An automatic control method for two-lift cranes

Abstract

An automatic control method for two-crane tandem lifting is proposed. Based on the structural and kinematic characteristics of traditional cranes, equations are established to define the spatial relationships and positions of the three crane movements. The main and auxiliary cranes are adjusted by using feedback from encoders and force sensors on each crane, along with position algorithms, to control the hook position and achieve tandem lifting. This method effectively increases the ship's lifting capacity, enhances automation, and reduces manual labor.

Description

Technical Field

[0001] This invention belongs to the field of automation control technology, specifically relating to an automatic control method for two cranes lifting in tandem. Background Technology

[0002] In recent years, with the introduction of major domestic and international strategies, automation has entered a new stage of development. Traditional tandem lifting operations still require two people to coordinate the lifting, resulting in slow operation speed and a large workload for coordination. Alternatively, it may be necessary to install a double crane, requiring major structural modifications such as adding a double platform, slewing mechanism, and other structural changes. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an automatic control method for two cranes to lift in tandem. Based on the structural and motion characteristics of traditional cranes, the spatial relationship and position equations of the three motions of the cranes are established. The motions and positions of the main and auxiliary cranes are adjusted by the detection feedback of the encoders and force sensors of each crane and the position algorithm feedback of the hook, so as to realize the joint lifting operation of the two cranes.

[0004] This invention provides an automatic control method for two cranes lifting simultaneously, including a hoisting encoder, a luffing encoder, a slewing encoder, and a tension sensor; the specific steps are as follows.

[0005] Step S1. Collect the parameters of the main crane and the auxiliary crane. The slewing angle of the main crane is α1, the slewing angle of the auxiliary crane is α2, the amplitude angle of the main crane is β1, the amplitude angle of the auxiliary crane is β2, e is the offset between the slewing center and the boom hinge point, D is the diameter of the lifting pulley, and d is the diameter of the lifting rope.

[0006] Step S2. Construct the crane coordinate system. X1, Y1, and Z1 are the coordinate values ​​of the main crane's boom head pulley hoisting rope lowering point in a coordinate system with the rotation center as the y-axis, the horizontal axis passing through the boom hinge point as the x-direction, and the plane perpendicular to these two axes as the z-direction. X2, Y2, and Z2 are the coordinate values ​​of the auxiliary crane's boom head pulley hoisting rope lowering point in a coordinate system with the rotation center as the y-axis, the horizontal axis passing through the boom hinge point as the x-direction, and the plane perpendicular to these two axes as the z-direction.

[0007] Step S3. The distance from the boom hinge point to the center of the boom head lifting pulley is L, the distance from the lifting beam lifting point is L0, the distance from the top pulley of the tower body to the hinge point is H1, the drum PCD is D0, the compensation ratio is n, the lifting ratio is m, and the distance between the two cranes is S; then

[0008] X1=((D+d) / 2-e+Lcosβ1)*cosα1,

[0009] Y1=Lsinβ1,

[0010] Z1=((D+d) / 2-e+Lcosβ1)*sinα1;

[0011] Therefore, α2 = atan(Z1 / (S-L0-X1)).

[0012] but

[0013] β2=acos((S-L0-X1-(((D+d) / 2-e)cosα2)) / (Lcosα2)),

[0014] X2=((D+d) / 2-e+Lcosβ2)*cosα2,

[0015] Y2=Lsinβ2,

[0016] Z2=((D+d) / 2-e+Lcosβ2)*sinα2;

[0017] Step S4. When the positions of the two crane hooks are inconsistent due to the luffing angle, the compensation amounts of the two cranes will be inconsistent, which will cause the position error of the two crane hooks, thus causing the lifting beam to tilt. When the tilt amount |ΔH|>L0*tan2.5 / 2, the follow-up crane needs to dynamically compensate: The compensation principle is that when the main crane luffs and retracts, the auxiliary crane retracts the rope; when the main crane luffs and lowers, the auxiliary crane releases the rope.

[0018] As a further technical solution of the present invention, the compensation amount ΔH during the lifting operation is: ΔH = L*(sinβ2+t1*sqrt(1+k12+2*k1*sin(β2-r1))+t2*sqrt(1+k22+2*k2*sin(β2-r2))+t3*sqrt(1+k32+2*k3*sin(β2-r3)))-L*(sinβ1+t1*sqrt(1+k12+2*k1*sin(β1-r1))+t2*sqrt(1+k22+2*k2*sin(β1-r2))+t3*sqrt(1+k32+2*k1*sin(β1 ...1))-L*(sinβ1+t1*sqrt(1+k12+2*k1*sin(β1-r1))+t2*sqrt(1+k22+2*k2*sin(β1-r2))+t3*sqrt(1+k32+2*k1*sin(β1-r1))-L*(sinβ1+t1*sqrt(1+k12+2*k1*sin(β1-r1))+t2*sqrt(1+k22+2*k2*sin(β1-r2))+t3*sqrt(1+k32+2*k1*k1*sin(β1-r1))-L*(sin 3*sin(β1-r3)))-ΔH', where t1=2, t2=0.5, t3=0.5, k1=0.265846169, k2=0.313670248, k3=0.282354261, r1=-6.340191746, r2=6.044092162, r3=-8.972626615, ΔH' is the height difference between the original main crane position and the auxiliary crane position. The main crane drum does not compensate Δw1=0. The auxiliary crane needs to increase the speed ΔW2=ΔH / π*D0 at the original speed to rise or fall. When ΔH≥0, the auxiliary crane falls; when ΔH<0, the auxiliary crane rises.

[0019] The advantage of this invention is that by adding an automatic control module with this method to a traditional single crane, the automated control operation of two cranes lifting in tandem can be realized. The main and auxiliary cranes are adjusted by using the detection feedback of the encoders and force sensors of each crane and the position feedback of the hook through position algorithm feedback, thereby improving the lifting capacity of the ship, enhancing the level of automation, and reducing manual labor. Detailed Implementation

[0020] This embodiment provides an automatic control method for two cranes lifting simultaneously, including a hoisting encoder, a luffing encoder, a slewing encoder, and a tension sensor; the specific steps are as follows.

[0021] Step S1. Collect the parameters of the main crane and the auxiliary crane. The slewing angle of the main crane is α1, the slewing angle of the auxiliary crane is α2, the amplitude angle of the main crane is β1, the amplitude angle of the auxiliary crane is β2, e is the offset between the slewing center and the boom hinge point, D is the diameter of the lifting pulley, and d is the diameter of the lifting rope.

[0022] Step S2. Construct the crane coordinate system. X1, Y1, and Z1 are the coordinate values ​​of the main crane's boom head pulley hoisting rope lowering point in a coordinate system with the rotation center as the y-axis, the horizontal axis passing through the boom hinge point as the x-direction, and the plane perpendicular to these two axes as the z-direction. X2, Y2, and Z2 are the coordinate values ​​of the auxiliary crane's boom head pulley hoisting rope lowering point in a coordinate system with the rotation center as the y-axis, the horizontal axis passing through the boom hinge point as the x-direction, and the plane perpendicular to these two axes as the z-direction.

[0023] Step S3. The distance from the boom hinge point to the center of the boom head lifting pulley is L, the distance from the lifting beam lifting point is L0, the distance from the top pulley of the tower body to the hinge point is H1, the drum PCD is D0, the compensation ratio is n, the lifting ratio is m, and the distance between the two cranes is S; then

[0024] X1=((D+d) / 2-e+Lcosβ1)*cosα1,

[0025] Y1=Lsinβ1,

[0026] Z1=((D+d) / 2-e+Lcosβ1)*sinα1;

[0027] Therefore, α2 = atan(Z1 / (S-L0-X1)).

