实验测试
//当对每个线性移动 '标称' 值的设置进行缓冲时, 将使用此结构, 因为在源 g 代码中已指定,
//如果加速管理处于活动状态, 则可能永远无法实际达到。
typedef struct {
// 由bresenham 算法用于跟踪直线的字段
long steps_x, steps_y, steps_z, steps_e; // 每个坐标轴所需走的步数
unsigned long step_event_count; // 完成这个block所需走的步数，steps_x, steps_y, steps_z, steps_e的最大值
long accelerate_until; // 梯形曲线中的加速距离，单位steps
long decelerate_after; // 加速和匀速的距离，单位steps
long acceleration_rate; // 加速率，用来计算加速度
unsigned char direction_bits; // 这个block的方向位，“1”反向，“0”正向，每一个位代表一个轴的方向 (refers to *_DIRECTION_BIT in config.h)
unsigned char active_extruder; // 所用到的有效的挤出头
#ifdef ADVANCE
long advance_rate;
volatile long initial_advance;
volatile long final_advance;
float advance;
#endif
// 运动规划器用于管理加速的字段
float nominal_speed; // 额定速度，即梯形曲线的匀速阶段的速度，单位 mm/sec
float entry_speed; // 进入速度，即从上一个block进入到这个block的速度，单位 mm/sec
float max_entry_speed; // 最大进入速度，进入速度不能超过这个值，单位 mm/sec
float millimeters; // 总路程，单位mm
float acceleration; // 加速度，单位 mm/sec^2
unsigned char recalculate_flag; // 连接处重新计算梯形速度曲线的标志
unsigned char nominal_length_flag; // 能达到额定速度的标志
// 梯形速度曲线产生器的设置参数
unsigned long nominal_rate; // 这个block的单位为steps/sec的额定速度
unsigned long initial_rate; // 梯形曲线的初始速度/进入速度，单位steps/sec
unsigned long final_rate; // 梯形曲线的退出速度，单位steps/sec
unsigned long acceleration_st; // 单位为steps/sec^2的加速度
unsigned long fan_speed; // 风扇速度
#ifdef BARICUDA
unsigned long valve_pressure;
unsigned long e_to_p_pressure;
#endif
volatile char busy; // 正在处理这个block的标志位，“1”表示正在执行这个block
} block_t;
//用于运动指令的环形缓冲器
block_t block_buffer[BLOCK_BUFFER_SIZE]; // A ring buffer for motion instructions
volatile unsigned char block_buffer_head; // Index of the next block to be pushed
volatile unsigned char block_buffer_tail; // Index of the block to process now
在缓冲区中添加一个新的线性移动。stepsx、y和z是mm中的绝对位置，微秒指定移动应该执行多少微秒。
为了加速计算，打电话者也必须以毫米的长度提供线路的物理长度。
*/
/* 规划直线路径 */
void plan_buffer_line(const float &x, const float &y, const float &z, const float &e, float feed_rate, const uint8_t &extruder)
{
//在存入这个字节后计算缓冲区的头指针
// Calculate the buffer head after we push this byte
int next_buffer_head = next_block_index(block_buffer_head);
//检测block是否有空间，如果没有空间等待并执行加热管理、轴不活跃性管理、lcd更新函数，直到缓冲区有空间
// If the buffer is full: good! That means we are well ahead of the robot.
// Rest here until there is room in the buffer.
while(block_buffer_tail == next_buffer_head)
{
manage_heater();
manage_inactivity();
lcd_update();
}
#ifdef ENABLE_AUTO_BED_LEVELING
apply_rotation_xyz(plan_bed_level_matrix, x, y, z);
#endif // ENABLE_AUTO_BED_LEVELING
//计算各轴目标位置的step数
// The target position of the tool in absolute steps
// Calculate target position in absolute steps
//this should be done after the wait, because otherwise a M92 code within the gcode disrupts this calculation somehow
long target[4];
target[X_AXIS] = lround(x*axis_steps_per_unit[X_AXIS]);
target[Y_AXIS] = lround(y*axis_steps_per_unit[Y_AXIS]);
target[Z_AXIS] = lround(z*axis_steps_per_unit[Z_AXIS]);
target[E_AXIS] = lround(e*axis_steps_per_unit[E_AXIS]);
//当有挤料的动作，且挤出头的温度低于extrude_min_temp时，不会执行挤料动作
//且如果挤料的长度超过EXTRUDE_MAXLENGTH时也不会执行挤料动作
#ifdef PREVENT_DANGEROUS_EXTRUDE
if(target[E_AXIS]!=position[E_AXIS])
{
if(degHotend(active_extruder)<extrude_min_temp)
{
position[E_AXIS]=target[E_AXIS]; //behave as if the move really took place, but ignore E part
SERIAL_ECHO_START;
SERIAL_ECHOLNPGM(MSG_ERR_COLD_EXTRUDE_STOP);
}
```
#ifdef PREVENT_LENGTHY_EXTRUDE
if(labs(target[E_AXIS]-position[E_AXIS])>axis_steps_per_unit[E_AXIS]*EXTRUDE_MAXLENGTH)
{
position[E_AXIS]=target[E_AXIS]; //behave as if the move really took place, but ignore E part
SERIAL_ECHO_START;
SERIAL_ECHOLNPGM(MSG_ERR_LONG_EXTRUDE_STOP);
}
#endif
```
}
#endif
//设定新的block
// Prepare to set up new block
block_t *block = &block_buffer[block_buffer_head];
// Mark block as not busy (Not executed by the stepper interrupt)
block->busy = false;
//设定各个轴的step数
// Number of steps for each axis
// default non-h-bot planning
block->steps_x = labs(target[X_AXIS]-position[X_AXIS]);
block->steps_y = labs(target[Y_AXIS]-position[Y_AXIS]);
block->steps_z = labs(target[Z_AXIS]-position[Z_AXIS]);
block->steps_e = labs(target[E_AXIS]-position[E_AXIS]);
block->steps_e *= volumetric_multiplier[active_extruder];
block->steps_e *= extrudemultiply;
block->steps_e /= 100;
block->step_event_count = max(block->steps_x, max(block->steps_y, max(block->steps_z, block->steps_e)));
//如果step_event_count低于5个step，则忽略这个指令
// Bail if this is a zero-length block
if (block->step_event_count <= dropsegments)
{
return;
}
//设定风扇速度
block->fan_speed = fanSpeed;
#ifdef BARICUDA
block->valve_pressure = ValvePressure;
block->e_to_p_pressure = EtoPPressure;
#endif
//设定各轴的移动方向
// Compute direction bits for this block
block->direction_bits = 0;
#ifndef COREXY
if (target[X_AXIS] < position[X_AXIS])
{
block->direction_bits |= (1<<X_AXIS);
}
if (target[Y_AXIS] < position[Y_AXIS])
{
block->direction_bits |= (1<<Y_AXIS);
}
#else
if ((target[X_AXIS]-position[X_AXIS]) + (target[Y_AXIS]-position[Y_AXIS]) < 0)
{
block->direction_bits |= (1<<X_AXIS);
}
if ((target[X_AXIS]-position[X_AXIS]) - (target[Y_AXIS]-position[Y_AXIS]) < 0)
{
block->direction_bits |= (1<<Y_AXIS);
}
#endif
if (target[Z_AXIS] < position[Z_AXIS])
{
block->direction_bits |= (1<<Z_AXIS);
}
if (target[E_AXIS] < position[E_AXIS])
{
block->direction_bits |= (1<<E_AXIS);
}
//设定挤出头编号
block->active_extruder = extruder;
//使能各个步进电机
//enable active axes
#ifdef COREXY
