How do I change the turning radius?

[ferreirajoaouerj]

Thank you for making this package available! How do I change the maximum turning radius?

[nathanlct]

Thanks for your interest!

There is no option to change it right now. The original paper only prescribes turning around a unit circle (eg. a circle of radius 1). Maybe there are some papers since then that compute the formulas for arbitrary radiuses.

Looking at the formula for path1 for instance:

u, t = R(x - math.sin(phi), y - 1 + math.cos(phi))

I didn't doublecheck this but I believe to get a radius of size rho, you would do

u, t = R(x - math.sin(phi), y + rho * (- 1 + math.cos(phi)))

Which might need a bit more work derivating for the other formulas but definitely doable with some time.

Hope this helps!

[memo1400]

@ferreirajoaouerj @nathanlct do you have a solution now for changing the turning radius?

[nathanlct]

@memo1400 I did not work on this on my end.

Just thinking of this now but wouldn't it work to scale all the points then scale them back?

ie. multiply all initial (x,y) coordinates by rho, compute the paths with the current code (ie a turning radius of 1) then divide the paths by rho and you would get paths with a turning radius of 1/rho (just a thought, don't have time to verify this right now)

[limdingwen]

@memo1400 I did not work on this on my end.

Just thinking of this now but wouldn't it work to scale all the points then scale them back?

ie. multiply all initial (x,y) coordinates by rho, compute the paths with the current code (ie a turning radius of 1) then divide the paths by rho and you would get paths with a turning radius of 1/rho (just a thought, don't have time to verify this right now)

This works, thank you! For reference, this is my code:

# Converts our node to RS library's node
def node_us_to_rs(r, source):
    (source_x, source_y), source_angle = source
    rho = 1 / r
    return source_x * rho, source_y * rho, degrees(source_angle)


# Converts a PathElement to a Movement
def convert_path_element_to_movement(r, element):
    rho = 1 / r
    if element.steering is Steering.STRAIGHT:
        return Straight(DEFAULT_SPEED if element.gear is Gear.FORWARD else -DEFAULT_SPEED, element.param / rho)
    else:
        return Curve(DEFAULT_SPEED if element.gear is Gear.FORWARD else -DEFAULT_SPEED, element.param *
                     (1 if element.steering is Steering.RIGHT else -1))