Journal of Robotics The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Design of a Sapling Branch Grafting Robot Sun, 23 Nov 2014 00:00:00 +0000 The automatic sapling grafting methods and grafting robot technologies are not comprehensively studied despite the fact that they are urgently required in practice. For this reason, a sapling grafting robot is developed to implement automatic grafting for saplings. The developed grafting robot includes clipping mechanism, moving mechanism, cutting mechanism, binding mechanism, and Arduino MCU based control system, which is capable of clipping, moving, positioning, cutting, grafting, and binding saplings. Experiments show that the stock cutting efficiency is 98.4%, the scion cutting efficiency is 98.9%, the grafting efficiency is 87.3%, and the binding efficiency is 68.9%. Qun Sun, Dongjie Zhao, Chong Wang, and Ying Zhao Copyright © 2014 Qun Sun et al. All rights reserved. Dynamics Modeling of a Continuum Robotic Arm with a Contact Point in Planar Grasp Thu, 20 Nov 2014 07:48:46 +0000 Grasping objects by continuum arms or fingers is a new field of interest in robotics. Continuum manipulators have the advantages of high adaptation and compatibility with respect to the object shape. However, due to their extremely nonlinear behavior and infinite degrees of freedom, continuum arms cannot be easily modeled. In fact, dynamics modeling of continuum robotic manipulators is state-of-the-art. Using the exact modeling approaches, such as theory of Cosserat rod, the resulting models are either too much time-taking for computation or numerically unstable. Thus, such models are not suitable for applications such as real-time control. However, based on realistic assumptions and using some approximations, these systems can be modeled with reasonable computational efforts. In this paper, a planar continuum robotic arm is modeled, considering its backbone as two circular arcs. In order to simulate finger grasping, the continuum arm experiences a point-force along its body. Finally, the results are validated using obtained experimental data. Mohammad Dehghani and S. Ali A. Moosavian Copyright © 2014 Mohammad Dehghani and S. Ali A. Moosavian. All rights reserved. Dynamics Modeling and Control of a Quadrotor with Swing Load Mon, 17 Nov 2014 07:39:03 +0000 Nowadays, aerial robots or Unmanned Aerial Vehicles (UAV) have many applications in civilian and military fields. For example, of these applications is aerial monitoring, picking loads and moving them by different grippers. In this research, a quadrotor with a cable-suspended load with eight degrees of freedom is considered. The purpose is to control the position and attitude of the quadrotor on a desired trajectory in order to move the considered load with constant length of cable. So, the purpose of this research is proposing and designing an antiswing control algorithm for the suspended load. To this end, control and stabilization of the quadrotor are necessary for designing the antiswing controller. Furthermore, this paper is divided into two parts. In the first part, dynamics model is developed using Newton-Euler formulation, and obtained equations are verified in comparison with Lagrange approach. Consequently, a nonlinear control strategy based on dynamic model is used in order to control the position and attitude of the quadrotor. The performance of this proposed controller is evaluated by nonlinear simulations and, finally, the results demonstrate the effectiveness of the control strategy for the quadrotor with suspended load in various maneuvers. S. Sadr, S. Ali A. Moosavian, and P. Zarafshan Copyright © 2014 S. Sadr et al. All rights reserved. Biological Immune System Applications on Mobile Robot for Disabled People Tue, 11 Nov 2014 06:59:32 +0000 To improve the service quality of service robots for the disabled, immune system is applied on robot for its advantages such as diversity, dynamic, parallel management, self-organization, and self-adaptation. According to the immune system theory, local environment condition sensed by robot is considered an antigen while robot is regarded as B-cell and possible node as antibody, respectively. Antibody-antigen affinity is employed to choose the optimal possible node to ensure the service robot can pass through the optimal path. The paper details the immune system applications on service robot and gives experimental results. Songmin Jia, Xue Zhao, Wenbin Qu, and Yuchen Li Copyright © 2014 Songmin Jia et al. All rights reserved. An Ethnomethodological Study of a Museum Guide Robot’s Attempt at Engagement and Disengagement Sun, 19 Oct 2014 12:34:33 +0000 We conducted a study of a museum guide robot’s attempt at engaging and disengaging the audience at predetermined points in time during a guided tour. We used “ethnomethodology” as a tool for our study and analysis. In this paper, we describe how we developed, tested, and analyzed a museum guide robot system that borrows cues from social scientists to manage