#include "Block.h"
#include "Planner.h"
#include "Conveyor.h"
+#include "StepperMotor.h"
+#include "Config.h"
+#include "checksumm.h"
+#include "Robot.h"
+#include "Stepper.h"
+
+#include <math.h>
+
+#define acceleration_checksum CHECKSUM("acceleration")
+#define max_jerk_checksum CHECKSUM("max_jerk")
+#define junction_deviation_checksum CHECKSUM("junction_deviation")
+#define minimum_planner_speed_checksum CHECKSUM("minimum_planner_speed")
// The Planner does the acceleration math for the queue of Blocks ( movements ).
// It makes sure the speed stays within the configured constraints ( acceleration, junction_deviation, etc )
// It goes over the list in both direction, every time a block is added, re-doing the math to make sure everything is optimal
Planner::Planner(){
- clear_vector(this->position);
- clear_vector_double(this->previous_unit_vec);
- this->previous_nominal_speed = 0.0;
+ clear_vector_float(this->previous_unit_vec);
this->has_deleted_block = false;
}
// Configure acceleration
void Planner::on_config_reload(void* argument){
- this->acceleration = THEKERNEL->config->value(acceleration_checksum )->by_default(100 )->as_number() * 60 * 60; // Acceleration is in mm/minute^2, see https://github.com/grbl/grbl/commit/9141ad282540eaa50a41283685f901f29c24ddbd#planner.c
- this->junction_deviation = THEKERNEL->config->value(junction_deviation_checksum )->by_default(0.05f)->as_number();
+ this->acceleration = THEKERNEL->config->value(acceleration_checksum )->by_default(100.0F )->as_number(); // Acceleration is in mm/s^2, see https://github.com/grbl/grbl/commit/9141ad282540eaa50a41283685f901f29c24ddbd#planner.c
+ this->junction_deviation = THEKERNEL->config->value(junction_deviation_checksum )->by_default( 0.05F)->as_number();
+ this->minimum_planner_speed = THEKERNEL->config->value(minimum_planner_speed_checksum )->by_default(0.0f)->as_number();
}
// Append a block to the queue, compute it's speed factors
-void Planner::append_block( int target[], float feed_rate, float distance, float deltas[] ){
-
- // Stall here if the queue is ful
- THEKERNEL->conveyor->wait_for_queue(2);
-
+void Planner::append_block( float actuator_pos[], float rate_mm_s, float distance, float unit_vec[] )
+{
// Create ( recycle ) a new block
- Block* block = THEKERNEL->conveyor->new_block();
- block->planner = this;
+ Block* block = THEKERNEL->conveyor->queue.head_ref();
// Direction bits
block->direction_bits = 0;
- for( int stepper=ALPHA_STEPPER; stepper<=GAMMA_STEPPER; stepper++){
- if( target[stepper] < position[stepper] ){ block->direction_bits |= (1<<stepper); }
+ for (int i = 0; i < 3; i++)
+ {
+ int steps = THEKERNEL->robot->actuators[i]->steps_to_target(actuator_pos[i]);
+
+ if (steps < 0)
+ block->direction_bits |= (1<<i);
+
+ // Update current position
+ THEKERNEL->robot->actuators[i]->last_milestone_steps += steps;
+ THEKERNEL->robot->actuators[i]->last_milestone_mm = actuator_pos[i];
+
+ block->steps[i] = labs(steps);
}
-
- // Number of steps for each stepper
- for( int stepper=ALPHA_STEPPER; stepper<=GAMMA_STEPPER; stepper++){ block->steps[stepper] = labs(target[stepper] - this->position[stepper]); }
-
+
// Max number of steps, for all axes
block->steps_event_count = max( block->steps[ALPHA_STEPPER], max( block->steps[BETA_STEPPER], block->steps[GAMMA_STEPPER] ) );
block->millimeters = distance;
- float inverse_millimeters = 0;
- if( distance > 0 ){ inverse_millimeters = 1.0/distance; }
- // Calculate speed in mm/minute for each axis. No divide by zero due to previous checks.
+ // Calculate speed in mm/sec for each axis. No divide by zero due to previous checks.
