Based on proven recirculating ball steering gear technology, the system integration of tedrive’s iHSA® module now enables the use of active driver assistance systems as well as many more safety and comfort functions in buses, too.
Bus passengers want to travel in comfort. Safety is assumed. The vehicle industry, on the other hand, is required to prioritize safety in its research and development work, so that their product development keeps pace with the challenges of increasing traffic. Bus manufacturers and the supply industry are therefore working together on technical solutions that anticipate issues presented by future traffic concepts. Steering system specialist tedrive has succeeded in achieving the first hydraulic steering system for buses and heavy trucks that enables the incorporation of active assistance systems into the steering setup.
By integrating the patented tedrive iHSA® module (intelligent Hydraulic Steering Assist) into conventional tedrive recirculating ball steering gear systems, tedrive has enabled the first ever integration of active driver assistance systems within the bus segment. This means a diverse array of functions that make bus journeys safer and more comfortable for drivers and passengers alike are now also conceivable for public transit buses and coaches. iHSA technology can be applied to tedrive’s hydraulic recirculating or rack-and-pinion steering units. Depending on manufacturer requirements, tedrive can therefore design iHSA technology to suit the entire range of bus types, from minibuses to double-decker coaches. As a precursor to autonomous driving, applications of iHSA technology include functions like active lane-keeping assistance, city mode or automated bus stop approach, which contribute to providing bus drivers with active and direct support.
“In the public transit and coach sector, we have to deal with high axle loads that are not suited to electrical steering systems,” explains Peter Heimbrock, Director of Product Development for tedrive Steering Systems GmbH. “So far, it has been possible to offer only very limited active driver assistance systems in this safety-sensitive vehicle segment. We can close a major chunk of this safety gap with iHSA steering.”
Based on tedrive’s proven recirculating ball steering gear technology, system integration of the iHSA module enables the incorporation of driver assistance systems like active lane-keeping assistance and crosswind compensation systems that go well beyond visual or haptic warning systems. The vehicle must be equipped with the sensors necessary to detect lane markings. If the vehicle leaves the specified lane, the sensors send a counter-steer signal to the iHSA module, which automatically controls the hydraulic steering valve. The resulting torque overlay activates the assistance systems networked with the iHSA module in a matter of milliseconds and the bus is actively kept in the right lane, without any input from the driver. The functionality extends well beyond existing, legally mandated lane departure warning systems. Automated approach to bus stops with ramps or high curbs and switching to “city mode” are further examples of applications that can be incorporated via the iHSA interface.