Testing if a point is reachable

Anyone have any advice testing to see if a point is reachable? I want to test to see if a point is reachable before attempting to run to it.

The kicker is that this is on a line tracking cell. The INRANGE function seems to not work on this type of robot, and after discussing with Kawi tech support, it only checks if the passed in point is within joint bounds, and not if it is reachable or not. It was returning a 64 everytime, but once I opened up the bounds on J7 (the conv tracking axis), it just returned 0 for every point tested, even for points obviously unreachable.

My next attempt was to attempt to convert a pose to joint, and use the error catch of ONE if the conversion failed. Either I didn't setup right, as the controller faults the moment I attempt the conversion. The ONE program is never entered/called.

.PROGRAM reachable()
ONE reachable_err
retry:
reachable = TRUE
POINT #jtest_point = test_point
IF NOT reachable GOTO retry
PRINT 4: "Point reachable"
.END
.PROGRAM reachable_err()
PRINT 4: "In Reachable_err"
PRINT 4: "Point not reachable"
reachable = FALSE
RETURNE
.END

My next idea is to write an IK solver in AS, but I would prefer not to do that.

Quote from kwakisaki

What is it you are actually looking at being reachable and at what point in the process?

When you start tracking, at what point are you looking whether it is reachable or not?

It all depends on how fast the algorithm for reachability checks ends up being. Ideally I would like do to the check repeatably while the conveyor is moving before moving to a point, and then releasing the robot to move when the point becomes reachable. Maybe with some padding so the robot doesn't get into an elbow lock position.

If I can't do it real time, I would like to develop an offline check that would output a range on conveyor for when a specific point is reachable.

Quote from kwakisaki

Is this for outside of the robot envelope (error), or within a certain zone to cancel the tracking of it?

For outside of robot envelope.

Quote from kwakisaki

Have you looked at CVPOS command?

Yes, I will need to use that command to pull out the current conveyor value for in range testing.

Quote from kwakisaki

Have you looked at ULIMIT and LLIMIT commands?

Haven't looked at these, but after looking at them in the AS manual, I'm not sure they will help that much. I'd like to keep the joint limits of the robots as open as possible.

Quote from kwakisaki

Have you looked at DISTANCE and DEST commands?

DISTANCE will be used if I have to go with the IK solver idea. I don't plan on using DEST as I only want to do the check before moving to the next point.

Maybe I can use distance to check the current position vs where the next point is. I would like to check orientation though.

I got it to work.

Inrange does function as a reachability test, but with how Kawasakis do their line tracking point teaching, it is pretty counter intuitive. From my testing, INRANGE checks reachability of the XYZOAT position of the pose, and then just checks to see if the ext axis is within the motion limits.

Since how I was originally using INRANGE was effectively testing taught points, so of course every point was reachable. The key is to shift the XYZOAT of the along the conveyor tracking vector by the delta of where the point was taught, and where the conveyor currently is, then run the inrange test.

I'm not in control of the touch up of the path, so when the people responsible for the the touchup finish, I want to verify if my chosen CVWAIT positions are still valid.

Also, the robot is overloaded in terms of its path. I need every mm of upstream real estate I can grab in order to not fall behind.

In addition to all that, the entire path is shifted by a vision system. One point that may be reachable at a certain conveyor position may be reachable in one offset, and not another.

Since I got it working I was able to make a graph of the upstream reachability of one of the paths: