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

<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>

The impact of open-loop vehicle stability on closed-loop control system performance: an analysis of four AUV concepts

OCEANS 92 Proceedings@m_Mastering the Oceans Through Technology ◽

10.1109/oceans.1992.607637 ◽

2005 ◽

Author(s):

D.E. Humphreys ◽

K.W. Watkinson

Keyword(s):

Control System ◽

System Performance ◽

Closed Loop ◽

Open Loop ◽

Vehicle Stability ◽

Closed Loop Control ◽

Loop Control ◽

Loop Control System ◽

The Impact

The Effect of the Closed-Loop Control System on Blood Glucose Control With Exercise: A Critically Appraised Topic

International Journal of Athletic Therapy & Training ◽

10.1123/ijatt.2020-0109 ◽

2021 ◽

pp. 1-4

Author(s):

Melanie A. Mason ◽

Anne C. Russ ◽

Ryan T. Tierney ◽

Jamie L. Mansell

Keyword(s):

Control System ◽

Blood Glucose ◽

Closed Loop ◽

Loop Group ◽

Open Loop ◽

Loop Control ◽

Loop Control System ◽

The Ideal

Context: Exercise can cause fluctuations in blood glucose control in type 1 diabetics. For athletes with type 1 diabetes, maintenance of blood glucose within an ideal range may be difficult. Objective: To determine, in individuals with type 1 diabetes, the effectiveness of the closed loop control system versus the open loop control system in keeping blood glucose levels in the ideal range with exercise. Data Sources: A search of PubMed was conducted in June of 2020 using the Boolean phrases: (closed loop control system OR artificial pancreas) AND type 1 diabetes AND exercise AND ideal range AND adolescents, artificial pancreas AND glucose prediction AND exercise. Study Selection: Titles were reviewed for relevance, the abstract was then assessed for applicability, and finally the full text was examined. Articles were included that examined the percent of time in the ideal blood glucose range when exercise occurred during that day. Articles were excluded that didn’t compare the closed loop and open loop control systems and articles that did not involve exercise. Data Extraction: The PEDro scale was used to determine the methodological quality of the included studies. The measure addressed was the percent of time in the ideal blood glucose range of 70-180 mg/dL. 95% Confidence Intervals and Cohen’s D were calculated for each article. Data Synthesis: The search yielded 268 articles and 3 were selected for inclusion. The two randomized controlled trials scored 9/10 on the PEDro scale and the randomized two-arm crossover clinical trial scored 9/10 on the PEDro scale. Percent time spent in the ideal blood glucose range when exercise was performed was significantly higher in the closed loop group versus the open loop group in each of the three studies. In one randomized control trial, mean time in the ideal range was 71.3% (SD = 17.6, 95% CI = 62.5, 80.10) in the closed loop group versus 64.7% (SD = 13.3, 95% CI = 58.1–71.4) in the open loop group. Cohen’s D was 0.4. In the second randomized control trial, mean time in the ideal range was 73.5% (SD = 8.4, 95% CI = 70.1, 76.9) for the closed loop group versus 50% (SD = 26.8, 95% CI = 39.1, 60.9). Cohen’s D was 1.2. The two-arm crossover clinical trial resulted in a mean time in target range of 84.1% (SD = 11.5, 95% CI = 79.0, 89.2) in the closed loop group versus 68.7% (SD = 13.9, 95% CI = 62.5, 74.9) in the open loop group. Cohen’s D was 1.2. Conclusions: For adolescents with type 1 diabetes who exercise, the closed loop control system maintains blood glucose levels in the ideal range for a longer percent of time versus an open loop system. Each patient should be evaluated on a case-by-case basis with his/her healthcare team. Future research should examine the closed loop control system on specific energy systems.

Research on the Control System of Ecological Architecture

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.174-177.3196 ◽

2012 ◽

Vol 174-177 ◽

pp. 3196-3201

Author(s):

Bo Xia

Keyword(s):

Control System ◽

Closed Loop ◽

Open Loop ◽

Closed Loop Control ◽

Open Loop Control ◽

Loop Control ◽

Loop Control System ◽

Ecological Architecture ◽

Building Control System

This paper proceeds from the basic conceptions of systematology and cybernetics and researches ecological architecture from one new angle. The paper divides the building control system into the open-loop control system and closed-loop control system, and further researches their principles.

