Automatic Path Research Articles

CAD-based automatic path generation and optimization for laser cladding robot in additive manufacturing

Additive manufacturing technology (AMT) is a topic that is of considerable ongoing interest. The application of robots enhances the flexibility and intelligibility of the AMT. However, the traditional robot teaching programming method is tedious and complicated, which is one of the key challenges for developing a robot AMT technique. This paper proposes a new robot programming method based on the computer-aided design (CAD). Firstly, the geometry information of the CAD model is extracted in accordance to the stereo lithography (STL) data format. Secondly, the CAD topological structure is established based on the edge topological information. On the premise of guaranteeing the model precision, the CAD model error is analyzed. The particle swarm optimization (PSO) method is applied to raise the efficiency of the process.Finally, the robot path is automatically generated layer-by-layer from the CAD model and the proposed method is validated by an experiment of cladding a blade. The experiment result shows that the CAD-based automatic path generation and optimization for laser cladding robot is of higher efficiency and better accuracy than the ones with the robot teaching programming method.

Automatic Path Planning of Industrial Robots Comparing Sampling-based and Computational Intelligence Methods

In times of industry 4.0 a production facility should be “smart”. One result of that property could be that it is easier to reconfigure plants for different products which is, in times of a high rate of variant diversity, a very important point. Nowadays in typical robot based plants, a huge part of time from the commissioning process is needed for the programming of collision free paths. This mainly includes the teach-in or offline programming (OLP) and the optimization of the paths. To speed up this process significantly, an automatic and intelligent planning system is necessary. In this work we present a system which can plan paths for industrial robots. We compare widely used sampling-based methods like PRM or RRT with Computational Intelligence (CI) based methods like genetic algorithms.

Automatic Path Tracking and Target Manipulation of a Magnetic Microrobot.

Recently, wireless controlled microrobots have been studied because of their great development prospects in the biomedical field. Electromagnetic microrobots have the advantages of control agility and good precision, and thus, have received much attention. Most of the control methods for controlling a magnetic microrobot use manual operation. Compared to the manual method, the automatic method will increase the accuracy and stability of locomotion and manipulation of microrobots. In this paper, we propose an electromagnetic manipulation system for automatically controlling the locomotion and manipulation of microrobots. The microrobot can be automatically controlled to track various paths by using visual feedback with an expert control algorithm. A positioning accuracy test determined that the position error ranges from 92 to 293 μm, which is less than the body size (600 μm) of the microrobot. The velocity of the microrobot is nearly proportional to the applied current in the coils, and can reach 5 mm/s. As a micromanipulation tool, the microrobot is used to manipulate microspheres and microgears with the automatic control method. The results verify that the microrobot can drag, place, and drive the microstructures automatically with high precision. The microrobot is expected to be a delicate micromachine that could play its role in microfluidics and blood vessels, where conventional instruments are hard to reach.

Step Ring-Based Three-Dimensional Path Planning Via Graphics Processing Unit Simulation for Subtractive Three-Dimensional Printing

In this paper, both software model visualization with path simulation and associated machining product are produced based on the step ring-based three-axis path planning to demo model-driven graphics processing unit (GPU) feature in tool path planning and 3D image model classification by GPU simulation. Subtractive 3D printing (i.e., 3D machining) is represented as integration between 3D printing modeling and computer numerical control (CNC) machining via GPU simulated software. Path planning is applied through visualization of surface material removal in high-resolution and 3D path simulation via ring selective path planning based on accessibility of path through pattern selection. First, the step ring selects critical features to reconstruct computer-aided design (CAD) design model as stereolithography (STL) voxel, and then, local optimization is attained within interested ring area for time and energy saving of GPU volume generation as compared to global automatic path planning with longer latency. The reconstructed CAD model comes from an original sample (GATech buzz) with 2D image information. CAD model for optimization and validation is adopted to sustain manufacturing reproduction based on system simulation feedback. To avoid collision with the produced path from retraction path, we pick adaptive ring path generation and prediction in each planning iteration, which may also minimize material removal. Moreover, we did partition analysis and G-code optimization for large-scale model and high density volume data. Image classification and grid analysis based on adaptive 3D tree depth are proposed for multilevel set partition of the model to define no cutting zones. After that, accessibility map is computed based on accessibility space for rotational angular space of path orientation to compare step ring-based pass planning verses global path planning of all geometries. Feature analysis via central processing unit (CPU) or GPU processor for GPU map computation contributes to high-performance computing and cloud computing potential through parallel computing application of subtractive 3D printing in the future.

