Falling robot

Hi,

I try to build a balancing 2 wheel robot, but it ends up to be a falling robot. :frowning:
I played around with kalman filter and PID controler.
What I experience is that at startup when the Y angle is small the robot does not give enough power to the motors.
When the angle is getting larger the motors speed up, but then it is too late.
Of course I increased the P factor of PID controller, but without success.
Any experience if a minimal speed is needed, even for small angles.
The motors have 11k u/minute, seems to be enough for a small wooden made robot.

Any comment id appreciated
Mr Mimi