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 adjustment. 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.