JPH09267614A - Vehicle bogie connection detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the coupling condition of a carriage onto an automatic running vehicle automatically with a simple structure without need for installation of a sensor on a jointing part. SOLUTION: The absolute value |IL+IR| of the total of the driving current IL of the left driving motor of an automatic running vehicle for towing a carriage and the driving current IR of a right driving motor is larger than a threshold value It when either of a work loaded vehicle or a work unloaded vehicle is towed. When neither of the vehicles is towed, automatic detection of work attachment and detachment is conducted, utilizing that it is the value It or less. In the case of a vehicle which conducts speed feedback control, a carriage jointing condition may be discriminated by a driving current command value in place of driving current vaue.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bogie connection detection device for a vehicle, and more particularly to a bogie connection detection device for a vehicle which is driven by a drive motor to pull the bogie to automatically travel on a predetermined traveling route.

[0002]

2. Description of the Related Art Conventionally, for example, when an assembly part or the like is conveyed to a predetermined work station in an automobile assembly line, an automatic traveling vehicle is used which is guided by a guide tape laid on a road surface for traveling. There is one that connects and pulls the bogie so that it can be detached.

For example, Japanese Unexamined Patent Publication No. 4-328008 discloses a device for automatically attaching and detaching a bogie of such an automatic vehicle.

Separately from this, as a traveling control method for a moving body, the motor drive current of the moving body traveling on a predetermined traveling route is measured, and the traveling resistance is determined by the measured value of the drive current to determine the acceleration / deceleration. A modified version is disclosed in JP-A-64-69202.

[0005]

By the way, for example, when a work such as an assembly part is conveyed by pulling a trolley by an automatic traveling vehicle in an automobile assembly line as described above, the work is placed at one station, for example. Automatically connect the dolly (work actual dolly) to the other station, disconnect the work actual dolly there, instead automatically connect the empty dolly, tow it to the original station, remove it, and add a new one. In order to perform an operation such as automatically connecting the actual work carriages, it is necessary to build a system that detects whether or not the carriages are securely attached and detached at each station and stops if there is an abnormal attachment or detachment. . However, as a method for automatically detecting the attachment / detachment of the dolly, conventionally, only a sensor is provided at the connecting portion, which complicates the apparatus and increases the cost.

Therefore, it is a problem to be able to automatically detect the connection state of the bogie to the autonomous vehicle with a simple structure. An object of the present invention is to solve such a problem.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a bogie connection detecting device for a vehicle which is driven by a drive motor to pull the bogie and automatically travels on a predetermined traveling route. It is characterized by comprising drive current detecting means for detecting and connection determining means for determining the connected state of the vehicle when the drive current value detected after completion of the operation for connecting the vehicle is equal to or more than a predetermined value. Here, if the vehicle is two-wheel drive,
It is preferable to detect the drive current values of the drive motors for the left and right drive wheels, and determine that the cart is connected when the value obtained by adding the drive current values of both drive motors is equal to or greater than a predetermined value. When the vehicle has one-wheel drive, the drive current of one drive motor that drives the drive wheels is detected, and when the drive current value is equal to or more than a predetermined value, it is determined that the vehicle is in the connected state. As a result, it is possible to automatically detect the connection state of the bogie to the autonomous vehicle with a simple configuration.

Further, in the case of a vehicle provided with a speed control means for feedback controlling the traveling speed, instead of detecting the current value of the drive motor, the drive current command value of the drive motor is detected and the drive current value is replaced by the drive current. The vehicle connection state may be determined based on the current command value. In the case where the trolley coupling state is determined based on the drive current command value as described above, if the vehicle is a two-wheel drive, the drive current command values of the drive motors for the left and right drive wheels are detected and the drive current command values of both drive motors are detected. When the value obtained by adding is greater than or equal to a predetermined value, it is preferable to determine that the vehicle is connected. When the vehicle is a single-wheel drive, the drive current command value of one drive motor that drives the drive wheels is detected, and when the drive current command value is equal to or greater than a predetermined value, it is determined that the vehicle is in the connected state. Configure. Also by this, it is possible to automatically detect the connection state of the bogie to the autonomous vehicle with a simple configuration.

It is preferable to provide drive stopping means for stopping the drive motor when the carriage connection detecting means does not determine that the carriage is connected so that the system is stopped when the carriage connection is abnormal.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a bogie connection detection device for a vehicle according to the present invention will be described with reference to FIGS.

