JP2007086913A - Conveyance truck traveling control method and traveling control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conveyance truck traveling control method which consecutively controls the traveling of conveyance trucks so that the inter-vehicle distance of the conveyance trucks becomes an optimum value fpr avoiding the collision of the trucks to improve conveyance efficiency. <P>SOLUTION: The conveyance speed of a subsequent conveyance truck is limited to the speed which is computed from a prescribed expression. According to this, a vehicle distance at each time between a preceding conveyance truck and a subsequent conveyance truck is optimized, and the conveyance distance interval at the time of conveyance is shortened, to improve the conveyance efficiency. Furthermore, a conveyance distance interval is reduced, thereby more conveyance trucks can simultaneously travel in a conveyance path of a fixed distance. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a travel control method and a travel control system for a transport carriage that transports various transport objects, and more particularly to a travel control method and a travel control system for a transport carriage that control the inter-vehicle distance of the transport cart.

  In a factory or a warehouse, a transport cart is often used to transport various transport items such as products or raw materials. Such a transport cart is important to control. In particular, when a plurality of transport carts travel in the same direction on the same transport path, it is very important to control the distance between the transport carts so that the transport carts do not collide with each other. Examples of conventionally known control methods for controlling the inter-vehicle distance of the transport carriage include a closed section control method and an initial inter-vehicle control method described below.

  The closed section control method is a method described in Patent Document 1, for example, and is also called a zone control method. In this closed section control method, a transport path in which a plurality of transport carriages travel in the same direction is divided into a plurality of closed sections (zones). It is set so that multiple carts do not enter the divided block sections at the same time. In addition, in the two trolleys that travel in succession, when the trailing carriage enters the blockage section adjacent to the blockage section where the preceding carriage exists, the subsequent carriage is set to decelerate / stop. If the preceding carriage advances to the next closed section during the deceleration / stop processing of the trailing carriage, the trailing carriage is set to start running again.

  The initial inter-vehicle distance control method is a method for controlling the inter-vehicle distance using a timer or the like. This will be described below with reference to FIGS. FIG. 1 is a diagram showing the procedure of the initial inter-vehicle control method, and FIG. 2 shows the speed change of the leading carriage 1 and the trailing carriage 2 on the coordinate with time on the horizontal axis and speed on the vertical axis. FIG. In the initial state, as shown in FIG. 1A, the leading carriage 1 and the trailing carriage 2 are stopped at a short inter-vehicle distance. From this state, as shown in FIG. 1 (b), the preceding carriage 1 starts traveling.

As shown by data 3 in FIG. 2, the preceding carriage 1 accelerates at a constant acceleration / deceleration rate until the maximum speed V _MAX is reached after the start of traveling. After reaching the maximum speed V _{MAX, the} vehicle travels at a constant speed. When the destination approaches, the vehicle decelerates at a constant acceleration / deceleration rate and finally stops. The time from the start of traveling of the preceding carriage 1 is measured by a timer or the like, and after the predetermined time _{TTIMER has} elapsed, the trailing carriage 2 starts to travel as shown in FIG. As shown by data 4 in FIG. 2, the trailing carriage 2 that starts traveling after a predetermined time T _TIMER changes in the same speed as the preceding carriage 1. Therefore, after a while after the preceding carriage 1 and the trailing carriage 2 start running, both carriages run at the maximum speed V _{MAX as} shown in FIG. 1 (d). The distance between the two vehicles at this time is L _MAX shown in FIG. The predetermined time _TTIMER is set so that the inter-vehicle distance L becomes a value at which the trailing carriage 2 can decelerate and stop to avoid a collision when the preceding carriage 1 stops suddenly due to a trouble or the like.
JP 10-338132 A

  However, in the above-described blockage section control method, since the length of the blockage section to be set is about several meters, the inter-vehicle distance cannot be managed finely, and the inter-vehicle distance is set to be larger than necessary. Even if the speed of the preceding carriage is low and the inter-vehicle distance can be set small, the inter-vehicle distance is set large.

  In the above initial inter-vehicle control method, the travel start times of the preceding and subsequent vehicles that change at the same speed are only shifted by a predetermined time, and optimization of the inter-vehicle distance of the vehicle that changes from time to time is not possible. Is possible. That is, when the initial inter-vehicle distance control method is used, the inter-vehicle distance is set larger than necessary in most of the time.

  Therefore, when controlling the transport carriage using the above-described closed section control method or initial inter-vehicle control method, the inter-vehicle distance between the preceding carriage and the following carriage is set to be larger than necessary, and the conveyance interval when transporting is set. Since it becomes longer, the conveyance efficiency is lowered.

  The present invention has been made in view of the above problems, and is a transport that improves transport efficiency by continuously controlling the travel of the transport carriage so that the inter-vehicle distance of the transport carriage becomes an optimum value that can avoid a collision. It is an object of the present invention to provide a traveling control method and a traveling control system for a cart.

In order to solve the above problems, according to the present invention, there is provided a travel control method for a transport carriage when a plurality of transport carriages travel on the same transport path, wherein any preceding transport in the plurality of transport carriages is performed. Travel control of a transport cart, wherein the travel speed (V ₂ ) of a subsequent transport cart that travels immediately after the preceding transport cart in the same direction as the cart is controlled to satisfy the following formula (1): Method.
V ₂ ≦ (−dt + √ ((dt) ² + 2 × (L + V ₁ ² / (2 × α ₁ ) −dL) / α ₂ )) × α ₂ ... Formula (1)
[However, L: distance between the preceding conveyance carriage and the following conveyance carriage, V ₁ : preceding conveyance carriage speed, V ₂ : subsequent conveyance carriage speed, α ₁ : preceding conveyance carriage acceleration / deceleration rate, α ₂ : subsequent conveyance. Cart acceleration / deceleration rate, dt: control delay, dL: transport cart position detection error]

In order to solve the above problems, according to the present invention, there is provided a travel control system for a transport cart when a plurality of transport carts travel on the same transport path, provided in each of the transport carts, A position detector for detecting the position of the transport carriage, a transmission device provided in each of the transport carriages for transmitting the detected position,
A receiving device for receiving the signal-transmitted position;
A first controller for determining a target travel position for each of the transport carriages;
A speed (V _SET) that is connected to the receiving device and the first controller, and is to be set to the transport carriage based on the travel position results received and accumulated from the receiver and the target travel position received from the first controller. ) Is calculated, a speed limit (V _LIMIT ) is calculated from the following formula (2) when the transport carriage is a subsequent transport carriage, and the speed of the transport carriage is set to the speed to be set (V _SET ) and the A travel control system is provided that includes a second controller that controls the transport carriage so as to have a smaller value of the speed limit (V _LIMIT ).
V _LIMIT = (− dt + √ ((dt) ² + 2 × (L + V ₁ ² / (2 × α ₁ ) −dL) / α ₂ )) × α ₂ ... Formula (2)
[However, L: distance between the preceding conveyance carriage and the following conveyance carriage, V ₁ : preceding conveyance carriage speed, V ₂ : subsequent conveyance carriage speed, α ₁ : preceding conveyance carriage acceleration / deceleration rate, α ₂ : subsequent conveyance. Cart acceleration / deceleration rate, dt: control delay, dL: transport cart position detection error]

  According to the present invention, it is possible to improve transport efficiency by continuously controlling the travel of the transport carriage so that the distance between the transport carriages becomes an optimum value that can avoid a collision.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 3 is a block diagram showing the configuration of the traveling control system 5 for implementing the present invention. As shown in FIG. 3, the transport carts 6 and 7 controlled by the present invention travel in the same direction on the travel rail 8 as the same transport path. The traveling control system 5 according to the present invention receives position detectors 9 and 10 and optical signal transmitters 11 and 12 provided on the transport carts 6 and 7 and signals wirelessly transmitted from the transport carts 6 and 7, respectively. The optical signal receivers 13 and 14 are connected to the optical signal receivers 13 and 14 and the host controller 15 as the first controller, and a second control command for the transporting carriage is issued based on information received therefrom. A transporting carriage control controller 16 serving as a control controller of the transporting carriage, and transporting carriage drive devices 17 and 18 which are connected to the transporting carriage control controller 16 and drive the transporting bases 6 and 7 in accordance with the travel control command.

  Transport carts 6 and 7 shown in FIG. 3 representatively represent two transport carts that run adjacent to each other among two or more transport carts that travel on the traveling rail 8 in the same direction. is there. Accordingly, there may be one or more other transport carts in front of the preceding transport cart 6 and after the subsequent transport cart 7, but there are other transport carts between the preceding transport cart 6 and the subsequent transport cart 7. There is no transport cart. As described above, the transport carts 6 and 7 include, for example, position detectors 9 and 10 such as an ABSOCODER that detect their travel positions, and optical signal transmission apparatuses 11 and 12 that wirelessly transmit signals of the detected travel positions. Respectively.

