Hardware Prototype Research Articles

PARTS—A 2D Self-Reconfigurable Programmable Mechanical Structure

Modular self-reconfigurable robots hold the promise of being capable of performing a wide variety of tasks. However, many systems fall short of either delivering this promised functionality due to constraints in system architecture or validating it on functional hardware prototypes. This paper demonstrates the functional capabilities of the Planar Adaptive Robot with Triangular Structure (PARTS) and documents the versatility of this robot system using a holistic approach that combines simulations and hardware demonstrations on a prototype with nine fabricated modules. PARTS is a two-dimensional modular robot consisting of modules with a shape-shifting triangular geometry capable of forming adaptable space-covering structures. Meta-modules and mesh restructuring techniques are presented as methods for achieving topological self-reconfiguration. The feasibility of these methods is demonstrated by applying them on a simulated reconfiguration example of 62 modules. The paper showcases the versatility of PARTS on the hardware prototype using task-specific configurations, including locomotion using a meta-module and a walker configuration, module-module interaction by establishing a bridge between two separated module clusters, and interaction with the environment using a gripper and supporting structure configuration. The results validate the versatility and emphasize the potential of the system’s design concept, motivating the transfer of the hardware architecture to the third dimension.

Ultra-high-speed four-dimensional hyperspectral imaging

We propose, to the best of our knowledge, a novel deep learning–enabled four-dimensional spectral imaging system composed of a reflective coded aperture snapshot spectral imaging system and a panchromatic camera. The system simultaneously captures a compressively coded hyperspectral measurement and a panchromatic measurement. The hyperspectral data cube is recovered by the U-net-3D network. The depth information of the scene is then acquired by estimating a disparity map between the hyperspectral data cube and the panchromatic measurement through stereo matching. This disparity map is used to align the hyperspectral data cube and the panchromatic measurement. A designed fusion network is used to improve the spatial reconstruction of the hyperspectral data cube by fusing aligned panchromatic measurements. The hardware prototype of the proposed system demonstrates high-speed four-dimensional spectral imaging that allows for simultaneously acquiring depth and spectral images with an 8 nm spectral resolution between 450 and 700 nm, 2.5 mm depth accuracy, and a 1.83 s reconstruction time.

Highly-integrable analogue reservoir circuits based on a simple cycle architecture

Physical reservoir computing is a promising solution for accelerating artificial intelligence (AI) computations. Various physical systems that exhibit nonlinear and fading-memory properties have been proposed as physical reservoirs. Highly-integrable physical reservoirs, particularly for edge AI computing, has a strong demand. However, realizing a practical physical reservoir with high performance and integrability remains challenging. Herein, we present an analogue circuit reservoir with a simple cycle architecture suitable for complementary metal-oxide-semiconductor (CMOS) chip integration. In several benchmarks and demonstrations using synthetic and real-world data, our developed hardware prototype and its simulator exhibit a high prediction performance and sufficient memory capacity for practical applications, showing promise for future applications in highly integrated AI accelerators.

Review on Close Loop Control of Novel Transformer Less Inverter Topology for Single Phase Grid Converter

The continuous urge for improvement in our standard of living has increased the consumption of electrical energy by leaps and bounds. This hike in energy consumption, draining of fossil fuels and degrading global environment has led to invention of green power generation systems. Thus, the global demand for renewable resources has led to flourishing of photovoltaic (PV) market. The enabling technology in the PV systems is the inverter, which could be either: 1) with transformer isolated or 2) without transformer non-isolated (transformer-less inverter). Recently, single phase transformerless voltage source inverters (VSI) have been extensively used for distributed photovoltaic grid tied systems. The objective of this paper is to review a few notable topologies and propose a new topology for transformer-less photovoltaic inverter. The analysis and design of the proposed topology is verified by simulating it on PSIM. Furthermore, the simulation results are validated by testing a proof-of-concept laboratory hardware prototype rated at 250 W. Keywords— Photovoltaic (PV) systems, transformer-less, single phase inverter

Integrated simulation and control environment for the development and safe start-up of cable driven parallel robots

