JP2798307B2 - Stop positioning guidance device for automatic guided vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stop guidance device capable of accurately positioning a stop position of an automatic guided vehicle.

[0002]

2. Description of the Related Art Conventionally, in an automatic guided vehicle, a distance from a reference wall surface is measured by a distance measuring sensor provided inside a vehicle body, and an autonomous traveling using an inward sensor such as a traveling distance sensor or a gyro is used. There is something to do.

As shown in FIG. 10, it is indispensable for these automatic guided vehicles N to accurately stop at the station ST when positioning a work or the like at various machining centers M / C. However, when the depth passage from the entrance frontage to the station ST is relatively long, it may not be possible to perform correction based on the so-called reference wall surface.

That is, the wall surface W is detected by the distance measuring sensors S2 and S3.
Although the distances D2 and D3 to the distance 1 can be obtained, the distance measuring sensor S1 provided on the traveling surface of the automatic guided vehicle N cannot obtain the long distance D1 exceeding the measurement limit. Therefore, when positioning the automatic guided vehicle at the above-described location, guidance and stop are performed by relying on an inward sensor such as a travel distance sensor or a gyro (not shown).

[0005]

However, in the conventional method, an error may be included in the output from the traveling distance sensor due to the influence of unevenness of the traveling road surface, wheel slip, or the like. When you control the car,
There has been a problem that the station ST cannot be stopped accurately, which affects the operation of the entire system.

The present invention has been devised to solve such a problem, and an object of the present invention is to position an unmanned guided vehicle at a station without relying only on an inward sensor based on internal calculation, and to provide a depth path to the station. It is an object of the present invention to provide an automatic guided vehicle stop positioning guidance device that can guide an automatic guided vehicle to stop while measuring the distance to a reference wall surface even when the distance is relatively long.

[0007]

According to the present invention, there is provided an automatic guided vehicle having a support frame projecting forward from a longitudinally extending connecting frame, and left and right horizontal frames fixed so as to hang down from the lower surface of the support frame. And a movable frame which is slidably held between the left and right horizontal frames, and a pusher which is slidable with respect to the movable frame is provided at the movable frame to stop and position the automatic guided vehicle. A guidance device, wherein first urging means for urging the movable frame forward of the stop guidance device, and second biasing force for urging a pressing piece against the movable frame forward of the stop guidance device. Means, the spring constant of the first biasing means,
The second urging means is configured to be smaller than the spring constant.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS. In order to facilitate understanding of the stop guidance device according to the present invention, an omnidirectional mobile trolley will be described first as an example of an automatic guided vehicle used in the present invention.

FIG. 6 is a side view of the omnidirectional mobile trolley 1, and FIG. 7 is a front view of the omnidirectional mobile trolley 1. An obstacle is detected around the vehicle body of the omnidirectional mobile trolley 1 by making direct contact with the obstacle. Obstacle detecting bumpers 4, 5, and 6, two non-contact type obstacle detecting devices 10A provided on each side of the vehicle body for detecting non-contact obstacles, and any position from the vehicle body In order to measure the distance from a reference wall surface (not shown) installed on the vehicle body, two distance measuring devices 7A are provided on each side surface of the vehicle body.
And a cargo handling device 2, 2 having a drive conveyor 3 provided on the upper surface of the vehicle body, a control device 8 for controlling traveling and cargo handling, and a battery BA. The distance measuring device 7A
.. May be of an optical type or an ultrasonic type.

The control device 8 stores travel distance data,
Signals are sent from the distance measuring devices 7A and the like, and various traveling control procedures and the like are described. Based on these, the traveling of the omnidirectional mobile trolley 1 and the control of cargo handling are performed. .

The omnidirectional mobile trolley 1 is provided with steering motors (described later) on all wheels 9FR, 9RR, 9FL, 9RL disposed at the four corners of the vehicle body.
It is configured to be able to rotate continuously by degrees. Further, two wheels arranged on a diagonal line of the vehicle body, for example, 9FR and 9RL are driving wheels each equipped with a traveling motor (described later), while the remaining two wheels, 9RR and 9FL are slave wheels. Configure the driving wheel. The mechanism of the 9FR driving wheels will be described with reference to FIG. 8. , A two-stage reduction gear 15 that meshes with the pinion gear 14, a spur gear 16 that is formed coaxially with the two-stage reduction gear 15, and a driven gear 17 that meshes with the spur gear 16 and fits into the vertical shaft 18. And a bevel pinion 19 fitted into the lower end of the vertical shaft 18.
And a bevel gear 20 meshing with the bevel pinion 19
To the bevel gear 20 with a key,
And a drive shaft 21 to be fixed.