THE PRIORITY OF INTERNATIONAL FREIGHT EXPRESSES IN THE OVERLAPPING SECTION OF RFC 7 AND RFC 9 KOLÍN - CESKA TREBOVA

This article deals with the railway traffic control and railway traffic equipment in terms of implementation of TSI. The main goal is to research the optimal priority of international freight expresses, especially in the overlapping sections, which represent critical line sections of European freight corridors. This article shows this problem in the context in the overlapping section of RFC 7 and RFC 9 Kolín – Ceská Trebová. There are mentioned possibilities of using of ETCS and implementation of automatic train paths.

Environment Detection and Path Planning Using the E-puck Robot

Automatic path planning is one of the most challenging problems confronted by autonomous robots. Generating optimal paths for autonomous robots are some of the heavily studied subjects in mobile robotics applications. This paper documents the implementation of a path planning project using a mobile robot in a structured environment. The environment is detected through a camera and then a roadmap of the environment is built using some algorithms. Finally a graph search algorithm called A* is implemented that searches through the roadmap and finds an optimal path for robot to move from start position to goal position avoiding obstacles

Adaptive sensitivity decision based path planning algorithm for unmanned aerial vehicle with improved particle swarm optimization

Automatic path planning is an essential aspect of unmanned aerial vehicle (UAV) autonomy. This paper presents a three dimensional path planning algorithm based on adaptive sensitivity decision operator combined with particle swarm optimization (PSO) technique. In the proposed method, an adaptive sensitivity decision area is constructed to overcome the defects of local optimal and slow convergence. By using this specified area, the potential particle locations with high probabilities are determined and other candidates are deleted to improve computational capacity. Then the searching space of particles is constrained in a limited boundary to avoid premature state. In addition, the searching accuracy is enhanced by the relative particle directivity from current location. The objective function is redesigned by taking into account the distance to destination and UAV self-constraints. To evaluate the path length, the paired-sample T-Test is performed and the straight line rate (SLR) index is introduced. In the two scenarios applied in this paper, our proposed method is 35.4%, 21.6% and 49.5% better compared with other three tested optimization algorithms in the path cost on average. Correspondingly it is 9.6%, 12.8%, and 25.3% better in SLR, which is capable of generating higher quality paths efficiently for UAVs.

An Efficient Way to Optimize Bandwidth using Dedicated Path Protection for Sonet/SDH Network

SONET stands for synchronous optical network which is a time-division multiplexing process (TDMA) for providing bandwidth Services for the end users which works at application level. High Speed data communication and telecommunication traffic are handled with the use of time division technology. For providing efficient high capacity networks required by telecommunication and data services the SONET/SDH standard is used since it uses TDMA for bandwidth services. The Service providers are looking forward to find automatic ways of commissioning the channels associated with the SONET/SDH since manual provisioning is not possible due to high bandwidth requirement. Another thing which is most important is to cover the protection of the optical network in case of failure of any path used for data transfer. An Automatic Path protection algorithm is implemented and moreover analyzed. The algorithm is works for LCAS, VCAT like issues. The Dedicated and shared path protection mechanism has been used for the efficient use of the SONET/SDH network. In this research the basic parameters like probability error, QOS of network, Accepted request and Rejected request have been analyzed by our algorithm. We also investigated the Bandwidth constraint. Using proposed algorithm we have improved the bandwidth utilization.

Process Simulation and Automatic Path Planning of Adhesive Joining

Adhesive joining is frequently used in the automotive industry. In the pursuit of reducing weight, adhesive joining is important due to the possibility of joining different types of materials. The process is often automatised in order to reduce cycle time. In this paper we aim to present a novel framework that includes detailed process simulation and automatic generation of collision free robot paths and in this way improve the quality of the joint and reduce both cycle time and processing time. To verify the simulations, the properties of the adhesive bead have been compared to experiments with good agreement.

Parallel genetic algorithm based automatic path planning for crane lifting in complex environments

Abstract Heavy lifting is a common and important task in industrial plants. It is conducted frequently during the time of plant construction, maintenance shutdown and new equipment installation. To find a safe and cost effective way of lifting, a team works for weeks or even months doing site investigation, planning and evaluations. This paper considers the lifting path planning problem for terrain cranes in complex environments. The lifting path planning problem takes inputs such as the plant environment, crane mechanical data, crane position, start and end lifting configurations to generate the optimal lifting path by evaluating costs and safety risks. We formulate the crane lifting path planning as a multi-objective nonlinear integer optimization problem with implicit constraints. It aims to optimize the energy cost, time cost and human operation conformity of the lifting path under constraints of collision avoidance and operational limitations. To solve the optimization problem, we design a Master–Slave Parallel Genetic Algorithm and implement the algorithm on Graphics Processing Units using CUDA programming. In order to handle complex plants, we propose a collision detection strategy using hybrid configuration spaces based on an image-based collision detection algorithm. The results show that the method can efficiently generate high quality lifting paths in complex environments.

