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Phasing Through the Flames: Rapid Motion Planning with the AGHF PDE for Arbitrary Objective Functions and Constraints

T0 review · 3 major / 5 minor · reviewed 2026-08-16 · deepseek-v4-flash

Pith's one-line read The paper claims that a generalized Affine Geometric Heat Flow PDE solves trajectory optimization with arbitrary coercive cost functions and constraint-violating initial guesses, producing feasible trajectories within seconds.

desk verdict A genuinely broader AGHF method with strong experiments, but its headline theorem overreaches: the proof silently assumes a nonnegative cost integral, and the Phase 1–Phase 2 feasibility guarantee is asserted rather than proven. read the letter →

arxiv 2505.01589 v1 pith:4ZRW7ZTI submitted 2025-05-02 cs.RO

classification cs.RO
keywords affinegeometricheatflowtrajectoryoptimizationoptimalcontrolmotionplanningconstraintsatisfactionpseudospectralmethodroboticmanipulatorsphase1-phase2algorithm
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper is trying to establish that AGHF-based trajectory optimization can handle arbitrary coercive cost functions, not just squared control effort, and that the initial guess may violate constraints if a Phase 1 feasibility step is inserted before the cost-minimizing Phase 2. The generalized Lagrangian adds a dynamic-consistency penalty to the user's cost and extracts controls from the evolving curve, and Theorem 7 bounds the gap between the extracted-control trajectory and a truly feasible one. If true, this removes the two practical blockers that kept AGHF methods from being general motion planners. The paper argues that the result is rapid generation of dynamically feasible, constraint-satisfying trajectories for high-dimensional arms, with hardware demonstrations on a real robot.

What carries the argument

The load-bearing object is the generalized action functional $A(x_s)$ together with the control-extraction map $u_s(t)=\begin{bmatrix}0&I\end{bmatrix}\bar{F}(x_s(t))^{-1}(\dot{x}_s(t)-F_d(x_s(t)))$, which turns any curve into a control signal. The AGHF PDE $\partial_s x = M^{-1}(\frac{d}{dt}\partial_{\dot{x}}L - \partial_x L)$ decreases this action by construction when $M\succeq 0$, with $M$ a user-specified positive-semidefinite and invertible matrix. In Phase 1, the cost $c$ is replaced by sums of penalty terms $b(g_j)=k_{\text{cons}}\,g_j^2\,S(g_j)$ with smooth activation $S$, making the action a feasibility measure; input constraints enter through inverse-dynamics evaluation of $u_s$ and its derivatives, avoiding state augmentation.

What would settle it

Run the Phase 1-Phase 2 algorithm on a manipulator with a narrow feasible corridor and an initial guess that violates the constraints, and check whether the Phase 2 output satisfies the state constraints at every sampled time; a single violation for any choice of $k_{\text{cons}}>k_d$ would refute the claimed guarantee. Separately, use a coercive running cost whose integral over the action sublevel set is negative, and check whether the Theorem 7 error bound still holds, since the proof bounds control energy by dropping a term it assumes nonnegative.

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Extended reading notes

Core claim

On its own terms, the paper's central claim is that the Affine Geometric Heat Flow PDE is not limited to minimizing squared control effort. The authors define an action functional $A(x_s)=\int_0^T (k_d\|\dot{x}_{P1}-x_{P2}\|_2^2 + c(x_s,\dot{x}_s,u_s))\,dt$ in which $u_s$ is recovered from the homotopy curve by control extraction, and they prove (Theorem 7) that for coercive $c$, large penalty $k_d$, and long enough evolution time $s_{\max}$, the control extracted from the AGHF solution, when integrated in the true dynamics, satisfies an explicit error bound converging to zero. They then add a Phase 1 evolution whose action functional penalizes constraint violations, so a trajectory that starts in collision or outside joint and input limits is first driven into the feasible set, and Phase 2 minimizes the user cost while maintaining feasibility. The paper reports that this pipeline solves Kinova-arm planning problems, including cuboid obstacle avoidance and hardware execution, in under three seconds.

Load-bearing premise

The central claim rests on the unproven premise that a sufficiently large penalty $k_{\text{cons}}>k_d$ drives a constraint-violating initial trajectory into the feasible set and keeps it there through Phase 2; the paper's Lemma 10 note explicitly says the constrained Lagrangian does not guarantee that the inequality constraints are eventually satisfied, and Theorem 7's proof additionally assumes the cost integral is nonnegative, which coercivity alone does not imply.