ABSTRACT This article presents a new environment designed to facilitate the conceptualization and automation of CDPRs (Cable Driven Parallel Robots). Utilizing a platform for robotic simulation, an industrial controller, and a data gateway to communicate both systems, it is possible to emulate CDPR motion in early design, development, and start-up phases. Thus, this simulation environment allows to test how the robot will behave in advance in order to obtain a safer and more reliable first operation with the real robot. An spatially under-constrained CDPR with four cables was used to validate the capabilities of the proposed integrated environment, comparing its performance against an industry-standard hardware prototype. Both the simulation model and the real prototype performed the same trajectory in order to assess a time delay and position errors between them. Evaluation results revealed that the simulation accurately replicated the performance of its industrial counterpart, with a peak divergence of 0.27% in the position of the robot under various speed scenarios. This occurs even when accounting for latency arising from data exchange connecting the industrial control unit to the simulation. The results have shown that the environment is suitable for trajectory control of new CDPR architectures under different dynamic conditions.

Development of bipolar high-current correction magnet power supply for TPS facility

Taiwan Photon Source (TPS) is a globally renowned 3 GeV synchrotron accelerator light source. With a successful decade of operation, various subsystems have continuously improved and maintained an optimal research facility environment. Presently, there is a concerted effort towards energy conservation. This technical report focuses on the future development of the TPS-II Permanent Magnet Trim Coil Power Supply for the correction magnet, emphasizing a Bipole high-current correction magnet power source. According to the prototype specifications, the maximum output current is 20 A with an operating voltage of 48 V. This augmentation increases the amplitude of the magnetic field correction in the permanent magnet-associated Trim core, providing greater flexibility in manufacturing the permanent magnet correction coils. To design a power supply with high current and stability, the system adopts the Danisense DP50-IP-B DC Current Transducers (DCCT) as the current feedback component and Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) as power switches in a full-bridge (H-bridge) configuration. The driving frequency is set at 40 kHz. Analog modulation control circuitry and protective circuits ensure precise control loop modulation. In the power laboratory, a hardware prototype circuit was constructed, featuring a 48 V input voltage, 20 A output current, a maximum power of 960W, and a current ripple component maintained within 100 μA. This experiment validates the control loop design of the prototype, showcasing the ability to achieve rapid and stable output current performance. Using a 1 V input reference signal for small-signal testing, the bandwidth displayed a -3 dB bandwidth of 8.51 kHz. Long-term current stability is within ± 10 ppm, and interface compatibility with the existing TPS correction magnet power source interface allows direct operation within the current system.

An open-access simultaneous electrocardiogram and phonocardiogram database

Objective. The EPHNOGRAM project aimed to develop a low-cost, low-power device for simultaneous electrocardiogram (ECG) and phonocardiogram (PCG) recording, with additional channels for environmental audio to enhance PCG through active noise cancellation. The objective was to study multimodal electro-mechanical activities of the heart, offering insights into the differences and synergies between these modalities during various cardiac activity levels. Approach. We developed and tested several hardware prototypes of a simultaneous ECG-PCG acquisition device. Using this technology, we collected simultaneous ECG and PCG data from 24 healthy adults during different physical activities, including resting, walking, running, and stationary biking, in an indoor fitness center. The data were annotated using a robust software that we developed for detecting ECG R-peaks and PCG S1 and S2 components, and overseen by a human expert. We also developed machine learning models using ECG-based, PCG-based, and joint ECG-PCG features, like R–R and S1–S2 intervals, to classify physical activities and analyze electro-mechanical dynamics. Main results. The results show a significant coupling between ECG and PCG components, especially during high-intensity exercise. Notable micro-variations in S2-based heart rate show differences in the heart’s electrical and mechanical functions. The Lomb-Scargle periodogram and approximate entropy analyses confirm the higher volatility of S2-based heart rate compared to ECG-based heart rate. Correlation analysis shows stronger coupling between R–R and R-S1 intervals during high-intensity activities. Hybrid ECG-PCG features, like the R-S2 interval, were identified as more informative for physical activity classification through mRMR feature selection and SHAP value analysis. Significance. The EPHNOGRAM database, is available on PhysioNet. The database enhances our understanding of cardiac function, enabling future studies on the heart’s mechanical and electrical interrelationships. The results of this study can contribute to improved cardiac condition diagnoses. Additionally, the designed hardware has the potential for integration into wearable devices and the development of multimodal stress test technologies.

