JPH0428640B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for preventing cranes such as tower cranes that raise and lower and swing with a suspended load attached at a construction site from colliding with buildings or other cranes during operation. . (Prior art and its problems) As a crane collision prevention method of this type, for example, a central control device can control the operating status of multiple cranes that interfere with each other by detecting the swing angle and heave angle of each crane. The central control device issues a warning, a control command, or a forced stop to each crane depending on the state of approach to the first and second warning areas regarding collision risk set in advance around the crane boom. (Refer to Japanese Patent Publication No. 56-22795). Another method is to orthogonally project each crane boom onto a horizontal plane, calculate the shortest distance between the crane booms in this state, and stop the operation of each crane boom when the distance approaches a preset allowable distance. Yes (see Special Publication No. 58-20877). However, in the former case, the warning area is set in advance regardless of the operating speed of each crane boom or the load being lifted, so even if a collision should be avoided, the crane responds excessively and the crane operation is restricted. There was a risk that this would reduce work efficiency and make it impossible to avoid a collision between one boom and the hoisted load or hook wire on the other. In addition, in the latter case, collisions are judged only based on data obtained by projecting the crane boom onto a horizontal plane, so if a collision occurs due to the movement of the suspended load or the angle of elevation, it may not function effectively and may fail. It was enough. (Objective of the Invention) Therefore, in order to improve the problems of the prior art described above, the present invention takes into consideration factors such as the weight and length of the suspended load, in addition to the swing angle and undulation angle of the boom and the length of the hook wire. In addition, the system grasps the operational status of the crane and predicts its operation, and based on this information, controls are activated to avoid crane collisions. This makes it possible to provide a reliable and safe crane collision prevention method, and also contributes to improving work efficiency. (Summary of the Invention) The crane collision prevention method of the present invention sequentially measures the boom rotation angle, boom luffing angle, and the length of the hook wire for a suspended load of a crane in operation at predetermined intervals, and combines these data with each other. The future trajectory of the crane in the horizontal and vertical projection planes is predicted based on the maximum length of the suspended load and the weight data of the suspended load, and on this trajectory, it is possible to prevent contact or intersection between cranes or between cranes and buildings, etc. Accordingly, a collision is determined, and if there is a possibility of a collision, a command for optimum avoidance operation of the crane is given. (Example) An example of the present invention will be described below based on the drawings. FIG. 1 is a block diagram showing the configuration of an apparatus used to implement the method of the present invention, which can be roughly divided into a detection section 1, a terminal control section 2, and a data transmission section 3.
and a central control section 4. Furthermore, code 5
is another crane system having the above 1, 2, and 3. In order to detect the rotation angle a of the crane boom 6 shown in FIG. In order to detect the heave angle b of the crane boom 6 shown in FIG. In order to detect the length c of the wire 9 connected to the wire 9, it is equipped with a wire length detector (not shown) using, for example, an absolute type rotary encoder attached to the winding portion of the wire to measure the winding amount. There is. Each of these detectors measures the length of the hook wire for each of the swinging angle and the luffing angle of the boom during operation of the crane, and sequentially sends this data to the terminal control unit 2. The reason for using absolute rotary encoders as each of the above-mentioned detectors is that once they are initialized at the time of installation, they can be read as absolute value data and can be used continuously even after a power outage is restored. The terminal control unit 2 is installed in the driver's seat of the crane and is operated by the driver, and processes each data sent from the detection unit 1 and also functions as the main computer of the central control unit 4. It is mainly composed of subcomputers that exchange information between the two. This subcomputer includes an input port that transmits data from the detection unit 1 to the subcomputer, and a horizontal and vertical projection of the crane in operation based on the data from the detection unit 1 processed by the subcomputer. A display that displays diagrams on a cathode ray tube, a RAM or ROM memory pack that stores execution programs and reception programs for controlling the subcomputer, and a memory pack that stores the execution program and reception program for controlling the subcomputer, and a A sound generator that issues an alarm in response to an instruction is connected to a communication line that exchanges signals between the subcomputer and the data transmission section 3. The above-mentioned memory pack may be built in the subcomputer, but it is made into a separate pack so that it is convenient for the main computer or the like to change the memory contents at any time. The data transmission section 3 transmits signals between the terminal control section 2 and the central control section 4, and uses optical communication to reduce the influence of radio wave interference and improve reliability. The central control unit 4 processes data from each terminal control unit provided in each crane, and also stores various information necessary for crane work in advance and provides these various types of information to each terminal control unit. The main computer is located in a central control room that is located away from where each crane is installed, and supervises each crane. This main computer includes a communication line that sends and receives signals to and from the data transmission section 3, a printer that displays and records processing information of the main computer in characters, a display that displays on a cathode ray tube, and a magnetic disk. A floppy disk for recording is connected to each. The various types of information stored in the main computer in advance include, for example, data on the number of cranes to be used and their installation locations, data on work scope regulation areas including buildings and their drawing methods,
There is a method for drawing graphic data of the crane's turning radius and permissible heave angle, data related to crane collision judgment, instruction data for optimal evacuation operation of the crane, etc. Next, a method for preventing crane collisions using the above device will be explained based on the work procedure.
