Digital Signal Processor Board Research Articles

Optimal Adaptive Fractional Order Integral Sliding Mode Controller-Energy Management Strategy for Electric Vehicles Based on Bald Eagle Search Algorithm

This research presents an optimal energy management system (EMS) for a lithium-ion battery-supercapacitor hybrid storage system used to power an electric vehicle. The storage systems are connected in parallel to the DC bus by bidirectional DC-DC converters and feed a synchronous reluctance motor through an inverter. The proposed energy management strategy is built on the idea to take full benefits of two combined methods: the bald eagle search algorithm and fractional order integral sliding mode control. To evaluate the effectiveness of the suggested optimal energy management strategy, an urban dynamometer driving schedule (UDDS) driving cycle is considered. The obtained results are compared to a classical fractional order integral sliding mode control-based energy management strategy in terms of voltage ripples, overshoots, and battery final state of charge. The ultimate results approve the ability of the proposed energy management system to enhance the power quality and enhance battery power consumption at the same time. Comprehensive processor-in-the-loop (PIL) cosimulations were conducted on the electric vehicle using the C2000 launchxl-f28379d digital signal processing (DSP) board to assess the practicability and effectiveness of the proposed EMS.

Implementation of Digital Signal Processor for Pulse Doppler Radar

This paper presents the design and implementation of a digital signal processor (DSP) board, utilizing a TMS320C50 family DSP chip, for pulse-Doppler radar systems. Pulse-Doppler radar systems often encounter challenges such as strong clutter, noise, and jamming in dealing with echoes. To overcome these challenges, advanced digital signal processing techniques are employed. The main objective of this paper is to introduce a cost-effective signal processing solution that significantly enhances the performance of the radar system and brings it up to speed with modern radar technologies. The hardware described in this work can also be effectively utilized for implementing various types of signal processing algorithms. Additionally, as a secondary objective, the paper presents the digital realization of a radar detector. Traditionally, this detector was constructed using an analog Doppler filter bank. However, in this work, it is digitally implemented using N digital filters in place of the analog bank. By utilizing the designed DSP board and implementing the radar detector digitally, this paper demonstrates the potential for improved performance and efficiency in pulse-Doppler radar systems. The advancements made in this work contribute to the development of cost-effective and technologically advanced radar systems. The research results are presented for four different wind conditions, showcasing the effectiveness of the proposed approach. Furthermore, the paper suggests an algorithm that combines parametric and non-parametric techniques and provides a detailed explanation of its implementation. Finally, using the non-parametric technique, the probability of detection curves (PD) are simulated with respect to the signal-to-clutter ratio (SCR) for each wind condition, and the simulation results are depicted and compared. The achievements of this paper include the proposal of an efficient approach for clutter suppression in ground surveillance pulse Doppler radar, the comparison of different clutter suppression algorithms, and the development of an algorithm that combines parametric and non-parametric techniques. The simulation results provide valuable insights into the performance of the proposed algorithms under different wind conditions.

Design and DSP implementation in HIL of nonlinear observers for a doubly fed induction aero-generator

This paper reports on the conception and digital signal processor (DSP)-based hardware-in-the-loop realisation of a nonlinear observer for a grid-connected variable speed wind turbine using a doubly fed induction generator (DFIG). The objective of this work is to build some observation structure based on the extended Kalman filter (EKF), the sliding mode observer (SMO) and the adaptive model reference adaptive system (MRAS) observer to observe certain quantities of the wind power system connected to the electrical grid in order to reduce the complexity and the cost of the hardware, to achieve an increased mechanical robustness, to operate in hostile environments, to have a higher reliability and to ensure an unchanged inertia of the system. The proposed observers will be combined with robust nonlinear controls based on the backstepping approach to control the wind energy conversion system (WECS). The whole will be implemented on a TMS320F28335 DSP board. A comparative analysis of the proposed observers will be carried out. Through the results of the DSP implementation in hardware in the loop (HIL), we will prove that this improved combination increases the desired performance.

