Constant MIN_JOINT_VELOCITY 

pub const MIN_JOINT_VELOCITY: [f64; 7];

Minimum joint velocity, i.e. -MAX_JOINT_VELOCITY.

libfranka 0.9.2 has no such array — its limitRate overloads take a single symmetric max_velocity — but the crate’s super::limit_rate_joint_velocities takes an upper and a lower bound, so the negated array is what a v5 control loop passes as the lower one.