Bosch introduces commercial vehicle steering systems that provide intelligent support and fuel economy.

• Servotwin steering system provides a wide range of assistance functions for trucks and buses
• Rear axle control makes commercial vehicles more manoeuvrable and efficient in city traffic

Electric steering is becoming increasingly popular. This is an indispensable element in driver assistance systems, such as driving support in a lane or a parking assistant, and a standard function in more and more modern cars. . Bosch uses the comprehensive experience of creating electric  steering control systems for passenger cars in the development of systems for commercial vehicles and buses. The company is constantly working on technological solutions for a new era of mobility: no accidents, stress and air emissions.

Electronic systems make safer and easier commercial vehicle managment

The Servotwin steering system from Bosch is the world's first integrated electro-hydraulic steering system for commercial vehicles, particularly for heavy trucks and buses. Servotwin is more efficient than previous steering systems due to the active change in the torque of the amplifier, depending on the driving conditions of the vehicle. It also has driver assistance functions that make driving safer and easier. One of these functions is the traffic assistant in the selected lane, which warns the driver in the event of an unintended departure from his lane. If he does not respond, the system intervenes and returns the vehicle to its lane. Also, this system helps in traffic jams and with slow traffic, while other electronic assistants automatically maintain the optimal distance to the vehicle in front. At the same time, the driver can take control at any time. Another situation where Servotwin helps the driver is a sudden side gusts of wind, that can be dangerous for trucks because of the large side surface area. The system determines how much the steering needs to be repositioned to compensate for the gust of wind, and activates the electric motor to assist in maneuvering.

Rear axle steering system makes trucks more manoeuvrable 

Bosch redesigned the rear axle electro-hydraulic steering system to facilitate the maneuvering of heavy commercial vehicles. This advantage will be appreciated by drivers of buses with a long wheelbase, as the modified system makes the turning radius smaller. Increased maneuverability is especially useful when driving around the city. In addition, driving the rear axle of a vehicle improves vehicle stability at high speeds, making it easier and safer to change lanes.

Here's how it works: the electro-hydraulic steering system for driving or driven rear axles of heavy trucks and buses operates independently of the front wheels. Its feature is an innovative combination of hydraulic cylinders and an electronic control unit. This means that the steering is electronically controlled, electrically controlled and does not require a mechanical or hydraulic connection between the front and rear axles. Thanks to the on-demand activation function, energy is required only when the steering is activated. The electric motor feeds the pump, which uses the working cylinder to create hydraulic pressure and transfer it to the rear axle. Compared to conventional steering systems, this solution saves up to 0.6 liters of fuel per 100 kilometers.

The Bosch electro-hydraulic rear axle steering system is suitable for both integration into vehicles in their production and for retrofitting commercial vehicles. All geometric parameters of the vehicle, such as the wheelbase and steering wheel angle, are individually programmed in the electronic control unit.

Source: www.bosch-automotive.com