scholarly journals Spontaneous and Evoked Eye Movements in Polyphemus Pediculus (Cladocera: Crustacea): A Case of Open-Loop Tracking?

1987 ◽  
Vol 131 (1) ◽  
pp. 323-336
Author(s):  
STEPHEN YOUNG ◽  
VICTORIA A. TAYLOR

1. Polyphemus eye movements were recorded in both pitching and yawing planes, both in a static visual environment and with a sinusoidally moving stimulus. 2. Spontaneous eye movements (average amplitude 1.7°) had different properties in the two planes, with trembling movements predominating in the pitching plane. A contour-sharpening function is proposed for these movements. 3. An attempt to analyse the eye movement response system using a Bode diagram shows a very poor fit to the data, leading to the conclusion that a closed-loop control system is an inappropriate model in this case. 4. The evoked eye movements are most convincingly represented by a model in which the time the stimulus takes to traverse a restricted sensitive zone in the central region of the eye controls the duration of a subsequent constant angular velocity saccade. The direction of the response movement follows the direction of the stimulus. A small-object tracking function is proposed for these movements.

2021 ◽  
Author(s):  
◽  
Jason Long

<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>


2013 ◽  
Vol 562-565 ◽  
pp. 260-264
Author(s):  
Chun Hua He ◽  
Qian Cheng Zhao ◽  
Da Chuan Liu ◽  
Zhen Chuan Yang ◽  
Gui Zhen Yan

A detailed analysis about the nonlinearity of a mode-matching MEMS vibratory gyroscope is presented in this paper, then closed loop control for the sense mode is adopted to improved the performances. Experimental results figure out that the mode-matching gyroscope with closed loop controlled sense mode achieves a scale factor of 65mV/deg/s with nonlinearity of 0.05% and asymmetry of 0.1%, and a bias instability of 0.77deg/h, while they are 60mV/deg/s, 1%, 4.6% and 9.8deg/h in the open loop controlled sense mode system, respectively. These performances can be improved by more than one order of magnitude in the closed loop control system.


Author(s):  
Melanie A. Mason ◽  
Anne C. Russ ◽  
Ryan T. Tierney ◽  
Jamie L. Mansell

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.


2021 ◽  
Author(s):  
◽  
Jason Long

<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>


2012 ◽  
Vol 174-177 ◽  
pp. 3196-3201
Author(s):  
Bo Xia

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.


Author(s):  
William J. Emblom

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.


2011 ◽  
Vol 219-220 ◽  
pp. 3-7
Author(s):  
Ning Zhang ◽  
Rong Hua Liu

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.


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