Automatic Collision Avoidance Research Articles

Fast Path Planning for Autonomous Ships in Restricted Waters

Presently, there is increasing interest in autonomous ships to reduce human errors and support intelligent navigation, where automatic collision avoidance and path planning is a key problem, especially in restricted waters. To solve this problem, a path-guided hybrid artificial potential field (PGHAPF) method is first proposed in this paper. It is essentially a reactive path-planning algorithm that provides fast feedback in a changeable environment, including dynamic target ships (TSs) and static obstacles, for steering an autonomous ship safely. The proposed strategy, which is a fusion of the potential field and gradient methods, consists of potential-based path planning for arbitrary static obstacles, gradient-based decision-making for dynamic TSs, and their combination with consideration of the prior path and waypoint selection optimization. A three-degree-of-freedom dynamic model of a Mariner class vessel and a low-level controller have been incorporated together in this method to ensure that the vessel’s positions are updated at each time step in order to acquire a more applicable and reliable trajectory. Simulations show that the PGHAPF method has the potential to rapidly generate adaptive, collision-free and International Regulations for Preventing Collisions at Sea (COLREGS)-constrained trajectories in restricted waters by deterministic calculations. Furthermore, this method has the potential to perform path planning on an electronic chart platform and to overcome some drawbacks of traditional artificial potential field (APF) methods.

Design of an Automatic Collision Avoidance System for Ships Based on Wireless Sensor Network

The system designed is a ship collision avoidance system based on consistent use of satellite positioning technology, spread spectrum communication technology and a wireless sensor network. The system design includes: an information collecting terminal, a data processing terminal and a mobile data terminal as the three main parts. CC2530 is selected as the master chip for the information collecting terminal, and the GPS module with NEO-6M UBLOX satellite positioning function is used to obtain the latitude, longitude, heading and other information. The AS62-T30 wireless communication module is used to realize the data interaction between ships, and a 0.96-inch OLED display module is used to show the current location of the ship, thus realizing the GPS positioning data receiving, data analysis, information display, data integration and transmission, and other functions. In terms of the software in the data processing terminal, QT5 is selected as the development environment, and QtSql as the database to process and store the data packet sent by the information collecting terminal. The system has many functions including real-time data analysis and alarm, real-time location annotation, track query, route planning and weather forecasting, etc.

A constant guidance law-based collision avoidance for unmanned aerial vehicles

A method of automatic collision avoidance based on constant guidance law is proposed to solve the problem that the collision avoidance time is difficult to be estimated accurately during the collision avoidance process. The guidance command of the collision avoidance method is constant, and the lower bound of the constant guidance command satisfying the safe collision avoidance requirement is given by geometric method. Then, a collision avoidance time estimation method based on particle swarm optimization is proposed. In addition, the attitude control loop adopts the nonlinear proportional-integral-derivative based on tracking-differentiator, and the sufficient conditions for the system stability are given using the T-passive method. The simulation results show that the collision avoidance time estimation error is small and the maneuvering range of collision avoidance is smaller than the collision avoidance method based on proportional guidance and nonlinear dynamic inverse guidance. This method can achieve collision avoidance under the influence of wind disturbance and safety distance abrupt change.

Study on Automatic Collision Avoidance System in Autonomous Vehicle

Study on Automatic Collision Avoidance System in Autonomous Vehicle

Automatic collision avoidance system for four-wheel independent drive vehicle by state-dependent Riccati equation

Automatic collision avoidance system for four-wheel independent drive vehicle by state-dependent Riccati equation

Neural-Learning-Based Telerobot Control With Guaranteed Performance.

In this paper, a neural networks (NNs) enhanced telerobot control system is designed and tested on a Baxter robot. Guaranteed performance of the telerobot control system is achieved at both kinematic and dynamic levels. At kinematic level, automatic collision avoidance is achieved by the control design at the kinematic level exploiting the joint space redundancy, thus the human operator would be able to only concentrate on motion of robot's end-effector without concern on possible collision. A posture restoration scheme is also integrated based on a simulated parallel system to enable the manipulator restore back to the natural posture in the absence of obstacles. At dynamic level, adaptive control using radial basis function NNs is developed to compensate for the effect caused by the internal and external uncertainties, e.g., unknown payload. Both the steady state and the transient performance are guaranteed to satisfy a prescribed performance requirement. Comparative experiments have been performed to test the effectiveness and to demonstrate the guaranteed performance of the proposed methods.

A review of essential technologies for collision avoidance assistance systems

Compared with automatic collision avoidance systems, collision avoidance assistance systems have attracted more research interest because they help avoid collisions in near-accident situations. However, ensuring the robustness and reliability of collision avoidance assistances is difficult because of problems in reliable environment recognition, accurate collision avoidance decision making, and driver acceptance. This article reviews and analyzes three essential technologies for collision avoidance assistance systems in intelligent environment-friendly vehicles. The architecture of the human-in-loop system is summarized, and available environment recognition methods used in collision avoidance assistances are compared. Moreover, the characteristics of path planning and collision avoidance decision making applied in emergency collision avoidance assistance systems are reviewed, and the advantages of applying haptic share control and yaw moment active intervention during path tracking are analyzed. The emer...

