Terminal Matters: Kinodynamic Planning with a Terminal Cost and Learned Uncertainty in Belief State-Cost Space
Pith reviewed 2026-05-15 05:56 UTC · model grok-4.3
The pith
A terminal cost in kinodynamic planning lets robots optimize goal quality and reliability without losing asymptotic optimality guarantees.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
We introduce a terminal-cost formulation for kinodynamic planning that allows terminal-state quality to be optimized alongside accumulated trajectory cost. We prove that AO-RRT preserves its asymptotic optimality under this augmented objective. We further extend the formulation to belief space and prove that minimizing the Wasserstein distance between the terminal belief and the goal improves a lower bound on the probability of reaching the goal region. The KiTe planner implements this terminal-cost objective with learned belief dynamics to encode goal preferences and improve reliability under uncertainty.
What carries the argument
The augmented objective that sums accumulated trajectory cost with a terminal cost term, where the terminal term is either a direct quality measure or the Wasserstein distance to the goal belief distribution.
If this is right
- AO-RRT retains asymptotic optimality when the objective includes a terminal cost.
- In belief space, Wasserstein-distance minimization tightens the lower bound on goal-reaching probability.
- Learned dynamics and uncertainty models allow the planner to operate on systems that lack closed-form uncertainty descriptions.
- Experiments on Flappy Bird, car parking, and planar pushing demonstrate consistently higher success rates under uncertainty, including in real-world pushing.
Where Pith is reading between the lines
- Goal preferences can be directly encoded by shaping the terminal cost to favor specific arrival states.
- Optimizing against modeled uncertainty may reduce the performance drop when transferring plans from simulation to hardware.
- The same terminal-cost structure could be grafted onto other asymptotically optimal sampling-based planners.
Load-bearing premise
The learned dynamics and process uncertainty models must accurately represent the true system behavior during actual deployment.
What would settle it
Run KiTe on a physical robot whose true dynamics deviate from the learned model and measure whether the observed goal-reaching success rate matches the improvement predicted by the Wasserstein lower bound.
Figures
read the original abstract
In many real-world robotic tasks, robots must generate dynamically feasible motions that reliably reach desired goals even under uncertainty. Yet existing sampling-based kinodynamic planners typically optimize accumulated trajectory costs and treat goal reaching as a feasibility check, rather than explicitly optimizing terminal-state quality, such as goal preference or goal-reaching reliability. In this work, we introduce a terminal-cost formulation for kinodynamic planning that allows terminal-state quality to be optimized alongside accumulated trajectory cost. We prove that AO-RRT, an asymptotically optimal kinodynamic planner, preserves its asymptotic optimality under this augmented objective. We further extend the formulation to belief space and prove that minimizing the Wasserstein distance between the terminal belief and the goal improves a lower bound on the probability of reaching the goal region. The resulting planner, KiTe, uses this terminal-cost objective to encode goal preferences and improve reliability under uncertainty. To support systems without analytical uncertainty models, we learn dynamics and process uncertainty directly from data and integrate the learned belief dynamics into planning. Experiments on Flappy Bird, Car Parking, and Planar Pushing show that KiTe consistently improves goal-reaching success under uncertainty. Real-world Planar Pushing experiments further demonstrate that KiTe can plan effectively with learned dynamics and uncertainty. Source code is available at https://github.com/elpis-lab/KiTe.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript introduces a terminal-cost formulation for kinodynamic planning that augments accumulated trajectory cost with an explicit terminal-state quality term. It proves that AO-RRT preserves asymptotic optimality under the augmented objective, extends the approach to belief space where minimizing the Wasserstein distance between terminal belief and goal belief improves a lower bound on goal-reaching probability, learns dynamics and process uncertainty from data, and reports improved success rates on Flappy Bird, Car Parking, and planar pushing tasks (including real-world experiments).
