endoscopes made using prototypes constructed from miniature CCD cameras and microwave transmitters. Finally, some concluding remarks relating to the work described in this thesis are given

Design of an In-situ Spinal Rod Cutter for Orthopaedic Surgeons

As spine deformities scoliosis and kyphosis progress in severity, surgical treatment is often required. Implant rods are attached by bone screws to the spinal vertebrae to correct these deformities and stabilize the spine. It can be difficult to cut these rods to the ideal length before implantation and sometimes these rods are too long and must be cut in-situ. Also, when revision surgery is performed to replace a rod section, in-situ rod cutting must be performed. The rods are difficult to cut and only manual rod cutting tools are available. These rod cutters are physically demanding to use and difficult to position while avoiding any spurious with the exposed spine. There is a clear need for an improved in-situ rod cutter. Thus, the objective of this thesis is to develop a new and improved design for an in-situ rod cutter. Experimental work was done to show that shear cutting and bolt-cutting techniques produced the most desirable results for cutting spinal rods in-situ. The shear cutting techniques required slightly less force than bolt cutting techniques and produced a cleaner rod cut with less deformation. It was found that cutting force increased with the diameter of the spinal rod, regardless of the rod material. Constraints and criteria were established to guide the design of a new in-situ rod cutter. It was decided that any attempt at designing a new in-situ cutter must include a non-manual power source for operation. Two design alternatives, a shear cutting design and bolt-cutting design were presented and scored in an engineering design process. A shear cutter design was initially chosen and work was done to implement the shear cutter design. However, the prototype fractured in initial testing and the shear cutter design was abandoned. A bolt-cutter design was then developed and a 3D printed prototype was made to demonstrate the mechanism involved. Analysis was performed to estimate the mechanical advantage of the mechanism used to amplify the force applied by a pneumatic cylinder used as the power source. Further development was required to implement the bolt-cutting design but initial progress in this design project was achieved. It is recommended that stress analysis, prototyping and testing be done to move this design towards application in spinal surgery