JPH0649524B2 - Traveling control method for moving body - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling control method for a moving body, and in particular, two traveling bodies equipped with a collision prevention device travel on substantially the same traveling path. The present invention relates to a method of controlling a moving body suitable for optimizing a traveling pattern of the moving body in the case.

[Conventional technology]

There are, for example, a ceiling crane in a factory, a stacker crane in an automated warehouse, and an unmanned carrier truck that travels on the ground, as the two traveling bodies substantially traveling on one traveling path.

In the case of an overhead crane, a driver rides on each overhead crane, runs his / her own overhead crane so as not to collide with the other crane, and handles cargo.

In the case of stacker cranes in automated warehouses, unmanned operation is performed, so the position of each stacker crane is determined by the ground control device, and each crane is instructed of the travelable position so that it will travel without collisions and cargo handling will be performed. I am trying. (Japanese Patent Laid-Open No. 59-48305) As described above, a running command is provided manually or automatically so that the two moving bodies do not collide, but if the command error is a malfunction of the control circuit, there is a risk of collision.

For this reason, a collision prevention device is provided that monitors the distance between the two moving bodies and stops the traveling when the distance becomes a predetermined distance or less.

There are various types of collision prevention devices.

An example of utilizing light rays is disclosed in Japanese Patent Publication No. 57-237. One of them is a projector that emits a beam of light and a receiver that receives the light are attached to each crane at a slight inclination with respect to the traveling direction of the crane. When the light from the projector is received by the light receiver of the other crane due to the reduction in the distance between the two cranes, the traveling of the crane is stopped. The other is to install a light emitter and a light receiver in the traveling direction of the crane. When the distance between the two cranes is more than a predetermined distance, the light receiver is receiving light. The device stops receiving light and stops traveling.

Further, as a wired type, there is one disclosed in Japanese Patent Publication No. Sho 55-316. In this system, two induction wires are laid along the traveling path of the crane, and each crane is provided with a transmitting antenna and a receiving antenna to emit different frequencies. The transmission / reception antenna is inductively coupled to the induction wire. When the two cranes approach each other within a predetermined distance or less, the other party's transmitted waves are received to detect the distance, and if the distance is less than or equal to the predetermined distance, an alarm is output.

The one disclosed in Japanese Examined Patent Publication No. 59-40748 uses a microwave having a high rectilinear traveling property as a distance detecting means.

[Problems to be solved by the invention]

In the above-mentioned conventional technique, when the distance is within a predetermined distance, an alarm signal is output to perform a stop operation to prevent a collision.

If the distance increases during deceleration due to the stop operation, the alarm signal is released and the stop operation is released.

In this case, we want to drive at the target position at high speed to improve cargo handling efficiency.

However, the technique for this purpose is not shown in the above-mentioned prior art.

An object of the present invention is to enable landing at a target position in a short time when the alarm signal is released during deceleration by the alarm signal.

[Means for solving problems]

The present invention finds a virtual traveling start point when the warning signal is released from the speed and position when the warning signal from the collision prevention device is released, and accelerates traveling based on the distance between this point and the target position. It is characterized in that an optimum traveling pattern including the above is created and the speed of the moving body is controlled based on this pattern.

[Work]

The virtual travel start point is obtained from this point so that when the vehicle is moved at a constant acceleration with an initial speed of zero, the moving body has the current speed at the current position. With this, the traveling speed pattern of the moving body can be newly obtained between the obtained virtual traveling start point and the traveling target position, regardless of the position of the actual traveling start point.
The traveling speed of the moving body can be accelerated according to the newly obtained traveling speed pattern. Therefore, even if the collision warning signal is output at the initial stage of acceleration and is released immediately after the collision warning signal is output, it is possible to shift to the acceleration operation as described above, and thus it is possible to prevent a significant increase in traveling time.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. This embodiment is applied to a stacker crane of an automated warehouse.

FIG. 1 shows an example of an automatic warehouse in which two stacker cranes 1A and 1B are traveling on one traveling rail 2. Shelf groups 5 and 5 each having a large number of shelves are provided on both sides of the traveling path. Loading / unloading port 6A for stacker crane 1A
Is on one end side in the traveling direction, and the loading / unloading port 6B for the stacker crane 1B is on the other end side.

The stacker cranes 1A and 1B are instructed by a higher-level controller 8 installed on the ground side, such as a target position and contents of loading and unloading.

The stacker cranes 1A and 1B are equipped with a rangefinder for detecting the position of the end of the traveling path from the origin, and the value is output to the control device 8. The control device 8 recognizes the distance between the two stacker cranes 1A and 1B based on the value of each distance meter. The origin of the stacker crane 1A is one end 2 of the road.
A, and the origin of the stacker crane 1B is at the other end 2B of the traveling path. Since the distance between the two origins is known in advance, the distance between the two stacker cranes 1A and 1B can be recognized.

The detector of the rangefinder is a pulse encoder that outputs a pulse by rolling the rail 2. The distance can be measured by counting the pulses.

The stacker cranes 1A and 1B are equipped with collision prevention devices 10A and 10B, respectively, for preventing collisions.

The structure of the collision prevention devices 10A and 10B will be described with reference to FIGS. FIG. 2 shows the structure of the collision prevention device 10A of one stacker crane 1A, and FIG. 3 shows the structure of the collision prevention device 10B of the other stacker crane 1B. As can be seen from this figure, two collision prevention devices 10
The configurations of A and 10B are the same. The structure of one of the stacker cranes 1A will be described with reference to FIG.

The collision prevention device 10A includes a light projector 20 that horizontally emits a beam of light toward the stacker crane 1B of the other party, and a light receiver (semiconductor position detector) 30 that receives reflected light from the stacker crane 1B of the other party. A collision prevention detection circuit 40 which inputs the data of the light receiver 30 and the signal of the traveling control device 90 and outputs an alarm signal ALM to the control device 90 when there is a risk of collision.

The light projector 20, the light receiver 30, the detection circuit 40, and the control device 90 are installed in the stacker crane 1A of its own.

The control device 50 outputs the current traveling speed VD of its own stacker crane and its traveling direction VF (that is, a signal indicating whether or not it is traveling toward its own origin 2A) to the detection circuit 40. The traveling speed VD of the vehicle is detected by the control device 90 based on the output of the pulse encoder in order to drive the vehicle at the target speed. The traveling direction VF is obtained from the output of the pulse encoder, or a command from the host controller 8 is used. The controller 90 activates the brake by the alarm signal ALM to start the stop operation. The control device controls the traveling motor and the like.

The projector 20 projects the light toward the frame or the like of the stacker crane 1B of the other party.

The light receiver 30 detects the position of the received light spot, and includes a lens 31 and a semiconductor position detection element 32.

There is a distance Y between the lens 31 and the projector 20.

If the opponent stacker crane 1B is at the position 1B ₁ , the reflected light is imaged (received) at the position B11 of the detection element 32 through the lens 31, and if it is at the position 1B ₂ , the reflected light is at the position B12. Enter the position. The detection circuit 40 detects in which position of the detection element 32 the light is received.

Since the distance Y between the lens 31 and the light projector 20 and the distance between the lens 31 and the detection element 32 are known, the light receiving angle of the reflected light can be obtained by detecting the light receiving position. Therefore, the distance between the two stacker cranes 1A and 1B is determined. Can be obtained (hereinafter, referred to as a relative distance) LS. That is, the relative distance LS with the stacker crane 1B of the other party can be measured by the principle of triangulation.

The detection element 32 has two output terminals A and B, and their values are determined by the light receiving position. The value of the output terminal A is divided by the sum of the output of the output terminal A and the output of B (A / (A
+ B)), the distance LS 'from the output terminal B to the light receiving position can be obtained. This determines the angle of incidence and then the relative distance LS between the two stacker cranes.

Techniques for obtaining such a light receiver 30 and a light receiving position are known. Generally, such a rangefinder is called a semiconductor position detector.

The configuration of the control device 40 will be described with reference to FIG. The two outputs A and B of the detection element 32 are amplified by the amplifiers 41 and 42, and an analog / digital converter (referred to as an A / D converter)
Digital signals 43a and 44a are generated at 43 and 44.

50 is a microcomputer, digital signal 4
Random access memory (RAM) 51 for storing 3a, 44a, etc., read only memory (ROM) 52 for storing reference information for collision prevention, and RO
A central processor unit (C that controls data of RAM51 according to the information of M52 and controls each device)
PU) 53 etc. Reference numeral 54 is a clock pulse generation circuit. Reference numeral 55 denotes an input / output interface, which inputs the traveling speed VD and the traveling direction VF from the traveling control device 90,
When there is a risk of collision, an alarm output ALM is output to the traveling control device 90. Reference numeral 58 is a control device for the projector 20. The traveling control device 90 is also composed of a microcomputer.

In this way, each of the collision preventing devices 10A and 10B obtains the relative distance LS with the stacker crane of the other party, and stops the stacker crane of its own when the distance is less than the predetermined distance.

In order to prevent the collision, it is necessary to obtain the traveling distance (that is, the stopping distance) when the stopping operation is started at the traveling speed. For this purpose, the traveling speed of the self and the traveling speed of the other stacker crane are required. Furthermore, each running direction is required.

