klipper-dgus/klippy/toolhead.py

601 lines
27 KiB
Python

# Code for coordinating events on the printer toolhead
#
# Copyright (C) 2016-2021 Kevin O'Connor <kevin@koconnor.net>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import math, logging, importlib
import mcu, chelper, kinematics.extruder
# Common suffixes: _d is distance (in mm), _v is velocity (in
# mm/second), _v2 is velocity squared (mm^2/s^2), _t is time (in
# seconds), _r is ratio (scalar between 0.0 and 1.0)
# Class to track each move request
class Move:
def __init__(self, toolhead, start_pos, end_pos, speed):
self.toolhead = toolhead
self.start_pos = tuple(start_pos)
self.end_pos = tuple(end_pos)
self.accel = toolhead.max_accel
self.timing_callbacks = []
velocity = min(speed, toolhead.max_velocity)
self.is_kinematic_move = True
self.axes_d = axes_d = [end_pos[i] - start_pos[i] for i in (0, 1, 2, 3)]
self.move_d = move_d = math.sqrt(sum([d*d for d in axes_d[:3]]))
if move_d < .000000001:
# Extrude only move
self.end_pos = (start_pos[0], start_pos[1], start_pos[2],
end_pos[3])
axes_d[0] = axes_d[1] = axes_d[2] = 0.
self.move_d = move_d = abs(axes_d[3])
inv_move_d = 0.
if move_d:
inv_move_d = 1. / move_d
self.accel = 99999999.9
velocity = speed
self.is_kinematic_move = False
else:
inv_move_d = 1. / move_d
self.axes_r = [d * inv_move_d for d in axes_d]
self.min_move_t = move_d / velocity
# Junction speeds are tracked in velocity squared. The
# delta_v2 is the maximum amount of this squared-velocity that
# can change in this move.
self.max_start_v2 = 0.
self.max_cruise_v2 = velocity**2
self.delta_v2 = 2.0 * move_d * self.accel
self.max_smoothed_v2 = 0.
self.smooth_delta_v2 = 2.0 * move_d * toolhead.max_accel_to_decel
def limit_speed(self, speed, accel):
speed2 = speed**2
if speed2 < self.max_cruise_v2:
self.max_cruise_v2 = speed2
self.min_move_t = self.move_d / speed
self.accel = min(self.accel, accel)
self.delta_v2 = 2.0 * self.move_d * self.accel
self.smooth_delta_v2 = min(self.smooth_delta_v2, self.delta_v2)
def move_error(self, msg="Move out of range"):
ep = self.end_pos
m = "%s: %.3f %.3f %.3f [%.3f]" % (msg, ep[0], ep[1], ep[2], ep[3])
return self.toolhead.printer.command_error(m)
def calc_junction(self, prev_move):
if not self.is_kinematic_move or not prev_move.is_kinematic_move:
return
# Allow extruder to calculate its maximum junction
extruder_v2 = self.toolhead.extruder.calc_junction(prev_move, self)
# Find max velocity using "approximated centripetal velocity"
axes_r = self.axes_r
prev_axes_r = prev_move.axes_r
junction_cos_theta = -(axes_r[0] * prev_axes_r[0]
+ axes_r[1] * prev_axes_r[1]
+ axes_r[2] * prev_axes_r[2])
if junction_cos_theta > 0.999999:
return
junction_cos_theta = max(junction_cos_theta, -0.999999)
sin_theta_d2 = math.sqrt(0.5*(1.0-junction_cos_theta))
R = (self.toolhead.junction_deviation * sin_theta_d2
/ (1. - sin_theta_d2))
# Approximated circle must contact moves no further away than mid-move
tan_theta_d2 = sin_theta_d2 / math.sqrt(0.5*(1.0+junction_cos_theta))
move_centripetal_v2 = .5 * self.move_d * tan_theta_d2 * self.accel
prev_move_centripetal_v2 = (.5 * prev_move.move_d * tan_theta_d2
* prev_move.accel)
# Apply limits
self.max_start_v2 = min(
R * self.accel, R * prev_move.accel,
move_centripetal_v2, prev_move_centripetal_v2,
extruder_v2, self.max_cruise_v2, prev_move.max_cruise_v2,
prev_move.max_start_v2 + prev_move.delta_v2)
self.max_smoothed_v2 = min(
self.max_start_v2
, prev_move.max_smoothed_v2 + prev_move.smooth_delta_v2)
def set_junction(self, start_v2, cruise_v2, end_v2):
# Determine accel, cruise, and decel portions of the move distance
half_inv_accel = .5 / self.accel
accel_d = (cruise_v2 - start_v2) * half_inv_accel
decel_d = (cruise_v2 - end_v2) * half_inv_accel
cruise_d = self.move_d - accel_d - decel_d
# Determine move velocities
self.start_v = start_v = math.sqrt(start_v2)
self.cruise_v = cruise_v = math.sqrt(cruise_v2)
self.end_v = end_v = math.sqrt(end_v2)
# Determine time spent in each portion of move (time is the
# distance divided by average velocity)
self.accel_t = accel_d / ((start_v + cruise_v) * 0.5)
self.cruise_t = cruise_d / cruise_v
self.decel_t = decel_d / ((end_v + cruise_v) * 0.5)
