Collision Hazard Research Articles

Equipment Sounds’ Event Localization and Detection Using Synthetic Multi-Channel Audio Signal to Support Collision Hazard Prevention

Construction workplaces often face unforeseen collision hazards due to a decline in auditory situational awareness among on-foot workers, leading to severe injuries and fatalities. Previous studies that used auditory signals to prevent collision hazards focused on employing a classical beamforming approach to determine equipment sounds’ Direction of Arrival (DOA). No existing frameworks implement a neural network-based approach for both equipment sound classification and localization. This paper presents an innovative framework for sound classification and localization using multichannel sound datasets artificially synthesized in a virtual three-dimensional space. The simulation synthesized 10,000 multi-channel datasets using just fourteen single sound source audiotapes. This training includes a two-staged convolutional recurrent neural network (CRNN), where the first stage learns multi-label sound event classes followed by the second stage to estimate their DOA. The proposed framework achieves a low average DOA error of 30 degrees and a high F-score of 0.98, demonstrating accurate localization and classification of equipment near workers’ positions on the site.

Autonomous Underwater Vehicle (AUV) Motion Design: Integrated Path Planning and Trajectory Tracking Based on Model Predictive Control (MPC)

This paper attempts to develop a unified model predictive control (MPC) method for integrated path planning and trajectory tracking of autonomous underwater vehicles (AUVs). To deal with the computational burden of online path planning, an event-triggered model predictive control (EMPC) method is introduced by using the environmental change as a triggering mechanism. A collision hazard function utilizing the changing rate of hazard as a triggering threshold is proposed to guarantee safety. We further give an illustration of how to calculate this threshold. Then, a Lyapunov-based model predictive control (LMPC) framework is developed for the AUV to solve the trajectory tracking problem. Leveraging a nonlinear integral sliding mode control strategy, we construct the contraction constraint within the formulated LMPC framework, thereby theoretically ensuring closed-loop stability. We derive the necessary and sufficient conditions for recursive feasibility, which are subsequently used to prove the closed-loop stability of the system. In the simulations, the proposed path planning and tracking control are verified separately and integrated and combined with static and dynamic obstacles.

Identification of Complex Multi-Vessel Encounter Scenarios and Collision Avoidance Decision Modeling for MASSs

Complex multi-vessel encounter situations are a challenging problem for ships to avoid collisions, and the International Regulations for Preventing Collision at Sea, 1972 (COLREGs) do not provide a clear delineation of multi-vessel encounter situations and the responsibility of collision avoidance (CA). Furthermore, Marine Autonomous Surface Ships (MASS), which realize autonomous navigation functions, face the problem of recognizing complex multi-ship encounter situations and the corresponding CA decisions. In this study, we adopt the velocity obstacle (VO) algorithm to visualize and identify the danger of multi-ship encounters with the own ship (OS) as the first viewpoint. Additionally, we consider the motion changes in target ships (TSs) and their possible CA behaviors as the basis of the ship’s CA decision-making. According to COLREGs, a simplified method for classifying the encounter situations of multiple clustered ships is proposed, considering the coupling of collision hazards and CA responsibilities between related TSs. On this basis, the corresponding CA decisions for each classified situation are proposed, and a large number of simulation experiments are conducted based on the proposed method by considering the three-ship and four-ship encounter model in the Imazu problem as an example. The experimental results indicate that the proposed method can effectively recognize the complex multi-ship encounter situation in the Imazu problem, and it can adjust the CA measures of the OS in time according to the COLREGs and the behavior of TSs. This provides the basis and reference for MASS when facing complex multi-ship encounter situations.

Verification and Validation for a Digital Twin for Augmenting Current SORA Practices with Air-to-Air Collision Hazards Prediction from Small Uncooperative Flying Objects

Future autonomous Unmanned Aerial Vehicles (UAV) missions will take place in highly cluttered urban environments. As a result, the UAV must be able to autonomously evaluate risks and react to unforeseen hazards. The current regulatory framework for missions implements SORA guidelines for hazard detection, but its application to air-to-air collision is limited. This research defined a rigorous verification and validation framework (V&V) for digital twins for use in future autonomous UAV missions. The researchers designed a sentry mission for a UAV to evaluate its capacity to detect small uncooperative flying objects. A digital twin of the DJI M300 vision system was built using a game engine and a V&V framework was developed to assure the quality of results in both virtual and real-world scenarios. The results showed the capability of the digital twin to identify vulnerabilities and worst-case scenarios in UAV mission operations, and how it can assist remote pilots in identifying air-to-air collision hazards. Furthermore, the probability of air-to-air collision was calculated for three sentry patterns, and the results were validated in the field. This research demonstrated the capability to identify vulnerabilities and worst-case scenarios in UAV mission operations. We present how the digital twin of an operational theatre can be exploited to assist remote pilots with the identification of air-to-air collision hazards of small uncooperative objects. Furthermore, we discuss how these results can be used to enhance current SORA-based risk assessment practices.

