- #1
aaddcc
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Hi everyone,
I've been racking my brain about this problem, but can't seem to figure it out. It seems like it should be easy, but I keep getting confused. Let's say I have an arbitrary parametric curve [itex]r(t)=<x(t), y(t)>[/itex]. I want the velocity in the tangential direction to be constant. That clearly means that the x and y components of velocity cannot be constant as the curve changes direction. I realize that the speed tangent to the path is considered [itex]|r'(t)|[/itex] (i.e. the magnitude of the velocity). That would imply that if I want a zero acceleration speed along the path I would need [itex](x''(t))^2+(y''(t))^2=0[/itex] (I removed the square root that is present in magnitude since it's zero)... Does that mean to solve for x(t) and y(t) I need to solve this second order differential equation? This is where I get confused, should the position function I get from calculating this differential equation be different than the original function I am given? Or will the original parametric function run at a constant speed to begin with?
The idea is that given a certain curve I'd like to get out x(t) and y(t) functions that run a constant speed along that curve. That means that the curves may be gotten via regression (i.e. someone draws the curve and it is modeled via splines or polynomials)
I've been racking my brain about this problem, but can't seem to figure it out. It seems like it should be easy, but I keep getting confused. Let's say I have an arbitrary parametric curve [itex]r(t)=<x(t), y(t)>[/itex]. I want the velocity in the tangential direction to be constant. That clearly means that the x and y components of velocity cannot be constant as the curve changes direction. I realize that the speed tangent to the path is considered [itex]|r'(t)|[/itex] (i.e. the magnitude of the velocity). That would imply that if I want a zero acceleration speed along the path I would need [itex](x''(t))^2+(y''(t))^2=0[/itex] (I removed the square root that is present in magnitude since it's zero)... Does that mean to solve for x(t) and y(t) I need to solve this second order differential equation? This is where I get confused, should the position function I get from calculating this differential equation be different than the original function I am given? Or will the original parametric function run at a constant speed to begin with?
The idea is that given a certain curve I'd like to get out x(t) and y(t) functions that run a constant speed along that curve. That means that the curves may be gotten via regression (i.e. someone draws the curve and it is modeled via splines or polynomials)
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