Operated Vehicle Research Articles

Stereo Vision System for Autonomous Ship Hull Inspection

The periodical hull inspection represents a necessary task to ensure the maintenance of a vessel since it allows to counteract decay, check for structural damages, and fight the biofouling phenomenon affecting the navigation efficiency. Typically, this task is executed by divers, resulting in a dangerous job for the human operator, or by Remotely Operated Vehicles, driven by highly trained users. Aiming at automating the task and increasing its operational safety, this work proposes a strategy to perform the ship hull inspection using an Autonomous Underwater Vehicle (AUV), equipped with a stereo camera and a proximity sensor, without a prior knowledge of the target shape. At first, the images from the stereo vision system allow to estimate the lateral velocity of the vehicle and its orientation with respect to the hull surface. Then, the proximity measurement, properly projected along the normal axis to the surface of the target, provides a measure of the distance of the AUV from the surveyed structure. Lastly, the robot control system exploits these estimates to perform the mission with a constant lateral velocity, maintaining both a predefined safety distance from the target and the optical axis of the camera orthogonal to the examined surface. The proposed approach has been tested in a simulated environment, performing the investigation of a simplified model of ship hull. The results suggest the feasibility of the strategy: during the simulations, the AUV completes the mission with a full autonomy, safely, obtaining a 3D reconstruction of the surveyed structure.

Motor Learning for Manoeuvring Control of a Remotely Operated Vehicle

The paper investigates the application of a bio-inspired control paradigm encompassing nonlinear function approximation and adaptive learning to design a manoeuvring controller for a remotely operated vehicle. The bio-inspired learning controller is adopted to overcome limitations introduced by unknown nonlinear dynamics as well as by environmental disturbances. The proposed controller is compared against a traditional adaptive controller with respect to tracking performance and control effort. Simulation results show that the bio-inspired controller displays better tracking performance when the structure of the system dynamics is unknown. Further, the paper shows that offline training of the functional approximator helps in delivering a smoother control effort, and that a bio-inspired integral action fulfils the disturbance rejection.

Tightly Coupled Binocular Vision-DVL Fusion Positioning Feedback for Real-time Autonomous Sea Organism Capture

Visual positioning is very significant for underwater robot autonomous manipulation. However, visual positioning feedbacks are often ineffective with unstable and discontinuous matching information during small target capture in underwater environment. Therefore, the low cost sea organism object positioning process should be applied with self-navigation and matching system in order to guide the underwater vehicle manipulator systems (UVMS) manipulation control. In order to improve the matching robustness and accuracy, this study established the underwater refraction and intrinsic & extrinsic parameter optimization model accurate calibration, designed an improved ORB feature matching method, with adaptive threshold to extract FAST feature points and non-maximum suppress to remove feature point blocks in the feature extraction stage. Moreover, the comparison of three pixel blocks norm values are proposed in the feature point description stage to improve the robustness of the descriptor. This paper has proposed a novel tightly coupled binocular vision-DVL fusion positioning feedback optimization algorithm with multi-state constraint Invariant Extended Kalman Filter to improve accurate real-time measurement for the capture of sea organism with limited features. Systematic tank and oceanic experiments have been performed to prove and analyze the purposed algorithm. Experimental results show that the algorithm can provide reliable positioning information in tank and complex seabed environment, which is effective for the underwater robot to realize accurate capture of marine organisms.

Dynamic Bayesian Networks for Reduced Uncertainty in Underwater Operations

This paper presents a novel framework for modelling dynamic Bayesian belief networks (BBNs) for online risk assessment in underwater operations. Existing frameworks spans from commercial software with restricted code access to non-profit open source frameworks. Frameworks with restricted code access often provides general user interfaces and visualization tools, while open source frameworks provides access to code for developers. The model presented in this paper pursues a best of both worlds scenario, where the model implementation should be uncomplicated while also providing visualization and verification to provide the user with a clear perception of the implemented model. The presented method is an expansion of the Bayesian model of the pomegranate python library, and simplifies the procedure of building, verifying and utilizing BBN models. The method is applied to a conceptual design of an underwater scenario case study with a model for an underwater vehicle manipulator system.

