400 kilograms weight savings compared with mechanical all-wheel drive reduces fuel consumption increases load capacity and provides greater economy
Especially attractive for vehicles which are mainly on-road
All-wheel drive is highly advantageous for commercial vehicles which deliver materials to construction sites, have to travel on softened ground or need to traverse hills and passes in winter. The hydrostatic ancillary drive Hydraulic Traction Assistant (HTA) offers an energy-efficient alternative to traditional all-wheel drive. HTA reduces the system weight by around 400 kilograms by comparison. The lower weight translates into greater useful load capacity and reduces fuel consumption.
Two hydraulically driven wheel-hub motors increase traction when needed on any axis in the vehicle. On-road the motors run in neutral mode to reduce drag losses to a fuel-saving minimum. Off-road and on difficult terrain the driver uses a toggle switch to activate traction mode, even while driving under load. In traction mode the HTA system provides additional power of around 50 kilowatt and additional torque of up to 6,000 Nm per wheel.
In creep speed mode HTA improves maneuverability and provides additional working gears which can be used at low, continuous vehicle speeds. There only the two wheel-hub motors drive the vehicle forward or in reverse; the mechanical gearbox is in a neutral position for this purely hydraulic action.
HTA can be integrated into existing vehicle concepts without any major modifications and does not affect the chassis design, maneuverability or the turning radius, and even provides advantages compared with mechanical AWD.
The HTA Hydraulic Traction Assistant system solution consists of radial piston hydraulic motors integrated into the axle, an axial piston variable pump, a valve block, an electronic controller as well as oil cooler and hydraulic tank. All the components are Rexroth products and have been proven over years in harsh applications on mobile work equipment. Of special interest to the vehicle OEM: as part of the Bosch Group Bosch Rexroth understands and meets the engineering requirements of the automotive sector, especially with respect to functional safety in compliance with ISO 26262. For OEMs this means a significant reduction in the system integration effort required.
HTA can be implemented in two or four axle vehicles and makes it possible to add the AWD function to vehicle types for which the purchase of a mechanical system would otherwise be prohibitively expensive. This includes especially any vehicle which spends the majority of its time on-road and seldom requires AWD – yet needs to safely and reliably handle difficult terrain when called upon. Such vehicles include tractors and towing vehicles, dumpers, fire trucks, concrete mixers and pumps, skip and bucket loaders, tank and silo trucks, and wood transporters.
Connectivity&Control Unit for the management of large vehicle fleets
2nd generation on-board diagnosis
A very large number of the vehicles that are registered as new vehicles each year belong to large vehicle fleets. In the case of insurance or leasing fleets, these vehicle fleets often include several thousand cars and trucks. To help the operators of such vehicle fleets to keep track of their vehicles, Bosch now offers the Connectivity&Control Unit (CCU), an innovative terminal device that monitors the technical condition of the individual vehicles and records their usage profiles.
The new Connectivity&Control Unit is connected to the on-board network via the OBD II contact (2nd generation on-board diagnosis), which legislation now requires for all modern vehicles, and is neatly hidden in the footwell or behind the dashboard. The electrical connection consists of just one wire, making the device quick and easy to install. It can also be easily removed without leaving behind any damage when the vehicle is taken out of the vehicle fleet at the end of its service life and sold as a used vehicle.
Customized analyses for fleet diagnosis The unit continually collects the vehicle’s operating data and is able to immediately identify any problems reported by the different ECUs in the vehicle electronics. The information collected in this way is automatically transmitted to a computing center, analyzed and made available to the vehicle fleet operators in a format that can be processed further by their computer systems. The OBD II contact also provides data on all the emissions-relevant vehicle systems. The type and scope of this information is standardized. Nevertheless, Bosch is still taking another big step forward; after all, thanks to the company’s technical expertise in this field, much more data can be elicited from this standardized diagnosis interface than is generally possible. This includes such information as the vehicle kilometer reading, the servicing intervals, fuel consumption and entries in the error memory, which not only affect engine management. All the knowledge that is obtained makes it first possible to provide the vehicle fleet operators with informative analyses as a fleet diagnostic service, which is indispensable for efficient fleet management. As a result, the vehicle fleet operator can completely rely on the expertise provided by Bosch in the interpretation of this information.
The use of the innovative Connectivity&Control Unit is an enormous help in saving money in the maintenance and the management of large vehicle fleets. Based on the data provided, maintenance and repairs can be done as required to make sure that all the vehicles on the road are always in the best possible technical condition. This ensures optimum profitability and efficiency for vehicle use and is good for the environment as well.
