Differential-Flatness and Control of Quadrotor(s) with a Payload Suspended through Flexible Cable(s)

Prasanth Kotaru; Guofan Wu; Koushil Sreenath

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arXiv · 1711.04895

Differential-Flatness and Control of Quadrotor(s) with a Payload Suspended through Flexible Cable(s)

Prasanth Kotaru·Guofan Wu·Koushil Sreenath

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Abstract

We present the coordinate-free dynamics of three different quadrotor systems : (a) single quadrotor with a point-mass payload suspended through a flexible cable; (b) multiple quadrotors with a shared point-mass payload suspended through flexible cables; and (c) multiple quadrotors with a shared rigid-body payload suspended through flexible cables. We model the flexible cable(s) as a finite series of links with spherical joints with mass concentrated at the end of each link. The resulting systems are thus high-dimensional with high degree-of-underactuation. For each of these systems, we show that the dynamics are differentially-flat, enabling planning of dynamically feasible trajectories. For the single quadrotor with a point-mass payload suspended through a flexible cable with five links (16 degrees-of-freedom and 12 degrees-of-underactuation), we use the coordinate-free dynamics to develop a geometric variation-based linearized equations of motion about a desired trajectory. We show that a finite-horizon linear quadratic regulator can be used to track a desired trajectory with a relatively large region of attraction.

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Prasanth Kotaru, Guofan Wu, Koushil Sreenath. 2017-11-14. Differential-Flatness and Control of Quadrotor(s) with a Payload Suspended through Flexible Cable(s). https://arxiv.org/abs/1711.04895

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