REVIEW 2 major objections 1 minor 19 references
Active-sensing deferred-decision optimization biases shared trajectories toward earlier target identification while preserving reachability to all candidates.
Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →
T0 review · grok-4.3
2026-06-26 10:18 UTC pith:AV4ED3AG
load-bearing objection The paper adds an active-sensing term to DDTO and claims a mixed-integer conic reformulation that keeps reachability while speeding identification, but the reformulation's fidelity to the original constraints is the step that needs checking. the 2 major comments →
Active Sensing and Deferred-Decision Trajectory Optimization for Robust Target Identification
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
AS-DDTO computes trajectories that remain coincident for as long as possible before separating toward individual targets, yet incorporates an explicit information-acquisition cost that biases the coincident portion into regions yielding earlier distinction under distance-dependent sensing, while the mixed-integer conic reformulation ensures recursive feasibility, belief concentration, and fixed-time coverage of the conformal candidate set.
What carries the argument
Active-Sensing Deferred-Decision Trajectory Optimization (AS-DDTO), which augments the DDTO objective with a trajectory-dependent information-acquisition term that steers coincident segments toward higher-distinguishing-power regions.
Load-bearing premise
Distance-dependent sensing must permit valid conformal candidate-set updates, and the mixed-integer conic reformulation must preserve the claimed recursive feasibility and belief-concentration guarantees.
What would settle it
Run the AS-DDTO planner and standard DDTO on identical candidate sets and sensing budgets; if the time to first correct identification is not statistically smaller for AS-DDTO across repeated trials with distance-dependent noise, the performance claim is falsified.
If this is right
- Reachability to every candidate target is preserved at every planning step.
- Belief mass concentrates on the true target as measurements accumulate.
- The raw conformal candidate set is covered within a fixed time horizon.
- Target identification occurs earlier than with plain DDTO under the same sensing budget.
Where Pith is reading between the lines
- The same biasing idea could be applied to search problems where the goal is to reduce uncertainty volume rather than identify a discrete target.
- Extending the conformal update rule to time-varying or adversarial sensing models would test robustness beyond the distance-dependent case studied.
- Because the coincident segment is explicitly steered, the method may naturally produce lower total control effort when early disambiguation shortens the required planning horizon.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper claims to develop Active-Sensing Deferred-Decision Trajectory Optimization (AS-DDTO) for robust target identification in mobile sensing systems. It extends DDTO by adding a trajectory-dependent information-acquisition term to bias coincident trajectories toward regions enabling earlier identification, while maintaining reachability to all candidate targets. The framework uses Bayesian and conformal updates for distance-dependent sensing, derives a mixed-integer conic reformulation, and provides guarantees on recursive feasibility, belief concentration, and fixed-time coverage. Numerical simulations demonstrate improved performance over standard DDTO.
Significance. If the mixed-integer conic reformulation is rigorously shown to preserve the necessary guarantees without introducing spurious feasible trajectories, this could be a significant contribution to active sensing and trajectory optimization under uncertainty. The approach combines reachability maintenance with active information gathering in a novel way, and the guarantees on belief concentration could enable reliable decision making in time-constrained scenarios.
major comments (2)
- [Mixed-integer conic reformulation (as described in abstract and framework)] The abstract states that the mixed-integer conic reformulation supplies guarantees on recursive feasibility, belief concentration, and fixed-time coverage. However, it is not clear whether this reformulation is equivalent to the original problem or a conservative approximation that maintains the reachability constraints to all candidates without relaxation. This is load-bearing for the central claim that the planner maintains reachability while biasing for earlier identification.
- [Framework for conformal updates and reformulation] The preservation of recursive feasibility and belief concentration under the distance-dependent conformal candidate-set updates needs explicit demonstration that the updates commute with the reformulated dynamics; otherwise the reachability claim may not hold.
minor comments (1)
- [Abstract] The abstract mentions 'numerical simulations' but does not specify the simulation setup, metrics, or baseline comparisons in detail, which would strengthen the presentation of results.
