An expert system for generation of anti-G control schedule for jet fighter pilots

https://doi.org/10.1016/S0957-4174(01)00059-8Get rights and content

Abstract

The high maneuverability of modern jet fighters often subjects the pilots to high Gz acceleration. One of the adverse effects of Gz acceleration is the G-induced loss of consciousness. The current protection scheme includes a pressure mask that supplies the pilots with nominal positive pressure breathing and a nominal pressurized G-suit. This paper presents a novel approach based on a combination of expert knowledge, pilots' anthropometric and physiologic data to generate control schedules of the G-suit and mask pressures of jet fighter pilots.

Introduction

Modern jet fighters are far more technologically advanced and maneuverable than those of World War II. Therefore, high Gz acceleration is more severe and is often encountered in modern days. In order to minimize the adverse physiological effects of Gz acceleration, an anti-G protection system is used to apply pressure to the pilot's body and provide positive pressure airflow to the pilot's breathing mask. Unfortunately, the technology of the currently used protection systems has remained conceptually similar to the original anti-G-suit and valve of 1940s (Wood, Edward, Edward, & Charles, 1946). Clearly, the current protection scheme is inadequate in protecting the modern jet fighter pilots from adverse physiological effects such as insufficient eye-level blood pressure, during Gz acceleration. The inadequate eye-level blood pressure will eventually lead to potential G-induced loss of consciousness (G-LOC).

The shortcomings of the current protection system have stimulated the research for a new anti-G valve hardware, and its accompanying G-suit and positive pressure breathing (PPB) protection profiles generating software. In an earlier work, an electronic anti-G valve has been introduced (Goldenberg, James, Farrell, Meidan, & Shapiro, 1992). The availability of the electronic valve created the need for a software that is capable of generating the pressure profiles. The concept of incorporating expert experience and knowledge into a software for automated protection profile generation is proposed (Engineering Services Incorporated, 1998).

Section snippets

Current protection technique

Currently, mechanical valves control the pressurization of the anti-G-suit and PPB systems for CF-18 pilots. The mechanical valve contains a weight assembly that moves under the influence of G-force and causes the supply port to open proportionally to the applied G-force. The valve's diaphragm senses the pressure and the supply port begins to close as the suit pressure approaches the desired level. As the G-force decreases, the weight assembly moves upwards exposing the exhaust port and the

Anti-G protection expert system

Undoubtedly, the most popular mode of knowledge representation with expert systems is a knowledge base expressed in terms of sets of rules. The knowledge base of the anti-G protection expert system (AGPES) consists of a collection of fuzzy rules. Fuzzy rules represent a particularly natural mode of knowledge representation in the field of physiology where experience and intuition are essential in handling situations. The ease of modification of the knowledge base is essential in creating a

AGPES validation

In order to verify the effectiveness of the AGPES, the subject information of two arbitrary subjects A and B are used. Table 2 shows the subject information obtained from the subject questionnaires.

A typical +Gz profile consists of a rapid increase in acceleration (within 3 s) to a plateau level. The plateau is maintained for a certain duration of time. Then, the acceleration is brought down to the initial normal level. Fig. 9(A) shows an example of such a profile. In general, the corresponding

Conclusion

This paper has presented a novel AGPES for generating non-linear pressure control schedules for mask and G-suit of jet fighter pilots. The AGPES also acts as a systematic learning tool that provides aerospace physiologists and researchers the capability to extract underlying indices in raw physiological data that reflect the physiological status of any subject. The KBM can be modified easily to incorporate new knowledge of Gz acceleration physiology, as they become available. Now, customized

References (7)

  • E Cox

    The fuzzy systems handbook

    (1999)
  • Crosbie, R. J. (1983). A servo controlled rapid response anti-G valve, aircraft and crew systems directorate. Naval Air...
  • Engineering Services Incorporated (1997). NGL calibration for simulated G tests. Technical Report prepared for Defence...
There are more references available in the full text version of this article.

Cited by (2)

View full text