Controlled Steering Pro

Why abandoning the boost-curve concept will pave the way for the future of steering

With Controlled Steering Pro, Sentient challenges what was once considered unsolvable compromises in the suspension and steering system.

The hydraulically boost-curve assisted steering gear was admittedly a very successful technology for more than half a century, until EPS, Electric Power Steering, finally matured enough to become the solution of choice. But surprisingly, since electronic control gives so many new opportunities, EPS typically still relies on a boost-curve with its limitations and drawbacks.

Sentient abandoned the boost-curve concept all together for Controlled Steering Pro, that instead uses sophisticated control algorithms together with advanced use of available signals. It provides high-fidelity feedback true to lateral acceleration rather than the sum of wanted and unwanted forces around the steering axis. It is therefore inherently disturbance free. Take forever farewell of torque steer, sensitivity to wide tires, road disturbances and other phenomena impairing steering feel and precision.

By innovative use of vehicle state information, Controlled Steering Pro can also deliver intuitive and tuneable over- and understeer feedback, a beloved attribute once taken almost for granted, but unfortunately lost in many modern cars with EPS.

Key attributes and features of Controlled Steering Pro:

• High-fidelity feedback
• Superior precision
• Disturbance free experience
• Limit handling feedback
• Integration with ADAS/AD
• Excellent Steering feel also with 4-wheel torque vectoring

If you are interested in the latter feature of how to achieve flawless steering together with 4-wheel torque vectoring, don’t miss this article. Link.

Controlled Steering Pro will allow the engineering team to precisely tune torque feedback, return control, disturbance elimination, on-centre feel e.t.c. according to the brand DNA. This takes attributes and quality of the steering experience to a new level.

It is also the start of a new optimisation opportunity for the complete front suspension and steering system. While being less constrained by very narrow targets for scrub radius, caster trail, king-pin inclination e.t.c., other parameters can be met more precisely. It is also possible to select a specific parameter like camber control during cornering to optimise it to achieve higher lateral performance.

An interesting chance is to reduce the forces needed to turn the wheels. This will allow for downsizing the steering gear with benefits for cost, weight and energy. Reducing needed steer forces will also reduce deflection, which will help to improve the steering feel it self.