CN110142215A - A method and device for correcting the error of moving distance of parcels in a sorting assembly line - Google Patents

Abstract

The invention relates to the technical field of a parcel sorting production line, in particular to a method and a device for correcting a parcel moving distance error of a sorting production line_KSaid distance of movement L_KThe distance from the parcel to the initial position of the sorting production line from a preset position K; calculating the distance L from the current position of the parcel to a predetermined position K_MeterUpdating the moving distance of the package on the sorting production line to be L_K+L_Meter(ii) a Obtaining the moving distance L of the preset position K +1 of the package on the sorting flow line_K+1Said distance of movement L_K+1Updating the moving distance of the parcel on the sorting production line to be L for the distance from the parcel at the preset position K +1 to the initial position of the sorting production line_K+1. According to the invention, through a sectional type correction method, the positioning accumulated error of the packages can be effectively controlled, and the sorting efficiency is improved; the sorting efficiency and the space utilization rate are improved; the cost of the matched equipment can be reduced.

Description

A method and device for correcting the error of moving distance of parcels in a sorting assembly line

technical field

The invention relates to the technical field of parcel sorting lines, in particular to a method and device for correcting the error of the moving distance of parcels in a sorting line.

Background technique

The logistics package sorting line is a kind of equipment that can realize automatic sorting. Its sorting and processing efficiency for logistics packages is much higher than manual manual sorting, and it has been widely used in the logistics industry.

During the sorting process, the moving distance of the package needs to be monitored in real time to ensure that the package can enter the correct sorting port. At present, the commonly used methods for calculating the moving distance of the package mainly include two: one is to set the friction wheel in contact with the assembly line belt, connect the encoder to the rotating shaft of the friction wheel, and calculate the distance of the package according to the diameter of the friction wheel, the number of rotations and other information. The moving distance; the other is to connect the encoder on the driving shaft of the assembly line, and calculate the moving distance of the package according to the information such as the diameter and rotation speed of the driving shaft.

When the friction wheel and encoder are used, there may be slippage between the friction wheel and the belt. Although the package does not move when the friction wheel slips, the moving distance of the package is still increased; When the diameter decreases after time wear, errors will also be introduced; by connecting the drive shaft to the encoder, there is also sliding friction between the belt and the drive wheel, which will also cause errors in the calculation of the moving distance.

The existing method of calculating the moving distance of the package will cause a certain error, and with the continuous growth of the assembly line, the error will continue to accumulate. When the package positioning error is too large, there will be a situation of positioning and sorting errors. At present, in order to avoid the above problems, the overall length of the sorting line is generally shortened, and the limited length of the sorting line will affect the sorting efficiency of the package.

SUMMARY OF THE INVENTION

In view of the above-mentioned technical problems in the related art, the present invention proposes a method and device for correcting the error of the moving distance of a package in a sorting line. higher picking efficiency.

For realizing the above-mentioned technical purpose, the technical scheme of the present invention is realized like this:

A method for correcting the error of the moving distance of a package in a sorting assembly line, comprising the following steps:

Obtain the moving distance L _{K of the package at the predetermined position K on the sorting line, where the moving distance L K is} the distance from the package at the predetermined position K to the starting position of the sorting line;

Calculate the distance L _meter from the current position of the package to the predetermined position K, and update the moving distance of the package on the sorting line as L _K + L _meter ;

Obtain the moving distance L K+1 of the package at the predetermined position K+1 on the sorting line, the moving distance L _{K +1} is the distance from the package at the predetermined position K+1 to the starting position of the sorting line, and update the package at the sorting line. The moving distance on the picking line is L _K+1 .

Preferably, calculating the distance L _meter from the current position of the package to the predetermined position K includes:

When the package runs to the predetermined position K, read the reading R _K of the encoder arranged on the surface of the sorting line and connected with the friction wheel;

Read the reading R of the encoder at the current position of the package;

Calculate the distance L _meter according to the following formula:

L _meter =π×D×(RR _K )/N, R≥R _K ;

Among them, D is the diameter of the friction wheel; π×D is the actual linear displacement of the friction wheel when it rotates one circle; N is the subdivision of the encoder; (RR _K )/N is that the friction wheel takes the predetermined position K as the starting point to reach the current position The number of turns.

