Actuator Gain Distributions in Serial Robotic Manipulators to Meet Specified Task Requirements

2008 ◽  
Author(s):  
Oziel Rios ◽  
Delbert Tesar
Keyword(s):  
Configuration Management ◽  
Robotic Manipulators ◽  
Effective Length ◽  
Management Problem ◽  
Motor Speed ◽  
Analytic Process ◽  
Performance Specifications ◽  
Finite Set ◽  
Manipulator Arm ◽  
System Output

A serial robotic manipulator arm is a complex electro-mechanical system whose performance is highly characterized by its actuators. The actuator itself is a complex nonlinear system whose performance can be represented by the speed and torque capabilities of its motor and its accuracy depends on the resolution of the encoder as well as its ability to resist deformations under load. The mechanical gain associated with the transmission is critical to the overall performance of the actuator since it amplifies the motor torque thus improving the force capability of the manipulator housing it, reduces the motor speed to a suitable output speed operating range, enables an improvement in responsiveness (acceleration) and amplifies the stiffness improving the precision under load of the overall system. In this work, a basic analytic process that can be used to manage the actuator gain parameters to obtain an improved arm design based on a set of desired/required performance specifications will be laid out. Key to this analytic process is the mapping of the actuator parameters (speed, torque, stiffness and encoder resolution) to their effective values at the system output via the mechanical gains of the actuators as well as the effective mechanical gains of the manipulator. This forward mapping of the actuator parameters allows the designer to determine how each of the parameters influences the functional capacity of the serial manipulator arm. The actuator gains are then distributed along the effective length of the manipulator to determine the distribution effects on the performance capabilities of the system. The analytic formulation is used to address the issue of configuration management of serial robotic manipulators where the goal is to assemble a system from a finite set of components that meets some required performance specifications. To this end, two examples demonstrating a solution of the configuration management problem are presented. In the first, a manipulator is configured that is intended for light-duty applications while in the second, several manipulators intended for medium and heavy-duty applications are configured. The analytic process developed in this work can reduce the effort in the initial phases of the design process and the total number of design iterations can be reduced.

Actuator Gain Distributions to Analytically Meet Specified Performance Capabilities in Serial Robot Manipulators

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Oziel Rios ◽  
Delbert Tesar
Keyword(s):  
Configuration Management ◽  
Effective Length ◽  
Management Problem ◽  
Motor Speed ◽  
Analytic Process ◽  
Performance Specifications ◽  
Serial Robot ◽  
Manipulator Arm ◽  
System Output ◽  
Forward Mapping

A serial robotic manipulator arm is a complex electromechanical system whose performance is characterized by its actuators. The actuator itself is a complex nonlinear system whose performance can be characterized by the speed and torque capabilities of its motor, and its accuracy depends on the resolution of the encoder as well as its ability to resist deformations under load. The mechanical gain associated with the transmission is critical to the overall performance of the actuator since it amplifies the motor torque, thus improving the force capability of the manipulator housing it, reduces the motor speed to a suitable output speed operating range, and amplifies the stiffness improving the precision under load of the overall system. In this work, a basic analytic process that can be used to manage the actuator gain parameter to obtain an improved arm design based on a set of desired/required performance specifications will be laid out. Key to this analytic process is the mapping of the actuator parameters (speed, torque, stiffness, and encoder resolution) to their effective values at the system output via the mechanical gains of the actuators as well as the effective mechanical gains of the manipulator. This forward mapping of the actuator parameters allows the designer to determine how each of the parameters influences the functional capacity of the serial manipulator arm. The actuator gains are then distributed along the effective length of the manipulator to determine their effects on the performance capabilities of the system. The analytic formulation is also demonstrated to be effective in addressing the issue of configuration management of serial robotic manipulators where the goal is to assemble a system that meets some required performance specifications. To this end, two examples demonstrating a solution of the configuration management problem are presented. The analytic process developed based on the mapping of the mechanical parameters of the actuator to their effective values at the system output is shown to dramatically reduce the effort in the initial phases of the design process, meaning that the number of design iterations can be dramatically reduced.

The Elastica With End-Load Flip-Over

1988 ◽  
Vol 55 (4) ◽  
pp. 845-848 ◽  
Author(s):  
J. F. Wilson ◽  
J. M. Snyder
Keyword(s):  
Cantilever Beam ◽  
Abrupt Change ◽  
Robotic Manipulators ◽  
Finite Deformations ◽  
Follower Load ◽  
System Parameters ◽  
Small Increment ◽  
Elastic Curves ◽  
Manipulator Arm

A high flexure manipulator arm is modeled as an elastic cantilever beam with a tip payload and an eccentric tip follower load that drives the arm. Shapes of the resulting elastic curves for finite deformations (the elastica) are calculated in terms of nondimensional system parameters. For critical combinations of these parameters, a small increment in the driving follower load causes an abrupt change in the shape of the elastica. The abrupt change in tip angle is typically of the order of π radians. These results are applicable to the design of high flexure robotic manipulators.

