Saturday 17 November 2018

Behind the wheel of the 2019 Mercedes-Benz Actros

Missing mirrors are the main distinguishing feature of the 2019 Mercedes-Benz Actros, but there’s a lot more going on under the skin, as Richard Simpson discovers

Mercedes-Benz has never been afraid to break new technical ground with its heavy trucks. Its SK Powerliner was the first production truck to feature an automated manual transmission (the EPS) as standard in 1989, and the first iteration of the Actros, introduced in 1996, was a pioneer of electronically-actuated braking. Both features are now standard across the industry.

And now Mercedes has done it again: the 2019 Actros will be the first production truck in the world to offer Level Two autonomous driving, as defined by the Society of Automotive Engineers. The truck is capable of driving itself on some roads, but still requires driver input at all times.

It also features an aircraft-style ‘glass cockpit’, with all information being displayed to the driver on screens, including the replacement of conventional rear-view mirrors with cameras and monitors, and many of the truck’s functions being controllable via a smartphone-style screen complete with downloadable apps.

There is no point in introducing technical changes like this for their own sake. Mercedes is claiming fuel savings of up to five per cent over equivalent predecessor models, plus considerable advances in safety and driver performance. Despite this, there are few mechanical changes to the vehicle, either in terms of driveline or styling: it’s all about the electronics and processing power.

The heart of the new truck is the Active Drive Assist system: this can brake, accelerate and steer the vehicle without the intervention of the driver, and it functions over the full range of speeds to offer semi-autonomous driving, although the involvement of a human driver is still a legal requirement.

Embodied within Active Drive Assist is a new version of Predictive Powertrain Control: the terrain-following road-reading system that already controlled gear selection and throttle position to ensure the correct ratio and engine power was always engaged on the previous model.

The latest version can now handle trucks transporting loads of up to 120 tonnes, and can be used with non-standard drivelines including all-wheel drive, and the optional Voith TurboRetarder. This now uses new truck-specific TomTom mapping which covers most rural main roads as well as major trunk routes, and its use enables the full five per cent fuel saving to be made on this type of road.

Savings of three per cent are possible on motorways, and improved aerodynamics play the most significant part here, together with a new, higher, final-drive ratio for trucks with the OM 471 engine. While new cab-side air deflectors play a part, a full half of the saving comes from the replacement of conventional rear-view mirrors with cameras mounted high above the doors in aerodynamic winglets.

Developed by Mercedes in a joint project with Bosch, the MirrorCam system also removes the large blindspots associated with conventional rear-view mirrors as the screen monitors are mounted inside the cab’s A-pillars. Conventional close-proximity mirrors to the front and near-side are retained.

A couple of brief drives in the new Actros on a training circuit near Berlin revealed that the MirrorCam system worked exceptionally well in the bright, sunny conditions of the day, with a great ability to ‘see’ into shadow. The view in the monitor is split between a wide-angle and long-range image, creating a similar picture to that given by conventional mirrors. But when the truck is turning, the cameras pan automatically to keep the trailer wheels in the picture: with conventional mirrors you just get a close-up of the trailer side or bulkhead.

Engage reverse, and the proportion of the screen showing the wide-angle image gets larger. Another clever feature is a yellow line on the screen which can be positioned to indicate where the rear of the trailer is, with an additional two yellow lines further behind as an aid to overtaking.

The new Actros’ self-steering activity is courtesy of another Bosch development: ServoTwin. A front-facing camera picks up road markings such as white lines on either side of the road, and the correct inputs to keep the truck on track are calculated before being fed to the electrohydraulic steering gear.

ServoTwin also senses driver input, with progressive warnings being sounded if the truck is being left to its own devices: after 60 seconds the Active Drive Assist system will relinquish control of the vehicle, this being a legal requirement rather than a technical one.

At low speed, ServoTwin reduces steering effort to almost nothing. With the aid of the MirrorCam system, those tricky moments backing onto bays are reduced to a minimum.

New Actros also breaks new ground with the Active Brake Assist 5 system, which is capable of detecting a child running out into the road from behind a car and applying the brakes automatically. The system uses a combination of the Active Drive Assist’s camera and its own radar to detect such hazards at speeds of up to 50 km/h.

Inside the truck, conventional dashboard instruments and switches have been consigned to the dustbin of history, and replaced with a glass Multimedia Cockpit. Information is imparted to the driver via two screens.

