Trajectory Planning

This paper addresses the solution of smooth trajectory planning for industrial robots in environments with obstacles using a direct method, creating the trajectory gradually as the robot moves. The method presented deals with the uncertainties associated with the lack of knowledge of kinematic properties of intermediate via-points since they are generated as the algorithm evolves looking for the solution. Several cost functions are also proposed, which use the time that has been calculated, to guide the robot motion. The method has been applied successfully to a PUMA 560 robot and four operational parameters (execution time, computational time, distance travelled and number of configurations) have been computed to study the properties and influence of each cost function on the trajectory obtained.

The authors discuss the overall structural design of a self-contained hydraulic six-legged machine, called MECANT I, which has been constructed for studying possible applications of legged vehicles in natural environments, like forests. First, the main mechanical solutions and control hardware of the machine are presented. The systematic approach to the motion planning of a legged vehicle and some algorithmical features are discussed. The special features of the leg control are presented. The use of a simulator in the design work is discussed, and the main principles of the control software structure, which supports fast software design and testing, are presented. Some continuing research topics and the present situation are discussed

We consider planning and control problems for underactuated manipulators, a special instance of mechanical systems having fewer input commands than degrees of freedom. This class includes robots with passive joints, elastic joints, or flexible links. Structural control properties are investigated, showing that manipulators with passive joints in the absence of gravity are the most difficult to control. With reference to

—This paper presents a B-spline based path planning approach for agricultural guidance applications which is able to handle successively generated trajectories. Additionally, the lateral controller which was used to calculate the steering angle is described and the method by which the required parameters were determined is introduced. We explain stepwise how the output of a perception system is used to determine the control points for the planner and why B-splines and Bézier curves are used to model the trajectory. Moreover, it is shown how the inputs for the path tracker are derived from the B-splines. The approach was implemented on two different farm machines where the performance of the planning and control approach were evaluated. Furthermore, both algorithms were used to build a windrow guidance demonstrator.

The goal of adaptive sampling in the ocean is to predict the types and locations of additional ocean measurements that would be most useful to collect. Quantitatively, what is most useful is defined by an objective function and the goal is then to optimize this objective under the constraints of the available observing network. Examples of objectives are better oceanic understanding, to improve forecast quality, or to sample regions of high interest. This work provides a new path-planning scheme for the adaptive sampling problem. We ...

In this study, the method of direct-motion parallel parking is introduced both in theory and in simulations for the vehicle with and without a trailer. The results show that not only a vehicle with a trailer park in parallel using direct motion, but also a vehicle with a trailer park in parallel in direct motion after the final value of the orientation angle is satisfied. Simulation results are given to verify the effectiveness of the proposed method.

Paper videos can be reached from this URL: http://www.youtube.com/playlist?list=PLENSkat0854vszuVfu9mnrEvHsVQGBBgB

In this paper a preliminary analysis of the energetic performance of an industrial manipulator is presented. In particular, the paper investigates the effects of the trajectory planning on the overall energy consumption of the manipulator in a pick & place task, focusing also on the location of the path within the workspace. An electro-mechanical model of the actuators and the inverse dynamic model of the robot have been developed and used to estimate the robot energy consumption when executing a basic motion task. Results are then collected into energy consumption maps, showing how the location of the task within the robot workspace affects the energetic performance of the robot.

This paper presents a novel robotic painting system able to create artworks using the palette knife technique. The implementation of this method with a robotic system is particularly challenging, since the robot needs to precisely manipulate the palette knife to pick up and release the color on the canvas. The painting system comprises a 6-DOF collaborative robot, a camera to acquire the information on the color position, and several algorithms for the artistic rendering of the images and for the planning of the trajectories that the robot has to follow. During the painting process the user can modify multiple parameters: both software, for example, stroke position and orientation, and hardware, for example, palette knife inclination and height, to obtain different stroke effects. Finally, the experimental results are discussed by analyzing the artworks painted by the novel robotic system.

Gryphon as a 5-DOF robot has the ability to emulate the gestures of human arm and hand. It has pivots for rotation around the elbow and wrist. The wrist has two operative pivots, for rotation and elevation. Unlike previous works which concentrate on using WALLI as Gryphon robots own software, in this paper a PC-based and XPC Target's real-time feature has been used.. Recently, techniques based on metaheuristics of natural computing, mainly evolutionary algorithms (EA), have been successfully applied to a large number of robotic applications. The aim of this paper is to evaluate a modified Biogeography-based Optimization (BBO) approach based on mutation operator to solve the trajectory planning of a Gryphon. Computer simulation results and practical experiments demonstrate that accurate trajectory tracking can be achieved by using the proposed method.