Research of Comprehensive Operation Vehicle for Apple Picking

Aiming at the defects of low mechanization, single function, poor integration of machinery, agronomy and high damage rate in apple picking process, a comprehensive operation equipment for apple picking was developed. Around the standardized apple cultivation mode with dwarf and dense planting, intensive and efficient, the research of multi-link mechanized operation technology method based on the integration of agricultural machinery and agronomy is carried out. The structure of apple picking comprehensive operation equipment is designed, including the orchard traffic system, chassis support device, operation platform, platform lifting device, apple collection device, apple conveying system, automatic sorting, bagging device and fruit box rotation platform, which solves the key technical problems of mechanization, such as adaptability of trafficability, extension of operation space and low loss of fruit delivery and fruit collection and placement. The damage of apples is reduced by adopting flexible collection, conveying device and the quality of apples is improved by adopting apple collection, automatic sorting and packing system to realize the second sorting and packing of apples. The design of the device can realize the integrated service of apple from picking to sealing and selling, eliminating the intermediate labour-intensive and time-consuming links, the production efficiency of apples is improved and the production cost is reduced. It laid a foundation for the realization of the whole mechanization of apple production.

A Comparison of Waterproof Motor Housings for Student Robotics Teams

Professionals and students alike create high-performance Remotely Operated Vehicles (ROV)s to complete a multitude of tasks underwater. The student ROV competition created by Marine Advanced Technology Education (MATE) simulates the tasks faced by the modern professional underwater robotics industry. Students often design their ROVs with techniques used by the professional underwater robotics industry. Unlike professionals, students do not have many resources comparing manufacturable ROV components that fit within their design restrictions. Without information about components that they choose to use on their ROVs, students might miss an opportunity to implement a better alternative technology. Such is the case with older Shaft Sealed Housings (SSH) and less common Magnetically Coupled Housings (MCH). In this paper, essential aspects of both alternative designs for waterproof motor housings are tested to determine overall performance. The waterproofness of each housing is tested experimentally over long periods of time in an environment simulating the most extreme depths experienced at the MATE ROV Competition. Maximum static torque is measured on a torque sensor. Cost and manufacturability of each housing are recorded in tables. Ultimately, student robotics teams are left to determine which motor housing best fits their design requirements, based on the data discovered and presented in this paper.

Operational failure assessment of Remotely Operated Vehicle (ROV) in harsh offshore environments

For an effective integrity assessment of marine robotic in offshore environments, the elements’ failure characteristics need to be understood. A structured probabilistic methodology is proposed for the operational failure assessment (OFA) characteristics of ROV. The first step is to assess the likely failure mode of the ROV system and its support systems. This captures the interaction and failure induced events during operation. The identified potential failure modes are further developed into logical connectivity based on the cause-effect relationship. The logical framework is modeled using the fault tree analysis technique to predict the ROV operational failure probability in an uncertain harsh environment. The fault tree analysis captured the logical relationship between the primary, intermediate, and top events probability. The importance measure criteria were adopted to identify the most probable events, links, and their importance on the failure propagation. The model was demonstrated with an ROV for deep arctic water subsea operations. The result identified the control system, communication linkages, human factor, among others, as most critical in the ROV operational failure. The methodology’s application provides core information on the Mean time between failure (MTBF) of the ROV system that could aid integrity management and provides a guide on early remedial action against total failure.

Optimal pool composition of commercial electric vehicles in V2G fleet operation of various electricity markets

The market ramp-up of electromobility is shifting vehicle-to-grid (V2G) issues into the focus of research and industry. Electric vehicles (EVs) have the potential to support the trend towards renewable energies in their role as storage units during idle times. To participate in balancing power and energy markets, EVs are pooled via aggregators. Instead of a random composition, aggregators can smartly compose their pools and add only those vehicles that actually contribute to the pool’s performance, gaining advantages over competitors. The optimization methods presented in this paper form optimized pool combinations based on the power and energy capability profiles of commercial EVs. Genetic algorithms are used to determine the revenues of the possible pools per participating EV. The use cases analyzed are the provision of balancing power on the frequency containment reserve (FCR) market of Central Europe and energy arbitrage trading on the European power exchange intraday continuous and day-ahead auction spot markets. The results show that through smart pool composition, an aggregator can increase revenue per vehicle by up to seven-fold across the markets compared to randomly assembled pools. In the Central European market, for example, the potential V2G revenues on the FCR market (380 €) exceeded those of arbitrage trading (28 € − 203 €) in 2020. In a simulation, we show the increased degradation of the vehicle battery in V2G operation compared to sole use for mobility with a smart charging strategy. However, the additional revenue can make V2G financially worthwhile, depending on costs for measuring equipment, bidirectional charging stations, and aggregator costs.

