Control method and device for crane, controller and crane

Abstract

The embodiment of the present invention provides a control method and device, a controller and a crane for a crane. The control method for the crane includes: determining that the boom is in a downward amplitude variation motion state at the current sampling moment; obtaining the pressure of the rodless chamber of the anti-tilt cylinder at the current sampling moment; when the pressure of the rodless chamber at the current sampling moment exceeds the preset pressure range, obtaining the preset pressure, the engine speed at the current sampling moment and the working angle of the boom at the current sampling moment; and controlling the control current of the variable pump at the next sampling moment according to the pressure of the rodless chamber at the current sampling moment, the preset pressure, the speed and the working angle. The embodiment of the present invention can ensure that the extension speed of the anti-tilt cylinder at the next sampling moment can follow the downward amplitude variation speed of the boom, realize the stability of the support reaction force during the downward amplitude variation of the boom, ensure the real-time response of the anti-tilt support reaction force of the whole vehicle boom system, and ensure the safety of the whole vehicle when the boom is dropped.

Description

Technical Field

[0001] The present invention relates to the technical field of crane control, and in particular to a control method and device for a crane, a controller and a crane. Background Art

[0002] In the existing lifting machinery and equipment, due to the change of the center of gravity of the boom and the rebound of the radius of the boom causing the backward tilt and other reasons, most of the medium and large tonnage equipment adopts a cylinder type anti-tilt device at the boom. The pressure oil source of the anti-tilt cylinder mostly adopts a metering pump. During the downward amplitude change of the boom, as the speed of the engine changes, the extension speed of the anti-tilt cylinder is difficult to match the downward amplitude change speed of the boom, that is, the extension speed of the anti-tilt cylinder is difficult to follow the downward amplitude change speed of the boom. For example, if the extension speed of the anti-tilt cylinder is too slow, the anti-tilt cylinder is prone to slipping out of the slot, which is dangerous to the whole vehicle; or if the extension speed of the anti-tilt cylinder is too fast, the anti-tilt cylinder generates too much support reaction force, which in turn causes the anti-tilt cylinder to generate high pressure and become unstable, thus damaging the anti-tilt cylinder. Therefore, it is urgent to propose a technical solution to solve the above technical problems in the prior art. Summary of the invention

[0003] The purpose of the embodiments of the present invention is to provide a control method and device for a crane, a controller and a crane to solve the above-mentioned technical problems existing in the aforementioned prior art.

[0004] In order to achieve the above-mentioned objectives, the first aspect of the present invention provides a control method for a crane, the crane includes an engine, a boom, an anti-tilt cylinder and a variable pump, the control method includes: determining that the boom is in a downward variable amplitude motion state at a current sampling moment; obtaining the pressure of the rodless chamber of the anti-tilt cylinder at the current sampling moment; when the pressure of the rodless chamber at the current sampling moment exceeds a preset pressure range, obtaining the preset pressure, the engine speed at the current sampling moment and the working angle of the boom at the current sampling moment; and controlling the control current of the variable pump at the next sampling moment according to the pressure of the rodless chamber at the current sampling moment, the preset pressure, the speed and the working angle, so as to adjust the pressure of the rodless chamber at the next sampling moment.

[0005] In the embodiment of the present invention, the preset pressure range is 3 bar-6 bar.

[0006] In the embodiment of the present invention, the preset pressure ranges from 3 bar to 6 bar.

[0007] In the embodiment of the present invention, the preset pressure is 5 bar.

[0008] In an embodiment of the present invention, controlling the control current of the variable pump at the next sampling moment according to the pressure, preset pressure, rotation speed and working angle of the rodless chamber at the current sampling moment includes: controlling the control current of the variable pump at the next sampling moment according to the following formula:

[0009]

[0010] Among them, I x is the control current of the variable pump at the next sampling moment, P is the pressure of the rodless chamber at the current sampling moment, S is the area of ​​the rodless chamber, k1 is the proportional coefficient between the extension length of the cylinder and the working angle of the boom, θ is the working angle, P x is the preset pressure, n is the speed, and k2 is the proportional coefficient between the output displacement of the variable pump and the control current of the variable pump.

[0011] A second aspect of the present invention provides a controller configured to execute the control method for a crane according to the aforementioned embodiment.

