JP3800904B2 - Speed control method for moving body - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, a traveling body that travels and drives the moving body at a traveling speed commanded by the traveling control means is provided on the moving body that moves within the set range, and the traveling control means The present invention relates to a speed control method and a speed monitoring method for a moving body configured to issue a speed command based on a set travel pattern.
[0002]
[Prior art]
Conventionally, in a mobile body, the travel drive means drives the mobile body to travel at a travel speed commanded from the travel control means, and the travel control means issues a speed command for a set travel pattern, but erroneously detects the travel speed. For various reasons, the moving body may not travel at the traveling speed commanded by the traveling 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 also a fear.
[0003]
Therefore, conventionally, a detection plate for forcibly decelerating or stopping the travel drive means is installed at the end of the moving range of the moving body, and if the detection plate is detected from the moving body side, it is compulsory. A configuration for stopping is considered.
[0004]
[Problems to be solved by the invention]
However, the above-described conventional configuration requires the above-described detection plate and the like, which complicates the installation work of equipment and the like, and the above-described detection plate moves due to the installation within the moving range of the moving body. When the moving body is moved near the end of the range, the moving body may be decelerated more than necessary to reduce the operating efficiency of the equipment.
[0005]
Further, when the vehicle is forcibly decelerated or stopped, the moving body vibrates, and there is a possibility that the load falls when the load is loaded.
Therefore, the present invention can avoid the forced deceleration of the moving body, can confirm whether the moving body is traveling at the traveling speed commanded from the traveling control means, simplify the installation work of the facility, An object of the present invention is to provide a speed control method and a speed monitoring method for a moving body that can improve the operation efficiency.
[0006]
[Means for Solving the Problems]
In order to achieve the above-described object, the invention according to claim 1 of the present invention is a travel drive means for driving the mobile body moving at a travel speed commanded by the travel control means to the mobile body moving in the set range. The travel control means is a speed control method for a moving body configured to give a speed command to the travel drive means based on a set travel pattern, and the travel control means instructs the travel drive means to decelerate. The actual moving distance at a predetermined time is obtained in advance during constant speed traveling, and the unit speed command of one unit speed command per scan is obtained from the speed command and the following delay time of the traveling speed of the moving body with respect to this speed command. The movement distance is calculated, the first time when the speed command value commanded at the time of deceleration becomes a predetermined ratio of the constant speed is stored, and the unit speed up to the predetermined time before the first time is stored. The total of the command speeds is obtained and the total of the unit speed commands is multiplied by the travel distance of the unit speed command per scan to obtain the theoretical travel distance, and the actual travel distance of the distance moving body at the predetermined time is calculated as the theoretical travel distance. The second traveling time when the amount of movement is the upper distance is obtained, learning is performed by calculating the difference between the second time and the first time, and when the vehicle is decelerated, the set traveling is preceded by the learned follow-up delay time. A speed command based on a pattern is output to the travel drive means.
[0007]
According to the above method, the first time when the speed command value at the time of deceleration becomes a predetermined ratio of a constant speed, and the actual moving distance of the distance moving body at the predetermined time is the theoretical movement amount at the first time. the difference between the second time when it becomes, the follow-up delay time of the running speed of the moving object is determined with respect to the speed command, during deceleration, the follow-up delay time amount corresponding preceding speed command according to the set running pattern traveling drive means The possibility that the moving distance of the moving body increases due to the follow-up delay of the traveling speed of the moving body and passes through the stop position is eliminated.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A case where the moving body speed control method and speed monitoring method of the present invention are applied to a stacker crane provided in an article storage facility will be described.
[0013]
As shown in FIG. 1, the article storage facility FS includes two storage shelves A that are installed at an interval so that the article loading and unloading directions are opposed to each other, and a work passage formed between the storage shelves A. A stacker crane (an example of a moving body) C that automatically travels in B is provided, and each storage shelf A has a large number of article storage portions D arranged in parallel in the upper and lower stages and on the left and right.
