scholarly journals On the Redundant-Drive Backlash-Free Robotic Mechanisms

1993 ◽  
Vol 115 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Sun-Lai Chang ◽  
Lung-Wen Tsai
Keyword(s):  
Dynamic Performance ◽  
End Effector ◽  
Joint Torques ◽  
Performance Requirements ◽  
Compliance Problem ◽  
Under Construction ◽  
Fail Safe ◽  
Gear Meshes ◽  
Redundant Drive ◽  
Innovative Concept

In this paper, we introduce a new and innovative concept for the control of backlash in gear-coupled robotic mechanisms. The concept utilizes redundant unidirectional drives to assure positive coupling of gear meshes at all times. Based on this concept, a methodology for the enumeration of admissible redundant-drive backlash-free robotic mechanisms has been established. Some typical two- and three-DOF mechanisms have been sketched. Furthermore, actuator torques have been derived as functions of either joint torques or end-effector dynamic performance requirements. A redundantly driven manipulator has the fail-safe advantage in that, except for the loss of backlash control, it can continue to function when one of its actuators fails. It does not have the compliance problem associated with tendon-driven manipulators. A two-DOF backlash-free experimental arm is currently under construction to demonstrate the principle.

scholarly journals Optimization of Dynamic Task Location within a Manipulator’s Workspace for the Utilization of the Minimum Required Joint Torques

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 288
Author(s):  
Adam Wolniakowski ◽  
Charalampos Valsamos ◽  
Kanstantsin Miatliuk ◽  
Vassilis Moulianitis ◽  
Nikos Aspragathos
Keyword(s):  
High Performance ◽  
Human Robot Interaction ◽  
Optimal Position ◽  
End Effector ◽  
Joint Torques ◽  
Dynamic Task ◽  
Arbitrary Position ◽  
Simulation Results ◽  
Set Up ◽  
Task Placement

The determination of the optimal position of a robotic task within a manipulator’s workspace is crucial for the manipulator to achieve high performance regarding selected aspects of its operation. In this paper, a method for determining the optimal task placement for a serial manipulator is presented, so that the required joint torques are minimized. The task considered comprises the exercise of a given force in a given direction along a 3D path followed by the end effector. Given that many such tasks are usually conducted by human workers and as such the utilized trajectories are quite complex to model, a Human Robot Interaction (HRI) approach was chosen to define the task, where the robot is taught the task trajectory by a human operator. Furthermore, the presented method considers the singular free paths of the manipulator’s end-effector motion in the configuration space. Simulation results are utilized to set up a physical execution of the task in the optimal derived position within a UR-3 manipulator’s workspace. For reference the task is also placed at an arbitrary “bad” location in order to validate the simulation results. Experimental results verify that the positioning of the task at the optimal location derived by the presented method allows for the task execution with minimum joint torques as opposed to the arbitrary position.

A Mechatronic Approach to Compact Fluid Disc Valve Design

1995 ◽  
Vol 209 (2) ◽  
pp. 115-125
Author(s):  
G A Parker ◽  
Y B Sun
Keyword(s):  
Low Cost ◽  
Dynamic Performance ◽  
Operating Mode ◽  
Industrial Applications ◽  
Test Results ◽  
Valve Design ◽  
Electromagnetic Characteristics ◽  
High Control ◽  
Fail Safe ◽  
Pilot Valve

The work presented in this paper deals mainly with a mechatronic approach to compact disc valve design and concentrates on improvements to the disc valve electromagnetic characteristics, the diaphragm design and the dynamic performance. A novel diaphragm-disc force motor has been successfully developed incorporating a pair of permanent ring magnets. It has the advantages of low electric power consumption at the null position, dual-lane electrical structure for fail-safe operation, high control accuracy and should be competitive with existing torque motors due to its low cost and simple construction. The research involved designing and testing a prototype disc pilot valve with a dual-lane operating mode. The test results showed that the valve has satisfactory static and dynamic characteristics for industrial applications.

Reliability-Based Design Optimization of Robotic System Dynamic Performance

2006 ◽  
Vol 129 (4) ◽  
pp. 449-454 ◽  
Author(s):  
Alan P. Bowling ◽  
John E. Renaud ◽  
Jeremy T. Newkirk ◽  
Neal M. Patel ◽  
Harish Agarwal
Keyword(s):  
Design Optimization ◽  
Reference Point ◽  
High Reliability ◽  
Dynamic Performance ◽  
Performance Measure ◽  
Robotic System ◽  
Reliability Based Design Optimization ◽  
End Effector ◽  
Reliability Based Design ◽  
Reliable Design

In this investigation a robotic system’s dynamic performance is optimized for high reliability under uncertainty. The dynamic capability equations (DCE) allow designers to predict the dynamic performance of a robotic system for a particular configuration and reference point on the end effector (i.e., point design). Here the DCE are used in conjunction with a reliability-based design optimization (RBDO) strategy in order to obtain designs with robust dynamic performance with respect to the end-effector reference point. In this work a unilevel performance measure approach is used to perform RBDO. This is important for the reliable design of robotic systems in which a solution to the DCE is required for each constraint call. The method is illustrated on a robot design problem.