Automatic path planning for an unmanned drone with constrained flight dynamics

In the article we solve path planning task for an agent being multirotor unmanned aerial vehicle (multicopter). We propose an approach of estimating path geometry constraints based on UAV flight dynamics model and control constraints. Than we introduce a new path finding method which takes into consideration those geometry constraints and study this method both theoretically and empirically.

Desenvolvimento e Validação de Algoritmos para Emprego de Sensores na Soldagem Robótica Orbital do Passe de Raiz de Tubulações

Resumo Os sistemas comerciais destinados à automação da soldagem orbital enfrentam desafios perante o controle da trajetória e a parametrização do processo. Os tubos e dutos do setor de Petróleo e Gás apresentam descontinuidades, advindas de sua fabricação, críticas para o processo de soldagem. Para superar isto, o presente trabalho investiga a utilização de sensores para correção em tempo real da soldagem orbital. Um robô antropomórfico atua na condução da tocha. Um sensor a arco para seguimento de junta e um sensor baseado no contato elétrico para procura da junta foram empregados. Um programa em forma de algoritmos para geração de uma trajetória orbital automática e alocação dos parâmetros de soldagem foi desenvolvido. A validação da estratégia proposta e do controle da tocha pelo sensor a arco foi realizada com depósitos em corpos de prova de tubos. A soldagem do passe de raiz com um processo MIG/MAG com controle de corrente no curto-circuito também foi executada em conjunto com o sensor a arco.

Research on Path Optimization with PSO for Unmanned Vehicle

The development of autonomous unmanned vehicles is of high interest to many organizations around the world and path planning is the key point of the navigation for the autonomous unmanned vehicle. Intelligent algorithms have been applied in this field and an essential aspect of unmanned vehicles autonomy is the ability for automatic path planning. In this paper, particle swarm optimization algorithm as one of new swarm intelligent optimization methods is introduced into a path planning for autonomous vehicle, which is constructed of a particle representation methods for vehicle routing problem with fast convergence speed. The results show that the particle swarm optimization algorithm can obtain the solution of the vehicle routing problem quickly and effectively. It is a good method for solving the vehicle routing problem.

The Design and Research of the Smart Path Tracing Car Based on the Image Recognition

To realize the smart car's automatic path tracing along the different types of path, a smart path tracing car based on car model is developed. In the design of the smart path tracing car, image processing affects the smart car's per- formance directly. This article adopts direct acquisition, direct edge detection algorithm and the improved edge detection algorithm to analyze and compare the road message acquired by COMS camera. Plenty of experiment data show that, un- der different light intensity, the edge detection algorithm can acquire image with better accuracy and efficiency, solving the contradiction between the system's rapidity and stability, and realizing the smart car's running along the guide curve stably and rapidly.

Proposing Operational Technology Based Procedure (OTBP) using Round Robin Scheduling Algorithm (RRSA)

This paper presents a review along with the analysis of different types of cyber hacking attacks and proposes a new methodology for reducing the attacks during client-server communication by providing a secure channel. The designed methodology is termed as an “OTBP-Using RRSA” (Operational Technology Based Procedure-using Round Robin Scheduling Algorithm) and its working is based on the time of request entered on the search engine during clientserver communication. It may help to provide security by automatic path encryption during request movement towards web server by following auto-generated unique hash address approach. The paper also discusses two different types of path hacking; viz. on-path hacking and off-path hacking by following different mechanisms such as path based authorization; path based traversing and path based access rules etc.

A hierarchic approach for path planning in virtual reality

This work considers path-planning processes for manipulation tasks such as assembly, maintenance or disassembly in a virtual reality (VR) context. The approach consists in providing a collaborative system associating a user immersed in VR and an automatic path planning process. It is based on semantic, topological and geometric representations of the environment and the planning process is split in two phases: coarse and fine planning. The automatic planner suggests a path to the user and guides him trough a haptic device. The user can escape from the proposed solution if he wants to explore a possible better way. In this case, the interactive system detects the users intention and computes in real-time a new path starting from the users guess. Experiments illustrate the different aspects of the approach: multi-representation of the environment, path planning process, users intent prediction and control sharing.

