Kinematic Characteristics and Dynamics Analysis of an Overconstrained Scissors Double-Hoop Truss Deployable Antenna Mechanism Based on Screw Theory

Large diameter space deployable antenna is the key equipment for communication and data transmission between spacecraft and base stations on earth. Based on the overconstrained scissors mechanism, a double-hoop truss deployable antenna mechanism is constructed in this paper, which can be used as the antenna support mechanism for satellites and other spacecraft, and its kinematic characteristics and dynamics are analyzed based on screw theory. First, the configuration and the overconstrained features of the double-hoop truss deployable mechanism are analyzed with the truss mechanism divided into a plurality of mechanism units. The geometric conditions for the double-hoop form are also investigated with the consideration of joint size effects. Then, based on the screw theory, the degree of freedom (DOF) of the mechanism is analyzed, showing that this mechanism has only one DOF. Next, the velocity and acceleration of the components in the mechanism are examined. Through the screw and screw derivatives operation, the velocities and accelerations of the components and the Jacobian matrixes are obtained. Finally, a dynamic model of the double-hoop truss deployable mechanism is established based on the Newton-Euler equation and the principle of virtual work, and this model is verified by the numerical calculation and simulation verification. The overconstrained scissors double-hoop truss deployable antenna mechanism proposed in this paper has a good application prospect in the field of space deployable antennas, and the theoretical analysis method in this paper can provide insights into other complex spatial deployable mechanisms.