JPH0527005Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a movement direction detection device, and more particularly to a device for optically detecting the direction of relative movement between two objects.

Prior Art and its Problems As a device for optically detecting relative movement between two objects, a device using laser light is known. However, devices using laser light have problems in that they have a complicated structure and are expensive.

Therefore, an apparatus for detecting movement using ordinary incoherent light has been proposed, for example, as disclosed in Japanese Unexamined Patent Publication No. 113762/1983. However, this device has a complicated configuration in that it requires a light receiver made up of many segments to capture the optical image pattern of the surface to be measured, and the direction of movement that can be detected depends on the arrangement direction of the segments. is defined, and has the problem that it is not suitable in principle for detecting the moving speed and moving direction when the moving direction changes.

Purpose of the invention The purpose of the present invention is to provide a moving direction detection device that can suitably detect the moving direction even if the moving direction changes, and that can be simplified in configuration. .

Composition of the Invention The moving direction detection device of the present invention includes an origin sensor that is provided on a moving object and detects the intensity of light from a point on a surface to be measured relatively moving in a predetermined direction as an origin, and the origin sensor described above. a plurality of remote point sensors provided on the movable body and detecting the intensity of light from a plurality of points on the measurement target surface provided at different distances in different directions from the origin; movement of the movable body; a speed sensor that detects the speed; an origin data means that reads the output of the origin sensor at a predetermined time and obtains the data as origin data; a remote point data means for reading the output of the remote point sensor corresponding to each time delayed from the predetermined time by a travel time corresponding to each of the distances, and obtaining the data as remote point data; Comparison and selection means for comparing the separation point data and selecting the separation point data having the maximum correlation; and direction determination means for obtaining the moving direction of the moving object based on the arrangement of the separation point sensor corresponding to the selected separation point data. It is characterized in that it is equipped with the following.

Note that the concept of "point" in the above-mentioned constituent elements refers to an area with a certain extent, and since this area is handled as an integral part, it is expressed as a "point."

Function The origin sensor detects the intensity of light at a point, and the detection direction is not specified. A plurality of remote point sensors also detect the intensity of light at a point, and the detection direction is not defined.

Since each remote point is provided in a different direction around the origin, the remote point sensor (hereinafter referred to as the corresponding remote point sensor) corresponding to the remote point that is on the moving direction line passing through the origin and behind the origin in the moving direction. A point sensor (referred to as a point sensor) passes through the same part of the measurement target surface as the origin sensor after a time delay corresponding to the time required to move from its separation point to the origin.

However, since each separation point is provided at a different distance from the origin, the delay time differs for each separation point.

Therefore, if data is first obtained from the origin sensor at a predetermined time, and then data is obtained from each separation point sensor after each delay time in descending order of the delay time for each separation point, the corresponding separation point sensor will be the origin sensor. The same data should be obtained, but since the other remote point sensors pass through a different part of the moving part of the origin sensor, they will not obtain the same data.

Therefore, if one selects one of the remote point data obtained for each remote point sensor that has a particularly strong correlation with the origin data obtained by the origin sensor, that remote point sensor is the corresponding remote point sensor, and It can be seen that the direction seen from the corresponding separation point to the origin is the direction of movement.

Embodiments Hereinafter, the present invention will be explained in more detail based on embodiments shown in the drawings. Here, FIG. 1 is a block diagram of the configuration of a moving direction detecting device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the positional relationship between the surface to be measured and a photodiode array, and FIG. 3 is a schematic diagram of the moving direction detecting device of the present invention. FIG. 4 is a block diagram of another embodiment of the moving direction detecting device of the present invention. Note that the present invention is not limited to the embodiments shown in the figures.

As shown in FIG. 1, the moving direction detection device 1 includes:
It comprises a photodiode array 2, an analog multiplexer 3, an analog-to-digital conversion circuit 4, a microcomputer 5, a display 6, and a vehicle speed sensor 7.

The photodiode array 2 includes isolated photodiodes P ₁ ,..., P _i ,..., P _x arranged in a spiral shape.
and the origin photodiode installed in the center.
It has P _p .