Intelligent method for Power flow using Artificial Neural Network with UPFC

It is slightly difficult to transmit such a large amount of electricity in very flexible and efficient way as the size of conventionally used relay and protective devices will increase while transmitting such a large amount of electricity which will increase the operating cost. So for transmission of such a large amount of electricity, Flexible Alternating Current Transmission Systems (FACTS) will have been found to be promising aspect in terms of the analysis of the power system. In this paper the comparative analysis of unified power flow controller(upfc) is presented in presence of LG fault. ANN controllers are applied in UPFC in MATLAB/SIMULINK environment. There is significant reductions in oscillations in rotor angle deviation of multimachine systems using ANN controller compare to conventional PI controller. Hardware prototype model of UPFC also shows improvement in voltage stably in multimachine. There is improvement in rotor angle stability of power system using ANN controller compared to conventional PI controller. Oscillations are reduced.

Implementation and testing of a 100 mK ADR backed by a 4He/3He sorption fridge for CMB-S4 project

CMB-S4 is a ground-based experiment that will use large-format bolometer arrays to map Cosmic Microwave Background (CMB) polarization with unprecedented sensitivity, including the search for a B-mode polarization pattern associated with cosmic inflation. The focal planes on which the superconducting detectors are mounted weigh about 20 kg each and must be cooled at 100 mK. To reach this temperature for a first receiver fielding prototype hardware, we have developed an Adiabatic Demagnetization Refrigerator (ADR) used in conjunction with an existing 4He/3He sorption refrigerator.The ADR unit described here is based on a Chromium Potassium Alum (CPA) salt pill. It is backed by a 3-stage (4He/3He/3He) sorption fridge, coupled through a 3He gas-gap heat switch. This heat switch is connected to a 3He stage of the sorption fridge to dissipate the heat generated by magnetization. The ADR is cycled with a 1.3 T magnetic field. The parasitic field at the detectors’ location during observations is kept below 2.5 µT thanks to a ferromagnetic shield. The pill is supported by Kevlar lines, which are doubly intercepted by the 4He and 3He stages of the sorption fridge to reduce conductive heat losses. With a total recycling time of 12 hours, this cryogenic assembly provides 2 µW of cooling power during 48 hours at 100 mK. The ADR has been designed by CEA/DSBT in France and is now implemented in a cryostat at Caltech.

Advanced UPFC Controllers to Improve Transient and Dynamic Stabilty of Power System

The industrial revolution is thought to have had its foundation in electricity. Electricity must be produced and transferred in greater quantities in order to meet the ever rising demand that must be delivered to numerous homes and businesses. it is slightly challenging to do so in a very flexible and efficient manner. So for transmission of such a large amount of electricity, In terms of the examination of the power system, (FACTS) will have been discovered to be a potential component. The comparative analysis of UPFC in the presence LG fault is described in this paper. Fuzzy logic controller has better performance in improving transient stability than conventional PI controller. System consist of multimachine power system with fault is simulated in MATLAB environment the results are also tested using prototype hardware model of set up 01 KVAR UPFC. There is improvement in rotor angle stability of power system using Fuzzy logic controller compared to conventional PI controller. Oscillations are also reduce with this FUZZY based UPFC controller

Design and Development of Agri-bot for Autonomous Seed Sowing and Harvesting

Abstract: This research delves into the development of an Autonomous Agriculture Robot (AAR) capable of performing seed sowing and harvesting operations. The AAR operates in two distinct modes: seed sowing and harvesting, leveraging advanced sensors and a control system to automate these critical agricultural processes. The AAR is engineered with dual operational modes, facilitated by an encoder system for precise autonomous navigation, servo actuation for operational control, and a Battery Management System (BMS) for efficient power usage. This paper details the design and development of a hardware prototype that presents the integration of these technologies. Validation results demonstrate the AAR’s capability to autonomously navigate and perform the defined tasks. The implementation of the AAR prototype signifies a pivotal step towards automating manual agricultural processes, potentially transforming the agricultural landscape by reducing labour requirements and increasing efficiency.

