On the Safety Design of Flight Control

The previous articles mainly talked about several points that must be done to develop a flight control. Different from the development of ordinary developers, the safety of flight control is the most important issue for consumer goods flight control and even industrial flight control. Let's briefly talk about the safety design of flight control by combining the open source PX4 firmware.

First, discuss the fault situation of flight control.

I have been doing research on aircraft for so many years, and I have always done it with awe. After all, things that fly in the sky fall horribly, and I am most afraid of watching a movie around a group of people who eat melons during the test. For various industrial applications, the safety of flight control is very important.

For safety design, we must first consider the fault situation. Generally speaking, flight control failures have the following aspects:

1. Communication failure

Real-time communication is needed between the aircraft and the ground terminal (remote controller or ground station). If communication fails, the consequences will be very serious, so flight control software needs to consider this factor. Communication failures are mainly:

A) loss of remote control signal

If the remote control signal is lost, the natural flying hand can't effectively control the aircraft, which is very dangerous. The author once encountered that the remote control was out of power, which caused the aircraft to blow up out of control. To add, the remote control is not calibrated before takeoff. Because the remote controller is calibrated, there is something wrong with the operation schedule of the remote controller in the flight control software, and the consequence is that the actual flight response is inconsistent with your operation, and then a flight accident occurs.

B) ground station signal loss

Generally speaking, this problem mainly exists when the flight control is fully autonomous, which has a lot to do with the data transmission equipment. Without the instruction of the ground station, the aircraft is in an unknown state.

2. Sensor failure

There are many sensors on the flight control. If the sensors fail, it will directly affect the flight stability. Regarding the sensors, it is also necessary to have a corresponding hierarchical relationship between them according to the flight mode.