Mercedes-Benz Urban eTruck Makes World Debut
Mercedes-Benz yesterday officially unveiled what many refer to as the truck from the future – the Urban eTruck at a gala event in Hanover, Germany.
Based on a unique concept, the Urban eTruck is powered by an all-electric drive with zero local emissions and is almost silent in operation.
The three-axle rigid Urban eTruck from Mercedes-Benz features a tailor-made concept for highly efficient and clean short-radius distribution.
This puts the Urban eTruck on a par with conventionally engined trucks when it comes to payload and suitability for everyday use. But at the same time, it is far more environmentally friendly, generates zero local emissions and makes barely any noise.
The revolutionary technical concept is part of an integrated system for eTrucks with a made-to-measure telematics service in FleetBoard and power supply using stationary battery storage. Standard-production vehicles of this type would be conceivable from the start of the next decade.
Apart from its range, one of the main technical factors behind the success of the electric drive is its weight balance. Electrically powered commercial vehicles need to perform similarly to a diesel-engined truck in this respect, too. The Urban eTruck need fear no comparison with its IC-engined counterparts.
The additional weight stands at only 1700 kg. As the EU Commission is in favour of increasing the permissible gross vehicle weight of trucks with alternative drives by a maximum of one tonne, this will more or less cancel out the weight disadvantage of the electric drive.
Innovative solution with electric motors adjacent to the wheel hubs
The outstanding features of the Urban eTruck include its drive with electrically powered rear axle and electric motors directly adjacent to the wheel hubs. The axle is based on the ZF AVE 130 and has already proved its worth in its basic version as a low-floor portal axle in buses from Mercedes-Benz. However, the axle has been comprehensively modified for use in the Urban eTruck. For instance, there is a new axle housing, which is significantly raised to give greater ground clearance. The method of axle attachment has also been reconfigured. Another characteristic of the axle used in this particular application is its super single tyres of size 495/45 R 22.5. The maximum permissible axle load of the drive axle is 11.5 t, which is at the usual level.
Electric motors: full torque from very low revs
For the Urban eTruck, the original low-floor axle has been provided with a liquid-cooled high-speed asynchronous three-phase motor on each side. The rated voltage is 400 V, while the maximum output is 2 x 125 kW. The motors have a peak torque of 2 x 500 Nm. In combination with the gearing, the torque at the wheel reaches 11 000 Nm.
A key advantage of electric motors: as the full pulling power is available from the start, the driving dynamics of the Urban eTruck are on a par with a diesel truck with comparable output.
Battery ensures a range of up to 200 km
An important factor in the everyday practicality of an electric drive is the range, which is decided mainly by the battery capacity. In an Urban eTruck it is of a modular configuration, which means that it can cater for a wide range of different requirements. The Urban eTruck comes with a basic battery pack of three modules with a total capacity of 212 kWh. This provides a range of up to 200 km, which is normally enough for a day’s delivery round. The batteries are of the lithium-ion type. They are powerful and durable in equal measure. The batteries are additionally charged during operation by regenerative braking, i.e. by converting the braking energy into electricity. When braking, the Urban eTruck’s electric motors act as generators and charge the batteries. This also reduces the strain on the service brakes.
The well-thought-out design of the Urban eTruck allows different variants of the battery pack. If a lower range is required, the Urban eTruck can be fitted with a compact battery pack with reduced capacity. Where customers require a longer range, the vehicle can be fitted with an additional battery pack. This enables each user to configure the Urban eTruck to suit their own usage profile and achieve the right balance between range, payload and acquisition costs.
The design of the Urban eTruck: both exciting and practical
The styling of the Urban eTruck is as innovative as its electric drive. It embodies the design philosophy of the Mercedes-Benz brand, which focuses on sensual purity – an expression that applies perfectly to the Urban eTruck. The contours of the driver’s cab are sleek and fluid with minimal detailing and no visible joints.
Across the roof, a three-dimensional spoiler connects the cab with the body of the truck. It has a wide vent at the front, which acts as air inlet for the cooling unit concealed behind the spoiler. Just like the roof spoiler, the aerodynamic skirting panels on the side of the cab fit almost flush with the body. The windscreen has been extended downwards. The mirror cams that replace the conventional outside mirrors are another distinctive feature on the truck.
Refrigerated body for short-radius food distribution
Just like the driver’s cab, the body of this three-axle truck is practical for real-life application despite its innovative design. It carries a typical 7.4 m long refrigerated body for use in fresh food distribution to supermarkets and retailers. The side panelling adds to the streamlined feel of the truck and improves its aerodynamics.
