% MotionGenesis file: StationaryHelicopterRetrievalKane.txt % Problem: Retrieval of capsized fishermen. % Copyright (c) 2009 Motion Genesis LLC. All rights reserved. %------------------------------------------------------------ NewtonianFrame N % Earth. RigidFrame B % Cable. Particle Q % Rescue basket and fishermen. %------------------------------------------------------------ Q.SetMass( m = 100 kg ) Constant g = 9.8 m/s^2 % Earth's gravitational acceleration. Variable theta'' % Pendulum swing angle. Variable Tension % Tension in cable. Constant L0 = 50 m % Initial cable length. Constant s = 2 m/s % Rate at which cable is retrieved. Specified L'' % Cable length (varies). SetDt( L = L0 - s*t ) %------------------------------------------------------------ % Rotation and translation kinematics. B.RotateZ( N, theta ) Q.Translate( No, -L*By> ) %------------------------------------------------------------ % Add relevant contact and distance forces. Q.AddForce( -m*g*Ny> + Tension*By> ) %------------------------------------------------------------ % Form equations of motion using Kane's method. SetGeneralizedSpeed( theta' ) Zero = System.GetDynamicsKane() Solve( Zero, theta'' ) %------------------------------------------------------------ % Input initial values and numerical integration parameters. Input theta = 1 deg, theta' = 0 deg/sec Input tFinal = 24.92 sec, tStep = 0.02 sec %------------------------------------------------------------ % List output quantities and solve ODEs. OutputPlot t sec, theta deg ODE() StationaryHelicopterRetrievalKane %------------------------------------------------------------ Save StationaryHelicopterRetrievalKane.html Quit