Beyond The Programmable Car

Automotive Industries, August, 1999 by Norman Mayersohn

Customizing a vehicle's electronic functions will be as simple as downloading software from the Internet. But challenges remain.

The dream of a "programmable" car is upon us, and it's as close as the dealer service department's diagnostic console. The capabilities being explored by Volvo, which leads the trend, will give service technicians, and possibly owners, the ability to customize vehicle functions, such as door lock operation or how long the headlights remain on after locking the doors -- and much more.

Last year's introduction of Volvo's P23 large-car platform (the S80 sedan) was a great leap forward by an automaker in its approach to on-board electronics -- and business in general -- in the Internet age. Volvo's strategy is modeled on the personal computing world, in which repairs and accessory installations are handled digitally by software upgrades and reloads, instead of the wrench work and replacement parts traditionally required on automobiles. And these upgrades are distributed on the Internet, through a secure server.

Volvo's advanced electronics system is possible because the S80 features the company's initial use of a sophisticated multiplex electronic system. Like many recent competitors, the system employs an in-car data network to carry messages over a data bus, between controls, sensors, actuators and microprocessor-driven modules. A high-speed section of the network, based on the Bosch-developed Controller Area Network (CAN) architecture, handles functions that demand quick response, such as engine management and traction control. A lower-speed channel links body functions such as light switching, door locks and power windows. The bridge between the two network sections is provided by a central electronic module located at the instrument panel.

Volvo's network system keeps wiring and connectors to a minimum, and enables the use of an electronically-controlled throttle. Messages travel over a twisted pair cable, enabling data, such as vehicle speed, to be shared by whichever systems need it, all without the need for dedicated wiring to deliver the signal to each destination. Traffic on the network cable is managed by a proprietary communications protocol known as Volcano.

The unspoken result of this system is that the relationship between hardware components and software has become more interdependent than ever before. For the S80, just adding a straightforward accessory such as a trailer hitch brings the necessity to install associated software, much the same as adding a DVD drive to your PC would, says Dave McHugh, an engineer at Volvo's Rockleigh, N.J., U.S. headquarters. First you must do the mechanical installation, he explains, then the electronic system must be configured to recognize the new pieces. Only by performing the required 10-minute setup routine -- not so different from adding a new printer and its associated driver software to your PC -- can the hitch installer notify the multiplex system of the added electrical loads of the trailer lights and brakes.

The possibilities are more exciting where the opposite is true -- accessories that are predominantly software, with the car already carrying the hardware components. In markets outside North America, where a cruise control may not be standard equipment, this function could be added to the existing electronic throttle system merely by adding the steering wheel buttons and, of course, software. This is much like a manufacturer adding traction control to an ABS-equipped car, a process simplified by the fact that the wheel-speed sensors and actuators are already in place. A trip computer application fits the same scenario, and the capability could even be extended to a customer who needs to download a GPS map via cellular link for a hastily-scheduled journey.

The Factory Feels The Changes

The manufacturing process is altered under the new business model, too. The various electronic modules distributed throughout the car (there are 18 in an S80) are designed around a Motorola PowerPC chip and installed on the assembly line without any resident software. Those digital instruction sets are loaded at the end of the line according to the car's equipment package, and the software carries a part number as any mechanical component would. This concept enables the use of generic modules in many areas (where only the software would differ between models and equipment levels).

But, of course, it exacts a price. For example, when the overhead module that controls the rear view mirror dimming is replaced in a repair, the car's network must be configured to recognize the new part. It also means that a known "good" module can not be simply bolted into a car for a quick-and-dirty diagnosis because the system will immediately know that an alien is aboard.

The conduit between Volvo and its cars is VADIS (Volvo Aftersales Diagnostic and Information System), which the company developed with Hewlett-Packard. It's a diagnostic station to which dealers are upgrading. The warehouse for all software is in Volvo's Gothenburg, Sweden, headquarters. Software will not be kept "on the shelf" at dealerships. The Volvo database holds all the information about the configuration of the car, what is installed and the possible combinations of compatible software. When a software installation is requested, the digital stream actually comes from dual replicated databases known as VITal (Vehicle Information Transfer and Loading), located in Sweden as well as at the company's Greensboro, N.C., data center. An encryption scheme has been designed to prevent unauthorized "hacking" and assure secure communications, including a coded "seal" for the vehicle's software when assembly is complete.