JP3019661B2 - Crane operation control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane operation control method which enables steadying of a rope-suspended crane and highly accurate positioning.

[0002]

2. Description of the Related Art In general, in crane operation, it is desired to shorten a so-called cycle time from lifting a load, traveling laterally to unloading the load, and to increase the cargo handling efficiency as much as possible. At this time, if a residual deflection of the load occurs at the end of the lateral traveling, the suspended load cannot be lowered for safety. Therefore, it is necessary to wait until the load deflection falls within an allowable range. This results in increased cycle times and reduced handling efficiency. In particular, in manned cranes, steady rest control based on the driver's intuition and experience is performed, and it takes a considerable amount of time to become skilled.

On the other hand, there are two types of steady rest control mechanisms in an unmanned crane, a mechanical control mechanism and an electric control mechanism. In the former mechanical control mechanism, since a movable portion such as a crane hook is structurally fixed, no shake is generated in principle, and complete swing prevention control is possible. However, for example, on the premise that existing equipment is modified, the latter electrical control mechanism is often more advantageous in terms of cost. Further, in the case of the mechanical control mechanism, it is necessary to wind the suspended load to the highest position before traveling, which is disadvantageous in terms of cycle time. From this point, the necessity of a crane provided with an electric steady rest control mechanism has been increased.

Conventionally, in a crane crane operation control method provided with an electric steady rest control mechanism, as shown in FIG. 9 (a), a plurality of time sections in which the trolley acceleration during operation is constant are combined. As shown in FIG. 9B, a control method is adopted in which the trolley speed pattern is controlled to be a polygonal line, and the swing angle is returned from the zero value at the start point to the zero value at the end point as shown in FIG. Often do. As an example of this, there is a control pattern for theoretically performing a steady rest in the shortest time (Ryuichi Yoshimoto, “Automation of Ore Unloader”, Machine Research Vol. 23, No. 1, P. 4.0-44).

In the technique described in Japanese Patent Publication No. Sho 61-31032, the crane acceleration / deceleration section during operation is divided into three sections in accordance with the attenuation of the rope run-out, and constant acceleration sections corresponding to the damping rate are combined. In this way, a steady rest control pattern is generated.

Similarly, in the technique described in Japanese Patent Publication No. 62-19354, the motor is sequentially driven, interrupted, and driven at the time of trolley acceleration, and the braking device is sequentially operated, released, and operated at the time of damping. The driving pattern is a combination of constant acceleration sections. Adopting the operation pattern as described above has an advantage that the steady-state control pattern can be generated with good visibility because the phase plane trajectory of the unsteady load draws an arc within the constant acceleration section, as is well known.

[0007]

However, the conventional crane operation control method described above has an advantage that a steady rest control pattern can be easily generated, but has the following three problems. Since rapid switching of the acceleration and rapid switching of the torque are performed, a slip occurs between the trolley wheel and the rail at the time of the switching. For this reason, the positioning accuracy and the steadying accuracy of the trolley deteriorate.

[0008] By sudden switching of acceleration or the like,
A load is imposed on a drive system including a motor, a motor shaft, and a reduction gear, and play is likely to occur. For this reason, the crane maintenance work is hindered. In the conventional crane operation control method using the electric steady rest method described above, it is necessary to grasp the swing cycle of the suspended load in advance when setting the operation pattern. However, it is difficult to accurately grasp not only the hanging wire length but also the swing period that changes according to the mass and size of the suspended load, and control accuracy is inevitably inferior.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned three problems, and enables high-precision positioning control and steady rest control, and can also improve the crane's integrity. It is an object of the present invention to provide a crane operation control method capable of setting an operation pattern that is not easily affected by a slight error in grasping a swing cycle.

[0010]

[Means for Solving the Problems]

A crane operation control method according to the present invention
Continuously change the acceleration of the trolley with suspended load
Change the speed of the trolley smoothly and without sudden change
In the control so that the acceleration of the trolley increases or decreases linearly from a zero value, the acceleration value at this time is linearly increased or decreased from an integral multiple of the swing period of the suspended load. After the reduced time is subtracted from the stored acceleration value, a change pattern that linearly decreases or increases from the stored acceleration value to zero value at the same time as the linearly increased or decreased time is held. Have

Also, the acceleration of the trolley with the suspended load suspended
The trolley speed changes suddenly by continuously changing
Smell that is controlled to change smoothly and smoothly
Te, acceleration of the trolley, after linearly increasing or decreasing the time by the zero value of the integral multiple of the swinging period of the suspended load,
The acceleration value at this point is held for an arbitrary time, and after that,
At the same time as the time of linearly increasing or decreasing, the stored acceleration value has a change pattern of linearly decreasing or increasing to zero value.

