Three discrete-time adaptive controllers are developed and applied to Four-bar linkage velocity control to reduce the input link velocity fluctuations without compromising the control system velocity transient response. The successful control techniques use the known mechanism kinematics and the mechanism input link position to control the nonlinear mechanism dynamics. The study shows that the adaptive controls are feasible to implement using current microprocessor technology, and the velocity control performance is improved when compared to an industry-standard analog servomotor control. However, more development is required to realize the full potential of the adaptive control technique. A nonlinear Four-bar dynamic model is developed using Kinematic Influence Coefficients. This model is used to develop the adaptive controls and to computer simulate the control scheme performances. The simulated model velocity response is compared qualitatively to experimental data and shown to be similar to an experimental device. / Master of Science