An anti-sway control method for bridge grab ship unloader based on input shaping and track planning

Abstract

The present invention discloses an anti-sway control method for a bridge-type grab ship unloader based on input shaping and track planning, which relates to the technical field of cranes. A system dynamics model of a bridge-type grab ship unloader that can describe variable amplitude motion, rotational motion and lifting motion is constructed, and trajectory planning is performed for the acceleration section, uniform speed section and deceleration section of the operation process according to the starting point and the end point. The swing period is estimated according to the length of the wire rope from the front end of the trunk beam of the bridge-type grab ship unloader to the center of the lifting weight, and the input signal is shaped based on the swing period to reduce the initial swing of the system. In the uniform speed section, the deflection angle is obtained in real time, and acceleration and deceleration control is performed according to the size and direction of the deflection angle, so as to better suppress the swing caused by the real-time disturbance during the movement. The present invention can achieve better anti-sway control and improve the stability and safety of the bridge-type grab ship unloader. The control method of the present invention is simple and easy to implement in engineering, and has a very broad prospect for engineering application.

Description

Technical Field

[0001] The invention relates to the technical field of cranes, and in particular to an anti-sway control method and electronic equipment for a bridge-type grab ship unloader based on input shaping and track planning. Background Art

[0002] A bridge grab ship unloader is a bridge crane that uses a mobile trolley to drive a grab to grab materials from the ship's cabin and unload the materials into the onboard hopper. It is an intermittent (or periodic) bulk material unloading machine. During the normal operation of the bridge grab ship unloader, it mainly relies on the variable amplitude movement and rotation movement of the ship unloader, and the lifting and lowering movement of the lifting mechanism to complete an operation cycle. Due to the inertia of each mechanism during acceleration and deceleration, under the influence of inertia, the movement state of the hoisting weight during the operation will lag behind or lead the movement of the mechanism. This lag or advance will cause the hoisting weight to reciprocate around the lifting point at the front end of the trunk beam. Under an operating cycle, if the hoisting weight deflection angle is not effectively controlled, the following problems will occur:

[0003] First, when the rotational motion is completed, the weight still has an angle of deviation, so it swings in space. The swing angle provides the initial disturbance to the system and generates inertial force, causing the weight to swing and eventually stop under the action of friction and wind resistance, but this process lasts a long time.

[0004] Secondly, the rotary motion will generate centrifugal force, causing the hanging weight to swing with a larger amplitude.

[0005] The above problems greatly reduce the operating efficiency and safety of the bridge grab ship unloader. Summary of the invention

[0006] In view of this, the present invention aims to provide an anti-sway control method for a bridge-type grab ship unloader based on input shaping and track planning, so as to reduce the swing of the bridge-type grab ship unloader during operation.

[0007] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0008] On the one hand, the present invention provides an anti-sway control method for a bridge grab ship unloader based on input shaping and track planning, comprising the following steps:

[0009] Measure the load mass and the load rope length of the bridge grab ship unloader to determine the starting position and target position of the cargo to be transported;

[0010] The trajectory of the operation process is planned offline according to the starting position and the target position; the trajectory includes: an acceleration section, a uniform speed section and a deceleration section; in the acceleration section, the end point of the trunk beam moves from the initial state to the speed specified by the design requirements, including the variable amplitude motion speed and the rotation speed; the uniform speed section is the motion stage from the end point of the trunk beam reaching the maximum allowable speed to the beginning of the deceleration section, and the goal is to control the crane to travel at a uniform speed to meet the long-distance operation; the goal of the deceleration section is to control the crane trolley to decelerate to zero and reach the target position;

[0011] Determining an initial driving force according to the offline trajectory planning;

[0012] estimating a swing period according to a rope length of the load, and shaping the initial driving force according to the swing period;

[0013] In the acceleration and deceleration stages, the motor is controlled to change speed based on the shaped driving force.

[0014] Further, shaping the driving force according to the swing period includes:

[0015] shaping the driving force according to the swing period;

[0016] Construct a dynamic model of the bridge grab ship unloader system that describes the luffing motion, rotation motion and lifting motion;

[0017] Inputting the shaped driving force into the dynamic model to predict the swing angle of the hanging weight;

[0018] It is determined whether the swing angle of the hanging weight is within a preset range. If not, the driving force is reshaped until the swing angle of the hanging weight is within the preset range.