Although it is possible to input the traveling speed and traveling direction of the other stacker crane via the host controller 8,
In the present embodiment, this is not adopted, and these are obtained by the temporal change of the relative distance LS. Further, the speed, the relative distance LS, and the alarm signal ALM obtained by the self are not notified to the other collision preventing device.

Each of the stacker cranes travels based on the command of the higher-level control device 8, and a command that does not cause a collision is issued. However, a delay of the command of the higher-level control device 8, a calculation error, or a travel control device A malfunction such as 90 is given. Therefore, in this embodiment, the collision prevention devices 10A and 10B are used as safety devices.

The collision prevention devices 10A and 10B determine the relative distance LS and stop the traveling when there is a risk of collision, but there is a case where it is not necessary to stop the traveling. Therefore, this will be described first.

FIG. 5 shows a combination of the traveling speed and traveling direction of the two stacker cranes. The direction of the arrow indicates the traveling direction, and the length of the arrow indicates the traveling speed. For example, in case No. 1 on the vertical axis, the two stacker cranes are traveling oppositely, and the traveling speed of the left stacker crane is higher than the traveling speed of the right stacker crane. Case No. 4 shows that two stacker cranes are traveling in the same direction. Case N
O.2 and 5 indicate that the traveling speeds of the two stacker cranes are the same. The black dots in Cases Nos. 3 and 7 indicate that the vehicle has stopped running.

In a on the abscissa, the left side shows the own stacker crane, and the right side shows the mating stacker crane. The horizontal axis b is opposite to the horizontal axis a.

In addition, in the figure, in the cases marked with X, a stop command (that is, an alarm signal ALM is output) is issued from the collision prevention device.
Is not output.

In addition, the code entered in the case with the X mark is the sixth
The step No. in the figure is shown. That is, it is the step NO. That decides to add the X mark.

The reason why the X mark is attached will be described below.

Regarding Case No. 3b and 7a. In this case, the stacker crane of its own is stopped. When the stacker crane is in the traveling stopped state, it is stopped by a command from the host controller 8 (this is called standby).
In some cases, the traveling is stopped by the operation of the collision prevention device.

It is convenient for the former to be able to travel for the next cargo handling. Therefore, in this case, the stop command is not output. Whether or not the vehicle is on standby can be recognized by the traveling control device 90.

The latter has been stopped by the operation of the collision prevention device, so it is necessary to continue the stopped state. However, if the distance from the stacker crane of the other party becomes large by continuing the stop, the traveling is started.

Case No. 4b, 5b, 6b, 7b, 8a, 8b. In this case, the own stacker crane is traveling on the side where the other stacker crane is not present, that is, the own stacker crane is traveling in the direction away from the other stacker crane. In this case, the stacker crane does not collide when the traveling is continued rather than stopping. Therefore, in this case, the stop command is not output.

Traveling to the side where the other stacker crane is not present means traveling to the right side in the case of the right stacker crane, and traveling to the left side in the case of the left stacker crane. This means that each stacker crane travels toward its own origin, as described in FIG. Therefore, the traveling direction of the stacker crane of its own can be determined by whether or not the traveling command is the origin direction. It can also be determined by determining whether or not the distance from the origin has increased.

Regarding Case 6a. This case is when the distance between the two stacker cranes is large. In this case, it is not necessary to stop the traveling of the own stacker crane. As a determination method in this case, in FIG. 6, in step S9, it is determined whether the relative speed VS obtained in step S7 is positive or negative.

Regarding Case 5a. In this case, the distance between the two stacker cranes does not change, that is, the two stacker cranes are traveling at a constant speed. As a determination method in this case, for example, in step S9 of FIG. 6, it can be determined whether the relative degree VS obtained in step S7 is zero or more. In the embodiment of FIG. 6, in order to improve the safety of collision prevention, the operation of the collision prevention device is not stopped in this case 5a.

Next, a normal traveling pattern of the stacker crane will be described with reference to FIG. When traveling to the target position, acceleration is performed with uniform acceleration (section I), constant speed traveling is performed (section II), deceleration is performed with uniform deceleration (section III), and constant speed traveling is performed at low speed (section IV). Finally, the brake is applied to stop. The traveling speed of the section II is determined by the distance LX from the traveling start point to the target position. Low-speed, constant-velocity traveling in section IV is called creep traveling. Thus, the traveling speed of the stacker crane differs depending on the distance LX and the section.

When the alarm signal ALM is used for deceleration during acceleration, as indicated by a broken line, the vehicle runs at a constant speed of P ₁ at which acceleration is stopped for T ₂ hours, and then decelerates. This is because if the deceleration operation immediately starts after acceleration, the load on the stacker crane is greatly affected. This time T ₂ is a short time. This time T ₂ is also secured when the alarm signal ALM is used to decelerate at the start of constant speed running.

