Robot Control

We report on our empirical studies of a new controller for a two-link brachiating robot. Motivated by the pendulum-like motion of an ape's brachiation, we encode this task as the output of a "target dynamical system." Numerical simulations indicate that the resulting controller solves a number of brachiation problems that we term the "ladder," "swing-up," and "rope" problems. Preliminary analysis provides some explanation for this success. The proposed controller is implemented on a physical system in our laboratory. The robot achieves behaviors including "swing locomotion" and "swing up" and is capable of continuous locomotion over several rungs of a ladder. We discuss a number of formal questions whose answers will be required to gain a full understanding of the strengths and weaknesses of this approach.

A globally convergent adaptive control scheme for robot motion control with the following features is proposed. First, the adaptation law possesses enhanced robustness with respect to noisy velocity measurements. Second, the controller does not require the inclusion of high gain loops that may excite the unmodeled dynamics and amplify the noise level. Third, we derive for the unknown parameter design a relationship between compensator gains and closed-loop convergence rates that is independent of the robot task. A simulation example of a two-DOF manipulator features some aspects of the control scheme.

This paper describes a Virtual Reality (VR) based system for automating data collection and surveying in a retail store using mobile robots. The manpower cost for surveying and monitoring the shelves in retail stores are high, because of which these activities are not repeated frequently causing reduced customer satisfaction and loss of revenue. Further, the accuracy of data collected may be improved by avoiding human related factors. We use a mobile robot platform with on-board cameras to monitor the shelves either autonomously or through tele-operation. A remote operator can control the robot from a console which shows a 3D of view of the store as well as, capture real images and videos of the store. The robot is designed to facilitate automatic detection of Out-of-Stock (OOS) situations. It would be possible for a single operator to control multiple robots placed at different stores thus optimizing the available resources. As the deployment of the proposed system does not require...

This paper describes design and implementation of a vision based platform for automated refueling tasks. The platform is an autonomous docking system in principle, with the specific application-refueling of vehicles. The system is based on monochromatic, monocular vision, and it utilizes very specialized image processing schemes. Image processing consists of very fast filtering and segmenting algorithms, as well as moment's computation. A robotic arm with 6 joints (FANUC M-6i), and a controller unit (R-J3), does the physical work. A serial interface, with very high-level commands, connects a supercomputing machine and the robot's controller. A practical setup would probably be scaled down to a special design robot, and a single processor controller with special VLSI chips for image processing. Results are very promising; the robot can identify the cap position, orientation, and height in real time with acceptable accuracy and reliability.

A continuous finite-time control scheme for rigid robotic manipulators is proposed using a new form of terminal sliding modes. The robustness of the controller is established using the Lyapunov stability theory. Theoretical analysis and simulation results show that faster and high-precision tracking performance is obtained compared with the conventional continuous sliding mode control method.

Trajectory generation has traditionally been formulated on the assumption that the environment is flat. On rough terrain, however, deviations of the angular velocity vector from the vertical lead to errors which accumulate in a manner similar to the accumulation of attitude errors in odometry. In practice, feedback control can compensate for these errors in modeling by adjusting the path in real time. In many realistic cases, however, the 3D shape of the terrain is known beforehand, so it is possible to incorporate terrain shape into the predictive model-rather than treat it as an unknown disturbance. This paper presents an algorithm for trajectory generation which compensates for terrain shape in a predictive fashion. The numerical implementation makes it adaptable readily to a broad class of vehicles and even a broad class of predictable disturbances beyond terrain shape. In support of the latter, we demonstrate the ability to invert models of actuator dynamics and wheel slip concurrently with 3D terrain. An example application for a the Rocky 7 Mars rover platform is presented.

Um Roboter auch in Anwendungen einsetzen zu können, für die klassische Industrierobotersteuerungen nicht geeignet sind, braucht es einfache, beherrschbare, zuverlässige und sichere Steuerungen, die aber offener, flexibler und ausbaufähiger sind als jene klassischer industrieller Roboter. Dass die Kosten für die Entwicklung solcher Robotersteuerungen sehr hoch sind, stellt eine grosse Barriere für den Markteintritt dieser Produkte dar. EEROS realisiert deshalb eine industriefähige Open Source Robotersoftware, welche die Flexibilität einer universellen und offenen Plattform bietet, aber trotzdem sicher und gleichzeitig einfach zu warten ist.

