Enforcing nonholonomic constraints in Aerobat, a roosting flapping wing model

TL;DR

This paper develops a multi-body dynamical model of a bio-inspired bat robot, Aerobat, and introduces a control method to enforce nonholonomic constraints for complex maneuvers like reorientation and landing.

Contribution

It derives a detailed dynamical system capturing biologically relevant degrees-of-freedom and proposes a nonlinear control approach to manipulate inertial and aerodynamic properties for precise maneuvers.

Findings

Successfully models Aerobat's complex flapping dynamics.

Demonstrates control of body reorientation through nonholonomic constraints.

Achieves desired angular momentum for landing maneuvers.

Abstract

Flapping wing flight is a challenging dynamical problem and is also a very fascinating subject to study in the field of biomimetic robotics. A Bat, in particular, has a very articulated armwing mechanism with high degrees-of-freedom and flexibility which allows the animal to perform highly dynamic and complex maneuvers, such as upside-down perching. This paper presents the derivation of a multi-body dynamical system of a bio-inspired bat robot called Aerobat which captures multiple biologically meaningful degrees-of-freedom for flapping flight that is present in biological bats. Then, the work attempts to manifest closed-loop aerial body reorientation and preparation for landing through the manipulation of inertial dynamics and aerodynamics by enforcing nonholonomic constraints onto the system. The proposed design paradigm assumes for rapidly exponentially stable controllers that enforce holonomic constraints in the joint space of the model. A model and optimization-based nonlinear controller is applied to resolve the joint trajectories such that the desired angular momentum about the roll axis is achieved.