Pursuing top steering feel – an eternal quest
The pursuit of a top steering feel is an eternal quest. When you go with Blueprint Steering, you will have greater feedback fidelity than ever. Is it also an opportunity for better front suspension characteristics?
Caster angle, caster offset, and wheel radius determine the caster trail, which together with the pneumatic trail, constitutes the lever around the steering axis that feeds torque back to the steering wheel when cornering. The feedback is roughly proportional, or rather degressive due to power steering, to the lateral load of the front tyres, and it gives an elegant measure of the vehicle’s lateral acceleration directly in the driver’s hands.
Another effect is that the pneumatic trail shortens when the tire reaches its maximum grip, which reduces torque feedback to the driver when the vehicle starts to understeer. This gives beautiful and intuitive feedback on the limit handling performance of the vehicle.
This is how it has been for some 100 years now, and it still forms the core of desired driver feedback. Now, with Blueprint Steering, Sentient takes this beloved feedback into the age of digitalisation and liberates it from suspension constraints. The benefits are significant and maybe also somewhat surprising:
First of all, steering feedback is now precisely tuned directly to lateral acceleration rather than the sum of wanted and unwanted forces around the steering axis. This gives inherently disturbance-free high-fidelity steering.
Feedback on the limit handling performance of the vehicle is made clearer than ever through the ingenious use of vehicle-state information. And the feedback is fully tuneable.
Just as steering feedback is freed from the caster angle; the caster angle is freed from delivering steering feedback. The opportunities are probably more plentiful than we have realised so far. We know how Blueprint Steering improves feedback, but the opportunities for front suspension design are yet to be explored.
This post is the second in the Kingpin series. First post was What is your favourite kingpin angle?
About Lars Markström
Vehicle Dynamics Attribute Leader, Lars Markström, at Sentient is an experienced vehicle dynamics Engineer. Few know as well as Lars how experienced drivers – and non experts – perceive and act on road conditions and upcoming situations. In articles on this website, marked “By Lars”, he reflects and go into details about vehicle dynamics, its history and development.