阅读说明：本技术 一种起重机大车电缆卷盘实时张力控制方法及其系统 (Real-time tension control method and system for cable reel of crane cart ) 是由 张焕兵 庞珽 程华国 韩文剑 曹睿 于 2021-07-19 设计创作，主要内容包括：本发明提供了一种起重机大车电缆卷盘实时张力控制方法及其系统,包括如下步骤：S1.利用悬链线方程计算出电缆合理卷绕曲线对应的最大张力F；S2.将S1计算出来的最大张力F作为预设张力F-(preset),计算电缆实际卷绕张力F-(actual)；S3.通过S2计算出来的电缆实际卷绕张力F-(actual)来计算电机实际卷绕转矩M-(motor),对起重机大车电缆卷盘实时张力进行控制。通过基于PC机的控制算法,已经保证了起重机大车电缆卷盘在电缆卷绕运动控制过程中的实时合理张力,位置环闭环控制只是多了一重电气保护功能,而非传统意义上的闭环PID控制思路。(The invention provides a real-time tension control method and a real-time tension control system for a cable reel of a crane cart, which comprise the following steps: s1, calculating a maximum tension F corresponding to a reasonable winding curve of the cable by using a catenary equation; s2, taking the maximum tension F calculated in the step S1 as a preset tension F preset Calculating the actual winding tension F of the cable actual (ii) a S3, calculating the actual winding tension F of the cable through S2 actual To calculate the actual winding torque M of the motor motor And controlling the real-time tension of the cable reel of the crane cart. The real-time reasonable tension of the crane cart cable reel in the cable winding motion control process is ensured through a control algorithm based on a PC, and the position ring closed-loop control only has one more electric protection function, rather than the traditional closed-loop PID control idea.)

1. A real-time tension control method for a cable reel of a crane cart is characterized by comprising the following steps:

s1, calculating a maximum tension F corresponding to a reasonable winding curve of the cable by using a catenary equation;

s2, taking the maximum tension F calculated in the step S1 as a preset tension F_presetCalculating the actual winding tension F of the cable_actual；

S3, calculating the actual winding tension F of the cable through S2_actualTo calculate the actual winding torque M of the motor_motorAnd controlling the real-time tension of the cable reel of the crane cart.

2. The method as claimed in claim 1, wherein the step S1 comprises the steps of:

the catenary curve of the corresponding cable is obtained according to a reasonable CD curve of the cable wound out of the crane cart cable reel, wherein C is a tangent point of the cable curve and the ground, D is a tangent point of the cable curve and the reel, and the equation is as follows:

in the formula (1), x and y are horizontal and vertical coordinates of a point on a catenary curve, H is the horizontal component force of the maximum tension F of a cable D point, and q is the weight of the cable in unit length;

(A) calculation of horizontal component force H

The tangent point C of the curve and the ground is taken as the origin of coordinates, and the coordinates (x) of any point on the curve are given according to the proper curve shape and working condition during calculation₀，y₀) Substituting the formula (1) to obtain:

let (q/H) x₀When Z, equation (2) is compiled over equation (3):

changing equation (3) to functional form f (z):

F(Z)＝ch(Z)-(y₀/x₀)Z-1...............................(4)

passing through any point (Z)₀，F(Z₀) Tangent to the curve, i.e. at this point f (z) the result is:

F'(Z₀)＝sh(Z₀)-(y₀/x₀)...................................(5)

the intersection point of the tangent and the abscissa is Z₁Then Z is₁＝Z₀-F(Z₀)/F'(Z₀)

Z₁Is a new approximate value of equation root Z in the formula (3); judgment of | Z₁-Z₀Whether | is less than that meeting the actual requirementA certain accuracy range is obtained, if true, Z₁Is an approximate value, if it is not true, then Z is₁Is given as Z₀Returning to the formula (5) to continue iterative computation; according to the iterative computation result of the computer, the value of Z is solved; the value of Z is the final iteration result which can meet the precision condition, namely the approximate root of the transcendental equation (3); substituting the value of Z into (q/H) x₀In the formula Z, the H value can be obtained;

(B) calculation of vertical component force W

Let the length of the catenary CD be L_CDAnd then:

vertical component force W ═ L of catenary_CDXq, q being the weight per unit length of the cable;

the maximum tension F at the cable D point is:

3. the method as claimed in claim 1, wherein the step S2 comprises the steps of:

in the formula, D₀To an initial coil diameter, D_modifyAnd D is the real-time roll diameter and K is the tension taper coefficient.

