JP3134136B2 - Moving object position detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting apparatus for a moving body, such as a self-propelled carrier of a carrier self-propelled conveyor, capable of detecting an absolute position of a moving body moving along a predetermined moving path.

[0002]

2. Description of the Related Art As a position detecting device for detecting an absolute position of a moving body, there is known a position detecting device described in Japanese Patent Application Laid-Open No. 53-89180.

[0003] This device is attached to the moving body at a constant pitch in the front-rear direction, which is the moving direction of the moving body, so as to correspond to the main scale arranged along the moving path of the moving body. The apparatus is provided with a main scale detectors and a processing device for obtaining the position of the moving body based on the output of the main scale detectors. The main scale is provided with a plurality of main address portions before and after at a pitch equal to that of the main scale detector. Each main address is
The main scale detector includes one of a positive logic detector for detecting a binary code "1" and the main scale detector includes a negative logic detector for detecting a binary code "0". One or a plurality of consecutive positive logic detectors are arranged such that the a-digit binary codes represented by the a consecutive main address parts starting from each main address part are all different for the main address parts of the number. Are formed alternately. Then, the processing device reads an a-digit binary code which is an output of the main scale detector, and thereby obtains the absolute position of the moving body.

[0004]

In the above-described position detecting device, the position detecting accuracy (resolution) is limited to the pitch of the main address of the main scale, that is, the pitch of the main scale detector. As a main scale detector, a photoelectric switch including a light emitter and a light receiver is generally used. However, since the light emitter and the light receiver have a certain size, the pitch can be reduced only to about several mm. . Therefore, the position detection accuracy cannot be made very high.

Further, the processing device is adapted to read a binary code which is an output of the main scale detector at a fixed time interval, and the main scale detector detects a boundary between main addresses before and after the main scale. When approaching, due to a variation in the sensitivity of the detector, a reading error such as reading an original “0” as “1” or conversely reading an original “1” as “0”. This causes a problem that an error occurs in the detection result.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a position detecting device for a moving body capable of solving the above-mentioned problem and accurately detecting an absolute position with a precision smaller than a pitch of a main address of a main scale.

[0007]

SUMMARY OF THE INVENTION A moving object position detecting apparatus according to the present invention moves a moving body so as to correspond to a main scale, a vernier scale, and a main scale arranged in parallel along a moving path of the moving body. M main scale detectors attached to the moving body at a constant pitch in the front-rear direction, and n attached to the moving body at a constant pitch in the front-rear direction to correspond to the vernier And a processing device for obtaining the position of the moving object based on the outputs of the main scale detector and the main scale detector. The main address portions are provided at the same pitch as the length detector, and each main address portion is a positive logic detector for detecting the binary code “1” by the main length detector and the binary code “0” by the main length detector. A predetermined number of main numbers consisting of one of the negative logic detectors that A main address portion comprising one or a plurality of continuous positive logic detection portions such that m consecutive binary address codes represented by m consecutive main address portions starting from each main address portion are all different. And a main address portion composed of a negative logic detecting portion are formed alternately, and a plurality of front and rear sub-address portions are provided on the sub-scale at a pitch that divides the pitch of the main address portion of the main scale by n. One sub-address portion for each of the sub-addresses comprises a first detection portion in which the vernier detector detects only one of the binary codes “1” and “0”, and the remaining sub-address portions are
The vernier detector includes a second detector that detects only a binary code different from the first detector, and the n vernier detectors have a pitch equal to (n + 1) times the pitch of the subaddress portion. The processing device determines the position corresponding to the sub-address of the vernier scale based on the n-digit binary code detected by the vernier detector, and detects the position by the vernier detector. When the n-digit binary code reaches a predetermined value, a position corresponding to the main address portion of the main scale is obtained based on the m-digit binary code detected by the main scale detector, and The position of the moving body is obtained from a position corresponding to the main address portion and a position corresponding to the sub address portion of the vernier scale.

[0008]

The processing device obtains a position corresponding to the subaddress portion of the vernier scale based on the n-digit binary code detected by the vernier scale detector, and obtains the m-digit position detected by the main scale detector. Since the position corresponding to the main address of the main scale is obtained based on the binary code, and the position of the moving body is obtained from the position corresponding to the main address of the main scale and the position corresponding to the sub-address of the vernier, The absolute position of the moving body can be detected with an accuracy equal to the pitch of the sub address portion, that is, 1 / n of the pitch of the main address portion. The pitch of the main scale detector which is n times the pitch of the sub-address portion of the sub-scale is smaller than the pitch of the sub-scale detector which is (n + 1) times the pitch of the sub-address portion. For this reason, the pitch of the main scale detector and the pitch of the main address part of the main scale that is equal to the pitch can be reduced to the same extent as in the past, and therefore, the absolute position of the moving body can be determined with 1 / n accuracy in the past. Can be detected.

