多无人机绳索悬挂协同搬运固定时间控制

Fixed-time Control for Cooperative Transportation of Payloads Suspended by Tethers from Multiple UAVs

针对多无人机绳索悬挂协同搬运跟踪控制问题,设计了一种新的固定时间协同跟踪控制算法。首先,通过旋量分析,计算系统不同状态下的有效旋量空间,并根据静力学平衡计算系统在有效旋量空间约束下的拉力容许裕度。其次,在保证绳索张紧以及最大拉力约束的条件下,基于微分平坦性以及绳索拉力优化分配算法,规划编队的期望跟踪轨迹。然后,基于Udwadia-Kalaba方程建立系统动力学模型,设计了连续的基于类超扭滑模和积分滑模的鲁棒控制项,以补偿系绳拉力给无人机造成的扰动,并设计了基于双极限齐次性原理的固定时间无人机协同外环位置控制器。针对无人机内环姿态稳定控制,设计了固定时间姿态稳定控制器。仿真结果表明,绳索拉力满足张紧和最大拉力约束,且设计的固定时间协同跟踪控制算法保证了系统在固定时间内稳定跟踪期望轨迹。

A new fixed-time cooperative tracking control algorithm is designed to solve the tracking control problem of cooperative transportation of payloads suspended by tethers from multiple UAVs.Firstly,through wrench analysis,the effective wrench space under different states of the system is calculated,and the allowable tension margin of the system under the constraint of the effective wrench space is calculated based on the statics balance.Secondly,under the condition of the rope tension and the maximum tension constraint,the desired tracking trajectory of the formation is planned based on differential flatness and optimal rope tension distribution algorithm.Then,the dynamic model of the system is established based on the Udwadia Kalaba equation.The continuous robust control terms based on super-twist-like sliding mode and integral sliding mode are designed to compensate the disturbance caused by tether tension,and the fixed-time coordinated outer loop position controller of UAV based on bi-limit homogeneity principle is designed.A fixed-time attitude stabilization controller is designed for UAV inner loop attitude stability control.The simulation results show that the rope tension meets the tension and maximum tension constraints,and the designed fixed-time cooperative tracking control algorithm ensures the stable tracking of the desired trajectory within a fixed-time.