diff --git a/stepper_plan.c b/stepper_plan.c index 75e71a9..dc72d71 100644 --- a/stepper_plan.c +++ b/stepper_plan.c @@ -37,7 +37,6 @@ uint8_t acceleration_management; // Acceleration management active? // NOTE: See bottom of this module for a comment outlining the reasoning behind the mathematics of the // following functions. - // Calculates the distance (not time) it takes to accelerate from initial_rate to target_rate using the // given acceleration: inline double estimate_acceleration_distance(double initial_rate, double target_rate, double acceleration) { @@ -118,7 +117,7 @@ inline double junction_jerk(struct Block *before, struct Block *after) { ); } -// The kernel called by recalculate_plan() when scanning the plan from last to first +// The kernel called by planner_recalculate() when scanning the plan from last to first entry. void planner_reverse_pass_kernel(struct Block *previous, struct Block *current, struct Block *next) { if(!current){return;} @@ -169,6 +168,7 @@ void planner_reverse_pass() { planner_reverse_pass_kernel(NULL, block[0], block[1]); } +// The kernel called by planner_recalculate() when scanning the plan from first to last entry. void planner_forward_pass_kernel(struct Block *previous, struct Block *current, struct Block *next) { if(!current){return;} // If the previous block is an acceleration block, but it is not long enough to @@ -185,6 +185,8 @@ void planner_forward_pass_kernel(struct Block *previous, struct Block *current, } } +// recalculate_plan() needs to go over the current plan twice. Once in reverse and once forward. This +// implements the forward pass. void planner_forward_pass() { int8_t block_index = block_buffer_tail; struct Block *block[3] = {NULL, NULL, NULL}; @@ -199,6 +201,9 @@ void planner_forward_pass() { planner_forward_pass_kernel(block[1], block[2], NULL); } +// Recalculates the trapezoid speed profiles for all blocks in the plan according to the +// entry_factor for each junction. Must be called by planner_recalculate() after +// updating the blocks. void planner_recalculate_trapezoids() { int8_t block_index = block_buffer_tail; struct Block *current; @@ -215,12 +220,27 @@ void planner_recalculate_trapezoids() { calculate_trapezoid_for_block(next, next->entry_factor, 0.0); } +// Recalculates the motion plan according to the following algorithm: +// 1. Go over every block in reverse order and calculate a junction speed reduction (i.e. Block.entry_factor) +// so that: +// a. The junction jerk is within the set limit +// b. No speed reduction within one block requires faster accelleration than the one, true constant +// acceleration. +// 2. Go over every block in chronological order and dial down junction speed reduction values if +// a. The speed increase within one block would require faster accelleration than the one, true +// constant acceleration. +// When these stages are complete all blocks have an entry_factor that will allow all speed changes to +// be performed using only the one, true constant acceleration, and where no junction jerk is jerkier than +// the set limit. Finally it will: +// 3. Recalculate trapezoids for all blocks. + void planner_recalculate() { planner_reverse_pass(); planner_forward_pass(); planner_recalculate_trapezoids(); } + void plan_enable_acceleration_management() { if (!acceleration_management) { st_synchronize(); @@ -278,7 +298,7 @@ void plan_buffer_line(int32_t steps_x, int32_t steps_y, int32_t steps_z, uint32_ ((settings.acceleration*60.0)/(ACCELERATION_TICKS_PER_SECOND))/ // acceleration mm/sec/sec per acceleration_tick travel_per_step); // convert to: acceleration steps/min/acceleration_tick if (acceleration_management) { - calculate_trapezoid_for_block(block,0,0); // compute a conservative acceleration trapezoid for now + calculate_trapezoid_for_block(block,0,0); // compute a conservative acceleration trapezoid for now } else { block->accelerate_until = 0; block->decelerate_after = 0; @@ -292,7 +312,12 @@ void plan_buffer_line(int32_t steps_x, int32_t steps_y, int32_t steps_z, uint32_ if (steps_z < 0) { block->direction_bits |= (1<