an audience. We have described how we began our study, the previous studies that we referred to, the initial attempts to test our concept, the development of the system, the real-world experiments, and the analysis of the data that we collected. We have described the tools of engagement and disengagement that the robot has used and presented the results of our statistical analysis of the experimental data. Most prominently, we found that a verbal gesture called “summative assessment” and a nonverbal gesture called the “lean-back” gesture are very effective as tools of disengagement. These tools help a robot guide to manage the audience in the same way as a human guide. Moreover, we found that a combination of the aforementioned two gestures is more effective than employing them separately. Madhumita Ghosh and Hideaki Kuzuoka Copyright © 2014 Madhumita Ghosh and Hideaki Kuzuoka. All rights reserved. Exponential Tracking Control Using Backstepping Approach for Voltage-Based Control of a Flexible Joint Electrically Driven Robot Mon, 08 Sep 2014 08:21:48 +0000 This paper addresses the design of exponential tracking control using backstepping approach for voltage-based control of a flexible joint electrically driven robot (EFJR), to cope with the difficulty introduced by the cascade structure in EFJR dynamic model, to deal with flexibility in joints, and to ensure fast tracking performance. Backstepping approach is used to ensure global asymptotic stability and its common algorithm is modified such that the link position and velocity errors converge to zero exponentially fast. In contrast with the other backstepping controller for electrically driven flexible joint robot manipulators control problem, the proposed controller is robust with respect to stiffness uncertainty and allows tracking fast motions. Simulation results are presented for both single link flexible joint electrically driven manipulator and 2-DOF flexible joint electrically driven robot manipulator. These simulations show very satisfactory tracking performances and the superiority of the proposed controller to those performed in the literature using simple backstepping methodology. Jean Bosco Mbede and Joseph Jean-Baptiste Mvogo Ahanda Copyright © 2014 Jean Bosco Mbede and Joseph Jean-Baptiste Mvogo Ahanda. All rights reserved. Path Following of Autonomous Vehicle in 2D Space Using Multivariable Sliding Mode Control Wed, 20 Aug 2014 08:27:09 +0000 A solution to the path following problem for underactuated autonomous vehicles in the presence of possibly large modeling parametric uncertainty is proposed. For a general class of vehicles moving in 2D space, we demonstrated a path following control law based on multiple variable sliding mode that yields global boundedness and convergence of the position tracking error to a small neighborhood and robustness to parametric modeling uncertainty. An error integration element is added into the “tanh” function of the traditional sliding mode control. We illustrated our results in the context of the vehicle control applications that an underwater vehicle moves along with the desired paths in 2D space. Simulations show that the control objectives were accomplished. Daxiong Ji, Jian Liu, Hongyu Zhao, and Yiqun Wang Copyright © 2014 Daxiong Ji et al. All rights reserved. Cam Drive Step Mechanism of a Quadruped Robot Thu, 10 Jul 2014 00:00:00 +0000 Bionic quadruped robots received considerable worldwide research attention. For a quadruped robot walking with steady paces on a flat terrain, using a cam drive control mechanism instead of servomotors provides theoretical and practical benefits as it reduces the system weight, cost, and control complexities; thus it may be more cost beneficial for some recreational or household applications. This study explores the robot step mechanism including the leg and cam drive control systems based on studying the bone structure and the kinematic step sequences of dog. The design requirements for the cam drive robot legs have been raised, and the mechanical principles of the leg operating mechanism as well as the control parameters have been analyzed. A cam drive control system was constructed using three cams to control each leg. Finally, a four-leg demo robot was manufactured for experiments and it showed stable walking patterns on a flat floor. Qun Sun, Chong Wang, Dongjie Zhao, and Cuihua Zhang Copyright © 2014 Qun Sun et al. All rights reserved. Design, Fabrication, and Swimming Performance of a Free-Swimming Tuna-Mimetic Robot Mon, 26 May 2014 09:30:41 +0000 High efficiency in cruising is a determining factor in developing tuna-mimetic robots. So far, a number of tuna-like robots have been made. Nevertheless, the University of Canterbury has developed its own tuna-like robot called UC-Ika 1 to investigate and to accordingly improve the swimming performance of the biomimetic swimming robots. In order to do so, the propulsion system of a tuna with respect to its thrust and resistive forces is