Armed for space services
April 01, 2008
Like a cherry picker crane, ERA will transport cosmonauts to the position where they work or from one external location to another, saving time and ef...
Dutch Space, a subsidiary of EADS in The Netherlands, has finished building the European Robotic Arm (ERA) for the European Space Agency (ESA). ERA will be attached to the Russian part of the International Space Station (ISS), which already features one robotic arm, the Canadarm2. With its different types of base points and payload mounting units, Canadarm2 cannot be used on the Russian module. The ERA, however, is designed to assemble and service the Russian segment of the ISS.
ERA consists of two approximately 5 m-long symmetrical arm sections made of carbon fiber, an Embedded Control Computer (ECC), and other components. With a total length of 11 m (36 ft.), ERA can reach out 10 m (33 ft.) into space and can position loads of up to 8,000 kg (17,660 lbs.) with a precision of 3 mm (0.1"). Both endpoints (end effectors) can be used as hands or feet. The robotic servicing device will handle the following tasks:
- Integrate the ISS
- Manipulate larger building blocks
- Exchange small and large replaceable units
- Install, replace, and deploy solar arrays
- Inspect the space station‚Äôs surfaces
- Control cosmonauts‚Äô extravehicular activities, such as space walks
Like a cherry picker crane, ERA will transport cosmonauts to the position where they work or from one external location to another, saving time and effort during space walks. ERA will use infrared cameras to inspect the space station‚Äôs external surfaces.
The control computer ECC embedded in the ERA is based on the ERC32 chip, a radiation-tolerant 32-bit RISC processor developed by Temic (now Atmel) for space applications. The ERC32 implementation follows SPARC V7 specifications.
ERA can perform automated, preprogrammed maneuvers via interactive operation control from the ISS and a ground station. Control system software from Terma, Denmark, was used to analyze, design, develop, and validate the onboard control software. This software monitors and controls tasks such as replacing payloads or inspecting and repairing the space station‚Äôs external surface, including failure detection, isolation, and recovery. Figure 2, courtesy of EADS/Dutch Space, shows the ERA control panel, with switch and button labels displayed in Russian and English.
The software executes on an autonomous computer located on the arm that communicates with sensors and actuators located in the joints, as well as the robotic arm‚Äôs basic end effectors and cameras. Within the ERA onboard software, a layer of bridging software facilitates communication with the station‚Äôs mission computer. The software was developed in Ada with support from Technospazio. This language is well matched to the design approach with Hierarchical Object-Oriented Design.
The Russian space agency Roskosmos has announced that its Multipurpose Laboratory Module, slated to launch from the Baikonur Cosmodrome in 2009, will carry ERA up to the ISS.
Germany‚Äôs elektro Automation magazine recently presented the results of the product contest held during the SPS/IPC/Drives automation exhibition and conference in Nuernberg last November. A panel of industry experts presented a list of 49 products vying for the Automation Award.
The winner ‚Äì the Handheld Mobile Computer MC9090ex from BARTEC GmbH, Germany ‚Äì features WLAN/Bluetooth connectivity, long-lasting lithium-ion batteries, and application in explosive environments. Turck‚Äôs metal sensor and analyzer, Euchner‚Äôs electronic key system, and Kontron‚Äôs service-free ThinkIO computer for C-clamp mounting also won awards.