Influence of End-Effector Velocities on Robotic Manipulator Dynamic Performance: An Analytical Approach

2003 ◽  
Author(s):  
ChangHwan Kim ◽  
Alan Bowling
Keyword(s):  
Quadratic Forms ◽  
Dynamic Performance ◽  
Optimal Solution ◽  
Problem Formulation ◽  
Optimization Techniques ◽  
Curve Analysis ◽  
Centrifugal Forces ◽  
End Effector ◽  
Nonconvex Problem ◽  
Torque Curve

This article explores the effect that end-effector velocities have on a nonredundant robotic manipulator’s ability to accelerate its end-effector as well as to apply forces/moments to the environment at the end-effector. The velocity effects considered here are the Coriolis and Centrifugal forces, and the reduction of actuator torque with rotor velocity, as described by the speed-torque curve. Analysis of these effects is accomplished using optimization techniques, where the problem formulation consists of a cost function and constraints which are all purely quadratic forms, yielding a nonconvex problem. An analytical solution, based on the dialytic elimination technique, is developed which guarantees that the globally optimal solution can be found. The PUMA 560 manipulator is used as an example to illustrate this methodology.

Optimization of Controllers for Gas Turbine Based on Probabilistic Robustness

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Chuanfeng Wang ◽  
Donghai Li ◽  
Zheng Li ◽  
Xuezhi Jiang
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Controller Design ◽  
Dynamic Performance ◽  
Optimization Method ◽  
Monte Carlo Experiment ◽  
Performance Requirements ◽  
System Robustness ◽  
Manufacturing Tolerances ◽  
Probabilistic Robustness

An optimization method for controller parameters of a gas turbine based on probabilistic robustness was described in this paper. As is well known, gas turbines, like many other plants, are stochastic. The parameters of a plant model are often of some uncertainties because of errors in measurements, manufacturing tolerances and so on. According to model uncertainties, the probability of satisfaction for dynamic performance requirements was computed as the objective function of a genetic algorithm, which was used to optimize the parameters of controllers. A Monte Carlo experiment was applied to test the control system robustness. The advantage of the method is that the entire uncertainty parameter space can be considered for the controller design; the systems could satisfy the design requirements in maximal probability. Simulation results showed the effectiveness of the presented method in improving the robustness of the control systems for gas turbines.

Design of Optimum Controller of APT Fine Tracking Control System

2013 ◽  
Vol 712-715 ◽  
pp. 2738-2741 ◽  
Author(s):  
Ming Qiu Li ◽  
Shu Hua Jiang
Keyword(s):  
Pid Control ◽  
Tracking Control ◽  
Control Algorithm ◽  
Tracking System ◽  
Dynamic Performance ◽  
Tracking Error ◽  
Stable State ◽  
Response Speed ◽  
Optimum Control ◽  
Performance Requirements

APT (Acquisition, Pointing, and Tracking) system of space laser communication adopts compound axis structure; it consists of coarse tracking and fine tracking system. Its response speed and tracking precision mainly rests with the fine tracking system. Traditional PID control algorithm often is used in APT fine tracking system. In order to improve the dynamic performance of the system and decrease the tracking error, optimum control technology was adopted in this paper. On the basis of considering the system dynamic performance requirements and tracking precision requirement, optimum controller was designed. The simulation result shows that the bandwidth of APT fine tracking system is up to 1310 Hz, and the stable state error is less than 0.002. Compared with PID control, optimum control can improve the tracking performance of system.

Optimisation of Diesel Engine for Hybrid Military Tracked Vehicles using Matlab-Simulink

2017 ◽  
Vol 67 (4) ◽  
pp. 360
Author(s):  
Hari Viswanath ◽  
A. Kumaraswamy ◽  
P. Sivakumar
Keyword(s):  
Diesel Engine ◽  
Dynamic Performance ◽  
Fuel Efficiency ◽  
Negative Power ◽  
Matlab Simulink ◽  
Performance Requirements ◽  
In Series ◽  
And Performance ◽  
High Power Batteries ◽  
Operating Points

<p class="Abstract">The demand in the technology requirements for diesel engines is growing keeping hybrid vehicles in mind. In future the diesel engine no longer drives the wheels directly; as a result the engine can be engaged at a limited number of operating points, thus, offering an opportunity to optimise the fuel efficiency and performance at those operating points. The extent to which this optimisation is possible is limited by practical considerations. Also if the positive and negative power peaks in vehicle during mobility (e.g. acceleration and regenerative braking respectively) can be accommodated by high-power batteries, then the size of the engine can be considerably reduced. The engine’s operating points depend on the power-control strategy. The consequences of modifications to these operating points will have an effect on performance and efficiency. As in series hybrid only a limited number of operating points are involved and dynamic performance requirements are not imposed on the diesel engine, significant improvements can be achieved by the optimisation of the diesel engine at these operating points. The feasibility of optimisation of the engine at these operating points can be done by modification on the injection systems, the valve timings and other such parameters. This kind of approach requires the use of complex and repeated experimental analysis of the engine which is costly, cumbersome and time consuming. An alternative to this kind of experimental approach is to develop a simulation model of the engine with the generator in Matlab- Simulink.</p>