An Improved NSGA-II Algorithm for MASS Autonomous Collision Avoidance under COLREGs

Autonomous collision avoidance decision making for maritime autonomous surface ships (MASS), as one of the key technologies for MASS autonomous navigation, is a research hotspot focused on by relevant scholars in the field of navigation. In order to guarantee the rationality, efficacy, and credibility of the MASS autonomous collision avoidance scheme, it is essential to design the MASS autonomous collision avoidance algorithm under the stipulations of the Convention on the International Regulations for Preventing Collisions at Sea (COLREGs). In order to enhance the autonomous collision avoidance decision-making capability of MASS in accordance with the relevant provisions of COLREGs, an improved NSGA-II autonomous collision avoidance decision-making algorithm based on the good point set method (GPS-NSGA-II) is proposed, which incorporates the collision hazard and the path cost of collision avoidance actions. The experimental results in the four simulation scenarios of head-on situation, overtaking situation, crossing situation, and multi-ship encounter situation demonstrate that the MASS autonomous collision avoidance decision making based on the GPS-NSGA-II algorithm under the constraints of COLREGs is capable of providing an effective collision avoidance scheme that meets the requirements of COLREGs in common encounter situations and multi-ship avoidance scenarios promptly, with a promising future application.

The ion beam interceptor concept for a space station collision avoidance with space debris

Space debris poses a great threat to space stations. When a collision hazard is detected, the space station's orbit should be adjusted. An alternative approach is to apply collision avoidance measures that consist in creating an external impact on the space debris object to change its orbit and increase the miss distance slightly. Such an impact can be carried out using a ground-based or orbital laser, through the use of nano-tugs thrusters, or by placing a cloud of particles in the path of the object. This study proposes to use the plume of a thruster of an active spacecraft called an Ion Beam Interceptor. When a potential collision is detected, the interceptor undocks from the space station, approaches the space debris object and directs an ion beam, which is generated by the spacecraft's thrusters, at it. Hitting into the surface of the object, the particles of the ion beam exert a force effect on it, which leads to the required change in the orbit. After the completion of the maneuver, the interceptor returns to the space station for refueling and servicing. The objective of the study is a preliminary assessment of the feasibility and effectiveness of the proposed approach of protecting a space station from space debris impact using an active spacecraft. A mission profile of the space station protection is proposed. A series of numerical simulations are performed to determine mission parameters and fuel costs. Based on an analysis of the orbits of space objects located near the space station, the maximum angle between the orbital planes of the dangerous object and the station are determined at which it is advisable to use the Ion Beam Interceptor. The developed concept also allows to implement just-in-time collision avoidance measures for space debris objects whose orbital planes are close to the plane of the space station.

Identification and Analysis of Micro-Doppler Signature of a Bird Versus Micro-UAV

The groundbreaking advancement of micro unmanned aerial vehicles (micro-UAVs) has been staggering. The diversity of micro-UAV operations is demanding in most sectors. However, the current regulatory framework for the civilian use of these devices is still insufficient. The operation of micro-UAVs may pose risks, including privacy violations and collision hazards. To address these concerns, a radar with advanced processing is needed. This study presents a preliminary design of an S-band continuous wave (CW) radar, which was simulated using MATLAB. The size of the rotating propeller blades of the micro-UAV ranges from 20 to 40 cm in length, while the size of a bird’s flapping wing measures 35 cm in length, comprising 22 cm for the upper arm and 13 cm for the lower arm. The analysis was conducted under hovering conditions, where the target's main body is stationary while its micro-parts move continuously. The Short-Time Fourier Transform (STFT) analysis successfully identified the unique signature of both targets. The results showed that the S-band CW radar design at 5 GHz is effective in extracting the micro-Doppler signature of a bird versus a micro-UAV. The extracted features can be used as additional characteristics for target classification in the future.

Evaluating the potential of bioacoustics in avian migration research by citizen science and weather radar observations.

