JPH0238862A - Angular speed meter - Google Patents

Abstract

PURPOSE:To extend a life with the elimination of errors by arranging a weighted blade about a rotating shaft, a hinge on the blade in such a manner as to be deformed when a torque works thereon and a optically line displacement meter for measuring a deformation caused. CONSTITUTION:When an angular speed input OMEGA is given, a torque is generated to deform hinges 3 and 3'. A parallel light beam from a projector 12 hits a mirror 11 to be reflected to photodetectors 13a and 13b. The element 13 is divided into two same pieces 13a and 13b which are so connected to invert outputs thereof and the separate photodetectors produce outputs proportional to an area exposed to a parallel beam. As the mirror tilts, an output is produced to be made proportional to an angle theta of inclination in a fine range thereof alpha. As outputs of elements 13 and 13' are the same in the size and opposite in the polarity, an output voltage is doubled when they are synthesized in reversal to allow the cancelling of effect of acceleration. This eliminates the need for a slip ring and extends a life.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an angular velocity meter that measures the angular velocity of a moving body such as an aircraft, a ship, or an automobile.

"Prior art" If the rotational momentum vector when an object is rotated is H2, and the input angular velocity vector around the axis perpendicular to this rotational axis is Ω, then
A torque vector T=HXΩ is generated, which is expressed as the vector product of H and Ω. Figure 6 shows the positional relationship between these hectares.

FIG. 7 shows a conventional angular velocity meter using this principle. l is the motor, 2 is the blade, 3 is the hinge, 4 is the strain sensitive element, 5
is a weight, 6 is a slip ring, and 7 is an electric wire. 2
', 3', 4', 5' are respectively 2.3. ,! , 5.

When there is an angular velocity input as indicated by Ω in the figure, a torque equal to the vector product T with the rotational motion JIH is generated, and the blade 2 bends at the hinge 3 as shown by the dotted line. The strain-sensitive element 4 is made of a material such as zinc oxide that converts strain into voltage, and this voltage is transmitted through a slip ring 6 by a lead wire (not shown) [! Guided by 7.

The blade 2' is attached to balance the blade 2, but since the output voltage of the strain sensing element 4' is subjected to distortion opposite to the strain sensing element 4, it is set to have opposite phases so that the output voltage is equal to the G! May be added to. In this way, the influence of acceleration is canceled out.

Since the blade 2 is rotating, when it reaches the θ degree as shown in FIG. 8, it is confused only by the Y-axis direction component Ωcosθ of Ω, and T=HXΩcosθ, so the output voltage changes in a sinusoidal manner. FIG. 9 shows the output voltage of the strain-sensitive element 4 versus θ. Since the phase of this output voltage has direction information of the angular velocity input in the YZ plane, if the output voltage is separated into voltages with different phases by 90', it can be used as a two-axis angular velocity meter.

``Problems to be Solved by the Invention'' As described above, the conventional angular velocity meter uses the slip ring 6, so it has short lifespan and has the disadvantage that it is difficult to obtain a stable rotor.

"Means for Solving the Problem" According to the present invention, when defining a rotation axis, an angular velocity input axis perpendicular thereto, and an output torque axis perpendicular to these axes on a frame that moves together with a moving object, the above-mentioned A weighted blade is provided to increase the angular momentum of rotation around the rotation axis, and the blade is provided with a hinge that deforms when torque around the output torque axis is applied, causing the blade to rotate and increase the angular velocity. An optical minute displacement measurement system is provided to measure the deformation when the input axis coincides with the angular velocity input axis. The deformation of the blade when the blade enters is measured when the blade aligns with the angular velocity input axis.

Embodiment 1 FIG. 1 shows an embodiment of the present invention, l is a motor, 2 is a blade, 3 is a hinge, 5 is a weight, 11 is a mirror, 1
2 is a light projector, and 13 is a light receiving element.

2'5'11'12' and 13' correspond to 2.5, 11, and 12.13, respectively.

As in the case of FIG. 7, when there is an angular velocity input Ω, a torque T is generated, and the hinges 3 and 3' are deformed as shown by the dotted lines. The light projector 12, the light receiving element 13, and the mirror 11 constitute an optical minute displacement measuring system as shown in FIG. This optical minute displacement measurement system is well known, so it will not be described in detail.
In FIG. 2, the parallel light beam from the projector 12 hits the mirror 11 and is reflected by the light receiving elements 13a and 13b. The light-receiving element 13 is divided into two parts 13a and 13b, which are connected so that the output is reversed, and each light-receiving element outputs an output proportional to the area hit by the parallel light beam.Therefore, the mirror 11 is a solid line. When the light receiving element 13a is located at the location shown by
The combined output of the mirror 13b is O, but when the mirror 11 is tilted as shown by the dotted line, an output is produced. This output is proportional to the tilt angle α within a small range.

Even in the case of FIG. 1, since the blade 2 rotates as in FIG. 7, the output of the light receiving elements 13, 13' becomes as shown in FIG. Here, θ is the same as shown in FIG.

The voltage at the output of the light-receiving element I3 when θ=180'' is the voltage when the mirror 11' reaches the light projector I2 and the light-receiving element 13. The same applies to the output of the light-receiving element 13'.

Since the outputs of the light receiving elements I3 and 13' have the same magnitude and opposite polarity, if they are combined in reverse, the output voltage will be doubled. Furthermore, the influence of acceleration can be canceled out.

In Fig. 4, if there is no angular velocity input and acceleration is applied in the X direction, the hinges 3 and 3' deform as shown by the dotted lines in Fig. 4, so the voltages of the light receiving elements 13 and 13' become in phase and cancel each other out. Fit.

Also, as shown by the dotted line in Fig. 4, the blade 2゜2'
Optical minute displacement measuring system 12', 13', 12'', 1 that reflects on mirror I1.11' when rotated to the axial position.
3", the output of the light receiving elements 13" and 13' will indicate the angular velocity around the Z axis, and will be used as a 2@ angular velocity meter. Fig. 5 shows another embodiment of this invention. ,
In the embodiment shown in FIG. 1, the output voltage is in a pulse form as shown in FIG. 3, and is easily affected by noise, but in the embodiment shown in FIG. 5, a disk 10 is rotated by a motor 1. disk lO
A large number of blades 2 are formed by forming radial grooves. Each blade 2 has a hinge 3 and a mirror 11 and operates in the same manner as in FIG. In this example, since there are a large number of blades 2, the output is cut only at the grooves, but a nearly continuous output voltage is obtained.

``Effects of the Invention'' As stated above, the angular velocity meter of this invention does not require a slip ring, has a long life, and measures the angular velocity around two axes by phase detection, as in the case of conventional ones, but by optical microscopic measurement. Since the output of the displacement measurement system itself indicates the angular velocity around each axis, the electric circuit is submerged in oil and a phase reference detector is not required.

Furthermore, it has the feature that errors caused by acceleration are canceled out.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a diagram showing an optical minute displacement measurement system, Fig. 3 is an output characteristic diagram of Fig. 1, and Fig. 4 is a state in which acceleration is applied. FIG. 5 is a perspective view showing another embodiment of the present invention, FIG. 6 is a diagram showing the relationship between the rotational momentum vector H, the input angular velocity vector Ω, and the torque vector T, and FIG. FIG. 8 is a perspective view showing the angular velocity meter, FIG. 8 is a view showing the blade rotated at θ degrees, and FIG. 9 is an output characteristic diagram.

Claims (2)

[Claims] (1) When defining a rotation axis, an angular velocity input axis perpendicular to the rotation axis, and an output torque axis perpendicular to these axes on a frame that moves together with the moving object, a weight is used to increase the angular momentum rotating around the rotation axis. The blade is provided with a hinge that deforms when a torque around the output torque axis is applied, and when the blade rotates and aligns with the angular velocity input axis, the blade deforms. An optical micro-displacement measuring system for measuring, that is, a light projector and a light receiving element provided on the angular velocity input axis in the frame, and a mirror provided on the blade, is provided, and the above when angular velocity input is input. An angular velocity meter that measures angular velocity by measuring the deformation of a blade when the blade coincides with the angular velocity input axis. (2) Another blade is provided in the opposite direction on the extension line of the above-mentioned blade, and another optical minute displacement measurement system is provided in the opposite direction on the angular velocity input axis, and the output of the above-mentioned optical minute displacement measurement system is An angular velocity meter whose output is the sum of angular velocity inputs and the difference of deformations due to acceleration in the direction of the rotation axis.