VDSim product roadmap¶

Last updated: 2026-06-20 · Tests: 388/388 ctest green (main) · 402 on VDSim-Thesis (+ VLA plant)

Living roadmap from early PoC through v0.6. Tracks what shipped in main vs what is planned. The VLA thesis closed-loop plant (python/vdsim_plant.py) ships on VDSim-Thesis only (tag vdsim-thesis-beta); core APIs it depends on are on main. Detail specs: docs/design/*; tire phases in design/TIRE_ROADMAP.md.

How to read

Shipped — in repo, default or opt-in, covered by ctest where applicable
Planned — scoped in design docs; not yet implemented
Opt-in — implemented but not default catalog (baseline frozen)
Thesis-only — on VDSim-Thesis; not merged to main yet

Velocity (recent): v0.5 terrain + tire T1/T2 → v0.6 L5 MBD (untagged) → per-wheel tire + direct-control session factory on main → VLA plant beta on thesis branch.

At a glance¶

Area	Shipped (high level)	Next
Dynamics L1–L5	L1–L3 planar/14-DOF; Ld4 hard-joint; Ld5 stunt + terrain; Ld5 high-fidelity MBD (design)	v0.6.0 tag; KC compliance; GUI terrain Play (v0.5.2); V2V
Tire	MF96 + LuGre default; MF2002 `.tir` (T1); belt transient (T2); per-axle/per-wheel `TireSetup`	GUI `.tir` import; T3 VLOW unified low-speed
Drivetrain	Engine inertia + open-diff; 2D torque map + gearbox + shift policy (v2, opt-in); catalog `drivetrain_v2` part	Engine-map workshop (UI); L1 powertrain
Brake / steer	Pluggable modules + deadtime; user-defined modules (C++/Python subclass)	Booster/MDPS physics
Catalog / runtime	`--scene=`, fleet, FMI; `make_direct_control_session`, `FrictionMapConfig`, `SimOutput` wheel GT	External part packs; VDS1 v4; Fx→τ contract (#1)
Closed-loop plant	Core session API on `main`	VLA `VDSimPlant` thesis-only → main PR when client done
GUI	3-tab scene UI, catalog API, workshops, multi-vehicle compare	GUI v2 (framework decision); terrain Play; `.tir` import
Validation	ISO 7401/4138/3888 re-baselined + CI-gated (`IsoBaseline`), 388 ctest	Adams x-check

timeline
    title Shipped milestones
    section PoC
        L1-L3 + MF96 + FMI : 2025
        ISO maneuvers + driver L5-L8 : 2025
    section v0.2
        Subsystem modules + deadtime : 2026-06
        GUI redesign + multi-vehicle : 2026-06
        Workshops shell : 2026-06
    section v0.3
        Parts catalog M1-M5 : 2026-06
        Drivetrain inertia : 2026-06
        LuGre tire tuned : 2026-06
    section v0.4
        Ld5 stunt jump loop : 2026-06
        Ld4 multibody M1-M7 : 2026-06
    section v0.5
        Terrain + L5 driving : 2026-06
        Tire T1 MF2002 backend : 2026-06
        Tire T2 belt transient : 2026-06
    section v0.6 (untagged)
        L5 free-3D inertial unsprung MBD : 2026-06
        Hardpoint anti-dive/roll-centre + progressive coil : 2026-06
        Gyroscopic wheel-spin coupling : 2026-06
        Per-wheel tire + direct_control session : 2026-06
    section Next
        v0.6.0 tag : planned
        GUI terrain Play (v0.5.2) : planned
        VLA plant main merge : thesis channel
        KC compliance + V2V : planned

1. Dynamics ladder¶

Item	Status	Notes
[x] Ld1 bicycle (5 state)	Shipped	`bicycle_dynamics.cpp`
[x] Ld2 seven-DOF planar	Shipped	Per-wheel Pacejka, Ackermann
[x] Ld3 fourteen-DOF (sprung + unsprung)	Shipped	Ride/heave/roll; L2 planar inner
[x] L1↔L2↔L3 cross-model consistency	Shipped	`PlanarMotionMatchesL2`, grid sweeps
[x] Low-speed kinematic blend (default tire)	Shipped	`LOW_SPEED_HANDLING.md`
[x] LuGre path skips blend	Shipped opt-in	Full dynamic EOM at all speeds
[x] Ld4 hardpoint kinematics (attach)	Shipped	Native kin YAML; `level=L4`
[x] Ld4 multibody M1–M7	Shipped	`LD4_MULTIBODY.md`; M4 runtime, M7 offline
[x] Ld5 6-DOF 3D body + quaternion	Shipped v0.4 (stunt)	`free_3d_dynamics.cpp`; terrain → v0.5
[x] 3D contact / airborne / ramp jump	Shipped v0.4	`V0.4_SLOPE_JUMP_DYNAMICS.md`
[x] Ld5 free-3D inertial unsprung MBD (per-corner world point mass + anisotropic 2-point bushing; energy-consistent on any surface; replaces the B1 lumped strut)	Shipped v0.6 (untagged)	`L5_MBD_FREE3D_UNSPRUNG.md`
[x] Hardpoint-emergent anti-dive/squat + roll-centre migration (wheel follows the real DAE travel path; tyre Fx/Fy → vertical reaction)	Shipped v0.6 (untagged)	active when a corner DAE is attached
[x] Progressive coil rate + damper (k_coil·(l−l_free)·MR from real spring eye-to-eye; bump/rebound asymmetric)	Shipped v0.6 (untagged)	wheel-rate fallback w/o spring hardpoints
[x] Gyroscopic wheel-spin coupling (Σ I_wheel·ω_spin lateral momentum; yaw↔roll at speed)	Shipped v0.6 (untagged)	`Stunt.GyroscopicWheelSpinCouplesYawToRoll`
[x] Per-substep contact re-query default in `SimSession` (exact on curved surfaces)	Shipped v0.6 (untagged)	no-op for non-free_3d
~~Ld5 → full 6-DOF multibody~~ (superseded designs: `L5_6DOF_MULTIBODY`, `L5_MBD_DYNAMIC_COUPLING`, `L5_MBD_RIGOROUS`)	Superseded by free-3D MBD above	kept for history
[x] Terrain + L5 general driving (heightmap hub contact, hill/cliff, inclined)	Shipped v0.5 (headless/batch/cosim; GUI → v0.5.2)	`V0.5_TERRAIN_L5.md`
[x] Curved banked track (`CurvedGround` + banked oval)	Shipped v0.5 (was v0.4 M3)	`V0.5_TERRAIN_L5.md` M5b
[ ] V2V collision	Planned	`V0.2_MULTIVEHICLE.md`

2. Tire¶

Today: empirical Pacejka MF96 (default) + library MF2002 evaluator + opt-in LuGre brush.

Future layers: design/TIRE_ROADMAP.md (belt transient, catalog MF, …).

2.1 Shipped¶

Item	Status	Reference
[x] Pacejka MF96 BCDE long/lat	Shipped	`pacejka_mf96.cpp`
[x] Combined slip (friction ellipse)	Shipped	Ch.03 §3.5
[x] Aligning moment \(M_z\) + trail falloff	Shipped
[x] Load sensitivity \(\mu_{\mathrm{eff}}(F_z)\)	Shipped
[x] Lateral relaxation length → `alpha_dyn_`	Shipped	Off when LuGre on
[x] Camber thrust (linear API)	Shipped	Ld4 forward
[x] Full Magic Formula `.tir` evaluator	Shipped lib	`magic_formula_tire.cpp`; not default catalog
[x] `python/tir_to_yaml.py`	Shipped	Workshop wire-up open
[x] LuGre decoupled \(z_{\mathrm{long}}, z_{\mathrm{lat}}\)	Shipped default	`V0.2_TIRE_LUGRE.md`
[x] `tire.kinematic_fallback` (LuGre off)	Shipped	ISO / legacy baseline
[x] MF96 as breakaway \(g(\cdot)\)	Shipped
[x] Asymmetric \(g\) floors (no long \(\mu F_z\); α-gated lat)	Shipped	2026-06 tuning
[x] ISO \(F_y\) sign (\(F_y = -F_{\mathrm{raw}}\))	Shipped
[x] Peak-axis combined ellipse (LuGre path)	Shipped	Skip triple circular clip
[x] RK4: \(z\) advanced 4× per substep (\(h/4\))	Shipped
[x] `fx_kin` = clipped LuGre \(F_x\) for wheel spin	Shipped
[x] Catalog preset `tire.lugre_on`	Shipped
[x] CLI `--lugre` / `--no-lugre`	Shipped
[x] GUI LuGre toggle + `fleet_overrides` persist	Shipped
[x] Scene `lugre_grade_demo.yaml`	Shipped
[x] `LuGreTire/*` integration tests	Shipped	209 ctest suite
[x] Theory ch.19 + user docs synced	Shipped
[x] Per-axle `TireSetup` (front/rear yaml, L1/L2/L3/L5)	Shipped 2026-06-20	`PerAxleTire.*`; catalog `tire_rear` slot
[x] Per-wheel `TireSetup` (FL/FR/RL/RR corner yaml)	Shipped 2026-06-20	`PerWheelTire.*`; catalog `tire_fr`/`tire_rl`/`tire_rr`

2.2 Planned (tire)¶

Phase	Item	Status
T1	`.tir` / MF2002 as catalog tire backend (`TireParams.backend`)	[x] merged
T1	MF2002 combined slip bypasses host friction ellipse	[x] merged
T1	GUI tire import + public sample `.tir`	[ ] (v0.5.2 GUI)
T1	Chrono Pac02 parity gate (`ctest -R ChronoPac02Parity`)	[x] pure-long ~2% + pure-lat ~1% gated
T1	LuGre \(g()\) from MF2002 \(F_{x0},F_{y0}\) (optional)	[ ]
T2	Belt transient (`belt_relax`, σ/\|Vx\| first-order)	[x] merged
T2	Filtered slip → MF96/MF2002 + LuGre (L2/L3/L5)	[x] merged
T2	bicycle (L1) belt wiring (MF + LuGre)	[x] merged
T3	VLOW-class unified low speed (reduce blend reliance)	[ ]
T4	MF2002 \(G_{x\alpha}, G_{y\kappa}\) on dynamic path	[ ]
T5	Turn-slip, inflation, temperature	[ ]
T6	External tire FMU co-sim; public benchmark report	[ ]

2.3 Belt transient (planned — summary)¶

Steady MF maps slip → force instantly. Real tires lag because the carcass/belt deflects first. Belt transient adds states (e.g. \(q_y\) or \(\alpha_{\mathrm{eff}}\)) with \(\tau \approx \sigma_y / |V_x|\) before the constitutive law — complementary to LuGre (contact bristle, presliding). See TIRE_ROADMAP.md §3.

3. Drivetrain¶

Item	Status	Reference
[x] Pluggable `IDrivetrain` module	Shipped	WS1 #159–162
[x] Open / locked / LSD split	Shipped
[x] `engine_rotational_inertia` reflected (\(I \cdot N_f^2\))	Shipped	`V0.2_DRIVETRAIN.md`
[x] Open-diff coupled 2x2 axle inertia (`open_axle_spin_accel`)	Shipped	engine inertia felt under symmetric accel, free under wheel-diff
[x] Legacy mode (`I_engine = 0`)	Shipped
[x] Catalog `drivetrain_v1` part type	Shipped
[x] Engine 2D torque map \(T(\mathrm{rpm},\theta)\) (Drivetrain v2, opt-in)	Shipped	theory ch.22; `powertrain:` block
[x] Multi-ratio gearbox + RPM coupling + gear-dependent reflected inertia	Shipped	`EngineGearbox`
[x] Shift policy (manual / auto-RPM / user-defined function, pybind callback)	Shipped	`set_shift_policy`
[x] Engine speed + gear in output (`engine_rpm()`, `current_gear()`)	Shipped	+ pybind
[x] Idle-floor + slipping launch clutch	Shipped
[x] Catalog `drivetrain_v2` part (materialize powertrain into chassis)	Shipped	`drivetrain.sedan_v2` part + `vehicle.sedan_powertrain` blueprint
[ ] Workshop engine map editor (WS2-6)	Planned	Stub in GUI
[x] ISO baseline unaffected (powertrain opt-in, default flat)	Shipped	`IsoBaseline` green

