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" |
5673fe39 | 20 | #include "StepperMotor.h" |
61134a65 JM |
21 | #include "Config.h" |
22 | #include "checksumm.h" | |
23 | #include "Robot.h" | |
8d54c34c | 24 | #include "ConfigValue.h" |
61134a65 JM |
25 | |
26 | #include <math.h> | |
b66fb830 | 27 | |
8b69c90d | 28 | #define junction_deviation_checksum CHECKSUM("junction_deviation") |
44de6ef3 | 29 | #define z_junction_deviation_checksum CHECKSUM("z_junction_deviation") |
8b69c90d JM |
30 | #define minimum_planner_speed_checksum CHECKSUM("minimum_planner_speed") |
31 | ||
edac9072 AW |
32 | // The Planner does the acceleration math for the queue of Blocks ( movements ). |
33 | // It makes sure the speed stays within the configured constraints ( acceleration, junction_deviation, etc ) | |
34 | // 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 | 35 | |
1b5776bf JM |
36 | Planner::Planner() |
37 | { | |
29e809e0 | 38 | memset(this->previous_unit_vec, 0, sizeof this->previous_unit_vec); |
558e170c | 39 | config_load(); |
da24d6ae AW |
40 | } |
41 | ||
edac9072 | 42 | // Configure acceleration |
1b5776bf JM |
43 | void Planner::config_load() |
44 | { | |
44de6ef3 | 45 | this->junction_deviation = THEKERNEL->config->value(junction_deviation_checksum)->by_default(0.05F)->as_number(); |
29e809e0 | 46 | this->z_junction_deviation = THEKERNEL->config->value(z_junction_deviation_checksum)->by_default(NAN)->as_number(); // disabled by default |
c5fe1787 | 47 | this->minimum_planner_speed = THEKERNEL->config->value(minimum_planner_speed_checksum)->by_default(0.0f)->as_number(); |
4cff3ded AW |
48 | } |
49 | ||
da24d6ae | 50 | |
4cff3ded | 51 | // Append a block to the queue, compute it's speed factors |
29e809e0 | 52 | void Planner::append_block( ActuatorCoordinates &actuator_pos, float rate_mm_s, float distance, float *unit_vec, float acceleration) |
da947c62 | 53 | { |
29e809e0 | 54 | float junction_deviation; |
c5fe1787 | 55 | |
edac9072 | 56 | // Create ( recycle ) a new block |
2134bcf2 | 57 | Block* block = THEKERNEL->conveyor->queue.head_ref(); |
aab6cbba | 58 | |
c5fe1787 | 59 | |
aab6cbba | 60 | // Direction bits |
29e809e0 | 61 | for (size_t i = 0; i < THEROBOT->n_motors; i++) { |
c8bac202 | 62 | int steps = THEROBOT->actuators[i]->steps_to_target(actuator_pos[i]); |
1cf31736 | 63 | |
558e170c | 64 | block->direction_bits[i] = (steps < 0) ? 1 : 0; |
78d0e16a | 65 | |
338beb48 | 66 | // Update current position |
c8bac202 JM |
67 | THEROBOT->actuators[i]->last_milestone_steps += steps; |
68 | THEROBOT->actuators[i]->last_milestone_mm = actuator_pos[i]; | |
338beb48 | 69 | |
78d0e16a MM |
70 | block->steps[i] = labs(steps); |
71 | } | |
1cf31736 | 72 | |
1b5776bf | 73 | junction_deviation = this->junction_deviation; |
44de6ef3 | 74 | |
29e809e0 | 75 | // use either regular junction deviation or z specific |
44de6ef3 | 76 | if(block->steps[ALPHA_STEPPER] == 0 && block->steps[BETA_STEPPER] == 0) { |
c5fe1787 | 77 | // z only move |
29e809e0 | 78 | if(!isnan(this->z_junction_deviation)) junction_deviation = this->z_junction_deviation; |
c5fe1787 JM |
79 | } |
80 | ||
1b5776bf | 81 | block->acceleration = acceleration; // save in block |
4fdd2470 | 82 | |
4cff3ded | 83 | // Max number of steps, for all axes |
1b5776bf | 84 | uint32_t steps_event_count = 0; |
29e809e0 | 85 | for (size_t s = 0; s < THEROBOT->n_motors; s++) { |