TEC and ROTI Measurements from a New GPS Receiver at BOWEN University, Nigeria

Scintillation and total electron content (TEC) are the two major examples of the top-side ionospheric parameters that are recorded differently by most Global Positioning System (GPS) receivers. The new GPS sensor created by the Atmospheric and Space Technology Research Associates (ASTRA), Cornell University, and the University of Texas, Austin have capability to record scintillation and TEC fluctuations simultaneously. Hence, the Connected Autonomous Space Environment Sensor (CASES) from ASTRA is a software-defined GPS receiver with the dual frequency of L1 C/A and L2C codes for space-weather monitoring and can be remotely programmed via an internet source. The receiver employs numerous novel techniques that make it suitable for space-weather studies compared to other nearby GPS receivers, such as different methods for eliminating local clock effects, an advanced triggering mechanism for determining scintillation onset, data buffering to permit observation of the prelude to scintillation, and data-bit prediction and wipe-off for robust tracking. Moreover, the CASES hardware is made up of a custom-built dual frequency, a digital signal processor board, and a “single board computer” with an ARM microcontroller. We have used the CASES GPS receiver newly installed at Bowen University, Iwo, Nigeria, to investigate the TEC and the rate of the TEC index (ROTI) around the equatorial region. Measurements of the TEC and ROTI showed similar variation trends in monthly, seasonal, and annual periods when compared to TEC and ROTI measurements from a nearby station, BJCO at Cotonou, Benin Republic. The newly installed GPS receiver looks promising for scientific use as it is the only one operational in Nigeria at the moment.

Dynamics and synchronization control of fractional conformable neuron system.

Dynamic analysis, electrical coupling and synchronization control of the conformable FitzHugh-Nagumo neuronal models have been presented in this work. Firstly, equations of the Adomian-Decomposition-Method and conformable neuron model have been introduced. The Adomian-Decomposition-Method has been employed for the numerical simulation analysis, since it converges fast and provides serial solutions. Fractional order and external current stimulus have been considered as bifurcation parameters and their effects on neuron model dynamics have been examined in detail. Then, the electrical coupling of the two conformable neuronal models without any controller has been revealed and the significance of the coupling strength parameter has been evaluated. To eliminate impact of the coupling strength parameter on synchronization status of neurons, Lyapunov control method has been employed for synchronization control. In the last step, the numerical simulation studies have been experimentally verified using the Texas Instrument Delfino digital signal processor board. Numerical simulation results together with experimental validation have showed that the types of dynamics of the related neuron model are not affected from the change of the fractional order of conformable derivative, but the frequency of the dynamic response of the neuronal model is changed from the alteration of the fractional order. The frequency of response of the neuron model increases with decreasing values of the fractional order. On the other hand, if there is no synchronization control method, the coupled neuron models exhibit response ranging from synchronous to asynchronous depending on the sign and value of the coupling parameter. Additionally, decreasing values of the fractional order may allow the coupled neurons to enter the synchronous state more quickly due to increasing frequency of response of the neuronal model. Finally, the coupled neuron models could exhibit synchronous behavior, that is determined by calculating the standard deviation results, regardless of the value of the coupling parameter by using the Lyapunov control method.

A Combined Control Scheme of Direct Torque Control and Field-Oriented Control Algorithms for Three-Phase Induction Motor: Experimental Validation

In this paper, a combined structure of algorithms based on field-oriented control (FOC) and direct torque control (DTC) is proposed for improving the performance of a three-phase induction motor (IM) over a wide range of torque loads. The objective of this study is to investigate the state-of-the-art research performed on the resilient intersection control management between FOC and DTC algorithms for IM drive. Three algorithms are employed in the proposed scheme: Direct Torque Stator Flux Control (DTSFC), Direct Torque Rotor Flux Control (DTRFC), and the FOC algorithm. The main aim of the control law is to launch the drive system by selecting DTSFC or DTRFC during the transient state while FOC is switched smoothly to the steady-state. The proposed method had several advantages, including the ability to produce torque beyond the pull-out torque range at 340%, high torque dynamics during transient state within 0.5 ms, low chattering up to 0.05 N.m, and fixed frequency at steady-state operation. Furthermore, a comprehensive comparison study has been conducted, including the most recent research, to verify the effectiveness and superiority of the proposed technique. Results were obtained using both MATLAB/Simulink environment and also were experimentally performed by using a dSPACE DS1103 digital signal processing board to verify the concept of the proposed control scheme.