Significance. If the stated proofs hold and the learned models are sufficiently accurate, the work supplies a principled mechanism for incorporating terminal preferences and uncertainty into asymptotically optimal sampling-based planners, with potential to increase reliability in stochastic robotic tasks. The open-source implementation is a positive factor for reproducibility.
major comments (2)
- [§4.2] §4.2 (belief-space extension): the proof that Wasserstein-distance minimization strictly raises the lower bound on P(reach goal) presupposes that the learned transition kernel and process noise exactly match the true stochastic dynamics; no forward-simulation error, calibration plots, or predicted-vs-empirical terminal-belief Wasserstein distances are reported for the planar-pushing experiments, leaving the real-world applicability of the bound unverified.
- [§3.1] §3.1, Eq. (7): the claim that AO-RRT remains asymptotically optimal with an additive terminal cost requires explicit verification that the terminal term does not alter the cost-to-go estimates or rewiring conditions in a way that violates the original optimality proof; the current sketch does not address how the terminal cost is propagated through the tree.
minor comments (3)
- [Table 1] Table 1 and Figure 4: success-rate improvements are reported without statistical significance tests or confidence intervals; adding these would strengthen the empirical claims.
- [Notation] Notation section: the belief-state cost space symbols (e.g., b, W, terminal cost) are introduced without a consolidated table, making cross-referencing cumbersome.
- [Related Work] Related-work paragraph: the discussion of prior belief-space RRT variants omits recent Wasserstein-based planning papers; a brief comparison would clarify novelty.
Simulated Author's Rebuttal
We appreciate the referee's constructive comments. We address each major point below and indicate the revisions we will make to the manuscript.
read point-by-point responses
-
Referee: [§4.2] §4.2 (belief-space extension): the proof that Wasserstein-distance minimization strictly raises the lower bound on P(reach goal) presupposes that the learned transition kernel and process noise exactly match the true stochastic dynamics; no forward-simulation error, calibration plots, or predicted-vs-empirical terminal-belief Wasserstein distances are reported for the planar-pushing experiments, leaving the real-world applicability of the bound unverified.
Authors: We agree that the theoretical guarantee relies on the accuracy of the learned model. While the real-world experiments show improved performance, we did not include explicit model validation metrics. In the revision, we will add forward-simulation error analysis, calibration plots, and comparisons of predicted versus empirical terminal-belief Wasserstein distances for the planar pushing experiments to verify the model's fidelity and support the practical relevance of the bound. revision: partial
-
Referee: [§3.1] §3.1, Eq. (7): the claim that AO-RRT remains asymptotically optimal with an additive terminal cost requires explicit verification that the terminal term does not alter the cost-to-go estimates or rewiring conditions in a way that violates the original optimality proof; the current sketch does not address how the terminal cost is propagated through the tree.
Authors: The terminal cost is a state-dependent additive term applied only at the goal-reaching nodes. Because it is independent of the path taken to reach a particular state, it does not affect the relative ordering of path costs during rewiring or the cost-to-go estimates in the tree. The asymptotic optimality is preserved as the proof can be adapted by considering the augmented cost function, where the terminal term is fixed for each terminal state. We will revise §3.1 to provide a more detailed explanation of how the terminal cost is incorporated into the tree propagation and rewiring logic, including an explicit verification that the original proof structure holds. revision: yes
Circularity Check
No significant circularity; proofs are independent mathematical derivations
full rationale
The paper's load-bearing claims consist of two explicit proofs: (1) preservation of AO-RRT asymptotic optimality under an additive terminal cost, and (2) that minimizing Wasserstein distance between terminal belief and goal belief raises a lower bound on goal-reaching probability. These are presented as new derivations resting on standard sampling-based planning assumptions and the definition of Wasserstein distance; they do not reduce to fitted parameters, self-definitions, or prior self-citations by construction. The learned dynamics component is used only for implementation and is not part of the optimality or bound proofs. No self-citation is invoked as the sole justification for uniqueness or ansatz. The derivation chain is therefore self-contained against external mathematical benchmarks.
