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Fix initial safe_speed in jerk code (#11417)

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Scott Lahteine 2018-07-30 22:50:08 -05:00 committed by GitHub
parent 2cc950d67e
commit b826bf4194
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1 changed files with 13 additions and 13 deletions
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24
Marlin/src/module/planner.cpp
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@ -1947,7 +1947,7 @@ bool Planner::_populate_block(block_t * const block, bool split_move,
else else
block->millimeters = millimeters; block->millimeters = millimeters;
const float inverse_millimeters = 1.0 / block->millimeters; // Inverse millimeters to remove multiple divides const float inverse_millimeters = 1.0f / block->millimeters; // Inverse millimeters to remove multiple divides
// Calculate inverse time for this move. No divide by zero due to previous checks. // Calculate inverse time for this move. No divide by zero due to previous checks.
// Example: At 120mm/s a 60mm move takes 0.5s. So this will give 2.0. // Example: At 120mm/s a 60mm move takes 0.5s. So this will give 2.0.
@ -2298,27 +2298,27 @@ bool Planner::_populate_block(block_t * const block, bool split_move,
/** /**
* Adapted from Průša MKS firmware * Adapted from Průša MKS firmware
* https://github.com/prusa3d/Prusa-Firmware * https://github.com/prusa3d/Prusa-Firmware
*
* Start with a safe speed (from which the machine may halt to stop immediately).
*/ */
const float nominal_speed = SQRT(block->nominal_speed_sqr);
// Exit speed limited by a jerk to full halt of a previous last segment // Exit speed limited by a jerk to full halt of a previous last segment
static float previous_safe_speed; static float previous_safe_speed;
const float nominal_speed = SQRT(block->nominal_speed_sqr); // Start with a safe speed (from which the machine may halt to stop immediately).
float safe_speed = nominal_speed; float safe_speed = nominal_speed;
uint8_t limited = 0; uint8_t limited = 0;
LOOP_XYZE(i) { LOOP_XYZE(i) {
const float jerk = ABS(current_speed[i]), maxj = max_jerk[i]; const float jerk = ABS(current_speed[i]), // cs : Starting from zero, change in speed for this axis
if (jerk > maxj) { maxj = max_jerk[i]; // mj : The max jerk setting for this axis
if (limited) { if (jerk > maxj) { // cs > mj : New current speed too fast?
const float mjerk = maxj * nominal_speed; if (limited) { // limited already?
if (jerk * safe_speed > mjerk) safe_speed = mjerk / jerk; const float mjerk = nominal_speed * maxj; // ns*mj
if (jerk * safe_speed > mjerk) safe_speed = mjerk / jerk; // ns*mj/cs
} }
else { else {
++limited; safe_speed *= maxj / jerk; // Initial limit: ns*mj/cs
safe_speed = maxj; ++limited; // Initially limited
} }
} }
} }
@ -2620,7 +2620,7 @@ void Planner::reset_acceleration_rates() {
// Recalculate position, steps_to_mm if axis_steps_per_mm changes! // Recalculate position, steps_to_mm if axis_steps_per_mm changes!
void Planner::refresh_positioning() { void Planner::refresh_positioning() {
LOOP_XYZE_N(i) steps_to_mm[i] = 1.0 / axis_steps_per_mm[i]; LOOP_XYZE_N(i) steps_to_mm[i] = 1.0f / axis_steps_per_mm[i];
set_position_mm_kinematic(current_position); set_position_mm_kinematic(current_position);
reset_acceleration_rates(); reset_acceleration_rates();
} }