  The optical signal receivers 13 and 14 are receivers that receive the traveling position signals wirelessly transmitted from the position detectors 9 and 10 provided on the transport carts 6 and 7. The travel position signals received by the optical signal receivers 13 and 14 are transmitted to the transport cart controller 16 so as to control the transport cart.

  The host controller 15 is a control controller that transmits a command such as a transport destination of each transport cart to the transport cart controller 16.

  The transport cart controller 16 is a control controller that controls the transport cart to travel so that the transport cart reaches the transport destination transmitted from the host controller 15. More specifically, the transport carriage controller 16 continues to control the travel of the subsequent transport carriage as follows until the subsequent transport carriage 6 reaches its destination. First, the transport cart controller 16 performs analysis using the travel position signals of the transport carts 6 and 7 continuously transmitted from the optical signal receivers 13 and 14. Next, based on the analysis result, a travel control command is transmitted to the transport carriage drive device 18 so as to control the travel of the subsequent transport carriage 7. In this embodiment, since the transport carriage 7 is a follower transport carriage that travels behind the transport carriage 6, the travel control command for preventing collision based on the analysis result is a transport carriage that drives the follower transport carriage 7. It is transmitted to the driving device 18. However, when the transport cart 6 is processed as a subsequent transport cart, a travel control command may be transmitted to the transport cart driving device 17 that drives the transport cart 6.

  The transport cart driving devices 17 and 18 drive and transport the transport carts 6 and 7, respectively, based on a travel control command such as a set speed transmitted from the transport platform control controller 16.

Next, in the travel control system 5 configured as described above, a method for controlling the travel of the trailing transport carriage 7 will be described with reference to FIGS. As shown in FIG. 3, two continuous transport carts 6 and 7 are traveling in the same direction on the travel rail 8. Here, consider the moment shown in FIG. 4A with respect to the preceding conveyance carriage 6 and the subsequent conveyance carriage 7. Figure 4 moment (a), prior conveying carriage 6 passes through the traveling position L ₁ of the distance L ₁ at a speed V ₁ from the traveling position origin O which starts to travel. Further, at this moment, the trailing transport carriage 7 passes through the travel position L ₂ of the distance L ₂ at a velocity V ₂ from the travel position origin O which starts to travel. As shown in FIG. 4, the travel position of the preceding transport carriage 6 is based on the position of the end on the subsequent transport carriage side, and the travel position of the subsequent transport carriage 7 is on the preceding transport carriage side. The position of the end is used as a reference. Accordingly, the inter-vehicle distance L between the preceding conveyance carriage 6 and the subsequent conveyance carriage 7 at this moment becomes L = L ₁ −L ₂ from L ₁ and L ₂ .

The traveling position L ₁ of the preceding transport carriage 6 at the moment of FIG. 4A is detected by the position detector 9 and optically transmitted to the optical signal receiving apparatus 13 as a traveling position signal by the optical signal transmitting apparatus 11. Similarly, the traveling position L ₂ of the row conveyance carriage 7 after the moment of Fig. 4 (a), detected by the position detector 10, the optical signal transmitter 12, an optical transmitter to an optical signal receiving apparatus 14 as the driving position signal Is done.

Information on the travel positions L ₁ and L ₂ of the transport carts 6 and 7 received by the optical signal receivers 13 and 14 is transmitted to the transport cart controller 16 connected to the optical signal receivers 13 and 14. The transport cart controller 16 continuously receives the travel position information of the transport carts 6 and 7 and stores it as travel position results. Further, the transport table controller 16 predetermines the target travel position of the subsequent transport cart 7 based on the transport destination command of the subsequent transport cart 7 received from the host controller 15. Based on this target travel position and travel position results, the transport carriage controller 16 determines a travel speed V _SET to be set for the subsequent transport carriage 7.

Further, the transport carriage controller 16 uses the speed command value or the speed measurement value received continuously to obtain the speeds V ₁ and V ₂ of the transport carriages 6 and 7 at the moment in FIG. calculate. Further, the transport carriage controller 16 analyzes information such as the travel positions L ₁ and L ₂ , the speeds V ₁ and V _2, and the inter-vehicle distance L of the transport carriages 6 and 7, and V _SET is calculated based on the analysis result. A speed limit V _LIMIT to be satisfied is calculated. Hereinafter, an equation for calculating the speed limit V _LIMIT will be specifically described.