807b9b57 | 86 | steps_event_count = std::max(steps_event_count, block->steps[s]); |
1b5776bf | 87 | } |
807b9b57 | 88 | block->steps_event_count = steps_event_count; |
4cff3ded | 89 | |
4cff3ded | 90 | block->millimeters = distance; |
aab6cbba | 91 | |
9db65137 | 92 | // Calculate speed in mm/sec for each axis. No divide by zero due to previous checks. |
1b5776bf | 93 | if( distance > 0.0F ) { |
da947c62 | 94 | block->nominal_speed = rate_mm_s; // (mm/s) Always > 0 |
1598a726 | 95 | block->nominal_rate = block->steps_event_count * rate_mm_s / distance; // (step/s) Always > 0 |
1b5776bf | 96 | } else { |
130275f1 MM |
97 | block->nominal_speed = 0.0F; |
98 | block->nominal_rate = 0; | |
436a2cd1 | 99 | } |
aab6cbba | 100 | |
4cff3ded AW |
101 | // Compute the acceleration rate for the trapezoid generator. Depending on the slope of the line |
102 | // average travel per step event changes. For a line along one axis the travel per step event | |
103 | // is equal to the travel/step in the particular axis. For a 45 degree line the steppers of both | |
104 | // axes might step for every step event. Travel per step event is then sqrt(travel_x^2+travel_y^2). | |
1cf31736 | 105 | |
aab6cbba AW |
106 | // Compute maximum allowable entry speed at junction by centripetal acceleration approximation. |
107 | // Let a circle be tangent to both previous and current path line segments, where the junction | |
108 | // deviation is defined as the distance from the junction to the closest edge of the circle, | |
109 | // colinear with the circle center. The circular segment joining the two paths represents the | |
110 | // path of centripetal acceleration. Solve for max velocity based on max acceleration about the | |
111 | // radius of the circle, defined indirectly by junction deviation. This may be also viewed as | |
112 | // path width or max_jerk in the previous grbl version. This approach does not actually deviate | |
113 | // from path, but used as a robust way to compute cornering speeds, as it takes into account the | |
114 | // nonlinearities of both the junction angle and junction velocity. | |
4dfd2dce JM |
115 | |
116 | // NOTE however it does not take into account independent axis, in most cartesian X and Y and Z are totally independent | |
117 | // and this allows one to stop with little to no decleration in many cases. This is particualrly bad on leadscrew based systems that will skip steps. | |
8b69c90d | 118 | float vmax_junction = minimum_planner_speed; // Set default max junction speed |
aab6cbba | 119 | |
29e809e0 JM |
120 | // if unit_vec was null then it was not a primary axis move so we skip the junction deviation stuff |
121 | if (unit_vec != nullptr && !THEKERNEL->conveyor->is_queue_empty()) { | |
e75b3def MM |
122 | float previous_nominal_speed = THEKERNEL->conveyor->queue.item_ref(THEKERNEL->conveyor->queue.prev(THEKERNEL->conveyor->queue.head_i))->nominal_speed; |
123 | ||
29e809e0 | 124 | if (junction_deviation > 0.0F && previous_nominal_speed > 0.0F) { |
e75b3def MM |
125 | // Compute cosine of angle between previous and current path. (prev_unit_vec is negative) |
126 | // NOTE: Max junction velocity is computed without sin() or acos() by trig half angle identity. | |
127 | float cos_theta = - this->previous_unit_vec[X_AXIS] * unit_vec[X_AXIS] | |
1b5776bf JM |
128 | - this->previous_unit_vec[Y_AXIS] * unit_vec[Y_AXIS] |
129 | - this->previous_unit_vec[Z_AXIS] * unit_vec[Z_AXIS] ; | |