if((block->steps_x != 0) || (block->steps_y != 0))
{
enable_x();
enable_y();
}
#else
if(block->steps_x != 0) enable_x();
if(block->steps_y != 0) enable_y();
#endif
#ifndef Z_LATE_ENABLE
if(block->steps_z != 0) enable_z();
#endif
// Enable all
if(block->steps_e != 0)
{
enable_e0();
enable_e1();
enable_e2();
}
/* 设定进给速率 */
if (block->steps_e == 0)
{
if(feed_rate<mintravelfeedrate) feed_rate=mintravelfeedrate;
}
else
{
if(feed_rate<minimumfeedrate) feed_rate=minimumfeedrate;
}
/* 计算各个步进电机要移动的步数 */
float delta_mm[4];
#ifndef COREXY
delta_mm[X_AXIS] = (target[X_AXIS]-position[X_AXIS])/axis_steps_per_unit[X_AXIS];
delta_mm[Y_AXIS] = (target[Y_AXIS]-position[Y_AXIS])/axis_steps_per_unit[Y_AXIS];
#else
delta_mm[X_AXIS] = ((target[X_AXIS]-position[X_AXIS]) + (target[Y_AXIS]-position[Y_AXIS]))/axis_steps_per_unit[X_AXIS];
delta_mm[Y_AXIS] = ((target[X_AXIS]-position[X_AXIS]) - (target[Y_AXIS]-position[Y_AXIS]))/axis_steps_per_unit[Y_AXIS];
#endif
delta_mm[Z_AXIS] = (target[Z_AXIS]-position[Z_AXIS])/axis_steps_per_unit[Z_AXIS];
delta_mm[E_AXIS] = ((target[E_AXIS]-position[E_AXIS])/axis_steps_per_unit[E_AXIS])*volumetric_multiplier[active_extruder]*extrudemultiply/100.0;
//计算移动的距离
if ( block->steps_x <=dropsegments && block->steps_y <=dropsegments && block->steps_z <=dropsegments )
{
block->millimeters = fabs(delta_mm[E_AXIS]);
}
else
{
block->millimeters = sqrt(square(delta_mm[X_AXIS]) + square(delta_mm[Y_AXIS]) + square(delta_mm[Z_AXIS]));
}
float inverse_millimeters = 1.0/block->millimeters; // Inverse millimeters to remove multiple divides
```
// Calculate speed in mm/second for each axis. No divide by zero due to previous checks.
```
float inverse_second = feed_rate * inverse_millimeters;
//计算排入行程的block数
int moves_queued=(block_buffer_head-block_buffer_tail + BLOCK_BUFFER_SIZE) & (BLOCK_BUFFER_SIZE - 1);
// slow down when de buffer starts to empty, rather than wait at the corner for a buffer refill
#ifdef OLD_SLOWDOWN
if(moves_queued < (BLOCK_BUFFER_SIZE * 0.5) && moves_queued > 1)
feed_rate = feed_rate*moves_queued / (BLOCK_BUFFER_SIZE * 0.5);
#endif
#ifdef SLOWDOWN
// segment time im micro seconds
unsigned long segment_time = lround(1000000.0/inverse_second);
if ((moves_queued > 1) && (moves_queued < (BLOCK_BUFFER_SIZE * 0.5)))
{
if (segment_time < minsegmenttime)
{ // buffer is draining, add extra time. The amount of time added increases if the buffer is still emptied more.
inverse_second=1000000.0/(segment_time+lround(2*(minsegmenttime-segment_time)/moves_queued));
#ifdef XY_FREQUENCY_LIMIT
segment_time = lround(1000000.0/inverse_second);
#endif
}
}
#endif
// END OF SLOW DOWN SECTION
//计算block的额定速度（mm/sec）和额定速率（step/sec）
block->nominal_speed = block->millimeters * inverse_second; // (mm/sec) Always > 0
block->nominal_rate = ceil(block->step_event_count * inverse_second); // (step/sec) Always > 0
// Calculate and limit speed in mm/sec for each axis
float current_speed[4];
float speed_factor = 1.0; //factor <=1 do decrease speed
for(int i=0; i < 4; i++)
{
current_speed[i] = delta_mm[i] * inverse_second;
if(fabs(current_speed[i]) > max_feedrate[i])
speed_factor = min(speed_factor, max_feedrate[i] / fabs(current_speed[i]));
}
// Max segement time in us.
