The touchscreen user interface is an inherently dynamic device that is becoming ubiquitous. The touchscreen’s ability to adapt to the user’s needs makes it superior to more traditional haptic devices in many ways. Most touchscreen devices come with a very large array of sensors already included in the package. This gives engineers the means to develop human-machine interfaces that are very intuitive to use. This thesis presents research that was done to develop a best touchscreen interface for driving an industrial crane for novice users. To generalize the research, testing also determined how touchscreen interfaces compare to the traditional joystick in highly dynamic tracking situations using a manual tracking experiment. Three separate operator studies were conducted to investigate touchscreen control of cranes. The data indicates that the touchscreen interfaces are superior to the traditional push-button control pendent and that the layout and function of the graphical user interface on the touchscreen plays a roll in the performance of the human operators. The touchscreen interface also adds great promise for allowing users to navigate through interactive textbooks. Therefore, this thesis also presents developments directed at creating the next generation of engineering textbooks. Nine widgets were developed for an interactive mechanical design textbook that is meant to be delivered via tablet computers. Those widgets help students improve their technical writing abilities, introduce them to tools they can use in product development, as well as give them knowledge in how some dynamical systems behave. In addition two touchscreen applications were developed to aid the judging of a mechanical design competition.

A helicopter can be used to transport a load hanging from a suspension cable. This technique is frequently used in construction, firefighting, and disaster relief operations, among other applications. Unfortunately, the suspended load swings, which makes load positioning difficult and can degrade control of the helicopter. This dissertation investigates the use of input shaping (a command-filtering technique for reducing vibration) to mitigate the load swing problem. The investigation is conducted using two different, but complementary, approaches. One approach studies manual tracking tasks, where a human attempts to make a cursor follow an unpredictably moving target. The second approach studies horizontal repositioning maneuvers on small-scale helicopter systems, including a novel testbed that limits the helicopter and suspended load to move in a vertical plane. Both approaches are used to study how input shaping affects control of a flexible element (the suspended load) and a driven base (the helicopter). In manual tracking experiments, conventional input shapers somewhat degraded control of the driven base but greatly improved control of the flexible element. New input shapers were designed to improve load control without negatively affecting base control. A method for adjusting the vibration-limiting aggressiveness of any input shaper between unshaped and fully shaped was also developed. Next, horizontal repositioning maneuvers were performed on the helicopter testbed using a human-pilot-like feedback controller from the literature, with parameter values scaled to match the fast dynamics of the model helicopter. It was found that some input shapers reduced settling time and peak load swing when applied to Attitude Command or Translational Rate Command response types. When the load was used as a position reference instead of the helicopter, the system was unstable without input shaping, and adding input shaping to a Translational Rate Command was able to stabilize the load-positioning system. These results show the potential to improve the safety and efficiency of helicopter suspended load operations.