Krisztian Enisz

Dr. Krisztian Enisz


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 February 2022 in Energies
Verified
Journal Article
Open access
PDF file
ISIstván Szalay
István Szalay
DFDénes Fodor
Dénes Fodor
KEKrisztian Enisz
Krisztian Enisz
HMHunor Medve
Hunor Medve
In this paper, a novel extended permanent magnet synchronous motor model is presented that incorporates a quadratic flux-current function to represent the polarity-dependent saliency. The proposed model enables the design of sensorless polarity detection algorithms required by the initial position detection of permanent magnet synchronous motors. The novelty of the model is that it integrates the polarity-dependent saliency into the traditional machine model and introduces a new machine parameter, the polarity-dependent saliency coefficient, to specify the Hessian matrix of the flux-current function. A measurement method is presented for determination of the elements of the Hessian and the polarity-dependent saliency coefficient. The solution of the model is given for high-frequency sinusoidal pulsating voltage injection. Experimental results show that the proposed extended model accurately predicts the amplitudes and phases of the second harmonics of the motor currents, which are the carriers of the polarity-dependent information. This information enables a current measurement-based polarity detection algorithm using the phase difference between the fundamental and second harmonic of the apparent d-axis current. Both the presented measurement data and the proposed model show that injection in the d-direction is optimal for polarity detection.

9 December 2023 in Machines
Verified
Journal Article
Open access
PDF file
NMNorbert Markó
Norbert Markó
EHErnő Horváth
Ernő Horváth
ISIstván Szalay
István Szalay
KEKrisztian Enisz
Krisztian Enisz
In a vehicle, wheel speed sensors and inertial measurement units (IMUs) are present onboard, and their raw data can be used for localization estimation. Both wheel sensors and IMUs encounter challenges such as bias and measurement noise, which accumulate as errors over time. Even a slight inaccuracy or minor error can render the localization system unreliable and unusable in a matter of seconds. Traditional algorithms, such as the extended Kalman filter (EKF), have been applied for a long time in non-linear systems. These systems have white noise in both the system and in the estimation model. These approaches require deep knowledge of the non-linear noise characteristics of the sensors. On the other hand, as a subset of artificial intelligence (AI), neural network-based (NN) algorithms do not necessarily have these strict requirements. The current paper proposes an AI-based long short-term memory (LSTM) localization approach and evaluates its performance against the ground truth.

20 December 2021 in IEEE Access
Verified
Journal Article
Open access
ISIstván Szalay
István Szalay
DFDénes Fodor
Dénes Fodor
KEKrisztian Enisz
Krisztian Enisz
HMHunor Medve
Hunor Medve
In this paper, we propose an extended permanent magnet synchronous motor model that incorporates a quadratic flux-current function to determine the polarity-dependent saliency and develop a sensorless initial position detection method that is capable of polarity detection. The quadratic model extension is based on the second-order Taylor polynomial of the flux-current function. We present the model equations in both the stator- and the rotor-oriented reference frames as well as the Park and inverse Park transforms of the quadratic terms and Hessian matrices. The transient behavior and the dependency of the extended model on the rotor position have been validated. The proposed initial position detection method injects non-modulated even square wave voltage signals and relies only on phase-current measurements. We analyzed the effect of the pulse length on the errors of the position estimation and polarity detection. We provide machine parameter-based approximations of the current components dependent on the rotor position and, based on them, present a quantitative pulse-length design method.

29 July 2024 in Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering
Verified
Journal Article
Closed access
KEKrisztian Enisz
Krisztian Enisz
ISIstván Szalay
István Szalay
EHErnő Horváth
Ernő Horváth
In this paper, we introduce a vehicle localization method designed for the SZEnergy race car, which competes in the Shell Eco-marathon. The proposed method comprises four different extended Kalman filter-based localization algorithms and a selection algorithm that determines the most suitable one based on vehicle speed, GNSS availability, and signal quality. The low-speed Kalman filters are based on a kinematic vehicle model while the high-speed variants are based on a dynamic vehicle model. Several measurements were performed during test maneuvers to evaluate the performance of the filters. The proposed method succesfully handles sensor miscalibration and GNSS outages.

19 November 2025 in Engineering Proceedings
Verified
Conference Paper
Open access
PDF file
RPRespected József Gábor Pázmány
Respected József Gábor Pázmány
ZSZoltan Szeli
Zoltan Szeli
KEKrisztian Enisz
Krisztian Enisz
In applied battery research, use-case-driven prediction is becoming increasingly important, particularly for predicting real-life load profiles. This study proposes techniques to forecast lifetime load profiles for traction batteries, comparing urban- and highway-dominated vehicular use cases. Both charging and discharging scenarios are analyzed. We examine the uncertainty in these profiles and conduct a sensitivity analysis to understand the relationship between load profiles and user behavior. In this study, we introduce a novel methodology that maps behavioral and environmental parameters to battery load clusters, enabling us to identify high-risk aging scenarios. Based on parameter studies, we perform load profile clustering to identify critical use case groups and observe key parameter interactions. We present a case study of an idealized driver under Hungarian environmental conditions to predict outlier battery usage in fleets. This novel approach enables more robust predictions of aging and performance degradation for automotive traction batteries across different user clusters.

7 November 2024 in Engineering Proceedings
Verified
Conference Paper
Open access
PDF file
KEKrisztian Enisz
Krisztian Enisz
EHErnő Horváth
Ernő Horváth
NMNorbert Markó
Norbert Markó
ZSZoltan Szeli
Zoltan Szeli
RPRespected József Gábor Pázmány
Respected József Gábor Pázmány
There are several global and local position estimation and refinement techniques based on the GNSS (Global Navigation Satellite System) and environmental monitoring (e.g., LIDAR, Light Detection and Ranging). These are usually based on a combination of multiple sensors using some form of sensor fusion, together with a filtering or observation technique. The behavior of these algorithms may vary depending on the applied sensor signals and on their accuracy under different environmental conditions and for different vehicle types. In the case of systems that also use GNSS signals, different procedures must also be prepared for signal dropouts and, in the worst case, drastic fluctuations in accuracy. The aim of this research is to present and compare the performance of different estimation procedures for different vehicles and environmental conditions.