Much has been written about theory and practice in the law, and the tension between practitioners and theorists. Judges do not cite theoretical articles often; they rarely "apply" theories to particular cases. These arguments are not revisited. Instead the Essay explores the working and interaction of theory and practice, practitioners and theorists. The Essay starts with a story about solving a legal issue using our intellectual tools - theory, practice, and their progenies: experience and "gut." Next the Essay elaborates on the nature of theory, practice, experience and "gut." The third part of the Essay discusses theories that are helpful to practitioners and those that are less helpful. The Essay concludes that practitioners theorize, and theorists practice. They use these intellectual tools differently because the goals and orientations of theorists and practitioners, and the constraints under which they act, differ. Theory, practice, experience and "gut" help us think, remember, decide and create. They complement each other like the two sides of the same coin: distinct but inseparable.

Of Theory and Practice

Open Dynamics Engine を用いたスノーボードロボットシミュレータの開発

The actuator power required to resist joint torque caused by the weight of robot links can be a significant problem. Gravity compensation is a well-known technique in robot design to achieve equilibrium throughout the range of motion and as a result to reduce the loads on the actuator. Therefore, it is desirable and commonly implemented in many situations. Various design concepts for gravity compensation are available in the literature. This paper proposes an overview of gravity compensation methods applied in robotics. The examined properties of the gravity compensation are disclosed and illustrated via kinematic schemes. In order to classify the considered balancing schemes three principal groups are distinguished due to the nature of the compensation force: counterweight, spring or active force developed by an auxiliary actuator. Then, each group is reviewed through sub-groups organized via structural features of balancing schemes. The author believes that such an arrangement of gravity compensation me...

Gravity compensation in robotics

Pacific Conference on Computer Graphics and Applications

In this paper, we present an efficient method based on geometric algebra for computing the solutions to the inverse kinematics problem (IKP) of the 6R robot manipulators with offset wrist. Due to the fact that there exist some difficulties to solve the inverse kinematics problem when the kinematics equations are complex, highly nonlinear, coupled and multiple solutions in terms of these robot manipulators stated mathematically, we apply the theory of Geometric Algebra to the kinematic modeling of 6R robot manipulators simply and generate closed-form kinematics equations, reformulate the problem as a generalized eigenvalue problem with symbolic elimination technique, and then yield 16 solutions. Finally, a spray painting robot, which conforms to the type of robot manipulators, is used as an example of implementation for the effectiveness and real-time of this method. The experimental results show that this method has a large advantage over the classical methods on geometric intuition, computation and real-time, and can be directly extended to all serial robot manipulators and completely automatized, which provides a new tool on the analysis and application of general robot manipulators.

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Solution of Inverse Kinematics for 6R Robot Manipulators With Offset Wrist Based on Geometric Algebra

Diagnosis measurement of vibration and noise, should allow monitoring of equipment defects, through a system of preventive maintenance, predictive. Automatic diagnosis of machinery and equipment was made in order to ensure a higher reliability of these and how to obtain a more extended life cycle without the occurrence of defects. Vibrations are always measured in analog format (time domain) and must be transformed into the frequency domain. Therefore Fast Fourier Transform (FFT) method is used to evaluate vibration Almega AX-V6 robot. The application of preventive and predictive maintenance management supports enterprise, because it proves effective, the information you provide in making decisions.

Establishing the State of Operation on Vibration Behavior of the Industrial Robot

In controlling the movements of the end-effector and joints of a manipulator in the workspace, an important problem is to identify the joints' best relative displacements to assure extreme precisions for the end-effector movements. Applications where multiple manipulators with a common controller are to be controlled in 3D space are more challenging compared to single robot control since the movements of the end-effectors of all robots must be determined using complex forward and inverse kinematics. In this paper, to solve the inverse kinematics problem in robots with redundant chains, a hybrid method that combines the convergence process through proper Iterative Pseudo Inverse Jacobian Matrix Method (IPIJMM) with the filtering of the errors by the Bipolar Sigmoid Hyperbolic Tangent Neural Network Method with Time Delay and Recurrent Links (BSHTNNM-TDRL). We have presentpd mathematical models of forward kinematics of a system of multiple manipulators, as well as the developed proper iterative algorithm to obtain spatial conventional and unconventional curves in different Euler planes for a case study of three robots moving simultaneously with extreme end-effector precision of less than 0.001 mm. We have shown how a system of three robots can be considered as a single parallel robot structure with three independent robotic components. The presented method is a numerical iterative approximation technique equipped with an intelligent error reduction algorithm, and together with the employed Virtual Instrumentations (VI) can be generalized to other robots tracking any conventional and unconventional space curves.

