JP2000191277A - Method and device for compensating deformation of boom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the safety of crane operation at the time of elevating cargo by generating the appropriate control signal on the basis of a target value of position and a real value of deformation, and controlling a crane boom in response to the control signal. SOLUTION: A boom monitor 14 supplies a data for showing a real value of elevation angle and boom length measured by a sensor 12 and values processed when necessary to a control device 10. The boom monitor 14 stores the target value to be utilized for control in a memory 16. A difference between the stored target value and a measured real value is supplied to the control device 10, and the control device 10 generates the control variable for controlling a hoist mechanism and an elevating mechanism while utilizing the operation value set by an operator mechanism 18 and input variables. With this control, since deformation of the boom due to a change of load is compensated, each jib is never displaced from the target value in the horizontal direction. With this structure, the operator 18 can concentrate the working area while being released from a part of the monitoring work.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for compensating a crane boom deformation generated when a load is raised and lowered.

[0002]

2. Description of the Related Art As is well known, when a crane boom lifts a load, the crane boom deforms in a state of no load in proportion to the load. In order to optimize the crane boom performance in consideration of the deformation, it is necessary to consider such deformation.

[0003] Problems may arise especially when lifting and lowering luggage. FIG. 3 shows a state where the luggage is not lifted,
That is, it shows the crane boom 1 under no load, and a load 2 to be raised and lowered is attached to a hook at the tip of the crane boom. When performing lifting luggage, elevating force F _lift to counteract the loading force F _L resulting from the weight of the load gradually increases. Elevating force F _lift the load force F _L
Only when the load is exceeded, the load can be lifted off the ground.
When elevating force F _lift is still somewhat less than the loading force F _L is considerable force is acting on the crane boom 1 In the baggage 2 is still completely on the ground. As a result, as shown in FIG. 4A, the crane boom 1 is deformed. The deformation of the crane boom 1 caused by the lifting force
The horizontal distance from the fulcrum of the superstructure to the jib, ie, generally the turning radius or boom length, increases.

FIG. 4B is a vector diagram showing the force applied to the load 2 when the boom is deformed as described above. The increase in turning radius of the crane boom 1, elevating force F _lift according to luggage, and a vertical component F _lift to overwhelm the weight F _L luggage, comprising a horizontal component F _P. When elevating force F _lift is sufficiently larger than the force brought about by the weight of the luggage, so luggage is rocked by the action of the force F _P exerted on the horizontal direction with the luggage elevating. This can create a dangerous situation. For example, when lifting a concrete wall from a truck, the lifted luggage may be out of control, which may pose a danger to nearby people and equipment. In such a state, it is necessary to further increase the force F ′ _{lift provided} by the lifting mechanism for lifting the load. This force F ′ _lift is higher than the lifting force F _lift required when the lifting force acts purely vertically due to no lateral displacement due to deformation as shown in FIG. Great power.

The same can be said when unloading luggage. That is, as shown in FIG. 5, the crane boom 1 supporting the lifted load is deformed as indicated by A in FIG. 5 when the load is just lowered to the ground. When the load is lowered to the ground and the force acting on the load 2 from the crane boom 1 gradually decreases, the crane boom 1 shifts to the non-load state without deformation as indicated by B in FIG. To remove the hook and release the load, the ribs on the boom 1 must be repositioned to be directly above the load 2, otherwise the crane hook at that time could release the load and rock at the same time. . However, the state when the load is unloaded is the same as when the same load is lifted because the frictional force acting between the load and the ground at the moment when the load is lowered will prevent the load from swinging. It's not as deadly or dangerous as it is.

In order to compensate for the deformation of the boom when the load is raised or lowered, the crane operator operates the lifting mechanism 3 to change the angle of the boom 1 so as to offset the increase or decrease in the turning radius due to the deformation. Need to be
That is, the operator raises and cancels the boom when lifting, and lowers the boom when lowering the load to reduce the deformation of the boom. The crane boom action must always be as optimal as possible and the crane boom deformation is considered to be significant with the large forces involved, so it is important to compensate appropriately for lifting and lowering the load. Become.

[0007]

In such a compensation operation, that is, in raising and lowering the boom,
The crane operator is the "controller". FIG. 6 shows the flow of information in such a compensation operation. The crane operator looks around the work area and notes the instantaneous radius of the unloaded crane boom, for example, when lifting loads. This serves as a target value for the boom turning radius in the perfect lifting procedure for the operator. Limiting device for the load lifting moment (limiting the loa
ding moment (LML)) gives the operator information obtained through sensors about the actual state of the boom, but that information is about the turning radius that is important for the operator, Useful as an actual value for the operator's control response. Other values relating to the actual condition of the crane are also displayed and taken into account in the compensation operation. To do so, the crane operator must not only look at the actual value displayed, but also constantly monitor his work area while monitoring his actions.

In such a compensation operation, the crane operator is required to be experienced, that is, to be an expert. Otherwise, uncontrollable or dangerous operating conditions are likely to occur during the lifting of the load. The crane operator needs to monitor several displays at the same time while operating the various levers that properly control the hoisting mechanism or lifting mechanism for lifting of the load, and the crane boom deformation. Must be properly tracked to compensate for This places considerable strain on the crane operator. In other words, if various control levers must be operated at the same time while various displays are being monitored, the crane operator may lose concentration and may not be able to look over the entire work area. When such a condition occurs, there are more opportunities for dangerous operating conditions to occur, which may pose a danger to nearby people and machines when lifting the load.

[0009] It is an object of the present invention to provide a method and apparatus for compensating for crane boom deformation which increases the safety of crane operation during load lifting.

[0010]

In accordance with the present invention, a controller receives data relating to a detected crane boom deformation as well as a target value for the crane boom position. The controller generates an appropriate control signal based on these two input variables: a target value for the position of the crane boom and the actual value of the crane boom deformation measured or derived from the measurement. At least one positioning device of the crane boom is controlled in response to the control signal. Therefore, the crane boom is maintained at an appropriate position which is almost the target position when the load is raised and lowered.

For example, if the lifting force is increased and the deformation of the crane boom is correspondingly increased by increasing the turning radius, the target position of the crane boom, particularly the target position of the jib of the crane boom, does not substantially change. The position of the crane boom is adjusted. Thereby, the jib of the crane boom is maintained without horizontal displacement directly above the load to be lifted, regardless of the magnitude of the lifting force at that moment. In particular, since the elevation angle of the crane boom is adjusted by the boom elevating mechanism, the jib of the crane boom is still maintained just above the load to be lifted even if the crane boom curvature increases.

Further, the elevation angle of the crane boom can be kept constant, and for example, the length of the crane boom, the position of the crane bogie, and the like can be changed. Such control can be performed, for example, by changing the boom length or the elevation angle, as long as the boom jib is at the time of lifting and lowering the load so that the jib of the boom faces almost directly above the grounded load, even if the state of the boom changes according to the lifting force. It can also be achieved by adjusting several manipulated variables simultaneously, such as

[0013] In detecting the deformation of the crane boom, values measured by several sensors may be used.
In this regard, it is particularly desirable to use the following sensors. A position attached to the crane boom jib and measuring the current elevation angle of the crane boom jib at the lower end; disposed on the transducer crane boom jib;
Position for measuring the current elevation angle of the crane boom jib Transducer Linear transducer for measuring the overall length of the crane boom, lifting mechanism, especially located at the top of the pressure transducer crane boom of the lifting cylinder and at the top of the lifting jib A nodal column, such as one or more strain gauges or load detecting rollers, positioned at a point and measuring the force currently acting on the jib
A transducer that measures the load or change in load on the boom (when the boom consists of multiple telescopic columns)

The data detected by all the sensors mentioned above can be used in detecting the deformation or turning radius of the crane boom. Needless to say, data detected by a crane or other sensors provided on the crane boom may be used to reinforce the control operation.

Further, the deformation of the crane boom may be detected by using any one of the aforementioned sensors or a combination thereof. Crane boom deformation
For example, the detection is performed by using only the data of the position transducer provided on the lower surface or the lower region of the boom, the position transducer provided on the upper side or the upper region of the crane boom, or the linear transducer for detecting the entire length of the clen boom. You can also.

Alternatively, data from other sensors for control operations that can detect the actual deformation of the crane boom can be used. This includes, for example, a pressure transducer mounted on a lifting cylinder,
Alternatively, it can be performed by using data of a linear transducer for detecting the entire length of the crane boom. Furthermore, data obtained by position transducers mounted in the upper or lower area of the crane boom can be used for this purpose, and the combination of the aforementioned sensors is suitable for controlling the deformation of the crane boom. Data can be detected.

In order to increase the control characteristics, it is desirable to obtain a crane boom deformation value based on a group of characteristics detected, for example, by performing a trial operation before actually using the crane. Combining the individual sensors described above is only given as a typical embodiment,
Other sensors can be used to measure certain variables, so that the overall deformation of the crane boom can also be detected from a combination of variables detected by these sensors.

In one preferred embodiment of the invention, the crane boom deformation is detected by the actual value of the crane's turning radius as detected by one or more suitable sensors. Also, as described above, along with the lifting force at that moment, the crane individual or actual boom length or actual boom elevation angle, or
The current deformation or radius of the boom may be determined based on several measured variables. In general, the amount of deformation of the boom can be detected using the measured variables or a combination thereof, and then how much the deformation or radius of the boom has changed. This provides a clue to the horizontal distance between the steady load and the boom jib.

Not only do the measurements aid in detecting boom deformation, but also other values, such as the rate and direction of the hoist or lift mechanism, can be input to the controller. Is desirable. This operation variable may be input by a crane operator operating a control lever. The controller detects a deformation time profile that can be predicted to occur on the boom from the desired speed of the hoist mechanism, and can appropriately control the boom positioning device to set the boom at the target position.

As a target value for the position of the boom, it is desirable to use the turning radius of the boom immediately before placing the load on the ground or immediately before lifting, and in any case, the jib is displaced to the side. Rather than directly above the luggage. If the control operation is performed in accordance with this target value, it is possible to avoid the state of the boom in lifting and unloading the load shown in FIGS. 4 and 5, respectively. Further, the position of the boom when operating the control device can be regarded as the target value. In that case, the operator needs to ensure that the control device is activated at the appropriate time, i.e. when the jib is exactly above the load.

The output signal from the control device is preferably such that a boom positioning device, such as a crane lifting mechanism, is controlled, so that the boom elevation angle rate and The changing direction of the elevation angle can be controlled by the moving speed (rate) and direction of the lifting mechanism. As a result, it is possible to control the deviation of the jib, which is the position immediately above the luggage, from the target position in the horizontal direction. For example, in the operation state shown in FIG. 4A in which the jib does not face directly above the load to be lifted, the lifting mechanism is controlled so that the elevation angle of the boom is increased, and the jib is positioned directly above the load. It is desirable to come to the position.

It is desirable to control the hoist mechanism as a boom positioning device by controlling the hoist mechanism so that one or both of the moving speed and the moving direction of the hoist mechanism are controlled. In the case of such a configuration, such control operation can be achieved, for example, by performing the control together with the control of the lifting mechanism as described above, whereby complete lifting and lowering of the load is controlled, and rapid movement of the load and the No sideways sway can be avoided.

Further, by automatically controlling only one variable or a plurality of certain variables of the above-described positioning device, whether the hoist mechanism should perform a lifting operation or a descending operation by a crane operator. Other control variables may be defined so as to detect whether or not. In this case, it is preferable that the control device be input with a variable capable of detecting the deformation or actual deviation of the boom from the target state, and from this variable, an appropriate output which is output to move the boom, especially the jib to a desired position. A control signal can be determined.

A plurality of variables such as the actual value of the boom angle, the actual value of the boom length, the measured lifting force, etc. are input to the control device, and the moving direction and speed of the hoist mechanism and the actual It is desirable to use a fuzzy controller because it is possible to consider an embodiment in which a plurality of variables such as a change direction and a change rate of the position are output from the control device. This type of control can be considered as a kind of fuzzy expert system, and its control response can be defined in a pseudo-natural language based on a linguistic expression. An example is the following control language.

WHEN radius of the jib position is rat
her large AND lifting is rapidTHEN raise the boom
angle quickly AND lift the load slowly (If the radius of the jib position is rather large and the
(Raise the boom angle and slow down the load.)

To explain here, the above-mentioned logic statement corresponds to a situation in which a large radius of control such as a long radius occurs and the crane operator commands high-speed lifting. In such a situation, a control signal that causes a rapid change of the radius to the target position, such as a rapid increase in the elevation angle of the boom with respect to the horizontal, is output from the fuzzy controller, and at the same time, the lifting speed of the load is reduced. The hoist mechanism is controlled so as to be relatively slow, that is, lower than the speed specified by the crane operator. In such a situation, it may be necessary to step down rather than lift the load in order to control the deformation of the boom.

In general, fuzzy control consists of a number of such linguistic conditions that describe various possible control actions. Generally speaking, such a control action consists of a control algorithm. In order to perform such a control operation, as described above, a skilled operator of the crane which can execute the raising and lowering operation of the boom may be used.

The device according to the invention for compensating for the deformation of the boom as it raises and lowers the load, so that the boom can be maintained substantially at the target position, that is, the boom is not substantially displaced horizontally from the target position. A positioning device for positioning is provided. One or a plurality of measuring devices are provided in the control device to detect deformation of the boom in order to determine a target value representing the position of the boom. Since the boom positioning device is connected to the control device, the target position of the boom is set by the control device from the defined target value and actual value.

Preferably, the device for measuring or detecting the deformation of the boom comprises one sensor or a plurality of sensors capable of measuring or detecting one or both of the turning radius and the bending of the boom as described above. It is desirable.

