Showing papers in "International Journal of Advanced Robotic Systems in 2011"
TL;DR: In this calibration pattern the main objective is to minimize systematic errors due to geometric calibration factor and an algorithm for solution of the intrinsic and extrinsic parameters is described.
Abstract: This work describes a method for calibration of the Velodyne HDL-64E scanning LIDAR system. The principal contribution was expressed by a pattern calibration signature, the mathematical model and t...
109 citations
TL;DR: This paper presents the investigation of the modelling and control of a quad-rotor helicopter and forms part of research involving the development of an unmanned aerial vehicle (UAV) to be used in search and rescue applications.
Abstract: This paper presents the investigation of the modelling and control of a quad-rotor helicopter and forms part of research involving the development of an unmanned aerial vehicle (UAV) to be used in ...
86 citations
TL;DR: An action based domain specific communication language for AIMM for routine and task definition is proposed, in order to lower the entry barriers for the users of the technology.
Abstract: This paper presents the concept "autonomous industrial mobile manipulation" (AIMM) based on the mobile manipulator "Little Helper" - an ongoing research project at Aalborg University, Denmark, concerning the development of an autonomous and flexible manufacturing assistant. The paper focuses on the contextual aspects and the working principles of AIMM. Furthermore, the paper deals with the design principles and overall hardware and software architectures of "Little Helper" from a functional and modular mechatronics point of view, in order to create a generic AIMM platform. The design challenges faced in the project is to integrate commercial off-the-shelf (COTS) and dedicated highly integrated systems into an autonomous mobile manipulator system with the ability to perform diverse tasks in industrial environments. We propose an action based domain specific communication language for AIMM for routine and task definition, in order to lower the entry barriers for the users of the technology. To demonstrate the "Little Helper" concept a full-scale prototype has been built and different application examples carried out. Experiences and knowledge gained from this show promising results regarding industrial integration, exploitation and maturation of the AIMM technology.
59 citations
TL;DR: The drawbacks of the previous methods based on Monte Carlo are pointed out in the paper, and improved strategies are presented systematically, and the optimal parameters are proposed to computer the shape and size of 2D and 3D workspace.
Abstract: Exact computation of the shape and size of robot manipulator workspace is very important for its analysis and optimum design First, the drawbacks of the previous methods based on Monte Carlo are pointed out in the paper, and then improved strategies are presented systematically In order to obtain more accurate boundary points of two-dimensional (2D) robot workspace, the Beta distribution is adopted to generate random variables of robot joints And then, the area of workspace is acquired by computing the area of the polygon what is a closed path by connecting the boundary points together For comparing the errors of workspaces which are generated by the previous and the improved method from shape and size, one planar robot manipulator is taken as example A spatial robot manipulator is used to illustrate that the methods can be used not only on planar robot manipulator, but also on the spatial The optimal parameters are proposed in the paper to computer the shape and size of 2D and 3D workspace Finally, we provided the computation time and discussed the generation of 3D workspace which is based on 3D reconstruction from the boundary points
59 citations
TL;DR: This chapter describes an educational system with a tele-operated android robot, named SAYA, that can express human-like facial expressions and perform some communicative functions with its head and eye movements, and it is utilized as a role of a teacher.
Abstract: This chapter describes an educational system with a tele-operated android robot, named SAYA, that can express human-like facial expressions and perform some communicative functions with its head and eye movements, and it is utilized as a role of a teacher. Two kinds of field experiments were conducted to investigate effectiveness of this educational system in actual educational fields. An experiment was conducted at both an elementary school and a university to estimate age-dependent differences of its effectiveness. The other experiment was carried out to verify whether children's interest, motivation, and concentration to the class, and science and technologies were enhanced.
58 citations
TL;DR: A new control strategy for noncompliant and compliant antagonistic tendon drives based on a biologically inspired puller-follower concept is applied to a succession of increasingly complex single-joint systems, starting with a linear and non Compliant system and ending with a revolute, nonlinearly tendon coupled and compliant system.