Further, the acceleration of the trolley with the suspended load suspended
The trolley speed can be increased rapidly by changing the
For those that are controlled to change smoothly and smoothly
Then, the acceleration of the trolley linearly increases from the zero value, and then decreases from the increased acceleration value to a zero value at the same time as the increased time. A time obtained by subtracting the linearly increased time and the linearly reduced time from the integral multiple of the swing period is held, and further, after linearly decreasing from this zero value, this decrease is performed. And has a change pattern that increases from the decreased acceleration value to a zero value at the same time as the elapsed time.

[0014]

According to the present invention, since the acceleration of the trolley changes continuously and the speed of the trolley changes smoothly without abrupt change, rapid switching of the acceleration and torque does not occur. For this reason, no slip occurs between the trolley wheel and the rail, so that the positioning accuracy and the steadying accuracy of the trolley are improved, and it is also preferable for maintenance work.

Further, if the swing cycle of the suspended load is set, the swing of the suspended load smoothly stops at the final target position, so that the precision of the suspension of the suspended load is high. This solves the first, second and third problems of the prior art.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a block diagram showing an automatic crane control device to which a crane operation control method according to an embodiment of the present invention is applied. In the figure, reference numeral 1 denotes a trolley, which travels in the x direction on a rail 2 while suspending a suspended load 3 attached to a lower end of a rope 4. The traveling of the trolley 1 is controlled by a trolley position detecting device 11, a rope length detecting device 12, a swing cycle calculating device 13, a trolley target moving position device 14, a speed pattern generating device 15, a motor A control device 16 and a speed control motor 17;

The trolley position detecting device 11 is a device for detecting the position of the trolley 1 traveling on the rail 2 from the starting point, and detects the traveling position of the trolley 1 from the rotation amount of the wheels of the trolley 1 and the like. Is available. The rope length detection device 12 is a device for detecting the length of the rope 4 during traveling, and detects the length of the rope 4 from the rotation amount of a winding motor of the rope 4 and the like.

The swing period calculating device 13 is a device for calculating the swing period of the suspended load 3 based on the detection signal from the rope length detecting device 12. This shake period calculation device 13
The swing period is calculated mainly based on the hanging rope information from the rope length detecting device 12. In some cases, the swing period is calculated in consideration of auxiliary information such as the suspended load mass.

The speed pattern generator 15 is configured to calculate the operation signal from the shake period calculator 13 and the trolley target moving position device 1.
4 is a device for generating a speed pattern to be given to the trolley 1 based on a signal from the trolley 1. The motor control device 16 is configured by a minor control loop for realizing an operation speed command externally given to the speed control motor 17.

With such an automatic control device, a crane operation control method according to each of the following embodiments of the present invention is realized. In each embodiment, as shown in FIG. 2, the mass of the suspended load 3 is m, the swing angle of the suspended load 3 is θ, the length of the rope 4 is L, and the position of the trolley 1 is x. It is assumed that the vehicle is traveling on the rail 2 at an acceleration d ² x / dt ² (hereinafter referred to as η). Assuming that the swing of the suspended load 3 is not large, a description will be given using a motion equation of the swing angle θ viewed from the trolley 1 expressed by the following equations (1) and (2).

L (d ² θ / dt ² ) = − gθ−η (1) or d ² θ / dt ² = −ω ² θ−η / L (2) (G is the gravitational acceleration, and ω ² = g / L.)

[0022] The (first embodiment) crane operation control method according to an embodiment of claim 1 is described. FIG. 3 is a time chart showing a trolley acceleration pattern applied in the present embodiment, and a trolley speed and a suspended load swing angle generated by the trolley acceleration pattern.

In this embodiment, the speed of the trolley 1 is smoothly and smoothly changed by suspending the load 3 and continuously changing the acceleration of the trolley 1 traveling on the rail 2. In this case, the trolley acceleration is controlled so as to form a pattern having an acceleration section I, a constant speed section II, and a deceleration section III, as shown in FIG. In FIG. 3, the upper side (positive direction) of the time axis t indicates the traveling direction of the trolley 1, and the lower side (negative direction) indicates the opposite direction to the traveling direction.

Hereinafter, a specific description will be given. (1) Acceleration section I As shown in FIG. 3A, this section is composed of a running start part A, an acceleration part B, and a constant velocity connection part C. In running start portion A, the driving start of the trolley 1, linearly increases from zero value acceleration η of the trolley 1 at a constant gradient only ₁ hour T. That is, in the section A, η = dv / dt = αt
(Α> 0) is set. As a result, the speed of the trolley 1 becomes the following equation (3) and increases quadratically, so that the trolley speed v draws a relaxation curve as shown in FIG. 3B. v = (1/2) αt ² (3)

As a result, since the speed of the trolley 1 does not suddenly change, the trolley 1 starts running smoothly, and its wheels do not slip or rattling does not occur in the drive system (not shown).