The study of nocturnal bird migration brings observational challenges because of reduced visibility and observability of birds at night. Remote sensing tools, especially radars, have long been the preferred choice of scientists to study nocturnal migrations. A major downside of these remote sensing tools is the lack of species-level information. With technological advances in recent decades and with improved accessibility and affordability of acoustic tools, sound recordings have steeply increased in popularity. In Europe, there is no exhaustive qualitative and quantitative evaluation of the content of such acoustic databases and therefore the value for migration science and migration-related applications, such as bird collision hazard assessments, is mostly unknown. In the present work we compared migration schedules estimated from citizen science data with quantitative temporal occurrence of species in four years of acoustic recordings. Furthermore, we contrasted acoustic recordings with citizen science observations and weather radar data from one spring and one autumn season to assess the qualitative and quantitative yield of acoustic recordings for migration-related research and applications. Migration intensity estimated from weather radar data correlated best at low levels with acoustic records including all species in spring while in autumn passerine species showed stronger correlation than the entire species composition. Our findings identify a minor number of species whose call records may be eligible for applications derived from acoustics. Especially the highly vocal species Song thrush and Redwing showed relatively good correlations with radar and citizen science migration schedules. Most long-distance passerine migrants and many other migrants were not captured by acoustics and an estimated seasonal average of about 50% of nocturnally migrating passerine populations remained undetected. Overall, the ability of acoustic records to act as a proxy of overall migration dynamics is highly dependent on the migration period and species involved.

Segmentation of Drone Collision Hazards in Airborne RADAR Point Clouds Using PointNet

Segmentation of Drone Collision Hazards in Airborne RADAR Point Clouds Using PointNet

Formation control for swarm system with dynamic obstacles

This paper presents a formation control method for a swarm system, wherein each agent is capable of avoiding dynamic obstacles to reach a target area on the plane. Firstly, the collision hazard area, where an agent collides upon entry, is established by integrating a partial differential equation-based distribution model of dynamic obstacles and a curve model of the front agents' deployment. Secondly, the coverage-based controller is designed for each agent by optimising the objective function concerning its respective visibility-limited Voronoi set on the manoeuvrable domain outside the collision hazard area, ensuring that the agent's trajectories remain within the target area. Simulation results finally demonstrate the effectiveness of the proposed approach.

Enhancing Safety on Construction Sites: A UWB-Based Proximity Warning System Ensuring GDPR Compliance to Prevent Collision Hazards.

Construction is known as one of the most dangerous industries in terms of worker safety. Collisions due the excessive proximity of workers to moving construction vehicles are one of the leading causes of fatal and non-fatal accidents on construction sites internationally. Proximity warning systems (PWS) have been proposed in the literature as a solution to detect the risk for collision and to alert workers and equipment operators in time to prevent collisions. Although the role of sensing technologies for situational awareness has been recognised in previous studies, several factors still need to be considered. This paper describes the design of a prototype sensor-based PWS, aimed mainly at small and medium-sized construction companies, to collect real-time data directly from construction sites and to warn workers of a potential risk of collision accidents. It considers, in an integrated manner, factors such as cost of deployment, the actual nature of a construction site as an operating environment and data protection. A low-cost, ultra-wideband (UWB)-based proximity detection system has been developed that can operate with or without fixed anchors. In addition, the PWS is compliant with the General Data Protection Regulation (GDPR) of the European Union. A privacy-by-design approach has been adopted and privacy mechanisms have been used for data protection. Future work could evaluate the PWS in real operational conditions and incorporate additional factors for its further development, such as studies on the timely interpretation of data.

Linking Deployment Outcomes to Program Impacts for Mobile Photo Enforcement

Previous research has delved into the effectiveness of Mobile Photo Enforcement (MPE) in curbing speed violations and enhancing road safety. This present study extends this investigation to explore the potential influence of MPE deployment efforts on subsequent collision occurrences. Specifically, the research team applied survival analysis techniques to examine the connection between MPE deployment variables and the duration between collisions. K-M survival estimates were employed to assess the survivability of classified groups, categorized based on deployment hours, visits, the ratio of hours to visits, and traffic count. The findings illuminated that the ratio of hours to visits emerged as the most impactful variable in prolonging the time interval between collisions and diminishing the likelihood of collisions. Notably, the anticipated reduction in collision hazards, signifying the occurrence of collisions, exhibited variations ranging from 22% to 52%. The most substantial decreases were observed when deployment occurred in high-traffic locations. These outcomes reinforce the positive impact of deployed MPE hours and visits in extending the duration between consecutive collisions, thus reducing the risk of collision occurrences.

