Method and system for optimizing pushing speed of dumping mechanism of bulk material system

Abstract

The invention discloses a pushing speed optimization method and optimization system for a bulk system dumping mechanism, and relates to the field of optimization design. The optimization method comprises the steps that a first bending moment angle curve of the dumping mechanism in the overturning process under the ideal dumping state is determined; defining a driving function of the dumping mechanism, and determining a first bending moment time history curve and a to-be-optimized second bending moment time history curve of the dumping mechanism under the driving function; according to constraint conditions of the dumping mechanism, the driving function is optimized by taking deviation statistical value minimization between the second bending moment time travel curve and the first bending moment time travel curve as an optimization target, so that a target optimization coefficient is obtained; and determining a target angle time travel curve of the dumping mechanism according to the target optimization coefficient. According to the optimal oil cylinder stroke and time travel curve control technology for achieving the minimum instantaneous oil cylinder force peak value, under the condition that the total pushing duration is not changed, compared with previous constant-speed oil cylinder pushing, fluctuation of a bending moment curve in the overturning process can be effectively reduced.

Description

Technical Field

[0001] The present application relates to the field of optimization design, and in particular to a method and system for optimizing the pushing speed of a bulk material system dumping mechanism. Background Art

[0002] The tipping mechanism, including the ear bin, is a temporary silo for harvesters of agricultural crops (such as corn). It serves as a temporary storage facility for harvested ears. Once the ear bin is full, the hydraulic cylinder expands and contracts, causing the bin to tilt, quickly transferring the harvested ears to the truck hopper for transport to a designated silo. Unlike traditional material transportation, ear bins are bulk materials. When the silo they are in tilts, they can slip or even fall within the bin. This overall shift in center of gravity, combined with the instantaneous impact of a falling ear, can cause a dramatic change in cylinder force, potentially exceeding the design load. Simply increasing cylinder specifications significantly increases costs.

[0003] The pushing time curve of the oil cylinder determines the flipping angle time curve of the fruit ear box, thereby affecting the overall shape of the fruit ear pile in the box. The existing technology generally adopts the oil cylinder to push at a uniform speed, without considering the influence of the oil cylinder pushing speed on the oil cylinder pushing force. If the oil cylinder pushing speed is fast, the box body will cause the fruit ear pile in the box to change drastically during the rapid flipping process, resulting in the rapid fall of the fruit ears during the pushing process, causing some fruit ears to fall instantly and cause excessive impact. The sudden increase in the oil cylinder force will cause the oil cylinder load to be too large, affecting the safety of the operation. Ideally, the slower the oil cylinder pushing speed, the better. This will reduce the sudden change of the fruit ear pile in the silo, thereby reducing the impact caused by the fall, and thus avoid causing a sudden increase in the oil cylinder force. However, a slow pushing speed will inevitably lead to an increase in the pushing time, affecting the efficiency of the flipping operation. Therefore, how to set the optimal oil cylinder pushing stroke curve so that the oil cylinder force is as stable as possible during the pushing process and avoids a sudden peak has become a difficult problem in the industry. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a method and system for optimizing the pushing speed of the dumping mechanism of a bulk material system, which is a new cylinder stroke control technology that reduces the instantaneous impact force of the cylinder during the flipping process without increasing the total flipping time.

[0005] In order to achieve the above-mentioned objectives, the first aspect of the present application provides a method for optimizing the pushing speed of a bulk material system dumping mechanism, the pushing speed optimization method comprising: determining a first bending moment angle curve during the flipping process of the dumping mechanism under an ideal dumping state; defining a driving function of the dumping mechanism, and determining a first bending moment time-history curve of the first bending moment angle curve under the driving function and a second bending moment time-history curve to be optimized of the dumping mechanism under the driving function, wherein the driving function is an angle time-history curve of the dumping mechanism during the flipping process, and the driving function includes a predetermined number of optimization coefficients; according to the constraints of the dumping mechanism, the driving function is optimized with the deviation statistics between the second bending moment time-history curve and the first bending moment time-history curve as the optimization goal to obtain a target optimization coefficient; and according to the target optimization coefficient, the target angle time-history curve of the dumping mechanism is determined.

[0006] In an embodiment of the present application, determining the first bending moment angle curve of the dumping mechanism during the flipping process in an ideal dumping state includes: in the ideal dumping state, pushing the dumping mechanism by a driving member; and determining the first bending moment angle curve between the applied bending moment of the driving member and the flipping angle of the dumping mechanism by discrete element modeling.

[0007] In the embodiment of the present application, the ideal dumping state is a dumping state in which the applied bending moment of the driving member and the flipping angle of the dumping mechanism can change smoothly.

[0008] In an embodiment of the present application, the deviation statistics include at least one of the following: variance, standard deviation, mean square error, mean absolute error, and root mean square error.

[0009] In an embodiment of the present application, the driving function is optimized with minimization of the deviation statistics between the second bending moment time-history curve and the first bending moment time-history curve as the optimization goal, including: defining the deviation statistics between the second bending moment time-history curve and the first bending moment time-history curve as the objective function; and iteratively optimizing the driving function through at least one of the following algorithms until the residual of the minimum value of the objective function reaches a convergence state: genetic algorithm, downhill method, annealing method.

[0010] In an embodiment of the present application, the driving function is any one of the following: a cubic polynomial function, a quartic polynomial function, a higher-order polynomial function greater than fourth order, a power function, and a trigonometric function; wherein the cubic polynomial function includes three optimization coefficients, and the quartic polynomial function, the trigonometric function, and the power function include four optimization coefficients.

[0011] In the embodiment of the present application, when the driving function is the cubic polynomial function, the following formula represents the driving function: : When the driving function is the fourth-order polynomial function, the following formula represents the driving function: ： When the driving function is the power function, the following formula represents the driving function: ： Alternatively, when the driving function is the trigonometric function, the driving function is expressed as follows: ： in, is the optimization coefficient.

[0012] In an embodiment of the present application, the constraint conditions include one or more of the following: a minimum specified angle constraint, a maximum specified angle constraint, and a flip angular velocity constraint.

[0013] In the embodiment of the present application, in the driving function When it is a cubic polynomial function, the following equations represent the minimum specified angle constraint, the maximum specified angle constraint, and the flip angular velocity constraint:

[0014]

[0015]

[0016] in, is the optimization coefficient, is the maximum flip angle, is the total flipping time.

[0017] The second aspect of the present application provides a pushing speed optimization system for a bulk material system dumping mechanism, the pushing speed optimization system comprising: a first curve determination device for determining a first bending moment angle curve of the dumping mechanism during a flipping process in an ideal dumping state; a second curve determination device for defining a driving function of the dumping mechanism, and determining a first bending moment time-history curve of the first bending moment angle curve under the driving function and a second bending moment time-history curve to be optimized of the dumping mechanism under the driving function, wherein the driving function is an angle time-history curve of the dumping mechanism during a flipping process, and the driving function includes a predetermined number of optimization coefficients; an optimization device for optimizing the driving function according to the constraints of the dumping mechanism, with the optimization goal of minimizing the deviation statistics between the second bending moment time-history curve and the first bending moment time-history curve, so as to obtain a target optimization coefficient; and a target curve determination device for determining a target angle time-history curve of the dumping mechanism according to the target optimization coefficient.

[0018] Existing technologies generally use a hydraulic cylinder to push at a constant speed, without considering the impact of the cylinder's pushing speed on the cylinder's pushing force. If the cylinder pushes at a high speed, the ears in the silo will shift rapidly during the rapid turning process, resulting in a sudden drop and excessive impact, causing a sharp increase in the cylinder's instantaneous load. If the push speed is too slow, the entire turning process will be significantly prolonged, affecting the turning efficiency.

[0019] Through the above-mentioned technical solution of the present invention, an "optimal cylinder stroke time curve control technology for minimizing the instantaneous cylinder force peak" is proposed. By optimizing the "box flip angle time curve", an equivalent optimization method of the "optimal cylinder stroke time curve" is obtained. This can achieve the situation where the total pushing time remains unchanged. Compared with the previous constant speed cylinder push, the fluctuation of the bending moment curve during the flipping process can be effectively reduced.

[0020] That is to say, the present invention reasonably distributes the angular velocity of the box rotation without increasing the total duration of the flipping action. In the range where it is not easy for the center of gravity to move significantly, the angular velocity of the box rotation is appropriately accelerated; in the stroke range where falling is likely to occur, the angular velocity of the box rotation is appropriately slowed down. In this way, the most reasonable cylinder pushing scheme that minimizes the cylinder force peak can be obtained.

[0021] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present application but do not constitute a limitation on the embodiments of the present application. In the accompanying drawings: Figure 1The following schematically shows a flow chart of a method for optimizing the pushing speed of a dumping mechanism of a bulk material system according to an embodiment of the present application; Figure 2 A schematic diagram schematically illustrates a calculation process of an objective function according to an embodiment of the present application; Figure 3 Schematically shows a schematic diagram of the change of the ideal bending moment value during the box flipping process according to an embodiment of the present application; Figure 4 A schematic diagram showing the change of bending moment values during the actual optimization process during the box flipping process according to an embodiment of the present application is shown; Figure 5 A schematic diagram showing a comparison between an ideal bending moment value and an actual optimized bending moment value according to an embodiment of the present application is shown; Figure 6 The following is a schematic diagram showing an optimization model analysis process according to an embodiment of the present application; Figure 7 Schematically shows a schematic diagram of the change in the position of the hinge point during the turning process of the box according to an embodiment of the present application; Figure 8 The schematic diagram shows the structure of a pushing speed optimization system of a bulk material system dumping mechanism according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the embodiments of the present application and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0024] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application are in compliance with the relevant provisions of national laws and regulations. In the embodiments of this application, certain software, components, models, and other existing solutions in the industry may be mentioned. These should be considered as exemplary. Their purpose is only to illustrate the feasibility of implementing the technical solution of this application, but it does not mean that the applicant has or will necessarily use such solutions.

[0025] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0026] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0027] In order to solve the problem of unstable cylinder force curve and large peak value in the existing cylinder stroke linear control, the present invention provides an optimal cylinder stroke time curve control technology to achieve the minimum cylinder force peak. Figure 1 The present invention schematically shows a flow chart of a method for optimizing the pushing speed of a dumping mechanism of a bulk material system according to an embodiment of the present application, which can be used to optimize the pushing speed of dumping mechanisms including corn ear boxes. It should be noted that the optimization method provided by this patent only uses corn ear boxes as an example. In addition, the optimization of the pushing speed of the loading and unloading process involving discrete materials in other bulk materials such as minerals, crops, and food can also be performed with reference to the optimization method proposed in this patent.

[0028] In addition, see Figure 2, the overall technical route of the present invention is: the present invention realizes the most stable optimization of the bending moment time-history curve by minimizing the total variance of the "bending moment time-history curve to be optimized" and the "ideal bending moment time-history curve". Specifically, the inventors found that when the total unloading time is set to more than twice the normal pushing time and the box body is turned over at a uniform speed, the fruit ears in the box can be regarded as a smooth transition at this time, and the phenomenon of fruit ears falling into the air will not occur, which will cause violent fluctuations in the bending moment load curve, and an approximate "ideal bending moment time-history curve under ideal and stable unloading state" can be obtained. Then, the total variance of the "bending moment time-history curve to be optimized" and the "ideal bending moment time-history curve" is used as the objective function, and the optimization goal is to minimize the objective function, and finally achieve the most stable optimization of the bending moment time-history curve, which is equivalent to the minimum peak value of the cylinder force and the most stable push of the cylinder force. The specific implementation process of this optimization is as follows: parameterize the box flip angle time history curve using, for example, a cubic polynomial, constrain the box's total flip angle and total flip duration to remain constant, minimize the total variance between the "bending moment time history curve to be optimized" and the "ideal bending moment time history curve" during the flip process as the optimization goal, apply an optimization algorithm to solve the optimal box flip angle time history curve, and finally, combine the hinge position relationship to obtain the optimal cylinder push time history curve. Therefore, by controlling the cylinder stroke based on this curve, the peak of the cylinder force curve can be minimized during the box flip process, thereby achieving the most stable cylinder force push state.

[0029] Specifically, the push speed optimization method 100 of the present invention may include the following steps S110-S140.

[0030] Step S110: Determine a first bending moment angle curve during the tipping process of the dumping mechanism in an ideal dumping state.

[0031] In the embodiment of the present application, step S110 may further include the following steps S111 - S112 .

[0032] Step S111: Under an ideal dumping state, the dumping mechanism is pushed by a driving member.

[0033] The ideal dumping state is a dumping state in which the applied bending moment of the driving member and the flip angle of the dumping mechanism change smoothly, for example, including: the dumping mechanism is flipped at a uniform speed and the total dumping time is greater than or equal to the set push time. The set push time can be set to a multiple of the normal push time or more, for example, 2-3 times. In other words, in order to obtain the ideal bending moment angle curve under the ideal dumping state, the total dumping time can be set to be greater than or equal to the set push time. In addition, other means that can achieve a smooth change between the applied bending moment of the driving member and the flip angle of the dumping mechanism can also be used.

