A state observer for using a slow camera as a sensor for fast control applications
R. Gahleitner, M. Schagerl - A state observer for using a slow camera as a sensor for fast control applications - SPIE Electronic Imaging 2013: Machine Vision Applications VI, San Francisco, United States of America, 2013, pp. 10
This contribution concerns about a problem that often arises in vision based control, when a camera is used as a
sensor for fast control applications, or more precisely, when the sample rate of the control loop is higher than the
frame rate of the camera. In control applications for mechanical axes, e.g. in robotics or automated production,
a camera and some image processing can be used as a sensor to detect positions or angles. The sample time in
these applications is typically in the range of a few milliseconds or less and this demands the use of a camera
with a high frame rate up to 1000 fps.
The presented solution is a special state observer that can work with a slower and therefore cheaper camera
to estimate the state variables at the higher sample rate of the control loop. To simplify the image processing for
the determination of positions or angles and make it more robust, some LED markers are applied to the plant.
Simulation and experimental results show that the concept can be used even if the plant is unstable like the