Michael Frey

• Dr.-Ing.
• Deputy Director at Karlsruhe Institute of Technology

A serious accident might occur as a direct result of a defective component or system, especially at an automated vehicle. The objective of this study is to establish a fault analysis methodology that can effectively improve the reliability of electric and automated vehicles. To achieve this, We proposed a method for identifying potential faults by...

Novel vehicle concepts are needed to meet the requirements of resource-conserving and efficient mobility in the future, especially in urban areas. In the automated, driverless electric vehicle concept U-Shift, a new form of mobility is created by separating a vehicle into a drive module and a transport capsule. The autonomous driving module, the so...

Increasing urbanisation and growing environmental awareness in society require new and innovative vehicle concepts. In the present work, the design freedoms of additive manufacturing (AM) are used to develop a front-axle wheel suspension for a novel modular vehicle concept. The development of the suspension components is based on a new method using...

The battery thermal management of electric vehicles can be improved using neural networks predicting quantile sequences of the battery temperature. This work extends a method for the development of Quantile Convolutional and Quantile Recurrent Neural Networks (namely Q*NN). Fleet data of 225 629 drives are clustered and balanced, simulation data fr...

div>This article presents the methodical development of a subframe for a novel on-the-road-modular vehicle concept, which was developed for the U-Shift project. The subframe serves as the basis for a modular chassis. This chassis offers the possibility to exchange chassis components by the operator, which means after completion by the manufacturer,...

Wheel-selective drives on the steered axle of a vehicle with Ackermann steering allow for the generation of steering torque without the use of a steering actuator. If different drive torques are applied to the left and right driven wheels, their effect on the steering torque is not balanced, and a resulting steering torque remains (differential ste...

div class="section abstract"> Given the rapid advancement of connected and automated transportation, its applications have significantly increased. They are being studied worldwide to shape the future of mobility. Key promises are a more comfortable, efficient and socially adapted kind of mobility. As part of the EU Horizon2020 project SHared autom...

div class="section abstract"> The increasing adoption of battery electric vehicles (BEVs), driven by the EU's target of no internal combustion engine vehicles from 2035 onwards, is driving significant changes in the automotive industry. However, the high degree of electrification and the unique low-speed acceleration behavior of BEVs therefore lead...

Electric Vehicles are subject to effects that lead to more or less rapid degradation of functions. This can cause hazards for the drivers and uninvolved road participants. For this reason, the must be detected and mitigated, to maintain the vehicle function even in critical situations until a safe operating mode can be established. This publication...

The Stanley controller is a proven approach for path tracking control in automated vehicles. If time delays occur, for example, in signal processing and steering angle control, precision and stability decrease. In this article, enhancements for the Stanley controller are proposed to achieve stable behavior with improved tracking accuracy. The appro...

At the Institute of Vehicle System Technology at the Karlsruhe Institute of Technology (KIT) a new inner drum test bench had been build up and put into operation in 2022. This test bench allows the analysis of PLT (passenger and light truck) and truck tires under realistic quasi-stationary and dynamic loads on different real track surfaces. The tes...

A high level of automation in vehicles is accompanied by a variety of sensors and actuators, whose malfunctions must be dealt with caution because they might cause serious driving safety hazards. Therefore, a robust and highly accurate fault detection and diagnosis system to monitor the operational states of vehicle systems is an indispensable prer...

Constant monitoring of driving conditions and observation of the surrounding area are essential for achieving reliable, high-quality autonomous driving. This requires more reliable sensors and actuators, as there is always the potential that sensors and actuators will fail under real-world conditions. The sensitive condition-monitoring methods of s...

In articulated vehicles steering is accomplished by adjusting the articulation angle. Commonly a steering actuator is used to pivot the two vehicle sections. This actuator can be dispensed with if the pivoting is controlled by selective distribution of the drive torques to the individually driven wheels instead. Since steering is a safety-critical...

An improvement in energy efficiency of Battery Thermal Management Systems (BTMS) can increase range and reduce well-to-wheel emissions of Battery Electric Vehicles (BEV). In this work, the potential of a predictive BTMS using Quantile Convolutional Neural Networks (QCNN) was examined. The QCNN provided quantile predictions of battery temperature ba...

The energy consumption caused by battery thermal management of electric vehicles can be reduced using predictive control. A predictive controller needs a prediction model of the battery temperature, for example for different battery cooling and heating thresholds. In the proposed method, cross-domain data from simulation, vehicle fleet and weather...

