Questions tagged [pid-controller]

A PID controller is a (closed) control loop feedback mechanism. It is used in industral control for proportional, integral and derivative feedback.

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6
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1answer
526 views

Tuning of a PID loop for heater element

I built a controller for a soldering iron (JBC C245/C210 specifically), which can supply up to 60W of power to the iron. I have a temperature control loop that runs at 10 Hz, which I am trying to tune ...
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2answers
165 views

Tuning PID without transfer function

I'm very new to control theory and I am stuck at PID tuning. I have a given Simulink model but I do not know the transfer function. I want to use a PID to provide new input from the output of the ...
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2answers
72 views

How can a system reach its steady-state if the I-action of a PID controller, u(t), doesn't go to zero as the system approaches its desired value?

The I-action of a PID controller, which integrates the error over time, results in the control signal: $$u(t) = \int_0^{t}e(T)\text{d}T$$ This means that, when the system reaches its desired value ...
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3answers
113 views

Is ther a standard circuit/component to control the temperature 500W resistive heating element from a PCB?

I have a 500W (230V) cartridge heater element and a K-type thermocouple. I want to use the feedback from the thermocouple to be able to vary the temperature of the cartridge heater. I have no concerns ...
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5answers
604 views

Why are two PID controllers needed for FOC (Field Oriented Control)?

I've been looking at code to do FOC and noticed that two PID controllers are usually used for torque control -- one that keeps Id near zero and another that maximises Iq. I understand why Id should ...
2
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2answers
324 views

Wiring diagram for laboratory-related aquarium equipment (PID, SSR..)

I am currently in the process of constructing a "thermal aquarium chamber", used to study the responses of various species to warming temperatures in their aquatic environment. The idea is to control ...
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1answer
569 views

Arduino PID temperature controller

I am running the below code on an Arduino Uno and it is partially working. I will try to explain the problem step by step: I start the soldering station from AC 230V The soldering station heats up ...
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3answers
102 views

PCB female jack and power supply male melted

I've been working in my thesis project which consist on a PID controler to mantain a certain temperature in a case. The heater module is made of two 40W-12V 3D printer resistors and one 15W-10 Ohm ...
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1answer
383 views

Conversion of 12 bit ADC/DAC data to floating point for PID operation

I am working with PIDs for temperature control. I have implemented the PID using floating point numbers. I am using 8051 for PID implementation.I have two queries: I have to apply the PID output to a ...
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0answers
68 views

Can't simulate simulink model

I'm trying to simulate the following chopper controlled dc motor in MATLAB Simulink using a PI controller. Now without the freewheeling/flyback diode across the motor terminals I can simulate the ...
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1answer
221 views

Brushless motor control poisition (design own PID?)

I got a few motor similar to the image below from a old scanner and I want to apply them in a robotic arm to move the arm because BLDC motors have a large torque I then control with arduino. Well, in ...
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1answer
31 views

Units of PID for car' velocity?

I'd like to duple check from units of PID gains for the velocity of car. This my equations for PI controller V (m/s), kp (1/sec), ki(1/sec^2), kp' (radians/sec) , ki' (radians/sec^2) and kd (no unit)...
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0answers
55 views

PID for pure first order process (no time delay)

So I have to make a PID control for a pure first order process (DC-motor) to control the rotational speed. I cant use ZN because there is no time delay in the process and oscillation can't be achieved....
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2answers
38 views

Can badly tuned Feedforward still decrease following error

Let's say we're trying to control the speed of a motor to 20 revs/sec, and we know that our controller output for that speed is approximately 5. We currently have a Proportional controller to drive ...
2
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1answer
49 views

PID controller - should terms be completely independant?

I was under the impression that the P, I and D terms of a PID controller should be calculated independently of each other. That is, they would all use the same error information, but none of the three ...
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3answers
114 views

Weird but consistent noise in LM35 measurement

I'm developing an incubator which includes a hot air pump. I'm generating the heat with 2 40W-12V ceramic resistor from 3D printer conected to a transistor (IRF540N) which is controlled by an ...
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1answer
43 views

Is Integral gain much use with a frequently changing setpoint?