For example, sensors for measuring the boom length, the boom elevation angle, or the actual lifting force acting on the boom may be used. Needless to say, as described above, it is not necessary to use all the sensors described above. One or more sensors can also be used to measure or detect boom deformation.

In a preferred embodiment, the lifting mechanism of the crane is used as a positioning device for controlling the position of the boom and maintaining the boom at a target position. In such an embodiment, one or both of the rate of change and the direction of change of the elevation angle of the boom may be adjusted to maintain the target position. Similarly, it is possible to use the hoist mechanism of the crane for the control action.

Further, by using the lifting mechanism and the hoist mechanism together, for example, by adjusting the lifting force generated by the hoist mechanism at the time of load lifting and the current position of the lifting mechanism, the target position of the boom can be appropriately maintained. It is also possible to prevent the boom from being significantly deformed or moving rapidly.

[0033]

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a control loop according to the present invention. This control loop allows the operator of the crane to enter and remove the control device from the circuit, and to provide the control device with one or both of the direction and speed of movement of the hoist mechanism. It is possible to define simple manipulated variables or target variables. Therefore, the operator cannot always maintain the jib of the boom directly above the load (target position) and cause dangerous swing as described above, for example, through one control lever of the hoist mechanism. Unloading and unloading of luggage can be performed while the control device is controlling the boom so that no horizontal jib movement occurs.

Data representing the actual values of the variables measured by the sensor 12, which determine the actual state of the boom, is input to the controller 10 shown in FIG. Sensors that measure the boom curvature or radius, boom elevation (more precisely, the elevation at the top and bottom of the boom), boom length, force acting on the boom, or pressure in the lifting cylinder Useful data from may be input. The actual value of the elevation angle of the boom and the actual value of the boom length are particularly useful values.

In this configuration, the values measured by the sensors are first supplied to the boom monitor 14. The boom monitor 14 is also adapted to handle other functions, such as, for example, load moment limitation (LML). Thereafter, the values detected by the sensors and the values further processed as necessary are output from the boom monitor 14 to the control device 10.
Supplied to At this stage, certain features have already been extracted from the measured values, for example, in utilizing the properties or performing appropriate calculations.

The boom monitor 14 records the actual value of the boom characteristic, such as the detected radius, measured by the sensors when the control operation is performed, as a target value to be used in a later control operation. There may be. Similarly,
As is clear from FIG. 1, the target value is stored in another memory (MEM) 1.
6 can also be stored. In this configuration, for example, when the control device is operated, the target value may be stored. However, it is also possible that the target value is automatically stored at the same time when the load is detected or when the load is unloaded. This may be done, for example, when a freely selectable pulling force (eg, 50 kg) is exceeded. The difference between the stored target value of this radius and the measured actual value, ie the error, is supplied to the control unit.

The operator 18 can input data to the control device 10 by operating a lever or manually operating switches. In this way, an input signal from the operator regarding the moving direction, the moving speed, etc. and the activation or deactivation of the control device is supplied. From these input variables, the control device detects output variables that control at least one of a hoist mechanism, a lifting mechanism, and a telescopic mechanism via a fuzzy control algorithm defined by a linguistic expression. A signal for controlling one or both of the change direction and the change rate is supplied to the hoist mechanism via the lines 10a and 10b or to the lifting mechanism via the lines 10c and 10d.

Such control may be performed by a control device also on a telescopic mechanism (not shown). The hoist mechanism may cause deformation of the boom via a lifting force acting on a lifting cable supported by the boom. The elevating mechanism sets or adjusts the elevation angle of the boom. In this arrangement, the boom length or elevation angle is such that each instantaneous deformation of the load, i.e., the boom caused by a change in load, is compensated in each case and each jib is displaced substantially horizontally from its target position. It must be constantly adjusted or controlled to avoid this.

FIG. 2 shows the flow of information in the operation of compensating for boom deformation according to the present invention. The crane operator first observes the working area. If the operator sees that he should lift the load, he initiates the control action and sets the operating value of the hoist mechanism with the control lever. Data representing actual values detected by sensors for the deformation of the boom is separately input to the control device, and these actual values are supplied from the boom monitor to the control device via, for example, a CAN bus.

