TÜV SÜD

Your challenges Nothing can undermine a customer’s confidence in your automotive brand more quickly than the presence of incessant noises and sounds, such as buzzes, squeaks and rattles (BSRs). While not typically related to automotive safety, BSRs are among the most frequently cited sources of dissatisfaction in automotive ratings and customer surveys, decreasing the current customers’ satisfaction of their purchasing or leasing decision, and giving prospective customers reasons to evaluate other automotive brands.

What is BSR testing?Testing for BSRs typically involves road simulation testing that helps to isolate the root cause (or causes) of vibrations and road harshness that produce unwanted sounds audible within an automobile’s passenger compartment. Additional assessments evaluate the extent to which automobile velocity, acceleration and force can produce or enhance these sounds. Not only that, retesting is conducted to evaluate the effectiveness of proposed fixes in reducing or eliminating them.

Why is BSR testing important for your business? Unresolved BSRs can result in costly rework and repairs during the manufacturing process, as well as excessive warranty expenses during the vehicles useful life. Additionally, BSRs can be a source of annoyance and frustration for consumers, negatively impacting perceptions of your brand’s quality and deterring customers from considering your products in the future. Therefore, identifying existing noise, vibration and harshness (NVH) causes will result in greater customer satisfaction and increased brand loyalty.

What are the advantages of servoelectric actuator (SEA) technology for BSR testing?SEA technology is far ahead of hydraulic or electromagnetic actuation in terms of key performance metrics, including force, velocity, acceleration, root mean square (RMS) error, NVH and energy consumption. Employing a ‘greener’ approach than the traditional servohydraulic systems, SEA technology also delivers higher performance and accuracy, resulting in an increased frequency of repeatable tests. When

Buzz, squeak and rattle (BSR) testing Customised testing solutions to increase your automotive quality

conducting tests using the SEA Four Poster system, no hydraulic oil is used, minimising the risk of high pressure line and/or hose rupture and subsequent pollution. In general, SEA testing solutions require only a modest investment, minimising the manufacturer’s costs and waste during testing in the effort to develop high-quality products.

Extended applications beyond tire coupled four posterDue to inherent higher fidelity and frequency bandwidth achieved using SEA technology, test engineers can employ a ‘dual use’ test system consisting of both Tire Coupled (TCA) and Body Coupled (BCA) actuation. By adding one, two or more Body Coupled actuators to a typical Tire Coupled Four Poster, test engineers can quickly switch from imparting motion through the tire patch to applying frequency-based power spectrums directly into the vehicle frame, completely bypassing the tire and suspension components. Power Spectral Density (PSD) shaped data can be accurately reproduced based on acquired field acceleration data at remote vehicle body locations, ensuring that vehicles are subjected to all vibration content scenarios experienced in actual service.

Some advantages of SEA technology compared to hydraulic/electromagnetic actuation

Four times higher continuous force capacity than previous electromagnetic actuators

Modular design for reconfiguration and servicing ease High efficiency through optimized use of magnetic flux Longer life fixed wiring and cooling systems design Liquid cooled for 25 times more efficient heat

dissipation than air cooled electric systems Quieter, virtually silent operation; less high-pitch

commutation noise or oil swoosh Direct cooling of fixed motor coils for higher force

capacity and longer life Improved temperature monitoring via built-in,

integrated thermocouples as opposed to discrete, non-contact infrared ‘spot’ sensors

Improved bearing design for longer life with greater side load capacity

Offset load management for no overheating problems Digital control for smoother, quieter, more efficient

performance Higher resolution encoder for better control accuracy Regeneration for higher energy efficiency Compatibility with global power supplies; direct

connection to 380-480vac 3 PH without additional cost for step-down transformers

Servoelectric vs. hydraulic technology: A sample comparison of four poster performance factors

Parameter Servoelectric Servo- hydraulic

Notes

Peak Force CapacityFpk

6,250 lb,27.8 kN

5.5 – 6.3 klb,24.5 – 28kN

Other peak force configurations available for both electric and hydraulic versions.

Continuous or Static ForceFstat or Fcont

3,650 lb 16.2 kN

5.5 – 6.3 klb,24.5 – 28kN

Static or continuous force required to support vehicle weight plus the average forces required during operation.

Max Speed at Max ForceVmax, Fmax

75.5 in/sec 1.92 m/sec

N/A Pressure drop in servohydraulics based on oil flow proportional to velocity.

Max Speed at Reduced Force Vmax,Fn

166 in/sec 4.2 m/sec

63 in/sec 1.6 m/sec

Vmax for servohydraulics based on dual 15 gpm servovalves with accumulation.

Typical FrequencyResponse at -3dB, Fn

149 Hz 40 Hz Servohydraulic response based on Moog G761 response, ignoring hydraulic resonance.

Energy Consumption,Continuous usage, /hr

7 kW 84 kW Servohydraulic 40 gpm @ 3000 psi + cooling.Servoelectric uses <20% of energy.

Energy Consumption,50% Duty Cycle, /hr

4 kW 77 kW Servoelectric uses very little power when idle.

