Space robot tracking control method for cold air propulsion

Abstract

The embodiment of the invention discloses a space robot tracking control method for cold air propulsion, which comprises the following steps of: S1, establishing a dynamic model of a space robot, introducing PID feedback control to obtain a feedforward feedback control model, and obtaining an expected thrust value of the space robot according to the feedforward feedback control model; S2, obtaining a theoretical thrust value of a thruster carried by the space robot; S3, converting the expected thrust value obtained in the step S1 into a switching value by a PWM wave method, using the switching value for controlling the on-off state of an electromagnetic valve to simulate the change of the magnitude of thrust so that the expected thrust value and an expected path are tracked, and acquiring the thruster connection duration top by the theoretical thrust value and the expected thrust value; and S4, in the propelling process, identifying the actual thrust value of the thruster by a hybrid identification method of a recursive least square-affine projection symbol algorithm by utilizing a sensor, updating the theoretical thrust value in the step S3 by the obtained actual thrust value, to acquire updated thruster connection duration top.

Description

technical field [0001] The invention relates to the field of aerospace technology. More specifically, it relates to a cold-air propulsion-oriented space robot tracking control method, computer equipment, and a computer-readable storage medium. Background technique [0002] Human exploration of the space field is becoming more and more frequent, and the number of spacecraft launched is gradually accumulating. However, the spacecraft is limited by its fuel load or the working time of its components, and its operating life in orbit is limited. Once the service time exceeds the predetermined life, it will become space junk. These satellites not only occupy a considerable amount of orbital resources, but also become uncommunicable and undockable non-cooperative targets due to energy exhaustion, which will pose a great threat to satellites in normal orbit. So the researchers proposed an on-orbit service plan, that is, to use service robots to capture these abandoned spacecraft t...

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Problems solved by technology

[0004] However, the maneuverability of the free-floating robot is extremely weak, and the posture of the main body can only be changed by the movement of the mechanical arm, and the displacement maneuver cannot be realized. However, the air-conditioning propulsion is an ideal displacement maneuvering method. The air-conditioning propulsion has a simple structure, high safety, and quick response. , has been widely used in space on-orbit service scenarios such as space rendezvous and docking

However, compared with the two-component or three-component thermal thruster, the specific impulse of cold gas propulsion is small. In order to ensure enough working fluid is carried, high-pressure gas cylinders are usually used to store gas, but the volume of gas molecules cannot be ignored in a high-pressure environment. The ideal gas state equation cannot be applied, there will be a significant difference between the theoretical thrust and the actual thrust, and the pressure of the cylinder will drop significantly after working for a period of time, which will also cause a change in thrust

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