JPS6024452A - Apparatus for measuring ground speed vector of moving object - Google Patents

Abstract

PURPOSE:To measure the speed and direction of a moving object, by a simple constitution wherein the measuring point image of a road surface is detected through the lens and the photosensor supported in an integrally rotatable manner by the moving object and predetermined processing is applied to the detected signal and the rotary angle signal. CONSTITUTION:The lens 12 and the photosensor 14 supported by a moving object are integrally rotated around a rotary shaft 18 through a motor driving apparatus 32 to detect the measuring point image 20 on the circular locus of a road surface 10. The detected signal is sent to a timing pulse generator 41 through an amplifier 36, a comparator 38 and a counter 40 and, when the rotary cycle of the output of the sensor 41 becomes max. (or min.), a pulse signal is sent to a gate circuit. The output signal of a rotary angle sensor 42 is sent to an operator circuit 50 through the circuit 46 to calculate the moving direction of the moving object. On the other hand, a zero level pulse is sent to a gate circuit 62 from the output of the counter 40 from the output of the counter 40 through a comparator 58 and a timing generator 60 and the rotary angle signal of the circuit 48 is sent to an operator circuit 64 through differential circuit 54 and the gate circuit 62 to calculate the moving speed of the moving object.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a ground speed vector measuring device of a moving object,
In particular, the present invention relates to a ground speed vector measuring device for a moving object suitable for measuring the speed and direction of a moving object such as a car moving on the ground.

[Background of the invention]

When measuring the speed and direction of a moving object such as a car moving on a road surface, two methods have been conventionally employed.

One method is to lower a wheel with casters to the road surface from a moving object and measure the direction and rotation speed of the wheel.The other method is to measure the flow of particles on the road surface toward the moving object. This is a method of determining the velocity by optically measuring the velocity in two axes of a fixed coordinate system.

By employing each of the above methods, the speed and direction of a moving object can be measured. However, in the case of the former method, if the speed direction suddenly changes, it cannot be followed, and the wheels vibrate on uneven road surfaces, making it impossible to measure correctly. In addition, the latter method requires separate speed measuring devices for two axes, resulting in a large-scale device and a corresponding increase in cost.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide a ground speed vector measuring device for a moving object that can measure the speed and direction of a moving object with a simple configuration. There is a particular thing.

[Summary of the invention]

In order to achieve the above object, the present invention has a lens facing the road surface, the lens is supported by a moving object, and has an optical axis tilted from the vertical axis with a rotating axis substantially parallel to the vertical axis. an optical system which is rotationally and flexibly supported and whose focal point of one of the lenses is adjusted to form an image of incident light from the measurement point at a measurement point where an extension of the optical axis intersects with the road surface; a photosensor that rotates around the rotation axis and converts a measurement point image formed by an optical system into an electrical signal; a rotation shaft drive device that drives the rotation axis and periodically changes its rotation speed; A signal generation circuit that converts an output signal of 7 otose/l into a pulse signal and generates a signal with a level corresponding to the number of pulses of this pulse signal, and detects the output level of the signal generation circuit and detects the output level of the signal generation circuit and detects the output level of the rotation shaft. a first timing pulse generation circuit that generates a timing pulse when the detection level within each rotation period reaches a maximum or minimum level within each rotation period, and a rotation angle sensor that detects the rotation speed of the rotation shaft; Upon receiving the detection output of the rotation angle sensor, the detection output of the rotation angle sensor at the time of generation of the timing pulse corresponding to the maximum or minimum level is shifted by +90'' or -900 according to the timing pulse, and the shifted rotation angle or the detection output of the rotation angle sensor is shifted by +90'' or -900. a first calculation unit that calculates a direction with respect to a reference direction; and a second calculation unit that generates a timing pulse when generation of a pulse signal by the detection output of the photosensor stops and the output level of the signal generation circuit approaches zero level. A timing pulse generation circuit, a differentiation circuit that differentiates the output signal of the rotation angle sensor, and a timing pulse from the second timing pulse generation circuit captures the output signal of the differentiation circuit, and is determined by the rotation of the optical system when the moving object is stopped. A second calculation unit calculates the speed of the moving object by multiplying the diameter of the circle formed by the set of measurement points and the level of the output signal of the differential circuit when the timing pulse is generated, and calculates the ground speed vector of the moving object. The present invention is characterized in that a measuring device is configured to measure the speed and direction of a moving object with a simple configuration.

[Embodiments of the Invention j Hereinafter, preferred embodiments of the present invention will be described based on the − aspect.

The if diagram shows the configuration of a preferred embodiment of the present invention.

In FIG. 1, an optical system having a lens 12 facing a road surface 10 and a phototransistor 4 constituting a photosensor are housed together in a housing 16. The lens 12 is rotatably supported by a rotating shaft 18 that is supported by a moving object (not shown) and is substantially parallel to the vertical axis, with the optical axis of the lens 12 being inclined from the vertical axis.

One focus of the lens 12 is adjusted to a measurement point 20 where the extended edge of the optical axis intersects with the road surface 10, and an enlarged measurement point image of road surface particles at the measurement point 20 is received by the phototransistor 14. It is adjusted to form an image on a surface. The measurement point image formed on the light-receiving surface of the phototransistor 14 is converted into an electric signal by the phototransistor 14, and this electric signal is sent to a brush fixed to a moving object via a slip ring 22 installed on the rotating shaft 18. 24.

A gear 26 is fixed to the lower part of the rotating shaft 18, and this gear 26 meshes with a gear 30 connected to a motor 28, which drives the motor drive unit @32. When the motor 28 is operated by vIK, the rotating shaft 18 is configured to rotate in the direction of the arrow x by the rotational drive of the gear 30.260. That is, in this embodiment, gears 26 and 30, motor 2
8. Rotary shaft drive device f composed of a motor drive device 32
By fK, the rotating shaft 18 can be rotationally driven in the direction of the arrow. Further, the rotary shaft driving device in this embodiment is configured to rotate the rotary shaft load 8 and to periodically change its rotational speed.

When the rotating shaft 18 rotates, the housing 16 connected to the rotating shaft 18 rotates together with the rotating shaft 18, and a circle is formed by a collection of measurement points 20 when the moving object is stopped. Furthermore, when the moving object moves at a certain speed over the road surface work 0, the change in brightness of the road surface particles is given to the phototransistor 14 as a measurement point image, and this measurement point image is converted into an electrical signal. The output signal of the phototransistor 14 is sent to a signal generation circuit 34 via a slip ring 22 and a brush 24.
supplied to

The signal generation circuit 34 includes an amplifier 36, a comparator 38, and a counter 40, and the amplifier 36 outputs a signal indicated by the second -faJ.

This fourth signal is compared with its threshold level Vl by a comparator 38, and from the comparator 38, the (
A pulse signal as indicated by bJ is output, and this pulse signal is counted by the counter 40. The counter 40 counts the output pulses of the comparator 38 and produces a signal with a level corresponding to the number of output pulses, that is, (
C) Ic As shown, it is configured to output a sinusoidal signal superimposed on a certain bias signal.

That is, the change in brightness of the road surface particles at the measuring point 2o is outputted by the transducer 4 as a signal shown in (a) in FIG. Therefore, by counting the output pulses of the comparator 38, a sinusoidal output signal can be output from the counter 4o. Also, move 11E!
+1lII! Phototransistor 1 depending on the speed of the I body
Since the frequency of the blade signal 4 changes, when the speed of the moving object is slow, the counter 40 outputs a signal as shown by the m line in (C), and - the speed of the blade moving object becomes faster. In this case, the signal shown by the solid line in (C) is output from the color/receiver 4o.

In addition, when the observation point 2o moves in a circular manner as seen from the moving object, as shown in Fig. 3, the road surface IQ as seen from the moving object
With respect to the flow direction Y, the velocity vector γω at the observation point 2°
The output signal of the phototransistor 14 at the point AIC where the direction of is the opposite direction K is the old signal with the highest frequency among the circular measurement points 20. - 10,000 points B, which is 180' apart from point A, that is, the point where the flow direction Y of the road surface lO and the relative vector γω of the observation point 2o are in the same direction, the relative velocity between the road surface 10 and the observation point 2o is the minimum. Therefore, the output signal of the phototransistor 14 at point B has the lowest frequency among the measurement points 2o. Therefore, by counting the output pulses of the comparator 38 by the counter 4o, the counter 4o
The cutting edge is biased at 16 as shown by IC in Figure 2.
This results in a sinusoidal signal superimposed on the signal.

Here, the angle between points A and H shown in FIG. 3 is perpendicular to the direction of movement of the moving object, so point A is the possible angle.

By adding +90' or -90' to the angle of the rotation axis 18 at B, the direction of the moving object relative to the reference direction can be determined.

Therefore, in this embodiment, the first timing is used to detect when the output level of the counter 4o within each rotation period of the rotating shaft 18 reaches the maximum or minimum level within each rotation period. A timing pulse generator 41 constituting a pulse generation circuit is provided, and one rotation axis 18 is provided.
a rotation angle sensor 42 that detects the rotation angle of the moving object; and a first calculation unit 4 that calculates the direction of the moving object with respect to the reference direction based on the rotation angle sensor 42 and the timing pulse generator 41.
4 is provided.

That is, the timing pulse generator 41 detects the output level of the counter 40, and as shown in FIG. It is configured to generate a timing pulse when the minimum level is reached, and the timing pulse of the timing pulse generator 41 is generated by the first calculation unit 44.
is supplied to the gate circuit 46 of.

On the other hand, the rotation angle sensor 42 fixed to the rotation shaft 18 is configured to detect the angle of the rotation shaft 18 and supply this detection signal to the angle sensor signal processing circuit 48. The angle sensor signal processing circuit 48 outputs a signal as shown in FIG. 2(e).

An arithmetic circuit 50 of the first arithmetic unit 44, which includes an angle sensor signal processing circuit 48, a gate circuit 46, and an arithmetic circuit 50.
When a timing pulse is output from the timing pulse generator 41, the gate circuit 46 is opened to take in the output signal of the angle sensor signal processing circuit 48, and the rotation angle sensor 42 at the time of generation of the timing pulse corresponding to the maximum or minimum level. The detection output is shifted by +90° or -90° as shown in tel Ic in FIG. 2, and the direction of the moving object with respect to the reference direction is calculated from the shifted rotation angle ψ.

In this embodiment, the detection output of the rotation angle sensor 42 is determined when the output level of the counter 40 within each rotation period of the rotating shaft 18 reaches the maximum or minimum level within each rotation period. can be shifted by 190 degrees or -90 degrees, and the direction of the moving object relative to the reference direction can be determined by the shifted rotation angle ψ.

By the way, as described above, the rotational speed of the rotating shaft 18 is periodically changed by the rotating shaft driving device. Therefore, if the width of the speed change of the rotating shaft 18 is made sufficiently large, there will be a rotational speed at which the flow speed of the road surface 10 and the circumferential speed of the measurement point 200 match. When the relative speed of the moving object and the speed of the rotating shaft 18 match, the output level of the counter 40 is approximately approximated to the level, so by detecting the output level of the counter 40, the road surface lO can be reduced. It is possible to detect the point in time when the flow velocity and the circumferential velocity of the observation point 200 match. That is, when the output level of the counter 40 is approximately close to zero level, the speed of the moving object and the circumferential speed of the observation point 200 are equal, so the output signal of the rotation angle sensor 42 at this point is differentiated, and this differential value and The speed of the moving object can be determined by multiplying by the radius of the circle formed by the 200 measurement points determined by the rotation of the optical system when the moving object is stopped.

Therefore, in this embodiment, a second timing pulse generation circuit 52 is provided for detecting that the output level of the counter 40 approaches zero level, and a differentiation circuit is provided for differentiating the output signal of the angle sensor signal processing circuit 48. 54, a differentiation circuit 54, and a second timing pulse generation circuit 52
A second arithmetic unit 56 is provided that calculates the speed of the moving object based on timing pulses from the moving object.

The second timing pulse generation circuit 52 includes a comparator 58 and a timing pulse generator 60 , and the output signal of the color/return signal 40 is supplied to the comparator 58 . Then, when the comparator 58 detects that the output level of the counter 40 has become a very small value close to the zero level, the comparison output of the comparator 58 is given to the timing pulse generator 60, The timing pulse generator 60 is configured to apply a timing pulse to the gate circuit 62 of the second arithmetic unit 56 when the output signal rises. -10,000, the differential circuit 54 is the angle sensor 1!
Issue processing time ji! Take in the output signal of r4B and use this ir
It is configured to differentiate the number g and supply a signal as shown in FIG. 2 to the gate circuit 62.

The second calculation unit 56, which is composed of a gate circuit 62 and a calculation circuit 64, opens the gate circuit 62 according to the timing pulse output from the timing pulse generator 60, takes in the output signal of the differentiating circuit 54 into the calculation circuit 64, and moves the signal. The radius r of the circle formed by the coincidence of the measurement points 20 determined by the rotation of the optical system when the object is stopped and the differential opening w when the timing pulse is generated! The speed of the moving object is calculated by multiplying by the level ω of the output signal of r54.

As described above, in this embodiment, when the output level of the counter 40 is approximately close to the zero level, the differential value of the rotation angle sensor 42 is multiplied by the radius r of the circle formed by the set of measurement points 20. You can measure the speed of a moving object.

As described above, according to the present embodiment, the speed and direction of a moving object can be measured with a simple configuration, so the cost can be reduced compared to conventional devices, and the speed and direction of a moving object can be measured. It becomes possible to carry out experiments to measure .

〔Effect of the invention〕

As explained above, according to the present invention, changes in road surface particles at a measurement point are converted into a sine wave signal, and when the output level within each period of this sine wave signal reaches the maximum or minimum level, the movement The direction of the moving object relative to the reference direction is determined by shifting the value detected as the angle perpendicular to the moving direction of the object by +90Q or -90°, and when the speed of the moving object and the circumferential speed of the observation point are equal, the above sine Taking this as the point in time when the wave signal approaches zero, we differentiate the angular change at the measurement point at this point, and calculate the radius of the circle formed by this differential value and the set of measurement points determined by the rotation of the optical system when the moving object is stopped. Since the speed of the moving object is calculated by multiplying , the speed and direction of the moving object can be measured with a simple configuration, and the production cost of the device can be reduced, which is an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, and FIG.
) to (f) are 4! of the apparatus shown in FIG. 1, respectively. FIG. 3 is a waveform diagram for explaining the action of the waveform, and FIG. 3 is a diagram for explaining the configuration of the apparatus shown in FIG. 1. 12...Lens, 14...Phototransistor, 1
8... Rotation axis, 20... Measurement point, 28... Motor, 34... Signal generation/loss circuit, 41... Timing pulse generator, 42... Rotation angle set/su, 44... . . . first calculation unit, 52 . . . second timing pulse generation circuit,
54... Differential circuit, 56... Second calculation section. Agent Tatsuyuki Unuma (and 1 other person) Figure 2 □ Time Figure 3

Claims (1)

[Claims] (1) It has at least a lens facing the road surface, is supported by a moving object, and has a rotation axis K that is substantially parallel to the vertical axis, and the lens is rotatably supported with its optical axis inclined from the vertical axis, and the optical axis The focal point of 10,000 points of the lens is at the measurement point where the extension line of v! intersects with the road surface. an optical system that forms an image of the incident light from the measurement point; an optical sensor that rotates around the rotation axis together with the optical system and converts the measurement point image formed by the optical system into an electrical signal; a rotary shaft drive device that drives the shaft and periodically changes its rotational speed;
7. A signal generation circuit that converts the output signal of the auto sensor into a pulse signal Kf and generates a signal with a level corresponding to the number of pulses of this pulse signal; and a signal generation circuit that detects the output level of the signal generation circuit and selects one of the detected levels for each of the rotating shafts. a first timing pulse generation circuit that generates a timing pulse when a detection level within a rotation period reaches a maximum or minimum level within each rotation period; a rotation angle sensor that detects a rotation angle of the rotation shaft; Upon receiving the detection output of the rotation angle sensor, the detection output of the rotation angle sensor at the time of generation of the timing pulse corresponding to the maximum or minimum level is shifted by +90° or -90' according to the timing pulse, and the rotation angle of the moving object is determined from the shifted rotation angle. a first calculation unit that calculates the direction with respect to the reference direction; and a second calculation unit that generates a timing noise when the generation of the pulse signal by detection by the sensor stops and the output level of the signal generation circuit approaches zero level. A timing nozzle generating circuit, a differentiating circuit that differentiates the output signal of the rotation angle sensor, and a second timing nozzle generating circuit capture the output signal of the differentiating circuit by the timing pulses of the rotation angle sensor, and when the moving object stops, the output signal of the differentiating circuit is captured. a second calculation unit that calculates the speed of the moving object by multiplying the radius of the circle formed by the set of one fixed point determined by the rotation of the system and the level of the output signal of the differential circuit when the timing pulse is generated; A ground speed vector measuring device for a moving object, characterized in that it has: