Research on Vision-based Position Measurement System for Rocket Propellant Loading

Abstract

In the process of rocket propellant loading, the propellant's own gravity and wind pendulum may cause the connector to exert a large force on the rocket body, which may lead to connector disconnection and fuel leakage, or even damage to the rocket body. To improve the reliability and safety of rocket propellant loading, a position measurement system based on dynamic orientation detection alignment technology is proposed to achieve tracking of the rocket refueling port. In this paper, the two-dimensional position of the target in the camera plane is quickly extracted by identifying the direction of the target image and the size of the marker in the image, while the distance between the target and the camera is accurately obtained by a laser rangefinder. With this measurement solution, the deviation of the connector from the propellant filler port at the current moment can be modified in real time, thus reducing the forces on the rocket and increasing its launch reliability.

Adaptive Impedance Control of a Novel Automated Umbilical System for Propellant Loading

“…In order to integrate the different working phases of the automatic umbilical system into the same control framework, a hybrid control framework of vision and force is proposed in the paper to realize the approach, tracking, and docking process of the umbilical system and to avoid the impact of state switching on the system stability. A vision-positioning system [10] that integrates a monocular camera and laser range finders is used to achieve accurate tracking of the rocket fuel port, which has higher definition accuracy and lower time lag compared with the traditional positioning methods. For the contact force problem generated during the mating and following stages of the umbilical system, this paper adopts an adaptive impedance control algorithm based on online environmental parameter estimation to guide the umbilical connector interacting with the rocket during mating and to allow the robot to track the dynamic motion of the rocket after mating.…”