Modulation-function-based finite-horizon sensor fault detection for salient-pole PMSM using parity-space residuals. - In: IFAC-PapersOnLine, ISSN 2405-8963, Bd. 54 (2021), 7, S. 61-66
An online model-based fault detection and isolation method for salient-pole permanent magnet synchronous motors over a finite horizon is proposed. The proposed approach combines parity-space-based residual generation and modulation-function-based filtering. Given the polynomial model equations, the unknown variables (i.e. the states, unmeasured inputs) are eliminated resulting in analytic redundancy relations used for residual generation. Furthermore, in order to avoid needing the derivatives of measured signals required by such analytic redundancy relations, a modulation-function-based evaluation is proposed. This results in a finite-horizon filtered version of the original residual. The fault detection and isolation method is demonstrated using simulation of various fault scenarios for a speed controlled salient motor showing the effectiveness of the presented approach.
https://doi.org/10.1016/j.ifacol.2021.08.335
Long-term dependency slow feature analysis for dynamic process monitoring. - In: IFAC-PapersOnLine, ISSN 2405-8963, Bd. 54 (2021), 3, S. 421-426
Industrial processes are large scale, highly complex systems. The complex flow of mass and energy, as well as the compensation effects of closed-loop control systems, cause significance cross-correlation and autocorrelation between process variables. To operate the process systems stably and efficiently, it is crucial to uncover the inherent characteristics of both variance structure and dynamic relationship. Long-term dependency slow feature analysis (LTSFA) is proposed in this paper to overcome the Markov assumption of the original slow feature analysis to understand the long-term dynamics of processes, based on which a monitoring procedure is designed. A simulation example and the Tennessee Eastman process benchmark are studied to show the performance of LTSFA. The proposed method can better extract the system dynamics and monitor the process variations using fewer slow features.
https://doi.org/10.1016/j.ifacol.2021.08.278
Robotized functional localization with TMS. - In: Brain stimulation, ISSN 1876-4754, Bd. 14 (2021), 6, S. 1652-1653
https://doi.org/10.1016/j.brs.2021.10.207
Compressed ultrasound computed tomography in NDT. - In: IEEE IUS 2021, (2021), insges. 4 S.
Ultrasound Computed Tomography (UCT) is challenging due to phenomena such as strong refraction, multiple scattering, and mode conversion. In NDT, large speed of sound contrasts lead to strong artifacts if such phenomena are not modeled correctly; however, enhanced models are computationally expensive. In this work, a two-step framework for Compressed UCT based on the integral approach to the solution of the Helmholtz equation is presented. It comprises a physically motivated forward step and an imaging step that solves a suitable inverse problem. Multiple scattering is accounted for through the use of Neumann series. Convergence problems of Neumann series in high contrast settings are addressed via Padé approximants. Compressed sensing is employed to reduce the computational complexity of the reconstruction procedure by reducing data volumes directly at the measurement step, avoiding redundancy in the data and allowing the ability to steer the admissible computational effort at the expense of reconstruction quality. The proposed method is shown to yield high quality reconstructions under heavy subsampling in the frequency and spatial domains.
https://doi.org/10.1109/IUS52206.2021.9593329
A 4-channel V-band beamformer featuring a switchless PALNA for scalable phased array systems. - In: 2021 IEEE/MTT-S International Microwave Symposium, (2021), S. 839-841
This paper presents a 4-channel bidirectional V-band beamformer adopting a switchless PALNA in a SiGe:C 130 nm BiCMOS technology, featuring ft/fmax of 250/340 GHz. Using such technique saves the silicon area occupied by the RF switches avoiding their lossy effect on PAs outputs and LNAs inputs. The designed beamformer contains PAs, LNAs, vector modulators with active balun, passive power dividers/combiners and an integrated SPI interface. On-wafer measurements show that the fabricated beamformer covers the band from 57 GHz to 66 GHz with an average small signal gain of 18 dB and 9 dB all over the channels in both Tx and Rx modes respectively. Furthermore, the beamformer achieves an OP1dB of 10.5 dBm in Tx mode and an IP1dB of -27 dBm in Rx mode. The circuit occupies 11 mm2 and consumes 230 mW and 100 mW per channel in Tx and Rx modes respectively.
https://doi.org/10.1109/IMS19712.2021.9574827
Preliminary investigations of microwave imaging algorithms for tissue temperature estimation during hyperthermia treatment. - In: 2021 International Conference on Electromagnetics in Advanced Applications (ICEAA), (2021), S. 079-084
Monitoring of the temperature distribution inside the tissue to be treated plays the key role in success and safety of thermal therapies. Active microwave imaging represents a promising approach for non-invasive tissue temperature monitoring during hyperthermia treatment. In the present paper, an approach for quantitative non-invasive tissue temperature estimation via UWB imaging is described. Two types of imaging algorithms are considered - Delay and Sum beamforming and Truncated Singular Value Decomposition scheme. The capabilities of the proposed imaging algorithms are demonstrated by experiments with liquid phantoms. The results of our investigation show that both imaging algorithms can be applied for detection and estimation of the temperature induced dielectric property changes.
