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Preliminary Design Review. Multispectral Camera Advisor : Prof. Mario Parente Team Parente #13 Simon Belkin Audrey C. Finken Matthew Walczak. Team Parente. Simon Belkin EE Team Manager. Matthew Walczak EE Website Master. Audrey Finken - EE. Outline . The Problem Background
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Preliminary Design Review Multispectral Camera Advisor: Prof. Mario Parente Team Parente #13 Simon Belkin Audrey C. Finken Matthew Walczak
Team Parente • Simon Belkin • EE • Team Manager • Matthew Walczak • EE • Website Master Audrey Finken - EE
Outline • The Problem • Background • Our solution • Application • Requirements • Design alternative • Timeline/MDR Goals
The Problem • Normal camera just take pictures with RGB color filter that show light at three different wavelengths.
The Problem: • We want to expand the capabilities of normal cameras by covering a wider spectrum of colors through the use of a Multispectral dddddddd33333333333 Camera.
Background The Camera will be operated by a microcontroller system that will position a filter in front of a monochrome camera and an image will be captured
Multispectral camera: background Images taken through different optical filter contain only certain wavelengths of the electromagnetic spectrum that the filter allows through.
Solution: Multispectral Camera • Create picture at different wavelengths that regular vision does not allow(Near Infrared). • Have various applications not accessible by regular cameras. • The provide more information to user.
Applications Food processing Agriculture Defects such as bruising on fruit are more easily isolated in an infrared image. By studying changes in reflectivity, growers can identify plant stress resulting from problems such as water shortage, nutrient deficiencies, or toxins long before there is any visible indication.
Requirement Analysis : specifications • Electronically control the filter wheel and monochrome camera attached to it. • Battery powered • Enclosing case big enough to hold monochromatic camera.
Filter Wheel • This consist of six or more optical band pass filters. • Filter are mounted in a computer controlled filter wheel located between lens and gray level sensor. • Calibration of color wheel turning to be able to have a particular step size.
Filter Wheel Challenge: Electronic part • Connection of the filter • Use logic analyzer • Use schematic of filter to figure out pins
Monochromatic camera • Choosing the Monochromatic camera • Photographs images through the filter wheel in particular frequency spectrum. • Camera settings • Frame rate, latency, exposure, aperture and gain • Enclosed area to prevent light between the Wheel and camera.
Monochromatic camera challenge :optics • Aberration: • Geometric: Each filter is tilted with respect to axis can cause distortion. • Chromatic : When different wavelengths of light aren't focused on same plane. • Ghosting: Images produce reflections between the image sensor and filter surface. • Can be solved via software • Minimize aberration with proper choice of lens and optics
Microcontroller circuit • Controls the filter wheel’s turning. • Will collect different image spectrums • Include a display mode • Raspberry pi (tentative) • Microcontroller development board • Arduino board or chip
Mechanical assembly • Having all the parts fit together • Filter • Optics (lens, camera) • Microcontroller
Design alternative: CCD • Using a CCD behind the filter wheel: • Advantages: • More sensitive to a broad range of wavelengths • Disadvantages: • Alignment • Have to deal with optical distortion.
