Minimum-Information LQG Control - Part II: Retentive Controllers
For control theorists, this extends rate-distortion theory to controllers with memory, but the results are theoretical and incremental to Part I.
This paper formulates retentive control under communication constraints as a sequential rate-distortion problem, reducing it to a memoryless problem studied in Part I. It explores the structure of the optimal solution and its phenomenology.
Retentive (memory-utilizing) sensing-acting agents may operate under limitations on the communication between their sensing, memory and acting components, requiring them to trade off the external cost that they incur with the capacity of their communication channels. In this paper we formulate this problem as a sequential rate-distortion problem of minimizing the rate of information required for the controller's operation under a constraint on its external cost. We reduce this bounded retentive control problem to the memoryless one, studied in Part I of this work, by viewing the memory reader as one more sensor and the memory writer as one more actuator. We further investigate the structure of the resulting optimal solution and demonstrate its interesting phenomenology.