In order to simplify the explanation, only one crane will be explained, but the same applies to other cranes. B. With the central control unit 4 and the terminal control unit 2 in operation, the main computer sends a program execution command to each subcomputer, and each terminal control unit 2 receives the command via the data transmission unit 3.
performs a memory acceptance regime. (b) The central control unit 4 transmits graphic data of a cross section of a building in the vicinity where the crane is installed, and the terminal control unit 2 that receives this data initializes the screen data in the buffer memory. C. From the central control unit 4 to the regulated area, building plan,
Fixed data such as maximum working radius, crane installation position data, etc. are transmitted, and the terminal control unit 2 that receives this data is stored in the buffer and combined with the building cross-section data as shown in Figs. 4 and 5. A horizontal plane projection view and a vertical plane projection view of the crane as shown are displayed on the same screen of the display. In FIGS. 4 and 5, the left half shows the horizontal projection plane, and the right half shows the vertical projection plane along BB' and CC', respectively. D. On the other hand, regarding one crane operation, the crane operator sets the maximum length of the suspended load and the weight of the suspended load before the operation, inputs it from the subcomputer, stores this data in the buffer of the subcomputer, and It is also stored in the memory of the main computer. (e) When crane work is started, the detection unit 1
detects the swing angle a, the lifting angle b, and the length c of the hook wire of the boom 6, and these data are sequentially input to the terminal control unit 2. The terminal control section 2 reads these data at predetermined time intervals based on the clock signal and transmits them to the central control section 4. F. The central control unit 4, which has received the first detection data from the terminal control unit 2, stores it in the buffer, calls the above-mentioned restricted area and other fixed data necessary for management, and creates an alarm between it and the detection data. Performs data calculations and other necessary calculation processing. This provides display data necessary for drawing Figures 2 and 3 in the initial state of the hook coordinates, boom rotation angle, boom luffing angle, boom plane, boom side surface, etc., and the need to issue an alarm in this initial state. Alarm data indicating whether or not the alarm exists is created, these display data and alarm data are stored in a buffer, and after being transmitted to the terminal control section 2, the interrupt controller is initialized so that it can accept the next detection data. G. The terminal control unit 2, which has received the display data and alarm data from the central control unit 4, displays the display data on the basic screen of the display and turns on the sound if there is a risk of collision if the work continues in this state. An alarm is generated from the generator. H. The terminal control unit 2 reads the next detection data following the above detection data, and the central control unit 4 receives this detection data via the data transmission unit 3.
Now, store the data in the buffer, and
Performs arithmetic processing on display data. Furthermore, the detection data read at predetermined time intervals based on the clock signal is determined from the detection data at the previous measurement point and the detection data at the current measurement point. The system calculates the predicted trajectory of the suspended load and wire, determines whether there is a possibility of a collision, and creates data for the optimal evacuation operation to avoid a collision. These display data and alarm data are sent to the terminal control unit 2.
