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It is common to develop extensive dynamic models for new equipment early in the design stage. While dynamic characteristics are often determined from impulse, step, and sinusoidal inputs to the models, the actual response of the equipment will be a response to inputs made by the human using control levers, knobs and switches. The work described here is the use of a robot manipulator that allows the human to provide natural motion and force inputs to the simulated dynamic system and to use the response to evaluate the performance of the system and controls. A heavy lift assist device is used as the test system here, where an operator grasps handles attached to the lifting jaws, and uses a large partially powered mechanism to provide load support. The kinematic and dynamic model of this system are derived and programmed to provide the expected system output in response to human motion and force inputs.

The demand for increased performance of heavy earthmoving equipment has spurred the development of computer control for machinery using fluid power systems. Application of standard automatic control components to these systems provides the opportunity to implement advanced control approaches that reduce the operator workload and improve performance. In this work, closed-loop control is applied to the joints of a typical three-link digging device. Because the changing configuration of the device greatly changes the dynamic characteristics, an adaptive control algorithm is introduced to modify the control parameters to maintain consistent performance of the implement.