Development and Performance Measurement of an Affordable Unmanned Surface Vehicle (USV)

Indonesia is a maritime country that has vast coastal resources and biodiversity. To support the Indonesian maritime program, a topography mapping tool is needed. The ideal topography mapping tool is the Unmanned Surface Vehicle (USV). This paper proposes the design, manufacture, and development of an affordable autonomous USV. The USV which is composed of thruster and rudder is quite complicated to build. This study employs rudderless and double thrusters as the main actuators. PID compensator is utilized as the feedback control for the autonomous USV. Energy consumption is measured when the USV is in autonomous mode. The Dynamics model of USV was implemented to study the roll stability of the proposed USV. Open-source Mission Planner software was selected as the Ground Control Station (GCS) software. Performance tests were carried out by providing the USV with an autonomous mission to follow a specific trajectory. The results showed that the developed USV was able to complete autonomous mission with relatively small errors, making it suitable for underwater topography mapping.

Воздействие гармонического сигнала на генератор квазипериодических колебаний Анищенко-Астахова

A harmonic effect on a modified Anishchenko-Astakhov generator capable of demonstrating two-frequency quasi-periodic oscillations in the autonomous mode is considered. The possibility of doubling the three-frequency tori in a non-autonomous system is shown. The possibility of the effect of chaos suppression by an external signal is demonstrated, which leads not only to periodic, but also to quasi-periodic modes when the influence amplitude exceeds a certain threshold.

A route calculation for unmanned vessel

Рассматривается проблема определения маршрута движения безэкипажного судна с учетом жестких требований контроля положения и курса судна. Современные электронно-картографические навигационно-информационные системы в режиме управления траекторией определяют точку поворота для выхода на новый участок маршрута, что недостаточно для управления безэкипажным судном в автономном режиме. Для повышения точности предложено проводить расчет траектории движения безэкипажного судна в географических координатах c учетом движения судна по радиусу поворота между участками траектории без перевода в прямоугольную систему координат. Показано, что при движении в свободной акватории проблема может быть сведена к решению обратной геодезической задачи. Предложен универсальный алгоритм расчета траектории в виде сегментов дуг большого круга, позволяющий получить путевые точки маршрута с любой заданной точностью. В случае возникновения ограничений на движение между двумя участками по внутреннему радиусу необходимо рассчитать альтернативный маршрут обхода препятствия. Для данного случая предложен расчетный маневр, полученный на основе решения задачи Дубинса. Альтернативный маршрут формируется в виде последовательности криволинейных сегментов, соответствующих заданному радиусу поворота. Алгоритм расчета путевых точек позволяет получить траекторию обхода препятствия с любой степенью детализации. A route calculation problem for unmanned vessels is investigated according to the control position and course high requirements. Present day electronic chart display and information systems (ECDIS) operating on the track control regime provide wheel-of-point calculation to course changing. It is not enough to control unmanned ship on the route in the autonomous mode. To increase control precision a new route calculation routine is suggested. The routine provides route calculation in the geodesic coordinates without Cartesian reference system mapping. It is shown that in the empty water the routine can be reduced to an inverse survey computation. A universal route calculation algorithm providing great circle arc segmentation with any given accuracy is suggested. In the case of course changing restricted area, it is needed to calculate an alternate route for obstacle or collision avoidance. The algorithm of alternate route calculation based on Dubins problem solution is applied. The route is found as a sequence of great circle arcs according to the ship turn radius. The shown algorithm allows finding avoidance route waypoints with any given resolution.

Power quality mitigation and transient analysis in AC/DC hybrid microgrid for electric vehicle charging

The usage of electric vehicles (EV) increased in recent years as the vehicles design and performances are nearly similar to petrol vehicles. The main source of energy for EV is taken from the grid for charging. So, the penetration of EVs in alternating current (AC) grid creates more power quality issues like voltage sag, swell and harmonics in the current. This energy can also be produced from the renewable energy resources like photovoltaic (PV) power generation. This PV energy can also be used as direct current (DC) grid. The electric vehicle chargers which come with intelligent grid operation is considered as load in this paper. This paper is an attempt to discuss the penetration of EVs in AC/DC hybrid micro grid which causes the power quality problems, and the power quality problem is mitigated by using the unified power quality conditioner (UPQC). The results are analyzed for three cases and four scenarios which is based on the function of UPQC and the action of smart charger in grid connected as well as autonomous mode operation of the AC/DC micro grid when the load is considered as dynamic load. The simulation is carried out in MATLAB2017b environment