The driverless and electrically powered vehicle concept U-Shift enables a new type of flexibility and efficiency for the mobility of tomorrow by separating the drive unit (driveboard) and transport capsule. In combination with various capsule types, the driveboard is used to transport both people and goods. In a first step, a rollable Mock-up was b...

In the automated, driverless, electric vehicle concept U-Shift, a new type of mobility is created by separating a vehicle into a drive module and a transport capsule. The autonomous driving module, known as a driveboard, is able to change the transport capsules independently and thus serves to transport both people and goods. The wide range of poss...

Safety verification and validation of autonomous driving functions up to SAE level 5 pose enormous challenges for car manufacturers. The paper argues that efficient improvement opportunities arise by suitably combining iterative development and verification processes that use self-learning approaches and well-defined quality and convergence criteri...

Notbremseinrichtung, umfassend einen Hydraulikzylinder (1) mit einem axial zur Translationsstange (8) auf dieser bewegbaren Kolben (9), der das Innenvolumen des Hydraulikzylinders in eine Arbeitskammer (2) und eine Systemkammer (3) mit einer Entlüftungsbohrung aufteilt, eine in Richtung der Arbeitskammer axial zur Translationsstange auf den Kolben...

A Prüfungsantrag gemäß § 44 PatG ist gestellt. Die folgenden Angaben sind den vom Anmelder eingereichten Unterlagen entnommen. (54) Bezeichnung: Relativführungsvorrichtung für eine radträgerseitig angeordnete Lenkanordnung (57) Zusammenfassung: Die Erfindung betrifft eine Relativ-führungsvorrichtung (1) für eine radträgerseitig angeordnete Lenkanor...

Fahrerassistenzsysteme, sowie autonomes Fahren leisten einen wesentlichen Beitrag, um Nutzfahrzeuge immer sicherer zu machen. Mit der Weiterentwicklung des automatisierten Fahrens steigt hierbei die Systemkomplexität, woraus sich Anforderungen an neue, gesamtheitliche Erprobungskonzepte entstehen. Um die Absicherung hochautomatisierter Fahrfunktion...

Localization and navigation not only serve to provide positioning and route guidance information for users, but also are important inputs for vehicle control. This paper investigates the possibility of using odometry to estimate the position and orientation of a vehicle with a wheel individual steering system in omnidirectional parking maneuvers. V...

Antriebsanordnung (2) für ein Fahrzeug (1), mit einem Fahrgestell (10), mit einer gelenkten Antriebsachse (24), wobei die gelenkte Antriebsachse (24) zwei Radeinheiten aufweist, wobei jede der Radeinheiten ein Rad (3), eine Radaufhängung zum Schwenken des Rads um eine Lenkachse (19), wobei die Radaufhängung an dem Fahrgestell (10) abgestützt ist, u...

This paper presents a data-driven risk-based framework to predict the safety confidence of automated driving functions using sensitivity and reliability analyses. Due to the rare nature of accidents, the Field Operational Tests will require prohibitive number of driving hours to prove the statistical superiority. Owing to the complexity of the auto...

Recently, individual electric mobility gains significance due to legislation and social discussion. Customers demand longer battery ranges. Advanced planning is a different and more sustainable approach. Potentially, they assist drivers in exploiting the installed range on long journeys. Earlier research of the authors showed that an optimal combin...

More electric vehicles are necessary to reach the goals set by international greenhouse gas legislation. However, low range, long charging time, and a sparse infrastructure compared to fuel-based individual mobility reduce customer acceptance of individual electric mobility. Energetic planning functions as range prediction can ease dealing with tho...

Es soll ein kompaktes und gewichtsreduziertes Radantriebsmodul 1 für ein Fahrzeug 2 bereitgestellt werden. Das Radantriebsmodul 1 umfasst eine Antriebsbaugruppe 3 zum Antrieb eines Rades 17 des Fahrzeugs 2. Die Antriebsbaugruppe 3 weist einen Elektromotor 5 auf, der einen Rotor 8 zur Erzeugung eines Antriebsdrehmoments umfasst, wobei der Rotor 8 al...

Increasing demands on reliability and safety of automated driving functions require an augmented usage of simulation tools for the efficient calibration of these functions. However, finding an optimal solution can be costly, especially when the objective function is represented by scenario simulations. To face these challenges, a novel optimization...