System Performance affected by: Accumulator pressure Servovalve wear Flow restrictions Hydraulic resonances Fluid dynamics Oil contamination Pressure losses

No No No No No No No

Yes Yes Yes Yes Yes Yes Yes

Servoelectric system performance unaffected by many physical parameters that limit servohydraulic systems.Servoelectric systems do not require retuning based on specimen variations or waveform content (same PID values for ALL conditions).

System Accuracy, % RMS Error –typical file playback

1% 10 – 30% Accuracy for servohydraulic depends greatly on tuning and waveform content.

Consumables Filters Seals Accumulators Servovalves Hydraulic oil Hydraulic hoses Cooling water & conditioning

Does not apply Repair/Replace annually

Annual maintenance costs for servoelectric systems are virtually eliminated.

Built-in Performance Monitoringand Diagnostics

Disp Limits Supply Power Voltage and Phase Current (Force) Limits Peak Velocity and Accel Control Dynamic Following Error Inertial Compensation Motor Temps Motor Cabling Displacement Feedback Energy Usage

Disp Limits Following

error not effective due to poor dynamic response

Servoelectric solution provides easier setup and usage, as well as extended built-in diagnostic functions for identifying and correcting problems when they do occur.

Regenerative Energy Yes No Regenerative returns captured energy back to the electric power system for greater efficiencies.

How can we help you? TÜV SÜD offers automotive manufacturers proven BSR diagnostic and prevention tools and methods that reduce vehicle rework and repair at the assembly plant, minimise dealership repairs, lower warranty expenses and increase customer satisfaction. We partner with top tier automobile manufacturers on-site around the world to identify and resolve BSR root causes. TÜV SÜD also assists you in implementing product and process improvements to help reduce the risk of future design

and quality issues. In addition to on-site services, TÜV SÜD also designs and builds customised solutions for BSR, NVH, performance and durability testing as well as other automotive assessments to meet your specific application and requirements. Such solutions include single and multiple specimen damper performance and durability test systems, elastomer characterisation test stands, single and multi-axis vibration systems, modular above ground or transportable servoelectric actuator (SEA) four poster testing systems, with the

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TÜV SÜD AG Westendstr. 199, 80686 Munich, Germany +49 89 5791-0 automotive@tuv-sud.com www.tuv-sud.com/automotive/BSR-testing

latter introducing the possibility of silent and efficient servoelectric road simulation. TÜV SÜD also offers on-site staffing solution, placing qualified test technicians at your facility to utilise these custom solutions to conduct required testing.

Our BSR testing services As an independent third-party service provider, TÜV SÜD offers complete solutions, from on-site testing services to the development of customised testing equipment.

On-site BSR testing and auditing servicesTÜV SÜD’s on-site testing services team has partnered with top tier OEMs for more than twenty years delivering testing services, root cause analysis and knowledge services, including: BSR resolution at OEM factory, including support in

design guides and validation as well as maintenance Four poster BSR testing, quality audits and drive file

replication comparison Body air leak/wind noise testing at OEM factory Full service competitive vehicle benchmarking

Custom-designed BSR test rigsTÜV SÜD designs and builds custom-designed BSR test rigs to simulate road conditions to isolate root causes for unwanted sounds audible to drivers and passengers. Specific types of test rigs include: Fixed, Ambient or Environmental Four Poster

(FAFP or FEFP) Fully Transportable Ambient or Environmental Four

Poster (TAFP or TEFP) Modular Above Ground Ambient or Environmental

Four Poster (MAGAFP or MAGEFP)

Your business benefits

Save time and money – by identifying BSRs and other quality considerations during the product development and automotive assembly processes.

Minimise risks – by taking advantage of our in-depth industry knowledge to address your unique problems reducing costly manufacturing and warranty rework that can also result in reputational harm.

Benefit from complete solutions – by utilising our one-stop-shop testing, certification, auditing and knowledge services for the full range of automotive products.

Gain a sustainable, competitive edge – by leveraging TÜV SÜD’s automotive industry expertise to develop innovate automotive products of the highest possible quality.

Why choose TÜV SÜD? For more than 150 years, TÜV SÜD has been the preferred testing and certification partner for automobile and automotive component manufacturers worldwide. Our specialised team for equipment solutions and technology is located in Holland, Michigan and has a wealth of experience supporting dozens of automotive customers. Our testing, engineering and installation experience with multiple four posters, combined with a strong track record of collaboration with local facility managers, construction companies, equipment manufacturers and contractors, yields high-performance customised systems installations and integration and on-time delivery for our customer. Due to our international presence in all major markets we can deliver local support and expertise. TÜV SÜD is fully committed to the long-term service support for all of the equipment we supply and we are able to accomplish this as a result of the deep involvement we have with our suppliers throughout the product development process.

Choose certainty. Add value. TÜV SÜD is a premium quality, safety, and sustainability solutions provider that specialises in testing, inspection, auditing, certification, training, and knowledge services. Represented in over 1000 locations worldwide, we hold accreditations in Europe, the Americas, the Middle East, Asia and Africa. By delivering objective solutions to our customers, we add tangible value to businesses, consumers, and the environment.

Related products and services

We also provide the following related products and services:

EMC and environmental testing SEA Damper Test Load Frames and testing SEA Elastomer Characterisation Load Frames

and testing Single and Multi-Axis SEA component vibration

test systems Interior and exterior component and electronics

testing Cooling system and fuel tank testing Tire and wheel testing Battery testing