LOOKAHEAD_FLUSH_TIME = 0.250
# Class to track a list of pending move requests and to facilitate
# "look-ahead" across moves to reduce acceleration between moves.
class MoveQueue:
def __init__(self, toolhead):
self.toolhead = toolhead
self.queue = []
self.junction_flush = LOOKAHEAD_FLUSH_TIME
def reset(self):
del self.queue[:]
self.junction_flush = LOOKAHEAD_FLUSH_TIME
def set_flush_time(self, flush_time):
self.junction_flush = flush_time
def get_last(self):
if self.queue:
return self.queue[-1]
return None
def flush(self, lazy=False):
self.junction_flush = LOOKAHEAD_FLUSH_TIME
update_flush_count = lazy
queue = self.queue
flush_count = len(queue)
# Traverse queue from last to first move and determine maximum
# junction speed assuming the robot comes to a complete stop
# after the last move.
delayed = []
next_end_v2 = next_smoothed_v2 = peak_cruise_v2 = 0.
for i in range(flush_count-1, -1, -1):
move = queue[i]
reachable_start_v2 = next_end_v2 + move.delta_v2
start_v2 = min(move.max_start_v2, reachable_start_v2)
reachable_smoothed_v2 = next_smoothed_v2 + move.smooth_delta_v2
smoothed_v2 = min(move.max_smoothed_v2, reachable_smoothed_v2)
if smoothed_v2 < reachable_smoothed_v2:
# It's possible for this move to accelerate
if (smoothed_v2 + move.smooth_delta_v2 > next_smoothed_v2
or delayed):
# This move can decelerate or this is a full accel
# move after a full decel move
if update_flush_count and peak_cruise_v2:
flush_count = i
update_flush_count = False
peak_cruise_v2 = min(move.max_cruise_v2, (
smoothed_v2 + reachable_smoothed_v2) * .5)
if delayed:
# Propagate peak_cruise_v2 to any delayed moves
if not update_flush_count and i < flush_count:
mc_v2 = peak_cruise_v2
for m, ms_v2, me_v2 in reversed(delayed):
mc_v2 = min(mc_v2, ms_v2)
m.set_junction(min(ms_v2, mc_v2), mc_v2
, min(me_v2, mc_v2))
del delayed[:]
if not update_flush_count and i < flush_count:
cruise_v2 = min((start_v2 + reachable_start_v2) * .5
, move.max_cruise_v2, peak_cruise_v2)
move.set_junction(min(start_v2, cruise_v2), cruise_v2
, min(next_end_v2, cruise_v2))
else:
# Delay calculating this move until peak_cruise_v2 is known
delayed.append((move, start_v2, next_end_v2))
next_end_v2 = start_v2
next_smoothed_v2 = smoothed_v2
if update_flush_count or not flush_count:
return
# Generate step times for all moves ready to be flushed
self.toolhead._process_moves(queue[:flush_count])
# Remove processed moves from the queue
del queue[:flush_count]
def add_move(self, move):
self.queue.append(move)
if len(self.queue) == 1:
return
move.calc_junction(self.queue[-2])
self.junction_flush -= move.min_move_t
if self.junction_flush <= 0.:
