Open source flight control (Px4, ardupilot)

In UAV （ model airplane ） In addition to professional researchers , There are also many enthusiasts who come one after another . Like in a computer “ Save the machine ”, There are also many self-organizing UAVs 、 Modified playing method .

Open source flight control

Flight control as the body “ The brain ”, Secondary development 、 Important research objects .PX4 and ardupilot It is currently the most popular in the UAV industry 、 The most comprehensive and advanced flight control software , Their codes are github Hosted on .
We mentioned PX4 and ardupilot It is an open source flight control software , So what hardware platform do they work on ？ once ardupilot stay APM Up operation , But because of it 8 Bit processor system is under high load and gradually quits the stage of history . later ,ardupilot Be transplanted to Pixhawk On , The native software of the latter is PX4, Therefore, the two are basically unified in the hardware layer .
Be careful ardupilot It uses GPL agreement , Follow linux equally , It is not allowed to release the code after secondary development as closed source commercial software ,PX4 The use of BSD agreement , Allow commercial use , Therefore, companies generally use PX4 Do product development .

There are many pairs on the Internet PX4 Code interpretation , It may be the content of follow-up learning .

Research direction

The research of general flight control algorithm includes guidance 、 control 、 Navigation .
Navigation ： Fuse the data of each sensor （ gyroscope 、 Accelerometer 、 Magnetometer 、 barometer 、GPS、 camera ）, Finally, the flight status of the aircraft is obtained （ Posture 、 Speed 、 Location ）. This is the basis of the whole system , In closed-loop control “ feedback ”. Research in this area focuses on visual images , Traditional inertial navigation +GPS There is no research space .
control ： As expected , Calculate the... Of the actuator “ action ”. The simplest attitude control , The rocker on the remote control corresponds to the attitude expectation of the UAV . Complex trajectory tracking 、 Path tracking 、 Fly autonomously according to the route planned by the ground station . These are relatively mature for the current UAV , It is no longer a research hotspot .
guidance ： UAV intelligence , Carry out more complex tasks . Such as avoiding obstacles in real time on the route , It belongs to the research of obstacle avoidance algorithm ; Track a ground target on the route , Content belonging to target tracking ; Search a certain area in minimum time , It belongs to the content of path planning .

Reference resources ：

https://zhuanlan.zhihu.com/p/348087627 Composition of traversing machine
https://zhuanlan.zhihu.com/p/73405858 The past and present life of open source flight control