control.c

CNC 的开放码,EMC2 V2.2.8版

	emcmotStatus->homing_active = 0;
	break;
    }
}

static void do_homing(void)
{
    int joint_num;
    emcmot_joint_t *joint;
    double offset, tmp;
    int home_sw_active, homing_flag;

    homing_flag = 0;
    if (emcmotStatus->motion_state != EMCMOT_MOTION_FREE) {
	/* can't home unless in free mode */
	return;
    }
    /* loop thru axis, treat each one individually */
    for (joint_num = 0; joint_num < num_joints; joint_num++) {
	/* point to joint struct */
	joint = &joints[joint_num];
	if (!GET_JOINT_ACTIVE_FLAG(joint)) {
	    /* if joint is not active, skip it */
	    continue;
	}
	home_sw_active = GET_JOINT_HOME_SWITCH_FLAG(joint);
	if (joint->home_state != HOME_IDLE) {
	    homing_flag = 1; /* at least one axis is homing */
	}
	
	/* when an axis is homing, 'check_for_faults()' ignores its limit
	   switches, so that this code can do the right thing with them. Once
	   the homing process is finished, the 'check_for_faults()' resumes
	   checking */

	/* homing state machine */

	/* Some portions of the homing sequence can run thru two or more
	   states during a single servo period.  This is done using
	   'immediate_state'.  If a state transition sets it true (non-zero),
	   this 'do-while' will loop executing switch(home_state) immediately
	   to run the new state code.  Otherwise, the loop will fall thru, and
	   switch(home_state) runs only once per servo period. Do _not_ set
	   'immediate_state' true unless you also change 'home_state', unless
	   you want an infinite loop! */
	do {
	    immediate_state = 0;
	    switch (joint->home_state) {
	    case HOME_IDLE:
		/* nothing to do */
		break;

	    case HOME_START:
		/* This state is responsible for getting the homing process
		   started.  It doesn't actually do anything, it simply
		   determines what state is next */
		if (joint->home_flags & HOME_IS_SHARED && home_sw_active) {
		    reportError(
			"Cannot home while shared home switch is closed");
		    joint->home_state = HOME_IDLE;
		    break;
		}
		/* set flags that communicate with the rest of EMC */
		SET_JOINT_HOMING_FLAG(joint, 1);
		SET_JOINT_HOMED_FLAG(joint, 0);
		SET_JOINT_AT_HOME_FLAG(joint, 0);
		/* stop any existing motion */
		joint->free_tp_enable = 0;
		/* reset delay counter */
		joint->home_pause_timer = 0;
		/* figure out exactly what homing sequence is needed */
		if (joint->home_search_vel == 0.0) {
		    if (joint->home_latch_vel == 0.0) {
			/* both vels == 0 means home at current position */
			joint->home_state = HOME_SET_SWITCH_POSITION;
			immediate_state = 1;
		    } else if (joint->home_flags & HOME_USE_INDEX) {
			/* home using index pulse only */
			joint->home_state = HOME_INDEX_ONLY_START;
			immediate_state = 1;
		    } else {
			reportError("invalid homing config: non-zero LATCH_VEL needs either SEARCH_VEL or USE_INDEX");
			joint->home_state = HOME_IDLE;
		    }
		} else {
		    if (joint->home_latch_vel != 0.0) {
			/* need to find home switch */
			joint->home_state = HOME_INITIAL_SEARCH_START;
			immediate_state = 1;
		    } else {
			reportError("invalid homing config: non-zero SEARCH_VEL needs LATCH_VEL");
			joint->home_state = HOME_IDLE;
		    }
		}
		break;

	    case HOME_INITIAL_BACKOFF_START:
		/* This state is called if the homing sequence starts at a
		   location where the home switch is already tripped. It
		   starts a move away from the switch. */
		/* is the joint still moving? */
		if (joint->free_tp_active) {
		    /* yes, reset delay, wait until joint stops */
		    joint->home_pause_timer = 0;
		    break;
		}
		/* has delay timed out? */
		if (joint->home_pause_timer < (HOME_DELAY * servo_freq)) {
		    /* no, update timer and wait some more */
		    joint->home_pause_timer++;
		    break;
		}
		joint->home_pause_timer = 0;
		/* set up a move at '-search_vel' to back off of switch */
		home_start_move(joint, -joint->home_search_vel);
		/* next state */
		joint->home_state = HOME_INITIAL_BACKOFF_WAIT;
		break;

