2 This file is part of Smoothie (http://smoothieware.org/). The motion control part is heavily based on Grbl (https://github.com/simen/grbl) with additions from Sungeun K. Jeon (https://github.com/chamnit/grbl)
3 Smoothie is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
4 Smoothie is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
5 You should have received a copy of the GNU General Public License along with Smoothie. If not, see <http://www.gnu.org/licenses/>.
10 #include "libs/nuts_bolts.h"
11 #include "libs/RingBuffer.h"
12 #include "../communication/utils/Gcode.h"
13 #include "libs/Module.h"
14 #include "libs/Kernel.h"
21 clear_vector(this->position
);
22 clear_vector_double(this->previous_unit_vec
);
23 this->previous_nominal_speed
= 0.0;
24 this->has_deleted_block
= false;
27 void Planner::on_module_loaded(){
28 this->on_config_reload(this);
31 void Planner::on_config_reload(void* argument
){
32 this->acceleration
= this->kernel
->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
33 this->max_jerk
= this->kernel
->config
->value(max_jerk_checksum
)->by_default(100 )->as_number();
34 this->junction_deviation
= this->kernel
->config
->value(junction_deviation_checksum
)->by_default(0.05)->as_number();
38 // Append a block to the queue, compute it's speed factors
39 void Planner::append_block( int target
[], double feed_rate
, double distance
, double deltas
[] ){
41 //printf("new block\r\n");
43 int steps
[3], steps_event_count
;
44 // Number of steps for each stepper
45 for( int stepper
=ALPHA_STEPPER
; stepper
<=GAMMA_STEPPER
; stepper
++){ steps
[stepper
] = labs(target
[stepper
] - this->position
[stepper
]); }
47 // Max number of steps, for all axes
48 steps_event_count
= max( steps
[ALPHA_STEPPER
], max( steps
[BETA_STEPPER
], steps
[GAMMA_STEPPER
] ) );
50 if (steps_event_count
<= 5)
53 // Stall here if the queue is ful
54 this->kernel
->player
->wait_for_queue(2);
56 Block
* block
= this->kernel
->player
->new_block();
57 block
->planner
= this;
59 // move precalculated values into block
60 memcpy(block
->steps
, steps
, sizeof(steps
));
61 block
->steps_event_count
= steps_event_count
;
64 block
->direction_bits
= 0;
65 for( int stepper
=ALPHA_STEPPER
; stepper
<=GAMMA_STEPPER
; stepper
++){
66 if( target
[stepper
] < position
[stepper
] ){ block
->direction_bits
|= (1<<stepper
); }
69 block
->millimeters
= distance
;
70 double inverse_millimeters
= 0;
71 if( distance
> 0 ){ inverse_millimeters
= 1.0/distance
; }
73 // Calculate speed in mm/minute for each axis. No divide by zero due to previous checks.
74 // NOTE: Minimum stepper speed is limited by MINIMUM_STEPS_PER_MINUTE in stepper.c
75 double inverse_minute
= feed_rate
* inverse_millimeters
;
77 block
->nominal_speed
= block
->millimeters
* inverse_minute
; // (mm/min) Always > 0
78 block
->nominal_rate
= ceil(block
->steps_event_count
* inverse_minute
); // (step/min) Always > 0
80 block
->nominal_speed
= 0;
81 block
->nominal_rate
= 0;
84 //this->kernel->streams->printf("nom_speed: %f nom_rate: %u step_event_count: %u block->steps_z: %u \r\n", block->nominal_speed, block->nominal_rate, block->steps_event_count, block->steps[2] );
86 // Compute the acceleration rate for the trapezoid generator. Depending on the slope of the line
87 // average travel per step event changes. For a line along one axis the travel per step event
88 // is equal to the travel/step in the particular axis. For a 45 degree line the steppers of both
89 // axes might step for every step event. Travel per step event is then sqrt(travel_x^2+travel_y^2).
90 // To generate trapezoids with contant acceleration between blocks the rate_delta must be computed
91 // specifically for each line to compensate for this phenomenon:
92 // Convert universal acceleration for direction-dependent stepper rate change parameter
93 block
->rate_delta
= (float)( ( block
->steps_event_count
*inverse_millimeters
* this->acceleration
) / ( this->kernel
->stepper
->acceleration_ticks_per_second
* 60 ) ); // (step/min/acceleration_tick)
96 // Compute path unit vector
98 unit_vec
[X_AXIS
] = deltas
[X_AXIS
]*inverse_millimeters
;
99 unit_vec
[Y_AXIS
] = deltas
[Y_AXIS
]*inverse_millimeters
;
100 unit_vec
[Z_AXIS
] = deltas
[Z_AXIS
]*inverse_millimeters
;
102 // Compute maximum allowable entry speed at junction by centripetal acceleration approximation.
