JP3104017B2 - Crane steady rest control system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steady rest control system for a crane, and more particularly, to a trolley for traversing, which is provided with a hoist provided so that it can be hoisted and lowered by a rope. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane steady rest control system suitable for performing oblique transfer at a constant speed.

[0002]

2. Description of the Related Art In a cargo handling operation using a crane, it is necessary to sufficiently attenuate the swing of the hanging implement at the position where the load is gripped and the position where the load is detached when loading and unloading the load. For this purpose, the crane is combined with a steady rest system. However, a container crane is more difficult than a simple steady rest because of the poor controllability due to the long rope length and the necessity of simultaneously executing the positioning of the hanging tool with respect to the target point.

Therefore, if the target point of the transfer is known in advance, the transfer trajectory should be planned in advance as a temporal pattern so that the deflection can be removed at the target point and the transfer time can be minimized. Is generally performed.

[0004]

Meanwhile, the steady rest system includes a mechanical steady rest by a mechanical damping mechanism,
It is roughly classified into an electric steady rest controlled by a trolley traverse motor. The electric steady rest is characterized in that it can realize a highly accurate steady rest compared with the mechanical steady rest because a traversing speed pattern when carrying a load is planned in advance. There are several proposals for planning the traversing speed pattern, but most of them are based on the assumption that the rope length is constant. However, in an actual cargo handling operation, a so-called oblique conveyance is often performed in which the hanging tool is hoisted or lowered when the trolley is traversing, so that the rope length is not constant and is not practical.

On the other hand, a method based on the assumption that the rope length changes is also proposed.
Vol. 561 (1993-5) "Practical application of steadying control technology for container cranes"}, which requires convergence calculation, takes a long time, requires complicated algorithms, It is not practical from such.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a crane steady rest control system capable of realizing a steady rest of a hanger and a highly accurate positioning upon arrival at a target point.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a trolley for traversing is provided with a hanger provided so as to be able to be wound up and down by a rope. In a steady rest control system for a crane adapted to carry, an acceleration pattern for changing the traversing speed of the trolley in a time series from a conveying section between a gripping position and a releasing position of the load by the crane, which can be known in advance. And a feed-forward section for creating a steady rest trajectory plan based on the feed section. The feed-forward section divides the transport section into an acceleration section with a maximum acceleration, a constant speed section with a maximum speed, and a deceleration section with a maximum deceleration. The acceleration section and the deceleration section are each divided into a plurality of sections such that a constant-speed traversing section is inserted in the middle thereof. The degree pattern is created in advance, and the start and stop timings of the winding operation in the oblique transport are determined in advance, and the time for each section in which the oblique transport is performed is determined based on the final point of the oblique transport. The length of the last section is calculated from the natural length of the pendulum at that rope length assuming that this is constant from the rope length that can be known in advance, and the space immediately before the last section is traced back by the time of the last section. From the rope length that can be known in advance at the time point, it is assumed that this is constant, and the time of the section immediately before the final section is calculated by the natural frequency of the pendulum at that rope length. It is characterized in that it is determined repeatedly until the first section.

Each of the acceleration section and the deceleration section is divided into five sections which perform three acceleration traverses and three deceleration traverses with a constant speed traverse therebetween, and an intermediate acceleration traverse section and an intermediate deceleration traverse. The time of the section may be determined in consideration of a condition necessary for minimizing the oblique conveyance.

Further, according to the present invention, position measuring means for measuring the hoisting and lowering positions of the hoist, traversing position measuring means for measuring the traversing position of the trolley, and measuring the traversing speed of the trolley. A traversing speed measuring means, a deflection angle measuring means for measuring a deflection angle of the rope, and an estimating means for estimating a deflection angle and a deflection angular velocity of the rope based on a measurement result from the deflection angle measuring means, The feed forward section, together with the acceleration pattern, a target value of a hoisting and lowering position of the hoist, a target value of a traversing position of the trolley, a target value of a traversing speed of the trolley,
A target value of the swing angle of the rope and a target value of the swing angular velocity of the rope are calculated, and further, each target value from the feedforward section, a measured value from each of the measuring means, and an estimation result from the estimating means. And a means for controlling the hoisting / lowering motor and the traversing motor in response to the above.