[0028] but

[0029] β2=acos((S-L0-X1-(((D+d) / 2-e)cosα2)) / (Lcosα2)),

[0030] X2=((D+d) / 2-e+Lcosβ2)*cosα2,

[0031] Y2=Lsinβ2,

[0032] Z2=((D+d) / 2-e+Lcosβ2)*sinα2;

[0033] Step S4. When the positions of the two crane hooks are inconsistent due to the luffing angle, the compensation amounts of the two cranes will be inconsistent, which will cause the position error of the two crane hooks, thus causing the lifting beam to tilt. When the tilt amount |ΔH|>L0*tan2.5 / 2, the follow-up crane needs to dynamically compensate: The compensation principle is that when the main crane luffs and retracts, the auxiliary crane retracts the rope; when the main crane luffs and lowers, the auxiliary crane releases the rope.

[0034] Compensation amount ΔH=L*(sinβ2+t1*sqrt(1+k12+2*k1*sin(β2-r1))+t2*sqrt(1+k22+2*k2*sin(β2-r2))+t3*sqrt(1+k32+2*k3*sin( β2-r3)))-L*(sinβ1+t1*sqrt(1+k12+2*k1*sin(β1-r1))+t2*sqrt(1+k22+2*k2*sin(β1-r2))+t3*sqrt(1+k32+2*k3*sin(β 1-r3)))-ΔH', where t1=2, t2=0.5, t3=0.5, k1=0.265846169, k2=0.313670248, k3=0.282354261, r1=-6.340191746, r2=6.044092162, r3=-8.972626615, ΔH' is the height difference between the original main crane position and the auxiliary crane position. The main crane drum does not compensate Δw1=0. The auxiliary crane needs to increase the speed ΔW2=ΔH / π*D0 at the original speed to rise or fall. When ΔH≥0, the auxiliary crane falls; when ΔH<0, the auxiliary crane rises.

[0035] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the specific embodiments described above. The specific embodiments and descriptions in the specification are merely for further illustrating the principles of the invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the claims and their equivalents.

Claims

1. An automatic control method for two cranes lifting in tandem, characterized in that, This includes a hoisting encoder, a luffing encoder, a slewing encoder, and a tension sensor; the specific steps are as follows: Step S1. Collect the parameters of the main crane and the auxiliary crane. The slewing angle of the main crane is α1, the slewing angle of the auxiliary crane is α2, the amplitude angle of the main crane is β1, the amplitude angle of the auxiliary crane is β2, e is the offset between the slewing center and the boom hinge point, D is the diameter of the lifting pulley, and d is the diameter of the lifting rope. Step S2. Construct the crane coordinate system. X1, Y1, and Z1 are the coordinate values ​​of the main crane's boom head pulley hoisting rope lowering point in a coordinate system with the rotation center as the y-axis, the horizontal axis passing through the boom hinge point as the x-direction, and the plane perpendicular to these two axes as the z-direction. X2, Y2, and Z2 are the coordinate values ​​of the auxiliary crane's boom head pulley hoisting rope lowering point in a coordinate system with the rotation center as the y-axis, the horizontal axis passing through the boom hinge point as the x-direction, and the plane perpendicular to these two axes as the z-direction. Step S3. The distance from the boom hinge point to the center of the boom head lifting pulley is L, the distance between the lifting beam lifting points is L0, the distance from the top pulley of the tower body to the hinge point is H1, the drum PCD is D0, the compensation ratio is n, the lifting ratio is m, and the distance between the two cranes is S; then X1=((D+d) / 2-e+Lcosβ1)*cosα1, Y1=Lsinβ1, Z1=((D+d) / 2-e+Lcosβ1)*sinα1; Therefore, α2 = atan(Z1 / (S-L0-X1)). but β2=acos((S-L0-X1-(((D+d) / 2-e)cosα2)) / (Lcosα2)), X2=((D+d) / 2-e+Lcosβ2)*cosα2, Y2=Lsinβ2, Z2=((D+d) / 2-e+Lcosβ2)*sinα2; Step S4. When the positions of the two crane hooks are inconsistent due to the luffing angle, the compensation amounts of the two cranes will be inconsistent, which will cause the position error of the two crane hooks, thus causing the lifting beam to tilt. When the tilt amount |ΔH|>L0*tan2.5 / 2, the follow-up crane needs to dynamically compensate: The compensation principle is that when the main crane luffs and retracts, the auxiliary crane retracts the rope; when the main crane luffs and lowers, the auxiliary crane releases the rope.