Long Paths and
Shortcuts to
Understanding VLA

Experiments in Planning, Reward Design,
and Adaptation to a New Robot

Alexei Kornaev, Dr.Sc., Prof.

Innopolis University

Physical AI & VLM
Lomonosov Academic Exchange Day
30 October 2026 · Moscow

Robot at a crossroads: go left, change your route; go right, change your mind

Our path to embodied robotics

Embodied
robotics
Long-term ambition
↓Set the robots free
↓Let them work hard
↓Let them hand over
their salaries to us
↓Let them take care of us
and the environment
Physical understanding
+ uncertainty
Future research:
physics-informed methods
PINN/iPINN · JEPA
knowing when to ask
→
Test on
our tasks
Limited perception
Complex goals
Changed embodiment
→
Reproduce existing
VLA systems
Within available compute
→
Our current focus
High-level planningGuide a fixed VLA executor
without retraining it
Reinforcement learningAdapt the policy in simulation
to a new robot: CDPR

The people behind the experiments

Alexei Kornaev
Alexei KornaevScientific supervisor
Alexander Maloletov
Alexander MaloletovHead, NTI Center*
Damir Nurtdinov
Damir NurtdinovVLA / RL, CDPR
Denis Degtyarev
Denis DegtyarevPlanner evaluation
Zlata Mishustova
Zlata MishustovaWheeled robot
Kamil Nuriev
Kamil NurievRewards, physical criteria
Egor Novikov
Egor NovikovVLA adaptation, rewards
Artem Tuzov
Artem TuzovData and tooling
Yuri Kazakov
Yuri KazakovCartography, control

*NTI Center for Robotics and Mechatronics Component Technologies

Part 1 · Planning above a fixed controller

  1. 01Planning above a fixed controller
  2. 02Learning for a new embodiment
  3. 03What comes next

Can better guidance help a controller that we do not retrain?

Planner pipeline: manipulation

Planner-pipeline graphical abstract showing manipulation and wheeled-robot applications
Manipulation study: planner-selected subgoals for a fixed SmolVLA executor.

Our contribution: measuring help, harm, and chance

Count what a net success rate hides.
Replay each task from the same start, with and without guidance; count rescued failures and disrupted successes separately.

Measure how much change happens without a planner.
Replay the fixed policy against itself to estimate its own outcome variability.

Test the cost and limits of intervention.
Compare planner models, reference goals and larger execution budgets to examine why progress may improve while completion does not.

What can the planner change?

RoboCerebra Ideal/case1: robot arm, three food boxes and a white organizer
“Put the three food boxes into the organizer.”
PlannerInstruction + observation↓ current goal

“Pick up the butter.”

↓Fixed SmolVLAImages + state + goal → actions

Pick / place cream cheese → Pick / place popcorn → Pick / place butter

The planner selects the request; the executor performs the action.

What did we test?

Fixed SmolVLA executor · three planner models · 1,230 matched episodes per planner

Normal operation

Long, multi-step tasks

Less visual input

Camera information removed

Reported faults

Predicate signal changed

Impossible tasks

Missing targets or blocked actions

Segment-based evaluation: state restored at subgoal boundaries. Reported faults alter the monitor signal.

Compare the same starting state

The same success rate can hide different successful episodes.

Restore the same initial state

Flat

Complete instruction

Fixed executor

Planner

Intermediate goals

Same executor

Same task, start, stress condition and control budget

Flat Planner Outcome
Success Success Both succeed
Failure Success Rescued
Success Failure Newly failed
Failure Failure Both fail

Initial-state pairing and later subgoal-boundary restoration are separate operations.

Manipulation: progress and changed outcomes

Qwen2.5-VL: +4.0 progress points · 70 rescued / 52 newly failed · net +18 completions (p = .12).

Manipulation: progress and changed outcomes
Upper block: 1,230 matched pairs, 13 conditions. Shaded rows use their own baselines.

Previously successful episodes can fail under guidance

Among the 176 episodes solved by the fixed policy:

Goal source Successes lost Conditional loss rate
Qwen2.5-VL 52 / 176 29.5%
Qwen3 56 / 176 31.8%
Reference goals 76 / 176 43.2%
Kimi-K2.5 77 / 176 43.8%

Manipulation: a paired execution demonstration

Left: Flat model (policy alone)Right: Planner-guided policy
Flat on the left · Planner on the right · original playback speedFlat on the left · Planner on the right · original playback speed
Flat on the left · Planner on the right · original playback speed

Kimi-K2.5 planner · shared execution clock · fixed policy in both branches.