A gyroscope-based rotation damper for a motor vehicle, includes a flywheel that is driven via a drive, rotates around an axis of rotation at an angular velocity, the flywheel being mounted in a gimbal on the motor vehicle structure by way of a first bearing element and a second bearing element. The flywheel is mounted rotatably around the angle of...

Despite a rapid increase of public interest for electric mobility, several factors still impede Battery Electric Vehicles’ (BEVs) acceptance. These factors include their limited range and inconvenient charging. For mitigating these limitations to users, certain BEV-specific services are required. Therefore, such services provide a reliable range pr...

A gyroscope-based rotation damper for a motor vehicle, includes a flywheel that is driven via a drive, rotates around an axis of rotation at an angular velocity (.omega..sub..phi.), the flywheel being mounted in a gimbal on the motor vehicle structure by way of a first bearing element and a second bearing element. The flywheel is mounted rotatably...

Die Erfindung betrifft ein Verfahren zum Testen eines Bremsassistenzsystems für ein Fahr-zeug, insbesondere für einen Lastkraftwagen. Erfindungsgemäß wird eine clusteranalytische Charakteri-sierung von Fahrsituationen basierend auf erfassten Sensor-signalen zur Umfelderfassung und deren Systemreaktionen im Fahrbetrieb des Fahrzeugs ermittelt.

In this paper, a method for the automated adaptive tuning of a Bayesian localization filter is investigated, since previously parameters were often only empirically determined. The method determines the optimal parameters offline using Monte Carlo Simulation (MCS) results and ground truth data. The method is applied to a previously developed Bayesi...

A rotation damper for a motor vehicle. A flywheel driven via a drive with angular velocity and rotating about an axis of rotation is cardanically mounted via a first bearing element and a second bearing element. The flywheel is rotatably mounted on the first bearing element at the rotational angle and the first bearing element is rotatably mounted...

This paper presents an adaptive verification framework for automated driving functions based on ontologies and data-mining techniques. Despite the recent rapid growth of driver assistance systems to consolidate road safety, they still have various challenges coping with dynamic traffic situations of daily life. Therefore, automotive systems enginee...

This works presents a driver assistance system for energy-efficient automated longitudinal control (ALC) of a battery electric vehicle (BEV). The ALC calculates a temporal velocity trajectory from map data. The trajectory is represented by a cubic B-spline function and results from an optimization problem with respect to travel time, driving comfor...

This paper presents the design of a central feedforward control for the two chassis control systems rear-wheel steering (RWS) and torque vectoring (TV) which have related areas of intervention in lateral dynamics. A control strategy is presented in order to follow desired target values consisting of yaw acceleration and sideslip angle velocity. Cen...

Die Erfindung betrifft ein Verfahren zum Testen eines Totwinkelassistenzsystems für ein Fahrzeug, insbesondere für einen Lastkraftwagen. Erfindungsgemäß werden im Bereich einer Schleppkurve befindliche Umgebungsobjekte durch Sensoren erfasst und deren Abstand und Relativgeschwindigkeit zum Fahrzeug ausgewertet, wobei eine Kritikalität von erfassten...

Die Erfindung betrifft ein Verfahren zum Testen eines Assistenzsystems für ein Fahrzeug, insbesondere für einen Lastkraftwagen. Erfindungsgemäß ist das Assistenzsystem als ein kartenbasiertes System zur Geschwindigkeitsbegrenzung ausgebildet, wobei Verkehrszeichen bild-und kartenbasiert erfasst und fusioniert werden und wobei erfasste Informationen...

The upcoming market introduction of highly automated driving functions and associated requirements on reliability and safety require new tools for the virtual test coverage to lower development expenses. In this contribution, a computationally efficient and accurate simulation environment for the vehicle’s lateral dynamics is introduced. Therefore,...

In 2050 almost 70 percent of the global population will live in cities due to progressive urbanization. This progress includes several challenges such as the increasing traffic within cities and thus a lack of space. Multidirectional vehicles with their high maneuverability in narrow spaces, are therefore a suitable vehicle type for the urban space...

Die Erfindung betrifft ein Verfahren, eine Vorrichtung und ein Computerprogrammprodukt zur Steuerung einer Bremsanlage eines Rades (4) in einem Fahrzeug (2), in welchem ein Fahrzeugaufbau (6) mittels eines Rad-Fahrwerk-Systems an das Rad (4) gekoppelt ist, wobei das Verfahren die Schritte umfasst: - Ermitteln eines Beobachtungswerts x, welcher eine...

