I want to know the program about "hold"

[Gosin]

I want to know the principle of “vex::brake::hold”, why it can brake. What I am thinking of is to keep it in the encoder position of the last moment with the built-in pid algorithm. But what I don’t understand is that when you hold it or turn its shaft, and it will give you a reversal force.
why？

[Xenon27]

It applies motor power to resist any changes in position.

[theol0403]

We just had a thread about this. Make sure you search a topic before creating a new one.

Motor Hold?

Many people would disagree. What a lot of drivers prefer is that the motor power is strictly controlled by the sticks, and when the sticks are 0, the motors coast at 0. Its like taking your foot off the gas pedal - you don’t want the car to brake, you just want to stop accelerating and slow down. Having the motors brake when the sticks are at 0 is very jolting, and many people do not want the robot to suddenly brake when they stop applying power. Well, many people prefer coast for the drivet…

How does braketype::hold work? and thoughts about it

hold does active PID to try to maintain the position: the higher the error the more power it tries to apply to counter the error. “Hold” means exactly that, it will try to hold the motor there. It uses the built-in PID that has been tuned to work for as many different outputs as possible. If it does not work for you, you need to use a custom PID. brake is passive. It actually shorts the leads of the motor causing it to generate it’s own power making it slow down. However, if you try to turn it,…

[M8R]

It’s just using PID to move motor back to position.
brakemode brake instead brakes motor electronically by just applying reverse current, so applied voltage goes in same direction as the back emf.

[Gosin]

I am sorry that I did not read it carefully, but I still want to know why, when the error is very small, the adjustment of the built-in pid can be so sensitive.

[theol0403]

Its just standard PID, running at a very high refresh rate, allowing for high gains.

Hardware Demo of a Digital PID Controller

[jpearman]

@M8R

brakemode brake instead brakes motor electronically by just applying reverse current, so applied voltage goes in same direction as the back emf.

brake mode just shorts the motor.