Trajectory Pattern Based Simultaneous Kinematic and Dynamic Optimal Design of High Speed Manipulators

1996 ◽  
Author(s):  
M. Tai ◽  
J. Rastegar
Keyword(s):  
Optimal Design ◽  
High Speed ◽  
High Performance ◽  
Current Approach ◽  
Operating Conditions ◽  
Control Problems ◽  
Structure And Motion ◽  
Design Variables ◽  
Trajectory Pattern ◽  
And Control

Abstract An integrated structure and motion pattern specific design approach is proposed for optimal design of high speed and accuracy computer controlled machines including robots. The approach is based on the Trajectory Pattern Method (TPM). The current approach to the design of such machines is to assume that the machine will be required to perform more or less any arbitrary and often unrealistic tasks. This assumption nearly always leads to designs based on the worst operating conditions. The proposed trajectory pattern based design methodology presented in this paper stems from a fundamentally new design philosophy. The philosophy behind the proposed approach is that machines in general and ultra-high performance machines in particular must only be designed to perform a class or classes of motions effectively. And that trajectory patterns, i.e., classes of parametric trajectories, exist with which high speed motions can be synthesized with minimal ensuing vibration and control problems. In the proposed approach, given the kinematic structure of the machine, its kinematic and dynamic parameters are optimized simultaneously with the parameters that describe a selected trajectory pattern. The controller parameters may also be included as design variables. In the present study, the optimality criterion employed is based on minimizing the higher harmonic portion of the actuating forces (torques) required for performing the selected class(es) of motion patterns. Trajectories that do not demand high frequency actuating torque harmonics are desirable since they reduce vibration and control problems in high performance systems and reduce settling time. Examples of the application of the proposed approach are presented.

Optimal Simultaneous Kinematic, Dynamic and Control Design of High Performance Manipulators Based on Trajectory Pattern Method

1998 ◽  
Author(s):  
J. Rastegar ◽  
L. Liu ◽  
M. Mattice
Keyword(s):  
High Speed ◽  
High Performance ◽  
Optimality Criterion ◽  
Control Design ◽  
Tracking Errors ◽  
Motion Patterns ◽  
Trajectory Pattern ◽  
And Control ◽  
Velocity Tracking ◽  
Trajectory Pattern Method

Abstract An optimal simultaneous kinematic, dynamic and control design approach is proposed for high performance computer controlled machines such as robot manipulators. The approach is based on the Trajectory Pattern Method (TPM) and a fundamentally new design philosophy that such machines in general and ultra-high performance machines in particular must only be designed to perform a class or classes of motions effectively. In the proposed approach, given the structure of the manipulator, its kinematic, dynamic and control parameters are optimized simultaneously with the parameters that describe the selected trajectory pattern. In the example presented in this paper, a weighted sum of the norms of the higher harmonics appearing in the actuating torques and the integral of the position and velocity tracking errors are used to form the optimality criterion. The selected optimality criterion should yield a system that is optimally designed to accurately follow the specified trajectory at high speed. Other objective functions can be readily formulated to synthesize systems for optimal performance. The potentials of the developed method and its implementation for generally defined motion patterns are discussed.

scholarly journals Lubricated Loaded Tooth Contact Analysis and Non-Newtonian Thermoelastohydrodynamics of High-Performance Spur Gear Transmission Systems

Lubricants ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 20 ◽  
Author(s):  
Gajarajan Sivayogan ◽  
Ramin Rahmani ◽  
Homer Rahnejat
Keyword(s):  
High Speed ◽  
High Performance ◽  
Spur Gear ◽  
Contact Analysis ◽  
Operating Conditions ◽  
Tooth Contact Analysis ◽  
Transmission Systems ◽  
Tooth Contact ◽  
Contact Kinematics ◽  
Loaded Tooth Contact Analysis

Energy efficiency and functional reliability are the two key requirements in the design of high-performance transmissions. Therefore, a representative analysis replicating real operating conditions is essential. This paper presents the thermoelastohydrodynamic lubrication (TEHL) of meshing spur gear teeth of high-performance racing transmission systems, where high generated contact pressures and lubricant shear lead to non-Newtonian traction. The determination of the input contact geometry of meshing pairs as well as contact kinematics are essential steps for representative TEHL. These are incorporated in the current analysis through the use of Lubricated Loaded Tooth Contact Analysis (LLTCA), which is far more realistic than the traditional Tooth Contact Analysis (TCA). In addition, the effects of lubricant and flash surface temperature rise of contacting pairs, leading to the thermal thinning of lubricant, are taken into account using a thermal network model. Furthermore, high-speed contact kinematics lead to shear thinning of the lubricant and reduce the film thickness under non-Newtonian traction. This comprehensive approach based on established TEHL analysis, particularly including the effect of LLTCA on the TEHL of spur gears, has not hitherto been reported in literature.