The industrialization of automated driving functions according to level 3 requires an efficient test and calibration concept to deal with an increased complexity, growing customer demands, and a larger vehicle fleet offered. Therefore, a method for a complexity reduction of the calibration parameter space is presented. In the two-step approach, a q...

This paper addresses an important problem of time series analysis at test benches. A new method is presented that allows automated segmentation of measurement time series using a Convolutional Neural Network (CNN). The CNN is trained for this purpose with specifically generated data. The results show a high quality and efficiency. The field of appl...

This paper introduces a novel method for comparison of similar time series, especially measurement and simulation data to identify problems in the observed system. It employs the technique for time series segmentation proposed in [1] together with Dynamic Time Warping (DTW) to jointly segment pairs of measurement and simulation time series. Further...

Die Erfindung betrifft ein Verfahren zum Testen eines Spurhalteassistenzsystems für ein Fahrzeug, insbesondere für einen Lastkraftwagen. Erfindungsgemäß wird ontologiebasiert eine Kategorie adäquater und relevanter Szenarien für existierende Feldtests extrahiert.

The B-spline function representation is commonly used for data approximation and trajectory definition, but filter-based methods for nonlinear weighted least squares (NWLS) approximation are restricted to a bounded definition range. We present an algorithm termed nonlinear recursive B-spline approximation (NRBA) for an iterative NWLS approximation...

A method for controlling a rotation damper operating according to the gyroscopic principle for a motor vehicle, wherein the rotation damper includes a flywheel, which is driven by a drive and rotating about a rotation axis with an angular velocity .omega..sub..phi., which is cardanically mounted via a first bearing element and via a second bearing...

A method for controlling a rotation damper operating according to the gyroscopic principle for a motor vehicle, wherein the rotation damper includes a flywheel, which is driven by a drive and rotating about a rotation axis with an angular velocity .omega..sub..phi., which is cardanically mounted via a first bearing element and via a second bearing...

This paper proposes a novel approach for automated functional testing of map-based fusion algorithms in complex vehicle networks. The hybrid data representation of detailed digital maps and physical automotive sensors provides an extended view of the ego-vehicle environment and thereby facilitates improved inferences and more competent decision-mak...

This paper investigates the possibility of estimating the actual pose of a passenger car while parking by adaptive multi-sensor data fusion. The newly developed Odometry 2.0 estimator includes multiple dead-reckoning models implemented by the adaptive measurement model of an Extended Information filter (EIF). The measurements of orientation and vel...

Road traffic noise is a nuisance to large parts of the German population and can lead to serious health impairments in the event of prolonged exposure. The acoustic condition of the road network plays an important role in this, but is difficult to record across the board. In order to be able to investigate the potential of the ATM method, in which...

Long-distance trucks are predestined for automated driving due to their high driving performance and long monotonous routes. Automation has the potential to increase road safety, improve fuel efficiency, optimise vehicle utilisation, increase driver productivity and reduce freight costs. Although the widespread use of full automation is not imminen...

This paper presents the usage of additional tire information in the form of cornering stiffness to enhance vehicle handling and stability with an adaptive rear-wheel steering control (RWS). The influence of varying cornering stiffness on driving behavior is dicussed in advance with a singletrack model. On the basis of an enhanced single-track model...

This work aims at classifying the road condition with data mining methods using simple acceleration sensors and gyroscopes installed in vehicles. Two classifiers are developed with a support vector machine (SVM) to distinguish between different types of road surfaces, such as asphalt and concrete, and obstacles, such as potholes or railway crossing...

In order to run a localization filter for parking systems in real time, the directional information must be directly available when a distance measurement of the wheel speed sensor is detected. When the vehicle is launching, the wheel speed sensors may already detect distance measurement in the form of Delta-Wheel-Pulse-Counts (DWPCs) without havin...

This paper presents an innovative approach toward data-driven scenario synthesis for verification of active safety functions. Despite the recent rapid growth of active safety to consolidate road safety, they still have various challenges coping with dynamic traffic situations of daily life. Therefore, automotive systems Engineering has established...

This paper presents an innovative approach for the verification of truck platooning functions in complex automotive sensor topologies. Truck platooning provides a promising business case for truck automation to increase road capacity and reduce fuel consumption. It has therefore been instrumental in the ongoing innovation of Cooperative Adaptive Cr...