Abstract: This paper proposes a new control strategy for noncompliant and compliant antagonistic tendon drives. It is applied to a succession of increasingly complex single-joint systems, starting with a lin...
58 citations
TL;DR: In this article, the performance evaluation of redundant parallel kinematic manipulators is investigated, and indices that assimilate motion/force transmissibility are proposed to evaluate the performance of redundant PKMs.
Abstract: Performance evaluation is one of the most important issues in the field of parallel kinematic manipulators (PKMs). As a very important class of PKMs, the redundant PKMs have been studied intensively. However, the performance evaluation of this type of PKMs is still unresolved and a challenging endeavor. In this paper, indices that assimilate motion/force transmissibility are proposed to evaluate the performance of redundant PKMs. To illustrate the application of these indices, three PKMs with different kinds of redundancies are taken as examples, and performance atlases are plotted based on the definitions of the indices. Transmissibility comparisons between redundant PKMs and the corresponding non-redundant ones are carried out. To determine the inverse solutions of the PKMs with kinematic redundancy, an optimization strategy is presented, and the rationality of this method is demonstrated. The indices introduced here can be applied to the performance evaluation of redundant parallel manipulators.
53 citations
TL;DR: This paper compares three inverse kinematic formulation methods for the serial industrial robot manipulators based on screw theory, and finds the method based on dual-quaternion gives the most compact and computationally efficient solution.
Abstract: In this paper, we compare three inverse kinematic formulation methods for the serial industrial robot manipulators. All formulation methods are based on screw theory. Screw theory is an effective way to establish a global description of rigid body and avoids singularities due to the use of the local coordinates. In these three formulation methods, the first one is based on quaternion algebra, the second one is based on dual-quaternions, and the last one that is called exponential mapping method is based on matrix algebra. Compared with the matrix algebra, quaternion algebra based solutions are more computationally efficient and they need less storage area. The method which is based on dual-quaternion gives the most compact and computationally efficient solution. Paden-Kahan sub-problems are used to derive inverse kinematic solutions. 6-DOF industrial robot manipulator's forward and inverse kinematic equations are derived using these formulation methods. Simulation and experimental results are given.
47 citations
TL;DR: AUVs (Autonomous Underwater Vehicle) were considered and chosen, as the most suitable tool for conduction survey concerning these global environmental problems, because the vehicle does not have to be connected to the support vessel by tether cable.
Abstract: There are concerns about the impact that global warming will have on our environment, and which will inevitably result in expanding deserts and rising water levels. While a lot of underwater vehicles are utilized, AUVs (Autonomous Underwater Vehicle) were considered and chosen, as the most suitable tool for conduction survey concerning these global environmental problems. AUVs can comprehensive survey because the vehicle does not have to be connected to the support vessel by tether cable. When such underwater vehicles are made, it is necessary to consider about the following things. 1) Seawater and Water Pressure Environment, 2) Sink, 3) There are no Gas or Battery Charge Stations, 4) Global Positioning System cannot use, 5) Radio waves cannot use. In the paper, outline of above and how deal about it are explained.
46 citations
TL;DR: The open-loop optimal control approach for generating the optimal trajectory of the flexible mobile manipulators in point-to-point motion is applied based on the Pontryagin's minimum principle and the effectiveness and capability of the proposed approach are demonstrated through simulation studies.
Abstract: Finding optimal trajectory is critical in several applications of robot manipulators. This paper is applied the open-loop optimal control approach for generating the optimal trajectory of the flexi...
46 citations
TL;DR: A time delay estimation based general framework for trajectory tracking control of robot manipulators is presented and experimental results verify high-accuracy trajectory tracking of industrial robot manipulator.
Abstract: A time delay estimation based general framework for trajectory tracking control of robot manipulators is presented. The controller consists of three elements: a time-delay-estimation element that cancels continuous nonlinearities of robot dynamics, an injecting element that endows desired error dynamics, and a correcting element that suppresses residual time delay estimation error caused by discontinuous nonlinearities. Terminal sliding mode is used for the correcting element to pursue fast convergence of the time delay estimation error. Implementation of proposed control is easy because calculation of robot dynamics including friction is not required. Experimental results verify high-accuracy trajectory tracking of industrial robot manipulators.
