My time at Intuitive was packed with myriad projects, each showcasing an important part of an engineer’s day-to-day. From background knowledge, to planning, to building, to measuring, we were able to look at the full scope of the engineering design process and every bit of work that goes into it. It was an illuminating window into engineering careers and definitely piqued my interest as something I’d like to explore in the future.
Plus, I got a cool hat.
Today we looked at creating a smaller version of an Optical Coherence Tomography machine—a non-invasive device used to create 3D images of tissue, often used for imaging retinas. Among other things, this device requires multiple scanning patterns, all of which are used to produce slightly different images. We implemented these in Python, plotting with matplotlib, in order to verify the correctness of our code. The next step is to put it on an Arduino.
Below: the code producing a scanning pattern approximating an Archimedes spiral. The code had to evenly space dots along the spiral arc, a nontrivial task with limited computing resources—the formula for determining arc length of an Archimedes spiral based on angle is complex and includes slow operations such as the natural log. In addition, we weren’t able to find a closed-form inverse for this function, which is necessary for actually plotting the points. However, we found that a second-order Taylor series provided an surprisingly good approximation and was easily computable and invertible. The code below utilizes the Taylor series and is effectively indistinguishable from a true Archimedes spiral.
Below: Me excitedly explaining the technique.
Today at Intuitive we looked at a real project mirroring the day-to-day work of engineers: measuring! Although engineering is often made out to be largely about design, it’s equally about ensuring that components and assemblies are built up to spec and continue functioning at capacity even under load.
The part we took a look at today was a linear actuator, a device that extends and retracts even when fighting significant force. We measured it loaded with weights and without, and plotted the voltage, current, and temperature over numerous trials.
Below: Overlaid voltage/time graphs for 216 trials.
Our fourth day at Intuitive, we began to work on more complex projects. Tymur and I implemented a servo motor—a finely and precisely controllable motor—starting only with a basic DC motor, potentiometer, and rubber band. We used a PID loop to set the position and added additional code to deal with complications like hysteresis of the rubber band.
Our second day at Intuitive Surgical was filled with background knowledge, from electrical engineering concepts like electronic components, circuits, and logic gates to mechanical engineering concepts like experimental design. We also took a look at some of the tools engineers make use of, including soldering and CAD tools.