Revolutionary display and control technology with a central display
Instead of conventional instruments, the Urban eTruck features a completely new display and control system consisting of two screens. The central 12.3 inch display shows the driver a wide range of information in an easily assimilated form. Instead of the usual data for controlling and monitoring the vehicle, the Urban eTruck gives detailed information about the route.
This is based on a road sign recognition system and on three-dimensional maps with all the essential information about the journey, including the physical features and bends. This information is connected to the drive control of the Urban eTruck.
The middle section of the central display shows the speed on the left-hand side. The central display shows a visual representation of a road and combines a great deal of information, starting with the route. The shape of the road on the display reflects the actual course of the road ahead, including any bends. It also shows the vehicles in front, their distance from the truck and their current speed.
Thanks to the stored map data, the automatic drive control also receives prior warning of braking and acceleration phases and road features such as traffic lights. The Urban eTruck automatically adjusts its speed in line with the road sign recognition system.
The battery capacity is always in the driver’s field of view
On the upper section of the display, a coloured horizontal line shows the driver whether the actual battery capacity corresponds to the planned capacity. Should it fall below a predefined tolerance level, the colour of the display changes from green to red. If this happens, the Urban eTruck can automatically introduce countermeasures and change the driving strategy. If the power reserves fall to such a level that there is a risk the truck won’t reach the next charging station, an additional warning light comes on. Both the driver and the vehicle co-ordinator can intervene in good time and set the engine management system to eco mode, which is geared towards maximising range. The vehicle co-ordinator can also optimise the route schedule.
Tablet provides information on the flow and consumption of energy, and the vehicle range
An additional tablet – similar to the well-established DispoPilot.guide tablet from FleetBoard – gives the driver a wide range of other useful information. For example, it provides details about the delivery run prior to setting off. It identifies the calculated driving times to charging stations and the expected duration of the stop. The driver’s prescribed break time is also entered on the tablet.
Range potato: range information in the form of a map
The planned journey is presented on a local map with a clever graphic known as the ‘range potato’, which shows the driver the maximum range based on the current level of battery charge. This dynamic display is continually updated based on real-time road conditions and the terrain. As a result, the driver will know how far the truck can travel based on the current power reserves.
Realistic forecast of the energy requirement for the entire journey
The third graphic presents a dynamic forecast of the energy required during the delivery run. It shows a target range marked by two lines. As long as the electricity consumption level moves between these two lines, the Urban eTruck will have sufficient energy to complete the journey. Colours are used for clarity. If the truck stays within the green area, it means there are no risks. Should the actual energy requirement move outside this band, the red markings warn the driver. These calculations are being made continuously based on the current operation strategy, the three-dimensional map, the route schedule and the traffic conditions.
Auto, agile or eco: choice of three modes depending on driving strategy
The Urban eTruck can operate in three different modes, which optimise the way in which it is driven and the use of the energy available. On a standard journey, the Urban eTruck is set to ‘auto’. This regulates the energy consumption so that the truck can complete the specified journey without any problems. The settings in this mode constantly change depending on the actual energy consumed. This ensures a balance between the range and the available power. The driver is able to change several parameters in auto mode. Changes to the cooling system of the body, however, are off-limits to ensure that the cold chain of the cargo is not subject to interference.
The second mode is ‘agile’ and it is a ‘power’ setting. In this mode, full power is available. This can be useful in hilly regions or if the speed needs to be increased to meet the time schedule, provided there is sufficient energy available.
The energy-saving ‘eco’ mode is selected if maximum range is required – for example, in the event of unexpectedly high energy usage. In this case, the torque of the electric motor is considerably reduced to achieve minimal consumption and maximum range. Energy recuperation is increased, i.e. energy is recovered through braking. Electrical accessories are also shut down.
At the touch of a button, the driver can also see a detailed picture of the energy flow. A number of displays combine to indicate the current status of the battery capacity: they show the energy in kilowatts used to cool the body of the truck, to power the electrical accessories in the driver’s cab and, most importantly, to power the two drive motors.
Truck connectivity and the FleetBoard for urban distribution telematics service
The information displays are based on intelligent networking mechanisms which involve connecting all the components and the people involved so that delivery, route and range are all in sync. Daimler FleetBoard makes an essential contribution with its innovative FleetBoard for urban distribution telematics service. The Daimler subsidiary is one of Europe’s leading providers of telematics solutions. At present there are around 180 000 vehicles using FleetBoard in operation with around 6000 customers. The FleetBoard for urban distribution telematics service connects driver and dispatcher via the FleetBoard app on the tablet. This allows the driver and the dispatcher to communicate in the usual way using the FleetBoard system. This includes the sending of messages, route plans, loading information and the truck navigation.
