CN102944238B - Method for determining relative position of planetary probe in process of approaching target - Google Patents

Abstract

The invention relates to a method for determining a relative position of a planetary probe in process of approaching a target and belongs to the technical field of autonomous navigation. The method comprises the following steps of: releasing a radio beacon through the planetary probe in the process of approaching a target celestial body according to a specific speed, measuring the distance data between the radio beacon and the planetary probe, and determining the position of the probe relative to the target celestial body by combining the measuring data of a unit vector of the probe relative to the position of the target celestial body extracted by an optical sensor carried by the planetary probe. According to the method, an orbit of the probe relative to the target celestial body can be autonomously determined in the approaching process, and the method is small in calculation mount, easy and convenient; and meanwhile, because the measuring information of the accompanying radio beacon is imported, optical measurement observation configuration through a pure target celestial body can be improved, and the orbit determination precision of the probe relative to the target celestial body is improved.

Description

A kind of planetary probe is close to relative position defining method in object procedure

Technical field

The present invention relates to a kind of planetary probe close to relative position defining method in object procedure, belong to autonomous navigation technology field.

Background technology

Increasing along with interplanetary exploration task, detector leaps, be diversion and soft landing target celestial body has become vital task and the problem of following deep space scientific exploration.In order to successfully complete scientific investigation task, the relative orbit of Approach phase detector determines to have very high precision, so that detector arrives target celestial body in the position expected.The uncertainty of detector Approach phase navigation accuracy and the information type measured by detector, measure data precision and detector kinetic model and observation model has much relations.The design of detector Approach phase air navigation aid directly determines the type of information measured by detector, and air navigation aid reasonable in design is the main path of the relative orbit determination precision improving detector.Detector Approach phase air navigation aid is the gordian technique being directly connected to detection mission difficulty action accomplishment, it is even related to the success or not of whole task, and therefore planetary probe Approach phase air navigation aid is one of research direction of giving priority to of space flight scientific research department of current various countries.

In the planetary probe Approach phase air navigation aid developed, in first technology [1] (see C.L.Thornton, J.S.Border.Radiometric tracking techniquesfor deep space navigation.USA:John Wiley & sons, Inc.2003:34 ~ 53).Classical navigate mode uses land station's measurement data, carries out tracking measurement by ground survey station to planetary probe, obtains the detector relatively oblique distance at planar survey station, oblique distance rate of change and VLBI measurement data.Based on the filtering technique of complexity, in conjunction with other almanac data, detector total state is estimated.These technology prove very reliable through the checking of repeatedly aerial mission and have robustness, but this observation needs continual measurement, while can not reach real-time process.Within the scope of exploration of solar system, radio signal postpones to reach a few hours, and which cannot meet the requirement of real-time of planetary probe Approach phase.

In first technology [2] (see W.M.Owen, N.Mastrodemos, B.P.Rush.Optical Navigation for Deep Impact.Proceedings of the AAS/AIAASpace Flight Mechanics Meeting:Tampa, Florida, January 22-26,2006:1231 ~ 1251).Based on the navigate mode of autonomous optical information owing to having the advantages such as independence is strong, precision is high, real-time is good, become the focus of scholars's research in recent years.Its main implementation is that the optical sensor that detector carries is taken pictures to target planet, extracts detector relative target position of heavenly body unit vector information, based on the track of this metrical information determination detector relative target celestial body.The change of unit vector measured value to vertically opposite velocity reversal state of detector relative target position of heavenly body is more responsive, and direction of visual lines state is unobservable, therefore, when during detector is close to target celestial body process, the angle of relative position and relative velocity is very little, this air navigation aid accurately can not determine the relative orbit state of detector three axle.

Summary of the invention

The object of the invention is to the problem poor for existing deep space probe Approach phase air navigation aid independence, relative orbit determination precision is not high, provide a kind of planetary probe close to the relative position defining method in object procedure.

A kind of planetary probe is close to relative position defining method in object procedure, its technical scheme is: planetary probe discharges radiobeacon by command speed in close to the process of target celestial body, by measuring the range data between radiobeacon and planetary probe, the measurement data of the detector relative target position of heavenly body unit vector that the optical sensor carried in conjunction with planetary probe extracts, realizes the determination of detector relative target position of heavenly body.Specifically comprise the steps:

Step 1, close to pre-task, determines the relative velocity vector of planetary probe relative target celestial body its relative velocity is v.

Step 2, at the task initial time t of planetary probe close to target celestial body ₀, the optical sensor utilizing planetary probe to carry is taken pictures to target celestial body, measures and obtains t ₀the position unit vector of moment detector relative target celestial body

Step 3, at t ₀in the moment, according to appointment flying speed release radiobeacon, make radio road sign facing to target celestial body flight.

