8 votes
Accepted

Is active noise cancellation useful in vehicles?

Some reasons why noise reduction in vehicle cabins is not a standard feature, yet: As @Trevor Archibald states, safety is a very good reason. There is still a need to hear some noises from outside ...
  • 9,527
5 votes

Why can't proportional gain alone, reduce the error to zero?

To understand why proportional gain won't drive the error point to zero, it is best just to look at the math. Consider the PID loop shown in the image below. The loop algebra in the $s$ domain comes ...
5 votes
Accepted

What is the effect of changing the angle of a helicopter flybar?

This angle is determined by the lift characteristics of the rotor and the rotational inertia of the whole helicopter. You are exactly correct that the angle changes the phase of the feedback. For the ...
  • 5,960
5 votes

How to convert a DC motor into a servo motor using a rotary encoder and a microcontroller?

At the very high level you will need 24V Power supply or a method to generate 24V 24V Motor controller Microcontroller - Arduino is a good place to start There are also prebuild motor controllers ...
3 votes
Accepted

How does feedback implementation look like in a real word closed- loop process?

Microprocessors. The measured value from a sensor (either an analog voltage or any other digital processed value) provides the microprocessor with the current output of the system. Internally, this ...
  • 1,079
3 votes
Accepted

How to improve a PID control loop by adding feedforward?

The idea of using a feedforward component in a control system is to provide near instant action of the plant output to the input command. So a suitable choice of transfer function which connects the ...
3 votes
Accepted

mass-friction-spring system with closed loop

Based on the information you've given, I believe your professor is suggesting that a friction term can be represented as shown in the following block diagram. The transfer function $G(s)$ relates ...
3 votes
Accepted

Can a PID controller have a simple on/off output?

So typically there is proportionality and a continuously varying (analogue) output. Correct. This could be an analog voltage or a digital value. In the case of a simple process like a domestic gas ...
  • 8,794
3 votes

Given drive rotation angle, controlling torque, how do I maintain movement speed with varied load?

This is typically done with a PID (Proportional, Integral, Derivative) control algorithm. There are heaps of literature about designing and optimizing PID controllers, so there's not much sense going ...
  • 4,501
3 votes
Accepted

Is lead filter same as PD combined with a low pass filter?

A lead filter implies that the zero has a lower frequency than the pole. While a PD controller with a low-pass-filter does not necessarily imply that order. Also a lead filter (usually) does not have ...
  • 1,603
2 votes
Accepted

Closed loop response of a discrete system

The plant and controller: $$\text{sys}=\frac{4700 s^2+4393 s+3.245\times 10^8}{s^4+7.574 s^3+120200. s^2}$$ $$pid=0.287\, +0.008 s+\frac{0.5}{s}$$ The closed-loop system obtained as $\frac{pid*sys}{...
  • 1,876
2 votes
Accepted

Calculating a derivative in a loop?

Your implementation is: ...
2 votes
Accepted

What type of control system is this? open loop?

This system can be considered "closed loop," since the control input is being determined by some sort of feedback loop (even though the mathematical expression of the feedback loop through the ...
2 votes

How can I get final value of $V_{out}$ at $t=∞$ in RC circuit?

The final value theorem is for a signal, not a transfer function. Use the transfer function to express the output signal $$ V_{\mathrm{out}}(s) = \frac{1}{RCs+1} V_{\mathrm{in}}(s),$$ with input $V_{\...
2 votes

What is a "Unidirectional Input" (?) Closed Loop Control Algorithm Called and How Does it Work?

Perhaps this is an X/Y problem. But here are some suggestions. 1 Design an over damped PID closed loop system. An over damped system will have poorer rise time. Assumptions required for this to work ...
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2 votes
Accepted

Feedback loop and zero - error in steady state

Let's start by obtaining the state space form of the closed-loop system (closed loop means that you plug in the equations the expression of the controller). The controller of this specific system has ...
2 votes

Can an electric motor act as a load for the electric generator rotated by that motor?

I think the procedure you want is: Start the motor. The only load will be the losses in the motor and the unloaded resistance of the generator. Adjust the generator excitation so that the voltage ...
  • 8,794
1 vote

How to convert a DC motor into a servo motor using a rotary encoder and a microcontroller?

Adding to the other answers. I just so happen to have done exactly this. I used a windshield wiper motor and a potentiometer but the principal is the same. Here's my arduino source code: https://...
  • 1,663
1 vote

How to convert a DC motor into a servo motor using a rotary encoder and a microcontroller?

You are at the right track. As the DC motor is rather fast for a potential slow microcontroller, using a discrete controller will improve the reliability and stability of the closed-loop system. Even ...
  • 1,079
1 vote
Accepted

Tuning Feedforward + PID Controller just with Feedforward Data

The System Identification Toolbox app is indeed the solution, but I can understand the amount of choices and options make it rather confusing at first. Especially if you have no prior knowledge to ...
  • 1,079
1 vote

What does "analytical design" mean?

I would think that this refers to using mathematical and physical principles and equations to predict the behaviour of a control system. The opposite would be to empirically design a control system, ...
  • 22.8k
1 vote
Accepted

Is it true that points of root locus only satisfiy the angle condition?

Suppose we have a system $G(s) = \frac{1}{s(s+1)}$ and controller $K$ (this is purely a gain) and we close the loop: $$T(s) = \frac{KG(s)}{1+KG(s)} = \frac{K\frac{1}{s(s+1)}}{1+K\frac{1}{s(s+1)}}$$ $$ ...
  • 1,079
1 vote

Feedback Control Question: Finding compensator numerator (B(s)) and denominator (A(s)) polynomials to satisfy a specific requirement

your question is ill-conditioned: If $A$ must have a higher degree than $B$, 2 things can happen: $A$ is a constant, meaning $B$ must be 0: which means you cannot solve the equation as there is no $s$ ...
  • 1,079
1 vote

Crossflow HX tube and fin, derive Tout hot side as a function of mdot hot side in

First, find the energy balance - basically mass flow x thermal capacity x delta T is the same on both sides. Edit to add There's an error in your energy balance: on the left hand side it's simply $\...
  • 4,651
1 vote

Finding stability of open loop system connected to closed loop system

Since you're worried about an open-loop system, in theory all you need to do is perform standard stability analysis on the open-loop system alone. The source of the input signal to the open loop ...
1 vote

Calculating a derivative in a loop?

Biswajit Banerjee already indicated that your code has bugs, which is why your results are so far off. I will explain in more detail where these bugs are: v_phi ...
  • 2,989
1 vote

mass-friction-spring system with closed loop

You can see how to obtain the transfer function of the mass spring system in many well documented links, e.g.: Xengineer 10 min youtube video Youtube Ryan Krauss Series 1, 2 - z, $\omega$, 3 - TFs, 4 ...
  • 22.8k
1 vote
Accepted

Physical interpretation of a Bode plot

I apologize in advance for the length of the text but as you can understand these concepts can't be easily defined in few words. I will do some research about the second question and come back to ...
1 vote

What 's the function of COMP pin(Pin 3) in LM5030 - Push Pull IC?

As indicated in LM5030 datasheet COMP is output to an error amplifier. The circuit for the LM3411 is as follows The COMP output from the LM5030 is an input to the LM3411 which is an precision ...
1 vote
Accepted

What is the name of my feedback procedure in control system that I am using?

I would call this dead reckoning, because you do not have any actual measurement of the position, but are just calculating it based on the estimated speed of the motor.
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