At this time, taking into account θ (0) = 0 and (dθ / dt) (0) = 0 as initial conditions, the deflection angle θ of the suspended load 3 can be obtained from the above equation (2). / Dt is expressed by the following equations (4) and (5). θ = α (sin (ωt) −ωt) / ω ³ L (4) dθ / dt = α (cos (ωt) −1) / ω ² L (5)

Accordingly, θ and dθ / dt (hereinafter referred to as φ) at the end of the section at t = T ₁ are given by the following equations (6) and (7). θ ₁ = α (sin (ωT ₁ ) −ωT ₁ ) / ω ³ L (6) φ ₁ = α (cos (ωT ₁ ) −1) / ω ² L (7) ) as a result, the locus of points (φ / ω, θ), as shown in FIG. 4, from the origin O P1 (φ ₁ / ω, will move in theta ₁₎ therebetween. That is, the swing angle θ of the suspended load 3 gradually increases from the zero value in the direction opposite to the traveling direction of the trolley 1 as shown in FIG. 3C and the two-dot chain line in FIG.

Next, in the acceleration section B, the running section A
Is held for an integral multiple of the swing period T of the suspended load 3. That is, in the section B, η = αT ₁ is set. As a result, the speed v of the trolley 1 becomes the following equation (8), and increases linearly, so that the trolley speed v is accelerated as shown in FIG. 3B. v = αT ₁ · t- (1/2) αT ₁ ² (8)

At this time, the final acceleration value ηma
x = αT ₁ is held for T ₂ time shown by the following equation (9).
The time T is the swing cycle of the suspended load 3, and the rope 4
Is determined by the length L. T ₂ = nT−T ₁ (9)

More specifically, in the section B, as shown in FIG. 4, a point P (φ / ω, θ) starts from P ₁ (φ ₁ / ω, θ ₁ ) and O ₁ (0, ₋₁ ). αT ₁ / g)
Move on the arc with. Therefore, the phase plane locus (φ / ω,
θ) reaches a point P ₂ (−φ ₁ / ω, θ ₁ ) that is symmetrical to P ₁ (φ ₁ / ω, θ ₁ ) with respect to the θ axis, that is, expressed by the following equation (10). The final acceleration value η = αT ₁ is held only for the time T ₂ . Here, n ₂ is any non-negative integer. T ₂ = 2δ ₁ / ω + n ₂ T (10)

Here, in FIG. 4, the following equations (11) to (13) hold. R ₁ = | O ₁ −P ₁ | = (φ ₁ / ω) ² + (αT ₁ / g−θ ₁ ) ² ... (11) sin (δ ₁ ) = − (φ ₁ / ω) / R ₁ (12) cos (δ ₁ ) = (αT ₁ / g−θ ₁ ) / R ₁ (13) Therefore, the above equations (10) to (13) are used. Thus, T ₂ is determined as in the following equation (9). Here, n is an arbitrary positive integer determined as long as T does not become negative. T ₂ = nT−T ₁ (9)

As described above, by determining T ₂ , the swing angle θ of the suspended load 3 is changed in the direction opposite to the traveling direction of the trolley 1 during the time T ₂ , as shown in FIG. , Gradually increasing,
Draw a symmetrical curve around the highest angle. Then, in the constant velocity connection portion C, the acceleration of the trolley 1 is linearly decreased from αT ₁ to a zero value with the same gradient as the running start portion A.

That is, in the section C, the acceleration η is
Set as in equation (14). For easy understanding, T ₁ ≦ T and n = 1, and T ₂ = T + T ₁ . η = −αt + α (2T ₁ + T ₂ ) = α (−t + T + T ₁ ) (14) As a result, the trolley speed v becomes a relaxation curve of a quadratic function as shown in FIG. Draw. As a result, no rapid speed change occurs in the trolley 1, and the trolley 1 smoothly increases in speed and reaches the maximum speed, so that the wheels do not slip or the drive system (not shown) does not rattle. .

The time T ₃ required for the trolley acceleration η to reach the zero value in the section C as described above is equal to T ₁ . This means that the connection conditions (10) to (13) with the end of section B
It is clear from consideration of. Moreover, the terminal velocity vmax of the trolley 1 at the end time _{t f = T 1 + T 2} + T 3 = T 1 + T of the section C, the moving distance x in the interval C is the following (1
5) and (16). vmax = αTT ₁ (15) x = αTT ₁ (T + T ₁ ) / 2 (16)

Here, the end time tf = T ₁ + T of the section C
_{When 2} + T ₃ = T ₁ + T, the deflection angle θ is given by the following equations (17) and (18). θ (t _f ) = 0 (17) φ (t _f ) = 0 (18) Therefore, in the section C, the point (φ / ω, θ) is shown in FIG. As described above, the movement starts from the point P ₂ (−φ ₁ / ω, θ ₁ ), and returns to the origin O again. That is, the swing angle θ of the suspended load 3 gradually decreases and returns to the zero value as shown in FIG. As a result, in the acceleration section I, the point (φ
/ Omega, theta), as shown in FIG. 4, after reaching the point P _1, starting from the origin, moves to the point P ₂ in an arc around the origin O, through a point P _2, again origin Returning to O, the swing stops at the origin O.

