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Re: comments on basic framework draft

From: Gerken, Stephen <sgerken@jaguarlandrover.com>
Date: Tue, 21 Jan 2014 09:07:46 -0800
Message-ID: <CAKt9RvrjUktVgQhZeWPC=+ArCLhfbmaHmHTG2VHcZfvLWUOFtw@mail.gmail.com>
To: jongseon.park@lge.com
Cc: "Rees, Kevron" <kevron.m.rees@intel.com>, Andy Gryc <AGryc@qnx.com>, public-autowebplatform@w3.org, Grant Courville <GCourville@qnx.com>, Tina Jeffrey <tjeffrey@qnx.com>
Hi Justin, Kevron, et al,

Thanks much for all your additional comments.

Kevron, you're quite correct that there is some awkwardness in array
comparisons.  Note further that an array [ Left, Front ] != an array [
Front, Left ], while for purposes of hardware location they are the same.
 For such purposes, where I used array, perhaps a better term would be
unordered set, although that is a math term not so much a programming one.

Justin, I think:
1) We should certainly allow hardware_device.zone[0] = Rear without
designation of left/center/right. Heating or a/c zones may differentiate
only into front left, front right, and rear, i.e. the rear zone is not
differentiated side to side.

2) What we really want for storage is an unordered set, not an array.  I
think Kevron is making IDL changes towards wrapping Zone in an API so users
may treat it as an unordered collection even if underneath it is
implemented in an array.  I have yet to read the updated IDL but wanted to
make sure I put in a reply before comments close.

3) We will not restrict combinations to those we think are valid, because
we trust that implementors may be more inventive than we are and will find
valid useful combinations that we haven't imagined.

4) An accelerometer has both a physical location in the vehicle, and also
an axis along which it is sensitive.  So, a manufacturer may put
accelerometers at multiple locations in the vehicle, perhaps one in front
center and one in rear center.  For each of these, it would be useful to
know both where it is located, and also whether the axis or axes on which
it is sensitive are vertical, horizontal forward/back, or horizontal side
to side.

I should note also that if an X/Y/Z coordinate system is used, these terms
need to be defined.  One manufacturer might consider the x/y plane to be
that tangent to the road at the location of the car, with the Z axis
vertical, while another might consider the x/y plane to be that tangent to
the front bumper of the car, with the Z axis horizontal along the driving
direction of the car.


Steve Gerken
-------------------
Linux Developer
MSX, as broker for Jaguar Land Rover

One World Trade Center, 121 SW Salmon Street, 11th Floor, Portland, Oregon,
97204
Email: sgerken@jaguarlandrover.com


On 21 January 2014 01:25, 박종선(Justin Park) <jongseon.park@lge.com> wrote:

