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 "an open torque controlled modular robot architecture for legged locomotion research"):
  Abstract: We present a new open-source torque-controlled legged robot system, with a low cost and low complexity actuator module at its core. It consists of a low-weight high torque brushless DC motor and a low gear ratio transmission suitable for impedance and force control. We also present a novel foot contact sensor suitable for legged locomotion with hard impacts. A 2.2 kg quadruped robot with a large range of motion is assembled from 8 identical actuator modules and 4 lower legs with foot contact sensors. To the best of our knowledge, it is the most lightest force-controlled quadruped robot. We leverage standard plastic 3D printing and off-the-shelf parts, resulting in light-weight and inexpensive robots, allowing for rapid distribution and duplication within the research community. In order to quantify the capabilities of our design, we systematically measure the achieved impedance at the foot in static and dynamic scenarios. We measured up to 10.8 dimensionless leg stiffness without active damping, which is comparable to the leg stiffness of a running human. Finally, in order to demonstrate the capabilities of our quadruped robot, we propose a novel controller which combines feedforward contact forces computed from a kino-dynamic optimizer with impedance control of the robot center of mass and base orientation. The controller is capable of regulating complex motions which are robust to environmental uncertainty.

Includes members:
  Member "stanford doggo an open source quasi direct drive quadruped":
    also connected through other hyperedges:
      (none)
  Member "quasi direct drive for low cost compliant robotic manipulation":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "offworld gym open access physical robotics environment for real world reinforcement learning benchmark and research")
  Member "learning a structured neural network policy for a hopping task":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "variable impedance control in end effector space an action space for reinforcement learning in contact rich tasks")
  Member "sim to real learning agile locomotion for quadruped robots":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "learning to fly via deep model based reinforcement learning")
  Member "oncilla robot a versatile open source quadruped research robot with compliant pantograph legs":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "learning active spine behaviors for dynamic and efficient locomotion in quadruped robots")
  Member "cable driven actuation for highly dynamic robotic systems":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "improved performance on moving mass hopping robots with parallel elasticity")
  Member "momentum control with hierarchical inverse dynamics on a torque controlled humanoid":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "multi agent manipulation via locomotion using hierarchical sim2real")
  Member "structured contact force optimization for kino dynamic motion generation":
    also connected through other hyperedges:
      - Hyperedge HE-7 (induced by source paper "accelerated admm based trajectory optimization for legged locomotion with coupled rigid body dynamics")

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)