// NOTE: Minimum stepper speed is limited by MINIMUM_STEPS_PER_MINUTE in stepper.c
- float inverse_minute = feed_rate * inverse_millimeters;
- if( distance > 0 ){
- block->nominal_speed = block->millimeters * inverse_minute; // (mm/min) Always > 0
- block->nominal_rate = ceil(block->steps_event_count * inverse_minute); // (step/min) Always > 0
+ if( distance > 0.0F ){
+ block->nominal_speed = rate_mm_s; // (mm/s) Always > 0
+ block->nominal_rate = ceil(block->steps_event_count * rate_mm_s / distance); // (step/s) Always > 0
}else{
- block->nominal_speed = 0;
- block->nominal_rate = 0;
+ block->nominal_speed = 0.0F;
+ block->nominal_rate = 0;
}
// Compute the acceleration rate for the trapezoid generator. Depending on the slope of the line
// To generate trapezoids with contant acceleration between blocks the rate_delta must be computed
// specifically for each line to compensate for this phenomenon:
// Convert universal acceleration for direction-dependent stepper rate change parameter
- block->rate_delta = (float)( ( block->steps_event_count*inverse_millimeters * this->acceleration ) / ( THEKERNEL->stepper->acceleration_ticks_per_second * 60 ) ); // (step/min/acceleration_tick)
-
- // Compute path unit vector
- float unit_vec[3];
- unit_vec[X_AXIS] = deltas[X_AXIS]*inverse_millimeters;
- unit_vec[Y_AXIS] = deltas[Y_AXIS]*inverse_millimeters;
- unit_vec[Z_AXIS] = deltas[Z_AXIS]*inverse_millimeters;
-
+ block->rate_delta = (block->steps_event_count * acceleration) / (distance * THEKERNEL->stepper->acceleration_ticks_per_second); // (step/min/acceleration_tick)
+
// Compute maximum allowable entry speed at junction by centripetal acceleration approximation.
// Let a circle be tangent to both previous and current path line segments, where the junction
// deviation is defined as the distance from the junction to the closest edge of the circle,
// path width or max_jerk in the previous grbl version. This approach does not actually deviate
// from path, but used as a robust way to compute cornering speeds, as it takes into account the
// nonlinearities of both the junction angle and junction velocity.
- float vmax_junction = MINIMUM_PLANNER_SPEED; // Set default max junction speed
-
- if (THEKERNEL->conveyor->queue.size() > 1 && (this->previous_nominal_speed > 0.0)) {
- // Compute cosine of angle between previous and current path. (prev_unit_vec is negative)
- // NOTE: Max junction velocity is computed without sin() or acos() by trig half angle identity.
- float cos_theta = - this->previous_unit_vec[X_AXIS] * unit_vec[X_AXIS]
- - this->previous_unit_vec[Y_AXIS] * unit_vec[Y_AXIS]
- - this->previous_unit_vec[Z_AXIS] * unit_vec[Z_AXIS] ;
-
- // Skip and use default max junction speed for 0 degree acute junction.
- if (cos_theta < 0.95) {
- vmax_junction = min(this->previous_nominal_speed,block->nominal_speed);
- // Skip and avoid divide by zero for straight junctions at 180 degrees. Limit to min() of nominal speeds.
- if (cos_theta > -0.95) {
- // Compute maximum junction velocity based on maximum acceleration and junction deviation
- float sin_theta_d2 = sqrt(0.5*(1.0-cos_theta)); // Trig half angle identity. Always positive.
- vmax_junction = min(vmax_junction,
- sqrtf(this->acceleration * this->junction_deviation * sin_theta_d2/(1.0-sin_theta_d2)) );
+ float vmax_junction = minimum_planner_speed; // Set default max junction speed
+
+ if (!THEKERNEL->conveyor->queue.is_empty())
+ {
+ float previous_nominal_speed = THEKERNEL->conveyor->queue.item_ref(THEKERNEL->conveyor->queue.prev(THEKERNEL->conveyor->queue.head_i))->nominal_speed;
+
+ if (previous_nominal_speed > 0.0F) {
+ // Compute cosine of angle between previous and current path. (prev_unit_vec is negative)
+ // NOTE: Max junction velocity is computed without sin() or acos() by trig half angle identity.
