human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "differential dynamic programming for multi phase rigid contact dynamics"):
  Abstract: A common strategy to generate efficient locomotion movements is to split the problem into two consecutive steps: the first one generates the contact sequence together with the centroidal trajectory, while the second step computes the whole-body trajectory that follows the centroidal pattern. While the second step is generally handled by a simple program such as an inverse kinematics solver, we propose in this paper to compute the whole-body trajectory by using a local optimal control solver, namely Differential Dynamic Programming (DDP). Our method produces more efficient motions, with lower forces and smaller impacts, by exploiting the Angular Momentum (AM). With this aim, we propose an original DDP formulation exploiting the Karush- Kuhn-Tucker constraint of the rigid contact model. We experimentally show the importance of this approach by executing large steps walking on the real HRP-2 robot, and by solving the problem of attitude control under the absence of external contact forces.

Includes members:
  Member "whole body nonlinear model predictive control through contacts for quadrupeds":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "guided constrained policy optimization for dynamic quadrupedal robot locomotion")
  Member "simultaneous contact gait and motion planning for robust multi legged locomotion via mixed integer convex optimization":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "whole body walking generation using contact parametrization a non linear trajectory optimization approach")
  Member "motion planning for quadrupedal locomotion coupled planning terrain mapping and whole body control":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "heuristic planning for rough terrain locomotion in presence of external disturbances and variable perception quality")
  Member "momentum control with hierarchical inverse dynamics on a torque controlled humanoid":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "multi agent manipulation via locomotion using hierarchical sim2real")
  Member "planning and execution of dynamic whole body locomotion for a hydraulic quadruped on challenging terrain":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "learning how to walk warm starting optimal control solver with memory of motion")
  Member "trajectory generation for multi contact momentum control":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "whole body walking generation using contact parametrization a non linear trajectory optimization approach")

Question: Please tell me which class the source paper belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.RO(Robotics)