The brown marmorated stinkbug (Halyomorpha halys) is an introduced plant pest from Asia that has invaded parts of the US (first seen in 1998), Europe, and perhaps other places.
Since it was introduced without its natural predators and can feed off a variety of crops plants it has done quite...
In both the cases, the flow cross section area of the pipe is reduced.But in case of nozzles the velocity increases,pressure reduces and the flow rate is maintained.But in case of flow control valve, flow rate changes.(Assuming the fluid to be incompressible) Why is there a difference between...
When I free dive (skin dive without a scuba air tank), I've noticed that by the time I get out of the water after about an hour (abalone diving or just recreational free diving), I feel like Jello and my blood pressure (BP) feels very low. I feel extremely relaxed and warm and happy. And after...
I’m designing a system where a sea water sample must have its temperature controlled between near its freezing point (-2°C) and +30°C to simulate sea temperatures. To control it, the sample will be in contact with a block, which will be controlled by an external circulating water bath. The image...
Homework Statement
Water flows over a dam as depicted below. Across section 1 and 2 we have a hydrostatic pressure distribution. Calculate the force on the dam.
The Attempt at a Solution
My question is regarding control volume. The solution manual has given us this:
The two hydrostatic...
Homework Statement
I have a situation as illustrated by the image above, where the red box illustrates the CV. The pressure on the left side of CV is P1, while the pressure on the right side of CV is P2. Here I´ve directed the pressure forces acting inwards on CV. The problem arises with Fk. I...
Hello everyone,
First off, i would like to apologize for any spelling errors. I am Portuguese and my english is going to be very simple.
I am in the process of building something and i am reaching out to the physics community for help solving a problem.
I am a CNC programmer and while i was in...
Good afternoon people. I wanted to implement a physical system using control just to put into practice what I have learned in school. To be more specific: I would like to implement an inverted pendulum like the one on the photo
In this system a control input (a force u) drives the cart (mass...
Possibly easy/concise question:
Is droop in PID control alway against the setpoint? (as the name implies?)
Background:
I have a humidifier that is consistently controlling high. The control point is room dewpoint, the room has outside air supply (dry in winter) and the humidifier uses plant...
Hi, I am trying to solve a control problem where I have to minimize the fuel consumption of a vehicle:
$$J=\int_{0}^{T} L(x(t), u(t),t) + g(x(T),T)dt$$
##L(u(t),v(t))=\sum\limits_{i,j=0}^{2} K_{i,j} u(t)^i v(t)^j ## is convex (quadratic) and the term ##g(x(T),T)## is to have a constraint in the...
Hi guys I was wondering if anyone had a good recommendation on a textbook to pick up on field oriented control, motor control, 3 phase control or modern motor control in general. Looking for a professional level text. I already have Electric Machinery Fundamentals by Chapman but looking for...
Does anyone have experience modeling active/reactive management in an inverter? I'm working on it for a project, more precisely I'm trying to implement that PQ control with references of voltage, as is seen in this image:
Problem is I've tried many PI regulators, and my I_dq doesn't want to...
I'm currently working on combining energy storage systems like flywheels and batteries to balance consumption/regeneration. I've been looking at using an optimal control scheme so that a cost function can be tailored to our wishes.
I'm curious about what other people in this field have been...
I am a TA for Automatic control class, I can't find an answer for my students about why we are still studying Routh-Hurwitz criterion as almost anyone can use computer software to find the roots of the closed-loop system and determine stability instead of doing these tedious hand calculations
Hello,
I have begun to teach myself Control Theory.
I am looking for a book that is focused for mechanical engineers. I do not mind examples in electrical engineering, but they bore me (no offense).
Also, I find some books begin with Laplace Transforms. Yet I found this online lecture...
Homework Statement
Homework Equations
Using Laplace
TF = C (s) / R (s)
The Attempt at a Solution
Laplacing the equation:
3s C(s) + C(s) = R(s) e-3s
So C(s) / R(s) = e-3s / (1 + 3s)
Book answer is B
I know ramp input is At. Do I laplace it as: A/s2?
