JPH0820902B2 - Space stabilizer - Google Patents

Description

The present invention relates to a space stabilizing device for a moving body-mounted image pickup device.

[Conventional technology]

FIG. 3 is a block diagram of a conventional space stabilizing device. In the figure, (1) is a motor attached to the moving body,
(2) is a gimbal rotating part that rotates relative to the moving body by the motor (1), (3) is a gimbal rotating part (2)
Fixed to the mirror part, (4) a light beam input to the mirror part (3), (5) a reflected light beam of the light beam (4) reflected by the mirror part (3), and (6) a gimbal rotating part. A gyro unit that is mechanically coupled to the angular velocity of the reflected light (5) in the inertial space, (7) is an angular velocity detected by the gyro unit (6), (8) is an angular velocity command, and (9) is an angular velocity (7 ) And the angular velocity command (8) for amplifying the difference, (10) a first amplifier for computing the torque command of the motor (1) from the output signals of the angular velocity (7) and the error calculator (9), Reference numeral (11) is an image pickup device for taking an image from the reflected light (5).

In the error calculator (9), a signal is supplied to the first amplifier (10) until there is no difference between the angular velocity (7) and the angular velocity command (8). Further, in the first amplifier (10), the torque command is supplied to the motor (1) until there is no difference between the angular velocity (7) and the output signal of the error calculator (9). Therefore, when the angular velocity command (8) is zero, the reflected light (5) input to the imaging device (11) can be spatially stabilized even when the moving body is shaken.

Next, the spatial stabilizing error in the conventional spatial stabilizing device will be described.

FIG. 4 is a block diagram expressing FIG. 3 by a transfer function. In the figure, (7) to (10) are the same as in FIG. The symbol G in the figure is the angular velocity in the inertial space of the reflected light (5) detected by the gyro part (6), θ
ε is the spatial stabilization error of the reflected light (5) corresponding to the output signal of the error calculator (9), ωI is the integral loop gain, and ω
R is the rate loop gain, JM is the inertia of the gimbal rotating part (2), and S is the Laplace operator.

The transfer function GM (S) of G → θε is obtained by performing the equivalent block conversion in FIG.

From the equation (1), it can be seen that the spatial stabilization error θε decreases as the loop gains ωI and ωR increase.

However, in reality, since there are constraints such as the influence of mechanical resonance, it is impossible to make ωI and ωR unnecessarily large because it will impair the stability of the system. That is θ
ε is uniquely determined by the mechanical system, that is, the gimbal rotating part (2).

[Problems to be Solved by the Invention]

The conventional spatial stabilizing device cannot increase the loop gains ωI and ωR for the above reasons, and thus has a problem that desired spatial stabilizing accuracy cannot be obtained.

The present invention has been made to solve the above problems, and an object thereof is to obtain a highly accurate space stabilizing device.

[Means for solving the problem]

The space stabilizing device according to the present invention is intended to perform coordinated control by adding a rotary shaft by another actuator to a rotary shaft by a conventional motor.

[Work]

Since the space stabilizing device according to the present invention controls the rotation axis by the actuator other than the motor by adding the conventional space stabilizing error as a position command, the space stabilizing device is highly precise and independent of the mechanical system of the gimbal rotating part. The device can be easily provided.

〔Example〕

FIG. 1 shows an embodiment of the present invention. In the figure, (1), (2), (4) to (11) are the same as in FIG. (12) is an actuator unit attached to the gimbal rotating unit (2) to generate rotational displacement, and (13) is a light beam (4) which is rotated by the actuator unit (12) relative to the gimbal rotating unit (2) and is input. Reflected light (5)
For providing the image pickup device (11) with a mirror, (14) an angle detector for detecting rotational displacement of the mirror (13) with respect to the gimbal rotating part (2), and (15) for an angle detector (14). Is a second amplifier for amplifying the difference between the angle (15) and the output signal of the error calculator (9) and calculating the torque command of the actuator section (12).

FIG. 5 is a block diagram expressing FIG. 1 by a transfer function. In the figure, (7) to (10) and (16) are the same as in FIG. The symbols G, θε, ωI, ωR, JM, S in the figure are the same as in FIG. 4, θ is the angle output from the angle detector (14), and ωp is the second amplifier (16). Position gain, τ is the total time constant of the actuator section (12) and mirror section (13), and θε 'is the differential signal of the amplifier (16).

Since the transfer function G → θε in FIG. 5 is the same as that in FIG. 4, it is expressed by the equation (1). In addition, the equivalent block transformation is performed to obtain the transfer function θ ε → θ as follows.

By the way, since θε ′ is θε ′ = θε−θ (3), substituting equation (2) Get. Therefore, the transfer function G′M of G → θε ′
(S) is as follows.

Substituting equations (1) and (4) into equation (5) Here, as can be seen from the equations (3) and (6), θε'indicates the spatial stabilization accuracy of the reflected light (5) in the present invention, and is independent of the magnitudes of τ and ωp. In the steady state, θ ε'is 1 / (ω
It is clear that it is p + 1) times better.

FIG. 2 shows an embodiment of the present invention. In the figure, (1) to (11) are the same as those in FIG. 3, and (16) are the same as those in FIG. (17) is an actuator unit that is attached to the moving body and produces a rotational displacement, and (18) is rotated relative to the moving body by the actuator unit (17).
The second mirror part (19) for further reflecting the reflected light of the light flux (4) input to the mirror part (3) of the above and providing the reflected light (5) to the imaging device (11) is An angle detector (20) for detecting the rotational displacement of the second mirror section (18) is an angle output by the angle detector (19).

The block diagram expressed by the transfer function of FIG.
It becomes a figure. That is, the transfer function G → θε ′ is obtained by the equation (6) in exactly the same manner as the embodiment of claim (1).

Therefore, the spatial stabilization accuracy θε ′ of the reflected light (5) according to the present invention is steadily superior to the conventional spatial stabilization accuracy θε by 1 / (ωp + 1) times regardless of the magnitudes of ωp and τ. it is obvious.

〔The invention's effect〕

As described above, according to the present invention, since the rotary shaft of another motor is added to the rotary shaft of the conventional motor to perform coordinated control, the rotary shaft is not affected by the mechanical system of the cymbal rotary portion and is highly accurate. There is an effect that can be obtained.

Further, the former control algorithm by the error calculator, the first amplifier and the second amplifier can be realized by a computer such as a microprocessor and a ROM in which the algorithm is recorded, and the same effect as the above-mentioned invention can be obtained. You can

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are block diagrams of the first and second inventions respectively, FIG. 3 is a block diagram of a conventional space stabilizing device, and FIG. 4 is the transmission of FIG. The block diagram expressed by the function, Fig. 5 is the first
FIG. 3 is a block diagram represented by the transfer functions of FIGS. In the figure, (1) is a motor, (2) is a gimbal rotating part, (3) is a first mirror part, (4) is a luminous flux, (5) is reflected light, (6) is a gyro part, and (7) is Is the angular velocity, (8)
Is an angular velocity command, (9) is an error calculator, (10) is a first amplifier, (11) is an image pickup device, (12) and (17) are actuator parts, (13) is a mirror part, (14), (19) is an angle detector, (15), (20) is an angle, (16) is a second amplifier,
(18) is a second mirror section. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] 1. A motor attached to a moving body, a gimbal rotating portion that is rotated by the motor relative to the moving body, an actuator portion attached to the gimbal rotating portion to generate a rotational displacement, and the actuator portion. A mirror unit that rotates relative to the gimbal rotating unit, an angle detector that detects the rotational displacement of the mirror unit with respect to the gimbal rotating unit, and the mirror that is mechanically coupled to the gimbal rotating unit. A gyro unit for detecting the angular velocity in the inertial space of the optical axis, an error calculator for amplifying the difference between the angular velocity command and the angular velocity detected by the gyro unit, the output signal of the error calculator and the gyro unit. A first amplifier for calculating the torque command of the motor from the angular velocity detected by the output signal of the error calculator and the angle of the angle detector. A second amplifier for calculating a torque command of the actuator unit from the space stabilizer device and an imaging apparatus for capturing an image from the light beam reflected by the mirror portion. 2. A motor attached to a moving body, a gimbal rotating portion that is rotated by the motor relative to the moving body, a first mirror portion fixed to the gimbal rotating portion, and the gimbal rotating portion. First mechanically coupled to the first part
A gyro unit for detecting an angular velocity in the inertial space of the optical axis input to the mirror unit, an actuator unit attached to the movable body to generate a rotational displacement, and a relative rotation with respect to the movable body by the actuator unit. Second
Mirror unit, an angle detector that detects the rotational displacement of the second mirror unit with respect to the moving body, an error calculator that amplifies the difference between the angular velocity command and the angular velocity detected by the gyro unit, and the error A first amplifier for calculating the torque command of the motor from the output signal of the calculator and the angular velocity detected by the gyro unit, and a torque command of the actuator unit from the output signal of the error calculator and the angle of the angle detector. A space stabilizing device comprising: a second amplifier that performs calculation; and an imaging device that captures an image from the light flux reflected by the first mirror unit and the second mirror unit.