4. Brake & steering¶

Item	Status	Reference
[x] `IBrakeSystem` / `ISteeringSystem` interfaces	Shipped	`V0.2_SUBSYSTEMS.md`
[x] Proportional brake + front/rear bias	Shipped
[x] EBD by \(F_z\)	Shipped
[x] Ratio steering + rack travel	Shipped
[x] Actuator deadtime (throttle/brake/steer)	Shipped	WS2-0
[x] Steering rack torque in STATE	Shipped
[x] LuGre column friction (separate module)	Shipped	Theory ch.17
[ ] Booster → line pressure → pad \(\mu\)	Planned
[ ] Brake thermal fade	Planned
[ ] ABS / ESC interface	Planned
[ ] MDPS assist, variable ratio	Planned
[ ] Column compliance model	Planned

5. Suspension & anti-roll¶

Item	Status	Reference
[x] Linear spring/damper per corner (L3)	Shipped
[x] `IAntiRollBar` per-wheel force (#162)	Shipped
[x] Ld4 hardpoint toe/camber into dynamics	Shipped	Fleet `susp_kinematics`
[x] Catalog `susp_ride`, `susp_kinematics` parts	Shipped
[x] Workshops: suspension tab	Shipped	WS2-1
[x] Progressive coil rate + bump/rebound stops (L5)	Shipped v0.6 (untagged)	MR(z_v) from real spring hardpoints; stops on wheel travel; `L5_MBD_FREE3D_UNSPRUNG.md`
[x] Genuine per-corner unsprung masses (L5 free-3D)	Shipped v0.6 (untagged)	inertial world particles, not body-relative DOF
[ ] Progressive / bump-stop spring curves (L3 catalog)	Planned	L3 ride model (L5 done)
[ ] Unsprung vs sprung damper split (L3)	Planned	PoC backlog
[ ] KC compliance (bushing) under load — full model	Planned	L5 link is a stiff penalty today
[ ] Dependent axle (twist-beam, solid beam)	Planned	Config stubs only
[x] Ld4 multibody M1–M7	Shipped	`LD4_MULTIBODY.md`; bushing step off in L4

6. Actuator, driver & control ladder¶

Item	Status	Reference
[x] Lc4 pedal (throttle/brake/steer) primary	Shipped	CARLA-compatible
[x] Lc5–Lc8 cascade (PI, PP, waypoint)	Shipped	Demos + theory ch.07–10
[x] Driver latency + noise	Shipped
[x] First-order actuator lag	Shipped
[ ] LQR / MPC (HPIPM)	Planned	PoC Phase 2
[ ] Per-channel actuator nonlinearities (beyond deadtime)	Planned	`references/actuator_nonlinearity.md`

7. Catalog, scenes & runtime¶

Item	Status	Reference
[x] `configs/catalog/` manifest + parts + blueprints	Shipped	v0.3 M1
[x] Legacy flat `vehicles/` / `tires/` removed	Shipped	M2
[x] `vdsim_realtime --scene=` only	Shipped	M3
[x] GUI `/api/catalog`, `/api/scene`, simconfig v3	Shipped	M4
[x] `fleet[]` + part overrides materialization	Shipped
[x] Maneuvers `configs/maneuvers/`	Shipped
[x] Python `Vehicle.preset()` / `Tire.preset()`	Shipped
[x] `TireSetup` pybind + `initialize_setup`	Shipped 2026-06-20	per-axle / per-wheel
[x] `IVehicleDynamics::tire(wheel)`	Shipped 2026-06-20	L1/L2/L5
[x] `make_direct_control_session` + `FrictionMapConfig`	Shipped 2026-06-20	CmdL1 direct path; `make_friction_ground()`
[x] `SimOutput` wheel GT (μ, μ_peak, α/κ peak, `tire_forces_wheel`)	Shipped 2026-06-20	`SimSession::output()`
[x] `ladder_lowering.hpp` (ISO-frozen L1–L3→L4 calib)	Shipped 2026-06-20	was duplicated in dynamics
[x] Steer deadtime via ActuatorModel (not ad-hoc lag)	Shipped 2026-06-20	`vp.steer_deadtime_s` on direct path
[x] `tools/import_part_pack.py` stub	Shipped	M5
[x] VLA plant beta (`VDSimPlant`, friction patch, obs contract)	Thesis-only	tag `vdsim-thesis-beta`; `design/VLA_THESIS_PLANT.md`
[x] VLA P1: `obs["roll"]`, `obs["pitch"]`	Thesis-only	L2–L5 qs angles
[x] VLA P1: 1-D + 2-D polygon friction map	Thesis-only	`PolygonFrictionGround`
[x] VLA P2: smooth patch blend (1 m) + steer lag docs	Thesis-only	`VDSIM_PLANT_TUTORIAL.md`
[x] VLA: `mu_peak` per wheel (realized friction circle)	Thesis-only	fixes useGT>1 artifact
[ ] VLA #0 Fx→τ C++ contract + `drive_split_front` (#6)	Planned	spec in `VLA_THESIS_PLANT.md`; thesis uses CmdL1 shim
[ ] VLA plant merge to `main`	Planned	after client delivery; single PR
[ ] C++ in-process catalog resolver	Planned	PARTS_CATALOG §12
[ ] External catalog zip import (full)	Planned
[ ] VDS1 protocol v4 (`vehicle_id` field)	Planned	Multi-vehicle I/O
[ ] In-engine V2V collision	Planned

8. GUI & workshops¶

Item	Status	Reference
[x] Full-screen `app.html` (3D + telemetry)	Shipped	v0.2 redesign
[x] 3-tab setup (vehicle / env / simulator)	Shipped
[x] Multi-vehicle fleet tree + viz	Shipped
[x] Data-comms panel (UDP targets)	Shipped	2026-06 week
[x] Scene save/load (simconfig v3)	Shipped
[x] Workshops window (susp/brake/steer/drivetrain)	Shipped	WS2
[x] Live tire/vehicle edit → plant	Shipped
[x] Catalog part picker in GUI	Shipped	v0.3 M4
[ ] Tire workshop: `.tir` import button	Planned	WS2-5
[ ] Engine map workshop (curves)	Planned	WS2-6
[ ] Stunt authoring preset panel (ramp / loop / banked)	Planned v0.5 (render-only today)	`V0.5_TERRAIN_L5.md` M5c

9. Co-simulation, FMI & integrations¶

Item	Status	Reference
[x] VDS1 UDP CMD/STATE (`vdsim_realtime`)	Shipped	200 Hz class
[x] FMI 2.0 export + round-trip Δ=0	Shipped
[x] Multi-vehicle single process	Shipped
[x] CARLA raycast ABI skeleton	Shipped	PoC ~45%
[ ] CARLA UE5 full sensor bridge	Planned	PoC backlog
[ ] External MF-Tyre / tire FMU co-sim	Planned	Tire T6
[ ] CarMaker ERG cross-validation	Planned	License + confidential data

10. Validation & credibility¶

Item	Status	Reference
[x] Analytic benchmarks (bicycle, coast, weight transfer)	Shipped	`VALIDATION.md`
[x] ISO 7401 step-steer runner	Shipped
[x] ISO 4138 understeer gradient	Shipped
[x] ISO 3888-2 DLC metric	Shipped
[x] ISO 8608 road PSD classes	Shipped
[x] 382 automated ctests	Shipped	2026-06-17
[x] 385 automated ctests (`main`, post core port)	Shipped	2026-06-20
[x] 388 automated ctests (`main`, SessionKind + KC + T3)	Shipped	2026-06-20
[x] 402 on `VDSim-Thesis` (+ VLA plant suite)	Shipped thesis	2026-06-20
[x] ISO matrix re-baseline (post engine inertia + LuGre) + CI gate	Shipped	`IsoBaseline`; VALIDATION.md table 2026-06-10
[x] Stunt / L5 validation suite	Shipped	`test_stunt`, `test_l5_strut_validation` (loop critical, ballistic jump, camber=L4 DAE, gyro, energy)
[x] KC geometry cross-validation (L5 DAE travel ≡ independent native kinematics, rtol-gated)	Shipped	`MultibodyKcXval.DaeTravelMatchesNativeKinematics`; rules out engine bugs (internal consistency)
[x] KC analytic anchor (pure-lateral trailing arm ⇒ camber/toe gain = 0, closed form)	Shipped	`MultibodyKcAnalytic.PureTrailingArmZeroCamberToe`; validates the engine vs math, not just itself
[x] External Chrono KC cross-val (camber/toe vs travel vs Chrono::Vehicle `ChSuspensionTestRig`, same hardpoints)	Reference CSV + gate green	`external/chrono_kc/` + `ChronoKcParity` (8 % / 0.1° bands; rebound reach ~−14 mm)
[ ] External Adams / physical KC-rig cross-val (absolute, third-party)	Planned	Chrono is an independent MBD but still a simulator; physical/commercial data remains the gap
[ ] Published commercial cross-val (open data)	Planned	Honest gap today

11. v0.4 — stunt physics (planned release)¶

Single tag v0.4.0 per V0.4_PLAN.md. Does not block tire T1/T2.

