Safety Interlocks Research Articles

Assessment of pencil beam scanning proton therapy beam delivery accuracy through machine learning and log file analysis

PurposeComprehensive Quality Assurance (QA) protocols are necessary for complex beam delivery systems like Pencil Beam Scanning (PBS) proton therapy. This study focuses on automating the evaluation of beam delivery accuracy using irradiation log files and machine learning (ML) models. MethodsIrradiation log files of 935 clinical treatment fields and routine QA beams were analysed to evaluate spot parameters and Monitor Unit (MU) accuracy. ML models predicted spot size along the X, Y, major, and minor axes. In-house scripts automated log file analysis and spot size predictions. Predicted spot sizes were compared with expected baselines, and the accuracy of spot position, symmetry, and MU for each spot in the beam was evaluated. ResultsMore than 99.5 % of spot positions were accurate within a 1 mm. The mean and Standard Deviation (SD) of X positional error were −0.021 mm (SD: 0.181 mm), and for Y positional error, they were −0.002 mm (SD: 0.132 mm). ML models accurately predicted spot sizes, with over 95 % of spots demonstrating size variations within 10 % of the baseline. The Root Mean Squared Error (RMSE) of X and Y spot size differences were 0.15 mm and 0.16 mm, respectively. Spot symmetry was within 10 %, and MU accuracy showed 95 % of spots with MU per spot variation less than 2 %. ConclusionThis method can validate the vendor’s beam delivery safety interlock system and serve as a quick alternative to patient-specific QA in adaptive treatment, where time is limited, as well as for routine QA spot parameter evaluations.

Hardware and software solutions for implementing nanospray desorption electrospray ionization (nano-DESI) sources on commercial mass spectrometers.

Nanospray desorption electrospray ionization (nano-DESI) is an ambient ionization mass spectrometry imaging (MSI) approach that enables spatial mapping ofbiological and environmental samples with high spatial resolution and throughput. Because nano-DESI has not yet been commercialized, researchers develop their own sources and interface them with different commercial mass spectrometers. Previously, several protocols focusing on the fabrication of nano-DESI probes have been reported. In this tutorial, we discuss different hardware requirements for coupling the nano-DESI source to commercial mass spectrometers, such as the safety interlock, inlet extension, and contact closure. In addition, we describe the structure of our custom software for controlling the nano-DESI MSI platform and provide detailed instructions for its usage. With this tutorial, interested researchers should be able to implement nano-DESI experiments in their labs.

Investigation of Hydrogen-Blended Natural Gas Pipelines in Utility Tunnel Leakage and Development of an Accident Ventilation Strategy for the Worst Leakage Conditions

The development of hydrogen-blended natural gas (HBNG) increases the risk of gas transportation and presents challenges for pipeline security in utility tunnels. The objective of this study is to investigate the diffusion properties of HBNG in utility tunnels and evaluate the effectiveness of various ventilation mechanisms. The numerical simulation software Fluent 2023 R1 is applied to simulate and analyze the leakage of small holes in a HBNG pipeline in the natural gas compartment. By examining the leaking behavior of HBNG through small holes in different circumstances, we aimed to identify the most unfavorable operational situation for leakage. Subsequently, we analyzed the ventilation strategy for sub-high-pressure pipes at various pressure levels in this unfavorable condition. This study’s findings demonstrate that blending hydrogen improves the gas diffusion capacity and increases the likelihood of explosion. The primary factors that influence the pattern of leakage are the size of the leaking holes and the pressure of the pipeline. The gas compartment experiences the most unfavorable working conditions for natural gas pipeline leaks when there are higher pressures, wider leak openings, higher hydrogen blending ratios (HBRs), and leaks in close proximity to an air inlet. When the HBR is 20%, the minimum accident ventilation rates for pressures of 0.4 MPa and 0.8 MPa are 15 air changes per hour and 21 air changes per hour, respectively. The maximum allowable wind speed for accident ventilation is 5 m/s, as regulated by China’s national standard, GB 50838-2015. This regulation makes it difficult to minimize the risk of leakage in a 1.6 MPa gas pipeline. It is recommended to install a safety interlock device to quickly shut off the pipeline in the event of a leak in order to facilitate the dispersion of the substance.

