The Flying-Ball-in-Tube Experiment

2012 ◽  
Author(s):  
Karl Lukas Knierim ◽  
Florian Malchow ◽  
Oliver Sawodny
Keyword(s):  
Control Theory ◽  
Real Time ◽  
Time Scale ◽  
Control Structure ◽  
Dynamical Behavior ◽  
Experimental Setup ◽  
Control Environment ◽  
Stability Properties ◽  
Unstable Behavior

One of the challenges in teaching applied control theory is to provide students with easy to understand experimental setups, which show complex but comprehensible dynamical behavior. We propose a flying-ball-in-tube experiment with stable, critically stable and unstable behavior. The benefit of the flying-ball-in-tube experiment are its in respect to time scale observable dynamics as well as the simplicity of the setup. A model of the flying-ball-in-tube experiment is derived and analyzed with respect to its stability properties. The derived model is identified and the predicted behavior is validated. In addition, the use of the experimental setup within a one week undergraduate practical is described. Within the course the students program the control environment on a micro controller within the FreeRTOS real time environment and design their own control structure.

Cognitive Multi-UAV Formation Flight: Principle, Low-Cost UAV Testbed, Controller Tuning and Experiments

2011 ◽  
Author(s):  
Long Di ◽  
Haiyang Chao ◽  
Jinlu Han ◽  
YangQuan Chen
Keyword(s):  
Real Time ◽  
Control Structure ◽  
Low Cost ◽  
Flight Test ◽  
Formation Flight ◽  
Experimental Setup ◽  
Test Results ◽  
Test Protocol ◽  
Multi Agent ◽  
Multi Uav

Cooperative UAV systems can have great advantages over isolated UAV systems, regarding application, safety, efficiency and many other perspectives. Motivated by challenges from practical multiple UAV formation flight, this paper presents our approaches towards cognitive formation flight. It introduces the principle ofmulti-UAV cognitive formation flight and the control structure utilized in our development, describes a low-cost UAV testbed developed by ourselves, and details the tuning procedures of the implemented multi-agent flight controller for stable and consistent formation flights. Different formation flight scenarios are also discussed and the experimental setup is presented including real-time issues and the formation flight test protocol. Routinized comprehensive flight test results are also shown at the end.

scholarly journals Dynamical visualization of anisotropic electromagnetic re-emissions from a single metal micro-helix at THz frequencies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
T. Notake ◽  
T. Iyoda ◽  
T. Arikawa ◽  
K. Tanaka ◽  
C. Otani ◽  
...  
Keyword(s):  
Real Time ◽  
Electromagnetic Waves ◽  
Electromagnetic Compatibility ◽  
Smart Antenna ◽  
Dynamical Behavior ◽  
Measurement Techniques ◽  
Spatial Evolution ◽  
Frequency Spectra ◽  
3D Objects ◽  
Current Oscillations

AbstractThe capability for actual measurements—not just simulations—of the dynamical behavior of THz electromagnetic waves, including interactions with prevalent 3D objects, has become increasingly important not only for developments of various THz devices, but also for reliable evaluation of electromagnetic compatibility. We have obtained real-time visualizations of the spatial evolution of THz electromagnetic waves interacting with a single metal micro-helix. After the micro-helix is stimulated by a broadband pico-second pulse of THz electromagnetic waves, two types of anisotropic re-emissions can occur following overall inductive current oscillations in the micro-helix. They propagate in orthogonally crossed directions with different THz frequency spectra. This unique radiative feature can be very useful for the development of a smart antenna with broadband multiplexing/demultiplexing ability and directional adaptivity. In this way, we have demonstrated that our advanced measurement techniques can lead to the development of novel functional THz devices.

Multirate Integration in Hybrid Electric Vehicle Virtual Proving Grounds

1998 ◽  
Author(s):  
Dario Solis ◽  
Chris Schwarz
Keyword(s):  
Real Time ◽  
Electric Vehicle ◽  
Time Scales ◽  
Electric Vehicles ◽  
Time Scale ◽  
Hybrid Electric Vehicle ◽  
Hybrid Electric Vehicles ◽  
Differential Algebraic Equations ◽  
Vehicle Systems ◽  
Hybrid Electric

Abstract In recent years technology development for the design of electric and hybrid-electric vehicle systems has reached a peak, due to ever increasing restrictions on fuel economy and reduced vehicle emissions. An international race among car manufacturers to bring production hybrid-electric vehicles to market has generated a great deal of interest in the scientific community. The design of these systems requires development of new simulation and optimization tools. In this paper, a description of a real-time numerical environment for Virtual Proving Grounds studies for hybrid-electric vehicles is presented. Within this environment, vehicle models are developed using a recursive multibody dynamics formulation that results in a set of Differential-Algebraic Equations (DAE), and vehicle subsystem models are created using Ordinary Differential Equations (ODE). Based on engineering knowledge of vehicle systems, two time scales are identified. The first time scale, referred to as slow time scale, contains generalized coordinates describing the mechanical vehicle system that includs the chassis, steering rack, and suspension assemblies. The second time scale, referred to as fast time scale, contains the hybrid-electric powertrain components and vehicle tires. Multirate techniques to integrate the combined set of DAE and ODE in two time scales are used to obtain computational gains that will allow solution of the system’s governing equations for state derivatives, and efficient numerical integration in real time.

scholarly journals Dynamic Efficiency Analysis of an Off-Shore Hydrocyclone System, Subjected to a Conventional PID- and Robust-Control-Solution

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2379 ◽  
Author(s):  
Petar Durdevic ◽  
Zhenyu Yang
Keyword(s):  
Robust Control ◽  
Real Time ◽  
Oil And Gas ◽  
Control Structure ◽  
Control Strategies ◽  
Direct Method ◽  
Water Concentration ◽  
Current Feedback ◽  
Oil Concentration ◽  
Offshore Oil And Gas

There has been a continued increase in the load on the current offshore oil and gas de-oiling systems that generally consist of three-phase gravity separators and de-oiling hydrocyclones. Current feedback control of the de-oiling systems is not done based on de-oiling efficiency, mainly due to lack of real-time monitoring of oil-in-water concentration, and instead relies on an indirect method using pressure drop ratio control. This study utilizes a direct method where a real-time fluorescence-based instrument was used to measure the transient efficiency of a hydrocyclone combined with an upstream gravity separator. Two control strategies, a conventional PID control structure and an H ∞ robust control structure, both using conventional feedback signals were implemented, and their efficiency was tested during severely fluctuating flow rates. The results show that the direct method can measure the system’s efficiency in real time. It was found that the efficiency of the system can be misleading, as fluctuations in the feed flow affect the inlet concentration more than the outlet oil concentration, which can lead to a discharge of large oil quantities into the ocean.

scholarly journals Real-time free-running time scale with remote clocks on fiber-based frequency network

Metrologia ◽  
2019 ◽  
Vol 56 (4) ◽  
pp. 045003
Author(s):  
Y C Guo ◽  
B Wang ◽  
F M Wang ◽  
F F Shi ◽  
A M Zhang ◽  
...  
Keyword(s):  
Real Time ◽  
Time Scale ◽  
Running Time ◽  
Free Running
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