I'm not sure where I'm wrong
Homework Statement
Write down the equations of motion and develop the continuous-time system.
Homework Equations
See my word doc. or PNG's.
The Attempt at a Solution
See my word doc. or PNG's.
I assumed that there was no friction as no information was given.
I can easily get the transfer...
Homework Statement
In a report I am asked to assess the speed of response of various systems, however I am not exactly sure what this means, be great if someone could explain
The Attempt at a Solution
Step response plots were produced for each simulation and MATLAB was used to assign...
So I have a coiled (Nichrome) heating element that's rated at 120VAC 60Hz. (Resistance of 14.4Ohms)
I am trying to use this heating element to warm up air blowing across it. I will have thermistor on the outlet end to monitor the temperature of the output air. This heater is coiled inside of a...
Hi, I am using mathlib as such:
text...$\mathlib{L}^2[a,b]$...text
though, I get the error:
<recently read> \mathlib l.235 ...d form the complex vector space $\mathlib {L}^2[a,b]$ which satisfie... The control sequence at the end of the top line of your error message was never \def'ed. If you...
I am struggling to fully grasp the concept of flow work for a non-deformabable control volume.
Nearly every source puts it in this way: flow work is the work required to push fluid into and out of the control volume and as such is defined as Pv on a unit mass basis. But how can this work be...
I'm not looking for fiction; I'm looking for physics.
Assumptions:
- An engine efficient enough that you can afford to thrust for very long periods - maybe fusion? (OK, that's fiction)
- A lot of maneuvering (eg. you could thrust until turnaround point and then decelerate)
- With a lot of...
Hello, in my final project for System Control i have been stuck for some time on this following task
What i cannot figure out is how to make all these condition work at the same time.
When I tried designing a PD controller in sisotool or MATLAB for the i and ii part it worked but i couldn't...
Homework Statement
Homework Equations
To find Ca / Rb we take Ra = 0 --- is this right?
I used mason's formula
P1 = -G2 G1 H1
Loop = G1, G2, -H1, -H2
Using Mason's Gain we get:
Delta1 = 1
Delta = 1 - G1G2H1H2
Using Mason's Gain
TF = -G1G2H1 Divided by ( 1 - G1G2H1H2)
But substituting the...
This article in Science mag news is about a fabric that can,
let more heat (via IR) out in hot weather, or
flipped over, keep more heat in the cold
Here is the Science article (not free).
The fabric also let's gasses and humidity pass through because it has nano-pores.
It has 4 layers: 2...
Hi,
I would like to provide the PLC control for a scenario where the temperature in a machine, heated by the two electric heaters, is controlled with use of 1 TCK and 2 s/s relays. Please see draft “PLC4” sent attach. The TCK is fixed to the machine and is not in a physical contact with the...
Hi! I am confused with the speed regulation for Isochronous control. In Droop control, we can surely solve for a value of speed regulation because droop allows the generator to have a varying frequency. However, in Isochronous control, the frequency and speed from no-load to full-load is the...
The butterfly valve I have is controlled by sending voltages to it. It accepts 0-10V and maps a specific voltage to a specific position from completely closed (zero degrees) to completely closed (90 degrees).
To clarify/reiterate it is not controlled by a servo motor.
I am using this valve to...
Homework Statement
https://i.imgur.com/WPAKuf4.png
seeking G(s) = \frac{\theta_2(s)}{\tau(s)}
Homework EquationsThe Attempt at a Solution
What does it mean when the viscous drag is parallel to the axis of rotation?[/B]
It also turns out that this system needs two equations. I can sort...
I have a huge interest in aviation and aerodynamics, despite being an EE student. I took Fluid Mechanics courses as electives, and I'm learning some aerodynamics on my own. I was thinking if there is any field of work where the knowledge of both an EE and aerodynamics/flight mechanics would be...
Homework Statement
[/B]
I am currently working on an assignment in which I create a six-state up/down counter. The purpose is to understand the functionality of flip-flops within a circuit among other things.
There are 3 input bits (Q2,Q1, Q0), and a 4th control bit (C) which determines the...
