During the uniform locomotion of legged robots with compliant legs, the body of the
robot exhibits quasi-periodic oscillations that have a disturbing eect on dierent onboard
sensors. Of particular interest is the camera sensor which suers from image
degradation in the form of motion-blur as a result of this camera motion. The eect of
angular disturbances on the camera are pronounced due to the perspective projection
property of the camera. The thesis focuses on the particular problem of legged robots
exhibiting angular body motions and attempts to analyze and overcome the resulting
disturbances on a camera carrying platform (head). Although the full problem is in 3D
with three independent axes of rotation, a planar analysis provides signicant insight
into the problem and is the approach taken in the thesis. A carefully modeled planar
version of an actual camera platform with realistic mechanical and actuator selections
is presented. Passive (ltering) and active (controller) approaches are discussed to
compensate/cancel motion generated disturbances.
We consider and comparatively evaluate PID and LQR based active control. Since
PID has the limitation of controlling only one output, PID-PID control is considered to
iv
control two states of the model. Due to its state-space formulation and the capability
of controlling an arbitrary number of states, LQR is considered.
In addition to standard reference signals, Gyroscope measured disturbance signals
are collected from the actual robot platform to analyze the bandwidth and test the
performance of the controllers. Inverted pendulum control performance is evaluated
both on a Matlab-Simulink as well as a precise electro-mechanical test setup. Since
construction of the planar head test setup is in progress, tests are conducted on simulation.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12613713/index.pdf |
| Date | 01 September 2011 |
| Creators | Akgul, Emre |
| Contributors | Saranli, Afsar |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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