103 // Let a circle be tangent to both previous and current path line segments, where the junction
104 // deviation is defined as the distance from the junction to the closest edge of the circle,
105 // colinear with the circle center. The circular segment joining the two paths represents the
106 // path of centripetal acceleration. Solve for max velocity based on max acceleration about the
107 // radius of the circle, defined indirectly by junction deviation. This may be also viewed as
108 // path width or max_jerk in the previous grbl version. This approach does not actually deviate
109 // from path, but used as a robust way to compute cornering speeds, as it takes into account the
110 // nonlinearities of both the junction angle and junction velocity.
111 double vmax_junction
= MINIMUM_PLANNER_SPEED
; // Set default max junction speed
113 if (this->kernel
->player
->queue
.size() > 1 && (this->previous_nominal_speed
> 0.0)) {
114 // Compute cosine of angle between previous and current path. (prev_unit_vec is negative)
115 // NOTE: Max junction velocity is computed without sin() or acos() by trig half angle identity.
116 double cos_theta
= - this->previous_unit_vec
[X_AXIS
] * unit_vec
[X_AXIS
]
117 - this->previous_unit_vec
[Y_AXIS
] * unit_vec
[Y_AXIS
]
118 - this->previous_unit_vec
[Z_AXIS
] * unit_vec
[Z_AXIS
] ;
120 // Skip and use default max junction speed for 0 degree acute junction.
121 if (cos_theta
< 0.95) {
122 vmax_junction
= min(this->previous_nominal_speed
,block
->nominal_speed
);
123 // Skip and avoid divide by zero for straight junctions at 180 degrees. Limit to min() of nominal speeds.
124 if (cos_theta
> -0.95) {
125 // Compute maximum junction velocity based on maximum acceleration and junction deviation
126 double sin_theta_d2
= sqrt(0.5*(1.0-cos_theta
)); // Trig half angle identity. Always positive.
127 vmax_junction
= min(vmax_junction
,
128 sqrt(this->acceleration
* this->junction_deviation
* sin_theta_d2
/(1.0-sin_theta_d2
)) );
132 block
->max_entry_speed
= vmax_junction
;
134 // Initialize block entry speed. Compute based on deceleration to user-defined MINIMUM_PLANNER_SPEED.
135 double v_allowable
= this->max_allowable_speed(-this->acceleration
,0.0,block
->millimeters
); //TODO: Get from config
136 block
->entry_speed
= min(vmax_junction
, v_allowable
);
138 // Initialize planner efficiency flags
139 // Set flag if block will always reach maximum junction speed regardless of entry/exit speeds.
140 // If a block can de/ac-celerate from nominal speed to zero within the length of the block, then
141 // the current block and next block junction speeds are guaranteed to always be at their maximum
142 // junction speeds in deceleration and acceleration, respectively. This is due to how the current
143 // block nominal speed limits both the current and next maximum junction speeds. Hence, in both
144 // the reverse and forward planners, the corresponding block junction speed will always be at the
145 // the maximum junction speed and may always be ignored for any speed reduction checks.
146 if (block
->nominal_speed
<= v_allowable
) { block
->nominal_length_flag
= true; }
147 else { block
->nominal_length_flag
= false; }
148 block
->recalculate_flag
= true; // Always calculate trapezoid for new block
150 // Update previous path unit_vector and nominal speed
151 memcpy(this->previous_unit_vec
, unit_vec
, sizeof(unit_vec
)); // previous_unit_vec[] = unit_vec[]
152 this->previous_nominal_speed
= block
->nominal_speed
;
154 // Update current position
155 memcpy(this->position
, target
, sizeof(int)*3);
157 // Math-heavy re-computing of the whole queue to take the new
160 // The block can now be used
166 // Recalculates the motion plan according to the following algorithm:
168 // 1. Go over every block in reverse order and calculate a junction speed reduction (i.e. block_t.entry_factor)
170 // a. The junction jerk is within the set limit
171 // b. No speed reduction within one block requires faster deceleration than the one, true constant
173 // 2. Go over every block in chronological order and dial down junction speed reduction values if
174 // a. The speed increase within one block would require faster accelleration than the one, true
175 // constant acceleration.