The energy demand of vehicles is influenced, not only by the drive systems, but also by a number of add-on systems. Electric vehicles must satisfy this energy demand completely from the battery. Hence, the use of power steering systems directly result in a range reduction. The “e²-Lenk” joint project funded by the German Federal Ministry of Educati...

This paper proposes a novel approach for automated functional testing of map-based fusion algorithms in complex vehicle networks. The hybrid data representation of detailed digital maps and physical automotive sensors provides an extended view of the ego-vehicle environment and thereby facilitates improved inferences and more competent decision-mak...

Zusammenfassung Die Arbeit beschreibt eine Untersuchung von Data-Mining-Ansätzen zur Klassifikation der Fahrbahnbeschaffenheit mittels einfacher Beschleunigungssensoren und Gyroskope. Ziel ist sowohl die Klassifikation des Fahrbahnmaterials als auch das Erkennen von Unregelmäßigkeiten wie z. B. Schlaglöcher oder Bahnübergänge. Aus den Sensorsignale...

In der Vergangenheit hat sich mit dem bis dato recht schleppend verlaufenen Markthochlauf von Elektrofahrzeugen gezeigt, dass der Kunde nicht bereit ist, für bezüglich ihrer Leistungsdaten wenig attraktive Fahrzeuge einen höheren Anschaffungspreis relativ zu konventionell angetriebenen Fahrzeugen zu bezahlen. Zur Erreichung des Ziels von einer Mill...

Modern electric drive trains provide a variety of new features besides propulsion. We design a novel power steering system for electric vehicles using wheel individual drives. Using a suitable chassis and control system, the drive train can induce a specific steering torque into the steering system. Hence, the power steering system becomes part of...

In electric cars, heating the cabin is similar to that of combustion engine vehicles. This causes two problems. First, the need of energy for this system is high and thus reduces the range of the car. Second, research results show that other systems could improve the driver's thermal comfort. Therefore a method to analyze different systems is neede...

Ride comfort is one of the main development tasks of automotive engineering. To achieve good ride comfort the damper and spring setup of a suspension system is very important. For an easy adjustment of these components the dynamic response of the suspension should be as good as possible. To analyse the dynamic response of a suspension in a range fr...

This paper proposes a novel approach for automated functional testing of map-based fusion algorithms in complex vehicle networks. The hybrid data representation of detailed digital maps and physical automotive sensors provides an extended view of the ego-vehicle environment and thereby facilitates improved inferences and more competent decision-ma...

The condition of the road infrastructure has severe impacts on the road safety, driving comfort, and on the rolling resistance. Therefore, the road infrastructure must be monitored comprehensively and in regular intervals to identify damaged road segments and road hazards. Methods have been developed to comprehensively and automatically digitize th...

Predictive control is a popular approach for further improving efficiency and performance of vehicular systems, enabling intelligent systems behavior appropriate to the driving situation. To calculate such control strategies, the future vehicle dynamics or subsequent states have to be predicted. We introduce a stochastic framework based on an expla...

Tire road noise is the major contributor to traffic noise, which leads to general annoyance, speech interference, and sleep disturbances. Standardized methods to measure tire road noise are expensive, sophisticated to use, and they cannot be applied comprehensively. This paper presents a method to automatically classify different types of pavement...

The type and condition of road surfaces have not only various influences on the vehicle itself and the passengers, but also affect people living close to road infrastructure and pedestrians. A big contributor to traffic noise is the tire road noise, not only above 40km/h, but in all driving conditions. Many studies show the effect of traffic noise...

Tire road noise is the major contributor to traffic noise, which has strong consequences for public health and is known as an environmental problem. The measurements in compliance with international standardized methods to measure tire road noise are expensive, sophisticated to use and are not sufficiently mobile. A new method based on a tire cavit...

Knowledge about the driving behavior of a driver is important for applications in many different areas, especially for Advanced Driver Assistance Systems. The driving style does not only affect the current driver and his vehicle but also his environment. For example, usage-based insurances classify the driving style in order to reward calm drivers...

This paper presents a novel approach for the verification of multisensor data fusion algorithms in complex automotive sensor networks. Multisensor fusion plays a central role in enhancing the interpretation of traffic situations, facilitating inferences and decision making. It has therefore been instrumental in the ongoing innovation of Advanced Dr...