The steering mechanism includes a pinion gear 24 fixed to an output shaft of a steering motor 23, a reduction gear 25 meshing with the pinion gear 24, a spur gear 26 formed coaxially with the reduction gear 25, and a spur gear 26. The internal gear 27 meshes with the internal gear 26 and a revolving gear case 28 fixed to the internal gear 27 and rotatably supported on the upper casing via a revolving bearing 34. Therefore,
The turning gear case 28 turns around the turning shaft 30 by turning the steering motor 23,
Further, by rotationally driving the traveling motor 11, the wheels 9FR can be rotated independently of the turning gear case 28.

An absolute encoder 29 detects how many times the turning gear case 28 has turned at an arbitrary absolute coordinate. Also, wheel 9FR
Has a mileage measuring wheel 3 for measuring the mileage.
1 (hereinafter referred to as a measurement wheel). Measuring wheel 31
Is a projection 3 which is a cylindrical portion of the revolving gear case 28.
2 is rotatably supported via a bearing by a sleeve-shaped bracket 33 which is loosely inserted into the bracket 2. The actual traveling distance of the omnidirectional mobile trolley 1 is calculated by detecting the number of rotations with various sensors (not shown) such as a rotary encoder pressed against the measuring wheel 31 and sending the data to the controller 8 via a counter or the like. Sent and calculated.

Next, a control block diagram of the omnidirectional mobile trolley 1 is shown in FIG. The control device 8 of the omnidirectional mobile trolley 1 includes a CPU 36 and a ROM that stores a running program of the omnidirectional mobile trolley 1 as a read-only memory.
And a working memory RAM which can be written to at any time, an interface 38 for exchanging various input / output signals from outside, and a servo controller 3 for controlling the traveling motor 11 and the steering motor 23.
9 is comprised. As signals input to the interface 38, an absolute encoder 29 for detecting a turning angle of the turning gear case 28, a gyro 40 for measuring a posture angle and a turning speed of the vehicle, and a distance between the vehicle and a reference wall are measured. 7H, bumpers 4, 5, 6 for detecting by contacting obstacles, non-contact obstacle detecting devices 10A, detection signals from a rotary encoder 29 for measuring the traveling distance of each wheel 9, etc. Is entered. Further, as the gyro 40, for example, an optical fiber gyro or the like can be suitably used.

As a result of the calculation performed by the CPU 36, the steering angle and the steering angle of each wheel 9 are controlled by the servo controller 39 via the interface 38.
Also, when the bumpers 4, 5, 6 and the non-contact type obstacle detection device that detect by contacting the obstacle detect an obstacle, or when an emergency stop signal or the like is sent,
The CPU can stop the vehicle by operating the electromagnetic brake 42 provided on the wheels 9.

Next, the guidance stopping device according to the present invention will be described. In the present example, the load guide WF and the load WR are placed on the front and rear of the stop guide device 43, and these also serve as a loading table that is transported to the machine tools such as various machining centers by the omnidirectional mobile trolley 1 as needed. Some examples are given below. As illustrated in FIG. 1, a support frame 44. . When,
The support frame 44. . Horizontal frame 47 fixed to the lower surface of . When,
The horizontal frame 47. . 46. A foot fixed below the . When,
A movable frame 49 slidably held between the horizontal frames 47, 47, and a pressing piece 50 slidable with respect to the movable frame 49.
It is composed of 48A, B and C are stoppers,
In order to prevent the load from shifting in the front-rear direction of the support frame 44, the load is fixed to the upper surface of the support frame 44.
Each stop guidance device 43 has a predetermined frontage number B.
K1. . Is given in advance.

As shown in FIG. 2, the movable frame 49 is fixed to the inner side surface of the horizontal frame 47, and is fixed to the rear end surface of a bracket 58 slidable with respect to the rack gear 57 whose tooth surface faces downward. . The movable frame 49 is formed of a reflective material having high reflection efficiency, so that the distance measuring device 7A. . Can be reliably reflected. A pinion gear 56 that meshes with the rack gear 57 and guide rollers 55F and 55R that roll on the upper surface of the rack gear 57 are supported on the outer surface of the bracket 58. or,
Spiral spring SP1 above the front end face of bracket 58
Is fixed at one end.

The other end of the spiral spring SP1 is fixed to a winding drum 52, and the winding drum 52 is fixedly supported by an upright portion 53 of a receiving piece 54. The receiving piece 54 is fixed to the horizontal frame 47 similarly to the rack gear 57. Therefore, usually, the bracket 58 is kept in a state of being drawn toward the spiral spring SP1 by the restoring force of the spiral spring SP1.

The pressing piece 50 is inserted through a guide cylinder 50A fixed to a substantially central portion of the movable frame 49, and one end of a spiral spring SP2 is fixed to a rear end portion 50R. The other end of the spiral spring SP2 is fixed to a winding drum 60 fixed to the back of the movable frame 49.
Therefore, similarly to the bracket 58, the pressing piece 50 also
It is kept biased forward.

The movable frame 49 and the horizontal frame 47 are used as reference wall surfaces of the omnidirectional mobile trolley 1, respectively, which will be described later. Further, the aforementioned spiral spring SP
1, SP2 is preferably a so-called constant torque type spring in which the torque does not fluctuate even when the elongation increases.
The spring constant of the spiral spring SP1 is the spiral spring SP
Compared to the spring constant of 2, an extremely small one is used. Although a spiral spring is used as an example of the urging means, other coil springs or leaf springs can be used.

[0021]

The operation in which the omnidirectional mobile trolley 1 is accurately stopped by the stop guidance device 43 will be described below with reference to FIGS. First, as shown in FIG. 3, the omnidirectional mobile trolley 1 is positioned to face the stop guidance device 43 based on the running program stored in the ROM. At this time, the vehicle body of the omnidirectional mobile trolley 1 is
The distance between the movable frame 49 serving as a reference wall surface is measured by the distance measuring devices 7C and 7D in front of the vehicle body to obtain L1. At this time, the obstacle detection bumper 4 does not contact the movable frame 49.

Next, as shown in FIG. 4, the omnidirectional mobile trolley 1 travels straight. At this time, the spring constant of the spiral spring SP1 linked to the movable frame 49 is set to be extremely smaller than that of the spiral spring SP2 linked to the pressing piece 50. Although SP1 is extended, the distance between the front end of the pressing piece 50 and the movable frame 49 does not change, and both can slide backward as one. Therefore, the distance between the omnidirectional mobile trolley 1 and the movable frame 49 remains L1 without changing, and in this state, the omnidirectional mobile trolley 1 continues to travel straight. At this time, the omnidirectional mobile trolley 1 is provided with distance measuring sensors 7A. .
Then, the distance between the horizontal frames 47, 47 of the stop guidance device 43 and the distance to the movable frame 49 are measured, and the vehicle travels straight while correcting the position and the posture angle of the vehicle body.

Then, as shown in FIG. 5, when the movable frame 49 reaches a position where the sliding is mechanically restricted, the pressing piece 5
The action of sliding backward while 0 extends the spiral spring SP2 is obtained. By this operation, the omni-directional mobile trolley 1
Then, when the distance measurement distance between the movable frame 49 and the movable frame 49 is reduced for the first time and the distance becomes LS, the traveling of the omnidirectional mobile trolley 1 may be stopped. These series of procedures, the distance LS, and the like are stored in the ROM of the storage unit 37.
The PU 36 can perform a sequential operation. Although an omni-directional mobile trolley has been described as an example of an unmanned transport vehicle, the present invention can be suitably applied to other unmanned vehicles such as a visual guidance vehicle.

[0024]

According to the present invention, even in a place where a depth path is long where a wall surface serving as a reference of a distance measuring sensor cannot be set up, it can be set up basically by sliding the reference plane. Distance measurement with the outer wall can be obtained by the distance measurement sensor, and the same effect as that of a station having a continuous reference plane can be obtained.By controlling the position and attitude angle of the automatic guided vehicle, you can go to any station. The stop can be guided accurately.

[0025]

[Brief description of the drawings]

FIG. 1 is a perspective view showing the present invention.

FIG. 2 is an enlarged perspective view showing the present invention.

FIG. 3 is a side view for explaining the operation of the present invention.

FIG. 4 is a side view for explaining the operation of the present invention.

FIG. 5 is a side view for explaining the operation of the present invention.

FIG. 6 is a side view of the omnidirectional mobile trolley.

FIG. 7 is a front view of the omnidirectional mobile trolley.

FIG. 8 is a cross-sectional view showing a mechanism of a driving wheel of the omnidirectional moving trolley.

FIG. 9 is a control block diagram of the omni-directional mobile trolley.

FIG. 10 is a conceptual diagram illustrating a conventional system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Omnidirectional carriage 28 Revolving gear case 31 Measuring wheel 43 Stop guidance device 44 Support frame 45 Connecting frame 47 Side frame 49 Movable frame 50 Push piece

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G05D 1/02 B65G 47/52 101

Claims (2)

(57) [Claims] A support frame protruding forward from a connection frame extending in a longitudinal direction, and a left and right horizontal frame fixed so as to hang down from a lower surface of the support frame form a path through which an automatic guided vehicle can enter. A movable frame slidably held between the left and right horizontal frames, and a stop positioning guidance device for an automatic guided vehicle provided with a pressing piece slidable with respect to the movable frame, the movable frame comprising: A first urging means for urging a frame forward of the stop guidance device, and a second urging means for urging a pressing piece against the movable guidance frame forward of the stop guidance device; A stop positioning guidance device for an automatic guided vehicle, wherein the spring constant of the urging means is smaller than the spring constant of the second urging means. 2. A stop positioning guidance device for an automatic guided vehicle, wherein the movable frame according to claim 1 is a reflection plate having high reflection efficiency.