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Method for estimating disturbance moment in power decreasing process

A technology for interfering torque and power descent, which is applied to the system of space flight vehicle returning to the earth's atmosphere, the guidance device of space flight vehicle, the landing device of space flight vehicle, etc. The effect of stickiness, improved safety, and reduced risk

Active Publication Date: 2013-09-18
BEIJING INST OF CONTROL ENG
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Problems solved by technology

[0004] The technical problem solved by the present invention is to provide a method for estimating the disturbance torque of the lander during the power descent process, aiming at the problem that the thrust of the braking engine cannot reach the center of mass, which may generate a large disturbance torque and endanger the safety of the landing during the power descent process of the lunar soft landing. Improving the safety of lander landings

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  • Method for estimating disturbance moment in power decreasing process
  • Method for estimating disturbance moment in power decreasing process
  • Method for estimating disturbance moment in power decreasing process

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Embodiment Construction

[0025] The lander is in the process of lunar soft landing power descent. The lander is equipped with a gyroscope, the descent and deceleration are accomplished by braking engines, and the attitude is controlled by jets.

[0026] Such as figure 1 As shown, the specific calculation process of the present invention is as follows:

[0027] (1) Estimation of lander mass characteristics

[0028] The consumption rate of propellant in the landing process depends on the thrust of the brake motor and the attitude control motor and their specific impulse. Assume the current time is t k , the last two cycles (using the time period [t k-2 ,t k-1 ] indicates) the thrust command issued by the guidance and braking engine is F cmd,k-2 ; The jet pulse width of each axis sent by the attitude control to the attitude control engine is T on,k-2,i (i=x, y, z represent the three coordinate axes of the lander), and the thrust output by the attitude control engine of each axis is F RCS,i (i=x, ...

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Abstract

The invention discloses a method for estimating a disturbance moment in a power decreasing process. In the process of decreasing soft landing power in the moon, the disturbance moment generated by centroid shift is possible to endanger landing. An important measure for early warning and answering is that the magnitude of the disturbance moment is estimated online. The method comprises the following steps of firstly, recursively calculating the residual mass of a lander by utilizing motor power and a pulse width command given out by a guidance and control system, and utilizing a curve (function) bound on the ground to calculate the height of center of mass of the lander and inertia; secondly, calculating a control moment according to the height of center of mass and a pulse width command; thirdly, carrying out difference on a gyro output to obtain an angular acceleration calculation value; fourthly, inversely calculating the disturbance moment by utilizing an attitude kinetic equation; finally, utilizing a filter to reduce the influence of noise on a disturbance moment estimated value. The invention provides a method for monitoring the change of the disturbance moment of the lander, and the method is beneficial to improve the robustness of the control system in the landing process and reduce the risk of landing.

Description

technical field [0001] The invention relates to a method for estimating the disturbance moment of a lander on-line during the power descent of the lunar soft landing, and belongs to the field of autonomous navigation, guidance and control of lunar exploration. Background technique [0002] The process of soft landing on the moon mainly depends on the brake engine installed on the lander to generate braking force, and the speed is reduced while the height is lowered to complete. For a type of lander that does not have the capability of thrust vector control, due to the limitations of brake engine manufacturing and installation accuracy, and the imbalance of propellant consumption during the descent process, it is impossible to maintain the thrust of the engine over the center of mass. Braking thrust during descent creates a disturbing moment on the lander. Normally, this disturbing moment needs to be counteracted by the attitude control system. However, once the disturbance...

Claims

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Application Information

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IPC IPC(8): B64G1/24B64G1/62
Inventor 李骥张洪华关轶峰赵宇黄翔宇于萍梁俊程铭何健王鹏基张晓文
Owner BEIJING INST OF CONTROL ENG
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