Autonomous Mechanical Assembly on the Space Shuttle: An Overview

The space shuttle will be equipped with a pair of 50 ft. manipulators used to handle payloads and to perform mechanical assembly operations. Although current plans call for these manipulators to be operated by a human teleoperator. The possibility of using results from robotics and machine intelligence to automate this shuttle assembly system was investigated. The major components of an autonomous mechanical assembly system are examined, along with the technology base upon which they depend. The state of the art in advanced automation is also assessed

Automatic generation of robot and manual assembly plans using octrees

This paper aims to investigate automatic assembly planning for robot and manual assembly. The octree decomposition technique is applied to approximate CAD models with an octree representation which are then used to generate robot and manual assembly plans. An assembly planning system able to generate assembly plans was developed to build these prototype models. Octree decomposition is an effective assembly planning tool. Assembly plans can automatically be generated for robot and manual assembly using octree models. Research limitations/implications - One disadvantage of the octree decomposition technique is that it approximates a part model with cubes instead of using the actual model. This limits its use and applications when complex assemblies must be planned, but in the context of prototyping can allow a rough component to be formed which can later be finished by hand. Assembly plans can be generated using octree decomposition, however, new algorithms must be developed to overcome its limitations

Pathfinder autonomous rendezvous and docking project

Capabilities are being developed and demonstrated to support manned and unmanned vehicle operations in lunar and planetary orbits. In this initial phase, primary emphasis is placed on definition of the system requirements for candidate Pathfinder mission applications and correlation of these system-level requirements with specific requirements. The FY-89 activities detailed are best characterized as foundation building. The majority of the efforts were dedicated to assessing the current state of the art, identifying desired elaborations and expansions to this level of development and charting a course that will realize the desired objectives in the future. Efforts are detailed across all work packages in developing those requirements and tools needed to test, refine, and validate basic autonomous rendezvous and docking elements

Vibration as an aid in robotic peg-in-hole assembly

This dissertation presents an analytical and experimental investigation of vibration assisted engagement for parts mating. A dynamic model of assembly is established by using Lagrange\u27s equation for impact to derive impact equations for a robotic manipulator in peg-in-hole assembly. The model can be used to analyze part motion and contact force in the mating of parts by robots. The impact equations of a SCARA robot are derived using this model and utilized to investigate how robot configuration, insertion speed, chamfer angle, coefficient of restitution and other system parameters affect impulsive force and departure angle in the assembly of a peg with a chamfered hole in the presence of position errors. In the analytical investigation, how the vibration amplitude, vibration frequency, frequency ratio, phase angle, uncertainty and tolerance of the assembly system affect the engagement time is analyzed. An algorithm is developed to determine the required time for engagement given a set of assembly and vibration parameters. An intelligent force-based approach is used in conjunction with this algorithm to aid mating of parts and is implemented in experiments to verify analytical results

The design and implementation of vision-based behavioural modules for a robotic assembly system

The work drsrrihrd in this thesis ia about, how to program robots to work re liably in the presence of uncertainty. Some architectural principle!: are proposed which address the problem of decomposing robotic assembly tasks into modular units such that a robot program can be implemented efficiently, tested easily, and can be maintained or modified without undue complexity. This architecture also provides a framework to integrate sensors into a robotic, assembly system.These modular units arc called behavioural modules. They perforin their tasks reliably. The problem of uncertainty is dealt with by encapsulating sensing and variation reducing strategies inside these modules. Experiments are performed with a working robotic assembly system using vision based behavioural modules. Analy sis of this system validates the principles presented in this thesis

Point Pair Feature based Object Detection for Random Bin Picking

Point pair features are a popular representation for free form 3D object detection and pose estimation. In this paper, their performance in an industrial random bin picking context is investigated. A new method to generate representative synthetic datasets is proposed. This allows to investigate the influence of a high degree of clutter and the presence of self similar features, which are typical to our application. We provide an overview of solutions proposed in literature and discuss their strengths and weaknesses. A simple heuristic method to drastically reduce the computational complexity is introduced, which results in improved robustness, speed and accuracy compared to the naive approach

NASA Automated Rendezvous and Capture Review. Executive summary

In support of the Cargo Transfer Vehicle (CTV) Definition Studies in FY-92, the Advanced Program Development division of the Office of Space Flight at NASA Headquarters conducted an evaluation and review of the United States capabilities and state-of-the-art in Automated Rendezvous and Capture (AR&C). This review was held in Williamsburg, Virginia on 19-21 Nov. 1991 and included over 120 attendees from U.S. government organizations, industries, and universities. One hundred abstracts were submitted to the organizing committee for consideration. Forty-two were selected for presentation. The review was structured to include five technical sessions. Forty-two papers addressed topics in the five categories below: (1) hardware systems and components; (2) software systems; (3) integrated systems; (4) operations; and (5) supporting infrastructure

Vision technology/algorithms for space robotics applications

The thrust of automation and robotics for space applications has been proposed for increased productivity, improved reliability, increased flexibility, higher safety, and for the performance of automating time-consuming tasks, increasing productivity/performance of crew-accomplished tasks, and performing tasks beyond the capability of the crew. This paper provides a review of efforts currently in progress in the area of robotic vision. Both systems and algorithms are discussed. The evolution of future vision/sensing is projected to include the fusion of multisensors ranging from microwave to optical with multimode capability to include position, attitude, recognition, and motion parameters. The key feature of the overall system design will be small size and weight, fast signal processing, robust algorithms, and accurate parameter determination. These aspects of vision/sensing are also discussed