Penyuluhan Penggunaan Lampu Navigasi Pada Kapal Nelayan Desa Wawontulap Untuk Menghindari Bahaya Tubrukan di Laut

Risks of transportation safety are still a common issue in Indonesia. Communities living in coastal and marine areas, the majority of whom work as fishermen, still rely on traditional knowledge and skills. Wawontulap Village is located in the Tatapaan District with a total of 80 active fishermen, most of whom use small-scale traditional fishing boats with 50 cc to 80 cc motor engines and without adequate navigation tools, thus impacting visibility for ship maneuvers. fisherman. The position and potential for catching larger fish at night is a challenge for the fishing community in Wawontulap Village. This is because at night many fishing or fishing boats with larger sizes also descend into the sea which can cause a collision hazard between ships. The problem of navigation tools in the form of navigation lights is deemed necessary to find a solution immediately. Navigation lights on board apart from functioning as navigation guides can also be used as lighting and communication tools in the form of light signals if fishermen need help at any time. the method of socialization and delivery of assistance in the form of 3 (three) navigation lights which were handed over symbolically to village officials (the old law). From this community service activity it shows that fishermen's knowledge of the importance of navigation lights becomes clear and the danger of ship collisions when fishermen go outside to catch fish can be avoided.

CIPSO-Based Decision Support Method for Collision Avoidance of Super-Large Vessel in Port Waters

Effective and timely collision avoidance decision support is essential for super-large vessels navigating in port waters. To guarantee the navigational safety of super-large vessels, this work proposes a collision avoidance decision support method based on the curve increment strategy with adaptive particle swarm optimization (CIPSO). Firstly, the objective function is constructed based on the multi-objective optimization method. Here, a fuzzy comprehensive evaluation (FCE)-based vessel collision hazard model and vessel speed-varying energy-loss model integrating the Convention on the International Regulations for Preventing Collisions at Sea (COLREGS) are involved. Furthermore, in response to the limitations of the PSO algorithm, which is prone to falling into local optima in the later stages of iteration, a curve increment strategy is incorporated. To improve the performance of the global optimization, it is optimized using a local followed by global search method. The iterative evolution of CIPSO is used to obtain the optimal decision value in the set domain of feasible solutions. Finally, the effectiveness and feasibility of the proposed method are verified by the numerical simulation and large vessel maneuvering simulator, which can provide collision avoidance decision support for ship pilots.

Drivers’ trust & reliance on automated braking at intersections: Effects of automation braking profile & in-vehicle displays

An online, video-based, within-subjects experiment was conducted to investigate the effects of three different automation braking profiles and three in-vehicle display designs on drivers’ trust and reliance on automated braking systems. 36 participants watched videos of automated braking at intersections (with different braking times and displays) and rated their trust in the automation and comfort with the automation’s braking time. They then watched the same videos and were asked to press the space bar and pause the video if they believed they should take over from the automation and brake. The braking profile had a significant effect on the trust and comfort ratings, while both the braking profile and display had a significant effect on the takeover time. The findings provide insights on drivers’ trust and reliance on automation that is designed to avoid lateral collision hazards at intersections.

Collision-free output-feedback super-twisting control of robotic surface vehicles for coordinated path following with experiments

This paper addresses the coordinated path following (CPF) control of robotic surface vehicles (RSVs) in the presence of multiple obstacles and lumped disturbances over a resource-constrained wireless network. A collision-free output-feedback super-twisting control architecture is proposed for CPF without using velocity measurements. Specifically, robust exact differentiator observers are designed at first to recover the unmeasured velocities, and estimate the lumped disturbances, simultaneously. Next, anti-disturbance output-feedback super-twisting control laws are proposed to achieve individual path following in earth-fixed reference frame, and an adaptive potential field with a user-defined collision hazard degree is introduced to avoid the collisions with obstacles. To reduce the network traffic, self-triggered path updating laws are then designed for avoiding the continuous transmitting and listening of neighboring RSVs. The stability analysis shows that the closed-loop system is input-to-state stable outside the collision avoidance region, and Zeno behavior will not happen. Experiments are finally conducted to validate the efficacy of the proposed collision-free output-feedback super-twisting control method for the self-triggered CPF of RSVs.