One is viewed through the steering wheel, and replicates the standard speedo and revcounter layout that you’d find on a normal instrument panel. On models fitted with the full Multimedia interactive package, the driver can also change the display to show a central speedo with vehicle-related information such as brake system pressures and fuel and AdBlue levels on the left, and driver-related content including hours, phone book and audio settings to the right.

When Active Drive Assist or Proximity Control Assist systems are selected, the screen changes again with a display suitable for assisted driving.

The second screen contains most of the switches that would be found on a truck dashboard, only displayed as icons in a form that will be instantly familiar to smartphone users. A series of physical switches along the bottom edge of the screen allows the driver to go through various menus without having to take his eyes off the road to scroll through the options available.

Reassuringly, the physical switches controlling functions such as gear selection on the PowerShift 3 transmission, lights, indicators etc are all carried over from the previous model and can be found by touch on or around the steering wheel.

The full interactive cockpit allows simultaneous connection of two mobile phones, and the downloading of a widening choice of apps, such as Merc’s own Fleetboard telematics system.

Apart from the absence of mirrors, the striking good looks of the predecessor model remain mostly unchanged, with just minor tweaks to the lighting. But while the handsome appearance of the Euro 6 Actros remains unchallenged by anything that has been launched since, some drivers appear disappointed by the reality of living with the truck. Besides an interior that lacks the wow factor of competition’s flagships, complaints centre around a harsh ride quality, lethargic gear engagement at a standstill from the PowerShift 3 transmission and a poor-quality bunk.

Mercedes has addressed some of these issues with the new truck.

The once optional single-leaf front suspension that gave such a jarring ride is no more, and the truck is now comfortable and sure-footed with enough feedback to let the driver know what’s going on underneath.

A new Scania-esque automated parking brake means the truck no longer hesitates before pulling away. This control can additionally be used to apply the trailer brakes only for tricky conditions such as when the truck is descending a slippery hill. It’s a feature that will rarely be used, but has the potential to save lives when it is needed.

The issue of the bunk remains unresolved. Even the roomy GigaSpace cab comes with insubstantial pieces of foam as standard. Mercedes argues that many fleet trucks have sleeper cabs that are never slept in, and therefore the standard bunk is adequate. But this argument surely falls on its face in the flagship GigaSpace, the purpose of which is to provide a roomy and comfortable environment for drivers who are out all week. No one buys a million-pound house, then sleeps on a camp bed.

Mercedes says there is a more comfortable memory foam mattress available at modest cost, either as a line-fit option or a replacement part, but this is not good enough in a market where most of the top competitors provide a proper sprung mattress as a standard fitment in their flagship trucks. The cost of a real mattress would be a very low percentage of the price of this otherwise impressive truck, while a good night’s sleep can literally be a lifesaver.

The order book for the new Actros opened at IAA, with first deliveries to the UK scheduled for April 2019.

Mercedes-Benz UK is also planning a large ride-and-drive event early next year so potential customers can experience all the new truck’s features. As a taste of the future of truck driving, it promises to be an event not to be missed.

What’s happened to the Antos?
Mercedes has chosen the introduction of the new Actros to retire the Antos name that it has used for its distribution trucks since the introduction of Euro 6. The trucks are still available, but they will bear Actros nameplates. Mercedes said that, particularly in the markets outside Europe where many used trucks end their days, the Antos name had never achieved the recognition that Actros had.

What about Arocs?
Arocs continues as the Mercedes construction and off-highway model range. Most of the new features standard on Actros can also be specified on the Arocs; however, standard Arocs models will retain a conventional dashboard and mirrors, with the new equipment available as options. Similarly, some of the new Actros’ features can be deleted if the customer doesn’t want them.

What if I don’t want the MirrorCam?
Every new Actros can be retrofitted with conventional mirrors: the mounts are ready for mirrors to be bolted on.

Will MirrorCam work in adverse conditions?
Mercedes says that it trialled camera systems from three suppliers before deciding to work with Bosch. The relatively low-resolution cameras are very robust and capable of working in a wide range of temperatures, and the coated lenses resist rain and dirt. The mounting arms will swing if subject to front or rear impacts, and they are mounted higher than the previous truck’s mirrors.

Won’t these innovations be prohibitively expensive?
Mercedes says that the 1.5 per cent reduction in fuel consumption should pay for the extra cost of the MirrorCam system in 100,000 km – or about a year in a long-distance truck.

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