#ifdef XY_FREQUENCY_LIMIT
#define MAX_FREQ_TIME (1000000.0/XY_FREQUENCY_LIMIT)
// Check and limit the xy direction change frequency
unsigned char direction_change = block->direction_bits ^ old_direction_bits;
old_direction_bits = block->direction_bits;
segment_time = lround((float)segment_time / speed_factor);
if((direction_change & (1<<X_AXIS)) == 0)
{
x_segment_time[0] += segment_time;
}
else
{
x_segment_time[2] = x_segment_time[1];
x_segment_time[1] = x_segment_time[0];
x_segment_time[0] = segment_time;
}
if((direction_change & (1<<Y_AXIS)) == 0)
{
y_segment_time[0] += segment_time;
}
else
{
y_segment_time[2] = y_segment_time[1];
y_segment_time[1] = y_segment_time[0];
y_segment_time[0] = segment_time;
}
long max_x_segment_time = max(x_segment_time[0], max(x_segment_time[1], x_segment_time[2]));
long max_y_segment_time = max(y_segment_time[0], max(y_segment_time[1], y_segment_time[2]));
long min_xy_segment_time =min(max_x_segment_time, max_y_segment_time);
if(min_xy_segment_time < MAX_FREQ_TIME)
speed_factor = min(speed_factor, speed_factor * (float)min_xy_segment_time / (float)MAX_FREQ_TIME);
#endif
// Correct the speed
if( speed_factor < 1.0)
{
for(unsigned char i=0; i < 4; i++)
{
current_speed[i] *= speed_factor;
}
block->nominal_speed *= speed_factor;
block->nominal_rate *= speed_factor;
}
//为梯形速度控制算法计算加速度并限幅
// Compute and limit the acceleration rate for the trapezoid generator.
float steps_per_mm = block->step_event_count/block->millimeters;
if(block->steps_x == 0 && block->steps_y == 0 && block->steps_z == 0)
{
block->acceleration_st = ceil(retract_acceleration * steps_per_mm); // convert to: acceleration steps/sec^2
}
else
{
block->acceleration_st = ceil(acceleration * steps_per_mm); // convert to: acceleration steps/sec^2
//为每个轴的加速度进行限幅
// Limit acceleration per axis
if(((float)block->acceleration_st * (float)block->steps_x / (float)block->step_event_count) > axis_steps_per_sqr_second[X_AXIS])
block->acceleration_st = axis_steps_per_sqr_second[X_AXIS];
if(((float)block->acceleration_st * (float)block->steps_y / (float)block->step_event_count) > axis_steps_per_sqr_second[Y_AXIS])
block->acceleration_st = axis_steps_per_sqr_second[Y_AXIS];
if(((float)block->acceleration_st * (float)block->steps_e / (float)block->step_event_count) > axis_steps_per_sqr_second[E_AXIS])
block->acceleration_st = axis_steps_per_sqr_second[E_AXIS];
if(((float)block->acceleration_st * (float)block->steps_z / (float)block->step_event_count ) > axis_steps_per_sqr_second[Z_AXIS])
block->acceleration_st = axis_steps_per_sqr_second[Z_AXIS];
}
block->acceleration = block->acceleration_st / steps_per_mm;
//block->acceleration_rate是为了控制器计算速度（step/s）而设定的加速度值，(F_CPU / 8.0)为定时器的时钟频率，(16777216.0 = <<24)
//加速度阶段的速度正常算法为：acc_step_rate = accelerate_time/(F_CPU / 8.0) * block->acceleration_st
//acc_step_rate和block->acceleration_st都为整数，利用下面设定该参数的方法可以避免产生小数(通过移位来实现的)
//加速度阶段的速度的实际计算方法：acc_step_rate = accelerate_time * (block->acceleration_st * (16777216.0 / (F_CPU / 8.0))>>24
block->acceleration_rate = (long)((float)block->acceleration_st * (16777216.0 / (F_CPU / 8.0))); //为了不产生小数
//预设不会做连接速度的计算
#if 0 // Use old jerk for now
// Compute path unit vector
double unit_vec[3];
unit_vec[X_AXIS] = delta_mm[X_AXIS]*inverse_millimeters;
unit_vec[Y_AXIS] = delta_mm[Y_AXIS]*inverse_millimeters;
unit_vec[Z_AXIS] = delta_mm[Z_AXIS]*inverse_millimeters;
// Compute maximum allowable entry speed at junction by centripetal acceleration approximation.
