There exist many peculiar characteristics in robot workcell applications. Major difficulties in the development arise in the followings; concurrency, autonomy, safety criticality, and real-time processing. The characteristics having been directly connected with requirements of robot programming. In addition, the level of abstraction in the robot programming is expected to be of the task-level in which capabilities of specification of objects and their tasks are required in terms of 'what to do' rather than 'how to do'. Neither existing robot specific languages nor general purpose programming languages satisfy the requirements in full. To cope with these requirements a new methodology other than the sequential one is desirable. Object-oriented paradigm is regarded to be strong enough to represent the structures and the behaviors of real world entities into software objects, so the notions can be naturally applied to modeling the robots and machines in robot workcells into corresponding objects.
In this thesis an object model for concurrent object-oriented robot programming system is proposed and the language features based on this model is studied. Two-threaded active object model, named $Task^{GT}$ is designed to support the requirements of workcell applications. The $Task^{GT}$ contains job sequences of a robot and is designed to be consolidated with one passive object which represents the robot. Methods of the passive object consist of basic operations of the robot. This mechanism is called task-object consolidation. The task-object consolidation is a programming technique using the $Task^{GT}$ which reflects human behavior in that an object needs a task as a worker needs a list of jobs assigned to him/her. With this programming technique we could achieve code reuse in elegant manner by letting the passive object has functions of a machine while the $Task^{GT}$ contains job sequences of the machine. This enables the same $Task^{GT}$ can be reused for different machines at the same time or later on.
To examine the suggested object model AutoTask, a concurrent object-oriented robot programming language is also designed and a safety guarantee mechanism using $Task^{GT}$ is suggested in which static and dynamic hazards detection facilities including collision avoidance reside.