# Enough moves have been queued to reach the target flush time.
self.flush(lazy=True)
MIN_KIN_TIME = 0.100
MOVE_BATCH_TIME = 0.500
SDS_CHECK_TIME = 0.001 # step+dir+step filter in stepcompress.c
DRIP_SEGMENT_TIME = 0.050
DRIP_TIME = 0.100
class DripModeEndSignal(Exception):
pass
# Main code to track events (and their timing) on the printer toolhead
class ToolHead:
def __init__(self, config):
self.printer = config.get_printer()
self.reactor = self.printer.get_reactor()
self.all_mcus = [
m for n, m in self.printer.lookup_objects(module='mcu')]
self.mcu = self.all_mcus[0]
self.can_pause = True
if self.mcu.is_fileoutput():
self.can_pause = False
self.move_queue = MoveQueue(self)
self.commanded_pos = [0., 0., 0., 0.]
self.printer.register_event_handler("klippy:shutdown",
self._handle_shutdown)
# Velocity and acceleration control
self.max_velocity = config.getfloat('max_velocity', above=0.)
self.max_accel = config.getfloat('max_accel', above=0.)
self.requested_accel_to_decel = config.getfloat(
'max_accel_to_decel', self.max_accel * 0.5, above=0.)
self.max_accel_to_decel = self.requested_accel_to_decel
self.square_corner_velocity = config.getfloat(
'square_corner_velocity', 5., minval=0.)
self.junction_deviation = 0.
self._calc_junction_deviation()
# Print time tracking
self.buffer_time_low = config.getfloat(
'buffer_time_low', 1.000, above=0.)
self.buffer_time_high = config.getfloat(
'buffer_time_high', 2.000, above=self.buffer_time_low)
self.buffer_time_start = config.getfloat(
'buffer_time_start', 0.250, above=0.)
self.move_flush_time = config.getfloat(
'move_flush_time', 0.050, above=0.)
self.print_time = 0.
self.special_queuing_state = "Flushed"
self.need_check_stall = -1.
self.flush_timer = self.reactor.register_timer(self._flush_handler)
self.move_queue.set_flush_time(self.buffer_time_high)
self.idle_flush_print_time = 0.
self.print_stall = 0
self.drip_completion = None
# Kinematic step generation scan window time tracking
self.kin_flush_delay = SDS_CHECK_TIME
self.kin_flush_times = []
self.last_kin_flush_time = self.last_kin_move_time = 0.
# Setup iterative solver
ffi_main, ffi_lib = chelper.get_ffi()
self.trapq = ffi_main.gc(ffi_lib.trapq_alloc(), ffi_lib.trapq_free)
self.trapq_append = ffi_lib.trapq_append
self.trapq_finalize_moves = ffi_lib.trapq_finalize_moves
self.step_generators = []
# Create kinematics class
gcode = self.printer.lookup_object('gcode')
self.Coord = gcode.Coord
self.extruder = kinematics.extruder.DummyExtruder(self.printer)
kin_name = config.get('kinematics')
try:
mod = importlib.import_module('kinematics.' + kin_name)
self.kin = mod.load_kinematics(self, config)
except config.error as e:
raise
except self.printer.lookup_object('pins').error as e:
raise
except:
msg = "Error loading kinematics '%s'" % (kin_name,)
logging.exception(msg)
raise config.error(msg)
# Register commands
gcode.register_command('G4', self.cmd_G4)
gcode.register_command('M400', self.cmd_M400)
gcode.register_command('SET_VELOCITY_LIMIT',
self.cmd_SET_VELOCITY_LIMIT,
desc=self.cmd_SET_VELOCITY_LIMIT_help)
gcode.register_command('M204', self.cmd_M204)
# Load some default modules
modules = ["gcode_move", "homing", "idle_timeout", "statistics",
"manual_probe", "tuning_tower"]
for module_name in modules:
self.printer.load_object(config, module_name)
# Print time tracking
def _update_move_time(self, next_print_time):
batch_time = MOVE_BATCH_TIME
kin_flush_delay = self.kin_flush_delay
lkft = self.last_kin_flush_time
while 1:
self.print_time = min(self.print_time + batch_time, next_print_time)
sg_flush_time = max(lkft, self.print_time - kin_flush_delay)
for sg in self.step_generators:
sg(sg_flush_time)
free_time = max(lkft, sg_flush_time - kin_flush_delay)
self.trapq_finalize_moves(self.trapq, free_time)
self.extruder.update_move_time(free_time)
mcu_flush_time = max(lkft, sg_flush_time - self.move_flush_time)
for m in self.all_mcus:
m.flush_moves(mcu_flush_time)
if self.print_time >= next_print_time:
break
def _calc_print_time(self):
curtime = self.reactor.monotonic()
est_print_time = self.mcu.estimated_print_time(curtime)
kin_time = max(est_print_time + MIN_KIN_TIME, self.last_kin_flush_time)
kin_time += self.kin_flush_delay
min_print_time = max(est_print_time + self.buffer_time_start, kin_time)
if min_print_time > self.print_time:
self.print_time = min_print_time
self.printer.send_event("toolhead:sync_print_time",
curtime, est_print_time, self.print_time)
def _process_moves(self, moves):
# Resync print_time if necessary
if self.special_queuing_state:
if self.special_queuing_state != "Drip":
# Transition from "Flushed"/"Priming" state to main state
self.special_queuing_state = ""
self.need_check_stall = -1.
