A Twelve-Step Program to More Efficient Robotics

them. When I went into work, everyone seemed normal. Even the system we were going to use seemed ordinary—a fairly traditional architecture, a standard sense-modelplan-act cycle augmented with expectationgeneration and execution-monitoring steps. I thought this would turn out to be an ordinary project, but thinking this way turned out to be my undoing, especially when the sensor man showed up pushing his wares. I wasn’t sure what the proper sensor modalities should be (my only previous experience had been with sonar), so when the sensor man suggested we use stereo imagery to build a detailed topographic map of the robot’s surroundings, I agreed. Many of my friends had used stereo, and frankly, I was curious to see what it was really like.2 We mounted cameras on a pan-tilt head, stuck it on our robot, and off we went. The images were carefully correlated to a fraction of a pixel. The generated depth data were converted to plan view height data and stored in a set of 3 grids, each placed at one quarter of the grid-cell size and extended to twice the range of the previous grid. The lowest-resolution grid was at approximately 1-meter cell size and was extended to 32 meters in all directions from the robot. The smallest grid was at 6-centimeter resolution and was extended for 8 meters in all directions. The grids contained height, slope, and roughness estimates for each cell as well as confidence values for the data in the cell—over 100,000 cells in the layers and half a dozen fields to 1 cell. These numbers were great because we were producing a lot of data—megabytes! Even though we were doing stereo day and night, it looked like our productivity was way up...we had reams of data. It got to the point where I could do ■ Sensor abuse is a serious and debilitating condition. However, one must remember that it is a disease, not a crime.1 As such, it can be treated. This article presents a case study in sensor abuse. This particular subject was lucky enough to pull himself out of his pitiful condition, but others are not so lucky. The article also describes a 12step behavior-modification program modeled on this and other successful case studies.