ABSTRACT

This chapter discusses how structure in the optical flow field can specify the state of the locomotion process and how the degree of specificity can be an important constraint on the control process. The perceptual component of the optimal control model generally assumes that the human operator is an “ideal observer” or Kalman filter with inputs that are functions of the “state variables” of the process being controlled. The strategy is to implicitly count the number of edges that pass by a particular optical locus. Controlled flight into terrain is a special example of the more general problem of collision control. The ratio of velocity to distance that specifies global optical flow rate specifies the instantaneous time-to-contact. The optical state space can be used to represent more than the optical boundaries. As an aircraft approaches the ground, the angular extent of objects on the ground expands in the optical flow field.