This paper describes the experiences using remote laboratories for education and research in the field of Control Engineering. The use of remote laboratories for education in subjects of control is increasingly becoming a resorted method by the universities in order to offer a flexible service in schedules with greater and better operation of available resources. Nevertheless, for research activities, remote laboratories are not widely used. The aim of this contribution is thereby to apply the experience of remote laboratories in research applications in order to share complex equipments among different researchers. Some experiments are carried out to demonstrate the effectiveness of using remote laboratories in research experiments related to robotic system. The results of the implementation of remote experimentations to control a 3-DOF parallel robot by using Distance Laboratory System (SLD) are exposed. The performance of the system is evaluated by the possibilities and functionality of the proposed remote laboratory platform.

This paper describes the design and evaluation of a new platform created in order to improve the learning experience of bilateral control algorithms in teleoperation. This experimental platform, developed at Universidad Politécnica de Madrid, is used by the students of the Master on Automation and Robotics in the practices of the subject called “Telerobotics and Teleoperation”. The main objective is to easily implement different control architectures in the developed platform and evaluate them under different conditions to better understand the main advantages and drawbacks of each control scheme. So, the student's tasks are focused on adjusting the control parameters of the predefined controllers and designing new ones to analyze the changes in the behavior of the whole system. A description of the subject, main topics and the platform constructed are detailed in the paper. Furthermore, the methodology followed in the practices and the bilateral control algorithms are presented. Finally, the results obtained in the experiments with students are also shown.

This paper presents a new Haptic Rate-Position controller, which allows manipulating a slave robot in a large workspace. Haptic information is displayed to the user so as to be informed when a change in the operation mode occurs. This controller allows performing tasks in a large remote workspace by using a haptic device with a reduced workspace such as Phantom. Experimental results have been carried out using a virtual slave robot, simulated with Open Dynamics Engine (ODE). A real IFMIF (International Fusion Materials Irradiation Facility) remote handling task has been simulated. Its goal is to carry out remote manipulation of test irradiated materials in a nuclear environment. The proposed algorithm has been compared with the classic Position controller in a Pick & Place manipulation and has shown much better levels of effectiveness.

Nowadays, almost all kinesthetic haptic devices commercially available have been conceived and developed for just one interaction point. Many mechanical conflicts arise when trying to put to work together two or more conventional haptic devices. Due to collisions and other incompatibilities the resulting workspace when using these configurations is usually too small, making this a non-viable option. Therefore, a new multi-finger haptic device called MasterFinger 3 is developed to meet the demands of freedom of movement within a wide workspace. The aim of the new haptic device presented in this paper is to allow an intuitive human-machine interaction in a natural fashion. This interaction permits the end-user to control and operate an advanced robotic hand precisely. In order to reach this purpose, the attitude of at least three fingers should be measured. Moreover, the attitude of the other two fingers can be deduced from those measurements. Consequently, the mechanical design and the electronic architecture are described in detail in the following sections.

The complexity in the execution of cooperative tasks is high due to the fact that a robot team requires movement coordination at the beginning of the mission and continuous coordination during the execution of the task. A variety of techniques have been proposed to give a solution to this problem assuming standard mobile robots. This work focuses on presenting the execution of a cooperative task by a modular robot team. The complexity of the task execution increases due to the fact that each robot is composed of modules which have to be coordinated in a proper way to successfully work. A combined tight and loose cooperation strategy is presented and a bar-pushing example is used as a cooperative task to show the performance of this type of system.

The modeling of a modular robot system is complex due to its capability of changing and forming countless robot configurations with a set of modules. The greater the number of modules added to the structure, more complicated is the robot and its modeling. A methodology to represent modular robot configurations as a fixed shape robot is presented. The equivalent model is obtained through the characterization of the module, graph theory and geometric modeling of robots. After the transformation, the resulting kinematic and dynamic parameters are similar to the traditional model of a single configuration robot. Once the equivalent model is obtained, it can be used within different robot applications.

This paper describes a modular robot system design SMART, based on three types of modules for urban search tasks. The system attempts to give a quick solution to natural and man-made disaster emergencies. It allows for rapid and cost-effective design and fabrication. The approach is based on the use of an inventory of three types of modules i.e., power and control module, joint module, and specialized module. They are interchangeable in different ways to form different robot configurations for a variety of tasks. Forward and inverse kinematics from assembled robot configurations are analyzed. Description of control motion modes for human-modular robot system interaction is presented.

The purpose of this paper is to analyze in some depth the kinematic behaviour of the human hand, in order to obtain simplified human hand models with the minimum and optimal number of Degrees of Freedom (DoF), and thus achieving an efficient manipulation task. The statistical analysis is carried out using Principal Components Analysis (PCA). Power and precision grasps are obtained with the use of a Cyberglove and a human hand model with 24 DoF. Finally, these experiments are used to evaluate the best DoF for an appropriate manipulation.

