JP3413518B2 - Travel control method and travel control device for self-propelled welding bogie - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling control method and a traveling control device for a self-propelled welding carriage. More specifically, the present invention relates to a traveling control method and a traveling control device for a self-propelled welding carriage in which the tip speed of the welding torch is constant.

[0002]

2. Description of the Related Art Conventionally, a reinforcing material such as a standing plate is attached to a main material by fillet welding a self-propelled welding carriage while following the reinforcing material such as a standing plate. And
In order to improve the accuracy of copying the self-propelled carriage to the standing plate,
Various proposals have been made.

For example, Japanese Laid-Open Patent Publication No. 4-319072 discloses that, when a robot that performs fillet welding of square-shaped members is run, it is within a range in which a groove scanning control of an arc sensor system by a high-speed rotary arc welding method is possible. Before and after the welding carriage of the grid welding robot that performs fillet welding of grid-shaped members with the grid welding robot that applies the arc sensor type groove tracking control method by high-speed rotating arc welding for the purpose of performing rough copy traveling control. A non-contact type distance detection sensor is attached to the welding cart, and the two distance detection sensors detect the distance between the grid-shaped member and the standing plate on the welding side, respectively, and the welding carriage is set so that the two detected distances become equal. A coarse copying traveling control method for a square welding robot has been proposed, which is characterized by controlling the relative speeds of traveling wheels inside and outside the vehicle.

Further, Japanese Laid-Open Patent Publication No. 8-132236 discloses a high-speed rotation for controlling the copying of the welding line by the arc sensor for the purpose of controlling the rough copying traveling of the welding carriage on the welding line only by the information of the arc sensor. In a traveling rough copying control method of a welding carriage equipped with an arc welding torch,
The X-axis position, which is a horizontal sliding device of the welding torch controlled by the arc sensor, is detected, the detected X-axis position is compared with a preset reference value, and the detected X-axis is further detected. A differential value of the axial position is calculated, a correction amount in the traveling direction of the welding carriage is calculated based on the deviation between the detected X-axis position and a reference value and the calculated differential value, and the calculated correction amount is calculated as described above. There has been proposed a coarse copying control method using an arc sensor, which is characterized by adding the respective speeds of the inner and outer wheels of the welding carriage and controlling the rough copying of the traveling of the welding carriage with the added wheel speeds.

However, in the control method proposed in Japanese Patent Application Laid-Open No. 4-319072, the control is complicated because the detection values from the distance detection sensors provided in front of and behind the welding carriage are always matched. However, there is a problem that the traveling of the welding carriage is not stable.

Further, in the control method proposed in Japanese Patent Application Laid-Open No. 8-132236, since the control is performed using the differential value of the detected value, there is a problem that the control becomes complicated.

Further, in the control method according to the proposals of JP-A-4-319072 and JP-A-8-132236, how to control the tip speed of the welding torch in steering the welding carriage, that is, the self-propelled welding carriage. There is no point in teaching how to keep it constant. Therefore, welding failure may occur due to uneven tip speed of the welding torch.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art, and is directed to a self-propelled welding carriage capable of achieving good welding despite the simplification of control. An object of the present invention is to provide a travel control method and a travel control device.

[0009]

A traveling control method for a self-propelled welding carriage according to the present invention is a traveling control method for a self-propelled welding carriage, which is a traveling pattern in which a vehicle travels straight for a certain period of time after being steered.
Is characterized by repeating.

In the traveling control method for the self-propelled welding carriage according to the present invention, it is preferable to drive the inner ring and the outer ring so that the tip speed of the welding torch is constant during steering, and the length of the welding torch is also controlled. It is more preferable to drive the inner and outer wheels by correcting the variation of

A traveling control device for a self-propelled welding carriage according to the present invention is a traveling control device for a self-propelled welding carriage, wherein the traveling control device turns a self-propelled welding carriage for a predetermined time < It is characterized in that it is configured so as to repeat a traveling pattern for going straight.

A traveling control device for a self-propelled welding carriage according to the present invention
In, a travel control device of the self-propelled welding vehicle,
Inner / outer ring speed calculation means for calculating the speeds of the inner and outer wheels with the tip speed of the welding torch being constant, and inner / outer wheel speed command value generation for generating inner / outer wheel speed command values based on the calculated values of the inner / outer wheel speed calculation means Preferably with means
Yes .

[0013] The traveling control device for a self-propelled welding vehicle of the present invention preferably comprises a correction unit that is the inner and outer wheel speed calculating means for correcting the variation of the length of the welding torch.

[0014]

Since the present invention is constructed as described above, the traveling control of the self-propelled welding carriage is simplified and the traveling of the self-propelled welding carriage is stabilized.

