Integrated Structure/Control Design of High Speed Flexible Robots Based on Time Optimal Control

1995 ◽  
Vol 117 (4) ◽  
pp. 503-512 ◽  
Author(s):  
Sudhendu Rai ◽  
Haruhiko Asada
Keyword(s):  
Optimal Control ◽  
Finite Element ◽  
High Speed ◽  
Control Design ◽  
Design Criterion ◽  
Time Optimal Control ◽  
Design Parameters ◽  
Element Analysis ◽  
Structure Control ◽  
Time Optimal

This paper presents the integrated structure/control design of high speed single link robots based on time-optimal control and finite element analysis. First, the solutions of a time optimal control problem are analyzed with respect to the arm link inertia and its structural flexibility. A new technique is developed to further reduce the optimal traveling time by redesigning the arm structure through the trade-off analysis between the arm inertia and its natural frequency. In the latter half of the paper, the design criterion is extended to multiple indices by considering residual vibrations, load bearing capacity and other design constraints. For suppressing residual vibrations, a simple feedback control is designed and its dynamic performance with respect to pole-zero locations is improved along with other criteria through mechanical structure modification. The finite element method is used as a modeling tool and the shape of the arm geometry is modified as design parameters. An arm is designed which performs much better as compared to the design which is done without considering the interactions between physical structure and control. The newly designed arm is tested by constructing an experimental setup. The results show significantly improved performance.

The Time-Optimal Control of the 4RRR Parallel Manipulator with Input Backlash

2014 ◽  
Vol 687-691 ◽  
pp. 616-622
Author(s):  
Liang Liang Zhang ◽  
Yao Jiang ◽  
Tie Min Li
Keyword(s):  
Optimal Control ◽  
Parameter Optimization ◽  
Parallel Manipulator ◽  
High Speed ◽  
Adaptive Method ◽  
Time Optimal Control ◽  
Redundant Actuation ◽  
Actuation Redundancy ◽  
Velocity Planning ◽  
Time Optimal

A time-optimal control of a 4RRR parallel manipulator with actuation redundancy is reported. A method using both redundant actuation and velocity planning is carried out to achieve the shortest moving time of the platform travelling through an assigned path without reducing precision caused by the backlashes in the actuators. The problem is simplified and an adaptive method of time-optimal control is designed based on the characteristics such as pre-coupling of time segments and decoupling of the redundant torques and time segments of this problem. The result demonstrates that this method can solve this problem with high speed. It serves as an example of both time-optimal control in robotics and multi-parameter optimization.

ROTOR RESONANCES ANALYSES OF HIGH-SPEED HIGH POWER PERMANENT-MAGNET ELECTRICAL MACHINES

2021 ◽  
pp. 95-108
Author(s):  
Wedad Alsadiq Alhawil ◽  
Ali A. Mehna ◽  
Asheraf Eldieb ◽  
Tarak Assaleh
Keyword(s):  
Finite Element ◽  
Permanent Magnet ◽  
High Speed ◽  
Natural Frequencies ◽  
Design Stage ◽  
Design Parameters ◽  
Element Analysis ◽  
Finite Element Program ◽  
Element Program ◽  
The Impact

High-speed electric machines (HSEMs) have been widely used in many of today’s applications.  For high-speed machines, in particular, it is very important to accurately predict natural frequencies of the rotor at the design stage to minimize the likelihood of failure. The main goal of this study is examine the design issues and performance of high-speed machines. For permanent-magnet synchronous motors (PMSM) driven by high-frequency drives, the rotor speed is normally above 30 000 rpm and it may exceed 100 000 rpm.  This study examined a 7-kw permanent magnet synchronous machine at 200,000 rpm. 3D finite element analysis (ANSYS WORKBENCH 15) was conducted to determine the natural frequencies and rotor patterns of a synchronous high-speed permanent magnetic motor, to assess the impact of leading design parameters, such as length, column diameter, span, bearings, material properties, and to compare the results of the finite element program with the results of analytical methods (i.e. critical speed).

Sign in / Sign up

Export Citation Format

Share Document