how we can help you drive up efficiency

The car is changing. Technology advances and innovative automotive electronic systems are driving up overall vehicle efficiency in both internal combustion and hybrid vehicles. However it is not just improvements in individual systems and components that are helping reduce fuel consumption, CO2 emissions and costs. Many of the real breakthroughs in vehicle efficiency are being achieved when the car is viewed as a complete, smart set of sub-systems.

Seeing how the power train works and communicates with other chassis, body electronics and infotainment systems, has opened the door to significant efficiency improvements. From replacing bulky, heavy mechanics and hydraulics to introducing intelligent start-stop and eco-telematics systems, efficiency gains can be made throughout the car. Enabling these innovative breakthroughs are the precise sensors, robust actuators and smart networking ICs from NXP.

But it doesn't stop there. As the car evolves from the internal combustion engine through micro- and mild-hybrids to full electrical vehicles, the only differences in the driving experience for drivers and passengers should be positive. And as an innovative leader in High Performance Mixed Signal solutions, our semiconductors are helping this happen.

Cut consumption by powering down body networks

Modern cars can feature up to 70 control units that consume power even if they are not needed. Listening to messages on the network and waiting for a request of activation might consume up to 2 W per unit. Existing sleep and standby modes of network components can help minimize power consumption by deactivating the unit, but only if all messaging on the network is completely stopped.

Partial networking is a new function that allows sleep and standby modes to be used while still being able to transfer messages across the network. This allows unused units to be deactivated when not in use (e.g. trailer module while driving without trailer; seat module while not adjusting the seat; etc.) and activated by means of a dedicated wake-up message. Deactivating a unit is achieved by setting the microcontroller into stop-mode but keeping it supplied for fast re-activation, so drivers do not experience decreased performance when pushing a button.

Although partial networking can be seen as a completely new automotive networking technology, NXP has offered products enabling this innovative technology for nearly a decade. With the automotive industry focusing more closely on energy saving features, partial networking is currently being evaluated in actual networks under varying conditions such as different bus load or signal quality. NXP supports these efforts with products like the UJA106x family or specially built prototypes based on devices that are in mass production.

Matching performance to the road ahead

More efficient propulsion systems, lighter mechanics, and aerodynamically optimized car shapes help reduce the consumption of new cars. There is another approach which can significantly influence fuel consumption and CO2 emission. By modifying conscious and anticipatory driving patterns brings a significant potential for saving - just look at the trend of hypermiling.

Sophisticated telematics solutions can support the driver by collecting and pre-processing information about the car, route and traffic situation. This can be achieved by linking sensors, navigation data, motor and power train ECUs together with external and infrastructure information.

With NXP's portfolio of transceivers, sensors and PowerMOS, much of this is already in place with advanced transmission, stop-start and EPS systems. Providing the integral link is NXP's Automotive telematics onboard unit platform (ATOP). A highly integrated cost efficient telematics system, it has been optimized on cost, form-factor, in-car connectivity and power-consumption, with completely integrated standard software and GSM pre-certification. Multi-service capable, it can serve applications in parallel like eCall, intelligent traffic management and Car-2-Infrastructure communication.

In the most complex stage such an Eco-Telematics system supports the driver with control applications actively to operate and manage the car and driving patterns. Depending on route profile and road conditions the control appliance will optimize the driving route, acceleration and deceleration for the lowest consumption, dynamically managing shift points and motor operating range. Charging and recuperation cycles for hybrid cars could also be managed by such systems.

Give steering a power boost when its needed

Electric power assisted steering (EPS / EPAS) consumes less fuel than conventional hydraulic power steering systems. Using an electric motor results in significant weight and space savings compared with hydraulic belt driven pump systems that need to provide a constant hydraulic pressure. EPS systems also provide the required level of power assistance when needed, based on vehicle speed and how quickly the steering wheel is turned.

With accurate steering column torque information, the right power assistance can be given precisely and smoothly through efficient electrical commutation of the servomotor. Aiming at contactless and wear-free operation, our portfolio of magneto-resistive sensors delivers the accuracy needed to measure torque, rotor position as well as steering column angle for EPS / ABS functions.

With a family of FlexRay transceivers NXP ensures robust and instant communications between EPS and ABS systems allowing the level of power assistance to be optimized for speed. And while small and medium cars generate sufficient power to drive EPS systems, more efficient PowerMOS devices extend the range of cars that can enjoy the benefits of EPS.

A next step in the evolution of steering systems will be steer-by-wire, leading to further savings in weight, space and power. As part of the FlexRay Consortium, NXP is helping develop the technology to make this a reality.

Optimize start-stop systems for efficiency

Start-stop systems automatically switch off the engine every time the vehicle is stood still (e.g. at a light or in a queue) and restart it instantly when needed. It is particularly efficient in urban traffic where this type of cycle is repetitive and systems using an Integrated Starter Alternator (ISA) can cut fuel consumption dramatically in heavy traffic conditions.

Instant communication between various systems and having them operate seamlessly is key for Start-Stop systems. Before switching the engine off, the Engine Control Unit needs to confirm that vehicle is halted and the gear has been disengaged. When the gear or the clutch is inserted and accelerator pedal pressed, the engine should immediately re-start.

NXP's automotive portfolio, from our sensors and networking products to audio amplifiers and immobilizers, has a significant role to play in start-stop systems. Amongst the more obvious requirements our portfolio ensures all communications are managed efficiently while accurately measuring speed and pedal position. Our low RDS(on) MOSFETs in KGD (Known Good Die) can handle the very high currents of the ISA inverter at the same time reducing energy waste.

But start-stop systems also have an impact on other systems, including car radio / infotainment and immobilization systems. As the engine restarts, board voltages can momentarily drop to 6 V. Audio amplifiers such as NXP's TDF853x / TDF859x Class D families and TDF854x Class AB series ensure audio quality is maintained during voltage drops, while with our keyless go ICs the car only starts when an active key is in the car.

With NXP's MOSFETs in KGD for active excitation, brake blending can easily be introduced further improving overall efficiency. This also enables the evolution from start-stop to micro and mild-hybrids and helps pave the way to full electric vehicles.

Get more from your transmission with optimized shifting

Choosing the right gear is fast becoming a very sophisticated design issue. Advanced transmission solutions enable increased comfort and fuel economy, and lower emissions. Electronically actuated and synchronized clutch and gearboxes can complete the clutch and gear shift operations more quickly and precisely, optimizing combustion and transmission.

Manual transmission used to be more efficient and offer greater driver feeling than automatic transmissions. But fully automatic or semi-automatic systems are increasingly becoming the preferred choice. Using real-time information from the engine and the wheels, as well as precise speed information in the transmission itself, enables the right gear to be selected and implemented smoothly and efficiently.

Faster shift times can be achieved in dual independent dry clutches but it requires accurate speed, position and torque sensors in addition to gear selection sensors. As contactless and wear-free sensors with high accuracy and wide air-gap capabilites, NXP's magnetoresistive sensors are ideal for this type of harsh environment application. Improvements in transmission also require fast and reliable communication between the engine, wheels and gearbox to maximize efficiency, exactly what is offered by NXP's FlexRay transceivers.