The knowledge representation and programming for robotic assembly task

Presents a knowledge representation and programming method for robotic assembly tasks. The methodology is explained through robotic assembly tasks with position and force control. The state space of assembly objects is abstractly defined using a qualitative landmark which consists of the state of an object and a robot. The current state and sensor input determines the next robot action, and the state of a robot is made to lead to the goal state. These concepts are formulated by using a finite state automaton. The action sequence is defined based on the control hierarchy structure which consists of four levels (control primitive level, control skill level, skill level and task level). The complicated assembly task can be represented by product and concatenation of control primitives in a lower level and various tasks can be defined by adding new control primitives. In the paper, the concept of a CRS (constraint reduction system) is introduced for making a robot task program. The CRS is realized by extended Prolog. All the action and primitives are considered as a process and can be uniformly described by the reduction rule of the CRS.