self.reactor.update_timer(self.flush_timer, self.reactor.NOW)
self._calc_print_time()
# Queue moves into trapezoid motion queue (trapq)
next_move_time = self.print_time
for move in moves:
if move.is_kinematic_move:
self.trapq_append(
self.trapq, next_move_time,
move.accel_t, move.cruise_t, move.decel_t,
move.start_pos[0], move.start_pos[1], move.start_pos[2],
move.axes_r[0], move.axes_r[1], move.axes_r[2],
move.start_v, move.cruise_v, move.accel)
if move.axes_d[3]:
self.extruder.move(next_move_time, move)
next_move_time = (next_move_time + move.accel_t
+ move.cruise_t + move.decel_t)
for cb in move.timing_callbacks:
cb(next_move_time)
# Generate steps for moves
if self.special_queuing_state:
self._update_drip_move_time(next_move_time)
self._update_move_time(next_move_time)
self.last_kin_move_time = next_move_time
def flush_step_generation(self):
# Transition from "Flushed"/"Priming"/main state to "Flushed" state
self.move_queue.flush()
self.special_queuing_state = "Flushed"
self.need_check_stall = -1.
self.reactor.update_timer(self.flush_timer, self.reactor.NEVER)
self.move_queue.set_flush_time(self.buffer_time_high)
self.idle_flush_print_time = 0.
flush_time = self.last_kin_move_time + self.kin_flush_delay
flush_time = max(flush_time, self.print_time - self.kin_flush_delay)
self.last_kin_flush_time = max(self.last_kin_flush_time, flush_time)
self._update_move_time(max(self.print_time, self.last_kin_flush_time))
def _flush_lookahead(self):
if self.special_queuing_state:
return self.flush_step_generation()
self.move_queue.flush()
def get_last_move_time(self):
self._flush_lookahead()
if self.special_queuing_state:
self._calc_print_time()
return self.print_time
def _check_stall(self):
eventtime = self.reactor.monotonic()
if self.special_queuing_state:
if self.idle_flush_print_time:
# Was in "Flushed" state and got there from idle input
est_print_time = self.mcu.estimated_print_time(eventtime)
if est_print_time < self.idle_flush_print_time:
self.print_stall += 1
self.idle_flush_print_time = 0.
# Transition from "Flushed"/"Priming" state to "Priming" state
self.special_queuing_state = "Priming"
self.need_check_stall = -1.
