presteer

Presteer is a term occasionally used in discussions of vehicle dynamics to describe anticipatory steering input applied before a vehicle begins to turn. In this sense, presteering seeks to influence the upcoming arc by initiating steering early, in order to counteract actuation delay, tire dynamics, and other latencies that can degrade cornering performance.

Because presteer is not a standard term in most automotive engineering reference works, its definition and scope vary. It is most commonly encountered in the context of driver-assistance systems and autonomous controls, where steering commands are generated from predictions of future vehicle state and road geometry rather than solely from immediate feedback.

Practically, presteering relies on sensors, prediction algorithms, and control schemes such as feedforward or model predictive control to compute a steering angle ahead of the actual turn. It is typically used in combination with feedback control to maintain stability and tracking accuracy.

Potential benefits include smoother path tracking, reduced reliance on tire friction during aggressive maneuvers, and improved response in systems with non-negligible steering latency. Potential drawbacks include sensitivity to prediction errors, possible oversteer if commands are miscalibrated, and challenges in preserving natural vehicle feel for human drivers.

Related concepts include steering latency, feedforward control, model predictive control, steer-by-wire, and autonomous-vehicle path planning.