4. The real-time tension control method for the cable reel of the crane cart according to claim 3, wherein the actual winding tension of the cable of S2 is calculated and divided into a multi-section interval control form by segmenting the distance of the cart in which the cart runs; if the absolute distance of the large vehicle is Length _ step, the running distance is divided into four sections, namely distance1, distance2, distance3 and distance4, 0< distance1< distance2< distance3< distance4,

then when 0<Length_step<When the distance is 1, the distance is,

in the formula, F_{actual_1}Is the actual winding tension of the first interval, F_{preset_1}Presetting tension for the first interval, K1 is the tension taper coefficient of the first interval, D₀To an initial coil diameter, D_{modify_1}The corrected value of the roll diameter in the first interval is obtained;

when distance1<Length_step<When the distance is 2, the distance is,

in the formula, F_{actual_2}Is the actual winding tension of the second interval, F_{preset_2}Presetting tension for the second interval, K2 is the tension taper coefficient of the second interval, D₀To an initial coil diameter, D_{modify_2}The roll diameter correction value of the second interval is obtained;

when distance2<Length_step<When the distance is 3, the distance is,

in the formula, F_{actual_3}Is the actual winding tension of the third interval, F_{preset_3}Presetting tension for the third interval, K3 is the tension taper coefficient of the third interval, D₀To an initial coil diameter, D_{modify_3}The roll diameter correction value of the third interval is obtained;

when distance3<Length_step<When the distance is 4, the distance is,

in the formula, F_{actual_4}Is the actual winding tension of the fourth interval, F_{preset_4}Presetting tension for a fourth interval, K4 is tension taper coefficient of the fourth interval, D₀Is a firstInitial winding diameter, D_{modify_4}Is the corrected value of the winding diameter in the fourth interval.

5. The method as claimed in claim 1, wherein the step S3 comprises the steps of:

the total torque of the cable is:

in the formula, F_actualFor the actual winding tension of the cable, in units N, D_maxThe maximum winding diameter, the unit m, i is the transmission reduction ratio, eta is the efficiency of the reduction gear, K_mIs a coefficient converted to a rated moment;

then

In the formula, plus signs of plus or minus signs represent forward rotation of the reel, minus signs represent reverse rotation of the reel, and M_motorActual winding torque of the motor, M, to be provided for the reel frequency converter_cableIs the total torque of the cable, Loss₀Is coefficient of static resistance, Loss_tIs the wind resistance coefficient, N_actFor the actual rotational speed, ρ is the density per unit length of the cable, H_centerThe central height of the cable reel of the cart is shown, g is the gravity acceleration, and D is the real-time winding diameter.

6. Method for real-time tension control of crane cart cable reels according to any of claims 1 to 5, characterized in that the calculation work is done in an industrial PC (1).

7. A system for using the crane cart cable reel real-time tension control method of any of claims 1 to 6, the system comprising:

the industrial PC (1) is used for performing real-time iterative operation and calculating the real-time tension of the cable reel of the cart in the cable winding motion process;

the reel driving module comprises a reel frequency converter (2), a reel frequency conversion motor (3) and an incremental encoder (4), wherein the reel frequency converter (2) is connected with the industrial PC (1), the reel frequency conversion motor (3) and the incremental encoder (4); an incremental encoder (4) is arranged on the reel variable frequency motor (3) and is used for detecting the real-time winding speed of the cable;

the cart driving module comprises a cart frequency converter (5), an absolute value encoder (6) and a cart variable frequency motor (7), wherein the cart frequency converter (5) is connected with the cart variable frequency motor (7); the absolute value encoder (6) is mounted on a free wheel of a cart mechanism driven by the cart variable frequency motor (7) and used for detecting the corresponding cable winding length in the cable winding movement process; and the industrial PC (1) is connected with the absolute value encoder (6) and is used for acquiring the corresponding cable winding length in the cable winding motion process.