Axiom & Free-Parameter Ledger
axioms (2)
- standard math Standard assumptions underlying asymptotic optimality of AO-RRT variants hold for the augmented terminal-cost objective
- domain assumption Wasserstein distance minimization between terminal belief and goal belief improves a lower bound on goal-reaching probability
Reference graph
Works this paper leans on
-
[1]
S. M. L aValle, Planning a lgorithms. Cambridge un iversity press, 2006. https://www.google.com/books/edition/Planning Algorithms/ -PwLBAAAQBAJ
work page 2006
-
[2]
`E. Pairet, J. D. Hern ´andez, M. Carreras, Y . Petillot, and M. Lahijanian, “Online mapp ing and mo tion p lanning unde r uncertainty f or safe navigation in unknown en vironments,”I EEE Trans. Autom. Sci. Eng., vol. 19, no. 4, pp. 3356–3378, 2022. https://ieeexplore.ieee.org/document/ 9610137
work page 2022
-
[3]
Chance- constrained multi-robot motion planning under gaussian uncertainties,
A. T heurkauf, J. Kottinger, N. Ahmed, and M . L ahijanian, “Chance- constrained multi-robot motion planning under gaussian uncertainties,” IEEE Robo t. Autom. L etters, v ol. 9, no. 1, pp. 835–842, 2024. https://ieeexplore.ieee.org/document/10333309
-
[4]
K. Nagami and M . Schwager, “ State es timation and be lief space planning unde r epistemic unce rtainty f or l earning-based pe rception systems,”I EEE Robo t. Autom. L etters, vol. 9, no. 6, pp. 511 8–5125,
- [5]
-
[6]
Learning compositional models o f r obot skills for t ask and mo tion p lanning,
Z. Wang, C. R. Garrett, L. P. Kaelbling, and T. Lozano-P´erez, “Learning compositional models o f r obot skills for t ask and mo tion p lanning,” Intl. J. of Robotics Resea rch, v ol. 40, no. 6-7, pp. 866–894, 2021. https://doi.org/10.1177/02783649211004615
-
[7]
Learning to poke b y poking: Experiential l earning o f i ntuitive physics,
P. Agrawal, A. V . Nair, P. Abbeel, J. Malik, and S . L evine, “Learning to poke b y poking: Experiential l earning o f i ntuitive physics,” i n Advances in Neu ral I nformation P rocessing S ystems, vol. 29, 2016. https://proceedings.neurips.cc/paper files/paper/2016/file/ c203d8a151612acf12457e4d67635a95-Paper.pdf
work page 2016
-
[8]
ActivePusher: Active Learning and Planning with Residual Physics for Nonprehensile Manipulation
Z. Zhong, S. Golestaneh, and C. Chamzas, “Activepusher: Active learning and p lanning w ith residual physics for nonprehensile man ipulation,” arXiv preprint arXiv:2506.04646, 2025. https://arxiv.org/abs/2506.04646
work page internal anchor Pith review Pith/arXiv arXiv 2025
-
[9]
Randomized kinodynamic planning,
S. M. LaValle and J. J. Kuffner Jr, “Randomized kinodynamic planning,” Intl. J. of Robotics Resea rch, v ol. 20, no. 5, pp. 378–400, 2001. https://journals.sagepub.com/doi/10.1177/02783640122067453
-
[10]
Asymptotically optimal sampling-based motion planning methods,
J. D. Gammell and M. P. Strub, “Asymptotically optimal sampling-based motion planning methods,” Annual Review of Control, Robot., and Autom. Syst., vol. 4, no. Volume 4, 2021, pp. 295–318, 2021. www.annualreviews. org/content/journals/10.1146/annurev-control-061920-093753
-
[11]
Asymptotically optimal sampling- based k inodynamic p lanning,
Y . Li,Z. Littlefield, and K. E. Bekris, “Asymptotically optimal sampling- based k inodynamic p lanning,”I ntl. J. of Robotics Resea rch, v ol. 35, no. 5, pp. 528–564, 2016. https://doi.org/10.1177/0278364915614386