Editorial extensions

If this is right

  • Any coercive running cost, such as time, energy, smoothness, or a task-specific risk term, can be optimized by the same AGHF flow instead of only squared control norm.
  • Users can seed the solver with straight-line or otherwise infeasible guesses, because Phase 1 handles collisions and limit violations before Phase 2 optimizes the objective.
  • Input limits can be enforced without augmenting the state dimension, since control extraction is computed via inverse dynamics and differentiated with recursive chain-rule algorithms.
  • The reported solve times, around 0.75 to 3 seconds for 7 to 21 degree-of-freedom arms, suggest the method is fast enough for online replanning in manipulation tasks under the tested settings.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If the feasibility phase behaves as robustly as the experiments suggest, the same two-phase structure could serve as a warm-start or repair step in model-predictive control, where the previous solution becomes infeasible after a disturbance.
  • The arbitrary-cost generalization invites testing on objectives the paper does not exercise, such as minimum-time motion with free terminal time or risk-aware costs, which would stress whether coercivity plus the dynamic penalty is the right sufficient condition.
  • Because Theorem 7's bound scales with $1/\sqrt{k_d}$, tuning $k_d$ should trade feasibility accuracy against numerical conditioning; a systematic study of that trade-off would be a natural follow-up.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 5 minor

Summary. The paper extends the Affine Geometric Heat Flow (AGHF) PDE trajectory optimization framework, previously limited to minimum-control-effort problems, to arbitrary coercive cost functions. It introduces a Lagrangian that combines a dynamic-consistency penalty with the user-specified cost, defines a control-extraction formula, and proves Theorem 7, which gives an O(1/kd) error bound between the AGHF trajectory and the trajectory obtained by forward-integrating the extracted control. The paper also proposes a Phase 1-Phase 2 algorithm intended to allow constraint-violating initial guesses, and a method for enforcing input constraints without augmenting the state space. The approach is evaluated against Crocoddyl, Aligator, and RAPTOR on pendulum and Kinova arms, and demonstrated on a real Kinova Gen3 robot. The central claim is that BLAZE rapidly generates dynamically feasible, constraint-satisfying trajectories from poor initial guesses.

Significance. If the theoretical guarantees were fully established, this would be a meaningful advance: it removes two restrictions of earlier AGHF methods, namely the restriction to squared-control costs and the need for constraint-satisfying initial guesses. The empirical study is broad and includes a real-hardware demonstration, which is valuable. The derivation of the dynamic-feasibility bound is self-contained and the control-extraction mechanism is clearly specified. However, the paper's core theoretical guarantees are not currently proven as written: the proof of Theorem 7 contains an unjustified nonnegativity step, Lemma 13 overclaims an L-infinity bound from an integral estimate, and the Phase 1-Phase 2 convergence claim is asserted rather than proved. These issues are load-bearing for the paper's main claims, but they appear repairable through corrected constants or strengthened assumptions.