Preferably, before acquiring the moving distance L _K of the package at the predetermined position K on the sorting line, the method further includes:

Set N predetermined positions on the sorting line, and obtain each predetermined position and the distance from the end position of the sorting line to the starting position of the sorting line.

Among them, the number of each predetermined position K∈{1,2,...,N}, the distance L _K∈ {L ₁ , L ₂ ,...,L _N } from each predetermined position to the starting position of the sorting line .

Preferably, obtaining the moving distance L _K of the package at the predetermined position K on the sorting line includes:

Detection sensors are respectively set at N predetermined positions and the end position of the sorting line. When the package runs to the predetermined position K, when the detection sensor at this position detects the passage of the package, the moving distance of the package is recorded as L _K .

Preferably, the detection sensor is a shot switch, and the transmitter and receiver of the shot switch are arranged on both sides of the sorting line. When the package moves between the transmitter and the receiver, all the The light emitted by the transmitter is blocked and cannot be irradiated on the receiver, and at this time, the through-beam switch is triggered.

The invention also relates to a correction device for the error of the moving distance of the parcels in the sorting line, the device comprising:

a distance detection device, configured to obtain the moving distance L _{K of the package at the predetermined position K on the sorting line, where the moving distance L K is} the distance from the package at the predetermined position K to the starting position of the sorting line;

The distance measuring device is configured to calculate the distance L _meter from the current position of the package to the predetermined position K, and update the moving distance of the package on the sorting line as L _K + L _meter .

Preferably, the distance detection device includes detection sensors arranged at N predetermined positions and an end position of the sorting line. When the package runs to the predetermined position K, when the detection sensor at this position detects the passage of the package, the moving distance of the package is recorded as L _K.

Preferably, the distance measuring device includes an encoder and a friction wheel; the friction wheel rolls on the surface of the sorting line, and the rotating shaft of the friction wheel is connected to the encoder.

Preferably, the distance measuring device is located anywhere in the sorting line.

Preferably, the detection sensor is a shot switch, and a plurality of shot switches on the sorting assembly line are arranged equidistantly and/or non-equidistantly.

Preferably, the length of the sorting line ranges from 4m to 50m.

Beneficial effects of the present invention:

In the method and device for correcting the moving distance error of a sorting line in the present invention, a plurality of detection sensors divide the sorting line into multiple sections, and the distance between each detection sensor and the starting position of the sorting line is fixed; When moving in one stage of the sorting line, there may be an error between the calculated moving distance of the package and the actual moving distance of the package. The error is corrected when the package enters the next stage, that is, when the package moves to the next stage of the sorting line, it will move The distance is corrected to the distance between the currently triggered detection sensor and the starting position of the sorting line, which is fixed and known to be the same as the actual moving distance of the package, so the error is corrected;

The method and device for correcting the error of the moving distance of the package in the sorting line can effectively control the accumulated error of the positioning of the package and improve the sorting efficiency through the segmented correction method; at the same time, the sorting line will not accumulate a large error. , you can use a longer sorting line, increase sorting positions, improve sorting efficiency and space utilization; when the number of sorting positions increases, the utilization rate of equipment such as front-end scanning of the sorting line can be increased, thereby reducing the supporting equipment. cost.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is a flowchart of a method for correcting the error of the moving distance of a package in a sorting assembly line according to an embodiment of the present invention;

FIG. 2 is a top view of the device for correcting the error of the moving distance of the parcels in the sorting line according to the embodiment of the present invention.

In the picture:

1. Sorting line; 2. Detection sensor; 3. Friction wheel; 4. Encoder.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art fall within the protection scope of the present invention.

As shown in FIG. 1 , the method for calibrating the error of the moving distance of the package in the sorting assembly line in this embodiment includes the following steps:

Step S1, obtaining the moving distance L _{K of the package at the predetermined position K on the sorting line, where the moving distance L K is} the distance from the package at the predetermined position K to the starting position of the sorting line;

Step S2, calculate the distance L _meter from the current position of the package to the predetermined position K, and update the moving distance of the package on the sorting assembly line to be L _K +L _meter ;

Step S3, obtain the moving distance L K+1 of the package at the predetermined position K+1 on the sorting line, and the moving distance L _{K +1} is the distance from the package at the predetermined position K+1 to the starting position of the sorting line, and update The moving distance of the package on the sorting line is L _K+1 .

Further, before acquiring the moving distance L _K of the package at the predetermined position K on the sorting line, the method further includes:

Step S0, set N predetermined positions on the sorting line, obtain each predetermined position and the distance from the end position of the sorting line to the starting position of the sorting line, respectively,

Among them, the number of each predetermined position K∈{1,2,...,N}, the distance L _K∈ {L ₁ , L ₂ ,...,L _N } from each predetermined position to the starting position of the sorting line .

In step S1, acquiring the moving distance L _K of the package at the predetermined position K on the sorting line includes setting detection sensors at N predetermined positions and the end position of the sorting line respectively. When the package runs to the predetermined position K, the detection of this position When the sensor detects the passage of the package, the moving distance of the package is recorded as L _K .

Specifically, the sorting assembly line is divided into N lengths, and detection sensors are respectively set at the starting position of each length and the end position of the sorting assembly line;

Calculate the distance a package travels on the sorting line:

When one of the detection sensors on the sorting line is triggered, the moving distance of the package on the sorting line is L _K , and L _K is the distance between the currently triggered detection sensor and the starting position of the sorting line.

In step S2, after the detection sensor at the predetermined position K is triggered, before the detection sensor at the next predetermined position K+1 is triggered, the distance L between the current position of the package and the detection sensor at the predetermined position K is _calculated , The moving distance of the package on the sorting line is L _K + L _meter .

In step S3, when the detection sensor at the next predetermined position K+1 is triggered, the moving distance of the package on the sorting line is corrected to L _K+1 by the L _K +L _meter , and L _K+1 is currently triggered The distance from the detection sensor of the predetermined position K+1 to the starting position of the sorting line.

On the sorting line, if the calculated moving distance (theoretical distance) of the package is different from the actual moving distance of the package, inaccurate positioning will occur during the positioning of the package, that is, a positioning error will occur; if the error is not eliminated in time, it will continue to The accumulation increases, which leads to the wrong positioning of the parcels on the sorting line and the occurrence of sorting errors.

In this embodiment, errors are eliminated by a segmented correction method to avoid error accumulation. The starting position and the end position of the sorting line are respectively set with detection sensors, and then multiple detection sensors are used to divide the sorting line into multiple sections. When the package moves on a section of the sorting line (moving between two adjacent test sensors) There may be an error between the theoretical moving distance and the actual moving distance. However, when the package moves to the next stage of the sorting line, there is a detection sensor at the starting position of the current stage, and the package triggers the detection sensor.

The detection sensor is triggered, indicating that the package actually moves to the position of the currently triggered detection sensor, and the distance between the detection sensor and the starting position of the pipeline is known, so the accurate value of the moving distance of the package can be obtained; Whether there is a deviation during the segment movement, the distance between the currently triggered detection sensor and the starting position of the sorting line is recorded as the moving distance of the package.

Using the above method, if there is an error in the positioning of the package in each section of the sorting line, it will be corrected at the beginning of the next section. Therefore, the accumulation of errors will not be caused, thereby avoiding the phenomenon of wrong positioning of the package, so that the package can be accurately positioned and can enter Correct sorting port.

