Drive systems

Fresh wind

Fresh wind

With the mobility revolution, not only are concepts such as electromobility and autonomous driving hitting the road, but more and more high-tech players from outside the industry are entering the market and bringing a breath of fresh air to the established automotive industry. The main driver of innovation is the software sector. The example of Nabtesco shows what is possible here. Together with adcos, a company of the Nabtesco Group, the transmission specialist has developed the world's first purely electromechanical steering and drive solution for commercial vehicles. Following successful field tests, the project is now being transferred to series production status.

To understand how important software has become for the automotive industry, it is worth taking a look at the number of lines of code (LOC). For example, the Mars rover Curiosity has five million LOC, a fighter jet has 25 million, and a luxury-class passenger car has 100 million. A fully autonomous vehicle would require far more than 300 million LOC. 90 percent of all innovations are now achieved through electronics or software. This is made possible primarily thanks to new players who are injecting momentum into the industry with innovative technologies and creative solutions and thus decisively advancing the mobility of the future. One of them is Nabtesco.

Robot technology in the driveline of commercial vehicles

The specialist for precision cycloidal gear units is primarily known from robotics. But the high-performance transmission systems also cut an excellent figure in the powertrains of commercial vehicles. Together with the software expertise of the incubator adcos, a specialized development partner for software and hardware solutions in the field of mechatronic systems and a company of the Nabtesco Group, an innovative steering technology has been created that is unique worldwide.

The so-called CV-EPS platform (CV-EPS = Commercial Vehicle Electronic Power Steering) is a purely electromechanical steering and drive solution. The modular concept (mechanical kit with software-based customizing) has been designed and industrialized to be integrated into a wide variety of commercial vehicles and is particularly interesting for future fields such as electromobility and autonomous driving.

Innovative steering and drive solution

The innovative drive concept consists of a cycloidal transmission specially adapted to vehicle construction, a specially designed two-channel motor, a control unit and a sophisticated steering algorithm. It complies with the ISO 26262-ASIL D standard and therefore meets the highest safety requirements. All safety-relevant elements have a redundant design.

With three gradations, the CV-EPS platform is equipped for all stages of autonomous driving. There is a single-channel variant with mechanical steering column connection and software-based support from the electric motor (Fail Safe), a variant with mechanical steering column connection and two-channel motor and ECU system (Fail Operational), and a two-channel variant without any mechanical steering column connection at all (Steer-by-Wire). The technology was developed specifically for high-voltage systems, and a 24/48-volt solution is in the works.

Next step: transfer to series production

In China, SRT buses (SRT = Super Virtual Rail Train) from the manufacturer CRRC / ZELC have already been operating with the steer-by-wire variant in regular service for two years. Further projects are in the planning stage. Initial talks are also underway in Europe. In parallel, Nabtesco is working on the transfer to series production and is setting up automotive-compliant production.

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