Jan Anthonis

Multiphysics NVH Modeling: Simulation of a Switched Reluctance Motor for an Electric Vehicle

This paper presents a multiphysics modeling of a switched reluctance motor (SRM) to simulate the acoustic radiation of the electrical machine. The proposed method uses a 2-D finite-element model of the motor to simulate its magnetic properties and a multiphysics mechatronic model of the motor and controls to simulate operating conditions. Magnetic forces on the stator are calculated using finite-element analysis and are used as the excitation on a forced response analysis that contains a finite-element model of the motor stator structure. Finally, sound power levels are calculated using the boundary element method. Simulation results of the model are shown and compared with experimental measurements for a four-phase 8/6 SRM.

Virtual engineering at work: the challenges for designing mechatronic products

The product race has become an innovation race, reconciling challenges of branding, performance, time to market and competitive pricing while complying with ecological, safety and legislation constraints. The answer lies in “smart” products of high complexity, relying on heterogeneous technologies and involving active components. To keep pace with this evolution and further accelerate the design cycle, the design engineering process must be rethought. The paper presents a mechatronic simulation approach to achieve this goal. The starting point is the current virtual prototyping paradigm that is widely adopted and that continues to improve in terms of model complexity, accuracy, robustness and automated optimization. Two evolutions are discussed. A first one is the extension to multi-physics simulation answering the design needs of the inherent multi-disciplinarity of “intelligent” products. Integration of thermal, hydraulic, mechanical, haptic and electrical functions requires simulation to extend beyond the traditional CAD-FEM approach, supporting the use of system, functional and perception models. The second evolution is the integration of control functions in the products. Where current industrial practice treats mechanical system design and control design as different design loops, this paper discusses their integration in a model-based design process at all design stages, turning concepts such as software-in-the-loop and hardware-in-the-loop into basic elements of an industrial design approach. These concepts are illustrated by a number of automotive design engineering cases, which demonstrate that the combined use of perception, geometric and system models allows to develop innovative solutions for the active safety, low-emission and high-comfort performance of next-generation vehicles. This process in turn poses new challenges to the design in terms of the specification and validation of such innovative products, including their failure modes and fault-tolerant behaviour. This will imply adopting a model-based system engineering approach that is currently already common practice in software engineering.

Modelling of Sprayer Boom Dynamics by Means of Maximum Likelihood Identification Techniques, Part 1: A Comparison of Input-output and Output-only Modal Testing

It is a well-known fact that the linear dynamic behaviour of mechanical structures can be studied by modelling the relation between force(s) [input(s)], acting on the structure, and their resulting structural vibration response(s) [output(s)]. For industrial structures, in their real in-operation conditions, it often becomes hard (or impossible) to experimentally measure the excitation. For this reason, attention has been paid to the development of system identification techniques that work on a basis of response data only. The use of such techniques allows the identification of modal models for structures excited by unknown ambient noise and vibration. In this contribution, controlled vibration experiments were conducted on a sprayer boom that was mounted on a tractor. A comparison was made between the results of a classic input-output and output-only modal analysis based on maximum likelihood system identification techniques. Due to the interaction between the dynamic artificial excitation device and the test structure, the output-only approach modelled the excitation device together with the test structure. The identified output-only modal parameters were validated by direct comparison to the identification results obtained on a classic input-output transfer function data set between the generator input signal and the structural responses.

Linear mechanical systems and dyadic transfer function matrices

For some linear mechanical systems, which can be written as a dyadic transfer function matrix (DTM), MIMO controller design can be reduced to a number of SISO designs. Internal stability of the SISO designs guarantees stability of the resulting MIMO controller. By relating the insights from modal analysis to system theory, necessary and sufficient conditions are derived for linear mechanical systems to have the DTM property. The main theorems are illustrated on an active suspension design of an agricultural spray boom.