An Optimization Based Methodology to Design Flexible Systems Subjected to Changing Operating Conditions

2005 ◽  
Author(s):  
Ritesh A. Khire ◽  
Anoop A. Mullur ◽  
Achille Messac
Keyword(s):  
Optimal Design ◽  
System Design ◽  
High Performance ◽  
Systematic Approach ◽  
Operating Conditions ◽  
Flexible Systems ◽  
Operating Life ◽  
Design Requirements ◽  
High Performance Level ◽  
Critical Aspects

Flexible systems maintain a high performance level under changing operating conditions or design requirements. Flexible systems acquire this powerful feature by allowing critical aspects of their design con guration to change during the operating life of the product or system. In the design of such systems, designers are often required to make critical decisions regarding the exible and the non-exible aspects of the design con guration. We propose an optimization based methodology to design exible systems that allows a designer to effectively make such critical decisions. The proposed methodology judiciously generates candidate optimal design versions of the exible system. These design versions are evaluated using multiobjective techniques in terms of the level of exibility and the associated penalty. A highly exible system maintains optimal performance under changing operating conditions, but could result in increased cost and complexity of operation. The proposed methodology provides a systematic approach for incorporating designer preferences and selecting the most desirable design version — a feature absent in several recently proposed exible system design frameworks. The developments of this paper are demonstrated with the help of a exible three-bar-truss design example.

An application of Taguchi method on the high-speed motorized spindle system design

2011 ◽  
Vol 225 (9) ◽  
pp. 2198-2205 ◽  
Author(s):  
C-W Lin
Keyword(s):  
Optimal Design ◽  
Taguchi Method ◽  
Machine Tool ◽  
High Speed ◽  
Signal To Noise Ratio ◽  
Design Stage ◽  
Original Design ◽  
Spindle System ◽  
Design Engineers ◽  
Design Variables

As spindle speeds increase, the variations caused by high-speed effects become more significant. Therefore, in the initial design stage, it is necessary for machine tool design engineers to construct a robust high-speed machine tool that possesses high first-mode natural frequencies (FMNFs) and is insensitive to high operating speeds. In this article, Taguchi method is used to identify the optimal values of design variables (DVs) for a robust high-speed spindle system with respect to the signal-to-noise ratio (SNR) of system FMNF. The L18 orthogonal array covers seven main DVs at three levels each, one main DV at two levels, and the noise factor spindle speeds at six levels. The results show that the new optimal design has improved the SNR of the FMNF by 2.06 dB from the original design; this implies that the quality loss has been reduced to 62 per cent of its original value. The optimal design has been verified by a confirmation numerical experiment.

Optimization Design on Headstock of Shape High-Speed Vertical Machining Center

2011 ◽  
Vol 121-126 ◽  
pp. 1023-1027
Author(s):  
Chun Zhang ◽  
Zhi Yuan Li
Keyword(s):  
Optimal Design ◽  
Response Surface ◽  
High Speed ◽  
Optimization Design ◽  
Parametric Model ◽  
Machining Center ◽  
Design Variables ◽  
Test Technology ◽  
Design Result ◽  
Ansys Workbench

Optimization design was a technology that searched and determined the optimal design. Parametric model of headstock was established in Pro/E, and the parametric model was imported into the ANSYS Workbench. Then multi-objective optimization design was carried out in DesignXplorer module based on test technology, response surface that the combinations of design variables aimed at the objective function was obtained, the situation which design variables changes impacted on performance parameters from the response surface was viewed, a relatively ideal optimal design result was chosen. The mass of improved headstock was reduced, under the condition that performance in all aspects was not diminished.

Optimal Design and Control of a Rotating Flexible Arm With ACLD Treatment

Aerospace ◽  
2003 ◽  
Author(s):  
E. H. K. Fung ◽  
D. T. W. Yau
Keyword(s):  
Optimal Control ◽  
Optimal Design ◽  
Shear Modulus ◽  
Optimal Control Problem ◽  
Control Problem ◽  
Performance Index ◽  
Flexible Arm ◽  
Design Variables ◽  
And Control ◽  
Optimal Design And Control

In this paper, the optimal design and control of a rotating clamped-free flexible arm with fully covered active constrained layer damping (ACLD) treatment are studied. The arm is rotating in a horizontal plane in which the gravitational effect and rotary inertia are neglected. The piezo-sensor voltage is fed back to the piezo-actuator via a PD controller. Finite element method (FEM) in conjunction with Hamilton’s principle is used to derive the governing equations of motion of the system which takes into account the effects of centrifugal stiffening due to the rotation of the beam. The damping behavior of the viscoelastic material (VEM) is modeled using the complex shear modulus method. The design optimization objective is to maximize the sum of the first three open-loop modal damping ratios divided by the weight of the damping treatment. A genetic algorithm, differential evolution (DE), combined with a gradient-based algorithm, sequential quadratic programming (SQP), is used to determine the optimal design variables such as the thickness and storage shear modulus of the VEM core. Next for the determined optimal design variables, the optimal control problem is performed to determine the optimal control gains which minimize a quadratic performance index. The control performance index is normalized with respect to the initial conditions and the optimal control problem is posed to solve a min-max optimization problem. The results of this study will be useful in the optimal design and control of adaptive and smart rotating structures such as rotorcraft blades or robotic arms.

Real-Time Validation and Control Environment for Parallel Robot Control Design

2011 ◽  
Author(s):  
A. Zubizarreta ◽  
E. Portillo ◽  
I. Cabanes ◽  
M. Marcos ◽  
Ch. Pinto
Keyword(s):  
High Speed ◽  
High Performance ◽  
Experimental Testing ◽  
Control Design ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Full Potential ◽  
Control Environment ◽  
High Level ◽  
And Control

Due to their high performance when executing high-speed and accurate tasks, parallel robots have became the focus of many researchers and companies. However, exploiting the full potential of these robots requires a correct mechatronic design, in which the designed mechanism has to be controlled by a suitable control law in order to achieve the maximum performance. In this paper a novel Validation and Control Environment (VALIDBOT) is proposed as a support for the control design and experimental testing stages of these robots. The proposed open and flexible environment is designed to meet rapid prototyping requirements, offering a high level framework for both students and researchers. The capabilities of the environment are illustrated with an application case based on a 5R parallel robot prototype in which a modified CTC controller is tested.

Effect on Heat Transfer of Particle Migration in Suspensions of Nanoparticles Flowing Through Minichannels

2004 ◽  
Author(s):  
Dongsheng Wen ◽  
Yulong Ding
Keyword(s):  
Heat Transfer ◽  
High Speed ◽  
High Performance ◽  
High Energy ◽  
Constant Heat Flux ◽  
Operating Conditions ◽  
Particle Migration ◽  
Wall Region ◽  
Self Diffusion ◽  
Small Channels

Thermal management is one of the greatest challenges in maintaining the functionality and reliability of high-speed micro-electronic systems such as MEMS and NEMS. This requires development of high performance heat transfer media, which can not only flow through micro- and nano-channels under local operating conditions, but also carry as more heat as possible out of the system. Recent work has shown that suspensions of nanoparticles with a size considerably smaller that 100nm but with thermal conductivity orders of magnitudes higher that the base liquids have a greater potential as a high energy carrier for the micro- and nano-systems. However, it is also known that particles in a suspension undergoing a shearing action may migrate, hence lead to non-uniformity. This indicates that the efficiency of heat transfer in the micro- and nano-channels may not be as superior as expected, which bears significance to the system design and operation. This work aims at addressing this issue by examine the effect of particle migration on heat transfer in small channels. This involves development of both flow and heat transfer models, and numerical solution to the models. The flow model takes into account the effects of the shear-induced and viscosity gradient-induced particle migrations, as well as self-diffusion due to the Brownian motion, which is coupled with an energy equation. The results show that particle migration leads to concentration of particles in the wall region can be much lower than that in the core region. Particle migration is also shown to increase the Nusselt number under both constant temperature and constant heat flux conditions.

scholarly journals Energy saving optimal design and control of electromagnetic brake on passenger car

2019 ◽  
Vol 10 (1) ◽  
pp. 57-70
Author(s):  
Donghai Hu ◽  
Yanzhi Yan ◽  
Xiaoming Xu
Keyword(s):  
Energy Consumption ◽  
Optimal Design ◽  
Energy Saving ◽  
Prediction Models ◽  
Control Method ◽  
Optimal Solution ◽  
Electromagnetic Brake ◽  
Design Variables ◽  
And Control ◽  
Optimal Design And Control

Abstract. In this paper, the optimal design and control method of electromagnetic brake for a typical city driving cycle are studied to improve its energy consumption characteristics. The prediction models of the braking performance and power consumption for electromagnetic brake were established, and their accuracies were verified on the hardware of the loop simulation platform. Moreover, the energy consumption based on the ECE-EUDC driving condition was taken as the objective function, and a mathematical model for the optimal design of the electromagnetic brake was established. Genetic Algorithm was used to seek global optimal solution of these design variables on the premise of the given electrical and space constraints. Finally, the effect of thermodynamic properties of electromagnetic brake on the energy consumption characteristics was analyzed, and the energy saving control method of electromagnetic brake was also proposed. Experimental results show that the energy saving optimal design and control that this paper investigates can significantly improve the energy efficiency of electromagnetic brake.

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