This paper presents the design and first test on a simulator of a vehicle trajectory-planning algorithm that adapts to traffic on a lane-structured infrastructure such as highways. The proposed algorithm is designed to run on a fail-safe embedded environment with low computational power, such as an engine control unit, to be implementable in commercial vehicles of the near future. The

— In this paper we propose a trajectory planning approach for autonomous vehicles on structured road maps. Thererfore we are using the well-known A * optimal path planning algorithm. We generate a safe optimal trajectory through a three-dimensional graph, considering the two-dimensional position and time. (1) The graph is generated dynamically with fixed time differences and flexible distances between nodes, based on the vehicle's velocity, using a structured road map. (2) Furthermore the position of dynamic obstacles is predicted over time along the road lanes. The proposed Flexible Unit A * (FU-A *) algorithm was tested for real-time applications with execution times of less than 50 ms on the car's main computer. The feasibility and reliability of FU-A * is validated by implementing on simulated autonomous car of Freie university " MadeInGermany " using the roadmap of Tempelhof, Berlin.

This paper presents a manned-vehicle/unmanned-aerial-vehicle (UAV) mission system that enables an operator in a manned aircraft to issue mission level commands to an autonomous aircraft in real time. A natural language interface allows the manned and unmanned vehicle to communicate in languages understood by both agents. A task scheduler transforms the commands into a dynamic mission plan consisting of task waypoints. These are then given to a mixed-integer linear programming (MILP)-based ...

Die Vision vom „autonomen Fahren“ ist heutzutage in aller Munde: Medien berichten über Erfolge aus der Forschung mit zahlreichen Versprechen naheliegender Markteinführungen, Automobilkonzerne starten ein Wettrüsten der Technologien und Softwareunternehmen treten in Konkurrenz zu Fahrzeugherstellern.
Dadurch keimt in der Gesellschaft die Hoffnung eines unfallfreien Straßenverkehrs auf. Man könnte sich endlich selbst während der Fahrt entspannt zurücklehnen, die Reise genießen, uneingeschränkt telefonieren, im Internet surfen oder anstehende Vorbereitungen treffen – anstatt sich über den Stau zu ärgern. Alten und kranken Menschen soll langfristig eine erhöhte, individuelle Mobilität ermöglicht werden. Auch zur effizienteren Nutzung der Rohstoffe sollen autonome Fahrzeuge einen Beitrag leisten: So wäre es denkbar, im Rahmen von Car-Sharing-Angeboten die Fahrzeuge autonom zu den Kunden fahren beziehungsweise sich eigenständig mit Energie versorgen zu lassen. Auch die Fahrt an sich könnte unter Berücksichtigung des Verkehrsflusses und des gesamten Streckenverlaufs aus energetischer Sicht optimiert werden. Diesbezüglich stehen einige Fragen im Raum: Ist dies alles noch eine Vision, die in ferner Zukunft liegt? Wird es „autonome Straßenfahrzeuge“ jemals geben oder stehen sie schon kurz vor der Markteinführung? Was heißt „autonomes Fahren“ grundsätzlich und welche technischen Herausforderungen sind hierbei zu lösen?

For many desirable applications of vision guided industrial robots, real-time visual servoing is necessary but also challenging. Difficulty comes from the limited sampling rate and response time of typical machine vision systems equipped on industrial robots. These factors are addressed as the dynamics of visual sensing. In addition, robot dynamics should also be fully considered when designing the control law. Considering these aspects, this paper presents a control scheme of visual servoing. A dual-rate adaptive tracking filter is presented to compensate the visual sensing dynamics. Based on the compensated vision feedback, the techniques of multi-surface sliding control and dynamic surface control are used to formulate a two-layer control law for target tracking. System kinematics and dynamics are decoupled and dealt with by the two layers of the control law respectively. The proposed method is validated through experiments on a SCARA robot.

The research presented in this paper focuses on the conceptual design of an innovative Air Traffic Management (ATM) system featuring automated 4-Dimensional Trajectory (4DT) Planning, Negotiation and Validation (4-PNV) functionalities to enable Intent Based Operations (IBO). In order to meet the demanding requirements set by national and
international organisations for the efficiency and environmental sustainability of air transport operations, a multi-objective 4DT optimization algorithm is introduced that represents the core element of the 4DT planning functionality. The 4-PNV system interacts with airborne avionics also developed for 4DT-IBO such as the Next Generation Flight Management System (NG-FMS) on-board manned aircraft and Next Generation Mission Management System (NG-MMS) for Remotely Piloted Aircraft Systems (RPAS). In this article we focus on the 4-PNV algorithms, and specifically on the multi-objective 4DT optimization algorithm for strategic and tactical online operations. Simulation case studies are carried out to test the key system performance metrics such as 4DT computational time in online tactical Terminal Manoeuvring Area (TMA) operations.

