The Human Condition

Electromagnetic Tracking

ram@undisclosed.example.com (ram) — Wed, 01 May 2024 17:54:19 +0000

Electromagnetic Tracking Electromagnetic tracking is a 50 year old technology for tracking the free 6DOF motion of a sensor, most often by inductive pickup of several fixed reference fields. It is a niche technology with several successful commercial products, mostly for biomedical tracking of human motion. In comparison to optical measurement (such as

Robert A. MacLachlan

ram@undisclosed.example.com (ram) — Tue, 16 Apr 2024 16:19:14 +0000

Robert A. MacLachlan NSH 3216 412-445-8113 ram@ri.cmu.edu Home: 6616 Dalzell Place Pittsburgh, PA 15217 412-521-0846 Mission: To develop innovative research systems that address important problems and advance human knowledge. My idea of fun is to work on a problem that no one knows how to solve, a problem where I can apply my broad knowledge, my intuition and my persistence.

Vacuum stuff

ram@undisclosed.example.com (ram) — Tue, 16 Apr 2024 16:12:06 +0000

Vacuum stuff I've built a high vacuum system off of mostly ebay parts plus custom electronics and software. It's a bell jar type chamber with a diffusion pump, with thermocouple, capacitive and cold cathode gauges, and mass flow controllers for process gas. Two microcontroller boxes control the high vacuum system (valve control and thermocouple gauges), and the process side (gauges, MFC). These communicate over USB to a laptop running Labview. The vacuum obtained is about 1e-5 Torr, which is …

Expedients

ram@undisclosed.example.com (ram) — Tue, 16 Apr 2024 16:06:47 +0000

Expedients Often it's necessary to build instruments for the calibration or characterization of the system actually under development. Here are a few examples. Calibration stage [ Calibration stage] In order to calibrate the ASAP position tracker we needed a calibration motion control system. We had been using a hexapod from Physik Instrumente, but it didn't have a big enough range of motion (especially angular), and it broke every time we used it, costing \$2K to fix. I found a Daedal XY …

Tracking

ram@undisclosed.example.com (ram) — Tue, 16 Apr 2024 16:04:11 +0000

Tracking [Tracker results] From 2003 to 2006 I developed a highly successful tracker for tracking moving objects from a moving vehicle using a single-axis laser scanner. As described in a Navlab publication this code formed the basis of an ongoing research program, including successful application to off-road robots with two-axis scanners.

ASAP position tracker

ram@undisclosed.example.com (ram) — Tue, 16 Apr 2024 16:02:37 +0000

ASAP position tracker [ ASAP/Micron 3DOF system] ASAP is a micron resolution kilosample/sec position tracker based on PSD (Position sensitive device) sensing. ASAP was originally developed for characterizing hand tremor and for ground truth in Micron development (using inertial sensors), but when the inertial approach didn't work, we change to using

Piezo Amp

ram@undisclosed.example.com (ram) — Tue, 16 Apr 2024 16:01:34 +0000

Piezo Amp The 3DOF Micron uses a bending-mode piezoelectric actuator which can be driven with voltages of -240..+480 V for maximum range of motion. This requires some sort of high-voltage amplifier for drive. Piezoelectric actuators have the nice property that they can be driven to an approximate position by applying a voltage to the actuator (open loop). Voltage drive is the most common approach, largely because there are off-the-shelf power opamps that can be used in this mode.

Micron

ram@undisclosed.example.com (ram) — Tue, 16 Apr 2024 15:37:08 +0000

Micron Micron is an actively stabilized instrument for microsurgery. Cam Riviere has been working on this in his lab since he came to CMU in the 90's, but I was a key contributor to getting the concept to actually work to any notable degree while handheld, which requires precise high bandwidth control in at least three degrees of freedom.

Labview

ram@undisclosed.example.com (ram) — Tue, 16 Apr 2024 15:27:53 +0000

Labview [Labview code] I've been programming primarily in Labview and Matlab for seven years now. It seems that Labview is getting some recognition at CMU as a suitable environment for novices and non-programmers (Lego robotics, etc.), but it is by no means limited to such uses. I believe Labview was a good choice for implementing Micron, and would not change my mind if I had to choose again.

Mindfulnest

ram@undisclosed.example.com (ram) — Tue, 16 Apr 2024 15:22:36 +0000

Mindfulnest The Mindfulnest project is developing a program to promote mindfulness practices in preschool classrooms. Simple controller devices are used by the kids. These have lights to give feedback to the user and a sensor that targets a desired behavior such as steady breathing. The controllers attach using bluetooth to a tablet which implements the interaction algorithm and logs data for research.

Medical Trauma Research

ram@undisclosed.example.com (ram) — Mon, 15 Apr 2024 18:27:01 +0000

Medical Trauma Research The Auton lab conducts research on applying machine learning to medicine, and as part of this the lab has implemented data collection and control infrastructure for a lab to conduct experiments on blood loss in pigs, including automatic administration of drugs to support blood pressure. I came on this project late, but supported the system, including writing a new device driver.

Breathecam

ram@undisclosed.example.com (ram) — Mon, 15 Apr 2024 14:53:48 +0000

Breathecam The Breathecam project deploys cameras for monitoring smoke emissions at industrial sites. These cameras take time lapse images at high resolution, and the backend software supports image mosaic across multiple cameras to give highly zoomable images. I was the engineer for a redesign to replace older cameras that were failing and could no longer be repaired due to use of a discontinued point-and-shoot camera. Camera technology had also progressed considerably since that design.

MKS 903ap cold cathode gauge

ram@undisclosed.example.com (ram) — Tue, 27 Nov 2018 14:58:14 +0000

MKS 903ap cold cathode gauge ( manual) [ MKS 903ap photo] This is a cold cathode (inverse magnetron) ion gauge for measuring in the range $3 \times 10^{-10}$ to $5 \times 10^{-3}$ Torr. I got mine on Ebay, and it was DOA. It was drawing way too much current and otherwise showing no signs of life. So, well, I could have returned it, but what would be the fun in that?