studied. Following that, the fish robot is designed and fabricated considering the tuna propulsion system. The robot is then tested several times to investigate its swimming performance. Comparison of the speed and efficiency of UC-Ika 1 with those of other tuna-like robots shows a promising improvement of cruising performance of UC-Ika 1. Sayyed Farideddin Masoomi, Axel Haunholter, Dominic Merz, Stefanie Gutschmidt, XiaoQi Chen, and Mathieu Sellier Copyright © 2014 Sayyed Farideddin Masoomi et al. All rights reserved. Research of a New 6-Dof Force Feedback Hand Controller System Wed, 16 Apr 2014 07:20:09 +0000 The field of teleoperation with force telepresence has expanded its scope to include manipulation at different scales and in virtual worlds, and the key component of which is force feedback hand controller. This paper presents a novel force feedback hand controller system, including a 3-dof translational and 3-dof rotational hand controllers, respectively, to implement position and posture teleoperation of the robot end effector. The 3-dof translational hand controller adopts innovative three-axes decoupling structure based on the linear motor; the 3-dof rotational hand controller adopts serial mechanism based on three-axes intersecting at one point, improving its overall stiffness. Based on the kinematics, statics, and dynamics analyses for two platforms separately, the system applies big closed-loop force control method based on the zero force/torque, improving the feedback force/torque accuracy effectively. Experimental results show that self-developed 6-dof force feedback hand controller has good mechanical properties. The translational hand controller has the following advantages: simple kinematics solver, fast dynamic response, and better than 0.05 mm accuracy of three-axis end positioning, while the advantages of the rotational hand controller are wide turning space, larger than 1 Nm feedback, greater than 180 degrees of operating space of three axes, respectively, and high operation precision. Xin Gao, Yifan Wang, Jingzhou Song, Qingxuan Jia, and Hanxu Sun Copyright © 2014 Xin Gao et al. All rights reserved. Kinematics, Singularity, and Workspaces of a Planar 4-Bar Tensegrity Mechanism Tue, 25 Mar 2014 09:12:02 +0000 Compared with conventional mechanisms, tensegrity mechanisms have many attractive characteristics such as light weight, high ratio of strength to weight, and accuracy of modeling. In this paper, the kinematics, singularity, and workspaces of a planar 4-bar tensegrity mechanism have been investigated. Firstly, the analytical solutions to the forward and inverse kinematic problems are found by using an energy based method. Secondly, the definition of a tensegrity mechanism’s Jacobian is introduced. As a consequence, the singularity analysis of the planar 4-bar tensegrity mechanism has been completed. Thirdly, the actuator and output workspaces are mapped. Finally, some attractive characteristics of the mechanism are concluded. Zhifei Ji, Tuanjie Li, and Min Lin Copyright © 2014 Zhifei Ji et al. All rights reserved. Kinematics Analysis of a Novel Five-Degree-of-Freedom Spatial Parallel Micromanipulator Tue, 25 Mar 2014 07:27:51 +0000 A study of the inverse kinematics for a five-degree-of-freedom (DOF) spatial parallel micromanipulator is presented here below. The objective of this paper is the introduction of a structural and geometrical model of a novel five-degree-of-freedom spatial parallel micromanipulator, analysis of the effective and useful workspace of the micromechanism, presentation of the obtained analytical solutions of the microrobot’s inverse kinematics tasks, and verification of its correctness using selected computer programs and computation environments. The mathematical model presented in this paper describes the behaviour of individual elements for the applied 2-DOF novel piezoelectric actuator, resulting from the position and orientation of the microrobot’s moving platform. Daniel Prusak, Konrad Kobus, and Grzegorz Karpiel Copyright © 2014 Daniel Prusak et al. All rights reserved. Rehabilitation Robotics 2013 Tue, 18 Mar 2014 09:06:10 +0000 Kazuhiko Terashima, Shigeyuki Suzuki, Oliver Sawodny, Ryojyun Ikeura, Ken'ichi Yano, and Ryo Saegusa Copyright © 2014 Kazuhiko Terashima et al. All rights reserved. Bra.Di.P.O. and P.I.G.R.O.: Innovative Devices for Motor Learning Programs Tue, 11 Mar 2014 00:00:00 +0000 Two mechatronics prototypes, useful for robotic neurotreatments and new clinical trainings, are here presented. P.I.G.R.O. (pneumatic interactive gait rehabilitation orthosis) is an active exoskeleton with an electropneumatic control. It imposes movements on lower limbs in order to produce in the patient’s brain proper motor cortex activation. Bra.Di.P.O. (brain discovery pneumatic orthosis) is an MR-compatible device, designed to improve fMRI (functional magnetic resonance imaging) analysis. The two devices are presented together because both are involved in the study of new robotic