The information is transmitted to the operator and the operator can perform an optimal evacuation operation or directly control the crane drive to avoid a collision. Furthermore, if it is determined that there is no risk of collision, the crane operation continues, repeating the above process and constantly predicting the next trajectory based on the latest detection data to prevent collisions. Incidentally, FIG. 6 is a flowchart showing an execution program of the central control section 4 and the terminal control section 2. Next, the above-mentioned trajectory prediction, collision determination, and optimal avoidance driving will be explained using drawings. First, Table 1 shows how to predict these trajectories.
Various types of data are required.

【table】

[Table] Among these data, those related to velocity and acceleration can be calculated by calculating the transition of each data detected at the two latest points sampled by the clock pulse. For example, if a boom that is rotating with a predetermined radius R1 with a suspended load as shown in Figure 14a and b stops at point P1, the boom will come to rest at point P1, but the suspended load will be affected by inertia. Then, it swings in the tangential direction X and moves to point P2, which is regulated by the length Lw of the wire, so the movable turning radius R2 increases and the collision danger area increases. For this reason, the swing width of the suspended load is
It is necessary to predict Lx and take measures to avoid collisions. The swing width Lx of the suspended load can be determined using the principle of a pendulum. First, from the principle of conservation of energy, the kinetic energy E1 of point P1 is equal to that of point P2.
Since it is equal to the potential energy difference E2 at point P1, from these we can obtain the formula for calculating the lifting height Hx of the suspended load caused by the swinging of the suspended load, and based on the Pythagorean theorem, we can calculate the swing width Lx of the suspended load. The formula for calculating the length of the wire is obtained using trigonometric functions.
Formulas for determining Lw are obtained, and from these formulas, the swing width Lx of the suspended load can finally be determined. In this way, the maximum length of the suspended load, the weight of the suspended load, etc. are taken into account to predict the trajectory of the collision danger area and take measures to avoid collisions. This significantly improves safety compared to systems that take measures to prevent collisions based on the assumption that the vehicle will follow the vehicle and turn around. FIG. 7 is a horizontal projection view showing a predicted trajectory when the boom is in a swinging state, and FIG. 8 is a vertical projection view showing a predicted trajectory when the boom is in an up-and-down state. As shown in FIG. 7, when the boom turns, the wire connected to the tip of the boom and the load suspended from the wire swing while turning. In this case, the wire may swing within the range of the envelope connecting the inner small circle shown by the solid line in the figure, and as the wire swings, the suspended load will move outside the circle shown by the solid line in the figure. There is a possibility that it will oscillate within the range of the envelope connecting the great circles. In the vertical plane projection view of FIG. 8, the swinging range is shown in which the wire is shown as an inner vertical triangle shown by a solid line, and the suspended load is shown at the base of the outer vertical triangle. Furthermore, if the boom angle is made smaller as shown in Figure 8, the wire and the suspended load will have a larger turning radius and will approach the ground side and collide, as shown by the imaginary lines in Figures 7 and 8. Since the expected trajectory is likely to be dangerous, the boom is operated to avoid this in advance by the above-mentioned means. FIGS. 9 and 10 are horizontal plane projection diagrams illustrating collision determination. In the case of Figure 9, it is predetermined that the crane with the lower priority (determined in advance) will be operated in such a way that the crane approaches the crane with the higher priority and then turns and returns. , it is determined that there is no possibility of collision. However, in the case of FIG. 10, it is determined that there is a possibility of collision between cranes A and B during the determination cycle. FIG. 11 to FIG. 13 are horizontal plane projection diagrams showing the optimal evacuation operation according to the predicted collision state. In FIG. 11, if the upper and lower cranes continue to operate as they are, there is a possibility that they will collide with the upper crane along the predicted locus of the hoisted load of the lower crane. Therefore, the collision is avoided by predicting this during the judgment period and decelerating the lower crane. In the case of FIG. 12, since a collision cannot be avoided by the deceleration operation, the operation of the lower crane is stopped to avoid the collision. In