Strains in Aluminum Stamp Formed Pans Resulting From Closed-Loop Control of Local Forces

Volume 2A: Advanced Manufacturing ◽

10.1115/imece2015-50172 ◽

2015 ◽

Author(s):

William J. Emblom

Keyword(s):

Control System ◽

Closed Loop ◽

Open Loop ◽

Smith Predictor ◽

Forming Limit ◽

Closed Loop Control ◽

Blank Holder ◽

Loop Control ◽

A stamp forming die, whose flexible blank holder was designed using FEA, was built. A closed-loop control system was used to control local punch forces and wrinkling by controlling both blank holder forces and draw bead penetration. The controllers for the draw beads featured an advanced PID controller with a Smith Predictor and Kalman Filter. A Bang-bang controller was also incorporated into the control system in order prevent control saturation. Fuzzy logic was used to transition from once controller to the other. Once closed-loop was implemented, tests were performed to evaluate the strains in the pans for various forming conditions. These results were compared to open-loop tests and it was found that the strains measured from closed-loop control tests resulted in more uniform strains and that the strains were further from the forming limit curves than strains from tests that were performed under open-loop conditions. Furthermore, it was seen that the strains in the regions were local force were controlled resulted in more uniform strain fields. Hence it was concluded that controlling local punch forces resulted in the strain control of critical regions.

Development of a Closed-loop Control System for the Movements of the Extruder and Platform of a FDM 3D Printing System

NIP & Digital Fabrication Conference ◽

10.2352/issn.2169-4451.2018.34.176 ◽

2018 ◽

Vol 2018 (1) ◽

pp. 176-181

Author(s):

Manuela F. Cerón Viveros ◽

Alvaro J. Rojas Arciniegas

Keyword(s):

Control System ◽

3D Printing ◽

Closed Loop ◽

Closed Loop Control ◽

Loop Control ◽

Loop Control System ◽

Printing System

An Expert Controller Based on Transient Response Patterns

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.219-220.3 ◽

2011 ◽

Vol 219-220 ◽

pp. 3-7

Author(s):

Ning Zhang ◽

Rong Hua Liu

Keyword(s):

Control System ◽

Transient Response ◽

Closed Loop ◽

Performance Criterion ◽

Response Patterns ◽

Loop Control ◽

Expert Control ◽

Loop Control System ◽

Control Decision

An expert control system based on transient response patterns and expert system techniques is proposed in this paper. Depending on the features of the closed-loop control system determines the control decision and adjusts the parameters of the controller. The proposed method requires minimal proper information about the controlled plant and, with the linear re-excitation learning method, the system is kept satisfying the performance criterion.

Closed-loop control system for well-defined oxygen supply in micro-physiological systems

Current Directions in Biomedical Engineering ◽

10.1515/cdbme-2017-0075 ◽

2017 ◽

Vol 3 (2) ◽

pp. 363-366

Author(s):

Tobias Steege ◽

Mathias Busek ◽

Stefan Grünzner ◽

Andrés Fabían Lasagni ◽

Frank Sonntag

Keyword(s):

Control System ◽

Oxygen Supply ◽

Closed Loop ◽

Microfluidic System ◽

Closed Loop Control ◽

Loop Control ◽

Cell Vitality ◽

AbstractTo improve cell vitality, sufficient oxygen supply is an important factor. A deficiency in oxygen is called Hypoxia and can influence for example tumor growth or inflammatory processes. Hypoxia assays are usually performed with the help of animal or static human cell culture models. The main disadvantage of these methods is that the results are hardly transferable to the human physiology. Microfluidic 3D cell cultivation systems for perfused hypoxia assays may overcome this issue since they can mimic the in-vivo situation in the human body much better. Such a Hypoxia-on-a-Chip system was recently developed. The chip system consists of several individually laser-structured layers which are bonded using a hot press or chemical treatment. Oxygen sensing spots are integrated into the system which can be monitored continuously with an optical sensor by means of fluorescence lifetime detection.Hereby presented is the developed hard- and software requiered to control the oxygen content within this microfluidic system. This system forms a closed-loop control system which is parameterized and evaluated.

Proceedings of the Institution of Mechanical Engineers Part I Journal of Systems and Control Engineering ◽

Adaptive synchronization of uncertain fractional-order chaotic systems using sliding mode control techniques

10.1177/0959651819849284 ◽

2019 ◽

Vol 234 (1) ◽

pp. 3-9 ◽

Cited By ~ 3

Author(s):

Bahram Yaghooti ◽

Ali Siahi Shadbad ◽

Kaveh Safavi ◽

Hassan Salarieh

Keyword(s):

Control System ◽

Sliding Mode Control ◽

Fractional Order ◽

Chaotic Systems ◽

Closed Loop ◽

Sliding Mode ◽

Closed Loop Control ◽

Loop Control ◽

In this article, an adaptive nonlinear controller is designed to synchronize two uncertain fractional-order chaotic systems using fractional-order sliding mode control. The controller structure and adaptation laws are chosen such that asymptotic stability of the closed-loop control system is guaranteed. The adaptation laws are being calculated from a proper sliding surface using the Lyapunov stability theory. This method guarantees the closed-loop control system robustness against the system uncertainties and external disturbances. Eventually, the presented method is used to synchronize two fractional-order gyro and Duffing systems, and the numerical simulation results demonstrate the effectiveness of this method.