[0014]
In the work path B, a traveling rail 1 is installed along the longitudinal direction of the storage shelf A, and a controller for inputting a loading / unloading command to the stacker crane C in the article loading / unloading section E installed on one end side of the work path B. E1 and a pair of loading platforms E2 are provided with the traveling rail 1 interposed therebetween, and the stacker crane C travels along the traveling rail 1 based on the loading / unloading command, and the loading platform E2 and the article storage unit D It is configured as a loading / unloading transport vehicle that loads and unloads articles F placed on the pallet P.
[0015]
As shown in FIG. 2, the stacker crane C includes a lifting platform 3 and a pair of front and rear lifting masts 4 that guide and support the lifting platform 3 so as to be movable up and down on a traveling vehicle body 2 that travels along the traveling rail 1. A fork device 5 for transferring articles is provided on the lifting platform 3.
[0016]
The lifting platform 3 is suspended and supported by lifting chains 8 connected to the left and right sides thereof. The lifting chain 8 is a guide sprocket 9 provided on the upper frame 7 and a guide sprocket provided on one lifting mast 4. 10 is connected to a take-up drum 11 provided at one end of the traveling vehicle body 2.
[0017]
Then, the take-up drum 11 is driven and rotated in the forward and reverse directions by an elevating electric motor M1, which is a so-called inverter type motor, so that the elevating platform 3 is driven up and down by unwinding and winding operation of the elevating chain 8. It is configured.
[0018]
The lifting position of the lifting / lowering base 3 is not shown in FIG. 2 or the like, but is connected to the rotary shaft of the take-up drum 11 and is connected to the drive-side rotary encoder 18 for detecting the amount of rotation of the lifting / lowering base 3. It is managed based on detection information with the mounted elevator-side rotary encoder 19. As shown in FIG. 3, the elevator base-side rotary encoder 19 has a sprocket 19 a attached to a rotating shaft thereof meshed with a chain 20 laid vertically on one side of the elevator mast 4. As the elevating and lowering of the sprocket 19a, the up and down movement of the elevating platform 3 is detected.
[0019]
The detection information of the drive-side rotary encoder 18 and the elevator platform-side rotary encoder 19 is input to the elevator controller 30 of the crane controller CC as shown in FIG.
[0020]
As shown in FIG. 3, the traveling vehicle body 2 is engaged with the traveling rail 1 so as to restrict the front and rear wheels 12 that can travel on the traveling rail 1 and the position of the traveling rail 1 in the lateral direction of the vehicle body. A lower position regulating rotor 13 provided in a pair of left and right sides and a traveling drive device 14 provided with a traveling electric motor M2 which is a so-called inverter type motor is provided.
[0021]
Further, as shown in FIG. 2, the upper frame 7 has a pair of left and right upper positions that sandwich the guide rail 6 from the left and right and roll about the vertical axis along the side surface as the stacker crane C travels. The regulating roller 17 is provided at the front and rear end portions in the traveling direction.
[0022]
One of the two wheels 12 on one end side in the longitudinal direction of the vehicle body is configured as a driving wheel 12a for propulsion driven by the traveling drive device 14 (traveling electric motor M2). The wheel on the end side is configured as a freely driven wheel 12b, and the stacker crane C travels by being driven by the travel drive device 14 while being prevented from falling by the upper position regulating roller 17 provided on the upper frame 7. It is configured to be able to run along the rail 1 freely.
[0023]
As shown in FIG. 3, the traveling position of the traveling vehicle body 2 is managed based on detection information of the vehicle body-side rotary encoder 21 attached to the traveling vehicle body 2. The vehicle-body-side rotary encoder 21 has a sprocket 21 a attached to its rotating shaft meshing with a chain 22 laid along the traveling rail 1, and the sprocket 21 a rotates as the traveling vehicle body 2 travels. The traveling movement of the traveling vehicle body 2 is detected.
[0024]
The detection information of the vehicle body side rotary encoder 21 is input to the traveling control unit 31 of the crane control device CC as shown in FIG.
As shown in FIG. 4, the crane control device CC receives a conveyance command from the controller E <b> 1, and moves the lifting body 3 up and down to the specified lifting position and the traveling vehicle body 2 as specified. The travel control unit 31 is moved to a position, and the transfer control unit 32 is configured to move the fork device 5 to move the article F and move the article F, and is controlled by the crane controller CC to convey the article F and store each article. The article F is transferred between the part D and the like.
[0025]
The traveling control of the traveling vehicle body 2 by the traveling control unit 31 of the crane control device CC will be described in detail.
A control block diagram of the traveling control unit 31 of the crane control device CC is shown in FIG.
[0026]
It is reset by a start signal, which will be described later, and is measured by a movement distance detection unit 41 that counts the pulse signal input from the vehicle body side rotary encoder 21 and measures the actual movement distance of the traveling body 2, and the movement distance detection unit 41. A speed detecting unit 42 that differentiates the moving distance and measures the actual speed, a time detecting unit 43 that is reset by a start signal, which will be described later, and measures the traveling time of the traveling main body 2, and a movement to the moving destination input from the controller E1 A travel pattern setting unit 44 (details will be described later) for setting a travel pattern based on the distance; an actual travel distance measured by the travel distance detection unit 41; an actual speed of the travel main body 2 detected by the speed detection unit 42; Speed is determined by the travel time measured by the time detection unit 43 and the set value of the travel pattern input from the travel pattern setting unit 44. A travel pattern generation unit 45 (details will be described later) for outputting the command value to the travel drive unit 14 and a speed command value output from the travel pattern generation unit 45 to the travel drive unit 14 are input and output with a time delay. The time delay unit 46, the actual travel distance measured by the travel distance detection unit 41, the actual speed of the travel main body 2 detected by the speed detection unit 42, the travel time measured by the time detection unit 43, and the time delay unit 46 It is composed of a pass / fail judgment unit 47 that inputs a time-delayed speed command value input from, and judges pass / fail of the running speed.
[0027]
The travel pattern setting unit 44 calculates a set value for setting a travel pattern indicated by a solid line in FIG. 6 based on the input movement distance Q. , The high-speed constant speed vH and the movement distance (deceleration start point) R for starting deceleration are obtained, and the high-speed constant speed vH, the deceleration start movement distance R, and the movement distance (input movement distance, Q (corresponding to the stop distance) is output to the traveling pattern generator 45. Since the travel speed v integrated is the travel distance, if the acceleration / deceleration and the "low speed" travel speed vL before the stop are set, the fast constant speed vH and the travel distance (deceleration start) Point) R can be obtained.
[0028]
The acceleration / deceleration speed α and the “low speed” traveling speed vL before stopping are set in advance in the traveling pattern generating unit 45, and when a high speed constant speed vH, a deceleration start moving distance R, and a moving distance Q are input, FIG. 6 can set a travel pattern indicated by a solid line, and when the travel pattern is set, the start signal is output to the movement distance detection unit 41 and the time detection unit 43, and at the same time, the output of the speed command value is started according to the set travel pattern. .
[Follow-up delay control]
The travel pattern generation unit 45 is configured to follow the control delay by the travel drive unit (motor M2) 14 and the drive wheel 12a (a delay until the speed of the travel body 2 changes in response to the speed command; the follow delay time is β. The deceleration setting pattern from the deceleration start point r is corrected. That is, as shown in FIG. 7, a “high speed” constant speed vH is multiplied by a delay time β to give a command deceleration start point (movement distance) before the deceleration start point r (corresponding to the hatched portion in FIG. 7). When r ′ is set and the actual travel distance measured by the travel distance detector 41 coincides with the command deceleration start point r ′, the speed command is preceded according to the deceleration travel setting pattern as shown by the broken line. Output (decrease) value. As a result, as indicated by the solid line, the speed of the traveling main body 2 changes according to the (ideal) set traveling pattern, and it is prevented that the moving distance increases due to the follow-up control delay and passes through the stop position.
[Learn delay time]
The traveling pattern generation unit 45 learns the delay time β by the following procedure prior to actual driving (see FIG. 8).
[0029]
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) is determined while traveling at the “high speed” constant speed vH.
[0030]
The moving distance Lm of the “unit speed command” is calculated from the actual moving distance Lx and the “high speed” constant speed vH. 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.
[0031]
Lm = Lx ÷ (Speed command total 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, and a predetermined time (for example, 1 sec) from the first time tx. Back up to the previous time, the sum of the speed command values is calculated, and the theoretical movement amount Lr (shaded portion A) is obtained.
[0032]
Lr = Lm × (total speed command value)
Next, the actual moving distance in a predetermined time (for example, 1 sec) is measured based on the actual moving distance measured by the moving distance detecting unit 41, and the time when the measured value Ly coincides with the theoretical moving amount Lr (first time). 2 hours ty). At this time, it can be determined that the actual speed is ½ of the constant speed vH. The measured value Ly when matched by the hatched portion B is shown.
[0033]
Next, the difference between the second time ty and the first time tx is calculated to determine and store the delay time β.
In this way, the follow-up delay time β can be learned.
[Speed monitoring]
Hereinafter, a speed monitoring method by the time delay unit 46 and the quality determination unit 47 will be described.
[0034]
As shown in FIG. 6, the speed v of the traveling body 2 is controlled by the set traveling pattern generated from the traveling pattern generation unit 45, but if there is no other abnormality due to the follow-up control delay (delay time β), The actual traveling speed shows a curve indicated by a broken line.
[0035]
A speed command value (hereinafter referred to as a delayed travel speed command value) is input to the pass / fail judgment unit 47 by the time delay unit 46 delayed by the follow-up delay time β. The pass / fail judgment unit 47 executes the following procedure every unit time (one scan).
[0036]
First, the travel speed 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 travel time measured by the time detection unit 43 is set. The estimated moving distance, the normal speed range of the traveling speed, and the normal time range of the traveling time are stored as one set.
[0037]
Next, when the estimated moving distance and the actual moving distance measured by the moving distance detecting unit 41 coincide with each other, the actual speed of the traveling body 2 detected by the speed detecting unit 42 at this time is stored as the normal speed stored together with the estimated moving distance. It is determined whether it is within the range, and subsequently, it is determined whether the traveling time measured by the time detector 43 is within the normal time range.
[0038]
If it is within 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, it is considered normal if the traveling time when the estimated moving distance is moved is within the range, and easy abnormality determination is avoided, and the number of stops due to the occurrence of abnormality can be reduced. If it is determined that there is an abnormality, a traveling abnormality signal is output to the controller E1 and the traveling pattern generator 45.
[0039]
When this traveling abnormality signal is input, the traveling pattern generation unit 45 sets the speed command value to zero and stops the traveling body 2.
The effect | action by the structure of the traveling control part 31 of the said crane control apparatus CC is demonstrated.
[0040]
When the travel control unit 31 receives the travel distance conveyance command from the controller E1, the travel control unit 31 forms a set travel pattern in which the deceleration range is corrected based on the previously learned follow-up delay time β, and travels the speed command value based on the set travel pattern. The vehicle body 2 travels by outputting to the drive unit 14 (motor M2).
[0041]
At this time, the speed is monitored, and when the vehicle 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 lowered in advance at the time of deceleration, the traveling body 2 decelerates according to the ideal speed pattern, so that there is no deviation in the moving distance, and there is no need for a forced stop. The main body 2 can be smoothly stopped, and the occurrence of vibration and shaking can be prevented.
