klipper-dgus/klippy/cartesian.py

142 lines
6.0 KiB
Python

# Code for handling the kinematics of cartesian robots
#
# Copyright (C) 2016 Kevin O'Connor <kevin@koconnor.net>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import logging
import stepper, homing
StepList = (0, 1, 2)
class CartKinematics:
def __init__(self, toolhead, printer, config):
self.steppers = [stepper.LookupMultiHomingStepper(
printer, config.getsection('stepper_' + n))
for n in ['x', 'y', 'z']]
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.need_motor_enable = True
self.limits = [(1.0, -1.0)] * 3
# Setup stepper max halt velocity
max_halt_velocity = toolhead.get_max_axis_halt()
self.steppers[0].set_max_jerk(max_halt_velocity, max_accel)
self.steppers[1].set_max_jerk(max_halt_velocity, max_accel)
self.steppers[2].set_max_jerk(
min(max_halt_velocity, self.max_z_velocity), max_accel)
def get_steppers(self, flags=""):
if flags == "Z":
return [self.steppers[2]]
return list(self.steppers)
def get_position(self):
return [s.mcu_stepper.get_commanded_position() for s in self.steppers]
def set_position(self, newpos, homing_axes):
for i in StepList:
s = self.steppers[i]
s.set_position(newpos[i])
if i in homing_axes:
self.limits[i] = (s.position_min, s.position_max)
def home(self, homing_state):
# Each axis is homed independently and in order
for axis in homing_state.get_axes():
s = self.steppers[axis]
# Determine moves
if s.homing_positive_dir:
pos = s.position_endstop - 1.5*(
s.position_endstop - s.position_min)
rpos = s.position_endstop - s.homing_retract_dist
r2pos = rpos - s.homing_retract_dist
else:
pos = s.position_endstop + 1.5*(
s.position_max - s.position_endstop)
rpos = s.position_endstop + s.homing_retract_dist
r2pos = rpos + s.homing_retract_dist
# Initial homing
homing_speed = s.homing_speed
if axis == 2:
homing_speed = min(homing_speed, self.max_z_velocity)
homepos = [None, None, None, None]
homepos[axis] = s.position_endstop
coord = [None, None, None, None]
coord[axis] = pos
homing_state.home(coord, homepos, s.get_endstops(), homing_speed)
# Retract
coord[axis] = rpos
homing_state.retract(coord, homing_speed)
# Home again
coord[axis] = r2pos
homing_state.home(coord, homepos, s.get_endstops(),
homing_speed/2.0, second_home=True)
# Set final homed position
coord[axis] = s.position_endstop + s.get_homed_offset()
homing_state.set_homed_position(coord)
def motor_off(self, print_time):
self.limits = [(1.0, -1.0)] * 3
for stepper in self.steppers:
stepper.motor_enable(print_time, 0)
self.need_motor_enable = True
def _check_motor_enable(self, print_time, move):
need_motor_enable = False
for i in StepList:
if move.axes_d[i]:
self.steppers[i].motor_enable(print_time, 1)
need_motor_enable |= self.steppers[i].need_motor_enable
self.need_motor_enable = need_motor_enable
def _check_endstops(self, move):
end_pos = move.end_pos
for i in StepList:
if (move.axes_d[i]
and (end_pos[i] < self.limits[i][0]
or end_pos[i] > self.limits[i][1])):
if self.limits[i][0] > self.limits[i][1]:
raise homing.EndstopMoveError(
end_pos, "Must home axis first")
raise homing.EndstopMoveError(end_pos)
def check_move(self, move):
limits = self.limits
xpos, ypos = move.end_pos[:2]
if (xpos < limits[0][0] or xpos > limits[0][1]
or ypos < limits[1][0] or ypos > limits[1][1]):
self._check_endstops(move)
if not move.axes_d[2]:
# Normal XY move - use defaults
return
# Move with Z - update velocity and accel for slower Z axis
self._check_endstops(move)
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 move(self, print_time, move):
if self.need_motor_enable:
self._check_motor_enable(print_time, move)
for i in StepList:
axis_d = move.axes_d[i]
if not axis_d:
continue
step_const = self.steppers[i].step_const
move_time = print_time
start_pos = move.start_pos[i]
axis_r = abs(axis_d) / move.move_d
accel = move.accel * axis_r
cruise_v = move.cruise_v * axis_r
# Acceleration steps
if move.accel_r:
accel_d = move.accel_r * axis_d
step_const(move_time, start_pos, accel_d,
move.start_v * axis_r, accel)
start_pos += accel_d
move_time += move.accel_t
# Cruising steps
if move.cruise_r:
cruise_d = move.cruise_r * axis_d
step_const(move_time, start_pos, cruise_d, cruise_v, 0.)
start_pos += cruise_d
move_time += move.cruise_t
# Deceleration steps
if move.decel_r:
decel_d = move.decel_r * axis_d
step_const(move_time, start_pos, decel_d, cruise_v, -accel)