Velocity Effects on Robotic Manipulator Dynamic Performance

2006 ◽  
Vol 128 (6) ◽  
pp. 1236-1245 ◽  
Author(s):  
Alan P. Bowling ◽  
ChangHwan Kim
Keyword(s):  
Quadratic Forms ◽  
Degrees Of Freedom ◽  
Optimization Problem ◽  
Dynamic Performance ◽  
Optimal Solution ◽  
Optimization Methods ◽  
Optimization Techniques ◽  
End Effector ◽  
Coriolis Forces ◽  
Torque Curve

This article explores the effect that velocities have on a nonredundant robotic manipulator’s ability to accelerate its end-effector, as well as to apply forces/moments to the environment at the end-effector. This work considers velocity forces, including Coriolis forces, and the reduction of actuator torque with rotor velocity described by the speed-torque curve, at a particular configuration of a manipulator. The focus here is on nonredundant manipulators with as many actuators as degrees-of-freedom. Analysis of the velocity forces is accomplished using optimization techniques, where the optimization problem consists of an objective function and constraints which are all purely quadratic forms, yielding a nonconvex problem. Dialytic elimination is used to find the globally optimal solution to this problem. The proposed method does not use iterative numerical optimization methods. The PUMA 560 manipulator is used as an example to illustrate this methodology. The methodology provides an analytical analysis of the velocity forces which insures that the globally optimal solution to the associated optimization problem is found.

scholarly journals Research on the Integration of Media Literacy Innovative Concept and Entrepreneurship Education and Digital Dynamic Creative Expression Talents

2021 ◽  
Vol 12 ◽  
Author(s):  
Jie Zhang ◽  
Mingming Zhang ◽  
Yaqian Liu ◽  
Ruimin Lyu ◽  
Rongrong Cui
Keyword(s):  
Digital Media ◽  
Media Literacy ◽  
Design Thinking ◽  
Rapid Development ◽  
Dynamic Performance ◽  
Entrepreneurship Education ◽  
Digital Design ◽  
Dynamic Expression ◽  
Specific Implementation ◽  
Innovative Concept

The rapid development of digital technology has created a variety of forms of digital media. In these emerging media, with the support of high-performance computers, increasingly dynamic performance has become possible, and the public has cultivated a preference for dynamic content cognition. This study, based on the basic characteristics of visual perception to the cognition of motion form, aims to cultivate the cognitive literacy of pan-digital media with innovative concepts and entrepreneurship education and to explore the cognition and innovative expression methods of dynamic language in digital design. The research leads the static oriented morphological exploration and expression to the dynamic expression and thinking of the same concept object. The basic thinking steps for students from “static” to “dynamic” are established, and students are encouraged to use “Synesthesia,” “metaphor” and other methods to carry out a “dynamic expression” level of emotional association. In the experiment, two different ways of design expression, static and dynamic, are required to design and evolve graphics. In this study, 50 freshmen were selected as the training objects for the planning and training of design thinking and performance means. In the visual elaboration and expression of the inner emotion of the same content with innovative concept and entrepreneurship education, not only should the changes and combinations of the graphics be innovated, but the emotional characteristics of the more abstract graphics should be explored as well. The feedback data of students’ thinking and cognition differences in the two stages of expression were obtained through a questionnaire and analyzed and compared. The experimental results show that after the training, students’ ability to develop innovative concepts and entrepreneurship education through dynamic expression, consciousness and perception were significantly improved. This research also provides a new vision and specific implementation method for the future training of digital dynamic innovation expression ability and the cultivation of innovative concepts of digital media literacy and entrepreneurship education.

A New Parallel Actuated Architecture for Exoskeleton Applications Involving Multiple Degree-of-Freedom Biological Joints

2018 ◽  
Vol 10 (5) ◽  
Author(s):  
Justin Hunt ◽  
Hyunglae Lee
Keyword(s):  
Parallel Manipulator ◽  
Dynamic Performance ◽  
Future Generation ◽  
Degree Of Freedom ◽  
Performance Requirements ◽  
Ankle Exoskeleton ◽  
And Control ◽  
Spherical Parallel Manipulator

The purpose of this work is to introduce a new parallel actuated exoskeleton architecture that can be used for multiple degree-of-freedom (DoF) biological joints. This is done in an effort to provide a better alternative for the augmentation of these joints than serial actuation. The new design can be described as a type of spherical parallel manipulator (SPM) that utilizes three 4 bar substructures to decouple and control three rotational DoFs. Four variations of the 4 bar spherical parallel manipulator (4B-SPM) are presented in this work. These include a shoulder, hip, wrist, and ankle exoskeleton. Also discussed are three different methods of actuation for the 4B-SPM, which can be implemented depending on dynamic performance requirements. This work could assist in the advancement of a future generation of parallel actuated exoskeletons that are more effective than their contemporary serial actuated counterparts.

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