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A. Stuck, M. Mijalkovic, M.Vidojevic, D. Popovic
Practical limitations of accurate magnetic measurements in industrial applications

The fundamental factors that limit the accuracy of magnetic measurements for field strengths typically encountered in industrial measurements of permanent magnets are discussed. In regions where magnetic fields can be considered homogenous, the accuracy of the measurement is limited by the stability of the magnetometer, the accuracy of its calibration, and the orthogonality of the sensor. However, the fieldsensitive volume's size and the measurement axis’s orthogonality determine the total accuracy in the nearfield region of small magnetic structures. Using measured magnetic images from encoder structures, it is shown that accurate measurements are achieved only by measuring all 3 magnetic field components in a tiny volume.

Milos Drutarovsky, Ondrej Benedik, Miroslav Sokol, Pavol Galajda, Jan Saliga, Jan Ligus, Cristian D Stratyinski
Custom Synthesizable VHDL Processor for Embedded Capacitive Angle Sensor Data Processing

We describe custom architecture of a small synthesizable soft processor for the next generation of proprietary capacitive angle sensor (CAPSE) developed by CTRL company for space applications. We process data streams from ADCs by custom developed 16-bit processor. The processor is written in platform independent VHDL code. It uses a small Leros (soft processor) control unit and several custom coprocessors including CORDIC, fixed-point fractional multiplier, and adder with barrel shifter optimized for fractional fixed-point arithmetic. We describe architecture of the proposed processor and present the results of developed custom processor mapping to the target FPGA circuit. The complete processor occupies only ∼2100 Logic Elements in target FPGA and complete firmware has less than 220 instructions. For a 10 kHz sampling rate, it requires less than 3 MHz system clock frequency.

Luiz G. Enger, Aleš Travnik, Peter Leitner, Florian Slanovc, Daniel Markó, Michael Ortner
Rapid Prototyping of Automotive Magnetic Positioning Systems

Magnetic position and orientation systems offer the advantages of contactless sensing, high precision, robustness and low cost. They are heavily employed in automotive and industrial applications. The standard development process of such system starts with a simulation that is followed by validation with experimental data. This work presents a platform to which different sensors and magnets can be attached, with complete six degrees of freedom for relative movement. It is thus quite flexible in terms of experiments it can perform. A system calibration scheme based on dipole approximation is presented, yielding sensor tolerances and allowing to compute the field of a corresponding magnet.

Noby George, Pavel Ripka, Václav Grim
Crosstalk in Gapped-core Contactless Current Sensor

A detailed analysis of the crosstalk in the gapped-core current sensor is presented in this paper. The gapped-core current transducer with a magnetic field sensor in the airgap is widely used to measure current in industries and laboratories. We examine the effect of a nearby current-carrying conductor on the performance of the gapped-core transducer, for the first time in this paper. The crosstalk is studied by considering various factors such as angular and linear displacement of the external conductor, core material, and position of the main conductor. A 3D Finite Element Method (FEM) based model is used to analyse the cross talk and results are presented in this paper. This analysis helps the designer to get detailed insight into the effect of the external conductor on the gapped core current transducer.

Michael Ortner, Alexandre Boisselet, Luiz G. Enger, Florian Slanovc, Peter Leitner, Daniel Markó
Analytical Models and Magnetic Position Systems

In this work, we promote the use of analytical solutions for magnetic position system design and analysis, which has become extremely convenient through the development of the open-source Magpylib computational package. We discard three common arguments against this ansatz by showing that analytical models are suitable for dealing with complex shapes, inhomogeneous magnetizations and even material interactions. Accuracy of analytical models is discussed, and the computational performance is demonstrated with three examples, a complex shape, an inhomogeneous magnet, and the calibration of a position system experiment. We find that analytical models can be powerful tools in this context.

Bruno Trinchera, Paolo Durandetto, Danilo Serazio
Quantum sampling modular setup for practical power measurements based on a programmable binary Josephson voltage standard

The new quantum SI opens the route to link the base unit definitions to fundamental constants of nature. In the spirit of the quantum SI, a similar traceability route can be implemented for alternating electrical quantities, such as electrical power. Its implementation is summarized in the present paper along with the main steps about the realization of a quantum-based sampling power standard carried out in the framework of the EMPIR project Quantum Power. A programmable Josephson voltage standard (PJVS) based on a 1-V SNS binary array provides the traceability of the power standard. The PJVS has been integrated into an existing sampling power standard and its main purpose is the real-time calibration of high-precision waveform digitizers using a new synchronous quantum power multiplexer (SQPM). Measurement scenarios and experimental characterization aimed at evaluating the gain and phase errors of the system constituents, and in particular of SQPM, are presented.

Jan Sobotka, Jirí Novák, Jirí Pinkava
Rapid Prototyping of Vehicle Software Defined Functions

A modern car is made up of a considerable amount of software running on many Electronic Control Units interconnected by communication infrastructure. Together it creates a rigid system, which is not easy to modify for running modified or custom code to implement new vehicle functions or gathering scientific data. The paper presents a modified (electric) vehicle architecture allowing rapid prototyping. The architecture enables control of particular vehicle functions by an independent computer, arbitrary vehicle data acquisition, and offers an interface for communication with the driver. Car-dependent and independent layers are used to provide an abstraction and hide details of a specific car model.

Sebastian Rivera, Rolf Slatter
Pole positioning for precise magnetic measurement systems

Modern drive systems rely in terms of accuracy and robustness on the quality of the used position sensors. For high accuracy applications optical position sensors are dominating the market with a trend towards more magnetic systems as their robustness in the field is superior compared to the optical counterparts. While the sensor itself has a great impact on system accuracy, the used scale or pole wheel is of similar importance when evaluating system architectures. ITK presents in this paper a machine setup for high accuracy, single pole writing machines either for linear or rotary magnetic scales. Baseline for the software architecture is the newly released DIN SPEC 91411 which unifies the nomenclature for magnetic measurement system. In addition the paper focus on a systematic approach to also measure the magnetic accuracy. Furthermore, new developments in write head design are presented as new hard magnetic coatings require higher fields for magnetization.

Jürgen Gerber, Rolf Slatter
DIN SPEC 91411: A standardized representation of magnetic scales

When it comes to scales for magnetic length and angle measurement systems, there has been no uniform terminology, no common drawing rules - neither for the mechanical nor for the magnetic parameters - and this has often led to misunderstandings or even errors in de-sign drawings. This primarily affects manufacturers of magnets, magnetic scales and sen-sors as well as machine or device manufacturers. A consortium consisting of a total of 13 companies and research institutions, mainly members of the Innovation Platform for Mag-netic Microsystems INNOMAG e. V., has now developed a DIN SPEC standard for the uni-form representation of magnetic measuring scales.

Erxat Arkin, Jiqing Fu, Qing He, Jia Kong
Atomic density calibration at high-temperature

Calibration of atomic density in vapour cell is very important for high precision quantum metrology and fundamental research. Here we propose to use spin noise spectroscopy(SNS) method for density estimation which would be more reliable than the common density estimation methods based on absorption spectrum or thermodynamic equation. We show our test with different density estimation methods, and show the robustness of SNS method.

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