ZF technology showcase – writing the future with TRW

It’s been a big year for ZF Friedrichshafen AG in 2015 – the German transportation component manufacturer celebrated its 100th anniversary in September, a century to the day of its formation as a supplier of gears for airship manufacturers, most notably Zeppelin.

It may have shifted its focus to the automotive industry in 1918 to conform to terms outlined in the aftermath of World War I, but its name (ZF stands for Zahnradfabrik, or gear factory in English) still defines it to this day. Even after diversifying into other components such as steering and suspension systems, the company’s transmissions – in particular its brilliant automatics – remain ZF’s most famous exports.

But times are a-changin’, and so is ZF – it has recently completed its acquisition into American rival TRW Automotive to leverage on the latter’s safety (reflected in the new Active & Passive Safety Technology branding) and braking expertise. It seems the conglomerate is extending its considerable reach to all corners of the industry, and with the combined might of both companies in one, ZF is already a top three automotive supplier, counting sales exceeding €30 billion and more than 130,000 employees in its wings.

And just six weeks after the ink dried on the merger agreement, ZF and TRW have impressively managed to work together to showcase what they envision the future to be, at the ZF Global Press Event 2015 at an ADAC test track in Linthe – approximately half an hour from Potsdam – at the height of the German summer. So, how does that future drive? Read on to find out.

Mobility megatrends, both today and in the future, are undoubtedly the driving force behind ZF’s merger with TRW. The industry is moving towards a safer tomorrow, and partial autonomous driving technology – including Autonomous Emergency Braking (AEB) – are steadily trickling down to such an extent that even cheap city cars have them as options.

On the more far-reaching side of things, fully autonomous cars appear very much on the horizon – apart from the barrage of self-driving cars showcased every year, major manufacturers such as Volvo, Honda, Toyota and Nissan have all promised to roll out production examples by the end of the year. Clearly, these active safety technologies will be very big business in the coming years, so it’s not hard to see ZF’s interest in them.

But the acquisition of TRW presented its own set of problems, as that triggered concerns of antitrust practices in a number of markets worldwide. Both ZF and TRW are major players in the production of steering systems, the former as part of a 50:50 joint venture with Bosch – called ZF Lenksysteme – which supplies systems to many manufacturers, including Proton and Perodua in Malaysia.

Along with a number of other divestitures from both ZF and TRW to comply with these antitrust laws, the former sold its stake in ZF Lenksysteme back to Bosch, which renamed the division to Robert Bosch Automotive Steering. ZF reps assured us that Bosch will continue to honour existing relationships and supply agreements, including the ones in Malaysia.

With ZF now in full control of both its steering and braking businesses, it has the potential to streamline the development of autonomous drive and active safety systems, and provide compelling, holistic solutions to carmakers, just as the world is moving towards these trends.

Such potential was revealed this year with the new G11 BMW 7 Series, which debuted the TRW-developed Remote Parking feature – this allows users to slot the car into and back out of a tight parking space (such as a garage) whilst outside the car, using the optional touchscreen Display Key. Unfortunately, the car wasn’t at Potsdam for us to test the tech, but we do get to try something a lot more impressive…

But first, something a little more plebeian – the first pavilion we are shuttled to highlights more traditional steering, chassis and braking components. Nothing traditional about the technology, however; items such as rear-wheel steering and a revolutionary new way of controlling the entire braking system will ensure that the internals of the car of the future will be completely unrecognisable from those from today, even though they are, broadly speaking, identical to drive to what we have now.

Four-wheel steering
One of the more interesting cars to sample here is an F10 BMW 5 Series, fitted with rear-wheel steering (Integral Active Steering in BMW-speak). First introduced as an option on the F01 7 Series, the system uses independent electric motors to nudge the toe link of each rear wheel in and out depending on the speed and steering angle.

The motors are controlled and coordinated by an ECU that gives the system the speed, subtlety and predictability that eluded mechanical systems of yore. At low speeds, the rear wheels turn in the opposite direction of the front wheels to increase agility; bring speeds higher and they all steer in the same direction for better high-speed stability.

Here, however, all the computer-controlled gubbins have been removed; instead, there’s a second steering wheel on the passenger side that manipulates the angle of the rear wheels. The experience of “driving” this particular F10 is surreal – the rear wheels may only turn up to three degrees, but the changes the system brings to the driving experience are profound.

