J Mays set to overhaul Ford's global design originally appeared on Autoblog on Tue, 06 Nov 2007 08:56:00 EST. Please see our terms for use of feeds.

Without a doubt, modern expectations for automotive performance, safety, and comfort are pushing "intelligence" throughout the vehicle, with microcontrollers showing up in a variety of devices that draw together chassis control, driver assistance, and risk management. At the SAE Convergence electronics show, Patrick Leteinturier from Infineon talked about the trends that we might expect for these tiny semiconductor brains.

Moore's Law may dictate growth in computational power of about an order of magnitude (10x) every five years or so, but that's not a reasonable assumption for automotive devices, according to Leteinturier. The reasons are numerous - the harsh automotive environment, customer expectations for longevity (20 years), and the heat generated by increased clock speeds (where as a PC CPU might dissipate 60W, something in the neighborhood of 1W is considered acceptable for automotive microcontrollers). Expect instead something more along a doubling of power every five years, with current engine management devices going from 250 million instruction cycles per second nowadays to about 2 billion/second by 2020. Memory will grow at a similar rate from 2MB to 16MB over the same period of time. Process geometry shrinks will also occur, but also not at the same rate of other electronic devices. The problem here once again is reliability, but another factor is the heavy use of analog circuits in the automotive environment - such devices can't be shrunk in the same manner as digital circuits.

Adding to reliability will be multiple redundant processors, although how these will be packaged is yet to be determined. Techniques such as built-in self test (BIST) and built-in self repair (BISR) will improve memory integrity (ever more important as storage space grows), and new memory storage technologies such as FeRAM might replace Flash in the next decade.

This might not be the most exciting innovation, but it's the sort of steady improvement on the component level that enables technology that's a bit more obvious in its impact on our driving experience.

[Source: Infineon]

SAE Convergence: Improving automotive microcontroller performance originally appeared on Autoblog on Fri, 20 Oct 2006 13:35:00 EST. Please see our terms for use of feeds.

Just a decade ago, engine management was a relatively simple affair. Spark advance and fuel injection quantities were the key parameters, and the determination of both was a relatively simple matter of determining engine speed and load and using those values to index a lookup table. Nowadays, however, technology to improve power, drivability, and fuel consumption - such as variable valve timing and lift, intake tuning, and variable displacement - have greatly complicated the task of calibrating an engine control unit (ECU).

Steve Magner from Ford was at the 2006 SAE Convergence electronics show to speak on this topic and discuss what steps might be taken in the future to improve engine performance and decrease time-to-market. He used the term "high degree of freedom" (HDOF) to describe the typical modern powerplant, and explained that the table-based method ("full factorial mapping") of calibrating ECUs has basically reached its limit. Where as it's desirable to complete the calibration of a new engine in about four months, a HDOF engine currently requires up to 15 months to fully define in the laboratory. In one example, developing just the timing maps for the EPA' s fuel economy test cycle involved 630 states of operation and three months of time on the dyno. Design-of-experiment techniques can be developed to simplify the mapping process, but at the cost of effectiveness - over 25% of a new technology's potential benefit can be lost via incomplete mapping efforts.

Ultimately, the solution proposed by Magner is the direct monitoring of combustion quality, with closed-loop feedback constantly working to optimize the various operation parameters. The two technologies currently being explored are pressure measurement and ion detection schemes, with the former being easier to implement but the latter perhaps being more cost-effective (indeed, Saab has used such a technique for quite some time, albeit with significantly reduced functionality than what is being discussed here). Variations between each cylinder will require that each carry its own sensor, and the required resolution (with data collected for each degree of crankshaft rotation) requiring computational horespower beyond that provided by modern ECUs. Systems based on digital signal processors (DSPs) may be of some use to make sense of all this data and react quickly enough during transients.

[Source: Ford]

SAE Convergence 2006: The difficulty in implementing effective engine management systems originally appeared on Autoblog on Thu, 19 Oct 2006 17:42:00 EST. Please see our terms for use of feeds.

Battery state-of-charge and state-of-health monitoring is normally thought of as technology that's most appropriate for hybrids, but at the SAE Convergence conference this week, BMW made a good case for including it on all motor vehicles. According to ACAD (the German equivalent of AAA), battery failures account for a full 53% of roadside electrical failures, and the situation only gets worse as increased electrical loads and fuel-saving techniques such as idle start/stop come into play.

The idea here is simple - by measuring voltage, current, and temperature, the amount of charge remaining in the battery can be assessed. Based upon this information, additional energy can then be provided by the charging system (via an increase in commanded idle speed), or non-essential loads (such as heated seats) can be momentarily disconnected until overall demand on the charging system decreases. Additionally, degradation of the battery over its usable life can also be monitored, with the potential to warn users of an impending battery failure before someone is forced to walk home.

The trick here is performing the measurements over a wide range of current (a few tens of milliamps during key-off and a draw of several hundred amps during cold-weather cranking) at an economical cost with a device that easily integrates with existing DIN-standard batteries. A rather slick piece of electronics consisting of a shunt, an application-specific integrated circuit (ASIC) based on a ARM7 core, 16-bit analog-to-digital conversion, local area network (LIN) serial communication, and a rugged package was developed by BMW and its suppliers. The device is now proliferating throughout the automaker's lineup, with Audi and Mercedes-Benz now also using the device.

[Source: BMW, Hella]

SAE Convergence 2006: BMW's Intelligent Battery Monitoring originally appeared on Autoblog on Wed, 18 Oct 2006 08:54:00 EST. Please see our terms for use of feeds.