> I have no objection to using array.
>
> Usually, zones have been defined as complete compound words as like
> "FrontLeft", "RearRight".
> It's much simpler although it has a limitation for extension.
>
> If we use a combination of "Front" and "Left" in an array, we need to
> consider something more.
>
> 1) Do we allow seatPosition.zone[0] = "Front" (without following 'left',
> 'center', 'right') ?
>    In case of 'Setting', users may want the command to take an effect on
> whole 'front' seats.
>
> 2) Do we allow seatPosition.zone[0] = "Left", seatPosition.zone[1] =
> "Front" as an opposite sequence?
>    If we don't restrict which element can be located in the array, the code
> must be much complicated.
>    So, we may need to make a rule as like that "Front", "Middle", "Rear"
> must be the first element of the array.
>
> 3) We will not care about which combination is possible.
>    It depends on the implementer, and if wrong or non-existing combination
> is used,
>    the system shall respond that 'It's not supported'. That's all. Right?
>
> 4) It's hard to imagine how to use X, Y, Z coordinates to zone with 'left',
> 'front' things.
>     I think it would be more clear to separate x, y, z axis from zone for
> the data types fit to those system.
>
> Is there any missing things to be considered?
>
>
> -----Original Message-----
> From: Rees, Kevron [mailto:kevron.m.rees@intel.com]
> Sent: Tuesday, January 21, 2014 2:09 AM
> To: Andy Gryc
> Cc: Gerken, Stephen; public-autowebplatform@w3.org; Grant Courville; Tina
> Jeffrey
> Subject: Re: comments on basic framework draft
>
> Having zones represented as an array seems reasonable.  In my own use
> cases, code would only have to modified slightly but ease-of-use is still
> preserved.  For example, instead of checking the  bitfild if the attribute
> is in "Front", you can use indexOf() with the same effect.
>
> If Justin is okay with using an array, I'll make the change with the other
> changes and push it for additional comment.
>
> -Kevron
>
>
>
> On Mon, Jan 20, 2014 at 8:12 AM, Andy Gryc <AGryc@qnx.com> wrote:
> > Thanks so much Stephen, I'm very glad that you helped fill out the
> > discussion we had on Tuesday.
> >
> > I completely agree with your comments regarding bitfields and how they
> > may not work for the purpose of extendability-I mentioned the same
> > concern on the call. The concept of lists will be needed elsewhere
> > too, so I think it's important that they are supported. For example,
> > in the QNX piece that I added types & ranges too, the same need for
> > lists came up in describing door configurations. I'll have to leave it
> > up to Kevron, Justin and anyone else WebIDL-expert who wants to chime
> > in (Paul? Aldric?) on precisely how we would implement it.
> >
> > I'm not sure what the right representation of zone would be, but thank
> > you so much for your use cases. They will greatly help us in figuring
> > out a proper representation.
> > --Andy
> >
> > From: <Gerken>, Stephen <sgerken@jaguarlandrover.com>
> > Date: Friday, 17 January, 2014 4:29 PM
> > To: "public-autowebplatform@w3.org" <public-autowebplatform@w3.org>
> > Subject: comments on basic framework draft
> > Resent-From: <public-autowebplatform@w3.org>
> > Resent-Date: Saturday, 18 January, 2014 5:17 PM
> >
> > Hi all,
> >
> > Below please find comments on the basic framework draft as found at
> > https://raw.github.com/tripzero/automotive-bg/master/vehicle_spec.html
> > as of 17th January 2014.
> >
> > The general appearance of the document is consistent with expectations
> > for a W3C standard.  The document is well laid out and well organized.
> >
> > The concept of "zone" as presented in the draft appears to be an
> > attempt to capture the concept that multiple sensors on a vehicle will
> > report data of the same data type, and that within a group of such
> > sensors reporting on a common data type, it may be useful to
> > distinguish individual sensors from one another on a basis of physical
> > location.  While the underlying concept is sound and worthwhile, the
> > particular implementation of "zone", as detailed in the draft, is
> incomplete.
> >
> > As drafted, "zone" is a solely planar distinction, with bitfielded
> > values for front/mid/rear, left/center/right.  For some vehicle
> > equipment, this division may be sufficient; many passenger car models
> > have four wheels, four seats, and four or five doors, which can be
> > adequately described as a wheel in the front right zone, a seat in the
> > rear left zone, or a door in the center rear zone (a hatchback).
> > However, even with these mundane examples, zones as currently
> > described do not adequately disambiguate equipment.  Some full-size
> > pickup trucks have dual rear wheels; for such models, "tire pressure
> > on wheel in right rear zone" describes two pressure sensors, one for
> > each of the dual right rear wheels.  We should not assume that no future