Intensive task-oriented repetitive physical therapies provided by individualized interaction between the patient and a rehabilitation specialist can improve hand motor performance in patients survived from stroke and traumatic brain injury. However, the therapy process is long and expensive and difficult to evaluate quantitatively and objectively. The goal of this research is to develop a novel wearable device for robotic assisted hand repetitive therapy. We designed a pneumatic muscle (PM) driven therapeutic device that is wearable and provides assistive forces required for grasping and release movements. The robot has two distinct degrees of freedom at the thumb and the fingers. The embedded sensors feedback position and force information for robot control and quantitative evaluation of task performance. It has the potential of providing supplemental at-home therapy in addition to in the clinic treatment.

There are five major elements required for the development of an intelligent robot system. Four of these are architectures: 1. Conceptual architecture 2. Functional architecture 3. Software architecture 4. Hardwarearchitecture The fifth element is the software development environment. The original NASREM document describes the conceptual architecture, and suggests the outlines of a functional architecture. Recent work at NIST is defming the functional architecture of the servo and primitive levels, and suggesting the outlines of software and hardware architectures. and s o f t w m development environments.

In this paper we consider the problem of controlling multiple robots manipulating and transporting an object in three dimensions via cables. We develop robot configurations that ensure static equilibrium of the object at a desired pose while respecting bounded tension constraints. Workspace and stability considerations are discussed as well as the effects of actuation and sensing errors on the performance

Currently, a major difficulty for the widespread use of robots in assembly and material handling comes from the necessity of feeding accurately positioned workpieces to robots. ``Bin picking'' techniques help reduce this constraint. This paper presents the application of matched filters for enabling robots with vision to acquire workpieces randomly stored in bins. This approach complements heuristic methods already reported. The concept of matched filter is an old one. Here, however, it is redefined to take into account robot end-effector features, in terms of geometry and mechanics. In particular, the proposed filters match local workpiece structures where the robot end-effector is likely to grasp successfully and hold workpieces. The local nature of the holdsites is very important as computation costs are shown to vary with the fifth power of structure size. In addition, the proposed filters tend to have a narrow angular bandwidth. An example, which features a parallel-jaw hand is developed in detail, using both statistical and Fourier models. Both approaches concur in requiring a very small number of filters (typically four), even if a good orientation accuracy is expected (two degrees). Success rates of about 90 percent in three or fewer attempts have been experimentally obtained on a system which includes a small minicomputer, a 128 × 128 pixel solidstate camera, a prototype Cartesian robot, and a ``universal'' parallel-jaw hand.

A flexible needle can be accurately steered by robotically controlling the orientation of the bevel tip as the needle is inserted into tissue. Here, we demonstrate the significant effect of friction between the long, flexible needle shaft and the tissue, which can cause a significant discrepancy between the orientation of the needle tip and the orientation of the base where the needle is controlled. Our experiments show that several common phantom tissues used in needle steering experiments impart substantial frictional forces to the needle shaft, resulting in a lag of over 45° for a 10 cm insertion depth in some phantoms; clinical studies have reported torques large enough to could cause similar errors during needle insertions. Such angle discrepancies will result in poor performance or failure of path planners and image-guided controllers, since the needles used in percutaneous procedures are too small for state-of-the-art imaging to accurately measure the tip angle. To compensate...

Human-robot interaction (HRI) for mobile robots is still in its infancy. Most user interactions with robots have been limited to tele-operation capabilities where the most common interface provided to the user has been the video feed from the robotic platform ...

In common industrial robots the mechanical and electrical structure as well as the control algorithms are given and constitute a closed system. This paper presents an alternative: a modular robot system that is regarded not as an isolated technical product, but as a part of an integrated solution. Instead of adapting an application to a given robot system, we are trying to adapt the robot to the application. A flexible robot system should be supported by a flexible, extendible and configurable controller. Through a teach pendant it is possible to record ·named points and/or complex trajectories. These can interactively be edited and joined to form operations. Real time programming is made simple by use of process and time primitives. The necessary routines for using these features are available. Joints, motors, sensors and also filters, control algorithms and the geometry of the robot can be described and parametrised through the configuration language of the control system .