Prototyping and Performance Analysis of a Step Driven Piezoelectric Energy Generation System

This paper presents a novel approach to harness energy from human footsteps using piezoelectric sensors. With a focus on addressing the energy needs of densely populated regions such as China and India, where foot traffic is abundant, this work endeavours to convert mechanical energy from footsteps into electrical energy. A prototype hardware model has been designed and presented to generate power through human foot movement, employing piezoelectric sensors arranged in series and connected via a rectifier diode to charge a battery. Additionally, a voltage booster is integrated to amplify voltage output, while an inverter facilitates the conversion of DC to AC power. Experimental investigations were conducted by varying the weights of individuals to establish a correlation between weight and resulting voltage outputs, culminating in a graphical representation of the data. The outcomes of our study showcase the feasibility of tapping into untapped energy reservoirs from foot traffic, thereby presenting promising applications for urban settings. This work contributes towards addressing energy challenges prevalent in densely populated areas and underscores the potential of piezoelectric energy harvesting technology as a sustainable energy solution.

Enhancing Electric Vehicle Performance with a Hybrid PI-Sliding Mode Controller for Battery Supercapacitor Integration

Nowadays, most of the works are based on electric vehicle usage for sustainable transportation using traditional energy storage device, such as battery. Usage of batteries in electric vehicles is having several disadvantages, for example, life span, temperature, and charge estimation. In this paper, a novel control scheme for battery and supercapacitor- (SC-) based hybrid energy storage system (HESS) using hybrid proportional and integral- (PI-) sliding mode control (SMC) for electric vehicle (EV) applications is introduced and implemented. This HESS with hybrid controller proves the usage of batteries in EVs to its fullest potential. The conventional control strategy for HESS follows two-loop voltage and current PI controllers with low-pass filter (LPF) and involves tuning of multiple control parameters with variations of source and load disturbances. Performance of the system is affected by tuning PI controller constants. A slow response time with linear PI controllers is long which is not advisable for starting and sudden jerk conditions of EVs. Moreover, the PI controller performance is affected by the system parameter variations during load changes. And these parameters are dynamic in nature due to nonideal conditions. In this paper, a hybrid PI-sliding mode controller (SMC) scheme is designed to control the bidirectional DC-DC converters to overcome the drawbacks of aforementioned issues. The combined PI-SMC controller reduces the tuning effort and reduces the effect of shift in operating point in controller performance. Linear modeling is done using small signal analysis for each subsystems. Permanent magnet synchronous machine (PMSM) is used as electric vehicle. The entire system and its controllers are simulated using MATLAB-Simulink, and detailed comparison is carried between conventional PI and proposed hybrid PI-SMC scheme to regulate the DC link voltage. The results are tabulated and show that the hybrid PI-SMC scheme outperforms in transient and steady-state conditions than the traditional PI controller. A scaled hardware prototype of 48 W set-up is developed using dSPACE-1104, and the experimental results have been carried out to verify the proposed system’s feasibility.

Development of grey wolf optimization based modified fast terminal sliding mode controller for three phase interleaved boost converter fed PV system

The conventional MPPT method has drawbacks, such as that under partial shading conditions, several peaks occur and identifying the global peak is difficult. It may converge to a local peak and lead to poor conversion efficiency and tracking efficiency. Implementation of a hybrid algorithm by integrating P&O and metaheuristic algorithms can perform better under partial shading conditions. But the tracking speed is low and the response time is longer. To mitigate the issues mentioned above, a new hybrid algorithm has been suggested that integrates GWO and a modified fast terminal sliding mode controller (MFTSMC). The suggested method with three phase ILBC is incorporated into the PV system. The MATLAB tool is employed to experiment with this study. The performance of GWO-MFTSMC is analysed through MATLAB/ SIMULINK and compared with the performance of ANN-FTSMC and PSO-FTSMC algorithm based MPPT techniques. A hardware prototype is developed and tested for 5 × 200 W solar PV modules with the GWO-MFTSMC algorithm. The proposed method conversion efficiency is 99.72% and 96.15% under simulation and hardware realisation, respectively, which is higher than the ANN-FTSMC and PSO-FTSMC methods.