I have a motor/encoder setup with a PI loop, where the motor needs to travel to a certain position following an accel/decel profile. The setpoint in this case is position at time T, which changes each ...
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1answer
114 views

Why treadmill motor speed controllers are not interchangeable?

Why treadmill motor speed controllers are not interchangeable? I just wonder why, if two different treadmills have different upper control consoles and different controllers why we can not switch ...
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0answers
49 views

Tuning PID Controller with high precision

I'm learning control theory at university and I have to design PID controller for this object G(s) = 10/s(s+1); But my teacher requires settling time <10s and %overshoot <=2% Anyone can suggest ...
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1answer
118 views

Low pass filter vs integrator

Context: I am programming a flight controller for an autonomous drone. I want it to be able to hover in place so I am working on a PID controller for the throttle to keep vertical velocity at 0. (...
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4answers
1k views

PID controller slowly oscillates out of control

I am trying to tune PID controllers for my drone. There are 3 controllers, one each for Pitch, Yaw and Roll. I have gotten Yaw tuned to a reasonable amount and I am assuming the values for Kp, Ki and ...
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1answer
145 views

Ziegler–Nichols method, use time value of 63% of process variable or steady-state level line?

I am attempting to use the Ziegler-Nichols method to PID tune a system. However, in calculating the tau/time constant value I have come across two different methods and am unsure which to use? ...
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29 views

Drive signal (duty cycle) calculation for PI compensator

I am trying to simulate an inverter with 4 ideal switching devices in LTSpice. I have the compensator working, however I don't the correct equation in terms of calculating the duty cycle. What I ...
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1answer
43 views

Advice on connecting heater directly to SP2 relay of PID controller?

I have an old Omega CN-9121 PID Controller and a 105Watts 115V Fibre heater mantle with an inbuilt K-type CHromel-Alumel temperature thermocouple also attached into it. I plan to use the PID ...
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2answers
374 views

main function is not defined [closed]

I am trying to build this code on MicroC using Pic16f877. It is a code using Kp and Ki values to control a motor. But when building, i keep getting the error main function is not defined. Below is the ...
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64 views

Closed-loop system with two cascaded P-controllers produces error increasing with time

The task: I control desired angle \$\theta_{d}\$ with two cascaded \$P\$-controllers, the outer is for desired angular velocity \$\omega_{d}\$ and the inner is for desired angular acceleration \$\dot{...
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1answer
91 views

Finding coefficients for a PID controller that minimize the integral of the squared error (ISE)

The problem The problem is to find the coefficients for the P, I and D terms of a PID controller used to regulate the object that minimize the the integral of the squared error (ISE): $$Q = \int_0^\...
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27 views

PI tuning from simulink scope?

I would like to use the method of Zigler-Nichols method for open loop. I got the step reponse from Simulink scope but How can I calculate the L and A from the scope?
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2answers
132 views

What do you do to help you grasp a concept or understand something you're seeing for the very first time?

Often in industry you come across a lot of different devices or even concepts you're seeing/hearing for the very first time. Things like encoders, resolvers, PID, pressure transmitters etc. I would ...
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0answers
53 views

Does having negative PID gains effects stability and realization of system?

Can we have a PID controller which has positive I gain and negative P gain? or will our system and controller will be not be realizable and will be unstable in this case due to a negative value of PID ...
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1answer
81 views

PID temperature controller

I am creating a Li-ion battery discharger. Only thing left is temperature control loop right now and I want to use PID for that purpose. I want to keep the temperature inside the device at max 95 ...
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1answer
229 views

Difference between stand alone pid and microcontroller based? Especially in terms of construction and applications? [closed]

My confusion is that what is the difference between a standalone pid controller such as the one shown in below link https://akytec.de/en/trm212.html And a microcontroller/microprocessor programming ...
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1answer
993 views

Analog PID vs digital PID? [closed]

What is the difference between hardware/standalone pid controller and that implemented in programming using microcontroller? I have also placed below links of two stand alone pid controllers https:/...
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0answers
49 views

Design of a controller

I am working on a project that requires me to design a controller knowing the following specifications: "The controller performance must be consistent under varying conditions. The rotor must ...
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1answer
761 views

How do we decide to use a lag compensation versus a PI compensation?

