PCT Home
Perceptual Control and Human Data Fusion
 

1. Introduction

2. Modes of Perception

3. Perceptual Control Introduction

4. Perceptual Control and imagination

5. Hierarchic Perceptual Control

6. Multiple data sources

7. Learning and Conflict

8. The Bomb in the Hierarchy

9. Degress of Freedom in the individual

10. Degrees of Freedom in the organization

11 Modes of Perception (Reprise)

12. Side Effects and Military intelligence

13. Communication

Basic elements of an Elementary Control System (ECS) showing an "imagination loop"

The simple ECS is not complete in the form shown earlier. It is capable of "imagining." In PCT, imagination is conceived as permitting the output to be connected directly back to the input. Since the output usually serves as a reference for lower-level perceptions that "should be" controlled to match their references, feeding back the output is equivalent to receiving those perceptions. It is the difference between a commander ordering "Take that hill" and the commander imagining "What would it be like if that hill were to be taken."

The ECS also can be augmented by the addition of a memory, which allows it to recapture a perception previously obtained, either in the form of a reference signal (which creates an error signal that leads to output) or as a perceptual signal perhaps together with a reference signal, leading to a perception but no error and thus no output.

Imagining: Planning

The imagination is not necessarily a direct connection between the output and the perceptual input function, as shown in the previous slide. It is likely to go through some kind of a world model, particularly at the higher control levels where the perceptual input function may be logical rather than analogue in form. The world model may well be implemented in parts of the complicated control network that are not currently being used for active control (and which might be specialized for the imagination function). It allows the output signal to have effects that are distributed over time, rather than being concentrated at the time the output signal is issued. The world model is built up through experience with the world, as well as by training. Testing out the likely effects of output by imagining through the world model is "planning."