[0034] The driving part is, for example, a cylinder, and its pushing design value is usually related to the total extension of the cylinder, which is generally 12 to 20 seconds. Therefore, the total dumping time can be set to more than twice the normal pushing time and the box can be turned over at a constant speed as the ideal dumping state, thereby obtaining the ideal driving function of the dumping mechanism. If the original design flipping time is 15s, the box can be regarded as flipping at a constant speed within 30-45s to reach the specified maximum flip angle as the input condition, thereby obtaining the ideal bending moment angle curve with smooth changes.

[0035] Step S112 : determining a first bending moment angle curve between the applied bending moment of the driving member and the flipping angle of the dumping mechanism by using a discrete element modeling method.

[0036] Discrete material parameters, such as ear parameters, are considered. During the actual modeling of the ear, the load on the ear involves calculating contact between particles and between particles and the wall. The applicant considers that, aside from the weight of the bin itself, the remaining loads are solely due to the discrete system of the ear. Specifically, this paper proposes establishing a discrete model of corn ears based on the parameters of the ears in the bin (including particle size, shape, and size distribution). The pile of ears at this tilt angle is considered as a whole, and the compressive stress on the bin is calculated based on the total mass of the remaining ears. This approach requires only input parameters such as the shape and total mass of the corn ear pile, combined with boundary conditions such as the contact parameters between the corn ears and the bin walls (static and dynamic friction coefficients, rebound coefficient, etc.), to complete the modeling. Since the ears in the bin are bulk materials, their shape changes during the tilting process, and their center of mass also changes accordingly. If the center of mass is considered to be unchanged relative to the bin, the cylinder force calculation will be inaccurate. Therefore, the present invention adopts discrete element simulation technology, uses the rotation of the box as a drive, and obtains the total bending moment value applied by the discrete system to the box at any time .See Figure 3 , where the horizontal axis is the flip angle and the vertical axis is the applied bending moment.

[0037] The physical significance of this method is that the total bending moment exerted by the discrete particles on the wall is only related to the shape of the particles in the box, and the shape of the fruit ear pile in the box is only related to the flip angle of the box. Since the flipping process of the fruit ear box is actually a rotational motion around the hinge point A, the driving function of the box can be directly defined in the discrete element model Through simulation calculation, the bending moment load applied by the discrete system to the box wall can be obtained. If the original design flip time is 15s, the box can be regarded as flipping at a constant speed within 30s to reach the specified maximum flip angle as the input condition, so as to obtain the first bending moment angle curve with a stable change. , that is, the ideal bending moment angle curve.

[0038] Step S120 : defining a driving function of the dumping mechanism, and determining a first bending moment time history curve of the first bending moment angle curve under the driving function and a second bending moment time history curve to be optimized of the dumping mechanism under the driving function.

[0039] As mentioned above, the total bending moment applied by the fruit ear discrete system to the wall is only related to its shape in the box, and the shape of the fruit ear pile in the box is only related to the flip angle of the box. Therefore, by controlling the flip angle time curve of the box, the variation range of the total bending moment can be controlled, thereby controlling the fluctuation range of the cylinder force. Based on this, this technology proposes an optimization control technology for "achieving the optimal box flip angle curve with the smallest peak of the cylinder force rise". Since the flipping process of the fruit ear box is actually a rotational motion around the hinge point A, the driving function of the box can be directly defined in the discrete element model Through simulation calculation, the bending moment load applied by the discrete system to the box wall can be obtained, that is, the second bending moment angle curve of the dumping mechanism under the driving function , which can be understood as the bending moment angle curve to be optimized, see Figure 4 Then, the time history curve of the box's flip angle can be controlled, i.e., the driving function , you can control the second bending moment angle curve and the first bending moment angle curve Specifically, the same angle time history curve to be optimized can be used to , transform the above two curves into the ideal bending moment time history curve under the angle time history curve and the bending moment time history curve to be optimized , so that the two curves can be combined to find the difference, see Figure 5 .

[0040] The driving function is defined as the angle-time curve of the tipping mechanism during the flipping process. For example, the driving function can be any of the following: a cubic polynomial function, a quartic polynomial function, a higher-order polynomial function greater than fourth degree, a power function, a trigonometric function, etc. The driving function should also include a predetermined number of optimization coefficients (parameters to be optimized), which serve as the control parameters for the flipping angle curve. A cubic polynomial function includes three optimization coefficients; a quartic polynomial function, a trigonometric function, or a power function includes four optimization coefficients; and a higher-order polynomial function greater than fourth degree includes more than four optimization coefficients. It is understood that the number of optimization coefficients corresponds to the degree of the function.