[0019] Furthermore, a dynamic model of the bridge grab ship unloader system describing the luffing motion, rotation motion and lifting motion is constructed, including:

[0020] Determine the position of the rotation center and the distance between the front end of the trunk and the rotation center L , the length of the wire rope from the center of the lifting weight to the front end of the trunk l , the rotation angle of the arm α , pitch angle β ;

[0021] The dynamic equations of variable displacement, rotation angle, rope length and weight swing angle are established based on the Lagrange equation.

[0022] Furthermore, the predicted swing angle of the hanging weight includes:

[0023] ;

[0024] ;

[0025] in, i 1 represents the swing angle in the lifting weight variable motion plane, i 2 represents the outward swing angle of the hanging weight. m Indicates the wind resistance and friction coefficient in the environment, , Respectively i 1、 i The second derivative of 2, , yes i 1、 i The first derivative of 2, , Respectively α The first and second derivatives of .

[0026] Further, the initial driving force is shaped according to the swing period, including:

[0027] The initial driving force is convolved with the pulse train of the different input shapers.

[0028] Furthermore, the pulse sequence input to the shaper satisfies the following constraint equation:

[0029] ;

[0030] in, represents the amplitude of the first pulse train, represents the amplitude of the second pulse train, represents the time lag of the first pulse train, represents the time lag of the second pulse train, Indicates the use to determine , Dimensionless number of proportional relationship, represents the swing period, Represents the damping ratio.

[0031] Furthermore, it also includes:

[0032] In the uniform speed section, the in-plane out-swing angle of the weight is obtained by the sensor at the front end of the trunk beam, and the in-plane out-swing angle of the weight is fed back to the rotating mechanism. Acceleration and deceleration control is performed according to the size and direction of the in-plane out-swing angle of the weight, so as to achieve a rapid stop of the weight when it reaches the end position.

[0033] Furthermore, acceleration and deceleration control is performed according to the size and direction of the out-of-plane swing angle of the hanging weight, including: feeding back the out-of-plane swing angle of the hanging weight to an anti-sway and anti-sway controller in real time, and suppressing the load swing angle by the rotation angular velocity.

[0034] Furthermore, the output of the anti-sway and anti-sway controller includes:

[0035] ;

[0036] ;

[0037] Among them, ψ represents the coefficient of the controller under different working conditions, is an adaptive function, is the outward swing angle of the hanging plane, Indicates the rotation angular velocity adjustment output by the controller. Indicates the running time, The start time of an operation cycle. The end time of an operation cycle.

[0038] On the other hand, the present invention also provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein when the processor executes the computer program, it implements the above-mentioned anti-sway control method for a bridge grab ship unloader based on input shaping and track planning.

[0039] Compared with the prior art, the solution of the present invention has the following beneficial effects:

[0040] The anti-sway control method for a bridge grab ship unloader based on input shaping and trajectory planning of the present invention adopts a fusion control strategy of input shaping and trajectory planning. Firstly, the initial input signal of the system is convolved with the pulse sequence of different input shapers, and the shaking caused by the movement of the crane's own mechanism is reduced, so that the initial swing of the system can be reduced. At the same time, the swing angle is fed back to the anti-sway and anti-sway controller in real time. The controller moves in the direction of reducing the swing amplitude according to the hook chasing principle, controls the rotation angular velocity and thus suppresses the load swing angle during the operation, so as to achieve a rapid stop at the unloading point, which can effectively improve the operating efficiency and safety of the bridge grab ship unloader. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0042] Figure 1Schematic diagram of a six-degree-of-freedom mathematical model of a bridge-type grab ship unloader in an embodiment of the present invention;

[0043] Figure 2 Schematic diagram of a control system of a bridge grab ship unloader according to an embodiment of the present invention;

[0044] Figure 3 It is a flow chart of the control method of the bridge grab ship unloader in the embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0046] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0047] Reference Figure 1~3 As shown, in an embodiment of the present invention, a method for controlling a bridge grab ship unloader against shaking based on input shaping and track planning comprises the following steps:

[0048] S1. Measure the load mass and the load rope length of the bridge grab ship unloader to determine the starting position and target position of the cargo to be transported.

[0049] S2. Perform offline trajectory planning for the operation process according to the starting position and the target position.

