Updated April 6, 2023
Introduction to Control System Interview Questions
A control system is a system that controls the output and provides the requested response. In this topic, we are going to learn about Control System Interview Questions. A basic block scheme for a control system is shown in the figure below.
A single block represents the control system here. Because different inputs control the output, this name has been given to the control system. We will use some mechanism to vary this data. We will look at the blocks inside the control system and adjust this feedback to get the desired response in the next segment of open-loop and closed-loop control systems.
Control system interview questions are as follows.
Part 1 – Control System Interview Questions (Basics)
This first part covers the basic Interview Questions.
1. What does the System mean?
If a certain function is performed by the number of elements connected, then the element group is called a system or an interconnection of different components for a specific task.
2. What’s the device time-invariant?
The time required to switch from one state to another is called transient time. During that time, the value of current and voltage is called a temporary response and the system in which the system’s input and output characteristics are not modified by time is called a time-invariable system.
3. What is Gain Margin?
The gain margin is the gain that varies until the system is stable, since if we continually raise the gain to a certain amount, the system is slightly stable, which leads to instability as the gain varies more. The magnitude of the G(j(j)H(j)(j) at the phase convergence frequency is mathematically reciprocal.
4. Where is Servomechanism used?
The servo mechanism is used to adjust the mechanical location of the unit using the output. In the governor value control system, the servomechanism is commonly used to control the turbine’s location at power stations and process it using the transducer, and the final value is called a mechanical movement of the value. Today, however, the governor controls the position of the value using Thyristor electronic controls. In the robotic hand movement, this device is also used.
5. Enlists the applications of Sampled Data Systems?
The following applications are given for the sampled data framework.
- Quantized data is used for high-speed rolling mills regulation.
- For numerically managed machine tool operations.
6. What is the cut-off Rate?
The cut-off rate is called the pitch near the cut-off frequency of the log magnitude curve. The reduction rate indicates the system’s ability to distinguish between signal and noise.
Part 2 – Control System Interview Questions (Advanced)
Let us now have a look at the advanced Interview Questions.
7. What is Servomechanism?
A certain motor type called a servo motor forms a servo-mechanism in combination with a rotary encoder or potentiometer. A potentiometer provides a position indicator in this system with an analog signal, and an encoder provides input to the location and RPM.
8. What are the Signal Flow Graphs’ critical characteristics?
SFG is a diagram containing a set of equations. It comprises nodes and branches that represent the flow of the signal in each branch of SFG. The network is represented by nodes in which the machine variable that is connected by direct branches is represented.
9. What is Close Loop & open Loop?
CLOSE LOOP: It tests the operator response method signals. This Means Tx knows the process and moves it to the control room. Where the PID controls and is provided to the final control item as needed by the process
Open Loop: This is simply to relay the process signals from the field sensibly and only for operator monitoring to the control room.
10. What’s Control Machine Feedback? What are its features?
Feedback is that a closed-loop control system, which enables the system to be contrasted with the system input, should have the output or some other managed system variable, such that an acceptable control action can be created as an output and input function.
Control Machine Feedback features include higher bandwidth, increased precision, decreased distortion, non-linearity, and oscillating or instability tendencies.
11. What Is Transfer Function?
The mathematical term refers to the machine output information, thus defining a system’s behaviour. The Laplace transformation from the output to the lap lace transformation of the input variable is expressed in accordance with the assumption that all initial conditions are zero.
12. What Is Analogous System?
Analog systems are called systems governed by the same types of equations. Analog systems can be physically completely different. For example, an electrical circuit made up of a mechanical system comprised of the proper combination of dashpots, weights, and springs, inductance, and power, or an acoustic system consisting of the proper arrangement of fine mesh screens, tubes, and cavities may be comparable.
This has been a guide to the list of Control System Interview Questions so that the candidate can crackdown these Interview Questions easily. You may also look at the following articles to learn more –