非定常耦合关联的多旋翼无人机自适应-非奇异终端滑模串级控制方法

Adaptive Non Singular Terminal Sliding Mode Cascade Control Method for Multi rotor Unmanned Aerial Vehicles with Unsteady Coupling Correlation

摘要:

多旋翼无人机在飞行过程中具有非定常耦合关联特性,导致其执行飞行任务容易受到外部扰动及惯性不确定性因素影响,难以保持良好的飞行平衡状态。为此,提出非定常耦合关联的多旋翼无人机自适应-非奇异终端滑模串级控制方法。该方法先考虑扰动风场、无人机负载等非定常耦合关联关系,检测无人机工作参数初始值。然后根据无人机飞行原理以及飞行任务,规划无人机的目标飞行轨迹,求解非奇异终端滑模串级控制目标。最后以构建的多旋翼无人机非奇异终端滑模面为外环控制、PID为内环控制,设计多旋翼无人机串级控制结构,根据飞行初始值与控制目标之间的偏差作为控制量,自适应生成非奇异终端滑模串级控制律,通过控制律的执行实现多旋翼无人机自适应-非奇异终端滑模串级控制任务。通过性能测试得出结论:在优化设计控制方法作用下,其转速控制误差、抖振程度以及最小奇异值取值更小,且在不同风场和负载工况下,多旋翼无人机的控制误差波动指数更低。优化设计方法在控制性能以及适应性能方面具有明显优势。

Abstract:

Multi rotor unmanned aerial vehicles have unsteady coupling characteristics during flight, which makes them susceptible to external disturbances and inertial uncertainties during mission execution, making it difficult to maintain good flight balance. Therefore, an adaptive non singular terminal sliding mode cascade control method for multi rotor unmanned aerial vehicles with unsteady coupling correlation is proposed. This method first considers the non-stationary coupling relationship between the disturbance wind field, drone load, etc., and detects the initial values of drone operating parameters. Then, based on the flight principle and mission of the drone, plan the target flight trajectory of the drone and solve the non singular terminal sliding mode cascade control objective. Finally, using the constructed non singular terminal sliding mode surface as the outer loop control and PID as the inner loop control, a multi rotor unmanned aerial vehicle cascade control structure is designed. Based on the deviation between the initial flight value and the control target as the control variable, an adaptive non singular terminal sliding mode cascade control law is generated, and the adaptive non singular terminal sliding mode cascade control task of the multi rotor unmanned aerial vehicle is achieved through the execution of the control law. The conclusion drawn from performance testing is that under the optimization design control method, the speed control error, vibration degree, and minimum singular value are smaller, and the fluctuation index of control error of multi rotor unmanned aerial vehicles is lower under different wind fields and load conditions. The optimization design method has significant advantages in terms of control performance and adaptability.