On-board model-based automatic collision avoidance: application in remotely-piloted unmanned aerial vehicles

This paper focuses on real-world implementation and verification of a local, model-based stochastic automatic collision avoidance algorithm, with application in remotely-piloted (tele-operated) unmanned aerial vehicles (UAVs). Automatic collision detection and avoidance for tele-operated UAVs can reduce the workload of pilots to allow them to focus on the task at hand, such as searching for victims in a search and rescue scenario following a natural disaster. The proposed algorithm takes the pilot's input and exploits the robot's dynamics to predict the robot's trajectory for determining whether a collision will occur. Using on-board sensors for obstacle detection, if a collision is imminent, the algorithm modifies the pilot's input to avoid the collision while attempting to maintain the pilot's intent. The algorithm is implemented using a low-cost on-board computer, flight-control system, and a two-dimensional laser illuminated detection and ranging sensor for obstacle detection along the trajectory of the robot. The sensor data is processed using a split-and-merge segmentation algorithm and an approximate Minkowski difference. Results from flight tests demonstrate the algorithm's capabilities for tele-operated collision-free control of an experimental UAV.

Automatic Collision Avoidance System in Electric Vehicle with Independently Driven Four Wheels Considering Vehicle Velocity

Automatic Collision Avoidance System in Electric Vehicle with Independently Driven Four Wheels Considering Vehicle Velocity

Strategies for Pre-Emptive Mid-Air Collision Avoidance in Budgerigars.

We have investigated how birds avoid mid-air collisions during head-on encounters. Trajectories of birds flying towards each other in a tunnel were recorded using high speed video cameras. Analysis and modelling of the data suggest two simple strategies for collision avoidance: (a) each bird veers to its right and (b) each bird changes its altitude relative to the other bird according to a preset preference. Both strategies suggest simple rules by which collisions can be avoided in head-on encounters by two agents, be they animals or machines. The findings are potentially applicable to the design of guidance algorithms for automated collision avoidance on aircraft.

The combination of analytical and statistical method to define polygonal ship domain and reflect human experiences in estimating dangerous area

The paper suggests a new method of collision avoidance stemming from the concept of the polygonal target ship domain. Since the last century, we have witnessed the current typical ship domains classified and described. In this proposition, firstly, the domain is a geometrical manner which is used in both analytical and statistical method, resulting in the signification of practical application and simulation. Secondly, such domain will be applied to target ship under the combination of two separated parts: “Blocking area” and “Action area” in order to define the area where the ship must keep outside and how the actions to avoid collision can be generated. Thirdly, the concept has suggested the number of mathematical models for different approaching encounters, including head-on, overtaking and crossing situation. Finally, the parameters of turning circle of the ship can be proposed in determining the size of the domain. Statistical evidences indicate that this method reflects a crew's real habit and psychological in maneuvering. As the result, simple domain is shaped like imagination of sailors, but more accurate in calculating boundary. It promises an effective solution for automatic collision avoidance method. The next researches of this paper have achieved positive results in finding shortest route for avoiding collision. Moreover, while using statistical methods, classical researches face a serious problem in a wide application with different areas, this concept can make up a beneficial solution for the popular application. The numerous ship domains which are in previous researches will be carried out to compare and point out the simplification and effectiveness of the new method in practice.

Trust of an Automatic Ground Collision Avoidance Technology: A Fighter Pilot Perspective

The present study examined the antecedents of trust among operational Air Force fighter pilots for an automatic ground collision avoidance technology. This technology offered a platform with high face validity for studying trust in automation because it is an automatic system currently being used in operations by the Air Force. Pilots (N = 142) responded to an online survey which asked about their attitudes toward the technology and assessed a number of psychological factors. Consistent with prior research on trust in automation, a number of trust antecedents were identified which corresponded to human factors, learned trust factors, and situational factors. Implications for the introduction of novel automatic systems into the military are discussed.

Multi-point Clamping with Automatic Collision Avoidance for Aircraft Structural Parts Machining

In order to solve the problem of machining motion collision between cutter and fixtures, a multi-point clamping system with automatic collision avoidance is proposed for aircraft structural parts. The system is developed in consideration of part localization and modular clamping functions, and independent of CNC machine tools for the convenience of application. And then, a model-based collision detecting algorithm is designed, which can be implemented by comparing the cutter's actual position extracted by ultrasonic sensors, and the calibrated positions of clamping points. Finally, a modular fixture system with automatic collision avoidance was manufactured and tested. From machining experiments, it indicates that the proposed fixture system can be highly efficient and very flexible to meet the aircraft structural parts machining requirements.