However, FleetBoard for urban distribution does even more: for the first time, the telematics system and the control for the drive train are interconnected. This means that the driver, the truck and the dispatcher are becoming more integrated than ever as a single unit. It starts with the scheduling: instead of the conventional fixed delivery runs used in food logistics, the Urban eTruck and FleetBoard for urban distribution offer a flexible system. It ensures that all the planned haulage work for the vehicle fleet can be completed without overextending or underutilising the range of the trucks.
Transport runs are compiled from scratch every day by vehicle co-ordinators. When planning the day’s deliveries, they have to factor in a range of variables including pallet space on trucks, loading weight, the range of the fleet and the permitted driving times of the drivers. If the calculations result in several possible alternatives for different trucks, the telematics system suggests an order of priority. The vehicles that are best suited for a particular journey are marked in colour on the co-ordinator’s screen.
The system even incorporates weather data in the precise planning process. The outside temperature and the time taken to open the doors of the load compartment are important for the energy consumption of a fresh food truck – the warmer it is, the higher the cooling requirement for the cargo on board.
The telematics system operates with an additional programme – a virtual monitor. This intervenes if the range changes due to unforeseen circumstances, such as unexpected return loads. When such circumstances push the the truck’s range to its limits, the virtual monitor outputs a warning. The additional requirement is either transferred to another truck with sufficient range or is firmly scheduled for the next delivery run.
Competitive overall costs with smart energy services
Up to now, electric drives have failed to make a breakthrough in the distribution sector because of their overall cost as well as their limited range. Supplying their eTrucks with power is an important factor for the cost calculations in hauliers’ operations. Daimler Trucks analyses the entire energy cycle and calculates the most economic solution for each individual customer.
The price and supply of electricity is a very complex issue. The deployment of trucks cannot be dependent on the times of day when electricity tariffs are lower – refrigerated vehicles have to supply goods to a tight schedule. To complicate matters further, if vehicle fleets charge the batteries of several electrically-powered trucks at the same time, the company’s power supply can come under pressure. If you are looking at a charging capacity of up to 150 kW per vehicle, 10 vehicles will require a total of 1.5 megawatts – that is equivalent to a small power plant.
Smart energy services: lower costs, better availability
The most straightforward way of supplying power to electric vehicles is also the most expensive. Anyone who simply connects the Urban eTruck – or any other electric vehicle – to their power supply as and when it needs charging may end up paying premium rates for their electricity. A far more cost-effective solution is for operators to employ regulated ‘smart’ charging to avoid times of peak demand by using defined charging cycles.
In some cases energy bills can be reduced even further if regulated charging is combined with a stationary battery storage unit. Such a device can be charged on a continual basis when electricity costs are at their lowest. The batteries for the truck fleet can then be charged as and when required. This means lower costs and better availability. Regardless of whether a battery storage unit makes sense in an individual case, the costs of an electric vehicle can be far lower than those of a diesel-powered truck when used together with smart energy solutions.
Trucks and energy storage from one company
Daimler develops customised solutions for stationary battery storage units to fit any requirements. Its newly established company Mercedes-Benz Energy GmbH acquires the energy storage units from the Daimler subsidiary Deutsche Accumotive. The storage units contain high-quality lithium-ion batteries that can be individually configured, depending on the intended use and power requirement.
Batteries from electrically-powered vehicles can also be redeployed as ‘second-use batteries’. These retain approximately 80 percent of their output capacity. Although they may have reached their limit for electric mobility, they can still be used in stationary storage units for many years to come.
Reducing electricity costs – becoming an energy service provider
The use of stationary battery storage units opens up a world of opportunities. They act as a buffer during expensive peaks in demand to lower electricity costs. This is particularly significant if a whole fleet of vehicles require charging at once.
What’s more, a company using battery-powered electric trucks can operate as an electricity provider itself, for example at weekends or on public holidays, when the trucks are not in use and do not require charging. This can involve using either the batteries in the vehicles – known as ‘vehicle2grid’ – or any stationary storage units that may be available to earn money by providing energy services. It means that even stationary vehicles are able to generate income.
Furthermore, it is possible to charge stationary storage units not just from the national grid but also using electricity generated by solar panels fitted on large warehouse roofs. This allows transport companies to charge some of their fleet with energy they have generated themselves, giving them much greater flexibility.