In the feedforward section, each target value is calculated by first calculating a target value of the traverse acceleration.
From the calculated result, the remaining target value can be calculated using the equation of motion of the pendulum.

It is preferable that the calculation of each of the target values is performed in synchronization with the sampling timing of the measured value in each of the measuring means.

[0012]

The present invention is characterized in that, in the planning of the transport trajectory of the trolley, it is possible to cope with the oblique transport in which the trolley is traversed and the hoist is lifted or lowered at the same time. By using this trajectory plan for oblique transport,
It is possible to automatically carry the cargo in a short time, and as a result, it is possible to improve the efficiency of the cargo handling work.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. Referring to FIG. 1, in a container crane, a container 13 is moved by a traverse operation of a trolley 10 and a suspender 12 provided on the trolley 10 so that the trolley 10 can be wound up or down by a rope 11.
Is carried. FIG. 1 shows a case where the container 13 loaded on the container ship 14 is unloaded. However, at the position where the container 13 is gripped on the container ship 14 and the position where the container 13 is separated on land, The cargo handling work is performed manually by the operator. Container 1
Above the release position 3, there is a section called a manual override area, and manual-automatic switching is performed in this section. Then, automatic conveyance is performed in a conveyance section between the gripping position of the container 13 and above the release position. In particular, in the section of the automatic conveyance, the conveyance of only the trolley 10 in the horizontal direction and the oblique conveyance in which the horizontal movement of the trolley 10 and the lifting or lowering of the hanging tool 12 are performed in parallel are performed. The present invention is characterized by the operation in the oblique conveyance.

FIG. 2 shows a control system of a container crane employing the steady rest control system according to the present invention. Here, a traversing motor 21 for traversing the trolley 10 is used.
To control the steadying, and also controls the hoisting motor 22 for hoisting (including the lowering, hereinafter referred to as hoisting) the hanging tool 12. This control system is roughly divided into a feedback (state feedback) unit 23 for performing control so as to follow various measured state quantities and a target state quantity, and a plan of a transfer trajectory of a steady rest (hereinafter, referred to as a plan). (Referred to as steady rest trajectory planning). For this purpose, although not shown, as a means for measuring various state quantities, a winding position measuring device for measuring the winding position of the hanging tool 12,
A hoisting speed measuring device for measuring the hoisting speed of the hanging tool 12, a traversing position measuring device for measuring the traversing position of the trolley 10, a traversing speed measuring device for measuring the traversing speed of the trolley 10, and a swing of the rope 11. A deflection angle measuring device for measuring the angle is provided. The feedback unit 23 estimates a swing angle and a swing angular velocity of the rope 11 based on the measurement result from the swing angle measuring device 19 and a pendulum length λ described later, and outputs a shake angle estimated value and a shake angular velocity estimated value. A state estimator 25 is included. The deflection angle measuring device 1
9 is a case where the inclination angle of the rope 11 is actually measured,
In some cases, the inclination angle of the rope 11 is calculated by well-known image processing.

The feed forward section 24 can know beforehand the transport section between the gripping position and the release position of the container 13 before the transport operation. Then, based on the acceleration pattern, an optimum steady rest trajectory plan is created so as to minimize the shake at the final point of the conveyance. With this steady rest trajectory plan, the target values of the hoisting and lowering positions of the hoisting device 12, the target value of the traverse position of the trolley 10, the target value of the traverse speed of the trolley 10, the target value of the swing angle of the rope 11, and the rope 11 Is calculated.

In the feedback section 23, a deviation between the target value of the traversing position and the measured value, a deviation between the target value of the traversing speed and the measured value, a deviation between the target value of the deflection angle and the estimated value, and a target value of the deflection angular speed are determined. The deviation from the estimated value is passed through a multiplication unit 26 of the gain Kt, and the deviation between the multiplication result and the traversing speed target value is output to a controller / driver 28 of the traversing motor 21 through a limiter 27. The multiplier 1 also includes a rope 1
1 and the hanging tool 12 are regarded as a pendulum, and the length λ is given through a converter 32 that converts the pendulum length λ from the result of the measurement of the winding position. This is to cope with a change in the rope length. In the feedback unit 23, the deviation between the target value and the measured value of the hoisting position and the deviation between the target value and the measured value of the hoisting speed are passed through a multiplication unit 29 of a gain Kh.
Further, the multiplication result is output to the controller / driver 31 of the hoisting motor 22 through the limiter 30. Note that the deviation between the target value and the measured value of the hoisting speed may be omitted.

