JPS5822800A - Signal processing system for artificial satellite loading inertia sensor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal processing method for an inertial sensor mounted on an artificial satellite.

In the future, it will be necessary to guide one artificial satellite (hereinafter referred to as a satellite) and combine multiple artificial satellites in orbit to construct a composite satellite system in outer space.

In order to realize such a satellite, it is necessary to set the thrust vector and align the coupling axis of the nine satellites at any time.
It is essential to make large attitude changes in any direction in dimensional space. For this reason, it is necessary to process the data of the inertial sensors mounted on the satellite to determine the attitude in real time with high precision throughout the entire inertial space.

This invention is essential for realizing the above-mentioned composite satellite system. This provides an inertial sensor signal processing method for realizing real-time attitude determination on orbit.

By the way, inertial sensors can be roughly divided into strap-down type (hereinafter abbreviated as ``Pρ method'') inertial sensors and stable platform type (hereinafter abbreviated as ``Pρ method'') inertial sensors, but as is well known, these methods have traditionally been used. On the other hand, independent signal processing methods were applied to each.

For this reason, from the perspective of the signal processing system, there is poor compatibility between the 8/D type inertial sensor and the P/1 = type inertial sensor, and it is necessary to prepare a signal 1 system to match the inertial sensor type, which is uneconomical. There was a drawback.

The present invention provides a signal processing method for an inertial sensor mounted on an artificial satellite that eliminates the above-mentioned conventional drawbacks.

An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a diagram showing the structural concept of an inertial sensor signal processing method according to the present invention. In the figure, (1) is an 8/111 type inertial sensor, (2) is an Euler angle variation calculation device, (31 is an Euler parameter update device, (4) is an Euler parameter compensation calculation device, and (5) is an attitude calculation device. be.

In such a configuration, an S/D type inertial sensor (1
), the rotational angular velocity ωjn around each axis of the satellite (where j
= 1.2,3. n is a time sequence).

Using this ωjn as input, the Euler angle variation calculation device (2) calculates the Euler angle variation (Δψ, Δφ, Δθ)n.

Using this (Δψ, 'Δφ, Δθ)n as input, the Euler parameter updating device (3) calculates the Euler parameter ρtn (1=1.2, 3.4) at the current time fn. Using this ρ1n as input, the Euler parameter compensation calculation device (4) calculates the optimum estimated value ρ1n of the Euler 2 meter. Using this ρ1n as input, the attitude calculation device (5) calculates and outputs the attitude U of the artificial satellite.

Further, when using the P71 type inertial sensor (7), the attitude Un of the satellite can be calculated by the method described above by switching the switch 8 to the N2 side.

The details of each device constituting the inertial sensor signal processing device (6) will be explained below using FIG. 2.

It smells like this, 1Bn-t, jBn-t,
kBn-1 Unit vector in each satellite axis direction at time tn-1, iBa, jBa, kBa are at time t
n is a unit vector in each satellite axis direction, Δφn is a yaw angle, Δφn is a roll angle, and Δθn is a pitch angle. Also, ω1n-1 and ω1o are each time fan # tIl
It is the rotation angle around each machine axis at l-1, and is measured by an inertial sensor.

Now, the posture TT at the previous stage in the process of sequential posture calculation
n-t (iBn-1, jBn-t, kBn-1)
Assuming that is known, the satellite attitude U11 (tBn, jB, , kBn) at the current tn FC is determined as follows.

The Euler angle variation calculation device (2) inputs the rotational angular velocity ωj1m around the satellite axis measured by the 8/D inertial sensor (1) at time tn, and calculates the previous stage attitude Unl (1Bn-) in the process of sequential attitude calculation. ' wholesale Q-1, k
Bn-t) and the current posture ElF, (iBn,
jBn.

kBn) and the Euler angle variation (Δφ mouth).

Δφn, Δθn) are calculated using the following formula.

However, in the Euler parameter updating device (3), the above (△ψn
, △φn, Δθn) as input, and the previous time t, 1-
The current Euler parameter ρ1n is calculated using the Euler parameter estimate ρ1n−1 at 1 using the following calculation equation.

however In the Euler parameter compensation calculation device (4).

Using the Euler parameter ρ1o as input, the optimal estimated value d1n of the Euler parameter is calculated using the following equation.

ρ1n=ρ1n+(1-(1-v)'/2, ρ1
n (4) In the attitude calculation device (5), the optimum estimated value ρ1n of the Euler parameter is input, and the attitude trn of the satellite with respect to the inertial reference coordinate is calculated by the following equation.

'Bo =CBCI]n (:' *o *o]”j
Bn =:, (Bc engineering). [o*tto) (
s) kBn = (BCz]n (Os◎, 1) 1 However, when using the P/? method inertial sensor (7), 1
As is well known, inertial sensors (Δψ0゜Δφro, Δφ
Since θn) can be measured, by directly substituting this into equation (3) and using the calculation method of equation (2) below, the above 8 can be obtained.
/I) Using the same calculation formula as when using an inertial sensor,
The attitude Un of the satellite can be calculated.

As is clear from the above, the inertial sensor signal processing method according to the present invention has the advantage of being able to commonly handle two important methods of inertial sensors, the S/D method inertial sensor and the P-type inertial sensor. has.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the structural concept of a signal processing device according to the present invention, and FIG. 2 is a diagram showing an example of a case where the relationship between the current satellite attitude and the determined value of the satellite attitude at the previous stage is given by the Euler angle. In Figure 1, (1) is the sA type inertial sensor, (
2) is an Euler angle variation calculation device, (31 is an Euler parameter update device), (4) is an Euler parameter compensation calculation device, (5) is an attitude calculation device, and (7) is a P/? method inertial sensor.

Claims (1)

[Claims] Using as input the angular velocity around the satellite's axis measured by an inertial sensor mounted on the artificial satellite, the Euler angle variation that provides the relationship between the previous attitude and the current attitude in the process of sequential attitude calculation is calculated. and an Euler parameter updating device that receives an output signal of the Euler angle variation calculation device and updates Euler parameters. an Euler parameter compensation calculation device that uses the output signal of the Euler parameter update device as input to calculate the optimum estimated value of the Euler parameter; and an attitude calculation device that uses the output signal of the Euler parameter compensation calculation device as input to calculate the attitude of one artificial satellite. A signal processing method for measuring values from a strap-down inertial sensor and a stable platform inertial sensor onboard a satellite.