Next, regarding the operation of the collision prevention devices 10A and 10B,
It will be described with reference to the drawings. The calculation of FIG. 6 is performed for each of the collision prevention devices 10A and 10B of the stacker cranes 1A and 1B. Both operations are the same, so one (ie,
Only the operation of the own stacker crane collision prevention device) will be described.

The activation of the flowchart of FIG. 6 is periodically performed by a timer interrupt.

First, the digital signal 43a of the output on the A side of the detection element 32
And the digital signal 44a on the B side are read to determine the relative distance LS between the two stacker cranes 1A and 1B.
(Step S1) This is performed as follows. The digital signals 43a, 44
The following equation is calculated using a, and the light receiving position of the detection element 32,
That is, the light receiving position LS 'from the output terminal B side is obtained.

The light receiving position LS 'can be obtained by another known calculation method.

If the light receiving position LS 'can be detected, the incident angle can be obtained, and the relative distance LS to the opponent stacker crane can be obtained. Since the relationship between the light receiving position LS 'and the relative distance LS is non-linear as shown in FIG. 9, using the table of the position LS' and the relative distance LS as shown in FIG.
The relative distance LS is obtained using the position LS 'as a parameter.
The relative distance LS is stored in the RAM 51.

Next, it is determined whether or not the vehicle is traveling toward the origin according to its own traveling direction VF given by the traveling control device 90. If the vehicle is traveling toward the origin, the process proceeds to step S33. (Step S3) If the vehicle is traveling toward the opponent, the following equation is calculated from the relative distance LS _-1 obtained in the previous processing and the relative distance LS obtained this time, and the relative speed VS to the opponent stacker crane is calculated. Ask. (Step S5) Here, T ₁ is the detection interval of the distance LS.

Next, it is determined whether this relative speed VS is smaller than zero. If the relative speed VS is less than zero, it indicates that the stacker crane of the other party is separated at a higher speed than the stacker crane of its own (cases No. 6a, 7a).
(Step S7) Next, it is determined whether or not the own traveling speed VD is zero. If it is not zero (Case No. 7a),
Then, the process proceeds to step S33. (Step S9) If the own traveling speed VD is zero in step S9 (case No. 7a), the relative speed VS is set to the traveling speed VE of the opponent in step S10. Opponent's running speed V
F has a negative value. This is because even if the traveling is stopped by the collision prevention device, the stopped state is released if the margin distance LK with the opponent becomes large. The margin distance LK is calculated in step S21.

In step S7, when the relative speed VS is equal to or greater than zero, the traveling speed VE of the opponent stacker crane is calculated using the following equation. (Step S11) VE = | VS | −VD (3) Here, VD is the own traveling speed VD input from the traveling control device 90 and is positive.

Next, if you give a deceleration command to prevent collision,
The travel distance (LD, LE) to the stop is expressed by equation (4), (5)
It is determined for each stacker crane 1A, 1B by the formula. (Steps S13, S15) Here, LD: Distance traveled until the stacker crane of its own stops LE: Distance traveled until the stacker crane of the other party βD: Deceleration of the own stacker crane βE: Deceleration of the other stacker crane Note that during acceleration When a stop command is given, Fig. 15 (A)
Since there is constant speed running for T ₂ hours, the actual stop distance L
D and LE are larger than the values of the expressions (4) and (5).
That is, (T ₂ · VD), (T ₂
The value of (VE) will be added respectively.

In the flowchart of FIG. 6, steps S23 and S
The prescribed distances K1 and K2 of 27 are the constant speed travel distance (T ₂ ·
VD) and (T ₂ VE) are set as constant values.

According to this, since it becomes inaccurate, it is possible to determine whether or not the self and the opponent are accelerating by the collision prevention device, and to add the constant speed travel distance to the stop distances LD and LE.

Next, the traveling direction of the other stacker crane is determined.
This is determined by whether or not the traveling speed VE of the opponent is zero or more. (Step S17) When the traveling speed VE of the opponent is zero or more, the two stacker cranes are traveling in opposition (case No. 1a,
1b, 2a, 2b, 3a), the formula (6) is calculated. (Step S19) When the traveling speed VE of the opponent is less than zero, two stacker cranes are traveling in the same direction (case N
O.4a, 5a), and formula (7) is calculated. (Step S21) LK = LS- (LD + LE) (6) LK = LS- (LD-LE) (7) As shown in FIG. 11, when the stop operation is started at the relative distance LS, stop The distance between the two stacker cranes is called the extra distance LK.

Then, it is judged whether or not this margin distance LK is equal to or greater than the specified values K1 and K2.
LM1 and ALM2 are output and the stop operation is commanded. (Steps S23, S25, S27, S29) The specified values K1 and K2 are measurement errors such as the relative distance LS,
It is determined in order to prevent a collision in consideration of the above-mentioned constant speed traveling distance, traveling distance until the next detection, stop error, positions of the light receiver 30 and the reflecting portion, and the like.