(2) Constant speed section II This section is, as shown in FIG. 3A, a section in which the acceleration η of the trolley 1 is kept at a zero value for a time T ₄ , that is, the trolley speed is set to the maximum speed vmax = is an interval to maintain αTT _1. Time T ₄ is set by the movement distance required for the final position to be reached and trolley deceleration (end point of the deceleration zone III) (deceleration section III). In this section, since no acceleration is applied to the trolley 1, the deflection angle θ is always zero, and no deflection occurs in the suspended load 3.

(3) Deceleration section III This section is a section in which the acceleration pattern of the acceleration section I is inverted to the negative side. That is, as shown in FIG. 3A, after the acceleration is reduced at a constant gradient for a time T ₁ ,
Only ₂ hours retained its acceleration, such subsequent, to zero value by increasing the acceleration at a constant gradient T ₁ times only. As a result, as shown in FIG. 3B, the speed of the trolley 1 decreases smoothly, decreases linearly, becomes zero, and the trolley 1 reaches the final target position. Therefore, in the deceleration section III, the point (φ / ω, θ) draws a trajectory symmetrical to the trajectory in the acceleration section I with respect to the (φ / ω) axis, as shown in FIG. That is, after reaching the point P _3, starting from the origin O, and moves to the point P ₄ in an arc around the origin O, through a point P _4, again returns to the origin O, the origin O
Stops swinging.

As described above, in this embodiment, if the swing period T of the suspended load 3 is set, the swing angle θ changes from the zero value at the starting point as shown in FIG. And return to zero at the end point. As a result, the swing of the suspended load 3 is automatically and completely stopped at the final target position, and therefore the swing load of the suspended load 3 is highly accurate. Further, as described above, since the speed of the suspended load 3 smoothly increases and decreases, the wheels of the trolley 1 do not slip and the drive system does not rattle. As a result, the positioning accuracy and the steadying accuracy of the trolley 1 are further improved, and are also preferable in maintenance work. In addition, the present embodiment can be said to be suitable for a case where the crane speed is relatively low, that is, for medium distance movement.

Finally, the acceleration parameter α and the acceleration section I
A method for determining the times T ₁ and T _{2 in} the constant speed section II will be described. The magnitude of the acceleration parameter α and the time T ₁ are the maximum acceleration ηmax and the speed v at the end of acceleration of the trolley 1.
max (the trolley speed at the end point of the acceleration section I, the constant speed section II) and the rated speed Vmax, αT ₁ ≦ ηmax vmax = nαTT ₁ ≦ Vmax T ₁ ≧ 0 T ₂ ≧ 0 (ie. nT ≧ T ₁ ) can be arbitrarily determined within a range that satisfies T ₁ ). However, in order to minimize the cycle time, trolley 1
Α within a range that does not impair the smooth operation of the crane including
Is preferably as large as possible.

For other parameters, for example,
First, a target speed V (≦ Vmax) at the time of completion of acceleration is determined, and n
αT ₁ = V / T is determined. Subsequently, the expression of the above αT ₁ ,
T ₁ is determined by determining n as small as possible within a range satisfying the expression of T ₂ . When the target travel distance is relatively short and the constant traveling section indicated by the constant speed section II becomes zero, the parameter can be further determined by using the above equation (16).

In the above embodiment, an operation pattern in which the speed of the trolley 1 at the end of the deceleration section III is not strictly reduced to zero is formed within the scope of the present invention, and various operations are performed during deceleration while approaching the target position at a low speed. It is possible to eliminate the influence of vibration due to external disturbance. If the value of the swing cycle T cannot be accurately grasped, the swing angle θ and the swing angular velocity φ (= dθ / at) during driving are determined without setting an acceleration pattern in advance, and the above-described embodiment is used. If the acceleration is switched so as to realize the locus of the point (φ / ω, θ) shown in FIG. 4, substantially the same control as above can be performed.

[0042] The (second embodiment) crane operation control method according to an embodiment of claim 2 is described. FIG. 5 is a time chart showing a trolley acceleration pattern applied in the present embodiment, and a trolley speed and a swing angle of the suspended load generated by the trolley acceleration pattern.

In this embodiment, the trolley acceleration is controlled so as to have a pattern having an acceleration section I, a constant speed section II and a deceleration section III as shown in FIG. , The same as the first embodiment, except that the acceleration interval I
Starting section A and constant velocity connection section C in (deceleration section III)
Is different from that of the first embodiment in that the required time is set to an integral multiple of the swing period T. In the following, for the sake of easy understanding, the required time of the running start portion A and the constant velocity connection portion C in the acceleration section I (deceleration section III) is set to be one time the swing cycle T.

(1) Acceleration section I This section is also composed of a running start part A, an acceleration part B and a constant velocity connection part C, as shown in FIG. In the running start portion A, at the start of running of the trolley 1, the acceleration η of the trolley 1 is linearly increased from a zero value at a constant gradient for a swing period T of the suspended load 3. That is, in the section A, η =
βt (β> 0) is set.

