JPS6147672B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a collision prevention device for a traveling robot running on a track formed by a combination of straight lines and circular arcs.

FIG. 1 shows a robot assembly system using robots 1a and 1b.

On the circulation track 2 consisting of a combination of straight lines and circular arcs, carriages 8a and 8b run in the direction of arrow A3.
The robots 1a and 8b are mounted on the traveling platforms 8a and 8b, respectively.
1b is placed. Peripheral devices 3a to 3e are appropriately arranged around the track 2. The robots 1a and 1b stop at the respective stations of the peripheral devices 3a to 3e and handle the assembly work of parts 4 sent to the peripheral devices. The assembly of the parts 4 is completed when the robots 1a and 1b complete one revolution on the circulation track 2.

In the figure, if the robot 1a stops at the station of the peripheral device 3c, and another following robot 1b starts running from the station of the peripheral device 3e during handling work, it will travel only a predetermined distance and then move to the next station. For example, if the robot travels to the station of the peripheral device 3a and stops, there will be no problem, but if the travel distance data is corrupted by external noise etc. and changes to a value larger than the predetermined distance, the rear robot 1b may A rear-end collision may occur with the robot 1a ahead. This rear-end collision destroys the robots 1a, 1b and the peripheral device 3c, and causes damage to the parts 4.

Conventionally, for devices running on straight tracks, a limit switch or the like is used to detect the traveling device in front, apply braking to the traveling drive device, and prevent a collision.
Alternatively, there are examples of relaxation, but there are no examples for the combination of straight and circular trajectories shown in FIG. 1, and there are no examples for assembly systems where assembly work is performed by robots. Therefore, there has been a demand for a collision prevention device that is simpler, safer, and more reliable than the conventional one.

The present invention was proposed based on the above requirements, and its purpose is to prevent collisions between adjacent running platforms at any position on a track consisting of a combination of straight lines and circular arcs, and to Preventing damage to peripheral equipment and products, ensuring safety in the production process,
To provide a collision prevention device for a traveling robot that significantly improves economic efficiency and is capable of immediately stopping a traveling platform drive part and a robot driving part even if a traveling platform collides with the robot from behind. It is in.

In order to achieve the above object, the present invention uses a detection switch attached to one end of the traveling platform and a reflector plate also installed at one end of the traveling platform opposite the detection switch to prevent the following traveling. The traveling base driving section and the robot driving section are stopped by detecting that the base approaches within a certain operating distance, and the shape of the reflector is adjusted according to the operating distance L, the trajectory arc radius R, and the traveling platform dimensions. A saucer-shaped polyhedron forming an inclined surface having an inclination angle determined from This system is characterized by a collision prevention device for a traveling robot that has dampers installed before and after the robot and a limit switch operated by the dampers to be able to respond in the unlikely event of a rear-end collision.

Embodiments of the present invention will be described below based on the drawings.

In FIGS. 2a and 2b, the carriage 8 on which the robot 1 and the carriage drive motor 15 are placed is supported by a pair of carriages 16a and 16b that can rotate independently about central axes 9a and 9b, respectively. There is.
Wheels 5 that roll on the track 2 and side rollers 7 that roll along the V-groove 6 of the track 2 are installed on the carts 16a and 16b. Therefore, the traveling platform 8 is
The vehicle can run smoothly along the straight and arcuate portions of the track 2.

A photoelectric switch 11 is installed in the center of the front of a truck 16a on the side (referred to as the front surface) in the direction of movement of the traveling platform 8, and a reflector plate 12 is installed in the center of the truck 16b on the opposite side (referred to as the rear surface). This photoelectric switch 11 is operated by a reflector plate 12 installed on the rear surface of the preceding traveling platform 8, as will be explained later. In addition, the front and rear carts 16a, 16b
Dampers 13 are installed on the left and right sides of the vehicle to absorb the shock caused by the collision of the traveling platform 8. Each of the dampers 13 is provided with a limit switch 14 that is activated by the stroke of the damper. Although the traveling device for driving the traveling platform 8 is not clearly shown in the figure, for example, it drives a pinion gear via a speed reducer connected to the traveling platform drive motor 15, and is arranged inside the track 2. This can be done by meshing the rack gear and pinion gear.

Next, the shape of the reflector used in the above collision prevention device will be explained.

In two sets of traveling robots 1a and 1b that travel on a track 2 using a combination of straight lines and circular arcs,
When the front and rear traveling robots collide, there are only the following four possible arrangements.

(1) When both robots 1a and 1b are on the straight part of the track 2a as shown in Figure 3.

(2) As shown in Figure 4, the leading robot 1a
is on the straight section 2a of the track 2, and the following robot 1b is on the arcuate section 2b of the track 2.

(3) As shown in Figure 5, the leading robot 1a
is on the arcuate section 2b of the track 2, and the following robot 1b is on the straight section 2a of the track 2.

(4) As shown in Figure 6, both robots 1a,
1b are both in the arcuate portion 2b of the track 2.

First, in Fig. 3, the following robot 1b
The photoelectric switch 11 installed on the front surface of the robot 1a and the reflection plate 12 installed on the rear surface of the preceding robot 1a face each other head-on since both robots 1a and 1b are located on the straight section 2a of the track 2. Therefore, if the reflection plate 12 is formed with a vertical surface, the optical axes of the light projected from the photoelectric switch 11 and the light reflected by the reflection plate 12 will coincide. Therefore, the operating distance L of the photoelectric switch 11 may be determined as shown in the figure. The value of this operating distance L is determined according to the acceleration/deceleration characteristics of the carriage drive unit. That is, in FIG. 8, the vertical axis represents the speed V (m/sec) of the traveling platform 8, and the horizontal axis represents the time T (sec). Now, assuming that the traveling platform 8 reaches a speed of 0 after t seconds from the maximum speed v, the deceleration α=v/t, and the distance until the robot 1b stops is expressed as s=1/2αt ² . Therefore, the operating distance L is determined by the following equation.

L=s+r=1/2αt ² +r where r is a margin value.

When the following robot 1b enters within the operating distance L determined in this manner, the photoelectric switch 11 is activated, thereby stopping the drive section of the traveling platform 8, and the following robot 1b collides with the preceding robot 1a. This can be prevented.

In the case of FIG. 4, the projected light from the photoelectric switch 11 installed on the front carriage 16a of the following robot 1b has an inclination angle θ ₁ with respect to the preceding reflecting plate 12. This angle of inclination _θ1 is determined from the central axis 9a of the front carriage 16a of the bot 1b to the photoelectric switch 11.
It is determined by the following formula from the distance l ₂ and the operating distance L.

θ ₁ =L+l ₂ /R Therefore, if an inclined surface having an inclination angle θ ₁ is formed at one end of the reflection plate 12, the following robot 1b can enter within the operating distance L, as explained in FIG. It becomes possible to detect this.

In the case of FIG. 5, since the preceding robot 1a is located on the circular arc portion 2b of the orbit 2, the inclination angle _θ2 is determined by the following formula.

θ ₂ =L+l ₁ /R where l ₁ is the distance from the center axis 9b of the truck 16b to the surface of the reflector 12.

In the case of FIG. 6, since both the preceding robot 1a and the following robot 1b are located on the circular arc portion 2b of the orbit 2, the inclination angle _θ3 is determined by the following formula.

θ ₃ =L+l ₁ +l ₂ /R Therefore, by forming the inclined surface of the reflecting plate at θ ₃ , the same effect as described above can be achieved.

In FIG. 7, the reflecting plate 12 is formed into a saucer shape having a vertical surface 12c and inclined surfaces 12a continuous to both ends thereof. The inclination angle of the inclined surface 12a changes from θ ₁ to θ ₃ as described above, but since the dimensions l ₁ and l ₂ are small compared to the radius R of the circular arc portion of the track 2, only a slight difference occurs. Therefore, for example, by setting the average inclination angle of θ ₁ to θ ₃ to θ, and forming an inclined surface having this inclination angle on the reflector plate 12, the optical axis 17 from the photoelectric switch 11 to the reflector plate 11 can operate in the same manner. The distance L will be held. Further, the reason why the reflective plate 12 is formed with inclined surfaces at both ends is to accommodate the case where the traveling platform 8 runs in the opposite direction to the direction indicated by the arrow A (clockwise) shown in FIGS. 4 to 6. be.

Next, the operation will be explained in more detail.

During the stopping operation at the station where the preceding robot 1a is located, the photoelectric switch 11 is
When the following robot 1b installed at 6a moves and approaches within the operating distance L of the photoelectric switch 11, the photoelectric switch 11 operates no matter where the robot 1a is on the track 2, and the control device of the robot 1b (Fig. (not shown) receives the operation signal and brakes the traveling base drive motor 15 of the robot 1b at a set deceleration to stop the robot 1b. Since this control distance is set in advance to be shorter than the operating distance L of the photoelectric switch 11,
The following robot 1b is the same as the preceding robot 1a.
can be stopped without colliding with the vehicle. At this time, the operation signal of the photoelectric switch 11 is transmitted to the robot 1.
It is possible to brake the robot arm b in the same way and stop it (not shown).

