Commit | Line | Data |
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df27a6a3 | 1 | /* |
5886a464 | 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) |
4cff3ded AW |
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. | |
df27a6a3 | 5 | You should have received a copy of the GNU General Public License along with Smoothie. If not, see <http://www.gnu.org/licenses/>. |
4cff3ded AW |
6 | */ |
7 | ||
8 | using namespace std; | |
9 | #include <vector> | |
4dc5513d MM |
10 | |
11 | #include "mri.h" | |
12 | #include "nuts_bolts.h" | |
13 | #include "RingBuffer.h" | |
14 | #include "Gcode.h" | |
15 | #include "Module.h" | |
16 | #include "Kernel.h" | |
4cff3ded AW |
17 | #include "Block.h" |
18 | #include "Planner.h" | |
3fceb8eb | 19 | #include "Conveyor.h" |
b66fb830 | 20 | |
8b69c90d JM |
21 | #define acceleration_checksum CHECKSUM("acceleration") |
22 | #define max_jerk_checksum CHECKSUM("max_jerk") | |
23 | #define junction_deviation_checksum CHECKSUM("junction_deviation") | |
24 | #define minimum_planner_speed_checksum CHECKSUM("minimum_planner_speed") | |
25 | ||
edac9072 AW |
26 | // The Planner does the acceleration math for the queue of Blocks ( movements ). |
27 | // It makes sure the speed stays within the configured constraints ( acceleration, junction_deviation, etc ) | |
28 | // It goes over the list in both direction, every time a block is added, re-doing the math to make sure everything is optimal | |
4cff3ded AW |
29 | |
30 | Planner::Planner(){ | |
1cf31736 | 31 | clear_vector_float(this->previous_unit_vec); |
4cff3ded AW |
32 | this->has_deleted_block = false; |
33 | } | |
34 | ||
35 | void Planner::on_module_loaded(){ | |
476dcb96 | 36 | register_for_event(ON_CONFIG_RELOAD); |
da24d6ae AW |
37 | this->on_config_reload(this); |
38 | } | |
39 | ||
edac9072 | 40 | // Configure acceleration |
da24d6ae | 41 | void Planner::on_config_reload(void* argument){ |
da947c62 MM |
42 | 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 |
43 | this->junction_deviation = THEKERNEL->config->value(junction_deviation_checksum )->by_default( 0.05F)->as_number(); | |
8b69c90d | 44 | this->minimum_planner_speed = THEKERNEL->config->value(minimum_planner_speed_checksum )->by_default(0.0f)->as_number(); |
4cff3ded AW |
45 | } |
46 | ||
da24d6ae | 47 | |
4cff3ded | 48 | // Append a block to the queue, compute it's speed factors |
da947c62 MM |
49 | void Planner::append_block( float actuator_pos[], float rate_mm_s, float distance, float unit_vec[] ) |
50 | { | |
edac9072 | 51 | // Create ( recycle ) a new block |
2134bcf2 | 52 | Block* block = THEKERNEL->conveyor->queue.head_ref(); |
aab6cbba AW |
53 | |
54 | // Direction bits | |
df27a6a3 | 55 | block->direction_bits = 0; |
78d0e16a MM |
56 | for (int i = 0; i < 3; i++) |
57 | { | |
58 | int steps = THEKERNEL->robot->actuators[i]->steps_to_target(actuator_pos[i]); | |
1cf31736 | 59 | |
78d0e16a MM |
60 | if (steps < 0) |
61 | block->direction_bits |= (1<<i); | |
62 | ||
338beb48 | 63 | // Update current position |
b2881caa | 64 | THEKERNEL->robot->actuators[i]->last_milestone_steps += steps; |
338beb48 MM |
65 | THEKERNEL->robot->actuators[i]->last_milestone_mm = actuator_pos[i]; |
66 | ||
78d0e16a MM |
67 | block->steps[i] = labs(steps); |
68 | } | |
1cf31736 | 69 | |
4cff3ded AW |
70 | // Max number of steps, for all axes |
71 | block->steps_event_count = max( block->steps[ALPHA_STEPPER], max( block->steps[BETA_STEPPER], block->steps[GAMMA_STEPPER] ) ); | |
72 | ||
4cff3ded | 73 | block->millimeters = distance; |
aab6cbba AW |
74 | |
75 | // Calculate speed in mm/minute for each axis. No divide by zero due to previous checks. | |
76 | // NOTE: Minimum stepper speed is limited by MINIMUM_STEPS_PER_MINUTE in stepper.c | |
