ParkingRobot/docs/superpowers/specs/2026-08-05-movementtest-longitudinal-time-step-design.md

MovementTest Longitudinal Time-Step Design

Goal

Reduce the observation-test longitudinal QP size without relaxing the solver accuracy, time budget, vehicle limits, or observe-only behavior.

Decision

Add a configurable OutputTimeStepSeconds to the trajectory-observation MovementTest with a default of 0.10d seconds.

The EM time horizon remains 6d seconds. At the parking-test speed limit of 0.20m/s, a 0.10-second knot interval corresponds to at most 0.02m of travel between knots.

Scope

• Add, snapshot, and validate OutputTimeStepSeconds in TrajectoryObservationSettings.
• Expose the setting in the MovementTest as a public field with a default of 0.10d.
• Copy it to the session-local EmPlannerConfiguration.Scheduling.OutputTimeStepSeconds.
• Verify custom settings reach the planning request and non-positive values are rejected.

Non-goals

• Keep TimeHorizonSeconds = 6d.
• Keep ObserverPeriodSeconds = 0.05d.
• Keep SolverTimeoutSeconds = 0.50d, MaximumOsqpIterations = 12000, and all 1e-5d solver tolerances.
• Do not change production EM defaults, maps, vehicle constraints, or command output behavior.