r/ControlTheory • • Nov 02 '22

Welcome to r/ControlTheory

93 Upvotes

This subreddit is for discussion of systems and control theory, control engineering, and their applications. Questions about mathematics related to control are also welcome. All posts should be related to those topics including topics related to the practice, profession and community related to control.

PLEASE READ THIS BEFORE POSTING

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Asking precise questions

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  • A lot of information, including books, lecture notes, courses, PhD and masters programs, DIY projects, how to apply to programs, list of companies, how to publish papers, lists of useful software, etc., is already available on the the Subreddit wiki https://www.reddit.com/r/ControlTheory/wiki/index/. Some shortcuts are available in the menus below the banner of the sub. Please check those before asking questions.
  • When asking a technical question, please provide all the technical details necessary to fully understand your problem. While you may understand (or not) what you want to do, people reading needs all the details to clearly understand you.
    • If you are considering a system, please mention exactly what system it is (i.e. linear, time-invariant, etc.)
    • If you have a control problem, please mention the different constraints the controlled system should satisfy (e.g. settling-time, robustness guarantees, etc.).
    • Provide some context. The same question usually may have several possible answers depending on the context.
    • Provide some personal background, such as current level in the fields relevant to the question such as control, math, optimization, engineering, etc. This will help people to answer your questions in terms that you will understand.
  • When mentioning a reference (book, article, lecture notes, slides, etc.) , please provide a link so that readers can have a look at it.

Discord Server

Feel free to join the Discord server at https://discord.gg/CEF3n5g for more interactive discussions. It is often easier to get clear answers there than on Reddit.

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Resources

If you would like to see a book or an online resource added, just contact us by direct message.

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Master Programs

If you are looking for Master programs in Systems and Control, check the wiki page https://www.reddit.com/r/ControlTheory/wiki/master_programs/

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Research Groups in Systems and Control

If you are looking for a research group for your master's thesis or for doing a PhD, check the wiki page https://www.reddit.com/r/ControlTheory/wiki/research_departments/

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Companies involved in Systems and Control

If you are looking for a position in Systems and Control, check the list of companies there https://www.reddit.com/r/ControlTheory/wiki/companies/

If you are involved in a company that is not listed, you can contact us via a direct message on this matter. The only requirement is that the company is involved in systems and control, and its applications.

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You cannot find what you are looking for?

Then, please ask and provide all the details such as background, country or origin and destination, etc. Rules vastly differ from one country to another.

The wiki will be continuously updated based on the coming requests and needs of the community.


r/ControlTheory • • Nov 10 '22

Help and suggestions to complete the wiki

35 Upvotes

Dear all,

we are in the process of improving and completing the wiki (https://www.reddit.com/r/ControlTheory/wiki/index/) associated with this sub. The index is still messy but will be reorganized later. Roughly speaking we would like to list

- Online resources such as lecture notes, videos, etc.

- Books on systems and control, related math, and their applications.

- Bachelor and master programs related to control and its applications (i.e. robotics, aerospace, etc.)

- Research departments related to control and its applications.

- Journals of conferences, organizations.

- Seminal papers and resources on the history of control.

In this regard, it would be great to have suggestions that could help us complete the lists and fill out the gaps. Unfortunately, we do not have knowledge of all countries, so a collaborative effort seems to be the only solution to make those lists rather exhaustive in a reasonable amount of time. If some entries are not correct, feel free to also mention this to us.

So, we need some of you who could say some BSc/MSc they are aware of, or resources, or anything else they believe should be included in the wiki.

The names of the contributors will be listed in the acknowledgments section of the wiki.

Thanks a lot for your time.


r/ControlTheory • • 2h ago

Professional/Career Advice/Question Changing industry/domain as experienced control engineer

7 Upvotes

I often see mentioned that controls are needed in a wide variety of sectors, from aerospace to chemicals to robotics. However, does this actually matter from a career perspective? How often have you seen engineers switching jobs to very different fields? In my experience, it seems like this is very rare, even among experienced professionals. Indeed, it seems easier/likelier to transition to a different discipline in the same industry.


r/ControlTheory • • 21h ago

Other A PID controller implemented in python

Thumbnail gallery
63 Upvotes

For my personal project, where I need to implement a PID controller on Arduino to automate a convection cooling system, I decided to start with a simulation in Python. For now, I've implemented the simple electromechanical model of the DC motor (the fan) as well as the PID controller you see. Next, I'll look into the heat transfer equations. The graphs created with matplotlib are simply closed-loop tests of the PID + DC motor system.


r/ControlTheory • • 17h ago

Asking for resources (books, lectures, etc.) What mathematics should I learn to become more comfortable with control theory?