scholarly journals Finding the Optimal Parameters for Robotic Manipulator Applications of the Bounded Error Algorithm for Iterative Learning Control

2017 ◽  
Vol 47 (4) ◽  
pp. 3-11 ◽  
Author(s):  
Kaloyan Yovchev
Keyword(s):  
Computer Simulation ◽  
Iterative Learning Control ◽  
Robotic Manipulators ◽  
Learning Control ◽  
Robotic Manipulator ◽  
Iterative Learning ◽  
Optimal Parameters ◽  
Manipulator Arm ◽  
Bounded Error ◽  
Optimal Values

Abstract This paper continues previous research of the Bounded Error Algorithm (BEA) for Iterative Learning Control (ILC) and its application into the control of robotic manipulators. It focuses on investigation of the influence of the parameters of BEA over the convergence rate of the ILC process. This is performed first through a computer simulation. This simulation suggests optimal values for the parameters. Afterwards, the estimated results are validated on a physical robotic manipulator arm. Also, this is one of the first reports of applying BEA into robots control.

Feedback Linearizing Control of Surge in an Axial Compression System: Theory and Experimental Validation

1995 ◽  
Author(s):  
O. O. Badmus ◽  
S. Chowdhury ◽  
C. N. Nett
Keyword(s):  
Feedback Control ◽  
Closed Loop ◽  
Controller Design ◽  
Dynamic Pressure ◽  
Axial Compressor ◽  
State Feedback Control ◽  
Effective Length ◽  
Control Input ◽  
System Input ◽  
System Output

This paper presents experimental demonstration of surge stabilization in an axial compressor rig with a feedback linearizing controller. The controller design approach is model-based, and hence a nonlinear surge model for the facility is first validated. The surge model is a modification of the classic one-dimensional incompressible fluid surge model, with an effective length function incorporated, to account for the increased path-length of the fluid in the compressor due to the imparted tangential forces of the blade. This model, which adequately describes the observed surge dynamics both in terms of amplitude and frequency of oscillation, is then used to develop the feedback control law. The feedback linearizing control input implicitly linearizes the dynamics between the system input, throttle area parameter, and the system output, inlet dynamic pressure. A linear state feedback control input, implemented on the feedback linearized system thus ensures stabilization of the surge dynamics in the original nonlinear model. Finally, the nonlinear based observer is included in closed loop implementation to enhance the tracking of the system output, and also to minimize the adverse effect of measurement noise, thereby improving closed loop system performance.

Effective Tool-Point Acceleration of Serial Chain Mechanisms Based on Basic Geometric Transformations

2009 ◽  
Vol 1 (4) ◽  
Author(s):  
Oziel Rios ◽  
Delbert Tesar
Keyword(s):  
Modular Design ◽  
Configuration Management ◽  
Optimal Solution ◽  
Point Force ◽  
Transmission Ratio ◽  
Management Problem ◽  
Geometric Transformations ◽  
Serial Chain ◽  
Six Dof ◽  
Forward Kinematic

In this paper, a method to manage the actuator parameters of a serial chain mechanism composed of revolute joints to achieve improved responsiveness characteristics (acceleration capability) based on the basic geometric parameters of the mechanism is presented. Here, an analytic framework presented by the authors in an earlier work, which exploits the geometric structure of this type of mechanism is extended to address the tool-point mass and acceleration. The manipulator’s geometry is reduced to a set of lengths, which are representative of the mechanical gains associated with the manipulator and they, along with the transmission ratio of the actuators, are used to map the actuator parameters to their effective values at the tool-point where a direct comparison to the task requirements can be made. With this method, minimal computations are required to evaluate the system’s performance since only the forward kinematic computations are required. The effects of the actuator transmission ratio parameter on the effective tool-point force, mass, and acceleration are investigated for a six-DOF serial chain manipulator. Through this case study, it is demonstrated how the transmission ratio is managed to balance the system’s effective tool-point force and mass to obtain an optimal tool-point acceleration. In addition to the investigation of the effects of the actuator parameters, the method is shown to be useful in the solution of the configuration management or modular design problem since the exponential design space can be searched for a globally optimal solution with minimal computations. The goal of the configuration management problem is to quickly configure and/or reconfigure a robotic manipulator from a finite set of actuator modules.