Simulated Author's Rebuttal
We thank the referee for their thoughtful review and constructive comments on the mixed-integer conic reformulation and conformal updates. We address each major comment below, clarifying the equivalence of the reformulation and committing to additional explicit demonstrations where needed.
read point-by-point responses
-
Referee: [Mixed-integer conic reformulation (as described in abstract and framework)] The abstract states that the mixed-integer conic reformulation supplies guarantees on recursive feasibility, belief concentration, and fixed-time coverage. However, it is not clear whether this reformulation is equivalent to the original problem or a conservative approximation that maintains the reachability constraints to all candidates without relaxation. This is load-bearing for the central claim that the planner maintains reachability while biasing for earlier identification.
Authors: The mixed-integer conic reformulation is derived as an exact equivalent of the original problem using standard exact reformulation techniques (big-M and perspective functions) that introduce no relaxation on the reachability constraints to all candidate targets. The proofs of recursive feasibility, belief concentration, and fixed-time coverage are established directly on this equivalent formulation. We will revise the abstract and framework section to explicitly state the exact equivalence and absence of relaxation on reachability. revision: yes
-
Referee: [Framework for conformal updates and reformulation] The preservation of recursive feasibility and belief concentration under the distance-dependent conformal candidate-set updates needs explicit demonstration that the updates commute with the reformulated dynamics; otherwise the reachability claim may not hold.
Authors: The conformal updates are applied to the candidate set prior to each optimization solve, and the reformulated dynamics remain linear. Because reachability is enforced exactly for the current (updated) candidate set at every step, the properties are preserved. We will add a dedicated lemma in the revised manuscript that explicitly shows the updates commute with the reformulation by demonstrating that the feasible set of the updated problem contains the appropriate projection of the prior feasible set, thereby maintaining recursive feasibility and belief concentration. revision: yes
Circularity Check
No significant circularity; derivation is self-contained
full rationale
The paper derives a mixed-integer conic reformulation of the DDTO problem and states guarantees on recursive feasibility, belief concentration, and fixed-time coverage. No equations or claims in the provided abstract reduce a prediction or guarantee to a fitted parameter defined by the method itself, nor do they rely on self-citation chains or ansatzes imported from prior author work. The reachability and identification claims rest on the reformulation and conformal updates, which are presented as derived results rather than tautological redefinitions. This is the common case of an optimization paper whose central steps are independent of the target outputs.
Axiom & Free-Parameter Ledger
read the original abstract
We study trajectory optimization in mobile sensing systems that must identify which member of a finite candidate set is the true target, while maintaining reachability to all potential candidate targets, under resource constraints. Deferred-Decision Trajectory Optimization (DDTO) addresses this setting by computing trajectories that reach individual targets but remain coincident for as long as possible before separating toward different targets. We propose Active-Sensing DDTO (AS-DDTO), which extends DDTO by adding a trajectory-dependent information-acquisition term to the planning objective. The resulting planner maintains reachability to candidate targets while biasing the coincident portion of the trajectories toward regions that enable earlier target identification. The framework supports Bayesian updates and conformal candidate-set updates for distance-dependent sensing. We derive a mixed-integer conic reformulation and provide guarantees on recursive feasibility, belief concentration, and fixed-time coverage for the raw conformal candidate set. Numerical simulations show improved target identification compared with standard DDTO under distance-dependent sensing uncertainty and limited sensing budget.
