When people work, they often take advantage of impacts between objects, for example, a worker impacts a nail with a hammer to drive it in. These impacts generate what are known as "impulsive forces" to do work. People take advantage of smaller impulsive forces to complete many common daily tasks too; inserting a key into a key hole, opening a stuck window, and cracking an egg. While the impacts between a plate and a table is much lighter than that applied to a nail, it is nonetheless just as useful. Today's robots have not been designed to take advantage of impulsive forces to accomplish tasks. The PI conducts an investigation into several fundamental and experimental issues surrounding impulsive robotic manipulation and develops methods for their use in robot control. Project results are advancing the theory of multi-body impacts and widening the capabilities of robots. Direct applications of the results are leading to faster and more agile robots for civil and military services and improved efficiency of industrial processes.
The technical goal of this project is to gain in-depth understanding about control of collision outcomes and, more importantly, integration of impact planning with motion planning in robot manipulation. The project consists of three phases. The first phase advances the Principal Investigator's recent work on compliant and multiple impacts to modeling of n-body simultaneous collisions, tackling issues that include state space condensation, impulse growth in high-dimensional space, sensitivity to physical parameters, and area and nonlinear contacts. In parallel with the analysis is the development of a graphical interface called MultiCollide for interactive collision simulation. The second phase investigates how a manipulator can impart via impact a desired motion to an object, solving an inverse impact problem that connects impact dynamics with trajectory planning and manipulator dynamics. The final phase focuses on two impulsive manipulation tasks that respectively address the following important issues: how to leverage contact compliance and geometry, and how to interleave impact planning with robot motion planning.