8. The crane cart cable reel real-time tension control system of claim 7, wherein said industrial PC (1) is a double-ford PC controller CX 5120.

9. The crane cart cable reel real-time tension control system of claim 7, wherein the industrial PC (1) drives the reel transducer (2) using EtherCAT bus communication.

10. The crane cart cable reel real-time tension control system of claim 7, wherein the industrial PC (1) collects the absolute value encoder (6) signal by means of DP communication.

Technical Field

The invention relates to the field of cranes, in particular to a crane cart cable reel real-time tension control method and a crane cart cable reel real-time tension control system.

Background

The technical difficulty of the crane cart cable reel is to ensure the synchronization of the winding speed and the moving speed of the equipment and to ensure the moderate tension of the cable in the winding process. As the hoisting machine needs to travel further, so that the winding radius of the inner layer to the outer layer of the reel differs by a factor of 3 or even more, its constant torque output puts higher tensile requirements on the cable. Under the condition of meeting the requirement of the coiling force of the outer layer cable, the coiling moment of the magnetic coupling is approximately constant, so that the tension borne by the inner layer cable is more than 3 times greater than that of the outer layer cable, and the high-voltage cable embedded with the optical fiber or the cable with low bearing tension is easily damaged.

Because the reel requires to hold more cables, the reel winding diameter is larger, and the cable receives a large fluctuation range of tension in the process of winding and unwinding the cable by the reel, the cable sheath is easy to damage. Under the conditions of large current, high reel rigidity requirement, large rotational inertia, large acceleration and high speed, the traditional cable reel basically adopts a single-layer multi-row winding roller form, and in order to ensure that the tension of a cable is always smaller than the tensile resistance of the cable, the torque of a vector frequency converter controlled variable frequency control motor alone cannot well meet the requirement of accelerated response. In a cart cable reel frequency conversion control system, aiming at the defect that a constant tension controlled variable frequency cable reel controlled by a vector frequency converter is adopted independently, the existing crane cart cable reel control method mainly combines the electrical control characteristic and the mechanical flexible driving characteristic of the frequency converter, the cable has electrical and mechanical dual protection in the winding process, but the torque of a variable frequency control motor still cannot well meet the requirement of accelerated response, and the accident caused by cable damage still happens occasionally.

Disclosure of Invention

The invention solves the problems that: the double protection of the cable, both electrical and mechanical, during the winding process is still insufficient to ensure that the torque of the variable frequency control motor meets the acceleration response requirements.

In order to solve the above problems, in one aspect, the present invention provides a method for controlling real-time tension of a cable reel of a crane cart, wherein the method comprises the following steps:

s1, calculating a maximum tension F corresponding to a reasonable winding curve of the cable by using a catenary equation;

s2, taking the maximum tension F calculated in the step S1 as a preset tension F_presetCalculating the actual winding tension F of the cable_actual；

S3, calculating the actual winding tension F of the cable through S2_actualTo calculate the actual winding torque M of the motor_motorAnd controlling the real-time tension of the cable reel of the crane cart.

Preferably, the step S1 includes the steps of:

obtaining a catenary curve of the corresponding cable according to a reasonable CD curve of the cable wound out of the crane cart cable reel, wherein the equation is as follows:

in the formula (1), x and y are horizontal and vertical coordinates of a point on a catenary curve, H is the horizontal component of the maximum tension F at the point D of the cable, and q is the weight of the cable per unit length.

