Siemens SINUMERIK 840D Function Manual page 382

B2: Acceleration and jerk
12.2 Functions
Substitute characteristic curve with curved path sections
In the case of curved path sections, normal and tangential acceleration are considered
together. The path velocity is reduced so that only up to 25 % of the speed-dependent
acceleration capacity of the axes is required for normal acceleration. The remaining 75 % of the
acceleration capacity is set aside for the tangential acceleration, i.e., deceleration/acceleration
on the path.
①
②
a
N
a :
ers
v
ers
r
Figure 12-7
Block transitions with continuous-path mode
If continuous-path mode is active, non-tangential block transitions result in axial velocity jumps
when the programmed path velocity is used for traversing.
As a result, the path velocity is controlled in such a way that prevents any axial velocity
proportion from exceeding the creep velocity v
Deceleration ramp with continuous-path mode and LookAhead
In the case of consecutive traversing blocks with short paths, an acceleration or deceleration
operation may be spread over several part program blocks.
In such a situation the "LookAhead" function also takes into account the parameterized speed-
dependent acceleration characteristic.
382
Normal range
Reducing range
Normal acceleration
Substitute characteristic curve constant acceleration
Substitute characteristic curve velocity
Path radius
Substitute path characteristic curve: Curved path
at the time of the block transition.
red
Function Manual, 06/2019, A5E47437747B AA
Axes and spindles