self.reactor.update_timer(self.flush_timer, eventtime + 0.100)
# Check if there are lots of queued moves and stall if so
while 1:
est_print_time = self.mcu.estimated_print_time(eventtime)
buffer_time = self.print_time - est_print_time
stall_time = buffer_time - self.buffer_time_high
if stall_time <= 0.:
break
if not self.can_pause:
self.need_check_stall = self.reactor.NEVER
return
eventtime = self.reactor.pause(eventtime + min(1., stall_time))
if not self.special_queuing_state:
# In main state - defer stall checking until needed
self.need_check_stall = (est_print_time + self.buffer_time_high
+ 0.100)
def _flush_handler(self, eventtime):
try:
print_time = self.print_time
buffer_time = print_time - self.mcu.estimated_print_time(eventtime)
if buffer_time > self.buffer_time_low:
# Running normally - reschedule check
return eventtime + buffer_time - self.buffer_time_low
# Under ran low buffer mark - flush lookahead queue
self.flush_step_generation()
if print_time != self.print_time:
self.idle_flush_print_time = self.print_time
except:
logging.exception("Exception in flush_handler")
self.printer.invoke_shutdown("Exception in flush_handler")
return self.reactor.NEVER
# Movement commands
def get_position(self):
return list(self.commanded_pos)
def set_position(self, newpos, homing_axes=()):
self.flush_step_generation()
ffi_main, ffi_lib = chelper.get_ffi()
ffi_lib.trapq_set_position(self.trapq, self.print_time,
newpos[0], newpos[1], newpos[2])
self.commanded_pos[:] = newpos
self.kin.set_position(newpos, homing_axes)
self.printer.send_event("toolhead:set_position")
def move(self, newpos, speed):
move = Move(self, self.commanded_pos, newpos, speed)
if not move.move_d:
return
if move.is_kinematic_move:
self.kin.check_move(move)
if move.axes_d[3]:
self.extruder.check_move(move)
self.commanded_pos[:] = move.end_pos
self.move_queue.add_move(move)
if self.print_time > self.need_check_stall:
self._check_stall()
def manual_move(self, coord, speed):
curpos = list(self.commanded_pos)
for i in range(len(coord)):
if coord[i] is not None:
curpos[i] = coord[i]
self.move(curpos, speed)
self.printer.send_event("toolhead:manual_move")
def dwell(self, delay):
next_print_time = self.get_last_move_time() + max(0., delay)
self._update_move_time(next_print_time)
self._check_stall()
def wait_moves(self):
self._flush_lookahead()
eventtime = self.reactor.monotonic()
while (not self.special_queuing_state
or self.print_time >= self.mcu.estimated_print_time(eventtime)):
if not self.can_pause:
break
eventtime = self.reactor.pause(eventtime + 0.100)
def set_extruder(self, extruder, extrude_pos):
self.extruder = extruder
self.commanded_pos[3] = extrude_pos
def get_extruder(self):
return self.extruder
# Homing "drip move" handling
def _update_drip_move_time(self, next_print_time):
flush_delay = DRIP_TIME + self.move_flush_time + self.kin_flush_delay
while self.print_time < next_print_time:
if self.drip_completion.test():
raise DripModeEndSignal()
curtime = self.reactor.monotonic()
est_print_time = self.mcu.estimated_print_time(curtime)
wait_time = self.print_time - est_print_time - flush_delay
if wait_time > 0. and self.can_pause:
# Pause before sending more steps
self.drip_completion.wait(curtime + wait_time)
continue
npt = min(self.print_time + DRIP_SEGMENT_TIME, next_print_time)
self._update_move_time(npt)
def drip_move(self, newpos, speed, drip_completion):
self.dwell(self.kin_flush_delay)
# Transition from "Flushed"/"Priming"/main state to "Drip" state
self.move_queue.flush()
self.special_queuing_state = "Drip"
self.need_check_stall = self.reactor.NEVER
self.reactor.update_timer(self.flush_timer, self.reactor.NEVER)
self.move_queue.set_flush_time(self.buffer_time_high)
self.idle_flush_print_time = 0.
self.drip_completion = drip_completion
# Submit move
try:
self.move(newpos, speed)
except self.printer.command_error as e:
self.flush_step_generation()
raise
# Transmit move in "drip" mode
try:
self.move_queue.flush()
except DripModeEndSignal as e:
self.move_queue.reset()
self.trapq_finalize_moves(self.trapq, self.reactor.NEVER)
# Exit "Drip" state
self.flush_step_generation()
# Misc commands
def stats(self, eventtime):
for m in self.all_mcus:
m.check_active(self.print_time, eventtime)
buffer_time = self.print_time - self.mcu.estimated_print_time(eventtime)
is_active = buffer_time > -60. or not self.special_queuing_state
if self.special_queuing_state == "Drip":
buffer_time = 0.