The Wavelet-Modulation Technique for 5-Level, Power Electronic Converters—Part II: Implementation and Experimental Performance

This article presents the implementation and experimental testing of the wavelet-modulation technique for three-phase ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$3\phi$</tex-math></inline-formula> ) 5-level (5L) power electronic converters (PECs). This version of the wavelet modulation technique is structured as a multiresolution analysis that can support a redundant nonuniform recurrent sampling-reconstruction of three reference-modulating signals. The reconstruction of reference-modulating signals is achieved by sets of resolution-segmented scale-base linearly combined synthesis wavelet basis functions, which are used as switching signals to activate the switching elements of a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$3\phi$</tex-math></inline-formula> , 5L, VS dc–ac PEC. The presented wavelet-modulation technique is implemented in real time using a digital signal-processing board. Switching pulses generated by the extended wavelet-modulation technique are used to operate <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$3\phi$</tex-math></inline-formula> , 5L, VS, diode-clamped and flying-capacitor dc–ac PECs. Experimental performance of the tested 5L dc–ac PECs is evaluated, when operated by the presented wavelet modulation, level-shifted pulsewidth modulation (PWM), phase-shifted PWM, and space vector modulation techniques. Experimental tests are conducted for linear, dynamic, and nonlinear loads fed by the tested 5L PECs. Test results show that magnitudes of output voltage fundamental components can be significantly increased, and harmonic distortions can be effectively reduced using the wavelet-modulation technique. These features are further demonstrated by performance comparisons with other techniques under similar operating conditions.

Model‐based online efficiency control of induction motor drives based on nonlinear technique

To accomplish benefits such as high accuracy and fast response, the model-based loss minimisation algorithms (LMAs) are introduced in the literature, as one of the main available techniques for minimising power losses in electrical motors. They are appropriate for dynamic applications, which necessitate very fast update of the control variable. This study proposes a novel real-time LMA based on super-twisting sliding mode controller (SMC) for induction motor (IM) drives, while keeping a good dynamic response. In this regard, a loss minimisation criterion for the efficiency optimisation is proposed and scrutinised. It is shown analytically that LMA will be realised if the nonlinear controller forces this criterion to zero. Moreover, a super-twisting SMC integrated with the iron loss is proposed which directly regulates both the power loss-minimising criterion and the electromagnetic torque by choosing those as control outputs. The stability of the super-twisting SMC is also verified through the Lyapunov's stability principle. The complete closed-loop control of the proposed LMA-based IM drive is successfully implemented in real-time using a digital signal processor board TMS320F28335 for a laboratory 3-phase IM drive of 2.2 kW. The performance and functionality of the proposed scheme are assessed through experimental results.

High-resolution, low-latency, bunch-by-bunch feedback system for nanobeam stabilization

We report the design, operation, and performance of a high-resolution, low-latency, bunch-by-bunch feedback system for nanobeam stabilization. The system employs novel, ultralow quality-factor cavity beam position monitors (BPMs), a two-stage analog signal down-mixing system, and a digital signal processing and feedback board incorporating a field-programmable gate array. The field-programmable gate array firmware allows for the real-time integration of up to fifteen samples of the BPM waveforms within a measured latency of 232 ns. We show that this real-time sample integration improves significantly the beam position resolution and, consequently, the feedback performance. The best demonstrated real-time beam position resolution was 19 nm, which, as far as we are aware, is the best real-time resolution achieved in any operating BPM system. The feedback was operated in two complementary modes to stabilize the vertical position of the ultrasmall beam produced at the focal point of the ATF2 beamline at KEK. In single-BPM feedback mode, beam stabilization to $50\ifmmode\pm\else\textpm\fi{}5\text{ }\text{ }\mathrm{nm}$ was demonstrated. In two-BPM feedback mode, beam stabilization to $41\ifmmode\pm\else\textpm\fi{}4\text{ }\text{ }\mathrm{nm}$ was achieved.

Prototyping Design of Low-Cost Bias-T Circuit Based-on Op-Amp for Visible Light Communication

The visible light communication (VLC) exploits the LED as an antenna in which only works on “forward bias” conditions. Therefore, when the VLC has an input signal with minus voltage it will be clipped, and only the positive side is transmitted by LED. If the VLC has an analog signal input with a completely positive amplitude, the LED may exhibit flicker-effect when the input frequency is relatively low to medium. Therefore, the correct method for LED conditioning is by lumping the information signal in the DC area. The “Bias Tee” (Bias-T) is a commercial module that is most commonly applied for LED conditioning with analog input signal characteristics. Although the performance is powerful and significant for transmitting the high-frequency, the cost is relatively inexpensive. Therefore, this study proposes a low-cost Bias-T module for a low bit-rate VLC system. Instead of the Bias-T generally, that uses an inductor and capacitor, this module is built by Op-Amps circuit which consists of 1) buffer Op-Amp as DC input (VDC-OFFSET), 2) variable Pre-Amplifier as signal information input (VINF), 3) summing amplifier to combine these two signals (VINF + VDC-OFFSET) and 4) current amplifier for increasing the high-power LED with no-flicker (stable illumination). The designed Bias-T is built on a discrete component. The evaluations involved three approaches, given the input signal: 1) with a single carrier in sine form, 2) analog signal from digital signal processing (DSP) board, 3) audio signal generated from a personal computer. In summary, the Bias-T works as properly as expected.

Optimal Tracking Control for PMSM With Partially Unknown Dynamics, Saturation Voltages, Torque, and Voltage Disturbances

This article proposes a novel optimal tracking control scheme for permanent magnet synchronous motors (PMSMs) with partially unknown dynamics, saturation voltages, and disturbances in both speed and current dynamics. The strict-feedback nonlinear system is employed to present the PMSM model. Augmented feedforward control inputs are proposed to transform a speed and current tracking control problem of conventional cascade structures to an optimal control problem of a new structure. Consequently, the saturated adaptive optimal control law is designed for the problem. The optimal solution of Hamilton–Jacobi–Issac equation, which provides the value to the control law, is approximated by a simple online approximator. An integral reinforcement learning technique is used to tune the approximator without observing unknown dynamics. It is proven that the optimal value function, the control law, and the worst disturbance law converge to the near-optimal values. The simulation and experiment on a PMSM prototype model of a load drive application with a digital signal processing board TMS320F28379D of Texas Instrument are conducted to justify the effectiveness of the proposed scheme.

Active Dosimetry with the Ability to Distinguish Pulsed and Non-Pulsed Dose Rate Contributions

This paper presents the concept of an active dosimetry system and its operational regime for pulsed radiation dose rate measurements. The plastic scintillator is suggested to be used for absorbed dose rate measurements. As long as the detector can be considered tissue equivalent, the energy weighting of pile-up events in terms of the dose is achieved. The real-time distinction of pulsed and non-pulsed dose rate contributions is based on the time structure of a single interaction and requires only basic information about the beam time structure (pulses duration and period). The detector connected to a fully digital signal processing board creates an active dosimetry system with adjustable parameters. Such a system was used for absorbed dose rate measurements in pulsed photon field mimicking radiation field outside the bunker of a medical LINAC, but also in the presence of a constant radiation component. The results show a linear dependence of a pulsed radiation contribution on the accelerator current in the investigated range of the total dose rate up to 8 μGy/h.

DOSIMETRY WITH THE ABILITY TO DISTINGUISH PULSED AND NON-PULSED DOSE CONTRIBUTIONS

The concept of an active dosimetry system for pulsed radiation dose rate measurements is presented. Real-time distinction of pulsed and non-pulsed radiation contributions is based on the time structure of a single interaction. A fast tissue equivalent plastic scintillator is exploited to minimize the pile-up effect influence on absorbed energy measurements. Being connected to a fully digital signal processing board, the detector creates an active dosimetry system with adjustable parameters. With this system, absorbed dose rate measurements were carried out in a photon field with a time structure mimicking a radiotherapeutic beam, but also in the presence of a constant radiation field. Measurements show a linear dependence of a pulsed radiation contribution on the accelerator current in the investigated range of the total dose rate up to 8 μGy h-1. While increasing the accelerator current by 1 μA, the pulsed radiation dose rate grows by (26.2±0.9) nGy h-1 when considering pile-up events.

A Proposed Non-Invasive Rogowski Coil Design for Measuring 3-Phase Currents Through a 3-Core Cable

In this article, a proposed non-invasive design of Rogowski coil to measure 3-phase currents through a 3-core cable is presented. Considering this design, there is no need to remove the insulation layers of a 3-core cable to measure its core currents. The adopted Rogowski coil design uses three separate coils wound at the same circular non-magnetic core with equal spacing between them. When the Rogowski coil is fitted around a 3-core cable, EMF is induced in each coil. The three induced EMFs are used to reconstruct the current passes through each cable core using a proposed current reconstruction technique. In order to validate the presented Rogowski coil design as well as the current reconstruction technique, theoretical verification is carried out using Power Simulation Program (PSIM) software. Hence, a 3-phase source feeds a 3-phase load is simulated. Also, simulation of the designed Rogowski coil as well as the adopted current reconstruction technique is carried out. The obtained theoretical results prove the accurate measurements of the Rogowski coil design and the introduced current reconstruction technique. For more validation, the Rogowski coil design is experimentally implemented. The implemented Rogowski coil is fitted around a 3-core cable that feeds a 3-phase load from a 3-phase source. The current reconstruction technique is implemented using a digital signal processing (DSP) board. The obtained experimental results give another evidence for the validity and efficacy of the proposed Rogowski coil design as well as the current reconstruction technique.

SHADE: Absorption spectroscopy enhancement with ambient light estimation and narrow-band detection

Ambient light (AML) limits the usage of absorption spectroscopy to strictly-controlled environments due to its impact on the quality of the signals. In medical applications for Optical instruments that require high reliability and validity results, it is indispensable to control AML impact. In this work, we present a multi-wavelength optical acquisition method, here called SHADE. The technique increases the quality of the optical signals, dynamically assesses AML, and enables mitigating the AML influence on the data. Our proposed technique involves four primary functions: (1) Multiplexing/demultiplexing of target wavelengths using a frequency-division method; (2) Robust signal recovery using inverse notch filters; (3) Concurrent AML intensity estimation; (4) A simple post-processing (offline) suppression of AML interference. We introduce the mathematical framework of SHADE to demonstrate the theoretical scope and limitations. SHADE was also experimentally tested by using a digital signal processing board under different conditions. The results confirmed the performance of the AML reconstruction and the potential of such a method for further improvements of the signal quality.

An adaptive delay compensation method based on a discrete system model for real-time hybrid simulation

The identification of delays and delay compensation are critical problems in real-time hybrid simulations (RTHS). Conventional delay compensation methods are mostly based on the assumption of a constant delay. However, the system delay may vary during tests owing to the nonlinearity of the loading system and/or the behavioral variations of the specimen. To address this issue, this study presents an adaptive delay compensation method based on a discrete model of the loading system. In particular, the parameters of this discrete model are identified and updated online with the least-squares method to represent a servo hydraulic loading system. Furthermore, based on this model, the system delays are compensated for by generating system commands using the desired displacements, achieved displacements, and previous displacement commands. This method is more general than the existing compensation methods because it can predict commands based on multiple displacement categories. Moreover, this method is straightforward and suitable for implementation on digital signal processing boards because it relies solely on the displacements rather than on velocity and/or acceleration data. The virtual and real RTHS results show that the studied method exhibits satisfactory estimation smoothness and compensation accuracy. Furthermore, considering the measurement noise, the low-order parameter models of this method are more favorable than that the high-order parameter models.