When the n-digit binary code detected by the vernier detector reaches a predetermined value, the main scale main code is detected based on the m-digit binary code detected by the main scale detector. Since the position corresponding to the address portion is obtained, the output of the main scale detector is read once while the moving body moves by one pitch of the main address portion of the main scale. The output of the main scale detector can be read when it arrives at the center of the main address section. For this reason, a reading error due to a variation in the sensitivity of the detector does not occur, and an accurate position can be detected.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to the detection of the absolute position of a self-propelled carrier in a carrier self-propelled conveyor will be described below with reference to the drawings.

As shown in FIG. 1, the carrier self-propelled conveyor is provided with a self-propelled carrier (moving body) (2) which runs by itself along a traveling rail (1). The conveyor comprises a plurality of carriers (2), only one of which is shown in the drawing. Although not shown, the carrier (2) has a driving roller and a plurality of driven rollers for suspending the carrier on the rail (1), a driving motor for driving the driving roller to run the carrier (2), In addition, a travel control device and the like are provided. Then, the carrier (2) is passed from the control station on the ground through the AC power line provided on the rail (1).
AC power is supplied to the control station, and signals are transmitted and received between the control station and the carrier (2) through a signal transmission line provided on the rail (1), whereby the traveling of the carrier (2) is controlled. You. Since such a carrier self-propelled conveyor itself is known, a detailed description thereof will be omitted.

FIG. 1 shows a carrier self-propelled conveyor.
Only the part of the carrier (2) relating to the position detecting device is shown, and FIG. 2 further shows a part thereof. In the following description, the direction of movement of the carrier (2) is referred to as the front-back direction, and one (left side in FIG. 1) is the front and the other (right side in FIG. 1)
After. Also, the left and right when viewing the front from behind are referred to as left and right.

Along the path of movement of the carrier (2),
(3) and vernier (4) are provided in parallel. Carrier (2)
, Five main scale detectors (photoelectric switches) (5) are attached at a constant pitch. The main scale detectors are collectively referred to by reference numeral (5), and when it is necessary to distinguish them, in order from the previous one, the first main scale detector (5a), the second main scale detector (5b), Third main scale detector (5c), fourth main scale detector (5c)
d) and the fifth main scale detector (5e). Each main scale detector (5) is composed of a light emitter (6) and a light receiver (7) which are arranged opposite to each other so as to sandwich the main scale (3) from both left and right sides. The output is the output of the main scale detector (5). The carrier (2) is provided with four front and rear detectors (photoelectric switches) (8) at regular intervals. The vernier detectors are also collectively referred to by reference numeral (8), and when it is necessary to distinguish them, in order from the previous one, the first vernier detector (8a), the second vernier detector (8b), Third vernier detector (8
c) and the fourth vernier detector (8d). Each vernier detector (8) is composed of a light emitter (9) and a light receiver (10) which are arranged opposite to each other so as to sandwich the vernier (4) from both left and right sides. The output is the output of the vernier detector (8). Emitter (6) of detector for main scale (5) and detector for vernier scale (8)
(9) and the light receivers (7) and (10) are mounted on one side of the carrier (2) via a suitable support member (15). Further, the carrier (2) is provided with a processing device (11) for determining the absolute position of the carrier (2) based on the outputs of the main scale detector (5) and the subscale detector (8). .

The details of the main scale (3), the vernier (4), the detector for the main scale (5) and the detector for the vernier (8) are shown in FIG.

The main scale (3) and the sub-scale (4) are integrally provided on a band-shaped scale plate (12) fixed by appropriate means (not shown) so as to be parallel to the rail (1). In this example, the main scale (3) is provided on the upper side, and the sub-scale (4) is provided on the lower side.

The main scale (3) includes a plurality of front and rear main address portions (13).
Are provided at the same pitch as the main scale detector (5). In this example, the main scale detector (5) and the main address (1
The pitch A in 3) is 2 mm. Each main address part (13) has a positive logic detector (13a) in which the main scale detector (5) detects a binary code "1" and a main logic detector (5) in which the binary code "0" is used. Of the negative logic detecting section (13b) for detecting Main address
The negative logic detection section (13b) of (13) is constituted by a convex portion protruding above the scale plate (12). Main address (13)
The positive logic detector (13a) of the scale plate (1a)
2) is constituted by the concave portion removed. The front and rear width of the main address portion (13) is equal to the pitch A, and one positive logic detection portion (13a) or a plurality of continuous positive logic detection portions (13a) forms one concave portion, One negative logic detector (13b) or a plurality of continuous negative logic detectors (13b) forms one convex portion. In this example, the front and rear width of the sensitive range of the main scale detector (5) is about half of the front and rear width of the main address portion (13), that is, about 1 mm. Positive logic detector (1
In 3a), there is nothing to shut off the transmitter (6) and the receiver (7) of the main scale detector (5).
(5) outputs the binary code "1". Negative logic detector
In (13b), this shuts off the transmitter (6) and the receiver (7) of the main scale detector (5),
(5) outputs the binary code "0". Positive logic detector
The main address part (13) composed of (13a) represents a binary code "1", and the main address part (13) composed of the negative logic detecting part (13b) represents a binary code "0".

