From 97d509d4d281ec8cafd6815aa9f2a4d7ba647548 Mon Sep 17 00:00:00 2001
From: Scott Lahteine <github@thinkyhead.com>
Date: Thu, 21 Dec 2017 16:51:08 -0600
Subject: [PATCH] Revert "Improved Core-compatible jerk code"
Reverting commit 3cd7659
---
Marlin/src/module/planner.cpp | 40 ++++++++++++++++++++++++-----------
1 file changed, 28 insertions(+), 12 deletions(-)
diff --git a/Marlin/src/module/planner.cpp b/Marlin/src/module/planner.cpp
index c344640852e..d17b5535c2b 100644
--- a/Marlin/src/module/planner.cpp
+++ b/Marlin/src/module/planner.cpp
@@ -1110,14 +1110,10 @@ void Planner::_buffer_steps(const int32_t (&target)[XYZE], float fr_mm_s, const
}
#endif
- // Calculate and limit speed in mm/sec for each axis, calculate minimum acceleration ratio
+ // Calculate and limit speed in mm/sec for each axis
float current_speed[NUM_AXIS], speed_factor = 1.0; // factor <1 decreases speed
- float max_stepper_speed = 0, min_axis_accel_ratio = 1; // ratio < 1 means acceleration ramp needed
LOOP_XYZE(i) {
const float cs = FABS((current_speed[i] = delta_mm[i] * inverse_secs));
- if (cs > max_jerk[i])
- NOMORE(min_axis_accel_ratio, max_jerk[i] / cs);
- NOLESS(max_stepper_speed, cs);
#if ENABLED(DISTINCT_E_FACTORS)
if (i == E_AXIS) i += extruder;
#endif
@@ -1162,9 +1158,6 @@ void Planner::_buffer_steps(const int32_t (&target)[XYZE], float fr_mm_s, const
}
#endif // XY_FREQUENCY_LIMIT
- block->nominal_speed = max_stepper_speed; // (mm/sec) Always > 0
- block->nominal_rate = CEIL(block->step_event_count * inverse_secs); // (step/sec) Always > 0
-
// Correct the speed
if (speed_factor < 1.0) {
LOOP_XYZE(i) current_speed[i] *= speed_factor;
@@ -1172,9 +1165,6 @@ void Planner::_buffer_steps(const int32_t (&target)[XYZE], float fr_mm_s, const
block->nominal_rate *= speed_factor;
}
- float safe_speed = block->nominal_speed * min_axis_accel_ratio;
- static float previous_safe_speed;
-
// Compute and limit the acceleration rate for the trapezoid generator.
const float steps_per_mm = block->step_event_count * inverse_millimeters;
uint32_t accel;
@@ -1276,6 +1266,32 @@ void Planner::_buffer_steps(const int32_t (&target)[XYZE], float fr_mm_s, const
}
#endif
+ /**
+ * Adapted from Průša MKS firmware
+ * https://github.com/prusa3d/Prusa-Firmware
+ *
+ * Start with a safe speed (from which the machine may halt to stop immediately).
+ */
+
+ // Exit speed limited by a jerk to full halt of a previous last segment
+ static float previous_safe_speed;
+
+ float safe_speed = block->nominal_speed;
+ uint8_t limited = 0;
+ LOOP_XYZE(i) {
+ const float jerk = FABS(current_speed[i]), maxj = max_jerk[i];
+ if (jerk > maxj) {
+ if (limited) {
+ const float mjerk = maxj * block->nominal_speed;
+ if (jerk * safe_speed > mjerk) safe_speed = mjerk / jerk;
+ }
+ else {
+ ++limited;
+ safe_speed = maxj;
+ }
+ }
+ }
+
if (moves_queued && !UNEAR_ZERO(previous_nominal_speed)) {
// Estimate a maximum velocity allowed at a joint of two successive segments.
// If this maximum velocity allowed is lower than the minimum of the entry / exit safe velocities,
@@ -1287,7 +1303,7 @@ void Planner::_buffer_steps(const int32_t (&target)[XYZE], float fr_mm_s, const
// Factor to multiply the previous / current nominal velocities to get componentwise limited velocities.
float v_factor = 1;
- uint8_t limited = 0;
+ limited = 0;
// Now limit the jerk in all axes.
const float smaller_speed_factor = vmax_junction / previous_nominal_speed;