From d874dfbd7039f974949185f92fa55f9a1ac41fa4 Mon Sep 17 00:00:00 2001 From: Sam Anthony Date: Mon, 8 Dec 2025 18:30:55 -0500 Subject: report: start introduction --- doc/report/report.tex | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) (limited to 'doc/report') diff --git a/doc/report/report.tex b/doc/report/report.tex index 630fa73..5d561b4 100644 --- a/doc/report/report.tex +++ b/doc/report/report.tex @@ -30,11 +30,33 @@ \end{abstract} \tableofcontents -\newpage \section{Introduction} +Combustion engines, such as those used to power passenger cars, require precise control over their operation in order to run efficiently and reliably. +Since the early 1970s, car engines have been electronically controlled by an EMS (engine management system) \cite{JapanSemi}. +An EMS is an embedded system consisting of an ECU (electronic control unit), sensors, and actuators. +The actuators include fuel injectors and spark plugs. +The sensors measure things such as crankshaft angle, intake manifold pressure, coolant temperature, and so on. +The ECU features a microcontroller that uses feedback from these sensor data to operate the actuators, thus allowing the engine to run. + +Sensor data are sent not only to the ECU, but also to a display system mounted in the cabin so that the driver may monitor the engine's health. +The display system is typically a set of gauges showing, for instance, engine speed, oil pressure, oil pressure, and coolant temperature, among other things. + +The sensor data are transported about the car via a network; CAN (controller area network) \cite{can20b} is ubiquitous. +Introduced by Bosch in the early 1990s and standardized by ISO 11898 \cite{CanHistory}, all cars sold in the United States are required to be equiped with a CAN bus \cite{CFR40.86.1806-05}. + +The display system in the cabin must convey sensor data to the driver. +Each datum represents the instantaneous value of a continuous quantity---speed, temperature, pressure, etc. +These data are visually encoded by the display system and shown to the driver. +Each datum is most effectively encoded as a graduated radial analog scale with the instantaneous value marked on said scale \cite{Panchal2025}. +The graduated scale takes advantage of vernier acuity: our ability to discern slight misalignment between line segments \cite{Strasburger2018}, while the radial marker leverages the hypercolumnar acuity of vision: our ability to detect minute changes in angle of a line segment \cite{Hubel1962}. +Put simply, an analog needle gauge is the best way to display information to the driver. +It is the reason why even modern digital display systems are often just skeuomorphs of analog gauges \cite{LifeRacingDisplays}. + + + TODO -- cgit v1.2.3