// Let a circle be tangent to both previous and current path line segments, where the junction
// deviation is defined as the distance from the junction to the closest edge of the circle,
// colinear with the circle center. The circular segment joining the two paths represents the
// path of centripetal acceleration. Solve for max velocity based on max acceleration about the
// radius of the circle, defined indirectly by junction deviation. This may be also viewed as
// path width or max_jerk in the previous grbl version. This approach does not actually deviate
// from path, but used as a robust way to compute cornering speeds, as it takes into account the
// nonlinearities of both the junction angle and junction velocity.
double vmax_junction = MINIMUM_PLANNER_SPEED; // Set default max junction speed
// Skip first block or when previous_nominal_speed is used as a flag for homing and offset cycles.
if ((block_buffer_head != block_buffer_tail) && (previous_nominal_speed > 0.0)) {
// Compute cosine of angle between previous and current path. (prev_unit_vec is negative)
// NOTE: Max junction velocity is computed without sin() or acos() by trig half angle identity.
double cos_theta = - previous_unit_vec[X_AXIS] * unit_vec[X_AXIS]
- previous_unit_vec[Y_AXIS] * unit_vec[Y_AXIS]
- previous_unit_vec[Z_AXIS] * unit_vec[Z_AXIS] ;
```
// Skip and use default max junction speed for 0 degree acute junction.
if (cos_theta < 0.95) {
vmax_junction = min(previous_nominal_speed,block->nominal_speed);
// Skip and avoid divide by zero for straight junctions at 180 degrees. Limit to min() of nominal speeds.
if (cos_theta > -0.95) {
// Compute maximum junction velocity based on maximum acceleration and junction deviation
double sin_theta_d2 = sqrt(0.5*(1.0-cos_theta)); // Trig half angle identity. Always positive.
