Loading...

Design & Prototyping of a Reflective Optical Hybrid Incremental-Absolute Encoder Based on Compact Disc Technology

Sadri, Sobhan | 2010

765 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: English
  3. Document No: 40406 (58)
  4. University: Sharif University of Technology, International Campus, Kish Island
  5. Department: Science and Engineering
  6. Advisor(s): Vossoughi, Gholamreza
  7. Abstract:
  8. The reflective optical rotary encoders are used greatly in automation systems for speed and position measurements. Their approach of reading code as pulses which results in position and speed information is very similar to what a CD-ROM driver performs to read the saved data as pits and lands on the compact disc data layer. Moreover, the micron size of pits and lands in compact disc promise a high-resolution, and low cost rotary encoder based on CD-ROM technology. In this thesis, two concepts of length coding and hybrid incremental-absolute coded discs are proposed. To verify the implementation of these concepts, the rotary encoder set based on CD-ROM technology is designed and tested. It uses both the CD-ROM driver and encoder designed components in one set. The experimental results on a rotating blank CD-R and a coded disc confirm the successful operation of designed rotary encoder. By implementing the conventional incremental disc and proposed coded discs on the CD-R, the designed rotary encoder is used to read these coded patterns. Although this approach of making coded discs imposes incredible limitation on the resolution, results confirms the effectiveness of proposed concepts and verifies that by designing a special coded disc with micron size codes on a circular path, the high-resolution and low cost rotary encoder is achievable.
  9. Keywords:
  10. Reflective Optical Encoder ; Optical Pickup Modeling ; Optical Pickup Identification ; Compact Disk Driver ; Focus Servo Circuit ; Focus Search Circuit

 Digital Object List

 Bookmark

...see more