Size Estimation Tools for Conventional Actuator System Prototyping in Aerospace

Abstract

Predicting the size of an actuator capable of reaching given performance requirements is a critical step for any systems design. Thus, to help in the prototyping and early development stages of such devices, simple mathematical models were developed, which can be used with little knowledge in actuation system design. Based on physical phenomenons at the heart of the actuation mechanism, these models can be used to estimate diameter and length, and therefore volume and weight of conventional actuators as a function of performance requirements. Models include linear hydraulic pistons and electric motors, divided into radial and axial flux machines. Off-the-shelf actuators and more aerospace specific products were used to validate and assess the accuracy of the models over a wide range of force and torque requirements. Simple sizing examples for aerospace actuation systems are also given as use-cases of the different tools. A discussion on model applicability, for various aircraft scales and applications concludes the paper.

Impact of Control Allocation Methods on the Design of Control Surface Layouts for Box-Wing Aircraft under Flying Qualities Constraints

“…This is achieved by iteratively reducing the span of each CS in a given layout, and by exploring different layouts entirely. The requirement of small CS spans, together with a contained number of CSs themselves, is usually desired to reduce system complexity, reduce weight, and/or reserve more space for high-lift devices [19,31]. The architecture of the optimization framework is shown in Figure 2, in the form of an Extended Design Structure Matrix (XDSM) [32].…”

In-flight Folding Wingtip System: Inspiration from the XB-70 Valkyrie

“…To complete the sizing analysis for large civil aircraft applications, additional system sizing should also be carried out, including the sizing of hydraulic and elecric actuators as a function of required torque for instance. Initial sizing methods for early design and protoype development stages were investigated by the authors concurrently to this work [35]. Non conventional actuation such as Shape Memory Alloy (thermal or magnetic) and their scaling potential should also be investigated, as they could lead to lighter and more power dense solutions, as recently shown in the SAW project led by NASA and Boeing researchers [22,23].…”

In-flight Wingtip Folding: Inspiration from the XB-70 Valkyrie

“…It is possible to nuance the gap in size, especially knowing that performances of the final device fitted on the civil aircraft wing are closely linked to the final system size, due to the trade-off in torque and rotation speed in the power hinge. The sizing of actuator elements and transmission rods are outside the scope of this paper, but motor and shaft dimensions can be relatively well predicted using simple physics based techniques (Dussart, Lone, & O'Rourke, 2019). Gearbox sizing with adequate teeth size for safe loads transmission is more tedious.…”

“…To complete the sizing analysis for large civil aircraft applications, additional system sizing should also be carried out, including the sizing of hydraulic and electric actuators as a function of required torque for instance. Initial sizing methods for early design and prototype development stages were investigated by the authors concurrently to this work (Dussart et al, 2019). Non-conventional actuation such as Shape Memory Alloy (thermal or magnetic) and their scaling potential should also be investigated, as they could lead to lighter and more power dense solutions, as recently shown in the SAW project led by NASA and Boeing researchers (Kamlet & Gibbs, 2018;Warwick, 2018).…”