scholarly journals Control system based on tracking balance car

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Yuechang Shi ◽  
Mingwei Xu ◽  
Jiuxin Gong
Keyword(s):  
High Speed ◽  
Center Of Gravity ◽  
Moment Of Inertia ◽  
Stable Operation ◽  
Running Speed ◽  
Approach Angle ◽  
Car Model ◽  
Departure Angle ◽  
The Moment ◽  
The Impact

For balanced cars, to achieve high-speed and stable operation, two efforts should be made. The first is to make the center of gravity of the car model as low as possible, which is conducive to upright stability. The second is to make the quality as concentrated as possible. Make the vehicle's steering more flexible and reduce the vehicle's moment of inertia. At the same time, the approach angle and departure angle of the car are very important considerations, because the running speed of the car model requires the car model to maintain a certain forward inclination to obtain acceleration. When the car model goes uphill, it also needs to consider the impact of the slope. Hanging the chassis requires a certain distance from the ground while lowering the center of gravity. The battery is the heaviest piece in the entire car. The location of the battery almost determines the height of the center of gravity, the size of the moment of inertia, and the departure angle of the approach angle. In order to reduce the noise of the car to the accelerometer and gyroscope, the sensor should be installed as low as possible.

Design, Simulation and Testing of Overpack Encapsulation Vessels

2012 ◽  
Author(s):  
A. Towse ◽  
J. Dodds
Keyword(s):  
Pressure Vessel ◽  
High Speed ◽  
Failure Modes ◽  
Inner Product ◽  
Central Position ◽  
Video Footage ◽  
Rule Approach ◽  
The Moment ◽  
Explicit Dynamic ◽  
The Impact

The paper presents an overpack designed to contain nuclear product cans which may become pressurised or contaminated. The overpack provides a protective barrier to an inner product can, and due to the possibility of leakage of gas from the contents, the overpack must also function as a pressure vessel. Furthermore, the overpack is required to provide physical protection to the inner can and proof of containment was therefore necessary under a number of different impact scenarios, both pre-pressurised and also with the simulation of pressurisation at the moment of impact. Additionally, the inner product can was to be maintained in a central position during the deceleration at impact. This paper focuses on the analytical design and substantiation of the impact of the system which was performed using an explicit dynamic solver for a number of impact orientations. The design of the overpack to satisfy the relevant pressure vessel Code are not discussed in detail. The potential failure modes of the overpack during impact were assessed and design improvements made over a number of iterations. Following completion of the design and simulation phase, prototypes were built and tested to verify the engineering design and analysis. The testing showed that simulation driven design in conjunction with a pressure vessel design by rule approach was successful in creating a solution for the product can encapsulation. A comparison between the analytical simulation and high-speed video footage of the testing was also made.

Inertial Properties of Football Helmets

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
James R. Funk ◽  
Roberto E. Quesada ◽  
Alexander M. Miles ◽  
Jeff R. Crandall
Keyword(s):  
Athletic Performance ◽  
Center Of Gravity ◽  
Moment Of Inertia ◽  
Head Protection ◽  
Hybrid Iii ◽  
Football Helmets ◽  
Male Hybrid ◽  
The Moment ◽  
Athletic Equipment

The inertial properties of a helmet play an important role in both athletic performance and head protection. In this study, we measured the inertial properties of 37 football helmets, a National Operating Committee on Standards for Athletic Equipment (NOCSAE) size 7¼ headform, and a 50th percentile male Hybrid III dummy head. The helmet measurements were taken with the helmets placed on the Hybrid III dummy head. The center of gravity and moment of inertia were measured about six axes (x, y, z, xy, yz, and xz), allowing for a complete description of the inertial properties of the head and helmets. Total helmet mass averaged 1834±231 g, split between the shell (1377±200 g) and the facemask (457±101 g). On average, the football helmets weighed 41±5% as much as the Hybrid III dummy head. The center of gravity of the helmeted head was 1.1±3.0 mm anterior and 10.3±1.9 mm superior to the center of gravity of the bare head. The moment of inertia of the helmeted head was approximately 2.2±0.2 times greater than the bare head about all axes.

Statistical Analysis of Damper Seal Clearance Divergence and Impact Upon Rotordynamic Stability

2004 ◽  
Author(s):  
Joseph Tecza ◽  
Thomas Soulas ◽  
Thomas Eldridge
Keyword(s):  
Response Surface ◽  
High Speed ◽  
Statistical Technique ◽  
Design Parameters ◽  
Stable Operation ◽  
Worst Case ◽  
Compressor Design ◽  
Design Values ◽  
The Stability ◽  
The Impact