Supervisor watchdog circuit to monitor an accelerator beam and control the safety interlock system

A supervisor watchdog circuit was developed to both monitor the dose and temperature at an accelerator beamline and provide signals to the safety interlock system of the accelerator. The implementation involved a D type flip-flop and subsequent logic gates to monitor the input and output signal states. It used a series of LEDs to inform the user about the state of the system and to enable identification of issues causing the beamline to shut down. The design allowed for a manual circuit restart to be performed to continue signal monitoring and accelerator operation. The supervisor watchdog circuit was installed at the tandem accelerator of the Reactor Materials Testing Laboratory at Queen’s University to monitor the beam properties during nuclear materials irradiation experiments. The scope for future improvements of the circuit such as automatic circuit restart in case of power fluctuations and addition of new signals is discussed.

The evolution of the interlocks for KSTAR

Korea Superconducting Tokamak Advanced Research (KSTAR) has three interlock systems. The Supervisory Interlock System (SIS) protects against damage to machines from abnormal events. The Fast Interlock System (FIS) prevents the destruction of the internal vacuum components from the uncontrolled plasma and heating beams. The Personal Safety Interlock (PSI) keeps humans from harmful environments and conditions.This paper presents the evolution of the KSTAR SIS and FIS operations since 2009. The SIS was implemented for KSTAR in 2007 and optimized the critical conditions and actuator actions to improve and avoid issues. The significant changes in the KSTAR interlocks are removing and changing the inappropriate interlock conditions and adding the required conditions to improve efficiency and fit the advanced experimental environments.The first implemented FIS independent of the Central Control System (CCS) in 2009 continues to upgrade its hardware and software to enable the interlocks and actions with high time resolution until 2017. The machine protection logic in the FIS evaluated and developed to reduce operational failures.This paper analyses the modified conditions for interlocks, the actions to protect machines, and their effects.

The Design and Simulation of Associated Protection for Low Voltage Shore-to-ship Power Supply System in Inland Port

Due to the complex environmental conditions of inland ports, it is of great significance to adopt associated protection to ensure the safe and reliable operation of the shore-to-ship power supply system. To accurately simulate the operating conditions of the shore-to-ship power supply system, the simulation model of the ship power system is established completely. According to the characteristics of the inland port, the simulation model of the shore-based power supply system is designed and established. Based on the established simulation model of a low voltage shore-to-ship power supply system, to meet its protection requirements of it, an associated protection method including safety interlock, under-voltage protection, and short-circuit protection is proposed. To verify the effectiveness of the associated protection, power faults are set in the shore-to-ship power supply system, and the action of the associated protection during the fault is analyzed by comparing the voltage and current waveforms of the shore-to-ship power supply system with associated protection and unprotected ones. The results show that the associated protection can effectively detect the power failures of the shore-to-ship power supply systems and take timely protection measures to ensure equipment safety.

서비스디자인방법론 기반 성범죄 예방을 위한 어플리케이션 설계

This study aims to determine the crime status of Daeyeon 1-dong, Nam-gu, Busan where studio apartments and multi-households are packed around the universities and to find out the request of prospective users after conducting a case study with the existing crime prevention application. The research method included field surveys, questionnaires, and interviews. The ideas were derived from the cases using service design methodology tools rather than the existing hardware-based systems or methods. Also, the improvement directions were derived from interviews with stakeholder, personas and examination of expert. Onjungil Supports used in this study is a service that can be linked to an all-day watch(safety interlock) through solidarity distinguished from an unilateral service that aims to prevent sexual crimes ensure women’s safe return and reduce anxiety based on various scenarios related to social problems through user experience(UX), Also, the service allows you to check local store information as well as local news through Ondongne Alert ‘e’ by locating registered sex offenders and informing the prevalence of sexual crimes in your area through Sex Offender Alert ‘e’. Although the services presented are difficult to achieve commercialization due to some limitations, it is expected to reach out the socially vulnerable groups considered to be at risk of crimes and help them to ensure security and safety of themselves. Finally, the service will contribute to lowering the overall rate of sexual crimes and reducing the anxiety towards potential risk.

An environmental monitoring and control system for the ATLAS ITk Outer Barrel quality control and integration

This paper describes the development of a system based on Programmable Logic Controllers (PLC) for safety interlocking and environmental monitoring during ATLAS ITk Outer Barrel (OB) loaded local support quality control (QC) and later integration. The system has been developed at CERN with a focus on scalability, maintainability and reliability, and is expected to be deployed at the different ITk OB loading and integration sites.