FIG. 1 is a front view (a), a plan view (b), and a side view (c) showing the device layout of a two-wheel turning drive type automatic vehicle.
It is a bottom view (d). This automatic vehicle 1 has two front wheels 2A and 2B, two rear wheels 3A and 3B, and two front wheels 2A and 2B.
A and 2B are two drive wheels of a motor drive type, and a rear wheel 3
Two of A and 3B are fixed driven wheels. The left and right two front wheels 2A and 2B, which are drive wheels, are supported by a swivel base 4 rotatably installed on the lower surface of the vehicle body 1A. A pair of drive motors 5A and 5B for steering and driving the two wheels are installed in the swivel base 4 at positions sandwiched by the left and right front wheels 2A and 2B. A guide sensor 7 is attached to the center of the front end of the swivel base 4 so as to be close to a guide tape (not shown) laid on the road surface 6. Further, an address sensor 8 is attached to the vehicle body 1A at an edge portion on one side of the lower surface so as to be close to an address plate (not shown) laid on the road surface 6. Also, the vehicle body 1A
A connecting portion 9 for connecting the truck is provided at the rear end.
Further, an upper part of the front surface of the vehicle body 1A is an operation display unit 13 in which an operation switch group 11 for various operations and an indicator light group 12 for displaying various operating states are arranged. An obstacle sensor 14 for detecting the approach of an obstacle is installed in the center of the front surface of the vehicle body 1A.

The guide sensor 7 is, for example, a plurality of Hall elements arranged in the lateral direction of the vehicle body at predetermined intervals.

The address sensor 8 receives guide command value signals for straight, left turn and right turn from an address plate having a combination pattern of N poles and S poles, and also travels at high speed, medium speed and low speed. Upon receiving the speed command value signal, the guide command value signal and the traveling speed command value signal are sent to the arithmetic unit (CP
U).

The device configuration for controlling the automatic vehicle 1 is composed of the guide sensor 7 and the address sensor 8 and a control unit. FIG. 2 is a block diagram of the device configuration. The control unit is the memory unit 2
1 and a calculation unit (CPU) 22, and has the functions of a left motor drive unit 23 and a right motor drive unit 24, and a left motor drive current detection unit 25 and a right motor drive current detection unit 26. The left motor drive unit 23 and the right motor drive unit 24 control the rotation speeds of the left drive motor 5A and the right drive motor 5B according to a command from the calculation unit 22, and perform branching control and trajectory control by the difference in the rotation speeds.

FIG. 3 is an explanatory view (a) of the guide position detection showing the trajectory control law of the automatic vehicle and a graph (b) of the rotational speed calculation formula of the left and right drive motors. FIG. 4 is a control block diagram of the trajectory control and the work attachment / detachment detection control.

In FIG. 3A, 30 is a guide tape laid on the road surface. The white arrow indicates the traveling direction of the vehicle integrated with the guide sensor 7. In FIG. 3A, the guide sensor 7 detects magnetism at a plurality of points (16 points in the example in the figure) at predetermined intervals in the lateral direction of the vehicle body, and the point where the guide tape 30 is located (left in the figure). 5 points located from 3 to 7)
To output an ON signal. At other points off the guide tape, the sensor signal is OFF.

FIG. 3A shows a straight traveling state, in which the guide command value of the straight traveling command from the immediately preceding address plate and the traveling speed command value of high speed, medium speed or low speed are used for the address sensor. 8 is input to the left drive motor rotation speed calculation unit 22b and the right drive motor rotation speed calculation unit 22c. In this case, the guide tape position calculation unit 22a receives the output of the guide sensor 7 and calculates the center of gravity by weighting each point of the ON signal, whereby the guide tape 3 is calculated.
The deviation (guide tape position) of the center line of 0 from the center position of the guide sensor 7 is obtained. Then, based on the deviation, the left drive motor rotation speed calculation unit 22b and the right drive motor rotation speed calculation unit 22c cause the left and right drive motors 5A and 5A to move.
The rotation speed of B is calculated. The left drive motor rotation speed calculation unit 22b and the right drive motor rotation speed calculation unit 22c
FIG. 3B shows a graph of the calculated value by. The calculated value is read from the memory unit 21 of the control unit for each of high speed, medium speed and low speed. Then, the left and right drive motors 5A and 5B
Is controlled and the traveling steering mechanism section 31 is driven, so that trajectory control is performed so that the center line of the guide tape 30 is centered on the center position of the guide sensor 7 and the vehicle travels straight.

When the automatic traveling vehicle 1 is turned left at the branch point of the guide tape, the guide command value of the left turn command and one of the traveling speed command values are passed through the address sensor 8 from the address plate before the branch point. It is input to the left drive motor rotation speed calculation unit 22b and the right drive motor rotation speed calculation unit 22c.
In this case, the left drive motor rotation speed calculation unit 22b and the right drive motor rotation speed calculation unit 22c detect the left edge of the guide tape 30 at the branch point by the ON signal of the guide sensor 7 so as to follow the left edge. Left and right drive motors 5A and 5B to turn the autonomous vehicle 1 left
Is calculated, and the autonomous vehicle 1 is turned left. Then, the guide tape position calculation unit 22a calculates the center of gravity with respect to the center line of the guide tape width with the left edge as a reference, and outputs the deviation. Then, based on the deviation, the left drive motor rotation speed calculation unit 22b and the right drive motor rotation speed calculation unit 22c calculate the rotation speeds of the left and right drive motors 5A and 5B, and also control the left and right drive motors 5A and 5B. hand,
Centering the center line of the guide tape to the center position of the guide sensor, the vehicle is turned left.

In the case of a right turn, the guide command value of the right turn command from the address plate before the branch point and also the running speed command value of either one of them are passed through the address sensor 8 to the left drive motor rotation speed calculation unit 22b and the right drive motor. It is input to the rotation speed calculation unit 22c. Then, the left drive motor rotation speed calculation unit 22b
The right drive motor rotation speed calculation unit 22c detects the right edge of the guide tape 30 at the branch point by the ON signal of the guide sensor 7, and the left and right drive motors 5A and 5B so as to turn the autonomous vehicle 1 left along the right edge. Calculate the rotation speed of. Then, the guide tape position calculation unit 22a
Calculates the center of gravity with respect to the center line of the width of the guide tape with the right edge as the reference to generate the deviation, and based on the deviation, the left drive motor rotation speed calculation unit 22b and the right drive motor rotation speed calculation unit 22c. Left and right drive motors 5A and 5B
Is calculated, and the left and right drive motors 5A and 5B are controlled to center the center line of the guide tape at the center position of the guide sensor and make a right turn.

The calculation unit 22 of the control unit includes the guide tape position calculation unit 22a, the left drive motor rotation speed calculation unit 22b and the right drive motor rotation speed calculation unit 2.
2c, and a work attachment / detachment determination unit 22d for detecting connection of the carriage.

The above-mentioned automatic vehicle 1 is used, for example, to pull a trolley in an automobile assembly line to convey a work such as an assembly part. FIG. 5 shows the route of the work transfer system. In this transport system, the automatic traveling vehicle 1 travels along a guide line formed by the guide tape 30, and automatically connects a dolly on which a work is placed at one station A, that is, a real work dolly 40A to the other station B. After pulling, the work actual truck 40A is removed and U-turned, and then the truck from which the work is unloaded, that is, the empty truck 40B is automatically connected, pulled to the original station A, removed there, and made another U-turn.
It is configured to repeat the operation of automatically connecting and pulling a new work actual carriage 40A. And
In order to detect whether or not the carriages 40A and 40B are securely attached and detached at the stations A and B, the left motor drive current detection unit 25 and the right motor drive current detection unit 26 are detected.
A dolly connection detecting means including a work attachment / detachment determination unit 22d is provided. The address plate is provided at each point of the guide line and at each station A, B. Then, the address sensor 8 of the autonomous vehicle 1 detects the command value from each address plate to operate the system.

The trolley connection detection means of the above system automatically detects the attachment / detachment of the work. At this time, the absolute value | IL + IR | of the sum of the drive current IL of the left drive motor and the drive current IR of the right drive motor is predetermined. The work attachment / detachment detection current value (threshold value) It of FIG.

The absolute value | IL + IR | of the sum of the drive current IL of the left drive motor and the drive current IR of the right drive motor is determined by the automatic traveling vehicle 1 by automatically connecting the work carriage 40A at the station A as described above. To the station B, where the work carriage 40A is removed and a U-turn is made.
The empty truck 40B is automatically connected, pulled to the original station A, removed there, and also made a U-turn, and the time elapsed while automatically connecting and pulling the new work actual truck 40A is shown in the time chart of FIG. It changes as shown. Then, the value of | IL + IR |
It is larger than the threshold value It when one of the empty carriages 40B is being towed, and it is less than or equal to It when no one is towing. The logic for automatic detection of work attachment / detachment in the above system utilizes this relationship between | IL + IR | and It.

7 and 8 are flow charts for executing the automatic detection of the work attachment / detachment.

FIG. 7 shows the main routine, which is started by pressing the start button (step S1).
Then, it is checked whether or not the address plate at the station position is detected (step S2), and when the address plate is detected, it is checked whether or not the command value of the address plate is the actual work vehicle traction command (step S3). . Then, if it is the work trolley command, the work attachment / detachment determination is executed by the subroutine shown in FIG. 8 for connecting the real dolly (step S).
4).

When the subroutine of FIG. 8 is entered, first, it is judged whether or not the work attachment / detachment is completed (step S10).
1). This determination can be made by detecting the address plate at the desorption completion position. Alternatively, the determination may be made based on the lapse of time after detecting the trolley command of the truck. Then, it makes a round trip until it is determined that the work attachment / detachment is completed, and when the work attachment / detachment is completed, the absolute value of the sum of the drive current IL of the left drive motor and the drive current IR of the right drive motor | IL
+ IR | is the predetermined work attachment / detachment detection current value (threshold value) I
If | IL + IR | is not equal to or less than It, it is judged that the load equivalent to the trolley of the trolley is applied, and it is determined that the trolley linkage is completed, and this subroutine is ended. However, if | IL + IR | is equal to or less than It, it is determined that the carriage is not connected, and an abnormality is determined, and a stop command is issued (step S103).

When the work attachment / detachment determination subroutine in step S4 is completed in this way, the process returns to the main routine to check whether or not a work empty truck traction command is issued (step S5).
If it is not the work empty truck traction command, the process proceeds to step S7 and the locus control described later is started.

If the work empty truck pull command is given in step S5, the address plate is detected, and if the work actual truck pull command is not found in step S3, if the work actual truck pull command is given, the empty truck is connected this time. Therefore, the workpiece attachment / detachment determination is executed by the subroutine shown in FIG. 8 (step S6). That is, it is determined whether or not the work attachment / detachment is completed (step S101). When the work attachment / detachment is completed, whether the absolute value | IL + IR | of the sum of the drive current IL of the left drive motor and the drive current IR of the right drive motor is equal to or smaller than It. If it is determined that | IL + IR | is not less than It, it is determined that the carriage connection is completed, the routine ends, and | IL + IR |
If t or less, a stop command is issued (step S103).
Then, the process returns to the main routine and proceeds to step S7 to enter the trajectory control.

If it is determined in step 2 that the address plate at the station position is not detected, the station S is used as it is.
Enter the locus control of 7 or less.

In the trajectory control from station S7 onward, first, the guide tape position is calculated (step S7). Then, the motor rotation speed is calculated based on the guide tape position (step S8), the motor rotation speed is set to the calculated value (step S9), and the motor is driven (step S).
10).

Then, it is checked whether or not there is a stop request (step S10), and steps S2 to S10 are executed until the stop request is issued.
When the stop request is made, the motor drive is stopped (step S12).

The automatic vehicle 1 is a two-wheel turning drive type, but a two-wheel fixed drive type in which two wheels are driven by a pair of motors fixed to the vehicle body and the other two wheels are caster driven wheels. A similar system can be applied to an autonomous vehicle. Also,
In the case of these two-wheel drive, as described above, the drive current values of the drive motors for the left and right drive wheels are detected, and when the value obtained by adding the drive current values of both drive motors is equal to or greater than a predetermined value, it is determined that the vehicle is in the connected state. However, if the vehicle is a one-wheel drive, it detects the drive current of one drive motor that drives that drive wheel,
When the drive current value is equal to or more than a predetermined value, the trolley-connected state is determined, so that the trolley-connected state can be similarly determined, that is, the work detachment can be automatically detected.

Further, in the case of a vehicle equipped with speed control means for feedback controlling the traveling speed, instead of detecting the current value of the drive motor, the drive current command value of the drive motor is detected, and the truck is driven by the drive current command value. You may make it determine a connection state. The device configuration in that case is as shown in FIG. 9, in which a left motor encoder 51 and a right motor encoder 52 are provided, and a memory unit 21 and an arithmetic unit (CPU) are provided.
The control unit composed of 22 includes a left motor drive unit 23, a right motor drive unit 24, and a left motor drive current detection unit 2.
5 and the functions of the right motor drive current detection unit 26, the left motor encoder input unit 53 and the right motor encoder input unit 54 are provided. Further, the control block diagram is as shown in FIG. 10, and the left motor encoder 51 and the right motor encoder 5 are used for speed feedback to the left drive motor 5A and the right drive motor 5B, respectively.
Left and right speed converter 5 for speed converting each output of 2
3, 54 and left and right PI control units 55 and 56 for adding the outputs of the speed conversion units 53 and 54 and outputting a drive current command value to each motor drive unit 23 and 24 as a speed command signal by PI control. There is. Then, the work attachment / detachment determination unit 22d is configured to automatically detect the work attachment / detachment in response to the outputs of the left and right PI control units. In this case, the work attachment / detachment determination unit 22d determines that the trolley is connected when the absolute value of the sum of the drive current command value of the left drive motor 5A and the drive current command value of the right drive motor is greater than or equal to a predetermined work attachment / detachment detection current command value. Configure to judge. This system can be applied to both two-wheel turning drive type and two-wheel fixed drive type vehicles, and also to one-wheel drive vehicles. In the case of a one-wheel drive vehicle, the drive current command value of one drive motor that drives the drive wheel is detected, and when the drive current command value is equal to or greater than a predetermined value, it is determined that the vehicle is in a connected state. Is.

[0034]

According to the present invention, it is not necessary to provide a sensor at the connecting portion to detect the connection state of the bogie to the automatic traveling vehicle, and the automatic detection can be performed with a simple structure.

[Brief description of drawings]

FIG. 1 is a device layout view of an autonomous vehicle.

FIG. 2 is a block diagram of a device configuration of an autonomous vehicle.

FIG. 3 is an explanatory diagram and a graph of a trajectory control law of an automatic vehicle.

FIG. 4 is a control block diagram of the automatic vehicle.

FIG. 5 is a route configuration diagram of a work transfer system for an automated vehicle.

FIG. 6 is a time chart showing changes in motor drive current due to work attachment / detachment.

FIG. 7 is a flowchart showing a main routine of automatic detection of workpiece attachment / detachment.

FIG. 8 is a flowchart showing a subroutine for workpiece attachment / detachment determination.

FIG. 9 is a block diagram of a device configuration of an automatic vehicle that performs speed feedback.

FIG. 10 is a control block diagram of an automatic vehicle that performs speed feedback.

[Explanation of symbols]

 1 Autonomous vehicle 5A, 5B Drive motor 8 Address sensor 21 Memory unit 22 Calculation unit 22d Workpiece attachment / detachment determination unit 25 Left motor drive current detection unit 26 Right motor drive current detection unit 40A Work vehicle 40B Empty truck 51 Left motor encoder 52 Right Motor encoder 55, 56 PI controller

Claims (7)

[Claims] 1. A trolley connection detection device for a vehicle that is driven by a drive motor to pull a trolley to automatically travel along a predetermined travel route, the drive current detection means detecting a drive current of the drive motor, and the trolley connection. A trolley connection detection device for a vehicle, comprising connection determination means for determining a trolley connection state when a drive current value detected by the drive current detection means after the operation is completed is a predetermined value or more. 2. The vehicle is a two-wheel drive, and the left and right drive wheels are driven by respective drive motors, and the drive current detection means detects drive current values of both drive motors. 2. The bogie connection detection device for a vehicle according to claim 1, wherein the detection means determines that the bogie connection state is established when the value obtained by adding the drive current values of the both drive motors is equal to or greater than a predetermined value. 3. The vehicle is one-wheel drive, one drive wheel is driven by one drive motor, and the drive current detecting means detects a drive current of the one drive motor. 2. The bogie connection detection device for a vehicle according to claim 1, wherein the bogie connection detection means determines that the bogie connection state is established when the drive current value of the one drive motor is equal to or more than a predetermined value. 4. A trolley connection detection device for a vehicle which is driven by a drive motor and tows a trolley to automatically travel on a predetermined travel route, the drive current command value detecting means detecting a drive current command value of the drive motor. And a trolley coupling of vehicles, which is configured to determine a trolley coupling state when the drive current command value detected by the drive current command value detecting means after the trolley coupling operation is completed is a predetermined value or more. Detection device. 5. The vehicle is a two-wheel drive, and the left and right drive wheels are driven by respective drive motors, and the drive current command value detecting means detects drive current command values of both drive motors. 5. The bogie connection detection device for a vehicle according to claim 4, wherein the bogie connection detection means determines that the bogie connection state is established when a value obtained by adding drive current command values of the both drive motors is equal to or larger than a predetermined value. 6. The vehicle is one-wheel drive and one drive wheel is driven by one drive motor, and the drive current command value detection means detects a drive current command value of the one drive motor. 5. The bogie connection detection device for a vehicle according to claim 4, wherein the bogie connection detection means determines that the bogie connection state is established when the drive current command value of the one drive motor is equal to or larger than a predetermined value. 7. The bogie connection detection of the vehicle according to claim 1, further comprising drive stop means for stopping the drive motor when the bogie connection detection means does not determine that the bogie connection state is established. apparatus.