The paper presents a holistic robot system specification methodology taking into account both the system structure and its activities. It is based on the concept of an embodied agent. Each agent is decomposed into cooperating subsystems. Previously subsystem activities were defined by a hierarchical finite state machine (HFSM). In that approach communication between subsystems was not specified explicitly. This paper utilises a Hierarchical Petri Net (HPN) with conditions as an alternative modelling tool. HPN can be obtained by transformation of the HFSM into HPN. The resulting HPN consists of consecutive layers: subsystem layer, behaviour layer and communication layer. The proposed methodology not only organizes in a systematic and holistic manner the development of the robot system, but also introduces a comprehensive description of concurrently acting subsystems. The HPN description can be utilised to automatically generate the robot controller code.

A robot system is designed as a set of embodied agents. An embodied agent is decomposed into cooperating subsystems. In our previous work activities of subsystems were defined by hierarchical finite state machines. With their states activities were associated. In that approach communication between subsystems was treated as an implementation issue. This paper represents activities of a robot system using hierarchical Petri nets with conditions. Such net is created by specifying consecutive layers: multi-agent robot system layer, agent layer, subsystem layer, behaviour layer and communication layer. This decomposition not only organizes in a systematic manner the development of a robot system, but also introduces a comprehensive description of concurrently acting subsystems. Based on those theoretical considerations, a tool was created for producing hierarchical Petri nets defining the model of a robotic system and enabling automatic generation of the robot controller code, resulting in a significant acceleration of the implementation phase. The capabilities of the tool are presented by the development of a robot controller performing a rudimentary task.

The paper presents a robotic system design methodology based on the concept of an embodied agent decomposed into communicating subsystems, whose activities are specified in terms of FSMs invoking behaviours parameterised by transition functions and terminal conditions. In the implementation phase, this specification is transformed into a system composed of a whiteboard providing communication means and logically labelled FSMs (LLFSMs) defining the system behaviour. These concepts are used to generate the code of the robot controller. The inclusion of inter-subsystem communication model completes the resulting system design with respect to our previous work that did not account for this model. Thus communication plays a central role in this presentation. The design methodology is exemplified with a rudimentary table tennis ball-collecting robot. The presented methodology and the implementation tools are suitable and beneficial for application to the design of other robotic systems.