A universal digital motion controller design for servo positioning mechanisms in industrial manufacturing

• A universal digital motion controller design with theoretical analysis is presented. • The controller uses a synergy of linear and nonlinear control with disturbance rejection, and achieves desirable performance. • The controller is fully parameterized, with the advantage of fast implementation and convenience of on‐line tuning. • The controller has the potential of integration with an identification algorithm to form a self‐tuning motion control system. • The design was verified on a DSP-controlled testbed, and demonstrated a competitive performance against the popular ADRC. A parameterized design of universal motion controller is proposed in discrete-time domain using composite nonlinear control approach for high-performance servo mechanisms in industrial automation. First, the model of servo mechanisms is converted into discrete-time state-space form, and a linear control law is designed, consisting of state feedback, reference feed-forward and disturbance compensation. Next, a nonlinear control law is constructed to smoothly modulate the closed-loop damping as the system output approaches the reference. To estimate the unmeasurable velocity and disturbance, a reduced-order extended-state observer is adopted. The final controller is a combination of the above three parts and is fully parameterized in some fundamental tuning parameters. The controller was applied to a permanent magnet synchronous motor (PMSM) drive, which usually serves as the actuator for high-performance motion control systems. After MATLAB simulation, experimental test using a digital signal processing board was conducted, to verify the effectiveness of the proposed design.

Development of a high-performance RF front end for HEPS 166.6 MHz low-level RF system

Digital low-level radio frequency (LLRF) system has been proposed for 166.6 MHz superconducting cavities at High Energy Photon Source. The RF field inside the cavities has to be controlled better than 0.03% (rms) in amplitude and $$0.03^\circ $$ (rms) in phase. A RF front end system is required to transform the RF signal from the cavity to IF signal before inputting into the digital signal processing (DSP) board, and up-convert the IF signal back to RF to drive the power amplifier. Connectorized off-the-shelf microwave components were used to realize the RF front end system. The local oscillator generation and distribution, choices of main components and design of down-/up-conversion channels have been elaborated in detail with a focus on minimizing nonlinearity and signal interferences among channels with optimized signal distribution loss. The RF front end has been incorporated with the existing DSP board and tested on a warm 166.6 MHz cavity in the laboratory. Excellent channel isolations and good linearities were achieved on the RF front end system. The RF field inside the cavity was controlled with a residual noise of 0.004% (rms) in amplitude and $$0.002^\circ $$ (rms) in phase, well below the HEPS specifications. The sensitivity to ambient environment changes have also been studied and presented in this paper. This demonstrates a first high-performance 166.6 MHz RF front end system and provides valuable insights into HEPS LLRF system development in the future.

Port Controlled Hamilton With Dissipation-Based Speed Control of IPMSM Drive

This paper presents a port controlled Hamilton with dissipation (PCHD) based control technique for high precision speed regulation of interior permanent magnet synchronous motor (IPMSM) drive. The PCHD controller is designed by assigning proper interconnection and damping matrix for multivariate, nonlinear, and time-varying IPMSM system to prove its passivity and ensure its global stability. A torque observer is also designed based on pole placement method to monitor the external load. The stability analysis of the proposed PCHD and uniformity between the proposed controller and proportional-integral (PI) controller are analyzed subsequently. The performance of the proposed controller is investigated in both simulation and experimental environment using MATLAB-Simulink and dSPACE digital signal processor board DS1104, respectively, at different operating conditions for a laboratory 5 hp motor. It is found that the proposed PCHD controller shows better performance than that of the conventional benchmark tuned PI controller in terms of speed tracking capability with load variations.

Digital Control of Bridgeless Interleaved PFC Boost Converter Based on Predicted Input Current

In this study, digital control of bridgeless interleaved power factor correction (PFC) boost converter is presented by using DSP (digital signal processor) for prediction of input current without any current sensing. The complex control methods which have current sensing are utilized to get minimum ripple for current and appropriate sharing of current for interleaved PFC converters that reduce input current ripple and improve power rating, so they are much more convenient than the classic PFC converters. The current signals do not need to be sampled for proposed predictive control approach due to sampling of the voltages of input and output. The sampled voltages of input and output are employed to calculate input current for the converter. The parameters of converter, calculated input current and reference current that acquired from the voltage loop compensator are employed for predicting following duty cycle. By this way, the complex signal processing and current measuring are taken out when compared with the conventional control methods. An experimental circuit of bridgeless interleaved PFC boost converter has been installed to apply the proposed predictive control method via DSP board. It is seen from the results that appropriate sharing of current, the low value of total harmonic distortion (THD) and high rate of power factor can be acquired thanks to using the proposed predictive control strategy.