Construction of New Branching Point and Operation of New Primary Beam Line at the J-PARC Hadron Facility

Construction of a new primary beam line, called the B-line, started in 2013 at the J-PARC Hadron Experimental Facility. The B-line is branched at the middle of an existing primary proton beam line (A-line) in the beam switching yard (SY), which is the connecting tunnel between the Main Ring (MR) and the Hadron experimental hall (HD-hall). At the branching point, about 0.1% of the primary beam is kicked off at 5 degrees using a Lanbertson magnet and two septum magnets. The Lambertson magnet has a field free hole in its yoke. The proton beam that goes through a field region is separated from the A-line, and it is extracted to the B-line. The rest of the beam that goes through the field free hole is transported through the existing primary beam line. Since a significant beam loss as much as 420 W occurs at the edge of field free hole, the magnets near the Lambertson magnet are operated under a very high radioactive environment. We have developed a “mini-chimney system” regarding easy maintenance of those magnets. The mini-chimney means a vertical tower of approximately 1m in height. The tower is comprised of water pipes, power electrodes, and signal cables for safety interlock. Those can be easily connected and disconnected at the top of chimney on the ceiling iron shields. In this paper we summarize the maintenance scheme developed for the B-line, as well as the design of B-line.In May 2020, the first proton beam was successfully extracted to the B-line by means of the Lambertson and the septum magnets. Up to now, the 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> protons per 5.2 sec accelerator cycle shot have been available.

Experimental methods in chemical engineering: Pressure

AbstractPressure and temperature are the most important state variables for monitoring physicochemical processes to detect deviations that might lead to explosions and to verify levels, flow rate, and solids/gas hold‐up. Pressure fluctuations in multi‐phase systems identify regime changes and flow anomalies. Pressure signals are the first indicator of a process upset and are tied into distributed control systems (DCS) to sound alarms when they drift to high or low and activate safety interlocks in the case of high, high‐high, low, and low‐low conditions. To maximize the information, it requires that pressure gauges (transducers) are installed and calibrated precisely. Pressure measuring devices include manometers, aneroid devices like bellows and Bourdon gauges, and electronic instruments—piezoresistive, piezoelectric, and capacitive. The electronic elements have the advantage of higher precision and faster response times to measure fluctuations. The Bourdon gauges are standard equipment for pressure regulators and are mounted on the exterior of vessels and pipes to facilitate visual inspections. Over 2 million articles indexed by the Web of Science Core collection mention pressure, and in 2021, chemical engineering ranks had over 7000 articles—only multidisciplinary material sciences and energy and fuels had more. A bibliometric analysis identified five research clusters: temperature, combustion, and kinetics; separation, membranes, and energy efficiency; carbon dioxide (capture and storage), water, and thermodynamics; methane, adsorption, and transport phenomena (e.g., diffusion and permeability); and modelling, optimization, and computational fluid dynamics (CFD).

Research on Safety Interlock System Design and Control Experiment of Combined Support and Anchor Equipment.

In view of the risk of collision with humans or equipment arising from a lack of protection in the operation process of combined support and anchor equipment on the heading face, this paper designs a safety interlock system for combined support and anchor equipment. Firstly, a mathematical model of hydraulic power system control and a valve control system based on feedforward–feedback optimization were established according to the power demand of the combined support and anchor equipment. Secondly, according to the reliability indexes of the safety interlock system, corresponding sensor, logic control and execution modules were designed. Ultrasonic sensor groups were arranged at the key positions of the combined support and anchor equipment to capture the position information in real time when the equipment was moving. Thus, the pump-valve hydraulic system was controlled through closed-loop feedback. The experimental results show that the safety interlock system of the combined support and anchor equipment can adjust the revolving speed of the permanent magnet synchronous motor (PMSM) in real time according to the distance from the obstacle, so as to control the pump outlet flow, and then perform interlocking safety control of the hydraulic cylinder’s movement speed. The system can effectively prevent damage to the surrounding equipment or personnel arising from equipment malfunction.

Control system for Thomson scattering diagnostic on XuanLong-50 spherical tokamak

The detailed design and implementation of the control system for the Thomson scattering (TS) diagnostic on the ENN's XuanLong-50 (EXL-50) spherical tokamak are presented. It consists of three main sub-systems connected by a local network and a master PC. The laser operation control sub-system manages the Nd-YAG laser operation, the safety interlock, and the laser alignment. The timing control sub-system manages the deployment and triggering sequence of each instrument. The waveforms of scattered signals are directly digitized with the data acquisition sub-system and are uploaded to the MDSplus database by the master PC. During the phase-I operation of EXL-50, the typical electron density is on the order of 1018m−3. The relatively low density results in a low signal level below the noise floor. The implementation of a multi-pulse averaging technique improves the signal-to-noise ratio (SNR) at the cost of time resolution.