[0041] Among them, when the driving function is a polynomial function, the purpose of this model is to obtain the variable flip angular velocity of the box, then the flip angular velocity The curve is at least about time The quadratic curve, therefore the flip angle curve At least for time In this way, the initial zero-time flip angle can be defined as 0°, and the following formula represents the driving function in the case of a cubic polynomial function: :

[0042] Therefore, it can be seen that the control parameters of the box flip angle curve include Three, the purpose of optimization is to finally get The optimal parameter value of .

[0043] In addition, the parameterization of the cabinet rotation angle time history curve in this patent is achieved by converting it into a cubic polynomial. In addition, polynomials greater than cubic, trigonometric functions, power functions, etc., as long as they can reflect the function of the cabinet rotation angular velocity process, can also be used as alternative solutions for the parameterization of the cabinet rotation angle time history curve. The details are as follows: 1) When the driving function is a quartic polynomial function, the driving function can be expressed as follows :

[0044] 2) When the driving function is a power function, the driving function can be expressed as follows :

[0045] 3) When the driving function is a trigonometric function, the driving function can be expressed as follows: :

[0046] Among them, the above formula They are all optimization coefficients, that is, the control parameters of the box flip angle curve. The purpose of optimization is to ultimately obtain the optimal parameter values of these optimization coefficients.

[0047] Step S130 : According to the constraints of the dumping mechanism, the driving function is optimized with the minimization of the deviation statistics between the second bending moment time history curve and the first bending moment time history curve as the optimization goal to obtain a target optimization coefficient.

[0048] Through the above steps S110-S120, the first bending moment angle curve and the second bending moment angle curve, i.e., the ideal bending moment angle curve, can be obtained. and the bending moment angle curve to be optimized Then, through the same angle time curve to be optimized, that is, the driving function , transform the above two curves into the ideal bending moment time history curve under the angle time history curve and the bending moment time history curve to be optimized , so that the two curves can be combined to find the difference, see Figure 5 In one embodiment, if the optimized bending moment time history curve is to be close to the most stable ideal bending moment time history curve, and The deviation statistics of is used as the objective function to minimize the deviation statistics. That is, by minimizing and The deviation statistics between them can be optimized to obtain the most stable bending moment load curve.

[0049] Specifically, if Figure 6 The optimization control technology described above can be optimized using relevant optimization algorithms, such as genetic algorithms, downhill methods, and annealing methods, to optimize the aforementioned optimization model. The optimization objective is to minimize the deviation statistics (i.e., the objective function) between the second moment time-history curve and the first moment time-history curve. The deviation statistics include at least one of the following: variance, standard deviation, mean squared error (MSE), mean absolute error (MAE), and root mean square error (RMSE). The mean squared error (MSE) is used to calculate the squared average of the differences between points on the curves and is more sensitive to large deviations; the mean absolute error (MAE) is used to calculate the average of the absolute differences between points on the curves and provides a direct reflection of the average deviation; the root mean squared error (RMSE) is the square root of the mean squared error, and its units are consistent with the original data. After multiple rounds of iterative optimization, the residual error of the objective function minimum stabilizes (reaches convergence). At this point, the objective function minimum is considered to have been found, i.e., the optimal flip angle control parameter with the minimum deviation statistics that satisfies the constraints has been found.

[0050] In the entire optimization model, the constraints may include one or more of the following: a minimum specified angle constraint, a maximum specified angle constraint, a flip angular velocity constraint, and the like.

[0051] The minimum specified angle constraint indicates the length of the flip When it is 0, the flip angle is also 0, and the optimization process must satisfy:

[0052] When the flip time (Total flip time), the flip angle should reach the maximum specified angle. That is, if the maximum flip angle of the box is , the total flipping time is , then the maximum specified angle constraint of the optimization process must satisfy:

[0053] In addition, to prevent the box from falling back during the flipping process, the box is required to always flip in one direction during the flipping and dumping process. Therefore, the flipping angular velocity is required to be always greater than 0, that is, the optimization process must meet the following requirements:

[0054] That is, in the driver function When it is a cubic polynomial function, the flip angular velocity constraint can be expressed as follows:

[0055] in, is the optimization coefficient, is the maximum flip angle, is the total flipping time.

[0056] Then, if we define The optimal solution is 、 、 , then the optimal box flip angle time history curve is:

[0057] Step S140: Determine the target angle time curve of the dumping mechanism according to the target optimization coefficient.

[0058] As mentioned above, the above optimization model can be optimized by using relevant optimization algorithms such as genetic algorithm, downhill method, annealing method, etc. After multiple rounds of iterative optimization calculation, the residual of the minimum value of the objective function reaches stability (reaches convergence state). At this time, it can be considered that the minimum value of the objective function has been found, that is, the optimal flip angle control parameter with the smallest deviation statistical value corresponding to the constraint conditions is found.

[0059] For example, if you define The optimal solution is 、 、 , then the optimal box flip angle time history curve is:

[0060] Then, it is necessary to perform an equivalent transformation of the optimal cylinder push time curve. Since the final box is driven by the cylinder, it is necessary to flip the optimal angle time curve. Converted into the optimal push control stroke of the cylinder , thereby achieving precise control of the expected flip angle.

[0061] Among them, the total length of the cylinder can be obtained according to the position relationship of the hinge point In one embodiment, the initial hinge point information may include initial position information of at least two fixed hinge points and at least one mobile hinge point, wherein the initial hinge point information may include the first fixed hinge point, the second fixed hinge point, and the mobile hinge point. For example, Figure 7 The figure shows the hinge point information of the dumping mechanism in an embodiment, which adopts a single-side oil cylinder arrangement. Among them, A, B, and C are the initial hinge points of the dumping mechanism. Hinge points A and B are fixed hinge points fixed to the frame, and their positions do not change with the rotation of the dumping mechanism. Hinge point C is a follower hinge point on the box body, that is, a mobile hinge point. C' is the new hinge point position after C moves during the pushing process. is the distance between AB, is the distance between AC, both are constant; the distance between BC That is the length of the cylinder. Since the length of the cylinder changes with the position of the moving hinge point C, it can be defined The length of the cylinder changes with time The function of the change, is the length of the cylinder in the initial state. Since the flip angle also changes with time, we can define is the flip angle over time The function of the change. Then in the flipping process, , so the flip angle can also be determined by the following formula As time pushes Angle time curve :

[0062] The total length of the cylinder can be obtained from the above hinge position relationship The function is:

[0063] Cylinder extension function That is, the total length of the cylinder during the flipping process Subtract the initial length ,Right now:

[0064] Therefore, according to By controlling the extension of the oil cylinder with the function, the box turning speed can be controlled with the minimum oil cylinder force.

[0065] It can be seen that the solution of the present invention can reasonably distribute the angular velocity of the box rotation without increasing the total duration of the flipping action. In the interval where the center of gravity of the fruit ears is not likely to move significantly, the angular velocity of the box rotation can be appropriately accelerated; in the stroke interval where the fruit ears are likely to fall, the angular velocity of the box rotation can be appropriately slowed down. In this way, the most reasonable cylinder pushing solution with the smallest cylinder force peak can be obtained.

[0066] This patent proposes an equivalent optimization method for minimizing the peak value of the cylinder force. It uses discrete element simulation technology and takes the rotation angle of the box as the drive. By controlling the flip angle time-history curve of the box, the deviation between the bending moment time-history curve and the ideal bending moment time-history curve can be controlled, making it closer to the ideal stable bending moment time-history curve. It can be seen that this patent proposes a method for calculating the cylinder force during the dumping process of the discrete system using only the discrete element model. This process does not require additional multi-body dynamics software to solve the cylinder force time-history curve. Compared with the coupled calculation of the "multi-body dynamics + discrete element" model, the optimal flip angle curve can be solved only by discrete element simulation software combined with the optimization algorithm, which can obtain accurate cylinder force response results more quickly, providing feasibility for the subsequent optimization of the flip angle time-history curve.

[0067] It should be noted that this patent provides an "optimal cylinder push time curve optimization technique" for minimizing instantaneous cylinder force peaks during the dumping process of a bulk material bin system. While this article uses a corn cob bin as an example, the method proposed in this patent can also be used to optimize the cylinder push time curve during the loading and unloading of discrete materials in other bulk materials, such as minerals, crops, and food.

[0068] In summary, existing technologies generally use a constant cylinder push speed, without considering the impact of cylinder push speed on cylinder push force. If the cylinder push speed is too fast, the ears in the silo will change drastically during the rapid turning process, resulting in a sudden drop and excessive impact, causing a sharp increase in the cylinder load. If the push speed is too slow, the entire turning process will be significantly prolonged, affecting the turning efficiency.

[0069] In this regard, this patent proposes an optimization control technology for "the optimal box flip angle curve to achieve a smooth transition of the cylinder force". By optimizing the "box flip angle time curve", an equivalent optimization method of "the optimal cylinder stroke time curve" is obtained. This can achieve the situation where the total pushing time remains unchanged. Compared with the previous constant speed cylinder push, the fluctuation of the bending moment curve during the flipping process can be effectively reduced.

[0070] The implementation process of the present invention is to parameterize the "rotation angle time curve" when the box is flipped, for example, into a cubic polynomial, and minimize the total variance of the "bending moment time curve to be optimized" and the "ideal bending moment time curve" during the cylinder pushing process as the optimization goal, and use the unchanged box flipping angle within the total time as a constraint condition to optimize and determine the "optimal rotation angle time curve" to achieve the selection of the "optimal box flipping time curve", and finally transform it to obtain the "optimal cylinder pushing stroke time curve" to achieve the most stable pushing state of the cylinder force.

[0071] on the other hand, Figure 8A schematic diagram of a push speed optimization system for a bulk material system dumping mechanism according to an embodiment of the present application is shown schematically. In the embodiment of the present application, the optimization system 200 may include: The first curve determining means 210 is used to determine a first bending moment angle curve during the tipping process of the dumping mechanism in an ideal dumping state; a second curve determining device 220, configured to define a driving function of the dumping mechanism, and determine a first bending moment time history curve of the first bending moment angle curve under the driving function and a second bending moment time history curve to be optimized of the dumping mechanism under the driving function, wherein the driving function is an angle time history curve of the dumping mechanism during a turning process, and the driving function includes a predetermined number of optimization coefficients; an optimization device 230 for optimizing the driving function according to the constraints of the dumping mechanism and taking minimization of a statistical value of a deviation between the second bending moment time history curve and the first bending moment time history curve as an optimization objective to obtain a target optimization coefficient; and The target curve determining device 240 is used to determine the target angle time curve of the dumping mechanism according to the target optimization coefficient.

[0072] In an embodiment of the present application, the first curve determining device 210 is specifically used to perform: pushing the dumping mechanism through the driving member under an ideal dumping state; and determining the first bending moment angle curve between the applied bending moment of the driving member and the flipping angle of the dumping mechanism by discrete element modeling.

[0073] In the embodiment of the present application, the ideal dumping state is a dumping state in which the applied bending moment of the driving member and the flipping angle of the dumping mechanism can change smoothly.

[0074] In the embodiment of the present application, the deviation statistics include at least one of the following: variance, standard deviation, mean square error, mean absolute error, and root mean square error.

[0075] In an embodiment of the present application, the optimization device 230 is specifically used to perform: defining the deviation statistic between the second bending moment time curve and the first bending moment time curve as the objective function; and iteratively optimizing the driving function through at least one of the following algorithms until the residual of the minimum value of the objective function reaches a convergence state: genetic algorithm, downhill method, annealing method.

[0076] In an embodiment of the present application, the driving function is any one of the following: a cubic polynomial function, a quartic polynomial function, a higher-order polynomial function greater than fourth order, a power function, and a trigonometric function; wherein the cubic polynomial function includes three optimization coefficients, and the quartic polynomial function, the trigonometric function, and the power function include four optimization coefficients.

[0077] In the embodiment of the present application, when the driving function is a cubic polynomial function, the following formula represents the driving function: : When the driving function is a quartic polynomial function, the following formula represents the driving function: ： When the driving function is a power function, the following formula represents the driving function: ： Or when the driving function is a trigonometric function, the following formula represents the driving function: ： in, is the optimization coefficient.

[0078] In the embodiment of the present application, the constraint condition includes one or more of the following: a minimum specified angle constraint, a maximum specified angle constraint, and a flip angular velocity constraint.

[0079] In the embodiment of the present application, in the driving function When it is a cubic polynomial function, the following equations express the minimum specified angle constraint, the maximum specified angle constraint, and the flip angular velocity constraint:

[0080]

[0081]

[0082] in, is the optimization coefficient, is the maximum flip angle, is the total flipping time.

[0083] Existing technologies generally use a hydraulic cylinder to push at a constant speed, without considering the impact of the cylinder's pushing speed on the cylinder's pushing force. If the cylinder pushes at a high speed, the ears in the silo will shift rapidly during the rapid turning process, resulting in a sudden drop and excessive impact, causing a sharp increase in the cylinder's instantaneous load. If the push speed is too slow, the entire turning process will be significantly prolonged, affecting the turning efficiency.

[0084] Through the above-mentioned technical solution of the present invention, an "optimal cylinder stroke time curve control technology for minimizing the instantaneous cylinder force peak" is proposed. By optimizing the "box flip angle time curve", an equivalent optimization method of the "optimal cylinder stroke time curve" is obtained. This can achieve the situation where the total pushing time remains unchanged. Compared with the previous constant speed cylinder push, the fluctuation of the bending moment curve during the flipping process can be effectively reduced.