Ideal basis for extensive safety and assistance functions
Starting 2013, assistance functions will become mandatory for commercial vehicles in the EU
In commercial vehicles, safety and assistance functions help drivers and freight to reach their destinations safely. Under an EU regulation, most of the new heavy commercial vehicle models in excess of 3.5 metric tons will have to be equipped with advanced emergency braking systems (AEBS) and lane departure warning systems (LDWS) effective November 2013. These assistance functions support drivers during emergency braking and warn them if they unintentionally drift out of lane. With its MRR mid-range radar, Bosch has developed a technology that uses the 77-gigahertz frequency band, and thus provides especially precise data about the vehicles on the road ahead. “The new sensor for commercial vehicles is a high-performing and cost-effective basis for emergency braking systems, as well as for convenience functions such as adaptive cruise control,” said Gerhard Steiger, the president of the Bosch Chassis Systems Control division. Bosch offers a 12-volt version of the sensor for light trucks, and a 24-volt version for heavy trucks. Series manufacture will start in 2013.
Powerful and compact thanks to 77 gigahertz A 77-gigahertz sensor is far more powerful than a 24-gigahertz one. Its object separation is up to three times more accurate, and it can measure speed and distance three to five times more accurately. It is also significantly more compact, and uses the 77-gigahertz frequency band, which has been permanently allocated to automotive applications worldwide. “The new MRR is especially suitable for vehicle platforms that are offered in all the world’s markets,” Steiger says. In addition, the measurement data from the sensor can be used to inform drivers how close they are to the vehicle in front.
Bosch employs silicon-germanium semiconductor technology for the high-frequency circuits. As they are highly integrated, they combine a simple mechanical design with small size and low weight. This means the sensor can be concealed in the bumper or mounted unobtrusively in the vehicle’s radiator grille. It is smaller and more cost-effective than the conventional 24-gigahertz sensors. The sensor is connected to the automotive electronics via CAN and Flexray interfaces.
For use at the rear of the vehicle, a 12-volt version is also available for light commercial vehicles. This allows drivers to be warned of vehicles that are in their blind spot, and that are approaching at speed from the rear. It also makes it much easier to reverse out of parking spaces where vision is restricted, as approaching vehicles can be reliably detected.
ESP® 9TE improves stability and shortens braking distance of light commercial vehicles with higher gross vehicle weight
More dynamic active build-up of pressure possible without additional precharge technology
ESP® 9LE for vehicles with high brake pressures
Technical basis for extensive range of additional functions
Following the launch of ESP® 9 in passenger cars, Bosch is now introducing this new generation also for light commercial vehicles. With ESP® 9TE, a number of additional ESP® functions will now be available for the first time for the weightier segment of light commercial vehicles weighing up to eight metric tons. These functions include brake prefill by bringing the brake pads into position, automatic braking in hazardous situations, and safety interventions on steep gradients. Bosch is planning to start series production in 2014. ESP® 9LE is already being manufactured. It has been optimized above all for the types of van commonly found in Europe, which have high pressures in their main brake cylinders. “With the new varieties of Bosch ESP®, significant improvements to the safety of light commercial vehicles can be made,” said Gerhard Steiger, president of the Bosch Chassis Systems Control division.
Modified to meet the specific demands of commercial vehicles Vans, sport utility vehicles, and pick-up trucks place greater demands on the brake system due to features such as gross vehicle weight, wheel base, and larger brake calipers. Both the ESP® 9TE and ESP® 9LE have been optimized to meet those demands. Both allow the kind of additional functions, including comfort functions, that are common in the passenger-car segment. In addition, automakers can offer the kind of stability support required specifically for vans. The load adaptive control function, for example, adapts the interventions by the ABS, TCS, and ESP® active safety systems to the respective load status, while roll-over mitigation acts to check roll-over by braking the individual wheels appropriately and reducing torque.
ESP® 9TE is designed above all for the U.S. market. While automakers in Europe tend to rely on compressed air brakes once vehicles exceed a weight of six to seven metric tons, pick-up trucks in the U.S. tend to be braked by larger brake calipers. For such calipers, the ESP® system requires above all a more dynamic active build-up of pressure, with a high delivery rate. What matters here are pump housing and valves optimized for flow, asymmetric pump elements, a powerful motor, and larger storage chambers. There is now no need for the precharge components that were often necessary in the past. Compared with standard ESP® systems, ESP® 9LE is equipped with a motor delivering greater torque, special valves, and larger storage chambers for the high pressures (up to 330 bar) typically found in the main brake cylinders of vans. In addition, it can support recuperative braking in hybrid vehicles, allowing the braking effect of the electric motor to be synchronized with conventional braking action.