If the position of each remote photodiode P _i is expressed by the distance l _i from the origin photodiode P _p and the angle θ _i with respect to a predetermined direction, then l _i =Δl・i+l _p θ _i =Δθ・i. . In addition, the origin photodiode is placed in the reference direction.
A hypothetical reference point set at a distance of l _p from P _p is represented by Q in FIG.

Analog multiplexer 3 receives select signal S
is given, the photodiode array 2
A selected one of the output signals of each of the photodiodes P _p to P _x is output.

The analog-to-digital conversion circuit 4 converts the analog signal output from the analog multiplexer 3 into a digital signal.

The number of bits of a digital signal is, for example, 1 bit to
Approximately 8 bits is sufficient. For example, in the case of 1 bit, the intensity of light captured by each photodiode P _p to P _x is simply divided into two levels, ``bright'' and ``dark.'' Specifically, it is necessary to use a comparison circuit. I can do it.
When using more than 1 bit, the intensity of the detected light can be divided into three or more levels from "bright" to "dark", and specifically, an A/D converter can be used.

The microcomputer 5 first selects the origin photodiode P _p , reads the digital signal output from the analog-to-digital conversion circuit 4, and stores it in the origin data area R _p .

Next, the vehicle speed v is obtained by the vehicle speed sensor 7, and a delay time T _i is calculated for each photodiode P _i based on the vehicle speed v, and each time the delay time T _i elapses, the photodiode is P _i is selected, and the digital signal output from the analog-to-digital conversion circuit 4 is read and stored in each remote point data area R _i .

The delay time T _i is calculated using the following formula.

T _i =K ₁・l _i /v (here, K ₁・l ₁ is the distance on the surface to be measured
r _i , and therefore T _i means the travel time from the departure point to the origin. ) After obtaining data for all remote point photodiodes P ₁ to P _x , next, calculate the correlation between the origin data area R _p and the contents (R _i ) of each remote point data area _Ri ,
The moving direction is determined based on the arrangement of the remote point photodiode P _{i nax} corresponding to the remote point data area R _{i nax} having the maximum correlation.

The display 6 displays the moving speed v and the moving direction based on the output from the microcomputer 5.

Next, the operation of the moving direction detection device 1 will be explained in more detail with reference to FIGS. 2 and 3. For convenience of explanation, it is assumed that the moving direction detection device 1 is mounted on a car and is moving in the direction of arrow α.

Figure 2 shows the state at a certain time _t0 , where the origin photodiode _P0 is at point A on the ground G.
The i-th remote photodiode P _i detects the light intensity at a point B _i which is a distance r _i away from point A. L is a lens, and K ₁ is determined by this lens.

As shown in FIG. 3, at time t ₀ , the microcomputer 5 switches the origin photodiode P ₀
Select , read the data four times at a short cycle τ, and set the origin data "1234" to the origin data area.
Get to R ₀ . Here, "1234" is point A on ground G
This is the pattern of brightness and darkness on the surface of the earth for a length of 4τv in the α direction.

Next, time t ₁ is a delay time T ₁ after time t 0 _.
(=t ₀ + T ₁ ), select the isolated photodiode P ₁ and read the data four times with a short cycle τ,
Obtain the remote point data string "9857" in the origin data area _R1 . Here, "9857" is 4τv in the α direction from the point B ₁ on the ground G corresponding to the remote photodiode P _1.
This is the pattern of light and darkness on the surface of the earth up to the length of .

Similarly, time t _i after time t ₀ by delay time T _i
(=t ₀ +T _i ), select the isolated photodiode P _i and read the data four times with a short period τ,
Obtaining the departure point data string in the origin data area R _i is repeated until i=x.

Next, the microcomputer 5 calculates a correlation value between the origin data string R ₀ and each remote point data string R ₁ to Rx.

This correlation calculation may be performed, for example, by performing an exclusive OR on each bit of two data strings, and using the number of bits that are "1" as a correlation value.

Next, the largest one is selected from among the correlation values obtained for each remote point data string, and the number Pi _nax of the remote point photodiode corresponding to that correlation value _is obtained.

For example, in the case shown in FIG. 3, P ₄ is read out as the number of the isolated photodiode having the largest correlation value.

