Development and validation of four bar linkage kinematic & kinetic models of the upper limb and joystick for use in virtual prototyping

This thesis details the development of a four bar linkage kinematic model of the upper limb and a hydraulic actuation heavy equipment joystick, which was validated through the use of a motion capture system. The kinematic model was then expanded to a four bar linkage kinetic model of the upper limb and joystick. This 2-D dynamic model determines the joint forces and moments at the shoulder, elbow, and wrist of the joystick operator during forward and backward motions. Partial validation of the kinetic model was achieved by comparing the operator input torque as determined by the model to the operator input torque measured during laboratory testing. These models can be used in combination with operator anthropometrics and joystick dimensions to evaluate operator cab configurations virtually, thus reducing the need for prototype development.