Design of an active suspension to suppress the horizontal vibrations of a spray boom

Abstract Spray-boom vibrations are one of the main causes of a non-homogeneous distribution of agro-chemicals. Yawing and jolting motions of the boom are most critical. A horizontal active suspension, reducing yawing and jolting is designed. The use of special and consequently expensive equipment hampers the breakthrough of active suspensions. Therefore the proposed active suspension is built from standard hydraulic equipment, suited for mobile applications. Coulomb friction and asymmetric behaviour introduces considerable non-linearities, complicating the derivation of a linear model and controller design. It is explained how to identify a model, approximating in the best-possible way the general linear behaviour of the system. By the H ∞ methodology and an iterative procedure, introduced in this paper, non-linearities are taken into account in the controller design without increasing the controller dimensions. The resulting controller is stable and shows good performance.

Modelling of sprayer boom dynamics by means of maximum likelihood identification techniques. Part 2: Sensitivity-based mode shape normalisation

Abstract Output-only modal analysis allows the estimation of modal models for structures in their real in-operation conditions. One of the main drawbacks of this approach is that a part of the modal model can no longer be estimated. As a result, the operational mode shape estimates remain incorrectly scaled, dependent on the unknown level of ambient excitation. This incompleteness somewhat restricts the applicability of in-operation modal models. No techniques were previously available for the normalisation of operational mode shapes purely based on experimental output-only data. Recently, a sensitivity-based normalisation approach, that can be used for output-only data, was proposed and successfully tested on simple laboratory structures. The principle behind the normalisation technique is the interpretation of the shifts in modal parameters induced by well-known structural modifications. In this contribution, the sensitivity-based normalisation approach was experimentally validated on a basis of vibration experiments performed on a tractor–sprayer combination.

Design of a Pressure Control System With Dead Band and Time Delay

This paper investigates the control of pressure in a hydraulic circuit containing a dead band and a time varying delay. The dead band is considered as a linear term and a perturbation. A sliding mode controller is designed. Stability conditions are established by making use of Lyapunov-Krasovskii functionals, nonperfect time delay estimation is studied and a condition for the effect of uncertainties on the dead zone on stability is derived. Also, the effect of different LMI formulations on conservativeness is studied. The control law is tested in practice.

Online Estimation of Vehicle Inertial Parameters for Improving Chassis Control Systems

Abstract Vehicle chassis control systems aim at increasing vehicle safety and performance, while ensuring superior passenger comfort. Nearly all control algorithms are sensitive to the inertial parameters of a vehicle. As the vehicle mass, the moments of inertia, and the centre of gravity (COG) position can change significantly during operation, an accurate online estimation of these properties could substantially improve the performance of an active system. This paper presents an innovative algorithm for the online estimation of the inertial parameters of a road-vehicle. Using low-frequent suspension displacement signals and suspension stiffness characteristics, the vehicle mass and horizontal COG position are estimated. A Monte Carlo method determines the most probable mass distribution. Based on the assigned passenger weight, anthropometric data sets allow to calculate the inertial properties of every passenger, eventually resulting in the inertial parameters of the complete, loaded vehicle. The accuracy of the proposed algorithm is validated by means of a test campaign on an accurate kinematics and compliance testrig.

Design of a Friction Independent Mass Flow Sensor by Force Measurement on a Circular Chute

Abstract A mass flow sensor for bulk flow measurements is designed. The sensor consists of a curved chute and the force executed by the flow on the chute is a measure for the force. By properly selecting the projection angle of the force, i.e . the direction in which the force is measured, the sensor can be made almost independent of the friction coefficient of the bulk. The selection of the projection angle involves an optimisation problem. To carry out the optimisation, a physical model of the differential force is derived. The differential force is the force executed on the chute by an infinitesimal mass. Based on the model of the differential force, a starting value for the optimisation process is computed. After the optimisation the influence of friction on the measurement is less than 0·5% per 0·1 change of the friction coefficient. For some installation conditions, the effect of friction on the force measurement can be completely eliminated.

Electromagnetic and Structural Analysis for a Surface-Mounted PMSM Used for Light-EV

This paper presents the performances of a surface-mounted permanent-magnet synchronous machine (SM-PMSM) from the electromagnetic and structural analysis point of view, which are evaluated numerically and through tests. The goal is to evaluate the possibility to use this SM-PMSM for the propulsion of a light-electric vehicle (L-EV), knowing that on one hand it has the best power density and, on the other hand, a torque wave with high ripples induces vibration and noise. This paper discusses the limits and the advantages for such a propulsion solution in order to evaluate its suitability for the L-EV applications.