First, the preceding conveying carriage 6 shown in FIG. 4 (a) to travel at a speed V ₁ is, for example decelerated at a predetermined deceleration rate alpha ₁ in troubles, finally stopped as shown in FIG. 4 (b) Assume a case. In the present embodiment, acceleration and deceleration rate alpha ₁ is set as a value that is determined by the amount of brake torque to inertia force when the preceding conveying carriage 6 travels to load the conveyed object, for example a transport carriage controller 16 Has been. FIG. 5 (a) is a diagram showing the speed change of the preceding transport carriage 6 at this time on coordinates with time on the horizontal axis and speed on the vertical axis. Preceding conveying carriage 6 is decelerated by deceleration rate alpha ₁ from the speed V _1, the moving distance L _S1 spend until the stop is equal to the area of the triangle OPQ was filled with oblique lines in FIG. 5 (a). That is, L _S1 = OP × OQ × 1/2. Here, since α ₁ is an acceleration / deceleration rate at which the speed V _{1 is set} to 0 after the time OQ has elapsed, OQ × α ₁ = V ₁ is established, and OQ = V ₁ / α ₁ . In addition, it is OP = _{V 1.} Therefore,
L _S1 = V ₁ × (V ₁ / α ₁ ) × 1/2 = V ₁ ² / (2α ₁ ) (3)
It becomes.

As described above, when the preceding conveying carriage 6 in trouble or the like to slow down and stop, the line conveying carriage 7 after shown in FIG. 4 (a) that travels immediately at the speed V ₂ is the control for preventing collision, Decelerated at a predetermined acceleration / deceleration rate α2 and stopped. In the present embodiment, acceleration and deceleration rate alpha _2, as a value that does not cause a slip when the trailing transport carriage 7 is decelerated, for example, it is set to the transport carriage driving device 18. FIG. 5B is a diagram showing the speed change of the trailing transport carriage 7 at that time on the coordinates with time taken on the horizontal axis and speed taken on the vertical axis. The trailing conveyance carriage 7 starts the actual stop operation in response to the preceding conveyance carriage 6 starting to decelerate / stop (point R in FIG. 5B) (point of FIG. 5B). S), there is a control delay dt (section RS in FIG. 5B) due to a transmission delay of the travel position signal, a control delay of the controller, a motor operation delay, and the like. In the present embodiment, the value of the control delay dt is the delay of the optical signal transmission / reception devices 11, 12, 13, and 14, the control period of the sequencer (not shown), the delay of the position detectors 9 and 10, and the transport carriage 7 This is calculated based on factors such as slipping of a motor (not shown) that drives the motor (that is, a delay that does not follow the speed reference). Accordingly, as shown in FIG. 5 (b), during the control delay dt preceding conveying carriage 6 from the start of the deceleration / stop, trailing transport carriage 7, continues to travel at the speed V _2, pressurizing after dt has elapsed Deceleration is started at the deceleration rate α2. The movement distance L _{S2 that} is spent from the start of the preceding conveyance carriage 6 to the deceleration / stop and the deceleration of the subsequent conveyance carriage 7 to the stop is represented by the area of the trapezoid ORST painted with diagonal lines in FIG. Will be equal. That is, L _S2 = OR × OU + US × UT × 1/2. Here, since α ₂ is an acceleration / deceleration rate at which the speed V _{2 is set} to 0 after the time UT has elapsed, UT × α ₂ = V ₂ is established, and UT = V ₂ / α ₂ . Further, OR = US = V ₂ and OU = dt. Therefore,
L _S2 = V ₂ × dt + V ₂ × (V ₂ / α ₂ ) × 1/2
= V ₂ ² / (2α ₂ ) + dtV ₂ ... Formula (4)
It becomes.

The condition that the preceding conveying cart 6 and the following conveying cart 7 do not collide is that the preceding conveying cart 6 stops at the inter-vehicle distance L (see FIG. 4A) at the moment when the preceding conveying cart 6 starts decelerating. This is that the distance obtained by adding the travel distance L _S1 to be spent is not smaller than the travel distance L _S2 to be spent until the trailing transport carriage 7 stops. That is,
L _S2 <L + L _S1・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Formula (5)
It is. When formula (5) is transformed, L _S2 −L _S1 <L. Further, the traveling positions of the transport carriages 6 and 7 are measured by position detectors 9 and 10 such as an ABSOCODER, for example, but errors may occur due to the wheels slipping on the traveling rail 8 during the measurement. Therefore, when this error is taken into consideration and the carriage position detection error dL is corrected by adding to the equation (5),
L _S2 −L _S1 + dL ≦ L (6)
It becomes. In the present embodiment, the value of the conveyance carriage position detection error dL is calculated empirically based on a traveling experiment result or the like.