K1 <K2.

The deceleration of the alarm signal ALM1 is larger than that of the alarm signal ALM2. In the case of the alarm signal ALM1, the traveling control device 90 sets the speed command to zero and activates the mechanical brake. In the case of the alarm signal ALM2, the traveling control device 90 activates the electric brake used for the normal stop operation. Deceleration βD, β
E is the case of the alarm signal ALM2. Deceleration βD, βE
Is the same as the deceleration in the deceleration control section in FIG. When the margin distance LK is small, the alarm signal ALM1 is output.

Even when the stop operation is started by the alarm signals ALM1 and ALM2, the flowchart of FIG. 6 is executed at predetermined time intervals. Therefore, if the allowance distance LK becomes larger than the specified value K2 due to its own stop operation, the alarm signals ALM1, A
Release LM2. (Steps S27, S31) The operation when the alarm signals ALM1, ALM2 are released will be described later.

Finally, the current relative distance LS is transferred to the storage area of the previous relative distance LS ₋₁ of the RAM 31. (Step S3
3) The flowchart of FIG. 7 shows the alarm signals ALM1 and ALM.
2 shows the operation of the traveling control device 90 to which 2 is input.

When the alarm signals ALM1 and ALM2 are input, it is determined whether or not the stacker crane of its own is on standby (stopping traveling while waiting for the next cargo handling command). When the vehicle is not on standby (running or stopped by the alarm signal ALM), the stop operation is executed based on the alarm signals ALM1 and ALM2. (Steps S41, S43) Next, if the own traveling speed VD is zero, addition for timekeeping is performed, it is determined whether the stop time by the alarm signal ALM has passed a predetermined time, and the predetermined time has passed. If so, the upper control device 8 is notified. (Steps S45, S47,
S49, S51) From two stacker cranes 1A, 1B to step S51
When there is a notification by the above, the higher-order computer 8 commands a manual operation or the like. This is a recovery means when the two stacker cranes are stopped by the operation of the collision prevention device in the cases 1a, 1b, 2a, 2b and the like.

The flowchart of FIG. 8 shows step S43 of FIG. First, it is determined whether or not the vehicle is accelerating. If the vehicle is accelerating, the current speed is maintained for T ₂ hours, and then the stop operation is started. (Steps S55, S57, S59, S59) On the other hand, if the vehicle is not accelerating, it is checked whether or not T ₂ time has elapsed after moving to constant speed running. (Step S63) T ₂
If the time has passed, the stop operation starts. If the time T ₂ has not elapsed, the constant speed running is continued for a short time and then the stop operation is started. (Steps S65, S67) As described above, when the relative distance between the two stacker cranes becomes a distance at which there is a risk of collision, the travel of the stacker crane, which may cause a collision due to travel, is stopped. In this case, since the relative distance LS and the traveling speed VE of the opponent are obtained by the own collision prevention device, the device sufficiently operates as a safety device. Then, since the distance LS to enter the stop operation changes depending on the own speed VD and the opponent's speed VE, it is possible to drive the vehicle at a higher speed and expand the range in which the vehicle can travel at a higher speed.

Also, when the stacker crane of own is traveling on the side where the other party is not present, or when it is on standby, it does not enter into the alarm action, so it is more safe and can prevent the decline of the high cargo handling ratio. Is.

Although the above has described the effect as the safety device, the present invention is also effective in improving the cargo handling efficiency. as mentioned above,
Since the distance to enter the stop operation is determined according to the speed of the two stacker cranes, the two stacker cranes can be brought closer to each other at a low speed, and the efficiency of cargo handling can be improved.

For example, in FIG. 11, point XA is the target point for loading the left stacker crane 1A, and point XB is the target point for loading the right stacker crane 1A. In this case, if the distance between XA and XB is low and the collision prevention device does not operate, the two stacker cranes 1A and 1B are simultaneously moved to their respective target points X.
It can be driven to A and XB. Therefore, the cargo handling efficiency can be improved.

On the other hand, a case where the distance between XA and XB is the distance at which the collision prevention device operates will be described. In this case, the cargo handling work of the stacker crane 1B is prioritized. The stacker crane 1A waits at the XA ₁ point, but this position can be made a short distance from the XB point. Then, when the stacker crane 1B starts traveling to the right side from the point XB, the traveling of the stacker crane 1A can be directly started.

Thus, the two stacker cranes can be brought close to each other without operating the collision prevention device, and the cargo handling efficiency can be improved. The running command is given by the control device 8 on the ground side.

In the above embodiment, it is possible not to measure the relative distance when the vehicle is traveling toward the origin and when the vehicle is on standby.

