Novel Coaxial and Differential Thrust Vector Control Systems for Small-Scale Rockets

Thrust vector control (TVC) systems enable directional control of thrust, making them crucial in the aerospace industry, particularly in propulsion systems. Typical TVC systems, which involve 2 linear actuators and a gimbal, give effective vectoring of thrust but pose challenges relating to weight, torque, and rise time. This study analyzes alternate TVC approaches which are inspired by robotics drivetrain systems: differential and coaxial swerve drive. This study compares these systems with a typical TVC to evaluate performance in the categories that follow: weight, cost, torque, manufacturability, rise time, and control. The differential TVC has superior torque, overcoming greater moments produced by the thrust and also has a faster rise time. However, it is more complex and uses large high load bearings which both lead to an increase in cost when compared to that of a standard TVC. In terms of weight, the differential TVC is comparable to a standard one. As for the coaxial design, it had similar benefits to the differential, providing faster rise time and more torque. Similar to the differential design, the coaxial design requires large high load bearings which are expensive. In contrast, the two-actuator gimbal system is simpler and more cost effective in large scale applications, although countered by less torque and slower rise times. Altogether, the results show that while a typical TVC retains its benefits in terms of cost and complexity, the differential and coaxial options show promise in small-scale rocketry and, with further optimizations, have potential in medium- and large-scale rocketry.