Cosmin Copot

Heuristic approaches in robot path planning

Autonomous navigation of a robot is a promising research domain due to its extensive applications. The navigation consists of four essential requirements known as perception, localization, cognition and path planning, and motion control in which path planning is the most important and interesting part. The proposed path planning techniques are classified into two main categories: classical methods and heuristic methods. The classical methods consist of cell decomposition, potential field method, subgoal network and road map. The approaches are simple; however, they commonly consume expensive computation and may possibly fail when the robot confronts with uncertainty. This survey concentrates on heuristic-based algorithms in robot path planning which are comprised of neural network, fuzzy logic, nature-inspired algorithms and hybrid algorithms. In addition, potential field method is also considered due to the good results. The strengths and drawbacks of each algorithm are discussed and future outline is provided. Autonomous navigation of a robot is a promising research domain due to its extensive applications.This survey concentrates on heuristic-based algorithms in robot path planning which are comprised of neural network, fuzzy logic, nature inspired algorithms and hybrid algorithms.The strengths and drawbacks of each algorithm are discussed and future outline is provided.

Identification and path following control of an AR.Drone quadrotor

This paper describes the process of identification and closed-loop control of an Parrot AR.Drone Unmanned Aerial Vehicle (UAV) as well as a path following application based on IMC position controllers. The research issue is to achieve position control of the AR.Drone quadrotor movement via its on-board sensory equipment and external webcam video stream. Firstly, transfer functions are detailed for pitch and altitude movements and a comparison is made between implemented PID and IMC controller performance for both simulation and practice. Furthermore, using IMC controllers, a path following application exhibits controller behavior from a practical point of view. It is concluded that the dynamic model and the controllers implemented on the quadrotor can serve as a reliable basis for more advanced applications.

Predictive Control Architecture for Visual Servoing of Robot Manipulators

Abstract A novel architecture for integrating reference trajectory and image prediction is proposed to be used in predictive control of visual servoing systems. In the proposed method, a new predictor is developed based on the relation between the camera velocity and the time variation of the visual features given by the interaction matrix. In addition, a reference trajectory is introduced to define the way how to reach the desired features over the prediction horizon starting from the current features. Simulations reveal the efficiency of the proposed architecture to control a 6 degrees of freedom robot manipulator.

Formation Control of UGVs using an UAV as Remote Vision Sensor

Abstract A leader-follower formation control scheme based on SRV-1 UGVs and an AR.DRONE 2.0 UAV as remote vision sensor is presented in this paper. The main advantage of the proposed strategy lies on the flexibility obtained from a flight remote sensor, as it makes possible to locate the agents at larger distances between them or to extend more easily the number of agents in the formation. A full description of the internal control designed for the UGVs and the UAV is presented, including the image processing procedure implemented to robustly measure the pose of the vehicles in the formation. Finally, experimental results using a triangular formation of three ground robots illustrates the effectiveness of the proposed control scheme.

Improved potential field method for unknown obstacle avoidance using UAV in indoor environment

This paper proposes a solution to real-time collision-free path planning for an AR. Drone 2.0 UAV using only on-board visual and inertial sensing. The proposed solution consists in a modified potential field method to overcome the non-reachable goal problem. The approach comprises three key components: pattern-based ground for localization, proposed potential field method for path planning and PD controllers for steering commands. By applying the proposed method, the quadrotor is successful in avoiding known/unknown obstacles and reaching the target in complex indoor environment. The results demonstrate the feasibility of the proposed strategy, which opens new possibilities for the agent to perform autonomous navigation.

Towards the Development of a Smart Flying Sensor: Illustration in the Field of Precision Agriculture.