The higher the traveling speed of the mobile bodies, the longer the distance between the mobile bodies to be measured. In the case of the above embodiment, when the distance becomes large, the incoming light of the reflected light from the other moving body becomes weaker,
It becomes difficult to measure the distance.

The embodiment of FIG. 12 is made in view of this point. FIG. 12 shows a means for obtaining the speed of the moving body B in the moving body A. In order to obtain the speed of the moving body A in the moving body B, the moving body A and the moving body B in FIG. 12 are referred to as the moving body B and the moving body A, respectively.

In FIG. 12, the projector 2 of the moving body A is attached to the moving body B.
The light receiver 110 is provided at the same height as 0. In addition, the moving body B
Is a wide-angle projector 120 that obliquely projects light toward the moving body A.
To provide. The wide-angle projector 120 emits light with a wide directivity angle, and can be regarded as a point light source from the light receiver 30 of the moving body A. Such a wide-angle projector 120 is known. The light receiver 110 may be any one that can detect the presence or absence of light from the light projector 20. Emitter 20, light receiver 11
0, the wide-angle projector 120, and the light receiver 30 are installed at positions where triangulation is possible. Projector 20 and wide-angle projector 120
The size of the light source is that it can receive light sufficiently even at a large distance.

The light projector 20 projects light at predetermined intervals according to a command from the detection circuit 40. The light receiver 110 is provided to instruct the wide-angle light projector 120 to emit light only when light is received. Detection circuit 40,
Reference numeral 40 instructs the light projector 20 to emit light and processes only the data received by the light receiver 30 within a predetermined time (extremely short time) as valid data.

Since the wide-angle projector 120 is provided in the moving body B in this way, the distance can be measured in the moving body A even if the distance is large.

In addition, since the light emitted from the projector 20 of the mobile unit A is intermittently emitted and the data received by the light receiver 30 within the predetermined time is used as valid data, it is possible to prevent malfunction by receiving other light sources. is there.

Although light is used to determine the distance in the above embodiment, microwaves may be used.

FIG. 13 is a configuration diagram when a microwave is used. The signal modulated by the oscillator 134 is emitted as a microwave from the antenna 132, reflected by the reflector 131 provided on the other moving body, and enters the antenna 132 again.

Here, a bead as shown in FIG. 14 is generated due to the time difference between the transmitted wave and the received wave.

In FIG. 14, solid line: transmitted wave broken line: received wave fo: center frequency fb: bead frequency fr: modulation frequency Tr: modulation period Δf: maximum frequency deviation Δt: time difference between transmitted wave and received wave b: average bead Frequency The average bead frequency is known to be directly proportional to the distance to the reflector. That is, Δt = 2R / C (10) where R: distance to reflector C: velocity of radio wave From FIG. 14, the following equation is obtained.

Phase correction circuit 135 and differential amplification circuit 1 for only the bead signal
Extract using 36. Since the obtained signal is a frequency, the F / V converter 137 is used to replace the frequency with an analog voltage. The output signal is further added to the A / D converter 13
8 is used to convert into a digital signal, and the signal is taken into the microcomputer 139.

In the microcomputer 139, the bead frequency is zero, that is, the A / D conversion output from the zero to the zero interval is zero.
The outputs are added and the total sum of the added values is divided by the measurement circuit. The result is the average bead frequency, which represents distance.

As described above, a known method other than this, for example, a Doppler method can be used for measuring the distance between the two moving bodies. Alternatively, it may be calculated by the host controller 8.

Next, the operation when the alarm signal is released will be described.

As shown by the broken line in FIG. 15 (A), when the alarm signal is output at P ₁ and the alarm signal is released at P ₂ during deceleration, the method of traveling to the target position will be examined. For example,
As indicated by the broken line, it is conceivable that the vehicle runs at the same speed as when the alarm signal was released. According to this, the traveling time is required to be significantly increased as compared with the case of the optimum traveling pattern indicated by the solid line. The same applies when an alarm signal is output during traveling at a constant speed and is released during deceleration.

As in cases No. 3a and 4a in FIG. 5, when the opponent is chasing the opponent, the traveling speed of the opponent increases during deceleration, and the distance to the destination position of the opponent is sufficient, such a problem occurs. Points are likely to occur.

This is because it is not possible to determine whether or not to accelerate the stacker crane when the collision warning is released.

The embodiment shown in FIG. 17 is for solving this problem. As shown in FIG. 15 (B), when the alarm signal is released at the point P ₂ , the vehicle is accelerated after traveling at a constant speed for T ₂ hours. That is, the virtual movement start point P ₀ at the speed of P ₃ points is obtained, the optimum traveling pattern is determined using the distance from the movement start point to the target position, and the speed control of the moving body is performed based on this pattern. It is a thing.