TL;DR: This paper shows how Q-learning approach can be used in a successful way to deal with the problem of mobile robot navigation, and addresses the issue of individual behavior design using fuzzy logic.
Abstract: This paper shows how Q-learning approach can be used in a successful way to deal with the problem of mobile robot navigation. In real situations where a large number of obstacles are involved, normal Q-learning approach would encounter two major problems due to excessively large state space. First, learning the Q-values in tabular form may be infeasible because of the excessive amount of memory needed to store the table. Second, rewards in the state space may be so sparse that with random exploration they will only be discovered extremely slowly. In this paper, we propose a navigation approach for mobile robot, in which the prior knowledge is used within Q-learning. We address the issue of individual behavior design using fuzzy logic. The strategy of behaviors based navigation reduces the complexity of the navigation problem by dividing them in small actions easier for design and implementation. The Q-Learning algorithm is applied to coordinate
TL;DR: The Simbiosis Smart Walker as mentioned in this paper is equipped with a set of sensor subsystems to acquire user-machine interaction forces and the temporal evolution of user's feet during gait.
Abstract: This paper presents the complete development of the Simbiosis Smart Walker. The device is equipped with a set of sensor subsystems to acquire user-machine interaction forces and the temporal evolution of user's feet during gait. The authors present an adaptive filtering technique used for the identification and separation of different components found on the human-machine interaction forces. This technique allowed isolating the components related with the navigational commands and developing a Fuzzy logic controller to guide the device. The Smart Walker was clinically validated at the Spinal Cord Injury Hospital of Toledo - Spain, presenting great acceptability by spinal chord injury patients and clinical staff.
TL;DR: An efficient and fast method for fine tuning the controller parameters of robot manipulators in constrained motion using a Lyapunov-based impedance approach and a 3DOF manipulator constrained to a circular trajectory is presented.
Abstract: This paper presents an efficient and fast method for fine tuning the controller parameters of robot manipulators in constrained motion. The stability of the robotic system is proved using a Lyapunov-based impedance approach whereas the optimal design of the controller parameters are tuned, in offline, by a Particle Swarm Optimization (PSO) algorithm. For designing the PSO method, different index performances are considered in both joint and Cartesian spaces. A 3DOF manipulator constrained to a circular trajectory is finally used to validate the performances of the proposed approach. The simulation results show the stability and the performances of the proposed approach.
TL;DR: The simulation results indicate that a perfect trajectory tracking of end-effector of the HPPM is achieved by the closed loop PD-type iterative learning controller.
Abstract: This paper investigates dynamic simulation and trajectory tracking control of hybrid-driven planar five-bar parallel mechanism (HPPM). To begin with, a simulation model of dynamics based on MATLAB/SimMechanics is established. Then, traditional PD control and closed loop PD-type iterative learning control of the HPPM are designed. At the end, the simulation based on SimMechanics is carried out, which acquires angular, angular velocity, angular acceleration of two driving links and constraint reaction of kinematic pairs at any time. In addition, the performance of the closed loop PD-type iterative learning control is compared with that of the traditional PD controller through simulations of the HPPM in the presence of the model external disturbances. The simulation results indicate that a perfect trajectory tracking of end-effector of the HPPM is achieved by the closed loop PD-type iterative learning controller.
TL;DR: The behavior of two finger based micro gripper which is made of Ionic Polymer Metal Composite (IPMC), an Electro Active Polymer (EAP), an EAP shows great potential as high-displacement and light weight actuator.
