human: Given a node-centered hypergraph: <hypergraph>, where nodes represent authors and hyperedges represent groups of authors who co-authored the same paper.

Details of the hypergraph:
Center node: "Modeling of braided pneumatic actuators for robotic control"
  Abstract: Braided pneumatic actuators exhibit non-linear force-length properties grossly similar to muscle, and have a high strength-to-weight ratio. These properties make them desirable for legged robots. The work emphasizes understanding the actuator properties for later use in simulation and control of legged robots. Static and dynamic mathematical models for the actuators are reported and verified through testing and simulation. In addition, a dynamic air flow model modulated by a solenoid valve was developed to provide modular actuation subroutines for simulation.

Connected through hyperedge HE-1 (induced by source paper "Design and control of a robotic leg with braided pneumatic actuators"):
  with members:
    (none)

Question: Please tell me which research area the center author belongs to. The 4 classes are: Computer science, Mathematics, Engineering, Economics, Psychology, Business. Directly output the class name.

gpt: Computer science