To start the process of hiring the best controls engineer, you need to know exactly what questions to ask during the interview. This article goes over the most important controls engineer interview questions that are used to find out how knowledgeable and good at solving problems candidates are. If you know these questions, you’ll know what to expect when the conversation gets technical, whether you’re the hiring manager or the person being interviewed.
Want to get hired as a control systems engineer? You’ll need to show off your technical skills and ability to solve problems to stand out from the other applicants. For this important job, you need to know how to run complicated systems in manufacturing, power, and aerospace, among others.
In this comprehensive guide we’ll explore the key control systems engineer interview questions you can expect, along with example answers to help you craft winning responses. Whether you’re fresh out of college or a seasoned professional use these tips to highlight your qualifications with confidence.
Why Control Systems Engineering Matters
Control systems engineering is a key part of automation, safety, and productivity in all kinds of industries. Feedback control mechanisms are used by control systems engineers to make processes that are accurate, quick, and dependable. Their work involves:
- Designing and implementing intricate control systems using tools like PLCs, PID controllers, and SCADA
- Conducting rigorous testing and analysis to ensure optimal performance
- Identifying and troubleshooting issues through systematic debugging and problem-solving
- Managing trade-offs between stability, speed, efficiency, and flexibility
- Adapting designs to meet requirements and overcome challenges
- Developing simulations and mathematical models to validate system behaviors
- Optimizing systems by tuning parameters and incorporating predictive algorithms
- Implementing safety mechanisms and redundancy to prevent failures
- Collaborating with electrical, mechanical, and software engineering teams
Technical Questions
Technical questions aim to assess your hands-on skills and engineering knowledge, Be prepared to explain your experience with specific tools and methodologies
What is your experience working with PLC and DCS control systems?
Distributed control systems (DCS) and programmable logic controllers (PLCs) are very important for automating factories. Show off your skills by listing projects where you used them to manage machines and processes.
Example: I have over 5 years of experience programming PLCs in ladder logic and functional block diagrams for automating assembly lines. I also implemented DCS using fieldbuses and SCADA to coordinate a chemical production process across multiple units. My work involved programming, configuration, testing, and troubleshooting of control hardware and software.
How do you troubleshoot and resolve control system issues related to variable frequency drives (VFDs)?
VFDs are prone to disturbances and faults. Share an example of diagnosing and fixing a VFD issue, explaining your systematic approach and technical knowledge.
Example: In one instance, a VFD was tripping repeatedly due to overcurrent. By analyzing drive fault codes and current measurements, I determined there was a ground fault in the motor wiring. I recommended replacing the damaged cable. Post-repair, I tuned the drive by adjusting acceleration/deceleration ramps to prevent future tripping.
Can you explain your experience implementing safety control systems?
Safety is paramount in control engineering. Demonstrate your ability to design fail-safe control mechanisms that adhere to industry standards.
Example: As the lead engineer, I implemented a safety PLC with redundant processors for an emergency shutdown system in an offshore platform. The system utilized safety relays, E-stop circuits, and safety-rated I/O modules. I conducted a thorough failure modes analysis to ensure SIL 3 compliance.
Have you worked with motion control systems?
Motion control expertise will be valued for robotics, CNC machines, conveyors etc. Elaborate on your motion control projects and the components used such as drives, controllers, and feedback sensors.
Example: Yes, I have implemented digital servo drive systems for coordinating 6-axis robotic arms. This involved programming the motion trajectory, tuning PID gains, and incorporating encoder feedback for precise positioning. I used industrial Ethernet for motion control networking.
Design and Problem-Solving Questions
You’ll be evaluated on your approach to core engineering responsibilities like design, troubleshooting, and project execution. Use real examples to demonstrate analytical thinking.
How would you design a control system for an industrial oven to maintain a uniform temperature profile?
Showcase your technical design skills by walking through key considerations like system modeling, choice of architecture, selection of controllers and sensors, and testing methods.
Example: I would start by studying oven dynamics through modeling and experimentation to identify thermal characteristics. Next, I would implement a modular distributed control system with PLCs and PID controllers in feedback loops for each zone, using RTDs for temperature sensing. Control logic would maintain setpoints by regulating heating elements and fans. Extensive simulations and tests would be conducted before commissioning.
Your team just implemented a new motor control system, but production data shows frequent shutdowns. How would you approach troubleshooting this?
Prove you can methodically diagnose issues by outlining steps like reviewing system logs, isolating potential fault sources, and scientifically testing hypotheses.
Example: I would begin by analyzing trend data to characterize the shutdowns and identify any patterns. I would check controller fault codes and logs for abnormalities and inspect the equipment layout. Through systematic isolation of variables, I would narrow down the source of the issue. Hypotheses would be tested by simulating failures and deliberately introducing controlled faults to observe their impact. I would ensure root cause identification before implementing corrective measures.
How would you optimize the energy efficiency of a pump control system?
Demonstrate optimization skills by discussing improvement approaches like adjustable speed drives, flow control methods, and use of real-time data.
Example: I would start by studying pump characteristics and loading trends through logged data. Next, I would install VFDs and program pump speeds based on real-time flow requirements rather than fixed speeds. I would also implement a cascaded flow control loop to minimize throttling losses. Using SCADA data, I could continuously fine-tune parameters for optimal efficiency at varying loads.
You are tasked with automating a complex manufacturing process. What factors would guide your control system design?
Show you can balance key considerations like safety, reliability, flexibility, and cost when approaching large projects.