As a preferred implementation of this embodiment, in step S2, _calculating the distance L from the current position of the package to the predetermined position K includes the following steps:

When the package runs to the predetermined position K, read the reading R _K of the encoder arranged on the surface of the sorting line and connected with the friction wheel;

Read the reading R of the encoder at the current position of the package;

Calculate the distance L _meter according to the following formula:

L _meter =π×D×(RR _K )/N, R≥R _K ;

Among them, D is the diameter of the friction wheel; π×D is the actual linear displacement of the friction wheel when it rotates one circle; N is the subdivision of the encoder; (RR _K )/N is that the friction wheel takes the predetermined position K as the starting point to reach the current position The number of turns.

Specifically, an encoder with a subdivision of N is set on the surface of the sorting line, the encoder is connected to a friction wheel with a diameter D, and the friction wheel rolls on the surface of the sorting line.

When the detection sensor at the predetermined position K is triggered, the reading of the encoder is R _K . After the detection sensor is triggered, before the detection sensor at the next predetermined position K+1 is triggered, the reading of the encoder is R at a certain moment. The formula calculates the L _meter .

The friction coefficient of the friction wheel body is high, and it can be driven by the belt when it is in contact with the belt surface of the sorting line. The encoder calculates the linear displacement according to the diameter D of the friction wheel and the number of turns, and the total linear displacement is equivalent to the calculated package. However, there is no absolute relative slippage between the friction wheel and the belt. If relative slippage occurs, it will cause a deviation between the calculated moving distance and the actual moving distance, resulting in errors.

Any segment of the sorting line may have a moving error of the package, which is corrected at the starting position of the next segment of the sorting line. Therefore, using the friction wheel and the encoder to calculate the moving distance of the package is based on the sorting of the current segment. From the starting position of the assembly line, calculate the theoretical moving distance of the package in this section. It can be seen that, even if there is an error in the theoretical moving distance of the package, it is only the error existing in the sorting line of the current section (the previous few Errors generated on the sorting line of the segment are corrected), and the deviation will be corrected when the package is moved to the next segment, so there will be no or no larger when positioning the package on the sorting line. deviations, thereby avoiding the occurrence of sorting errors.

As a preferred implementation of this embodiment, the detection sensor is an opposite-to-shoot switch, and the transmitter and receiver of the opposite-to-shoot switch are arranged on both sides of the sorting assembly line. When the package moves between the transmitter and the receiver, the transmitter sends The light is blocked and cannot be irradiated on the receiver, and the beam switch is triggered at this time.

The detection sensor preferably adopts an on-shoot switch. When the package passes between the transmitter and the receiver, the package blocks the on-off light between the two, and the on-off switch generates a switch signal. The corresponding controller receives the signal and calculates The value of the moving distance of the package calculated by the device is replaced by the distance between the currently triggered shooting switch and the starting position of the sorting line (this distance is a known value), thereby completing the correction of the error.

The beam switch has the advantages of high sensitivity, less susceptible to interference, low power consumption, and long service life.

As shown in FIG. 2 , the present invention also provides a correction device for the error of the moving distance of the package in the sorting line, including: a distance detection device, which is configured to obtain the moving distance L _K of the package at the predetermined position K on the sorting line, so The moving distance L _K is the distance from the package at the predetermined position K to the starting position of the sorting assembly line; the distance measuring device is configured to calculate the distance L _meter from the current position of the package to the predetermined position K, and updates the package in the sorting assembly line. The moving distance is L _K + L _meter .

Specifically, the distance detection device includes detection sensors 2 arranged at N predetermined positions and an end position of the sorting line 1. When the package runs to the predetermined position K, the detection sensor at this position detects the passage of the package and records the moving distance of the package. is L _K .

The detection sensors 2 are respectively set at the starting position and the end position of the sorting line 1, and a plurality of detection sensors 2 are arranged at intervals along the running direction of the sorting line 1;

The distance measuring device includes an encoder 4 and a friction wheel 3 ; the friction wheel 3 rolls on the surface of the sorting assembly line 1 , and the rotating shaft of the friction wheel 3 is connected to the encoder 4 .

