Grid Surface
Libraries:
Simscape /
Multibody /
Curves and Surfaces
Description
The Grid Surface block creates a Cartesian grid surface that you can use to model contact problems. The Grid Surface block supports the contact with the Point or Point Cloud block. You must use the positive normal side of the grid surface for contact, which the positive z-axis of the reference frame points to. Otherwise, the contacting part will be ejected to the positive side through the surface.
The grid surface has a similar format to the grid generated by the ndgrid
function in MATLAB®. To model a grid surface, use the X Grid Vector and Y Grid Vector parameters to specify
the coordinates in the x and y directions of the
grid surface, then use the Z Heights parameter to specify
the elevations of the grid points in the z direction. You can use the
block to create a surface that represents a square, rectangular, or non-uniform
grid.
The image shows an illustration of a grid surface whose Z Heights
parameter is specified as [0 0 0.5 0.5; 0 0 0.5 0.5; 0 0 0 0; 0 0 0
0]
. The columns of the matrix are along the x-axis, and
the rows of the matrix are along the y-axis.
To create a grid surface using LiDAR data, you must convert the scattered data to gridded
data before using it in the Grid Surface block. To
convert the data, you can use a scatteredInterpolant
object to create an
interpolant function by using the x, y, and
z values of the LiDAR data, create x and
y grid vectors that represent the domain of the grid, then use
the grid vectors as the query points of the interpolant function to produce
z values of the grid surface. The produced z
values form a matrix in the ndgrid
format that can be used to
specify the Z Heights parameter. You can also use the griddata
function to produce z values for a grid
surface, but you need to transpose the output matrix to the ndgrid
format.
Note
To have the best simulation performance, the spacing in the x
and y grid vectors should be as large as possible but small
enough to represent the surface with sufficient accuracy. To change the spacing of
the grid vectors and compute the corresponding z values , you can
use the griddedInterpolant
object or interp2
function.
Generally, you need to clean the LiDAR data before converting it to gridded data, such as
removing outliers or NaN values. To clean the data, use the isnan
and isoutlier
functions.
Ports
Frame
Geometry
Parameters
Version History
Introduced in R2021b
See Also
Spatial Contact
Force | Point Cloud | griddata
| isnan
| isoutlier
| scatteredInterpolant
| griddata
| griddedInterpolant
| interp2