Furthermore, if the following robot 1b collides with the preceding robot 1a for some reason, the dampers 13 installed on each of the robots 1a and 1b operate. The stroke of the damper 13 activates the limit switch 14, and this signal allows all power drives to be stopped immediately and mechanical brakes to be applied. Therefore, all the robots can be stopped, so damage to the robots 1a, 1b and the peripheral devices 3a to 3e can be prevented, and the parts 4 can be prevented from being damaged. In this embodiment, a photoelectric switch is used as the detection switch, but the detection switch is not limited to this, and for example, an ultrasonic switch may be used.

As is clear from the above description, according to the present invention, collisions can be prevented whether the robot is on a straight section or an arcuate section of the track, and damage to the robot and peripheral devices can be prevented and It is possible to prevent damage to the product and improve the safety and economic efficiency of the production process.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the configuration of an assembly system using a traveling robot, Fig. 2a is a plan view showing a collision prevention device according to an embodiment of the present invention, Fig. 2b is a side view thereof, and Fig. 3 6 to 6 are plan views illustrating the relationship between the arrangement and operating distance of adjacent traveling robots running on a trajectory formed by a combination of straight lines and circular arcs, and FIG. 7 is a reflection plate used in an embodiment of the present invention. FIG. 8 is a diagram showing the deceleration characteristics of the carriage driving section. 1a, 1b...Robot, 2...Orbit, 3a,
3b, 3c, 3d, 3e... Peripheral equipment, 4... Parts, 5... Wheels, 6... V groove, 7... Side rollers, 8, 8a, 8b... Travel platform, 9a, 9b...
Central axis, 11...Photoelectric switch, 12...Reflector, 13...Damper, 14...Limit switch, 15...Traveling platform drive motor, 16a, 16b
...Truck, 17...Optical axis.

Claims (1)

[Scope of Claims] 1. A collision prevention device for a traveling robot consisting of a plurality of scanning platforms on which a robot is mounted and traveling on a trajectory made of a combination of straight lines and circular arcs, which is attached to one end of the scanning platform. and a detection switch that stops the driving section of the traveling platform and the driving section of the robot when a following traveling platform approaches within an operating distance L determined from the deceleration characteristics of the traveling platform, and a detection switch facing the detection switch. A transmitting means is attached to one end of the preceding running platform and sends a proximity signal to the detection switch, the transmission means being attached to one end of the preceding running platform and transmitting a proximity signal to the detection switch, the transmission means being connected to a vertical plane facing the detection switch, the operating distance L, the radius R of the orbital arc portion, and the traveling distance. Inclination angle θ determined from the table dimensions
a concave reflecting plate formed by opposing inclined surfaces arranged symmetrically on both sides of the vertical plane; and a concave reflector plate attached to the front and rear ends of the traveling base, and configured to prevent the traveling base from colliding with each other when the traveling base collides with each other. 1. A collision prevention device for a traveling robot, comprising: a damper that absorbs impact; and a limit switch that is activated by the operation of the damper and stops the driving section of the traveling platform and the driving section of the robot. 2 When the operating distance L is the deceleration α of the carriage drive unit, the time t required for the carriage drive unit to reach zero speed from its maximum speed, and the margin r, it is expressed by the following formula: A collision prevention device for a traveling robot according to claim 1, wherein the device is a collision prevention device for a traveling robot. L = 1/2α・t ² + r 3 When the reflecting plate has a working distance L, a radius R of the orbital arc portion, and a running platform size l (l = l ₁ orl ₂ or l ₁ +l ₂ , see Fig. 2), Claim 1, characterized in that it is formed from a saucer-shaped polyhedron formed by forming inclined surfaces at both ends with an inclination angle θ determined by the following formula, and connecting these inclined surfaces with vertical surfaces. Collision prevention device for the traveling robot described above. θ=(L+l)/R 4 The collision prevention device for a traveling robot according to any one of claims 1 to 3, wherein the detection switch is a photoelectric switch. 5. Claims 1 to 3, characterized in that the detection switch is an ultrasonic switch.
Collision prevention device for a traveling robot according to any one of the following paragraphs.