At present, the common package moving distance calculation device only includes a distance measuring device, and the moving distance of the package on the sorting line 1 can only be calculated by the distance measuring device; although the friction wheel 3 is used to contact the belt surface of the sorting line 1, However, there may still be a phenomenon that the friction wheel 3 and the belt slip with each other. If the friction wheel 3 slips, the calculated moving distance of the package is not the same as the actual moving distance of the package. Use the calculated moving distance of the package for positioning. If the actual moving distance of the package deviates greatly from the calculated moving distance, a positioning error will occur.

In the device of this embodiment, a detection sensor 2 is added, which is arranged on the sorting line 1 . Preferably, the detection sensor 2 is a shot switch, and a plurality of shot switches on the sorting line 1 are equidistant and/or non-equidistant. . The distance between each detection sensor 2 and the starting position of the sorting line is fixed, and it is known that when the package moves on the sorting line 1, when it moves to the position of a detection sensor 2, the detection sensor 2 is triggered. When the detection sensor 2 is triggered, the calculated moving distance of the package is updated to the distance between the currently triggered detection sensor 2 and the starting position of the sorting line 1 to realize error correction.

The device adds a detection sensor 2 to the sorting line 1. The position of the detection sensor 2 is fixed. When the detection sensor 2 is triggered, the moving distance of the package can be corrected. Therefore, the accumulation of errors can be avoided or reduced. error, so that the positioning of the package is more accurate, and the sorting accuracy and sorting efficiency are improved.

At the same time, since the error correction can be realized, a longer sorting line 1 can be used, for example, the length of the sorting line 1 is in the range of 4m-50m. The length of the sorting line 1 is increased, and more sorting positions can be added on it, that is, there is no need to set up more sorting lines 1 for the same number of sorting positions, which improves the utilization rate of the workplace space.

Scanning and other equipment needs to be installed at the front end of the sorting line 1. If the length of the sorting line 1 can be increased, more sorting positions can be added, and the sorting line 1 can process more packages. Therefore, the front end of the sorting line 1 is installed. The utilization rate of equipment is improved, which can reduce the use cost of supporting equipment.

Preferably, the distance measuring device is arranged at any position of the sorting line 1 . The distance measuring device realizes the distance measurement calculation according to the rolling of the friction wheel 3, and the friction wheel 3 can be rolled at any position of the sorting line 1. Therefore, it can be set in a position convenient for installation and arrangement.

As shown in Figure 2, the sorting line is a device for correcting the moving distance error of the package. The diameter of the friction wheel 3 is D, and the number of subdivisions of the encoder 4 is N. Each of the shot switches is triggered, at this time, the encoder 4 reads R ₁ , when the package passes the second shot switch, the encoder 4 reads R ₂ , and when it passes the Kth shot switch, the encoder 4 reads The reading is R _K , and the sorting line is divided into multiple sections by multiple shooting switches. When the K-th section (between the K-th shooting switch and the K+1-th shooting switch), the reading of the encoder at a certain moment is R, therefore, the distance L of the package from the starting position of the sorting line can be calculated according to the following formula:

L=π×D×(RR _K )/N+L _K , R _K ≤R≤R _K+1 ;

π×D is the actual linear displacement of the encoder 4 when it rotates one circle; (RR _K )/N is the number of turns that the encoder 4 rotates from the K-th shooting switch position as the starting point to the current position; L _K is the K-th shooting switch position. The distance between the shooting switch and the starting position of the sorting line.

The current package moves between the K-th on-shoot switch and the K+1-th on-off switch, when the package moves to the K+1-th on-off switch position, L=L _K+1 , at L=π×D In ×(RR _K )/N+L _K , π×D×(RR _K )/N is only the calculated theoretical value and there may be a deviation from the actual moving distance. When the package moves to the K+1th shot switch When in position, the moving distance of the package is corrected to the correct value, and the moving distance of the package will be corrected when each shooting switch is triggered, so as to avoid the accumulation of errors.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (10)