As described above, the operation value of the hoist mechanism determined by the operator and the data representing the actual value of the deformation of the boom detected by the sensors are input to the control device. The controller uses these input information, that is, the input variables,
For example, a control signal for controlling one or both of the movement of the winch of the hoist mechanism and the control of the lifting / lowering mechanism of the boom is generated. By controlling the movement of the winch or controlling the boom elevating mechanism, the position and shape of the boom can be changed. Therefore, the crane operator need only determine the operating value, such as the desired speed for lifting the load. In the control operation for controlling the crane boom, such as the lifting mechanism or the hoist mechanism, since the operation value determined by the operator is taken into consideration, the radius of the boom does not change. The boom monitor, which acts to determine or limit the load moment as described above,
Display the actual measured value of the boom to the crane operator.

Thus, the control according to the present invention frees the crane operator from part of the monitoring work previously required for unloading and unloading, thereby concentrating on the work area.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a control loop according to the present invention.

FIG. 2 shows the information flow according to the invention for controlling the deformation of the crane boom.

FIG. 3 is a diagram showing a boom in a non-loaded state with luggage attached.

FIG. 4 is a diagram showing a boom deformed from a normal position in a load state and an action vector of a force on the boom.

FIG. 5 is a comparison diagram showing the crane boom after the load is placed on the ground and the crane boom in a loaded state.

FIG. 6 is a diagram showing a flow of information when the crane operator conventionally moves the boom up and down.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Crane boom 2 ... Luggage (load) 3 ... Lifting mechanism 10 ... Control device 12 ... Detection device

Claims (18)

[Claims] 1. A crane boom (1) for raising and lowering a load (2).
Detecting a deformation of the boom (1); and transmitting data representing the detected deformation of the boom (1) to the control device (1).
0), and a target value representing a target position of the boom (1) is supplied to the control device (1).
0), and outputting from the control device (10) a signal for controlling at least one device for positioning the boom (1) such that the boom (1) is substantially maintained at the target position. A boom deformation compensation method characterized by comprising: 2. The method according to claim 1, wherein the boom comprises:
A boom deformation compensation method, wherein the deformation of (1) is detected by measuring the curvature of the boom (1). 3. The method of claim 1, wherein the boom is
A boom deformation compensation method, wherein the deformation of (1) is detected by measuring a radius of the boom (1). 4. The method of claim 1, wherein the boom is
A boom deformation compensation method, wherein the deformation of (1) is detected by measuring an elevation angle of the boom (1). 5. The method of claim 1, wherein the boom
A boom deformation compensation method, wherein the deformation of (1) is detected by measuring the length of the boom (1). 6. The method of claim 1, wherein the boom
A boom deformation compensation method, wherein the deformation of (1) is detected by measuring a magnitude of a lifting force acting on the boom (1). 7. The method according to claim 1, wherein at least one of the moving speed and the moving direction of the hoist mechanism or the lift mechanism is manually supplied to the control device when the load is raised or lowered. Boom deformation compensation method. 8. The method of claim 1, wherein a radius of the boom before unloading or unloading is used as the target value for the position of the boom. Deformation compensation method. 9. The method according to claim 1, wherein a radius of the boom at the time when the control operation is started is used as the target value for the position of the boom. Method. 10. The method according to claim 1, wherein the at least one device for positioning the boom is a boom lifting mechanism, and at least one of a moving speed and a moving direction of the lifting mechanism is the control device. A boom deformation compensation method characterized by being controlled by: 11. The method according to claim 1, wherein said at least one device for positioning the boom is a boom hoist mechanism, and wherein at least one of a moving speed and a moving direction of the hoist mechanism is the control device. A boom deformation compensation method characterized by being controlled by: 12. The method of claim 1, wherein the control algorithm is executed by a fuzzy controller. 13. A crane boom for raising and lowering a load (2).
(1) at least one positioning device (3) for changing the position of the boom (1), at least one detecting device for measuring the deformation of the boom (1), and a boom (1) target value setting means for determining a target value for the position, and connected to the detection device for measuring the deformation of the boom, and also connected to the target value setting means, while the positioning device A boom deformation compensating device connected to the control device for maintaining the boom at its target position during work. 14. The boom deformation compensator according to claim 13, wherein the detector comprises a device for measuring at least one of a boom curvature and a radius. 15. The apparatus according to claim 13, wherein said detection device comprises a device for measuring at least one of an elevation angle of the boom, a length of the boom, and a lifting force acting on the boom. A boom deformation compensator characterized by the above-mentioned. 16. Apparatus according to claim 13, wherein said positioning device comprises a lifting mechanism (3) capable of changing the elevation angle of the boom. 17. The apparatus according to claim 13, further comprising a hoist mechanism for raising and lowering the load, wherein the hoist mechanism changes at least one of the moving speed and the moving direction of the load in response to the control device. A boom deformation compensating device. 18. Apparatus according to claim 16, wherein said control device (10) controls at least one of a rate of change and a direction of change of the elevation angle of the boom. apparatus.