Influences of Closed Loop Control Componentson the Performance of Ultra-Precision Machines

2014 ◽  
Vol 625 ◽  
pp. 207-212
Author(s):  
Christian Brecher ◽  
Dominik Lindemann ◽  
Christian Wenzel
Keyword(s):  
Closed Loop ◽  
Research Work ◽  
Step Response ◽  
Precision Machining ◽  
Closed Loop Control ◽  
Servo Drive ◽  
Loop Control ◽  
Ultra Precision ◽  
Servo Drives ◽  
Accuracy And Repeatability

At Fraunhofer IPT a test bench has been setup to analyze closed loop control components and their interfaces with focus on their application in ultra-precision machining applications. This paper will present the results of the analysis of feedback and servo drive systems and will give a close inside on the influences of linear scales and analog and digital servo drives for applications in ultra-precision machining. The performed measurements include the analysis of the position accuracy and repeatability (step response test) as well as the determination of the dynamic frequency characteristics (stiffness / compliance) of an air bearing axis. With respect to the aforementioned measurements the tests have been performed under the variation of linear scales (vendor, pitch, signal, sampling frequency, etc.) and servo drives (vendor, switching or linear amplifiers, PWM frequency, control architecture, DC bus voltage, etc.). The paper will give a summary on the results of the analyzed topics, carefully chosen regarding their relevance to ultra-precision machining. Finally, a short outlook to future research work concerning the analysis of CNC controls will be given.

Efficient Linear Approach for the Closed-Loop Control of a Ionic Polymer Bending Actuator

2016 ◽  
Vol 97 ◽  
pp. 75-80 ◽  
Author(s):  
Bertrand Tondu ◽  
Aiva Simaite ◽  
Ganesh Kumar Hari Shankar Lal Das ◽  
Philippe Soueres ◽  
Christian Bergaud
Keyword(s):  
Closed Loop ◽  
Open Loop ◽  
Step Response ◽  
Order System ◽  
Initial Slope ◽  
Vertical Position ◽  
Control Voltage ◽  
Closed Loop Control ◽  
Loop Control ◽  
Bending Actuator

Tri-layer electroactive bending polymeric artificial muscles generally exhibit no overshoot during open-loop step response with a non-zero initial slope when the output is the vertical position of the bending sample tip. We propose to identify such a bending step contraction by a nonlinear system derived from a linear first order system in the form: where the parameters k, T and r depend on the u-control voltage. We show the relevance of this approach for identifying the step-response of a PEDOT:PSS/PVDF/ionic liquid actuator developed at the laboratory. As a consequence, we try to show that a linear PI-controller, including voltage constraints, is a simple and an efficient approach for a closed-loop control of the bending actuator.

Dynamical Identification Model of Laser Cladding Width in Metal Parts Laser Shaping Process

2013 ◽  
Vol 820 ◽  
pp. 216-219
Author(s):  
Shu Juan Jiang ◽  
Fei Fei Yu ◽  
Mao Zheng Fu
Keyword(s):  
Laser Cladding ◽  
Closed Loop ◽  
Scanning Speed ◽  
Step Response ◽  
Closed Loop Control ◽  
Loop Control ◽  
Simulating Experiment ◽  
Metal Parts ◽  
Shaping Process

The dynamical model of laser cladding width is identified by the method of step response experiments. Mathematical models between the cladding width and the laser power, the scanning speed, or the powder flowrate are established respectively according to corresponding experimental results. Simulating experiment results verify the validity of these models. The dynamical identification lays foundation for the closed loop control in laser shaping process so as to improve the quality of the laser formed parts.

Research on Closed-Loop Control of the Step Response

2011 ◽  
Vol 127 ◽  
pp. 71-76 ◽  
Author(s):  
Xin Ping Wang ◽  
Jian Jun Dang ◽  
Zhi Cao Zhao
Keyword(s):  
Closed Loop ◽  
Dynamic Performance ◽  
Thermal Power ◽  
Step Response ◽  
Closed Loop Control ◽  
Loop Control ◽  
Intermediate Variable ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Control System Model

Based on the analysis of six kinds of working points, the process function of torpedo thermal power propulsion system is solved. The results show that the process transfer function is approximate to inertial link. PI control algorithm is presented and its parameters are deduced. The algorithm can not only control the output variables, but also can monitor the intermediate variable. Closed-loop control system model is established. Variable speed characteristics of torpedo at constant depth and steady speed characteristics in depth-changed process are simulated by MATLAB. Simulation results indicate that the system has satisfactory dynamic performance and the control quality performs well.

Dynamical Identification Model of Laser Cladding Height in Metal Parts Laser Shaping Process

2012 ◽  
Vol 591-593 ◽  
pp. 1050-1053 ◽  
Author(s):  
Shu Juan Jiang ◽  
Ai Zhong He
Keyword(s):  
Closed Loop ◽  
Scanning Speed ◽  
Step Response ◽  
Closed Loop Control ◽  
Forming Process ◽  
Loop Control ◽  
Metal Parts ◽  
Shaping Process ◽  
Identification Model

The metal parts laser shaping process dynamical identification is fulfilled by the method of experiment. Through step response experiments, mathematical models between the cladding height and the laser power, the scanning speed, or the powder flowrate are established respectively. Simulating experiments validate these identification models. From the identification models, the metal parts laser shaping process is understood, which is the basement for designing closed loop control in forming process and is significant to improve the quality of formed parts.

The Impact of Visual Feedback Type on the Mastery of Visuo-Motor Transformations

2012 ◽  
Vol 220 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Sandra Sülzenbrück
Keyword(s):  
Empirical Research ◽  
Visual Feedback ◽  
Closed Loop ◽  
Motor Planning ◽  
Visual Input ◽  
Closed Loop Control ◽  
Loop Control ◽  
Feedback Type ◽  
Effective Use ◽  
The Impact

For the effective use of modern tools, the inherent visuo-motor transformation needs to be mastered. The successful adjustment to and learning of these transformations crucially depends on practice conditions, particularly on the type of visual feedback during practice. Here, a review about empirical research exploring the influence of continuous and terminal visual feedback during practice on the mastery of visuo-motor transformations is provided. Two studies investigating the impact of the type of visual feedback on either direction-dependent visuo-motor gains or the complex visuo-motor transformation of a virtual two-sided lever are presented in more detail. The findings of these studies indicate that the continuous availability of visual feedback supports performance when closed-loop control is possible, but impairs performance when visual input is no longer available. Different approaches to explain these performance differences due to the type of visual feedback during practice are considered. For example, these differences could reflect a process of re-optimization of motor planning in a novel environment or represent effects of the specificity of practice. Furthermore, differences in the allocation of attention during movements with terminal and continuous visual feedback could account for the observed differences.

118-LB: Glucose Variability throughout the Menstrual Cycle on Closed-Loop Control in Type 1 DM

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 118-LB
Author(s):  
CAROL J. LEVY ◽  
GRENYE OMALLEY ◽  
SUE A. BROWN ◽  
DAN RAGHINARU ◽  
YOGISH C. KUDVA ◽  
...  
Keyword(s):  
Menstrual Cycle ◽  
Closed Loop ◽  
Glucose Variability ◽  
Closed Loop Control ◽  
Loop Control ◽  
Type 1 Dm
Sign in / Sign up

Export Citation Format

Share Document