(A) Calculation of horizontal component force H

The tangent point C of the curve and the ground is taken as the origin of coordinates, and the coordinates (x) of any point on the curve are given according to the proper curve shape and working condition during calculation₀，y₀) For example (2, 2.5), in place of formula (1):

let (q/H) x₀When Z, equation (2) is compiled over equation (3):

changing equation (3) to functional form f (z):

F(Z)＝ch(Z)-(y₀/x₀)Z-1...............................(4)

passing through any point (Z)₀，F(Z₀) Tangent to the curve, i.e. at this point f (z) the result is:

F'(Z₀)＝sh(Z₀)-(y₀/x₀)...................................(5)

the intersection point of the tangent and the abscissa is Z₁Then Z is₁＝Z₀-F(Z₀)/F'(Z₀)

Z₁Which is a new approximation of the equation root Z of equation (3). Judgment of | Z₁-Z₀Whether | is less than a certain precision range that meets the actual requirement, e.g. actual requirement | Z₁-Z₀|<10^ -4, if true, Z₁Is an approximate value, if it is not true, then Z is₁Is given as Z₀Returning to equation (5), the iterative calculation continues. And solving the value of Z according to the iterative calculation result of the computer. The value of Z can satisfy the | Z₁-Z₀|<The final iteration result of the 10-4 condition, i.e., overriding the approximate root of equation (3). Substituting the value of Z into (q/H) x₀In the formula Z, the H value can be obtained.

(B) Calculation of vertical component force W

Let the length of the catenary CD be L_CDAnd then:

vertical component force W ═ L of catenary_CDAnd x q, q is the weight of the cable per unit length.

The maximum tension F at the cable D point is:

preferably, the step S2 includes the steps of:

in the formula, D₀To an initial coil diameter, D_modifyAnd D is the real-time roll diameter and K is the tension taper coefficient.

Preferably, the actual winding tension calculation of the cable of S2 is divided into a form of multi-segment interval control by segmenting by the distance the cart travels. If the absolute distance of the large vehicle is Length _ step, the running distance is divided into four sections, namely distance1, distance2, distance3 and distance4, 0< distance1< distance2< distance3< distance4,

then when 0<Length_step<When the distance is 1, the distance is,

in the formula, F_{actual_1}Is the actual winding tension of the first interval, F_{preset_1}Presetting tension for the first interval, K1 is the tension taper coefficient of the first interval, D₀To an initial coil diameter, D_{modify_1}Is the corrected value of the first interval winding diameter.

When distance1< Length step < distance2,

in the formula, F_{actual_2}Is the actual winding tension of the second interval, F_{preset_2}Presetting tension for the second interval, K2 is the tension taper coefficient of the second interval, D₀To an initial coil diameter, D_{modify_2}And the corrected value of the roll diameter in the second interval.

When distance2< Length step < distance3,

in the formula, F_{actual_3}Is the actual winding tension of the third interval, F_{preset_3}Presetting tension for the third interval, K3 is the tension taper coefficient of the third interval, D₀Is the initial coil diameter，D_{modify_3}And the corrected value of the third interval roll diameter.

When distance3< Length step < distance4,

in the formula, F_{actual_4}Is the actual winding tension of the fourth interval, F_{preset_4}Presetting tension for a fourth interval, K4 is tension taper coefficient of the fourth interval, D₀To an initial coil diameter, D_{modify_4}Is the corrected value of the winding diameter in the fourth interval.

Preferably, the step S3 includes the steps of:

the total torque of the cable is:

in the formula, F_actualIs the actual winding tension (unit N) of the cable, D_maxIs the maximum winding diameter (unit m), i is the transmission reduction ratio, eta is the efficiency of the speed reducer, generally 0.8-0.9, K_mIs a factor converted to a rated (locked rotor) torque.

Then

In the formula, plus signs of plus or minus signs represent forward rotation of the reel, minus signs represent reverse rotation of the reel, and M_motorActual winding torque of the motor, M, to be provided for the reel frequency converter_cableIs the total torque of the cable, Loss₀Is coefficient of static resistance, Loss_tIs the wind resistance coefficient, N_actFor the actual rotational speed, ρ is the density per unit length of the cable, H_centerThe central height of the cable reel of the cart is shown, g is the gravity acceleration, and D is the real-time winding diameter.

