{
  "engine": "Project Chrono / PyChrono",
  "engine_version": "9.0.1",
  "experiment": "STEP-derived wheel rolling on a flat floor under a fixed speed controller",
  "material_density_kg_m3": 7800.0,
  "gravity_m_s2": 9.81,
  "contact_friction": 1.5,
  "initial_axle_m": [-0.5, 0.05, 0.0],
  "target_spin_rad_s": -6.0,
  "spin_ramp_s": 0.3,
  "speed_controller_gain_N_m_s_rad": 0.05,
  "maximum_drive_torque_N_m": 0.1,
  "settling_s": 0.5,
  "minimum_rolling_distance_m": 0.2,
  "maximum_relative_spin_error": 0.1,
  "minimum_floor_contact_fraction": 0.5,
  "duration_s": 2.0,
  "time_step_s": 0.0005,
  "required_relative_axle_height_variation_reduction": 0.7,
  "maximum_relative_mass_change": 1e-6,
  "maximum_envelope_change_mm": 1e-6,
  "maximum_external_added_mm3": 0.0001,
  "maximum_bore_intrusion_mm3": 0.0001,
  "maximum_hub_missing_mm3": 0.0001
}