Although lag and PI compensation apparently have the same objective of improving the steady state response, how does one decide which one to use?
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1answer
75 views

Equivalent compensator of pid controller?

As we know that pi controller is equivalent to lag compensator and pd controller is equivalent to lead compensator, so what will be equivalent of lead-lag compensator?
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2answers
779 views

Controller vs compensator?

Both these terms: controller(forexample PID controller) and compensator(Lead compensator) are often encountered in control systems,but what is difference between these two? Brain douglas in this ...
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1answer
43 views

confusion regarding QNET VTOL(Vertical Take off and Landing)

I was reading a manual about QNET VTOL and i came across a block diagram(shown in attached snapshot) In the explaination of diagram, manual writes that The VTOL device is broken down into two ...
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1answer
50 views

4-20mA PLC analog output ground referencing for other devices

I'm currently using a PLC to control an induction heating coil. I'm using a chinese induction driver that allows 4-20mA PID input. This device runs off standard australian 230v AC 50hz. I've ...
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2answers
2k views

Difference between pid controller and on-off controller?

I want to know difference between pid controller and on-off controller especially in regards to the operation of both? The following link gives difference between pid controller and on-off controller ...
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2answers
153 views

Confusion understanding transient behaviour?

I am trying to simulate PID controllers in MATLAB Simulink, but I am bit confused by the term "transient behaviour" in how its extreme highlighted forms (aggressive and robust) will affect the system ...
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3answers
2k views

Confusion in PID loop for the case of zero error?

I am already studying PID control and some how to some extent I have understood it except one main confusion. When the difference between reference input \$r(t)\$ and current output value \$y(t)\$ is ...
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2answers
606 views

Why use PI controller for speed, instead of full PID?

I am building a two-wheels self-balancing robot and using PID controller to control its speed. The measured value is the encoder signals from the Hall sensors on the back of the DC geared motors. But ...
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1answer
82 views

Read Data from Temperature Controller using MATLAB, Need Help

I am trying to read data from a temperature controller called ATR-401 using MATLAB's tool box called Instrument Control Toolbox but every time i try to read data from it i get an error "A timeout ...
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3answers
1k views

How stable are PID loops really?

This is not a question about tuning PID loops for stability. I am assuming the output looks stable. The question is: Do PID loops ever achieve absolute stability, or is there inevitably a periodic ...
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2answers
365 views

Using PID relay to drive multiple contactors

I am a physicist by training but have been tasked with designing a heating controller box for a custom application that will be used in an industrial setting. I would like to make sure that I am ...
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2answers
172 views

How can I decide relay on-off periods depending on the PID output [closed]

In my PID project, I am using discrete time PID formula as follows. u(k)=u(k-1)+Kc * [(e(k) – e(k-1)) + (Ts*e(k))/Ti + Td/Ts * (e(k) – 2*e(k-1) + e(k-2)) As you know PID output increases over time ...
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1answer
976 views

Can my PID controller have negative p value and positive i value for a PID logic

I am building my first PID controller. My process variable and my actuator value are inversly related, meaning if actuator value increases process variable decreases, and vice versa. So I have tried ...
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1answer
61 views

µC control of a force testing machine

At work we have a machine that is used for testing and calibrating force sensors. It basically consists of a huge lever that is actuated by an electric motor with a gear reduction and a calibrated ...
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1answer
98 views

How to get from theory to a working Industry Control System?

EE Student here who recently finished the classical control theory class. I was wondering the process of how the industry or anyone goes from drawing block diagrams to actually implementing in ...

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