First, a general method for giving a speed command will be described with reference to FIGS. 15 (A) and 15 (C). This is known. Suppose there is no other stacker crane.

When the target position is input from the host controller 8 to the microcomputer of the traveling controller 90, the microcomputer causes the stacker crane to travel in the pattern shown by the solid line in FIG. 15 (A).

I: Acceleration control section In this section, the traveling control device 90 controls the speed command so that the stacker crane performs uniform acceleration traveling. (Step S71) Here, the speed command V is obtained by the following equation.

V = υ + α · T ₃ (21) where, ν: current traveling speed of the stacker crane α: acceleration T ₃ : unit time That is, the equation (21) is executed every time T ₃ , and the speed command V By updating and outputting the obtained value to a traveling drive device (not shown), the stacker crane is caused to perform uniform acceleration motion.

The uniform acceleration control is ended when the expression (22) or the expression (23) is satisfied. (Step S73, S74) LM ≒ (LX -LC-T 4 · υ) / 2 ... (22) υ = V max ...... (23) LM: traveling of the stacker crane from the travel start point to the current distance LX: traveling Distance from the start point to the target position LC: A constant value in the travel distance of the creep travel section IV T ₄ : A constant speed travel time in the constant speed travel section II, which is a value determined corresponding to the distance LX to the target position, I remember in advance.

υ: Current traveling speed V _max : Maximum traveling speed That is, from the distance LX to be traveled, the creep distance LC
And, when the actual traveling distance LM becomes substantially equal to the half of the distance excluding the constant speed traveling distance (T ₄ · υ), the acceleration operation is terminated. Of course, the maximum running speed V
_{When it reaches max} , it ends.

II: Constant speed control section In this section, the traveling control device 90 controls the speed command V so that the stacker crane performs constant speed traveling. (Step S75) Here, the speed command V is given by the following equation.

V = VI (24) where VI is the speed command value at the end of acceleration.

The constant speed control ends when the following formula is satisfied.

Where υ: current traveling speed β: deceleration LN: distance from the current position to the target position, that is, the speed command obtained by the position control method at the point where the distance to the target position is LN When the current running speed υ and the current running speed υ almost match, the constant speed control is ended. (Step S77) III: Deceleration control section In this section, the traveling control device 90 controls the speed command V so that the stacker crane performs uniform deceleration traveling. (Step S79) Here, the speed command V is obtained by the following equation.

V = υ−β · T ₃ (26) That is, the equation (25) is executed at each time T ₃ , the speed command V is updated, and the obtained value is output to the traveling drive device, thereby stacking the stacker. Move the crane to a constant speed.

The deceleration control ends when the following formula is satisfied. (Step S81) υ ≈ V _min (27) Here, V _min is the minimum traveling speed.

That is, when the stacker crane is decelerated to the minimum travel command V _min , the uniform deceleration control ends.

IV: Creep traveling section In this section, the traveling control device 90 causes the stacker crane to travel at the minimum speed V _min so that the speed command V =
_Apply V _min to the drive.

(Step S83) The creep traveling is ended when the position of the stacker crane almost reaches the traveling target point. (Step S8
5) Next, brake and stop. (Step S7
7) In this case, when there is a high possibility that the stop point will be ahead of the target position, the distance LX may be obtained by subtracting the traveling distance in step S87 from the distance LX.

Hereinafter, with respect to the setting of the optimum traveling pattern when the alarm signal ALM is released, FIG. 15 (B), (C),
This will be described with reference to FIG.

Now, the speed when the alarm signal ALM2 is output during the deceleration traveling and released during the deceleration is the same as the speed in the original deceleration control section, and neither constant speed operation nor acceleration operation should be performed.

Further, as shown by the curve Q1 in FIG. 15 (C), when the alarm signal is output during traveling at a constant speed and the release position of the alarm signal is within the original deceleration control section, the speed is the original deceleration control. It is slower than the speed in the section and can be accelerated. Here, since the original deceleration control section has a short distance, it will not be accelerated.

In FIG. 17, first, the case where the traveling speed υ is zero when the alarm signals ALM1 and ALM2 are released will be described.
(Step S101) In this case, the following equation is calculated and the value is used as the distance LX from the current position to the target position to update the previous distance LX. (Step S103) LX-LM (31) Here, LX is the previous traveling distance LX.

Then, the process proceeds to the acceleration control (step S51). (Step S105) If the vehicle is traveling when the alarm signal is released, the traveling speed at the time of release is set as the target speed. (Step S11
1) Then, the following formula is immediately calculated, and if the current position is within the creep travel distance, the creep control (step S63)
Move to. (Steps S113 and S115) LN ≦ LC (32) If the current position is ahead of the creep running section,
The following formula is calculated, and if the current point is the original deceleration control section, the process proceeds to constant velocity control (step S55). (Step S12
1, S123) LN ≦ LC + LG (33) Here, LG is a distance required for the original deceleration traveling, and is determined corresponding to the distance LX (that is, corresponding to the speed during constant speed traveling). It is a value that can be stored and is stored. The distance LG is set to prevent acceleration traveling when the alarm signal ALM2 is input during the deceleration traveling and canceled during the deceleration traveling.

In the constant speed control of step S55, it is determined in step S57 whether or not the vehicle should travel at constant speed.

If the current position is ahead of the deceleration control section, the virtual traveling start point P is calculated using the following equation with the current traveling speed υ as a reference.
_Ask for ₀ . (Step S131) Next, when a predetermined time T ₂ has elapsed since the constant speed traveling was started in step S111 (step S133), the distance LX from the traveling start point P ₀ to the target position is obtained by the following equation,
Update the previous distance LX. (Step S135) LX-LM + 1 (35) where LX is the previous distance LX.

Next, the process proceeds to step S73, and it is determined whether or not to accelerate according to the new distance LX. If the distance LX is large, the vehicle is accelerated.

According to the above-described embodiment, the virtual traveling start point is obtained based on the traveling speed when the warning signal is released, and the traveling pattern is determined based on the new distance LX from the traveling start point to the target point. If the distance LX is large, acceleration is performed and the vehicle can travel to the target position early.

If the alarm signal is canceled within the original deceleration control section, acceleration does not occur, but since the distance is small, there is no actual harm.

In the embodiment shown in FIG. 18, when the deceleration is canceled within the original decelerated travel section, it is determined whether or not the acceleration is performed at the speed υ. That is, step S
Instead of 121, the following formula is used. (Step S125) Here, VG is a permissible error value of the speed in the original decelerated traveling section. It is also provided to prevent unnecessary acceleration.

Then, instead of step S123, the vehicle is decelerated.
(Step S127) In the embodiment of FIGS. 17 and 18, it is a matter of course that the structure of the collision prevention device for outputting the alarm signal may be the same as the conventional one.

〔The invention's effect〕

According to the present invention, an alarm signal is output in the initial stage of the acceleration operation, and the alarm signal is released immediately after that, that is, even when the traveling speed of the moving body when the alarm signal is released is low,
A virtual traveling start point is obtained using the position and traveling speed at that point, and an optimal traveling speed pattern can be created between this virtual traveling start point and the target position. Therefore, the traveling time of the moving body can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram of an automated warehouse according to an embodiment of the present invention, FIG. 2 is a block diagram of a collision prevention device according to an embodiment of the present invention, and FIG. 3 is a collision prevention device according to an embodiment of the present invention. FIG. 4 is a configuration diagram of a collision prevention detection circuit according to an embodiment of the present invention, FIG. 5 is a diagram illustrating a combination of traveling speed and traveling direction of two stacker cranes, and FIG. FIG. 7 is a flowchart of a collision prevention device according to an embodiment of the invention, FIG. 7 is a flowchart of a traveling control device according to an embodiment of the present invention, and FIG. 8 is a flowchart of a traveling control device according to an embodiment of the present invention. FIG. 10 is a diagram showing the relationship between the light receiving position and the distance, FIG. 10 is a correction table of the light receiving position and the distance, FIG. 11 is an explanatory diagram when two stacker cranes are stopped, and FIG. FIG. 13 is a block diagram of a collision prevention device according to another embodiment of the present invention, and FIG. 13 is a distance measuring device according to another embodiment of the present invention. Diagram, FIG. 14 is a diagram for explaining the characteristics of microwaves, FIG. 15 (A), (B),
(C) is a travel pattern diagram, FIG. 16 is a flow chart of the travel control device, FIG. 17 is a flow chart of the travel control device of one embodiment of the present invention, and FIG. 18 is a travel of another embodiment of the present invention. 3 is a flowchart of a control device for a vehicle. 1A, 1B …… Stacker crane, 2A, 2B …… Origin, 8 …… Ground side control device, 10A, 10B …… Collision preventive device, 20 …… Emitter, 30 …… Receiver, 31 …… Semiconductor position detection Bowl, 40 ……
Collision prevention detection circuit, 90 ...... Running control device, 110 ......
Receiver, 120 …… Wide-angle projector, 132 …… Antenna

Claims (1)

[Claims] 1. A virtual traveling start point when the warning signal is released from the speed and position when the warning signal from the collision prevention device is released, and acceleration is performed based on the distance between this point and the target position. A travel control method for a mobile body, which comprises creating an optimum travel pattern including travel and controlling the speed of the mobile body based on this pattern.