human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "planning and execution of dynamic whole body locomotion for a hydraulic quadruped on challenging terrain"
  Abstract: We present a framework for dynamic quadrupedal locomotion over challenging terrain, where the choice of appropriate footholds is crucial for the success of the behaviour. We build a model of the environment on-line and on-board using an efficient occupancy grid representation. We use Any-time-Repairing A* (ARA*) to search over a tree of possible actions, choose a rough body path and select the locally-best footholds accordingly. We run a n-step lookahead optimization of the body trajectory using a dynamic stability metric, the Zero Moment Point (ZMP), that generates natural dynamic whole-body motions. A combination of floating-base inverse dynamics and virtual model control accurately executes the desired motions on an actively compliant system. Experimental trials show that this framework allows us to traverse terrains at nearly 6 times the speed of our previous work, evaluated over the same set of trials.

Connected through hyperedge HE-1 (induced by source paper "learning how to walk warm starting optimal control solver with memory of motion"):
  with members:
    - "memory of motion for warm starting trajectory optimization"
    - "crocoddyl an efficient and versatile framework for multi contact optimal control"
    - "passive whole body control for quadruped robots experimental validation over challenging terrain"
    - "differential dynamic programming for multi phase rigid contact dynamics"
    - "simultaneous contact gait and motion planning for robust multi legged locomotion via mixed integer convex optimization"
    - "trajectory optimization through contacts and automatic gait discovery for quadrupeds"

Connected through hyperedge HE-2 (induced by source paper "heuristic planning for rough terrain locomotion in presence of external disturbances and variable perception quality"):
  with members:
    - "application of wrench based feasibility analysis to the online trajectory optimization of legged robots"
    - "simultaneous contact gait and motion planning for robust multi legged locomotion via mixed integer convex optimization"
    - "motion planning for quadrupedal locomotion coupled planning terrain mapping and whole body control"
    - "on line and on board planning and perception for quadrupedal locomotion"

Connected through hyperedge HE-3 (induced by source paper "contact planning for the anymal quadruped robot using an acyclic reachability based planner"):
  with members:
    - "learning agile and dynamic motor skills for legged robots"
    - "simultaneous contact gait and motion planning for robust multi legged locomotion via mixed integer convex optimization"
    - "a convex model of momentum dynamics for multi contact motion generation"
    - "hierarchical planning of dynamic movements without scheduled contact sequences"

Connected through hyperedge HE-4 (induced by source paper "whole body nonlinear model predictive control through contacts for quadrupeds"):
  with members:
    - "the control toolbox an open source c library for robotics optimal and model predictive control"
    - "a family of iterative gauss newton shooting methods for nonlinear optimal control"
    - "an efficient optimal planning and control framework for quadrupedal locomotion"
    - "automatic differentiation of rigid body dynamics for optimal control and estimation"
    - "trajectory optimization through contacts and automatic gait discovery for quadrupeds"
    - "hierarchical planning of dynamic movements without scheduled contact sequences"
    - "projection based whole body motion planning for legged robots"
    - "trajectory generation for multi contact momentum control"

Connected through hyperedge HE-5 (induced by source paper "differential dynamic programming for multi phase rigid contact dynamics"):
  with members:
    - "whole body nonlinear model predictive control through contacts for quadrupeds"
    - "simultaneous contact gait and motion planning for robust multi legged locomotion via mixed integer convex optimization"
    - "motion planning for quadrupedal locomotion coupled planning terrain mapping and whole body control"
    - "momentum control with hierarchical inverse dynamics on a torque controlled humanoid"
    - "trajectory generation for multi contact momentum control"

Connected through hyperedge HE-6 (induced by source paper "contact implicit optimization of locomotion trajectories for a quadrupedal microrobot"):
  with members:
    - "fast trajectory optimization for legged robots using vertex based zmp constraints"
    - "an efficient optimal planning and control framework for quadrupedal locomotion"
    - "trajectory optimization through contacts and automatic gait discovery for quadrupeds"

Connected through hyperedge HE-7 (induced by source paper "simultaneous contact gait and motion planning for robust multi legged locomotion via mixed integer convex optimization"):
  with members:
    - "motion planning for quadrupedal locomotion coupled planning terrain mapping and whole body control"
    - "the actuation consistent wrench polytope awp and the feasible wrench polytope fwp"
    - "fast trajectory optimization for legged robots using vertex based zmp constraints"
    - "trajectory optimization through contacts and automatic gait discovery for quadrupeds"
    - "hierarchical planning of dynamic movements without scheduled contact sequences"

Connected through hyperedge HE-8 (induced by source paper "motion planning for quadrupedal locomotion coupled planning terrain mapping and whole body control"):
  with members:
    - "differential dynamic programming for multi phase rigid contact dynamics"
    - "simultaneous contact gait and motion planning for robust multi legged locomotion via mixed integer convex optimization"
    - "structured contact force optimization for kino dynamic motion generation"
    - "a convex model of momentum dynamics for multi contact motion generation"
    - "on line and on board planning and perception for quadrupedal locomotion"

Question: Please tell me which class the center node 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)