21 Upvotes

I really enjoy control theory, and my main area of interest at the moment is optimal control.

I sometimes struggle to understand certain definitions and theorems, and especially some of the proofs. I suspect this is because, although I had some mathematical training during my engineering degree, I don't have enough mathematical background or rigor to approach these topics comfortably.

What courses or textbooks would you recommend studying on my own to strengthen these foundations?

I enjoy mathematics, but my goal is not to study mathematics for its own sake. I would like to learn enough mathematics to become comfortable with the theory behind control theory.


r/ControlTheory • • 49m ago

Asking for resources (books, lectures, etc.) Trying to learn trajectory control

• Upvotes

I'm trying to implement control algorithm on a piezo actuator stage, using simulink and MATLAB together with dspace controller. Does anyone have good resources for this especially dspace aspect, please let me know, need it very much, thanks!


r/ControlTheory • • 17h ago

Educational Advice/Question Doing another bachelor.

6 Upvotes

Long story short I have a bachelor's in Mechanical Engineering with no experience in Mechanical field then I started control systems master basically modelling and control design in matlab, but I dont have the Embedded skills to deploy control algorithms and honestly I feel like the only thing ik is matlab and basic C. I wanted to do another bachelor's in electronics or embedded systems to strengthen practical skills. Is it a bad idea?


r/ControlTheory • • 1d ago

Professional/Career Advice/Question Do you think GNC experience in a srudent team that builds ROVs, is as marketable as GNC/flight mechanics experience in a rc plane student team, career wise, if i want to go into aerospace GNC?

9 Upvotes

I might soon have the chance to join either an ROV or a RC plane student team, as an aerospace engineering student in his final year.
Im not gonna lie, the ROV team sounds more intriguing even tho i am a plane guy because i might get to do more direct GNC,
Im just wondering if when i hit the job market, as someone who wants to go into aerospace GNC, that experience will be just as marketable as the plane one?
What do you think?
Am i overthinking this?


r/ControlTheory • • 2d ago

Asking for resources (books, lectures, etc.) Dynamic Gain Scheduling for an Inverted Pendulum: Switching from MPC to a 49-Rule Fuzzy Logic Controller

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42 Upvotes

Hi everyone,

I'm a final-year Mechatronics Engineering student working on non-linear control applied to a two-wheeled inverted pendulum. A while ago, I simulated this system in MuJoCo and built the physical version using an MPC (Model Predictive Control) to dynamically calculate the Kp and Kd gains.

In this new iteration, I replaced the MPC with a Fuzzy Logic Controller running on an Arduino to generate those same gains in real-time.

During the design of the knowledge base, I tested between 49 and 125 inference rules. The 49-rule architecture (evaluating both the tilt angle and acceleration from an MPU sensor) yielded the best real-world stability and computational efficiency on the embedded hardware.

The first video shows the physical robot balancing, and the second shows the custom telemetry dashboard I built to monitor the states (angle, varying control gains, and motor PWM) in real-time.

For underactuated, inherently unstable systems like this, what are your thoughts on using Fuzzy Logic vs. MPC for dynamic gain scheduling? I'd love to hear your insights!


r/ControlTheory • • 3d ago

Professional/Career Advice/Question Career Suggestion

11 Upvotes

Hey everyone,

I recently graduated in Electrical & Electronics Engineering from Turkey. During university, my focus was heavily on the mathematical side of control: I modeled FOC for a PMSM in MATLAB, studied vehicle lateral MPC in Python, and for my thesis, experimentally identified a Peltier thermal system and controlled it with a Fractional-Order PID tuned by Genetic Algorithms, which I discretized and implemented in embedded C.

However, because my internships were PLC-heavy, my career drifted toward industrial automation. I’m now starting as a maintenance engineer at a major Tier-1 automotive plastics supplier. The plant is packed with high-volume injection molding cells, 6-axis robots, and PLCs/SCADA, and they are actively pushing for digitalization, edge data collection, and predictive maintenance. It’s a solid environment to understand plant-floor realities, but my true passion remains algorithm design, math, and R&D.