treatments of patients affected by ictus or brain stroke or in some motor learning experimental investigations carried out on healthy subjects. Guido Belforte, Gabriella Eula, Silvia Sirolli, Paolo Bois, Elisabetta Geda, Federico D'Agata, Franco Cauda, Sergio Duca, Marina Zettin, Roberta Virgilio, Giuliano Geminiani, and Katiuscia Sacco Copyright © 2014 Guido Belforte et al. All rights reserved. A Large-Scale Multibody Manipulator Soft Sensor Model and Experiment Validation Thu, 06 Feb 2014 14:03:49 +0000 Stress signal is difficult to obtain in the health monitoring of multibody manipulator. In order to solve this problem, a soft sensor method is presented. In the method, stress signal is considered as dominant variable and angle signal is regarded as auxiliary variable. By establishing the mathematical relationship between them, a soft sensor model is proposed. In the model, the stress information can be deduced by angle information which can be easily measured for such structures by experiments. Finally, test of ground and wall working conditions is done on a multibody manipulator test rig. The results show that the stress calculated by the proposed method is closed to the test one. Thus, the stress signal is easier to get than the traditional method. All of these prove that the model is correct and the method is feasible. Wu Ren, Yunxin Wu, Zhaowei Zhang, and Fan Hu Copyright © 2014 Wu Ren et al. All rights reserved. Improving Inverse Dynamics Accuracy in a Planar Walking Model Based on Stable Reference Point Thu, 06 Feb 2014 13:39:51 +0000 Physiologically and biomechanically, the human body represents a complicated system with an abundance of degrees of freedom (DOF). When developing mathematical representations of the body, a researcher has to decide on how many of those DOF to include in the model. Though accuracy can be enhanced at the cost of complexity by including more DOF, their necessity must be rigorously examined. In this study a planar seven-segment human body walking model with single DOF joints was developed. A reference point was added to the model to track the body’s global position while moving. Due to the kinematic instability of the pelvis, the top of the head was selected as the reference point, which also assimilates the vestibular sensor position. Inverse dynamics methods were used to formulate and solve the equations of motion based on Newton-Euler formulae. The torques and ground reaction forces generated by the planar model during a regular gait cycle were compared with similar results from a more complex three-dimensional OpenSim model with muscles, which resulted in correlation errors in the range of 0.9–0.98. The close comparison between the two torque outputs supports the use of planar models in gait studies. Alaa Abdulrahman, Kamran Iqbal, and Gannon White Copyright © 2014 Alaa Abdulrahman et al. All rights reserved. Swarm Robot Control for Human Services and Moving Rehabilitation by Sensor Fusion Sun, 02 Feb 2014 13:01:57 +0000 A current trend in robotics is fusing different types of sensors having different characteristics to improve the performance of a robot system and also benefit from the reduced cost of sensors. One type of robot that requires sensor fusion for its application is the service robot. To achieve better performance, several service robots are preferred to work together, and, hence, this paper concentrates on swarm service robots. Swarm service mobile robots operating within a fixed area need to cope with dynamic changes in the environment, and they must also be capable of avoiding dynamic and static obstacles. This study applies sensor fusion and swarm concept for service mobile robots in human services and rehabilitation environment. The swarm robots follow the human moving trajectory to provide support to human moving and perform several tasks required in their living environment. This study applies a reference control and proportional-integral (PI) control for the obstacle avoidance function. Various computer simulations are performed to verify the effectiveness of the proposed method. Tresna Dewi, Naoki Uchiyama, Shigenori Sano, and Hiroki Takahashi Copyright © 2014 Tresna Dewi et al. All rights reserved. Development of Assistive Robots Using International Classification of Functioning, Disability, and Health: Concept, Applications, and Issues Thu, 19 Dec 2013 11:26:12 +0000 Many assistive robots for elderly and disabled people have been developed in the past few decades. However, very few of them became commercially available. The major cause of the problem is that the cost-benefit ratio and the risk-benefit ratio of them are not good or not known. The evaluation of them should be done in the light of the impacts of assistive technologies on users’ whole life, both in short-term and long-term. In this paper, we propose a framework of evaluation and design of assistive robots using ICF (International Classification of Functioning, Disability, and Health). The goal of the framework