Paper:

# Optimal Position and Attitude Control of Quadcopter Using Stochastic Differential Dynamic Programming with Input Saturation Constraints

## Satoshi Satoh^{*}, Hironori Saijo^{**}, and Katsuhiko Yamada^{*}

^{*}Graduate School of Engineering, Osaka University

2-1 Yamadaoka, Suita, Osaka 565-0871, Japan

^{**}Graduate School of Engineering, Kyoto University

Kyotodaigaku-katsura, Nishikyo-ku, Kyoto 615-8246, Japan

This paper considers the position and attitude control of a quadcopter in the presence of stochastic disturbances. Basic quadcopter dynamics is modeled as a nonlinear stochastic system described by a stochastic differential equation. Subsequently, the position and attitude control is formulated as a nonlinear stochastic optimal control problem with input saturation constraints. To solve this problem, a continuous-time stochastic differential dynamic programming (DDP) method with input saturation constraints is newly proposed. Finally, numerical simulations demonstrate the effectiveness of the proposed method by comparing it with the linear quadratic Gaussian and the deterministic DDP with input saturation constraints.

*J. Robot. Mechatron.*, Vol.33, No.2, pp. 283-291, 2021.

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