A servo hydraulic pump system energy-saving operation optimization method

Abstract

The application discloses a kind of servo hydraulic pump system energy-saving operation optimization method, it is related to hydraulic pump energy-saving technical field, for solving energy utilization rate reduction, system energy consumption and equipment thermal load increase problem, by in container loading and unloading operation process, port crane executes lifting and lowering action, servo hydraulic pump under different operating conditions The output pressure, flow and power fluctuation are obvious, by in crane starting stage, the initial running speed of operation database is retrieved, in combination with the oil supply of hydraulic pump, the current output efficiency is evaluated and power peak is monitored, when entering condition is satisfied, enter operating condition distribution mechanism, the displacement direction of crane and boom offset angle are classified, determine whether it is in lifting or descending state, collect hoisting load to generate load state, in combination with motion state to evaluate energy consumption level, based on energy consumption level, pressure regulation or energy recovery is carried out on servo hydraulic pump, to ensure that port crane meets operation efficiency, reduces energy consumption and equipment thermal load.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic pump energy saving, more particularly, the present application relates to a servo hydraulic pump system energy saving operation optimization method. BACKGROUND

[0002] With the continuous expansion of port logistics transportation scale, the port crane is widely used in container loading and unloading operation, the existing port crane mostly adopts hydraulic pump driving mode to provide power for hydraulic system, the output pressure and flow of hydraulic pump frequently fluctuate in the operation process, especially when the lifting and descending actions are alternately performed, the hydraulic pump load condition is unstable, and the power peak value is too high and energy is wasted.

[0003] The prior art has the following disadvantages:

[0004] At present, the prior art realizes basic oil supply and pressure control of the hydraulic pump through fixed speed driving or overflow valve adjustment, cannot dynamically optimize the hydraulic pump operation parameters according to the real-time operation condition of the crane, lacks comprehensive analysis of operation characteristics such as boom deflection angle, displacement direction and lifting load, resulting in reduced energy utilization rate, increased system energy consumption and equipment thermal load, therefore, a servo hydraulic pump system energy saving operation optimization method is proposed.

[0005] The above information disclosed in the background section is only used to enhance the understanding of the background of the present disclosure, and therefore it can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0006] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present application provide a servo hydraulic pump system energy saving operation optimization method, which solves the problems proposed in the above background technology by using an output efficiency evaluation mechanism combining the initial running speed of the servo motor and the oil supply amount of the hydraulic pump, a working condition deployment mechanism based on the operation state and load state of the crane, and a pressure regulation and energy recovery strategy driven by energy consumption level.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical scheme, a servo hydraulic pump system energy saving operation optimization method, comprising the following steps:

[0008] Step S1: when the port crane is started, the initial running speed of the servo motor is retrieved through the operation database, the monitoring period is set, the oil supply amount of the hydraulic pump in the monitoring period is collected, and the flow change characteristic of the hydraulic pump is calculated based on the oil supply amount;

[0009] Step S2: the output efficiency of the servo hydraulic pump is evaluated by comprehensively considering the initial running speed and the flow change characteristic, the output power peak value of the servo hydraulic pump in the monitoring period is obtained, and whether to enter the working condition deployment mechanism is judged in combination with the output efficiency;

[0010] Step S3: In the working condition matching mechanism, the speed component and the boom offset angle of the port crane are detected, and the displacement direction and the boom offset angle are comprehensively used to classify the motion state of the port crane;

[0011] Step S4: The load state of the port crane is generated by collecting the hoisting load of the port crane, the energy consumption level of the port crane is evaluated in combination with the motion state, and the pressure regulation or energy recovery of the servo hydraulic pump is selected based on the energy consumption level.

[0012] In a preferred embodiment, in step S1, when the port crane starts, a preset monitoring period is divided into multiple monitoring time points, and the initial running speed matched with the current crane model and the work shift is retrieved from the operation database;

[0013] The oil supply amount of the hydraulic pump is collected by the flow sensor arranged on the outlet pipeline of the hydraulic pump within the preset monitoring period, and the oil supply amounts of the hydraulic pump at each detection time point are combined into an oil supply amount set in chronological order.

[0014] In a preferred embodiment, in step S1, in the oil supply amount set, the oil supply amounts of the hydraulic pump at adjacent monitoring time points are subtracted to obtain the oil supply amount change, and the median of the oil supply amount change is taken as the oil supply amount reference value;

[0015] The difference between each oil supply amount change and the oil supply amount reference value is taken to obtain the change amount deviation value;

[0016] The median of the change amount deviation value is taken as the oil supply deviation median, and the ratio of the oil supply deviation median to the oil supply amount reference value is taken as the flow change feature.

[0017] In a preferred embodiment, in step S2, each historical initial running speed matched with the current servo motor model is retrieved from the historical database, and the average value of each historical initial running speed is taken as the initial running speed threshold;

[0018] The absolute value of the difference between the initial running speed threshold and the initial running speed is taken to obtain the speed deviation amount, and the ratio of the speed deviation amount to the initial running speed threshold is taken as the speed deviation ratio;

[0019] The speed deviation ratio and the flow change feature are respectively standardized to obtain the speed deviation factor and the flow change factor;

[0020] The output efficiency of the servo hydraulic pump is calculated by the speed deviation factor and the flow change factor.

[0021] In a preferred embodiment, in step S2, within the preset monitoring period, the output power of the servo hydraulic pump at each monitoring time point is collected by the hydraulic power sensor;

[0022] The maximum value of the output power is taken as the output power peak value of the servo hydraulic pump, and the output power peak value of the servo hydraulic pump is normalized to obtain an output power peak value coefficient;

[0023] The ratio of the output power peak value coefficient to the output efficiency is taken as the operation state score of the servo hydraulic pump;

[0024] If the operation state score is greater than a preset state score threshold, it is determined that the working condition deployment mechanism is entered;

[0025] On the contrary, it is determined that the working condition deployment mechanism is not entered.

[0026] In a preferred embodiment, in step S3, in the working condition deployment mechanism, the instantaneous displacement of the hook in the three-dimensional coordinate system is obtained through the hook displacement sensor arranged on the port crane;

[0027] The velocity component is calculated based on the increment of the instantaneous displacement of the hook in each direction in the three-dimensional coordinate system;

[0028] The offset angle of the boom relative to the reference vertical direction is detected by the angle sensor arranged on the boom of the port crane, which is defined as the boom offset angle.

[0029] In a preferred embodiment, in step S3, the motion state of the port crane is classified based on the velocity component and the boom offset angle, and the motion state includes the ascending state, the descending state and the translation state;

[0030] Further, if the absolute value of the vertical direction velocity component is greater than the synthesis of the horizontal direction velocity component, the motion state is classified according to the vertical direction motion, i.e. it is determined to be the ascending state or the descending state;

[0031] If the synthesis of the horizontal direction velocity component is greater than the absolute value of the vertical velocity component, the motion state is classified according to the translation state.

[0032] In a preferred embodiment, in step S4, the actual external load borne by the hook is obtained as the hoist load by the weighing sensor arranged on the hook of the port crane;

[0033] The load state of the port crane is generated based on the hoist load, including the empty load state, the medium load state and the full load state;

[0034] The load state and the motion state are defined as input variables, and the energy consumption level is output through fuzzy reasoning, including high energy consumption, medium energy consumption and low energy consumption.

[0035] In a preferred embodiment, in step S4, the operation strategy of the servo hydraulic pump is selected based on the energy consumption level obtained by fuzzy reasoning:

[0036] When the energy consumption level is high energy consumption or medium energy consumption, the pressure regulation operation is performed;

[0037] When the energy consumption level is low energy consumption, the energy recovery mode is started;

[0038] The energy recovery mode is performed when the motion state of the port crane is a descending state, and if the motion state of the port crane is not a descending state, the normal operating parameters of the hydraulic pump are maintained.

[0039] Technical effects and advantages of the present application:

[0040] In the container loading and unloading process, the output pressure, flow and power fluctuation of the servo hydraulic pump under different working conditions are obvious when the port crane performs lifting and descending actions, and if only fixed speed or simple overflow valve control is relied on, it is easy to cause energy consumption to rise and power peak to be too large, by retrieving the initial operating speed of the operation database at the start-up stage of the crane, the current output efficiency is evaluated in combination with the oil supply of the hydraulic pump and the power peak is monitored, when the entry condition is met, the working condition allocation mechanism is entered, the displacement direction and the boom deflection angle of the crane are classified, it is judged whether it is in lifting or descending state, the load state is further collected, the energy consumption level is evaluated in combination with the motion state, and the servo hydraulic pump is selected for pressure regulation or energy recovery based on the energy consumption level, so that the port crane can meet the operation efficiency while reducing energy consumption and equipment thermal load. BRIEF DESCRIPTION OF DRAWINGS

[0041] Fig. 1 The implementation flowchart of the energy-saving operation optimization method of the servo hydraulic pump system of the present application.

[0042] Fig. 2 The step schematic diagram of the energy-saving operation optimization method of the servo hydraulic pump system of the present application. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0044] The application can obviously cause energy consumption to increase and power peak to be too large if only fixed speed or simple overflow valve control is relied on to control the output pressure, flow and power fluctuation of the servo hydraulic pump under different working conditions during the container loading and unloading process. The initial running speed of the servo motor is obtained by calling the operation database during the starting stage of the crane, the current output efficiency is evaluated in combination with the oil supply of the hydraulic pump, and the power peak is monitored. When the entering condition is met, the working condition adjustment mechanism is entered, the displacement direction and the boom deflection angle of the crane are classified, the lifting load is further collected to generate the load state, the energy consumption level is evaluated in combination with the motion state, and the servo hydraulic pump is controlled in pressure or energy is recovered based on the energy consumption level.

[0045] Embodiment 1

[0046] Please refer to Figs. 1-2 An energy-saving operation optimization method of a servo hydraulic pump system, comprising the following steps:

[0047] Step S1: When the port crane is started, the initial running speed of the servo motor is obtained by calling the operation database, the monitoring period is set, the oil supply of the hydraulic pump in the monitoring period is collected, and the flow change characteristic of the hydraulic pump is calculated based on the oil supply;

[0048] Step S2: The output efficiency of the servo hydraulic pump is evaluated in combination with the initial running speed and the flow change characteristic, the output power peak of the servo hydraulic pump in the monitoring period is obtained, and whether to enter the working condition adjustment mechanism is judged in combination with the output efficiency;

[0049] Step S3: In the working condition adjustment mechanism, the speed component and the boom deflection angle of the port crane are detected, and the motion state of the port crane is classified in combination with the displacement direction and the boom deflection angle;

[0050] Step S4: The lifting load of the port crane is collected to generate the load state, the energy consumption level of the port crane is evaluated in combination with the motion state, and the servo hydraulic pump is controlled in pressure or energy is recovered based on the energy consumption level.

[0051] The specific implementation is as follows:

[0052] In step S1, when the port crane is started, the monitoring period is preset and divided into multiple monitoring time points, and the initial running speed matched with the current crane model and operation shift is obtained by calling the operation database;

[0053] The initial running speed of the servo motor refers to the running speed of the servo motor when the crane is started;

[0054] The oil supply amount of the hydraulic pump is collected by a flow sensor arranged on the outlet pipeline of the hydraulic pump in a preset monitoring period, and the oil supply amount of the hydraulic pump at each detection time is recorded, and the oil supply amounts of the hydraulic pump at each detection time are combined into an oil supply amount set in time sequence;

[0055] In the oil supply amount set, the oil supply amounts of the hydraulic pump at adjacent monitoring times are subjected to difference operation to obtain an oil supply amount change, the median of the oil supply amount changes is taken as an oil supply reference value, each oil supply amount change is subjected to difference operation with the oil supply reference value and the absolute value is taken to obtain each change amount deviation value, the median of the change amount deviation values is taken as an oil supply deviation median, and further, the ratio of the oil supply deviation median to the oil supply reference value is taken as a flow change characteristic;

[0056] The flow change characteristic reflects the fluctuation degree of the oil supply amount of the hydraulic pump relative to the oil supply reference value in the monitoring period, and the greater the flow change characteristic, the more unstable the oil supply amount change, and the lower the operating efficiency of the hydraulic pump.

[0057] It should be explained that the preset detection period refers to a time window set for collecting the oil supply amount of the hydraulic pump and the output power peak value of the servo hydraulic pump, and is set according to the starting and falling time of the crane; the operation database refers to a local or cloud database for storing historical operation data and strategy execution results of the port crane, which is used to obtain the initial operating speed matching the current crane model and the operation shift in this embodiment; the flow sensor is a sensing device for real-time detection of the instantaneous flow of hydraulic oil.

[0058] In step S2, each historical initial operating speed matching the current servo motor model is called from the historical database, the average value of each historical initial operating speed is taken as an initial operating speed threshold, and the absolute value of the difference between the initial operating speed threshold and the initial operating speed is taken as a speed deviation amount;

[0059] The ratio of the speed deviation amount to the initial operating speed threshold is taken as a speed deviation proportion, reflecting the deviation degree of the initial operating speed relative to the initial operating speed threshold;

[0060] When the initial operating speed is lower, the hydraulic pump speed rises with a lag, resulting in lower output efficiency of the servo hydraulic pump; when the initial operating speed is too high, the oil supply amount of the hydraulic pump rises sharply, which may cause the overflow valve to open prematurely or the oil suction to be insufficient, resulting in lower output efficiency of the servo hydraulic pump. The greater the flow change characteristic, the more intense the fluctuation of the oil supply amount, and the lower the output efficiency of the servo hydraulic pump; the smaller the flow change characteristic, the more stable the oil supply amount change, and the higher the output efficiency of the servo hydraulic pump;

[0061] It should be explained that the historical database is used to store the historical operation data of the port crane in different operation shifts, including the initial operating speed of the servo motor, etc.

[0062] The speed deviation proportion and the flow change feature are standardized respectively to obtain a speed deviation factor and a flow change factor, and the output efficiency of the servo hydraulic pump is calculated by the speed deviation factor and the flow change factor: wherein, and is a preset adjustment coefficient, is a speed deviation factor, is a flow change factor, is an output efficiency of the servo hydraulic pump;

[0063] It should be explained that the standardization processing method includes but is not limited to standard linear transformation based on interval scaling, Z-Score standardization method based on statistics, or normalization method based on nonlinear mapping function, and the application method of standardization processing is not described here; the preset adjustment coefficient refers to a proportional parameter for adjusting the weight of the speed deviation factor and the flow change factor in the output efficiency calculation, the value range is 0 to 1 interval, which can be set according to the energy consumption analysis result of historical operation data and the load change feature, for example, the correlation between the speed deviation factor, the flow change factor and the energy consumption deviation can be calculated by analyzing the energy consumption data in the past one statistical period, so as to preset the adjustment coefficient.

[0064] In the preset monitoring period, the output power of the servo hydraulic pump at each monitoring time is collected by the hydraulic power sensor, and the maximum value of the output power is taken as the output power peak value of the servo hydraulic pump;

[0065] The output power peak value of the servo hydraulic pump is standardized to obtain an output power peak value coefficient;

[0066] The ratio of the output power peak value coefficient and the output efficiency is taken as the operation state score of the servo hydraulic pump;

[0067] The preset state score threshold is compared with the operation state score to determine whether to enter the working condition deployment mechanism:

[0068] If the operation state score is greater than the preset state score threshold, it is determined to enter the working condition deployment mechanism;

[0069] On the contrary, it is determined not to enter the working condition deployment mechanism;

[0070] The greater the operation state score result is, the lower the output efficiency is, the higher the output power peak value is, and the hydraulic pump is in a higher load and lower efficiency state.

[0071] It should be noted that the hydraulic power sensor refers to a measuring device capable of sensing the outlet pressure and flow of the hydraulic system at the same time and completing the power calculation inside the sensor or in the control system; the preset state score threshold refers to a comparison reference value for judging whether the servo hydraulic pump enters the working condition deployment mechanism, which can be set according to historical operation data, for example, the distribution characteristics of the operation state scores of several shifts are counted, and the operation state score of the 80th percentile is taken as the preset state score threshold.

[0072] In step S3, in the working condition deployment mechanism, the instantaneous displacement of the hook in the three-dimensional coordinate system is obtained by the hook displacement sensor arranged in the port crane within the preset sampling period, and the speed component of the port crane is calculated based on the instantaneous data;

[0073] Specifically, in the three-dimensional coordinate system, the transverse direction is set as the x-axis, the longitudinal direction is set as the y-axis, and the vertical direction is set as the z-axis. Within the sampling period, the speed component is calculated according to the increment of the instantaneous displacement of the hook in each direction, and the formula is as follows:

[0074]

[0075] are the speed components of the hook in the x, y, and z directions, respectively; are the instantaneous displacements of the hook in the x, y, and z directions, respectively; is the length of the sampling period.

[0076] It should be noted that the displacement sensor is a measuring device capable of outputting the displacement information of the hook in the three-dimensional coordinate system, which is used to convert the actual spatial displacement of the hook into quantifiable numbers. The specific implementation forms include encoders, laser range finders, inertial measurement units, or other displacement detection devices, and are not limited to a single type. The sampling period refers to a fixed time interval for data collection of the signals output by the displacement sensor, which is used to sample continuous discrete values to reflect the displacement change rule of the hook over time. The setting principle of the sampling period satisfies the Nyquist sampling theorem, that is, the sampling frequency is greater than twice the characteristic frequency of the hook movement, so as to avoid distortion of the displacement information. In actual application, the movement frequency of the port crane during hoisting is in the range of 0.5-5 Hz, and the sampling period can be set to 10 ms-50 ms to realize high-precision calculation of the speed component and consider the real-time performance of data processing.

[0077] ​​​​​​Meanwhile, the angle sensor installed on the boom of the port crane detects the angle of deviation of the boom relative to the reference vertical direction, which is defined as the boom deviation angle. The reference vertical direction is the direction in which the boom coincides with the vertical direction when there is no deviation. When the boom is completely vertical, the boom deviation angle θ = 0°. When the boom deflects horizontally, the boom deviation angle θ > 0°. The value range is 0° ≤ θ ≤ 90°.

[0078] It should be noted that the angle sensor is a measuring device that detects the deflection angle of the boom relative to the reference vertical direction. It is used to convert the actual spatial attitude of the boom into a quantifiable angle signal. The specific implementation forms are encoder-type angle sensors, inertial measurement units, or gyroscope-based attitude sensors, etc., and are not limited to a single type.

[0079] The motion state of port cranes is classified based on velocity components and boom offset angle, and the classification rules are as follows:

[0080] When the vertical velocity component And the boom offset angle satisfies That is, when the boom is kept in an approximately vertical position, the port crane is determined to be in an ascending state;

[0081] When the vertical velocity component And the boom offset angle satisfies That is, when the boom is kept in an approximately vertical position, the port crane is determined to be in a lowering state;

[0082] When the lateral velocity component and the longitudinal velocity component satisfy Or the boom offset angle satisfies At that time, it was determined that the port crane was in a translational state.

[0083] It should be noted that, The offset angle threshold is set by measuring the mechanical installation deviation and structural tolerance of the boom in a static state to obtain the static offset angle range. Under typical operating conditions, the dynamic swing amplitude of the boom caused by inertia or external disturbances (such as wind load) is collected to obtain the dynamic offset angle range. Based on this, combined with the accuracy requirements for motion state discrimination in port crane operations and the response speed of servo hydraulic pump control, an angle value higher than the upper limit of static deviation and dynamic swing amplitude is selected as the offset angle threshold. This avoids misjudgment due to slight vibrations, while ensuring sensitive identification of obvious horizontal offsets. In practical applications, this threshold is generally set to 2° to 5°.

[0084] For other cases that do not fully meet the above classification conditions, such as: both the vertical and horizontal velocity components are not zero, or the boom offset angle is greater than the offset angle threshold and the vertical velocity component is not zero, then classification will be carried out according to priority rules:

[0085] Specifically, if the absolute value of the vertical velocity component The resultant quantity greater than the horizontal velocity component If the motion state is classified according to the vertical direction, it is determined to be either an upward or downward state; if the resultant quantity of the horizontal velocity component is... Greater than the absolute value of the vertical velocity component Then the motion state is classified according to the translation state.

[0086] In step S4, the load weight is obtained by a weighing sensor installed on the hook of the port crane. The load weight refers to the actual external load borne by the hook of the port crane during operation. Its value includes the weight of the hoisted goods and the vertical component of gravity of the hook and its auxiliary connecting parts. The formula is as follows:

[0087] ;

[0088] in, For the lifting weight, The weight of the goods being hoisted. This represents the vertical component of gravity of the hook and its connecting parts. is the gravitational acceleration constant.

[0089] It should be noted that a load cell is a measuring device that can convert the external load borne by the hook into a quantifiable digital signal, and is used to convert the mechanical action of the load weight into numerical information that can be used for calculation and analysis.

[0090] The load status of the port crane is generated based on the lifting weight:

[0091] when When this happens, the port crane's load status is determined to be unloaded.

[0092] when When this occurs, the load condition of the port crane is determined to be medium load.

[0093] when When this happens, the port crane is determined to be in a fully loaded state.

[0094] It should be noted that, , and The threshold for determining the load condition is set based on the rated load of the port crane. and unloaded weight First, determine the weight range. Then, considering typical operating conditions and safety factors, divide the entire weight range into load level intervals, with interval boundary values... The selection of the load level is determined by historical operation data statistics, so that each load level covers the typical operation state of the corresponding weight interval.

[0095] The load state and the motion state are defined as input variables, and the energy consumption level is defined as an output variable. The energy consumption level is divided into high energy consumption, medium energy consumption, and low energy consumption.

[0096] Fuzzy rules are developed to describe the influence of different input variables on the output variable, for example:

[0097] If the motion state is the ascending state and the load state is the full load state, the energy consumption level is high energy consumption.

[0098] If the motion state is the ascending state and the load state is the medium load state, the energy consumption level is medium energy consumption.

[0099] If the motion state is the translation state and the load state is the full load state, the energy consumption level is medium energy consumption.

[0100] If the motion state is the descending state and the load state is the full load state, the energy consumption level is low energy consumption.

[0101] If the motion state is the descending state and the load state is the empty load state, the energy consumption level is low energy consumption.

[0102] It needs to be explained that the division of fuzzy sets is adjusted according to actual needs, and the energy consumption level can be divided into three or more sets to better classify different conditions.

[0103] Based on the energy consumption level obtained by the above fuzzy reasoning, the operation strategy of the servo hydraulic pump is selected:

[0104] When the energy consumption level is high or medium, the pressure control operation is performed, and the set values of the hydraulic pump outlet pressure and instantaneous flow are adjusted to reduce energy loss under the premise of meeting the lifting demand, thereby optimizing the overall efficiency of the hydraulic system.

[0105] When the energy consumption level is low, the energy recovery mode is started, the hydraulic pump is passively reversed, and the motor is driven into the power generation state, the potential energy released by the load weight is fed back to the power grid through the energy feedback unit, realizing the reuse of energy.

[0106] It needs to be noted that the energy recovery mode needs to be performed when the motion state of the port crane is in the descending state. If the motion state of the port crane is not in the descending state, the normal operating parameters of the hydraulic pump are maintained to maintain the stability of the operation.

[0107] Finally, it should be noted that the terms "first" and "second", and the like, herein do not denote any order, quantity, combination or important / primary / secondary status, but are used to merely distinguish one element from another, and do not imply any actual relationship or sequence between or among the elements.

[0108] Also, the use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless otherwise specified, "or" means "and / or". Unless otherwise noted, the use of the singular includes the plural.

[0109] It should also be understood that, unless clearly indicated otherwise, terms such as "comprise", "comprising", "include", "including", "contain", "containing", "have", "having" or variants thereof are used inclusively and that terms such as "consist of" or "consisting of" are used exclusively.

[0110] The various embodiments described in this specification are presented by way of example, and are not intended to limit the scope of the disclosure. The various embodiments described in this specification can be combined or combined in any order, and the same or similar parts can be mutually referred to.

[0111] The above description of disclosed embodiments is not intended to be exhaustive or to be limited to the precise forms disclosed. Modifications and alterations are possible that will become apparent to those of ordinary skill in the art, which are within the scope of this disclosure. It should be understood that this application is not to be limited to the particular embodiments illustrated herein, but can be practiced with modification and alteration within the scope and spirit of the following claims. Accordingly, the application is not to be limited as by the recited means, materials or actions for performing the operations herein.

Claims

1. A method for optimizing energy saving operation of a servo-hydraulic pump system, characterized by: The method comprises the following steps: Step S1: When the port crane starts, the initial running speed of the servo motor is retrieved from the operation database, the monitoring period is set, the oil supply amount of the hydraulic pump in the monitoring period is collected, and the flow change characteristic of the hydraulic pump is calculated based on the oil supply amount; In step S1, in the oil supply amount set, the oil supply amounts of the hydraulic pump at adjacent monitoring times are subtracted to obtain the oil supply amount change, and the median of the oil supply amount change is taken as the oil supply amount reference value; The absolute value of the difference between each oil supply amount change and the oil supply amount reference value is taken as the change amount deviation value; The median of the change amount deviation value is taken as the oil supply deviation median, and the ratio of the oil supply deviation median to the oil supply amount reference value is taken as the flow change characteristic; Step S2: The output efficiency of the servo hydraulic pump is evaluated by comprehensively considering the initial running speed and the flow change characteristic, the output power peak value of the servo hydraulic pump in the monitoring period is obtained, and whether to enter the working condition adjustment mechanism is judged in combination with the output efficiency; Step S3: In the working condition adjustment mechanism, the speed component and the boom offset angle of the port crane are detected, the displacement direction and the boom offset angle are comprehensively considered, and the motion state of the port crane is classified; In step S3, the motion state of the port crane is classified based on the speed component and the boom offset angle, and the motion state includes the rising state, the falling state and the translation state; Step S4: The load state of the port crane is generated by collecting the hoisting load weight, the energy consumption level of the port crane is evaluated in combination with the motion state, and the pressure regulation or energy recovery of the servo hydraulic pump is selected based on the energy consumption level; In step S4, the load state of the port crane is generated based on the hoisting load weight, and includes the empty load state, the medium load state and the full load state; The load state and the motion state are defined as input variables, the energy consumption level is output through fuzzy reasoning, and includes high energy consumption, medium energy consumption and low energy consumption; In step S4, the energy consumption level obtained based on the fuzzy reasoning is used to select the operation strategy of the servo hydraulic pump: When the energy consumption level is high or medium, the pressure regulation operation is performed; When the energy consumption level is low, the energy recovery mode is started; The energy recovery mode is performed when the motion state of the port crane is the falling state, and if the motion state of the port crane is not the falling state, the normal operation parameters of the hydraulic pump are maintained.

2. The servo hydraulic pump system energy-saving operation optimization method according to claim 1, wherein: In step S1, when the port crane starts, the monitoring period is preset and divided into multiple monitoring times, and the initial running speed matched with the current crane model and the operation shift is retrieved from the operation database; In the preset monitoring period, the oil supply amount of the hydraulic pump is collected through the flow sensor arranged on the outlet pipeline of the hydraulic pump, and the oil supply amounts of the hydraulic pump at each detection time are combined into an oil supply amount set in chronological order.

3. The servo hydraulic pump system energy-saving operation optimization method according to claim 1, wherein: In step S2, the historical initial running speeds matched with the current servo motor model are retrieved from the historical database, and the average value of the historical initial running speeds is taken as the initial running speed threshold value. The absolute value of the difference between the initial operating speed threshold value and the initial operating speed is obtained as a rotational speed deviation amount, and the ratio of the rotational speed deviation amount to the initial operating speed threshold value is taken as a rotational speed deviation ratio; The rotational speed deviation ratio and the flow change feature are standardized respectively to obtain a rotational speed deviation factor and a flow change factor; The output efficiency of the servo hydraulic pump is calculated through the rotational speed deviation factor and the flow change factor.

4. The energy-saving operation optimization method of the servo hydraulic pump system according to claim 3, characterized in that: In step S2, the output power of the servo hydraulic pump at each monitoring time is collected by the hydraulic power sensor within a preset monitoring period; The maximum value of the output power is taken as the output power peak value of the servo hydraulic pump, and the output power peak value is standardized to obtain an output power peak value coefficient; The ratio of the output power peak value coefficient to the output efficiency is taken as the operation state score of the servo hydraulic pump; If the operation state score is greater than a preset state score threshold value, it is judged to enter the working condition deployment mechanism; Otherwise, it is judged not to enter the working condition deployment mechanism.

5. The energy-saving operation optimization method of the servo hydraulic pump system according to claim 1, characterized in that: In step S3, in the working condition deployment mechanism, the instantaneous displacement of the hook in the three-dimensional coordinate system is obtained by the hook displacement sensor arranged on the port crane; The velocity component is calculated based on the increments of the instantaneous displacement of the hook in each direction of the three-dimensional coordinate system; The offset angle of the boom relative to the reference vertical direction is detected by the angle sensor arranged on the boom of the port crane, which is defined as the boom offset angle.

6. The energy-saving operation optimization method of the servo hydraulic pump system according to claim 5, characterized in that: In step S3, further, if the absolute value of the vertical direction velocity component is greater than the synthetic amount of the horizontal direction velocity component, the motion state is classified according to the vertical direction motion, i.e. it is judged to be in the ascending state or the descending state; If the synthetic amount of the horizontal direction velocity component is greater than the absolute value of the vertical velocity component, the motion state is classified according to the translation state.

7. The energy-saving operation optimization method of the servo hydraulic pump system according to claim 6, characterized in that: In step S4, the actual external load borne by the hook is obtained as the hoisting load by the weighing sensor arranged on the hook of the port crane.

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