Assumptions and Limitations

• Base vehicle dynamics are 3-DOF (vx, vy, yaw_rate) with single-track abstraction.
• Point-mass backend is available as an alternative model and assumes zero yaw moment in diagnostics by construction.
• Tire model implements Pacejka-style lateral force only in this phase.
• Longitudinal force limits are represented by configurable accel/brake envelopes.
• Point-mass backend uses an isotropic friction-circle with speed-dependent normal load from aerodynamic downforce.
• Quasi-static mode solves a lateral speed envelope via fixed-point iteration with configurable tolerance and iteration cap in SimulationConfig.numerics.
• Transient mode solves a minimum-time optimal-control problem on the fixed centerline with bounded controls and dynamic-state propagation.
• In transient mode, SingleTrackModel steering limits are configured through SingleTrackPhysics.max_steer_angle and SingleTrackPhysics.max_steer_rate.
• Transient PID gain scheduling (when enabled) is speed-only in v1: no preview controller, no explicit curvature/load-state scheduling.
• pid_gain_scheduling_mode="physics_informed" uses deterministic heuristics based on flat-road longitudinal authority and clipped speed scaling.
• Aero model uses constant coefficients (c_l, c_d) and rigid ride height.
• The lap-time solver is decoupled from specific vehicle equations and only depends on the VehicleModel API contract.
• Track data expects closed-loop CSV with columns: x, y, elevation, banking.
• Current Spa import uses real centerline coordinates, while elevation and banking are set to 0.0 until higher-fidelity telemetry/map layers are integrated.

These simplifications are intentional to keep the architecture extensible for future modules: full vehicle, powertrain, and energy management.