The Schaeffler electromechanical acitve roll control system uses integrated torque sensor to enable progressive control to improve cornering performance.
Precision bearing and automotive systems manufacturer Schaeffler has introduced an innovative electromechanical active roll control system that prevents the vehicle from tilting when cornering at high speed. The system will go into volume production at the Schweinfurt production plant in Germany.
The electromechanical active roll control system from Schaeffler comprises of a transmission, an electric motor with electronic components and an integrated torque sensor. The electric motor and its high transmission, three-stage planetary gear unit rotate the two halves of the roll control system in opposite directions, which produces a torque that has a stabilising effect on the vehicle body. A non-contact torque sensor accurately identifies this torque, which is used to quickly and precisely control the actuator.
To increase driver comfort, the system also incorporates an innovative decoupling element made from a high-strength, thermally stable elastomer. This allows minor irregularities in the road to be absorbed, which significantly reduces the number of control interventions required when the vehicle is travelling on poor quality roads. Transmission of shock impulses to the active roll control system and, consequently, to the chassis, is therefore reduced or completely eliminated.
Unlike hydraulic systems, which constantly consume energy, even in standby mode, due to their continuous pumping action, electromechanical active roll control only draws on electrical power when it is needed. This is because the electric motor only consumes power when the system twists and creates torque. Only a relatively low electrical loss of resistance must be compensated for in order to maintain the force.
Reduction in fuel consumption
The benefits of electromechanical active roll control include a reduction in fuel consumption by up to 0.3 litres/100km compared to vehicles fitted with hydraulic roll control systems. This also creates superior system dynamics compared to hydraulic systems and more precise steering control. In addition, the system can be fitted to hybrid and all-electric vehicles. Assembly at the vehicle manufacturer’s plant and maintenance are also simplified.
Dr Tomas Smetana, Vice President Chassis Actuators at Schaeffler commented: “Our system prevents the rolling motion or yawing of the vehicle that can occur when taking corners and so makes a significant contribution to increased driver comfort and handling. With electromechanical active roll control, Schaeffler is also helping to reduce fuel consumption and vehicle emissions compared to hydraulic systems.”
By putting the first volume-produced electromechanical active roll control system with highly dynamic and precision control into a luxury passenger car, Schaeffler is integrating into the vehicle system not only improved vehicle stability through corners, but is also increasing driver comfort on poor quality road surfaces, as well as agility. The result is a perfectly tuned vehicle with an ideal combination of comfort and high performance.
To ensure high quality standards for electromechanical active roll control, all assembled components are monitored and documented using the MaQS (Manufacturing Quality System). This enables 100% traceability of individual parts back to all Schaeffler sub-suppliers, including all relevant product and assembly characteristics. This sophisticated production and quality assurance system was introduced by Schaeffler as part of its Industry 4.0 initiative.