[0050] The trajectory mainly includes three parts: acceleration section, uniform speed section and deceleration section. In the acceleration section, the end point of the trunk moves from the initial state to the speed specified by the design requirements, including the variable amplitude movement speed and the rotation speed; the uniform speed section is the movement stage from the end point of the trunk reaching the maximum allowable speed to the beginning of the deceleration section, and the goal is to control the crane to travel at a uniform speed to meet the possible long-distance operation; the goal of the deceleration section is to control the crane trolley to decelerate to zero and reach the target position.

[0051] S3. Determine the initial driving force according to the offline trajectory planning.

[0052] The initial driving force here includes operating parameters such as speed and acceleration.

[0053] In the acceleration phase, the goal is to control the crane trolley to accelerate and drive to the target position to ensure that the load swing state can return to zero again after the acceleration phase. To ensure that the speed of the crane trolley is 0 when it reaches the target position, it is necessary to calculate the acceleration of this phase in conjunction with the subsequent phases. .

[0054] The goal of the uniform speed stage is to control the crane to travel at a uniform speed to meet the possible long-distance operation. The acceleration in this stage If it is 0, the running time of this stage needs to be calculated according to the target position.

[0055] The deceleration stage aims to control the crane trolley to decelerate to zero and reach the target position. To ensure that the load swing angle returns to zero, the acceleration Need to meet:

[0056] ;

[0057] To ensure that the swing angle does not exceed the maximum load swing angle during operation i max Limit, acceleration Need to meet:

[0058] .

[0059] S4. Estimate the swing period according to the rope length of the load, and shape the initial driving force according to the swing period.

[0060] Specifically, the swing period is estimated based on the length of the wire rope from the front end of the bridge grab ship unloader's trunk to the center of the load. T :

[0061] .

[0062] S5. In the acceleration section and the deceleration section, the motor is controlled to change speed based on the driving force after shaping.

[0063] In a specific implementation, S4 may be executed according to the following steps, including:

[0064] S42. Construct a dynamic model of the bridge grab ship unloader system that describes the amplitude variation motion, rotation motion and lifting motion;

[0065] Specifically, a dynamic model of the bridge grab ship unloader system that can describe the variable amplitude motion, rotation motion and lifting motion is established based on the Lagrange equation. The model has three state variables as input: the depression angle β of the front end of the trunk beam, the rotation angle α and the length of the lifting rope. l , and other non-driven state variables such as Figure 1 As shown in , the model has a total of six degrees of freedom.

[0066] The coordinates of the hoisting position are as follows:

[0067] ;

[0068] The matrix form of the dynamic model of the bridge grab ship unloader system can be obtained from the Lagrangian function:

[0069] ;

[0070] ;

[0071] ;

[0072] Among them, M represents the inertia matrix, C represents the Coriolis force matrix, G represents the gravity vector part, U contains the input, F contains the air resistance and friction terms, f is the friction compensation coefficient, and d is the air resistance coefficient. Due to the inertia of each mechanism during acceleration and deceleration, under the influence of inertia, the movement state of the hanging weight during the operation will lag behind or lead the movement of the mechanism. This lag or lead will cause the hanging weight to reciprocate around the hanging point at the front end of the trunk, resulting in a swing angle.

[0073] S42, shaping the initial driving force according to the swing period;

[0074] Among them, based on the swing period T The shaping process of the input signal (initial driving force) is as follows: the initial input signal of the system is convolved with the pulse sequence of different input shapers, and the trajectories of the acceleration section, uniform speed section and deceleration section are planned to reduce the shaking caused by the movement of the crane's own mechanism and the initial swing of the system, thereby achieving the purpose of reducing the swing of the load.

[0075] The pulse sequence input to the shaper must satisfy the following constraint equation:

[0076]

[0077] in, represents the amplitude of the first pulse train, represents the amplitude of the second pulse train, represents the time lag of the first pulse train, represents the time lag of the second pulse train, Indicates the use to determine , Dimensionless number of proportional relationship, represents the swing period, Represents the damping ratio.

[0078] S43, inputting the shaped driving force into the dynamics model to predict the swing angle of the hanging weight;

[0079] Among them, in the Lagrangian function, the in-plane deflection angle i 1 and out-of-plane deflection i 2The corresponding expression is:

[0080] ;

[0081] ;

[0082] S44, judging whether the swing angle of the hanging weight is within the preset range, if not, returning to S42 to reshape the driving force until the swing angle of the hanging weight is within the preset range.