Overarching Control of Flexi Grid Optical Networks: Interworking of GMPLS and OpenFlow Domains

Optical transport networks provide transport, multiplexing, routing, management, supervision, and survivability of optical channels. Within a flexible dense wavelength division multiplexing grid, the optical spectrum can be allocated in multiples of a width granularity, depending on the client signal rate and modulation format. A control plane (CP) can be used for efficient and dynamic provisioning and recovery of flexi-grid connections. Two main CP architectures coexist, with common functions like addressing, automatic topology discovery, network abstraction, path computation, and connection provisioning: a distributed generalized multiprotocol label switching CP (with optional path computation element, PCE path computation and instantiation/modification) and a CP based on software-defined networking, with a logically centralized controller and an open protocol, such as the OpenFlow protocol. Both architectures have their own strengths and weaknesses, and are being extended to address the new requirements associated with the aforementioned emerging optical technologies, such as flexible spectrum allocation, efficient corouted connection setup, and configuration of related optical parameters. However, new use cases such as remote data center interconnection highlight the need for multidomain service provisioning, and heterogeneous CP interworking, potentially requiring an overarching control. Different alternatives, with varying degrees of integration and flexibility, are available: straightforward approaches characterized by the adaptation of one control model to the other or more advanced interworking requiring the definition of common models (e.g., a subset of attributes for network elements) and of coordination and orchestration functions. This paper discusses the main relevant interworking architectures and presents a selected set of use cases and proof-of-concepts.

Automatic Impairment-aware Optical Path Switching in Multi-core Fiber Link Based on Multi-ring Structure

We developed a novel multicore fiber (MCF) link based on a multiring structure composed of field programmable gate array (FPGA)-based optical switching units for highly reliable networks. The switching algorithm implemented on the FPGA in the unit has five high-functioning processes capable of coping with multiple link failures in the network. To verify the operations of this MCF link, we experimentally demonstrated automatic impairment-aware optical path switching when a failure occurred in an MCF link based on a two-ring structure. We were able to perform path recovery by switching within a relatively short period of time, 7.6 ms, which is sufficiently less than that required by ITU-T. The restoration path that substitutes for the failed working path was also optimized for low-loss transmissions by selecting the path having the minimum number of units through which a signal passes. These results indicate that the link will be useful for optical network designs that simultaneously need to ensure high capacity and reliable transmissions in businesses such as data centers.

An interactive motion planning framework that can learn from experience

The accessibility verification of the assembly/disassembly plays an important role in the process of product design. In the last decade, the sampling based motion planners have been successfully applied to solve the accessibility verification. However, the narrow passage which is a common problem in the assembly tasks is still a bottleneck. Meanwhile, the requirement of perception and emotion assessment drives the interaction between users and automatic path planners in the virtual assembly process. In this paper, a curve matching method is used to explore the implicit relationship between the topological information of scenarios and the motion of objects, based on which an interactive motion planning framework that can learn from experience is constructed.Our framework consists of two main processes: a learning process and a motion generation process. In the former process, the motion segment (a part of motion path) and its related scenario segment (a part of workspace passed through by the object) are gathered, after an interactive motion planning process finds a collision-free motion path or reaches the conclusion of inaccessibility. According to the similarity between the skeletons of scenario segments, the gathered scenario segments and motion segments are organized by a hierarchical structure in the motion library. The latter process permits users to control only one point in the workspace for the selection of a new scenario, and then the similar scenarios are retrieved from the motion library, to help quickly detect the connectivity of the new scenario and generate a repaired motion path to guide users with feasible manipulations. We highlight the performance of our framework on a challenging problem in 2D, in which a non-convex object passes through a cluttered environment filled with randomly shaped and located non-convex obstacles.

The Role of the Helicopter Pilot in Terms of Relevant Requirements for Helicopter Takeoff

Currently, the German Aerospace Center performs research on assistance systems for helicopters that help pilots to perform their missions even in bad weather conditions. One part of the assistance system is the navigation system with automatic flight path planning. The objective of this article is to clarify if pilots perform the planning of flight paths in the same way. An interview with 68 participants was conducted to evaluate essential differences between the pilots’ cognitive processes and build a basis for the user-centered design of the navigation system. The interview assessed user-specific requirements that can be used as input for the path planning algorithms. The results recommend the usage of individual pilot requirements for path planning applications. With individually adjusted navigation systems, the potential mismatch between pilots’ expectations and the actually computed flight paths is expected to be minimized.