Efficient and lightweight in-memory computing architecture for hardware security

This paper introduces an innovative solution for improving the efficiency and speed of the Advanced Encryption Standard (AES) based cryptographic algorithm. The approach leverages in-memory computing (IMC) and is versatile for application across a broad spectrum of IoT applications, including robotic autonomous vehicles and various other scenarios. To achieve this goal, memristor (MR) designs are proposed to emulate the arithmetic operations required for different phases of the AES algorithm, enabling efficient in-memory processing. The key contributions of this work include; 1) The development of a 4 bit-MR state element for implementing different arithmetic operations in an AES hardware prototype; 2) The creation of a pipeline AES design for massive parallelism and MR integration compatibility; and 3) The hardware implementation of the AES-IMC based architecture using the MR emulator. The results show that AES-IMC performs better than existing architectures in terms of higher throughput and energy efficiency. Compared to conventional AES hardware, AES-IMC achieves a 30% power enhancement with comparable throughput. Additionally, when compared to state-of-the-art AES-based NVM engines, AES-IMC demonstrates comparable power dissipation and a 62% increase in throughput. The IMC architecture enables cost-effective real-time deployment of AES, leading to high-performance computing. By leveraging the power of in-memory computing, this system is able to provide improved computational efficiency and faster processing speeds, making it a promising solution for a wide range of applications in the field of autonomous driving and robotics. The potential benefits of this system include improved safety and security of unmanned devices, as well as enhanced performance and cost-effectiveness in a variety of computing environments.

Wind–PV–Battery Hybrid Off-Grid System: Control Design and Real-Time Testing

The paper presents the design and implementation of decentralized control for a PV–wind–battery hybrid off-grid system with limited power electronics devices and sensors. To perform well without using any maximum power point tracking (MPPT) technique from the wind turbine (WT) based on a permanent-magnet brushless DC generator (PMBLDCG) and solar panels (PVs) and balance the power in the system, a cascade control structure strategy based on a linear active disturbance rejection controller (LADRC) is developed for the two-switch DC-DC buck-boost converter. Moreover, to ensure an uninterruptible power supply to the connected loads with a constant voltage and frequency, a cascade d-q control structure based on LADRC is developed for the interfacing single-phase inverter. Furthermore, the modeling and controller parameters design are presented. The performance under all operation conditions of the hybrid off-grid configuration and its decentralized control is validated by simulation using MATLAB/Simulink and in real-time using a small-scale hardware prototype.

A high gain Z-source boost DC–DC converter with common ground for solar PV applications

This paper proposes a high-gain dc–dc converter with common ground utilizing a Z-source network for low voltage solar photovoltaic (PV) applications. This converter features a common ground and a high output–input voltage conversion factor at a low duty cycle. These converters find their most common application in grid-tied or stand-alone solar photovoltaic systems, particularly those with low output voltages that must be increased to the required level. The presented converter operating duty ratio is within 0–0.5 and maintains similar voltage stress on Z-network components since it employs the conventional Z-source configuration. The presented converter provides a common ground between source and load, unlike conventional Z-network converter. A type-2 closed-loop voltage controller and state–space average model evaluate the converter’s dynamic behavior for reliable and steady performance. A laboratory hardware prototype of 250 Watts is built and low gate signals are generated by using a ARM cortex M4 Microcontroller (STM32F407VGT6). The experimental results confirm that the proposed converter, with a gain of 10.46 and a power of 250 Watts, has a maximum efficiency of around 93%. The experimental results validates the effectiveness of the proposed converter under both constant and shifts in amounts of solar irradiation.