Teaching Manipulator Kinematics by Painting With Light

2011 ◽  
Author(s):  
Michael Shomin ◽  
Jonathan Fiene
Keyword(s):  
Inverse Kinematics ◽  
Three Dimensional ◽  
Robotic Manipulators ◽  
Video Camera ◽  
Robotic Arm ◽  
End Effector ◽  
Teaching Platform ◽  
Manipulator Arm ◽  
Servo Controller ◽  
Six Degree Of Freedom

In this paper, we examine the creation and benefits of a new teaching platform to introduce and reinforce the key concepts of robotic manipulators in an introductory-level robotics course. This system combines a vintage PUMA 260 six-degree-of-freedom robotic arm with modern control circuitry and a Matlab API. The API operates as a servo controller for the robot, thereby allowing students to apply their knowledge of inverse kinematics to a real manipulator arm. To further motivate the exploration of manipulators, we have developed an open-ended project where students engage in the art of three-dimensional light painting. To facilitate this activity, a tricolor LED has been affixed to the end-effector of the robot. With a digital SLR camera, we take a long-exposure photograph as the robot is driven through a trajectory, effectively painting a picture with the end effector. We have also developed a method to quickly assemble pseudo-long-exposure photographs and videos using an inexpensive video camera. We believe this novel setup and project are an effective way to engage and motivate students to learn the underlying math and dynamics of robotic manipulators.

Practical Tracking Control Under Actuator Saturation for a Class of Flexible-Joint Robotic Manipulators Driven by DC Motors

2022 ◽  
Author(s):  
Jian Li ◽  
Lingling Zhu
Keyword(s):  
Tracking Control ◽  
Actuator Saturation ◽  
Reference Signal ◽  
Robotic Manipulators ◽  
Flexible Joint ◽  
Related Literature ◽  
Dc Motors ◽  
System Output ◽  
Compensation Technique ◽  
Theoretical Results

Abstract This paper is devoted to the practical tracking control for a class of flexible-joint robotic manipulators driven by DC motors. Different from the related literature where control constraint is neglected and the disturbances are excluded or only exist in one subsystem, actuator saturation is considered in this paper while the disturbances are present in all the three subsystems. This leads to the incapability of the traditional schemes on this topic. For this, a novel control design scheme is proposed by skillfully incorporating adaptive dynamic compensation technique, constructive methods of command filters and an auxiliary system for the actuator saturation into the backstepping framework, and in turn to design a practical tracking controller which ensures that all the states of the resulting closed-loop system are bounded and the system output practically tracks the reference signal. It is worthwhile strengthening that a more wider class of reference signals can be tracked since they are only first order continuously differentiable but twice or more in the related literature. Finally, a numerical example is provided to validate the effectiveness of the proposed theoretical results.

Task-Based Configuration Management for Modular Serial Robotic Manipulators

2007 ◽  
Author(s):  
Oziel Rios ◽  
Ganesh Krishnamoorthy ◽  
Aaron Hulse ◽  
Lucas Koran ◽  
Benjamin Gully ◽  
...  
Keyword(s):  
Performance Metrics ◽  
Robotic Manipulators ◽  
Optimization Methods ◽  
Task Requirements ◽  
Pick And Place ◽  
Finite Set ◽  
System Requirements ◽  
Pick And Place Operation ◽  
Insight Into ◽  
Nonlinear Nature

Modular robotic systems have become popular in recent years due to the ease of reconfigurability to satisfy varying task requirements. Due to the nonlinear nature of the actuator performance parameters, it is often difficult to map component specifications to the overall system performance making it cumbersome to use these parameters to design the system. Specifying system requirements based on task specifications, on the other hand, provides greater insight into how the system must perform in order to complete a given task and the resources required to achieve this performance. In this paper, we present a method for optimal design of modular robotic manipulators using a finite set of actuators to execute various tasks. Three different tasks — material removal, welding and a pick-and-place operation — which have different requirements in terms of the force, speed, precision and energy required to perform them, are considered. A set of five actuators is used to form different serial robotic manipulator configurations whose ability to accomplish the task is then evaluated using various performance metrics. A sequential filtering method is used to eliminate infeasible manipulator configurations and the remaining feasible set of manipulator configurations are then optimized using the weighted sum and compromise multiobjective optimization methods to determine a Pareto optimal manipulator configuration to accomplish each of the three tasks individually, in addition to a fourth manipulator configuration that is capable of accomplishing all the three tasks.

scholarly journals Worked out Results of IPCCR Framework for AMS Projects

2018 ◽  
Vol 7 (2.32) ◽  
pp. 86
Author(s):  
Srinivasa Rao Kosiganti ◽  
Dr Y. Prasanth
Keyword(s):  
Change Management ◽  
Configuration Management ◽  
Incident Management ◽  
Management Problem ◽  
Problem Management ◽  
Management Change ◽  
Important Concept ◽  
Release Management

The IPCCR framework that was designed to reduce CAPEX and OPEX of Application Support and Maintenance Projects, has helped to understand Incident, Problem, Change, Configuration and Release and directly impacts the costs that are accrued.  Using Proper Incident Management, Problem Management, Change Management, Configuration Management and Release Management, which are the key ingredients of ITIL V3.2 and DevOps reduces the costs of Capital Expenses and Operational Expenses.  The important concept of Known Error Database will subsequently reduce the Operational Expenses as much as possible.  

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