Maximizing the swing of a human-operated wrecking ball

A common use of mobile cranes is swinging a wrecking ball into structures to knock them down. This process is typically achieved by an experienced operator who moves the crane back and forth to increase the payload swing, thereby increasing the force at impact. This is a very challenging process, even for a highly-experienced crane operator. This paper analyzes a controller designed to aid the operator in achieving large-amplitude payload swings. The proposed controller is obtained by following a design method similar to input shaping. Usually, input shaping intercepts the operator's commands and modifies them so that they do not induce large oscillations. However, a similar method can be used to create commands that increase the oscillation. This paper illustrates the design process, then presents a series of operator studies that test the effectiveness of the controller in a small-scale wrecking application.