Abstract: This paper presents the behavior of two finger based micro gripper which is made of Ionic Polymer Metal Composite (IPMC), an Electro Active Polymer (EAP). An IPMC shows great potential as high- displacement and light weight actuator. Low mass force generation capability is utilized for micro gripping in micro assembly. IPMC responds to low voltage in the range of 0-3V. The material contains an electrolyte which transport ions in response to an external electric field. IPMC actuation for micro gripping is produced by deflecting material according to bending moment theory. An external electric field generated by suitable RC circuit causes this deflection. It is found that an IPMC actuates from 1-5 seconds. The maximum jaw opening and closing position of micro gripper are found to be 5 mm and 0.5 mm respectively. The effect of tempearture, as observed, shows that the acceptable limit varies from 23.10C to 30.40C while an IPMC is in operation. An experimental
TL;DR: A novel robot-assisted rehabilitation system based on motor imagery electroencephalography (EEG) is developed for regular training of neurological rehabilitation for upper limb stroke patients, where the patient's EEG of upper limb movement imagination is translated to control rehabilitation robot directly.
Abstract: Stroke is a leading cause of disability worldwide. In this paper, a novel robot-assisted rehabilitation system based on motor imagery electroencephalography (EEG) is developed for regular training ...
TL;DR: Simulation results show that the proposed CGA will always select the safest path avoiding obstacles within the manipulator workspace regardless of whether there is a unique feasible solution, in terms of joint limits, or there are multiple feasible solutions.
Abstract: A novel continuous genetic algorithm (CGA) along with distance algorithm for solving collisions-free path planning problem for robot manipulators is presented in this paper. Given the desired Cartesian path to be followed by the manipulator, the robot configuration as described by the D-H parameters, and the available stationary obstacles in the workspace of the manipulator, the proposed approach will autonomously select a collision free path for the manipulator that minimizes the deviation between the generated and the desired Cartesian path, satisfy the joints limits of the manipulator, and maximize the minimum distance between the manipulator links and the obstacles. One of the main features of the algorithm is that it avoids the manipulator kinematic singularities due to the inclusion of forward kinematics model in the calculations instead of the inverse kinematics. The new robot path planning approach has been applied to two different robot configurations; 2R and PUMA 560, as non-redundant manipulato...
TL;DR: The design of the propulsion system and depth control of a robotic fish and an undulating fin is designed and implemented to produce propulsive force that produces sinusoidal wave to propel the robot.
Abstract: Biomimetic robots can potentially perform better than conventional robots in underwater vehicle designing. This paper describes the design of the propulsion system and depth control of a robotic fish. In this study, inspired by knife fish, we have designed and implemented an undulating fin to produce propulsive force. This undulating fin is a segmental anal fin that produces sinusoidal wave to propel the robot. The relationship between the individual fin segment and phase angles with the overall fin trajectory has also been discussed. This propulsive force can be adjusted and directed for fish robot manoeuvre by a mechanical system with two servomotors. These servomotors regulate the direction and depth of swimming. A wireless remote control system is designed to adjust the servomotors which enables us to control revolution, speed and phase differences of neighbor servomotors of fins. Finally, Field trials are conducted in an outdoor pool to demonstrate the relationship between robotic fish speed and fin parameters like phase difference, the number of phase and undulatory amplitude.
TL;DR: A new locomotion mode to use in a crawling robot, inspired of real inchworm, is described, showing a reduction of 5 to 37 percent in torque consumption in comparison with the gradient based method.
Abstract: This paper describes a new locomotion mode to use in a crawling robot, inspired of real inchworm. The crawling device is modelled as a mobile manipulator, and for each step of its motion, the associated dynamics relations are derived using Euler-Lagrange equations. Next, the Genetic Algorithm (GA) is utilized to optimize the trajectory of the free joints (active actuators) in order to minimize the consumed effort (e.g. integral of square of torques over the step time). In this way, the results show a reduction of 5 to 37 percent in torque consumption in comparison with the gradient based method. Finally, numerical simulation for each step motion is presented to validate the proposed algorithm.
TL;DR: Experimental results with the mobile robot developed in the lab show that the proposed joint conditional random field Filter (JCRFF) has higher precision and better stability than joint probabilities data association filter (JPDAF).