Further, according to the preferred embodiment of the present invention, the tip speed of the welding torch is kept constant during steering, so that a stable welding bead is obtained and the welding quality is improved.

Further, according to another preferred embodiment of the present invention, even if the length of the welding torch varies due to weaving, the variation can be corrected and the self-propelled welding carriage can be run to perform welding.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described based on the embodiments with reference to the accompanying drawings, but the present invention is not limited to such embodiments.

FIG. 1 shows a state where fillet welding of a standing plate is performed by a self-propelled welding carriage whose traveling is controlled by a traveling control method according to an embodiment of the present invention. Further, FIG. 2 shows a schematic diagram of the self-propelled welding carriage.

The self-propelled welding carriage A has a carriage body 10, a welding torch holding portion 20, a traveling portion 30, and a distance measuring portion 40.
The welding torch 50 and the movement restricting portion 60 are provided as main components.

The trolley body 10 is, for example, a thin rectangular parallelepiped. However, the form of the trolley body 10 is not limited to a rectangular parallelepiped, and may be an appropriate form.

The welding torch holding portion 20 has a torch holding member 21, and is arranged in the central portion of the upper surface 11 of the trolley body 10 with the torch holding member 21 facing the side facing the standing plate B. The tip 21 of the torch holding member 21
The welding torch 50 is attached to a so that the weaving operation is possible.

The traveling unit 30 includes a traveling mechanism 31 including two traveling wheels 32 and 33, and a pair of ball casters 36 and 37.
And a posture holding mechanism 35 composed of.

The two running wheels 32 and 33 are arranged in a column shape toward the side facing the standing plate B at the center of the lower part of the carriage. Each of the traveling wheels 32 and 33 is individually driven by a drive device to drive the carriage body 10. After that, of the running wheels 32.33, the one closer to the standing plate B is the inner ring 3
The outer ring 3 is the one that is far from the standing plate B.
I will call it 3. Further, an axis relating to the traveling wheels 32 and 33 is referred to as a front-rear axis FL, and an axis orthogonal to this and passing through the center of the bogie main body 10 is referred to as a transverse axis LL.

The one side 36 of the pair of ball casters 36, 37 has a transverse axis L on the lower surface of the front end of the carriage body 10.
The other side 37 is disposed on the transverse axis LL on the lower surface of the rear end of the bogie body 10. Further, the mounting heights of the ball casters 36 and 37 are adjusted so that the posture of the carriage main body 10 is stable when the traveling mechanism 31 causes the self-propelled welding carriage A to travel.

The distance measuring section 40 comprises a pair of laser distance sensors 41 and 42. One of the pair of laser distance sensors 41, 42 is disposed on the upper surface of the tip of the carriage body 10 on the side facing the standing plate B, and the other is the carriage body 10.
The upper surface of the rear end portion is arranged at a position symmetrical with respect to the front-rear axis FL. Hereinafter, the laser distance sensor located on the upper surface of the front end will be referred to as 41 front end distance sensor 41, and the laser distance sensor 42 located on the upper surface of the rear end will be referred to as rear end distance sensor 42.

The welding torch 50 is an arc welding torch having a known arc sensor. The movement restricting unit 60 is composed of a pair of limit switches 61 and 62. One of the pair of limit switches 61, 62 is arranged on the transverse axis LL at the end face of the carriage main body 10, and the other 62 is arranged on the transverse axis LL at the rear end face of the carriage main body 10. It

The control device 70 is a so-called one-chip microcomputer and is arranged at an appropriate position outside the carriage body 10. As shown in FIG. 3, the control device 70 uses the inner and outer ring speed calculation means 71 for calculating the speeds of the inner and outer wheels that keep the tip speed of the welding torch 50 constant, and the calculated values of the inner and outer ring speed calculation means 71. The inner / outer wheel speed command value generating means 72 for generating the inner / outer wheel speed command value based on the above. In this case, it is preferable that the inner / outer ring speed calculation means 71 is provided with a correction unit 73 for correcting the variation in the length of the welding torch 50. The inner / outer wheel speed calculation means 71, the inner / outer wheel speed command value generation means 72, and the correction section 73.
Is realized by storing a program corresponding to the control logic described later in the one-chip microcomputer.

Therefore, as shown in FIG. 3, the control device 70 includes a laser distance sensor 41,
42, measured values from the arc sensor, detected values from the limit switches 61 and 62 of the movement restricting unit 60,
And other necessary information is input from the main controller (not shown), and the input measured value, detected value, etc. are arithmetically processed to generate a command value to the drive device 38 of the traveling mechanism 31. Is output.

Next, an example of traveling control of the self-propelled welding carriage A by the control device 70 will be described with reference to FIGS. 1 and 4.

(1) Based on the measured values from the front end distance sensor 41 and the rear end distance sensor 42, the distance from the standing plate B of the carriage body 10 and the angle formed by the standing plate B and the carriage body 10 are calculated.

(2) From the calculated distance from the standing plate B of the trolley body 10 and the angle between the standing plate B and the trolley body 10,
The velocities of the inner ring 32 and the outer ring 33 that make the trolley body 10 parallel to the standing plate B and keep the tip speed of the welding torch 50 constant are calculated. The calculation of the velocities of the inner ring 32 and the outer ring 33 that keep the tip velocity of the welding torch 50 constant will be described later.

(3) The bogie body 10 is made parallel to the standing plate B by driving the inner ring 32 and the outer ring 33 at a calculated speed for a predetermined time, for example, 0.75 seconds. That is, the self-propelled welding carriage A is steered.

(4) While maintaining the tip speed of the welding torch 50 at the above speed, the inner ring 32 and the outer ring 33 are driven at the same speed for a predetermined time, for example, 1.25 seconds. That is, the self-propelled welding carriage A is moved straight.

(5) Again, based on the measured values from the front end distance sensor 41 and the rear end distance sensor 42, the trolley body 1
A distance of 0 from the standing plate B and an angle formed by the standing plate B and the carriage main body 10 are calculated.

(6) From the calculated distance from the standing plate B of the carriage main body 10 and the angle formed by the standing plate B and the carriage main body 10,
The velocities of the inner ring 32 and the outer ring 33 that make the trolley body 10 parallel to the standing plate B and keep the tip speed of the welding torch 50 constant are calculated.

(7) The inner race 32 and the outer race 33 are driven at a calculated speed for a predetermined time, for example, 0.75 seconds to steer the self-propelled welding carriage A so that the carriage main body 10 is parallel to the standing plate B. .

(8) While maintaining the tip speed of the welding torch 50 at the above speed, the inner ring 32 and the outer ring 33 are driven at the same speed for a predetermined time, for example, for 1.25 seconds to drive the self-propelled welding carriage A straight.

After that, this steering and straight traveling are repeated until the standing plate B
Fillet welding in a predetermined range of. The reason why the steering and the straight traveling are alternately repeated is as follows.

Since there is a manufacturing error in the diameter of the inner ring 32 and the diameter of the outer ring 33, when the inner ring 32 and the outer ring 33 are driven at the same speed, the trolley body 10 causes the standing plate B to rise due to the manufacturing error.
Is no longer parallel to. Therefore, the inner wheel 3 is steered periodically.
The deviation of the trolley body 10 due to the manufacturing error of the outer ring 33 and the outer ring 33 is corrected. In this case, the tip distance sensor 41
Also, the traveling speed of the self-propelled welding carriage A may be controlled by constantly calculating the speed at which the carriage main body 10 is parallel to the standing plate B based on the measured value of the rear end distance sensor 42, but this makes the control complicated. . Therefore, in this embodiment, in order to avoid complicated traveling control, steering and straight traveling are alternately repeated.

Next, with reference to FIG. 5, the calculation of the speeds of the inner ring 32 and the outer ring 33 for keeping the tip speed of the welding torch 50 constant during steering will be described.

In FIG. 5, the tip speed of the welding torch 50 is V, the speed of the inner ring 32 is β · V, and the speed of the outer ring 33 is α ·.
V, the distance between the inner ring 32 and the outer ring 33 is L1, the welding torch 5
The distance from the tip of 0 to the inner wheel 32 is set to L2, the distance between the virtual turning center O and the outer wheel 33 is set to x, and the steering angle is set to θ.

In this case, the tip speed V of the welding torch 50,
The speed β · V of the inner ring 32 and the speed α · V of the outer ring 33 are expressed by the following equations (1), (2), and (3), respectively.

[0043]   V = (x + L1 + L2) (dθ / dt) (1)   α · V = x (dθ / dt) (2)   β · V = (x + L1) (dθ / dt) (3)

From the above equation (1),   x (dθ / dt) = V− (L1 + L2) (dθ / dt) (4) To get

The above equation (4) is replaced by the above equations (2) and (3).
To obtain the following equations (5) and (6).

[0046]   α · V = V− (L1 + L2) (dθ / dt) (5)   β · V = V− (L2) (dθ / dt) (6)

Therefore, the tip speed V of the welding torch 50 is
In order to keep constant, the speeds of the outer ring 33 and the inner ring 32 may be set as in the following equations (7) and (8).

[0048]   α · V = V− (L1 + L2) (θ / t) (7)   β · V = V− (L2) (θ / t) (8)

FIG. 6 is a block diagram showing an example of control logic for generating the speed command value. As described above, this control logic forms the inner / outer wheel speed calculation means 71 and the inner / outer wheel speed command value generation means 72.

By the way, when the welding line is traced using the arc sensor, the length of the welding torch 50 changes due to the difference in the welding current between the standing plate B and the lower plate (main material) due to weaving. And the distance L2 between the inner ring 32 and the inner ring 32 changes. In that case, as shown in FIG. 7, it can be dealt with by changing the gain of the amplifier of the control logic shown in FIG. 6 to (L2 + dL2) in which the variation of the distance L2 is corrected. Here, dL2 indicates the variation of the distance L2.

As described above, according to this embodiment, the tip speed of the welding torch 50 when the self-propelled welding carriage A is steered, that is, the welding speed can be made constant, so that the welding bead generated due to the non-uniform welding speed is generated. It will never be a meandering beat. Therefore, meandering of the welding bead is avoided and welding quality is improved.

Although the present invention has been described based on the embodiments, it is not limited to the embodiments according to the present invention, and various modifications can be made. For example, although the self-propelled welding carriage is driven by two wheels in the embodiment, it may be driven by four wheels although the control logic is somewhat complicated.

[0053]

As described in detail above, according to the present invention,
It is possible to obtain an excellent effect that the traveling control of the self-propelled welding carriage is simplified and the traveling of the self-propelled welding carriage is stabilized. Further, according to the preferred embodiment of the present invention, since the tip speed of the welding torch is kept constant during steering, an excellent effect that a stable welding bead is obtained and welding quality is improved is also obtained.

Furthermore, according to another preferred embodiment of the present invention, even if the length of the welding torch varies due to weaving, the variation can be corrected and welding can be performed while the self-propelled welding carriage is running. Excellent effect can also be obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing a state where a standing plate is welded by a self-propelled welding carriage according to an embodiment of the present invention.

FIG. 2 is a schematic view of a self-propelled welding carriage according to an embodiment of the present invention.

FIG. 3 is a block diagram of a control device mounted on the self-propelled welding cart.

FIG. 4 is a travel time chart of the self-propelled welding cart.

FIG. 5 is an explanatory diagram of a steering method in traveling control of the present invention.

FIG. 6 is a block diagram of control logic in the traveling control method of the present invention.

FIG. 7 is a block diagram of another control logic in the traveling control method of the present invention.

[Explanation of symbols]

10 dolly body 20 Welding torch holder 30 running section 40 Distance measuring unit 50 welding torch 60 Movement Control Department 70 Control device A self-propelled welding cart

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takahisa Iizuka 118 Futtsuka, Noda City, Chiba Prefecture Kawasaki Heavy Industries, Ltd. inside Noda Factory (72) Inventor Jun Ito 118 Futatsuka, Noda City, Chiba Kawasaki Heavy Industries Ltd. Noda Factory (56) Reference JP-A-8-132236 (JP, A) JP-A-4-319072 (JP, A) JP-A-2-107104 (JP, A) JP-A-7-184411 (JP, A) Actual development Sho 59-169609 (JP, U) Actual development Hei 5-70768 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G05D 1/02 B23K 9/12

Claims (6)

(57) [Claims] 1. A travel control method for a self-propelled welding carriage, comprising: repeating a travel pattern in which a vehicle is steered and then goes straight for a certain period of time . 2. The traveling control method for a self-propelled welding carriage according to claim 1, wherein the inner ring and the outer ring are driven so that the tip speed of the welding torch is constant during steering. 3. The traveling control method for a self-propelled welding trolley according to claim 2, wherein the inner ring and the outer ring are driven by compensating for a variation in the length of the welding torch. 4. A travel control device for self-propelled welding vehicle, after the travel control device, which is steered self-propelled welding vehicle
A traveling control device for a self-propelled welding carriage, which is configured to repeat a traveling pattern in which a vehicle travels straight for a certain period of time . 5. An inner / outer ring speed calculation means for calculating the speeds of the inner ring and the outer ring for keeping the tip speed of the welding torch constant, and an inner / outer wheel for generating inner / outer wheel speed command values based on the calculated values of the inner / outer ring speed calculation means. The traveling control device for the self-propelled welding carriage according to claim 4 , further comprising a wheel speed command value generating means. 6. The traveling control device for the self-propelled welding carriage according to claim 5, wherein the inner / outer ring speed calculation means has a correction portion for correcting a variation in the length of the welding torch.