High-pressure sensors for electro-hydraulic steering systems

First Sensor has already been supplying this customer with pressure sensors since 2011. The call for tenders was issued as part of the transition to a new series of vehicles. This additional contract follows seamlessly from the existing supply agreement. According to Dr. Dirk Rothweiler, CEO of First Sensor, the deciding factor was not just the attractive price structure, but also the quality of the products delivered so far.

He said: “The stable and reliable performance of our sensors is the foundation for our longstanding, successful collaboration with our key customers. Based on this, we are working together to make the mobility of tomorrow a reality. Anyone who wants to take their hands off the steering wheel in the future will have to consider our solutions.”

Electro-hydraulic steering systems are an initial step towards autonomous driving. In steer-by-wire systems, the steering command is transmitted from the steering wheel to vehicle’s wheels entirely through electronic means without any mechanical connection.

This allows the vehicle to stay within a lane, to countersteer, or to park automatically, for instance. These systems stand out in part for having lower fuel consumption than purely hydraulic steering systems. The pressure sensors are based on T-Bridge technology, which can be used to generate a pinpoint reading of the mechanical stress through small piezoresistive sensor elements manufactured separately from the main body section.

The sensor chips are distinctive for their high measuring sensitivity. At the same time, they are not sensitive to heat and can be used for pressure changes up to 3,000bar. Among other uses, these force and high-pressure sensors built on T-Bridge technology are suitable for controlling pressure in hydraulic applications or cooling agents and for monitoring overpressure in medical applications.

“Our pressure sensors are an important component of steer-by-wire because they measure oil pressure, which is needed to build up the required steering force,” explained Wilhelm Prinz von Hessen, Managing Director of First Sensor Mobility, which specialises in developing and manufacturing customer-specific sensor solutions in the target market of mobility for the First Sensor Group.

The company develops and produces various OEM sensor solutions in accordance with the ISO/TS 16949 quality management system for the automobile industry. Aside from high-performance pressure sensors for measuring oil, tank, and gas pressures, its range of services notably includes optical sensors and camera systems for the market segments of passenger vehicles, special-purpose vehicles, commercial vehicles, and transport.