is the realization of the life design and the improvement of the quality of life using assistive technologies. We describe the concept of utilizing ICF in the development process of assistive robots, and demonstrate its utility by using some examples of practical application such as the analysis of daily living, the design of assistive robots and the evaluation of assistive robots. We also show the issues of using ICF for further development of the framework. Hideyuki Tanaka, Masahiro Yoshikawa, Eimei Oyama, Yujin Wakita, and Yoshio Matsumoto Copyright © 2013 Hideyuki Tanaka et al. All rights reserved. A Bioinspired 10 DOF Wearable Powered Arm Exoskeleton for Rehabilitation Thu, 12 Dec 2013 12:07:08 +0000 The developed exoskeleton device (Exorn) has ten degrees of freedom to control joints starting from shoulder griddle to wrist to provide better redundancy, portability, and flexibility to the human arm motion. A 3D conceptual model is being designed to make the system wearable by human arm. All the joints are simple revolute joints with desired motion limit. A Simulink model of the human arm is being developed with proper mass and length to determine proper torque required for actuating those joints. Forward kinematics of the whole system has been formulated for getting desired dexterous workspace. A proper and simple Graphical User Interface (GUI) and the required embedded system have been designed for providing physiotherapy lessons to the patients. In the literature review it has been found that researchers have generally ignored the motion of shoulder griddle. Here we have implemented those motions in our design. It has also been found that people have taken elbow pronation and supination motion as a part of shoulder internal and external rotation though both motions are quite different. A predefined resolved motion rate control structure with independent joint control is used so that all movements can be controlled in a predefined way. Soumya Kanti Manna and Subhasis Bhaumik Copyright © 2013 Soumya Kanti Manna and Subhasis Bhaumik. All rights reserved. Exoskeleton Technology in Rehabilitation: Towards an EMG-Based Orthosis System for Upper Limb Neuromotor Rehabilitation Thu, 12 Dec 2013 11:30:22 +0000 The rehabilitation of patients should not only be limited to the first phases during intense hospital care but also support and therapy should be guaranteed in later stages, especially during daily life activities if the patient’s state requires this. However, aid should only be given to the patient if needed and as much as it is required. To allow this, automatic self-initiated movement support and patient-cooperative control strategies have to be developed and integrated into assistive systems. In this work, we first give an overview of different kinds of neuromuscular diseases, review different forms of therapy, and explain possible fields of rehabilitation and benefits of robotic aided rehabilitation. Next, the mechanical design and control scheme of an upper limb orthosis for rehabilitation are presented. Two control models for the orthosis are explained which compute the triggering function and the level of assistance provided by the device. As input to the model fused sensor data from the orthosis and physiology data in terms of electromyography (EMG) signals are used. Luis Manuel Vaca Benitez, Marc Tabie, Niels Will, Steffen Schmidt, Mathias Jordan, and Elsa Andrea Kirchner Copyright © 2013 Luis Manuel Vaca Benitez et al. All rights reserved. Motion Path Design for Specific Muscle Training Using Neural Network Wed, 04 Dec 2013 12:08:24 +0000 Specific muscle training is expected to be used for efficient rehabilitation and care prevention. In this paper, we propose algorithms for designing a motion path capable of strengthening specific muscles. By using the proposed algorithms, it is possible to design a motion path maximizing the activity of an agonist muscle and minimizing that of other muscles. For training, the load is applied by using a 2-link arm. EMG signal is measured during a training experiment, and the degree of muscular revitalization is evaluated by the amplitude of EMG signal. Finally, the effectiveness of the proposed approach is demonstrated through experiments. Kenta Itokazu, Takanori Miyoshi, and Kazuhiko Terashima Copyright © 2013 Kenta Itokazu et al. All rights reserved. An Obstacle Avoidance Method for Action Support 7-DOF Manipulators Using Impedance Control Wed, 20 Nov 2013 09:03:51 +0000 An obstacle avoidance method of action support 7-DOF manipulators is proposed in this paper. The manipulators are controlled with impedance control to follow user's motions. 