bluuebunny/crossref_metadata_2025_split huggingface dataset:
A study of application areas for modular robots
Authors: Harrison R. , Western R. H. , Moore P. R. , Thatcher T. W. 
Published: March 2009

SUMMARYThe paper describes a study of potential industrial applications where modular robots can be used in preference to conventional pedestal mounted robots and/or specially designed automatic machines. The study was conducted with reference to a particular family of pneumatically actuated robot modules.The paper also describes a modular robotic system which was designed to automate assembly processes in the manufacture of a family of egg coddlers. The manipulator comprises multi-axis groups of modules which operate concurrently to perform the assembly operations. Flexibility is incorporated through the use of a hierarchical control system architecture.
An approach for negating the view that technology ‘competes’ with humans
Authors: Primrose P. L. , Leonard R. 
Published: March 2009

SUMMARYEngineers have traditionally invested in Advanced Manufacturing Technology (AMT), such as FMS, Robots, CAD/CAM, CNC and MRP to achieve a reduction in the labour force. Similarly, government incentives for introducing AMT, have also placed an undue emphasis on the ‘need to replace labour with technology’. This policy creates severe industrial relations problems and leads to the view that technology, especially robots, ‘competes’ with human beings for employment. Research at U.M.I.S.T. has shown that AMT is much more viable when the objective of the investment is to increase a company's overall competitive ability, thereby generating increased sales which, in turn, necessitates an INCREASED labour force. The paper discusses various aspects of AMT and in each case it is shown how the acceptability of the investment is improved when the new technology is viewed ‘company-wide’. When this occurs, technology is viewed as being ‘complementary to’ and not ‘instead of’ humans.
Robust tracking control for robot manipulators: theory, simulation, and implementation
Authors: Dawson D. , Quf† Z. , Duffie J. 
Published: March 2009

SUMMARYIn this paper, we propose a robust controller for the tracking of robot motion. This controller is a nonlinear-based controller that compensates for the uncertainties present in the manipulator dynamic equation. The main result of this paper is that we explicitly show how the response of the tracking error can be modified by adjusting the control parameters. The corresponding stability result for the tracking error is Global Exponential Stability (GES). We then illustrate how similar control approaches are related to the proposed controller. Finally, simulation and experimental results are utilized to illustrate the performance of the robust controller.
Geometric tools for the off-line programming of robots
Authors: Stobart R. K. 
Published: March 2009

SUMMARYOff-line programming of robots has a number of clear advantages over traditional ‘teach1’ methods which require the robot to be taken out of production. However, off-line programming techniques require extensive geometric facilities which are ideally provided by a geometric modelling system.The use of modelling covers the planning of the robot workcell, as well as the detailed planning of the robot operations. Assembly, in particular, requires detailed geometric information concerning geometric features and solid properties.
Towards sensor-based general purpose robot programming language
Authors: Milovanovic Rajko 
Published: March 2009

SUMMARYWe present an analysis of currently available user language facilities for sensor-based programming of robot assembly tasks. A common criterion is defined that a language support for sensor-based programming must satisfy. Finally, drawing upon a novel mechanism of generalized exception, we present a framework for a complete solution of these problems in a high level block structured and complex language, as well as a possible implementation of such tools.
A structured geometric database in an off-line robot programming system
Authors: Aken L. Van , Brussel H. Van 
Published: March 2009

SUMMARYThis work describes a hierarchically structured geometric database in an off-line robot programming system. The data structure contains the numerical definition of the frame variables, as well as an indicator of the respective reference frames. Moreover, the physical relations between the objects in the environment are included. The database is implemented such that it continuously reflects the actual structure of the environment. As a result, all calculations of the frame locations are carried out automatically. Moreover, the programming system is capable to autonomously updating the numerical information after changes in the environment. Making this database the heart of a robot programming system greatly simplifies the off-line programming of complex robot tasks, like f.i. assembly tasks.
Iterative learning control with feedback using Fourier series with application to robot trajectory tracking
Authors: Lee Jong-Woon , Lee Hak-Sung , Bien Zeungnam 
Published: March 2009

SUMMARYThe Fourier series is employed to approximate the input/output (I/O) characteristics of a dynamic system and, based on the approximation, a new learning control algorithm is proposed in order to find iteratively the control input for tracking a desired trajectory. The use of the Fourier series approximation of I/O renders at least a couple of useful consequences: the frequency characteristics of the system can be used in the controller design and the reconstruction of the system states is not required. The convergence condition of the proposed algorithm is provided and the existence and uniqueness of the desired control input is discussed. The effectiveness of the proposed algorithm is illustrated by computer simulation for a robot trajectory tracking. It is shown that, by adding a feedback term in learning control algorithm, robustness and convergence speed can be improved.
An investigation of fuzzy logic control of flexible robots
Authors: Lin Yueh-Jaw , Lee Tian-Soon 
Published: March 2009

