klipper/klippy/chelper/kin_extruder.c

101 lines
3.2 KiB
C

// Extruder stepper pulse time generation
//
// Copyright (C) 2018-2019 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU GPLv3 license.
#include <stddef.h> // offsetof
#include <stdlib.h> // malloc
#include <string.h> // memset
#include "compiler.h" // __visible
#include "itersolve.h" // struct stepper_kinematics
#include "pyhelper.h" // errorf
#include "trapq.h" // move_get_distance
// Calculate the definitive integral of the move distance
static double
move_integrate_distance(struct move *m, double start, double end)
{
double half_v = .5 * m->start_v, sixth_a = (1. / 3.) * m->half_accel;
double si = start * start * (half_v + sixth_a * start);
double ei = end * end * (half_v + sixth_a * end);
return ei - si;
}
// Calculate the definitive integral of extruder with pressure advance
static double
pa_move_integrate(struct move *m, double start, double end)
{
if (start < 0.)
start = 0.;
if (end > m->move_t)
end = m->move_t;
double pressure_advance = m->axes_r.y;
double avg_v = m->start_v + (start + end) * m->half_accel;
double pa_add = pressure_advance * avg_v;
double base = (m->start_pos.x + pa_add) * (end - start);
return base + move_integrate_distance(m, start, end);
}
// Calculate the definitive integral of the extruder over a range of moves
static double
pa_range_integrate(struct move *m, double start, double end)
{
double res = pa_move_integrate(m, start, end);
// Integrate over previous moves
struct move *prev = m;
while (unlikely(start < 0.)) {
prev = list_prev_entry(prev, node);
start += prev->move_t;
res += pa_move_integrate(prev, start, prev->move_t);
}
// Integrate over future moves
while (unlikely(end > m->move_t)) {
end -= m->move_t;
m = list_next_entry(m, node);
res += pa_move_integrate(m, 0., end);
}
return res;
}
struct extruder_stepper {
struct stepper_kinematics sk;
double half_smooth_time, inv_smooth_time;
};
static double
extruder_calc_position(struct stepper_kinematics *sk, struct move *m
, double move_time)
{
struct extruder_stepper *es = container_of(sk, struct extruder_stepper, sk);
double hst = es->half_smooth_time;
if (!hst)
// Pressure advance not enabled
return m->start_pos.x + move_get_distance(m, move_time);
// Apply pressure advance and average over smooth_time
double area = pa_range_integrate(m, move_time - hst, move_time + hst);
return area * es->inv_smooth_time;
}
void __visible
extruder_set_smooth_time(struct stepper_kinematics *sk, double smooth_time)
{
struct extruder_stepper *es = container_of(sk, struct extruder_stepper, sk);
double hst = smooth_time * .5;
es->half_smooth_time = hst;
es->sk.gen_steps_pre_active = es->sk.gen_steps_post_active = hst;
if (! hst)
return;
es->inv_smooth_time = 1. / smooth_time;
}
struct stepper_kinematics * __visible
extruder_stepper_alloc(void)
{
struct extruder_stepper *es = malloc(sizeof(*es));
memset(es, 0, sizeof(*es));
es->sk.calc_position_cb = extruder_calc_position;
es->sk.active_flags = AF_X;
return &es->sk;
}