Stereo Vision System for Vision-Based Control of Inspection-Class ROVs

The inspection-class Remotely Operated Vehicles (ROVs) are crucial in underwater inspections. Their prime function is to allow the replacing of humans during risky subaquatic operations. These vehicles gather videos from underwater scenes that are sent online to a human operator who provides control. Furthermore, these videos are used for analysis. This demands an RGB camera operating at a close distance to the observed objects. Thus, to obtain a detailed depiction, the vehicle should move with a constant speed and a measured distance from the bottom. As very few inspection-class ROVs possess navigation systems that facilitate these requirements, this study had the objective of designing a vision-based control method to compensate for this limitation. To this end, a stereo vision system and image-feature matching and tracking techniques were employed. As these tasks are challenging in the underwater environment, we carried out analyses aimed at finding fast and reliable image-processing techniques. The analyses, through a sequence of experiments designed to test effectiveness, were carried out in a swimming pool using a VideoRay Pro 4 vehicle. The results indicate that the method under consideration enables automatic control of the vehicle, given that the image features are present in stereo-pair images as well as in consecutive frames captured by the left camera.

Distributions of microplastics and larger anthropogenic debris in Norfolk Canyon, Baltimore Canyon, and the adjacent continental slope (Western North Atlantic Margin, U.S.A.)

Anthropogenic debris has been reported in all studied marine environments, including the deepest parts of the sea. Finding areas of accumulation and methods of transport for debris are important to determine potential impacts on marine life. This study analyzed both sediment cores and Remotely Operated Vehicle video to determine the density and distribution of debris, including both micro- and macroplastics, in Norfolk and Baltimore canyons. The average microplastic density in Norfolk Canyon sediment was 37.30 plastic particles m−2 within the canyon and 21.03 particles m−2 on the adjacent slope, suggesting that microplastics could accumulate within submarine canyons. In video transects from both Norfolk and Baltimore canyons, the largest amounts of macroplastic were recorded near the canyon heads. Our findings contribute to a growing evidence base that canyons and their associated benthic invertebrate communities are important repositories and conduits for debris to the deep sea.

Development of marker detection method for estimating angle and distance of underwater remotely operated vehicle to buoyant boat

The paper proposes a Marker Detection Method for Estimating the Angle and Distance of Underwater Remotely Operated Vehicle (ROV) to Buoyant Boat. To keep the ROV aligned with the boat, a marker and visual recognition system are designed. The marker is placed facing down under the boat and a method is developed to recognize the angle and distance of the marker from a facing up camera on the ROV. By considering space, payload, heat dissipation, and buoyancy in a micro class ROV, there are limited options for computing power that can be utilized. This challenge demands a lightweight visual recognition technique for small computers. The proposed method consists of two steps. The marker designing step explains how the marker is constructed of simple components. The marker recognizing step is based on image processing that uses threshold and blob filtering. They are blob size and blob circularity filters which are used to eliminate unwanted information. The real-time orientation and distance estimation by using one camera are the superiority of this method. The proposed method has been tested by using an 11x11 cm2 marker size. The detection rate of the marker is 90% and can be detected up to 120 cm from the camera. The marker can be tilted up to 50° and still has an 80% detection rate. The method can estimate marker rotation angle accurately with a 1.75° average error. The method can estimate the distance between the marker and camera with a -0.62 cm average error. The blob filter is also proven to be superior to a regular dilating and eroding method.

