Coordinate System Standards?
Coordinate System Standards?
(OP)
I've nearly completed a 3D computer model of the chassis and suspension bits for a Lotus 41 but have realized I don't know what's used as the origin point or the orientation of the Cartesian Coordinate System that's normally used in the automotive industry. Is there any standard and what is it?
Keith
Keith





RE: Coordinate System Standards?
I have seen Z=0 at the bottom of the body, but that would introduce changes of sign for a lot of chassis work, so it is not a smart move.
Cheers
Greg Locock
RE: Coordinate System Standards?
That is the GM standard, and I believe Ford and DCX also use it. There is another known automotive standard (I want to attribute it to SAE, but I could be wrong). I remember seeing it about a decade ago and thinking it was quirky, but if it wasn't SAE it was an equally reputable source.
I recall this one had origin in about the same location as yours. Positive x was pointing to the drivers' left ("driver's side" in US, "passenger's side" to you Aussies), and positive y pointed toward rear of car. +z was "up"
The standard you describe is what I am most familiar with. If somebody can add or correct my 10-year-old recollection, please chime in.
Brad
RE: Coordinate System Standards?
Cheers
Greg Locock
RE: Coordinate System Standards?
Cheers,
Brad
RE: Coordinate System Standards?
The vehicle is divided into three planes X,Y,Z
Zero X plane (vertical transverse zero plane) runs roughly across the engine bulk head. Therefore X+ is to the rear of the vehicle. X- to the front of the vehicle.
Zero Y plane (Vertical longitudinal zero plane) runs through the longitudinal median of the vehicle. When facing the vehicle front Y+ is to the left of the zero plane and Y- to the right.
Zero Z plane (horizontal zero plane) runs roughly through the centre line of the wheels. Z+ is upwards, Z- is downwards.
Check the ISO standard for the exact positions.
RE: Coordinate System Standards?
Keith
RE: Coordinate System Standards?
X starts from the front of the car with positive direction towards the back of the car.
Z starts from the ground (bottom of wheels)
Y is at center of vehicle with positive direction toward the passenger side and negative is driver side