JPS62215873A - Initial setting circuit of integrator - 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] [Field of Industrial Application] The present invention relates to an integrator that calculates the velocity or displacement of an object by integrating the acceleration of the object, and in particular, an integrator that detects a hand movement signal from a camera or the like using an accelerometer. , relates to an improvement of an integrating circuit for determining camera movement speed, etc. from the signal.

[Prior art]

Conventionally, a camera pre-detection device using an accelerometer is configured as shown in Fig. 6, and as shown by arrow 4, in this case, the system is for vertical pre-detection of the camera, but this is also used for horizontal pre-detection. (Rotate the pre-sensitivity axis by 90@ for vertical shake,
In other words, align it in the direction perpendicular to the page. ) can also be used.

In the figure, 1 is the camera body, 2 is the lens barrel, 3a,
3b is an accelerometer whose acceleration detection direction is indicated by arrows 3a', 3
It is b. 5 is a differential amplifier that takes the difference between the outputs of the accelerometers 3a and 3b; 6 is an integrating circuit that integrates the difference; in the first-order integrating circuit as shown in FIG. The output is converted into velocity, and similarly, in a second-order integration circuit as shown in FIG. 7(b), this is converted into displacement to obtain the output cuff.

FIG. 7(a) shows a known integration circuit using an operational amplifier 8. Integration is started by turning off the reset switch 14, which is normally turned on in the reset state, and the capacitor 10 is charged by the resistor 9. Ru. To explain the operation of camera pre-detection when the integrating circuit is used as shown in FIG. ) generates a minute pre. At this time, different pre-accelerations are input to the accelerometers 3a and 3b attached to the camera. That is, when the camera moves around the 0 point, the acceleration applied to the accelerometer 3a, which is farther away from the 0 point, is greater than that of the accelerometer 3b.

The difference between the outputs of the accelerometers 3a and 3b is converted to a differential amplifier 5.
By calculating this, the acceleration that occurs when the camera moves (moves) in the four directions of the arrows can be obtained.

The differential output of the above acceleration signals is shown in FIG. 8(a).

As shown in (b), it can be approximated to a sine group. (Generally, camera play is generated by superposition of sinusoids.) In the case of FIG. 8(a), the difference signal between the acceleration signals output from the acceleration detectors 3a and 3b of FIG. 6 is 15 (acceleration a), the integration start point when integrating the difference signal is at the peak of the signal, that is, at the time of zero velocity (
Starting from time tS=O) on the horizontal axis, the speed output is 16 (
Although the velocity V) is stable, the photographer does not always aim at the subject from this state, and as shown in FIG. tS=O), it can be seen that the speed 16' requires a certain amount of time until the speed output becomes stable as shown in the figure. That is, the time required for stabilization is affected by the time constant of the resistor 9 and capacitor 10 shown in FIGS. 7(a) and 7(b). In general, camera shake exists at a frequency of about 1 to 30 Hz, and it has been confirmed that the camera shakes at a rate of about 1 to 30 times per second, and was calculated by integrating the acceleration obtained in this way. If the integration constant of the integrator, resistor 9, and capacitor 10 are set to improve the detection accuracy of camera pre-speed and camera pre-displacement, it will take at least 3 seconds for the output signal of the above-mentioned integration circuit to become stable. .

FIG. 9 shows another conventional example of the above-mentioned integrating circuit. In the figure, the same parts as in FIG. 7 are designated by the same reference numerals. This integrating circuit turns off the switch 18 and turns on the switch 17 to change the settings of the time constants of the resistor 9 and the capacitor 10 in order to shorten the time until the integrated output becomes stable. After the output becomes stable, switch 18 is turned on and switch 17 is turned on. However, even with this method, it takes at least one second for the integral output signal to stabilize, so the photographer must hold the camera and aim at the subject while waiting. It had some drawbacks.

[Purpose of the invention]

The present invention has been made in order to eliminate the drawbacks of the above-mentioned conventional example, and provides an integrator initialization circuit that allows stable camera pre-output to be obtained with a short waiting time.

〔Example〕

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

In FIG. 1, the part indicated by A is the integrator B in the next stage that inputs the acceleration signal input from the input terminal 11 as described above and the signal from the high frequency signal source 24 whose frequency is relatively higher than that of the signal. This is a switch mechanism for inputting to In the figure, 19a is a non-motorized push button, 20 is a spring member fitted into a notch 26 of the push button 19a, and is connected to the acceleration signal input terminal.

Reference numeral 21 is the same as the spring member 20, and is connected to a high frequency signal source 24. Reference numeral 22 denotes a conductive member which, together with the coil spring 23, normally contacts the spring member 21 through a contact surface 22' and is in a conductive state.

Next, the operation of the switch mechanism A section will be explained.

First, when the photographer holds the camera and aims at the subject, only the high-frequency signal 24 is sent to the integrator B because the spring member 21 of the push button 19a is in contact with the conductive member 22 before starting to integrate the pre-acceleration. has been input to. When the photographer presses the push button 19a in the direction of the arrow 25 when the photographer starts the shutter release, the spring member 20 contacts the surface 221 of the conductive member 20 and conducts electrically from the input terminal 11. The acceleration signal is input to the integrator B, and when the push button is further pressed, the contact point 21 separates from the contact surface 22', so that the high frequency signal 24
is no longer input to integrator B.

In the above process, the push button 19a is pushed in, and the spring member 20 and the contact surface 221, and the spring member 21 and the contact surface 22
' becomes conductive, the time ts in FIG. 4(a)
=o(27) to 34, the signal from the high frequency signal source is superimposed on the acceleration signal 15' shown in FIG. 8(b) and input to the A divider B. When,
Looking at the timing at which the acceleration signal is input to the integrator, it often has a DC component, and this DC component is modulated by the high frequency signal as shown at 15" in FIG. 4(a). , the signal is not integrated by the integrator B, and the influence of the initial DC bias that occurs at the beginning of the integration is removed.When the push button 19a of FIG. Since the signal 24 is cut off, the high frequency signal is no longer input to the IA divider B. Therefore, only the 1Hz acceleration signal is input to the integrator B, and the integrated output 16'' shown in FIG. 4(a) is obtained. (velocity V) is output.

Figure 4(b) shows the speed signal 16''' obtained in this way.
This figure is a comparison of the speed signal 16' obtained by a conventional integrator, and as shown in the figure, it can be seen that the speed signal of the present invention stabilizes in a short time.

The push button 19a shown in FIG. 1 can also be used as a camera release button, for example, to improve operability.
The device is simplified.

FIG. 2 shows another embodiment of the present invention, which shows a switch mechanism configured such that when the operation button 19a is pressed, the output of the accelerometer and the output of the high frequency signal source 24 are simultaneously input to the integrator B. In this example, the contact 20 and the contact surface 22' and the contact 21 and the contact surface 222 are electrically connected at the same time. FIG. 5 shows an integral waveform (velocity signal) according to the embodiment of FIG. 2, in which the accelerometer output signal and the high frequency signal are simultaneously input to the integrator B at the time point when the time axis ts is 32. This shows still another embodiment, in which the conductive member 22 shown in FIG. By connecting the switch 24 to the switch 24, the high frequency signal source 24 is normally not driven because the switch is in an off state. Since the high-frequency signal R24 starts driving when the photographer presses the push button 19a, the high-frequency signal source does not need to output any signal except for the start of integration, so there is no wasteful power consumption.

It is also possible to use known analog switches that control the mechanical switches shown in FIGS. 1, 2, and 3 using electrical signals.

〔Effect of the invention〕

As described above, according to the present invention, the camera pre-acceleration can be calculated by adding a higher frequency signal compared to the pre-acceleration signal to the input of the integrator that integrates the acceleration signal caused by camera shake to obtain the pre-velocity etc. Since it is possible to reduce the period of instability of the output signal after planting due to the initial integral value, a stable camera pre-output signal can be obtained in a short time.

Furthermore, the present invention is not limited to camera pre-detection.
Needless to say, the present invention can be widely applied to, for example, position detection of industrial robots.

[Brief explanation of drawings]

Figure 1 is a circuit diagram showing one embodiment of the present invention, Figures 2 and 3 are circuit diagrams showing one embodiment of the present invention.
The figure is a circuit diagram showing another embodiment of the present invention, FIG. 4(a) is a waveform diagram showing the input/output signals of FIG.
Figure (b) is a waveform diagram comparing the present invention and a conventional example, and Figure 5 is an output waveform diagram based on the circuit diagram of Figure 2. Fig. 6 is a diagram showing the camera acceleration detection system used in the present invention, Fig. 7 (a) and (b) are the integrator circuit ports used in the present invention, and Fig. 8 (a) and (b) are the integral A diagram showing input and output waveforms of the circuit. FIG. 9 is an integral circuit diagram used in the present invention. 3a, 3b; Accelerometer. ll; Acceleration signal input terminal. 19a; push button. 20.21. switch contact piece. 22; Conductive member. 24; High frequency signal source. A: Switch mechanism. B: Integral circuit.

Claims (2)

[Claims] (1) In an integrator that calculates the velocity or displacement of the object based on the output signal of an acceleration detector that detects the acceleration of the object, the input of the integrator is connected to the input of the integrator through a first switch means to compare the acceleration signal with the output signal of the acceleration detector. A high frequency signal source that outputs a high frequency signal with a high frequency is connected to an acceleration signal source that outputs the acceleration signal via a second switch means, and the high frequency signal is Said first
The high frequency signal is input to the integrator by a switch means, and the high frequency signal is input to the integrator for a predetermined period of time from the start of integration of the acceleration signal. initial setting circuit. (2) In the integrator according to claim 1, when the integration is started, the second switch means and the first switch means are simultaneously closed, and a predetermined constant An initial setting circuit for an integrator, wherein the first switch means is brought into an open state after a period of time has elapsed.