Since five main scale detectors (5) are provided, a 5-digit binary code corresponding to five consecutive main address portions (13) is detected by these. Then, for a predetermined number of main address portions (13) consecutive before and after, each main address portion (13)
The main address part (1) comprising one or a plurality of consecutive positive logic detectors (13a) so that the five consecutive binary address codes represented by the five consecutive main address parts (13) starting with 13) and a main address portion (13) composed of a negative logic detecting portion (13b) are formed alternately. Assuming that the number of the main scale detectors (5), that is, the number of the main address portions (13) simultaneously detected thereby is m, the maximum (2 ^m -2) continuous main address portions (13) are The main address section (13) composed of the positive logic detecting section (13a) so that all five 5-digit binary codes represented by five consecutive main address sections (13) starting from the main address section (13) are different. And negative logic detector (13b)
The main address portions (13) can be formed alternately.
The number of such main address portions (13) increases as the number of main scale detectors (5) increases.

Each of the main address portions (13) of the main scale (3) corresponds to a 5-digit binary code represented by the five main address portions (13), each of which has a leading portion. A unique main address consisting of a different 5-digit binary code is attached. This main address is
It is determined to increase by one as the main address (13) advances one by one from the rear.

The sub-scale (4) has a plurality of sub-addresses (14) in front and behind.
Are provided at a pitch B that divides the pitch A of the main address portion (13) into four equal parts. In this example, since the pitch A of the main address part (13) is 2 mm, the pitch B of the sub address part (14) is 0.1 mm.
5 mm. The front and rear width of the sub-address portion (14) is equal to the pitch B. Four consecutive subaddresses (14) constitute one block. Therefore, such a block is provided on the vernier scale (4) at a pitch equal to the pitch A of the main address. Will be. One of the four sub-addresses (14) of each block is a first detector (positive logic detector) (1) in which the vernier detector (8) detects the binary code "1".
4a), and the other three are a second detector (negative logic detector) (14b) in which the vernier detector (8) detects the binary code "0".
Consisting of The arrangement of the first detector (14a) and the second detector (14b) in all blocks is the same. Therefore, in the entire vernier scale (4), the first detecting portions (14a) are provided at a pitch equal to the pitch A of the main address portion (13), one for every four sub-address portions (14). Have been. The first detecting portion (14a) of the sub-address portion (14) is formed by a vertically long slit formed in the scale plate (12). The second detector (14b) of the subaddress (14) is provided with a scale plate (12) between these slits.
Is constituted by the part that remains as it is. In this example, the front and rear width of the sensitive range of the vernier detector (8) is also about half of the front and rear width A of the main address portion (13), that is, about 1 mm. When at least half of the sensitive range of the vernier detector (8) faces the first detector (14a), the vernier detector
The binary code "1" is output from (8), and otherwise, the binary code "0" is output from the vernier detector (8).

The pitch C of the vernier detector (8) is the subaddress (1
It is 5 (= 4 + 1) times the pitch B (0.5 mm) of 4), and in this example, it is 2.5 mm. Since four vernier detectors (8) are provided, a 4-digit binary code is detected by them. This binary code changes each time the carrier (2), that is, the detector for vernier scale (8) moves by the pitch B of the subaddress section (14), and the binary code changes for each block composed of four subaddress sections (14). The same changes are repeated. In response to such a change in the binary code, “00”, “01”, “1”
A subaddress consisting of a two-digit binary code of "0" and "11" is attached, and the subaddress is used to position the carrier (2) in each block with the same precision as the pitch B of the subaddress (14). Is represented. Pitch B of subaddress (14) (0.5m
m) is 1/4 of the pitch A (2 mm) of the main address portion (13), so that the main address is the upper five digits and the sub address is the lower two digits.
The pitch A of the main address, that is, the pitch A of the main scale detector (5), is determined by the absolute address consisting of a 7-digit binary code.
The absolute position of the carrier (2) is represented with an accuracy of 1/4 of the following.

The processing device (11) reads the output of the vernier detector (8) at regular time intervals, and reads the output of the vernier detector (8).
Vernier scale (4) based on the 4-digit binary code detected in (8)
A position corresponding to the sub-address portion (14), that is, the sub-address is obtained. Also, the four-digit two-digit number detected by the vernier detector (8)
When the hex code reaches a predetermined constant value, the output of the main scale detector (5) is read, and the main scale is detected based on the 5-digit binary code detected by the main scale detector (5). Main address of shaku (3)
The position corresponding to (13), that is, the main address is obtained. Then, the absolute address indicating the absolute position of the carrier (2) is obtained from the main address and the subaddress.

Next, the operation of the processing device (11) will be described in more detail with reference to FIGS.

FIGS. 3 and 7 show that the carrier (2) is a vernier (4).
4 is located at a position corresponding to the subaddress "00" of the block of the subaddress portion (14), FIG. 4 is located at a position corresponding to the subaddress "01", and FIG. 5 is corresponding to the subaddress "10". 6 shows a state at the position corresponding to the subaddress "11".

In the state shown in FIG. 3, the center (the center of the sensitive range) of the first vernier detector (8a) is located at the front end (the forefront) of the second detector.
It is located at the boundary between (14b) and the middle (second from the front) second detector (14b), and the output of the detector (8a) is "0". The center of the second vernier detector (8b) is located at the middle of the second detector (1).
4b) and the rear end (third from the front) of the second detector (14b), and the output of the detector (8b) is "0".
The center of the third vernier detector (8c) is located at the rear end of the second detector (14b).
And the first detector (14a).
The output of c) is "1". The center of the fourth vernier detector (8d) is located at the boundary between the first detector (14a) and the front end second detector (14b), and the output of the detector (8a) is "1". Becomes The 4-digit binary code detected by the vernier detector (8) is "0011", which corresponds to the subaddress "00". In the state shown in FIG. 3, the main scale (5) is positioned so that all the main scale detectors (5) are located at the center of the front and rear width of the main address (13) of the main scale (3). 3) and main scale detector
The positional relationship with (5) and the positional relationship between vernier (4) and detector for vernier (8) are determined.

From the state shown in FIG. 3, the carrier (2) is
When the vehicle advances by one pitch B in 4), the state shown in FIG. 4 is obtained.
In the state of FIG. 4, the center of the first vernier detector (8a) is located at the boundary between the first detector (14a) and the front end second detector (14b), and the detector (8a ) Is "1". The center of the second vernier detector (8b) is located at the boundary between the front end second detector (14b) and the middle second detector (14b).
The output of b) is "0". The center of the third vernier detector (8c) is located at the boundary between the middle second detector (14b) and the rear second detector (14b), and the output of the detector (8c) is It becomes "0". The center of the fourth vernier detector (8d) is located at the rear end of the second detector (1d).
It is located at the boundary between 4b) and the first detector (14a), and the output of the detector (8a) is "1". And detector for vernier scale
The 4-digit binary code detected in (8) is "1001", which corresponds to the subaddress "01".

In the state shown in FIG. 4, the carrier (2) is
When the vehicle advances by one pitch B in 4), the state shown in FIG. 5 is obtained.
In the state shown in FIG. 5, the center of the first vernier detector (8a) is located at the boundary between the second detector (14b) and the first detector (14a) at the rear end. The output of 8a) is "1". The center of the second vernier detector (8b) is located between the first detector (14a) and the second end of the front end.
It is located at the boundary with the detector (14b), and the output of the detector (8b) is "1". The center of the third vernier detector (8c) is located at the boundary between the front end second detector (14b) and the intermediate second detector (14b), and the output of the detector (8c) is " 0 ". The center of the fourth vernier detector (8d) is located at the boundary between the middle second detector (14b) and the rear second detector (14b), and the output of the detector (8a) is It becomes "0". And detector for vernier scale
The 4-digit binary code detected in (8) is “1100”, which corresponds to the subaddress “10”.

From the state shown in FIG. 5, the carrier (2) is
When the vehicle advances by one pitch B in 4), the state shown in FIG. 6 is obtained.
In the state shown in FIG. 6, the center of the first vernier detector (8a) is located at the boundary between the intermediate second detector (14b) and the rear second detector (14b). The output of the container (8a) becomes "0".
The center of the second vernier detector (8b) is located at the rear end of the second detector (14b).
And the first detector (14a).
The output of b) is "1". The center of the third vernier detector (8c) is located at the boundary between the first detector (14a) and the front end second detector (14b), and the output of the detector (8c) is "1". Becomes The center of the fourth vernier detector (8d) is located at the boundary between the front end second detector (14b) and the middle second detector (14b), and the output of the detector (8a) is " 0 ". And detector for vernier scale
The 4-digit binary code detected in (8) is "0110", which corresponds to the subaddress "11".

From the state shown in FIG. 6, the carrier (2) is
4), the main scale detector (5) and the vernier detector (8) are moved from the state of FIG. 3 by one pitch of the main address (13). It will be in the state advanced by A minutes. At this time, the relationship between the subaddress portion (14) and the detector for vernier scale (8) returns to the state shown in FIG.
In the same manner as the state described above, it is again located at the center of the front and rear width of the main address (13). The above operation is repeated as the carrier (2) further advances.

When the carrier (2) moves forward, as described above, every time the carrier (2) moves forward by one pitch B of the subaddress (14), the output of the vernier detector (8) is 4 The binary code of the digit is “0011”, “1001”, “1100”, “0”
The operation that changes in the order of “110” is repeated. In the intermediate state where the carrier (2) moves forward by one pitch B of the subaddress (14), a binary code other than the above-mentioned four types of binary codes is output from the vernier detector (8). May appear,
If the corresponding subaddress is determined only when one of the above four types of binary codes is obtained, the subaddress becomes "00", "01",
The operation that changes in the order of “10” and “11” is repeated.

When the carrier (2) moves backward, the output of the vernier detector (8) is output every time the carrier (2) moves backward by one pitch B of the subaddress (14). The four-digit binary code is “0011”, “0110”, “1100”, “1”
001 "is repeated. In this case as well, when the output of the vernier detector (8) is one of the above four binary codes, the corresponding subaddress is obtained, so that the carrier (2) can move backward. As
The operation in which the subaddress changes in the order of “00”, “11”, “10”, “01” is repeated.

The processor (11) reads the output of the main scale detector (5) when the output of the vernier detector (8) is "0011" in the state of FIG. 3 or FIG. , Converts the binary code into a corresponding main address. In the state shown in FIG. 3 or FIG. 7, as described above, all the main scale detectors (5) are located at the center of the front and rear width of the main address portion (13) of the main scale (3). As a result, a reading error due to a variation in sensitivity of the main scale detector (5) does not occur, and the main address can be obtained accurately. 5 which is the output of the main scale detector (5)
The binary code of the digit is “01111” in the state of FIG. 3 and “10111” in the state of FIG.
Corresponds to the main address "01010", and the state in FIG. 7 corresponds to the main address "01011".

When the carrier (2) moves forward, the output of the main scale detector (5) is read in the state of FIG.
1010 ", the main address" 01010 "does not change until the state of FIG. 7 is reached. When the state of FIG. 7 is reached, the output of the main scale detector (5) is read and the main address is read. Changes to “01011”. When the carrier (2) moves backward, the output of the main scale detector (5) is read in the state of FIG. 7 and the main address becomes "01011". “01011” does not change, and when the state of FIG. 3 is reached, the output of the main scale detector (5) is read and the main address changes to “01010”. The main address obtained each time the carrier (2) moves by one pitch A of the main scale detector (5), and the carrier (2) is one of the sub-addresses (14) as described above. The absolute address is obtained as follows based on the subaddress obtained every time the robot moves by the pitch B.

When the carrier (2) moves forward, a 7-digit binary code representing the main address whose upper 5 digits are the main address and the lower 2 digits are "00", and the upper 5 digits are "000000". Then, an absolute address is obtained by adding a 7-digit binary code representing a sub address whose lower 2 digits are sub addresses. When the carrier (2) moves forward and reaches the state shown in FIG. 3, the output "0011" of the vernier detector (8) is read, and the subaddress "00" is obtained. vessel
The output “01111” of (5) is read and the main address “0” is read.
1010 "is required. Then, the upper 5 digits are the main address "01010" and the lower 2 digits are "00". A 7-digit binary code "0101000" representing the main address, and the upper 5 digits are "000000" and the lower A 7-digit binary code "00" representing a subaddress whose two digits are a subaddress "00"
00000 "and the absolute address" 010100
0 ”is required. When the carrier (2) advances to the state shown in FIG. 4, the output "1001" of the vernier detector (8) is read, and the subaddress "01" is obtained. At this time, since the main address remains “01010”, the same seven-digit binary code “0” as before the main address “01010” is represented.
101000 "and the 7-digit binary code" 0000001 "representing the subaddress" 01 "are added, and the absolute address" 0
101001 ”is required. When the carrier (2) moves forward to the state shown in FIG. 5, the output of the vernier detector (8) becomes "110".
"0" is read, and a subaddress "10" is obtained. Then, as described above, the same 7-digit binary code "0101" as before.
000 "and a 7-digit binary code" 0000010 "representing the subaddress" 10 "are added, and the absolute address" 0101 "is added.
010 ”is required. When the carrier (2) advances to the state shown in FIG. 6, the output "0110" of the vernier detector (8) is read, and the subaddress "11" is obtained. And
As above, the same 7-digit binary code "010100" as before
0 "and a 7-digit binary code" 0 "representing the subaddress" 11 ".
0000011 ”and the absolute address“ 010101 ”
1 "is required. When the carrier (2) advances and reaches the state shown in FIG. 7, the output "0011" of the vernier detector (8) is read, and the subaddress "00" is obtained. ) Is read, and the main address "01011" is obtained. And this main address "0
711 binary code “010110”
0 "and a 7-digit binary code" 0 "representing the subaddress" 00 ".
000000 ”and the absolute address“ 01011 ”
00 ”is required. Thus, while the carrier (2) moves forward and the state changes in the order of FIGS. 3, 4, 5, 6, and 7, the absolute addresses are "0101000" and "01010".
01 "," 0101010 "," 0101011 ",
It changes like “0101100” and increases by “1”. The same applies to the other parts of the main scale (3) and the vernier scale (4) .If the carrier (2) moves forward, the sub-address (14)
The absolute address increases by "1" each time the vehicle advances by one pitch B.

When the carrier (2) moves backward, an absolute address is obtained by adding a 7-digit binary code representing a main address and a 7-digit binary code representing a subaddress.
The 7-digit binary code representing the main address is the same as in the case of forward movement, where the upper 5 digits are the main address and the lower 2 digits are “00”.
It is. Unlike the forward code, the 7-digit binary code representing the subaddress is “000000” when the subaddress is “00”.
"0" and "1111111" when the subaddress is "11"
(Corresponding to decimal "-1"), "1111110" when the subaddress is "10" (corresponding to "-2" in decimal), and "1111101" when the subaddress is "01".
(Corresponding to the decimal number “−3”)). Carrier (2) is moving backward and FIG.
When the state becomes, the output of the vernier detector (8) becomes "00".
11 "is read, and the subaddress" 00 "is obtained. At the same time, the output" 10111 "of the main scale detector (5) is read, and the main address" 01011 "is obtained. Then, a 7-digit binary code “010” representing the main address “01011”
1100 ”and a 7-digit binary code“ 00000000 ”representing the subaddress“ 00 ”are added to obtain the absolute address“ 01 ”.
01100 ”is required. When the carrier (2) moves backward to the state shown in FIG. 6, the output of the vernier detector (8) becomes "011".
"0" is read, and the subaddress "11" is obtained. At this time, since the main address remains "01011", the same 7-digit binary code "0101100" as before the main address "01011" and the subaddress "11" are used.
The digit binary code “1111111” is added to obtain the absolute address “0101111”. When the carrier (2) moves backward and enters the state shown in FIG. 5, the output "1100" of the vernier detector (8) is read, and the subaddress "10" is obtained. Then, similarly to the above, the same seven-digit binary code "0101100" and the seven-digit binary code "1111110" representing the subaddress "10" are added to obtain the absolute address "0101010". When the carrier (2) moves backward and enters the state shown in FIG. 4, the output of the vernier detector (8) becomes "1".
001 "is read, and the subaddress" 01 "is obtained. And, as described above, the same 7-digit binary code "0" as before.
101100 "and the seven-digit binary code" 1111101 "representing the subaddress" 01 "are added, and the absolute address" 0 "is added.
101001 ”is required. When the carrier (2) moves forward to the state shown in FIG. 3, the output of the vernier detector (8) becomes "001".
1 is read, and the subaddress "00" is obtained. At the same time, the output "01111" of the main scale detector (5) is read, and the main address "01010" is obtained. Then, a seven-digit binary code “01” representing the main address “01010” is used.
01000 "and a seven-digit binary code" 00000000 "representing the subaddress" 00 "are added to obtain the absolute address" 0 ".
101000 "is required. Thus, the carrier
(2) moves backward, and the state is as shown in FIGS. 7, 6, 5, 4, and 3.
While the order changes, the absolute address is “0101100”,
“0101011,” “0101010,” “0101”
001 "," 0101000 ", and" 1 "
Decrease by one. The same applies to the other parts of the main scale (3) and the vernier scale (4). When the carrier (2) moves backward, the absolute address is changed every time the carrier (2) moves backward by one pitch B in the subaddress section (14). Decrease by "1".

As is apparent from the above description, the absolute addresses in the respective states shown in FIGS. 3 to 7 are equal to each other both in the case of forward movement and in the case of reverse movement. Therefore, the same position is represented by the same absolute address regardless of whether the vehicle is moving forward or backward,
The position of (2) is accurately detected. The moving direction of the carrier (2) can be known by appropriate means. For example, the direction of movement of the carrier (2) can be known from the control signals for forward and backward travel from the control station on the ground, the rotation direction of the drive motor, and the like. Also, as described above, the order of change of the 4-digit binary code output from the vernier detector (8) differs between when the carrier (2) moves forward and when it moves backward. The direction of movement of the carrier (2) can be known.

FIG. 8 shows an example of the configuration of the processing device (11) for realizing the above-described operation.

In FIG. 8, the outputs of the five main scale detectors (5) are input to the conversion circuit (16), and the five outputs of the conversion circuit (16) are connected to the five main scale FFs (D flip-flops). (D) of (17)
Input to the terminal (data terminal). Main scale FF code (17)
When it is necessary to distinguish the FFs for the first main scale, the FF for the second main scale (17b), the FF for the third main scale (17c), the FF for the third main scale, FF for shaku (17d) and 5th
It will be called FF for main scale (17e). 5 main scale FFs
The Q terminal (output terminal) of (17) is connected to five input terminals of the absolute address operation circuit (18). 4 vernier detectors
The output of (8) is input to four AND circuits (19). AN
The D circuits are collectively referred to by reference numeral (19), and when it is necessary to distinguish them, they will be referred to as a first AND circuit (19a), a second AND circuit (19b), a third AND circuit (19c), and a fourth AND circuit (19d). I do. The output of the first vernier detector (8a) is input to the second and third AND circuits (19b) and (19c), and the inverted signal of the output of the detector (8a) is input to the fourth AND circuit (19d). . The output of the second vernier detector (8b) is a third and fourth AND circuit
(19c) and (19d), and the inverted signal of the output of the detector (8b) is input to the first AND circuit (19a). Third vernier detector
The output of (8c) is input to the first and fourth AND circuits (19a) and (19d), and the inverted signal of the output of the detector (8c) is input to the second AND circuit (19b). The output of the fourth vernier detector (8d) is input to the first and second AND circuits (19a) and (19b), and the inverted signal of the output of the detector (8d) is input to the third AND circuit (19c). . The outputs of the four AND circuits (19) are input to four input terminals of a four-input two-output multiplexer (20), and the two outputs of the multiplexer (20) are used as two vernier FFs (D flip-flops). Input to the D terminal of (21). The vernier scale FFs are collectively referred to by the reference numeral (21), and when it is necessary to distinguish them, the first vernier scale FF (21a) and the second vernier scale FF are arranged in descending order.
(21b). The Q terminals of the two vernier FFs (21) are connected to two input terminals of the absolute address operation circuit (18). The output of the first AND circuit (19a) is input to the CLK terminals (clock pulse input terminals) of the five main scale FFs (17). The outputs of the four AND circuits (19) are also input to an OR circuit (22), and the output of the OR circuit (22) is used as the CLK terminal of two vernier FFs (21) and the absolute address operation circuit. Enter in (18).

The conversion circuit (16) includes a ROM in which the correspondence between the 5-digit binary code output from the main scale detector (5) described above and the main address is stored as a correspondence table. The conversion circuit (16) converts the 5-digit binary code detected by the main scale detector (5) into a corresponding main address, which is sent to five main scale FFs (17). Can be The first main scale F
F (17a) is the digit of the main address “2 ⁴ ” and the second main scale FF (17
b) is the main address "2 ³ " digit, the third main scale FF (17c) is the main address "2 ² " digit, and the fourth main scale FF (17d) is the main address "2 ¹ ". , The fifth main scale FF (17e) is the main address "2
⁰ "digit.

In the multiplexer (20), based on the outputs of the four AND circuits (19), the 4-digit binary code output from the vernier detector (8) is converted into a sub-address, which is converted to 2 bits. It is sent to the FFs for vernier scale (21). The first vernier FF (21
a) corresponds to the subaddress "2 ¹ " digit, and the second vernier scale FF (21b) corresponds to the subaddress "2 ⁰ " digit. 1A
The output of the ND circuit (19a) is "0" when the output of the vernier detector (8) is "0".
It turns on when it becomes "011", and at this time, the subaddress "00" corresponding to the binary code "0011" is output from the multiplexer (20). The second AND circuit (19
The output of (b) is turned on when the output of the vernier detector (8) becomes "1001". At this time, the subaddress "01" corresponding to the binary code "1001" is used as a multiplexer ( Output from 20). The output of the third AND circuit (19c) turns on when the output of the vernier detector (8) becomes "1100". At this time, the binary code "1100"
Is output from the multiplexer (20). The output of the fourth AND circuit (19d) is a vernier detector
Turns on when the output of (8) becomes "0110",
At this time, the subaddress "11" corresponding to the binary code "0110" is output from the multiplexer (20). The correspondence between the output of the vernier detector (8) and the subaddress is as described above.

When the output of the first AND circuit (19a) is turned on, the CLK terminal of the main scale FF (17) is turned on, and the main address at that time is the absolute address as the output Q of the main scale FF (17). Input to the arithmetic circuit (18). On the other hand, when any one of the outputs of the four AND circuits (19) is turned on, the output of the OR circuit (22) is turned on, and the CLK terminal of the vernier FF (21) is turned on,
The subaddress at that time is input to the absolute address arithmetic circuit (18) as the output Q of the vernier FF (21). At the same time, OR circuit
When the output of (22) turns on, the absolute address operation circuit
In (18), based on the main address and the sub-address inputted thereto, an absolute address is obtained as described above, and a binary code representing the absolute address is output from the seven output terminals (23). . The absolute address thus obtained is used for display, control, and the like.

In the above embodiment, the numerical values indicating the number of elements, the dimensions of each part, and the like are merely examples, and can be appropriately changed as needed.

The present invention can also be applied to position detection of a moving body other than a self-propelled carrier.

[0043]

According to the position detecting device for a moving object of the present invention, as described above, the position of the moving object can be accurately detected with a relatively simple structure and with a precision smaller than the pitch of the main address of the main scale. It can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a portion of a position detection device of a self-propelled carrier in a carrier self-propelled conveyor according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing parts of a main scale detector and a sub scale detector of the position detection device of FIG. 1;

FIG. 3 is an explanatory diagram showing a relationship between a main scale, a vernier, a main scale detector, and a vernier detector in a certain state.

FIG. 4 shows a state where the carrier is at a subaddress portion 1 of the vernier scale from the state of FIG.
It is explanatory drawing which shows the relationship of the main scale, the vernier scale, the detector for main scales, and the detector for vernier scales in the state advanced by the pitch.

FIG. 5 shows a state where the carrier is a subaddress 1 of the vernier scale from the state of FIG.
It is explanatory drawing which shows the relationship of the main scale, the vernier scale, the detector for main scales, and the detector for vernier scales in the state advanced by the pitch.

FIG. 6 shows a state where the carrier is at a subaddress 1 of the vernier scale from the state of FIG.
It is explanatory drawing which shows the relationship of the main scale, the vernier scale, the detector for main scales, and the detector for vernier scales in the state advanced by the pitch.

FIG. 7 shows a state where the carrier is at the subaddress 1 of the vernier scale from the state of FIG.
It is explanatory drawing which shows the relationship of the main scale, the vernier scale, the detector for main scales, and the detector for vernier scales in the state advanced by the pitch.

FIG. 8 is a block diagram illustrating an example of a processing device of the position detection device of FIG. 1;

[Explanation of symbols]

 (1) Running rail (2) Carrier (moving body) (3) Main scale (4) Vernier scale (5) Detector for main scale (5a) Detector for first main scale (5b) Detection for second main scale (5c) Detector for third main scale (5d) Detector for fourth main scale (5e) Detector for fifth main scale (8) Detector for vernier scale (8a) Detector for first vernier scale ( 8b) Detector for second vernier scale (8c) Detector for third vernier scale (8d) Detector for fourth vernier scale (11) Processing device (13) Main address (13a) Positive logic detector (13b) Negative logic detection section (14) Secondary address section (14a) First detection section (14b) Second detection section

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B65G 43/00-43/10 B65G 1/00-1/20 G05D 1/02

Claims (1)

(57) [Claims] 1. A main scale, a sub-scale, and a main scale which are arranged in parallel along a moving path of a moving body, and are arranged at a constant pitch in a front-rear direction which is a moving direction of the moving body so as to correspond to the main scale. M main scale detectors attached, n vernier detectors attached to the moving body at a constant pitch in the front-rear direction corresponding to the vernier scale, and main scale detectors; A processing device for obtaining the position of the moving object based on the output of the vernier detector is provided. The main scale has a plurality of front and rear main address portions provided at the same pitch as the main scale detector. The address part is composed of one of a positive logic detection unit in which the main scale detector detects a binary code "1" and a negative logic detection unit in which the main scale detector detects a binary code "0", and For a predetermined number of successive main address parts, m consecutive main addresses starting from each main address part A main address portion composed of one or more continuous positive logic detection portions and a main address portion composed of negative logic detection portions are formed alternately so that the m-digit binary codes represented by the ground portion are all different. A plurality of front and rear subaddress portions are provided on the vernier scale at a pitch that divides the pitch of the main address portion of the main scale into n equal parts, and one subaddress portion for every n pieces is provided with a vernier detector. It comprises a first detector for detecting only one of the binary codes "1" and "0", and the remaining sub-addresses include only a binary code for which the vernier detector is different from the first detector. A second detection unit for detecting
The n vernier detectors are arranged at a pitch equal to (n + 1) times the pitch of the subaddress, and the processing device converts the n-digit binary code detected by the vernier detector into a binary code. The position corresponding to the sub-address portion of the vernier scale is obtained based on the value of m, which is detected by the main scale detector when the n-digit binary code detected by the vernier detector reaches a predetermined value. The position corresponding to the main address of the main scale is obtained based on the binary code of the digit,
A position detecting device for a moving body, wherein a position of the moving body is obtained from a position corresponding to a main address portion of the main scale and a position corresponding to a subaddress portion of the vernier scale.