[0083] The deflection angle is generated by the luffing mechanism i 1Open-loop feedforward control through input shaping. By reducing the shaking caused by the crane's own mechanism movement, the initial swing of the system can be reduced, and the in-plane swing angle generated by the variable amplitude movement can be effectively controlled. i 1.

[0084] In another embodiment, the anti-sway control method further includes:

[0085] S6. In the uniform speed section, the outward swing angle of the hanging weight is obtained through the sensor at the front end of the trunk beam, and the outward swing angle of the hanging weight is fed back to the rotating mechanism. Acceleration and deceleration control is performed according to the size and direction of the outward swing angle of the hanging weight to achieve a rapid stop of the hanging weight when it reaches the end position.

[0086] It should be noted that in S6 i 2, and the control of S3 to S5 in the above embodiment i The control of 1 is relatively independent and can be executed separately or together.

[0087] Out-of-plane deflection angle caused by rotational motion i 2. Control is achieved through a rotating mechanism.

[0088] In the uniform speed section, the deflection angle is obtained by the sensor at the front end of the trunk beam, and the deflection angle is fed back to the rotating mechanism. Acceleration and deceleration are controlled according to the size and direction of the deflection angle to achieve a rapid stop when the load reaches the end position.

[0089] Acceleration and deceleration control is performed according to the size and direction of the deflection angle. i 2 Real-time feedback is given to the anti-sway and anti-sway controller. The controller moves in the direction of reducing the swing amplitude according to the anti-sway algorithm, controls the rotation angular velocity and thus suppresses the load swing angle to reduce it.

[0090] In order to describe the controller design process more clearly, Figure 2 The block diagram of the control system is shown. The input of the control system is the angular velocity of the turntable oh The controlled objects are the motor and the mechanical transmission system of the door machine, and the output is the angular displacement of the door machine rotation. i , the feedback value is the external deflection angle of the lifting weight plane i 2. The feedback value is the rotation angular velocity adjustment amount oh c .

[0091] Anti-sway mechanism: Anti-sway follows the load movement in the same direction by controlling the anti-sway device, reducing the torque, reducing the actual amplitude, and continuously following to reduce the load swing amplitude until the load stops swinging.

[0092] The anti-sway controller uses the following anti-sway algorithm:

[0093] ;

[0094] ;

[0095] in, It represents the rotation angular velocity adjustment output by the controller, ψ represents the coefficient of the controller under different working conditions, r ( t ) is an adaptive function to prevent the sudden change of the feedback control quantity from causing a large impact on the system. Definition i The positive and negative directions of 2 are positive when the weight is on the left side of the zero point and negative when it is on the right side of the zero point.

[0096] The closed-loop feedback control of the present invention in the uniform speed section can suppress the swing of the hanging object within the working cycle, thereby better suppressing the swing caused by the real-time disturbance during the movement process, with a faster response speed, and at the same time, can enhance the stability and safety of the bridge grab ship unloader.

[0097] In the above embodiment, the fusion control strategy of input shaping and trajectory planning is adopted. First, the initial input signal of the system is convolved with the pulse sequence of different input shapers. By reducing the shaking caused by the movement of the crane's own mechanism, the initial swing of the system can be reduced, and the in-plane swing angle generated by the variable amplitude movement can be effectively controlled. i 1; At the same time, by feeding back the swing angle to the anti-sway and anti-sway controller in real time, the outward swing angle caused by the rotational motion is reduced according to the hook chasing principle. i 2 Real-time feedback is given to the anti-sway and anti-sway controller. The controller moves in the direction of reducing the swing amplitude according to the anti-sway algorithm, controls the rotation angular velocity and then suppresses the load swing angle to reduce it, so as to achieve a rapid stop at the unloading point. The anti-sway control method of the bridge grab ship unloader based on input shaping and trajectory planning adopts the fusion control strategy of input shaping and trajectory planning, which can effectively improve the operation efficiency and safety of the bridge grab ship unloader.

