What's a goniometer?
Technically speaking, a goniometer is a device used to measure angles. For example, physiotherapists might use a goniometer to measure the range of motion of a patient's joint.
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We've designed no regular goniometer. This machine will be used for developing machine learning algorithms for Defense Research and Development Canada. Confused? We were at first too.
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Our device can move a camera (like a smart phone) and a light source to any angular position in a hemisphere around a target object. So if you want an overhead view of your apple with 45 degree lighting - we've got you covered.
The Automated Goniometer
The design team spent 8 months working to develop this novel laboratory device. We focused our work in three main areas: mechanical design, electrical design, and software design. Here we describe some of the highlights from each area.
Mechanical Design
The mechanical design consists of a light arc, camera arc, turntable, frame, and power train. All of these components are made from aluminum to keep the weight down. Three stepper motors are used to control the moving arcs and turntable. The power is transferred through a drive shaft with pulleys and timing belts, and the components are mounted to a rectangular frame. The arcs were fabricated using a waterjet and custom machining tools.
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Electrical Design
The electrical system consists a PLC (programmable logic controller), three motor drivers, lights, fuses, two power supplies, and more. The bulk of the electrical components are housed in a fiberglass control box which connects to the goniometer via four big cables. We used a matrix design to control 35 lights with just 12 wires. Nevertheless, wire management was huge:Â in total, over 60 wires are used!
Software Design
The user controls the goniometer through a touchscreen located on the control box. Here the user can choose an angle for the camera and light, choose a resolution to gather datasets, or input a predefined path for the goniometer to execute. The goniometer was programmed using a PLC with ladder logic.
Solving a Problem
Machine learning in object recognition is based on gathering thousands of images taken from different angles. These images are taken from ground level but also in the air. Current databases don't have enough images because they are difficult to obtain. The automated goniometer is a test bench where thousands of images of an object can be collected with different lighting angles without ever having to leave the ground.
The Design Team
We're four 4th year design engineering students from the University of Prince Edward Island
