Think about cars from the past. Actuators drove almost every mechanical and hydraulic system. Nowadays, there's an alphabet soup of electronic components and systems. Electronic sensors augment or have even replaced the various mechanical systems. Some high-end cars feature as many as 70 electronic-control units (ECUs). The average car has up to 35 sensors, while a high-end model has up to 60. The typical car also carries about a half-dozen airbags. What it all means is that today's cars are much more sophisticated, safer, and easier to drive. They're also much smarter than their predecessors, and they continue to acquire greater intelligence.
On the safety side, federally mandated standards will drive the inclusion of these features and others, like tire-pressure monitoring, in the next few years. According to market research firm IC Insights, the worldwide automotive IC electronics market will grow from nearly $13 billion today to nearly $20 billion by 2009. Market research data from iSuppli, Philips, and Strategy Analytics show growth in airbag, driver warning, security, and body and chassis electronics (Fig. 1).
More airbags that also are smarter are being deployed in vehicles. Hightech side curtain bags that provide head and neck protection for front-and rear-seat passengers are common in many cars. Front-impact airbags now include sensors that identify children and very small adults: The airbag will deploy with less force to minimize injuries to those occupants.
Many examples of "smart" cars are already out there. The Toyota 2006 Lexus LS460's Intelligent Parking Assist system, which processes images from rear and front cameras, uses the results to control electronic power steering and a "drive by wire" electronic throttle. The system parks the car with the touch of a button and with just a little braking on the driver's part.
Also, the LS460's Vehicle Dynamic Integrated Management system mines data from a variety of sensors to anticipate skidding. It uses this data, in addition to any inputs from the driver, to help the driver recover control of the car. It regains control by activating electronically controlled brakes, electronic power steering, anti-lock brakes, vehicle stability control, braking-assist, electronic brake-force distribution, and engine-torque features.
If that's not enough, the climate control system adjusts itself based on the ambient temperature, as well as on the body heat emanating from the car's occupants. With increasing car intelligence, though, consumers may begin to ask how much intelligence is necessary. Even the cars of the future should maintain some kind of driver control.
Radar And Cameras Emphasize Driving
After years of work to reduce deaths and injuries from car accidents through the use of seatbelts and airbags, automakers and their suppliers are shifting to technologies that prevent accidents. For instance, clusters of LEDs on tail lamps and rear-window brake lights, as well as LED headlights, provide brighter illumination levels and last longer than regular light bulbs.
On cars like the Mercedes-Benz S-class, 24/77-GHz radar-guided systems play a big role in improving safety. Brake Assist, Parking Assist, Pre-Safe, Distronic Plus, and Adaptive Brake features use seven radar sensors (five in the front bumper and two in the back bumper) to greatly enhance safety levels (Fig. 2).
With these features, the car can sense an impending crash, enabling the driver to take evasive action. The radar system allows for automatic brake application. Plus, it will close the sunroof and tighten the seatbelts if a potential collision is detected.
Speaking of radar, today's radar-based, adaptive cruise-control systems are flourishing. They can be found in many Mercedes-Benz and Toyota models. The Volkswagen Passat, as well BMW's Series-3 cars, also feature such radar.
To improve traffic safety, Nissan developed its Distance Control Assist System to help drivers control the distance between themselves and the vehicle in front of them. The system determines the following distance of the driver, as well as the relative speed of both cars, using a radar sensor in the front bumper (Fig. 3).
If the driver releases the accelerator pedal or isn't pressing the accelerator pedal, the system automatically applies the brakes. If the system determines that braking is required, an indicator appears on the instrument panel and a buzzer sounds. The accelerator pedal then automatically moves upward to help the driver switch to the brakes.