scholarly journals Performance and stability of fly-inspired, saccade-based hybrid control

2021 ◽  
Author(s):  
Brock A Davis ◽  
Jean-Michel Mongeau
Keyword(s):  
Experimental Data ◽  
Hybrid Control ◽  
Fruit Fly ◽  
Human Vision ◽  
Discrete Movements ◽  
Switching Threshold ◽  
Flying Insects ◽  
And Performance ◽  
Control System Model ◽  
Hybrid Control System

In a way analogous to human vision, the fruit fly Drosophila melanogaster and many other flying insects generate smooth and saccadic movements to stabilize and shift their gaze in flight, respectively. It has been hypothesized that this combination of continuous and discrete movements benefits both flight stability and performance, particularly at high frequencies or speeds. Here we develop a hybrid control system model to explore the effects of saccades on the yaw stabilization reflex of D. melanogaster. Inspired from experimental data, the model includes a first order plant, a Proportional-Integral (PI) continuous controller, and a saccadic reset system that fires based on the integrated error of the continuous controller. We explore the gain, delay and switching threshold parameter space to quantify the optimum regions for stability and performance. We show that the addition of saccades to a continuous controller provides benefits to both stability and performance across a range of frequencies. Our model suggests that Drosophila operate near its optimal switching threshold for its experimental gain set. We also show that based on experimental data, D. melanogaster operates in a region that trades off performance and stability. This trade-off increases flight robustness to compensate for environmental uncertainties such as wing damage.

Research on hybrid control system of quadrotor UAV

2013 ◽  
Vol 33 (3) ◽  
pp. 858-861 ◽  
Author(s):  
Guoqing XIA ◽  
Yuefeng LIAO ◽  
Lu WANG
Keyword(s):  
Control System ◽  
Hybrid Control ◽  
Quadrotor Uav ◽  
Hybrid Control System

scholarly journals Hox dosage contributes to flight appendage morphology in Drosophila

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rachel Paul ◽  
Guillaume Giraud ◽  
Katrin Domsch ◽  
Marilyne Duffraisse ◽  
Frédéric Marmigère ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Differential Expression ◽  
Hox Genes ◽  
Expression Profiles ◽  
Fruit Fly ◽  
Insect Species ◽  
Wing Morphology ◽  
Hox Proteins ◽  
Spatial Expression ◽  
Flying Insects

AbstractFlying insects have invaded all the aerial space on Earth and this astonishing radiation could not have been possible without a remarkable morphological diversification of their flight appendages. Here, we show that characteristic spatial expression profiles and levels of the Hox genes Antennapedia (Antp) and Ultrabithorax (Ubx) underlie the formation of two different flight organs in the fruit fly Drosophila melanogaster. We further demonstrate that flight appendage morphology is dependent on specific Hox doses. Interestingly, we find that wing morphology from evolutionary distant four-winged insect species is also associated with a differential expression of Antp and Ubx. We propose that variation in the spatial expression profile and dosage of Hox proteins is a major determinant of flight appendage diversification in Drosophila and possibly in other insect species during evolution.

Human Stereopsis, Fusion, and Stereoscopic Virtual Environments

1995 ◽  
Author(s):  
Elizabeth Thorpe Davis ◽  
Larry F. Hodges
Keyword(s):  
Virtual Environments ◽  
Visual Cues ◽  
Spatial Information ◽  
Spatial Perception ◽  
Human Perception ◽  
Stereoscopic Vision ◽  
Human Vision ◽  
Spatial Factors ◽  
Stereoscopic Displays ◽  
And Performance