	    case HOME_INITIAL_BACKOFF_WAIT:
		/* This state is called while the machine is moving off of
		   the home switch.  It terminates when the switch is cleared
		   successfully.  If the move ends or hits a limit before it
		   clears the switch, the home is aborted. */
		/* are we off home switch yet? */
		if (! home_sw_active) {
		    /* yes, stop motion */
		    joint->free_tp_enable = 0;
		    /* begin initial search */
		    joint->home_state = HOME_INITIAL_SEARCH_START;
		    immediate_state = 1;
		    break;
		}
		home_do_moving_checks(joint);
		break;

	    case HOME_INITIAL_SEARCH_START:
		/* This state is responsible for starting a move toward the
		   home switch.  This move is at 'search_vel', which can be
		   fairly fast, because once the switch is found another
		   slower move will be used to set the exact home position. */
		/* is the joint already moving? */
		if (joint->free_tp_active) {
		    /* yes, reset delay, wait until joint stops */
		    joint->home_pause_timer = 0;
		    break;
		}
		/* has delay timed out? */
		if (joint->home_pause_timer < (HOME_DELAY * servo_freq)) {
		    /* no, update timer and wait some more */
		    joint->home_pause_timer++;
		    break;
		}
		joint->home_pause_timer = 0;
		/* make sure we aren't already on home switch */
		if (home_sw_active) {
		    /* already on switch, need to back off it first */
		    joint->home_state = HOME_INITIAL_BACKOFF_START;
		    immediate_state = 1;
		    break;
		}
		/* set up a move at 'search_vel' to find switch */
		home_start_move(joint, joint->home_search_vel);
		/* next state */
		joint->home_state = HOME_INITIAL_SEARCH_WAIT;
		break;

	    case HOME_INITIAL_SEARCH_WAIT:
		/* This state is called while the machine is looking for the
		   home switch.  It terminates when the switch is found.  If
		   the move ends or hits a limit before it finds the switch,
		   the home is aborted. */
		/* have we hit home switch yet? */
		if (home_sw_active) {
		    /* yes, stop motion */
		    joint->free_tp_enable = 0;
		    /* go to next step */
		    joint->home_state = HOME_SET_COARSE_POSITION;
		    immediate_state = 1;
		    break;
		}
		home_do_moving_checks(joint);
		break;

	    case HOME_SET_COARSE_POSITION:
		/* This state is called after the first time the switch is
		   found.  At this point, we are approximately home. Although
		   we will do another slower pass to get the exact home
		   location, we reset the joint coordinates now so that screw
		   error comp will be appropriate for this portion of the
		   screw (previously we didn't know where we were at all). */
		/* set the current position to 'home_offset' */
		offset = joint->home_offset - joint->pos_fb;
		/* this moves the internal position but does not affect the
		   motor position */
		joint->pos_cmd += offset;
		joint->pos_fb += offset;
		joint->free_pos_cmd += offset;
		joint->motor_offset -= offset;
		/* The next state depends on the signs of 'search_vel' and
		   'latch_vel'.  If they are the same, that means we must
		   back up, then do the final homing moving the same
		   direction as the initial search, on a rising edge of the
		   switch.  If they are opposite, it means that the final
		   homing will take place on a falling edge as the machine
		   moves off of the switch. */
		tmp = joint->home_search_vel * joint->home_latch_vel;
		if (tmp > 0.0) {
		    /* search and latch vel are same direction */
		    joint->home_state = HOME_FINAL_BACKOFF_START;
		} else {
		    /* search and latch vel are opposite directions */
		    joint->home_state = HOME_FALL_SEARCH_START;
		}
		immediate_state = 1;
		break;

	    case HOME_FINAL_BACKOFF_START:
		/* This state is called once the approximate location of the
		   switch has been found.  It is responsible for starting a
		   move that will back off of the switch in preparation for a
		   final slow move that captures the exact switch location. */
		/* is the joint already moving? */
		if (joint->free_tp_active) {
		    /* yes, reset delay, wait until joint stops */
		    joint->home_pause_timer = 0;
		    break;
		}
		/* has delay timed out? */
		if (joint->home_pause_timer < (HOME_DELAY * servo_freq)) {
		    /* no, update timer and wait some more */
		    joint->home_pause_timer++;
		    break;
		}
		joint->home_pause_timer = 0;
		/* we should still be on the switch */
		if (! home_sw_active) {
		    reportError(
			"Home switch inactive before start of backoff move");
		    joint->home_state = HOME_IDLE;
		    break;
		}
		/* set up a move at '-search_vel' to back off of switch */
		home_start_move(joint, -joint->home_search_vel);
		/* next state */
		joint->home_state = HOME_FINAL_BACKOFF_WAIT;
		break;