In the Unmanned Aerial Vehicles (UAVs) one of the simplest navigational requirements is the capability of path following. Researchers have developed several algorithms over the years for path following. Some of these algorithms are carrot chasing algorithm, line-of-sight based path following (PLOS) and non-linear guidance law (NLGL). But there is not sufficient information available in existing literatures in comparative performance analysis of these algorithms. This project report has discussed the need of flight planning as well as existing literatures on flight control. One of the widely used control methodologies for UAV is pure pursuit control which is discussed mathematically in this report. Equations of motion of UAV assuming it as a point mass are also presented in this report.
After that specific missions of straight line path following and circular orbit or loiter path following are selected for analysis. All the three path following algorithms are simulated for these missions. Then based on cross-track deviation and total control effort most suitable path following algorithm is selected. Apart from path following this report has also demonstrated effectiveness of A-star algorithm in deriving an optimum path in between origin and destination while avoiding randomly generated obstacles.

The trajectories of a soccer ball for the most important kicks in the football game - a corner kick and a direct free kick are studied in the current paper. The soccer ball is modelled as an ideal rigid hollow spherical body with six degrees of freedom, which performs a general motion in an immovable air environment with constant parameters. The ball 3D orientation is determined by the three Cardan angles. The aerodynamic forces and moments with which the air environment acts to the ball are taken into account. Two of the most dangerous areas of the football goal are defined. Differential equations which describe the motion of the soccer ball are solved numerically by MatLab-Simulink.

The internship will have as main objective the modeling of  Quadrotor  using the environment Matlab / Simulink . to do this I will concentrate on the principle of flight, then I will attack the control and the stabilization of the drone by using different methods non-linear and robust control that will guarantee the stabilization and good control of the flying drone.
The first part is devoted to the presentation of the adopted model. Then we will demonstrate the algorithms for calculating the set of commands used, all we will make a presentation and analysis of the results of simulations for the purpose of making a comparison between the algorithms of controllers developed in terms of dynamic performance and their ability to stabilize. the system during flight using different trajectories (simple and complex) variations in time and under the effect of possible disturbance. Finally we will detail the equations of a nonlinear observer in sliding mode for the estimation of states of our system.
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Le stage aura comme objectif principal la modélisation d’un drone du type Quadrotor sous l’environnement Matlab/Simulink pour ce faire je vais me concentrer sur le principe de vol, puis je vais attaquer la commande et la stabilisation du drone en utilisant différents types de commande non linéaire et robuste qui va nous garantir la stabilisation et la bonne commande de l’engin volant.

La première partie est consacrée à la présentation du modèle adopté. Ensuite, on démontrera les algorithmes de calcul de l’ensemble des commandes utilisées, toutes on fera une présentation et analyse des résultats des simulations pour le but de faire une comparaison entre les algorithmes des contrôleurs développés en termes de performances dynamiques et leurs capacités à stabiliser le système pendant le vol sous différentes trajectoires (simples et complexes) variantes dans le temps et sous l’effet de perturbation possible. Finalement on détaillera les équations d’un observateur non linéaire en régime glissant pour l’estimation
d’états de notre système.
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Si vous avez des questions sur ce travail, n'hésitez pas à me contacter sur mon adresse mail.
If you have any questions about this project, do not hesitate to contact me on my email address.

e-mail : iliass.elmouderrib@gmail.com

good reading!

Global Navigation Satellite Systems (GNSS) can support the development of low-cost and high performance navigation and guidance architectures for Unmanned Aircraft Systems (UAS) and, in conjunction with suitable data link technologies, the provision of Automated Dependent Surveillance (ADS) functionalities for cooperative Sense-and-Avoid (SAA). In non-cooperative SAA, the adoption of GNSS can also provide the key positioning and, in some cases, attitude data (using multiple antennas) required for automated collision avoidance. A key limitation of GNSS for both cooperative (ADS) and non-cooperative applications is represented by the achievable levels of integrity. Therefore, an Avionics Based Integrity Augmentation (ABIA) solution is proposed to support the development of an Integrity-Augmented SAA (IAS) architecture suitable for both cooperative and non-cooperative scenarios. The performances of this IAS architecture were investigated in representative simulation case studies by testing the ability of the SAA system to exploit the predictive (caution) and reactive (warning) integrity flags generated by ABIA. Additionally, the ABIA False Alarm Rate (FAR) and Detection Probability (DP) performances were examined and an initial evaluation of the complementarity with Space-Based and Ground-Based Augmentation Systems (SBAS/GBAS) was accomplished. Simulation results show that the proposed IAS architecture is capable of performing high-integrity conflict detection and resolution when GNSS is used as the primary source of navigation data and there is a clear synergy with state-of-the art SBAS/GBAS in all applicable flight phases.

