Integrating Acoustics into the Design of Motion Systems

“The motors in a motion system will often squeal, squawk or hiss” says George Bennett in Designing Quiet Motion Systems, and for most of us, “quiet has become a symbol of quality”. Nowadays, it becomes crucial to integrate acoustics into the design stage of motion systems to quiet the product when people are standing next to it.

It seems we know much about the theory of the complex noise generation in motion systems. Today, different simulation tools available on the market enable us to analyse and minimize the acoustic noise at the source, in the design stage of a motor including its command.
Nevertheless, constructing and industrialising a whisper quiet motion system remains an ultimate challenge, in addition to other imperatives such as controllability, energy efficiency, material, or production costs.

This article simply explains the role and the influence of the different parts composing a standard system and proposes a substitute quieter version.
Starting from the physical origin of the noise, through the impact of the current loop in the motor drive, and an alternative quieter voltage drive, taking into account the correct use of the motion & feedthrough sensors or generator, G. Bennett sets some recommendations in his article Designing Quiet Motion Systems.

The author wonders if quiet motors indicates a quality product: … but how about a bit of tranquillity in a world increasingly noisy? Maybe in the near future we will hear electric vehicles whistling like birds while approaching a pedestrian crossing.

You may also like to discover more in those articles:
Magneto-vibroacoustic analysis: a new dedicated context  – Fabrice Marion
From Tesla to Pascal, a magneto-vibroacoustic analysis linking electromagntism to mechanical  –  K. Vansant

Typical noisy point to point position loop

Typical noisy point to point position loop (G. Bennett, Designing Quiet Motion Systems, www.e-driveonline.com)

Distribution of the magnetic force in a motor analysed in a finite element software

Distribution of the magnetic force in a motor analysed in a finite element software

Vibration response and total mechanical power in a mechanical simulation environment

Vibration response and total mechanical power in a mechanical simulation environment