	    case HOME_FINAL_BACKOFF_WAIT:
		/* This state is called while the machine is moving off of
		   the home switch after finding its approximate location.
		   It terminates when the switch is cleared successfully.  If
		   the move ends or hits a limit before it clears the switch,
		   the home is aborted. */
		/* are we off home switch yet? */
		if (! home_sw_active) {
		    /* yes, stop motion */
		    joint->free_tp_enable = 0;
		    /* begin final search */
		    joint->home_state = HOME_RISE_SEARCH_START;
		    immediate_state = 1;
		    break;
		}
		home_do_moving_checks(joint);
		break;

	    case HOME_RISE_SEARCH_START:
		/* This state is called to start the final search for the
		   point where the home switch trips.  It moves at
		   'latch_vel' and looks for a rising edge on the switch */
		/* is the joint already moving? */
		if (joint->free_tp_active) {
		    /* yes, reset delay, wait until joint stops */
		    joint->home_pause_timer = 0;
		    break;
		}
		/* has delay timed out? */
		if (joint->home_pause_timer < (HOME_DELAY * servo_freq)) {
		    /* no, update timer and wait some more */
		    joint->home_pause_timer++;
		    break;
		}
		joint->home_pause_timer = 0;
		/* we should still be off of the switch */
		if (home_sw_active) {
		    reportError(
			"Home switch active before start of latch move");
		    joint->home_state = HOME_IDLE;
		    break;
		}
		/* set up a move at 'latch_vel' to locate the switch */
		home_start_move(joint, joint->home_latch_vel);
		/* next state */
		joint->home_state = HOME_RISE_SEARCH_WAIT;
		break;

	    case HOME_RISE_SEARCH_WAIT:
		/* This state is called while the machine is moving towards
		   the home switch on its final, low speed pass.  It
		   terminates when the switch is detected. If the move ends
		   or hits a limit before it hits the switch, the home is
		   aborted. */
		/* have we hit the home switch yet? */
		if (home_sw_active) {
		    /* yes, where do we go next? */
		    if (joint->home_flags & HOME_USE_INDEX) {
			/* look for index pulse */
			joint->home_state = HOME_INDEX_SEARCH_START;
			immediate_state = 1;
			break;
		    } else {
			/* no index pulse, stop motion */
			joint->free_tp_enable = 0;
			/* go to next step */
			joint->home_state = HOME_SET_SWITCH_POSITION;
			immediate_state = 1;
			break;
		    }
		}
		home_do_moving_checks(joint);
		break;

	    case HOME_FALL_SEARCH_START:
		/* This state is called to start the final search for the
		   point where the home switch releases.  It moves at
		   'latch_vel' and looks for a falling edge on the switch */
		/* is the joint already moving? */
		if (joint->free_tp_active) {
		    /* yes, reset delay, wait until joint stops */
		    joint->home_pause_timer = 0;
		    break;
		}
		/* has delay timed out? */
		if (joint->home_pause_timer < (HOME_DELAY * servo_freq)) {
		    /* no, update timer and wait some more */
		    joint->home_pause_timer++;
		    break;
		}
		joint->home_pause_timer = 0;
		/* we should still be on the switch */
		if (!home_sw_active) {
		    reportError(
			"Home switch inactive before start of latch move");
		    joint->home_state = HOME_IDLE;
		    break;
		}
		/* set up a move at 'latch_vel' to locate the switch */
		home_start_move(joint, joint->home_latch_vel);
		/* next state */
		joint->home_state = HOME_FALL_SEARCH_WAIT;
		break;

	    case HOME_FALL_SEARCH_WAIT:
		/* This state is called while the machine is moving away from
		   the home switch on its final, low speed pass.  It
		   terminates when the switch is cleared. If the move ends or
		   hits a limit before it clears the switch, the home is
		   aborted. */
		/* have we cleared the home switch yet? */
		if (!home_sw_active) {
		    /* yes, where do we go next? */
		    if (joint->home_flags & HOME_USE_INDEX) {
			/* look for index pulse */
			joint->home_state = HOME_INDEX_SEARCH_START;
			immediate_state = 1;
			break;
		    } else {
			/* no index pulse, stop motion */
			joint->free_tp_enable = 0;
			/* go to next step */
			joint->home_state = HOME_SET_SWITCH_POSITION;
			immediate_state = 1;
			break;
		    }
		}
		home_do_moving_checks(joint);
		break;

	    case HOME_SET_SWITCH_POSITION: