Collaborative operation control system driven by parallel pumps of crane based on working condition identification

Abstract

The invention discloses a cooperative operation control method and system driven by parallel pumps of a crane based on working condition identification, and belongs to the technical field of engineering machinery, and the cooperative operation control system comprises an intelligent working condition sensing and control module, a discrete hydraulic driving module, a cooperative speed regulation module and a dynamic response execution module, a parallel pump set strategy is dynamically configured in combination with working condition identification of load pressure, a cargo boom angle and a handle input signal, and flow is smoothly output as required on the basis of grading of light loads, medium loads and heavy loads and cooperative adjustment of the number of matched constant delivery pumps and the rotating speed of a motor according to the single-action working condition; aiming at the hoisting and variable-amplitude composite action, a variable-speed volume control or pump valve cooperative control mode is selected by judging the state of a proportional switch electromagnetic valve, the flow distribution and dynamic response are optimized, the energy efficiency is improved to 82% or above, meanwhile, the speed fluctuation rate control of + / -5% is realized, and the method is suitable for the electric upgrading scene of the crane.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engineering machinery, in particular to a crane hydraulic drive control system based on working condition recognition, which is especially suitable for the coordinated control of hoist, luffing single action and composite action under the architecture of motor direct drive parallel pump. BACKGROUND

[0002] With the improvement of energy efficiency, operation precision and environmental protection requirements in the field of engineering machinery, the traditional crane hydraulic system gradually exposes the following technical defects in energy consumption, control performance and multi-machine collaborative operation: First, high energy consumption and low efficiency: traditional cranes generally use engine-driven double load-sensitive pump systems, which have low energy efficiency, serious emission pollution and high noise. In addition, the hydraulic system with a single power source, such as pure electric or pure fuel drive, cannot meet the power demand under complex working conditions, resulting in over-sized motor or engine power selection, further increasing energy consumption and cost. Second, insufficient control precision: the traditional hydraulic system relies on throttle valves to regulate flow under single action conditions, resulting in significant throttling loss and system efficiency below 60%. When performing composite operation, the flow distribution of hoist and luffing action relies on manual experience, making it difficult to achieve dynamic collaborative control and resulting in high speed fluctuation rate of more than ±15% and poor composite action coordination. Third, multi-machine collaboration and information island problem: when multiple cranes operate independently, device state data relies on manual reporting, which is time-consuming and inaccurate, making it difficult to achieve real-time collaborative scheduling and causing safety hazards. Although existing collaborative control systems introduce sensors and communication networks, they have weak anti-interference ability and imperfect dynamic threshold adjustment mechanism, making it difficult to adapt to distance deviation and load fluctuation under complex working conditions. Fourth, limitations of hybrid power systems: existing hybrid power technologies such as motor-hydraulic parallel drive optimize energy consumption but have issues such as unreasonable power distribution and delayed dynamic response. For example, the motor drive system has poor resistance to load fluctuations, and the hydraulic system has poor starting characteristics, resulting in unstable rotation action. Fifth, high maintenance complexity: the traditional system has complex structure such as redundant components like shaft couplings and compensation shafts, high installation and maintenance costs, and relies on manual experience for fault diagnosis, lacking predictive maintenance methods based on intelligent algorithms.

[0003] To address the above problems, some technologies attempt to optimize through hybrid power architecture such as the oil-electric dual-drive of Zoomlion or intelligent collaborative control such as the convolutional neural network fault diagnosis of Anhui Jianghe Intelligence, but still have the following shortcomings: First, the dynamic power distribution strategy of the hybrid power system is not fine enough, and adaptive adjustment is not achieved in combination with real-time working condition recognition; Second, multi-machine collaborative control lacks efficient priority scheduling and dynamic safety distance adjustment mechanism, making it difficult to respond to sudden load changes; Third, there is a lack of pump-valve collaborative control algorithm for composite action, resulting in step impact when switching flow and affecting operation stability.

[0004] The prior art fails to effectively solve the problems of energy consumption optimization, precise coordination of composite actions and intelligent maintenance of the crane under complex working conditions. Therefore, a collaborative control system based on working condition perception and dynamic strategy is urgently needed to integrate multi-source signals, optimize parallel pump driving configuration and realize precise flow distribution among multiple actions, thereby improving system energy efficiency and control accuracy. SUMMARY

[0005] The purpose of the present application is to provide a crane parallel pump driving collaborative operation control system based on working condition recognition, which significantly improves energy efficiency, optimizes composite action control accuracy, enhances system reliability and improves operation experience.

[0006] The purpose of the present application is achieved by the following technical solutions:

[0007] A crane parallel pump driving collaborative operation control system based on working condition recognition, characterized in that it comprises:

[0008] An intelligent working condition perception and control module 01, comprising a controller 1, a hoist handle 2, an amplitude handle 3, a pressure sensor 32 and an angle sensor 33, wherein the controller 1 receives input signals from the handles 2, 3 and feedback signals from the sensors 32, 33 for working condition recognition and outputs control instructions;

[0009] A discrete hydraulic driving module 02, comprising a motor 4 and six coaxially connected constant displacement pumps, wherein the constant displacement pumps constitute a hoist main oil supply path and the constant displacement pumps constitute an amplitude main oil supply path;

[0010] A collaborative speed regulation module 03, comprising one-way valves at the outlets of the constant displacement pumps, overflow valves and seven proportional switch electromagnetic valves, wherein the proportional switch electromagnetic valves 27 control the on-off of the hoist and amplitude main oil paths;

[0011] A dynamic response execution module 04, comprising a hoist reversing electromagnetic valve 28, an amplitude reversing electromagnetic valve 29, a hoist motor 30 and an amplitude oil cylinder 31;

[0012] The controller 1 controls the excitation state of the proportional switch electromagnetic valves and the rotating speed of the motor 4 according to the working condition recognition results, so as to realize on-demand output of parallel pump flow and collaborative control of composite actions.

[0013] As a more optimal technical solution of the present application, the working condition recognition comprises:

[0014] Based on the load pressure signal of the pressure sensor 32, the load is divided into light load <5MPa, medium load 5-10MPa and heavy load ≥10MPa;

[0015] Based on the angle signal of the angle sensor 33, the angle of the crane arm is divided into small amplitude <50° and large amplitude ≥50°;

[0016] Based on the input direction signal of the handle 2, 3, the action type is determined as lifting or lowering.

[0017] As a more preferred technical solution of the application, the parallel pump configuration strategy of the hoisting action is:

[0018] Under light load conditions, initially enable two fixed displacement pumps;

[0019] Under medium load conditions, initially enable two fixed displacement pumps when lifting, and initially enable three fixed displacement pumps when lowering;

[0020] Under heavy load conditions, initially enable one fixed displacement pump when lifting, and initially enable two fixed displacement pumps when lowering.

[0021] As a more preferred technical solution of the application, the parallel pump configuration strategy of the amplitude variation action is:

[0022] Under light load and small amplitude, initially enable three fixed displacement pumps when lifting, and initially enable two fixed displacement pumps when lowering;

[0023] Under light load and large amplitude, initially enable two fixed displacement pumps when lifting, and initially enable three fixed displacement pumps when lowering;

[0024] Initially enable two fixed displacement pumps under medium load;

[0025] Initially enable one fixed displacement pump under heavy load and small amplitude, initially enable two fixed displacement pumps when lowering, and initially enable one fixed displacement pump when lifting under heavy load and large amplitude.

[0026] As a more preferred technical solution of the application, the switching rule of the parallel pump configuration strategy is:

[0027] When the motor 4 speed reaches 2000r / min, one fixed displacement pump is added to participate in oil supply, and the flow is smoothly increased;

[0028] When the motor 4 speed is lower than 950r / min, one fixed displacement pump is reduced to participate in oil supply, and the flow is smoothly reduced;

[0029] The motor 4 starting speed is 600r / min when single pump driving, and the highest speed is 3000r / min when six pump full driving.

[0030] As a more preferred technical solution of the application, in the composite action control:

[0031] When the proportional switch electromagnetic valve 27 is disconnected, the maximum number of oil pumps is limited to three, the maximum flow demand motor speed is taken as the actual speed, and the other action is realized by adjusting the proportional valve opening to achieve pump valve cooperative control;

[0032] When the proportional switch electromagnetic valve 27 is turned on, the hoist handle signal threshold is locked in the composite action cut-in stage, and the hoist system flow is gradually reduced to 3 pump configuration until the proportional switch electromagnetic valve 27 is completely turned off.

[0033] The application also provides a parallel pump driving digital flow on-demand smooth control method based on working condition recognition, which is realized based on the above-mentioned collaborative operation control system and comprises the following steps:

[0034] Step S1: Real-time acquisition of load pressure P of the pressure sensor 32, arm support angle θ of the angle sensor 33 and the direction signal of the handle;

[0035] Step S2: When P<5MPa, the light load mode is entered, the hoist is enabled with 2 pumps and the luffing is enabled with 3 pumps when θ<50°, and the hoist is enabled with 3 pumps and the luffing is enabled with 2 pumps when θ≥50°;

[0036] Step S3: When 5MPa≤P<10MPa, the medium load mode is entered, the lifting action is enabled with 2 pumps and the lowering action is enabled with 3 pumps;

[0037] Step S4: When P≥10MPa, the heavy load mode is entered, 1 pump is enabled for small amplitude (θ<50°) and 1 pump is enabled for lifting (θ≥50°) and 2 pumps are enabled for lowering;

[0038] Step S5: Monitoring of the motor 4 rotating speed, 1 pump is added when the rotating speed is ≥2000r / min and 1 pump is reduced when the rotating speed is ≤950r / min, the single pump starting rotating speed is 600r / min, and the upper limit of the six-pump full drive rotating speed is 3000r / min.

[0039] The different parallel pump configuration strategies in the above method correspond to different numbers of quantitative pumps participating in driving work, and the quantitative pumps 5, 6 and 7 of the hoisting system or the quantitative pumps 8, 9 and 10 of the luffing system are sequentially combined to supply oil, so that the variable displacement driving of the quantitative pumps in different numbers is realized. In the initial parallel pump configuration strategy, the motor speed is dynamically adjusted in the range of 600-2000 r / min with the increase and decrease of the handle opening. When the motor speed reaches 2000 r / min, the number of driving quantitative pumps increases. Taking the initial one quantitative pump work as an example, the output flow of the hoisting or luffing system can be divided into six adjustment stages J1-J6 with the change of the handle electric signal. In the J1 driving stage, the number of working quantitative pumps is one, and the motor speed increases and decreases with the increase and decrease of the hoisting handle electric signal, so as to realize system flow control. When the motor 4 speed is greater than or equal to 2000 r / min, the coordinated control proportional switch electromagnetic valve excitation state and the motor speed are adjusted, the number of driving quantitative pumps increases by one, and the J2 stage is entered. The change of the parallel pump displacement changes according to the rules: on the basis of the combination of n quantitative pumps in the previous stage, when the motor speed reaches 2000 r / min, the (n+1)th quantitative pump outputs oil in combination; when the handle input electric signal gradually decreases, the motor speed is less than 950 r / min, and the current stage is adjusted to the previous stage smoothly. In the J6 stage, when the handle input electric signal continues to increase, six quantitative pumps are combined to supply oil, and the maximum motor speed can reach 3000 r / min.

[0040] As a more optimal technical solution of the application, in the control method, the pump group switching process meets the following smooth conditions:

[0041] If the motor speed is greater than or equal to 2000 r / min for 2 seconds during the operation of the previous n pumps, the (n+1)th pump is enabled;

[0042] If the speed is less than or equal to 950 r / min for 3 seconds, the nth pump is closed, and the switching process adopts an S-shaped speed curve transition.

[0043] The application also provides a hoisting and luffing composite control method driven by parallel pumps, which is realized based on the above collaborative operation control system and includes the following steps:

[0044] Before control starts, it is judged whether the proportional switch electromagnetic valve 27 connected to the two main oil circuits is de-energized.

[0045] Suppose one: when the proportional switch electromagnetic valve 27 is de-energized, the maximum speed regulation stage is limited to J3, the demand motor speed of the system with larger flow is taken as the actual motor speed, the variable speed volume control of a certain action is realized, and the pump valve composite control is realized for another action by controlling the valve opening of the three proportional switch electromagnetic valves;

[0046] Hypothesis II: When the proportional switch solenoid valve 27 is powered on, the controller sets the threshold value of the winch handle electrical signal in this stage to the electrical signal value at the composite action cut-in time before the proportional switch solenoid valve 27 is completely powered off.

[0047] The first stage of the amplitude handle input control signal is to control the winch system flow to gradually decrease to the J3 stage, and after the proportional switch solenoid valve 27 is completely powered off, hypothesis I is entered.

[0048] The beneficial effects are as follows:

[0049] The present application provides a kind of collaborative operation control method, based on the collaborative operation control system implementation, comprising: by sensor signal identification working condition, determine initial parallel pump configuration;According to handle input signal dynamic adjustment motor speed and proportional valve opening, realize flow output on demand;In composite action, by coordinating motor speed and valve opening, realize the accurate collaborative control of winch and amplitude.

[0050] The present application significantly reduces throttling loss, improves system efficiency and control accuracy through working condition adaptive pump group configuration, motor-valve collaborative speed regulation and composite action optimization strategy, and is applicable to the demand of crane electrification upgrade, specifically:

[0051] Significant energy efficiency improvement: through working condition adaptive parallel pump dynamic configuration, eliminate the throttling loss of traditional variable pump system, light load working condition energy efficiency is improved from 58% to 82%;Motor speed and valve opening collaborative adjustment reduces invalid power consumption, and comprehensive energy consumption is reduced by 30%-45%.

[0052] Composite action control accuracy optimization: winch and amplitude speed fluctuation rate is reduced from ±15% of traditional system to ±5%;Composite action switching response time is shortened from 2.1s to 0.8s.

[0053] System reliability enhancement: discrete quantitative pump structure simplifies hydraulic circuit, and failure rate is reduced by 40%;Double overload protection mechanism of overflow valve 25, 26 and controller 1 ensures the safety of extreme working condition.

[0054] Operation experience improvement: flow smooth adjustment strategy avoids step impact, improves driver operation comfort;Intelligent working condition identification reduces the need for manual intervention, reduces operation complexity. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 It is a collaborative operation control principle diagram of crane parallel pump drive based on working condition identification.

[0056] Figure 2 It is a flow chart of parallel pump configuration strategy discrimination of automobile crane winch system.

[0057] Figure 3Is the truck crane luffing system parallel pump configuration strategy identification flow chart.

[0058] Figure 4 Is parallel pump driven single action discrete flow regulation stage switching flow.

[0059] Figure 5 Is the truck crane winch, luffing composite action flow on demand smooth control flow chart. DETAILED DESCRIPTION

[0060] The following detailed description of the technical implementation process of the present application is combined with the drawings and examples.

[0061] The following embodiments involve a handle signal, pressure and angle sensor signal and motor speed signal as input to the controller, the controller outputs an electrical signal to control seven proportional switch solenoid valves, winch, luffing two reversing solenoid valves, motor speed truck crane winch, luffing action speed regulation system.

[0062] The following embodiment is based on the parallel pump flow on demand smooth output control method based on working condition recognition, according to the identification signal to determine the working condition and its parallel pump configuration strategy, and with the speed of 950r / min and 2000r / min as the stage switching point, the parallel pump configuration strategy is adjusted, the proportional switch solenoid valve is powered on and the motor speed is controlled, the flow is realized on demand smooth output.

[0063] One of the following embodiments of parallel pump driven automobile crane compound action control method, first detect the excitation state of proportional switch solenoid 27 connected to two main oil circuit. When the proportional switch solenoid valve 27 loses power, limit the maximum speed stage for J3, take the maximum flow system demand motor speed as the actual speed of the motor, realize the variable speed volume control of a certain action, and realize the pump valve compound control through controlling the valve opening of three proportional switch solenoid valves for another action; Otherwise, the first stage of the input control signal of the luffing handle is to control the flow of the winch system to gradually decrease to the J3 stage, until the proportional switch solenoid valve 27 loses power completely, and then the compound action control enters the proportional switch solenoid valve 27 loss of power state. In this way, the precise control of the compound action of the crane winch and the luffing is realized. The system includes four parts: intelligent working condition sensing and control module (01), discrete hydraulic drive module (02), cooperative speed regulation module (03) and dynamic response execution module (04). The intelligent working condition sensing and control module (01) includes controller 1, winch handle 2 and luffing handle 3, and pressure sensor 32 and angle sensor 33. The discrete hydraulic drive module (02) includes motor 4 and six fixed displacement pumps. The cooperative speed regulation module (03) includes unidirectional valve, relief valve and seven proportional switch solenoid valves connected to the outlet of each fixed displacement pump. The dynamic response execution module (04) includes winch reversing solenoid valve 28, luffing reversing solenoid valve 29, winch motor 30 and luffing cylinder 31.

[0064] The specific structure is as follows:

[0065] The six fixed displacement pumps in the parallel pump system are coaxial and series connected with the motor 4, each fixed displacement pump has the same displacement and independent output, the outlet of each fixed displacement pump is connected with unidirectional valve and proportional switch solenoid valve in parallel, fixed displacement pumps 5, 6 and 7 constitute the main oil supply circuit of the winch system, fixed displacement pumps 8, 9 and 10 constitute the main oil supply circuit of the luffing system, the two main oil supply circuits are connected with winch motor 30 and luffing cylinder 31 through winch reversing solenoid valve 28 and luffing reversing solenoid valve 29 respectively, the two reversing solenoid valves are connected with relief valves in parallel, and the on-off of the two oil circuits is controlled through electromagnetic reversing valve 27 between the two main oil circuits. The input signals of winch handle 2 and luffing handle 3 and the feedback signals of pressure sensor 32 and angle sensor 33 enter the controller to realize the working condition identification, and output the excitation state of each proportional switch solenoid valve and the motor speed.

[0066] In order to reduce the throttling loss caused by the frequent switching of parallel pump configuration strategy and improve the working efficiency of the crane hydraulic system, the working conditions are identified according to the pressure signals of the pressure sensor, the angle signals of the crane boom collected by the angle sensor and the handle signals. According to the load pressure signal fed back by the crane pressure sensor 32, the hoisted objects can be divided into three types: light load (load pressure < 5 MPa), medium load (5 MPa ≤ load pressure < 10 MPa) and heavy load (10 MPa ≤ load pressure). According to the angle of the crane boom fed back by the angle sensor 33, the hoisting can be divided into small amplitude hoisting (angle < 50°) and large amplitude hoisting (50 ≤ angle < 90°). Then, according to the initial handle signal, it is judged whether the hoisted object is lifted (positive signal) or lowered (negative signal) during the winding or luffing action.

[0067] Different parallel pump configuration strategies are designed based on the identified working conditions. For the winding action, when the light load condition, the initial working speed is generally fast, and two fixed displacement pumps are driven; when the medium load condition, if the lifting action is performed, the initial working speed is low, then two fixed displacement pumps are driven initially, otherwise, three fixed displacement pumps are driven initially; when the heavy load condition, if the lifting action is performed, one fixed displacement pump is driven initially, otherwise, two fixed displacement pumps are driven initially.

[0068] For the luffing action, when the light load condition, small amplitude hoisting is performed, if the luffing lifting is performed, three fixed displacement pumps are driven initially, otherwise, two fixed displacement pumps are driven; similarly, when the light load condition, large amplitude hoisting is performed, if the luffing lifting is performed, two fixed displacement pumps are driven initially, otherwise, three fixed displacement pumps are driven. When the medium load condition, two fixed displacement pumps are driven initially. When the heavy load condition, small amplitude hoisting is performed, one fixed displacement pump is driven initially; when the large amplitude hoisting is performed, if the luffing lowering is performed, two fixed displacement pumps are driven initially, otherwise, one fixed displacement pump is driven initially.

[0069] For the parallel pump system, different configuration strategies of the parallel pump can be switched by controlling the on-off state of the proportional solenoid valve at each pump port, and different numbers of fixed displacement pumps are involved in driving the work to form different parallel pump configuration strategies. The winding system fixed displacement pumps 5, 6 and 7 and the luffing system fixed displacement pumps 8, 9 and 10 are sequentially combined for oil supply. According to the number of fixed displacement pumps, the parallel pump system has six configuration strategies, which realizes variable displacement driving of different numbers of fixed displacement pump combination oil supply.

[0070] Different parallel pump configuration strategy switching rules: when the motor speed reaches 2000r / min, the output oil of the nth fixed displacement pump gradually converges, and the total flow gradually increases stably; when the handle input electric signal gradually decreases, the motor speed is less than 950r / min, and the current stage is adjusted to the previous stage stably, the output oil flow of the nth fixed displacement pump is reduced stably, and the total flow is reduced stably. When a single fixed displacement pump is driven, the motor 4 starts from zero speed to 600r / min; when six fixed displacement pumps are combined to supply oil, when the handle input electric signal continues to increase, the motor speed can reach 3000r / min.

[0071] Under certain parallel pump configuration strategy, the motor speed changes with the increase and decrease of the control handle opening degree within a certain speed range, and when the parallel pump configuration switches, in order to ensure the continuous and stable output flow of the parallel pump system, for a certain time fixed flow output, the proportional switch electromagnetic valve port opening degree and the motor speed satisfy the following relationship:

[0072]

[0073] In the formula: n is the motor speed 4; V is the displacement of the fixed displacement pump; c is the proportional switch electromagnetic valve port flow coefficient; A is the proportional switch electromagnetic valve opening area; △p is the pressure difference between the two fixed displacement pump outlets; and p is the density of the hydraulic oil.

[0074] Before the coordinated control of the winch and the amplitude compound action starts, the excitation state of the proportional switch electromagnetic valve 27 connecting two main oil paths is judged; when the proportional switch electromagnetic valve 27 is de-energized and disconnected, the maximum configuration is limited to three fixed displacement pumps combined to supply oil, the demand motor speed of the maximum flow system is taken as the actual speed of the motor, the variable speed volume control of a certain action is realized, and for another action, the pump valve compound control is realized by controlling the valve port opening degree of the three proportional switch electromagnetic valves.

[0075] When the proportional switch electromagnetic valve 27 is energized and connected, from the compound action cut-in moment to the proportional switch electromagnetic valve 27 is completely de-energized and disconnected, the controller sets the winch handle electric signal threshold value of this stage to the electric signal value at the compound action cut-in moment; the first stage of the amplitude handle input control signal is to control the winch system flow to gradually decrease to three fixed displacement pumps combined to supply oil, until the proportional switch electromagnetic valve 27 is completely de-energized and disconnected.

[0076] As shown in Figure 1 The application is applied to the parallel pump driving system of the automobile crane: the motor simultaneously drives six fixed displacement pumps with the same displacement, the outlets of the fixed displacement pumps are connected with check valves and proportional switch electromagnetic valves, the proportional switch electromagnetic valve 27 is connected in communication between the winch and the amplitude main oil supply path after the check valves in the winch and the amplitude total oil supply path. It comprises:

[0077] Intelligent working condition perception module, integrated handle, pressure and angle sensor signals, real-time identification of load, amplitude and action type;

[0078] Discrete hydraulic drive module, 6 fixed displacement pumps supply oil in two groups, supporting dynamic pump group configuration switching;

[0079] Cooperative speed regulation module, proportional valve and motor speed matching, smooth flow regulation;

[0080] Composite action control strategy, based on proportional valve state selection volume control and pump valve cooperative mode, to ensure the stability of composite action.

[0081] The control signals of the hoist handle 2 and the luffing handle 3 in the intelligent working condition perception and control module 01, the pressure signal of the pressure sensor 32, the angle signal of the angle sensor 33 and the speed signal of the motor 4 are input to the controller 1, and the controller 1 outputs the speed of the motor 4 and the excitation state of the seven proportional switch electromagnetic valves, the hoist reversing valve 28 and the luffing reversing valve 29.

[0082] Discrete hydraulic drive module (02): motor 4 and 6 fixed displacement pumps, each fixed displacement pump is coaxial with motor 4 in series, each fixed displacement pump has the same displacement and independent output.

[0083] Different number of fixed displacement pumps participate in driving work to form different parallel pump configuration strategies, hoist system fixed displacement pumps 5, 6 and 7 or luffing system 8, 9 and 10 fixed displacement pumps are sequentially combined to supply oil, realizing variable displacement drive of different number of fixed displacement pump combination oil supply. When one fixed displacement pump works, fixed displacement pump 5 supplies oil first; when two fixed displacement pumps work, fixed displacement pumps 5 and 6 are combined to supply oil; when three fixed displacement pumps are judged to work, fixed displacement pumps 5, 6 and 7 supply oil together. Similarly, when luffing alone, fixed displacement pumps 8, 9 and 10 are sequentially combined to supply oil.

[0084] Cooperative speed regulation module (03): each fixed displacement pump outlet is connected with a one-way valve and a proportional switch electromagnetic valve. Among them, the proportional switch electromagnetic valve 27 controls the on-off of the hoist oil way and the luffing oil way. The one-way valves 23 and 24 prevent backflow of oil, and the flow valves 25 and 26 are connected with the hoist and luffing system oil ways respectively to protect the system oil way.

[0085] Dynamic response execution module (04) includes hoist reversing electromagnetic valve 28, luffing reversing electromagnetic valve 29, hoist motor 30, luffing oil cylinder 31, and hoist motor 30 load end connected with pressure sensor 32 for collecting system pressure and identifying working load condition.

[0086] The initial working state of each control element when the system starts: the 7 proportional switch solenoid valves are all de-energized, the proportional switch solenoid valve 27 is disconnected, and the oil paths of the remaining proportional switch solenoid valves are connected; the reversing solenoid valves 28 and 29 are both de-energized and are in the neutral position; and the motor 4 has a rotational speed of zero. Considering the minimum working rotational speed of the fixed displacement pump, the working rotational speed range of the motor is limited to 600-3000 r / min.

[0087] In order to reduce the throttling loss caused by frequent switching of the parallel pump configuration strategy and improve the working efficiency of the hydraulic system of the crane, the load can be divided into light load, medium load and heavy load according to the load pressure signal fed back by the crane pressure sensor 32, and the load can be divided into small amplitude lifting and large amplitude lifting according to the angle of the jib fed back by the angle sensor 33, and then the lifting or amplitude action of the hoist is judged to be lifting (positive signal) or lowering (negative signal) according to the initial signal of the handle.

[0088] For the hoist action, when the load pressure < 5 MPa, it is judged to be a light load condition, the process action speed is generally fast, and 2 fixed displacement pumps are driven at the initial work; when 5 MPa ≤ load pressure < 10 MPa, it is judged to be a medium load condition, if the lifting action is performed, the initial speed is low, then 2 fixed displacement pumps are driven at the initial work, otherwise, 3 fixed displacement pumps are driven at the initial work; when 10 MPa ≤ load pressure, it is judged to be a heavy load condition, if the lifting action is performed, then 1 fixed displacement pump is driven at the initial work, otherwise, 2 fixed displacement pumps are driven at the initial work.

[0089] For the amplitude action, when the load pressure < 5 MPa, it is a light load condition, at this time, small amplitude lifting (angle < 50°), if the amplitude lifting is performed, then 3 fixed displacement pumps are driven at the initial work, otherwise, 2 fixed displacement pumps are driven; similarly, for the light load condition, when large amplitude lifting (50 ≤ angle < 90°), if the amplitude lifting is performed, then 2 fixed displacement pumps are driven at the initial work, otherwise, 3 fixed displacement pumps are driven. When 5 MPa ≤ load pressure < 10 MPa, it is a medium load condition, 2 fixed displacement pumps are driven at the initial work. When 10 MPa ≤ load pressure, it is a heavy load condition, when small amplitude lifting (angle < 50°), 1 fixed displacement pump is driven at the initial work; when large amplitude lifting (50 ≤ angle < 90°), if the amplitude lowering is performed, then 2 fixed displacement pumps are driven at the initial work, otherwise, 1 fixed displacement pump is driven at the initial work. The optimal parallel pump configuration strategy is determined through working condition identification to reduce frequent variable displacement switching.

[0090] The parallel pump configuration strategy discrimination process for the hoist action and the amplitude action of the truck crane is shown in Figure 2 and Figure 3 .

[0091] Taking the winch as an example, when the winch motor 30 acts alone, the driver operates the winch handle 2 to output an electric signal to the controller 1, and the controller 1 determines the parallel pump configuration strategy through working condition identification. When the working condition identification determines that one fixed displacement pump drives at the initial work, the winch system output flow changes with the winch handle 2 electric signal and can be divided into six adjustment stages, and the digital flow adjustment stage switching is as shown in Figure 4

[0092] J1 stage: the winch handle 2 inputs an electric signal to the controller 1, the controller outputs the control proportional switch electromagnetic valve 21 to be powered, the valve port is closed, the fixed displacement pump 5 is independently supplied with oil, the reversing valve 28 is powered to the left (or right) position, the motor 4 is started from zero speed to 600 r / min at a high speed, and the speed increases or decreases with the increase or decrease of the winch handle electric signal, realizing the winch system flow control.

[0093] J2 stage: on the basis of J1 stage, when the winch handle 2 input electric signal continuously increases, the motor 4 speed reaches 2000 r / min, in order to meet the flow demand, the proportional switch electromagnetic valve 19 is proportionally powered, the valve port is gradually closed, the fixed displacement pump 6 and the fixed displacement pump 5 output flow are jointly supplied with oil, and at the same time the motor 4 speed gradually reduces, the winch oil way flow is smoothly improved, until the proportional switch electromagnetic valve 19 valve port is completely closed, enters J2 stage, the fixed displacement pump 5 and 6 combination oil supply, the motor 4 speed increases or decreases with the increase or decrease of the winch handle electric signal.

[0094] In order to ensure the continuous stability of the winch system output flow, for a certain moment fixed flow output, the proportional switch electromagnetic valve port opening and the motor speed meet the following relationship:

[0095]

[0096] When the winch handle 2 input electric signal continuously increases, the flow control enters the next stage J3; otherwise, when the winch handle 2 input electric signal gradually decreases, the motor speed is less than 950 r / min, the proportional switch electromagnetic valve 19 is proportionally powered off, the valve port is gradually opened, the flow output by the fixed displacement pump 6 is smoothly reduced, at the same time the motor 4 speed gradually increases, the winch oil way flow is smoothly reduced. Until the proportional switch electromagnetic valve 19 valve port is completely opened, return to the previous stage, that is, J1 stage, the fixed displacement pump 5 is independently supplied with oil.

[0097] ​J4 stage: in J3 stage, when the winch handle 2 input electric signal continues to increase, the motor 4 speed reaches 2000r / min, proportional switch solenoid valve 27 and 22 proportional electricity, into the winch system oil way of quantitative pump 8 output flow smoothly, while the motor 4 speed gradually reduces, the winch oil way flow smoothly, until the proportional switch solenoid valve 27 and 22 proportional electricity, into J4 stage, quantitative pump 5, 6, 7, 8 combination oil supply, motor 4 speed with winch handle electric signal increase and decrease change. When in J4 stage, winch handle 2 input electric signal gradually decreases, the motor speed is less than 950r / min, proportional switch solenoid valve 27 and 22 proportional power off, while the motor 4 speed gradually increases, quantitative pump 8 input flow smoothly reduces until stop, the winch oil way flow smoothly reduces, flow regulation returns to the previous stage, namely J3.

[0098] J3, J5 stage and J2 stage principle is the same, in the previous stage n quantitative pump combination oil supply drive basis, when the motor 4 speed reaches 2000r / min again, the n+1 quantitative pump output oil gradually into; when the winch handle 2 input electric signal gradually decreases, the motor speed is less than 950r / min, then adjust to the previous stage from the current stage.

[0099] J6 stage: in J5 stage, when the winch handle 2 input electric signal continues to increase, the motor 4 speed reaches 2000r / min, quantitative pump 10 output flow gradually into the winch system oil way, in this stage, 6 quantitative pump simultaneously smooth oil supply, motor 4 speed with winch handle electric signal increase and decrease change, the motor 4 highest speed can reach 3000r / min, when the motor speed is less than 950r / min, adjust to the previous stage.

[0100] When the initial work of working condition recognition and judgment 2 quantitative pump drive, proportional switch solenoid valve 21 and 19 are powered on at the same time, the valve port is closed, and the quantitative pump 5 and 6 are simultaneously supplied as the working pump. The motor 4 speed increases or decreases with the handle opening degree, when the speed is greater than or equal to 2000r / min, the system flow regulation enters J3 stage, and the number of working quantitative pump is 3; otherwise, the motor speed changes in the range of 600-2000r / min with the increase or decrease of the handle opening degree, and the low configuration stage, namely J1 stage, does not appear.

[0101] When the initial work of working condition recognition and judgment 3 quantitative pump drive, the adjustment principle is the same as above, and the low configuration stage, namely J1 and J2 stage, does not appear.

[0102] When the amplitude cylinder 31 acts, the flow control principle is the same as the above winch motor 30 control principle, which will not be repeated.

[0103] The compound action process of the winch handle 2 inputting control signals and the luffing handle 3 inputting control signals again. The specific winch and luffing compound action flow control process is shown in the following table. Figure 5

[0104] Firstly, the controller 1 judges whether the proportional switch electromagnetic valve 27 is de-energized or not. Assuming that the proportional switch electromagnetic valve 27 is de-energized, the valve port is closed. Then, the winch and luffing hydraulic systems form two independent hydraulic systems, and the maximum speed regulation stage of a single action is J3. In order to eliminate the coupling of the parallel pump displacement speed regulation and the speed regulation, the adjustment stage of each action alone and the corresponding motor 4 speed are calculated according to the electrical signals of the winch handle 2 and the luffing handle 3. The required motor speed of the maximum flow system of the two hydraulic systems is taken as the actual motor speed of the motor 4, the parallel pump variable speed volume control of a certain action is realized, the pump valve compound control of another action is realized according to the proportional switch electromagnetic valve port opening degree of the parallel pump configuration control, the advantages of the parallel pump + proportional valve are fully played, and the energy loss of the load pressure overflow in the compound action process is reduced.

[0105] Assuming that the proportional switch electromagnetic valve 27 is energized, the valve port is opened, and the winch handle 2 electrical signal control input is from the compound action cut-in time to the proportional switch electromagnetic valve 27 being completely de-energized. The controller 1 sets the winch handle 2 electrical signal threshold value in this stage as the electrical signal value at the compound action cut-in time,

[0106] In order to improve the stability of the compound action, the first stage of the luffing handle 3 inputting control signals is to control the winch system flow to be smoothly reduced to the J3 stage, and the maximum motor speed is 2000r / min. With the gradual increase of the luffing handle 3 inputting control signals, the motor speed gradually increases, the proportional switch electromagnetic valve 27 is de-energized, and the valve port opening gradually closes. When the proportional switch electromagnetic valve 27 is completely de-energized, the valve port is completely closed, the winch handle 2 electrical signal threshold value returns to the original state, and the luffing handle 3 inputting control signals continues to increase. The adjustment principle of the winch and luffing hydraulic system compound action is the same as that of the assumption one.

[0107] Embodiment 1

[0108] In this embodiment, the motor 4 drives six constant displacement pumps with a displacement of 28mL / r. The winch system main oil way constant displacement pumps 5-7 and the luffing system main oil way constant displacement pumps 8-10 are connected through the proportional switch electromagnetic valve 27. The system rated pressure is 35MPa, and the motor speed range is 600-3000r / min.

[0109] ​The technical implementation process of the present application is described in detail below in combination with the drawings and examples. In the present embodiment, the motor 4 drives six constant displacement pumps with a displacement of 28 mL / r, the main oil path constant displacement pumps 5-7 of the hoist system and the main oil path constant displacement pumps 8-10 of the amplitude system are connected through the proportional switch electromagnetic valves 27, the system rated pressure is 35 MPa, and the motor speed range is 600-3000 r / min.

[0110] 1. System initialization and working condition recognition.

[0111] Initialization state:

[0112] All proportional switch electromagnetic valves 19-22, 25-27 lose power, the valve port is opened; the hoist reversing valve 28 and the amplitude reversing valve 29 are in the middle position; the motor 4 speed is 0.

[0113] Working condition sensing and recognition process:

[0114] Signal acquisition: the controller 1 reads the voltage signal -10V-+10V of the hoist handle 2 and the amplitude handle 3, the load pressure value 0-35 MPa of the pressure sensor 32, and the angle 0°-90° of the angle sensor 33 in real time.

[0115] Load classification:

[0116] Light load: pressure <5 MPa, such as empty hook lifting;

[0117] Medium load: 5 MPa≤pressure <10 MPa, such as medium-sized hoisting objects;

[0118] Heavy load: pressure≥10 MPa, such as heavy equipment hoisting.

[0119] Amplitude classification:

[0120] Small amplitude: angle <50°, short distance operation;

[0121] Large amplitude: angle≥50°, long arm operation.

[0122] Action type judgment:

[0123] Positive voltage signal + of the handle corresponds to lifting action, negative voltage signal- corresponds to lowering action.

[0124] 2. Single action control implementation, taking hoist lifting as an example.

[0125] 2.1 Light load condition, pressure <5 MPa.

[0126] Step 1: parallel pump configuration initialization.

[0127] Controller 1 enables 2 fixed displacement pumps 5, 6 according to light load condition, controls proportional switch solenoid valve 19, 21 to be closed, and the rest of the valves remain open.

[0128] Step 2: Motor speed regulation.

[0129] The winch handle 2 inputs +5V signal, and the controller 1 outputs PWM signal to drive the motor 4 to start at 1200r / min.

[0130] Flow calculation: Total flow Q = 2 × 28mL / r × 1200r / min = 67.2L / min.

[0131] Step 3: Stage switching control.

[0132] If the handle signal increases to +8V, the motor speed increases to 2000r / min, and the flow = 2 × 28 × 2000 = 112L / min. At this time, the controller triggers the third pump 7 to join:

[0133] The proportional switch solenoid valve 20 gradually closes, the opening degree decreases from 100% to 0%, and the fixed displacement pump 7 gradually supplies oil;

[0134] The motor speed synchronously decreases to 1400r / min, and the total flow remains 112L / min, 3 × 28 × 1400 = 117.6L / min, realizing smooth transition of flow.

[0135] If the handle signal decreases to +3V, the motor speed is lower than 950r / min, the third pump 7 exits, and the motor speed returns to 1200r / min.

[0136] 2.2 Heavy load condition pressure ≥ 10MPa.

[0137] Step 1: Parallel pump configuration initialization.

[0138] Controller 1 enables 1 fixed displacement pump 5, and only proportional switch solenoid valve 21 is closed.

[0139] Step 2: Low speed and high torque output

[0140] The motor 4 starts at 600r / min, and the flow Q = 28 × 600 = 16.8L / min, matching the heavy load low speed requirement.

[0141] If acceleration is required, the motor speed gradually increases to 2000r / min, then the second pump 6 joins, and the motor speed decreases to 1200r / min, and the total flow = 2 × 28 × 1200 = 67.2L / min.

[0142] 3. Compound action cooperative control, winch lifting + amplitude lowering.

[0143] 3.1 Proportional switch solenoid valve 27 is off, independent oil circuit mode.

[0144] Step 1: Maximum flow priority control.

[0145] Winch demand flow: 3 pump 5-7 drive, motor speed 1800 r / min flow = 3 x 28 x 1800 = 151.2 L / min;

[0146] Amplitude demand flow: 2 pump 8-9 drive, motor speed 1600 r / min flow = 2 x 28 x 1600 = 89.6 L / min;

[0147] Controller 1 takes higher speed 1800 r / min as the actual motor speed, and the winch system realizes flow control through variable speed, and the amplitude system compensates the flow to 89.6 L / min through adjusting the opening of proportional switch solenoid valve 25 opening = 60%.

[0148] 3.2 Proportional switch solenoid valve 27 is on, oil circuit sharing mode.

[0149] Step 1: Compound action cut-in.

[0150] The winch is 3 pump drive, J3 stage, and the amplitude handle 3 input -6V signal requests lowering.

[0151] Controller 1 locks the winch handle signal threshold +6V, and controls the proportional switch solenoid valve 27 to gradually open.

[0152] Step 2: Flow redistribution.

[0153] The winch system flow is gradually reduced from 3 pump, 151.2 L / min to 2 pump, 2 x 28 x 1600 = 89.6 L / min;

[0154] The released constant pump 7 supplies oil to the amplitude system through the proportional switch solenoid valve 27, and the motor speed is increased to 2000 r / min, and the amplitude flow is increased to 3 x 28 x 2000 = 168 L / min.

[0155] Step 3: Mode switching is completed.

[0156] When the proportional switch solenoid valve 27 is completely closed, the winch and the amplitude enter the independent control mode and operate according to the rules of 3.1.

[0157] 4. Safety protection mechanism.

[0158] Overflow protection: The winch and amplitude main oil circuit overflow valves 25, 26 are set to 35 MPa, and oil is released when the pressure is too high.

[0159] Fault handling: If pressure sensor 32 detects a pressure surge, such as ≥ 40 MPa, controller 1 immediately cuts off power supply to the motor, and all proportional valves reset to the open state.

[0160] 5. Implementation effect

[0161] Energy consumption comparison: The efficiency of the traditional system is 58% under light load, and the present application is improved to 82% by on-demand pump group configuration;

[0162] Response speed: The composite action switching time is shortened from 2.1s of the traditional system to 0.8s;

[0163] Control accuracy: The hoisting speed fluctuation rate is reduced from ±15% to ±5%.

[0164] The above examples are only for the purpose of clearly illustrating the technical details of the present application, and those skilled in the art can make adaptive adjustments within the scope of the claims.

[0165] It should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations. The statement "including a limited element" does not exclude the existence of other identical elements in the process, method, article or equipment including the element.

[0166] Although embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A collaborative operation control system for crane parallel pump drive based on working condition identification, characterized in that: include: Intelligent working condition sensing and control module 01: includes a controller 1, a winch handle 2, a luffing handle 3, a pressure sensor 32, and an angle sensor 33. The controller 1 receives input signals from the handles 2 and 3 and feedback signals from the sensors 32 and 33 to identify the working condition and output control instructions. Discrete hydraulic drive module 02: includes motor 4 and 6 coaxial quantitative pumps connected in series, wherein the quantitative pumps constitute the main oil supply circuit for the winch and the main oil supply circuit for the luffing; Coordinated speed control module 03: includes the one-way valve and overflow valve at the outlet of each metering pump and 7 proportional switch solenoid valves, among which the proportional switch solenoid valve 27 controls the on-off of the winch and luffing main oil circuits; Dynamic response execution module 04: includes a winch reversing solenoid valve 28, a luffing reversing solenoid valve 29, a winch motor 30 and a luffing cylinder 31; The controller 1 controls the excitation state of the proportional switch solenoid valve and the speed of the motor 4 according to the working condition identification result, so as to realize the coordinated control of the flow output of the parallel pump on demand and the compound action.

2. The collaborative operation control system of crane parallel pump drive based on working condition identification according to claim 1 is characterized in that: The working condition identification includes: Based on the load pressure signal of the pressure sensor 32, the load is divided into light load <5MPa, medium load 5-10MPa and heavy load ≥10MPa; The boom angle signal based on the angle sensor 33 is divided into small amplitude <50° and large amplitude ≥50°; Based on the input direction signals of handles 2 and 3, the action type is determined to be lifting or lowering.

3. The collaborative operation control system for crane parallel pump drive based on working condition identification according to claim 1, characterized in that: The parallel pump configuration strategy for the hoisting action is: Under light load conditions, two metering pumps are initially enabled; Under medium load conditions, two metering pumps are initially activated when lifting, and three metering pumps are initially activated when lowering; Under heavy load conditions, one metering pump is initially enabled during lifting, and two metering pumps are initially enabled during lowering.

4. The parallel pump configuration strategy for the amplitude-changing action is: When the load is light and the amplitude is small, 3 metering pumps are initially activated when lifting, and 2 metering pumps are initially activated when lowering; When the load is light and the amplitude is large, two metering pumps are initially activated when lifting, and three metering pumps are initially activated when lowering; At medium load, two metering pumps are initially enabled; When the load is heavy and the amplitude is small, one metering pump is initially activated. When the load is heavy and the amplitude is large, two metering pumps are initially activated when lowering, and one metering pump is initially activated when lifting.

5. The collaborative operation control system of crane parallel pump drive based on working condition identification according to claim 1, characterized in that: The switching rules of the parallel pump configuration strategy are: When the speed of motor 4 reaches 2000r / min, a quantitative pump is added to participate in the oil supply, and the flow rate increases steadily; When the speed of motor 4 is lower than 950r / min, one metering pump is reduced to participate in the oil supply, and the flow rate decreases steadily; When a single pump is driven, the starting speed of the motor 4 is 600 r / min, and when all six pumps are driven, the maximum speed is 3000 r / min.

6. The collaborative operation control system for crane parallel pump drive based on working condition identification according to claim 1, characterized in that: In compound action control: When the proportional switch solenoid valve 27 is disconnected, the maximum number of oil supply pumps is limited to 3, and the motor speed with the maximum flow demand is taken as the actual speed. Another action is to achieve pump-valve coordinated control by adjusting the proportional valve opening; When the proportional switch solenoid valve 27 is turned on, the winch handle signal threshold is locked during the compound action cut-in phase, and the winch system flow is gradually reduced to a 3-pump configuration until the proportional switch solenoid valve 27 is completely disconnected.

7. A digital flow on-demand smooth control method for parallel pump drive based on working condition identification, characterized in that: The collaborative operation control system of the crane parallel pump drive based on working condition identification according to claim 1 is implemented, comprising: Step S1: acquiring the load pressure P of the pressure sensor 32, the arm angle θ of the angle sensor 33, and the direction signal of the handle in real time; Step S2: When P<5MPa, the system enters the light load mode. When θ<50°, two winch pumps are enabled and three luffing pumps are enabled. When θ≥50°, three winch pumps are enabled and two luffing pumps are enabled. Step S3: When 5MPa≤P<10MPa, the medium load mode is entered, pump 2 is activated for lifting action, and pump 3 is activated for lowering action; Step S4: When P≥10MPa, enter the heavy load mode, and activate one pump for small amplitude (θ<50°), and activate one pump for large amplitude (θ≥50°) to increase or two pumps for decrease; Step S5: Monitor the speed of motor 4. When it is ≥2000r / min, add one pump. When it is ≤950r / min, reduce one pump. The starting speed of a single pump is 600r / min. The upper limit of the speed of full drive of six pumps is 3000r / min.

8. The method for digital flow on-demand smooth control of parallel pump drive based on working condition identification according to claim 5 is characterized in that The pump group switching process meets the following smooth conditions: When pump n is running in the previous stage, if the motor speed is ≥2000r / min for 2 seconds, the n+1 pump will be enabled; If the speed is ≤950r / min for 3 seconds, the nth pump will be turned off and the switching process will adopt an S-shaped speed curve transition.

9. A parallel pump driven winch luffing compound control method, characterized in that: The collaborative operation control system of the crane parallel pump drive based on working condition identification according to claim 1 is implemented, comprising: Before starting control, determine whether the proportional switch electromagnetic 27 connecting the two main oil circuits is de-energized; Assumption 1: When the proportional switch solenoid valve 27 loses power, the maximum speed regulation stage is limited to J3. The required motor speed of the system with a larger flow rate is used as the actual motor speed to achieve variable speed volume control for a certain action. For another action, the valve opening of the three proportional switch solenoid valves is controlled to achieve pump-valve compound control. Assumption 2: When the proportional switch solenoid valve 27 is energized, from the time the compound action is cut in to the time the proportional switch solenoid valve 27 is completely de-energized, the controller sets the electric signal threshold of the winch handle in this stage to the electric signal value at the time the compound action is cut in; The first stage of the luffing handle input control signal is to control the winch system flow to gradually decrease to the J3 stage. When the proportional switch solenoid valve 27 is completely de-energized, it enters assumption one.

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