Sensing is an important element to quantify productivity, product quality and to make decisions. Applications, such as mapping, surveillance, exploration and precision agriculture, require a reliable platform for remote sensing. This paper presents the first steps towards the development of a smart flying sensor based on an unmanned aerial vehicle (UAV). The concept of smart remote sensing is illustrated and its performance tested for the task of mapping the volume of grain inside a trailer during forage harvesting. Novelty lies in: (1) the development of a position-estimation method with time delay compensation based on inertial measurement unit (IMU) sensors and image processing; (2) a method to build a 3D map using information obtained from a regular camera; and (3) the design and implementation of a path-following control algorithm using model predictive control (MPC). Experimental results on a lab-scale system validate the effectiveness of the proposed methodology.

A hierarchical global path planning approach for mobile robots based on multi-objective particle swarm optimization

Display Omitted A novel hierarchical global path planning approach for mobile robots in a cluttered environment.A proposed particle swarm optimization with an accelerated update methodology based on Pareto dominance principle.Providing optimal global robot paths with computational efficiency. In this paper, a novel hierarchical global path planning approach for mobile robots in a cluttered environment is proposed. This approach has a three-level structure to obtain a feasible, safe and optimal path. In the first level, the triangular decomposition method is used to quickly establish a geometric free configuration space of the robot. In the second level, Dijkstras algorithm is applied to find a collision-free path used as input reference for the next level. Lastly, a proposed particle swarm optimization called constrained multi-objective particle swarm optimization with an accelerated update methodology based on Pareto dominance principle is employed to generate the global optimal path with the focus on minimizing the path length and maximizing the path smoothness. The contribution of this work consists in: (i) The development of a novel optimal hierarchical global path planning approach for mobile robots moving in a cluttered environment; (ii) The development of proposed particle swarm optimization with an accelerated update methodology based on Pareto dominance principle to solve robot path planning problems; (iii) Providing optimal global robot paths in terms of the path length and the path smoothness taking into account the physical robot system limitations with computational efficiency. Simulation results in various types of environments are conducted in order to illustrate the superiority of the hierarchical approach.

A Three-Year Feedback Study of a Remote Laboratory Used in Control Engineering Studies

This paper discusses the results of a feedback study for a remote laboratory used in the education of control engineering students. The goal is to show the effectiveness of the remote laboratory on examination results. To provide an overview, the two applications of the remote laboratory are addressed: 1) the Stewart platform, and 2) the quadruple water tank system. Combining both applications allows a broad spectrum of practical examples featuring challenging control aspects such as multiple-input–multiple-output control, decoupling, non-minimum phase systems, open-loop unstable systems, and PID control design. The remote laboratory feedback study was performed using a five-point Likert-type scale survey to elicit the students’ level of satisfaction with the laboratory. Three years of student examination results were also studied to compare performance before and after integrating the remote laboratory. In the first of these years there was no use of the remote laboratory. In the second year, the remote laboratory was introduced on a voluntary basis, and in the third year the remote laboratory was obligatory. Student feedback indicates that the remote laboratory needs further development to counter its limitations. A major conclusion of the survey was that there is keen interest in the remote laboratory to provide practical experience in the training of a control engineer. It can be concluded that the remote laboratory has a positive effect on student examination results.

MIMO Fuzzy Control for Autonomous Mobile Robot

This paper addresses the design and implementation of multi-input multi-output (MIMO) fuzzy control for mobile robot. Firstly, MIMO fuzzy control is apply to track different desired trajectories. Secondly, the controller performs on robot for navigation purpose to avoid obstacles and reach defined target. The proposed MIMO fuzzy controller was investigated based on several conducted MATLAB simulation scenarios for mobile robot. The simulation results are presented to demonstrate the effectiveness of our new control algorithm.

Fractional order control of a DC motor with load changes

This paper investigates the robustness of a fractional-order controller against the load changes of a DC motor. The gains and time constants of the DC motor are modified by means of a change in the brake. Two different setups of a DC motor, one with 25% brake and the other with 50% brake are considered in the experimental evaluation. The closed-loop performances of the fractional-order controller are compared with integer-order controller using the same performance criteria and the same tuning algorithm. Both controllers were designed based on time domain specifications. The experimental results show that the fractional-order controller outperforms the classical controller under nominal conditions as well as under gain variations situation.