Abstract: Object tracking can improve the performance of mobile robot especially in populated dynamic environments. A novel joint conditional random field Filter (JCRFF) based on conditional random field with hierarchical structure is proposed for multi-object tracking by abstracting the data associations between objects and measurements to be a sequence of labels. Since the conditional random field makes no assumptions about the dependency structure between the observations and it allows non-local dependencies between the state and the observations, the proposed method can not only fuse multiple cues including shape information and motion information to improve the stability of tracking, but also integrate moving object detection and object tracking quite well. At the same time, implementation of multi-object tracking based on JCRFF with measurements from the laser range finder on a mobile robot is studied. Experimental results with the mobile robot developed in our lab show that the proposed method has higher precision and better stability than joint probabilities data association filter (JPDAF).
TL;DR: It is shown that considering the natural saturations of every control stage in practical robots, the classical PID becomes a type of saturated nonlinear PID controller, and global asymptotical stability is proved via Lyapunov stability theory.
Abstract: An unsolved ancient problem in position control of robot manipulators is to find a stability analysis that proves global asymptotic stability of the classical PID control in closed loop with robot manipulators. The practical evidence suggests that in fact the classical PID in industrial robots is a global regulator. The main goal of the present paper is theoretically to show why in the practice such a fact is achieved. We show that considering the natural saturations of every control stage in practical robots, the classical PID becomes a type of saturated nonlinear PID controller. In this work such a nonlinear PID controller with bounded torques for robot manipulators is proposed. This controller, unlike other saturated nonlinear PID controllers previously proposed, uses a single saturation for the three terms of the controller. Global asymptotical stability is proved via Lyapunov stability theory. Experimental results are presented in order to observe the performance of the proposed controller.
TL;DR: In this paper, the stabilization and position tracking control of an underactuated spherical robot is discussed, including the actuator dynamics, the complete dynamic model of the robot, and the control of the linear motion.
Abstract: This paper discusses the stabilization and position tracking control of the linear motion of an underactuated spherical robot. Including the actuator dynamics, the complete dynamic model of the rob...
TL;DR: A study in the design optimization for a class of planar parallel robots that feature an in-parallel structure with two degrees of freedom and maximization of two key performance characteristics is presented.
Abstract: Parallel robots exhibit salient merits over their serial counterparts in applications where both accuracy and dynamic response are required. However, due to the strong dependence of geometric parameters and their performances, the corresponding design problems for the parallel robots are much more complex and the adequacy and effectiveness of the design method become more critical. In this paper, a study in the design optimization for a class of planar parallel robots is presented. The robots feature an in-parallel structure with two degrees of freedom. Dimension synthesis is performed through maximization of two key performance characteristics, addressing not only workspace but also dexterity of the robots under consideration. Optimal designs are attained using both parametric study and simplex algorithm. Results are shown by way of computer simulations aided with graphic visualizations.
TL;DR: The review shows that with state of the art artificial intelligence, robots can work autonomously but still require human supervision, and that multiple robot deployment (MRD) is more economical, shortens mission durations, adds reliability as well as addresses missions impossible with one robot and payload constraints.
Abstract: The interaction between humans and robots is undergoing an evolution. Progress in this evolution means that humans are close to robustly deploying multiple robots. Urban search and rescue (USAR) can benefit greatly from such capability. The review shows that with state of the art artificial intelligence, robots can work autonomously but still require human supervision. It also shows that multiple robot deployment (MRD) is more economical, shortens mission durations, adds reliability as well as addresses missions impossible with one robot and payload constraints. By combining robot autonomy and human supervision, the benefits of MRD can be applied to USAR while at the same time minimizing human exposure to danger. This is achieved with a single-human multiple-robot system (SHMRS). However, designers of the SHMRS must consider key attributes such as the size, composition and organizational structure of the robot collective. Variations in these attributes also induce fluctuations in issues within SHMRS deployment such as robot communication and computational load as well as human cognitive workload and situation awareness (SA).Research is essential to determine how the attributes can be manipulated to mitigate these issues while meeting the requirements of the USAR mission.
TL;DR: An A*-based predictive motion planner is represented for navigation tasks and a generalized pedestrian motion model is proposed and trained by the statistical learning method to deal with the uncertainty.
