Arne Nykänen

Influence of Inverter Modulation Strategy on Electric Drive Efficiency and Perceived Sound Quality

This paper presents an evaluation of different modulation techniques and different levels of switching frequency randomization for a rear axle electrical drive unit used in automotive applications. Inverter and machine losses, and perceived sound quality of high-frequency acoustic noise are investigated by finite element calculations, experimental testing, and subjective noise assessment. Additionally, stator current harmonics, airgap flux density harmonics, and force density harmonics are compared for space vector modulation (SVM) and discontinuous pulsewidth modulation through finite element modeling. The main conclusion is that, primarily in the field weakening region, significant energy savings can be achieved (up to 17% decrease in total inverter losses with a switching frequency of 10 kHz). This is obtained without deterioration of perceived sound quality by the use of discontinuous pulsewidth modulation with switching frequency randomization. Furthermore, randomization of the switching frequency does not improve the perceived sound quality of the acoustic noise when using SVM. However, for discontinuous pulsewidth modulation, improvements in perceived sound quality when randomizing the switching frequency are observed, primarily below base speed.

Response Times for Visual, Auditory and Vibrotactile Directional Cues in Driver Assistance Systems

The number of advanced driver assistance systems is constantly increasing. Many of the systems require visual attention, and a way to reduce risks associated with inattention could be to use multis ...

Car Ride Before Entering the Lab Increases Precision in Listening Tests

Subjects who are well aware of what to judge commonly yield more consistent results in laboratory listening tests. This awareness may be raised by explicit instructions and training. However, too e ...

Prominence of Different Directions of Hub Forces and Moments in Structure-Borne Tire Noise

In the automotive industry, tire noise is an important factor for the perceived quality of a product. A useful method to address such NVH problems is to combine recordings with measurements and/or ...

Determination of Radiated Sound Power from an Electric Rear Axle Drive In-Situ and its Contribution to Interior Noise

System and component target setting for noise and vibration are important activities within automotive product development. New challenges arise when electric motors are introduced into cars tradit ...

Stud Noise Auralization

During the winter special winter tires are used to prevent the car from slipping and the grip can be improved by using studded tires. Studded tires are known to cause higher noise levels and noise ...

3D Auditory Displays for Parking Assistance Systems

The objective of this study was to investigate if 3D auditory displays could be used to enhance parking assistance systems (PAS). Objective measurements and estimations of workload were used to ass ...

Signal Sound Positioning Alters Driving Performance

Many of the information systems in cars require visual attention, and a way to reduce both visual and cognitive workload could be to use sound. An experiment was designed in order to determine how ...

Assessment of changes in automotive sounds caused by displacements of source and listening positions

Artificial head recordings are commonly used to measure and evaluate soundquality. In sound quality assessments, spatial qualities are crucial both forcorrect localization and separation of sources ...