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Andri Bezzola, PhD
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Audio Product Development at Samsung Audio LabBetter and Faster With Simulations
Overview
• Introduction
• Nonlinear Distortion in a Woofer
• Optimization of SAMSUNG LED WALL HF Waveguide
• Conclusion & Outlook
2COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
3COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Samsung ElectronicsFast Facts 1969 Vision2020 320,671
Year Founded
Inspire the World,Create the Future
# of Employees(Dec 2017)
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD 4
Global R&D Network
OF ENTIRE WORKFORCE
15
40.7 M DAILY
INVESTMENT (USD)
14.9 B TOTAL
INVESTMENT (USD)
Issued Patents
5
0 5000 10000
2014
2015
2016
2017
Issued US Utility Patents By Year
Toshiba
Qualcomm
Microsoft
Sony
Canon
IBM
Samsung
EuropeUS
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Top 10 Patentees in 20172016: 3rd
2015: 2nd
2014: 1st
6COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Samsung Audio LabValencia, CA
2013 First Hire
1700 Lab Area in m2
2 Anechoic Chambers
3 Listening Rooms
2 Transducer Test Rooms
7
21 FTEs | 300+ Years of Audio Engineering and Research Experience4 PhD | 6 MSc | 8 Active Musicians
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
8COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
• Acoustic simulations for tweeter phase plug
• Acoustic simulations for woofer lens
• Static Electromagnetic simulations for woofer driver
Samsung Audio Lab Products2015 R-Series Wireless Speaker
9COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
• Acoustic simulations for height channel
• Project launch to CES prototype: 6 weeks
• Project launch to mass production: 5 months
• First Samsung soundbar to ever achieve 5 star rating from Home Cinema Choice
Samsung Audio Lab Products 2016 First Dolby ATMOS Soundbar K950
Loudspeakers are Multiphysics, Multiscale, and Nonlinear
10
AC/DC Nonlinear magnets Saturation in steel
Structural Mechanics Anisotropic materials Large deformations Frequency dependent damping
Acoustics f = 20 Hz to 20 kHz λ = 17 m to 17 mm Infinite domains and far-field
measurements Losses in narrow regions
Heat Transfer Temperature from -20°C to 200°C
Fluid Dynamics Turbulent bidirectional air flow
through ports and vents
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
11COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Nonlinear DistortionSounds Bad
LinearWoofer
Non-Linear Woofer
Track 1
Track 2
12
Nonlinear DistortionAnti-Distortion
LinearWoofer
Non-Linear Woofer
Corrected
Track 1
Track 2
𝒈(𝑿, 𝒖)
𝒇(𝑿)
1/s C𝑢 [𝑉] 𝑥 [𝑚𝑚]𝑋�̇�+
𝑋 = [𝑥, �̇�, 𝑖] 𝑔 𝑋, 𝑢 = [0, 0, 𝑢 𝐿 𝑥⁄ ]�̇� = 𝑔 𝑋, 𝑢 + 𝑓 𝑋 𝐶 = 1, 0, 0𝑥 = 𝐶 𝑋
𝑓 𝑋 = 1
𝑀
�̇�
−𝐾 𝑥 𝑥 − 𝑅 �̇� + 𝐵𝐿 𝑥 𝑖 +𝑖
2 𝑑𝐿 𝑥
𝑑𝑥
1
𝐿 (𝑥)−𝐵𝐿 𝑥 �̇� − 𝑅 𝑖 −
𝑑𝐿 𝑥
𝑑𝑥�̇� 𝑖
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
13COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
COMSOL Apps for Calculation of Kms(x)Geometry Import
14COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
COMSOL Apps for Calculation of Kms(x)Selection Definition
15COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
COMSOL Apps for Calculation of Kms(x)Material Definition
16COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
COMSOL Apps for Calculation of Kms(x)Mesh Setup
17COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
COMSOL Apps for Calculation of Kms(x)Solve
18COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
COMSOL Apps for Calculation of Kms(x)Outstroke and Instroke
19COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
COMSOL Apps for Calculation of Kms(x)Results
20COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
COMSOL Apps for Calculation of BL(x)Geometry Import
21COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
COMSOL Apps for Calculation of BL(x)Selection Definition
22COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
COMSOL Apps for Calculation of BL(x)Material Choice
23COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
COMSOL Apps for Calculation of BL(x)Mesh
24COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
COMSOL Apps for Calculation of BL(x)B-Field and BL Curve
25COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
COMSOL Apps for Calculation of BL(x)B-Field and BL Curve
InductanceCoupling of B-Field, Current, and Velocity
26
• Self Inductance of a Wire Loop
𝑉 𝑡 = 𝐿𝑑𝑖 𝑡
dt= −
𝑑Φ
𝑑𝑡• Magnetic Flux
Φ = 𝐵 𝑑𝑎
= 𝜇 𝜇 𝐻 𝑑𝑎
• Ampère’s Law
𝛻 × 𝐵 = 𝜇 𝐽
• Current in Voice Coil
𝑖 = 𝑉 − 𝐵𝐿 𝑣 −
𝑑Φ𝑑𝑡
𝑅
• Magnetic Force on Voice Coil
𝐹 = 𝐵𝐿 𝑖
Le: Inductance
i: Current in the voice coil wire
Φ: Magnetic flux through voice coil
B: Magnetic flux density vector field
μ : Magnetic permeability in vacuum
μ : Relative permeability (saturation dependent)
H: Magnetic strength
BL: Radial component of magnetic B-field integrated over the length of the voice coil wire
J: Total current density per square meter
Vo: Applied voltage from amplifier
v: Voice coil velocity
Re: Resistance of voice coil wire
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
27
Non-Linear Distortion in a WooferCoupling PDE and ODE
Lumped Model (ODE)
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
FEM (PDE)
Moving Mesh for Large Deformations
28
Prescribed Deformation x(t) from ODE
Free DeformationLaplace smoothing ensures even distribution
Static MeshEverywhere else
Continuity ConditionBetween moving mesh and static mesh
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
A Better Approach in COMSOL®:Moving Physics
29
u: Voice coil position from ODEN0: Number of turnsh0_VC : Height of voice coilIcoil: Current in voice coil
𝑖 =𝑉 − 𝐵𝐿 𝑣 − 𝑉
𝑅
𝑉 = −𝑑𝜙
𝑑𝑡=
2 𝜋𝑅 𝑁
ℎ
𝑑𝐴
𝑑𝑡 𝑝𝑤1 𝑧 − 𝑢 𝑑𝑧
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhDCOMSOL is a registered trademark of COMSOL AB.