[0042]
When the traveling speed of the traveling vehicle body 2 shifts to “low speed” vL and reaches the moving distance Q, the brake is activated to stop the traveling vehicle body 2.
As described above, the traveling main body 2 decelerates according to an ideal speed pattern, and therefore, there is no shift in the moving distance, and forced deceleration can be avoided. Falling can be prevented.
[0043]
In addition, since the fact that the speed of the crane C is generated according to the set traveling pattern is monitored in the direction of speed and the direction of time, it is accurately determined whether the vehicle is traveling at the commanded traveling speed. Can be confirmed.
[0044]
In addition, since traveling is controlled so that forced deceleration can be avoided and the traveling speed at this time is monitored, there is no need to install a plate to be detected at the end of the work path as in the prior art, and installation work of equipment is not required. Simplification and equipment operation efficiency can be improved.
[0045]
Similarly to the travel control unit 31, the lift control unit 30 sets a set lift pattern of the lift 3 that takes into account the follow-up delay time, corresponding to the set travel pattern, and drives the lift electric motor M <b> 1. The lifting platform 3 can be stopped at an accurate movement distance, and the lifting speed can be monitored in the same manner so that an abnormality can be found.
[0046]
In the above embodiment, the traveling vehicle body 2 and the lifting platform 3 of the stacker crane C are exemplified as the moving body MB that moves in the set range, and the case where the present invention is applied to the article storage facility FS is illustrated. However, it can be applied to control of various mobile bodies MB such as travel control of automatic guided vehicles.
[0047]
In the above embodiment, the so-called inverter type motors M1 and M2 (travel driving device 14) are exemplified as the travel drive means MD that travels and drives the mobile body MB, but the travel drive means MD itself includes the mobile body MB. It is provided with a means for detecting the traveling speed, and is provided with a circuit for performing feedback control so that the speed commanded from the traveling control means MC and the detected traveling speed coincide with each other. The specific configuration of the travel drive means MD that travels and drives the mobile body MB at the travel speed can be variously changed.
[0048]
In the above embodiment, the speed detection means VS counts the output pulses of the rotary encoder such as the vehicle body side rotary encoder 21 and detects the speed of the moving body MB from the moving amount of the moving body MB. The specific configuration of the speed detection means VS can be variously changed, for example, by installing a so-called linear encoder along the line and detecting the amount of movement of the moving body MB.
[0049]
【The invention's effect】
As described above, according to the present invention, the moving body can be stopped at the stop position without performing forced deceleration, and there is no need to install a plate to be detected at the end of the work path as in the prior art. Simplification of the system and the operation efficiency of the equipment 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 travel 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 follow-up delay control method for the article storage facility.
FIG. 8 is an explanatory diagram of a method for 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 (1)

The moving body that moves in the setting range is provided with a travel drive means that travels the mobile body at a travel speed commanded by the travel control means, and the travel control means has a set travel pattern with respect to the travel drive means. A speed control method for a moving body configured to give a speed command based on the speed command,
The speed command commanded at the time of deceleration by the travel control means and the follow-up delay time of the travel speed of the moving body with respect to this speed command ,
While traveling at a constant speed, the actual travel distance at a predetermined time is obtained, the travel distance of a unit speed command per scan is calculated from this actual travel distance Lx, and the speed command value commanded during deceleration is a predetermined ratio of the constant speed. Is stored, the total of the unit speed commands up to a predetermined time before the first time is obtained, and the movement speed of the unit speed command per scan is added to the total of the unit speed commands. Multiplication is performed to obtain a theoretical movement amount, and a second time when the actual movement distance of the distance moving body in the predetermined time becomes the theoretical movement amount is obtained, and the second time and the first time are calculated. Learn by calculating the difference ,
A speed control method for a moving body, wherein a speed command based on the set travel pattern is output to the travel drive means in advance by a learned follow-up delay time during deceleration.

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