+ float cos_theta = - this->previous_unit_vec[X_AXIS] * unit_vec[X_AXIS]
+ - this->previous_unit_vec[Y_AXIS] * unit_vec[Y_AXIS]
+ - this->previous_unit_vec[Z_AXIS] * unit_vec[Z_AXIS] ;
+
+ // Skip and use default max junction speed for 0 degree acute junction.
+ if (cos_theta < 0.95F) {
+ vmax_junction = min(previous_nominal_speed, block->nominal_speed);
+ // Skip and avoid divide by zero for straight junctions at 180 degrees. Limit to min() of nominal speeds.
+ if (cos_theta > -0.95F) {
+ // Compute maximum junction velocity based on maximum acceleration and junction deviation
+ float sin_theta_d2 = sqrtf(0.5F * (1.0F - cos_theta)); // Trig half angle identity. Always positive.
+ vmax_junction = min(vmax_junction, sqrtf(this->acceleration * this->junction_deviation * sin_theta_d2 / (1.0F - sin_theta_d2)));
+ }
+ }
}
- }
}
block->max_entry_speed = vmax_junction;
-
- // Initialize block entry speed. Compute based on deceleration to user-defined MINIMUM_PLANNER_SPEED.
- float v_allowable = this->max_allowable_speed(-this->acceleration,0.0,block->millimeters); //TODO: Get from config
+
+ // Initialize block entry speed. Compute based on deceleration to user-defined minimum_planner_speed.
+ float v_allowable = max_allowable_speed(-acceleration, minimum_planner_speed, block->millimeters); //TODO: Get from config
block->entry_speed = min(vmax_junction, v_allowable);
// Initialize planner efficiency flags
// the maximum junction speed and may always be ignored for any speed reduction checks.
if (block->nominal_speed <= v_allowable) { block->nominal_length_flag = true; }
else { block->nominal_length_flag = false; }
- block->recalculate_flag = true; // Always calculate trapezoid for new block
-
+
+ // Always calculate trapezoid for new block
+ block->recalculate_flag = true;
+
// Update previous path unit_vector and nominal speed
- memcpy(this->previous_unit_vec, unit_vec, sizeof(unit_vec)); // previous_unit_vec[] = unit_vec[]
- this->previous_nominal_speed = block->nominal_speed;
-
- // Update current position
- memcpy(this->position, target, sizeof(int)*3);
+ memcpy(this->previous_unit_vec, unit_vec, sizeof(previous_unit_vec)); // previous_unit_vec[] = unit_vec[]
// Math-heavy re-computing of the whole queue to take the new
this->recalculate();
-
+
// The block can now be used
block->ready();
+ THEKERNEL->conveyor->queue_head_block();
}
-
-// 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_t.entry_factor)
-// so that:
-// a. The junction jerk is within the set limit
-// b. No speed reduction within one block requires faster deceleration 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() {
- RingBuffer<Block,32>* queue = &THEKERNEL->conveyor->queue;
+ Conveyor::Queue_t &queue = THEKERNEL->conveyor->queue;
- int newest = queue->prev_block_index(queue->head);
- int oldest = queue->tail;
-
- int block_index = newest;
+ unsigned int block_index;
Block* previous;
Block* current;
- Block* next;
-
- current = &queue->buffer[block_index];
- current->recalculate_flag = true;
- // if there's only one block in the queue, we fall through both while loops and this ends up in current
- // so we must set it here, or perform conditionals further down. this is easier
- next = current;
-
- while ((block_index != oldest) && (current->recalculate_flag))
+ /*
+ * a newly added block is decel limited
+ *
+ * we find its max entry speed given its exit speed
+ *
+ * for each block, walking backwards in the queue:
+ *
+ * if max entry speed == current entry speed
+ * then we can set recalculate to false, since clearly adding another block didn't allow us to enter faster
+ * and thus we don't need to check entry speed for this block any more
+ *
+ * once we find an accel limited block, we must find the max exit speed and walk the queue forwards
+ *
+ * for each block, walking forwards in the queue:
+ *
+ * given the exit speed of the previous block and our own max entry speed
+ * we can tell if we're accel or decel limited (or coasting)
+ *
+ * if prev_exit > max_entry
+ * then we're still decel limited. update previous trapezoid with our max entry for prev exit
+ * if max_entry >= prev_exit
+ * then we're accel limited. set recalculate to false, work out max exit speed
+ *
+ * finally, work out trapezoid for the final (and newest) block.