e75b3def MM |
130 | |
131 | // Skip and use default max junction speed for 0 degree acute junction. | |
132 | if (cos_theta < 0.95F) { | |
29e809e0 | 133 | vmax_junction = std::min(previous_nominal_speed, block->nominal_speed); |
e75b3def MM |
134 | // Skip and avoid divide by zero for straight junctions at 180 degrees. Limit to min() of nominal speeds. |
135 | if (cos_theta > -0.95F) { | |
136 | // Compute maximum junction velocity based on maximum acceleration and junction deviation | |
137 | float sin_theta_d2 = sqrtf(0.5F * (1.0F - cos_theta)); // Trig half angle identity. Always positive. | |
29e809e0 | 138 | vmax_junction = std::min(vmax_junction, sqrtf(acceleration * junction_deviation * sin_theta_d2 / (1.0F - sin_theta_d2))); |
e75b3def MM |
139 | } |
140 | } | |
aab6cbba | 141 | } |
4cff3ded | 142 | } |
aab6cbba | 143 | block->max_entry_speed = vmax_junction; |
1cf31736 | 144 | |
8b69c90d | 145 | // Initialize block entry speed. Compute based on deceleration to user-defined minimum_planner_speed. |
c9cc5e06 | 146 | float v_allowable = max_allowable_speed(-acceleration, minimum_planner_speed, block->millimeters); |
29e809e0 | 147 | block->entry_speed = std::min(vmax_junction, v_allowable); |
aab6cbba AW |
148 | |
149 | // Initialize planner efficiency flags | |
150 | // Set flag if block will always reach maximum junction speed regardless of entry/exit speeds. | |
151 | // If a block can de/ac-celerate from nominal speed to zero within the length of the block, then | |
152 | // the current block and next block junction speeds are guaranteed to always be at their maximum | |
153 | // junction speeds in deceleration and acceleration, respectively. This is due to how the current | |
154 | // block nominal speed limits both the current and next maximum junction speeds. Hence, in both | |
155 | // the reverse and forward planners, the corresponding block junction speed will always be at the | |
156 | // the maximum junction speed and may always be ignored for any speed reduction checks. | |
157 | if (block->nominal_speed <= v_allowable) { block->nominal_length_flag = true; } | |
158 | else { block->nominal_length_flag = false; } | |
2134bcf2 MM |
159 | |
160 | // Always calculate trapezoid for new block | |
161 | block->recalculate_flag = true; | |
1cf31736 | 162 | |
aab6cbba | 163 | // Update previous path unit_vector and nominal speed |
c8bac202 JM |
164 | if(unit_vec != nullptr) { |
165 | memcpy(this->previous_unit_vec, unit_vec, sizeof(previous_unit_vec)); // previous_unit_vec[] = unit_vec[] | |
166 | }else{ | |
29e809e0 | 167 | memset(this->previous_unit_vec, 0, sizeof this->previous_unit_vec); |
c8bac202 | 168 | } |
1cf31736 | 169 | |
df27a6a3 | 170 | // Math-heavy re-computing of the whole queue to take the new |
4cff3ded | 171 | this->recalculate(); |
1cf31736 | 172 | |
df27a6a3 | 173 | // The block can now be used |
433d636f | 174 | block->ready(); |
2134bcf2 MM |
175 | |
176 | THEKERNEL->conveyor->queue_head_block(); | |
4cff3ded AW |
177 | } |
178 | ||
1b5776bf JM |
179 | void Planner::recalculate() |
180 | { | |
a617ac35 | 181 | Conveyor::Queue_t &queue = THEKERNEL->conveyor->queue; |
4dc5513d | 182 | |
a617ac35 | 183 | unsigned int block_index; |
4cff3ded | 184 | |
391bc610 MM |
185 | Block* previous; |
186 | Block* current; | |
391bc610 | 187 | |
a617ac35 MM |
188 | /* |
189 | * a newly added block is decel limited | |
190 | * | |