-
[12]
Asymptotically optimal planning by feasible kinodynamic planning in a state–cost space,
K. Hauser and Y .Zhou, “Asymptotically optimal planning by feasible kinodynamic planning in a state–cost space,”I EEE Trans. Robot., vol. 32, no. 6, pp. 1431–1443, 2016. https://ieeexplore.ieee.org/document/7588078
-
[13]
Rapidly-exploring random belief trees for motion planning under uncertainty,
A. Bry and N. Roy, “Rapidly-exploring random belief trees for motion planning under uncertainty,” in IEEE Intl. Conf. Robot. Autom. (ICRA), 2011, pp. 723–730. https://ieeexplore.ieee.org/document/5980508 19
-
[14]
Chance cons trained rrt for probabilistic robustness to en vironmental uncertainty,
B. L uders, M. Kothari, and J. How, “ Chance cons trained rrt for probabilistic robustness to en vironmental uncertainty,” in AIAA guidance, navigation, and con trol conference, 2010, p. 8160. https://dspace.mit.edu/handle/1721.1/67648
work page 2010
-
[15]
Stochastic robustness interval f or motion p lanning w ith s ignal t emporal l ogic,
R. B. Ily es, Q. H. Ho, and M . L ahijanian, “ Stochastic robustness interval f or motion p lanning w ith s ignal t emporal l ogic,” i n IEEE Intl. Conf. Robot. Autom. (I CRA), 2023, pp. 571 6–5722. https://ieeexplore.ieee.org/document/10161409
-
[16]
Gaussian be lief tr ees for chance cons trained as ymptotically optimal motion p lanning,
Q. H. Ho, Z. N. Sunberg, and M . L ahijanian, “Gaussian be lief tr ees for chance cons trained as ymptotically optimal motion p lanning,” in IEEE Intl. Conf. Robot. Autom. (I CRA), 2022, pp. 11 0 29–11 035. https://ieeexplore.ieee.org/document/9812343
-
[17]
Refined analysis of asymptotically-optimal kinodynamic planning in the s tate-cost space,
M. Kleinbort, E. Granados, K. Solovey, R. Bonalli, K. E. Bekris, and D. Halperin, “Refined analysis of asymptotically-optimal kinodynamic planning in the s tate-cost space,” in IEEE Intl. Conf. Robot. Autom. (ICRA), 2020, pp. 6344–6350. https://ieeexplore.ieee.org/document/ 9197236
work page 2020
-
[18]
Efficient and as ymptotically optimal kinodynamic mo tion p lanning via dom inance-informed regions,
Z. Littl efield and K . E. Bekris, “Efficient and as ymptotically optimal kinodynamic mo tion p lanning via dom inance-informed regions,” i n IEEE/RSJ Intl. Conf. on Intell. Robots and S yst. (IROS), 2018, pp. 1–9. https://ieeexplore.ieee.org/document/8593672
-
[19]
The importance o f a su itable d istance function in be lief-space planning,
Z. Littl efield, D. Klimenko, H. Kurniawati, and K . E. Bekris, “The importance o f a su itable d istance function in be lief-space planning,” i nRobo tics Resea rch: V olume 2 , 2017, pp. 683–700. https://doi.org/10.1007/978-3-319-60916-4 39
-
[20]
Motion p lanning under uncertainty f or r obotic tasks w ith long time ho rizons,
H. Kurniawati, Y . Du, D. Hsu, and W . S. L ee, “ Motion p lanning under uncertainty f or r obotic tasks w ith long time ho rizons,”I ntl. J. of Robotics Resea rch, v ol. 30, no. 3, pp. 308–323, 2011. https://journals.sagepub.com/doi/abs/10.1177/0278364910386986
-
[21]
An online pomdp so lver for uncertainty planning in d ynamic en vironment,
H. Kurniawati and V . Yadav, “An online pomdp so lver for uncertainty planning in d ynamic en vironment,” i n Intl. Symp. on Robo tics Research, 2016, pp. 611–629. https://link.springer.com/chapter/10.1007/ 978-3-319-28872-7 35