Rotordynamic stability in a high-speed, high-pressure centrifugal compressor is achieved through introducing stabilizing forces and managing destabilizing forces. It becomes the original equipment manufacturer’s (OEM) responsibility to provide sufficient stabilizing influence to ensure acceptable operational behavior. A variety of mechanisms exist to provide stability: damper bearings, de-swirl elements on seals, shunt holes and damper seals are commonly provided by the compressor manufacturer to combat instability. The application of damper seals provides a significant increase in rotordynamic stability if designed properly. A previous case study (Camatti, et. al. [1]) presented the detrimental effect of damper seal clearance divergence and seal gas pre-swirl upon predicted stability. Accurate prediction of rotordynamic stability requires knowledge of the destabilizing influences, and evaluation of the variation possible in the stability promoting elements. In particular, the damper seal can be strongly influenced by the presence of divergence in the seal-to-rotor clearance and can result in unexpected at-load behavior. One approach to ensure stable operation is to perform a “worst case” evaluation. However, this often results in excessive compromise (large seal clearance and impact on aerodynamic performance) to “eliminate” the possibility of unstable operation. A different and new approach is to define an acceptable envelope of probability. This study presents a statistical evaluation of the impact of damper seal clearance divergence, along with other compressor design parameters, and provides a method for ensuring stable operation regardless of manufacturing or operational variation. The logarithmic decrement is evaluated as a function of compressor design values and a statistical response surface is created. From the response surface and defined variation in design values, a measure of probability for instability can be obtained. Allowable parameter variation can be restricted to ensure stable operation. Three case studies will be presented where the potential for instability exists and the risk quantified using this statistical technique. Additionally, in one of these cases, test results are presented to support the analytical work.

scholarly journals THE IMPACT OF AUTOMATED TRADING SYSTEMS ON FINANCIAL MARKET STABILITY

2019 ◽  
pp. 255
Author(s):  
Violeta Todorović ◽  
Aleksandra Pešterac ◽  
Nenad Tomić
Keyword(s):  
Financial Markets ◽  
High Speed ◽  
Algorithmic Trading ◽  
Stock Trading ◽  
Trading Systems ◽  
Financial Market Stability ◽  
The Moment ◽  
The Impact ◽  
Choice Of Instruments ◽  
The Way

The way in which financial markets operate has substantially been changed by the development of information technology. Automation of trading systems in financial markets represents the last phase of depersonalizing activities previously done by traders. Algorithmic trading development enabled computers to determine the moment and the way of executing sales orders. Computers still do not make autonomous decisions regarding the choice of instruments to be traded or trading criteria. They implement the strategy a trader has decided on, choosing a favorable moment. This reduces the impact of human emotions on decision making and enables overcoming possible problems which arise due to neglecting or lack of concentration. High-frequency trading enables the execution of algorithmic operations at a high speed. The main goal of the paper is to determine advantages and dangers produced by algorithmic stock trading.

scholarly journals ДОСЛІДЖЕННЯ ВПЛИВУ ЗМІЩЕННЯ ПАКУВАННЯ ВЗДОВЖ ОСІ БОБІНОТРИМАЧА НА КРИТИЧНІ ШВИДКОСТІ

2020 ◽  
Vol 144 (2) ◽  
pp. 13-23
Author(s):  
Б. С. Завертанний ◽  
О. П. Манойленко ◽  
О. О. Акимов
Keyword(s):  
High Speed ◽  
Center Of Mass ◽  
Axial Direction ◽  
Dynamic Loads ◽  
Practical Significance ◽  
Stable Operation ◽  
Direct Drive ◽  
Critical Speeds ◽  
The Impact

Creation of a mathematical model of the mechanism of winding of rewinding machines, research of influence of size of shift of packing on critical speeds and development of recommendations for the decision of the set task. Method. When working out the thread for packaging, high-speed winding mechanisms are subject to high requirements, both for the quality of the resulting packaging and for the speed of the bobbin holder. When installing the spool on the spool holder, it is possible to shift it in the axial direction from the design position, which leads to a change in the position of the center of mass of the package with the spool, and in accordance with changes in dynamic loads on the spool holder. Therefore, there is a need to determine the magnitude of the impact of the displacement of the package along the axis of the bobbin holder on the operating speeds of the equipment and the quality of the resulting packages. In the winding process, the placement of the package on the bobbin holder of the winding mechanism of the rewinding machine plays an important role. The displacement of the center of mass of the package affects both the operating speed of the equipment and the quality of the package. In rewinding machines, a mechanism for controlling the thickness of the package is installed, which controls the speed processes during winding. When the coil is shifted towards the top of the cone, incomplete packing (less weight) is developed. When shifted to the side opposite the top of the packing cone, on the contrary, the weight of the packing increases. In addition, the magnitude of the displacement of the package affects the dynamic loads of the winding mechanism. Results. The influence of the magnitude of the packing displacement along the axis of the bobbin holder on the critical speeds of the winding mechanism and the quality of packing is determined. Scientific novelty. The study and analysis of the influence of the magnitude of the displacement of the bobbin with packaging on the critical speeds of the winding mechanism are conducted. The magnitude of the influence of the position of the masses of the center of the coil with packing relative to the bobbin holder on the value of the critical speeds of the winding mechanism is determined. The obtained results allow to control the range of working speeds of the winding mechanism depending on the parameters of the position of the spool on the spool holder, which can be used to adjust the speed of the winding process when packing the spool and make changes when designing the rewinding equipment. The method of determining the maximum possible speeds in the process of rewinding textile material on rewinding machines with direct drive of the bobbin, taking into account the position of the bobbin on the bobbin holder, which can be used in the design of new mechanisms or modernization of existing ones. Practical significance. A dynamic model of the winding mechanism has been developed. The magnitude of the influence of packing displacement on critical speeds is shown. Methods and designs for improving the quality of packaging and stable operation of equipment are proposed.

