Transient Solver Examples

This section demonstrates the transient solver mode.

Core idea:

• solver_mode="quasi_static" computes an envelope-constrained speed profile.
• solver_mode="transient_oc" solves a dynamic, control-constrained lap problem.

In transient mode, ApexSim supports two driver models:

• driver_model="pid" (default): deterministic closed-loop driver with optional speed-dependent gain scheduling.
• driver_model="optimal_control": full minimum-time control optimization.

Both enforce vehicle dynamics consistency, track-following feasibility, tire/friction feasibility, and control bounds (longitudinal command, plus steering angle/rate for SingleTrackModel).

Use this section when you need dynamic states (vx, vy, yaw_rate, controls) and want to capture effects that are weak in quasi-static mode (for example yaw inertia in maneuver-heavy scenarios).

Pages

1. Point-Mass Transient Lap
2. Single-Track Transient Lap

Scripts

• examples/transient/transient_point_mass_lap.py
• examples/transient/transient_single_track_lap.py

Both scripts export standardized KPI/plot artifacts plus transient_trace.csv with the full time/state/control traces for external analysis. Each script also supports:

• --driver-model pid|optimal_control
• --pid-scheduling-mode off|physics_informed|custom