ZF presents prototype of fully electric steering system
ZF has unveiled its ReAX EPS, what the company says is the world’s first prototype of a fully electric steering system for commercial vehicles. It reortedly eliminates the need for hydraulics and associated peripheral components. Its electric motor offers complete servo power of up to 70 N·m. Additionally, ZF’s electrically powered steering (EPS) system is designed to support steer-by-wire applications in the future.The ZF ReAX EPS also reportedly offers increased efficiency with reduced packaging space and weight, compared to traditional hydraulic steering systems.
“With the ReAX EPS, we are presenting a prototype for a commercial vehicle steering system that can simplify and accelerate the advance of electrification, including 48 V onboard vehicle power supply systems and steer-by-wire options, and do so with the high efficiency and reliability,” said Mitja Schulz, Head of CV Steering Systems at ZF.
ZF developed the ReAX EPS, based on its established electromechanical steering concept designed for passenger cars, adapting the technology to trucks and buses. An actuator system powered by a 70 N·m electric motor, equipped with an integrated control unit, transmission, and sensors is the critical component delivering increased power.
“After the first test-drives, the ReAX EPS operates more efficiently than our most advanced electro-hydraulic system to date. It also weighs significantly less,“ noted Schulz. The compact unit creates more installation space in the vehicle, useful for other systems, such as electric drives that interact with the new steering system. The ReAX EPS can be used with automated driving functions as it incorporates electronic controls allowing for inputs from camera, radar, and other vehicle data to influence steering for enhanced safety and autonomous operations.
The ReAX EPS is a critical system component for enabling trucks and buses to act. Networked with control electronics such as the ZF ProAI, environmental sensors, and other vehicle systems, the intelligent steering system is designed to handle many tasks, ranging from lateral control to SAE Level 4 automated driving. This means, for example, that the truck is capable of steering itself on certain sections of the highway or in loading areas, so the driver can work on other activities or rest in the meantime.
The ReAX EPS also offers comparable support for individual networked safety and comfort functions. This includes, for example, the OnTraX lane keeping assist (LKA) function, which helps keep vehicles in the driving lane. ReAX EPS has also integrated other popular features from the volume-produced commercial vehicle lines, such as the active steering wheel return to the center position, compensation for road crown and cross winds as well as speed-dependent steering assist. In addition, almost any preferred steering wheel feel can be programmed as a feature for the respective OEM or as an option selection for the driver.