scholarly journals Microscopic Change in Hardened Cement Paste Due to High-Speed Impact

2018 ◽  
Author(s):  
Yuya Sakai ◽  
Ivwananji Sikombe ◽  
Keiko Watanabe ◽  
Hiroyuki Inoue
Keyword(s):  
Cement Paste ◽  
High Speed ◽  
Impact Load ◽  
Hardened Cement ◽  
Hardened Cement Paste ◽  
High Speed Impact ◽  
Gas Gun ◽  
Microscopic Change ◽  
The Moment ◽  
The Impact

Impact load was applied to hardened cement paste (HCP) specimens using a gas gun to investigate microscopic changes in the specimens and develop a better response model of concrete subjected to impact load. Plasma emission was observed at the moment of impact at 420 m/s and the colour of the portion near the impact point turned brighter. This brighter portion was analysed, and it was observed that the pore structure was coarser compared to the other portion; however, the results of thermogravimetry and X-ray diffraction analysis were similar. A possible reason is that the generated heat was instantaneous and the rate of the temperature increase in the HCP decreased due to evaporation of water in the HCP. These results indicate that during impact at a few hundred m/s, porosity increase due to heat effect is more dominant than porosity decrease due to mechanical compaction.

scholarly journals Exploration of Center of Gravity, Moment of Inertia, and Launch Direction for Putters with Ball Speed Normalizing Face Properties

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 2
Author(s):  
Jacob Lambeth ◽  
Dustin Brekke ◽  
Jeff Brunski
Keyword(s):  
Weight Distribution ◽  
Design Strategy ◽  
Center Of Gravity ◽  
Moment Of Inertia ◽  
Sweet Spot ◽  
Ball Speed ◽  
Impact Location ◽  
The Face ◽  
The Moment ◽  
Novel Design

The forgiveness of golf putters is traditionally achieved through weight distribution. Putters are often designed with large footprints, which help to increase the moment of inertia (MOI), but consequently move the center of gravity (CG) farther behind the face. The use of higher MOI putters will result in less ball speed loss on impacts away from the sweet spot (i.e., more forgiveness). It has been shown that certain face properties, such as milling patterns, grooves, or soft inserts, can be leveraged to have a similar effect. This paper explores the relationships between impact location, MOI, CG depth, discretionary mass placement, and launch direction for these putters. A novel design strategy is proposed. Minimizing CG depth for putters with ball speed normalizing face properties, even at the expense of MOI, can result in more consistent launch direction and distance control for the average player.

Lamboley Test of EC-12 Model Yachts

1995 ◽  
Vol 32 (01) ◽  
pp. 33-42
Author(s):  
Lon Robinson ◽  
Larry Robinson
Keyword(s):  
East Coast ◽  
Center Of Gravity ◽  
Simultaneous Equations ◽  
Moment Of Inertia ◽  
Radius Of Gyration ◽  
Pendulum Test ◽  
The Moment ◽  
Righting Moment ◽  
Boat Speed

Comparative evaluations were conducted using a Lamboley pendulum test to determine the radius of gyration in the pitch axis and to locate the center of gravity of the East Coast 12-Meter (EC-12M) model sail yachts. The Lamboley simultaneous equations were solved using a computer programmed for this purpose. From these data, the righting moment at 20 deg heel and the moment of inertia in the pitch axis, without the rig, were calculated and plotted. Critical pitching frequencies were calculated, assuming a nominal mast and rig; and critical wavelengths were calculated and plotted versus boat speed.

scholarly journals A comparative study of performance of AC and DC electric drive control systems with variable moment of inertia

2021 ◽  
Vol 10 (2) ◽  
pp. 588-597
Author(s):  
Addasi E. Said ◽  
Abdullah M. Eial Awwad
Keyword(s):  
Control System ◽  
Control Systems ◽  
Electric Drive ◽  
Moment Of Inertia ◽  
Motor Shaft ◽  
System Operation ◽  
Drive Control ◽  
The Moment ◽  
The Impact ◽  
Variable Moment

In electric drive control systems, the main goal is to maintain the driving motor speed to meet the mechanism’s requirements. In some practical industrial applications the mechanically-coupled load to the motor shaft has a varying mass during the system operation. Therefore, the change of mass changes the value of the moment of inertia of the system. The moment of inertia impacts the system operation, particularly the transient performance. Therefore, the variation of moment of inertia on the motor shaft during its operation creates additional challenges to accomplish a high-quality speed control. The main purpose of the current work is to study the impact of the variation of moment of inertia on the performance of both AC and DC electric drive control systems and to make a comparison between them. A mathematical analysis and simulations of the control system models had been presented; one time with three-phase induction motor and another time with DC motor, both with variable moment of inertia. A simulation of both systems had been accomplished using the Simulink software in MATLAB. The simulation results of operation of these systems have been analysed in order to get useful conclusions and recommendations for the electric drive control system designer.

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