A Posture Recognition System to Track Drivers’ Activities While Driving

To improve traffic safety, different systems were invented to warn drivers when detecting a conflict. However, drivers may be already aware of such conflicts. In these cases, warning drivers may not effective and may lead drivers to not pay attention to warnings in the case of serious conflicts. The purpose of this study is to develop a novel posture recognition system to detect different driver activities while driving. If drivers are not braking or decelerating in the case of a conflict, they are alerted and notified about the conflict. The proposed system is based on a passive method for measuring bodypostures by using two force sensor arrays to inspect the pressure patterns exhibited in the driver’s seat and backrest. Different sensors' distributions were tested to find the most suitable distribution to improve the accuracy of the recognition. A virtual reality (VR) driving simulation was developed to test the accuracy of recognition in an immersive environment. Experiments were carried out to test the posture recognition accuracy in both realistic and VR settings. The results showed that the system could recognize different postures with high accuracy. Such a system can be used to alert drivers and disengage autonomous mode in the case of self-driving and autonomous vehicles when the situation unsafe.

Analyzing the Effect of Autonomous Ridehailing on Transit Ridership: Competitor or Desirable First-/Last-Mile Connection?

Ridehailing services (e.g., Uber or Lyft) may serve as a substitute or a complement—or some combination thereof—to transit. Automation as an emerging technology is expected to further complicate the current complex relationship between transit and ridehailing. This paper aims to explore how US commuters’ stated willingness to ride transit is influenced by the price of ridehailing services and whether the service is provided by an autonomous vehicle. To that end, a stated preference survey was launched around the US to ask 1,500 commuters how they would choose their commute mode from among choices including their current mode and other conventional modes as well as asking them to choose between their current mode and an autonomous mode. Using a joint stated and revealed preference dataset, a mixed logit model was developed and analyzed. The results show that ridehailing per se might not be a significant competitor to transit, especially if it is integrated with transit as a first-/last-mile service. The total share of transit (transit-only riders plus those who use transit in connection with first-/last-mile ridehailing) remains substantially flat as set against conventional ridehailing services, even if ridehailing fares decrease. On the other hand, when the ridehailing price is significantly reduced by automation, our analysis suggests a decline in total transit ridership and an increase in ridehailing, especially for solo ridehailing. Also, it was found that autonomous pooled ridehailing might not be as appealing to commuters as autonomous solo ridehailing.

Aspects Regarding the Design, Practical Realization and Implementation of a Functional Prototype of Wheeled Minirobot for Engineering Reconnaissance

For this scientific paper, a study was carried out on communication railways in order to identify potential threats that could hinder the achievement of the objectives of a national or international mission and the modalities to counter the respective threats by using a remote-controlled robotic technological product or operating in autonomous mode [1]. The paper is divided into four chapters. The first chapter presents the engineering reconnaissance syntagm, its importance in the military field and the importance of implementing robotic technologies in such actions. In the second chapter deals with the actual making of the prototype, taking into account the established hypotheses and operational objectives. The third chapter describes the real field simulation of the designed and constructed prototype to confirm its usefulness on the battlefield and to convince as many military structures as possible to implement/integrate it with the troops and the fourth chapter describes the conclusions and proposal.

Improved control of energy consumption by a photovoltaic system equipped with a storage device to meet the needs of a local facility

+This paper has considered improving the management of energy consumption by a photovoltaic system with a storage device for a local object connected to the network. The aim of the study is to reduce expenditures when paying for electricity consumed from the network, when loading an object, independent of the time of year, and to eliminate energy generation to the grid. An energy generation control algorithm has been improved whereby the state of battery charge during the day is based on a forecast. That could reduce electricity consumption at night with better utilization of rechargeable battery and photovoltaic battery power during the day. It is proposed to use autonomous operation by disconnecting from the network during peak tariff hours and during the day with enough energy generation by a photovoltaic battery. This would ensure the normal functioning of an object in the event of a possible deterioration in the quality of voltage in the network while reducing the loss of energy in the inverter. Predictive control of the expected battery charge at the next checkpoint (at 0.5 hours or less between control points) has been proposed. A control system structure has been developed whereby a rechargeable battery current is set depending on an operational mode, the tariff zone, and the projected generation by a photovoltaic battery while reducing the modulation frequency under an autonomous mode. In this case, the modes are switched and the structure is changed taking into consideration the state of battery charge. Simulation in the daily cycle has shown the possibility of reducing the cost of electricity consumed from the network by 1.7‒8 times at two or three tariff rates. Simulation of electromagnetic processes in the system confirms acceptable regulation indicators when switching the structure, as well as a decrease in the energy loss in an inverter under an autonomous mode by up to 40 %