Method and device for controlling falling amplitude of crane, electronic equipment and storage medium

Abstract

The invention discloses a crane falling and amplitude variation control method and device, electronic equipment and a storage medium. The crane falling and amplitude changing control method comprises the steps that current working condition information of a crane is obtained; on the basis of a pre-generated four-dimensional feed-forward control model, a feed-forward control current value is calculated according to the current working condition information, and the four-dimensional feed-forward control model represents the mapping relation between the working condition information and the main arm descending valve control current of the crane in the constant-speed descending state; the actual descending speed of the main arm of the crane is obtained and compared with the set expected descending speed, and a closed-loop correction current value is calculated through a closed-loop control algorithm based on the speed error; and superposing the feedforward control current value and the closed-loop correction current value to obtain a total control current, and outputting the total control current to a main arm descending valve of the crane so as to control the descending speed of the main arm of the crane. According to the invention, the descending process of the main arm is stable and constant in speed, and the stability and safety of the hydraulic control crane in the amplitude variation action are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engineering machinery control, and particularly relates to a crane falling amplitude control method and device, electronic equipment and a storage medium. BACKGROUND

[0002] The crane is a heavy engineering machinery widely used in the fields of construction, port, logistics, etc., and the amplitude (i.e., the pitch) action of the main arm is one of the core operation functions. In the hoisting operation, the falling amplitude (lowering) process of the main arm has very high requirements for stability and safety. At present, the falling amplitude control of the main arm of most hydraulic control cranes (such as truck cranes, crawler cranes, etc.) mainly relies on the direct driving of the hydraulic oil circuit by the hydraulic control handle. In the hydraulic control crane, the traditional control process of the falling amplitude action of the main arm is in turn: engine starting, main pump oil supply, multi-way valve mid-position unloading, plate motion hydraulic control handle, pilot pressure push valve, high-pressure oil into amplitude cylinder, throttling of return oil through amplitude balance valve, and return oil tank.

[0003] Due to the direct driving of the hydraulic oil circuit by the handle, the signal does not pass through the controller, and the system cannot analyze the operation intention in real time, resulting in low control precision, slow response, and blocked intelligent upgrading. In the falling amplitude process, the system completely relies on the operator to visually observe the falling speed of the main arm and adjust the handle opening in real time to achieve uniform speed lowering. However, this operation method is very difficult and has significant defects:

[0004] Visual lag: the human eye has a delay in perceiving speed changes, especially when the boom is long, the falling speed changes quickly, and the operator has difficulty in judging in time and accurately.

[0005] High difficulty of fine adjustment: a small displacement (millimeter level) of the hydraulic control handle will cause a significant change in flow, and it is extremely difficult to rely on hand feeling for fine adjustment, especially when the operator is tired or lacks experience, and alternating oscillation of "over-adjustment" and "under-adjustment" is likely to occur.

[0006] Poor anti-interference ability: external disturbances such as swinging of the hoisted load and gusts of wind will instantaneously break the system balance, the operator needs to deal with multiple variables at the same time, the spirit is highly nervous, and the control effect is unstable.

[0007] High risk of low position braking: when the main arm is at a low position, the gravitational acceleration effect is significant, and the distance and time window left for the operator to perform braking operation are extremely short, and a slightly slow reaction may lead to out-of-control emergency stop and even cause safety accidents.

[0008] The traditional hydraulic control crane handle is directly connected to the oil circuit, the handle opening signal is not input to the controller, the system is "blindly adjusted" in the luffing speed, the operator visually adjusts the speed, the fine adjustment is difficult, the crane is easily over-adjusted or under-adjusted under the disturbance of swing and wind, the low gravity acceleration distance is short, the braking window is narrow, the crane is easily stopped or out of control, and the intelligent upgrading is blocked. In summary, the existing crane luffing control method has the problems of high operation difficulty, poor operation safety and precision. SUMMARY

[0009] The application provides a crane luffing control method, device, electronic equipment and storage medium, which realizes automatic, stable and accurate control of the main arm lowering speed, reduces the operation difficulty, and significantly improves the operation safety, precision and operation comfort on the basis of not changing the original hydraulic system of the whole vehicle by adopting a feedforward and slow closed loop compound control strategy.

[0010] According to an aspect of the application, a crane luffing control method is provided, and the crane luffing control method comprises:

[0011] Obtaining current working condition information of the crane, wherein the working condition information comprises at least one of a main arm elevation angle, a main arm length, a load of a hoisted load and a hydraulic oil temperature;

[0012] Calculating a feedforward control current value according to the current working condition information based on a pre-generated four-dimensional feedforward control model, wherein the four-dimensional feedforward control model represents a mapping relationship between the working condition information and a main arm lowering valve control current of the crane in a uniform speed lowering state;

[0013] Obtaining an actual lowering speed of the main arm of the crane, and comparing the actual lowering speed with a set expected lowering speed, and calculating a closed loop correction current value by a closed loop control algorithm based on a speed error;

[0014] Superimposing the feedforward control current value and the closed loop correction current value to obtain a total control current, and outputting the total control current to the main arm lowering valve of the crane to control the lowering speed of the main arm of the crane.

[0015] Optionally, the calculating of the feedforward control current value according to the current working condition information based on the pre-generated four-dimensional feedforward control model comprises:

[0016] Substituting the main arm elevation angle, the load of the hoisted load, the main arm length and the hydraulic oil temperature into a formula of the four-dimensional feedforward control model to calculate the feedforward control current value;

[0017] The calculation formula of the four-dimensional feedforward control model is as follows:

[0018] I = (K1+K2·M)·sinθ + (K3 +K4·M)·cosθ +K5·L+K6·T

[0019] wherein I is a feedforward control current value, K1 is a no-load gravity coefficient, K2 is a load-gravity coupling coefficient, M is a percentage of hoisting load, θ is a main boom elevation angle, L is a main boom length coefficient, T is a hydraulic oil temperature coefficient, K3 is a no-load friction term coefficient, K4 is a load-friction coupling coefficient, K5 is a boom length correction coefficient, and K6 is a temperature correction coefficient.

[0020] Optionally, the closed-loop control algorithm is a position-based incremental PI control algorithm, and a control period of the closed-loop control algorithm is 5 seconds.

[0021] Optionally, the pre-generating the four-dimensional feedforward control model comprises:

[0022] A main boom uniform speed descent experiment is performed under a plurality of typical working condition combinations, the working condition combinations including different main boom elevation angles, main boom lengths, hoisting loads, and hydraulic oil temperatures.

[0023] When a stable uniform speed descent is reached under each working condition combination, a control current value of the main boom descent valve is recorded.

[0024] The recorded experimental data of the plurality of control current values are fitted to generate the four-dimensional feedforward control model.

[0025] Optionally, the outputting the total control current to the main boom descent valve of the crane comprises:

[0026] The total control current is subjected to amplitude limiting processing, so that an absolute value of the total control current does not exceed a preset maximum current threshold, to limit a maximum descent speed of the main boom of the crane.

[0027] According to another aspect of the present application, a crane descent amplitude control device is provided, the crane descent amplitude control device comprising:

[0028] A working condition acquisition module is configured to acquire current working condition information of the crane, the working condition information including at least one of a main boom elevation angle, a main boom length, a hoisting load, and a hydraulic oil temperature.

[0029] A feedforward control module is configured to calculate a feedforward control current value based on a pre-generated four-dimensional feedforward control model according to the current working condition information, the four-dimensional feedforward control model representing a mapping relationship between the working condition information and a main boom descent valve control current of the crane in a uniform speed descent state.

[0030] A closed-loop control module is configured to acquire an actual descent speed of the main boom of the crane, and compare the actual descent speed with a set expected descent speed, and calculate a closed-loop correction current value based on a speed error through a closed-loop control algorithm.

[0031] An output control module is configured to superimpose the feedforward control current value and the closed-loop correction current value to obtain a total control current, and output the total control current to a main boom lowering valve of the crane to control a lowering speed of the main boom of the crane.

[0032] Optionally, the crane falling-swinging controlling device further comprises:

[0033] A current calibration module is configured to perform a main boom uniform speed lowering experiment of the crane under a plurality of typical working condition combinations and record data.

[0034] A model solidification module is configured to generate the four-dimensional feedforward control model based on the data recorded by the current calibration module.

[0035] Optionally, the output control module is further configured to perform amplitude limiting processing on the total control current, so that an absolute value of the total control current does not exceed a preset maximum current threshold.

[0036] According to another aspect of the present application, an electronic device is provided, and the electronic device comprises:

[0037] at least one processor; and

[0038] a memory connected to the at least one processor in communication; wherein,

[0039] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute the crane falling-swinging controlling method according to any one of the embodiments of the present application.

[0040] According to another aspect of the present application, a computer readable storage medium is provided, and the computer readable storage medium stores computer instructions for enabling a processor to implement the crane falling-swinging controlling method according to any one of the embodiments of the present application when executed by the processor.

[0041] The technical scheme of the embodiment of the present application provides a novel crane falling amplitude control method independent of a hydraulic control handle opening degree signal, on the basis of not changing a whole vehicle hydraulic system, a feedforward and slow closed loop compound control strategy is adopted to realize smooth and uniform speed of a main arm in a falling process, operation difficulty and manual intervention are reduced, and intelligent upgrading of a hydraulic control crane is realized; current working condition information of the crane is acquired, a four-dimensional feedforward control model is generated in advance, a feedforward control current value is calculated according to the current working condition information, an actual falling speed of the main arm of the crane is acquired, and is compared with a set expected falling speed, a closed loop correction current value is calculated based on a speed error through a closed loop control algorithm, the feedforward control current value and the closed loop correction current value are superposed to obtain a total control current, the total control current is output to a main arm falling valve of the crane to control the falling speed of the main arm of the crane, the motion state of the main arm of the crane is monitored in real time, the accurate regulation of the falling speed of the amplitude is realized in combination with the closed loop control strategy, and the stability, accuracy and safety of the hydraulic control crane in the amplitude action are significantly improved. In summary, the present application solves the problems of large operation difficulty, poor operation safety and accuracy in the prior art, realizes automatic, smooth and accurate control of the falling speed of the main arm, has the beneficial effects of low operation difficulty, significantly improved operation safety and operation comfort, reduced operation difficulty and manual intervention, and improved intelligent level of the system.

[0042] It should be understood that the content described in this part is not intended to identify key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0044] Figure 1 It is a flow chart of a crane falling amplitude control method according to the embodiment of the present application.

[0045] Figure 2 It is an architecture schematic diagram of feedforward and slow closed loop control of a main arm falling amplitude of a hydraulic control crane according to the embodiment of the present application.

[0046] Figure 3 It is a structure schematic diagram of a crane falling amplitude control device according to the embodiment of the present application.

[0047] Figure 4It is a structure schematic diagram of electronic equipment for realizing the crane falling amplitude control method of the embodiment of the present application. DETAILED DESCRIPTION

[0048] In order for those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0049] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to only those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0050] Figure 1 It is a flow chart of a crane falling amplitude control method according to the embodiment of the present application. The embodiment can be applicable to a liquid control machine type device such as a truck crane, a crawler crane, a self-propelled straight arm aerial work platform, a forklift crane, etc. The method can be executed by a crane falling amplitude control device, which can be realized in the form of hardware and / or software, and can be configured in an electronic device. The crane includes a vehicle body, a chassis, a turret, a main arm, an amplitude changing mechanism, a hydraulic system, and the above-mentioned crane falling amplitude control device. The crane falling amplitude control device is electrically connected with a sensor network and a main arm lowering valve of the crane. The crane can automatically realize stable, uniform speed, and safe falling during falling amplitude operation, and has significant intelligent operation advantages.

[0051] Figure 2 It is a schematic diagram of a feedforward and slow closed loop control architecture of a liquid control crane main arm falling amplitude according to the embodiment of the present application. Figure 2 It is a schematic diagram of a feedforward and slow closed loop control architecture of a liquid control crane main arm falling amplitude. Figure 2The given in the formula refers to the expected main arm lowering speed value. The feedforward controller is used to calculate the main arm lowering valve control amount in advance according to the set value and the system mode, to compensate for the system relationship and hydraulic delay. The feedback controller is used to adjust the deviation at a slow speed according to the actual speed and the set value, to ensure that the main arm lowering speed is within the set value. The actuator is used to control the main arm lowering valve. The sensors include: a main arm angle sensor, a main arm length sensor, a hydraulic oil temperature sensor, and a pressure sensor (load information).

[0052] The hydraulic control crane adopts a hydraulic control handle, and the system cannot directly obtain the handle opening degree. Therefore, the main arm falling amplitude valve needs to be kept open, and the handle needs to be pushed to conduct the oil path and realize the "main arm falling". However, the main arm falling amplitude valve port is fixed, and the handle opening degree actually corresponds to the acceleration. If there is no continuous and correct adjustment, the main arm will continuously accelerate and fall, and it is difficult to realize uniform speed falling. The present application proposes a feedforward + closed loop double loop control, which automatically adjusts the valve according to the working condition, so that the main arm falls at the given speed. First, the valve driving current required for the main arm to fall at a uniform speed is measured under various typical working conditions, a four-dimensional (arm length, elevation angle, load, temperature) current surface is generated, and then a fitting function related to the falling amplitude valve control is fitted. When the system is running, the system calculates the feedforward opening current according to the current working condition, opens the valve port to the position about to fall, and is in an equivalent state of not being forced. However, the feedforward opening current cannot realize the process of accelerating and decelerating the main arm, nor can it eliminate the system static error. Therefore, the system expects the falling speed as the target, and the PID calculates the speed error in real time to output the error elimination current, which is used to offset the disturbances such as leakage and temperature, to ensure no static error.

[0053] The final current = feedforward opening current + error elimination current, which continuously drives the falling amplitude valve. The feedforward prevents continuous acceleration, and the closed loop strictly guards the expected falling speed; when the handle is returned to the center, the oil path is also closed synchronously, and the main arm is smoothly decelerated to stop. The manual intervention characteristics of the hydraulic control handle are retained, and "pushing how much, walking how much, not overspeed" is realized by automatically adjusting the valve, and the main arm is truly safely, uniformly and controllably lowered.

[0054] As shown in Figure 1 , the crane falling amplitude control method comprises:

[0055] S110, acquiring current working condition information of the crane, the working condition information comprising at least one of: a main arm elevation angle, a main arm length, a hoisted load, and a hydraulic oil temperature.

[0056] Specifically, current calibration and data collection. This step is an offline preparation phase. Under safe conditions, the main arm is lowered by the crane controlled by an automated program. The system traverses different hydraulic oil temperatures (such as 20°C and 50°C), main arm lengths (divided into several gears from the shortest to the longest), hoist loads (divided into several gears from empty to rated load), and main arm elevation angles (from the maximum elevation angle, such as 78°, to a smaller angle, such as 15°, at a slow rate). Under each combination of working conditions, the system automatically adjusts the lowering valve current until the actual lowering speed of the main arm stabilizes at a small expected speed value (for example, 0.5° / s) set by the system, at which point it is determined to be in "uniform speed" state. The system continuously records the working condition parameters (main arm elevation angle, main arm length, hoist load, and hydraulic oil temperature) and the corresponding stable valve current value at this time as data storage.

[0057] Model solidification. The large amount of data collected in the previous step is cleaned and statistically analyzed, and a fitting algorithm is used to fit the data into a multi-dimensional function model with main arm elevation angle, main arm length, hoist load, and hydraulic oil temperature as independent variables, i.e. a four-dimensional feedforward control model, which is solidified into the controller.

[0058] Obtain real-time working condition information. In the online control phase, the system periodically reads from the existing sensors of the crane: the elevation angle provided by the main arm angle sensor, the length provided by the main arm length sensor (often converted to a relative coefficient of 0~1), the hoist load percentage calculated by the pressure sensor (such as the pin shaft sensor or the oil cylinder pressure sensor), and the temperature provided by the hydraulic oil temperature sensor (often normalized). These data are appropriately filtered to improve data reliability.

[0059] S120, based on the pre-generated four-dimensional feedforward control model, calculate the feedforward control current value according to the current working condition information, and the four-dimensional feedforward control model represents the mapping relationship between the working condition information and the main arm lowering valve control current of the crane in the uniform speed lowering state.

[0060] Specifically, the real-time main arm elevation angle, main arm length, hoist load, and hydraulic oil temperature values obtained are substituted into the model calculation formula solidified in the middle to directly calculate the feedforward control current value required to achieve uniform speed lowering under the current working condition. This step calculates quickly and can respond to changes in working conditions in real time.

[0061] S130, obtain the actual lowering speed of the main arm of the crane, and compare it with the set expected lowering speed, and calculate the closed-loop correction current value based on the speed error through a closed-loop control algorithm.

[0062] Specifically, the control period of the closed-loop control algorithm is greater than 1 second. The system performs closed-loop control once every long period (for example, every 5 seconds). The average angular velocity of the main arm falling in the past 5 seconds is calculated, compared with the expected falling speed set by the system, and the speed error is obtained. The position type incremental PI algorithm is used to calculate the closed-loop correction current value. The closed-loop correction current value is subjected to anti-saturation limiting to obtain the final closed-loop correction current value.

[0063] S140, superimpose the feedforward control current value and the closed-loop correction current value to obtain a total control current, and output the total control current to the main arm falling valve of the crane to control the falling speed of the main arm of the crane.

[0064] Specifically, the feedforward current and the closed-loop correction current are superimposed to obtain a target total control current. The total control current is subjected to final limiting processing to ensure that its absolute value does not exceed the maximum current threshold set according to the valve performance and safety requirements. Finally, the total control current is output to the proportional solenoid of the main arm falling valve through a ramp function generator (to prevent current from suddenly changing) to drive the valve core to act, thereby controlling the flow entering the luffing cylinder and achieving precise control of the falling speed of the main arm. When the operator releases the handle or the handle is returned to the center, the control system detects that the falling instruction disappears, and the total control current is smoothly reduced to zero, and the main arm is then smoothly decelerated and stopped.

[0065] The technical scheme of the embodiment of the present application provides a novel crane luffing control method independent of the opening signal of the hydraulic control handle. Without changing the whole vehicle hydraulic system, a feedforward and slow closed-loop compound control strategy is adopted to realize smooth and uniform falling of the main arm, reduce the operation difficulty and manual intervention, and realize intelligent upgrading of the hydraulic control crane. By acquiring current working condition information of the crane, calculating a feedforward control current value based on a pre-generated four-dimensional feedforward control model according to the current working condition information, acquiring the actual falling speed of the main arm of the crane, comparing the actual falling speed with the expected falling speed, calculating a closed-loop correction current value based on the speed error through a closed-loop control algorithm, superimposing the feedforward control current value and the closed-loop correction current value to obtain a total control current, outputting the total control current to the main arm falling valve of the crane to control the falling speed of the main arm of the crane, and monitoring the motion state of the main arm of the crane in real time, the precise adjustment of the luffing falling speed is realized in combination with the closed-loop control strategy, and the stability, precision and safety of the hydraulic control crane in the luffing action are significantly improved. In summary, the present application solves the problems of high operation difficulty, poor operation safety and precision in the prior art, realizes automatic, smooth and precise control of the falling speed of the main arm, has low operation difficulty, significantly improves the operation safety and operation comfort, reduces the operation difficulty and manual intervention, and improves the intelligent level of the system.

[0066] Optionally, the pre-generated four-dimensional feedforward control model comprises:

[0067] The main arm uniform descent experiment is carried out under a variety of typical working condition combinations, including different main arm elevation angles, main arm lengths, hoisting loads and hydraulic oil temperatures;

[0068] When the stable uniform descent is reached under each working condition combination, the control current value of the main arm descent valve is recorded;

[0069] The recorded experimental data of multiple control current values are fitted to generate a four-dimensional feedforward control model.

[0070] Optionally, based on the pre-generated four-dimensional feedforward control model, the feedforward control current value is calculated according to the current working condition information, which includes:

[0071] The main arm elevation angle, hoisting load, main arm length and hydraulic oil temperature are substituted into the formula of the four-dimensional feedforward control model to calculate the feedforward control current value;

[0072] The calculation formula of the four-dimensional feedforward control model is as follows:

[0073] I = (K1+K2·M)·sinθ + (K3 +K4·M)·cosθ +K5·L+K6·T

[0074] Wherein, I is the feedforward control current value, K1 is the empty load gravity coefficient, K2 is the load-gravity coupling coefficient, M is the percentage of the hoisting load, θ is the main arm elevation angle, L is the main arm length coefficient, T is the hydraulic oil temperature coefficient, K3 is the empty load friction term coefficient, K4 is the load-friction coupling coefficient, K5 is the arm length correction coefficient, and K6 is the temperature correction coefficient.

[0075] Specifically, the first step is to calibrate the current.

[0076] Preparation before experiment:

[0077] 1. Equipment: fall amplitude closed-loop controller with speed feedback, angle encoder, pin shaft load sensor, and oil temperature probe are all connected to the CAN recorder.

[0078] 2. Safety: draw an angle-amplitude red line on the ground; the amplitude bypass speed limiting valve is mechanically redundant; the test wind speed is <6 m / s.

[0079] 3. The oil temperature is kept constant at 20℃±1℃ (closed loop of water cooling machine), and then increased to 50℃±1℃ for another round.

[0080] Closed-loop automatic scanning:

[0081] 1. Set the desired descent speed of the system (slow, small inertia, conducive to steady state).

[0082] 2. Nested loop (oil temperature→arm length→load→angle).

[0083] Hydraulic oil temperature coefficient T: 20 ℃ → 50 ℃.

[0084] Main arm length coefficient L: 0% → 25% → 50% → 75% → 100% (automatic positioning of telescopic rope scale).

[0085] Percentage of hoisting load M: 0% → 25% → 50% → 75% → 100% (weighing scale counterweight, error <2%).

[0086] Main arm elevation angle θ: 78° → 15°, continuous slow arm lowering (about 0.5° / s).

[0087] Record every 50 ms: main arm elevation angle θ, percentage of hoisting load M, main arm length coefficient L, hydraulic oil temperature coefficient T, actual speed v, valve current i.

[0088] When |actual speed - given speed| < 0.01° / s for 500 s, it is judged to be uniform speed, the frame data is marked as a golden point and stored in the SD card in real time.

[0089] Second step, model solidification.

[0090] 1. Use 20-point moving average denoising; remove transition points with acceleration > 0.02 m / s².

[0091] 2. Box by θ every 5°, take the median of i in the box, get 2×5×5×14 ≈ 700 golden points.

[0092] 3. Least squares fitting four-dimensional curve, R²≥0.98; if the local error is > 3%, make a 2° step encryption sweep in this θ area, and fit twice until the error is <2%.

[0093] Finally get the corresponding formula:

[0094]

[0095] It should be noted that: the main arm lowering valve feedforward current model selects θ (main arm elevation angle), M (percentage of load of the hoist), L (main arm length coefficient), T (hydraulic oil temperature coefficient) four-dimensional variables, which is the smallest complete set considering physical interpretation, ready-made sensors and small calculation burden. The sin / cos term of θ directly corresponds to the gravity component and the normal pressure of the pin shaft, M and L linearly scale the moment and inertia, and the first term of T contains the viscosity, leakage and flow gain changes of the oil, and the six-coefficient formula can explain more than 98% of the current demand, and the MCU can complete the operation in tens of microseconds; Four dimensions come from the sensors equipped on the crane, without increasing the hardware cost, and the coefficients can be linearly transplanted to different tonnages on the same platform, greatly shortening the introduction of new products.

[0096]

[0097] Third step, obtain working condition information.

[0098] The system obtains the boom angle, boom length, hydraulic oil temperature and current load information according to the sensors equipped on the whole vehicle.

[0099] Fourth step, obtain the feedforward control current value.

[0100] The current working condition information is input into the formula obtained by fitting to obtain the feedforward control current value.

[0101] Optionally, the closed-loop control algorithm is a position incremental PI control algorithm, and the control period of the closed-loop control algorithm is 5 seconds.

[0102] Specifically, in the fifth step, closed-loop control. The current boom lowering speed is calculated once every 5 seconds and closed-loop control is performed, slow closed-loop control, to avoid rapid speed adjustment and shaking phenomenon.

[0103] When the main arm lowering speed reaches the system limited maximum speed, relevant deceleration operation is performed. If the maximum speed is not reached, continuous acceleration is performed.

[0104] Feedback error e fb = ω ref – ω avg . Wherein, ω avg is the average angular velocity of the main arm lowering in 5s (° / s), and ω ref is the system set given speed (° / s).

[0105] PI feedback update (position incremental type, 5s period): AI = AI + Kp·e fb + Ki·e fb ·5.

[0106] Anti-saturation limiting: AI = sat (AI, ±80 mA).

[0107] Feedforward current I ff = ω ref / K ff , K ff = ω / I 稳态 . K ff is a steady-state gain, which can be obtained by analyzing the calibration current.

[0108] Total control current output I out = sat(I ff + AI, ±80mA).

[0109] Fifth step, output current control.

[0110] The calculated feedforward current and the calculated closed-loop control current are superimposed together, and then output to the main arm lowering valve according to the set slope control algorithm.

[0111] The overall process is: according to the current working condition information, the valve given value required for the main arm to just lower is calculated, then the super-slow PI closed-loop control is used, and the two currents are superimposed to control the main arm lowering valve together, so that the main arm lowering speed reaches the system default given speed. Finally, the main arm uniform speed is realized through the artificial control handle. Among them, the feedforward control is used first to eliminate about 90% of the gravity disturbance, and then the super-slow PI control of 0.2 Hz is used to eliminate the residual error and smooth the edge error.

[0112] Unlike the traditional analog chain of "handle, pilot pressure, valve opening, human eye correction", the scheme of the embodiment introduces a digital chain of "sensor, four-dimensional analytical formula, 0.2 Hz super-slow PI" on a pure hydraulic crane: the feedforward current is calculated in real time according to the angle, arm length, load and oil temperature, 90% of the gravity disturbance is eliminated in advance, and the residual static error is smoothed to ±0.02 m / s by the super-slow PI light push valve bias of 5s; the system gives the maximum target speed, limits the main arm lowering speed from the output end (the maximum current of the lowering valve), and does not need to care about the size of the handle control oil way, which not only retains the original hydraulic hardware, but also obtains the electric control level uniform speed and intelligent upgrading control effect. The system writes the maximum lowering speed directly, caps it on the valve current end, and the hydraulic handle opening is completely empty. No matter how the driver pulls, the main arm lowering speed will not exceed the maximum lowering speed, and if the maximum speed is reached, the uniform speed will be lowered according to the set maximum speed. 90% of the gravity disturbance is pre-eliminated by the feedforward formula, and the remaining residual error is given to the 0.2 Hz super-slow PI, which is smoothed once every 5s, and the speed fluctuation is reduced from ±0.3 m / s to ±0.02 m / s, and the long arm low position also says goodbye to the sudden stop. The whole logic only calls the existing sensors on the vehicle, zero hardware modification, and the program can be online after brushing, and the new and old cranes can be upgraded painlessly.

[0113] Compared with the prior art, the present application has the following remarkable beneficial effects:

[0114] Control precision and smoothness are greatly improved: about 90% of the disturbances caused by gravity, load, arm length, oil temperature changes are compensated in advance through feedforward control, and the residual static error is eliminated by super slow closed-loop control, which can greatly reduce the main arm lowering speed fluctuation from the traditional ±0.3 m / s to ±0.02 m / s or less, achieving truly high-precision uniform speed lowering and effectively avoiding sudden stopping.

[0115] The operation difficulty is significantly reduced: the operator no longer needs to closely observe the speed and frequently adjust the handle. Only by pushing the handle to issue the falling instruction, the system can automatically maintain the preset uniform speed lowering, freeing the operator from heavy and high-precision physical and mental labor, reducing fatigue and improving work comfort.

[0116] Intelligent upgrade cost is low and compatibility is good: the scheme is completely based on the existing standard sensors (angle, length, pressure, temperature sensors) in the crane, without any modification to the hydraulic pipeline, valve group, handle and other core hardware. Only the corresponding controller and software program need to be updated or installed, so that the existing hydraulic control crane and new models can realize intelligent function upgrade at a very low cost, with good market promotion prospects.

[0117] The operation habit of the hydraulic control system is retained: the system does not change the original connection relationship between the hydraulic control handle and the hydraulic system, and the push-pull operation feeling of the handle is retained, only the intelligent speed management is added to the function, which conforms to the original habit of the operator and is easy to accept.

[0118] Optionally, outputting the total control current to the main arm lowering valve of the crane includes:

[0119] The total control current is limited in amplitude to make the absolute value of the total control current not exceed a preset maximum current threshold, so as to limit the maximum lowering speed of the main arm of the crane.

[0120] Specifically, the total control current is finally limited in amplitude to ensure that its absolute value does not exceed a maximum current threshold set according to valve performance and safety requirements, so that the operation safety is significantly enhanced.

[0121] By limiting the total control current in amplitude at the control output end, the absolute maximum speed of the main arm lowering is set. No matter how the operator operates the hydraulic control handle, the main arm falling speed will not exceed this safety threshold, which fundamentally eliminates the risk of out-of-control caused by operation error or reaction delay, especially when the safety is improved at low position.

[0122] Figure 3 is a structural schematic diagram of a crane lowering amplitude control device provided according to an embodiment of the present application, like Figure 3The crane falling amplitude control device is integrated in a whole vehicle controller of the crane or a separate intelligent control unit, and the crane falling amplitude control device comprises:

[0123] The working condition acquisition module 201 is configured to acquire current working condition information of the crane, and the working condition information comprises at least one of a main arm elevation angle, a main arm length, a hoisting load and a hydraulic oil temperature.

[0124] Specifically, the working condition acquisition module 201 comprises a current calibration sub-module, which tests and records a current corresponding to each angle in a uniform speed falling state of each working condition according to a predetermined rule.

[0125] The working condition acquisition module 201 comprises a model solidification sub-module, which fits data obtained by the current calibration sub-module to obtain a four-dimensional fitting formula related to the main arm length, the main arm angle, the hoisting load and the hydraulic oil temperature.

[0126] The working condition acquisition module 201 comprises a working condition updating sub-module, which acquires the main arm length, the main arm angle, the hoisting load and the hydraulic oil temperature information of the whole machine in real time, and adopts different filtering modes for different sensors and data characteristics to obtain the most suitable data.

[0127] The feedforward control module 202 is configured to calculate a feedforward control current value based on a four-dimensional feedforward control model generated in advance according to the current working condition information, and the four-dimensional feedforward control model represents a mapping relationship between the working condition information and a main arm falling valve control current of the crane in a uniform speed falling state.

[0128] Specifically, the feedforward control module 202 inputs the working condition information obtained by the working condition updating sub-module into the four-dimensional fitting formula obtained by the model solidification sub-module to calculate the feedforward control current value.

[0129] The closed-loop control module 203 is configured to acquire an actual falling speed of the main arm of the crane and compare the actual falling speed with a set expected falling speed, and calculate a closed-loop correction current value based on a speed error through a closed-loop control algorithm.

[0130] Specifically, the closed-loop control module 203 uses a position type incremental PID to control the falling valve once every 5 seconds to eliminate the final static error.

[0131] The output control module 204 is configured to superimpose the feedforward control current value and the closed-loop correction current value to obtain a total control current, and output the total control current to the main arm falling valve of the crane to control the falling speed of the main arm of the crane.

[0132] Specifically, the output control module 204 outputs the total control current in a ramp manner according to a set parameter.

[0133] The crane falling amplitude control device provided by the embodiment of the application can execute the crane falling amplitude control method provided by any embodiment of the application, has the function modules and beneficial effects corresponding to the execution method.

[0134] Optionally, the crane falling amplitude control device further comprises:

[0135] The current calibration module is configured to perform a main arm uniform speed descending experiment of the crane under a plurality of typical working condition combinations and record data.

[0136] The model solidification module is configured to generate a four-dimensional feedforward control model based on the data recorded by the current calibration module.

[0137] Specifically, the crane falling amplitude control device can further comprise a current calibration module and a model solidification module for offline calibration. After calibration before the product is shipped, the functions of the two modules can be realized by a development tool.

[0138] With reference to Figure 3 Optionally, the feedforward control module 202 is configured to calculate a feedforward control current value based on the pre-generated four-dimensional feedforward control model according to current working condition information, specifically comprising:

[0139] The main arm elevation angle, the hoisting load, the main arm length and the hydraulic oil temperature are substituted into the formula of the four-dimensional feedforward control model to calculate the feedforward control current value.

[0140] The calculation formula of the four-dimensional feedforward control model is as follows:

[0141] I = (K1+K2·M)·sinθ + (K3 +K4·M)·cosθ +K5·L+K6·T

[0142] wherein I is the feedforward control current value, K1 is a gravity coefficient of the empty load, K2 is a load-gravity coupling coefficient, M is a percentage of the hoisting load, θ is the main arm elevation angle, L is a main arm length coefficient, T is a hydraulic oil temperature coefficient, K3 is a friction term coefficient of the empty load, K4 is a load-friction coupling coefficient, K5 is an arm length correction coefficient, and K6 is a temperature correction coefficient.

[0143] With reference to Figure 3 Optionally, the output control module 204 is further configured to perform amplitude limiting processing on the total control current, so that the absolute value of the total control current does not exceed a preset maximum current threshold.

[0144] Figure 4A structural diagram of an electronic device 1 that can be used to implement embodiments of the present application is shown. The electronic device is intended to represent various forms of digital computers, such as laptops, desktops, tablets, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. The electronic device can also represent various forms of mobile devices, such as personal digital assistants, cellular telephones, smartphones, wearable devices (e.g., headsets, glasses, watches, etc.), and other similar computing devices. The components shown here, their connections and relationships, and their functions, are meant to be examples only, and are not intended to limit the implementations of the present application described and / or claimed in this document.

[0145] As shown in Figure 4 The electronic device 1 includes at least one processor 11, and a memory, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., connected in communication with the at least one processor 11, where the memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes according to the computer programs stored in the read-only memory (ROM) 12 or loaded from the storage unit 18 into the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 1 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0146] Various components in the electronic device 1 are connected to the I / O interface 15, including an input unit 16, such as a keyboard, a mouse, etc., an output unit 17, such as various types of displays, speakers, etc., a storage unit 18, such as a magnetic disk, an optical disk, etc., and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 1 to exchange information / data with other devices through a computer network, such as the Internet, and / or various telecommunication networks.

[0147] The processor 11 can be various general and / or special purpose processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 performs various methods and processes described above, such as the crane load swing control method.

[0148] In some embodiments, the crane swing control method can be implemented as a computer program tangibly embodied in a computer readable storage medium, e.g., storage unit 18. In some embodiments, parts or all of the computer program can be loaded and / or installed onto electronic device 1 via, e.g., ROM 12 and / or communication unit 19. When the computer program is loaded onto RAM 13 and executed by processor 11, one or more steps of the crane swing control method described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to perform the crane swing control method by other means, e.g., with the aid of firmware.

[0149] Various implementations of the systems and techniques described above can be realized in digital electronic circuitry, integrated circuitry, specially designed application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device.

[0150] Computer programs used to implement the methods of the application can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the computer program, when executed by the processor of the computer or other programmable data processing apparatus, enables the systems and methods as claimed in the claims to be implemented. The computer program can be executed entirely on a machine, partially on a machine and partially on a remote machine or entirely on a remote machine or server.

[0151] In the context of the present application, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. A computer-readable storage medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. More specific examples of a machine-readable storage medium will include one or more lines of a program of instructions in a transitory signal, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0152] To provide for interaction with a user, the systems and techniques described here can be implemented on an electronic device having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the electronic device. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0153] The systems and techniques described here can be implemented in a computing system that includes a back end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front end component (e.g., a user computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0154] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system, to solve the defects of large management difficulty and weak business scalability in traditional physical host and VPS service.

[0155] It should be understood that the various forms of flow shown above can be reordered, added to, or have steps deleted. For example, the steps described in the present application can be performed in parallel, in series, or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, which are not limited herein.

[0156] The above detailed description does not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method of load swing control of a crane, characterized by, The method comprises: obtaining current working condition information of the crane, the working condition information comprising at least one of a main boom elevation angle, a main boom length, a load weight and a hydraulic oil temperature; calculating a feedforward control current value according to the current working condition information based on a pre-generated four-dimensional feedforward control model, the four-dimensional feedforward control model representing a mapping relationship between the working condition information and a main boom lowering valve control current of the crane in a uniform speed lowering state; obtaining an actual lowering speed of the main boom of the crane and comparing the actual lowering speed with a set expected lowering speed, and calculating a closed-loop correction current value based on a speed error through a closed-loop control algorithm; superimposing the feedforward control current value and the closed-loop correction current value to obtain a total control current, and outputting the total control current to the main boom lowering valve of the crane to control the lowering speed of the main boom of the crane.

2. The method of claim 1, wherein, The calculating of the feedforward control current value according to the current working condition information based on the pre-generated four-dimensional feedforward control model comprises: substituting the main boom elevation angle, the load weight, the main boom length and the hydraulic oil temperature into a formula of the four-dimensional feedforward control model to calculate the feedforward control current value; the formula of the four-dimensional feedforward control model is as follows: I = (K1+K2·M)·sinθ + (K3 +K4·M)·cosθ +K5·L+K6·T wherein I is the feedforward control current value, K1 is an empty load gravity coefficient, K2 is a load-gravity coupling coefficient, M is a percentage of the load weight, θ is the main boom elevation angle, L is a main boom length coefficient, T is a hydraulic oil temperature coefficient, K3 is an empty load friction term coefficient, K4 is a load-friction coupling coefficient, K5 is an arm length correction coefficient, and K6 is a temperature correction coefficient.

3. The method of claim 1, wherein, The closed-loop control algorithm is a position type incremental PI control algorithm, and a control period of the closed-loop control algorithm is 5 seconds.

4. The method of claim 1, wherein, The pre-generation of the four-dimensional feedforward control model comprises: performing main boom uniform speed lowering experiments under a plurality of typical working condition combinations, the working condition combinations comprising different main boom elevation angles, main boom lengths, load weights and hydraulic oil temperatures; recording control current values of the main boom lowering valve when stable uniform speed lowering is achieved under each working condition combination; performing fitting processing on the recorded experimental data of the plurality of control current values to generate the four-dimensional feedforward control model.

5. The method of claim 1, wherein, The outputting of the total control current to the main boom lowering valve of the crane comprises: performing amplitude limiting processing on the total control current to make an absolute value of the total control current not exceed a preset maximum current threshold, so as to limit a maximum lowering speed of the main boom of the crane.

6. Crane swing control apparatus, characterized in that The method comprises: a working condition obtaining module configured to obtain current working condition information of the crane, the working condition information comprising at least one of a main boom elevation angle, a main boom length, a load weight and a hydraulic oil temperature; a feedforward control module configured to calculate a feedforward control current value according to the current working condition information based on a pre-generated four-dimensional feedforward control model, the four-dimensional feedforward control model representing a mapping relationship between the working condition information and a main boom lowering valve control current of the crane in a uniform speed lowering state; The closed-loop control module is configured to acquire an actual lowering speed of the main boom of the crane, compare the actual lowering speed with a set expected lowering speed, and calculate a closed-loop correction current value based on a speed error through a closed-loop control algorithm; The output control module is configured to superimpose the feedforward control current value and the closed-loop correction current value to obtain a total control current, and output the total control current to a main boom lowering valve of the crane to control the lowering speed of the main boom of the crane.

7. The apparatus of claim 6, wherein, The crane lowering amplitude control device further comprises: The current calibration module is configured to perform a uniform-speed lowering experiment of the main boom of the crane under a plurality of typical working condition combinations and record data; The model solidification module is configured to generate the four-dimensional feedforward control model based on the data recorded by the current calibration module.

8. The apparatus of claim 6, wherein, The output control module is further configured to perform amplitude limiting processing on the total control current, so that an absolute value of the total control current does not exceed a preset maximum current threshold.

9. An electronic device, comprising: comprise: one or more processors; a memory configured to store one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors are caused to implement the method according to any one of claims 1-5.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program, when executed by a processor, implements the method according to any one of claims 1-5.

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