https://doi.org/10.1109/ICEAA52647.2021.9539731
Implementation options of control systems for a cantilever calibration device. - In: Proceedings of 2021 IV International Conference on Control in Technical Systems (CTS), (2021), S. 3-6
The article describes global approaches to control of the cantilever calibration device. The idea of the device consists in electromagnetic compensation of the influence of cantilever forces. The development of regulators is based on the simulation of mechanical processes when the cantilever is applied to the load cell with the principle of electromagnetic compensation; the identification of the processes is performed. In addition, in the course of the study, a comparison was made of PID controllers implemented on various actuator systems: an analog circuit, a current source, a dSPACE real-time system, a microcontroller. The purpose of developing and comparing regulators was to improve characteristics of the system: regulation time, overshoot, noise amplitude.
https://doi.org/10.1109/CTS53513.2021.9562880
Magnetoresistance of carbon nanotubes filled by iron. - In: Proceedings of the 2021 IEEE 11th International Conference "Nanomaterials: Applications & Properties" (NAP-2021), (2021), S. NMM05-1-NMM05-5
Paper presents the results of experimental investigations of magnetoresistance of filled with iron multi-walled carbon nanotubes. Multi-walled carbon nanotubes have been prepared by pyrolysis of benzene in a tubular quartz furnace at a temperature of 950˚C with use ferrocene as a source of iron. The obtained by this method carbon nanotubes contain in the inner cavity the particles of the magnetic phase, namely iron, iron carbide and iron oxides in various concentrations. The electrical resistance of bulk specimens of modified carbon nanotubes have been carried out in the temperature interval from 4.2 K to 293 K and in magnetic field up to 2 T. It is shown that magnetoresistance of modified carbon nanotubes is determined by a combination of two effects: the giant magnetoresistance effect and anisotropic magnetoresistance effect, moreover, the relative contribution of each effect depends on the concentration of the magnetic phase.
https://doi.org/10.1109/NAP51885.2021.9568395
Reliability improvement of UWB tracker for hospital asset management system : case study for TEE probe monitoring. - In: The role of AI in health and social revolution in turbulence era, (2021), S. 69-74
With a limited number of workers or staff in the hospital, it is not possible to manually monitor all of the medical device in the hospital. Many medical devices were lost by mistake, many assets went unused because they were not well-stocked, and many assets were destroyed without recognizing it. This will undoubtedly be very negative to hospitals in terms of resources, which are often expensive, and will, of course, diminish the effectiveness and efficiency of medical services. The necessity for hospitals to modernize their technology is apparent. The rapid advancement of technology allows us to overcome these issues, in fact, IoT-based technology is now so advanced that paper-based technology must be gradually phased out. The technology is a real-time location system (RTLS), there are many different ways to implement this technology, one of them is to use Ultra-Wide band (UWB) technology, with this solution, hospitals can track the location of their medical device, as well as other information - this including the Transesophageal Echo (TEE) Probe. DWM1001 is one of the UWB modules that researchers can develop, but its deployment in hospitals still need more research and reliability. This study will address techniques for improving the reliability of anchor mapping and hybrid Wi-Fi solutions as backup solutions.
https://doi.org/10.1109/ICOIACT53268.2021.9563986
Energy-efficient autonomous resource selection for power-saving users in NR V2X. - In: 2021 IEEE 32nd Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), (2021), S. 972-978
Energy efficiency has recently drawn significant attention in diverse applications, such as vehicle-to-everything (V2X) communications. This paper investigates a joint energy efficiency and sum-rate maximization problem in autonomous resource selection in the 5G new radio (NR) vehicular communication while catering for reliability and latency requirements. An autonomous resource allocation problem is formulated as a ratio of sum-rate to energy consumption, where the objective is to maximize the total energy efficiency of power-saving users subject to the reliability and latency requirements. The energy efficiency problem is a mixed-integer programming optimization problem that is computationally complex when the number of users increases. Therefore, a heuristic algorithm, density of traffic-based resource allocation (DeTRA), is proposed to solve the problem. The traffic density per traffic type is considered a metric to split the radio resources and trigger an appropriate resource selection strategy. The simulation results show that the proposed algorithm outperforms the existing schemes in terms of energy efficiency.
https://doi.org/10.1109/PIMRC50174.2021.9569365