Substituting L _{S1 in} equation (3) and L _S2 in equation (4) into equation (6),
V ₂ ² / (2α ₂ ) + dtV ₂ −V ₁ ² / (2α ₁ ) + dL ≦ L (7)
It becomes. Solving the equation (7) with respect to _{V 2,}
V ₂ ≦ (−dt + √ ((dt) ² + 2 × (L + V ₁ ² / (2 × α ₁ ) −dL) / α ₂ )) × α ₂ ... Formula (1)
[However, L: distance between the preceding conveyance carriage and the following conveyance carriage, V ₁ : preceding conveyance carriage speed, V ₂ : subsequent conveyance carriage speed, α ₁ : preceding conveyance carriage acceleration / deceleration rate, α ₂ : subsequent conveyance. Cart acceleration / deceleration rate, dt: control delay, dL: transport cart position detection error]
Is obtained. That is, the above equation (1) is an equation that the traveling speed (V ₂ ) of the trailing conveyance carriage 7 should satisfy in order to ensure a vehicle-to-vehicle distance that can avoid collision. Therefore, as shown in the following formula (2), the right side of the formula (1) is the speed limit V _LIMIT described above.
V _LIMIT = (− dt + √ ((dt) ² + 2 × (L + V ₁ ² / (2 × α ₁ ) −dL) / α ₂ )) × α ₂ ... Formula (2)
[However, L: distance between the preceding conveyance carriage and the following conveyance carriage, V ₁ : preceding conveyance carriage speed, V ₂ : subsequent conveyance carriage speed, α ₁ : preceding conveyance carriage acceleration / deceleration rate, α ₂ : subsequent conveyance. Cart acceleration / deceleration rate, dt: control delay, dL: transport cart position detection error]

The transport cart controller 16 uses the information such as the travel positions L ₁ and L ₂ , the speeds V ₁ and V ₂ and the inter-vehicle distance L of the transport carts 6 and 7 to limit the speed limit V _LIMIT (that is, the right side of Expression (2)). Value). The calculated speed limit V _LIMIT and V _SET are compared, the smaller value is selected as the travel speed to be set in the trailing transport carriage 7, and a travel control command is transmitted to the transport carriage drive device 13. The transport cart drive device 18 drives the trailing transport cart 7 to the selected travel speed in accordance with the travel control command.

In the above embodiment, in the two transport carts 6 and 7 traveling in the same direction on the travel rail 8, the travel speed (V) of the subsequent transport cart 7 traveling immediately after in the same direction as the preceding transport cart 6. ₂ ) is controlled so as to satisfy the formula (2), so that the inter-vehicle distance of the transport carriage at each time is optimized, and the transport distance interval at the time of transport is shortened to improve the transport efficiency. . Further, the conveyance time interval can be shortened by shortening the conveyance distance interval. Furthermore, since the conveyance distance interval is shortened, more conveyance carts can be simultaneously driven in a conveyance path having a certain length.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, this invention is not limited to the example which concerns. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  In the above-described embodiment, the relationship between two transport carts that travel adjacent to each other in the front-rear direction has been described. However, the number of transport carts that travel adjacent to each other in the front-rear direction may be three or more.

  In the above-described embodiment, the traveling rail is used as the transport path. However, the transport path may be a transport path that provides a track to the transport carriage by other means. The conveyance path which is not provided may be sufficient.

  In the above-described embodiment, a rotary absolute coder or the like is used as the position detector. However, not only a rotary encoder but also other types of position detectors such as a linear encoder may be used.

6 and 7 show the results of a simulation comparison between the traveling control method according to the present invention and the initial inter-vehicle distance control method. FIG. 6 is a diagram showing the speed change of the transport carriage on coordinates with the horizontal axis representing time and the vertical axis representing speed. The speed changes of the preceding conveyance carriage and the subsequent conveyance carriage when two continuous conveyance carriages are travel-controlled according to the initial inter-vehicle distance control method are indicated by thin lines A and B, respectively. On the other hand, the thick line C shows the simulation result when only the trailing carriage is controlled using the traveling control method of the present invention. The simulation results indicated by the thick line C show that the acceleration / deceleration rate of the preceding conveyance carriage is 1.5 m / s ² and the acceleration / deceleration rate of the trailing conveyance carriage is 0.35 m / s ² (0.4 m / s ² at no load). The calculation was performed with the control delay set to 0.7 sec and the carriage position detection error set to 0.3 m. In this case, it is assumed that the preceding transport carriage has the same speed change as that in the initial inter-vehicle distance control method. The transport time of the trailing transport carriage is 44 seconds when controlled according to the initial inter-vehicle control method, whereas it is 41 seconds when controlled by the control method of the present invention, and the result is greatly shortened. Has been obtained.