Swinging through a series of twisties, turning the rear wheels in the opposite direction to the front wheels produces changes in direction that seems impossible on the near-five-metre behemoth. Coming across a wide stretch of tarmac, I discover that I could actually steer the car with just the rear wheels.

We then come across a slalom, where the engineer in the driver’s seat showed how rear-wheel steering is able to either increase or reduce the effort required to steer around the cones, depending on whether the rear wheels were steering together or in the opposite direction to the front wheels. Turning the car with all wheels steering in concert is a particular struggle.

Integrated Brake Control
Next, we jump into another F10, this time an ActiveHybrid 5 fitted with ZF TRW’s new Integrated Brake Control. The system controls the entire braking system, replacing the vacuum servo, electronic stability control system and the cables, sensors, switches and electronic controllers that come with them. Driven by a quick-acting brushless electric motor, the precision ball screw actuator is claimed to provide superior braking performance and stability control capabilities when compared to traditional systems.

With the use of electronic throttle control now widespread and steer-by-wire making its production debut on the Infiniti Q50, braking is now the last remaining car control input still mostly controlled mechanically. Although IBC retains the use of a hydraulic system to operate the brakes themselves, the immediate response and sensitivity of electronic control is said to be ideal for use in Autonomous Emergency Braking (AEB) as well as partial and fully-autonomous driving.

There are other benefits, too – IBC enables the implementation of full regenerative braking on hybrid and fully-electric vehicles, as well as fully blending the switch from regenerative to conventional friction braking. It’s lighter as well, with ZF TRW claiming that the single unit is around 25-30% lighter than a typical component set. Small wonder, then, that IBC is set to see its first mass-production use as early as 2018.

It has to be said, however, that despite IBC simulating the brake pedal feel of a traditional servo-assisted system, initial driving reveals a slightly unnatural sensation when pushing the pedal, having neither quite the progressiveness nor the weight of a regular pedal. You get used to it after a while, but on first blush it seems that engineers still have some ways to go before banishing the rather disconcerting feel.

But at least there’s no denying the stopping prowess of IBC. As I accelerate at full throttle down a long straight, the engineer sitting beside me unleashes the full braking force available at the ActiveHybrid 5’s disposal. Rapid deceleration comes swiftly and suddenly – apparently the system is able to deliver a deceleration of up to 1 g in under 150 milliseconds – producing a violent tug at my internal organs as the car comes to a shuddering halt. It takes me the rest of the drive back to the station just to get my breath back.

Advanced Urban Vehicle
The star of the show – and ZF’s centenary celebrations – is a little electric runabout based on the old Suzuki Splash. Dubbed the Advanced Urban Vehicle, its unassuming late-2000s appearance hides a number of, um, advanced technologies designed to make driving and parking in the city an absolute cinch.

At the heart of the AUV is what ZF is calling an electric Twist Beam (eTB). Developed specifically for use in small vehicles and city cars, the system incorporates a compact drive unit, integrating an electric motor and transmission, on either side of the torsion beam. Each motor is capable of 40 kW (54 hp) and can be calibrated to provide torque vectoring across the rear wheels.

Together with the lack of an engine in front, this allows the engineers to redesign the front suspension and axle to provide as much as 75 degrees of steering lock, compared to around 40 degrees on a regular vehicle. As such, the turning circle diameter shrinks to under seven metres, enabling the AUV to trace a 180-degree U-turn manoeuvre within a standard two-lane road, with the aforementioned torque vectoring function making it possible for the car to turn with such extreme wheel deflections without understeering.

Such a small turning circle not only makes the AUV extremely manoeuvrable around town, but it also makes the car ridiculously easy to park, even in very tight spaces. To make the job even easier, the car’s Smart Parking Assist enables it to park itself completely autonomously in both parallel and perpendicular spaces, using 12 ultrasound sensors and two infrared sensors around the car to sense the surroundings.

The whole process can either be activated using the touchscreen display inside the vehicle, or outside the vehicle via an app on a smartphone, tablet or smartwatch – the car will even drive itself at walking pace to find a suitable spot. You can even control the car using the apps, enabling you to literally walk the car to where you want it to go.

