Imbus/grbl-imbus
1
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Improved fix for rare lowering feed/rapid override bug.

Browse source 
[fix] In the previous hot fix, there was still (rarer) potential for
very small floating point errors incorrectly handle an override
deceleration and crash Grbl. Re-factored the if-then statement in terms
of speed changes, rather than distance, to completely eliminate the
issue.
This commit is contained in:
Sonny Jeon 2017-08-01 10:27:42 -06:00
parent 477a94cd49
commit 5967839ab3
3 changed files with 13 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

2
grbl/grbl.h
View file

@ -23,7 +23,7 @@
// Grbl versioning system
#define GRBL_VERSION "1.1f"
#define GRBL_VERSION_BUILD "20170731"
#define GRBL_VERSION_BUILD "20170801"
// Define standard libraries used by Grbl.
#include <avr/io.h>

9
grbl/stepper.c
View file

@ -734,7 +734,7 @@ void st_prep_buffer()
} else {
// Decelerate to cruise or cruise-decelerate types. Guaranteed to intersect updated plan.
prep.decelerate_after = inv_2_accel*(nominal_speed_sqr-exit_speed_sqr);
prep.decelerate_after = inv_2_accel*(nominal_speed_sqr-exit_speed_sqr); // Should always be >= 0.0 due to planner reinit.
prep.maximum_speed = nominal_speed;
prep.ramp_type = RAMP_DECEL_OVERRIDE;
}
@ -806,15 +806,14 @@ void st_prep_buffer()
switch (prep.ramp_type) {
case RAMP_DECEL_OVERRIDE:
speed_var = pl_block->acceleration*time_var;
mm_var = time_var*(prep.current_speed - 0.5*speed_var);
mm_remaining -= mm_var;
if ((mm_remaining <= prep.accelerate_until) || (mm_var <= 0.0)) {
if (prep.current_speed-prep.maximum_speed <= speed_var) {
// Cruise or cruise-deceleration types only for deceleration override.
mm_remaining = prep.accelerate_until; // NOTE: 0.0 at EOB
mm_remaining = prep.accelerate_until;
time_var = 2.0*(pl_block->millimeters-mm_remaining)/(prep.current_speed+prep.maximum_speed);
prep.ramp_type = RAMP_CRUISE;
prep.current_speed = prep.maximum_speed;
} else { // Mid-deceleration override ramp.
mm_remaining -= time_var*(prep.current_speed - 0.5*speed_var);
prep.current_speed -= speed_var;
}
break;