Advanced Control Techniques For Efficient And Robust Operation Of Advanced Life Support Systems

Abstract

This paper examines the structure and performance of three control strategies for a regenerative life support system constrained by mass balance equations. A novel agent-based control strategy derived from economic models of markets is compared to two standard control strategies, proportional feedback and optimal control. The control systems require different amounts of knowledge about the underlying system dynamics, utilize different amounts of information about the current state of the system, and differ in their ability to achieve system-wide performance goals. Simulations illustrate the dynamic behavior of the life support system after it is perturbed away from its equilibrium state or nominal operating point under the three different control strategies. The performance of these strategies is discussed in the context of system-wide performance goals such as efficiency and robustness.

Hypothesis: The Systemic Circulation as a Regulated Free‐market Economy. A New Approach for Understanding the Long‐term Control of Blood Pressure

“…The idea is derived from quantitative descriptions of the operation of free capitalistic markets, where large numbers of individual decisions by consumers and suppliers serve to allocate limited resources; the primary (but not only) source of communication between consumers and suppliers is through the price mechanism based on the complex laws of supply and demand. Human‐engineered control systems based on the market model have been devised to regulate processes as diverse as artificial life‐support environments, stability of large buildings or other civil structures, telephone and computers services and electric power distribution 10–12 . Here, I will explore the consequences of envisioning the long‐term control of arterial pressure as a process analogous to the operation of a free‐market economy using the simple expedient of assuming arterial pressure (or, more precisely, its reciprocal) is analogous to price.…”

“…However, the fact that free markets can result in relatively stable prices over long periods of time while allocating some resources in a manner acceptable to both consumers and suppliers suggests that this is viable control strategy. Theoretical work on market‐based control systems supports this contention 9–12 . Therefore, the design of the cardiovascular control system could have evolved to use a similar strategy; perhaps driven especially by the relative robustness of such decentralized control schemes.…”

“…Human-engineered control systems based on the market model have been devised to regulate processes as diverse as artificial lifesupport environments, stability of large buildings or other civil structures, telephone and computers services and electric power distribution. [10][11][12] Here, I will explore the consequences of envisioning the long-term control of arterial pressure as a process analogous to the operation of a free-market economy using the simple expedient of assuming arterial pressure (or, more precisely, its reciprocal) is analogous to price. I see two immediate benefits to this approach.…”

“…Theoretical work on market-based control systems supports this contention. [9][10][11][12] Therefore, the design of the cardiovascular control system could have evolved to use a similar strategy; perhaps driven especially by the relative robustness of such decentralized control schemes.…”