T HIS CHAPTER introduces important elementary building blocks character-izing the different multi-controller architectures developed throughout this 25

manuscript. Among these blocks let us cite: obstacle avoidance (based on LimitCycles) and target reaching/tracking elementary controllers. Their set-point definitions and main features will be emphasized showing their general use in several navigation tasks. Furthermore, a complete multi-controller architecture, dedicated to reactive navigation in cluttered environments will be presented. Some details about the perceptive aspects will also be discussed.