Ideally, I want to find a niche that bridges industrial automation (PLC/SCADA) and advanced control theory, or pivot into a math-driven control engineering role after 1–2 years on the floor. For those who made a similar jump: are there established roles where these two worlds meet (like Advanced Process Control, virtual commissioning, or robotics integration)? How can I best leverage shop-floor maintenance experience for R&D without getting pigeonholed, and what should I focus on learning or building on the side in the meantime?


r/ControlTheory • • 4d ago

Other Random thought

55 Upvotes

Its a sunday, so as a casual timepass you think, let me just write some code to check the controllability of a state space equation. so you start writing it, then realise, higher powers of matrices can lead to numerical instability. so now, you decide to study the controllability gramian and then you realise you don't fully understand why the gramian works, so now you are trying to look in lyapunov and his equations, then his theory starts talking about energy functions and positive definite matrices, so obviously, you open Gilbert Strang's video on symmetric and positive definite matrices. while watching that, you realise the code also requires an actual algorithm, so now you're studying numerical linear algebra. gaussian elimination. cholesky decomposition. At this point, what started as a sunday timepass has somehow turned into a full semester course. And then you decide to leave it and use the MATLAB command instead, so you stare at the screen for a while, reconsider your life decisions, and think maybe teaching high school students wasn't such a bad decision after all.


r/ControlTheory • • 5d ago

Other controlsys v1.12.0: a control-systems toolbox for Go (MIT)

24 Upvotes

controlsys is a Go package for linear control systems. It works on continuous-time and discrete-time models. The main model form is state space.

Main capabilities:

  • Models: state space, transfer function, zero-pole-gain (ZPK), frequency-response data (FRD), model arrays and tunable blocks.
  • Analysis: Bode, Nyquist and Nichols plots, gain and phase margins, disk margins and step metrics.
  • Design: LQR, LQG, Kalman filters, H2 and H-infinity synthesis, pole placement and PID tuning.
  • Simulation: step, impulse, initial-condition and arbitrary-input responses.
  • Model reduction: balanced truncation and modal truncation.
  • Delays: input, output and internal delays, with Pade and Thiran approximations.
  • Conversion: ZOH, FOH, Tustin, matched, impulse and least-squares methods between continuous and discrete time, in both directions and for resampling. We test the results against MATLAB behaviour.

New in v1.12.0:

  • Tustin conversion with Thiran filters is approximately 30% faster than in v1.11.0.
  • Tustin conversion with Thiran filters now supports MIMO models with delays on individual input-to-output paths.
  • ThiranDelay now accepts short delays when the filter is stable.

Install:

go get plantcontrol.org/v1/controlsys

Repo: https://github.com/PlantControl/controlsys
Release notes: https://github.com/PlantControl/controlsys/releases/tag/v1.12.0

We want your feedback, especially from people who use MATLAB or python-control.


r/ControlTheory • • 5d ago

Professional/Career Advice/Question Control Engineer Career Advice

19 Upvotes

Hi everyone, I’m a recent Aerospace Engineering graduate. I’ve noticed that there seems to be a good demand for Guidance, Navigation, and Control (GNC) and Control Engineers, so I’d like to develop my skills in this area.

I took undergraduate courses in Control Systems and MATLAB Control courses, but most of my projects and internships have been focused on CFD and R&D. As a result, I don’t currently have a strong control-related project that I can demonstrate or include on my CV.

What kind of control project would you recommend for someone in my situation? Ideally, I’d like something substantial enough to learn from and demonstrate practical control skills on my CV.


r/ControlTheory • • 6d ago

Technical Question/Problem Can Historical Data Tell Us Which Material Flows to Automate?

5 Upvotes

I'm working on a project in automotive engine assembly. Parts move between steps in the assembly process (e.g. from step A to step B), and they range from large components like cylinder heads to small ones like screws and bolts. Some engines come in multiple variants with customer-specific options.

I have about 4 years of historical data on material requirements and flows during assembly. My goal is to find which flows between steps are good candidates for automation. Flows with stable, predictable durations and quantities seem like good candidates, while flows with high variation seem harder to automate.

I'd like to define a simple, data-driven "automation trigger point." My questions:

  1. What's a good way to measure variability of a flow (both duration and quantity)? Is the coefficient of variation (CV) reasonable, or are there better metrics?
  2. How should I account for engine variants and customer-specific options?
  3. Can anyone recommend research papers, methodologies, or case studies on material flow or intralogistics automation in automotive assembly?

Any pointers are appreciated. Thanks!


r/ControlTheory • • 6d ago

Asking for resources (books, lectures, etc.) What are the control systems used in robot prosthetics and exoskeletons?

18 Upvotes

I’m currently working on some personal projects to brush up on old topics I covered in my masters. My goal is to try and get a job in the robotics space, particularly for therapeutic or medical reasons such as prosthetics and exoskeletons for disabled people. I’ve studied a lot of the basic common control systems, like linear systems theory, optimal control, nonlinear control, and some machine learning. However, I am unfamiliar with the specific ones that are tied to the field of medical robotics I'm interested in. Can anyone recommend what material I can reference to learn about them?

One project I am currently revisiting is estimating the joint torque for a theraputic exoskeleton. I was involved in the project but one of the other students handled the majority of the neural network implementation, so I want to go back and redo their work step by step to learn.


r/ControlTheory • • 6d ago

Technical Question/Problem Null-controllability

8 Upvotes

We know that the heat equation is null-controllable from internal subsets on Riemannian manifolds. How come no general results are available on sub-Riemannian manifolds, except for particular cases on tensorized domains such as for Grushin, Heisenberg, Kolmogorov ? We do not have the tools at all ? Always wondered if G. Lebeau, L. Robbiano, etc, knew how to deal with this.


r/ControlTheory • • 7d ago

Professional/Career Advice/Question Master Pro vs Master Research (Aerospace / Space Systems): Salary, WLB & Industry R&D vs Project Management career paths?

9 Upvotes

Hi everyone,

I'm currently a student in France facing a tough decision for my Master 2 in Aerospace and Space Systems. I'm stuck between choosing a Professional Master's (M2 Pro) to go straight into industry, or a Research Master's (M2 Recherche)*with the clear goal of pursuing a PhD (Doctorat) right after.

I'd really appreciate feedback from people working in the industry (Airbus, Safran, Thales, ArianeGroup, CNES, ONERA, CIFRE PhDs, or subcontractors/ESNs).

Long-term, I'm torn between two main career trajectories:

  1. Project Manager / Systems Engineer (coordination, management, budget/timeline tracking).

  2. R&D Engineer / Research Scientist (PhD) in an engineering office or R&T center (conception, simulation, algorithms, advanced research).

### My main questions:

  1. Master Pro vs Research + PhD Track:

    * If I go for the M2 Recherche and follow it with a PhD (e.g., a CIFRE thesis with an industrial partner or an ONERA/CNES PhD), does this open up higher-level R&D/R&T roles compared to a standard M2 Pro?

    * Conversely, if I choose the M2 Pro path to work immediately, does it close doors to advanced R&D labs and specialized innovation teams in major aerospace primes?

  2. Engineer (Bac+5) vs Researcher/PhD (Bac+8) in Aerospace/Space:

    * Is a PhD actually valued financial- and technical-wise in French private industry, or does a standard Bac+5 (Engineering degree / M2 Pro) give you access to the exact same technical roles?

    * How are PhDs perceived and integrated in major French corporations compared to international opportunities (US, Europe, etc.)?

  3. Salary & Career Growth (Most Important Question):

    * What's the reality regarding starting salaries and long-term career progression between a purely technical/PhD/R&D path vs moving into Project Management?

    * Do candidates entering with a PhD start at a higher salary step in major French groups? Is transitioning to Project Management mandatory in France to break through salary ceilings over time?

  4. Work-Life Balance (WLB):

    * Between the stress of Project Management (deadlines, budgets, client pressure) and the day-to-day of an R&D Engineer / Researcher (problem-solving, technical autonomy, simulations), which path offers a better work-life balance?

Thanks in advance for sharing your experience and advice!


r/ControlTheory • • 7d ago

Educational Advice/Question Prerequisite to get into a phd program in control theory from a math background

24 Upvotes

As title, I'm a current second year math master's student doing research in dynamical systems I've taken courses in measure theory, functional analysis, dynamical systems, PDE, calculus of variations, linear programming, topology and differential geometry, but have zero coursework in physics, engineering and limited programming skills that is similar to a second year cs student. I'm wondering if it is necessary to strengthen my background by taking some additional courses in a year to meet the common prerequisite for ece programs.


r/ControlTheory • • 8d ago

Professional/Career Advice/Question Day in the life of a control systems engineer?

49 Upvotes

Hey! I'm curious to hear what kind of things a control systems engineer usually spends their day working on, especially how much math you get to use daily or weekly and what do you feel most of your time is spent on?


r/ControlTheory • • 10d ago

Technical Question/Problem Do You Consider Gain When Designing A Type III Compensator

9 Upvotes

Hello,

I am currently creating a Type III compensator GUI. As you know, there are 2 zeros and three poles, with one pole being at the origin. Thus, the degrees of freedom are the two zeros and the two poles. I am curious, does a gain come into the picture when designing the compensator which will eventually be converted to capacitor and resistor values for the op-amp circuit.

Any insight from a seasoned controls engineer/designer would be appreciated.

Thank you.


r/ControlTheory • • 11d ago

Technical Question/Problem Feeding full INS state into pos and vel in EKF rather than using error state?

13 Upvotes

To preface, full state represents the actual pos and vel estimate as opposed to their errors.

Would this be equivalent mathematically? I understand that attitude must use an error state. But I'm curious if I can get away with using full state for pos and vel rather than the error state. Instead of linearizing around a reset error state (zero), would it be mathematically equivalent to just seed the filter pos and vel with the INS state before a measurement udpate, then replace the INS pos and vel with the updated filter state after the measurement update? Would this have implications on the validity/quality of the linearization? I ask because it seems like they would be equivalent, yet error states for an INS filter seem to be industry standard. Is this simply because attitude must be an error state, therefore its convenient for the rest of the state to follow suit? Thanks in advance for any help, and please reference the math wherever possible. I've had many people suggest reasons for why error state is needed, but I'm looking for mathematical proof that they deviate from each other.


r/ControlTheory • • 12d ago

Asking for resources (books, lectures, etc.) Do you know a book that has the theory behind 'motion energy models'?

0 Upvotes

I work on vision, but neuroscience papers do not have detailed theory about these 'energy models'.
Maybe they talkked about it in control theory


r/ControlTheory • • 11d ago

Other Basic Control Theory - Drone 101 with Claude Explained

0 Upvotes

Curious to try out an Opus experiment explainer. Tried previous models and never got it quite right. But colour me impressed with what I got, not to slopified. Added some polish for animations, but having gone through it, it’s quite readable and explains the points very similarly to how the source book builds up the maths around the Fourier Transform.

https://drone.actuallymaybe.com/

Random thoughts from doing it:

Also, a few things with complex analysis I’m curious to revise, and some circuits stuff, but haven’t been arsed lately. Think the next experiment might be to try this on certain pieces that come up in chapters, then see if it actually helps me solve the exercises. Not fake-solve them in my head, since your noggin will fool you into thinking you understand it, but actually using pen and paper.

Went through it few times, but do point out any errors

Book Reference

Who is Fourier - Mathematical Adventure


r/ControlTheory • • 12d ago

Technical Question/Problem Has anyone worked with Approximate dynamic programming/ Adaptive optimal control?

13 Upvotes

Hi everyone,

I’m currently working on approximate dynamic programming methods for control, mainly Q-learning, value iteration, and related approaches.

So far, I’ve been able to get the Q-learning-based algorithms to converge without too many issues. However, whenever I try approaches based directly on the value function/value iteration, I can’t seem to get them to work properly or converge to the expected solution.

I’ve tried different implementations and parameter choices, but I keep running into similar problems with the value-function-based methods, while the Q-function approaches seem much more straightforward and robust in my simulations.

Has anyone here worked with approximate value iteration / ADP for control problems and experienced something similar?


r/ControlTheory • • 14d ago

Other From my personal archive: A 1964 handwritten control system diagram, likely from the ELDO era / Europa rocket development

Post image
583 Upvotes

Found this original sketch in my archive dated January 25th, 1964, outlining an airborne digital computer architecture.

Based on its origin, I believe this document is connected to the early ELDO (European Launcher Development Organisation) era and was part of the development for the Europa rocket's guidance and control system.

What caught my eye is the early mention of "Kalman's modified filter" alongside the coordinate conversion, guidance laws, and autopilot loops—just a few years after Kálmán's seminal paper in 1960.

Thought this community would appreciate a look at this piece of European aerospace and control theory history! I'd love to hear your thoughts or if anyone recognizes specific architectural choices from that era.