Is it possible to increase the power of brake mode, only when enabled?
You can use PID control to hold position or attempt to maintain 0 velocity
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Brake mode isn’t an active breaking mechanism and shouldn’t be relied on to counter gravity (i.e. for a climber), though it may work in certain cases (such as with very high gear reductions). It is essentially a short-circuit inside the motor controller that uses the back-emf from the motor (think of how motors used in reverse become generators) to to drove the motor opposite the direction of rotation.
The problem is that when it works, it prevents motion, which leads to a reduction in back-emf, which reduces the braking force and allowing it to move again. The end result is that it will slowly slip down under gravity.
If you’re only worried about when the bot is enabled, you can definitely use @Ryan_Blue 's suggestion (active control using PID or whatever), or change gearing
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One positive aspect of brake mode is that it doesn’t pull any significant battery power.
Active braking (applying torque in the opposite direction of the load) -does- consume battery power.
BOTH methods heat up the motor and drive! Brake mode heating is limited by the stored mechanical energy being dissipated, though!
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This was for anti-drift on an arm-like mechanism, and we solved it by using a PID controller as suggested by Ryan. It would be ideal to have a mechanism that did not need this sort of thing, or to fix the issue mechanically, but given how close to comp we were we just did a slightly sloppy solution and I guess it worked out ok.
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