major comments (3)
  1. [Appendix B, Eqs. (33)-(34)] The inference from C1 >= integral(kd||uc||^2 + c)dt to integral(||uc||^2)dt <= C1/kd is valid only if integral(c)dt >= 0. Coercivity in Definition 1 supplies only c >= alpha||(x,xdot,u)||_infinity - beta, which permits the cost integral to be negative. The correct immediate consequence is integral(||uc||^2)dt <= (C1 + beta*T)/kd, or the theorem must explicitly assume a nonnegative cost. Since the later Gronwall bound in Eq. (46) relies on this term being O(1/kd), Theorem 7 as written is not proven. I note that the gap is repairable by carrying the beta*T term, so this is not a fatal flaw, but the proof must be corrected.
  2. [Appendix B, Lemma 13] The proof of Lemma 13 bounds an integral of the coercivity lower bound, but the stated conclusion, ||xdot||^2_Linfinity + ||x||^2_Linfinity <= (beta + C*T)/alpha, does not follow from such an integral estimate. A coercive function can have a narrow spike of large amplitude whose integral contribution is small, so an L1-type bound on the integrand does not control L-infinity norms. For continuous curves the argument shows that unboundedness on a set of positive measure contradicts A(x) <= C, but it does not yield the uniform quantitative bound asserted in the lemma. This matters because the lemma is used to establish the boundedness of x that underlies the constants C2 and C3 in Theorem 7. The lemma needs stronger assumptions, such as c >= alpha(||x||^2 + ||xdot||^2 + ||u||^2) - beta, or an explicit compactness assumption on the sublevel set.
  3. [Section V and Section IV-A] The Phase 1-Phase 2 procedure is described as guaranteeing convergence from constraint-violating initial guesses, but no theorem in the manuscript establishes that Phase 1 drives the trajectory into the feasible set or that Phase 2 preserves feasibility. Section IV-A explicitly concedes that the constrained Lagrangian 'does not guarantee that the inequality constraints within (OCP) are eventually satisfied,' and the heuristic argument in Section V based on kcons > kd does not fill this gap. The statement that 'with a sufficiently large kcons and smax ... the trajectory will remain within the feasible set throughout the evolution' needs a proof or an explicit assumption on the penalty structure and the initial guess. As written, the abstract's claim of 'guaranteeing satisfactory convergence' from constraint-violating initial guesses is unsupported.
minor comments (5)
  1. [Appendix B, Lemma 13 statement] The notation ||xdot||^2_Linfinity and ||x||^2_Linfinity is not defined; presumably squared L-infinity norms are intended, but the right-hand side (beta + C*T)/alpha is not dimensionally consistent with the proof, which bounds an integral rather than an L-infinity norm.
  2. [Section VI-A] The sentence 'the Lagrangian satisfies the coercive requirement due to the definition of the extracted control input' is unclear: coercivity is a property of the cost function c, not of control extraction. The text should state explicitly which assumption on c is being used.
  3. [Appendix C, Eq. (48)] The displayed expression for the inverse of Fbar(xs) appears to be a transpose rather than an inverse; the final inverse-dynamics formula is correct for B = I, but the intermediate derivation should be checked and rewritten.
  4. [Title and Abstract] The phrase 'arbitrary cost functions' is stronger than the coercivity assumption required by Theorem 7; the paper should qualify the scope, for example 'arbitrary coercive cost functions,' to align the claims with the theory.
  5. [Table I] Table I reports a higher objective cost for BLAZE than for Aligator (738.7 vs 635.9) when both methods succeed; a sentence in Section VI-D interpreting this in light of Section VIII's acknowledgment that the penalty formulation does not minimize as aggressively would help the reader.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the AGHF action is explicitly constructed to reproduce the OCP objective on feasible curves, while the dynamic-feasibility and control-extraction bounds are independent derivations.

full rationale

The central derivation is self-contained and not circular. Definition 6 deliberately sets L so that the Action Functional A equals the OCP cost integral on dynamically feasible curves, and the paper openly states this design goal ("we must design L carefully") rather than presenting cost-minimization as an emergent prediction. Theorem 7's control-extraction argument is an independent derivation from the dynamics (2), Definition 5, and the Bellman-Gronwall inequality; it does not assume its own conclusion. The only substantive flaw I identified is a proof error, not a circularity: in Appendix B, Eq. (33) gives C1 >= integral(kd||uc||^2 + c)dt, and Eq. (34) concludes integral||uc||^2 dt <= C1/kd without requiring integral(c)dt >= 0. Coercivity in Definition 1 supplies only c >= alpha||x, xdot, u||_infty - beta, so c may be negative on the relevant sublevel sets; a repair would need a beta*T correction term, but the resulting bound would still be O(1/kd), so the theorem is plausibly repairable. Similarly, the Phase 1-Phase 2 guarantee in Section V is asserted by reference to Section IV-A even though Lemma 10 explicitly notes that the constrained Lagrangian does not guarantee eventual satisfaction of inequality constraints; that is an unsupported premise, not a reduction of the conclusion to its input. The self-citation [13] is used only for the pseudospectral method-of-lines implementation and default parameter values (Section VI-A, Appendix D), not for the load-bearing theory. No fitted parameter is renamed as a prediction, no uniqueness result is imported from the authors' prior work, and no known result is merely renamed; the derivation chain is therefore not circular.