> vehicle with dual wheels will be a passenger car.
> >
> > Additionally, other equipment types will not disambiguate easily in a
> > planar zone concept.  For example, existing JLR models have up to 24
> camera views.
> > Some cameras may be front-mounted but side-facing, while others may be
> > front-mounted but rear-facing.  There may be camera clusters in which
> > many cameras share a common mount point, for example in the rear right
> > quadrant, and for which the cameras are distinguished from one another
> > by view angle, view direction, spectrum of sensitivity, resolution, or
> > other factors not contained in a planar zone concept.  Generally,
> > equipment types for which a planar zone does not adequately locate a
> single sensor include:
> >  + microphones, which may have multiple vertical placements within a
> > given planar zone;  + microphones, again, in that two mics in close
> > physical proximity may have different sensitivities;  + audio
> > speakers, which may have multiple vertical placements within a given
> > planar zone;  + audio speakers, again, for which woofers and tweeters
> > may share a planar zone;  + tire pressure, in the case of dual wheels
> > mentioned above;  + accelerometers, which in addition to physical
> > location, also have axes of sensitivity;  + cameras, which may have
> > differences of view angle, view direction, spectrum, and resolution as
> > discussed above;  + airbags, for which a right front zone may have
> > multiple airbags located in a body pillar and in the roof,
> > collectively forming a side curtain, and also an additional airbag
> > located in the front of the right front zone in the dash.
> >
> > In light of the above examples of the diversity of sensors in modern
> > vehicles, and bearing in mind the creativity of current and future
> > automotive engineers, it would seem prudent to permits manufacturers
> > to specify bases for disambiguation of equipment which are not
> > restricted to a purely physical planar location, or even to a
> > predetermined set of bases of which we are currently aware.
> >
> > As a technical point on the specific implementation of Zone, the
> > current implementation is as a bitfield.  This means Zone exists as a
> > single field within the interface, which is masked against predefined
> > constants in order to extract information from that field about which
> > specific zones are on or off.  Effectively, the Zone field carries
> > information as a fixed-length array of boolean values, where the array
> > length is either 16 (for a short, as currently defined) or 32 (if
> > altered to a long). With either 16 or 32 maximum possible masks, it is
> > entirely possible that the number of actual useful bases of
> > disambiguation would exceed the array length, leading to an awkward
> > overlaying situation; if this data type is for microphones, 0x80 means
> > speech spectrum, but if this data type is for speakers, 0x80 means
> > tweeters.  While subtyping the zone masks based on the data type is a
> > possible means of extending the zone space beyond 16 (or 32) values,
> > this approach is awkward to document and difficult to code correctly, and
> should be avoided if possible.
> >
> > It would be preferable for Zone to be an actual array, not a bitfield.
> > If Zone were an actual array, it could still be an array of ints, but
> > since masks wouldn't be necessary, the number of meaningful values of
> > those ints could be 2 ^^ 16 instead of 16.  So for example:
> > const short Front = 0x0001;
> > const short Middle = 0x0002;
> > const short Rear = 0x0003;
> > const short Left = 0x0004;
> > const short Center = 0x0005;
> > const short Right = 0x0006;
> > const short Xaxis = 0x0007;
> > const short Yaxis = 0x0008;
> > const short Zaxis = 0x0009;
> > ...
> > const short MfgBase = 0x8000;
> > const short JLROuter = MfgBase + 0x0040; const short JLRInner =
> > MfgBase + 0x0041; ...
> > VehicleCommonDataType{ ... readonly attribute Zone[] zone; ... }...
> > such that a returned instance tpres of VehicleTirePressureDataType has
> > tpres.zone[0] == Rear, tpres.zone[1] == Left, tpres.zone[2] == JLRInner.
> >
> > Also, as a minor copyediting detail, the word "information" in the
> > draft is variously misspelled as "inforomation" and "Infomration".
> >
> > Generally however it's clear that a lot of effort and thought has gone
> > into bringing the document to it's current draft state, and there is
> > good material here which is worth building upon as the scope of the
> > document is fleshed out.
> >
> > Regards,
> > Steve Gerken
> > -------------------
> > Linux Developer
> > MSX, as broker for Jaguar Land Rover
> >
> > One World Trade Center, 121 SW Salmon Street, 11th Floor, Portland,
> > Oregon,
> > 97204
> > Email: sgerken@jaguarlandrover.com
> >
>
>
Received on Tuesday, 21 January 2014 17:08:16 UTC

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