Three-dimensional posture fixing and local locating method for lunar surface inspection prober

Abstract

The invention relates to a three-dimensional gesture determining and local positioning method of a lunar surface rover, which comprises the following steps: (1) ascertaining the rolling and pitching angles by use of a triaxial accelerometer with sensitivity while the rover is still; (2) determining the drift angle gesture by means of a sun sensor; (3) using the axial gesture and the gyro deviationas the state quantity, the rolling and pitching angles established by the triaxial accelerometer, the drift angle determined by the sun sensor as well as three gyro outputs as the measuring information, building a state equation and a measuring equation, and estimating the triaxial and gyro deviations by means of extended Kalman filter; (4) after compensating the gyro outputs by virtue of the estimated gyro deviations while the rover is in motion, calculating the gesture changes of the rover, finishing the preestimation of the gyro gesture, and fulfilling gesture update; (5) acquiring the information about the rotation speed of the driving wheels of the rover, the rotating angle of the steering wheel, the rotating angle of the left and right rocker arms, and getting the position incrementof the rover in the body coordinate system by use of the forward kinematics relationship. The invention has the advantages of high precision of gesture determining and positioning, simple calculationand easy implementation of the engineering.

Description

technical field [0001] The invention relates to a method for three-dimensional attitude determination and local positioning of a lunar surface inspection probe, which is suitable for autonomous attitude determination and positioning of the probe in complex and unknown terrains such as the lunar surface and the surface of Mars, or autonomous navigation of ground field vehicles. Background technique [0002] Lunar surface patrol probes are a type of probes that carry out inspections on the lunar surface, also known as lunar exploration vehicles, lunar rovers, etc. Lunar surface patrol probes and planetary vehicles can also be collectively referred to as probe vehicles. In a broad sense, the lunar surface inspection probe is a spacecraft that can move on the surface of the moon and complete tasks such as detection, sampling, and delivery. In a narrow sense, the lunar surface patrol probe is a spacecraft that can adapt to the lunar environment and carry scientific detection inst...

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Problems solved by technology

[0006] However, the shortcomings of the above-mentioned existing methods are mainly reflected in: (1) using the output of the two-axis accelerometer to solve the tilt angle, which will cause a large error when the tilt angle is large, or when the local gravitational acceleration changes greatly compared with the conventional value ; (2) Use the yaw axis gyro to measure the yaw angle, without considering the roll and pitch angles caused by terrain fluctuations; (3) Use the horizontal two-dimensional position information, or use the geometric relationship between the left and right wheels to establish the yaw attitude The relationship between the sun sensor and the output of the sun sensor is used to correct the position; although this method is simple and suitable for flat terrain, but the model error is large, it is not suitable for complex undulating terrain; (4) In order to improve the positioning accuracy of fixed attitude, select more State quantities are used as values ​​to be estimated, such as position error, attitude error, and inertial sensor deviation. The established state equation and measurement equation are relatively complicated. Although the attitude determination and local positioning accuracy have been improved to a certain extent, due to the complexity of calculation, It is difficult to implement engineering applications; (5) The commonly used dead reckoning method only uses the speed of the left and right wheels to calculate the mileage, without considering the impact of terrain height changes, this method will lead to large errors in complex terrain

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