As a result, the speed of the trolley 1 becomes
Which is a quadratic function, the trolley speed v
Draws a relaxation curve as shown in FIG. v = (1/2) βt ² (21) As a result, the trolley 1 does not suddenly switch speeds, so that the trolley 1 starts running smoothly, its wheels slip, or a drive system (not shown). There is no backlash.

At this time, the swing angle θ of the suspended load 3 is given by θ (0) = 0 and φ (0) = 0 as initial conditions.
From the above equation (2), θ and φ are expressed by the following equations (22) and (23). θ = β (sin (ωt) −ωt) / ω ³ L (22) φ = β (cos (ωt) −1) / ω ² L (23)

Therefore, θ and φ at the end of the section where t = T = 2π / ω are given by the following equations (24) and (25). θ (T) = − βT / ω ² L (24) φ (T) = 0 (25) As a result, the locus of the point (φ / ω, θ) is shown in FIG. As shown in the figure, the object moves from the origin O to a point P1 (0, -βT / ω ² L). That is, the swing angle θ of the suspended load 3 is
As shown in FIG. 5C, the trolley 1 gradually decreases from the zero value in the direction opposite to the traveling direction.

Next, in the acceleration section B, the starting section A
Is held for the time T _{1 of the} suspended load 3. That is, in the section B, η = βT = 2πβ / ω is set. As a result, the speed v of the trolley 1 is given by the following equation (26), and increases linearly.
It accelerates as shown in FIG. v = βT · t− (１ ／) βT ² (26)

Then, the final acceleration value ηmax = βT is held for the time T ₁ . At this time, considering the above equations and the equations (24) and (25) as initial conditions, θ and φ are expressed by the following equations (27) and (28) from the above equation (2). θ (t) = − βT / ω ² L (27) φ (t) = 0 (28)

That is, in the section B, as shown in FIG. 6, the point (φ / ω, θ) is the point P ₁ (0, −βT / ω ^2).
L). Accordingly, in this section B, as shown in FIG. 5C, the swing angle θ of the suspended load
7) Do not move while maintaining the static balance angle determined by the formula.

In the constant velocity connection portion C, the acceleration of the trolley 1 is decreased linearly from βT to a zero value with the same gradient as the running start portion A. That is, in the section C, the acceleration η (d
v / dt) is set as in the following equation (29). η = −βt + β (2T + T ₁ ) (29) Thus, the trolley speed v draws a relaxation curve of a quadratic function as shown in FIG. 5B. As a result, no rapid speed change occurs in the trolley 1, and the trolley 1 smoothly increases in speed and reaches the maximum speed vmax. Therefore, the wheels slip and the drive system (not shown) does not rattle. Absent.

Here, in the above equation (29), taking into account the above equations (27) and (28), which are the connection conditions with the end of section B,
By solving the equation (2), the deflection angle θ and the deflection angular velocity φ in this section C are obtained.
Becomes the following equations (30) and (31). θ (t) = − β {sin · ω (t−T ₁ ) −ω (t−2T−T ₁ )} / ω ³ L (30) φ (t) = − β ｛cos · ω (t−T ₁ ) -1｝ / ω ² L (31)

Therefore, at the end of this section C, t =
Than 2T + T _1, the deflection angular velocity φ and the deflection angle θ, the following
Equations (32) and (33) are obtained. θ (2T + T ₁ ) = 0 (32) φ (2T + T ₁ ) = 0 (33)

Thus, in the section C, the point (φ /
ω, θ) is, as shown in FIG. 6, the point P1 (0, -βT /
ω ² L) to the origin O, so that when the maximum speed is reached, both φ and θ become zero. As a result, in the acceleration zone I, the point (φ / ω, θ), as shown in FIG. 6, and reaches the point P _1, starting from the origin, then greeted the point P _{1 one} hour T The origin O returns again, and the swing stops at the origin O.

The moving distance x of the trolley 1 in the acceleration section I is expressed by the following (34). x = βT (T + T ₁ ) (2T + T ₁ ) / 2 (34) Here, a method of determining the acceleration parameter β, the time T _1, and the shake period T will be described. The acceleration parameter β and the time T ₁ are determined with respect to the maximum speed vmax generated at the end point of the acceleration section I in consideration of the acceleration torque of the motor of the trolley 1 and the maximum frictional force of the wheels and rails, as follows (35), (36) ) Can be determined within the range that satisfies the formula. However, to shorten the cycle time as much as possible, take as large as possible β within the range described below, and it is preferable to take as small as possible T _1. βT ₁ (T + T ₁ ) = v _max (35) T ₁ ≧ 0 (36)

On the other hand, the swing period T is the length L of the rope 4,
Alternatively, if necessary, it can be determined in advance by measuring the mass m of the suspended load 3 or the like. However, if there is no direct information on the length L of the rope 4 or the mass m of the suspended load 3, or if there is only limited information on these, the swing cycle T can be set accurately in advance. Can not. However, according to the present embodiment, the deflection angle θ
By measuring the time until the point P1 (or the point P2) at which becomes zero to the maximum, the oscillation period T can be easily detected. Accordingly, by determining the time T ₁ (or time T ₂ ) of the section B using the detected information, the steady stop of the suspended load 3 is achieved while achieving the end speed of the acceleration section I, that is, the target speed vmax at the end of the acceleration. It can be carried out.