Vehicle rollover warning system based on TTR method with inertial measurement

This paper presents a theoretical and experimental study conducted on the rollover warning of wheeled off-road operating vehicles. The time to rollover warning algorithm was studied with real-time vehicle roll angle and roll angle velocity as the input variables, and lateral load transfer ratio was used as the rollover determination index. Subsequently, a vehicle dynamics model was built using CarSim software, and a warning algorithm was established in the MATLAB/Simulink environment. The rollover joint simulation in CarSim and MATLAB/Simulink was conducted under typical working conditions. Finally, combined with inertial measurements, a rollover warning system was independently developed. In addition, the rollover warning system was installed on a light forest firefighting truck to verify the feasibility of the system via a real vehicle experiment, and the law of vehicle rollover motion was also studied. The serpentine experiment and steady-state rotation experiment were conducted. The experimental results showed that at identical front-wheel steering angles, the roll angle and lateral acceleration increased with an increase in the vehicle speed. Furthermore, for identical vehicle speeds, the roll angle and lateral acceleration of the vehicle increased with an increase in the front-wheel steering angle. The dangerous vehicle speed was 50 km h−1 in the serpentine condition and 40 km h−1 in the steady-state rotation condition. The risk trend and alarm signal obtained by the rollover warning system were consistent with the actual situation. Thus, this can assist drivers in judging the rollover risk and effectively improve the active safety of special vehicles. Furthermore, it also provides a reference for further research on active rollover control technology of special vehicles.

FASILITAS DAN SISTEM KOMPENSASI DAMPAKNYA PADA KINERJA KARYAWAN DI BANK BJB SYARIAH KCP. KUNINGAN

Good employee performance will be achieved if you pay attention to what factors can influence it. The case that occurred at Bank BJB Syariah KCP Kuningan was that employees complained about work facilities and the compensation system. The method used in this study is a descriptive method with a qualitative approach. With two data sources, namely primary data sources consisting of leaders and all employees at Bank BJB Syariah KCP. Brass and secondary data sources consisting of documents both in writing and photos at Bank BJB Syariah KCP. Brass. Data collection techniques used are interviews, observation and documentation. The research instrument is the researcher himself as the main instrument in the research, observation guide and interview guide. The results showed that the facilities provided by Bank BJB KCP. Kuningan is inadequate, the internet network is often disturbed, the lack of operational vehicles, the parking area is not large enough, thus disrupting employee performance. As for compensation, the institution has given it fairly and fairly well in accordance with existing regulations. Both of these things certainly have an impact on employee performance, so that it can be said that the failure of the BJB Syariah Bank, Kuningan Sub-Branch Office, has not been able to meet the needs to improve employee performance.

Assessment of the Economic Efficiency of the Operation of Low-Emission and Zero-Emission Vehicles in Public Transport in the Countries of the Visegrad Group

Transport is one of the key sectors of the European economy. However, the intensive development of transport caused negative effects in the form of an increase in the emission of harmful substances. The particularly dramatic situation took place in the V4 countries. This made it necessary to implement solutions reducing emissions in transport, including passenger transport. Such activities can be implemented in the field of implementation of low-emission and zero-emission vehicles for use. That is why the European Union and the governments of the Visegrad Group countries have developed numerous recommendations, communications, laws, and strategies that order carriers to implement low- and zero-emission mobility. Therefore, transport organizers and communication operators faced the choice of the type of buses. From an economic point of view, each entrepreneur is guided by the economic efficiency of the vehicles used. Hence, the main aim of the article was to conduct an economic evaluation of the operational efficiency of ecological vehicles. As more than 70% of vehicles in use in the European Union are still diesel driven, the economic efficiency assessment was also made for vehicles with traditional diesel drive. To conduct the research, the method of calculating the total cost of ownership of vehicles in operation was used. As a result of the research, it was found that electric buses are the cheapest in the entire period of use (15 years), and then those powered by CNG. On the other hand, the cost of using hydrogen buses is the highest. This is due to the high purchase prices of these vehicles. However, the EU, as well as the governments of individual countries, support enterprises and communication operators, by offering them financing for investments. The impact of the forecasted fuel and energy prices and the planned inflation on operating costs was also examined. In this case, the analyses showed that the forecasted changes in fuel and energy prices, as well as the expected inflation, will significantly affect the costs of vehicle operation and the economic efficiency of using various types of drives. These changes will have a positive impact on the implementation of zero-emission vehicles into exploitation. Based on the analyses, it was found that in 2035 hydrogen buses will have the lowest operating costs.