An 18.3 MJ charging and discharging pulsed power supply system for the Space Plasma Environment Research Facility (SPERF): The integrated control subsystem.

The Space Plasma Environment Research Facility uses a coil system with the corresponding pulsed power supply (PPS) system to generate a very flexible magnetosphere-like magnetic configuration. Its purpose is to investigate the 3D asymmetric reconnection and the processes of trapping, acceleration, and transport of energetic charged particles restrained in a dipole magnetic field configuration, as well as the physical mechanism of the dipolarization front in the magnetotail. The control and monitoring function of the PPS system is realized by the integrated control subsystem, which adopts a two-layer network structure of the control layer and device layer and is developed based on the Experimental Physics and Industrial Control System framework. The control layer includes a remote control system that consists of an engineer station and an operator station and the data storage system. Both the engineer station and operator station are developed by Control System Studio. The data storage system is based on the combination of the Hierarchical Data Format 5 database and MySQL database, and the data management software of the data storage system is developed based on LabVIEW. The synchronous trigger device, the safety interlocking device, the local controller of each set of PPS, and the module controller of each discharge module are the device layer. Their hardware is designed and developed based on the Field Programmable Gate Array, and their software is based on the Quartus II platform and programmed with the Verilog Hardware Description Language language. The function of the integrated control subsystem is verified by the discharge test of the PPS system.

Processing of the Quench Detection Signals for CS Model Coil of CFETR

The Center Solenoid Model Coil (CSMC) is a pre-research project of CFETR, and its task is to design and manufacture the CS superconducting model coil to gain wider experience in solving the related technical problems existing in design and construction of CFETR CS coils. The expected achievement is to charge the CSMC up to the operation current of 47.65 kA and the maximum magnetic field to 12 T with a swift rump rate of 1.5 T&#x002F;s without quench. Although adequate operational margins have been taken into in the design to avoid the quenches, such events cannot be completely excluded in the life of the CSMC. In order to prevent quench from damaging the CSMC, the quench detection by voltage measurements plays an important role in the protection of the CSMC during commissioning and operation scenarios. To improve the accuracy and reliability of CSMC quench detection, an all-digital quench detection system based on FPGA has been designed for the processing of quench detection signals. This paper describes the design of the quench detection signal processing system, including the composition of quench detection units, the auxiliary compensation for further denoising, the discriminant of quench, and the safety interlock system.

Safety assurance of an industrial robotic control system using hardware/software co-verification

As a general trend in industrial robotics, an increasing number of safety functions are being developed or re-engineered to be handled in software rather than by physical hardware such as safety relays or interlock circuits. This trend reinforces the importance of supplementing traditional, input-based testing and quality procedures which are widely used in industry today, with formal verification and model-checking methods. To this end, this paper focuses on a representative safety-critical system in an ABB industrial paint robot, namely the High-Voltage electrostatic Control system (HVC). The practical convergence of the high-voltage produced by the HVC, essential for safe operation, is formally verified using a novel and general co-verification framework where hardware and software models are related via platform mappings. This approach enables the pragmatic combination of highly diverse and specialised tools. The paper's main contribution includes details on how hardware abstraction and verification results can be transferred between tools in order to verify system-level safety properties. It is noteworthy that the HVC application considered in this paper has a rather generic form of a feedback controller. Hence, the co-verification framework and experiences reported here are also highly relevant for any cyber-physical system tracking a setpoint reference.

MOBILE AGRICULTURAL MACHINERY: SOURCES OF INJURIES AND WAYS TO ELIMINATE THEM

The results of research related to injury of operators of mobile agricultural machinery due to absence or imperfection of safety interlocks design are given. Information is given on the level of injuries of agricultural workers due to harmful and (or) dangerous working conditions, including due to the imperfection of agricultural equipment in terms of labor protection parameters. The components of harmful and (or (dangerous working conditions and their share in non-compliance with regulatory requirements guaranteeing the regulatory framework of the country for safety and harmlessness of work are named. Specific data are given for eight enlarged groups of economic activity on labor protection indicators (the number of injured and dead) for comparison as of the beginning of 2021 and 2019. The share for the same conditions of the number of workers, including the share of workers in harmful and (or) dangerous working conditions, employed in heavy work and work with labor process strain, is given. As an example, the imperfection of dump trucks and self-unloading trailers is given in terms of blocking the spontaneous uncontrolled lowering (fall) of their bodies, which usually cause severe and fatal injuries. The complex of measures that prevent injuries is regarded.

