JPS6111877B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crane collision prevention method for preventing collisions between retractable and swing type cranes installed in close proximity to each other.

When two or more cranes are installed adjacent to each other, preventing collisions with each other has become an extremely important safety issue.

Conventionally, overhead cranes use detection means such as photoelectric, ultrasonic, or microwave to detect when two cranes are approaching each other and stop one of the cranes, but this method does not require complicated movements. It is unsuitable for swinging, retracting cranes, etc. In other words, in such conventional methods, two opposing
Although it is possible to prevent collisions between the crane bodies on the platform, it is extremely difficult to prevent collisions between the jib or boom of the swinging section. There is also a method of preventing collisions by attaching an antenna to the jib or boom, but since the mutual relationship between the jib or boom changes irregularly, the characteristics are unstable and expensive, making it impractical.

The present invention has been made in consideration of the above points, and
For retractable and swing type cranes, angle sensors such as synchro electric equipment installed on each crane detect the swing angle and heave angle of both cranes, and based on these detected values, a calculator is used to determine the jib or boom between the cranes. This invention provides a crane collision prevention method that calculates the approach distance of each crane, and issues a collision prevention signal to the control equipment of each crane in accordance with the calculation result.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, in the present invention, first,
Each of the No. 1 crane and No. 2 crane (the jib crane is shown in the figure) is equipped with a synchro electric transmitter and receivers A ₁ and B ₁ for detecting turning angles, and a synchro electric transmitter and receivers A 1 and B 1 for detecting the heave angle. A transmitter and receivers A ₂ and B ₂ are provided respectively. Note that any suitable angle sensor other than the synchro electric sensor may be used. Next, as shown in Fig. 2, signals S ₁ to _{S 4} of the turning angle and heave angle of the No. 1 and No. 2 cranes are sent from the receivers of these synchro electric machines A and B, respectively, to determine the distance between the cranes. A computing unit 10 is provided to calculate the approach distance and issue an approach signal CS.

The crane collision prevention method according to the present invention is to check whether cranes No. 1 and No. 2 will collide based on the calculation results of the calculation unit 10, and the checking method will be described below.

If the jibs of No. 1 and No. 2 cranes are now in the position shown in Figure 3, whether or not the jibs will collide can be determined by looking down from the tip of one jib to the other crane's jib on the plan view. It is determined by the lengths p and q of the perpendicular lines. In addition, Fig. 3 a is a schematic side view of both cranes, b is a side view of the jibs 12 and 22, and c is a schematic side view of the jib 1.
2, 22 is a plan view. In other words, from the tip of jib 12 of No. 1 crane to jib 2 of No. 2 crane
2 and rope 23, the length of the perpendicular from the tip of jib 12 to the vertical plane is p, and similarly from the tip of jib 22 of No. 2 crane to the jib of No. 1 crane. 12 and the rope 13, the length of the perpendicular from the tip of the jib 22 to the vertical plane is q. Next, determine the length of each crane's jib as L ₁ ,
If L ₂ , the value of the jib length measured in plan view
l ₁ and l ₂ are determined by the following equations due to the influence of the undulation angles α ₁ and α ₂ .

l ₁ = L ₁ cosα ₁ ...(1) l ₂ = L ₂ cosα ₂ ...(2) Using these l ₁ and l ₂ to express the above p and q, the following equation is obtained.
It is expressed by (3) and (4).

p=|tanβ ₁・(S−l ₂ cosβ ₂ ) −l ₂ sinβ ₂ −C|・|cosβ ₁ | =|S sinβ ₁ −l ₂ Sin(β ₁ +β ₂ ) −C cosβ ₁ ...(3 ) q=|tanβ ₂・(S−l ₁ cosβ ₁ )−l ₁ sinβ ₁ +C|・|cosβ ₂ | =|S sinβ ₂ −l ₁ sin(β ₁ +β ₂ ) +Ccosβ ₂ | ...(4) In addition, α ₁ and α ₂ are the undulation angles seen from the side of each jib of No. 1 and No. 2 cranes, β ₁ and β ₂ are the turning angles seen from the plane, and S is the angle between the corner jib base points. The distance C represents the position difference between No. 1 and No. 2 cranes as seen from the plane. (3) above,
(4) In the formula, S is a constant if the crane is a fixed type,
In the case of a traveling type, it becomes a variable. Further, S is set to zero when two cranes run on the same running track, and when the cranes run on parallel running tracks, C is set to the interval between the two tracks.