SUMMARYIn this paper a control law, which consists of a fuzzy logic controller plus a nonlinear effects negotiator for a flexible robot manipulator, is presented. The nonlinear effects negotiator is used to enhence the control system's ability in dealing with the uncertainty of the mathematical model. The control algorithm is simple and easy to tune as opposed to conventional control law which requires time consuming gains selections. To obtain fuzzy control rules, an error response plane method is proposed.
Learning control for robot motion under geometric end-point constraint
Authors: Arimoto Suguru , Naniwa Tomohide 
Published: March 2009

SUMMARYLearning control is a new approach to the probelm of skill refinement for robotic manipulators. It is considered to be a mathematical model of motor program learning for skilled motions in the central nervous system.This paper proposes a class of learning control algorithms for improving operations of the robot arm under a geometrical end-point constraint at the next trial on the basis of the previous operation data. The command input torque is updated by a linear modification of present joint velocity errors deviated from the desired velocity trajectory in addition to the previous input. It is shown that motion trajectories approach an e-neighborhood of the desired one in the sense of squared integral norm provided the local feedback loop consists of both position and velocity feedbacks plus a feedback term of the error force vector between the reactive force and desired force on the end-point constrained surface. It is explored that various passivity properties of residual error dynamics of the manipulator play a crucial role in the proof of uniform boundedness and convergence of position and velocity trajectories.
Minimum jerk for trajectory planning and control
Authors: Kyriakopoulos K.J. , Saridis G.N. 
Published: March 2009

SUMMARYIt has been experimentally verified that the jerk of the desired trajectory adversely affects the performance of the tracking control algorithms for robotic manipulators. In this paper, we investigate the reasons behind this effect, and state the trajectory planning problem as an optimization problem that minimizes a norm of joint jerk over a prespecified Cartesian space trajectory. The necessary conditions are derived and a numerical algorithm is presented.
An approach to autonomous robot assembly
Authors: Koditschek Daniel E. 
Published: March 2009

SUMMARYAssembly problems require that a robot with fewer actuated degrees of freedom manipulate an environment containing a greater number of unactuated degrees of freedom. From the perspective of control theory, these problems hold considerable interest because they are characterized by the presence of non-holonomic constraints that preclude the possibility of feedback stabilization. In this sense they necessitate the introduction of a hierarchical controller. This paper explores these issues in the simple instance when all of the pieces to be assembled are constrained to lie on a line. A hierarchical controller is devised for this problem and is shown to be correct: the closed loop system achieves any desired final assembly from all initial configurations that lie in its connected component in configuration space; the generated sequence of motions never causes collisions between two pieces. Further examination of this approach interprets the controller's mediation of conflicting subgoals as promoting an M-player game amongst the pieces to be assembled.
Information-efficient robotic control
Authors: Maimon Oded , Last Mark 
Published: March 2009

SUMMARYThe work demonstrates a new approach to design of a level of intelligent control of robotic systems. The analytical model results in operational decisions. The structure of these decisions make them readily available to be implemented as an expert system. The approach is applied to a case study of mobile supervisory robots. The model presented here was motivated by manufacturing robotic systems and a type of autonomous robots that collect information at different sites for safety and other control purposes. The robot actions are directly affected by the obta~ned data. At each site the amount of available information (and thus the correctness of the robot decision) can be increased if the robot keeps collecting data at that site for a longer period of t~me. This means a delay in reacting and in reaching next site and accordingly, a decrease in the general amount of robot's information on the whole system.The method of finding an economic amount of information collected by a robot at each site is based on the theory of controlled discrete event stochastic systems developed in our earlier works. This theory combines he basic concepts of discrete event control extended to stochastic systems with some aspects of information economics.
A qualitative theoretical framework for ‘common-sense’ based multiple contact robotic manipulation
Authors: Ananthanarayanan S.P. , Goldenberg A.A. , Mylopoulos J. 
Published: March 2009