Milestone	Item	Status
M1	T23 jump C++ + contact `is_valid`	[x]
M2	RampGround + ramp scene + GUI render	[x]
M3	CurvedGround + banked scenario	→ v0.5 (M5b)
M4	Ld5 core + jump on Ld5	[x]
M5	LoopGround + `vertical_loop_demo.yaml`	[x]
M6	Loop validation (✓) + theory `20_ld5_stunt`	[x]

v0.4.0 tagged. Descoped to v0.5 (now shipped): banked curve (CurvedGround/banked_oval, M5b). Still deferred to v0.5.2 GUI: stunt authoring panel (render-only today).

12. Version history (checklist)¶

PoC → v0.1 (2025)¶

L1–L3 dynamics + MF96 tire
Combined slip, \(M_z\), diff, EBD, aero
FMI 2.0, Python bindings, ISO runners
Driver L5–L8, scenarios (step, DLC, skidpad, …)

v0.2 — composable vehicle (2026-06)¶

WS1 subsystem modules (brake, steer, drivetrain, susp, ARB)
WS2 workshops shell + deadtime bridge
WS3 scene UI redesign + data-comms
WS4 part registry + fleet assembly
Multi-vehicle runtime (single process)

v0.3 — parts catalog (2026-06)¶

M1 catalog resolver + manifest
M2 migrate configs, delete legacy trees
M3 --scene= CLI
M4 GUI catalog API + simconfig v3
M5 docs sweep + import stub
Drivetrain engine_rotational_inertia
LuGre tire default on + kinematic_fallback part + tests + docs

v0.4 — stunt / Ld5 (2026-06, tagged)¶

Stunt / Ld5 / 3D contact (this doc §11)
Ld4 multibody M1–M7

v0.5.0 — terrain + L5 (2026-06, tagged)¶

Terrain + L5 general driving (heightmap hub contact, hill/cliff/inclined, banked)

v0.5.1 — tire layers (2026-06, tagged)¶

Tire T1 MF2002 .tir backend + combined-slip ellipse bypass
Tire T2 belt transient (L2/L3/L5, MF+LuGre, validation, theory ch.21)
ISO re-baseline (flat, sedan L2 LuGre) + CI gate IsoBaseline

v0.6.0 — L5 high-fidelity MBD (2026-06, on `main`, untagged)¶

Ld5 free-3D inertial unsprung MBD (per-corner world point mass + anisotropic 2-point bushing; energy-consistent on any surface; replaces the B1 lumped strut)
Hardpoint-emergent anti-dive/squat + roll-centre migration (wheel constrained to the real DAE travel path; tyre Fx/Fy → vertical reaction)
Progressive coil rate + damper from the real spring eye-to-eye geometry (MR(z_v), bump/rebound asymmetric); wheel-rate fallback without spring hardpoints
Gyroscopic wheel-spin coupling (yaw↔roll at speed)
Per-substep contact re-query default in SimSession; contact sampled at the wheel particle (exact on curved surfaces, no false contact leaving a loop/bank)
385/385 ctest; design L5_MBD_FREE3D_UNSPRUNG.md

v0.6.1 — core port from thesis (2026-06-20, on `main`)¶

TireSetup per-axle / per-wheel + catalog cosim slots + PerAxleTire / PerWheelTire tests
make_direct_control_session, FrictionMapConfig, polygon friction canonical path
IVehicleDynamics::tire(wheel), SimOutput wheel GT fields
ladder_lowering.hpp; steer deadtime via actuator on direct-control path
v0.6.2 tag — SessionKind + KC compliance + T3 VLOW (code ready)

v0.6.2 — core quality + tire T3 (2026-06-20, on `main`)¶

SessionKind (Standard / DirectControl) replaces SimConfig.direct_control_path
KC bushing compliance in L3/L4 hard-joint step (compliance_targets_rad under tire load)
T3: TireParams.low_speed_mode (kinematic_blend | tire_vlow) + vlow_speed_eps
388/388 ctest

v0.5.2+ (planned)¶

GUI terrain Play (M4) + stunt authoring (M5c) + .tir import — browser-gated
Tire: bicycle (L1) belt (MF+LuGre) + Chrono Pac02 parity gate — done
Engine-map workshop UI (drivetrain v2 already in core)
Brake/steer physics upgrade
L5 next cut: KC compliance model, gyro axis tilt + spin-up reaction
GUI v2 (framework + design system — see HANDOFF)
CARLA full bridge · open benchmark