Example: Safety would be my primary concern, so I would incorporate redundant and fail-safe mechanisms. The system must be reliable and maintain high uptime, so proven, robust components would be used. It should adapt easily to new product variants, so I would choose flexible PLCs and modular software. However, costs must be managed, so maximizing existing infrastructure and open-source tools would help optimize budgets.
Behavioral Questions
Behavioral questions evaluate your soft skills and professional attributes. Reflect on your past experiences to demonstrate well-rounded competencies.
Tell me about a time you successfully recovered a failing control system. What actions did you take?
Prove you can act decisively under pressure by outlining measured steps you took to diagnose issues and implement solutions.
Example: When an automated parking system began failing sporadically, I conducted a root cause analysis using trend data. This pointed to a network comms fault between controllers. After replacing damaged network cables and switches, I monitored the system closely for a week to ensure all errors were resolved before reopening the facility.
Describe a complex control system project you worked on. What challenges did you face and how did you overcome them?
Showcase engineering complexity you’ve handled. Discuss specific hurdles and the technical or creative solutions you devised.
Example: I led development of control systems for a multi-axis robot with tight precision and speed requirements. Interference between axes was a major issue. To overcome this, I developed custom gain-scheduling and cross-coupling compensation algorithms. This achieved precise coordination between motions.
Tell me about a time you had to simplify a complex concept or process for a colleague or client. How did you approach explaining it?
Demonstrate your communication skills by sharing how you restructured highly technical details into easy-to-understand language and instructions.
Example: For our sales team, I created visual presentations and analogies to explain PID control concepts. I compared process variables to driving speeds, setpoints to speed limits, and PID corrections to adjusting the gas pedal. This helped them grasp the technology’s value in simple terms.
Give me an example of a time you had to be flexible or adapt to change on a project. What was the situation and how did you handle it?
Share an instance where project constraints forced you to alter designs or solutions. Spotlight adaptability and creative problem-solving.
Example: Due to hardware delivery delays, we had to modify our motor control system design from 3-phase to single-phase motors. To adapt, I redesigned the power supply and filtering circuits and optimized control loop gains for dynamic stability with the new motors.
Questions to Ask the Interviewer
The interview is a two-way street – you should ask questions to assess the role and company. Here are some options:
- How will this role contribute to the company’s objectives over the next 5 years?
- What technologies are utilized in your current control systems?
- Are there opportunities for continuing education or professional development?
- What attributes make engineers successful in your organization?
- What does a typical day look like for control systems engineers at your company?
Take Control of Your Interview Prep
Using this guide with detailed questions, sample answers, and tips, you’ll have the preparation needed to highlight your specialist expertise as
Q2 What are the key considerations when integrating new technology into an existing control system? (System Integration)
When integrating new technology into an existing control system, the key considerations include:
- Check to see if the new technology works with the hardware and software that are already in place. This includes checking communication protocols, electrical interfaces, and data formats.
- Scalability: Check to see if the new technology can grow with your business and is adaptable enough to handle more upgrades.
- Safety and Compliance: Make sure that the integration follows all safety rules and regulations in the industry.
- Performance Effects: Think about how the new technology will change the system’s overall performance, such as how fast it processes information and how quickly it responds.
- Cost: Figure out the total cost of ownership, which includes the initial investment, upkeep, and any downtime that might happen during integration.
- Plan for as little downtime as possible while the integration process is going on.
- Training: Figure out what training your staff needs to use and take care of the new technology effectively.
- Support and Maintenance: Think about whether the new technology has support and maintenance services available.
Q Explain the concept of feedback in control systems and its significance. (Control Systems Theory)
In control systems, feedback is a basic idea in which the system’s output is checked against the setpoint that was intended. The error signal is the difference between these two signals. It tells the system what to do to get the output closer to the setpoint. Feedback is significant for several reasons:
- Error Correction: Feedback helps fix any differences between what the system actually does and what it wants to do.
- Stability: Well-thought-out feedback can make a system more stable, stopping oscillations and making sure it always works the same way.
- Feedback lets systems adjust to changes and disturbances in the environment, keeping performance at a high level.
- Accuracy: Systems can move more accurately toward a setpoint or path when they get feedback.
There are two kinds of feedback loops: positive and negative. Negative feedback is more common in control systems to make sure they behave correctly and consistently.
Top 20 Controls Engineer Interview Questions & Answers in 2024
FAQ
What does a control systems engineer do?
What does a control engineer need to know?
How do you answer a control engineer interview question?
There is only one way to answer this question-mention the roles you have been performing in your work. You definitely know your mandates and what will be expected of you in your new workplace. It is time to tell that to the interviewer. A controls engineer mainly designs and develops systems that drive manufacturing operations.
What is a control systems engineer interview?
As a controls engineer, or control systems engineer, the interview is an opportunity for you to showcase your skills and interpersonal abilities while also providing the interviewer with an idea of what your characteristics are as an employee.
How do you answer a control system interview question?
Some positions may require you to have advanced or basic knowledge of various control systems to this question may help interviewers determine if you have qualifications for these roles. In your answer, you may clearly state the three components in a control system, explaining the purpose of each one.
What are the most frequently asked control system interview questions?
A list of top frequently asked Control System interview questions and answers are given below. 1) What is meant by System? When the number of elements connected performs a specific function then the group of elements is said to constitute a system or interconnection of various components for a specific task is called system. Example: Automobile.