vmax_junction = min(vmax_junction,
sqrt(block->acceleration * junction_deviation * sin_theta_d2/(1.0-sin_theta_d2)) );
}
}
```
}
#endif
//设定连接处的最大速度
// Start with a safe speed
float vmax_junction = max_xy_jerk/2;
float vmax_junction_factor = 1.0;
if(fabs(current_speed[Z_AXIS]) > max_z_jerk/2)
vmax_junction = min(vmax_junction, max_z_jerk/2);
if(fabs(current_speed[E_AXIS]) > max_e_jerk/2)
vmax_junction = min(vmax_junction, max_e_jerk/2);
vmax_junction = min(vmax_junction, block->nominal_speed);
float safe_speed = vmax_junction;
if ((moves_queued > 1) && (previous_nominal_speed > 0.0001)) {
float jerk = sqrt(pow((current_speed[X_AXIS]-previous_speed[X_AXIS]), 2)+pow((current_speed[Y_AXIS]-previous_speed[Y_AXIS]), 2));
// if((fabs(previous_speed[X_AXIS]) > 0.0001) || (fabs(previous_speed[Y_AXIS]) > 0.0001)) {
vmax_junction = block->nominal_speed;
// }
//计算vmax_junction_factor
if (jerk > max_xy_jerk) {
vmax_junction_factor = (max_xy_jerk/jerk);
}
if(fabs(current_speed[Z_AXIS] - previous_speed[Z_AXIS]) > max_z_jerk) {
vmax_junction_factor= min(vmax_junction_factor, (max_z_jerk/fabs(current_speed[Z_AXIS] - previous_speed[Z_AXIS])));
}
if(fabs(current_speed[E_AXIS] - previous_speed[E_AXIS]) > max_e_jerk) {
vmax_junction_factor = min(vmax_junction_factor, (max_e_jerk/fabs(current_speed[E_AXIS] - previous_speed[E_AXIS])));
}
//计算vmax_junction
vmax_junction = min(previous_nominal_speed, vmax_junction * vmax_junction_factor); // Limit speed to max previous speed
}
//计算max_entry_speed
block->max_entry_speed = vmax_junction;
// Initialize block entry speed. Compute based on deceleration to user-defined MINIMUM_PLANNER_SPEED.
double v_allowable = max_allowable_speed(-block->acceleration,MINIMUM_PLANNER_SPEED,block->millimeters);
block->entry_speed = min(vmax_junction, v_allowable);
// Initialize planner efficiency flags
// Set flag if block will always reach maximum junction speed regardless of entry/exit speeds.
// If a block can de/ac-celerate from nominal speed to zero within the length of the block, then
// the current block and next block junction speeds are guaranteed to always be at their maximum
// junction speeds in deceleration and acceleration, respectively. This is due to how the current
// block nominal speed limits both the current and next maximum junction speeds. Hence, in both
// the reverse and forward planners, the corresponding block junction speed will always be at the
// the maximum junction speed and may always be ignored for any speed reduction checks.
if (block->nominal_speed <= v_allowable) {
block->nominal_length_flag = true;
}
else {
block->nominal_length_flag = false;
}
block->recalculate_flag = true; // Always calculate trapezoid for new block
// Update previous path unit_vector and nominal speed
memcpy(previous_speed, current_speed, sizeof(previous_speed)); // previous_speed[] = current_speed[]
previous_nominal_speed = block->nominal_speed;
#ifdef ADVANCE
// Calculate advance rate
if((block->steps_e == 0) || (block->steps_x == 0 && block->steps_y == 0 && block->steps_z == 0)) {
block->advance_rate = 0;
block->advance = 0;
}
else {
long acc_dist = estimate_acceleration_distance(0, block->nominal_rate, block->acceleration_st);
float advance = (STEPS_PER_CUBIC_MM_E * EXTRUDER_ADVANCE_K) *
(current_speed[E_AXIS] * current_speed[E_AXIS] * EXTRUTION_AREA * EXTRUTION_AREA)*256;
block->advance = advance;
if(acc_dist == 0) {
block->advance_rate = 0;
}
else {
block->advance_rate = advance / (float)acc_dist;
}
}
/*
SERIAL_ECHO_START;
SERIAL_ECHOPGM("advance :");
SERIAL_ECHO(block->advance/256.0);
SERIAL_ECHOPGM("advance rate :");
SERIAL_ECHOLN(block->advance_rate/256.0);
*/
#endif // ADVANCE
//计算梯形加减速（*重点*）
calculate_trapezoid_for_block(block, block->entry_speed/block->nominal_speed,
safe_speed/block->nominal_speed);
// Move buffer head
block_buffer_head = next_buffer_head;
//记录目前的位置
// Update position
memcpy(position, target, sizeof(target)); // position[] = target[]
//重新对所有的block做路径规划（*重点*）
planner_recalculate();
//使能步进电机中断
st_wake_up();
}