Thermal/structural/optical integrated design for optical window of a high-speed aerial optical camera

2015 ◽  
Author(s):  
Gaopeng Zhang ◽  
Hongtao Yang ◽  
Chao Mei ◽  
Kui Shi ◽  
Dengshan Wu ◽  
...  
Keyword(s):  
High Speed ◽  
Integrated Design ◽  
Optical Window

Aspects Regarding Pneumatic System Simulated Control

2010 ◽  
Vol 166-167 ◽  
pp. 291-296 ◽  
Author(s):  
Rares Ciprian Mîndru ◽  
Vistrian Maties ◽  
Ciprian Lapusan ◽  
Ioan Adrian Cosma
Keyword(s):  
Differential Equations ◽  
High Speed ◽  
Integrated Design ◽  
Control Algorithms ◽  
Pneumatic Actuators ◽  
Positioning Systems ◽  
Electromagnetic Valve ◽  
Modeling Simulation ◽  
Mathematical Analyses ◽  
And Control

The paper proposes a large approach to pneumatic systems starting from the mathematical laws, written in the form of differential equations, which govern the operation of pneumatic systems and continuing with the simulation model. The concept of integrated design includes all approaches, needed for an optimal and deep system understanding, such as modeling, simulation and control. Pneumatic actuators have a nonlinear functionality because of air compressibility, the existing frictions and the valves nonlinearities. Because of these, they are used in high speed applications and simple positioning systems. Thus, the mathematical analyses of pneumatic systems have received a special attention. The differential equations were implemented in Matlab Simulink, and the model input represents the voltage on the electromagnetic valve, and the output seen on the "scope" represents the movement of the piston pneumatic axis. Some control algorithms are implemented and applied to the model and seen the basic differences.

Experimental validation on the integrated design and control of a parallel robot

Robotica ◽  
2005 ◽  
Vol 24 (2) ◽  
pp. 173-181 ◽  
Author(s):  
Qing Li
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Dynamic Models ◽  
Integrated Design ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Approximation Techniques ◽  
Control Approach ◽  
Modeling Errors ◽  
And Control

Due to the demands from the robotic industry, robot structures have evolved from serial to parallel. The control of parallel robots for high performance and high speed tasks has always been a challenge to control engineers. Following traditional control engineering approaches, it is possible to design advanced algorithms for parallel robot control. These approaches, however, may encounter problems such as heavy computational load and modeling errors, to name it a few. To avoid heavy computation, simplified dynamic models can be obtained by applying approximation techniques, nevertheless, performance accuracy will suffer due to modeling errors. This paper suggests applying an integrated design and control approach, i.e., the Design For Control (DFC) approach, to handle this problem. The underlying idea of the DFC approach can be illustrated as follows: Intuitively, a simple control algorithm can control a structure with a simple dynamic model quite well. Therefore, no matter how sophisticate a desired motion task is, if the mechanical structure is designed such that it results in a simple dynamic model, then, to design a controller for this system will not be a difficult issue. As such, complicated control design can be avoided, on-line computation load can be reduced and better control performance can be achieved. Through out the discussion in the paper, a 2 DOF parallel robot is redesigned based on the DFC concept in order to obtain a simpler dynamic model based on a mass-balancing method. Then a simple PD controller can drive the robot to achieve accurate point-to-point tracking tasks. Theoretical analysis has proven that the simple PD control can guarantee a stable system. Experimental results have successfully demonstrated the effectiveness of this integrated design and control approach.

Numerical Simulation Studies on the Performance of a Diffuser Attached With Last Stage Compressor Outlet Guide Vanes

2019 ◽  
Author(s):  
A. T. Sriram
Keyword(s):  
High Speed ◽  
Guide Vane ◽  
Integrated Design ◽  
Computational Domain ◽  
Simulation Studies ◽  
Allowable Limit ◽  
Guide Vanes ◽  
Compressor Rotor ◽  
Overall Performance ◽  
Last Stage

Abstract Combustor pre-diffuser is an important element connecting the compressor and combustor. The design of pre-diffuser should be in such a way that the flow velocity to be within allowable limit to hold the flame in the combustor and also it should recover pressure with less amount of total pressure loss. The general practice is to design the compressor and combustor separately for their performance. However, integrated design of outlet guide vanes and pre-diffuser is given importance, on nowadays, to improve the overall performance. Basically, the outlet guide vane blades are modified to improve the performance. In the present work, numerical simulations studies have been carried out for a well-known high speed compressor, NASA Stage 37, to identify the influence of blade parameters. The computational domain consists of compressor rotor, stator and combustor pre-diffuser. The stator blades serve as outlet guide vanes. In literature, studies were shown that there is improvement in introducing blade sweep. Also, blade lean was shown some advantages for the case of a pre-diffuser with axial inlet and radial outlet with flow turning. However, in the present case of axial inlet and axial outlet, blade lean has not shown improvement in the performance. A diffuser showing slightly unstable condition in the conventional design, Area Ratio (AR) of 1.5 in the present case, has shown improvement with the presence of blade sweep.