(2) Constant speed section II This section is, as shown in FIG. 5A, a section in which the acceleration η of the trolley 1 is kept at a zero value for a time T ₁ , that is, the trolley speed is set to the maximum speed vmax. This is the section to be maintained. In this section, since no acceleration is applied to the trolley 1, the deflection angle θ is always zero, and the deflection of the suspended load 3 does not occur.

(3) Deceleration section III This section is a section in which the acceleration pattern of the acceleration section I is inverted to the negative side. That is, as shown in FIG. 5 (a), after the acceleration is reduced at a constant gradient for a time T, then T ₁
The acceleration is held for a time, and after that, the acceleration is increased to a zero value by a constant gradient for a time T. This allows
As shown in FIG. 5B, the speed of the trolley 1 decreases smoothly and linearly, and then reaches a zero value.
Reaches the final target position. Therefore, the deceleration section
In III, point (φ / ω, θ), as shown in FIG. 6, the point _{P 2 (0, βT / ω} 2 L) starting from the origin O to reach the, T ₁ hour by point P ₂ After that, the origin O returns again, and the swing stops at the origin O.

As described above, in this embodiment, if the swing cycle T of the suspended load 3 is set, the swing angle θ changes from the zero value at the starting point as shown in FIG. And return to zero at the end point. As a result, the swing of the suspended load 3 is automatically and completely stopped at the final target position, and therefore the swing load of the suspended load 3 is highly accurate. Further, as described above, since the speed of the suspended load 3 smoothly increases and decreases, the wheels of the trolley 1 do not slip and the drive system does not rattle. As a result, the positioning accuracy and the steadying accuracy of the trolley 1 are improved, and the maintenance work is preferable.

[0060] In addition, without any precise information about the mass m of the length L and the suspended load 3 of the rope 4, the time until the P ₁ point showing the maximum value of the deflection angle theta (or P ₂ points) By measuring, the shake period T can be easily detected. Further, in this embodiment, the maximum swing angle during operation does not exceed the balancing angle determined by the maximum acceleration of the crane. Further, the fluctuation of the deflection angle immediately before the completion of the control is very small. As a result, the positioning accuracy and the steadying accuracy are further improved. In addition, it can be said that the present embodiment is suitable for long-distance travel in which the constant speed traveling section at the maximum speed is relatively long.

Incidentally, without being limited to the above embodiment,
Various modifications are possible within the scope of the invention. That is, in the present embodiment, the movement of the trolley 1 is controlled based on the time such as T, but the swing angle θ or the swing angular velocity φ is controlled.
Alternatively, the operation of the trolley 1 can be controlled in the same manner as described above with reference to the trolley position x. For example, the deflection angular velocity φ
Is adopted as a reference parameter of the motion, and the acceleration η is switched to a constant value based on the time (φ = 0) at which the deflection angle θ is the maximum. In this way, the residual vibration of the suspended load 3 that may occur when there is some error in the calculation of the vibration period T can be extremely reduced. Other configurations, operations, and effects are the same as those in the first embodiment, and thus description thereof is omitted.

(Third Embodiment) A crane operation control method according to a third embodiment will be described. FIG. 7 is a time chart illustrating a trolley acceleration pattern applied in the present embodiment, and a trolley speed and a suspended load swing angle generated by the trolley acceleration pattern. This embodiment is different from the first embodiment in that the trolley acceleration is controlled so as to have a pattern having an acceleration section I, a constant speed section II and a deceleration section III as shown in FIG. The second embodiment is the same as the first and second embodiments, except that the acceleration section I (deceleration section III) includes a start section A and a constant velocity connection section C.

(1) Acceleration section I As shown in FIG. 7 (a), this section comprises only a running start portion A and a constant velocity connection portion C. In running start portion A, the driving start of the trolley 1, linearly increases from zero value acceleration η of the trolley 1 at a constant gradient only ₁ hour T. That is, in the section A, η = γt (γ> 0) is set. As a result, the speed of the trolley 1 becomes the following equation (41), and increases in a quadratic function.
(B), a relaxation curve is drawn. v = (1/2) γt ² (41)

At this time, the deflection angle θ of the suspended load 3 is given by θ (0) = 0 and φ (0) = 0 as initial conditions.
From the above equation (2), θ and φ are expressed by the following equations (42) and (43). θ = γ (sin (ωt) −ωt) / ω ³ L (42) φ = γ (cos (ωt) −1) / ω ² L (43)

Therefore, θ and φ at the end of the section at t = T ₁ are given by the following equations (44) and (45). θ (T ₁ ) = θ ₁ = γ (sin (ωT ₁ ) −ωT ₁ ) / ω ³ L (44) φ (T ₁ ) = φ ₁ = γ (cos (ωT ₁ ) −1 ^{) / ω 2 L ............... (45} ) Consequently, the locus of points (φ / ω, θ), as shown in FIG. 8, from the origin _{O P 1 (φ 1 / ω} , θ 1) between Will be moved. That is, the swing angle θ of the suspended load 3 is, as shown in FIG.
It gradually increases from zero.

Next, in the constant velocity connection portion C, the trolley 1
Is linearly decreased from γT ₁ to a zero value with the same gradient as the running start portion A. That is, in the section C, the acceleration η is set as in the following equation (46). η = −γt + 2γT ₁ (46)

Accordingly, the trolley speed v is expressed by the following equation (47), and as shown in FIG. 7B, a relaxation curve of a quadratic function continuous with the relaxation curve of the section A is drawn. ^{v = - (1/2) γt 2} + 2γT 1 t-γT 1 2 ............... (47) As a result, in the acceleration zone I, since no sudden speed switched trolley 1, the trolley 1 is smoothly The vehicle does not run, and its wheels do not slip or rattle does not occur in a drive system (not shown).

Here, by solving the above equation (2) with the above equations (44) and (45) as initial conditions, at the end of the interval at t = 2T ₁ ,
The shake angle θ and the shake angular velocity φ are expressed by the following equations (48) and (49). However, c1 and c2 are represented by the following equations (50) and (51). θ (2T ₁ ) = θ ₂ = c ₁ · sin (ωT ₁ + c ₂ ) (48) φ (2T ₁ ) = φ ₂ = c ₁ · ω · cos (ωT ₁ + c ₂ ) + γ / ω ² L... (49) c ₁ · sin (c ₂ ) = θ ₁ + γT ₁ / ω ² L = γ · sin (ωT ₁ ) / ω ³ L... (50) c _1. cos (c ₂ ) = φ ₁ / ω−γ / ω ³ L = γ (cos (ωT ₁ ) −2) / ω ³ L (51) As a result, in the section C, the point (φ / Ω, θ) is
As shown in FIG. 8, from the point P ₁ (φ ₁ ω, θ ₁ ) to the point P ₂
(Φ ₂ / ω, θ ₂ ).

(2) Constant speed section II In this section, as shown in FIG. 7 (a), the acceleration η of the trolley 1 is determined by setting the operation time from the start of the trolley acceleration to the integral multiple of the swing period T. This is a section in which the trolley speed is maintained at the maximum speed vmax until the value becomes zero. In this section, the point (φ / ω, θ) is, as shown in FIG. 8, the point P ₂ (φ ₂ / ω, θ ₂ ) centered on the origin O.
, And moves on an arc at an angular velocity ω.

By the way, the operation time until the trolley 1 reaches the intermediate point Q of this section can be expressed by the following equation (52). _{Tc = T 2/2 = nT} / 2-T 1 ............... (52) Then, the middle point P ₃ shown in FIG. 8 corresponding to the midpoint Q (phi
₃ / ω, θ ₃ ) is the angle ωTc of the point P ₂ around the origin O.
Only by rotating and considering the above equation (50),
It becomes zero as in equation (53). θ ₃ = θ (nT / 2 + T ₁ ) = φ ₂ · sin (ωTc) / ω + θ ₂ · cos (ωTc) = φ ₂ · sin (nωT / 2−ωT ₁ ) / ω + θ ₂ · cos (nωT / 2− ωT ₁ ) = (− 1) ^{n + 1} · sin (ωT ₁ ) ｛c ₁ · cos (ωT ₁ + c ₂ ) + γ / (ω ³ L)｝ + (− 1) ⁿ · cos (ωT ₁ ) · c ₁ · sin (ωT ₁ + c ₂ ) = (− 1) ⁿ (c ₁ · sin (c ₂ )) − γ · sin (ωT ₁ ) / (ω ³ L)) = 0 (53)

Therefore, from the start point of the acceleration section I to the intermediate point Q of the constant speed section II, the point (φ / ω, θ)
As shown in FIG. 8, a point P ₁ (φ ₁ / ω, θ
₁ ) and a point P ₂ (φ ₂ / ω, θ ₂ ), and moves between points P ₃ (φ ₃ / ω, θ ₃ ) in an arc centered on the origin O. That is, the swing angle θ of the suspended load 3 gradually decreases in the traveling direction of the trolley 1 and returns to a zero value at the intermediate point, as shown in FIG. 7C.

(3) Deceleration section III This section is a section obtained by inverting the acceleration pattern of the acceleration section I to the negative side around the midpoint Q based on the above equation (52). That is, from the midpoint Q of the constant speed section II to the deceleration section
Up to the end point III, the acceleration, speed, and deflection angle θ of the trolley 1 take a process reverse to the acceleration, speed, and deflection angle θ from the starting point of the acceleration section I to the intermediate point Q of the constant speed section II.
Therefore, the point (φ / ω, θ) is, as shown in FIG.
Returning to the origin O from the point P ₃ (φ ₃ / ω, θ ₃ ) via the points P ₄ and P _5, taking the φ / ω axis between the start point of the acceleration section I and the constant velocity section II. The trajectory is symmetrical to the trajectory.

