View Single Post
  #21   Spotlight this post!  
Unread 07-10-2013, 19:36
RyanCahoon's Avatar
RyanCahoon RyanCahoon is offline
Disassembling my prior presumptions
FRC #0766 (M-A Bears)
Team Role: Engineer
 
Join Date: Dec 2007
Rookie Year: 2007
Location: Mountain View
Posts: 689
RyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond repute
Re: calculating position using follower wheels

Quote:
Originally Posted by Ether View Post
5a) What are the XY coordinates 30 seconds later?
Spoiler for 5a:
T=0: (0,0) pi/12 (from +Y axis)

F(t) = 5*sin(t/2)
S(t) = 4*sin(t/2.2)
dQ = 1.5*sin(t/2.5)

Q(t) = (Integrate[1.5*Sin[t/2.5], t, 0, t]) + Pi/12 = 4.0118-3.75*Cos[0.4*t]

T=30:
dX(t) = F(t)*Sin[Q(t)]+S(t)*Cos[Q(t)]
X = Integrate[dX(t), t, 0, 30]
= Integrate[5*Sin[t/2]*Sin[4.0118-3.75*Cos[0.4*t]] + 4*Sin[t/2.2]*Cos[4.0118-3.75*Cos[0.4*t]], t, 0, 30]
= -5.94429

dY(t) = F(t)*Cos[Q(t)]-S(t)*Sin[Q(t)]
y = Integrate[dY(t), t, 0, 30]
= Integrate[5*Sin[t/2]*Cos[4.0118-3.75*Cos[0.4*t]] - 4*Sin[t/2.2]*Sin[4.0118-3.75*Cos[0.4*t]], t, 0, 30]
= -9.11027


Quote:
Originally Posted by Ether View Post
5b) What is the path length traveled during that 30 seconds?
Spoiler for 5b:
T=0: (0,0) pi/12 (from +Y axis)

FWD = 5*sin(t/2) ft/s
STR = 4*sin(t/2.2) ft/sec
RCW = 1.5*sin(t/2.5) radians/sec

T=30:
distance = Integrate[Sqrt[(dX(t))^2+(dY(t))^2], t, 0, 30]
= Integrate[Sqrt[(5*Sin[t/2]*Sin[4.0118-3.75*Cos[0.4*t]] + 4*Sin[t/2.2]*Cos[4.0118-3.75*Cos[0.4*t]])^2+(5*Sin[t/2]*Cos[4.0118-3.75*Cos[0.4*t]] - 4*Sin[t/2.2]*Sin[4.0118-3.75*Cos[0.4*t]])^2], t, 0, 30]
= 129.597
__________________
FRC 2046, 2007-2008, Student member
FRC 1708, 2009-2012, College mentor; 2013-2014, Mentor
FRC 766, 2015-, Mentor
Reply With Quote