Almost finished is still unfinished

Policy aloneWith planner
Final frames of one Kimi pair: policy alone reaches six of six subgoals, planner-guided policy five of six
Final state under the same control budget

One matched episode

6 / 6Policy alone

5 / 6With planner

The guided policy gets close,
but the task is incomplete.

Kimi-K2.5 · Ideal/case5/seed0
Different from the Qwen headline experiment.

Count completed tasks as well as partial progress.

Manipulation study: findings

More progress did not clearly translate into more finished tasks.
Guidance helped intermediate steps, but the overall completion benefit remained uncertain.

Guidance could help one attempt and disrupt another.
Some tasks that succeeded with the policy alone failed after planner intervention.

Useful guidance still depended on execution.
Reference subgoals did not ensure completion; extra time did not improve Qwen3 completion in the tested comparison.

Planner pipeline: wheeled-robot navigation

Planner-pipeline graphical abstract showing manipulation and wheeled-robot applications
Second study: object search with a fixed detector and Nav2 navigation stack.

Wheeled robot: task and comparison

Can planner guidance help the robot reach the requested object when the baseline cannot construct or retain a usable target?

Flat system

Fixed search, detection and approach sequence.

The robot must reach the designated object, not just another object of the same class.

Planner-enabled system

Qwen3-VL selects navigation skills and uses target context and memory.

Same starting pose and heading; five scenes, five trials per scene and system.

Fixed detector and Nav2 executor. This evaluates the broader planner-enabled stack, including memory and interpretation.

Mobile navigation: scene-level completion

System 1
Visible and reachable
2
Fixed scan
3
Outside the map
4
Around the corner
5
Implicit description
Total
Flat 5/5 5/5 1/5 2/5 0/5 13/25
Planner 5/5 5/5 5/5 4/5 5/5 24/25
Physical wheeled-robot evaluation scenes

Five reused scenes × five trials; manual, unblinded scoring. Comparison includes memory and semantic interpretation.

Guidance helped recover a usable target

Mobile-robot corridor scene: blocked approach to the localized target, repositioning and retry
Target localized → approach blocked
Reposition → retry the remembered target

13/25Flat

24/25Planner

Target Flat Planner
Already usable 10/10 10/10
Needs memory or interpretation 3/15 14/15

Success: reached the designated object.

Benefit concentrated where the baseline lacked a usable target.

Physical mobile robot · detector + Nav2 · five scenes × five trials · unblinded scoring

Mobile navigation: observation and execution

First half: supplied mobile-robot demonstration · 2× speedFirst half: supplied mobile-robot demonstration · 2× speed
First half: supplied mobile-robot demonstration · 2× speed
Second half: continued demonstration · 2× speedSecond half: continued demonstration · 2× speed
Second half: continued demonstration · 2× speed

Interpret the requested target, retain useful observations, and navigate using the detector and Nav2 stack.

Wheeled-robot study: findings

The planner helped when the target was hard to identify or remember.
Context and memory helped continue the search and approach.

Simple cases already worked with the baseline.
When the target was visible and usable, extra guidance added little.

The benefit came from the whole system.
Planning, memory and interpretation worked with the fixed detector and navigator.

The evidence is limited to the tested scenes.
Broader reliability still needs evaluation.

Part 2 · Learning for a new embodiment

  1. 01Planning above a fixed controller
  2. 02Learning for a new embodiment
  3. 03What comes next

How can a robot learn new actions from its attempts—and keep its earlier skills?

From the base policy to our reward experiment

OpenVLA-OFT

Images + state + instruction → robot actions
Our starting policy in LIBERO

Starting action policy

SimpleVLA-RL

Collect simulated attempts;
update the policy using rewards

Rollout-and-update framework
PolicyImages + state + instruction
→
RolloutsAttempts at the task
→
RewardScore progress or success
→
RL updateImprove the policy

OpenVLA-OFT gives us the policy; we test how reward design changes its learning.

Training feedback = numerical reward · CDPR uses a different policy: SmolVLA

OpenVLA-OFT: the policy we build on

Inputs

Camera observations, language instruction and robot state.

Action prediction

Continuous actions predicted in chunks with parallel decoding.

Optimized fine-tuning

The OFT recipe studies action representation, decoding and learning objectives.

Our use

An OpenVLA-OFT-based policy, adapted with LoRA in the LIBERO reward study.

Kim, Finn & Liang (2025), Fine-Tuning Vision-Language-Action Models: Optimizing Speed and Success. https://arxiv.org/abs/2502.19645

SimpleVLA-RL: learning from simulated rollouts

SimpleVLA-RL: learning from simulated rollouts
Sample trajectories, score outcomes, and update the policy from relative performance.

