JP2001236124A - Speed control method and speed monitoring method for mobile object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speed control method of a mobile object capable of evading forced deceleration of the mobile object. SOLUTION: A speed instruction instructed in the case of deceleration and delay time β for follow of running speed of a running main body for the speed instruction are calculated and a speed instruction by a set running pattern is outputted from a point r' of moving distance to a running driving device by preceding by the calculated delay for follow in the case of deceleration. By this method, the running main body is decelerated at an ideal speed curve in the case of deceleration, therefore, a fear of passing a stop position by increase of the moving distance of the running main body due to the delay for follow of the running speed of the running main body is dissolved and the forced deceleration is evaded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a moving body which moves in a set range, provided with traveling driving means for driving the moving body at a traveling speed instructed by traveling control means, and the traveling control means comprises: The present invention relates to a speed control method and a speed monitoring method of a moving body configured to give a speed command to the travel driving means based on a set travel pattern.

[0002]

2. Description of the Related Art Conventionally, in a moving body, a traveling drive means drives the traveling body at a traveling speed instructed by the traveling control means, and the traveling control means issues a speed command of a set traveling pattern. For various reasons such as erroneous detection of the speed, the moving body may not run at the running speed commanded by the running control means. When the moving body moves in the set range, if the above-described problem occurs near the end of the moving range, the moving body collides with the end of the moving range at high speed, and the moving body is damaged. There is fear.

Therefore, conventionally, a detection plate for forcibly decelerating or stopping the traveling drive means is installed at the end of the moving range of the moving body, and the detection plate is detected from the moving body side. A configuration in which a forced stop is performed has been considered.

[0004]

However, in the above-mentioned conventional configuration, the above-mentioned detection plate and the like are required, which complicates the installation work of the equipment and the like, and the above-mentioned detection plate is moved by the moving range of the moving body. Due to the fact that the moving body is installed near the end of the moving range, the moving body may be decelerated more than necessary and reduce the operation efficiency of the equipment.

[0005] When forcible deceleration or stop is performed,
When the moving body vibrates and a load is loaded, the load may drop. Therefore, the present invention can avoid forced deceleration of the moving body, can confirm whether the moving body is traveling at the traveling speed instructed by the traveling control means, simplify the installation work of the equipment, and improve the equipment. It is an object of the present invention to provide a speed control method and a speed monitoring method of a moving body that can improve operation efficiency.

[0006]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, a moving object moving in a set range is provided at a traveling speed instructed by traveling control means. A traveling drive means for traveling and driving the moving body is provided, wherein the traveling control means is configured to give a speed command to the traveling driving means based on a set traveling pattern, and A speed command instructed by the travel control means at the time of deceleration and a tracking delay time of the traveling speed of the moving body with respect to the speed command are previously learned, and the deceleration of the set travel pattern is advanced by the learned tracking delay time at the time of deceleration. Is output to the travel driving means.

According to the above method, at the time of deceleration, the speed command according to the set traveling pattern is output to the traveling driving means ahead of the following delay time of the traveling speed of the moving body with respect to the speed command, and the following of the traveling speed of the moving body is performed. The delay increases the moving distance of the moving body and eliminates the possibility of passing the stop position.

According to a second aspect of the present invention, in the first aspect of the present invention, the learning of the following delay time of the traveling speed of the moving body is performed by determining the actual moving distance in a predetermined time while traveling at a constant speed. From the actual movement distance, a movement distance of a unit speed command per one scan is calculated, and a first time when a speed command value at the time of deceleration reaches a predetermined ratio of the constant speed is stored. The total of the unit speed commands up to a predetermined time before the time is obtained, and the total of the unit speed commands is multiplied by the moving distance of the unit speed command per one scan to obtain a theoretical movement amount. A second time when the actual moving distance of the distance moving body reaches the theoretical movement amount is obtained, and the difference is calculated by calculating a difference between the second time and the first time.

According to the above method, the first time when the speed command value at the time of deceleration reaches a predetermined ratio of a constant speed, and the actual moving distance of the distance moving body in the predetermined time are theoretically the first time. The following delay time is obtained from the difference from the second time when the movement amount is reached.

According to a third aspect of the present invention, the moving body moving in the set range is provided with traveling drive means for driving the moving body at a traveling speed instructed by the traveling control means, and the traveling control means is provided. Is a speed monitoring method of a moving body configured to give a speed command to the travel driving means based on a set travel pattern, wherein the speed command issued by the travel control means and the movement corresponding to the speed command are provided. From the following delay time of the running speed of the body, the moving amount of the moving body is estimated, and the normal range is set for each of the running time and the running speed at the time of estimating the moving amount, and the actual moving amount of the moving body is measured. , When this actual travel and the estimated travel match,
The running speed is determined to be normal if any one of the normal ranges is within the normal range, and the running speed is determined to be abnormal if any of the ranges are not within the normal range.

