klipper/klippy/kinematics/polar.py

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# Code for handling the kinematics of polar robots
#
# Copyright (C) 2018-2021 Kevin O'Connor <kevin@koconnor.net>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import logging, math
import stepper
class PolarKinematics:
def __init__(self, toolhead, config):
# Setup axis steppers
stepper_bed = stepper.PrinterStepper(config.getsection('stepper_bed'),
units_in_radians=True)
rail_arm = stepper.PrinterRail(config.getsection('stepper_arm'))
rail_z = stepper.LookupMultiRail(config.getsection('stepper_z'))
stepper_bed.setup_itersolve('polar_stepper_alloc', 'a')
rail_arm.setup_itersolve('polar_stepper_alloc', 'r')
rail_z.setup_itersolve('cartesian_stepper_alloc', 'z')
self.rails = [rail_arm, rail_z]
self.steppers = [stepper_bed] + [ s for r in self.rails
for s in r.get_steppers() ]
for s in self.get_steppers():
s.set_trapq(toolhead.get_trapq())
toolhead.register_step_generator(s.generate_steps)
config.get_printer().register_event_handler("stepper_enable:motor_off",
self._motor_off)
# Setup boundary checks
max_velocity, max_accel = toolhead.get_max_velocity()
self.max_z_velocity = config.getfloat(
'max_z_velocity', max_velocity, above=0., maxval=max_velocity)
self.max_z_accel = config.getfloat(
'max_z_accel', max_accel, above=0., maxval=max_accel)
self.limit_z = (1.0, -1.0)
self.limit_xy2 = -1.
max_xy = self.rails[0].get_range()[1]
min_z, max_z = self.rails[1].get_range()
self.axes_min = toolhead.Coord(-max_xy, -max_xy, min_z, 0.)
self.axes_max = toolhead.Coord(max_xy, max_xy, max_z, 0.)
def get_steppers(self):
return list(self.steppers)
def calc_tag_position(self):
bed_angle = self.steppers[0].get_tag_position()
arm_pos = self.rails[0].get_tag_position()
z_pos = self.rails[1].get_tag_position()
return [math.cos(bed_angle) * arm_pos, math.sin(bed_angle) * arm_pos,
z_pos]
def set_position(self, newpos, homing_axes):
for s in self.steppers:
s.set_position(newpos)
if 2 in homing_axes:
self.limit_z = self.rails[1].get_range()
if 0 in homing_axes and 1 in homing_axes:
self.limit_xy2 = self.rails[0].get_range()[1]**2
def note_z_not_homed(self):
# Helper for Safe Z Home
self.limit_z = (1.0, -1.0)
def _home_axis(self, homing_state, axis, rail):
# Determine movement
position_min, position_max = rail.get_range()
hi = rail.get_homing_info()
homepos = [None, None, None, None]
homepos[axis] = hi.position_endstop
if axis == 0:
homepos[1] = 0.
forcepos = list(homepos)
if hi.positive_dir:
forcepos[axis] -= hi.position_endstop - position_min
else:
forcepos[axis] += position_max - hi.position_endstop
# Perform homing
homing_state.home_rails([rail], forcepos, homepos)
def home(self, homing_state):
# Always home XY together
homing_axes = homing_state.get_axes()
home_xy = 0 in homing_axes or 1 in homing_axes
home_z = 2 in homing_axes
updated_axes = []
if home_xy:
updated_axes = [0, 1]
if home_z:
updated_axes.append(2)
homing_state.set_axes(updated_axes)
# Do actual homing
if home_xy:
self._home_axis(homing_state, 0, self.rails[0])
if home_z:
self._home_axis(homing_state, 2, self.rails[1])
def _motor_off(self, print_time):
self.limit_z = (1.0, -1.0)
self.limit_xy2 = -1.
def check_move(self, move):
end_pos = move.end_pos
xy2 = end_pos[0]**2 + end_pos[1]**2
if xy2 > self.limit_xy2:
if self.limit_xy2 < 0.:
raise move.move_error("Must home axis first")
raise move.move_error()
if move.axes_d[2]:
if end_pos[2] < self.limit_z[0] or end_pos[2] > self.limit_z[1]:
if self.limit_z[0] > self.limit_z[1]:
raise move.move_error("Must home axis first")
raise move.move_error()
# Move with Z - update velocity and accel for slower Z axis
z_ratio = move.move_d / abs(move.axes_d[2])
move.limit_speed(self.max_z_velocity * z_ratio,
self.max_z_accel * z_ratio)
def get_status(self, eventtime):
xy_home = "xy" if self.limit_xy2 >= 0. else ""
z_home = "z" if self.limit_z[0] <= self.limit_z[1] else ""
return {
'homed_axes': xy_home + z_home,
'axis_minimum': self.axes_min,
'axis_maximum': self.axes_max,
}
def load_kinematics(toolhead, config):
return PolarKinematics(toolhead, config)