SUMMARYThis paper presents a qualitative theoretical formulation for synthesis and analysis of multiple contact dexterous manipulation of an object, using a robot hand. The motivation for a qualitative theory is to build a formalisation of ‘human-like’ common-sense reasoning in robotic manipulation. Using this formalisation, a robot hand can perform finger-tip manipulative movements by analysing the physical laws that govern the robot hand, the object, and their interaction. Traditionally, such analysis have been framed in quantitative terms leading to mathematical systems which become intractable very quickly. Also, quantitative synthesis and analysis, often demand an accurate specification of the parameters in the universe of discourse, which is almost impossible to provide. The qualitative approach inherently encounters both these problems successfully.The qualitative theory is presented in three developmental stages. A qualitative framework of spatial information in the context of dexterous manipulation has been provided. Qualitative models of an object configuration and transformations in them that occur during a manipulation process, have been developed. Finally, the development of a ‘quasi-static’ qualitative framework of a dexterous manipulation process that performs the desired object transformation, has been presented.
Using NASREM for telerobot control system development
Authors: Lumia Ronald 
Published: March 2009

SummaryUsing a functional architecture such as the NASA/NIST Standard Reference Model for Telerobot Control System Architecture (NASREM) to implement specific applications is helpful because much of the work resides in the infrastructure and the infrastructure is the same for all applications. Rather than recreating this infrastructure, our approach is to develop the additional 20% of the code which tailors the infrastructure for the specific application. This paper describes the process by which a system based on NASREM is developed.
Solving the motion planning problem by using neural networks
Authors: Chan R.H.T. , Tam P.K.S. , Leung D.N.K. 
Published: March 2009

SUMMARYThis paper presents a new neural networks-based method to solve the motion planning problem, i.e. to construct a collision-free path for a moving object among fixed obstacles. Our ‘navigator’ basically consists of two neural networks: The first one is a modified feed-forward neural network, which is used to determine the configuration space; the moving object is modelled as a configuration point in the configuration space. The second neural network is a modified bidirectional associative memory, which is used to find a path for the configuration point through the configuration space while avoiding the configuration obstacles. The basic processing unit of the neural networks may be constructed using logic gates, including AND gates, OR gates, NOT gate and flip flops. Examples of efficient solutions to difficult motion planning problems using our proposed techniques are presented.
A tactile sensor based on thin-plate deformation
Authors: Ellis R.E. , Ganeshan S.R. , Lederman S.J. 
Published: March 2009

SUMMARYTraditionally, tactile sensors have been designed using compliant, rubber-like materials; when such a sensitized gripper grasps or otherwise manipulates an object, the normal strain deformation in the compliant material is sampled. The resulting information can be used to deduce simple local geometry of the contact, but the transduction process does not typically permit use of the individual strains in determining large-scale properties of the object (e.g., the inertia). Measurements of inertial parameters of grasped objects require accurate, low-hysteresis transduction that few tactile sensors currently provide.An alternative is to work from the task specification, and determine the tactile information that is necessary to accomplish the task. Here, we consider how to sense the length and mass of a uniform object that is gripped in a gravitational field, and show the design and assessment of a new kind of tactile sensor that is based on the theory of the deformation of thin plates. Features of this design include its potentially rugged realization, and its high-accuracy measurement that is more typical of force sensors than of tactile sensors.
On the use of optical fibres in a pulsed time-of-flight laser rangefinder
Authors: Nissilä Seppo , Kostamovaara Juha 
Published: March 2009

SummaryThe pulsed time-of-flight laser rangefinding technique has been used in many industrial measurement applications, including 3D-coordinate measuring devices, hot surface profilers and mobile robot sensors. Optical fibres, typically 1–10 m in length and 100–400 μm in diameter can be used to guide optical pulses to the separate sensing head of the measurement device. The use of a large multimode fibre may cause problems, however, when aiming at millimetre accuracy, as the construction and adjustment of the optics of the sensor head may affect the transit time linearity and measurement accuracy via multimode dispersion. Environmental effects, such as bending, vibration due to the moving sensing head and temperature, also cause measurement errors. The error sources are studied and characterized in this paper.
A tuning procedure for stable PID control of robot manipulators
Authors: Kelly Rafael 
Published: March 2009

SummaryIn this paper we propose some simple rules for PID tuning of robot manipulators. The procedure suggested requires the knowledge of the structure of the inertia matrix and the gravitational torque vector of the robot dynamics, but only upper bounds on the dynamics parameters are needed. This tuning procedure is extracted from the stability analysis by using a suitable Lyapunov function together with the LaSalle invariance principle. We show that with this guideline, the overall closed-loop system is asymptotically stable. This procedure is illustrated for a two degrees-of-freedom robot
A motion planning strategy for multifingered hands considering sliding and rolling contacts
Authors: Chong Nak Young , Choi Donghoon , Suh Il Hong 
Published: March 2009