Assumptions & free parameters 5 free parameters · 5 assumptions · 0 invented entities

The theoretical guarantee rests on regularity and feasibility assumptions, plus an unstated nonnegativity condition on the cost integral in the proof. The numerical demonstrations require manually tuned penalty weights, activation sharpness, evolution horizon, and pseudospectral order. No new physical entities are introduced.

free parameters (5)
  • kd (dynamic consistency penalty) = 10^4 to 10^14 across experiments
    Weights the term kd||dot_x_P1 - x_P2||^2 in the action; Theorem 7 requires it to be sufficiently large but gives no constructive value, so it is tuned per experiment as shown in Tables IX-XI.
  • kcons constraint penalty weights = 10^4 to 10^10 depending on constraint and experiment
    Scaling for the state and input penalty terms b(g_j) and b(h_i); the paper relies on these being sufficiently large to approximate hard constraints, and they are tuned per task, e.g., ksph, kstate, kinput, kcuboid.
  • ccons activation sharpness = 50 to 200
    Hyperparameter in the tanh activation S(g) that controls how quickly the penalty turns on at constraint violation; chosen per constraint type and experiment.
  • smax PDE evolution horizon = 0.01 to 100
    Total evolution time of the AGHF PDE; Theorem 7 requires it to be sufficiently large, but the actual values are selected per experiment to get convergence.
  • pseudospectral polynomial order p = 7 or 12
    Order of the Chebyshev/pseudospectral discretization along time; affects accuracy and computational cost and is chosen per experiment.
assumptions (5)
  • domain assumption Assumption 2: Fd and F are C2, globally Lipschitz, F has constant rank almost everywhere, c, gj, and hi are C2, and a feasible trajectory for (OCP) exists.
    Section II; this is the regularity and feasibility premise for Theorem 7 and the AGHF convergence. It may fail for some robotic systems without a compact-domain restriction.
  • domain assumption The cost function c in the action is coercive.
    Required by Theorem 7 and Lemma 13 to obtain L-infinity bounds; not true of all arbitrary cost functions, which limits the paper's 'arbitrary cost' claim.
  • ad hoc to paper The proof of Theorem 7 implicitly assumes the cost integral is nonnegative, or otherwise that C1 bounds the kd term.
    Appendix B, Eq. (33)-(34); coercivity alone does not guarantee a nonnegative integral of c, so the bound on the extracted control energy may fail for costs with negative regions.
  • domain assumption Penalty terms with sufficiently large kcons approximate hard inequality constraints.
    Section IV-A; the paper itself notes that inequality constraints are not guaranteed to be satisfied, so this is a heuristic premise rather than a proved guarantee.
  • domain assumption The control extraction matrix \bar F = [Fc, F] is invertible for all relevant states.
    Definition 5 requires choosing Fc, e.g., via Gram-Schmidt, so that \bar F is invertible; this is necessary for the extracted control input to be well-defined.

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Cite this review

Pith. "Pith review of Phasing Through the Flames: Rapid Motion Planning with the AGHF PDE for Arbitrary Objective Functions and Constraints." pith.science (2026). https://pith.science/paper/4ZRW7ZTI

@misc{pith2026250501589,
  author       = {Pith},
  title        = {Pith review of: Phasing Through the Flames: Rapid Motion Planning with the AGHF PDE for Arbitrary Objective Functions and Constraints},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/4ZRW7ZTI}},
  note         = {Machine review of arXiv:2505.01589}
}
read the original abstract

The generation of optimal trajectories for high-dimensional robotic systems under constraints remains computationally challenging due to the need to simultaneously satisfy dynamic feasibility, input limits, and task-specific objectives while searching over high-dimensional spaces. Recent approaches using the Affine Geometric Heat Flow (AGHF) Partial Differential Equation (PDE) have demonstrated promising results, generating dynamically feasible trajectories for complex systems like the Digit V3 humanoid within seconds. These methods efficiently solve trajectory optimization problems over a two-dimensional domain by evolving an initial trajectory to minimize control effort. However, these AGHF approaches are limited to a single type of optimal control problem (i.e., minimizing the integral of squared control norms) and typically require initial guesses that satisfy constraints to ensure satisfactory convergence. These limitations restrict the potential utility of the AGHF PDE especially when trying to synthesize trajectories for robotic systems. This paper generalizes the AGHF formulation to accommodate arbitrary cost functions, significantly expanding the classes of trajectories that can be generated. This work also introduces a Phase1 - Phase 2 Algorithm that enables the use of constraint-violating initial guesses while guaranteeing satisfactory convergence. The effectiveness of the proposed method is demonstrated through comparative evaluations against state-of-the-art techniques across various dynamical systems and challenging trajectory generation problems. Project Page: https://roahmlab.github.io/BLAZE/

Figures

Figures reproduced from arXiv: 2505.01589 by the authors.