Li et al. (2025), SimpleVLA-RL, Figure 2. https://arxiv.org/abs/2509.09674

LIBERO reward comparison

Published starting point

OpenVLA-OFT policy
SimpleVLA-RL rollout-and-update recipe
LoRA fine-tuning in simulation

Ten LIBERO-Spatial manipulation tasks.

Our reward experiment

Same 61.0% initialization
160 updates: terminal-only and dense + phase
Terminal verifier coefficient: 5

300 validation rollouts per endpoint.

Train the manipulator policy; vary reward feedback; keep the native success test.

Reward new progress, not repeated motion

ReachGraspLiftMovePlace
Within one phase
0.20.60.30.60.8
+0.2+0.400+0.2

No extra progress credit for returning to an old maximum.

Our LIBERO reward method. Unweighted illustrative increments; progress baseline resets at each new phase. Success verifier unchanged.

Dense + phase feedback improved the endpoint

LIBERO-Spatial · OpenVLA-OFT-based policy · 160 updates each

020406080100%
Terminal only
61.7%
Dense + phase
65.3%

Common initialization: 61.0% · terminal reward weight: 5
300 validation rollouts per endpoint

+3.6 percentage points between final endpoints

Descriptive endpoint gain; independent training-seed uncertainty is not established.

Intermediate feedback: benefit and design cost

Feedback Updates Success
Terminal only 160 61.7%
Dense + phase 160 65.3%
Phase only 110 62.3%

Dense shaping rewards new progress: Δpt = max(pt − pbest, 0).

Dense + phase reached a higher endpoint here. Its progress functions require task-specific design; binary milestones need completion predicates.

Terminal coefficient: 5 for terminal-only and dense + phase; 1 for phase-only. Phase-only also uses fewer updates.

A cable robot changes the control problem

Overview of simulated cable-driven parallel robot, cables supporting a gripper over an apple and bowl
Cable-driven parallel robot (CDPR) · simulation

“Put the apple into the bowl.”

Five policy channels

Translation: x, y, z
Yaw
Gripper

Fixed inverse kinematics maps
Cartesian targets to cable lengths.

Empty gripper→Grasp + lift→Carry + place

Bootstrapping control on a new robot

Dense simple-skill acquisition, binary refinement and balanced self-imitation, then milestone-based full-task RL with a SmolVLA residual controller
Acquire → consolidate → compose. Pretrained SmolVLA + a newly initialized residual.

SmolVLA with a learned CDPR correction

SmolVLA residual controller with 518 observation features and a 40-dimensional action prior

CDPR: learn skills, retain them, then combine them

Learn with RLTry a simple skill
→
Check retentionTest earlier skills
→
SIL if neededRehearse successes
→
Continue RLLearn the next skill

Learn the parts

Approach, pickup and placement have separate instructions and starting states. Dense rewards guide initial progress; binary success rewards refine each skill.

Then learn the whole task

SIL means self-imitation learning. It retains earlier skills using successful actions. Before full-task RL, fit scripted-oracle and assisted complete-task trajectories. Then train from empty-gripper starts.

CDPR stage transitions were validation-guided and manual. Full-task RL and evaluation use unassisted starts.

RL: improve actions using rewards

Try the task → score the attempts → update the policy.

ℒRL=ℒclip−ηℋ\mathcal L_{\mathrm{RL}}=\mathcal L_{\mathrm{clip}}-\eta\mathcal H

Small policy updates

PPO-style clipping reduces the incentive for large action-likelihood changes; it does not impose a hard bound on the update.

LRL is the training loss.
Lclip is the clipped policy loss.

Compare attempts

Group-relative credit (GRPO-style) compares attempts from the same scene.

H encourages exploration.
η controls its strength.

Learning a new skill can erase an old one

Reaching success

Before learning to carry and place
64.1%
After learning to carry and place
5.3%

What happened?

Placement practice starts with the object already held.

The policy learns transport and release, but its earlier reaching skill deteriorates.

Learning the latest skill can overwrite useful earlier behavior.

Isolated reaching test · three evaluation rounds per condition.

SIL: recover skills by imitating successful actions

SIL means self-imitation learning: fit the policy to its own successful actions.

ℒSIL=mean⁡[(predicted action−recorded successful action)2]\mathcal L_{\mathrm{SIL}}=\operatorname{mean}\!\left[(\text{predicted action}-\text{recorded successful action})^2\right]

Balance successful actions by instruction, fit the policy, check retention, then resume RL.

Separate recovery evaluation · reaching: 3 rounds; placement: 2 rounds per condition.

Skill Before SIL After SIL
Reaching 8.0% 31.1%
Plate placement 50.0% 52.3%
Bowl placement 23.05% 27.65%

Partial recovery; separate from the preceding forgetting test.

Full-task RL: keep credit for a successful pickup

After consolidation and oracle/assisted fitting: full-task RL · empty-gripper start

Approach ✓

Milestone achieved

→

Held pickup ✓

Milestone achieved

→

Placement ×

Task incomplete

Keep local credit

Approach and pickup retain their
milestone-specific learning signal.

Train the remaining step

Suppress the negative completion bonus
on achieved approach/pickup milestones.

Preserve useful partial behavior while learning to finish.

Milestones assign training credit; evaluation uses no external skill switching.

CDPR: 70.61% strict completion in simulation

Development validation: 723 / 1,024 · 512 plate + 512 bowl attempts

Marginal outcome rates, all attempts

Physical grasp
92.48%
Held lift
88.28%
Strict completion
70.61%

Zero-to-100% scale.
One training lineage.
Development validation.

Selected historical successes

Apple into plateApple into plate
Apple into plate
Apple into bowlApple into bowl
Apple into bowl

Historical examples; separate from the 70.61% endpoint.

Transport and release remain the main bottleneck.

Strict success: grasp, held lift, intentional correct release; no carry slip or wrong placement. All attempts include numerical failures.

Full-task completion across destination types

Outcome All attempts
Strict completion 723/1,024 · 70.61%
Plate completion 393/512 · 76.76%
Bowl completion 330/512 · 64.45%
Carry slip 16.70%
Wrong placement 14.16%

Development validation used during training. Empty-gripper starts, one instruction, no teacher assistance. All attempts retained; event flags can overlap.

CDPR adaptation: procedure and observed outcome

Three problems

New action interface
Too few successful complete rollouts
Earlier skills degrade during new training

Three responses

SmolVLA prior + learned residual
Simple skills first; binary milestones later
Balanced self-imitation + oracle/assisted fitting

The complete pipeline produced a policy that grasps, carries and places under one instruction.

Partial skill recovery and 70.61% development-validation completion. Each ingredient’s independent contribution remains to be tested.

Part 3 · What comes next

  1. 01Planning above a fixed controller
  2. 02Learning for a new embodiment
  3. 03What comes next

What should the robot predict—and when should it ask for help?

Physical understanding and decisions under uncertainty

Planned VLA work

01

Predict physical consequences

PINN / iPINN and JEPA: test contact and task-outcome predictions.

02

Estimate when the model may be wrong

Calibrate error estimates to trigger replanning, verification or human help.

03

Choose useful experience

Test selective simulation and replay at matched compute.
Engineering-control cartography motivates a VLA extension.

Near term: independent evaluation and physical deployment tests.

What the experiments establish

Planning changes both successes and failures.
Count rescued and lost successes alongside the executor’s own variability.

Adaptation requires learning and retaining skills.
The combined CDPR pipeline reached 70.61% strict success in simulation development validation.

The next checks are independent evaluation and hardware tests.
Use matched component comparisons to establish which training stages contribute.

References: policies, planning and reinforcement learning

Kim, Finn & Liang (2025). Fine-Tuning Vision-Language-Action Models: Optimizing Speed and Success.

Li et al. (2025). SimpleVLA-RL: Scaling VLA Training via Reinforcement Learning.

Shukor et al. (2025). SmolVLA.

Xiao et al. (2025). Probe, Learn, Distill.

Study manuscripts: planner evaluation and staged VLA adaptation.

Bootstrapping Vision-Language-Action Models for New Robot Embodiments with Staged Reinforcement Learning — manuscript draft

References: related workshop publications

Salloum, Mifsud Bonici, Ibrahim, Osinenko & Kornaev (2026). Diversity-Aware Adaptive Collocation for Physics-Informed Neural Networks via Sparse QUBO Optimization and Hybrid Coresets.
AI&PDE, ICLR 2026 Workshop.

Degtiarev, Ryabkova & Kornaev (2026). LLM-Driven Loss Balancing for Physics-Informed Neural Networks.
AI&PDE, ICLR 2026 Workshop.

Nurtdinov, Korshuk, Kornaev & Maloletov (2025). Evaluation of a Robust Control System in Real-World Cable-Driven Parallel Robots.
ICLR 2025 Workshop: Towards Agentic AI for Science.

Related publications; workshop venues identified explicitly.