# Questions tagged [feedback-loop]

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### How to repeat on ABAQUS FEM simulations without reloading the mesh?

I would like to perform several FEM simulations on a given mesh with ABAQUS, where only the orientation of an element set would change in between. Currently, I'm just generating several inp files (...
30 views

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

I'm looking for a generic term/process that explains how we can make a closed- loop control system. The typical elements of a closed loop systems are controller, actuator, plant and sensors. If you ...
42 views

### What is the feedback signal used in the speed control of a brushless DC motor?

In a brush-less DC (BLDC) motor the commonly used speed is sensed using the feedback from Hall effect sensors and the back or counter EMF. The linked article on Wikipedia also mentions that 'Other ...
214 views

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

Operating/ Rated Voltage: 24V No load Speed: 350 rpm No load Current: 150mA (max) Max efficiency: 1.4 Kg-cm/300 rpm/ 14.2W/ 0.87A Max power: 4.5 Kg-cm/180 rpm/28.2W/1.4A Stall Current: 2.9 A (max) ...
34 views

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

I wish to find the polynomials B(s) and A(s) in the following compensator equation: A(s)D(s) + B(s)N(s) = F(s) Given, $$N(s) = s - 2$$ $$D(s) = s^2 - 1$$ $$F(s) = s^2 + 3*s + 4$$ Condition The degree ...
27 views

### What does "analytical design" mean?

What is meant by "designing analytically" ? Especially in control systems design Does it mean theoretically design?
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### Is it true that points of root locus only satisfiy the angle condition?

So , I was reading a course book : ''Modern Control Engineering '' by Ogata and I came forward this statement that made me skeptical: ''The points of root locus only satisfiy the angle - condition. ...
79 views

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### Low accuracy current feedback measurement in motor control

Given a very low accuracy current sensor in a 3 phase inverter (in my case used for motor control) what is the best way to tackle the issue and keep reasonable performance and robustness at the same ...
128 views

### Physical interpretation of a Bode plot

I have a few questions regarding the physical interpretation of the information presented on a Bode plot. I believe it is one of those cases where I "don't know what I don't know", so please bear with ...
250 views

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

I'm a student. Now, I am learning to use LM5030 IC to design a Push-Pull converter. So, I read LM5030's datasheet and can not understand the function of COMP pin (Pin 3). The red line is Feedback ...
4k views

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

The crux of a PID controller is:- output = Kp * error + Ki * integral + Kd * derivative So typically there is proportionality and a continuously varying (analogue) output. In the case of a simple ...
2k views

### How to improve a PID control loop by adding feedforward?

Assume you have a system model that is controlled by a PID controller (feedback). You want to add feedforward to improve the characteristics of the controlled system. How can you design the transfer ...
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### Finding stability of open loop system connected to closed loop system

I have a simple cruise control closed-loop system with negative feedback and have no problem using the Nyquist stability criterion to find its stability. However, I have another function that ...
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### Calculating a derivative in a loop?

I am not sure where else to post this, so here goes. I have a velocity profile ($v_{\phi}$) for a radial distance ($r$). From this velocity profile I am trying calculate the shear rate ($y$) which ...
672 views

### What type of control system is this? open loop?

Suppose I have a liquid in a container, the type of liquid is such that it expands when its temperature rises. The contrainer is marked with scale to measure the height of liquid expanded. There is a ...
47 views

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

I have created a self balancing robot. It uses PID control to control its pitch angle and gets the feedback from gyroscope and accelerometer. But I have not used any sensor to feedback the ...
536 views

### mass calculation from transfer function or bodeplot

I have a double mass rotary model. The two masses are connected by an axis which together acts as a spring damper system of the fourth order. The system is actuated by a motor and the angle of ...
692 views

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

I am curious to know the difference between a lead compensator (lead filter) and a PD controller with a low pass filter. From the theory I can see that the transfer function of both these controllers ...
987 views

### Closed loop response of a discrete system

I have trasfer functions of a plant and a controller in laplace domain. I checked for the closed loop response by applying a step response. The system is found to be stable. I checked the response ...
3k views

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

I was told that the proportional gain alone cannot the drive the error signal to zero in a feedback loop. Why is that? If there is a tiny error, there will be a tiny or larger (depending on the number ...
595 views

### Is active noise cancellation useful in vehicles?

The cabin noise of vehicles is a large concern in the luxury market. Why haven't any automakers used the same techniques as are employed in active noise cancelling headphones. In these devices a ...
311 views

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

I'm working on design of a 3D movement drive (for 3D printers/CNC mills etc) using DC motors and helical drive. A DC motor drives the leadscrew actuator which supports the working elements (head, ...
703 views

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

A helicopter flybar is a kind of gyroscopic stabilizer which acts in feedback to the pitch of the blades. The effect, in words, is that as the helicopter starts to pitch or roll in a particular ...