I've started moving my linear delta printer using LinuxCNC, and despite
using the joints-axis code, I'm still having non-trivial issues with
non-trivial kinematics.
Basically, the problem boils down to the "boxy" perspective of LinuxCNC,
where most limits (position, velocity, and acceleration) are
On Thu, Dec 26, 2013 at 09:17:18AM -0600, Charles Steinkuehler wrote:
> simple "move the joint until the switch closes". IMHO there needs to be
> a way to write programmable homing routines that can perform coordinated
> motion in joint and/or world space, But one thing at a time...
I don't see
On 12/26/2013 10:17 AM, Chris Radek wrote:
> On Thu, Dec 26, 2013 at 09:17:18AM -0600, Charles Steinkuehler wrote:
>
>> simple "move the joint until the switch closes". IMHO there needs to be
>> a way to write programmable homing routines that can perform coordinated
>> motion in joint and/or wor
The way I understand it - the kins are 'on top' of motion at the
moment. (I don't know if ja4 solves this - but I think it is the
start).. So motion calculates the xyzabcuvw limits - then they get run
through the kins module which could depending on the machine layout -
multiply or divide the
On Dec 26 2013 10:03 AM, Charles Steinkuehler wrote:
> On 12/26/2013 10:17 AM, Chris Radek wrote:
>> On Thu, Dec 26, 2013 at 09:17:18AM -0600, Charles Steinkuehler
>> wrote:
>>
>>> simple "move the joint until the switch closes". IMHO there needs
>>> to be
>>> a way to write programmable homing
2013/12/26 Charles Steinkuehler
> I'm more concerned about being able to set coordinated acceleration and
> velocity limits, so I can avoid having to perform X and Y moves at 57 %
> of my available max velocity and acceleration just so the occasional XYZ
> move doesn't exceed 100% of machine limi
On Thu, Dec 26, 2013 at 6:03 PM, Charles Steinkuehler <
char...@steinkuehler.net> wrote:
> On 12/26/2013 10:17 AM, Chris Radek wrote:
> > On Thu, Dec 26, 2013 at 09:17:18AM -0600, Charles Steinkuehler wrote:
> >
> >> simple "move the joint until the switch closes". IMHO there needs to be
> >> a w
On Thu, Dec 26, 2013 at 10:00:28PM +0200, Andrew wrote:
>
> The solution I can think of: calculating each joint velocity and
> acceleration before each move (at several points at least for a long moves)
> and then decreasing XYZ velocities to fit joint velocities to their limits.
This is exactly
On 12/26/2013 2:00 PM, Andrew wrote:
>
>> Details:
>> Given a maximum X, Y, and Z velocity of 1.0, the maximum speed of an XY
>> move is 1.414 (or SQRT(2)), and the maximum speed of an XYZ move is 1.73
>> (or SQRT(3)), so I have to set my limits to 1/1.73 (0.577) of the actual
>> limits or the mac
2013/12/26 Chris Radek
> On Thu, Dec 26, 2013 at 10:00:28PM +0200, Andrew wrote:
> >
> > The solution I can think of: calculating each joint velocity and
> > acceleration before each move (at several points at least for a long
> moves)
> > and then decreasing XYZ velocities to fit joint velocitie
2013/12/26 Charles Steinkuehler
> Yes, the problem can get arbitrarily hard, depending on exactly what you
> want to check and if you're doing things like mapping the move into
> joint space in order to run the check. That's a big reason I think the
> limit check(s) should be plug-able.
>
For no
2013/12/26 Andrew
> > Yes, that is very reasonable. Just calculate the scale and use usual
> planning.
> The task can also be reversed: increase world velocity to the maximum
> allowed by joint constraints. This can be useful for G0 moves.
>
Umm, sorry for offtopic, am I the only one to be missi
On Dec 26 2013 2:47 PM, Viesturs Lācis wrote:
> 2013/12/26 Andrew
>
>> > Yes, that is very reasonable. Just calculate the scale and use
>> usual
>> planning.
>> The task can also be reversed: increase world velocity to the
>> maximum
>> allowed by joint constraints. This can be useful for G0 mov
>
> The limits should definitely be pluggable to account at least for angular
> limits of ball joints etc.
> BTW some standard cone workspace for AB axes would be OK for many parallel
> robots.
>
> But usual kinematics module seems enough for velocities and accelerations
> check if the planner coul
2013/12/26 Robert Ellenberg
> >
> > The limits should definitely be pluggable to account at least for angular
> > limits of ball joints etc.
> > BTW some standard cone workspace for AB axes would be OK for many
> parallel
> > robots.
> >
> > But usual kinematics module seems enough for velocities
2013/12/26 EBo
> On Dec 26 2013 2:47 PM, Viesturs Lācis wrote:
> > 2013/12/26 Andrew
> >
> >> > Yes, that is very reasonable. Just calculate the scale and use
> >> usual
> >> planning.
> >> The task can also be reversed: increase world velocity to the
> >> maximum
> >> allowed by joint constrain
2013/12/27 Andrew
> 2013/12/26 Robert Ellenberg
> >
> > For many parallel robots some combinations of cones and cylinders can
> describe their actual workspace pretty well.
> For a serial robot arm it's can be more complicated but those cones and
> cylinders (along with joints limits) are much b
On 12/26/2013 3:52 PM, EBo wrote:
> On Dec 26 2013 2:47 PM, Viesturs Lācis wrote:
>> 2013/12/26 Andrew
>>
Yes, that is very reasonable. Just calculate the scale and use
>>> usual
>>> planning.
>>> The task can also be reversed: increase world velocity to the
>>> maximum
>>> allowed by joint
2013/12/26 EBo
> I was going to ask the same thing... If the issue is with the rapid
> traverse that is set limited with the max velocity. Are you sure that
> the max velocity is set correctly?
>
OK for a trivial kins this can be a solution. Max velocity can be limited
to joint velocity and jo
2013/12/27 Charles Steinkuehler
> So is there a "maximum feedrate" setting for g0 moves?
IMHO that is what max velocity in [TRAJ] section meant for.
Viesturs
--
Rapidly troubleshoot problems before they affect your bus
re: work envelopes
heres a simplified overview of several work envelopes
http://thnet.co.uk/thnet/robots/25.htm
regards
TomP tjtr33
--
Rapidly troubleshoot problems before they affect your business. Most IT
organizatio
On gio, 2013-12-26 at 16:28 -0600, Charles Steinkuehler wrote:
> On 12/26/2013 3:52 PM, EBo wrote:
> > On Dec 26 2013 2:47 PM, Viesturs Lācis wrote:
> >> 2013/12/26 Andrew
> >>
> Yes, that is very reasonable. Just calculate the scale and use
> >>> usual
> >>> planning.
> >>> The task can als
On Dec 26 2013 8:34 PM, TJoseph Powderly wrote:
> re: work envelopes
>
>
> heres a simplified overview of several work envelopes
> http://thnet.co.uk/thnet/robots/25.htm
> regards
> TomP tjtr33
I think the one that caused the initial issue is a delta-tau machine.
I cannot find a work envelope pi
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