[0085] That is to say, the present invention reasonably distributes the angular velocity of the box rotation without increasing the total duration of the flipping action. In the range where it is not easy for the center of gravity to move significantly, the angular velocity of the box rotation is appropriately accelerated; in the stroke range where falling is likely to occur, the angular velocity of the box rotation is appropriately slowed down. In this way, the most reasonable cylinder pushing scheme that minimizes the cylinder force peak can be obtained.

[0086] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0087] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A method for optimizing the pushing speed of a bulk material system dumping mechanism, characterized in that: The push speed optimization method includes: determining a first bending moment angle curve of the dumping mechanism during a tipping process in an ideal dumping state; defining a driving function of the dumping mechanism, and determining a first bending moment time history curve of the first bending moment angle curve under the driving function and a second bending moment time history curve to be optimized for the dumping mechanism under the driving function, wherein the driving function is an angle time history curve of the dumping mechanism during a flipping process, and the driving function includes a predetermined number of optimization coefficients; According to the constraint conditions of the dumping mechanism, the driving function is optimized with minimization of a deviation statistic between the second bending moment time history curve and the first bending moment time history curve as an optimization objective to obtain a target optimization coefficient; and A target angle time curve of the dumping mechanism is determined according to the target optimization coefficient.

2. The push speed optimization method according to claim 1, characterized in that: Determining a first bending moment angle curve during the tipping process of the dumping mechanism in an ideal dumping state includes: In the ideal dumping state, the dumping mechanism is pushed by a driving member; and A first bending moment angle curve between the applied bending moment of the driving member and the flip angle of the dumping mechanism is determined by discrete element modeling.

3. The push speed optimization method according to claim 2, characterized in that: The ideal dumping state is a dumping state in which the applied bending moment of the driving member and the flipping angle of the dumping mechanism can change smoothly.

4. The push speed optimization method according to claim 1, characterized in that: The deviation statistics include at least one of the following: variance, standard deviation, mean square error, mean absolute error, and root mean square error.

5. The push speed optimization method according to claim 1 or 4, characterized in that: The optimizing the driving function with minimizing the deviation statistics between the second bending moment time-history curve and the first bending moment time-history curve as an optimization goal includes: defining a deviation statistic between the second bending moment time history curve and the first bending moment time history curve as an objective function; and The driving function is iteratively optimized by at least one of the following algorithms until the residual of the minimum value of the objective function reaches a convergence state: genetic algorithm, downhill method, annealing method.

6. The push speed optimization method according to claim 1, characterized in that: The driving function is any one of the following: a cubic polynomial function, a quartic polynomial function, a higher-order polynomial function than the fourth order, a power function, and a trigonometric function; The cubic polynomial function includes three optimization coefficients, and the quartic polynomial function, the trigonometric function, and the power function include four optimization coefficients.

7. The push speed optimization method according to claim 6, characterized in that: When the driving function is the cubic polynomial function, the following formula represents the driving function: : When the driving function is the fourth-order polynomial function, the following formula represents the driving function: : When the driving function is the power function, the following formula represents the driving function: : or When the driving function is the trigonometric function, the driving function is expressed by the following equation: : in, is the optimization coefficient.

8. The push speed optimization method according to claim 1, 6 or 7, characterized in that: The constraint conditions include one or more of the following: a minimum specified angle constraint, a maximum specified angle constraint, and a flip angular velocity constraint.

9. The push speed optimization method according to claim 8, characterized in that: In the driver function When is a cubic polynomial function, the following equations represent the minimum specified angle constraint, the maximum specified angle constraint, and the flip angular velocity constraint: in, is the optimization coefficient, is the maximum flip angle, is the total flipping time.

10. A pushing speed optimization system for a bulk material system dumping mechanism, characterized in that: The push speed optimization system includes: a first curve determining device for determining a first bending moment angle curve during the tipping process of the tipping mechanism in an ideal tipping state; a second curve determining device, configured to define a driving function of the dumping mechanism, and determine a first bending moment time-history curve of the first bending moment angle curve under the driving function, and a second bending moment time-history curve to be optimized of the dumping mechanism under the driving function, wherein the driving function is an angle time-history curve of the dumping mechanism during a turning process, and the driving function includes a predetermined number of optimization coefficients; an optimization device for optimizing the driving function according to the constraint conditions of the dumping mechanism with minimization of a statistical value of a deviation between the second bending moment time history curve and the first bending moment time history curve as an optimization objective, so as to obtain a target optimization coefficient; and The target curve determining device is used to determine the target angle time curve of the dumping mechanism according to the target optimization coefficient.

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