Sitting in the AUV, the experience feels absolutely surreal – the driver cranks the steering wheel, first to the typical lock position of a regular car, then way, way past it. We watch in awe as the car starts to turn literally on a dime, spinning around as if sitting on a turntable. The torque vectoring technology is plain to see, too; from the outside, the inside rear wheel crawls almost to a standstill to facilitate the very tight turn.

We also get a try at another new technology, called PreVision Cloud Assist – when you’re driving, the system monitors the route you take, records the vehicle position, speed and longitudinal and lateral acceleration, and sends that data into the cloud. Run the same route again and the car will calculate the most efficient way around each corner, based on both the data retrieved from the cloud as well as live data coming in, and will reduce the torque from the motors to slow down to the correct speed before entering the bend.

As such, the car will not actually need to use any mechanical braking to negotiate the bend. You won’t have to touch any of the pedals, only steer – ZF claims the system not only protects the vehicle’s battery and braking system, but also ensures better safety, especially around blind corners. Going around a tight, technical course, the AUV zipped along at a fast clip, seemingly faster than my steering inputs could keep up – it’s set up for absolute efficiency, after all – but the car always made it round a corner without drama.

Highway Driving Assist
More semi-autonomous features to be discovered here – the next is Highway Driving Assist that makes highway driving easier and more comfortable. The test vehicle, an Opel Insignia Tourer, is fitted with an S-Cam 3 camera that detects lane markings, along with a forward-facing AC1000 radar system; together, they provide active cruise control as well as lane centring assist functions. The latter, as the name suggests, keeps the car in the centre of the lane without the driver touching the steering wheel.

But so what – even a Ford Ranger has similar features nowadays, doesn’t it? Well, whilst the driver of the Opel is taking us on a typical cruise along an autobahn, she shows us something astounding – a fully-autonomous lane change. With a tug on the indicator stalk, the car glides into the fast lane to overtake a bunch of slow-moving traffic, all with her hands off the steering wheel.

This particular car has had its rear-facing sensors removed, so it wouldn’t be able to detect, for example, a fast-moving car coming past – but the technology is there for it to do just that.

These features are moving towards production vehicles at a steady rate. In fact, Tesla already has the functionality – which it calls Autopilot – in its Model S sedan, albeit still in beta phase at the moment. As for more mainstream manufacturers, Audi is said to be implementing the technology in its next A8, slated to make its debut in 2017.

Emergency Steering Assist
This one is a little bit more thrilling – we were shepherded into another Insignia Tourer, this time fitted with Emergency Steering Assist. Similar to the automatic collision avoidance system showcased by Opel last month, the active safety system is able to sense an oncoming obstacle, warn the driver and, should there be no evasive reaction taken, automatically take over the steering and brakes to avoid said obstacle.

Similar to Highway Driving Assist, ESA uses a camera and radar to sense the obstacle, and the system calculates an emergency trajectory the car has to follow out of the predicament. The belt-driven electric power steering provides the required amount of force, delivering the violent steering manoeuvre needed to guide the car out of harm’s way.

Experiencing the manoeuvre in real-life is frankly terrifying – the system waits for the last possible moment before automatically braking hard, then yanking the steering wheel left and right; the car swings around the fake Opel Meriva standing in as the obstacle with millimetric precision. ZF TRW says the system can also assist the driver who initiates the evasive manoeuvre by themselves – in this situation EPS system will deliver extra steering force to help them clear the obstacle.

Composite leaf spring rear axle for multi-link suspension
ZF is also showcasing a new multi-link rear suspension designed specifically for smaller cars, utilising transverse leaf springs for a more compact and lightweight design. Of course, other cars have used a similar set up before, most notably with several generations of the Chevrolet Corvette, and more recently in the new Volvo XC90 for improved third-row seating and luggage space at the rear.

However, the main difference of this particular system is that the composite leaf spring, by itself, makes up one of the three links that locate the rear wheels. Since the leaf spring replaces not only conventional coil springs and anti-roll bar but also one of the control arms, it promises to be even simpler (i.e. cheaper), lighter and more space-saving than traditional transverse leaf spring set ups.

The spring is made from glass fibre-reinforced plastic (GRP), the strength of which, ZF says, can outperform that of high-strength steel springs if designed properly. The material can also be designed to be very elastic, which, for a spring, is a very good thing. A drive in a prototype Mk7 Volkswagen Golf fitted with the system exhibited no major surprises in terms of ride and handling. The car feels precise, stable and neutral through the bends, all while retaining a supple ride – well-known characteristics on the latest Golf.