Described appointment flying speed is

$\sqrt[v]{1-{(\frac{\stackrel{\→}{v}}{v}\·{\stackrel{\→}{n}}_0)}^2}.$

Described radiobeacon adopts X-band, S-band or UHF waveband wireless electron detector, carries out communicating and measuring with planetary probe.

Step 4, close to the t in process ₁in the moment, the optical sensor adopting planetary probe to carry measures the distance ρ between planetary probe and radiobeacon ₁;

Step 5, at t ₁in the moment, the optical sensor that planetary probe carries is taken pictures to target celestial body, measures detector relative target position of heavenly body unit vector

Step 6, utilizes the measured value of above-mentioned steps and ρ ₁, calculate t ₁the position vector of moment planetary probe relative target celestial body

Beneficial effect

The invention provides a kind of planetary probe of release accompanying flying radiobeacon combining target celestial body optical measurement that utilizes close to target relative position defining method, this location determining method can be autonomous the track of determination detector relative target celestial body in close to process, calculated amount is little, simple and convenient, simultaneously owing to introducing accompanying flying aerogram target metrical information, the simple observation configuration adopting target celestial body optical measurement can be improved, improve the track determination precision of detector relative target celestial body.

Accompanying drawing explanation

Fig. 1 is that planetary probe of the present invention is close to relative position defining method process flow diagram in object procedure;

Fig. 2 be in specific embodiment planetary probe close to the process schematic of target.

Embodiment

In order to object of the present invention and advantage are described better, below in conjunction with the drawings and specific embodiments, the present invention will be further described.

In the present embodiment planetary probe close to target celestial body process as shown in Figure 2, planetary probe close to the relative position defining method flow process in object procedure as shown in Figure 1, specifically comprises the steps:

Step 1, at the relative velocity vector close to pre-task determination planetary probe relative target celestial body its relative velocity is v.The present embodiment is using the moment of 10 kilometers, planetary probe distance objective celestial body as close to task initial time t ₀, the relative velocity vector in this moment is recorded by conventional surface observational system $\stackrel{\→}{v}={[100m/s,100m/s,100m/s]}^T.$

Step 2, at the initial time t of planetary probe close to target celestial body ₀, the optical sensor utilizing planetary probe to carry is taken pictures to target celestial body, measures t ₀moment detector relative target position of heavenly body unit vector

Step 3, at t ₀moment, according to speed release radio road sign, makes radio road sign facing to target celestial body flight;

Step 4, close to the t in process ₁in the moment, measure the distance ρ between planetary probe and radio road sign beacon ₁;

Step 5, at moment t ₁, the optical sensor that planetary probe carries is taken pictures to target celestial body, measures detector relative target position of heavenly body unit vector

Step 6, utilizes the measured value of above step and ρ ₁, calculate t ₁the position vector of moment planetary probe relative target celestial body

The determination precision adopting method of the present invention that final goal relative position determination precision can be made to compare based on ground observation by mathematical simulation checking improves more than 100 meters, reaches within 250 meters.

Claims (3)

1. planetary probe is close to a relative position defining method in object procedure, it is characterized in that: comprise the following steps:

Step 1, close to pre-task, determines the relative velocity vector of planetary probe relative target celestial body its relative velocity is v;

Step 2, at the task initial time t of planetary probe close to target celestial body ₀, planetary probe is taken pictures to target celestial body, measures and obtains t ₀the position unit vector of moment detector relative target celestial body

Step 3, at t ₀in the moment, according to appointment flying speed release radiobeacon, radiobeacon is made to face toward target celestial body flight;

Described appointment flying speed is

$v\sqrt{1-{(\frac{\stackrel{\→}{v}}{v}\·{\stackrel{\→}{n}}_0)}^2};$

Step 4, close to the t in process ₁in the moment, the optical sensor adopting planetary probe to carry measures the distance ρ between planetary probe and radiobeacon ₁;

Step 5, at t ₁in the moment, planetary probe is taken pictures to target celestial body, measures detector relative target position of heavenly body unit vector

Step 6, utilizes the measured value of above-mentioned steps and ρ ₁, calculate t ₁the position vector of moment planetary probe relative target celestial body ${\stackrel{\→}{r}}_1=\frac{{\mathrm{\ρ}}_1}{{\stackrel{\→}{n}}_0\·{\stackrel{\→}{n}}_1}{\stackrel{\→}{n}}_1.$

2. a kind of planetary probe according to claim 1 is close to relative position defining method in object procedure, it is characterized in that: described radiobeacon adopts X-band, S-band or UHF waveband wireless electron detector, carries out communicating and measuring with planetary probe.

3. a kind of planetary probe according to claim 1 is close to relative position defining method in object procedure, it is characterized in that: the optical sensor adopting planetary probe to carry is taken pictures to target celestial body.