Figures (11)  Tables (4)

    • Figure 1. 

      The structure of fixed-wing UAV.

    • Figure 2. 

      Control flow block diagram of the proposed method.

    • Figure 3. 

      MUAVS communication topology schematic diagram.

    • Figure 4. 

      Estimation results of unknown disturbance under the IDO.

    • Figure 5. 

      Comparison of estimation results of unknown disturbance under the IDO and ESO.

    • Figure 6. 

      3D diagram of APF-based rectangular formation obstacle avoidance.

    • Figure 7. 

      3D diagram of CBF-based rectangular formation obstacle avoidance.

    • Figure 8. 

      Comparison tracking results and error for UAV3 under the CBF and APF.

    • Figure 9. 

      Comparison tracking results and error for UAV4 under the CBF and APF.

    • Figure 10. 

      Three-axis position tracking of UAV formation.

    • Figure 11. 

      Flight path angles and speed of the UAV formation.

    • Number X Y Z
      UAV1 0 3 5
      UAV2 0 −3 5
      UAV3 0 3 −5
      UAV4 0 −3 −5

      Table 1. 

      Relative position between UAV$ _i $ and UAV$ _0 $.

    • Number Obstacle position Obstacle radius
      Obstacle1 (30, 50, 41) 7
      Obstacle2 (45, 30, 35) 9
      Obstacle3 (50, 60, 45) 8
      Obstacle4 (70, 55, 75) 12
      Obstacle5 (80, 83, 85) 5

      Table 2. 

      Parameter setting of the obstacles.

    • Method $ {e_{3x}} $(m) $ {e_{3y}} $(m) $ {e_{3z}} $(m) $ {e_{4x}} $(m) $ {e_{4y}} $(m) $ {e_{4z}} $(m)
      CBF 1.00 3.19 4.71 3.07 4.40 5.74
      APF 4.15 6.23 8.41 2.74 3.73 11.92

      Table 3. 

      Average MAE of three-axis position.

    • Method $ {e_{3x}} $(m) $ {e_{3y}} $(m) $ {e_{3z}} $(m) $ {e_{4x}} $(m) $ {e_{4y}} $(m) $ {e_{4z}} $(m)
      CBF 1.40 3.19 4.71 3.89 4.67 5.76
      APF 5.29 6.27 8.89 7.69 4.54 12.81

      Table 4. 

      Average RMSE of three-axis position.