+ */
+
+ /*
+ * Step 1:
+ * For each block, given the exit speed and acceleration, find the maximum entry speed
+ */
+
+ float entry_speed = minimum_planner_speed;
+
+ block_index = queue.head_i;
+ current = queue.item_ref(block_index);
+
+ if (!queue.is_empty())
{
- block_index = queue->prev_block_index(block_index);
+ while ((block_index != queue.tail_i) && current->recalculate_flag)
+ {
+ entry_speed = current->reverse_pass(entry_speed);
- next = current;
- current = &queue->buffer[block_index];
+ block_index = queue.prev(block_index);
+ current = queue.item_ref(block_index);
+ }
- current->recalculate_flag = false;
+ /*
+ * Step 2:
+ * now current points to either tail or first non-recalculate block
+ * and has not had its reverse_pass called
+ * or its calc trap
+ * entry_speed is set to the *exit* speed of current.
+ * each block from current to head has its entry speed set to its max entry speed- limited by decel or nominal_rate
+ */
- current->reverse_pass(next);
- }
+ float exit_speed = current->max_exit_speed();
- previous = current;
- current = next;
+ while (block_index != queue.head_i)
+ {
+ previous = current;
+ block_index = queue.next(block_index);
+ current = queue.item_ref(block_index);
- // Recalculates the trapezoid speed profiles for flagged blocks in the plan according to the
- // entry_speed for each junction and the entry_speed of the next junction. Must be called by
- // planner_recalculate() after updating the blocks. Any recalulate flagged junction will
- // compute the two adjacent trapezoids to the junction, since the junction speed corresponds
- // to exit speed and entry speed of one another.
- while (block_index != newest)
- {
- current->forward_pass(previous);
+ // we pass the exit speed of the previous block
+ // so this block can decide if it's accel or decel limited and update its fields as appropriate
+ exit_speed = current->forward_pass(exit_speed);
- // Recalculate if current block entry or exit junction speed has changed.
- if (previous->recalculate_flag || current->recalculate_flag )
- {
- previous->calculate_trapezoid( previous->entry_speed/previous->nominal_speed, current->entry_speed/previous->nominal_speed );
- previous->recalculate_flag = false;
+ previous->calculate_trapezoid(previous->entry_speed, current->entry_speed);
}
-
- block_index = queue->next_block_index(block_index);
- previous = current;
- current = &queue->buffer[block_index];
}
- // Last/newest block in buffer. Exit speed is set with MINIMUM_PLANNER_SPEED. Always recalculated.
- current->calculate_trapezoid( current->entry_speed/current->nominal_speed, MINIMUM_PLANNER_SPEED/current->nominal_speed );
- current->recalculate_flag = false;
-}
+ /*
+ * Step 3:
+ * work out trapezoid for final (and newest) block
+ */
-// Debug function
-void Planner::dump_queue(){
- for( int index = 0; index <= THEKERNEL->conveyor->queue.size()-1; index++ ){
- if( index > 10 && index < THEKERNEL->conveyor->queue.size()-10 ){ continue; }
- THEKERNEL->streams->printf("block %03d > ", index);
- THEKERNEL->conveyor->queue.get_ref(index)->debug();
- }
+ // now current points to the head item
+ // which has not had calculate_trapezoid run yet
+ current->calculate_trapezoid(current->entry_speed, minimum_planner_speed);
}
+
// Calculates the maximum allowable speed at this point when you must be able to reach target_velocity using the
// acceleration within the allotted distance.
float Planner::max_allowable_speed(float acceleration, float target_velocity, float distance) {
return(
- sqrt(target_velocity*target_velocity-2L*acceleration*distance) //Was acceleration*60*60*distance, in case this breaks, but here we prefer to use seconds instead of minutes
+ sqrtf(target_velocity*target_velocity-2.0F*acceleration*distance) //Was acceleration*60*60*distance, in case this breaks, but here we prefer to use seconds instead of minutes
);
}