PID algorithm the difference between rotating inverted pendulum and balance car. This post is updated.

I do PID algorithm background and experience: I electronic information science and technology, is now a junior student, the direction of control is quite interested, just went to the university when the lab teacher said PID algorithm, that year in summer camp preparation national Electronic design competition, I am practicing to do a former specialist topic, Windsurfing angle control system, still do not know what PID is a thing, the teacher let me add pid to this topic. At that time gave some electronic version of some tutorials, but did not read .... Later on the four-rotor is very interested in, want to get a play and then personally write a program to do a, bought the PIX fly control play for a long time, I did do a simple flight control, I do the flight control can only fly, nothing innovative features ... (This process must have more than a year, a long story, because of the high cost of playing aircraft and low efficiency, and finally do not continue, anyway, the PID is now very familiar with, this period also done a balanced car and inverted pendulum, want to ask the PID can contact me QQ522414928, at any time on-line. )

I used to play four rotors and spent a lot of money on airplanes:

1. inverted pendulum and balance car the most popular understanding and interpretation (also I tried to summarize the experience): The electronic contest rotating inverted pendulum in the end how sick, many people think that 1 PID as long as the parameter is moderate this problem can be solved , Because the balance of the car a PID can stand up, many people think that the inverted pendulum with the balance of the car, a lot of people have been working hard for a long time to think that the mechanical structure is not good or the program and parameters to write the wrong and give up, I have always believed that 1 PID can solve this problem, did a period of time to give up simple control angle following a PID really can let the pendulum stand up, but ignored a very important detail, is the motor speed when the balance, and in the balance when the motor speed will be very fast, this time will maintain the state of the high-speed motor operation, However, this high-speed rotation is obviously a short-term balance, so the inverted pendulum with a single-stage PID will instantly balance down immediately.

　　So for the inverted pendulum of this system, single-stage PID algorithm is not realized, at least need a two-level PID control to stand firm.

The balance of the car, did several, there is a single-stage PID algorithm, there are multi-level PID algorithm:

The following are the problems of PID Cascade and set encountered when studying inverted pendulum:　

　　2. Toss a long time PID problem, especially the Cascade PID, previously also want to not understand the Cascade PID outer ring output Why to the inner ring PID input, later want to understand. However, today, there is a new discovery, the study of such a long cascade of PID, today dawned, the string-level PID formula deduction, the cascade of two PID two formulas into a formula is not the same as the PID formula, thank the owner of the balance of the car to remind, never deduced before, Unexpectedly: Cascade pid= and Level PID, after the study of a variety of balance tracking problem completely do not consider the difficult to understand the Cascade PID, a direct PID does not, and then a PID can be, has been tangled problem so simple, and the Cascade PID and PID are inverted pendulum test a bit, The result is the same effect. Only the second PID parameter = The parameter of the original CASCADE outer ring PID * (multiply) The parameters of the original cascade PID inner ring

Result: Cascade pid= and Level PID,MD is actually a thing, but the PID is easier than the Cascade PID to achieve some

Using OPENMV to do the PID ball color tracking:

Rotating inverted Pendulum:

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PID algorithm the difference between rotating inverted pendulum and balance car. This post is updated.