177 // When these stages are complete all blocks have an entry_factor that will allow all speed changes to
178 // be performed using only the one, true constant acceleration, and where no junction jerk is jerkier than
179 // the set limit. Finally it will:
181 // 3. Recalculate trapezoids for all blocks.
183 void Planner::recalculate() {
184 //this->kernel->streams->printf("recalculate last: %p, queue size: %d \r\n", this->kernel->player->queue.get_ref( this->kernel->player->queue.size()-1 ), this->kernel->player->queue.size() );
185 this->reverse_pass();
186 this->forward_pass();
187 this->recalculate_trapezoids();
190 // Planner::recalculate() needs to go over the current plan twice. Once in reverse and once forward. This
191 // implements the reverse pass.
192 void Planner::reverse_pass(){
194 int block_index
= this->kernel
->player
->queue
.tail
;
195 Block
* blocks
[3] = {NULL
,NULL
,NULL
};
197 while(block_index
!=this->kernel
->player
->queue
.head
){
198 block_index
= this->kernel
->player
->queue
.prev_block_index( block_index
);
199 blocks
[2] = blocks
[1];
200 blocks
[1] = blocks
[0];
201 blocks
[0] = &this->kernel
->player
->queue
.buffer
[block_index
];
202 if( blocks
[1] == NULL
){ continue; }
203 blocks
[1]->reverse_pass(blocks
[2], blocks
[0]);
208 // Planner::recalculate() needs to go over the current plan twice. Once in reverse and once forward. This
209 // implements the forward pass.
210 void Planner::forward_pass() {
212 int block_index
= this->kernel
->player
->queue
.head
;
213 Block
* blocks
[3] = {NULL
,NULL
,NULL
};
215 while(block_index
!=this->kernel
->player
->queue
.tail
){
216 blocks
[0] = blocks
[1];
217 blocks
[1] = blocks
[2];
218 blocks
[2] = &this->kernel
->player
->queue
.buffer
[block_index
];
219 if( blocks
[0] == NULL
){ continue; }
220 blocks
[1]->forward_pass(blocks
[0],blocks
[2]);
221 block_index
= this->kernel
->player
->queue
.next_block_index( block_index
);
223 blocks
[2]->forward_pass(blocks
[1],NULL
);
227 // Recalculates the trapezoid speed profiles for flagged blocks in the plan according to the
228 // entry_speed for each junction and the entry_speed of the next junction. Must be called by
229 // planner_recalculate() after updating the blocks. Any recalulate flagged junction will
230 // compute the two adjacent trapezoids to the junction, since the junction speed corresponds
231 // to exit speed and entry speed of one another.
232 void Planner::recalculate_trapezoids() {
233 int block_index
= this->kernel
->player
->queue
.head
;
237 while(block_index
!= this->kernel
->player
->queue
.tail
){
239 next
= &this->kernel
->player
->queue
.buffer
[block_index
];
240 //this->kernel->streams->printf("index:%d current:%p next:%p \r\n", block_index, current, next );
242 // Recalculate if current block entry or exit junction speed has changed.
243 if( current
->recalculate_flag
|| next
->recalculate_flag
){
244 current
->calculate_trapezoid( current
->entry_speed
/current
->nominal_speed
, next
->entry_speed
/current
->nominal_speed
);
245 current
->recalculate_flag
= false;
248 block_index
= this->kernel
->player
->queue
.next_block_index( block_index
);
251 // Last/newest block in buffer. Exit speed is set with MINIMUM_PLANNER_SPEED. Always recalculated.
252 next
->calculate_trapezoid( next
->entry_speed
/next
->nominal_speed
, MINIMUM_PLANNER_SPEED
/next
->nominal_speed
); //TODO: Make configuration option
253 next
->recalculate_flag
= false;
258 void Planner::dump_queue(){
259 for( int index
= 0; index
<= this->kernel
->player
->queue
.size()-1; index
++ ){
260 if( index
> 10 && index
< this->kernel
->player
->queue
.size()-10 ){ continue; }
261 this->kernel
->streams
->printf("block %03d > ", index
);
262 this->kernel
->player
->queue
.get_ref(index
)->debug(this->kernel
);
266 // Calculates the maximum allowable speed at this point when you must be able to reach target_velocity using the
267 // acceleration within the allotted distance.
268 double Planner::max_allowable_speed(double acceleration
, double target_velocity
, double distance
) {
270 //sqrt(target_velocity*target_velocity-2L*acceleration*60*60*distance) //Was acceleration*60*60*distance, in case this breaks, but here we prefer to use seconds instead of minutes
271 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