This review considers some important landmarks in animal evolution, asking to what extent specialized action selection mechanisms play a role in the functional architecture of different nervous system plans, and looking for ‘forced moves’ or ‘good tricks’ (Dennett, 1995) that could possibly transfer to the design of robot control systems. A key conclusion is that while cnidarians (e.g. jellyfish) appear to have discovered some good tricks for the design of behavior-based control systems—largely lacking specialized selection mechanisms; the emergence of bilaterians may have forced the evolution of a central ganglion, or ‘archaic brain’, whose main function is to resolve conflicts between peripheral systems. Whilst vertebrates have many interesting selection substrates it is likely that here too, the evolution of centralized structures such as the medial reticular formation and the basal ganglia may have been a forced move due to the need to limit connection costs as brains increased in size.

Current available robotic systems provide limited support for CAD-based model-driven visualization, sensing algorithm development and integration, and automated graphical planning systems, This paper describes ongoing work which provides the functionality necessary to apply advanced robotics to automated manufacturing and assembly operations. An interface has been built which incorporates 6-DOF tactile manipulation, displays for three dimensional graphical models, and automated tracking functions which depend on automated machine vision. A set of tools for single and multiple focal plane sensor image processing and understanding has been demonstrated which utilizes object recognition models. The resulting tool will enable sensing and planning from computationally simple graphical objects.

Recently, robotic based monitoring system framework has seen a fast development as far as innovation established. Temperature and humidity for any real product design is most widely recognized the physical estimation architects. The need to ensure a safer environment, to cut down production losses and monitor certain delicate conditions in which production activities are carried out is very vital within industries in the present age. The objectives of this study are to design a prototype mobile robot to measure the temperature and humidity of an environment, to design an algorithm that could be used to control the robot via mobile using a Bluetooth technology. The design of a prototype mobile robot method in this study elaborates hardware and software implementation. The prototypes of mobile robot functioned significantly to full capacity and displayed the measured temperature and humidity values on a 16×2 LCD screen located in the robot and send a copy to smart phone. The prototype design module defined the temperature and humidity for a specified or particular area corresponding with the movement of robot via Bluetooth when the application scope located in few meters.

E-mail system has been designed once to be one of the most reliable internet services. All possible steps were taken in the protocol to assure either a positive delivery of e-mail or the return of an error message. This is now circumvented in many ways by various antispam techniques and the SMTP protocol cannot be considered reliable anymore. The paper discusses some of the current SMTP protocol modifications that are considered harmful and proposes a way for maintaining the reliability of the protocol while increasing the immunity to spam.

The robotics literature of the last two decades contains many important advances in the control of flexible joint robots. This is a survey of these advances and an assessment for future developments, concentrated mostly on the control issues of flexible joint robots.

This paper presents the design of a decupled sliding mode control algorithm for the PUMA 560 robot arm position control. The Lagrange-Euler model of the robot is used for calculation of control law. Computer simulations of the robot with the decoupled sliding mode control and exact and non-exact model are described. The control algorithm is simple and has a good robustness with respect to the robot model uncertainty.

A macro/micro manipulator system, consisting of a large (macro) robot carrying n small (micro) high-performance robot, has been proposed as a means of enhancing the functionality of n manipulator. The objective of the research presented in this' paper was to investigate the inherent features in dynamic performance of such a system, and to evaluate its feasibility.

{ Whenever a sensor is mounted on a robot hand it is important t o k n o w the relationship between the sensor and the hand. The problem of determining this relationship is referred to as the hand-eye calibration problem. Hand-eye calibration is important in at least two types of tasks: (i) map sensor centered measurements into the robot workspace frame and (ii) allow the robot to precisely move the sensor. In the past some solutions were proposed in the particular case of the sensor being a TV camera. With almost no exception, all existing solutions attempt to solve a homogeneous matrix equation of the form AX = X B . This paper has the following main contributions. First we show that there are two possible formulations of the hand-eye calibration problem. One formulation is the classical one that we just mentioned. A second formulation takes the form of the following homogeneous matrix equation: M Y= M 0 Y B . The advantage of the latter formulation is that the extrinsic and intrinsic parameters of the camera need not be made explicit. Indeed, this formulation directly uses the 3 4 perspective matrices (M and M 0 ) associated with 2 positions of the camera with respect to the calibration frame. Moreover, this formulation together with the classical one cover a wider range of camera-based sensors to be calibrated with respect to the robot hand: single scan-line cameras, stereo heads, range nders, etc. Second, we develop a common mathematical framework to solve for the hand-eye calibration problem using either of the two formulations. We represent rotation by a unit quaternion. We present two methods, (i) a closed-form solution for solving for rotation using unit quaternions and then solving for translation and (ii) a non-linear technique for simultaneously solving for rotation and translation. Third, we perform a stability analysis both for our two methods and for the classical linear method developed by Tsai & Lenz TL89]. This analysis allows the comparison of the three methods. In the light of this comparison, the non-linear optimization method, that solves for rotation and translation simultaneously, seems to be the most robust one with respect to noise and to measurement errors.