Perfectly Matched Feedback Control and Its Integrated Design for Multiaxis Motion Systems

2004 ◽  
Vol 126 (3) ◽  
pp. 547-557 ◽  
Author(s):  
Syh-Shiuh Yeh ◽  
Pau-Lo Hsu
Keyword(s):  
Feedback Control ◽  
High Speed ◽  
Feedforward Control ◽  
Phase Error ◽  
Integrated Design ◽  
Cnc Machining ◽  
Dynamic Responses ◽  
Tracking Accuracy ◽  
Control Loops ◽  
Contouring Accuracy

For motion systems with multiple axes, the approach of matched direct current gains has been generally adopted to improve contouring accuracy under low-speed operations. To achieve high-speed and high-precision motion in modern manufacturing, a perfectly matched feedback control (PMFBC) design for multiaxis motion systems is proposed in this paper. By applying stable pole-zero cancellation and including complementary zeros for uncancelled zeros for all axes, matched dynamic responses across the whole frequency range for all axes are achieved. Thus, contouring accuracy for multiaxis systems is guaranteed for the basic feedback loops. In real applications, the modeling error is unavoidable and the degradation and limitations of the model-based PMFBC exist. Therefore, a newly designed digital disturbance observer is proposed to be included in the proposed PMFBC structure for each axis to compensate for undesirable nonlinearity and disturbances to maintain the matched dynamics among all axes for the PMFBC design. Furthermore, the feedforward control loops zero phase error tracking controller are employed to reduce tracking errors. Experimental results on a three-axis CNC machining center indicate that both contouring accuracy and tracking accuracy are achieved by applying the present PMFBC design.

scholarly journals Design of a Testing Mechanism for Stent Failure Rates and Displacement Under Extreme Bending Conditions

2009 ◽  
Vol 3 (2) ◽  
Author(s):  
J. Henneman ◽  
J. Allen ◽  
R. Giasolli ◽  
P. Schneider
Keyword(s):  
Human Body ◽  
Stress Reduction ◽  
High Speed ◽  
Integrated Design ◽  
Femoral Arteries ◽  
Arterial Plaque ◽  
Cycle Count ◽  
External Stresses ◽  
Torsional Loads ◽  
Application Frequency

Stents are commonly associated with the mechanical support of the coronary arteries to improve blood flow and retain residual plaque following various angioplasty procedures. However, they are becoming more frequently used in other vessels in the human body, such as the carotid and femoral arteries. The femoral arteries transverse through the hip region, and are the sites of potential plaque build-up. Thus the design of a stent for the specific biomechanical stresses and conditions of this location is of growing interest. The effectiveness of stent designs are quantified by their ability to survive in the human body without failing mechanically, dislocating, or invoking a major inflammatory response. Common methods of failure are mechanical, including fractures and dislocations. Several different instruments are commercially available for the testing of stents under various stresses and application frequency. However, these machines generally test with small bending angles or they apply nonphysiological axial, radial and torsional loads; thus they are not idealized for motions to mimic accurate biomechanical motion. Specifically, for the design of a stent localized in the hip region, a test for significant bending cases is necessary. The placement of stress on a mock artery should be applied solely to the ends of a mock artery to remove any radial or axial stresses not caused directly from the bending motion. Furthermore, visualization of the stent inside the mock artery is desired for tracking displacement of the stent and cycle count until failure. The ability to quantify the mechanical failure and dislocation of stent designs under extreme bending conditions is a prerequisite to the optimization of physical stent designs and of stent spacing, orientation and placement. We compare a proprietary stent-like design (Innovasc Inc., Honolulu, HI) placed at fixed intervals versus a commercially available SMART stent (Cordis Corporation, Warren, NJ). Both designs are intended to retain the arterial plaque while minimizing the stress applied to the artery wall to prevent restenosis. The new stent prototype designs are uniquely configured to enable points of stress reduction along the length of interest. Early preliminary experiments with the Innovasc design show promising results in the reduction of restenosis in porcine models. Stent designs are tested in mock arteries of latex and silicone. The mock arteries are selected for internal diameters and thicknesses to match artery properties. Two symmetric cylinders holsters are allowed to rotate freely and are affixed to the ends of the mock arteries. A simple linkage system drives the two cylinders together and apart, allowing for the mock arteries to bend at a fixed angle of 120 degrees at frequencies (∼10–20 Hz) without external stresses for one million cycles. Images are captured using a X-Stream Vision High-Speed CMOS camera (Integrated Design Tools, Tallahassee, FL) via a trigger system. Failure points and dislocations are noted and measured using the NIH ImageJ imaging software.

Design Analysis of Double Optical Window of High Speed Aerial Remote Sensor

2015 ◽  
Vol 35 (1) ◽  
pp. 0122007
Author(s):  
徐钰蕾 Xu Yulei ◽  
王乃祥 Wang Naixiang ◽  
许永森 Xu Yongsen
Keyword(s):  
High Speed ◽  
Design Analysis ◽  
Optical Window ◽  
Remote Sensor

EXPERIMENTAL INVESTIGATION OF BOUNDARY LAYER STATE ON THE MODEL OF INTEGRATED DESIGN HIGH-SPEED VEHICLE AND ITS IMPACT UPON THE CONVERGENT INTAKE STARTING

2018 ◽  
Vol 49 (6) ◽  
pp. 595-609
Author(s):  
Stanislav Sergeevich Alyoshin ◽  
Valerii Nikolaevich Golubkin ◽  
Anatoly Aleksandrovich Gubanov ◽  
Ivan Valerievich Nazhimov ◽  
Vadim Alekseevich Talyzin ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Experimental Investigation ◽  
High Speed ◽  
Integrated Design ◽  
High Speed Vehicle
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