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Planner acceleration bugfix and speedup v2

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.) Use already existing inverse_millimeters instead of /
block->millimeters.
.) Prevent overflow during acceleration calculation by checking if float
is necessary. Idea modified from Sailfish.
.) Save two uint32_t or even float multiplications by checking if
step[AXIS] has steps and if max acceleration is lower than accel. If
not, there is no need to check this axis.
This commit is contained in:
Sebastianv650 2016-10-23 12:47:46 +02:00
parent aa99bd8d13
commit c397b9d60a
2 changed files with 36 additions and 9 deletions
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40
Marlin/planner.cpp
View file

@ -115,6 +115,8 @@ float Planner::min_feedrate_mm_s,
long Planner::position[NUM_AXIS] = { 0 };
uint32_t Planner::cutoff_long;
float Planner::previous_speed[NUM_AXIS],
Planner::previous_nominal_speed;
@ -1013,26 +1015,42 @@ void Planner::_buffer_line(const float &a, const float &b, const float &c, const
}
// Compute and limit the acceleration rate for the trapezoid generator.
float steps_per_mm = block->step_event_count / block->millimeters;
float steps_per_mm = block->step_event_count * inverse_millimeters;
uint32_t accel;
if (!block->steps[X_AXIS] && !block->steps[Y_AXIS] && !block->steps[Z_AXIS]) {
// convert to: acceleration steps/sec^2
accel = ceil(retract_acceleration * steps_per_mm);
}
else {
#define LIMIT_ACCEL(AXIS) do{ \
if (max_acceleration_steps_per_s2[AXIS] < (accel * block->steps[AXIS]) / block->step_event_count) \
accel = (max_acceleration_steps_per_s2[AXIS] * block->step_event_count) / block->steps[AXIS]; \
#define LIMIT_ACCEL_LONG(AXIS) do{ \
if (block->steps[AXIS] && max_acceleration_steps_per_s2[AXIS] < accel) { \
const uint32_t comp = max_acceleration_steps_per_s2[AXIS] * block->step_event_count; \
if (accel * block->steps[AXIS] > comp) accel = comp / block->steps[AXIS]; \
} \
}while(0)
#define LIMIT_ACCEL_FLOAT(AXIS) do{ \
if (block->steps[AXIS] && max_acceleration_steps_per_s2[AXIS] < accel) { \
const float comp = (float)max_acceleration_steps_per_s2[AXIS] * (float)block->step_event_count; \
if ((float)accel * (float)block->steps[AXIS] > comp) accel = comp / (float)block->steps[AXIS]; \
} \
}while(0)
// Start with print or travel acceleration
accel = ceil((block->steps[E_AXIS] ? acceleration : travel_acceleration) * steps_per_mm);
// Limit acceleration per axis
LIMIT_ACCEL(X_AXIS);
LIMIT_ACCEL(Y_AXIS);
LIMIT_ACCEL(Z_AXIS);
LIMIT_ACCEL(E_AXIS);
if (block->step_event_count <= cutoff_long){
LIMIT_ACCEL_LONG(X_AXIS);
LIMIT_ACCEL_LONG(Y_AXIS);
LIMIT_ACCEL_LONG(Z_AXIS);
LIMIT_ACCEL_LONG(E_AXIS);
} else {
LIMIT_ACCEL_FLOAT(X_AXIS);
LIMIT_ACCEL_FLOAT(Y_AXIS);
LIMIT_ACCEL_FLOAT(Z_AXIS);
LIMIT_ACCEL_FLOAT(E_AXIS);
}
}
block->acceleration_steps_per_s2 = accel;
block->acceleration = accel / steps_per_mm;
@ -1303,8 +1321,12 @@ void Planner::set_position_mm(const AxisEnum axis, const float& v) {
// Recalculate the steps/s^2 acceleration rates, based on the mm/s^2
void Planner::reset_acceleration_rates() {
LOOP_XYZE(i)
uint32_t highest_acceleration_allaxes_steps_per_s2;
LOOP_XYZE(i) {
max_acceleration_steps_per_s2[i] = max_acceleration_mm_per_s2[i] * axis_steps_per_mm[i];
if (max_acceleration_steps_per_s2[i] > highest_acceleration_allaxes_steps_per_s2) highest_acceleration_allaxes_steps_per_s2 = max_acceleration_steps_per_s2[i];
}
cutoff_long = 4294967295UL / highest_acceleration_allaxes_steps_per_s2;
}
// Recalculate position, steps_to_mm if axis_steps_per_mm changes!

5
Marlin/planner.h
View file

@ -166,6 +166,11 @@ class Planner {
* Nominal speed of previous path line segment
*/
static float previous_nominal_speed;
/**
* Limit where 64bit math is necessary for acceleration calculation
*/
static uint32_t cutoff_long;
#if ENABLED(DISABLE_INACTIVE_EXTRUDER)
/**