Achieving extreme precisions for multiple manipulators using a proper coupled neural network matrix method and LabVIEW instrumentation

The actual required productivity, accuracy and reliability impose that the robots must be optimized concerning the dynamic behavior. The joints and robots bodies are necessary to be optimized for their usability performance to assure the productivity requirements. The global dynamic compliance (GDC) is one of the most important dynamic parameters of the dynamic behavior of the industrial robots. The viscose global dynamic damper coefficient (VGDDC) is other important parameter of the dynamic behavior what must be optimized to obtain the desired dynamic behavior, the avoiding of the resonance frequencies. The paper shows one new assisted method of the GDC analyzes of the industrial robot with LabVIEW virtual instrumentation (VI) in three different cases: with/without smart magnetorheological damper (MRD) and with aero damper. The created VI-s assures to obtain the assisted research of the dynamic behavior. With this research was possible to determine in the frequencies domain, the robot GDC and the viscose global dynamic damper equivalent coefficient (VGDDEC) value in a case with MRD and finally the transmission of the vibration from the floor to the robot’s tool center point (TCP). This method and the created virtual LabVIEW instrumentation are generally and they are possible to apply in many others dynamic behavior researches.

Optimizing the Global Dynamic Compliance by Using the Smart Damper and LabVIEW Instrumentation

One of the most important problem to solve in the robots Kinematics and Dynamics is analyze of the joint’s angular and linear accelerations. Because the movements of the robot’s bodies going in the 3D space, the mathematical algorithm must be written in the complex matrix form. The paper show how some cases of the trapezoidal relatives’ velocities characteristics in a joints determine the variation of the acceleration’s vectors in the 3D space. The maximal values of these variations of the angular and linear accelerations influence the variation of the moments and forces. The analyze was made by using the Neutrosophic theory and vitual LabVIEW instrumentation. In a literature are described some methods of the assisted analyze of the acceleration without show the used mathematical model, without one critical analyze of the cases that must be avoid and finally without some conclusions for the researchers. The paper shown all LabVIEW virtual instruments (VI) used for this assisted research. By solving the assisted research of the acceleration will be open the way to the assisted research of the robots’ dynamic behavior, to choose the optimal constructive and functional parameters (dimensions of the bodies, simultaneously, successive or complex configurations of the movements in the robot’s joints, optimal values of the constant relative joint’s velocities, etc.) of the robots to obtain the minimum variation of the forces and moments. The method that was shown in the paper solves one small part of the complex problems of the robot’s kinematics and dynamics.

Neutrosophic Theory Applied in the Multi Objectives Optimization of the Robot’s Joints Accelerations with the Virtual LabVIEW Instrumentation

Assisted analyze of the elements and systems with Extenics theory is necessary to choose the optimal value and the optimal minim field called the attraction field of the working point. With this study easily can be determined all influences to the current working point. The Extenics theory was defined by prof.Cai Wen in 1983 and contents the mathematical, philosophy and logical models with the goal to solve the contradictory problem. This paper show the applying the Extenics theory to the optimal choose of the working area of the hydraulic cylinder in the precision-stability field and define some classes of this precision-stability by using the Extenics transformations and dependent functions. The research was made by using the proper virtual LabVIEW instrumentation with the possibility to work on-line and to see all transformation of the dynamic behavior. We established the affiliation of one precision-stability classes by see the changes of the proper form of the dependent function values in the used 2D dimensions. The paper shown the assisted study case of the contraction transformation defining finally the minimal attraction field like the optimized place of the working point.

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Adrian Olaru

Papers

Establishing the State of Operation on Vibration Behavior of the Industrial Robot

Achieving extreme precisions for multiple manipulators using a proper coupled neural network matrix method and LabVIEW instrumentation

Optimizing the Global Dynamic Compliance by Using the Smart Damper and LabVIEW Instrumentation

Neutrosophic Theory Applied in the Multi Objectives Optimization of the Robot’s Joints Accelerations with the Virtual LabVIEW Instrumentation

Solving of the contradictory problem of the precision- Stability by using the extenics theory