work page 2016
-
[22]
L earning online be lief prediction for efficient pomdp p lanning in au tonomous driving,
Z. Huang, C. T ang, C. Lv, M. T omizuka, and W . Zhan, “L earning online be lief prediction for efficient pomdp p lanning in au tonomous driving,”I EEE Robo t. Autom. L etters, v ol. 9, no. 8, pp. 70 23–7030,
- [23]
-
[24]
Risk contours map for risk bounded motion planning under perception uncertainties
A. M. Jasour and B. C. Williams, “Risk contours map for risk bounded motion planning under perception uncertainties.” inRobo tics: Science and Systems, 2019, pp. 22–26. https://m.roboticsproceedings.org/rss15/p56.pdf
work page 2019
-
[25]
Distributionally robust sampling-based motion planning under uncertainty,
T. Summers, “Distributionally robust sampling-based motion planning under uncertainty,” i n IEEE/RSJ I ntl. Conf. on Intell. Robots and S yst. (I ROS). I EEE P ress, 2018, p. 6518–6523. https: //doi.org/10.1109/IROS.2018.8593893
-
[27]
Robust-rrt: Probabilistically-complete mo tion p lanning for uncertain non linear systems,
A. Wu, T. L ew, K. Solovey, E. Schmerling, and M. Pavone, “Robust-rrt: Probabilistically-complete mo tion p lanning for uncertain non linear systems,” in Intl. Symp. on Robo tics Resea rch, 2022, pp. 5 38–554. https://link.springer.com/chapter/10.1007/978-3-031-25555-7 36
-
[28]
Sampling-based motion planning for optimal probability of collision under environment uncertainty,
H. Lu, H. Kurniawati, and R. Shome, “Sampling-based motion planning for optimal probability of collision under environment uncertainty,” in IEEE/RSJ I ntl. Conf. on Intell. Robots and S yst. (I ROS), 2024, pp. 3138–3145. https://ieeexplore.ieee.org/document/10801890
-
[29]
On the p itfalls of heteroscedastic unce rtainty estimation w ith p robabilistic neu ral networks,
M. Seitzer, A. T avakoli, D. Antic, and G. Martius, “ On the p itfalls of heteroscedastic unce rtainty estimation w ith p robabilistic neu ral networks,” i n Intl. Conf. on Learning Rep resentations, Apr. 2022. https://openreview.net/forum?id=aPOpXlnV1T
work page 2022
-
[30]
Dropout as a ba yesian app roximation: Representing mode l uncertainty i n deep learning,
Y .Gal and Z . Ghahramani, “ Dropout as a ba yesian app roximation: Representing mode l uncertainty i n deep learning,” i n Intl. Conf. on Mach ine Learning, v ol. 4 8, 20–22 Jun 2 016, pp. 1050–105 9. https://proceedings.mlr.press/v48/gal16.html
-
[31]
D. Holzm¨uller, V .Zaverkin, J. K¨astner, and I. Steinwart, “A framework and benchmark for deep batch active learning for regression,”J ournal of Machine Learning Resea rch, v ol. 24, no. 1 64, pp. 1– 81, 2023. https://dl.acm.org/doi/abs/10.5555/3648699.3648863
-
[32]
A. Amini, W. Schwarting, A. Soleimany, and D. Rus, “Deep evidential regression,” in Advances in Neu ral I nformation P rocessing S ystems,
-
[33]
https://dl.acm.org/doi/10.5555/3495724.3496975
-
[34]
URL https://doi.org/10.1146/ annurev-control-061623-094742
A. Orthey, C. Chamzas, and L. E. Kavraki, “ Sampling-based motion p lanning: A comparative review,” Annual Review o f Control, Robot., and Autom. Syst., v ol. 7, no. 1, pp. 285–310, J uly 2024. https://doi.org/10.1146/annurev-control-061623-094742
-
[35]
J. Van Den Be rg, P. Abbeel, and K . Goldberg, “Lqg-mp: Optimized path p lanning for r obots w ith mo tion unce rtainty and imperfect state information,”I ntl. J. of Robotics Research, vol. 30, no. 7, pp. 895–913,