130275f1 | 77 | if( distance > 0.0F ){ |
da947c62 MM |
78 | block->nominal_speed = rate_mm_s; // (mm/s) Always > 0 |
79 | block->nominal_rate = ceil(block->steps_event_count * rate_mm_s / distance); // (step/s) Always > 0 | |
436a2cd1 | 80 | }else{ |
130275f1 MM |
81 | block->nominal_speed = 0.0F; |
82 | block->nominal_rate = 0; | |
436a2cd1 | 83 | } |
aab6cbba | 84 | |
4cff3ded AW |
85 | // Compute the acceleration rate for the trapezoid generator. Depending on the slope of the line |
86 | // average travel per step event changes. For a line along one axis the travel per step event | |
87 | // is equal to the travel/step in the particular axis. For a 45 degree line the steppers of both | |
88 | // axes might step for every step event. Travel per step event is then sqrt(travel_x^2+travel_y^2). | |
89 | // To generate trapezoids with contant acceleration between blocks the rate_delta must be computed | |
90 | // specifically for each line to compensate for this phenomenon: | |
aab6cbba | 91 | // Convert universal acceleration for direction-dependent stepper rate change parameter |
da947c62 | 92 | block->rate_delta = (block->steps_event_count * acceleration) / (distance * THEKERNEL->stepper->acceleration_ticks_per_second); // (step/min/acceleration_tick) |
1cf31736 | 93 | |
aab6cbba AW |
94 | // Compute maximum allowable entry speed at junction by centripetal acceleration approximation. |
95 | // Let a circle be tangent to both previous and current path line segments, where the junction | |
96 | // deviation is defined as the distance from the junction to the closest edge of the circle, | |
97 | // colinear with the circle center. The circular segment joining the two paths represents the | |
98 | // path of centripetal acceleration. Solve for max velocity based on max acceleration about the | |
99 | // radius of the circle, defined indirectly by junction deviation. This may be also viewed as | |
100 | // path width or max_jerk in the previous grbl version. This approach does not actually deviate | |
101 | // from path, but used as a robust way to compute cornering speeds, as it takes into account the | |
102 | // nonlinearities of both the junction angle and junction velocity. | |
8b69c90d | 103 | float vmax_junction = minimum_planner_speed; // Set default max junction speed |
aab6cbba | 104 | |
e75b3def MM |
105 | if (!THEKERNEL->conveyor->queue.is_empty()) |
106 | { | |
107 | float previous_nominal_speed = THEKERNEL->conveyor->queue.item_ref(THEKERNEL->conveyor->queue.prev(THEKERNEL->conveyor->queue.head_i))->nominal_speed; | |
108 | ||
109 | if (previous_nominal_speed > 0.0F) { | |
110 | // Compute cosine of angle between previous and current path. (prev_unit_vec is negative) | |
111 | // NOTE: Max junction velocity is computed without sin() or acos() by trig half angle identity. | |
112 | float cos_theta = - this->previous_unit_vec[X_AXIS] * unit_vec[X_AXIS] | |
113 | - this->previous_unit_vec[Y_AXIS] * unit_vec[Y_AXIS] | |
114 | - this->previous_unit_vec[Z_AXIS] * unit_vec[Z_AXIS] ; | |
115 | ||
116 | // Skip and use default max junction speed for 0 degree acute junction. | |
117 | if (cos_theta < 0.95F) { | |
118 | vmax_junction = min(previous_nominal_speed, block->nominal_speed); | |
119 | // Skip and avoid divide by zero for straight junctions at 180 degrees. Limit to min() of nominal speeds. | |
120 | if (cos_theta > -0.95F) { | |
121 | // Compute maximum junction velocity based on maximum acceleration and junction deviation | |
122 | float sin_theta_d2 = sqrtf(0.5F * (1.0F - cos_theta)); // Trig half angle identity. Always positive. | |
123 | vmax_junction = min(vmax_junction, sqrtf(this->acceleration * this->junction_deviation * sin_theta_d2 / (1.0F - sin_theta_d2))); | |
124 | } | |
125 | } | |
aab6cbba | 126 | } |
4cff3ded | 127 | } |
aab6cbba | 128 | block->max_entry_speed = vmax_junction; |
1cf31736 | 129 | |
8b69c90d | 130 | // Initialize block entry speed. Compute based on deceleration to user-defined minimum_planner_speed. |
da947c62 | 131 | float v_allowable = max_allowable_speed(-acceleration, minimum_planner_speed, block->millimeters); //TODO: Get from config |
aab6cbba AW |
132 | block->entry_speed = min(vmax_junction, v_allowable); |
133 | ||
134 | // Initialize planner efficiency flags | |
135 | // Set flag if block will always reach maximum junction speed regardless of entry/exit speeds. | |
136 | // If a block can de/ac-celerate from nominal speed to zero within the length of the block, then | |
137 | // the current block and next block junction speeds are guaranteed to always be at their maximum | |
138 | // junction speeds in deceleration and acceleration, respectively. This is due to how the current | |
139 | // block nominal speed limits both the current and next maximum junction speeds. Hence, in both | |
140 | // the reverse and forward planners, the corresponding block junction speed will always be at the | |
141 | // the maximum junction speed and may always be ignored for any speed reduction checks. | |
142 | if (block->nominal_speed <= v_allowable) { block->nominal_length_flag = true; } | |
143 | else { block->nominal_length_flag = false; } | |
2134bcf2 MM |
144 | |
145 | // Always calculate trapezoid for new block | |
146 | block->recalculate_flag = true; | |
1cf31736 | 147 | |
aab6cbba | 148 | // Update previous path unit_vector and nominal speed |
3a425ecb | 149 | memcpy(this->previous_unit_vec, unit_vec, sizeof(previous_unit_vec)); // previous_unit_vec[] = unit_vec[] |
1cf31736 | 150 | |
df27a6a3 | 151 | // Math-heavy re-computing of the whole queue to take the new |
4cff3ded | 152 | this->recalculate(); |
1cf31736 | 153 | |
df27a6a3 | 154 | // The block can now be used |
3a4fa0c1 | 155 | block->ready(); |
2134bcf2 MM |
156 | |
157 | THEKERNEL->conveyor->queue_head_block(); | |
4cff3ded AW |
158 | } |
159 | ||
160 | ||
161 | // Recalculates the motion plan according to the following algorithm: | |
162 | // | |
163 | // 1. Go over every block in reverse order and calculate a junction speed reduction (i.e. block_t.entry_factor) | |
164 | // so that: | |
165 | // a. The junction jerk is within the set limit | |
166 | // b. No speed reduction within one block requires faster deceleration than the one, true constant | |
167 | // acceleration. | |
168 | // 2. Go over every block in chronological order and dial down junction speed reduction values if | |
169 | // a. The speed increase within one block would require faster accelleration than the one, true | |
170 | // constant acceleration. | |
171 | // | |
172 | // When these stages are complete all blocks have an entry_factor that will allow all speed changes to | |
173 | // be performed using only the one, true constant acceleration, and where no junction jerk is jerkier than | |
174 | // the set limit. Finally it will: | |
175 | // | |
176 | // 3. Recalculate trapezoids for all blocks. | |
177 | // | |
178 | void Planner::recalculate() { | |
a617ac35 | 179 | Conveyor::Queue_t &queue = THEKERNEL->conveyor->queue; |
4dc5513d | 180 | |
a617ac35 | 181 | unsigned int block_index; |
4cff3ded | 182 | |
391bc610 MM |
183 | Block* previous; |
184 | Block* current; | |
391bc610 | 185 | |
a617ac35 MM |
186 | /* |
187 | * a newly added block is decel limited | |
188 | * | |
189 | * we find its max entry speed given its exit speed | |
190 | * | |
d30d9611 MM |
191 | * for each block, walking backwards in the queue: |
192 | * | |
a617ac35 MM |
