Day 48, Tuesday, 3 November, 2015 Inertial Navigation Systems The magical, mysterious, always everywhere box The ball in the trunk Dead Reckoning: Direction and Distance Roll, Pitch, Yaw and X, Y, Z Gyroscopes Mechanical Optical Accelerometers iPhone Inertial Navigation Units
Important motion equations avg v = ∆d/∆t = d f – d i / t f - t i avg a = ∆v/∆t = v f – v i / t f – t i d = d 0 + v t position with constant velocity d = d 0 + v 0 t + ½ a t 2 position with constant acceleration v = v 0 + a t velocity with constant acceleration d = d 0 + ½ (v + v 0 )t final position with constant velocity v 2 = v a (d – d 0 ) final velocity with constant acc tan = opp /adj direction of travel
Newton’s 3 Laws of Motion 1. Inertia: An object at rest will remain at rest. An object moving will move in a straight line with constant speed, if and only if the net force acting on it = F = ma 3. F a on b = -F b on a (for every action there is an = and opposite reaction)
A Ball in the Trunk
Dead Reckoning Direction Distance
Roll, Pitch, and Yaw
X, Y, Z Roll, Pitch, Yaw
Gyroscope Inertia keeps the spinning mass from moving out of the plane of rotation
Gyroscopic Stabilization Gyroscopic Stabilization is how bicycles stay up Old navy trick
An “Artificial Horizon” is a Mechanical Gyroscope
Optical gyroscopes Ring Laser gyroscope Fiber Optic Loop gyroscope
Inertial Navigation Unit using Gyroscopes and accelerometers Gyroscope (roll) differentiating circuit Gyroscope (pitch) differentiating circuit Gyroscope (yaw) differentiating circuit Accelerometer (X) integrating circuit Accelerometer (Y) integrating circuit Accelerometer (Z) integrating circuit
Circuits can Differentiate and Integrate
Differentiating Circuit
Integrating Circuit
Inertial Navigation System
Accelerometer on a microchip
The engineering term is “catastrophic failure”
Credits INS ples/PNG/inertial-navigation-system.png Differenitating and Integrating Circuits momanual/electricity_and_magnetism/ac_c ircuits/rc_integration_and_differentiation.ht ml
Credits II Gyroscope diagram 3D_Gyroscope%5B1%5D.png X, Y, Z and Roll, Pitch, Yaw diagram ges/7/7e/Roll_pitch_yaw.gif
Credits III Artificial Horizon HorizonIndicatorGyroscope.jpg Accelerometer on a microchip oscope.gif Ring Laser gyroscope media/16/ BDBE9561.jpg