-
[36]
https://journals.sagepub.com/doi/abs/10.1177/0278364911406562
-
[37]
M. Kleinbort, K. Solovey, Z. Littlefield, K. E. Bekris, and D. Halperin, “Probabilistic comp leteness o f rrt f or geometric and k inodynamic planning with forward propagation,”I EEE Robot. Autom. Letters, vol. 4, no. 2, pp. i–vii, 2019. https://ieeexplore.ieee.org/document/8584061
-
[38]
A micro lie theory for state estimation in robotics,
J. Sola, J. Deray, and D. Atchuthan, “ A micro lie theory f or state es timation in robotics,” arXiv preprint arXiv:1812.01537, 2018. https://arxiv.org/abs/1812.01537
-
[39]
Effective sampling and d istance metrics for 3D rigid body path planning,
J. Kuffner, “Effective sampling and d istance metrics for 3D rigid body path planning,” in IEEE Intl. Conf. Robot. Autom. (ICRA), vol. 4, Apr. 2004, pp. 3993–3998. https://ieeexplore.ieee.org/document/1308895
-
[40]
C. Gaz, M. Cognetti, A. Oliva, P. Robuffo Giordano, and A. De Luca, “Dynamic identification o f t he franka em ika panda robot with retrieval of f easible pa rameters us ing pena lty-based op timization,” IEEE Robo t. Autom. L etters, v ol. 4, no. 4, pp. 4147–4154, 2019. https://ieeexplore.ieee.org/document/8772145/
-
[41]
Mujoco: A physics engine for model- based control,
E. Todorov, T. Erez, and Y . Tassa, “Mujoco: A physics engine for model- based control,” in IEEE/RSJ Intl. Conf. on Intell. Robots and Syst. (IROS), 2012, pp. 5026–5033. https://ieeexplore.ieee.org/document/6386109
-
[42]
The Open Motion Planning Library,
I. A. S ¸ucan, M. Moll, and L. E. Kavraki, “The Open Motion Planning Library,”I EEE Robo t. Autom. Magazine, v ol. 1 9, no. 4, pp. 7 2–82, December 2012, https://ompl.kavrakilab.org
work page 2012
-
[43]
P. Polack, F. Altch´e, B. d’Andr´ea Novel, and A. de La Fortelle, “The kinematic b icycle mode l: A consistent model f or planning feasible trajectories for autonomous vehicles?” in IEEE Intell. Veh. Symp. (IV), 2017, pp. 812–818. https://ieeexplore.ieee.org/document/7995816
-
[44]
Benchmarking in manipulation research: Using the yale-cmu-berkeley object and model set,
B. Calli, A. Walsman, A. Singh, S. Srinivasa, P. Abbeel, and A. M. Dollar, “Benchmarking in manipulation research: Using the yale-cmu-berkeley object and model set,”I EEE Robot. Autom. Magazine, vol. 22, no. 3, pp. 36–52, 2015. https://ieeexplore.ieee.org/document/7254318
-
[45]
Expansion-grr: Efficient generation of smooth g lobal r edundancy r esolution roadmaps,
Z. Zhong, Z. Li, and C. Chamzas, “Expansion-grr: Efficient generation of smooth g lobal r edundancy r esolution roadmaps,” i n IEEE/RSJ Intl. Conf. on Intell. Robots and S yst. (I ROS), 2024, pp. 8854–8860. https://ieeexplore.ieee.org/document/10801917
-
[46]
Task and mo tion planning for execution in the real,
T. Pan, R. Shome, and L. E. Kavraki, “Task and mo tion planning for execution in the real,”I EEE Trans. Robot., v ol. 40, pp. 3356–3371,
- [47]
-
[48]
Regret-based samp ling o f pareto fronts for multiobjective robot planning problems,
A. Botros, N. Wilde, A. Sadeghi, J. Alonso-Mora, and S . L. Smith, “Regret-based samp ling o f pareto fronts for multiobjective robot planning problems,”I EEE Trans. Robot., vol. 40, pp. 3778–3794, 2024. https://ieeexplore.ieee.org/document/10599820
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.