7-DOF manipulators are able to avoid obstacles without changing the orbit of the end-effector because they have kinematic redundancy. A joint rate vector is used to change angular velocity of an arbitrary joint with kinematic redundancy. The priority of avoidance is introduced into the proposed method, so that avoidance motions precede follow motions when obstacles are close to the manipulators. The usefulness of the proposed method is demonstrated through obstacle avoidance simulations and experiments. Masafumi Hamaguchi and Takao Taniguchi Copyright © 2013 Masafumi Hamaguchi and Takao Taniguchi. All rights reserved. Design and Evaluation of the AIRGAIT Exoskeleton: Leg Orthosis Control for Assistive Gait Rehabilitation Wed, 06 Nov 2013 16:06:27 +0000 This paper introduces the body weight support gait training system known as the AIRGAIT exoskeleton and delves into the design and evaluation of its leg orthosis control algorithm. The implementation of the mono- and biarticular pneumatic muscle actuators (PMAs) as the actuation system was initiated to generate more power and precisely control the leg orthosis. This research proposes a simple paradigm for controlling the mono- and bi-articular actuator movements cocontractively by introducing a cocontraction model. Three tests were performed. The first test involved control of the orthosis with monoarticular actuators alone without a subject (WO/S); the second involved control of the orthosis with mono- and bi-articular actuators tested WO/S; and the third test involved control of the orthosis with mono- and bi-articular actuators tested with a subject (W/S). Full body weight support (BWS) was implemented in this study during the test W/S as the load supported by the orthosis was at its maximum capacity. This assessment will optimize the control system strategy so that the system operates to its full capacity. The results revealed that the proposed control strategy was able to co-contractively actuate the mono- and bi-articular actuators simultaneously and increase stiffness at both hip and knee joints. Mohd Azuwan Mat Dzahir and Shin-Ichiroh Yamamoto Copyright © 2013 Mohd Azuwan Mat Dzahir and Shin-Ichiroh Yamamoto. All rights reserved. Constraint Study for a Hand Exoskeleton: Human Hand Kinematics and Dynamics Mon, 09 Sep 2013 08:58:21 +0000 In the last few years, the number of projects studying the human hand from the robotic point of view has increased rapidly, due to the growing interest in academic and industrial applications. Nevertheless, the complexity of the human hand given its large number of degrees of freedom (DoF) within a significantly reduced space requires an exhaustive analysis, before proposing any applications. The aim of this paper is to provide a complete summary of the kinematic and dynamic characteristics of the human hand as a preliminary step towards the development of hand devices such as prosthetic/robotic hands and exoskeletons imitating the human hand shape and functionality. A collection of data and constraints relevant to hand movements is presented, and the direct and inverse kinematics are solved for all the fingers as well as the dynamics; anthropometric data and dynamics equations allow performing simulations to understand the behavior of the finger. Fai Chen Chen, Silvia Appendino, Alessandro Battezzato, Alain Favetto, Mehdi Mousavi, and Francesco Pescarmona Copyright © 2013 Fai Chen Chen et al. All rights reserved. Using the Functional Reach Test for Probing the Static Stability of Bipedal Standing in Humanoid Robots Based on the Passive Motion Paradigm Thu, 11 Apr 2013 11:52:43 +0000 The goal of this paper is to analyze the static stability of a computational architecture, based on the Passive Motion Paradigm, for coordinating the redundant degrees of freedom of a humanoid robot during whole-body reaching movements in bipedal standing. The analysis is based on a simulation study that implements the Functional Reach Test, originally developed for assessing the danger of falling in elderly people. The study is carried out in the YARP environment that allows realistic simulations with the iCub humanoid robot. Jacopo Zenzeri, Dalia De Santis, Vishwanathan Mohan, Maura Casadio, and Pietro Morasso Copyright © 2013 Jacopo Zenzeri et al. All rights reserved. A Comparison between Two Force-Position Controllers with Gravity Compensation Simulated on a Humanoid Arm Mon, 11 Mar 2013 17:25:25 +0000 The authors propose a comparison between two force-position controllers with gravity compensation simulated on the DEXTER bioinspired robotic arm. The two controllers are both constituted by an internal proportional-derivative (PD) closed-loop for the position control. The force control of the two systems is composed of an external proportional (P) closed-loop for one system (P system) and an external proportional-integrative (PI) closed-loop for the other system (PI system). The simulation tests performed with the two systems on a planar representation of the DEXTER, an eight-DOF bioinspired arm, showed that by varying the stiffness of the environment, with a correct setting of parameters, both systems ensure the achievement of the desired force regime and with great precision the desired position. The two controllers do not have large differences in performance when interacting with a lower stiffness