Preferably, the calculation of the above three steps is performed in the industrial PC1, the reel frequency converter 2 is a common frequency converter capable of providing torque control, and the operation control algorithm of the reel driving module is independent of the reel frequency converter 2.

In another aspect, the present invention further provides a system using the method for controlling real-time tension of a cable reel of a crane cart, wherein the system comprises:

the industrial PC (personal computer) 1 is used for performing real-time iterative operation and calculating the real-time tension of the cable reel of the cart in the cable winding motion process;

the reel driving module comprises a reel frequency converter 2, a reel frequency conversion motor 3 and an incremental encoder 4, wherein the reel frequency converter 2 is connected with the industrial PC1, the reel frequency conversion motor 3 and the incremental encoder 4; the reel variable frequency motor 3 is provided with an incremental encoder 4 for detecting the real-time speed of cable winding;

the cart driving module comprises a cart frequency converter 5, an absolute value encoder 6 and a cart variable frequency motor 7, wherein the cart frequency converter 5 is connected with the cart variable frequency motor 7; the absolute value encoder 6 is arranged on a free wheel of a cart mechanism driven by the cart variable frequency motor 7 and used for detecting the corresponding cable winding length in the cable winding movement process; the industrial PC1 is connected to the absolute value encoder 6, and is configured to obtain a corresponding cable winding length during a cable winding movement.

Preferably, the industrial PC1 is the double-ford PC controller CX 5120.

Preferably, the industrial PC1 drives the reel frequency converter 2 in an EtherCAT (ethernet control automation technology) bus communication manner.

Preferably, the industrial PC1 acquires the signal of the absolute value encoder 6 by means of DP (Decentralized peripheral, full name PROFIBUS-DP), a PROFIBUS communication protocol running on a 485 serial port.

Compared with the prior art, the real-time tension control method and the system for the cable reel of the crane cart have the following beneficial effects:

(1) the real-time tension control method and the system of the crane cart cable reel are based on the control mode of real-time tension calculation of an upper computer PC or a PAC industrial PC, only a catenary equation is required to be established according to a winding curve, the industrial PC is adopted for iterative operation, the real-time result of the iterative operation is used as a process quantity to participate in the real-time control of the winding tension, and the real-time tension control method and the system are the first protection limit of the real-time tension control of the winding process;

(2) the real-time tension multi-section differential tension taper control mode of the crane cart cable reel real-time tension control method and the system thereof ensure the soft protection limit of the maximum tension in the whole cable coiling and cable releasing process, and is the second protection limit of the real-time tension control in the winding process;

(3) the real-time tension control method and the system for the crane cart cable reel are based on the acquisition of the absolute winding position by an absolute value encoder arranged on a free wheel of a cart mechanism, and are the third protection limit for the real-time tension control in the winding process.

Drawings

FIG. 1 is a flow chart of a method of the present invention;

FIG. 2 is a CD curve graph of the cable being spooled by the crane cart cable reel of the present invention;

FIG. 3 is a catenary graph of the corresponding cable of FIG. 2 of the present invention;

FIG. 4 is a schematic diagram of the system of the present invention.

Description of reference numerals:

1. industrial PC; 2. a reel frequency converter; 3. a reel variable frequency motor; 4. an incremental encoder; 5. a cart frequency converter; 6. an absolute value encoder; 7. a cart variable frequency motor; C. the tangent point of the cable curve and the ground; D. the tangent point of the cable curve and the reel; F. a maximum tension; H. horizontal component force; w, vertical component force.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

Example one

A real-time tension control method for a cable reel of a crane cart is provided, as shown in figure 1, wherein the method comprises the following steps:

s1, calculating a maximum tension F corresponding to a reasonable winding curve of the cable by using a catenary equation;

s2, taking the maximum tension F calculated in the step S1 as a preset tension F_presetCalculating the actual winding tension F of the cable_actual；

S3, calculating the actual winding tension F of the cable through S2_actualTo calculate the actual winding torque M of the motor_motorAnd controlling the real-time tension of the cable reel of the crane cart.

Wherein the step S1 includes the following steps:

the CD curve shown in fig. 2 is reasonable because the cable tension of the CD curve is not large, and the cable winding and cable arranging of the cable reel can be performed freely. Fig. 3 is a catenary curve of the corresponding cable of fig. 2, with the equation:

in the formula (1), x and y are horizontal and vertical coordinates of a point on a catenary curve, H is the horizontal component of the maximum tension F at the point D of the cable, and q is the weight of the cable per unit length.

(A) Calculation of horizontal component force H

The tangent point C of the curve and the ground is taken as the origin of coordinates, and the coordinates (x) of any point on the curve are given according to the proper curve shape and working condition during calculation₀，y₀) For example (2, 2.5), in place of formula (1):

let (q/H) x₀When Z, equation (2) is compiled over equation (3):

changing equation (3) to functional form f (z):

F(Z)＝ch(Z)-(y₀/x₀)Z-1...............................(4)

passing through any point (Z)₀，F(Z₀) Tangent to the curve, i.e. at this point f (z) the result is:

F'(Z₀)＝sh(Z₀)-(y₀/x₀)...................................(5)

the intersection point of the tangent and the abscissa is Z₁Then Z is₁＝Z₀-F(Z₀)/F'(Z₀)

Z₁Which is a new approximation of the equation root Z of equation (3). Judgment of | Z₁-Z₀Whether | is less than a certain precision range that meets the actual requirement, e.g. actual requirement | Z₁-Z₀|<10^ -4, if true, Z₁Is an approximate value, if it is not true, then Z is₁Is given as Z₀Returning to equation (5), the iterative calculation continues. And solving the value of Z according to the iterative calculation result of the computer. The value of Z can satisfy the | Z₁-Z₀|<The final iteration result of the 10-4 condition, i.e., overriding the approximate root of equation (3). Substituting the value of Z into (q/H) x₀In the formula Z, the H value can be obtained.

(B) Calculation of vertical component force W

Let the length of the catenary CD be L_CDAnd then:

vertical component force W ═ L of catenary_CDAnd x q, q is the weight of the cable per unit length.

The maximum tension F at the cable D point is:

wherein the step S2 includes the following steps:

in the formula, D₀To an initial coil diameter, D_modifyAnd D is the real-time roll diameter and K is the tension taper coefficient.

The actual winding tension of the cable of S2 is calculated and divided into a multi-section control mode by segmenting according to the running distance of the cart. If the absolute distance of the large vehicle is Length _ step, the running distance is divided into four sections, namely distance1, distance2, distance3 and distance4, 0< distance1< distance2< distance3< distance4,

then when 0<Length_step<When the distance is 1, the distance is,

in the formula, F_{actual_1}Is the actual winding tension of the first interval, F_{preset_1}Presetting tension for the first interval, K1 is the tension taper coefficient of the first interval, D₀To an initial coil diameter, D_{modify_1}Is the corrected value of the first interval winding diameter.

When distance1< Length step < distance2,

in the formula, F_{actual_2}Is the actual winding tension of the second interval, F_{preset_2}Presetting tension for the second interval, K2 is the tension taper coefficient of the second interval, D₀To an initial coil diameter, D_{modify_2}And the corrected value of the roll diameter in the second interval.

When distance2< Length step < distance3,

in the formula, F_{actual_3}Is the actual winding tension of the third interval, F_{preset_3}Presetting tension for the third interval, K3 is the tension taper coefficient of the third interval, D₀To an initial coil diameter, D_{modify_3}And the corrected value of the third interval roll diameter.

When distance3< Length step < distance4,

in the formula, F_{actual_4}Is the actual winding tension of the fourth interval, F_{preset_4}Presetting tension for a fourth interval, K4 is tension taper coefficient of the fourth interval, D₀To an initial coil diameter, D_{modify_4}Is the corrected value of the winding diameter in the fourth interval.

Wherein the step S3 includes the following steps:

the total torque of the cable is:

in the formula, F_actualIs the actual winding tension (unit N) of the cable, D_maxIs the maximum winding diameter (unit m), i is the transmission reduction ratio, eta is the efficiency of the speed reducer, generally 0.8-0.9, K_mIs a factor converted to a rated (locked rotor) torque.

Then

In the formula, plus signs of plus or minus signs represent forward rotation of the reel, minus signs represent reverse rotation of the reel, and M_motorActual winding torque of the motor, M, to be provided for the reel frequency converter_cableIs the total torque of the cable, Loss₀Is coefficient of static resistance, Loss_tIs the wind resistance coefficient, N_actFor the actual rotational speed, ρ is the density per unit length of the cable, H_centerThe central height of the cable reel of the cart is shown, g is the gravity acceleration, and D is the real-time winding diameter.

The calculation work of the three steps is completed in the industrial PC1, the reel frequency converter 2 is a common frequency converter capable of providing torque control, and the operation control algorithm of the reel driving module does not depend on the reel frequency converter 2.

Example two

There is provided a system using the method for real-time tension control of a cable reel of a crane cart according to the first embodiment, as shown in fig. 4, wherein the system comprises:

the industrial PC (personal computer) 1 is used for performing real-time iterative operation and calculating the real-time tension of the cable reel of the cart in the cable winding motion process;

the reel driving module comprises a reel frequency converter 2, a reel frequency conversion motor 3 and an incremental encoder 4, wherein the reel frequency converter 2 is connected with the industrial PC1, the reel frequency conversion motor 3 and the incremental encoder 4; the reel variable frequency motor 3 is provided with an incremental encoder 4 for detecting the real-time speed of cable winding;

the cart driving module comprises a cart frequency converter 5, an absolute value encoder 6 and a cart variable frequency motor 7, wherein the cart frequency converter 5 is connected with the cart variable frequency motor 7; the absolute value encoder 6 is arranged on a free wheel of a cart mechanism driven by the cart variable frequency motor 7 and used for detecting the corresponding cable winding length in the cable winding movement process; the industrial PC1 is connected to the absolute value encoder 6, and is configured to obtain a corresponding cable winding length during a cable winding movement.

Wherein, the industrial PC1 is a Kyofu PC controller CX 5120.

The industrial PC1 drives the reel frequency converter 2 in an EtherCAT (ethernet control automation technology) bus communication manner.

The industrial PC1 acquires the signal of the absolute value encoder 6 through a DP (Decentralized peripheral, full-name PROFIBUS-DP), which is a PROFIBUS communication protocol running on a 485 serial port.

The system in the embodiment is based on a Beckman PC controller CX5120, real-time iterative operation is performed by using an operation resource of industrial PC1, an EtherCAT bus control method is adopted to drive the reel frequency converter 2, an incremental encoder 4 is installed on the reel frequency conversion motor 3 and used for detecting the real-time speed of cable winding, and the industrial PC1 acquires signals of an absolute value encoder 6 installed on a free wheel of a cart mechanism driven by a cart frequency conversion motor 7 in a DP communication mode and acquires the corresponding length of a cable in the process of cable winding movement. Different from the common mode of PLC (programmable logic controller) + tension controller or PLC + vector frequency converter control, the embodiment adopts the incremental encoder 4 to obtain a speed closed loop, adopts the absolute encoder 6 to obtain a position closed loop, the absolute encoder 6 only plays a supplementary limiting role in a real-time tension control system of a crane cart cable reel, and the control algorithm of an upper computer based on the industrial PC1 already ensures real-time reasonable tension of the cart cable reel in the cable winding motion control process, the position loop closed loop control only has one more electric protection function for the maximum tension of the cable, and is not a closed loop PID (proportional Integral Differential, Integral and Differential combined control algorithm) control idea in the traditional sense.

Although the present invention has been disclosed above, the scope of the present invention is not limited thereto. Various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are intended to be within the scope of the invention.