Abstract: To make robots coexist and share the environments with humans, robots should understand the behaviors or the intentions of humans and further predict their motions. In this paper, an A*-based predictive motion planner is represented for navigation tasks. A generalized pedestrian motion model is proposed and trained by the statistical learning method. To deal with the uncertainty, a localization, tracking and prediction framework is also introduced. The corresponding recursive Bayesian formula represented as DBNs (Dynamic Bayesian Networks) is derived for real time operation. Finally, the simulations and experiments are shown to validate the idea of this paper.
TL;DR: Simulation results show that the TLSF scheme can suppress the oscillation and damping in formation of large robot teams.
Abstract: In this paper, a stable leader-following formation control for multiple non-holonomic mobile robot systems using only limited on-board sensor information is proposed. The control can be used for the conventional single leader - single follower (SLSF) or for novel two leaders - single follower (TLSF) schemes. The control algorithm utilizes estimations of the leaders' translational and angular accelerations in a simple form to reduce the measurement of indirect information. Simulation results show that the TLSF scheme can suppress the oscillation and damping in formation of
TL;DR: The passive joints of the new 2-DOF planar parallel translating manipulators are universal joint and the struts of it do not bear the bending moment, which gives the planarallel manipulator a good architecture to resist the force which is perpendicular to the kinematics plane.
Abstract: This paper focuses on the kinematic characteristics of the 3-UPU (universal-prismatic- universal) parallel manipulator in one of singular configurations. The motion of the moving platform is analyzed by changing the layout of the universal joints. A layout of universal joints in the singular configuration is discussed in detail by deriving the kinematic and constraint equations. Solving the equations, the kinematic characteristics in such case is obtained. At the same time the kinematic characteristics is simulated by the commercial software and the results of the simulation verify it. Based on the kinematics characteristics of it, the application of the singular configuration is presented. And a compound limb which can translate freely along a circular path is presented. Finally, the some new 2-DOF (degree of freedom) planar parallel translating manipulators whose orientation can remain constant are put forward by the compound limb. The passive joints of the new 2-DOF planar parallel translating manipulators are universal joint and the struts of it do not bear the bending moment. It gives the planar parallel manipulator a good architecture to resist the force which is perpendicular to the kinematics plane.
TL;DR: Experimental results showed that global localization can be achieved with high robustness and accuracy using the proposed localization method, and a charge-coupled device camera and artificial landmarks for self-localization.
Abstract: In this paper, we propose a robust and real-time localization method for dynamic environments based on a sensor network; the method combines landmark image information obtained from an ordinary camera and distance information obtained from sensor nodes in an indoor environment. The sensor network provides an effective method for a mobile robot to adapt to changes and guides it across a geographical network area. To enhance the performance, we used a charge-coupled device (CCD) camera and artificial landmarks for self- localization. Experimental results showed that global localization can be achieved with high robustness and accuracy using the proposed localization method.
TL;DR: The paper proposes derivative-free nonlinear Kalman Filtering for MIMO nonlinear dynamical systems and tests the performance of the proposed nonlinear filtering scheme through simulation experiments on benchmark nonlinear multi-input multi-output dynamical Systems, such as robotic manipulators.
Abstract: The paper proposes derivative-free nonlinear Kalman Filtering for MIMO nonlinear dynamical systems. The considered nonlinear filtering scheme which is based on differential flatness theory extends the class of systems to which Kalman Filtering can be applied without the need for calculation of Jacobian matrices. To deduce if a dynamical system is differentially flat, the following should be examined: (i) the existence of the flat output, which is a variable that can be written as a function of the system's state variables (ii) the system's state variables and the input can be written as functions of the flat output and its derivatives. Nonlinear systems satisfying the differential flatness property can be written in the Brunovsky form via a transformation of their state variables and control inputs. After transforming the nonlinear system to the canonical form it is straightforward to apply the standard Kalman Filter recursion. The performance of the proposed derivative-free nonlinear filtering scheme is ...