As is apparent from the above description, the steady-state control is directly related to the traversing position and the traversing speed, and the swing angle and the swing angular velocity. The control of the hoisting or lowering is independent of the steadying. Done.

In the steady rest trajectory planning, first, a traverse speed target value which is one of the target values in FIG. 2 is calculated. Once the traversing speed is calculated, other target values are calculated using the pendulum equation of motion.

FIG. 3 shows a traversing speed and an acceleration pattern based on a conveyance trajectory plan when the rope length is constant. Since the maximum allowable acceleration is determined for a container crane, using it as much as possible makes it possible to convey it in a short time. However, when considering the steady rest at the final point,
It is necessary to cut off the maximum acceleration at an appropriate timing to adjust the magnitude of the shake. FIG. 3 shows the situation.
In the acceleration section until reaching the maximum traversing speed and the deceleration section from the maximum speed to the stop, a constant-speed traversing is inserted between the traversing at the maximum acceleration or the maximum deceleration. That is, in the acceleration section, the acceleration traverse-the constant speed traverse-
Through the acceleration traverse-constant speed traverse-acceleration traverse, the vehicle reaches the constant speed traverse at the maximum speed, and in the deceleration section, reaches the final point through deceleration traverse-constant speed traverse-deceleration traverse-constant speed traverse-deceleration traverse. I have to.

In FIG. 3, an acceleration section A, constant speed sections B, D,
Acceleration section E and deceleration section G, constant speed sections H and J, deceleration section K
Is dependent on the natural angular frequency ω (and thus the period T) of the pendulum determined by the rope length, and τ =
π / (3ω). Here, ω is the natural angular frequency of the pendulum, ω = 2π / T, T is the period of the pendulum, and π is the pi.

The intervals C and I have a degree of freedom so that they can be determined from the remaining acceleration / deceleration times required to reach or stop at the maximum speed Vx, respectively. The section F of the maximum speed Vx is calculated from the transport distance to be moved.

FIG. 4 shows the hanging tool 1 in the pattern shown in FIG.
2 shows the deflection angle and the deflection angular velocity.

When the rope length changes, that is, in the case of oblique conveyance, the concept shown in FIG. 3 is basically used. However, the time to be allocated to the section where the rope length changes (winding or lowering is operated simultaneously) is set as described below.

At the time of the planning, the hoisting or lowering speed is premised on the maximum allowable speed in order to achieve the shortest transport time. The speed is assumed to be constant in the trajectory planning.

Hereinafter, a case where the lowering is performed from the middle of the section F in FIG. 3 to the section K will be described with reference to FIG. The end point of the final section K is the final target point or a point slightly above it. Therefore, the rope length y11 there can be known in advance on the steady rest trajectory plan.

In the present invention, the plan is advanced so that the time goes back from the last point. First, when y11 is determined, the natural angular frequency ω11 of the pendulum at that rope length is determined. If the last section K is represented by ω11, the time t11 of the last section is determined. Then, the rope length y10 which is traced back from the last section by the time t11 can be calculated because the unwinding speed is known. Using the same concept, the time t of the sections J, H, and G is sequentially determined.
10, t8 and t7 are calculated. In addition, time t9 of section I
Has a degree of freedom, it may be determined in consideration of other conditions (for example, the traversing position at which the lowering starts). In the acceleration section, the time point at which the vehicle reaches the maximum speed Vx is similarly set as the final point. Then, a degree of freedom is given to the time t3 of the section C.

Based on the above concept, the traverse acceleration pattern and the start timing of the hoisting or lowering operation are planned in advance of the automatic conveyance. Although each target value of the state quantity shown in FIG. 2 is calculated from the traversing acceleration pattern, it takes time to calculate the target value in a batch. Therefore, a method of sequentially calculating a target value at the next sampling time point is adopted at each sampling timing for each measuring device in the control device. Thus, the control device can execute the steadying for automatic conveyance without being restricted by time.

