Adaptive Sliding Mode Control of Suppressing Quadrotor Payload Swing with Variable-Length Cable

With the development of drone technology, quadrotor transportation has become an important application direction. Most of the control designs for a quadrotor with a cable-suspended payload (QCSP) are aimed at fixed cable lengths, but there are few controller designs for varying cable length QCSP with broad application prospects. In this paper, a controller for varying cable length QCSP is designed using parameter adaptive multi-layer sliding mode structure to control the payload swing, quadrotor position tracking and single-layer sliding mode structure to control the cable length of the suspension system. The nonlinear coupling problem in the QCSP is solved by a simple method, avoiding tedious design reasoning and parameter ad-justment. Simulation experiments were conducted and compared with traditional PD controllers, proving the effectiveness of this method in suppressing load swing angles of varying cable length QCSP.