Collision hazard modeling and analysis in a multi-mobile robots system transportation task with STPA and SPN

This paper investigates the ability to use complex multi-mobile robotic systems in risky and dynamic environments, such as industrial plants and laboratories, with the presence of the human factor. More specifically, it presents an approach to analyze the dominant risk, extract, model and quantify the hazard scenarios, then propose requirements using the combination between two methods: System Theoretic Process Analysis (STPA) and Stochastic Petri Nets (SPN). This approach is demonstrated with a case study related to a chemical transportation task within a miniature analysis laboratory in oil and gas industry. The main purposes of this article are: to investigate how the risk and safety of these systems should be managed, to create a framework for modeling collision hazard scenarios, further a Monte Carlo simulation is performed to quantify the collision frequency and unavailability. In addition, to generate the required constraints and requirements in order to improve the safe operation of robots within the laboratory. The novel contribution of this study is to provide a hazard assessment approach suited to multi-controller and autonomous systems while considering coordination between controllers. Hence, the current study proposes a set of safety requirements, which allow designers and programmers to improve autonomy features in mobile robots. The STPA-SPN combination offers better modeling and assessment of robot's performance as well as their hazard frequency.

Autonomous Following for Unmanned Ground Vehicles on Unstructured Scenario: Risk and Performance Assessment

Military unmanned ground vehicles are often used in wild natural environment, autonomous following and accompanying security are typical functions. In order to make a quantitative assessment about the autonomous following performance of unmanned ground vehicles on unstructured scenarios, a set of evaluation index system construction method is proposed based on the combination of risk analysis and key performance indexes. First, the kinematics model of autonomous vehicle following in straight and curve based on meta-trajectory is established. Second, the key indexes affecting the following performance are analyzed and obtained from collision risk and lost risk. Third, the evaluation index system of autonomous following performance is constructed from five dimensions: average following speed, collision risk, collision hazard degree, following stability and lost risk. Finally, two unmanned vehicles are tested, the results show that the conclusion based on the constructed evaluation index system can significantly reflect the difference of autonomous following performance, which is basically consistent with the subjective evaluation of the test personnel.

The effect of the operational environment on the survivability of passenger ships

The in-force probabilistic framework for passenger ship survivability assessment covers collision hazards. The framework primarily pertains to a static approach. Nonetheless, more complex dynamic analyses usually employ the same damage definitions, adding besides the breach characteristics, the environmental condition selection or, more precisely, the irregular wave environment necessary to simulate the damage scenarios. The traditional dynamic approaches to survivability consider only the significant wave height sampled from statistical formulations, with the wave period deriving from a constant steepness assumption. However, wave height and period influence ship dynamics in waves differently, especially concerning survivability after damage. Therefore, aiming at a direct assessment of ship survivability and the probability of loss of lives determination in realistic operational scenarios, it is essential to properly study the influence of combined variations of wave height and periods and their occurrence. The present study proposes a methodology for dynamic simulations in site-specific conditions derived from the Global Wave Statistics. The study documents the process in two critical collision damages for a reference passenger ship, using wave height and period combinations typical of the main sea areas of interest for passenger ships and performing a sensitivity analysis on the simulations needed to evaluate survivability. This enhanced analysis allows identifying the limiting environmental conditions for the critical damage cases, including the effect of heading variations, determining the ship’s survivability to specific damage in an operational area.

Analysis of Collision Hazard Prevention With Operating Radar NICD – 453 Type On MV Amrta Jaya 1

The navigation system is the key to the safety of the ship in carrying out the voyage. RADAR will be very useful during bad weather, foggy conditions and sailing at night, especially when navigational instructions such as beacons, buoys, hills or buildings cannot be visually observed. So prospective ship officers must understand and understand to use RADAR navigation tools. To find out the target position and reduce the accident rate in the shipping lane, the role of RADAR in supporting shipping safety is needed. This study aims to analyze the prevention of collision hazards by using the Maneuvering Board in the operation of the Binocular RADAR at MV AMRTA JAYA 1. The type of research used in this study is quantitative research. In this case the data collection techniques used are documentation and observation. Documentation is in the form of searching for information in the form of books and documents, while observation is in the form of an approach to the object of research. From the results of research conducted, it can be seen that the method used to calculate the RADAR Plotting Sheet can be done by theoretical methods with formulas and scale methods with mathematical logic. The two methods can be used with the same results but with different time efficiency. The use of muvering boards and RADAR Plotting Sheet calculations can help identify the presence or absence of a collision hazard, and help estimate the closest distance, time taken, course and speed of the target ship.