193 | * if max entry speed == current entry speed |
194 | * then we can set recalculate to false, since clearly adding another block didn't allow us to enter faster | |
d30d9611 MM |
195 | * and thus we don't need to check entry speed for this block any more |
196 | * | |
197 | * once we find an accel limited block, we must find the max exit speed and walk the queue forwards | |
a617ac35 | 198 | * |
d30d9611 | 199 | * for each block, walking forwards in the queue: |
a617ac35 MM |
200 | * |
201 | * given the exit speed of the previous block and our own max entry speed | |
202 | * we can tell if we're accel or decel limited (or coasting) | |
203 | * | |
204 | * if prev_exit > max_entry | |
d30d9611 | 205 | * then we're still decel limited. update previous trapezoid with our max entry for prev exit |
a617ac35 | 206 | * if max_entry >= prev_exit |
d30d9611 | 207 | * then we're accel limited. set recalculate to false, work out max exit speed |
a617ac35 | 208 | * |
d30d9611 | 209 | * finally, work out trapezoid for the final (and newest) block. |
a617ac35 MM |
210 | */ |
211 | ||
212 | /* | |
213 | * Step 1: | |
214 | * For each block, given the exit speed and acceleration, find the maximum entry speed | |
215 | */ | |
216 | ||
217 | float entry_speed = minimum_planner_speed; | |
218 | ||
219 | block_index = queue.head_i; | |
220 | current = queue.item_ref(block_index); | |
221 | ||
222 | if (!queue.is_empty()) | |
391bc610 | 223 | { |
a617ac35 | 224 | while ((block_index != queue.tail_i) && current->recalculate_flag) |
391bc610 | 225 | { |
a617ac35 | 226 | entry_speed = current->reverse_pass(entry_speed); |
391bc610 | 227 | |
a617ac35 MM |
228 | block_index = queue.prev(block_index); |
229 | current = queue.item_ref(block_index); | |
2134bcf2 | 230 | } |
13e4a3f9 | 231 | |
d30d9611 MM |
232 | /* |
233 | * Step 2: | |
234 | * now current points to either tail or first non-recalculate block | |
235 | * and has not had its reverse_pass called | |
236 | * or its calc trap | |
237 | * entry_speed is set to the *exit* speed of current. | |
238 | * each block from current to head has its entry speed set to its max entry speed- limited by decel or nominal_rate | |
239 | */ | |
2134bcf2 | 240 | |
a617ac35 | 241 | float exit_speed = current->max_exit_speed(); |
4cff3ded | 242 | |
a617ac35 MM |
243 | while (block_index != queue.head_i) |
244 | { | |
245 | previous = current; | |
246 | block_index = queue.next(block_index); | |
247 | current = queue.item_ref(block_index); | |
248 | ||
249 | // we pass the exit speed of the previous block | |
250 | // so this block can decide if it's accel or decel limited and update its fields as appropriate | |
251 | exit_speed = current->forward_pass(exit_speed); | |
2134bcf2 | 252 | |
a617ac35 MM |
253 | previous->calculate_trapezoid(previous->entry_speed, current->entry_speed); |
254 | } | |
4cff3ded | 255 | } |
a617ac35 | 256 | |
d30d9611 MM |
257 | /* |
258 | * Step 3: | |
259 | * work out trapezoid for final (and newest) block | |
260 | */ | |
261 | ||
a617ac35 MM |
262 | // now current points to the head item |
263 | // which has not had calculate_trapezoid run yet | |
264 | current->calculate_trapezoid(current->entry_speed, minimum_planner_speed); | |
4cff3ded | 265 | } |
aab6cbba | 266 | |
a617ac35 | 267 | |
aab6cbba AW |
268 | // Calculates the maximum allowable speed at this point when you must be able to reach target_velocity using the |
269 | // acceleration within the allotted distance. | |
1ad23cd3 | 270 | float Planner::max_allowable_speed(float acceleration, float target_velocity, float distance) { |
aab6cbba | 271 | return( |
95b4885b | 272 | 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 |
aab6cbba AW |
273 | ); |
274 | } | |
275 | ||
276 |