I am trying to write a Labview program to control two AD9854's which will generate the signal for AODs in an optical trapping setup. Unfortunately I'm not an EE and I don't have much experience with Labview so I was wondering if someone already had the VI's to do this with Labview FPGA. We have...
HI,
i have a first order controller (ts/ks+k) which contain some oscillations and its settling time is very huge, i wanted the controller to have settling time of 10seconds and remove the oscillations. in order to remove the noise and get the expected settling time i added a filter ( s/cs+1)...
Hi everybody, I'm a PhD student working on solution-processed kesterite PV cells. The material is spin-coated and I personally believe that its wetting properties are influenced by environmental parameters like temperature and humidity.
To control these parameters, or at least reduce their...
I know this is so vague as to be unanswerable - at least no answer better than I might come up with through a bit of experimentation - but it's late and I'm lazy.
After having my new Smart TV with soundbar for several months now, it has spontaneously started doing something different.
The new...
Hi guys,
I have a question about engine torque control in automatic transmissions and dual clutch transmissions. I've seen cases where the engine torque is decreased on an up-shift and increased during a downshift. Why is this done?
I have seen in several documents on field oriented control for example in the below document. The inputs to the PI controller are phase currents but the outputs are voltages that is iSqref and iSdref is converted into Vsqref and VSdref. How the current signals are automatically converted to...
As an airplane lover, I would like to know if a normal mobile phone (in my case a Galaxy S3 ) could recive the frequency that ATC uses, I think that is called VHF.
Note: I'm sure that it isn't illegal
Hello everyone.
Iam working on a course in multivariable control theory and I stumbled over the Identity Matrix.
I understand what the identity matrix is, though the use of it is a mistery...
I was reading about going from state space to transfer functions and I found this expressions...
Robotic limbs are often controlled by having electrode sensors on the limb stump pick up signals which are used to control the robotic limbs movements. This approach has had it limitations.
By replicating aspects of how natural legs work in the healing stump, prosthetic limb control can be...
Im drawing a system using control systems engineering. It changes over time and many factors affect each other. So far I've been using draw.io for drawing program architecture and it works great but I am looking for something more directed at flowcharts/control systems.
Requirements:
>Layers...
Hi guys,
I need to determine the performance of a single expansion ramp nozzle (SERN) from CFD results with different nozzle pressure ratios (NPR). For some NPR the nozzle is overexpanded and for some underexpanded.
Now the impact of the control volume definition on especially the axial thrust...
So, I have a Bachelor's degree in Electronics and Communications (outside of US) and I wanted to pursue work in nuclear fusion so I had applied for an MS in nuclear engineering in the US. I have gotten admission in the University of Florida.
Anyway, I was sharing this information elsewhere on...
Hi everyone.
I'm designing a steady state feedback H2 control system.
Actually, my major is tribology and I have no experience in designing control system.
So it is really big problem for me.
Anyway, this is my simple model of tribometer which applies normal load on the surface.
(is it...
The international Journal of Greenhouse Gas Control.
It has an Impact Factor of around 4, but what's the perception? Is it respected? Is it considered a good journal?
There isn't a qualitative judgment online. My boss seems to look down on it, but it has a good impact factor.
I am currently working on turbine design for small scale ORC system to produce power from low-enthalpy heat source. In ORC, turbine inlet pressure and flow rate are controlled by pump, and turbine inlet temperature is determined by evaporator when the flow rate of refrigerant and enthalpy of...
Hi all,
I am not a physics major and have spent some time learning via the university of Google. I would really appreciate a second set of eyes on what I am calculating and tell me if I am correct, or if I have done something wrong along the way. I am trying to calculate MOI and need results...
Homework Statement
How to show a block diagram can be simplified to a standard first order form for the diagram shown in the image attached and the question is shown in 1.a
Homework Equations
Standard first order form K/(1+tD) where K gain and t is time constant
The Attempt at a Solution...
Good afternoon people; recently I decided to give a study break from control engineering; now I'm back. I'm studying again control theory and I see some good results. By the way I got stuck in a topic called root locus method. Now my issue is not about how to sketch the root loci graph (BTW I...