SummaryAn algorithm for the motion planning of the multifingered hand is proposed to generate finite displacements and changes in orientation of objects by considering sliding contacts as well as rolling contacts between the fingertip and the object at the contact point. Specifically, a nonlinear optimization problem is firstly formulated and solved to find the minimum joint velocity and the minimum contact force to impart a desired motion to the object at each time step. Then, the relative velocity at the contact point is found by calculating the velocity of the fingertip and the object at the contact point. Finally, time derivatives of the surface variables and the contact angle of the fingertip and the object at the current time step is computed using the Montana's contact equation to find the contact parameters of the fingertip and the object at the next time step. To show the validity of the proposed algorithm, a numerical example is illustrated by employing the robotic hand manipulating a sphere with three fingers each of which has four joints
Stochastic Hamilton's principle and noisy sliding surfaces in the tracking control of manipulators
Authors: Jumarie Guy 
Published: March 2009

SummaryIn the tracking control of manipulators via the sliding scheme, it may happen that sometimes, because of various inaccuracies, the definition of the actual sliding surface involves errors terms which may be either deterministic or, on the contrary, stochastic. This paper considers this last case and shows how one can estimate the new performances of the system so disturbed. A stochastic Hamilton's principle is applied, by combining the Lagrange parameter technique with results of the dynamic programming approach.
A new representation for a robot grasping quality measure
Authors: Varma Venugopal K. , Tasch Uri 
Published: March 2009

SummaryWhen an object is held by a multi-fingered hand, the values of the contact forces can be multivalued. An objective function, when used in conjunction with the frictional and geometric constraints of the grasp, can however, give a unique set of finger force values. The selection of the objective function in determining the finger forces is dependent on the type of grasp required, the material properties of the object, and the limitations of the röbot fingers. In this paper several optimization functions are studied and their merits highlighted. The paper introduces a graphical representation of the finger force values and the objective functions that enable one to select and compare various grasping configurations. The impending motion of the object at different torque and finger force values are determined by observing the normalized coefficient of friction plots.
The method of minimal neighborhood: a new and most effective iterative method for minimum cost trajectory planning in robot manipulators
Authors: Duleba Ignacy 
Published: March 2009

SummaryIn this paper a method of minimal neighborhood for cost optimal trajectory planning along prescribed paths is introduced. The method exploits the phase-plane approach. In the phase-plane, in an iterative procedure, subareas of search are built, called neighborings, which surround the current-best trajectory. In each iteration, in order to find the next-best trajectory, the dynamic programming (pruned to the subarea) is used. The method of minimal neighborhood makes the neighborings as small as possible and therefore speeds up computations maximally. The tests carried out on a model of the IRb-6 ASEA robot have shown that the method of minimal neighborhood is much faster than dynamic programming applied to the whole phase-plane, while preserving the quality of the resulting trajectory.
Coping with joint velocity limits in first-order inverse kinematics algorithms: analysis and real-time implementation
Authors: Chiacchio Pasquale , Chiaverini Stefano 
Published: March 2009

SummaryA major problem in inverse kinematics algorithms is that the generated joint velocities to be fed to the joint servos may cause violation of the speed limits of the joint actuators. In this paper, it is shown how to properly cope with joint velocity limits in first-order inverse kinematics algorithms; the proposed technique guarantees tracking of the desired end-effector path. This goal is achieved by suitably slowing down the task-space trajectory when joint velocity limits are encountered. The time law is modified through a time warp such that the introduced virtual time allows fulfillment of the velocity constraints. A case study is developed to show the effectiveness of the proposed method and a kinematic control scheme based on the presented technique is implemented to demonstrate feasibility under real-time constraints.
Comparing two algorithms for automatic planning by robots in stochastic environments
Authors: Christiansen Alan D. , Goldberg Kenneth Y. 
Published: March 2009

SummaryPlanning a sequence of robot actions is especially difficult when the outcome of actions is uncertain, as is inevitable when interacting with the physical environment. In this paper we consider the case of finite state and action spaces where actions can be modeled as Markov transitions. Finding a plan that achieves a desired state with maximum probability is known to be anNP-Completeproblem. We consider two algorithms: an exponential-time algorithm that maximizes probability, and a polynomial-time algorithm that maximizes a lower bound on the probability. As these algorithms trade off plan time for plan quality, we compare their performance on a mechanical system for orienting parts. Our results lead us to identify two properties of stochastic actions that can be used to choose between these planning algorithms for other applications.
A novel approach to flexible robotic assembly systems
Authors: Billatos Samir B. 
Published: March 2009

SummaryThis paper presents a novel approach to designing and manufacturing of a universal gripper to be used with industrial robots in flexible assembly systems. Important issues that impact greatly on the efficiency of the gripper are also discussed in this paper. Such issues include the degree of compliance allowed by the robotic wrist and the way these grippers are actuated. The gripper has been proven to be extremely flexible and low in cost.