| 1. |
- Jonsson, Marie, 1979-, et al.
(författare)
-
Fixture design using Configurators
- 2008
-
Ingår i: Proceedings of the 2008 Swedish Production Symposium.
-
Konferensbidrag (refereegranskat)abstract
- Design and manufacture of fixtures are among one of the major cost drivers in product industrialization. Modular or reconfigurable fixture solutions that may be adapted to encompass a large variety of parts or products have been researched and employed in applications ranging from machining to assembly. These solutions have not only the potential to reduce fixture manufacturing cost, but they also render it possible for different solutions to facilitate and speed up actual design work. The process of designing fixtures today is complicated, time consuming and require long experience by the tool designer. In this paper we present the Configurator approach - add on programs to the CAD-software which aids the designer in the design process. The Configurators are semi-automated and interactive, designed to use in compliance with the ART-concept, a reconfigurable fixture concept for assembly applications. The Configurator approach has been tested on industrial cases and parts of the results are presented in this paper.
|
|
| 2. |
- Kihlman, Henrik
(författare)
-
Affordable automation for airframe assembly : developing of key enabling technologies
- 2005
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Building aircraft is a challenging field. An aircraft has a life expectancy of 40 years, compared to just 10 years for a car. Given the vibrations of flying at close to Mach one at an altitude of 10,000 meters, these machines must function flawlessly in a tough environment. This demands high quality in the assembly processes. The typical part joining process in the automotive industry is welding, whereas in the aircraft industry, assembly is made through drilling, followed by fastening. The typical tolerances for part location in aircraft assembly, as well as for hole drilling, is +/- 0.2 mm.This dissertation discusses the use of industrial robots, widely used for welding and pick-and-place operation for automotive industry, in the automation of the aircraft industry, and specifically for the drilling of holes in the assembly process of airframe parts. The dissertation presents how a new drilling technology called orbital drilling is incorporated with and industrial robot. Orbital drilling reduces the cutting forces up to ten times compared to conventional drilling using a spiral cutter.The robot is also utilized for performing changeovers between different airframe structure types. A novel jointed reconfigurable tooling system called Affordable Reconfigurable Tooling (ART) is presented, which uses the robot to reconfigure flexible fixture modules. The ART system can also be rebuilt, which means that the tool is dismantled and reused for a completely different product family (e.g. wings, fins or fuselage sections). This is made possible through a modular framework, i.e. not welded as with conventional tooling, but rather jointed by screws.Robots, originally developed for the automotive industry, have an accuracy which is ten times less accurate than that required for aerospace applications. To help meet this limitation in the use of robots in aircraft assembly, an additional metrology system, used in the aircraft industry for calibrating assembly tooling, is integrated into the robot controller. The feedback loop enables the robot to be positioned to ±0.05 mm absolute accuracy. This integration is made possible by existing embedded software packages for the robot and the metrology system.The processes in the system are programmed in a software package with an intuitive user interface in a 3D-environment, normally used for the offline-programming of robots in automotive industry. The planning is intuitive, and an approach towards a process planning abstraction level is presented where processes are defined directly on the coordinate frames constituting the robot trajectories and manual operations. Tolerance on accuracy requirements are dynamically programmed in the same environment. The metrology system, working online with the robot controller, eliminates most of the calibration work required in traditional robot programming. Changes in the operation planning take less than a minute to run physically with the best tolerance.
|
|
| 3. |
- Kihlman, Henrik, 1973-, et al.
(författare)
-
Flexible Fixtures with Low Cost and Short Lead Times
- 2006
-
Ingår i: SAE Technical Paper Series. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents preliminary result in a flexible fixture solution for airframe assembly comprising a modular steel framework called Box-joint and flexible tooling modules called Hexapods. The solution is comprises a framework that is screwed together instead of welding beams together, which enables re-building the framework when performing change-over in a more extensive reconfiguration. The Hexapods are parallel legged passive fixture stands that can change their configuration to facilitate easy setup in a change-over between handle different assemblies. A solution to configure the Hexapods manually is described. The investment cost can be kept low by using a metrology system to provide for high accuracy in the tool configuration process instead of using precision parts in the fixture system.
|
|
| 4. |
- Kihlman, Henrik, et al.
(författare)
-
On the Use of Force Feedback for Cost Efficient Robotic Drilling
- 2007
-
Ingår i: SAE Technical Paper Series. - Los Angeles, CA, US : Society of Automotive Engineers. - 0148-7191.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Drilling is one of the most costly and labour-intensive operations in aircraft assembly. Rather than automating with expensive fixtures and precise machinery, our approach is to make use of standard low-cost robot equipment in combination with sensor feedback. The focus is to eliminate the sliding movement of the end-effector during the clamp-up, called the skating effect, and to keep the end-effector orthogonal to the surface, thus avoiding holes that are not perpendicular. To that end, force feedback is used for building up pressure to clamp up an end-effector to the work-piece surface prior to drilling. The system, including the planning of force parameters for each hole to be drilled, was programmed in DELMIA. The drilling was accomplished with the aid of an extension to the ABB Rapid language called ExtRapid, which is an XML-like code that is interpreted by the force feedback controller downstream in the process. Although experimental results are from drilling, the conceptual idea is believed to be useful in many other applications requiring external sensor feedback control of industrial robots.
|
|
| 5. |
- Millar, Alison, et al.
(författare)
-
Reconfigurable Flexible Tooling for Aerospace Wing Assembly
- 2009
-
Ingår i: SAE Technical Paper Series. - 400 Commonwealth Drive, Warrendale, PA, United States : Society of Automotive Engineers. - 0148-7191.
-
Konferensbidrag (refereegranskat)abstract
- Traditionally, in the civil aerospace industry, assembly fixtures are large, bespoke, permanent structures that are costly to both design and manufacture. Additionally, the time to design, manufacture and install a large fixture can be significant with lead times in excess of 24 months. Within Airbus Operations Ltd there is a requirement to reduce non-recurring costs, reduce the time to market and improve the capacity and flexibility of equipment. This means that while the costs and lead times must be reduced, the utilisation of the tooling should be increased. Flexible and reconfigurable fixtures have not yet been deployed within Airbus Operations Ltd due to the assembly sizes and complex component configurations. However, they offer the potential for reducing costs by utilising off the shelf components. Using standard parts and implementing design tools can reduce the design time. The reconfigurable and flexible nature of the fixture will also enable embodiment of late component design changes with minimal time and cost impact. This paper presents the design, manufacture and installation of a reconfigurable fixture to assemble a wing box section in a research environment. This tooling demonstrator is then being used to evaluate the technical and industrial benefits of reconfigurable fixtures for aircraft wing sub assemblies and assemblies at Airbus.
|
|