environment. In case of an environment with greater rigidity, the PI system is more stable. The subsequent implementation of these control systems on the DEXTER robotic bioinspired arm gives guidance on the design and control optimisation of the arms of the humanoid robot named SABIAN. Giovanni Gerardo Muscolo, Kenji Hashimoto, Atsuo Takanishi, and Paolo Dario Copyright © 2013 Giovanni Gerardo Muscolo et al. All rights reserved. Simplified Robotics Joint-Space Trajectory Generation with a via Point Using a Single Polynomial Thu, 28 Feb 2013 09:22:44 +0000 This paper presents novel fourth- and sixth-order polynomials to solve the problem of joint-space trajectory generation with a via point. These new polynomials use a single-polynomial function rather than two-polynomial functions matched at the via point as in previous methods. The problem of infinite spikes in jerk is also addressed. Robert L. Williams II Copyright © 2013 Robert L. Williams. All rights reserved. Task Allocation and Path Planning for Collaborative Autonomous Underwater Vehicles Operating through an Underwater Acoustic Network Tue, 19 Feb 2013 15:25:05 +0000 Dynamic and unstructured multiple cooperative autonomous underwater vehicle (AUV) missions are highly complex operations, and task allocation and path planning are made significantly more challenging under realistic underwater acoustic communication constraints. This paper presents a solution for the task allocation and path planning for multiple AUVs under marginal acoustic communication conditions: a location-aided task allocation framework (LAAF) algorithm for multitarget task assignment and the grid-based multiobjective optimal programming (GMOOP) mathematical model for finding an optimal vehicle command decision given a set of objectives and constraints. Both the LAAF and GMOOP algorithms are well suited in poor acoustic network condition and dynamic environment. Our research is based on an existing mobile ad hoc network underwater acoustic simulator and blind flooding routing protocol. Simulation results demonstrate that the location-aided auction strategy performs significantly better than the well-accepted auction algorithm developed by Bertsekas in terms of task-allocation time and network bandwidth consumption. We also demonstrate that the GMOOP path-planning technique provides an efficient method for executing multiobjective tasks by cooperative agents with limited communication capabilities. This is in contrast to existing multiobjective action selection methods that are limited to networks where constant, reliable communication is assumed to be available. Yueyue Deng, Pierre-Philippe J. Beaujean, Edgar An, and Edward Carlson Copyright © 2013 Yueyue Deng et al. All rights reserved. Computationally Efficient Iterative Pose Estimation for Space Robot Based on Vision Thu, 07 Feb 2013 13:31:51 +0000 In postestimation problem for space robot, photogrammetry has been used to determine the relative pose between an object and a camera. The calculation of the projection from two-dimensional measured data to three-dimensional models is of utmost importance in this vision-based estimation however, this process is usually time consuming, especially in the outer space environment with limited performance of hardware. This paper proposes a computationally efficient iterative algorithm for pose estimation based on vision technology. In this method, an error function is designed to estimate the object-space collinearity error, and the error is minimized iteratively for rotation matrix based on the absolute orientation information. Experimental result shows that this approach achieves comparable accuracy with the SVD-based methods; however, the computational time has been greatly reduced due to the use of the absolute orientation method. Xiang Wu and Ning Wu Copyright © 2013 Xiang Wu and Ning Wu. All rights reserved. Minimum Energy Demand Locomotion on Space Station Mon, 28 Jan 2013 09:41:25 +0000 The energy of a space station is a precious resource, and the minimization of energy consumption of a space manipulator is crucial to maintain its normal functionalities. This paper first presents novel gaits for space manipulators by equipping a new gripping mechanism. With the use of wheels locomotion, lower energy demand gaits can be achieved. With the use of the proposed gaits, we further develop a global path planning algorithm for space manipulators which can plan a moving path on a space station with a minimum total energy demand. Different from existing approaches, we emphasize both the use of the proposed low energy demand gaits and the gaits composition during the path planning process. To evaluate the performance of the proposed gaits and path planning algorithm, numerous simulations are performed. Results show that the energy demand of both the proposed gaits and the resultant moving path is also minimum. Wing Kwong Chung and Yangsheng Xu Copyright © 2013 Wing Kwong Chung and Yangsheng Xu. All rights reserved.