return is_active, "print_time=%.3f buffer_time=%.3f print_stall=%d" % (
self.print_time, max(buffer_time, 0.), self.print_stall)
def check_busy(self, eventtime):
est_print_time = self.mcu.estimated_print_time(eventtime)
lookahead_empty = not self.move_queue.queue
return self.print_time, est_print_time, lookahead_empty
def get_status(self, eventtime):
print_time = self.print_time
estimated_print_time = self.mcu.estimated_print_time(eventtime)
res = dict(self.kin.get_status(eventtime))
res.update({ 'print_time': print_time,
'stalls': self.print_stall,
'estimated_print_time': estimated_print_time,
'extruder': self.extruder.get_name(),
'position': self.Coord(*self.commanded_pos),
'max_velocity': self.max_velocity,
'max_accel': self.max_accel,
'max_accel_to_decel': self.requested_accel_to_decel,
'square_corner_velocity': self.square_corner_velocity})
return res
def _handle_shutdown(self):
self.can_pause = False
self.move_queue.reset()
def get_kinematics(self):
return self.kin
def get_trapq(self):
return self.trapq
def register_step_generator(self, handler):
self.step_generators.append(handler)
def note_step_generation_scan_time(self, delay, old_delay=0.):
self.flush_step_generation()
cur_delay = self.kin_flush_delay
if old_delay:
self.kin_flush_times.pop(self.kin_flush_times.index(old_delay))
if delay:
self.kin_flush_times.append(delay)
new_delay = max(self.kin_flush_times + [SDS_CHECK_TIME])
self.kin_flush_delay = new_delay
def register_lookahead_callback(self, callback):
last_move = self.move_queue.get_last()
if last_move is None:
callback(self.get_last_move_time())
return
last_move.timing_callbacks.append(callback)
def note_kinematic_activity(self, kin_time):
self.last_kin_move_time = max(self.last_kin_move_time, kin_time)
def get_max_velocity(self):
return self.max_velocity, self.max_accel
def _calc_junction_deviation(self):
scv2 = self.square_corner_velocity**2
self.junction_deviation = scv2 * (math.sqrt(2.) - 1.) / self.max_accel
self.max_accel_to_decel = min(self.requested_accel_to_decel,
self.max_accel)
def cmd_G4(self, gcmd):
# Dwell
delay = gcmd.get_float('P', 0., minval=0.) / 1000.
self.dwell(delay)
def cmd_M400(self, gcmd):
# Wait for current moves to finish
self.wait_moves()
cmd_SET_VELOCITY_LIMIT_help = "Set printer velocity limits"
def cmd_SET_VELOCITY_LIMIT(self, gcmd):
max_velocity = gcmd.get_float('VELOCITY', None, above=0.)
max_accel = gcmd.get_float('ACCEL', None, above=0.)
square_corner_velocity = gcmd.get_float(
'SQUARE_CORNER_VELOCITY', None, minval=0.)
requested_accel_to_decel = gcmd.get_float(
'ACCEL_TO_DECEL', None, above=0.)
if max_velocity is not None:
self.max_velocity = max_velocity
if max_accel is not None:
self.max_accel = max_accel
if square_corner_velocity is not None:
self.square_corner_velocity = square_corner_velocity
if requested_accel_to_decel is not None:
self.requested_accel_to_decel = requested_accel_to_decel
self._calc_junction_deviation()
msg = ("max_velocity: %.6f\n"
"max_accel: %.6f\n"
"max_accel_to_decel: %.6f\n"
"square_corner_velocity: %.6f" % (
self.max_velocity, self.max_accel,
self.requested_accel_to_decel,
self.square_corner_velocity))
self.printer.set_rollover_info("toolhead", "toolhead: %s" % (msg,))
if (max_velocity is None and
max_accel is None and
square_corner_velocity is None and
requested_accel_to_decel is None):
gcmd.respond_info(msg, log=False)
def cmd_M204(self, gcmd):
# Use S for accel
accel = gcmd.get_float('S', None, above=0.)
if accel is None:
# Use minimum of P and T for accel
p = gcmd.get_float('P', None, above=0.)
t = gcmd.get_float('T', None, above=0.)
if p is None or t is None:
gcmd.respond_info('Invalid M204 command "%s"'
% (gcmd.get_commandline(),))
return
accel = min(p, t)
self.max_accel = accel
self._calc_junction_deviation()
def add_printer_objects(config):
config.get_printer().add_object('toolhead', ToolHead(config))
kinematics.extruder.add_printer_objects(config)