Module eta 

ETA estimation for queued elevators (closed-form trapezoidal travel time). Travel-time estimation for trapezoidal velocity profiles.

Given an elevator’s kinematic parameters (max speed, acceleration, deceleration), an initial speed, and a remaining distance to a target, [travel_time] returns the seconds required to coast in, brake, and arrive at rest. Used by Simulation::eta and Simulation::best_eta to walk a destination queue and sum per-leg travel plus per-stop door dwell.

The profile mirrors movement::tick_movement at the closed-form level — the per-tick integrator and the closed-form solver agree to within a tick on the same inputs. ETAs are estimates, not bit-exact: load/unload time, dispatch reordering, and door commands issued mid-trip will perturb the actual arrival.

Functions

travel_time

Closed-form travel time, in seconds, for a trapezoidal/triangular velocity profile from initial speed v0 to a full stop over distance.