This paper describes a new methodology for designing bilateral controllers based on transparency that applies a modified scheme of control by state of convergence. The design is based on modelling the behavior of the master and slave which regard state space equations, and also taking into account that perfect transparency cannot be reached. This methodology allows designing the controllers in order to obtain the convergence between the state of the master and the slave. Furthermore, it consequently provides a higher degree of transparency to the operator. The paper explains criteria in achieving convergence between the master and the slave, and so as with transparency on a steady state. A set of equations that calculate controller gains have been obtained by applying such criteria. In order to verify this new methodology, a master-slave system of 3 DoF have been used.

This paper presents a new bilateral control scheme for time-delayed teleoperation designed to achieve transparency. The control scheme allows that the slave follows the master in spite of the time delay, ant that the force displayed to the operator was exactly the reaction force from the environment. In addition, the interaction force of the slave with the environment is adapted to the master/slave ratio when it is reflected to the operator, improving the transparency of the system. The bilateral control scheme can be used in contact situations or non-contact situations of the slave with the environment. Together with the control scheme, the paper describes an analytical design method that allows the obtaining of the control gains.

A parallel robot testbed based on Stewart-Gough platform calledactive-Helideckis designed, developed and tested as a helicopter floating Helideck. The objective of this testbed is to show the advantages of helicopters that use an active Helideck upon landing on and taking off from ships or from offshore structures. Active-helideck compensates simulated movements of a ship at sea. The main goal of this study is to maintain the robotpsilas end effector (Helideck) in a quasi-static position in accordance to an absolute inertial frame. Compensation is carried out through the coordinate action of its six prismatic actuators in function of an inertial measurement unit. Moreover, the simulation of the sea movement is done by a parallel robot calledshipplatformwith three degrees of freedom. The ship platform is built with a vertical oscillation along the z axis, i.e. heave, and rotates on remaining axes, i.e. roll and pitch. Active Helideck is able to compensate simulated movements by considering the ship as an inertial frame as observed in the experiment.

This paper shows the advantages of having a modular system with 3-DoF spherical actuator in the base module to perform tasks that require displacement and object manipulation. Having 3-DoF actuator improves the complexity of coordination patterns and control algorithms of the modular system more relevantly as compared to having only 1 or 2DoF actuator in the module. Nevertheless, modules with actuators of only 1 or 2DoF require more modules to be assembled together in order to achieve complex tasks. Experiments performed with RobMAT modular system proves that a 3DoF actuator in the module is better, because tasks such as displacement, obstacle climbing and object manipulation, can be efficiently carried out with systems of 2 modules, 4 modules and 6 (maximum) modules connected together.

This paper presents a discrete design and control method of teleoperation systems. The design method is based on the state space formulation and it allows to obtain the control gains for any teleoperation system where the master and the slave manipulators would be represented by nth-order discrete linear transfer functions. The control method allows that the slave follows the master through the state convergence between the master and the slave. The method is able also to establish the desire dynamics of this convergence and the dynamics of the slave manipulator. The advantage of this method is that it can be applied to control a teleoperation system where the master and the slave are modeled by transfer functions of different order. In order to validate the control method, simulation results are shown considering a teleoperation system where the master and the slave are modeled by discrete transfer functions of different order

This paper concerns the continuity of vision based robot control law. Recently, we have proposed a way of allowing the temporary disappearance of image features during the control task based on weighted features. Futher more, we have redefined the camera invariant visual servoing approach in order to take into account the change of image features when zooming in or out during a positioning task. In this paper, we study ho to select some parameters of the weight function and we propose a local stability analysis of the invariant visual servoing approach with weighted features. Finally, experimental results demonstrate the improvements that can be achieved in the performance of vision-based control task.

A redundancy resolution technique devoted to grasp synthesis is presented. Given a set of contact points and a certain robot arm and gripper, the goal is to select both the best assignment of gripper fingers to contact points and the best joint values that allow the fingers to reach such contact points. The system proposed is based on the generation of an inverse kinematics tree where fast searches can be performed in order to find the optimum configuration. Optimality is defined as similarity to previously stored examples over a hierarchical structure of configuration data, which includes finger assignments and robot joints.