According to the above method, the travel distance of the moving body is estimated by taking into account the speed command output based on the set travel pattern and the follow-up delay time, and the travel time and travel speed at this time are within the normal range. Is set, it is determined whether the travel time and the travel speed when the actual travel distance coincides with the estimated travel distance are each within a normal range, and if it is within one of the normal ranges, it is determined to be normal. If not within the normal range, it is determined to be abnormal. Even if there is an error in the speed direction, if there is no error in the time direction, it is determined to be normal.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. A case will be described in which the speed control method and the speed monitoring method of the moving object of the present invention are applied to a stacker crane provided in an article storage facility.

As shown in FIG. 1, in an article storage facility FS, two storage shelves A installed at intervals so that the article taking-out directions are opposed to each other, and formed between the storage shelves A. A stacker crane (an example of a moving body) C that automatically travels along the work path B is provided, and each of the storage shelves A
, A number of article storage units D are vertically arranged in multiple stages and side by side.

A traveling rail 1 is installed in the work passage B along the longitudinal direction of the storage shelf A. An article loading / unloading section E installed at one end of the work passage B sends a loading / unloading command to the stacker crane C. An input controller E1 and a pair of loading tables E2 sandwiching the traveling rail 1 are provided, and the stacker crane C moves the traveling rail 1 based on a loading / unloading command.
, And is configured as a loading / unloading transport vehicle that carries out the loading / unloading of the articles F placed on the pallet P between the loading table E2 and the article storage section D.

As shown in FIG. 2, the stacker crane C is mounted on a traveling vehicle body 2 traveling along a traveling rail 1.
A lifting platform 3 and a pair of front and rear lifting masts 4 for guiding and supporting the lifting platform 3 so that the lifting platform 3 can be freely moved are provided. The lifting platform 3 is provided with a fork device 5 for transferring articles.

The elevating platform 3 is suspended and supported by an elevating chain 8 connected to both left and right sides thereof, and the elevating chain 8 is provided with a guide sprocket 9 provided on an upper frame 7.
And a guide sprocket 10 provided on one of the lifting masts 4, and connected to a winding drum 11 provided at one end of the traveling vehicle body 2.

The take-up drum 11 is driven and rotated by a lifting / lowering electric motor M1, which is a so-called inverter type motor, in the normal and reverse directions, and the lifting / lowering table 3 is driven up and down by feeding and lifting of the lifting / lowering chain 8. It is configured to be.

Although not shown in FIG. 2 or the like, the elevation position of the elevation table 3 is connected to the rotating shaft of the winding drum 11 and a drive-side rotary encoder 18 for detecting the amount of rotation thereof; It is managed on the basis of the detection information from the lift table side rotary encoder 19 attached to the table 3. As shown in FIG. 3, the lift encoder side rotary encoder 19 has a sprocket 19a attached to its rotary shaft.
Is meshed with a chain 20 laid on one side of the lifting mast 4 in the vertical direction. The sprocket 19a rotates with the lifting and lowering of the lifting pedestal 3, and detects the vertical movement of the lifting pedestal 3.

As shown in FIG. 4, the information detected by the rotary encoder 18 on the drive side and the rotary encoder 19 on the lift base is input to the lift control unit 30 of the crane controller CC.

As shown in FIG. 3, the traveling vehicle body 2
Two front and rear wheels 12 that can run freely on the running rail 1 and two lower right and left position controls provided at two front and rear positions that engage with the running rail 1 so as to limit the position of the running rail 1 in the vehicle width direction. And a traveling drive unit 14 provided with a traveling electric motor M2, which is a so-called inverter type motor.

As shown in FIG. 2, a pair of right and left guide rails 6 are sandwiched between upper and lower frames 7 so as to roll around the vertical axis along the side surfaces of the stacker crane C as the stacker crane C travels. Are provided at the front and rear ends in the traveling direction.

One of the two wheels 12 at one end in the vehicle longitudinal direction is formed as a propulsion drive wheel 12a driven by a traveling drive device 14 (traveling electric motor M2). The other wheel in the other direction is configured as a free-wheeling driven wheel 12b, and the stacker crane C
The upper position regulating roller 17 provided on the upper frame 7
, And is configured to be able to self-travel along the traveling rail 1 by being driven by the traveling driving device 14.

As shown in FIG. 3, the traveling position of the traveling vehicle body 2 is managed based on detection information of a vehicle-side rotary encoder 21 attached to the traveling vehicle body 2. The body-side rotary encoder 21 has a sprocket 21a attached to its rotating shaft meshed with a chain 22 laid along the traveling rail 1, and the sprocket 21a rotates as the traveling body 2 travels. , The traveling movement of the traveling vehicle body 2 is detected.

As shown in FIG. 4, the information detected by the rotary encoder 21 on the vehicle body side is input to the traveling control section 31 of the crane control device CC. The above crane control device CC
As shown in FIG. 4, a lift control unit 30 that raises and lowers the lift 3 to a designated lift position in response to a transfer command from the controller E1, and a travel that moves the traveling vehicle body 2 to a designated travel position The control unit 31 includes a transfer control unit 32 that transfers the article F by moving the fork device 5 out and back, and is controlled by the crane control unit CC to transfer the article F and to each article storage unit D. The transfer of the article F is performed.

The traveling control unit 3 of the crane control device CC
1 will be described in detail. FIG. 5 shows a control block diagram of the traveling control unit 31 of the crane control device CC.

A moving distance detecting section 41 which is reset by a start signal described later and counts a pulse signal input from the vehicle body side rotary encoder 21 to measure an actual moving distance of the traveling main body 2, and a moving distance detecting section 41. A speed detecting unit 42 for differentiating the measured moving distance to measure an actual speed, a time detecting unit 43 reset by a start signal to be described later to measure the traveling time of the traveling main body 2, and a destination inputted from the controller E1. Travel pattern setting unit 44 that sets a travel pattern based on the travel distance up to
(Details will be described later), the actual moving distance measured by the moving distance detecting unit 41, the actual speed of the traveling body 2 detected by the speed detecting unit 42, the traveling time measured by the time detecting unit 43, and the traveling pattern. The speed command value is set based on the set value of the running pattern input from the setting unit 44 by the running drive unit 14.
Running pattern generating section 45 for outputting to (details will be described later)
And a time delay unit 46 for inputting a speed command value output from the running pattern generating unit 45 to the running driving unit 14 and outputting the command with a delay, and an actual moving distance and speed detection measured by the moving distance detecting unit 41. The actual speed of the traveling main body 2 detected by the section 42, the traveling time measured by the time detecting section 43, and the time command value of the time delay inputted from the time delay section 46 are inputted to determine whether the traveling speed is good or not. The determination unit 47 is configured.

The running pattern setting section 44 calculates a set value for setting a running pattern indicated by a solid line in FIG. 6 based on the input moving distance Q. From the “low” traveling speed vL, a high-speed constant speed vH and a moving distance (deceleration start point) R at which deceleration is started are determined.
H, a deceleration start movement distance R, and a movement distance (corresponding to the input movement distance and stop distance) Q are output to the traveling pattern generation unit 45. Since the traveling distance is obtained by integrating the traveling speed v, if the acceleration / deceleration and the “low” traveling speed vL before the stop are set, the traveling distance at which the deceleration starts (the deceleration start) Point) R can be obtained.

The acceleration / deceleration α and the “low” traveling speed vL before stopping are also set in advance in the traveling pattern generation unit 45, and a constant high speed vH, a deceleration start moving distance R, and a moving distance Q are input. Then, the running pattern shown by the solid line in FIG. 6 can be set. When the running pattern is set, the start signal is output to the moving distance detecting section 41 and the time detecting section 43, and at the same time, the output of the speed command value is performed according to the set running pattern. To start. [Follow-up delay control] The above-mentioned travel pattern generation section 45 is configured to provide a follow-up control delay by the travel drive section (motor M2) 14 and the drive wheels 12a (a delay until the speed of the travel body 2 changes in response to a speed command; The delay setting pattern from the deceleration start point r is corrected in consideration of the delay time β. That is, as shown in FIG.
The deceleration start point for command (movement distance) before the deceleration start point r by multiplying the constant speed vH by the delay time β.
R ′ (corresponding to the hatched portion in FIG. 7) is set, and when the actual movement distance measured by the movement distance detection unit 41 matches this command deceleration start point r ′, as shown by the broken line,
First, a speed command value is output (lowered) in accordance with the deceleration traveling setting pattern. As a result, as shown by the solid line, the speed of the traveling main body 2 changes according to the (ideal) set traveling pattern, and the travel distance increases due to the delay in the following control.
Passing through the stop position is prevented. [Learning Time Learning] The traveling pattern generation unit 45 learns the delay time β according to the following procedure prior to actual driving (see FIG. 8).

First, based on the actual moving distance measured by the moving distance detecting unit 41, the actual moving distance (shaded portion C) Lx in a predetermined time (for example, 1 sec) while traveling at a "high speed" constant speed vH is obtained.

The actual moving distance Lx and the "high speed" constant speed v
From H, the moving distance Lm of the “unit speed command” is calculated. For example, if a speed command value of vH is output every 0.1 sec, vH × (1 sec ÷ 0.1 sec) is the speed command total value.

Lm = Lx ÷ (total speed command value) Next, the first time tx when the speed command value at the time of deceleration becomes a predetermined ratio (1/2 in FIG. 8) of the constant speed vH is stored. A predetermined time (for example, 1 second) from the first time tx.
c) Calculate the total of the speed command values by going up to the previous position to obtain the theoretical movement amount Lr (shaded area A).

Lr = Lm × (total value of speed command values) Next, the actual moving distance in a predetermined time (for example, 1 sec) is measured from the actual moving distance measured by the moving distance detecting unit 41, and the measured value Ly (Second time ty) when is equal to the theoretical movement amount Lr. At this time, it can be determined that the actual speed has become 1/2 of the constant speed vH. The measurement value Ly when matching is shown by the hatched portion B.

Next, the difference between the second time ty and the first time tx is calculated to obtain the delay time β, which is stored. Thus, the following delay time β can be learned. [Speed monitoring] Hereinafter, the time delay unit 46 and the pass / fail judgment unit 4
7 will be described.

As shown in FIG. 6, the traveling pattern generator 4
The speed v of the traveling main body 2 is controlled by the set traveling pattern generated from Step 5, but if there is no other abnormality due to the following control delay (delay time β), the actual traveling speed shows a curve indicated by a broken line. .

A speed command value (hereinafter, referred to as a delayed traveling speed command value) is input to the pass / fail determination unit 47 with a delay of a following delay time β by a time delay unit 46. The pass / fail judgment unit 47 executes the following procedure for each unit time (one scan).

First, the travel distance of the traveling body 2 is estimated by integrating the delay speed command value. Next, a normal speed range (speed monitoring allowable range) is set in the vertical direction of the delay speed command value, and a normal time range (speed monitoring allowable range time) before and after the traveling time measured by the time detection unit 43 is set. The normal moving speed range of the estimated moving distance, the running speed, and the normal time range of the running time are stored as one set.

Next, when the estimated moving distance matches the actual moving distance measured by the moving distance detecting section 41, the actual speed of the traveling body 2 detected by the speed detecting section 42 at this time is stored together with the estimated moving distance. Then, it is determined whether or not the traveling time measured by the time detecting unit 43 is within the normal time range.

If it is within any one of the ranges, it is determined to be normal, and if it is not within either range, it is determined to be abnormal. As a result, even if the traveling speed is determined to be abnormal, if the traveling time when the vehicle travels the estimated moving distance is within the range, it is regarded as normal, and simple abnormality determination can be avoided, and the number of stops due to occurrence of abnormality can be reduced. If it is determined to be abnormal, a traveling abnormality signal is output to the controller E1 and the traveling pattern generator 45.

When this traveling abnormality signal is input, the traveling pattern generator 45 sets the speed command value to zero and stops the traveling main body 2. The operation of the travel control unit 31 of the crane control device CC will be described.

When the travel control unit 31 receives the transport command of the moving distance from the controller E1, the travel control unit 31 forms a set travel pattern in which the deceleration range is corrected by the follow-up delay time β learned in advance, and based on the set travel pattern, a speed command. The value is output to the traveling drive unit 14 (motor M2) to travel the traveling vehicle body 2.

At this time, the speed is monitored, and if the speed deviates from the normal speed range and the normal time range due to some abnormality, an abnormal signal is output, the traveling vehicle body 2 is stopped, and the controller E1 is notified. In addition, since the speed command value is reduced in advance during deceleration, the traveling main body 2 decelerates according to the ideal speed pattern, so that the moving distance does not deviate and the forced stop is not required. The main body 2 can be stopped smoothly, and the occurrence of vibration and shaking can be prevented.

The traveling speed of the traveling vehicle body 2 is "low" v
When the vehicle moves to L and reaches the moving distance Q, the brake is operated to stop the traveling vehicle body 2. As described above, the traveling main body 2 decelerates according to the ideal speed pattern, so that the moving distance does not deviate and the forced deceleration can be avoided, so that the vibration of the stacker crane C during traveling and the movement of the article (luggage) F can be avoided. Falling can be prevented.

Since the occurrence of the speed of the crane C according to the set traveling pattern is monitored in the direction of the speed and the direction of the time, it is determined whether the vehicle is traveling at the instructed traveling speed. Can be accurately confirmed.

The traveling is controlled so as to avoid forced deceleration, and the traveling speed at this time is monitored.
It is no longer necessary to install a plate to be detected at the end of the work passage unlike the related art, so that the installation work of the equipment can be simplified and the operation efficiency of the equipment can be improved.

Similarly to the travel control unit 31, the elevation control unit 30 sets a set elevation pattern of the elevator 3 corresponding to the set travel pattern in consideration of the following delay time, and controls the electric motor M1 for elevation. The elevator 3 can be driven to stop at an accurate moving distance, and the ascent / descent speed can be monitored in the same manner to detect an abnormality.

In the above-described embodiment, the present invention is applied to the article storage facility F by exemplifying the traveling body 2 of the stacker crane C and the lift 3 as moving objects MB moving in the set range.
Although the case where it is applied to S is illustrated, it can be applied to control of various moving objects MB such as traveling control of an automatic guided vehicle.

In the above embodiment, the so-called inverter type motors M1 and M2 (traveling drive device 14) are illustrated as the traveling drive means MD for travelingly driving the moving body MB. Means for detecting the traveling speed of the body MB, and a circuit for performing feedback control so that the speed commanded from the traveling control means MC matches the detected traveling speed. The specific configuration of the traveling drive means MD for traveling and driving the moving body MB at the instructed traveling speed can be variously changed.

In the above embodiment, the speed detecting means VS
Detects the speed of the moving body MB from the amount of movement of the moving body MB by counting output pulses of a rotary encoder such as the body-side rotary encoder 21.
A so-called linear encoder is installed along
The specific configuration of the speed detecting means VS can be variously changed, such as detecting the amount of movement of B.

[0049]

As described above, according to the present invention, the moving body can be stopped at the stop position without forcibly decelerating, and it is not necessary to dispose the plate to be detected at the end of the work passage as in the prior art. In addition, the facility installation work can be simplified and the operation efficiency of the facility can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of an article storage facility using a moving body speed control method and a speed monitoring method according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a stacker crane of the article storage facility.

FIG. 3 is an enlarged view of a main part of a stacker crane of the article storage facility.

FIG. 4 is a control configuration diagram of the article storage facility.

FIG. 5 is a block diagram of a traveling control unit of the crane control device of the article storage facility.

FIG. 6 is an explanatory diagram of a set traveling pattern and a speed monitoring method of the article storage facility.

FIG. 7 is an explanatory diagram of a tracking delay control method of the article storage facility.

FIG. 8 is an explanatory diagram of a method of learning a delay time of the article storage facility.

[Explanation of symbols]

 MB Moving body MC Travel control means MD Travel drive means VS Speed detection means 21 Rotary encoder

Claims (3)

[Claims] 1. A traveling driving means for traveling and driving the moving body at a traveling speed instructed by traveling control means is provided on a moving body moving in a set range, and the traveling control means is provided with respect to the traveling driving means. A speed control method of a moving body configured to give a speed command based on a set running pattern, comprising: a speed command instructed at the time of deceleration by said running control means, and a running speed of the moving body with respect to the speed command. A speed control method for a moving body, wherein a following delay time is learned in advance, and a speed command according to the set traveling pattern is output to the traveling driving means ahead of the learned following delay time during deceleration. 2. The learning of a following delay time of a traveling speed of a moving body, the actual traveling distance in a predetermined time during traveling at a constant speed is determined,
The movement distance of the unit speed command per scan is calculated from the actual movement distance, and the first time when the speed command value at the time of deceleration reaches a predetermined ratio of the constant speed is stored. Calculating a total of the unit speed commands up to a predetermined time before, multiplying the sum of the unit speed commands by a moving distance of the unit speed command per one scan to obtain a theoretical movement amount; 2. The method according to claim 1, wherein a second time when the actual movement distance of the body becomes the theoretical movement amount is obtained, and the difference is calculated by calculating a difference between the second time and the first time. Speed control method for moving objects. 3. A travel driving means for driving the moving body at a traveling speed instructed by travel control means is provided on a moving body moving in a set range, and the travel control means is provided with respect to the travel drive means. A speed command of the moving body configured to give a speed command based on the set running pattern, and a delay time for following the speed command instructed by the running control means and a running speed of the moving body with respect to the speed command. From the above, the moving amount of the moving body is estimated, the travel time and the running speed at the time of estimating the moving amount are respectively set to normal ranges, the actual moving amount of the moving body is measured, and the actual moving amount is estimated. When the moving distances match, the traveling speed is judged to be normal if it is within one of the normal ranges, and the traveling speed is judged to be abnormal if it is not within one of the normal ranges. Method.