NCI Parameters

Rapid Traverse Velocity (`G0`)

The Rapid Traverse Velocity is used when an interpreter command G0 is executed. See section Rapid traverse velocity for a brief description of the interpreter command G0.

Velo Jump Factor

The reduction factor C0[i] is the Velo Jump Factor.

Background information

Segment transitions

Segments are geometric objects. We consider them as curves in the sense of differential geometry, parameterized by means of their length arc.

A segment transition from a segment S_in to a segment S_out is called of geometric type Ck, where k is a natural number (including 0) describing k continuous arc length differentials for each segment and the corresponding k^th derivatives at the transition point.

C0 transitions: Have a knee-point at the transition point.

C1 transitions: Appear smooth, but are not smooth in dynamic terms. At the segment transition point, there is a jump in acceleration.

C2 transitions: Are dynamically smooth and their smoothness is only jerk-limited.

Ck transitions: are dynamically smooth.

Segment dynamics

Velocity v: The segment set velocity v changes at the segment transition from v_in to v_out. At the segment transition the set velocity is always reduced to the lower of the two values.

Acceleration a: At the segment transition, the current path acceleration is always reduced to zero.

Jerk j: At the segment transition, the jerk changes according to the geometry of the segment transition. This jerk change can cause a noticeable dynamic jump.

Velocity reduction modes for C0 transitions

Several reduction methods are available for C0 transitions. One of them is the reduction method VELOJUMP. The reduction method VELOJUMP reduces the velocity after permitted velocity jumps for each axis.

The VELOJUMP reduction method for C0 transitions

Basically v_link = min(v_in, v_out) applies. For the axis [i], the allowed absolute velocity jump is v_jump[i] = C0[i] * min(A+[i], -A-[i]) * T, where C0[i] is the reduction factor, A+[i], A-[i] is the acceleration or deceleration limits for the axis [i], and T is the cycle time. The VELOJUMP reduction method ensures that the path velocity is reduced at the segment transition v_link until the absolute step change in the set axis velocity of axis [i] is at most v_jump[i]. However, v_min has priority: if v_link is smaller than v_min, then v_link is set to v_min. In the case of motion reversal with no programmed stop, there will be a step change in axis velocity.