Figures
Reference graph
Works this paper leans on
-
[1]
A survey on active simultaneous localization and mapping: State of the art and new frontiers,
J. A. Placed, J. Strader, H. Carrillo, N. Atanasov, V . Indelman, L. Car- lone, and J. A. Castellanos, “A survey on active simultaneous localization and mapping: State of the art and new frontiers,”IEEE Transactions on Robotics, 2023
2023
-
[2]
Sensor-model-based trajectory optimization for uavs to enhance detection performance: An optimal control approach and experimental results,
M. Zwick, M. Gerdts, and P. St ¨utz, “Sensor-model-based trajectory optimization for uavs to enhance detection performance: An optimal control approach and experimental results,”Sensors, vol. 23, 2023
2023
-
[3]
Deferring decision in multi-target trajectory optimization,
P. Elango, S. B. Sarsilmaz, and B. Acikmese, “Deferring decision in multi-target trajectory optimization,” inAIAA SciTech 2022 Forum, 2022
2022
-
[4]
Deferred-decision trajec- tory optimization,
P. Elango, S. B. Sarsilmaz, and B. Ac ¸ıkmes ¸e, “Deferred-decision trajec- tory optimization,”arXiv preprint arXiv:2502.06623, 2025
-
[5]
On trajectory optimization for active sensing in gaussian process models,
J. L. Ny and G. J. Pappas, “On trajectory optimization for active sensing in gaussian process models,” inIEEE Conference on Decision and Control, 2009
2009
-
[6]
Actively learning gaussian process dynamics,
M. Buisson-Fenet, F. Solowjow, and S. Trimpe, “Actively learning gaussian process dynamics,” inConference on Learning for Dynamics and Control, 2020
2020
-
[7]
Active sensing for target tracking: A bayesian optimisation approach,
X. Liu and L. Mihaylova, “Active sensing for target tracking: A bayesian optimisation approach,” inProceedings of the 27th International Con- ference on Information Fusion, 2024
2024
-
[8]
Joint sensor scheduling and target tracking with efficient bayesian optimisa- tion,
X. Liu, C. Lyu, S. A. Soleymani, W. Wang, and L. Mihaylova, “Joint sensor scheduling and target tracking with efficient bayesian optimisa- tion,” in2023 Sensor Signal Processing for Defence Conference, 2023
2023
-
[9]
Sensor management using an active sensing approach,
C. Kreucher, K. Kastella, and A. O. Hero Iii, “Sensor management using an active sensing approach,”Signal Processing, vol. 85, 2005
2005
-
[10]
Conformal prediction: A gentle introduction,
A. N. Angelopoulos and S. Bates, “Conformal prediction: A gentle introduction,”Foundations and Trends in Machine Learning, vol. 16, 2023
2023
-
[11]
Conformal prediction for uncertainty-aware planning with diffusion dynamics model,
J. Sun, Y . Jiang, J. Qiu, P. Nobel, M. J. Kochenderfer, and M. Schwager, “Conformal prediction for uncertainty-aware planning with diffusion dynamics model,”Advances in Neural Information Processing Systems, vol. 36, 2023
2023
-
[12]
Conformalized quantile re- gression,
Y . Romano, E. Patterson, and E. Candes, “Conformalized quantile re- gression,”Advances in Neural Information Processing Systems, vol. 32, 2019
2019
-
[13]
Codit: Conformal out-of-distribution detection in time-series data,
R. Kaur, K. Sridhar, S. Park, S. Jha, A. Roy, O. Sokolsky, and I. Lee, “Codit: Conformal out-of-distribution detection in time-series data,” arXiv preprint arXiv:2207.11769, 2022
-
[14]
Safe planning in dynamic environments using conformal prediction,
L. Lindemann, M. Cleaveland, G. Shim, and G. J. Pappas, “Safe planning in dynamic environments using conformal prediction,”IEEE Robotics and Automation Letters, vol. 8, no. 8, pp. 5116–5123, 2023
2023
-
[15]
Combination of conformal predictors for classification,
P. Toccaceli and A. Gammerman, “Combination of conformal predictors for classification,” inProc. Workshop on Conformal and Probabilistic Prediction and Applications, 2017, pp. 39–61
2017
-
[16]
Coverage control for mobile sensing networks,
J. Cortes, S. Martinez, T. Karatas, and F. Bullo, “Coverage control for mobile sensing networks,”IEEE Transactions on robotics and Automation, vol. 20, no. 2, pp. 243–255, 2004
2004
-
[17]
An optimal control approach to the multi-agent persistent monitoring problem,
C. G. Cassandras, X. Lin, and X. Ding, “An optimal control approach to the multi-agent persistent monitoring problem,”IEEE Transactions on Automatic Control, vol. 58, no. 4, pp. 947–961, 2012
2012
-
[18]
Optimal multi-agent persistent monitoring of the uncertain state of a finite set of targets,
S. C. Pinto, S. B. Andersson, J. M. Hendrickx, and C. G. Cassandras, “Optimal multi-agent persistent monitoring of the uncertain state of a finite set of targets,” in2019 IEEE 58th Conference on Decision and Control (CDC). IEEE, 2019, pp. 4280–4285
2019
-
[19]
Mixed integer linear programming formulation tech- niques,
J. P. Vielma, “Mixed integer linear programming formulation tech- niques,”Siam Review, vol. 57, no. 1, pp. 3–57, 2015
2015
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.