Abstract—This paper presents a control strategy for indus-trial robot manipulators which consists of the combination of a calibration-free, vision-based control method with an impedance control approach. The vision-based, robot control method known as camera-space manipulation ...

CONTROLAB is an environment which integrates intelligent systems and control algorithms aiming at applications in the area of robotics. Within CONTROLAB, two neural network architectures based on the backpropagation and the recursive models are proposed for the implementation of a robust speaker-independent word recognition system. The robustness of the system using the backpropagation network has been largely verified through use by children and adults in a totally uncontrolled environment such as large public halls for the exhibition of new technology products. Initial experimental results with the recursive network show that it will be able to overcome the backpropagation network major drawback, which is the frequent generation of false alarms. In addition, within CONTROLAB, a multivariable self-tuning algorithm is proposed to perform high-precision control of the trajectory, to be followed by a robot arm. High-precision control is achieved due to the ability of the algorithm to ...

The complexity of walking robots poses a number of control problems due to the large number of degrees of freedom involved in the robot's motion. This work deals with the design of a hexapod robot, whose legs have 3 rotative joints and the same configuration. The kinematics ...

A general neural-network (connectionist) model for fuzzy logic control and decisioddiagnosis systems is proposed. The proposed connectionist model can be contrasted with the traditional fuzzy logic control and decision system in their network structure and learning ability. Such fuzzy controVdecision networks can be constructed from training examples by machine learning techniques, and the connectionist structure can be trained to develop fuzzy logic rules and find optimal input/output membership functions. By combining both unsupervised (selforganized) and supervised learning schemes, the learning speed converges much faster than the original backpropagation learning algorithm. This connectionist model also provides humanunderstandable meaning to the normal feedforward multilayer neural network in which the internal units are always opaque to the users. The connectionist structure also avoids the rulematching time of the inference engine in the traditional fuzzy logic system. ' h o examples are presented to illustrate the performance and applicability of the proposed connectionist model. Index T e m -Connectionist, distributed representation, defuzzifier, fuzzifier, fuzzy logic rule, membership function, receptive field, supervised and unsupervised learning. I. INTRODUCITON URING the past decade, fuzzy logic [ l ] has found a D variety of applications in various fields ranging from industrial process control [2], [3] to medical diagnosis [4] and securities trading [SI. Most notably, a fuzzy logic system has been applied to control nonlinear, time-varying, ill-defined systems [2], to control systems whose dynamics are exactly known, such as servomotor position control [6] and robot arm control [7], and to manage complex decision-making or diagnosis systems [4], [5].

With this project, we aim to design a robot arm. This robot arm will be controlled wirelessly through a wearable glove. This will be done via a bluetooth connection. Moreover, the use of many circuit elements they use in their own projects for beginners will be shown. Systems can be briefly you out with this project:
• Arduino use,
• Use of  bluetooth module,
• Communication between two Arduinos,
• Using Servo motor with Flex sensor data.
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Intelligent control can significantly improve the performance of a robotic manipulator. The paper will review some ways of incorporating intelligence into a robotic control system. Specific attention will be given to techniques of approximate reasoning, particularly fuzzy-logic-based control. First, several concepts of approximation will be explored and their application in approximate reasoning will be discussed. A general model for knowledge-based decision making will be presented, and the special cases as applicable to some common concepts of approximation will be studied. Practical example considered will include sensor-based manipulation in fish processing tasks, which employs on-line measurement of task impedance; tuning of parameters of a robotic motion controller; and intelligent restructuring of a flexible production system that consists of multiple, robotic workcells. Other trends and possibilities will be indicated.

Typical quadrotor aerial robots used in research weigh less than 3 kg and carry payloads measured in hundreds of grams. Several obstacles in design and control must be overcome to cater for expected industry demands that push the boundaries of existing quadrotor performance. The X-4 Flyer, a 4 kg quadrotor with a 1 kg payload, is intended to be prototypical of useful commercial quadrotors. The custom-built craft uses tuned plant dynamics with an onboard embedded attitude controller to stabilise flight. Independent linear SISO controllers were designed to regulate flyer attitude. The performance of the system is demonstrated in indoor and outdoor flight.