klipper-dgus/klippy/cartesian.py

148 lines
6.6 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, printer, config):
self.steppers = [stepper.PrinterStepper(
printer, config.getsection('stepper_' + n), n)
for n in ['x', 'y', 'z']]
self.max_z_velocity = config.getfloat('max_z_velocity', 9999999.9)
self.max_z_accel = config.getfloat('max_z_accel', 9999999.9)
self.need_motor_enable = True
self.limits = [(1.0, -1.0)] * 3
def set_max_jerk(self, max_xy_halt_velocity, max_velocity, max_accel):
self.steppers[0].set_max_jerk(max_xy_halt_velocity, max_accel)
self.steppers[1].set_max_jerk(max_xy_halt_velocity, max_accel)
self.steppers[2].set_max_jerk(0., self.max_z_accel)
def build_config(self):
for stepper in self.steppers:
stepper.build_config()
def set_position(self, newpos):
for i in StepList:
s = self.steppers[i]
s.mcu_stepper.set_position(int(newpos[i]*s.inv_step_dist + 0.5))
def home(self, homing_state):
# Each axis is homed independently and in order
for axis in homing_state.get_axes():
s = self.steppers[axis]
self.limits[axis] = (s.position_min, s.position_max)
# 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
homepos = [None, None, None, None]
homepos[axis] = s.position_endstop
coord = [None, None, None, None]
coord[axis] = pos
homing_state.home(list(coord), homepos, [s], s.homing_speed)
# Retract
coord[axis] = rpos
homing_state.retract(list(coord), s.homing_speed)
# Home again
coord[axis] = r2pos
homing_state.home(
list(coord), homepos, [s], s.homing_speed/2.0, second_home=True)
# Set final homed position
coord[axis] = s.position_endstop + s.get_homed_offset()*s.step_dist
homing_state.set_homed_position(coord)
def motor_off(self, move_time):
self.limits = [(1.0, -1.0)] * 3
for stepper in self.steppers:
stepper.motor_enable(move_time, 0)
self.need_motor_enable = True
def _check_motor_enable(self, move_time, move):
need_motor_enable = False
for i in StepList:
if move.axes_d[i]:
self.steppers[i].motor_enable(move_time, 1)
need_motor_enable |= self.steppers[i].need_motor_enable
self.need_motor_enable = need_motor_enable
def query_endstops(self, print_time):
endstops = [(s, s.query_endstop(print_time)) for s in self.steppers]
return [(s.name, es.query_endstop_wait()) for s, es in endstops]
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, move_time, move):
if self.need_motor_enable:
self._check_motor_enable(move_time, move)
inv_accel = 1. / move.accel
inv_cruise_v = 1. / move.cruise_v
for i in StepList:
if not move.axes_d[i]:
continue
mcu_stepper = self.steppers[i].mcu_stepper
mcu_time = mcu_stepper.print_to_mcu_time(move_time)
step_pos = mcu_stepper.commanded_position
inv_step_dist = self.steppers[i].inv_step_dist
step_offset = step_pos - move.start_pos[i] * inv_step_dist
steps = move.axes_d[i] * inv_step_dist
move_step_d = move.move_d / abs(steps)
# Acceleration steps
accel_multiplier = 2.0 * move_step_d * inv_accel
if move.accel_r:
#t = sqrt(2*pos/accel + (start_v/accel)**2) - start_v/accel
accel_time_offset = move.start_v * inv_accel
accel_sqrt_offset = accel_time_offset**2
accel_steps = move.accel_r * steps
count = mcu_stepper.step_sqrt(
mcu_time - accel_time_offset, accel_steps, step_offset
, accel_sqrt_offset, accel_multiplier)
step_offset += count - accel_steps
mcu_time += move.accel_t
# Cruising steps
if move.cruise_r:
#t = pos/cruise_v
cruise_multiplier = move_step_d * inv_cruise_v
cruise_steps = move.cruise_r * steps
count = mcu_stepper.step_factor(
mcu_time, cruise_steps, step_offset, cruise_multiplier)
step_offset += count - cruise_steps
mcu_time += move.cruise_t
# Deceleration steps
if move.decel_r:
#t = cruise_v/accel - sqrt((cruise_v/accel)**2 - 2*pos/accel)
decel_time_offset = move.cruise_v * inv_accel
decel_sqrt_offset = decel_time_offset**2
decel_steps = move.decel_r * steps
count = mcu_stepper.step_sqrt(
mcu_time + decel_time_offset, decel_steps, step_offset
, decel_sqrt_offset, -accel_multiplier)