the case of FIG. 13, since a collision cannot be avoided even by the above-mentioned stop, the collision is avoided by reversing the lower crane. Although not shown, as another method of avoidance operation, it is also possible to change the undulation angle of the crane and the amount of hoisting of the hook wire. (Effects of the Invention) As is clear from the above embodiments, the crane collision prevention method of the present invention is based on the latest data such as the crane's swing angle, luffing angle, and hook wire length sampled at predetermined intervals. The possibility of a collision is determined by predicting the trajectory of the crane in the horizontal projection plane and the vertical projection plane, and based on the determination result, the crane is operated in an optimal evacuation operation to prevent a collision. In this way, since the future trajectory is predicted from the latest data sequentially sampled from the crane in operation, the crane operation is excessively restricted as in the conventional method of setting a warning area in advance. Moreover, by adding the suspended load to the conditions, it is possible to deal with interference between the boom of one crane and the wire of the other crane, and changes in the suspended load due to differences in boom turning speed. Furthermore, compared to the conventional method in which collisions are determined only based on the horizontal projection plane of the crane, since the crane operation in the vertical projection plane can also be grasped, more accurate collision determination and collision avoidance can be achieved. It should be noted that the present invention is not limited to the above-mentioned embodiments, and various embodiments can be obtained within the scope of the gist.
For example, in the embodiment, the control section is installed separately into the central control section and the terminal control section, but it is also possible to perform these functions all at once in the central control section.

[Brief explanation of drawings]

Fig. 1 is an overall block diagram showing a device for carrying out the crane collision prevention method of the present invention, Fig. 2 is a plan view showing an outline of the crane operation, Fig. 3 is a side view of the same, Figs. Figure 5 is a diagram of the operating state of the crane displayed on the display, Figure 6 is a flowchart of the control unit, Figure 7 is an explanatory diagram of predicting the trajectory of the crane using horizontal plane projection, and Figure 8 is an explanatory diagram of the same vertical plane projection. , FIG. 9 and FIG. 10 are explanatory diagrams of crane collision determination, FIGS. 11 to 13 are explanatory diagrams of optimal evacuation operation of the crane, and FIG. 14 is an explanatory diagram of turning operation of the crane including elements of a suspended load. Explanation of symbols, 1...Detection unit, 2...Terminal control unit, 3...Data transmission unit, 4...Central control unit, 5
...Other crane systems, 6...Boom, 7...
...Hanging load, 8...Hook, 9...Wire, a...
...Turning angle of the boom, b...Luffing angle of the boom, c...
...Length of hook wire.

Claims (1)

[Claims] 1. Data on the number of cranes and their installation locations, data on work area control areas including buildings, methods for drawing horizontal and vertical projections, and graphic data on crane turning radius and permissible undulation angles are stored on the computer. Input various information in advance, such as the drawing method, data related to crane collision judgment, and instruction data for optimal evacuation operation of the crane.
Based on this data, the horizontal and vertical projection planes of the work range control area, including the crane and the building, are displayed on the display, and the maximum length and weight of the suspended load are set and sent to the computer prior to the crane operation. After inputting the information, after starting crane work, the boom swing angle and boom luffing angle of the operating crane and the length of the hook wire for lifting loads are sequentially measured at predetermined intervals, and each of these detected data is sent to the computer. At the same time, the computer calculates the trajectory of the operating crane and the suspended load in the horizontal projection plane and the vertical projection plane based on each of these detection data and displays it on the display. The predictions of the future trajectories of the crane, the hook wire, and the suspended load are calculated from the changes in each detection data detected at the two locations, and the operating crane and the suspended load are It determines the possibility of colliding with or crossing structures, etc., and if there is no possibility of collision, it continues the operation as it is, and if there is a possibility of collision, it decelerates the crane in operation. 1. A method for preventing a collision of a crane, characterized in that the optimum evasive operation control of either stopping, reversing, or reversing is instructed.