The relation between open loop and closed loop properties of multivariable feedback systems: A practical example

1984 ◽  
Author(s):  
Jim Freudenberg ◽  
Douglas Looze
Keyword(s):  
Closed Loop ◽  
Open Loop ◽  
Feedback Systems ◽  
Multivariable Feedback

scholarly journals Closing the Loop: Implementing Real-time Audio Feedback Systems in Musical Robots

2021 ◽  
Author(s):  
◽  
Jason Long
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Open Loop ◽  
Feedback Systems ◽  
Cruise Control ◽  
Audio Feedback ◽  
Loop Control ◽  
Manual Intervention ◽  
Closed Loop Control System ◽  
Loop Control System

<p>A closed-loop control system is any configuration that feeds information about its output back into the control stream. These types of systems have been in use for hundreds of years in various engineering related disciplines to carry out operations such as keeping rooms at the correct temperature, implementing cruise control in cars, and precisely positioning industrial machinery. When a musician performs a piece, a type of biological closed loop is invoked in which the player continuously listens to the sound of their instrument, and adjusts their actions in order to ensure their performance is as desired.  However, most musical robots do not possess this ability, instead relying on open-loop systems without feedback. This results in the need for much manual intervention from the operators of these robots, unintuitive control interfaces for composing and performing music with them, and tuning, timing, dynamics and other issues occurring during performances.  This thesis investigates applying closed-loop audio feedback techniques to the creation of musical robots to equip them with new expressive capabilities, interactive applications, musical accuracy, and greater autonomy. In order to realise these objectives, following an investigation of the history of musical automata and musical robotic control systems, several new robotic musical instruments are developed based on the principals of utilising embedded musical information retrieval techniques to allow the instruments to continuously ‘listen’ to themselves while they play.  The mechanical and electronic systems and firmware of a closed-loop glockenspiel, a modular unpitched percussion control system, and a robotic chordophone control system are described in detail, utilising new software and hardware created to be accessible to electronic artists. The novel capabilities of the instruments are demonstrated both through quantitative evaluations of the performance of their subsystems, and through composing original musical works specifically for the instruments. This paradigm shift in musical robotic construction paves the way for a new class of robots that are intuitive to use, highly accurate and reliable, and possess a unique level of musical expressiveness.</p>

scholarly journals Closing the Loop: Implementing Real-time Audio Feedback Systems in Musical Robots

2021 ◽  
Author(s):  
◽  
Jason Long
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Open Loop ◽  
Feedback Systems ◽  
Cruise Control ◽  
Audio Feedback ◽  
Loop Control ◽  
Manual Intervention ◽  
Closed Loop Control System ◽  
Loop Control System

<p>A closed-loop control system is any configuration that feeds information about its output back into the control stream. These types of systems have been in use for hundreds of years in various engineering related disciplines to carry out operations such as keeping rooms at the correct temperature, implementing cruise control in cars, and precisely positioning industrial machinery. When a musician performs a piece, a type of biological closed loop is invoked in which the player continuously listens to the sound of their instrument, and adjusts their actions in order to ensure their performance is as desired.  However, most musical robots do not possess this ability, instead relying on open-loop systems without feedback. This results in the need for much manual intervention from the operators of these robots, unintuitive control interfaces for composing and performing music with them, and tuning, timing, dynamics and other issues occurring during performances.  This thesis investigates applying closed-loop audio feedback techniques to the creation of musical robots to equip them with new expressive capabilities, interactive applications, musical accuracy, and greater autonomy. In order to realise these objectives, following an investigation of the history of musical automata and musical robotic control systems, several new robotic musical instruments are developed based on the principals of utilising embedded musical information retrieval techniques to allow the instruments to continuously ‘listen’ to themselves while they play.  The mechanical and electronic systems and firmware of a closed-loop glockenspiel, a modular unpitched percussion control system, and a robotic chordophone control system are described in detail, utilising new software and hardware created to be accessible to electronic artists. The novel capabilities of the instruments are demonstrated both through quantitative evaluations of the performance of their subsystems, and through composing original musical works specifically for the instruments. This paradigm shift in musical robotic construction paves the way for a new class of robots that are intuitive to use, highly accurate and reliable, and possess a unique level of musical expressiveness.</p>