This paper presents an agile approach to facilitate the rapid development of traffic sign classification algorithms in heavy vehicles under a wide range of visibility conditions. A vision-based traffic sign recognition system makes a significant contribution to improving the transportation safety by enhancing the driver’s awareness on important roa...

This paper deals with an advanced approach for the verification of ADAS algorithms in complex automotive sensor networks. We introduce a real-time modular framework that can benchmark the performance of the ADAS algorithms at the electronic system level using a Hardware-in-the-Loop (HiL) co-simulation. The presented research provides a generic arch...

Am Beispiel der Entwicklung einer neuartigen Lenkkraftunterstützung auf Basis radselektiver Antriebe werden die Notwendigkeit unterschiedlicher Simulationsmodelle und der zugehörige Auswahlprozess vorgestellt. Durch das Ziel sowohl ein Fahrwerk auszulegen als auch die Fahrdynamik zu regeln, ergeben sich unterschiedliche Anforderungen an die Modelle...

The project "Intelligent Assisted Steering System with Optimum Energy Efficiency for Electric Vehicles (e²-Lenk)" focuses on a novel assisted steering concept for electric vehicles. We analysed different suspensions to use with this innovative power steering concept driven by wheel individual drive torque at the front axle. Our investigations show...

Nicht nur die Antriebsmaschinen, sondern auch zahlreiche Zusatzsysteme beeinflussen den Energiebedarf von Fahrzeugen. Bei Elektrofahrzeugen muss dieser Energiebedarf vollständig durch die Batterie abgedeckt werden. Somit resultiert der Einsatz von Systemen wie bspw. der Lenkkraftunterstützung direkt in einer Reduktion der Reichweite. Das durch das...

This paper presents a novel approach for the verification of multisensor data fusion algorithms in complex automotive sensor networks. Multisensor fusion plays a central role in enhancing the interpretation of traffic situations, facilitating inferences and decision making. It has therefore been instrumental in the ongoing innovation of Advanced Dr...

In this paper we present an online learning approach to predict driver behavior and resulting vehicle states. The driver is represented by driver states x→ and a control function ƒ c . Kernel Density Estimation is used for online estimation of current driver states. Data sampling methods are introduced to observe the virtual driver states. The driv...

Tire road noise is considered as the major noise source in traffic noise and even as a health problem today. Existing methods to measure the tire road noise suffer from several disadvantages, which led to the development of an alternative method, namely the tire cavity sound measurement method. Due to the high costs of the developed prototypes, thi...

Field Operational Tests are conducted in the automotive industry to obtain data in large-scale testing programs under real operating conditions. In this paper we present a novel measuring device, which has many advantages compared to common instrument devices employed for Field Operational Tests. It consists of a Micro-Electro-Mechanical System ine...

A new approach substitutes the damper of a passenger car by a cardanic gimbaled flywheel mass. The constructive design leads to a rotary damper in which the vertical movement of the wheel carrier leads to revolution of the rotational axis of the flywheel. In this arrangement, the occurring precession moments are used to control damping moments and...

Today, body vibration energy of passenger cars gets dissipated by linear working shock absorbers. A new approach substitutes the damper of a passenger car by a cardanic gimbaled flywheel mass. The constructive design leads to a rotary damper in which the vertical movement of the wheel carrier leads to revolution of the rotational axis of the flywhe...

The braking performance of recent vehicles is controlled by the interaction between the antilock braking system (ABS) and the transmitted force between road and tire. Because of tire and suspension elasticity, an abrupt braking or the ABS regulation initiates tire belt and wheel axle oscillations, which lead to a closed loop of acceleration and for...

A new approach substitutes the damper of a passenger car by a cardanic gimbaled flywheel mass. The constructive design leads to a rotary damper in which the vertical movement of the wheel carrier leads to revolution of the rotational axis of the flywheel. In this arrangement, the occurring precession moments are used to control damping moments and...

A new approach substitutes the damper of a passenger car by a cardanic gimbaled flywheel mass. The constructive design leads to a rotary damper in which the vertical movement of the wheel carrier leads to revolution of the rotational axis of the flywheel. In this arrangement, the occurring precession moments are used to control damping moments and...

Even while at a standstill, motors of electric vehicles are generating high tyre torques leading to an increase in tyre/road noise of up to 10 dB in the near fi eld. to reduce such driving torque-dependent tyre noise, systematic tests were carried out on the acoustically optimised inner drum test rig at institute of Vehicle system technology at the...