8HP eight-speed automatic transmission
The trademark ZF 8HP eight-speed automatic transmission needs no introduction – fitted on the majority of rear-wheel drive BMW models, plus a host of other cars from the likes of Audi, Jaguar and Land Rover, the gearbox is famous for its fast, buttery-smooth shifts, quick responses and impressive frugality since it was introduced in 2009.

Of course, with the competition quickly catching up in terms of ratios and shift quality, ZF can’t afford to stand still, so it has introduced a new, updated second-generation ‘box that promises to be more efficient than before. The biggest change is a higher ratio spread from 7.0 to 7.8, thanks to optimised gearsets – this alone enables engine speeds to be reduced by 50 rpm across the board, improving fuel economy by almost 1%.

Other improvements include new multidisk separation for reduced internal losses, a clutch that decouples the transmission under deceleration and braking, a new oil pump with reduced pressure (therefore using less energy overall) and a new torque converter that allows for a faster hydrodynamic transmission of power (enabling an earlier closing of the lock-up clutch).

Also, the gearbox’s so-called “coasting” function now operates at speeds of up to 160 km/h, and its auto start/stop function shuts the engine down without any discernible delay, down from 1.5 seconds previously. Elsewhere, ZF has also built in the ability to perform multiple downshifts as well, to further improve response. All in all, the new transmission is claimed to be able to cut fuel consumption by as much as 3%.

The second-generation 8HP made its production debut last year in the updated BMW 520d, which also received a new engine in the form of a 190 PS/400 Nm B47D20 2.0 litre turbodiesel; predictably, that’s what we have here to test the transmission. In practice the changes admittedly aren’t all that apparent – although you would probably appreciate the savings in the long run – but the new coasting function makes itself clear, dropping revs to idle with the foot off the throttle.

We also tried out other applications of the first-generation 8HP, including a Maserati Ghibli S Q4 – where the transmission’s quicker, sportier side is teamed perfectly with the rorty 410 PS 3.0 litre biturbo V6 – along with, oddly, a more hundrum Iveco Daily van. In both vehicles, the gearbox’s pleasantly seamless nature still shines through, as it has always done.

9HP nine-speed automatic transmission
Relatively new to ZF’s gearbox range is the 9HP nine-speed automatic transmission for transverse-mounted front- and all-wheel drive applications (rather than mounted longitudinally, as is the case with the 8HP), an upgrade from the previous six-speeder. The compact unit, which made its market debut in 2013 on the Range Rover Evoque, measures just six millimetres longer than its predecessor and weighs 7.5 kg less, despite the three extra gear ratios.

The tiny size is possible thanks to it having two out of the four planetary gearsets being nested, along with the inclusion of a new compact hydraulic vane-type pump as well as twin computer-controlled dog clutches (rather than bulky, inefficient conventional clutch packs). A torque converter is used as the standard starting element, with a multi-level torsion damper system minimising hydraulic losses. Quick bridging of the torque converter lock-up clutch is also facilitated at low speeds.

Boasting an extremely wide ratio spread of 9.84, the 9HP offers a reduction in fuel consumption of up to 16% at a constant speed of 120 km/h, compared to the old six-speed ‘box. Testing it out on a Jeep Renegade, we find the new transmission to be slightly more hesitant to downshift and a little less responsive compared to the 8HP – at least in this application. Nevertheless it’s still as smooth an experience as any; the transmission’s seamlessness was almost CVT-like as it piled on the ratios.

In summary, the 360-degree taster all things ZF and TRW has been a real eye-opener. The German automotive components giant appears to have been shrewd in tapping into TRW’s strengths as a safety leader, and it seems the marriage between the two was a match made in heaven, given how quickly their synergies are already bearing fruit.

The integration of each other’s services has enabled ZF TRW to deliver technical solutions that, on this evidence, are intriguing and refreshing, from self-parking city cars that rotate effortlessly, to new autonomous driving and collision avoidance systems – envisioning new heights in safety and convenience that really aren’t too far away from reality. We can’t wait to see what’s next.

Looking to sell your car? Sell it with Carro.