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| author | Kevin O'Connor <kevin@koconnor.net> | 2016-10-25 21:05:31 -0400 |
|---|---|---|
| committer | Kevin O'Connor <kevin@koconnor.net> | 2016-10-31 11:06:19 -0400 |
| commit | f0cefebff7c9077dd5f39a9d265cada04b76e6b6 (patch) | |
| tree | f37f754cd2fd8a3d60e9e51dcb16c84d296c7fc6 /klippy/cartesian.py | |
| parent | 2904a0bbac514bcde6b758ba002bb1e32a28106d (diff) | |
| download | kutter-f0cefebff7c9077dd5f39a9d265cada04b76e6b6.tar.gz kutter-f0cefebff7c9077dd5f39a9d265cada04b76e6b6.tar.xz kutter-f0cefebff7c9077dd5f39a9d265cada04b76e6b6.zip | |
cartesian.py: Determine start step offset using last commanded position
The existing code calculates the number of steps in a move and then
spreads them out evenly throughout that move. Change the code so that
step timing is based on where the head is commanded to be relative to
the axis step locations. This makes the timing more accurate - in
particular the axis velocities will be more accurate during cornering
introduced by the lookahead code. It also results in slightly
smoother stepper motion which results in better step compression.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Diffstat (limited to 'klippy/cartesian.py')
| -rw-r--r-- | klippy/cartesian.py | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/klippy/cartesian.py b/klippy/cartesian.py index c3a34db7..16db25d2 100644 --- a/klippy/cartesian.py +++ b/klippy/cartesian.py @@ -97,20 +97,22 @@ class CartKinematics: inv_accel = 1. / move.accel inv_cruise_v = 1. / move.cruise_v for i in StepList: - new_step_pos = int( - move.end_pos[i]*self.steppers[i].inv_step_dist + 0.5) - steps = new_step_pos - self.stepper_pos[i] - if not steps: + inv_step_dist = self.steppers[i].inv_step_dist + new_step_pos = int(move.end_pos[i]*inv_step_dist + 0.5) + step_pos = self.stepper_pos[i] + if new_step_pos == step_pos: continue self.stepper_pos[i] = new_step_pos + steps = move.axes_d[i] * inv_step_dist + step_offset = step_pos - move.start_pos[i] * inv_step_dist + 0.5 sdir = 0 if steps < 0: sdir = 1 steps = -steps + step_offset = 1. - step_offset mcu_time, so = self.steppers[i].prep_move(move_time, sdir) move_step_d = move.move_d / steps - step_offset = 0.5 # Acceleration steps #t = sqrt(2*pos/accel + (start_v/accel)**2) - start_v/accel |