Figure 1
Figure 1. This paper introduces BLAZE, a Phase 1 - Phase 2 Affine Geometric Heat Flow (AGHF) framework, to rapidly solve optimal control problems while [PITH_FULL_IMAGE:figures/full_fig_p001_1.png] view at source ↗
Figure 2
Figure 2. A bar plot comparing the mean solve times for four different trajectory [PITH_FULL_IMAGE:figures/full_fig_p008_2.png] view at source ↗
Figure 3
Figure 3. A plot showing the evolution of the Action Functional versus the AGHF [PITH_FULL_IMAGE:figures/full_fig_p008_3.png] view at source ↗
Figures from the paper (1 more)
Figure 4
Figure 4. Figure 4: This figure shows a visualization of one of the task-based scenarios [PITH_FULL_IMAGE:figures/full_fig_p009_4.png]

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Forward citations

Cited by 1 Pith paper

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    EL-AGHF evolves a trajectory and a dual multiplier together through a PDE, enforcing dynamic admissibility in inadmissible control directions with finite penalties.

Reference graph

Works this paper leans on

24 extracted references · 15 canonical work pages · cited by 1 Pith paper

  1. [1]

    Mini cheetah: A platform for pushing the limits of dynamic quadruped control,

    B. Katz, J. D. Carlo, and S. Kim, “Mini cheetah: A platform for pushing the limits of dynamic quadruped control,” in 2019 International Conference on Robotics and Automation (ICRA) , 2019, pp. 6295–6301

  2. [2]

    RADIUS: Risk-Aware, Real-Time, Reachability-Based Motion Planning,

    J. Liu, C. E. Adu, L. Lymburner, V . Kaushik, L. Trang, and R. Vasudevan, “RADIUS: Risk-Aware, Real-Time, Reachability-Based Motion Planning,” in Proceedings of Robotics: Science and Systems , Daegu, Republic of Korea, July 2023

  3. [3]

    Dy- namic locomotion in the mit cheetah 3 through convex model- predictive control,

    J. Di Carlo, P. M. Wensing, B. Katz, G. Bledt, and S. Kim, “Dy- namic locomotion in the mit cheetah 3 through convex model- predictive control,” in 2018 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) , 2018, pp. 1–9

  4. [4]

    Optimization-based locomotion planning, estimation, and con- trol design for the atlas humanoid robot,

    S. Kuindersma, R. Deits, M. Fallon, A. Valenzuela, H. Dai, F. Permenter, T. Koolen, P. Marion, and R. Tedrake, “Optimization-based locomotion planning, estimation, and con- trol design for the atlas humanoid robot,” Autonomous robots, vol. 40, pp. 429–455, 2016

  5. [5]

    Let’s make a splan: Risk-aware trajectory optimization in a normalized gaussian splat,

    J. Michaux, S. Isaacson, C. E. Adu, A. Li, R. K. Swayampakula, P. Ewen, S. Rice, K. A. Skinner, and R. Vasudevan, “Let’s make a splan: Risk-aware trajectory optimization in a normalized gaussian splat,” arXiv preprint arXiv:2409.16915 , 2024

  6. [6]

    Nonlinear observer based control design for an under-actuated compliant robotic hand,

    R. Garcia-Rosas, J. M. Portella-Delgado, Y . Tan, and D. Ne ˇsi´c, “Nonlinear observer based control design for an under-actuated compliant robotic hand,” in 2016 Australian Control Conference (AuCC), 2016, pp. 21–26

  7. [7]

    Hamilton-jacobi reacha- bility in reinforcement learning: A survey,

    M. Ganai, S. Gao, and S. L. Herbert, “Hamilton-jacobi reacha- bility in reinforcement learning: A survey,” IEEE Open Journal of Control Systems , vol. 3, pp. 310–324, 2024

  8. [8]

    Opti- mizeddp: An efficient, user-friendly library for optimal control and dynamic programming,

    M. Bui, G. Giovanis, M. Chen, and A. Shriraman, “Opti- mizeddp: An efficient, user-friendly library for optimal control and dynamic programming,” arXiv preprint arXiv:2204.05520 , 2022

Show all 24 references
  1. [9]

    Crocoddyl: An efficient and versatile framework for multi-contact optimal control,

    C. Mastalli, R. Budhiraja, W. Merkt, G. Saurel, B. Hammoud, M. Naveau, J. Carpentier, L. Righetti, S. Vijayakumar, and N. Mansard, “Crocoddyl: An efficient and versatile framework for multi-contact optimal control,” in 2020 IEEE International Conference on Robotics and Automat...