  FIG. 7 is a diagram showing the inter-vehicle distance of the two transport carts of FIG. 6 on the coordinates with time as the horizontal axis and inter-vehicle distance as the vertical axis. A thin line D indicates a time change in the inter-vehicle distance when two transport carts are travel-controlled according to the initial inter-vehicle control method. On the other hand, what is indicated by a thick line E is a time change of the inter-vehicle distance when only the trailing carriage is controlled according to the traveling control method of the present invention. The maximum inter-vehicle distance in the case of the initial inter-vehicle control method is 25.5 m. On the other hand, the inter-vehicle distance when controlled by the traveling control method of the present invention is about 14 m at the maximum, and is lower than the value when controlled by the initial inter-vehicle control method at all times.

  According to the present invention, it is possible to improve the conveyance efficiency of a plurality of conveyance carts traveling on the same conveyance path.

It is a figure explaining the procedure of the initial inter-vehicle distance control method. It is a figure explaining the procedure of the initial inter-vehicle distance control method. It is a block diagram which shows the structure of the traveling control system which implements this invention. It is explanatory drawing explaining the traveling control method of this invention. It is explanatory drawing explaining the traveling control method of this invention. It is a figure which shows the simulation result which compared the conventional type initial distance control method and the traveling control method by this invention. It is a figure which shows the simulation result which compared the conventional type initial distance control method and the traveling control method by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 Traveling control system 6 Leading conveyance trolley 8 Traveling rail 9,10 Position detector 11,12 Optical signal transmission device 13,14 Optical signal receiving device 15 Host controller 16 Conveyance cart control controller 17,18 Conveyance cart drive device

Claims (2)

A traveling control method for a transport cart when a plurality of transport carts travel on the same transport path,
Control is performed so that the traveling speed (V ₂ ) of the succeeding transport cart that travels immediately after the preceding transport cart in the same direction as an arbitrary preceding transport cart among the plurality of transport carts satisfies the following expression (1). A traveling control method for a transport carriage, characterized in that:
V ₂ ≦ (−dt + √ ((dt) ² + 2 × (L + V ₁ ² / (2 × α ₁ ) −dL) / α ₂ )) × α ₂ ... Formula (1)
[However, L: distance between the preceding conveyance carriage and the following conveyance carriage, V ₁ : preceding conveyance carriage speed, V ₂ : subsequent conveyance carriage speed, α ₁ : preceding conveyance carriage acceleration / deceleration rate, α ₂ : subsequent conveyance. Cart acceleration / deceleration rate, dt: control delay, dL: transport cart position detection error] A transport control system for a transport cart when a plurality of transport carts travel on the same transport path,
A position detector provided on each of the transport carriages for detecting the position of each transport carriage;
A transmission device provided in each of the transport carriages for transmitting a signal of the detected position;
A receiving device for receiving the signal-transmitted position;
A first controller for determining a target travel position for each of the transport carriages;
A speed (V _SET) that is connected to the receiving device and the first controller, and is to be set to the transport carriage based on the travel position results received and accumulated from the receiver and the target travel position received from the first controller. ) Is calculated, a speed limit (V _LIMIT ) is calculated from the following formula (2) when the transport carriage is a subsequent transport carriage, and the speed of the transport carriage is set to the speed to be set (V _SET ) and the A travel control system comprising: a second controller that controls the transport carriage so as to be a smaller value of the speed limit (V _LIMIT ).
V _LIMIT = (− dt + √ ((dt) ² + 2 × (L + V ₁ ² / (2 × α ₁ ) −dL) / α ₂ )) × α ₂ ... Formula (2)
[However, L: distance between the preceding conveyance carriage and the following conveyance carriage, V ₁ : preceding conveyance carriage speed, V ₂ : subsequent conveyance carriage speed, α ₁ : preceding conveyance carriage acceleration / deceleration rate, α ₂ : subsequent conveyance. Cart acceleration / deceleration rate, dt: control delay, dL: transport cart position detection error]

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