Two fundamental purposes of human spatial perception, in either a real or virtual 3D environment, are to determine where objects are located in the environment and to distinguish one object from another. Although various sensory inputs, such as haptic and auditory inputs, can provide this spatial information, vision usually provides the most accurate, salient, and useful information (Welch and Warren, 1986). Moreover, of the visual cues available to humans, stereopsis provides an enhanced perception of depth and of three-dimensionality for a visual scene (Yeh and Silverstein, 1992). (Stereopsis or stereoscopic vision results from the fusion of the two slightly different views of the external world that our laterally displaced eyes receive (Schor, 1987; Tyler, 1983).) In fact, users often prefer using 3D stereoscopic displays (Spain and Holzhausen, 1991) and find that such displays provide more fun and excitement than do simpler monoscopic displays (Wichanski, 1991). Thus, in creating 3D virtual environments or 3D simulated displays, much attention recently has been devoted to visual 3D stereoscopic displays. Yet, given the costs and technical requirements of such displays, we should consider several issues. First, we should consider in what conditions and situations these stereoscopic displays enhance perception and performance. Second, we should consider how binocular geometry and various spatial factors can affect human stereoscopic vision and, thus, constrain the design and use of stereoscopic displays. Finally, we should consider the modeling geometry of the software, the display geometry of the hardware, and some technological limitations that constrain the design and use of stereoscopic displays by humans. In the following section we consider when 3D stereoscopic displays are useful and why they are useful in some conditions but not others. In the section after that we review some basic concepts about human stereopsis and fusion that are of interest to those who design or use 3D stereoscopic displays. Also in that section we point out some spatial factors that limit stereopsis and fusion in human vision as well as some potential problems that should be considered in designing and using 3D stereoscopic displays. Following that we discuss some software and hardware issues, such as modelling geometry and display geometry as well as geometric distortions and other artifacts that can affect human perception.

CMAC Based Hybrid Control System for Solving Electrohydraulic System Nonlinearities

2014 ◽  
Vol 4 (2) ◽  
pp. 47-72
Author(s):  
Amro Shafik ◽  
Magdy Abdelhameed ◽  
Ahmed Kassem
Keyword(s):  
Neural Network ◽  
Control System ◽  
Hybrid Control ◽  
Learning Algorithm ◽  
Cerebellar Model Articulation Controller ◽  
Stick Slip ◽  
Electrohydraulic System ◽  
Cmac Neural Network ◽  
Wide Range ◽  
Hybrid Control System

Automation based electrohydraulic servo systems have a wide range of applications in nowadays industry. However, they still suffer from several nonlinearities like deadband in electrohydraulic valves, hysteresis, stick-slip friction in valves and cylinders. In addition, all hydraulic system parameters have uncertainties in their values due to the change of temperature while working. This paper addresses these problems by designing a suitable intelligent control system that has the ability to deal with the system nonlinearities and parameters uncertainties using a fast and online learning algorithm. A novel hybrid control system based on Cerebellar Model Articulation Controller (CMAC) neural network is presented. The proposed controller is composed of two parallel controllers. The first is a conventional Proportional-Velocity (PV) servo type controller which is used to decrease the large initial error of the closed-loop system. The second is a CMAC neural network which is used as an intelligent controller to overcome nonlinear characteristics of the electrohydraulic system. A fourth order model for the electrohydraulic system is introduced. PV controller parameters are tuned to get optimal values. Simulation and experimental results show a good tracking performance obtained using the proposed controller. The controller shows its robustness in two working environments. The first is by adding different inertia loads and the second is working with noisy level input signals.

scholarly journals Design and Simulation of Eight-Rotor Unmanned Aerial Vehicle Based on Hybrid Control System

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xueqiang Shen ◽  
Jiwei Fan ◽  
Haiqing Wang
Keyword(s):  
Control System ◽  
Unmanned Aerial Vehicle ◽  
Flight Control ◽  
Hybrid Control ◽  
Dynamic Performance ◽  
System Response ◽  
Hybrid Controller ◽  
Aerial Vehicle ◽  
Switching Method ◽  
Hybrid Control System

In order to control the position and attitude of unmanned aerial vehicle (UAV) better in different environments, this study proposed a hybrid control system with backstepping and PID method for eight-rotor UAV in different flight conditions and designed a switching method based on altitude and attitude angle of UAV. The switched process of hybrid controller while UAV taking off, landing, and disturbance under the gust is verified in MATLAB/Simulink. A set of appropriate controllers always matches to the flight of UAV in different circumstances, which can speed up the system response and reduce the steady-state error to improve stability. The simulation results show that the hybrid control system can suppress the drift efficiently under gusts, enhance the dynamic performance and stability of the system, and meet the position and attitude of flight control requirements.

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