  2. [10]

    Rapid trajectory optimization using c-frost with illustration on a cassie-series dynamic walking biped,

    A. Hereid, O. Harib, R. Hartley, Y . Gong, and J. W. Grizzle, “Rapid trajectory optimization using c-frost with illustration on a cassie-series dynamic walking biped,” in 2019 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2019, pp. 4722–4729

  3. [11]

    Rapid bipedal gait optimization in casadi,

    M. Fevre, P. M. Wensing, and J. P. Schmiedeler, “Rapid bipedal gait optimization in casadi,” in 2020 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) , 2020, pp. 3672–3678

  4. [12]

    Affine geometric heat flow and motion planning for dynamic systems,

    S. Liu, Y . Fan, and M.-A. Belabbas, “Affine geometric heat flow and motion planning for dynamic systems,” IFAC-PapersOnLine, vol. 52, no. 16, pp. 168–173, 2019, 11th IFAC Symposium on Nonlinear Control Systems NOLCOS 2019. [Online]. Available: https://www.sciencedirect. com/s...

  5. [13]

    Bring the heat: Rapid trajectory optimization with pseudospec- tral techniques and the affine geometric heat flow equation,

    C. E. Adu, C. E. R. Chuquiure, B. Zhang, and R. Vasudevan, “Bring the heat: Rapid trajectory optimization with pseudospec- tral techniques and the affine geometric heat flow equation,” IEEE Robotics and Automation Letters, vol. 10, no. 4, pp. 4148– 4155, 2025

  6. [14]

    L. C. Evans, Partial differential equations. American Mathe- matical Society, 2022, vol. 19

  7. [15]

    A homotopy method for motion planning,

    S. Liu and M. A. Belabbas, “A homotopy method for motion planning,” arXiv preprint arXiv:1901.10094 , 2019

  8. [16]

    Geometric motion plan- ning for affine control systems with indefinite boundary condi- tions and free terminal time,

    S. Liu, Y . Fan, and M.-A. Belabbas, “Geometric motion plan- ning for affine control systems with indefinite boundary condi- tions and free terminal time,” arXiv preprint arXiv:2001.04540, 2020

  9. [17]

    Mid-air motion planning of robot using heat flow method with state constraints,

    Y . Fan, S. Liu, and M.-A. Belabbas, “Mid-air motion planning of robot using heat flow method with state constraints,” Mechatronics, vol. 66, p. 102323, 2020. [Online]. Available: https://www.sciencedirect.com/science/ article/pii/S0957415820300039

  10. [18]

    W. E. Schiesser, The numerical method of lines: integration of partial differential equations . Elsevier, 2012

  11. [19]

    Featherstone, Rigid body dynamics algorithms

    R. Featherstone, Rigid body dynamics algorithms . Springer, 2014

  12. [20]

    Analytical Derivatives of Rigid Body Dynamics Algorithms,

    J. Carpentier and N. Mansard, “Analytical Derivatives of Rigid Body Dynamics Algorithms,” in Robotics: Science and Systems (RSS 2018) , Pittsburgh, United States, Jun. 2018. [Online]. Available: https://laas.hal.science/hal-01790971

  13. [21]

    Polak, Optimization: algorithms and consistent approxima- tions

    E. Polak, Optimization: algorithms and consistent approxima- tions. Springer Science & Business Media, 2012, vol. 124. 10

  14. [22]

    PROXDDP: Proximal Constrained Trajectory Optimization,

    W. Jallet, A. Bambade, E. Arlaud, S. El-Kazdadi, N. Mansard, and J. Carpentier, “PROXDDP: Proximal Constrained Trajectory Optimization,” 2023, https://inria.hal.science/hal- 04332348v1

  15. [23]

    Rapid and robust trajectory optimization for humanoids,

    B. Zhang and R. Vasudevan, “Rapid and robust trajectory optimization for humanoids,” 2024. [Online]. Available: https://arxiv.org/abs/2409.00303

  16. [24]

    L. N. Trefethen, Approximation Theory and Approximation Practice, Extended Edition . SIAM, 2019. 11 APPENDIX A PROOF OF LEMMA 4 Proof: To prove this result, we construct the variation of the Action Function with respect to s using Taylor Expansion and Integration by Parts. Thi...

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