A Multidisciplinary Approach for the Mapping, Automatic Detection and Morphometric Analysis of Ancient Submerged Coastal Installations: The Case Study of the Ancient Aegina Harbour Complex

The documentation of underwater cultural heritage (UCH) is the basis for sustainable maritime development including its protection, preservation, and incorporation in coastal zone management plans. In this study, we present a multidisciplinary, non-intrusive downscale approach for the documentation of UCH implemented on the coastal area of Aegina Island, Greece, where a unique submerged harbour complex is preserved. This approach succeeded in obtaining information that serves both geomorphological and archaeological purposes in a time- and cost-effective way, while obtaining information of centimeters to millimeters scale. The geomorphology of the area was mapped in detail through marine geophysical means while ancient submerged conical rubble structures and breakwaters were documented using automatic seafloor segmentation techniques, revealing previously unknown sites of archaeological interest. The structures’ parameters were extracted from the acoustic data to analyze their morphometry, while photogrammetry was realized using a Remotely Operated Vehicle to expose their micro-structure. The spatial distribution of the structures revealed the construction of a well-planned harbour complex with multiple passages and different possible functionalities. Finally, through the structures’ morphometric analysis (geometry and terrain statistical parameters) their preservation status was revealed, demonstrating the anthropogenic impact on the submerged ancient structures due to the modern harbor activity.

Volcanic Structures and Magmatic Evolution of the Vesteris Seamount, Greenland Basin

The formation of isolated seamounts distant from active plate boundaries and mantle plumes remains unsolved. The solitary intraplate volcano Vesteris Seamount is located in the Central Greenland Basin and rises ∼3,000 m above the seafloor with a total eruptive volume of ∼800 km3. Here, we present a new high-resolution bathymetry of Vesteris Seamount and a detailed raster terrain analysis, distinguishing cones, irregular volcanic ridges, volcanic debris fans, U-shaped channels and lava flows. The slope angles, ruggedness index and slope direction were combined with backscatter images to aid geologic interpretation. The new data show that the entire structure is a northeast to southwest elongated stellar-shaped seamount with an elongated, narrow summit surrounded by irregular volcanic ridges, separated by volcanic debris fans. Whole-rock geochemical data of 78 lava samples form tight liquid lines of descent with MgO concentrations ranging from 12.6 to 0.1 wt%, implying that all lavas evolved from a similar parental magma composition. Video footage from Remotely Operated Vehicle (ROV) dives shows abundant pyroclastic and hyaloclastite deposits on the summit and on the upper flanks, whereas lavas are restricted to flank cones. The seamount likely formed above a weak zone of the lithosphere possibly related to initial rifting parallel to the nearby Mohns Ridge, but the local stress field increasingly affected the structure of the volcano as it grew larger. Thus, we conclude that the evolution of Vesteris Seamount reflects the transition from deep, regional lithospheric stresses in the older structures to shallower, local stresses within the younger volcanic structures similar to other oceanic intraplate volcanoes. Our study shows how the combination of bathymetric, visual and geochemical data can be used to decipher the geological evolution of oceanic intraplate volcanoes.

Prescribed performance based sliding mode path-following control of UVMS with flexible joints using extended state observer based sliding mode disturbance observer

The accuracy and stability of an underwater vehicle manipulator system (UVMS) are essential for performing underwater tasks. However, exogenous disturbance and unmodeled dynamics will lead to poor UVMS performance in terms of degraded transient behavior and large steady-state errors. In this paper, the path following problem with prescribed performance of a UVMS with flexible joints is addressed. First, a terminal sliding mode control scheme with prescribed performance is presented along with a novel extended state observer (ESO) based sliding mode disturbance observer (SMDO). The proposed controller simplifies the parameter tuning process by ensuring the predefined system behaviors of interest right after the design. Subsequently, a path following scheme is designed for the UVMS such that the position of both base vehicle and robot arms can converge to the specified path in 3-D space. Finally, numerical simulations and comparisons are conducted to show the effectiveness of the proposed method in terms of trajectory tracking in the presence of environmental disturbances and modeling uncertainties.