13. External messaging (approved)¶

Shipped today

Open-core L1–L5 vehicle dynamics with Pacejka MF tire, optional LuGre brush + belt transient layers, opt-in MF2002 .tir backend, per-wheel tire setup, drivetrain v2 (engine map + gearbox), parts catalog, real-time UDP/FMI, and ISO-standard validation (385 ctests on main). The L5 model is a hardpoint-driven free-3D multibody: anti-dive/squat, roll-centre migration and a progressive coil rate emerge from the suspension geometry, energy-consistent on arbitrary surfaces (banks, loops, jumps).

In active development

v0.6 release tag; Adams/KC cross-validation of hardpoint-emergent geometry; full bushing compliance; workshop importers; GUI terrain play; VLA closed-loop plant (thesis channel, merge to main after client sign-off) — default baselines frozen per phase.

Do not claim (yet)

MF-Tyre product parity, published real-vehicle cross-validation, Adams-validated KC numbers, or production sign-off.

Doc	Role
`design/V0.2_PLAN.md`	v0.2 workstreams (historical + status)
`design/V0.4_PLAN.md`	Stunt / Ld5
`design/V0.4_SLOPE_JUMP_DYNAMICS.md`	Grade, terrain, T23 jump path
`design/L5_MBD_FREE3D_UNSPRUNG.md`	L5 free-3D MBD (shipped): unsprung, anti-dive/roll-centre, progressive coil, gyro
`design/L5_6DOF_MULTIBODY.md`, `L5_MBD_DYNAMIC_COUPLING.md`, `L5_MBD_RIGOROUS.md`	Superseded L5 MBD designs (history)
`design/TIRE_ROADMAP.md`	Tire phases T1–T6 detail
`design/V0.2_DRIVETRAIN.md`	Engine inertia
`design/V0.2_TIRE_LUGRE.md`	LuGre shipped spec
`design/PARTS_CATALOG.md`	Catalog M1–M5
`VALIDATION.md`	Evidence matrix
`HANDOFF.md`	Agent handoff / current sprint
`design/VLA_THESIS_PLANT.md`	VLA closed-loop plant spec (thesis channel)
`VDSIM_PLANT_TUTORIAL.md`	VLA plant user guide (thesis branch)

15. Development priorities (`main`, 2026-06-20)¶

Ordered for implementation (not doc-only). ISO / default subsystem numbers stay frozen unless an explicit re-baseline is agreed.

P	Track	Task	Why now
P0	Release	Tag v0.6.1 (core port) + v0.6.2 (quality/T3)	v0.6.0 already tagged
P1	Contract	#1 Fx→τ C++ path + force-intent API (`VLA_THESIS_PLANT.md` §#0)	Blocks clean plant merge; thesis uses CmdL1 shim
P1	Contract	#6 `drive_split_front` vs brake bias semantics	AWD thesis acceptance; design conflict with `brake_bias_front`
P2	API	#2 `SessionKind` generalisation (`plant_path` / direct control)	[x] 2026-06-20
P2	L5	KC compliance (bushing under load)	[x] 2026-06-20 (L3/L4 step; quasi-static bushing)
P2	Validation	Chrono KC offline build → un-skip `ChronoKcParity`	[x] 2026-06-20 (reference CSV + gate green)
P4	Tire	T3 VLOW unified low-speed (reduce kinematic blend reliance)	[x] 2026-06-20 (`low_speed_mode`, `vlow_speed_eps`)
P3	GUI	v0.5.2: terrain Play or `.tir` import (pick one)	Browser-gated; no headless path
P3	GUI	Framework decision (React/Svelte + Figma) before more `app.js` polish	HANDOFF: external review 4/10
—	Thesis	VLA hotfix only on `VDSim-Thesis`; merge plant PR when client done	`vdsim-thesis-beta` frozen baseline

Explicitly not now: V2V collision, GUI full rearchitecture without framework choice, MF-Tyre parity claims, ISO number re-baselining.