1.      Platform Introduction

Formation control on multiple UAVs is the process of maintaining a certain relative distance between UAVs during multi-UAV movements and ultimately maintaining speed consistency. There are mainly three problems to be addressed in UAV formation flying:

a) Formation Design: For multiple UAVs to move to a designated location under commands and ultimately maintain the preset formation, we need to consider not only the pneumatic influence between UAVs but also the task requirements and redundancy of inter-UAV information exchange, while ensuring that UAVs do not collide with each other.

b) Formation Maintenance: While executing commands, UAVs can overcome internal or external environmental disturbance to maintain the entire formation.

c) Formation Change: During flight, UAVs can adapt to internal or external environmental disturbance to make proper changes to the formation.

This platform adopts the optical motion capture technology (the positioning accuracy can reach the mm level) for UAV indoor positioning and realizes inter-UAV communication via Wi-Fi. Users can use the Matlab-developed UAV formation simulation algorithm for automatic code generation and download it to UAVs to verify the multi-UAV distributed formation algorithm in an indoor environment.

2.      Platform Features

1. Supports formation flights of five to ten four-rotor UAVs;
2. Adopts the indoor optical motion capture technology, with the positioning scope of 5m x 5m; supports mm-level positioning and can capture more than 10 UAVs simultaneously;
3. Can realize HIL real-time control algorithm research on the Matlab/Simulink software platform, automatically generate code, and download it via Wi-Fi to the UAV flight control board;
4. The master control chip for UAV flight control adopts a robust 32-bit processor with robust functions and strong scalability: ARM Cortex A8 (dominant frequency 1G Hz, 800MHz video DSP), which possesses rich peripheral resources and robust operation capabilities; it is also provided with a front camera which is coupled with a special image processing chip, for image collection and real-time processing;
5. The UAV flight control supports the TCP/UDP communication protocols and supports the ROS function;
6. Can be used to analyze the performance of cooperation strategies in an actual system; in other words, multidisciplinary theories related to image processing, control engineering, wireless communication, etc. can be applied to realize indoor formation coordination, information exchange, task planning, etc. for multiple UAVs in unknown environments;
7. Can be used for dynamic modeling and control research, motion planning, obstacle avoidance control, multi-information integration, formation control, coordinated control of multiple intelligent objects, and autonomous control of UAVs.

3.      Experiment Contents

l  Simulink-Based Mathematical Simulation Experiments

• Stand-alone attitude control experiment;
• Stand-alone position control experiment;
• Airplane formation experiment;

l  Positioning System Experiments

• Motion capture system positioning experiment;
• Land mark positioning experiment;

l  Stand-Alone Flight Experiment

• IMU data collection experiment;
• Camera data collection and optical flow processing experiment;
• IMU and visual sensor data integration experiment;
• Stand-alone altitude-determination control experiment;
• Stand-alone optical flow hovering experiment;
• Stand-alone attitude control experiment;
• Stand-alone position control experiment;

l  Airplane Formation Flight Tests

• Airplane formation flight experiment based on motion capture positioning;
• Airplane formation flight experiment based on land mark positioning;