JPS6052492A - Method of controlling travelling of moving body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a traveling control method for a moving object.

[Background of the invention]

As devices for controlling the movement of moving objects, those having positioning guidance means such as electromagnetic induction type, tape optical type, capacitance type, and ultrasonic type are known (Magazine ``Sensor Technology J1
January 982 issue etc. ).

The moving body described here is a mechanical equipment (such as a transfer crane) that has left and right running wheels and a running motor for driving each of the running wheels, and that moves vertically and horizontally by driving the motors to rotate. say.

Now, in the past, of the above-mentioned methods, the electromagnetic induction method has been the most commonly used.This method involves embedding electric wires on the road surface along the travel direction in order to move a moving object on a designated travel path. The magnetic field strength emitted from this electric wire is captured by an antenna installed on the moving object to detect the magnetic field strength on both the left and right sides in the direction of travel. The left and right motors are controlled in such a way that the left and right magnetic field strengths are equalized.

In other words, the moving object is guided in a direction in which the center of the moving object is located at the buried electric wire. Therefore, the mobile object is
It will move on the running course.

However, such conventional methods not only require construction work to bury the electric wires in the road surface, but also have problems such as the road surface where the burying work is carried out cracks under the load of the moving object.
Further, each time the running route is changed, it is necessary to bury the electric wires, which makes it difficult to change the running route.

Therefore, the following method was devised to easily guide the positioning of a moving object. In other words, instead of using conventional electric wires, we construct road markings by painting white paint on the road surface or pasting viscoelastic thin film material on the road surface.In addition, we use imaging technology that inputs road markings as images instead of antennas. This is a method in which a device is installed, the input image is processed, and automatic positioning guidance is performed by mark recognition.

However, in the case of this method, the image of road marks affixed to the running road is input, the input image is subjected to image processing calculations to determine the state quantity, and the control for moving the crane on the running road is performed from this state quantity. Since the amount (operation signal) is calculated directly and the rotational speed of the traveling motor is controlled thereby, there is a problem in that the calculation processing time increases. An increase in calculation processing time leads to a deterioration in control responsiveness from detection to actual control, and when a moving object is driven at high speed, the problem arises that the moving object becomes thick (deviates from the traveling path). .

Therefore, this method has a problem in that the moving speed of the moving body cannot be increased as compared to the electromagnetic induction method, and the cargo handling efficiency is significantly reduced.

[Purpose of the invention]

The object of the present invention is to attach road markings to the running path of the road surface,
In a travel control method for a moving object that captures an image of the mark, inputs the image, and performs image calculation processing to perform automatic positioning guidance, the calculation processing speed is increased to enable faster operation. It is an object of the present invention to provide a method for controlling running of the body.

[Summary of the invention]

The present invention inputs images of a plurality of road marks placed on a running road using an imaging device mounted on a moving object, processes the images, and calculates the trajectory correction amount and attitude angle of the moving object with respect to the running path.
Based on the amount of movement and the amount of trajectory correction and attitude angle among these signals, the number of rotations of the left and right travel motors is determined by referring to a table, and the rotation is calculated based on the time differential value of the amount of trajectory deviation and the time differential amount of the attitude angle. The present invention is characterized in that an operation signal is set based on the set number of rotations and the switching control time, and the speeds of the left and right traveling motors are controlled in accordance with this signal.

[Embodiments of the invention]

Hereinafter, an example in which the present invention is applied to a transfer crane (a type of moving body) in a yard system will be described in detail using the drawings.

First, the yard system will be explained using FIG. Normally, in the yard system, the container crane 4 carries the container 1 from the ship 3 shown in FIG. The system is such that cargo is handled and transported and stacked in Yard 2.

Next, the configuration of the transf 1 crane 6 will be explained with reference to FIG. 2. The transf1 crane (hereinafter simply referred to as a crane) 6 has a girder 9 on which a trolley 8 runs, both legs 10 that support the girder 9, and a running equipment fill that supports both m10.
a, 11b, and running wheels 13g, 13b, 13c rotatably attached to this running device.
, 13d. The running wheels 13a to 13d run by receiving rotational driving force from the running motors 12a and 12b. The traveling motors 12g, 12b are mounted on the traveling equipment [11a, 11b] on both sides. The traveling motors 12a, 12b transmit rotational driving force through a reduction gear that decelerates their rotation, and a chain sprocket type power transmission device that connects the rotational output shaft of the reduction gear and the running wheels 13a, 13b. Transmit to the ring. Reference numeral 14 denotes a road mark placed on the road surface. 15a and 15b are running! ! This is an imaging device that is attached to the side of the TFL 11a and ILB, and inputs the road mark 14 as an image, converts it into an electric signal, and outputs it. 16a and 16b indicate input areas (subject areas) of the imaging devices 15a and 15b. 1' is a lifting IItWl for lifting the container 1.

Next, the traveling control section of the crane will be explained using FIG. 3. The travel control section is actually mounted on the crane, but is not shown in FIG. As shown in FIG. 3, the configuration of the travel control section includes an image detector section, a controller I, a data memory column, a travel control program memory 4, an interface (material), and a control amplifier 31a.
, 31b, and traveling motors 12a, 12b. In FIG. A current is generated on the circuit by projecting the light onto the photodiode and exciting the photodiodes arranged in a matrix, and after converting the current into a voltage by applying a load resistance, the preamplifier amplifies the voltage. . Of course, the Imaging 1i 5115 m does not necessarily have such a configuration, and may be a known imaging device (such as ITV).
is sufficient. The image detector n is this imaging device 115a.
, an A/D converter that converts the analog signal amplified by the preamplifier 21 into a binary digital signal, an image memory that stores the converted signal, and an image WgI.
It is composed of an image processing device j2B that performs image processing calculations on the contents of the image memory according to the ll algorithm, and a program memory 5 that stores a program for image processing calculations.

This image processing operation will be explained in detail later. Orbit deviation amount (y) which is the calculation result obtained by image processing calculation
, attitude angle (ψ), and movement amount (x) are input to controller I. Controller I inputs this orbit deviation amount (y), attitude angle (ψ
), travel distance (x), and other travel conditions are stored in a data memory column, and the left and right travel motors 12m and 12b are controlled based on instructions from program memory 4, which stores a program for executing travel control algorithms. The rotation speed and switching control time are calculated and a combined signal of these is output as a motor control signal. The control signals for the left and right travel motors are supplied to the left and right control amplifiers 31a and 31b via an interface, respectively, to control the travel motors 12a and 12b, respectively. The control algorithm in controller n will be explained in detail later.

Now, the above-mentioned orbital deviation fi(y)32. Attitude angle (ψ)
The amount of movement (x) 34 is shown as shown in FIG. In addition, each travel motor 12a is operated based on the travel operation of the crane 60.
, 12b (control signals) are provided in two tables as shown in FIGS. 5 and 6.

Calculated from okara. That is, several driving patterns (patterns A to E in this example) are prepared in advance according to the driving conditions, one pattern is first selected according to the driving condition, and then when driving in that pattern, What to do with the motor is determined based on the time differential amount of the attitude angle (ψ) and the time differential amount of the orbit deviation (y), and finally the control amount is determined. How to specifically determine the control amount from the two tape lures 36 will be described next. In FIG. 5, the orbit deviation jl(y) is plotted along the horizontal axis, and the attitude angle (?) is plotted along the vertical axis, and these are expressed in a two-dimensional matrix. Here, five running modes A to E are set depending on the combination of the size of y and 9. In Fig. 5, the amount of track deviation (y) with respect to the road surface marking mark 14 on the running route is '& (+) on the right side, 1- (1-) on the left side.
In addition, the attitude angle (ψ) 33 indicates a rightward inclination (+) and a leftward inclination (-). In addition, the allowable orbit deviation amount is Fs, y
1'6, and the allowable attitude angles ψ,, ψ,' are set. Therefore, according to the table shown in FIG. 5, if the magnitude of the orbital deviation amount (y) and the magnitude of the attitude angle (ψ) are known, it is possible to select a travel mode commensurate with them. Next, the switching control time for the rotation speed of each travel motor is
This can be determined using a table as shown in FIG. In FIG. 6, four time i allocation modes are set based on combinations where the horizontal axis represents the value of the amount of trajectory deviation (y). Therefore, the nail, d! I!
Depending on the value of dt di - acceleration time TI and deceleration time T during period T
, (duty ratio) can be controlled, and FIG. 7 clearly shows that the control signals can be determined using the two tables shown in FIGS. 5 and 6.

In FIG. 7, running shades A-E are determined according to the running state, which is the output of the image detector. Therefore, for example, in the D mode (the traveling state Y of the crane 6 shown in FIG.
,＜)' ＜Y＊ ＊ψ〈ψ. In the case of (D mode), the rotation speed ω of the left travel motor 12a in FIG. 1 is set to be larger than the rotation speed ω of the right travel motor 12+). In other words, it can be said that the mode in which ω1>ω2 is controlled is the D shade. A description of the other modes will be omitted, but this can be understood from FIG.

Next, the image processing calculation operation of the image detector n and the control operation of the controller n in FIG. 3 described above will be explained.

! @8 Figure (A) is an operation flowchart showing the image processing calculation operation, which will be explained as follows.

First, when the power is turned on for the first time, initial settings are automatically made in step (a).

Thereafter, the operations of steps (L,) to (j) shown in the figure are executed.

Step (b)... The image of the road mark 14 is input, converted into a binary digital signal, and the signal is stored in the image memory. Specifically, the analog image signal generated by the image projected onto the solid-state image sensor 18 through the lens 17 in FIG. Thereafter, the digital signals are sequentially stored in an image memory column. Then, using this accumulated data, the digital signals are binarized,
Store it in the image memory column again. Here, the binarization process uses the difference in brightness between the road surface and the mark 14 on the road surface,
Based on the threshold value set in 1+JI, a conversion process is performed in which the road surface signal that is below the threshold value is set to a 10" level, and the road surface marking mark 140 number that is above the threshold value is set to a 11" level. be.

Step (C)... Calculate the number of 11# (g) from the binary signal stored in the image memory to determine whether the road mark 14 is actually detected. If it is determined that the data is not detected (the number of 11" is less than the expected number), an invalid code indicating that the data is invalid is output and the process jumps to step (b) again. If the data is normal ( If the mark 14 has been detected), the process advances to the next step (d).

Step, Pu (d)... Binarized @1", 00
After performing feature extraction processing of the four corner edge signals of the road mark 14 image from the signals of 2, their two-dimensional address (XIr ylL (X1+ Y
Calculate sL and (x4・ya), and use those addresses (1) The center address (No') of the road mark 14 image
e y6') is calculated.

Step (e)... Determine that the center address determined in step (d) is tilted to the left, that is, in the case of FIG. 4.

Step (f)...The address (xl, y6) set in the program memory 5 is subtracted from the center address (Xo'+Y@') calculated in step (d).
Step (g) to calculate the orbital deviation amount y...Two-point address calculated in step (a) (XIr Yl) + (Xsy ys)
Using this, the attitude angle ψ (=tan-'-"-") is calculated.

X, -X□ Step (h)...Add the number of marks 14 input one after another from the time of startup to calculate the mark position [X,
Step (i)...The calculated y, ψ, and X are output (transmitted) to a controller n for controlling travel.

Step (j): Check whether step (i) has been performed reliably. If OK, return to step (b) and repeat the process from step (b).

Part 8 (B) is a flowchart showing the travel control operation of controller n, which will be explained as follows.

Step (person): When the operator presses the power switch to turn on the power, the internal circuit is automatically initialized. For example, it may clear all data in the data memory or set the starting address of the travel control program stored in the program memory.

Step (B)...... Command from outside (for example,
In the case where the travel distance of the crane 6 is determined by an operator's manual command or a data command via a communication device, the additional number of road marks 14 during the travel is set. In other words, the crane 6 is positioned in the traveling direction by counting (adding) the number of marks, and then calculating the number of traveling stops x
It is a relative address format in which it is successively compared with 0 and when the difference becomes zero, it is recognized that the planned position has been reached.

Steps (C), (D)...Receive state quantity signals such as orbit deviation amount y, attitude angle ψ, and mark position rflX transmitted from image detector n, and detect errors therein. Check and store in the data memory section □ Steps (E), (F)...The state quantity signals of the orbit deviation amount y and attitude angle ψ before the crane travels are within the allowable values yl, ψ. If not, in step (F), an acceleration command pattern is given to each of the left and right travel motors 12a and 12b, and the attitude correction operation of the vehicle body is performed during the track deviation with respect to the travel path, and the crane 6 is controlled to be positioned on the travel path. do.

Steps (G), (H)... A predetermined running pattern table based on y and ψ of the state quantity signals (stored in the data memo 928) manually input and stored in step (D) The corresponding running pattern is determined from (the table shown in FIG. 5). Then, the number of rotations of each of the left and right travel motors that match this travel pattern is determined.

Steps (I), (J)...Step (1))
Of the state quantity signals obtained in , y and ψ are time-differentiated, respectively, and dy/dt and d(p/dt are calculated. Based on these time-differentiated values, refer to the table shown in Figure 6. Then, the switching control time T for the number of rotations of the left and right traveling motors 12a and 12b determined in steps (G) and (H),
, T, is determined.

Step (K)...The rotation speed ω1 of the left and right travel motors determined in the above step. ω1 and its switching control time T, , T, are set, and an operation signal combining them is sent to the control amplifier 31a,
31b. Control amplifier 31a.

31b takes in this signal, amplifies it operationally, and controls the speed of the travel motors 12a, 12b.

Steps (L), (M)... Set position lu
For x, it is determined whether the crane 6 has actually reached the position, and if it has not reached the position, step (
Return to step C) and repeat steps (C) to (K). When it reaches the limit, a deceleration command to the traveling motor is output in the form of a pattern.

As a result, the crane 6 moves to the planned position,
Stop. When moving to the next position after stopping,
Return to step (B), number of travel stops for the next position
Set a and perform the operations from steps (C) to (M).

Next, a correction control method based on changes in traveling track deviation in the above-described embodiment of the present invention and how to give commands from the controller at the initial stage of operation will be explained with reference to FIGS. 9 and 10.

First, in FIG. 9, when a suitable operating signal is given to the control amplifiers 31a, 31b in the form of voltage from the controller n, the control amplifiers 31g, 31b operationally amplify this and send the output current to the traveling motors 12a, 12b. give. As a result, the rotational speeds of the traveling motors 12a, 12b are adjusted, the rotational speeds of the left and right traveling wheels 13a, 13b are changed, and the crane 6 moves at the planned speed on the traveling path.

During the movement process, when the trajectory deviation and attitude of the vehicle body change with respect to the running path (marked), the trajectory deviation amount y, attitude angle ψ, and movement amount X are detected by the single image detector n.
These are given to controller n. controller n
uses the detected state quantity signals (y, ψ, and As a result, the crane can be controlled so that the left and right meandering motion associated with its travel is within a certain range, and can be stopped at a predetermined position.

Figure 1θ shows the operation signal (
This figure shows an example of the control amplifier input signal. In this example, at the initial stage of travel and during positioning, a slow operation period ts4 It r is applied to each of the left and right travel motors.
tsZ tX is provided. At the beginning of the run,
When the crane body deviates significantly from the traveling path, the controller n gives an initial command, and the time ji+h' required for y, ψ, etc. to fall below permissible values is set as nt+ for slowing down.

In addition, at the end of travel (positioning stop), h+ is monitored for a period sufficient to stop the crane at the planned position.
is the running period.

〔Effect of the invention〕

As explained in detail above, according to the present invention, the calculation of the operation signal is uniquely determined by the running state quantity,
This results in extremely high-speed calculations, making it possible to achieve stable travel control even when moving objects are driven at high speeds.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a yard system, Fig. 2 is a perspective view of a transfer crane, Fig. 3 is a system block diagram showing an embodiment of the present invention, and Fig. 4 is a diagram showing the running state of the transfer crane. Figure 1J5 is for explaining the embodiment of Fig. 3 and is a diagram showing a table for determining the running mode, and Fig. 6 is for explaining the embodiment of Fig. 3, showing the amount of trajectory deviation and attitude. FIG. 7 is a diagram showing a table for determining the motor speed switching time from the time differential value of the angle, and FIG. A) and Figure 8 (B
) is an operation flowchart showing the operation of the embodiment shown in FIG. 3, FIG. 9 is a block diagram for explaining the method of controlling the steering 2 positioning, and FIG. It is a figure showing an example (signal). 6...Transfer crane, 12a, 12t
)...Travel motor, 13a-13d...
・Running wheel, 14...Road mark, 15@, 15
b... Imaging device, 22... Image detector, I... Controller, 31a, 31b...
...control amplifier, proverb...orbit deviation amount,...
...attitude angle, movement distance, travel mode table, ah...switching control time table % correction...travel motor operation amount table Agent Patent Attorney Akio Takahashi (Figure 1'4 Figure 1'6 Figure 8 (A) Age δ7 (B) Age (Figure 1)

Claims (1)

[Claims] 1. In a device that controls the running of a moving object that has running wheels on both the left and right sides and has left and right running motors that drive the running wheels, a road mark is attached to the running road and an imaging device that uses the road mark is used. image is inputted through the computer, and the input image is subjected to image calculation processing to determine the amount of trajectory deviation, attitude angle, and amount of movement of the moving body, and further, the time differential value of the amount of trajectory deviation and the time derivative of the attitude angle. calculate an operation signal for controlling the left and right traveling motors by referring to a table from the orbit deviation amount, the attitude angle, the time differential value of the trajectory deviation amount, and the time differential value of the attitude angle; A traveling control method for a moving object, comprising controlling the left and right traveling motors in accordance with the operation signal.