3-D printed injection system for capillary electrophoresis.

Commercial systems for capillary electrophoresis are designed for the unattended analysis of several samples, and are usually large, complex, and expensive. We report a compact system for manual injection of a single sample in capillary electrophoresis, which is ideal for method development and for student training. The injector consists of two parts that are manufactured by three-dimensional printing (STL and STEP files are included as ESI). One part is immobile and holds an electrode for powering electrophoresis and a gas line for pressurized injection and pumping fluids through the capillary. The second part is removable and is used to hold washing solutions, separation electrolyte, or sample. Conventional machining is used to tap holes to hold the electrode, separation capillary, gas line, and safety interlock. The system is used for either pressure or electrokinetic sample injection, and can be used to pump fluids through the capillary for changing background electrolytes and reconditioning the capillary between runs. We coupled the injection system to our high-dynamic range laser-induced fluorescence detector and evaluated the system by performing capillary zone electrophoresis on solutions of fluorescein. Electrokinetic injection produced a linear response across five orders of magnitude dynamic range (slope of the log-log calibration curve was 1.02), concentration detection limits of 5 pM, and mass detection limits of 1 zmol. Pressure injection produced a linear response across at least four orders of magnitude (slope of the log-log calibration curve was 0.92), concentration detection limits of 2 pM, and mass detection limits of 10 zmol.

Data Acquisition System for Chemical Iodine Generation Suitable for Flowing Medium Chemical Oxygen Iodine Laser

Development of infrared flowing medium lasers needs to be envisaged in a manner that practical aspects such as system compactness, short readiness time, low system size, weight and power are met to make them field deployable. In this context, the critical aspect of in-situ production of lasing species (Iodine) in Chemical Oxygen Iodine Lasers (COIL), one of the most potent flowing medium lasers, has been investigated. The paper dwells on chemical generation of iodine and its precise flow and parameter control by implementing a customised Data Acquisition System (DAS). Iodine is generated in a chemical reaction of Cuprous Iodide (CuI) with chlorine. This is achieved by precisely controlled flow of chlorine diluted with a carrier gas (N2 ) in a ratio of 1:2. DAS includes regulated gas feed, accurate thermal stabilisation, relevant diagnostics and implementation of necessary safety interlocks in a real time operation scenario for establishing the system efficacy and scalability. The studies have demonstrated chemically generated iodine flow rate of ~ 1.2 mmol.s-1 for Cl2 flow rate of ~3 mmol.s-1 all measured in real time using the developed DAS with a conversion efficiency of 80%. Developed I2 supply system has potential to deliver iodine on demand with required flow rates, measurement uncertainty of ~ 4.5 percent and advantages of smaller specific weight and size with reduced system readiness time and electrical power supply using DAS system with adequate safety interlocks.

Preliminary Design of Monitoring System of ITER Static Magnetic Field Test Facility

The structure and characteristics of the ITER static magnetic field test facility is introduced. The preliminary design scheme of the monitoring system of the facility is proposed. According to the characteristics of the facility that it includes several subsystems, multiple signal types and is suffered from electromagnetic interference, the solution given combines NI CompactRIO embedded system, NI PXIe and Ethernet exchange technology. It can realize signal acquisition, status monitoring, safety interlock, parameter setting and other function. Also, the scheme covers the methods to weaken the interference from the surrounding magnetic field on the system itself and improve the stability of the system. The preliminary design scheme complies with control, data acquisition and communication specifications from ITER, and meets the SIL level assessment requirements in the concept phase.

Design of a personnel safety interlock system for proton therapy

Proton therapy is the most advanced radiotherapy approach in the world, and causes less damage to normal human tissue than traditional radiotherapy. Because the treatment process produces a high-energy proton beam, the personnel safety interlock system mainly considers measures to protect personnel from radiation hazards during beam preparation and the beam release process. Unlike other safety interlock systems, the personnel safety interlock system designed in this study focuses on the safety and stability of the system itself. The hardware and software of important interlock control loops are designed and developed according to the requirements of Safety Integrity Level 3 specified by IEC61508. A set of redundant ring networks was developed to ensure that damage to a certain network line does not affect the normal operation of the system. A set of friendly operation interfaces and data storage systems were developed to ensure that the operator can monitor the data in real time and trace the data. The personnel safety interlock system mainly includes a beam enabling function, clearance function, and emergency stop function. The system was put into actual use and successfully ensured personnel safety.