Scope
The more extreme the demands placed on future technology, the more interesting advanced robotics becomes. Robotics that goes beyond simple pick-and-place robots and deals with intelligent, stand-alone systems that can operate in a multitude of environments. These systems are finding their niche in a wide range of applications: handling hazardous materials, the maintenance and inspection of nuclear reactors, the precise positioning of measuring equipment, microsurgery and offshore work ranging from maintenance on production platforms to drilling deep sea wells.
Extravehicular Man-Machine Interface for ERA ('Remote control' for astronauts)
Our latest crowning achievement is the development of the European Robotic Arm (era), a 10 meter long, stand-alone space robot, which will be part of the International Space Station (iss). The robot has a state-of-the-art control system that allows it to be operated by an astronaut as well as having the ability to operate autonomously. The control system represents significant technological advances in the fields of path planning and collision avoidance. The era continuously calculates its own position and location and can move about with great reliability and accuracy. In space era is able to move objects with mass of thousands of kilos with a positional accuracy of better than 5 mm. era is further able to interact with its environment using a camera and torque-force sensor.
Dutch Space is a specialist when it comes to advanced control systems. Another good example is the development of Attitude and Orbit Control Systems (aocs) such as the extremely accurate (2 arcsec) position control system used in Europe's infrared Space Observatory (iso) satellite, launched in 1995. Furthermore the efficiency with which the aocs was capable of dealing with highly demanding manoeuvres gave a significant contribution to extending the mission life-time by ten months. Another achievement is the aocs for the Bepposax, a satellite still contributing to the sensational detection and accurate pinpointing of gamma ray burst in the cosmos. At present, the Herschel Planck acms is under development.
The simultaneous control of a large number of sensors and actuators, driven by an autonomous computer with dedicated software, applies to the control of aocs systems and is also necessary in robotics systems with a large degree of freedom. It also applies in many complex control systems such as machines for the automated digging of tunnels.
Control engineering makes use of a combined system and mechatronics approach. Synergy with other disciplines such as software engineering, mechanical and thermal engineering is an integral aspect of our activities.
Analysis techniques
Discipline oriented
- Classical control methods
- Modern control techniques
- Control System Engineering
- Mechatronics approach
- use of:
- modal data of flexible structures
- lumped thermal models
Application field oriented
- Attitude Control Satellite: SO, BeppoSAX, Herschel Planck
- Robot Control: European Robotic Arm
- Active thermal control: SCIAMACHY
- Servo control: small wing control
- Precision Motion Control: Very Large Telescope Delay Lines
- Active vibration control: Defense programmes payload isolation
Analysis tools
Includes:
- Modern Control Toolboxes of MATLAB
- The standard non real time simulation tool used is MATLAB SIMULINK. An extensive simulation capability is also available with the generic EUROSIM simulation environment developed by Dutch Space. Eurosim provides hard real-time simulation with hardware in the loop and has been used for ERA.
Examples
- Use of the ERA Simulation Facility, ESF, simulating the full hardware and software of the European Arm, including also multibody dynamics with flexibility.
- Very accurate motion control for the delay line's of the Very Large Telescope (VLT) (20 nanometer position accuracy over a 60 m. track.)
- Active Thermal Control for the Scanning Imaging Absorption Spectrometer for Atmospheric Cartography on the ENVISAT satellite