Although the embodiment has been described as applied to a container crane, the present invention is not limited to a container crane, but is generally most suitable for a crane having a long rope length.

[0029]

According to the present invention described above, in automatic conveyance including oblique conveyance, automatic conveyance can be performed in a short time, and in addition, high-performance anti-sway and positioning can be achieved when reaching the final target point. it can. Therefore, the operator can smoothly shift to the work of grasping or releasing the luggage, and as a result, the efficiency of the cargo handling work can be improved as a whole.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a container crane to which the present invention is applied.

FIG. 2 is a block diagram illustrating a configuration of a control system of the present invention.

FIG. 3 is a diagram for explaining a trolley traverse speed pattern and an acceleration pattern when the rope length is constant.

FIG. 4 is a diagram showing a swing angle and a swing angular velocity of the hanging tool in the case of the pattern of FIG. 3;

FIG. 5 is a diagram for explaining a method of setting the time of each section in a plurality of sections constituting a deceleration section according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Trolley 11 Rope 12 Hanging equipment 13 Container 14 Container ship 15 Operator cab

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B66C 13/00-13/54

Claims (5)

(57) [Claims] 1. A crane comprising: a trolley for traversing provided with a hanger which can be hoisted and lowered by a rope, and which performs a diagonal conveyance for hoisting or lowering the hanger at a constant speed during traversing. In the steady rest control system, a steady rest trajectory plan is created based on an acceleration pattern that changes the trolley's traversing speed in a time series from a transport section between a gripping position of the crane and a release position which can be known in advance. A feed forward section that divides the transport section into an acceleration section with a maximum acceleration, a constant speed section with a maximum speed, and a deceleration section with a maximum deceleration, and also divides the acceleration section and the deceleration section. Each of the acceleration patterns, which is divided into a plurality of sections so that a constant-speed traversing section is included on the way, is created in advance. In addition, the start and stop timings of the winding operation in the skew conveyance can be determined in advance, and the time for each section in which the skew conveyance is performed can be known in advance at the last point of the skew conveyance with reference to the last point. Assuming this to be constant from the rope length, the time of the last section is calculated from the natural frequency of the pendulum at that rope length, and the space immediately before the last section is known in advance at the time of going back by the time of the last section. Considering this as a constant from the possible rope length, the time of the section immediately before the final section is calculated based on the natural frequency of the pendulum at that rope length, and thereafter, this is repeated until the first section of the oblique conveyance. A crane steady rest control system characterized in that it is determined. 2. The crane steady rest control system according to claim 1, wherein the acceleration section and the deceleration section are respectively divided into five sections that perform three acceleration traverses and three deceleration traverses across a constant speed traverse. The anti-sway control of the crane, wherein the time of the intermediate acceleration traversing section and the intermediate deceleration traversing section is determined in consideration of a condition necessary to minimize the skew conveyance. system. 3. The steady rest control system for a crane according to claim 2, wherein: a position measuring means for measuring a hoisting and lowering position of the hoist; a traversing position measuring means for measuring a traversing position of the trolley; A traversing speed measuring means for measuring a traversing speed of the trolley, a deflection angle measuring means for measuring a deflection angle of the rope, and a deflection angle and a deflection angular velocity of the rope are estimated based on a measurement result from the deflection angle measuring means. An estimating unit, wherein the feedforward unit, together with the acceleration pattern, a target value of a hoisting and lowering position of the hoist, a target value of a traversing position of the trolley, a target value of a traversing speed of the trolley, the rope The target value of the swing angle and the target value of the swing angular velocity of the rope are calculated. Sway Control system of the crane, characterized in that it comprises measurements and means for controlling the motor and the motor for rampant for estimation result and the receiving and winding / unwinding from said estimating means from. 4. The crane steady rest control system according to claim 3, wherein each of the target values in the feedforward section is calculated by first calculating a target value of the traversing acceleration, and moving the pendulum from the calculated result. A steady rest control system for a crane, wherein a remaining target value is calculated using an equation. 5. The steady rest control system for a crane according to claim 4, wherein the calculation of each of the target values is performed in synchronization with a sampling timing of the measured value in each of the measuring means. Control system.