[ODE] ODE 1.0 gyroscopic terms

[Erin Catto]

The gyroscopic term creates a nonlinear differential equation for the
velocities where the angular acceleration depends on the square of the
angular velocity.

See: http://scienceworld.wolfram.com/physics/EulersEquationsofMotion.html

Consider:

dx/dt = k * x^2

If x becomes large, then the slope becomes steep and the numerical
integrator (explicit Euler) will have to take small time steps to avoid
large errors. However, ODE uses a fixed step-size, so it can't adapt to the
steep slope. Therefore, the integrator becomes unstable.

Erin

-----Original Message-----
From: ode-bounces at q12.org [mailto:ode-bounces at q12.org] On Behalf Of STenyaK
(Bruno Gonzalez)

What's wrong with the gyroscopic forces anyway? Does someone know what's
making it unstable? I am not a physics expert, but gyroscopic effects do not
seem that complex.. maybe it's a bug in the code?