Performance Comparison of a DC–DC Boost Converter With Conventional and Non-linear SMC Controller in Dual Loop Structure

Generally, the control system confronts various control techniques in the dual-loop control concept. Most of the studies deal with two different controllers in their loops, which increases the problem of designing two distinct procedures with lengthened calculations. In this article, different control techniques like conventional proportional integral (PI), proportional integral derivative (PID), and nonlinear sliding mode control (SMC) have been discussed, and the implementation of SMC in the Dual loop control of a DC–DC Boost converter is presented. The converter’s dynamic behavior is observed by driving their analytical equations. The effective controller for the proposed converter is ascertained by their comparative analysis. The proposed concept is validated with MATLAB/Simulink and a hardware prototype. The controller’s response is compared for various disturbances. Here, dual-loop SMC is put forward in both loops and its competence is confirmed with a minimal settling period of 0.005 sec and a percentage overshoot of 0.2% during the startup conditions, whereas during the line disturbances a minimum peak time of 0.0001 sec is achieved with a settling time of 0.025 sec. Additionally, a nil percentage overshoot and a settling time of 0.02 sec with a 0.001 sec peak time are attained during the load variations. Furthermore, a settling time of 0.01 sec and a percentage overshoot of 0.8% is reached during the reference voltage variations. From the numerical analysis, it is contemplated that an appropriate selection of SMC controllers in both the outer and inner loop results in optimal performance of the converter during the closed loop operation. Finally, the SMC + SMC controller exhibits superior controlling action compared to PI + PI and PID + PID controllers.

A novel multi-port high-gain bidirectional DC–DC converter for energy storage system integration with DC microgrids

Bidirectional converters have often been used in numerous applications like DC microgrids, renewable energy, hybrid energy storage systems, electric vehicles, etc. The paper proposes a novel multi-port high-gain (NMPHG) bidirectional DC–DC converter that supports DC microgrid (DC-MG) applications. The main contributions of the proposed converter are high step-up/step-down conversion gain, multiple input ports, lower switch voltage stress, and lower component count owing to the single converter with multiple input ports for DC microgrid applications. The detailed operational principle, analysis, and design considerations of proposed NMPHG bidirectional DC–DC converters are discussed. Furthermore, the loss analysis, detailed comparison with similar works, and efficiency analysis with non-modalities during forward power flow (LV to HV) and reverse power flow (HV to LV) modes are presented. The efficiency of the proposed converter is found to be 93.8% in forward power flow and 92.9% in reverse power flow modes at rated power. Finally, a hardware prototype of the proposed NMPHG bidirectional DC–DC converters is implemented with 100 W in FPF mode and 200 W in RPF mode with a TMS320F28335 processor and validated with theoretical counterparts.

Development of High-Temperature Permanent Magnet Synchronous Motor for Autonomous Robotic Navigation: A Design and Finite Element Analysis Approach

The traditional industrial robots come with the prime mover, i.e. Electric Motors (EM) which ranges from a few hundred too few kilo watts of power ratings. However, for autonomous robotic navigation systems, we require motors which are light weighted with the aspect of high torque and power density. This aspect is very critical, when the EMs in robotic navigations are subjected to harsh high temperature survival conditions, where the sustainability of the performance metrics of the electromagnetic system of the EMs degrade with the prevailing high temperature conditions. Hence, this research work address and formulate the design methodology to develop a 630 W High Temperature PMSM (HTPMSM) in the aspect of high torque and power density, which can be used for the autonomous robotic navigation systems under high temperature survival conditions of 200°C. Two types of rotor configurations i.e. the Surface Permanent Magnet type (SPM) and the Interior Permanent Magnet type (IPM) of HTPMSM are examined for its optimal electromagnetic metrics under the temperature conditions of 200°C. The 630 W HTPMSM is designed to deliver the rated torque of 2 Nm within the volumetric & diametric constraints of D x L which comes at 80 x 70 mm at the rated speed of 3000 rpm with the survival temperature of 200°C with the target efficiency of greater than 90%. The FEM based results are validated through the hardware prototypes for both SPM and IPM types, and the results confirm the effectiveness of the proposed design methodology of HTPMSM for sustainable autonomous robotic navigation applications.