This paper presents the design of a parallel robot that is used to play table tennis. The object of this application is to evaluate the level of integration between high-speed robotic systems and vision systems in unknown and dynamic environments. The parallel robot is based on a DELTA robot. The optimization method uses a global condition index based on the condition number of the Jacobian matrix. Firstly, we present the geometric model and kinematic analysis of the parallel robot. The optimization defines the dimensions of the manipulator. Using ADAMS/spl reg/, we obtain the maximum speed of the end-effector and the maximum torque of the motors for a set of typical trajectories of the ball in table tennis. Finally, we display the prototype of the built manipulator.

In the recent past, the visibility problem in vision-based control has been widely investigated. The proposed solutions generally have a common goal: to always keep the object in the camera's field of view during the visual servoing. Contrary to this solution, we propose a new approach based on the concept of allowing the changes of visibility in image features during the control task. To this aim, the camera invariant visual-servoing approach has been redefined in order to take into account the changes of visibility in image features. A new smooth task function using weighted features is presented, and a continuous control law is obtained starting from it by imposing its exponential decrease to zero. Furthermore, the local stability analysis of the invariant visual-servoing approach with weighted features is presented. Finally, this promising way of dealing with the visibility issue has been successfully tested with an eye-in-hand robotic system.

This paper presents a study of the kinematics and dynamics performance of a climbing parallel robot (CPR) to avoid nodes on structural frames. To avoid a structural node, a CPR can acquire some determined postures. A series of postures can be combined to generate the convenient movements to climb along the structural node. The postures of a CPR must be studied to detect its feasibility, because the postures can drive the robot near its singular configurations. Also, the forces originated in the actuators to evade the structural nodes are evaluated. Therefore, the goal of this paper is to show that a Stewart-Gough (S-G) parallel platform can be used as a climbing robot, because a CPR can avoid structural nodes easily and elegantly, in contrast with other types of robots. To support the simulation results presented in the first part of this paper, an experimental testbed has been developed to study the dynamic performance of the CPR prototype around a structural node. The results obtained are very interesting, and show that an industrial potential to use the parallel S-G robot as a climbing robot exists.

This paper presents the operations of a 3-D camera and a video processing device aiming at the improved performance of teleoperated tasks. The video processing device has two operation modes: a) one for the stereoscopic image visualization, and b) other for the blending of video and graphic images. Main results are shown; considering specially the influence of the different video frequencies, corresponding to PAL and VGA formats. Finally, two telerobotic applications, on which these devices have been successfully applied, are described.

Proposes an application of the Stewart-Gough parallel platform as a climbing robot and its kinematics control to climb through long structures describing unknown spatial trajectories, such as palm trunks, tubes, etc. First, the description and design of the climbing parallel robot is presented. Second, the inverse and forward kinematics analysis of a mobile six-degrees-of-freedom parallel robot is described, based on spatial constraint formulation. Finally, the gait pattern and the climbing strategy of the parallel robot is described. The information from this research is being used in an actual climbing parallel robot design at Miguel Hernandez University of Elche (Alicante), Spain.

Outage-free maintenance of electrical power lines has been conducted throughout the years in order to fulfil the increasing demand of uninterrupted power supply. In these techniques care regarding electric shock and falls must be exercised while the work is performed on or near energized elements. In order to increase the safety and comfort of the workers as well as the overall efficiency, a teleoperated system for live-line maintenance, called ROBTET, has been developed for the electrical utility IBERDROLA. ROBTET is described in detail in the paper. It has two hydraulic-driven master-slave teleoperated manipulators on top of an insulated boom over a truck. The operator commands the manipulators from a cabin on the truck via a pair of master arms, while he receives visual feedback through a vision system. Multimedia display, voice commands, stereo vision and force-feedback are some of the new features implemented in order to achieve the required telepresence of the operator and hence increase the performance of the system.

In master-slave teleoperation systems the control loop is closed through the human operator. He acts as a controller generating actuating signals based in visual and kinesthetic cues. It is then indispensable to have a model of his behavior in order to design and study this type of systems coherently. Up to now only simplified arm dynamic models have been included in the study of bilateral control schemes. This paper makes use of already existing human-in-the loop models, developed for aircraft piloting, in order to construct a complete and simple model of human behavior for master-slave teleoperation systems with visual and kinesthetic feedback. The model was validated through several experiments with two different master arms and under various circumstances of operation. It includes complete human dynamic behavior: both the generation of control actions and limb dynamics.

Digital regulators for continuous plants are designed today by means of conventionalz-transfer function methods. With thesez-transfer functions the value of the system outputy(t) can be learned only at instants spacedTseconds apart, whereTis the sampling period. A technique is proposed where the value ofy(t) can be learned at instants spacedT/nseconds apart, wherenis any integer. This technique is based on multirate sampling. First a method to calculate the output multirate sampled sequence is described. Then an efficient algorithm to calculate the multirate sampling discrete transfer function from the normal discrete transfer function is proposed.