Dynamic Simulation Transducer A
30COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Dynamic Simulation Transducer B
31COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Quantifiably Better Drivers Through Simulation
32
Driver A Driver B
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
BL(x(t))Static BL(x)
BL(x(t))Static BL(x)
33
Optimizing a WaveguideSAMSUNG LED WALL
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
34COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Optimizing a WaveguideSpecific Constraints
• Very wide sweet spot
• Control sound horizontally and vertically
• Limited space available
• Must be able to play at high volume
Traditional Cinema Loudspeaker SystemsWaveguides and Compression Drivers
35COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Best Frequency Response at Sweet Spot
36
Measured
Target
Equalized
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Equalization (EQ)
Optimal Frequency Response at Many Points
37
Normalized to Sweet Spot
Φ [∘]
Φ
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Optimizing a WaveguideParametrization
• 3 Bezier Cross Sections
• Waveguide depth (fixed)
• Inner Diameter (fixed)
• Outer Diameter (fixed, except 45°)
• Tangency to driver exit and baffle
• Strength of tangency given by 𝐿 , 𝐿
38
Throataxis
1+(3x2) =
7 Control Variables
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Optimizing a WaveguideTarget
• Fixed 1 dB down at 20° and
10 kHz
• Fixed 6 dB down at 60° and
10 kHz
• Straight lines with variable
values at 1 kHz
• 2 additional control variables
39
Straight Lines in Off-Axis Plot
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Optimizing a WaveguideCOMSOL® Implementation
• LiveLink™ for SOLIDWORKS®
• Pressure Acoustics, Frequency Domain (acpr)
– Semi-infinite domain (PML)
– Speaker mounted to infinite wall (3 x symmetry)
– Constant acceleration at throat
• Optimization
– Parameter Optimization
– Nelder-Mead
• Mesh
– Free tetrahedral and swept mesh (in PML)
• Study
– Frequency Domain, 3rd octave frequencies
40COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhDCOMSOL and LiveLink are trademarks or registered trademarks of COMSOL AB. SOLIDWORKS is a registered trademark of Dassault Systèmes SolidWorks Corp.
Optimizing a WaveguideOptimization
41COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Optimizing a Waveguide3D Printed Prototype
• Measured in 2π-configuration
• Mounted flush to wall of 2πanechoic chamber
42COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Optimizing a WaveguideOff-Axis Results
43
SimulatedMeasured
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
SimulatedMeasured
Horizontal Off-Axis Response Vertical Off-Axis Response
Optimizing a WaveguideResults
44
Directivity Plots: Horizontal Plane
Simulated Measured
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Optimizing a WaveguideResults
45
Directivity Plots: Vertical Plane
Simulated Measured
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Other Fun Simulations
46
Topology Optimization for Acoustics
Straight Port Flared Port
Fluid-Structure & Fluid-Acoustic Interaction
Bezzola, A., “Numerical Optimization Strategies for Acoustic Elements in Loudspeaker Design,” in 145th Audio Eng. Soc. Int. Conv. 2018, p.10046, New York City, 2018
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
47
Conclusion & Outlook
COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
• Loudspeakers are inherently multiphysics
• Simulations with COMSOL® are integral to
product development at Samsung Audio Lab
• Simulation Apps accelerate product
development
• Optimization reduces development time
• Simulations need empirical backup,
simulation engineers need a team!
• Do not hesitate to consult COMSOL support
COMSOL is a registered trademark of COMSOL AB.
Thank you!
SAMSUNG PROPRIETARY/CONFIDENTIAL – INTERNAL USE ONLYCopyright © 2014 Samsung Research America. All rights reserved.
Thank you!Thank you!
Copyright © 2017 Samsung Research America All rights reserved. Samsung Research America and the Samsung Logo are trademarks or registered trademarks of Samsung Group or its affiliates in the U.S. and other countries. Other names may be trademarks of their respective owners.
This document is provided for informational purposes only and is not intended as advertising. All warranties relating to the information in this document, either express or implied, are disclaimed to the maximum extent allowed by law. The information in this document is subject to change without notice.
Andri Bezzola, [email protected]/in/andribezzola
48COMSOL Conference | 2018-10-23 | Lausanne, Switzerland | Andri Bezzola, PhD
Special thanks to:
• Alyona Friedel and Zoran Vidakovic
• COMSOL Support Team
• COMSOL Team in Los Angeles
• Samsung Research America
• Samsung Audio Lab Team