Development of airborne hardware and software requires thorough verification, which is costly and time-consuming. Controllers in modern aircraft are upgraded regularly after the initial entry into service.
Bypassing is based on the concept of rapid control prototyping (RCP) by emulating a controller using a real-time target machine and a Simulink® model of the control algorithm. During bypassing, the controller is integrated into the test setup while only certain functions or variables are changed and influenced by the real-time target machine. This saves time since you only need to adapt a small part of the code.
Bypassing requires the partitioning of the controller code. After this initial effort tasks such as testing new functions, parameter tuning, and certification verification can be executed much more efficiently.
Depending on the application and the controller hardware, there are several ways to perform bypassing. One way is to use bypass hooks or service calls to jump from the controller to the real-time system. Another method is to change values in the memory (RAM) to overwrite specific outputs of the functions.