[0098] In the technical solution of the present invention, an electronic device is also provided, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the above-mentioned anti-sway control method of the bridge grab ship unloader based on input shaping and track planning can be implemented.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bridge grab ship unloader anti-sway control method based on input shaping and track planning, characterized in that: The following steps are involved: Measure the load mass and the load rope length of the bridge grab ship unloader to determine the starting position and target position of the cargo to be transported; The trajectory of the operation process is planned offline according to the starting position and the target position; the trajectory includes: an acceleration section, a uniform speed section and a deceleration section; in the acceleration section, the end point of the trunk beam moves from the initial state to the speed specified by the design requirements, including the variable amplitude motion speed and the rotation speed; the uniform speed section is the motion stage from the end point of the trunk beam reaching the maximum allowable speed to the beginning of the deceleration section, and the goal is to control the crane to travel at a uniform speed to meet the long-distance operation; the goal of the deceleration section is to control the crane trolley to decelerate to zero and reach the target position; Determining an initial driving force according to the offline trajectory planning; estimating a swing period according to a rope length of the load, and shaping the initial driving force according to the swing period; In the acceleration and deceleration stages, the motor is controlled to run at variable speed based on the driving force after shaping; The step of shaping the driving force according to the swing period includes: shaping the driving force according to the swing period; Construct a dynamic model of the bridge grab ship unloader system that describes the variable amplitude motion, rotation motion and lifting motion, including: determining the position of the rotation center, the distance between the front end of the trunk beam and the rotation center L , the length of the wire rope from the center of the lifting weight to the front end of the trunk l , the rotation angle of the arm α , pitch angle β ; Based on the Lagrange equation, the dynamic equations of variable displacement, rotation angle, rope length and weight swing angle are established; Inputting the shaped driving force into the dynamic model to predict the swing angle of the hanging weight; Determining whether the swing angle of the hanging weight is within a preset range, and if not, reshaping the driving force until the swing angle of the hanging weight is within the preset range; Among them, the predicted swing angle of the lifting weight includes: ； ； in, θ 1 represents the swing angle in the lifting weight variable motion plane, θ 2 represents the outward swing angle of the hanging weight. μ Indicates the wind resistance and friction coefficient in the environment, , Respectively θ 1、 θ The second derivative of 2, , yes θ 1、 θ The first derivative of 2, , Respectively α The first and second derivatives of .

2. The anti-sway control method of a bridge grab ship unloader based on input shaping and track planning as claimed in claim 1, characterized in that: The initial driving force is shaped according to the swing period, including: The initial driving force is convolved with the pulse train of the different input shapers.

3. The anti-sway control method of a bridge grab ship unloader based on input shaping and track planning as claimed in claim 2, characterized in that: The pulse sequence of the input shaper satisfies the following constraint equation: ； in, represents the amplitude of the first pulse train, represents the amplitude of the second pulse train, represents the time lag of the first pulse train, represents the time lag of the second pulse train, Indicates the use to determine , The dimensionless number of the proportional relationship, represents the swing period, Represents the damping ratio.

4. The anti-sway control method of a bridge grab ship unloader based on input shaping and track planning as claimed in claim 1, characterized in that: Also includes: In the uniform speed section, the in-plane out-swing angle of the weight is obtained by the sensor at the front end of the trunk beam, and the in-plane out-swing angle of the weight is fed back to the rotating mechanism. Acceleration and deceleration control is performed according to the size and direction of the in-plane out-swing angle of the weight, so as to achieve a rapid stop of the weight when it reaches the end position.

5. The anti-sway control method of a bridge grab ship unloader based on input shaping and track planning as claimed in claim 4, characterized in that: Acceleration and deceleration control is performed according to the size and direction of the plane outward swing angle of the hanging weight, including: feeding back the plane outward swing angle of the hanging weight to the anti-sway and anti-sway controller in real time, and suppressing the load swing angle by the rotation angular velocity.

6. The anti-sway control method of a bridge grab ship unloader based on input shaping and track planning as claimed in claim 5, characterized in that: The output of the anti-sway and anti-sway controller includes: ； ； Among them, ψ represents the coefficient of the controller under different working conditions, is an adaptive function, is the outward swing angle of the hanging plane, Indicates the rotational angular velocity adjustment output by the controller. Indicates the running time, The start time of an operation cycle. The end time of an operation cycle.

7. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and capable of running on the processor. When the processor executes the computer program, an anti-sway control method for a bridge grab ship unloader based on input shaping and track planning as described in any one of claims 1 to 6 is implemented.

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