In robotics, a robotic paradigm is a mental model of how a robot operates. A robotic paradigm can be described by the relationship between the three basic elements of robotics: Sensing, Planning, and Acting. It can also be described by how sensory data is processed and distributed through the system, and where decisions are made.

Hierarchical/deliberative paradigm

• The robot operates in a top-down fashion, heavy on planning.
• The robot senses the world, plans the next action, acts; at each step the robot explicitly plans the next move.
• All the sensing data tends to be gathered into one global world model.

The reactive paradigm

• Sense-act type of organization.
• The robot has multiple instances of Sense-Act couplings.
• These couplings are concurrent processes, called behaviours, which take the local sensing data and compute the best action to take independently of what the other processes are doing.
• The robot will do a combination of behaviours.

Hybrid deliberate/reactive paradigm

• The robot first plans (deliberates) how to best decompose a task into subtasks (also called “mission planning”) and then what are the suitable behaviours to accomplish each subtask.
• Then the behaviours starts executing as per the Reactive Paradigm.
• Sensing organization is also a mixture of Hierarchical and Reactive styles; sensor data gets routed to each behaviour that needs that sensor, but is also available to the planner for construction of a task-oriented global world model.