In this paper, we present a novel robotic system that produces watercolour paintings by means of a 6-degree-of-freedom collaborative robot. After an analysis of traditional watercolour, different non-photorealistic rendering techniques are applied in order to elaborate digital images into artworks. Several algorithms, aimed at processing both the backgrounds and the details, are implemented. Then, the resulting rendering is converted into a sequence of trajectories that the robot reproduces on paper. During the process, the artist controlling the system can change both the algorithm parameters and the hardware variables (e.g. brush type, colour dilution, etc.) in order to obtain a different artistic rendering. The challenge is indeed not to faithfully reproduce an image but to introduce a personal and original contribution to the artwork. The robotic painting system described in this paper was named "Busker Robot" and it is the first automatic system that uses the watercolour technique for artistic rendering. It was installed at the "Algorithmic Arts and Robotics" exhibition during the international event "Trieste Next" (Trieste, Italy, September 2017) and won an Honorable Mention at the 2018 International Robotic Art Competition (RobotArt).

In this paper, we present non-photorealistic rendering techniques that are applied together with a painting robot to realize artworks with original styles. Our robotic painting system is called Busker Robot and it has been considered of interest in recent art fairs and international exhibitions. It consists of a six degree-of-freedom collaborative robot and a series of image processing and path planning algorithms. In particular, here, two different rendering techniques are presented and a description of the experimental setup is carried out. Finally, the experimental results are discussed by analyzing the elements that can account for the aesthetic appreciation of the artworks.

The concept of religious leadership is examined in the light of three aspects of leadership – individual, territorial, and political – that are illustrated by the itineraries of three sheikhs, each in leadership roles in Tripoli (Lebanon). Using personal and biographical elements, this article reflects particularly on the role of local belonging, in this case the urban territory that produces this new leadership and helps to explain the regional implications of a religious and political commitment.

This paper presents a smooth spline interpolation technique for five-axis machining of sculptured surfaces. The tool tip and orientation locations generated by the CAM system are first fitted to quintic splines independently to achieve geometric jerk continuity while decoupling the relative changes in position and orientation of the cutter along the curved path. The nonlinear relationship between spline parameters and displacements along the path are approximated with ninth order and seventh order feed correction splines for position and orientation, respectively. The high order feed correction splines allow minimum deviation from the reference axis commands while preserving continuous jerk on three translational and two rotary drives. The proposed method has been experimentally demonstrated to show improvements in reducing the excitation of inertial vibrations while improving tracking accuracy in five-axis machining of curved paths found in dies, molds and aerospace parts.

This paper presents Multi Objective Trajectory Optimization (MOTO) algorithms that were developed for integration in state-of-the-art Air Traffic Management (ATM) and Air Traffic Flow Management (ATFM) systems. The MOTO algorithms are conceived for the automation-assisted replanning of 4-Dimensional Trajectories (4DT) when unforeseen perturbations arise at strategic and tactical online operational timeframes. The MOTO algorithms take into account updated weather and neighbouring traffic data, as well as the related forecasts from selected sources. Multiple user-defined operational, economic and environmental objectives can be integrated as necessary. Two different MOTO algorithms are developed for future implementation in ATM systems: an en-route variant and a Terminal Manoeuvring Area (TMA) variant. In particular, the automated optimal 4DT replanning algorithm for en-route airspace operations is restricted to constant flight level to avoid violating the current vertical airspace structure. As such, the complexity of the generated trajectories reduces to 2 dimensions plus time (2D+T), which are optimally represented in the present 2D ATM display formats. Departing traffic operations will also significantly benefit from MOTO-4D by enabling steep/continuous climb operations with optimal throttle, reducing perceived noise and gaseous emissions.

Energy saving in robotic and mechatronic systems is becoming an evermore important topic in both industry and academia. One strategy to reduce the energy consumption, especially for cyclic tasks, is exploiting natural motion. We define natural motion as the system response caused by the conversion of potential elastic energy into kinetic energy. This motion can be both a forced response assisted by a motor or a free response. The application of the natural motion concepts allows for energy saving in tasks characterized by repetitive or cyclic motion. This review paper proposes a classification of several approaches to natural motion, starting from the compliant elements and the actuators needed for its implementation. Then several approaches to natural motion are discussed based on the trajectory followed by the system, providing useful information to the researchers dealing with natural motion.