Design and Kinematic Analysis of Cable-driven Parallel Mechanism for Helicopter Model in Formation Flight

A cable-driven parallel suspension mechanism for helicopter model in formation flight in wind tunnel test is designed and analyzed in this paper. Based on the working condition requirements of two helicopters in formation flight, a 16 cables suspension structure is designed, and the kinematic relationship of single helicopter for cooperative motion between the movable pulley suspension point and the helicopter model is established. Furthermore, based on the relative position and orientation of two helicopters, the kinematic model between two helicopters in formation flight is also established. Additionally, six degrees of freedom movement and cooperative formation flight movement can be achieved through motion control of the parallel mechanism, which verifies the feasibility of the kinematic model. The simulation results show that the parallel suspension mechanism designed in this paper has large workspace and good stability. And it can avoid interference among the cables, and between the cables and the model, which contributes to imitate the interaction of airflow among the aircrafts in formation flight and improves the effectiveness and credibility of wind tunnel test results.