Next, the microcomputer 5 determines the traveling direction of the automobile from the arrangement of the photodiode _P4 , and displays this on the display 6. That is, the α direction is displayed.

Once the moving direction is obtained as described above, the process returns to the initial operation and repeats the same process to update the moving direction.

The moving direction detection device 1 of the above embodiment was capable of detecting the moving direction over a 360 degree range, but if a remote photodiode is provided for only half a revolution, the moving direction can be detected over a 180 degree range. It becomes possible. In such a case, a specific example is a case where only forward movement is to be detected. In addition, if the direction of movement changes only by a narrow angle, it is sufficient to provide separate photodiodes corresponding to the angle.

FIG. 4 shows a moving direction detection device 10 according to another embodiment of the present invention.

In this moving direction detection device 10, the output value of the origin photodiode P _p is sampled and held in the sample-hold circuit 8 at a predetermined time t ₀ , and the output value of each off-point photodiode is sampled and held at a time t _i after each delay time T _i . Select P _i and analog multiplexer 3
is output to the differential amplifier 9, and the difference with the output value of the sample and hold circuit 8 is read through the analog-to-digital conversion circuit 4, and the direction of movement is determined from the placement of the photodiode P _{i nio} that minimizes the difference. judge.

Effects of the invention According to the invention, an origin sensor is provided on a moving body and detects the intensity of light with a point on a surface to be measured relatively moving in a predetermined direction as an origin, and together with the origin sensor, the moving body a plurality of remote point sensors that detect the intensity of light from a plurality of points on the measurement target surface provided at different distances in different directions from the origin, and detect the moving speed of the moving body; a speed sensor that reads the output of the origin sensor at a predetermined time and obtains the data as origin data; an off-point data means for reading the output of an off-point sensor corresponding to each time delayed from the predetermined time by a travel time corresponding to the distance, and obtaining the data as off-point data; the origin data and each off-point data; and a direction determining means for obtaining the moving direction of the mobile body based on the arrangement of the remote point sensors corresponding to the selected remote point data. A moving direction detecting device is provided, which is capable of suitably detecting the direction of relative movement between relatively moving objects.
In addition, no complicated calculations are required in this case, and the direction of movement can be determined simply by comparing the data from which remote point sensor is most similar to the data from the origin sensor. It has the advantage that it can be implemented with a simple configuration.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the configuration of a moving direction detecting device according to an embodiment of the present invention, Fig. 2 is an explanatory diagram of the positional relationship between the measurement target surface and the photodiode array, and Fig. 3 is the principle of the moving direction detecting device of the present invention. The explanatory diagram, FIG. 4, is a block diagram of another embodiment of the moving direction detecting device of the present invention. Explanation of symbols, 1... Movement direction detection device, 2...
Photodiode array, 3...Analog multiplexer, 4...Analog-to-digital conversion circuit, 5
... Microcomputer, 6 ... Display, 7 ... Vehicle speed sensor, 8 ... Sample hold circuit, 9 ... Differential amplifier, P _p ... Origin photodiode, P ₁ to Px ... Remote point photodiode, R _p
...Origin point data area, R ₁ to R _x ... Remote point data area.

Claims (1)

[Claims for Utility Model Registration] 1. (a) An origin sensor that is provided on a moving object and detects the intensity of light using a revolution on a surface to be measured that moves relatively in a predetermined direction as the origin; (b) The above. (c ) a speed sensor that detects the moving speed of the moving object; (d) origin data means that reads the output of the origin sensor at a predetermined time and obtains the data as origin data; The output of the remote point sensor corresponding to each time delayed from the predetermined time by the travel time corresponding to each distance calculated from each distance and the moving speed by the speed sensor is read, and the data is used as remote point data. (f) comparison and selection means for comparing the origin data and each of the remote point data and selecting the remote point data having the greatest correlation; and (g) the remote point data corresponding to the selected remote point data. A moving direction detecting device comprising a direction determining means for obtaining the moving direction of the moving body based on the arrangement of point sensors. 2. The moving direction detection device according to claim 1, wherein a plurality of distance sensors are arranged in a spiral shape.