PID stands for proportional-integral-derivative – the three most essential factors in PID controllers. We’ve all seen PIDs with crazy or unintuitive settings, but a good PID is a beautiful thing! PIDs are vital for successful control loops.
PID Autotuning Explained
PID autotune is a method for estimating an ideal PID controller’s parameters using an open-loop step test. Autotuning uses feedback, but the process only estimates the value of each parameter rather than directly measuring it. Instead of adjusting each setpoint individually, all three are adjusted together to achieve maximum measured response at this new position.
PID autotuning is generally faster than PID tuning using the classical PID algorithm. Since there are three unknown parameters, an open-loop test with at least three steps in each direction is required to estimate the relationship between each parameter and measured response. As a result of this assumption, it’s best to apply autotuning when operating in a specific region of the PID parameters, known as the PID Tune Window.
How Does PID Autotuning Work?
PID autotuning works by finding the combination of Kp, Ki, and Kd that produces stable control in an open-loop test. As every PID controller operates in a closed-loop where error feedback is continually monitored, there are some disadvantages that you must consider when using PID autotune for closed-loop operation.
In practice, autotuning is very effective for most controlled processes with a limited number of steps in each direction. The application usually improves over PID tuning methods when PID parameters are far from an appropriate setting. It is a quick way to estimate PID parameters when PID tuning does not produce the desired results.
PID autotune is the holy grail of PID tuning. It can make PIDs perform better in seconds. It will help you get closer to your goals when it comes to PID tuning. However, this extraordinary technology can also be a curse if you don’t use it properly.
PID Autotune, In Reality, What Can It Do For You?
PIDs are why most of us have perfectly cooked food, crispy popcorn, and delicious beverages. This technology keeps our 3D printers standing upright at whatever orientation they are placed in. The PID technology can also handle acceleration for self-driving cars, so things don’t fall over. That’s the reason PID controllers are everywhere!
However, if you use PID autotune on PIDs for PID control loops, you are in for the wrong time. PID technology is an incredible new feature that automates PID tuning.
There are two common PID controllers that users use today: open and closed-loop PID controllers and open-loop PID controllers. The latter one uses the output of the PID controller without any feedback while closed-loop PID controllers have some sort of feedback system. They are aware of how well their actions are controlling the parameters.
What Are the Benefits of PID Autotuning?
It’s no secret that PID autotuning offers multiple advantages. This is a powerful technology that has benefited many over the years.
Some of the benefits of PID technology include-
- Faster convergence
- Faster settling time
- Reduced steady-state error/overshoot
- Increased robustness against parameter variation
- Higher bandwidth with little or no impact on performance
- Better parallelism with other automatic control loops
- Optimized PID controller parameters.
The best thing about PID Autotune is that it enables multiple PID loops to converge simultaneously when each loop includes a PID controller. The technology causes the process to oscillate or exhibit other instability problems when various PID loops operate parallel.
PID technology is everywhere now because it offers various advantages. If you have any more questions about PID autotune or anything related to PID technology, reach out to Pi Control Solutions. You will have all the answers you need and get the right solution if you partner with this globally recognized venture.
