A recent progression of heavy lift assist device is to place the human operator closer to the end effector to provide close coupling of the operator input and the payload. This close coupling of the human for control and the power of a heavy lift assist device provides improved accuracy with ease of handling in the case of heavy and bulk objects. However, collisions with obstacles may still occur in a crowded manufacturing environment due to the large work piece inertia characteristics, inappropriate motion command from the operator and inattention or fatigue of the human operator. In this research, a fictitious force field is assigned to each obstacle in the workspace. As a work piece moves closer to an object, an impedance force is calculated and combined with the control forces, in order to prevent collisions. In addition, a set of impedance fields are developed and applied that associate desired trajectories with the layout of the workspace. Thus, the force fields guide the work piece to achieve advantageous orientations and positions during the material handling operation. This includes adjustment of the height of the work piece for placement on tables, orientation to preset positions, and optimizing the configuration of the lift assist robot during motion. Experimental results show that this approach to augmentation provides the operator with a natural and effective interface to the heavy lift assist device.