Cost-Effective Remote Operated Vehicle

Remote operated vehicles (ROVs) are robotic submersibles controlled typically by a person at the surface of a water body. ROVs can be applied to surveillance, environmental, and data recording jobs or tasks. The vehicle design may be modified to remove or add additional capabilities depending upon the specific purpose of the ROV. In this paper, we explore using remote operated vehicles as a cheap and affordable water exploration platform. ROV’s high cost is a prohibitive barrier to entry, preventing widespread adoption of ROV for personal, research, and conservation uses. To address this problem, our paper explores a cost effective ROV with video capturing and directional control capabilities. Using state-of-the-art robotic technologies, a cost-effective competitive ROV is designed and constructed. This ROV was tested to a depth of 7 meters and has the potential to reach depths of up to 30 meters per its design.

Proposed Methodology to Quantify the Amount of Methane Seepage by Understanding the Correlation Between Methane Plumes and Originating Seeps

In recent years, discoveries of methane plumes (also called methane flares) have been reported in various sea areas around the world. Clusters of naturally seeping methane bubbles rising from the seafloor are visualized as methane plumes on the echograms of quantitative echo sounders and multibeam sonars. In order to determine if seeping methane can be used as energy resources and its environmental impact, it is necessary to estimate the amount of naturally seeping methane. From April, 2020, a 3-year project is being conducted in Japan to evaluate the amount of methane seepage from methane plumes. The authors propose the following steps to quantify the amount of methane seepage accurately. First of all, methane plumes in the Exclusive Economic Zone (EEZ) of Japan are mapped out using acoustic devices such as quantitative echo sounders and multibeam sonars. Secondly, methane bubbles of a few millimeters in diameter from methane seeps at seafloor are collected and sampled using a cone-shaped collector with 20 cm in diameter, operated by Remotely Operated Vehicle (ROV). If we can identify the number of seep mouths that form into one single plume, we will be able to quantify the methane seepage from one plume. Based on this result, calibration of the mean backscattering strength and the amount of seeping methane from methane plumes becomes possible and will be applied to the mapped plumes in order to estimate the methane seepage in the EEZ of Japan. Once this calibration is established, it can be applied to the methane plumes observed worldwide, and methane seepage can be quantified simply by acoustic observations of methane plumes. In this study, a method to verify the correlation between methane plumes and methane seeps is introduced, as well as a method to locate methane seeps effectively using the Target Position function of a quantitative echo sounder. The authors intend to use this as the basic data for establishing a method to estimate the amount of methane released from a methane plume by observing the methane plume acoustically.

The Discovery and Preliminary Geological and Faunal Descriptions of Three New Steinahóll Vent Sites, Reykjanes Ridge, Iceland

During RVMS Merianexpedition MSM75, an international, multidisciplinary team explored the Reykjanes Ridge from June to August 2018. The first area of study, Steinahóll (150–350 m depth), was chosen based on previous seismic data indicating hydrothermal activity. The sampling strategy included ship- and AUV-mounted multibeam surveys, Remotely Operated Vehicle (ROV), Epibenthic Sledge (EBS), and van Veen grab (vV) deployments. Upon returning to Steinahóll during the final days of MSM75, hydrothermal vent sites were discovered using the ROV Phoca (Kiel, GEOMAR). Here we describe and name three new, distinct hydrothermal vent site vulnerable marine ecosystems (VMEs); Hafgufa, Stökkull, Lyngbakr. The hydrothermal vent sites consisted of multiple anhydrite chimneys with large quantities of bacterial mats visible. The largest of the three sites (Hafgufa) was mapped, and reconstructed in 3D. In total 23,310 individual biological specimens were sampled comprising 41 higher taxa. Unique fauna located in the hydrothermally venting areas included two putative new species of harpacticoid copepod (Tisbesp. nov. andAmphiascussp. nov.), as well as the spongeLycopodina cupressiformis(Carter, 1874). Capitellidae Grube, 1862 and Dorvilleidae Chamberlin, 1919 families dominated hydrothermally influenced samples for polychaetes. Around the hydrothermally influenced sites we observed a notable lack of megafauna, with only a few species being present. While we observed hydrothermal associations, the overall species composition is very similar to that seen at other shallow water vent sites in the north of Iceland, such as the Mohns Ridge vent fields, particularly with peracarid crustaceans. We therefore conclude the community overall reflects the usual “background” fauna of Iceland rather than consisting of “vent endemic” communities as is observed in deeper vent systems, with a few opportunistic species capable of utilizing this specialist environment.