Based on such arithmetic expressions, the present invention calculates No.
Synchro electric machine A ₁ for detecting the heave angle and turning angle installed on the No. 1 crane and the No. 2 crane, respectively.
Based on the signals S ₁ to _{S 4} from A ₂ , B ₁ , and B ₂ , it is checked whether the calculation result by the calculator 10 satisfies the following two conditions to determine whether or not there is a collision between the two cranes. judge.

() Correct projection length of both cranes' jibs to the ground l ₁ ,
When the sum of l ₂ is greater than the distance S between both cranes shown in Figure 3, l ₁ cosβ ₁ + l ₂ cosβ ₂ = L ₁ cosα ₁・cosβ ₁ + L ₂ cosα ₂・cosβ ₂ >S () both Length p, q of the perpendicular line from the tip of the crane's jib to the vertical plane including the jib and rope of the other machine
reaches within a predetermined value A at which the risk of collision is considered to be high, p≦A...(a) or q≦A...(b) Furthermore, Figure 4 shows the above calculation. A specific example of the configuration of the arithmetic unit 10 is shown. The above conditions (
A) and (b) are determined by comparators 14 and 15, and the determined output is sent to an OR circuit 16. The above conditions () and () are determined by an AND circuit 17, and its output becomes an alarm signal.

As described above, in the crane collision prevention method according to the present invention, predetermined calculations are performed in accordance with the swing angle of the crane and the heave angle of the jib or boom detected using an angle sensor such as a synchro electric machine. This system determines whether there is a mutual collision at high speed and with high precision, and can prevent collisions between cranes moving in three dimensions.Moreover, the predetermined calculation formula is made up of trigonometric functions, sine and cosine. , it has the excellent advantage that the arithmetic device is simple and can be realized at low cost. This method can be applied not only to preventing collisions between cranes, but also to preventing collisions with buildings.

[Brief explanation of drawings]

FIG. 1 is a simplified diagram showing an example of the configuration of a crane section for carrying out the method according to the present invention, FIG. 2 is a block diagram showing an example of the configuration of the electrical processing section, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a block diagram showing an example of the configuration of the arithmetic unit according to the same embodiment. A ₁ , B ₁ ... Synchro electric machine for detecting the rotation angle of the crane, A ₂ , B ₂ ... Synchro electric machine for detecting the heave angle of the crane, 10... Arithmetic unit, S ₁ , S ₃ ... Heave angle α ₁ , α ₂
detection signal of S ₂ , S ₄ ... detection signal of turning angle β ₁ , β ₂ , CS ... approach signal, 12, 22 ... jib, 13,
23...rope.

Claims (1)

[Claims] 1. Detect the turning angle and undulation surface of each jib of two or more cranes, as well as the two-dimensional distance between the jib base points of each crane, and also detect the jib length unique to each crane and these detected values. Based on the respective applicable swing angles and heave angles, calculate the length of the perpendicular line from the tip of the jib of each crane to the vertical plane containing the jib of the other crane and the load lifting rope, and In a crane collision prevention method that issues an alarm when the length of the calculated perpendicular line becomes less than a preset value based on the permissible approach distance between both jibs, the orthogonal projected length of each jib onto the ground is further calculated, and when the calculated sum of the orthogonal projected lengths of both jibs on the ground is shorter than the distance between the jib base points of the two cranes, generation of the warning is prohibited. Method.