ISO 5110:2023

INTERNATIONAL ISO
STANDARD 5110
First edition
2023-08
Test method for flight stability of
a multi-copter unmanned aircraft
system (UAS) under wind and rain
conditions
Méthode d'essai relative à la stabilité en vol d'un multicoptère
télépiloté dans des conditions de vent et de pluie
Reference number
© ISO 2023
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General principles . 2
4.1 Test purpose . 2
4.2 Test condition . 2
4.3 Test apparatus. 2
4.4 Test method . 3
4.4.1 General . 3
4.4.2 Take-off and landing stability test under wind. 5
4.4.3 Take-off and landing stability test under wind and rainfall . 5
4.4.4 Six-directional flight stability test under wind . 5
4.4.5 Six-directional flight stability test under wind and rainfall . 5
4.4.6 Flight stability test under wind during a 360° rotational flight . 5
4.4.7 Flight stability test under wind and rainfall during a 360° rotational flight . 5
4.5 Measurement system . 5
5 Test process . 6
5.1 Preparatory procedure . 6
5.2 Test procedure . 6
5.2.1 Take-off landing stability under wind . 6
5.2.2 Take-off landing stability under wind and rainfall . 6
5.2.3 Six-directional flight stability under wind . 7
5.2.4 Six-directional flight stability under wind and rainfall . 8
5.2.5 360° rotational stability under wind . 9
5.2.6 360° rotation stability under wind and rainfall . 9
6 Examination and evaluation . 9
Annex A (informative) Examples of the multi-copter UAS flight stability test .10
Annex B (informative) Example of the report format for the multi-copter UAS flight
stability test .18
Bibliography .20
iii
Foreword
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iv
Introduction
Multi-copter unmanned aircraft (UA) find a wide variety of applications ranging from individual
hobbies, such as image capture and racing, to a rapidly increasing number of commercial purposes,
such as precision farming, delivery, and inspection. Multi-copter UA control and flight dynamics are
unique relative to those of well-known fixed and rotary wing configurations, and therefore must
be fully understood to ensure their safe usage and integration into commercial applications. This
document identifies a manner of determining system level flight stability by evaluating the multi-copter
UA’s automated control system capability to maintain its spatial position when faced with a variety of
simulated temperature, wind, gust, rainfall and ice conditions. The test method for the flight stability
of the multi-copter unmanned aircraft system (UAS) provides the test condition, procedure, report
format, etc. The principal advantage of the test method is its ability to evaluate the flight stability of
a multi-copter UAS considering actual flight conditions. All tests are performed considering real-time
flight status. The purpose of the test method is to evaluate and improve the flight stability of a multi-
copter UAS through experiments conducted under various environmental conditions.
v
INTERNATIONAL STANDARD ISO 5110:2023(E)
Test method for flight stability of a multi-copter unmanned
aircraft system (UAS) under wind and rain conditions
1 Scope
This document specifies the procedures for testing flight stability of a multi-copter unmanned aircraft
system (UAS) and is applicable to multi-copter type UAS that can take-off and land vertically. A
commercial multi-copter UAS weighing over 250 g to less than 150 kg is discussed in this document.
Further, this document is applicable to military and civilian multi-copter UAS. However, quantitatively
specific stability criteria for the test are not specified in this document.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
flight stability
ability to maintain the parameters of motion (linear and angular positions, speed) within predefined
tolerances and time when exposed to external disturbances
Note 1 to entry: Flight stability of a multi-copter UAS can be defined as its spatial precision of take-off, landing,
hovering and moving intended by a pilot or autopilot flight program used while being subjected to various flight
environments.
3.2
manual mode
mode in which an aircraft flies with complete autopilot stabilization of three axes of motion (pitch,
roll, and yaw), heading hold (via a compass), height hold (via barometric pressure sensor), and lateral
position hold (via GNSS or optically)
Note 1 to entry: The pilot commands the aircraft to move to a different height or lateral position as required.
Once the pilot control input is released, autopilot stabilizes the UA.
3.3
autopilot mode
mode in which an aircraft moves according to pre-programmed waypoints (vertically or horizontally)
and/or performs take-off or landing operations without any pilot input
Note 1 to entry: Flight control for the entire duration or for some parts of the flight is performed without a pilot.
4 General principles
4.1 Test purpose
The purpose of this test method is to measure the flight stability of a multi-copter UAS under given
operational conditions. To check the overall performance of each component of the multi-copter UAS,
such as propulsion, control, and battery management systems, an actual test flight of the multi-copter
UAS in a test device is performed. For flight stability evaluations of the multi-copter UAS, actual flight
conditions are considered, while all tests are performed inflight. The proposed stability test method and
device are expected to satisfy numerous commercial multi-copter UAS manufacturers and developers
by evaluating and improving the flight stability of their multi-copter UASs via experimental results.
4.2 Test condition
Flight stability measurements of a multi-copter UAS are performed in a test device especially designed
for simulating flight conditions and measuring real-time spatial position of a multi-copter UA. In the
test device, the multi-copter UA is capable of flying under several environmental conditions, such as
temperature (from −20 °C to 50 °C), wind speed (from 0 m/s to 30 m/s), rain fall (from 0 mm/h to
20 mm/h, from 0 °C to 50 °C), ice (from −20 °C to 0 °C) and gust. Testing relative to rainfall does not
assess the ingress protection (water) of the multi-copter UAS. Particularly, position data of the multi-
copter UA during the stability test are stored to evaluate flight stability. The test conditions are adjusted
depending on the purpose and operation condition of the multi-copter UAS because not every multi-
copter UA test requires a high cost test device or a long test period. Based o
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