191 | * we find its max entry speed given its exit speed | |
192 | * | |
d30d9611 MM |
193 | * for each block, walking backwards in the queue: |
194 | * | |
a617ac35 MM |
195 | * if max entry speed == current entry speed |
196 | * then we can set recalculate to false, since clearly adding another block didn't allow us to enter faster | |
d30d9611 MM |
197 | * and thus we don't need to check entry speed for this block any more |
198 | * | |
199 | * once we find an accel limited block, we must find the max exit speed and walk the queue forwards | |
a617ac35 | 200 | * |
d30d9611 | 201 | * for each block, walking forwards in the queue: |
a617ac35 MM |
202 | * |
203 | * given the exit speed of the previous block and our own max entry speed | |
204 | * we can tell if we're accel or decel limited (or coasting) | |
205 | * | |
206 | * if prev_exit > max_entry | |
d30d9611 | 207 | * then we're still decel limited. update previous trapezoid with our max entry for prev exit |
a617ac35 | 208 | * if max_entry >= prev_exit |
d30d9611 | 209 | * then we're accel limited. set recalculate to false, work out max exit speed |
a617ac35 | 210 | * |
d30d9611 | 211 | * finally, work out trapezoid for the final (and newest) block. |
a617ac35 MM |
212 | */ |
213 | ||
214 | /* | |
215 | * Step 1: | |
216 | * For each block, given the exit speed and acceleration, find the maximum entry speed | |
217 | */ | |
218 | ||
219 | float entry_speed = minimum_planner_speed; | |
220 | ||
221 | block_index = queue.head_i; | |
222 | current = queue.item_ref(block_index); | |
223 | ||
1b5776bf JM |
224 | if (!queue.is_empty()) { |
225 | while ((block_index != queue.tail_i) && current->recalculate_flag) { | |
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 | |
121844b7 | 236 | * or its calculate_trapezoid |
d30d9611 MM |
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 | |
1b5776bf | 243 | while (block_index != queue.head_i) { |
a617ac35 MM |
244 | previous = current; |
245 | block_index = queue.next(block_index); | |
246 | current = queue.item_ref(block_index); | |
247 | ||
248 | // we pass the exit speed of the previous block | |
249 | // so this block can decide if it's accel or decel limited and update its fields as appropriate | |
250 | exit_speed = current->forward_pass(exit_speed); | |
2134bcf2 | 251 | |
a617ac35 MM |
252 | previous->calculate_trapezoid(previous->entry_speed, current->entry_speed); |
253 | } | |
4cff3ded | 254 | } |
a617ac35 | 255 | |
d30d9611 MM |
256 | /* |
257 | * Step 3: | |
258 | * work out trapezoid for final (and newest) block | |
259 | */ | |
260 | ||
a617ac35 MM |
261 | // now current points to the head item |
262 | // which has not had calculate_trapezoid run yet | |
263 | current->calculate_trapezoid(current->entry_speed, minimum_planner_speed); | |
4cff3ded | 264 | } |
aab6cbba | 265 | |
a617ac35 | 266 | |
aab6cbba AW |
267 | // Calculates the maximum allowable speed at this point when you must be able to reach target_velocity using the |
268 | // acceleration within the allotted distance. | |
1b5776bf JM |
269 | float Planner::max_allowable_speed(float acceleration, float target_velocity, float distance) |
270 | { | |
1598a726 JM |
271 | // Was acceleration*60*60*distance, in case this breaks, but here we prefer to use seconds instead of minutes |
272 | return(sqrtf(target_velocity * target_velocity - 2.0F * acceleration * distance)); | |
aab6cbba AW |
273 | } |
274 | ||
275 |