Bilevel Optimization for Real-Time Control with Application to Locomotion Gait Generation
<|reference_start|>Bilevel Optimization for Real-Time Control with Application to Locomotion Gait Generation: Model Predictive Control (MPC) is a common tool for the control of nonlinear, real-world systems, such as legged robots. However, solving MPC quickly enough to enable its use in real-time is often challenging. One common solution is given by real-time iterations, which does not solve the MPC problem to convergence, but rather close enough to give an approximate solution. In this paper, we extend this idea to a bilevel control framework where a "high-level" optimization program modifies a controller parameter of a "low-level" MPC problem which generates the control inputs and desired state trajectory. We propose an algorithm to iterate on this bilevel program in real-time and provide conditions for its convergence and improvements in stability. We then demonstrate the efficacy of this algorithm by applying it to a quadrupedal robot where the high-level problem optimizes a contact schedule in real-time. We show through simulation that the algorithm can yield improvements in disturbance rejection and optimality, while creating qualitatively new gaits.<|reference_end|>
@article{olkin2024bilevel,
    title={Bilevel Optimization for Real-Time Control with Application to
  Locomotion Gait Generation},
    author={Zachary Olkin, Aaron D. Ames},
    journal={arXiv preprint arXiv:2409.12366},
    year={2024},
    archivePrefix={arXiv},
    eprint={2409.12366},
    primaryClass={eess.SY cs.RO cs.SY}
}