Perfect Multivariable Feedback Theory

1997 ◽  
Vol 07 (02) ◽  
pp. 129-151
Author(s):  
M.-D. Tong ◽  
W.-K. Chen
Keyword(s):  
Closed Loop ◽  
Continuous System ◽  
Open Loop ◽  
Feedback Network ◽  
Loop Network ◽  
The Stability ◽  
Return Difference ◽  
And Control ◽  
Z Transformation ◽  
Multivariable Feedback

The paper nicely combines the state-space description with the input-output description and elegantly formulates the multivariable feedback theory as well as obtains a number of useful results for modern network and control theory. In particular, it reveals various kinds of duality between a multivariable feedback network and its associated inverse network, such as structure duality, transfer function matrix (determinant) duality and duality on controllability (observability). It also thoroughly studies four pairs of the (null) return difference matrices of a multivariable feedback network and its associated inverse network, and presents not only the dual properties about these (null) return diferrence matrices and their respective determinants, but also treats the relationships among these determinants, the characteristic polynomials of a closed-loop network (the multivariable feedback network), its associated closed-loop inverse network, and their respective corresponding open-loop networks. Finally, the stability criteria, the testing criteria for a minimum-phase matrix and the sensitivity matrices are discussed. Although all of these results are obtained for a continuous system, they are also suitable for a discrete system provided that we use the z-transformation instead of the Laplace transformation.

On closed-loop equilibrium strategies for mean-field stochastic linear quadratic problems

2020 ◽  
Vol 26 ◽  
pp. 41
Author(s):  
Tianxiao Wang
Keyword(s):  
Optimal Control ◽  
Closed Loop ◽  
Optimal Control Problems ◽  
Mean Field ◽  
Open Loop ◽  
Time Inconsistency ◽  
Control Problems ◽  
Linear Quadratic ◽  
Linear Quadratic Optimal Control ◽  
Equilibrium Strategies

This article is concerned with linear quadratic optimal control problems of mean-field stochastic differential equations (MF-SDE) with deterministic coefficients. To treat the time inconsistency of the optimal control problems, linear closed-loop equilibrium strategies are introduced and characterized by variational approach. Our developed methodology drops the delicate convergence procedures in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. When the MF-SDE reduces to SDE, our Riccati system coincides with the analogue in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. However, these two systems are in general different from each other due to the conditional mean-field terms in the MF-SDE. Eventually, the comparisons with pre-committed optimal strategies, open-loop equilibrium strategies are given in details.

Comparison of Dc-Dc SEPIC, CUK and Flyback Converters Based LED Drivers

2020 ◽  
pp. 99-107
Author(s):  
Erdal Sehirli
Keyword(s):  
Integrated Circuit ◽  
Closed Loop ◽  
Input Voltage ◽  
Open Loop ◽  
Current Sensor ◽  
Switching Frequency ◽  
Led Driver ◽  
Advantages And Disadvantages ◽  
Led Drivers ◽  
Conduction Mode

This paper presents the comparison of LED driver topologies that include SEPIC, CUK and FLYBACK DC-DC converters. Both topologies are designed for 8W power and operated in discontinuous conduction mode (DCM) with 88 kHz switching frequency. Furthermore, inductors of SEPIC and CUK converters are wounded as coupled. Applications are realized by using SG3524 integrated circuit for open loop and PIC16F877 microcontroller for closed loop. Besides, ACS712 current sensor used to limit maximum LED current for closed loop applications. Finally, SEPIC, CUK and FLYBACK DC-DC LED drivers are compared with respect to LED current, LED voltage, input voltage and current. Also, advantages and disadvantages of all topologies are concluded.

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