1. a correction method of a sorting assembly line package moving distance error, is characterized in that, comprises the following steps: Obtain the moving distance L _{K of the package at the predetermined position K on the sorting line, where the moving distance L K is} the distance from the package at the predetermined position K to the starting position of the sorting line; Calculate the distance L _meter from the current position of the package to the predetermined position K, and update the moving distance of the package on the sorting line as L _K + L _meter ; Obtain the moving distance L K+1 of the package at the predetermined position K+1 on the sorting line, the moving distance L _{K +1} is the distance from the package at the predetermined position K+1 to the starting position of the sorting line, and update the package at the sorting line. The moving distance on the picking line is L _K+1 . 2. the method for correcting the error of the moving distance of the sorting assembly line package according to claim 1, is characterized in that, The distance L _meter from the current position of the package to the predetermined position K includes: When the package runs to the predetermined position K, read the reading R _K of the encoder arranged on the surface of the sorting line and connected with the friction wheel; Read the reading R of the encoder at the current position of the package; Calculate the distance L _meter according to the following formula: L _meter =π×D×(RR _K )/N, R≥R _K ; Among them, D is the diameter of the friction wheel; π×D is the actual linear displacement of the friction wheel when it rotates one circle; N is the subdivision of the encoder; (RR _K )/N is that the friction wheel takes the predetermined position K as the starting point to reach the current position The number of turns. 3. the method for correcting the error of the moving distance of the sorting assembly line package according to claim 1, is characterized in that, Before the obtaining of the moving distance L _K of the package at the predetermined position K on the sorting line, the method further includes: Set N predetermined positions on the sorting line, and obtain each predetermined position and the distance from the end position of the sorting line to the starting position of the sorting line. Among them, the number of each predetermined position K∈{1,2,...,N}, the distance L _K∈ {L ₁ , L ₂ ,...,L _N } from each predetermined position to the starting position of the sorting line . 4. the method for correcting the error of the moving distance of the sorting assembly line package according to claim 3, is characterized in that, The moving distance L _K of the obtained package at the predetermined position K on the sorting line includes: Detection sensors are respectively set at N predetermined positions and the end position of the sorting line. When the package runs to the predetermined position K, when the detection sensor at this position detects the passage of the package, the moving distance of the package is recorded as L _K . 5. the method for correcting the error of the moving distance of the sorting assembly line package according to claim 4, is characterized in that, The detection sensor is a shot switch, and the transmitter and receiver of the shot switch are arranged on both sides of the sorting line. When the package moves between the transmitter and the receiver, the The light emitted by the transmitter is blocked and cannot be irradiated on the receiver. At this time, the through-beam switch is triggered. 6. A correction device for the error of the moving distance of a sorting assembly line package, comprising: a distance detection device, configured to obtain the moving distance L _{K of the package at the predetermined position K on the sorting line, where the moving distance L K is} the distance from the package at the predetermined position K to the starting position of the sorting line; The distance measuring device is configured to calculate the distance L _meter from the current position of the package to the predetermined position K, and update the moving distance of the package on the sorting line as L _K + L _meter . 7. The device for correcting the error of the moving distance of the package in a sorting assembly line according to claim 6, characterized in that, The distance detection device includes detection sensors arranged at N predetermined positions and end positions of the sorting line. When the package runs to the predetermined position K, when the detection sensor at this position detects that the package has passed, the moving distance of the package is recorded as _LK. . 8. The device for correcting the error of the moving distance of the package in a sorting assembly line according to claim 6, characterized in that, The distance measuring device includes an encoder and a friction wheel; The friction wheel rolls on the surface of the sorting assembly line, and the rotating shaft of the friction wheel is connected to the encoder. 9. The correction device for the error of the moving distance of the package in the sorting assembly line according to claim 8, characterized in that, The distance measuring device is arranged at any position of the sorting line. 10. The device for correcting the error of the moving distance of the package in a sorting assembly line according to claim 7, characterized in that, The detection sensor is a shoot-through switch, and a plurality of the shoot-through switches are arranged equidistantly and/or non-equidistantly on the sorting assembly line.