Magnetic Bearing Measurement Configurations and Associated Robustness and Performance Limitations

2002 ◽  
Vol 124 (4) ◽  
pp. 589-598 ◽  
Author(s):  
Nancy Morse Thibeault ◽  
Roy S. Smith
Keyword(s):  
Closed Loop ◽  
Magnetic Bearing ◽  
Loop System ◽  
Relative Degree ◽  
System Configuration ◽  
Performance Limits ◽  
Closed Loop System ◽  
And Performance ◽  
Parameter Values ◽  
Bearing System

We obtain bounds on achievable sensitivity and complementary sensitivity reduction for a magnetic bearing system in three measurement configurations. We use the sensitivity reduction bounds to deduce achievable robustness and performance limits for each system configuration. We then show how these limits vary with varying magnetic bearing physical dimensions and other parameter values as well as varying closed-loop system bandwidth and controller relative degree. Using all of this information, we derive guidelines for designing magnetic bearing systems and their controllers, for each measurement configuration considered, for greatest achievable robustness and performance.

Safety and Performance of the Omnipod®Hybrid Closed-Loop System in Adolescents with Type 1 Diabetes over Five Days Under Free-Living Conditions

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1376-P
Author(s):  
GREGORY P. FORLENZA ◽  
BRUCE BUCKINGHAM ◽  
JENNIFER SHERR ◽  
THOMAS A. PEYSER ◽  
JOON BOK LEE ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Closed Loop ◽  
Living Conditions ◽  
Loop System ◽  
Closed Loop System ◽  
Free Living ◽  
And Performance ◽  
Free Living Conditions

Safety and Performance of the Omnipod® Hybrid Closed-Loop System in Adults with Type 1 Diabetes over Five Days Under Free-Living Conditions

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 207-OR
Author(s):  
BRUCE A. BUCKINGHAM ◽  
JENNIFER SHERR ◽  
GREGORY P. FORLENZA ◽  
THOMAS A. PEYSER ◽  
JOON BOK LEE ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Closed Loop ◽  
Living Conditions ◽  
Loop System ◽  
Closed Loop System ◽  
Free Living ◽  
And Performance ◽  
Free Living Conditions

scholarly journals Safety and Performance of the Omnipod Hybrid Closed-Loop System in Adults, Adolescents, and Children with Type 1 Diabetes Over 5 Days Under Free-Living Conditions

2020 ◽  
Vol 22 (3) ◽  
pp. 174-184 ◽  
Author(s):  
Jennifer L. Sherr ◽  
Bruce A. Buckingham ◽  
Gregory P. Forlenza ◽  
Alfonso Galderisi ◽  
Laya Ekhlaspour ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Closed Loop ◽  
Living Conditions ◽  
Loop System ◽  
Closed Loop System ◽  
Free Living ◽  
And Performance ◽  
Free Living Conditions

215-OR: Safety and Performance of the Omnipod Hybrid Closed-Loop System in Young Children Aged 2-6 Years with Type 1 Diabetes

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 215-OR ◽  
Author(s):  
BRUCE A. BUCKINGHAM ◽  
GREGORY P. FORLENZA ◽  
JENNIFER SHERR ◽  
ALFONSO GALDERISI ◽  
LAYA EKHLASPOUR ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Young Children ◽  
Closed Loop ◽  
Loop System ◽  
Closed Loop System ◽  
And Performance

Sensitivity Comparison to Loop Latencies Between Damping Versus Stiffness Feedback Control Action in Distributed Controllers

2014 ◽  
Author(s):  
Ye Zhao ◽  
Nicholas Paine ◽  
Luis Sentis
Keyword(s):  
Closed Loop ◽  
Impedance Control ◽  
Tracking Error ◽  
Loop System ◽  
Tracking Performance ◽  
System Stability ◽  
Step Response ◽  
Tracking Accuracy ◽  
Closed Loop System ◽  
And Performance

This paper studies the effects of damping and stiffness feedback loop latencies on closed-loop system stability and performance. Phase margin stability analysis, step response performance and tracking accuracy are respectively simulated for a rigid actuator with impedance control. Both system stability and tracking performance are more sensitive to damping feedback than stiffness feedback latencies. Several comparative tests are simulated and experimentally implemented on a real-world actuator to verify our conclusion. This discrepancy in sensitivity motivates the necessity of implementing embedded damping, in which damping feedback is implemented locally at the low level joint controller. A direct benefit of this distributed impedance control strategy is the enhancement of closed-loop system stability. Using this strategy, feedback effort and thus closed-loop actuator impedance may be increased beyond the levels possible for a monolithic impedance controller. High impedance is desirable to minimize tracking error in the presence of disturbances. Specially, trajectory tracking accuracy is tested by a fast swing and a slow stance motion of a knee joint emulating NASA-JSC’s Valkyrie legged robot. When damping latencies are lowered beyond stiffness latencies, gravitational disturbance is rejected, thus demonstrating the accurate tracking performance enabled by a distributed impedance controller.

scholarly journals Design of Fractional Order PID Controller Based Particle Swarm

2014 ◽  
Vol 7 (4) ◽  
pp. 24-39
Author(s):  
Abdelelah Kidher Mahmood ◽  
Bassam Fadel Mohammed
Keyword(s):  
Fractional Order ◽  
Pid Controller ◽  
Closed Loop ◽  
Particle Swarm ◽  
Optimization Methods ◽  
Loop System ◽  
Closed Loop System ◽  
Unknown Parameters ◽  
And Performance ◽  
Fractional Order Pid

Fractional order PID (FOPID) controller is a special kind of PID controller whose derivative and integral order are fractional rather than integer which has five parameters to be tuned. This paper presents study of the implementation of tuning method and performance enhancement of the closed loop system by use of the fractional order PID (PIλDμ) controller utilizing a MATLAB/Simulink. The tuning methods for these type controllers have many mixed tools of the available optimization methods and update artificial optimization methods in the design. In this paper particle swarm optimization has been implemented to design FOPID controller in which the unknown parameters are determined minimizing a given integral of time weighted absolute error (ITAE). The main specification of this paper is that the all five parameters of (PIλDμ) have been found directly without spreading the steps. It has been shown that the response and performance of the closed loop system with FOPID controller is much better than integer order PID controller for the same system and with better robustness.

Safety and Performance of the Omnipod®Hybrid Closed-Loop System in Children Aged 6-12 Years with Type 1 Diabetes over Five Days Under Free-Living Conditions

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1377-P
Author(s):  
JENNIFER SHERR ◽  
GREGORY P. FORLENZA ◽  
BRUCE BUCKINGHAM ◽  
THOMAS A. PEYSER ◽  
JOON BOK LEE ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Closed Loop ◽  
Living Conditions ◽  
Loop System ◽  
Closed Loop System ◽  
Free Living ◽  
And Performance ◽  
Free Living Conditions

scholarly journals Virtual Actuators with Virtual Sensors

2005 ◽  
Vol 219 (5) ◽  
pp. 370-377 ◽  
Author(s):  
P J Gawthrop
Keyword(s):  
Closed Loop ◽  
Bond Graph ◽  
Loop System ◽  
Relative Degree ◽  
Transfer System ◽  
Closed Loop System ◽  
Virtual Sensor ◽  
Virtual Sensors ◽  
Degree Conditions

The virtual actuator approach to bond graph based control is extended to use virtual sensor inputs; this allows relative degree conditions on the controller to be relaxed. Furthermore, the effect of the transfer system can be eliminated from the closed-loop system. Illustrative examples are given.

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