Here, a method of determining the acceleration parameter γ and the time T1 will be described. The maximum acceleration η _max , the maximum speed v _max , and the moving distance x in this embodiment are as follows (54) to
It is expressed by equation (56). η _max = γT ₁ (54) v _max = γT ₁ ² (55) x = γnTT ₁ ² (56)

With respect to the target moving distance x represented by the above equation (56), it is preferable to take the integer n as small as possible within the allowable range of acceleration and speed in order to reduce the cycle time.
The time T ₁ is preferably set to be short within a range where smooth acceleration / deceleration can be realized, and can be determined in combination with the parameter γ within a range satisfying the above equation (55). Note that this embodiment can be said because the operating time is T + 2T _1, is suitable for short-range mobile. Other configurations, operations, and effects are the same as those in the first and second embodiments, and thus description thereof is omitted.

[0075]

As described above, according to the crane operation control method of the present invention, the speed of the trolley does not change abruptly and smoothly, and abrupt switching of acceleration and torque does not occur. Since no slip occurs between the trolley and the trolley, the positioning accuracy and the steadying accuracy of the trolley are improved, and this is preferable for maintenance work.

According to the second aspect of the present invention,
Highly accurate positioning and steadying of the trolley can be achieved without previously knowing the swing cycle of the suspended load that changes according to the wire length and weight of the suspended load. Further, since the angle fluctuation rate immediately before the completion of acceleration and deceleration can be kept very small, there is an excellent effect that the operation becomes very robust with respect to the error in the speed pattern switching time, and further leads to an improvement in the steadying accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an automatic crane control device applied to a crane operation control method according to each embodiment of the present invention.

FIG. 2 is a schematic side view showing a crane applied to each embodiment.

FIG. 3 is a time chart showing physical quantities controlled by the crane operation control method of the first embodiment. FIG. 3 (a) shows trolley acceleration, and FIG. 3 (b) shows trolley speed. 3 (c) shows the swing angle of the suspended load.

FIG. 4 is a phase diagram of a deflection angle θ and its angular velocity.

5A and 5B are time charts showing physical quantities controlled by the crane operation control method of the second embodiment. FIG. 5A shows a trolley acceleration, and FIG. 5B shows a trolley speed. 5 (c) shows the swing angle of the suspended load.

FIG. 6 is a phase diagram of a deflection angle θ and its angular velocity.

FIGS. 7A and 7B are time charts showing physical quantities controlled by the crane operation control method of the third embodiment. FIG. 7A shows trolley acceleration, and FIG. 7B shows trolley speed. 7 (c) shows the swing angle of the suspended load.

FIG. 8 is a phase diagram showing a deflection angle θ and its angular velocity.

9 is a time chart showing a conventional crane operation control method, FIG. 9 (a) shows acceleration, FIG. 9 (b) shows speed, and FIG. 9 (c) shows deflection angle. .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Trolley 3 Suspended load 4 Rope I Acceleration section II Constant speed section III Deceleration section A Starting part of running B Accelerating part C Constant velocity connecting part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-70694 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B66C 13/00-15/06

Claims (3)

(57) [Claims] 1. The acceleration of a trolley with a suspended load suspended.
Continuously changing the speed of the trolley without sudden change
A crane operation system that controls changes smoothly and smoothly.
In the control method, the acceleration of the trolley linearly increases or decreases from a zero value, and then the acceleration value at this time is linearly increased or decreased from an integral multiple of the swing period of the suspended load. Is subtracted from the stored acceleration value, and then has a change pattern that linearly decreases or increases from the stored acceleration value to zero value at the same time as the linearly increased or decreased time. A crane operation control method, comprising: 2. The acceleration of a trolley with a suspended load suspended.
Continuously changing the speed of the trolley without sudden change
A crane operation system that controls changes smoothly and smoothly.
In the control method, after the acceleration of the trolley linearly increases or decreases from a zero value for a time that is an integral multiple of the swing period of the suspended load, the acceleration value at this time is held for an arbitrary time. A crane operation control method, characterized in that the crane operation control method has a change pattern that linearly decreases or increases from the held acceleration value to zero value at the same time as the linearly increasing or decreasing time. 3. The acceleration of a trolley with a suspended load suspended.
Continuously changing the speed of the trolley without sudden change
A crane operation system that controls changes smoothly and smoothly.
In the control method, the acceleration of the trolley linearly increases from a zero value, and then decreases from the increased acceleration value to a zero value at the same time as the increased time. After a time obtained by subtracting the linearly increased time and the linearly decreased time from an integral multiple of the load swing period, the time is further reduced. A crane operation control method, characterized in that the crane operation control method has a change pattern that increases from the reduced acceleration value to a zero value at the same time as the reduced time.