AISデータを用いた避航操船の行動分析に基づく衝突危険度評価

Developments of autonomous ships are progressed in the world and algorithms for automatic collision avoidance or its decision support are widely required. Following factors are essential for the algorithm such as, selection of a target ship to avoid collision risks; determination of a start time of collision avoidance manoeuvre; and determination of a way to avoid the target ship. Authors analysed collision avoidance cases of a coastal sea area, which are extracted from an AIS database. The four moments during the collision avoidance manoeuvre, e.g. start time of collision avoidance, is identified with the AIS database. Then, conditions of a give-way and a stand-on ships at the moments are analysed by behaviour analysis. In this paper, the conditions at the start time of collision avoidance manoeuvre is focused. As the result, it is found that the condition at the start time is expressed by a simple equation composed of two parameters: the distance to the give-way and the stand-on ships; and the rate of change in relative bearing to the stand-on ship. Additionally, an assessment diagram to evaluate the collision risk is developed.

A Reactive COLREGs-Compliant Navigation Strategy for Autonomous Maritime Navigation

Abstract: This paper reports the development of an automatic collision avoidance technique for unmanned marine vessel incorporating standard collision regulations or COLREGs, defined by the International Maritime Organisation. Like any ship, all unmanned vessels must adhere to COLREGs at all times in order to minimise or eliminate the risk of collisions. The proposed approach is essentially a reactive path planning algorithm based on a modified well known Artificial Potential Fields (APF) framework. It is shown through simulations that the proposed strategy is able to generate COLREGs-compliant trajectories in the presence of both stationary and dynamic obstacles. Rules 13, 14 and 15 of the COLREGs, which apply to the overtaking, head-on and crossing scenarios respectively, are simulated for multiple dynamic vessels in an environment inclusive of land features.

Automatic collision avoidance in PowerINSPECT

The 2015 version of PowerINSPECT, the world’s leading hardware-independent metrology software, includes automatic collision avoidance, faster import of large CAD files, quicker preparation of longer inspection reports, and improved display of results from point-cloud data, plus many other customer-requested enhancements.

Generation of safe tool-path for 2.5D milling/drilling machine-tool using 3D ToF sensor

The complexity of multi-axis, milling and drilling CNC machines and the demand of high precision for complex parts production increase the importance of safe and efficient tool-paths generation during manufacturing. In these machines, multi-tool working in the same area, or static un-programed machine elements, such as fixtures, another work-part may cause collision problems. It is important to know the collision risks in advance during production in order to avoid unexpected production stops, and machinery damage. This research study is focusing on automatic collision detection and avoidance for safe non-functional (rapid) tool-path generation in a static 2.5D milling or drilling machining environment, as an initial step toward complex, dynamic multi-axis machine-tool manufacturing. A 3D vision based Time of Flight (ToF) sensor provides the depth information about the manufacturing scene that are exploited by the method presented for taking an effective decision to automatically detect and avoid collisions in order to achieve safe tool-path during production. The concept presented opens up new areas for research and application of ToF camera in a CNC manufacturing environment for tool-path planning. The results obtained are for traversal safe tool-paths in a static environment, which will be adapted to more complex and dynamic real machining scenarios by integrating it with STEP-NC technology in future.

The Research of Ship ACA Actions at Different Stages on Head-On Situation Based on CRI and COLREGS

He, Y.; Huang, L.; Xiong, Y., and Hu,W., 2015. The research of ship ACA actions at different stages on head-on situation based on CRI and COLREGS.In order to study the Automatic Collision-Avoidance (ACA) actions of vessels in head-on situation in accordance with rules of International Regulation for Preventing Collision at Sea (COLREGS 72) and ordinary practice of seaman, stags of vessel's meeting process were separated by Collision Risk Index (CRI) and Time to Immediate Danger (TID). The reason to correct Collision-Avoidance (CA) actions at different stages are different. CRI and TID were derived from defined Situation Elements (SE) in head -on situation. Then computing models of them and ACA actions at different stages were presented. The basis of this research is the center moved ship's elliptical domain theories and MMG three-free dimensional digital model which is calculated by ship's hydrodynamic equations. The following is proved by simulations: The mathematic models presented ensure rapid and reliable convergence of SE computing; new CRI model is much more in line with the thinking process of navigators and practice at sea than before; ACA actions in accordance with COLREGS rules and ordinary practice of seaman, can be produced by program. The research may make big improvement to the final achievement of ACA of ship in head-on situation.

An Automatic Collision Avoidance System Based on LiDAR

For vehicle-borne LiDAR, a mathematical model is built for the computation and reconstruction of laser point cloud with the scanning data, GPS data and IMU data. 3D point cloud of the road and the scenery on the both sides of the road is obtained. Then according to the trajectory of the vehicle, 3D roaming for the scenery on the both sides of the road is realized using OpenGL 3D engine technology. This technology provides a probably feasible way for anti-collision of vehicles and aircrafts when driven at night, in the heavy fog or flying between the mountains.

Research on Deep Sea Sonar in Marine Navigation of the Ship Anti Collision

in view of the current situation of ship has collision with sea mountain , design and develop the sonar of ship collision avoidance system based on PLC.its main purpose is to remind the crew in front of mountains and ship automatic collision avoidance. The design is based on the minimum distance of ship and mountain, put forward the system scheme: measure the two objects distance by sonar , using this system as the control core , the information is analyzed and calculated by this system. When the distance between ship and mountains is less than the minimum safe distance.so this system will alarm crews and as deceleration avoidance .