[0012] A third aspect of the present invention provides a control device for a crane, the crane includes an engine, a boom, an anti-tilt cylinder and a variable pump, the control device includes: a pressure sensor, configured to detect the pressure of the rodless chamber of the anti-tilt cylinder; an angle sensor, configured to detect the working angle of the boom; an engine controller, configured to provide the engine speed; and the controller of the aforementioned embodiment.

[0013] In an embodiment of the present invention, the crane further includes an oil tank, and the control device further includes: a manual reversing valve (2), a first working oil port of the manual reversing valve being connected to the rodless chamber, a second working oil port of the manual reversing valve being connected to the rod chamber of the anti-tilt cylinder, an oil inlet of the manual reversing valve being connected to an oil outlet of the variable pump, and an oil outlet of the manual reversing valve being connected to the oil tank; a first overflow valve (10), an input oil port of the first overflow valve being connected to the rodless chamber and the rod chamber of the anti-tilt cylinder; a second overflow valve (4), an input oil port of the second overflow valve being connected to the rodless chamber; a third overflow valve (5), an output port of the third overflow valve being connected to the rodless chamber; The oil inlet is connected to the rodless chamber; a throttle valve (7), the oil input port of the throttle valve is connected to the oil output port of the third overflow valve; a first electromagnetic reversing valve (6), the oil input port of the first electromagnetic reversing valve is connected to the oil output port of the third overflow valve; a second electromagnetic reversing valve (8), the oil input port of the second electromagnetic reversing valve is connected to the oil output port of the throttle valve; and a check valve (9), the oil input port of the check valve is connected to the oil output port of the first overflow valve, the oil output port of the second overflow valve, the oil output port of the first electromagnetic reversing valve and the oil output port of the second electromagnetic reversing valve, and the oil output port of the check valve is connected to the oil tank.

[0014] A fourth aspect of the present invention provides a crane, comprising: an engine; a boom; an anti-backward tilt cylinder; a variable displacement pump; and the control device for the crane of the aforementioned embodiment.

[0015] In an embodiment of the present invention, the crane is a crawler crane.

[0016] The embodiment of the present invention can achieve the following technical effects through the above-mentioned technical scheme: by real-time monitoring whether the pressure of the rodless chamber exceeds the preset pressure range during the downward amplitude change movement of the boom, and when the pressure of the rodless chamber exceeds the preset pressure range, adjusting the control current of the variable pump according to the pressure of the rodless chamber, the preset pressure, the engine speed and the working angle of the boom, the output displacement of the variable pump can be adjusted, and then the pressure of the rodless chamber can be adjusted, so that the pressure of the rodless chamber at the next sampling moment can be within the preset pressure range, thereby ensuring that the extension speed of the anti-tilt cylinder at the next sampling moment can follow the downward amplitude change speed of the boom, achieving the stability of the support reaction force during the downward amplitude change of the boom, ensuring the real-time response of the anti-tilt support reaction force of the whole vehicle boom system, protecting the anti-tilt cylinder from neither being out of the groove nor having high pressure, and solving the technical problem that the anti-tilt cylinder is prone to being out of the groove or having too high pressure during the downward amplitude change of the boom, thereby ensuring the safety of the whole vehicle when the boom is lowered.

[0017] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

[0019] Figure 1 is a flow chart of a control method 100 for a crane according to an embodiment of the present invention;

[0020] Figure 2 is a schematic structural diagram of a control device 200 for a crane according to an embodiment of the present invention;

[0021] Figure 3 is a schematic structural diagram of a crane 300 according to an embodiment of the present invention;

[0022] Figure 4 is a structural schematic diagram of a crane anti-tilt control system according to an example of the present invention; and

[0023] Figure 5 It is a control logic diagram of a crane anti-tilt control system according to an example of the present invention. DETAILED DESCRIPTION

[0024] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

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

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

[0027] like Figure 1 As shown, in an embodiment of the present invention, a control method 100 for a crane is provided. The crane includes an engine, a boom, an anti-backward tilt cylinder, and a variable displacement pump. The control method 100 for the crane includes the following steps:

[0028] Step S110: Determine whether the boom is in a downward variable amplitude motion state at the current sampling moment. For example, the working angle of the boom at the current sampling moment, that is, the angle between the boom and the horizontal plane, and the working angle of the boom at the previous sampling moment can be obtained and compared. If the working angle of the boom at the current sampling moment is less than the working angle of the boom at the previous sampling moment, it will be determined that the boom is in a downward variable amplitude motion state at the current sampling moment. If the working angle of the boom at the current sampling moment is not less than the working angle of the boom at the previous sampling moment, it will be determined that the boom is not in a downward variable amplitude motion state at the current sampling moment. Of course, the embodiment of the present invention is not limited to this. For example, it is also possible to determine whether the boom is in a downward variable amplitude motion state by obtaining the state of the crane's operating mechanism. The time interval between any two adjacent sampling moments, that is, the sampling period, has a value range of, for example, 200ms-500ms, and can take values ​​such as 200ms, 350ms, and 500ms.

[0029] Step S130: Obtain the pressure of the rodless chamber of the anti-tilt oil cylinder at the current sampling time. For example, the pressure of the rodless chamber can be obtained by a pressure sensor or other pressure detection device.

[0030] Step S150: When the pressure of the rodless cavity at the current sampling time exceeds the preset pressure range, the preset pressure, the engine speed at the current sampling time, and the working angle of the boom at the current sampling time are obtained. The preset pressure is, for example, set in advance and stored locally. For example, the engine speed can be obtained through an engine controller or a speed detection device. For example, the working angle of the boom can be obtained through an angle detection device such as an angle sensor.

[0031] Step S170: Control the control current of the variable pump at the next sampling moment according to the pressure of the rodless chamber at the current sampling moment, the preset pressure, the rotation speed and the working angle to adjust the pressure of the rodless chamber at the next sampling moment.

[0032] Among them, the setting of the preset pressure range can, for example, ensure that when the pressure of the rodless chamber is within the preset pressure range, the extension speed of the anti-tilt cylinder follows the downward amplitude change speed of the boom, thereby ensuring the safety of the boom lowering. The setting of the preset pressure can, for example, ensure that when the pressure of the rodless chamber at the current sampling moment exceeds the preset pressure range, the control current of the variable pump at the next sampling moment is controlled according to the obtained parameters such as the pressure of the rodless chamber at the current sampling moment, the preset pressure, the engine speed at the current sampling moment, and the working angle of the boom at the current sampling moment, so that the pressure of the rodless chamber at the next sampling moment is within the preset pressure range. Those skilled in the art can determine the appropriate preset pressure range and the value of the preset pressure through conventional technical means such as debugging or testing so that the settings of the two can meet the above requirements, which will not be repeated here.

[0033] The embodiment of the present invention determines whether the pressure of the rodless chamber at the current sampling moment exceeds the preset pressure range when it is determined that the boom is in a downward amplitude variation motion state at the current sampling moment. When the pressure of the rodless chamber at the current sampling moment exceeds the preset pressure range, the control current of the variable pump at the next sampling moment is controlled according to the pressure of the rodless chamber at the current sampling moment, the preset pressure, the speed of the engine at the current sampling moment and the working angle of the boom at the current sampling moment. This can adjust the output displacement of the variable pump and ultimately adjust the pressure of the rodless chamber so that the pressure of the rodless chamber at the next sampling moment is within the preset pressure range, thereby ensuring that the extension speed of the anti-tilt cylinder at the next sampling moment can follow the downward amplitude variation speed of the boom, thereby ultimately achieving the purpose of ensuring the safety of boom lowering.

[0034] Specifically, the preset pressure range is, for example, 3 bar to 6 bar.

[0035] Specifically, the preset pressure ranges from 3 bar to 6 bar, for example. That is, the preset pressure can be any value between 3 bar and 6 bar, such as 3 bar, 3.5 bar, 5 bar, 6 bar and the like.

[0036] Specifically, the value of the preset pressure is, for example, 5 bar.

[0037] Specifically, the control current of the variable pump at the next sampling time is controlled according to the pressure of the rodless chamber at the current sampling time, the preset pressure, the rotation speed and the working angle, that is, step S170 includes, for example:

[0038] The control current of the variable pump at the next sampling moment is controlled according to the following formula:

[0039]

[0040] Among them, I x is the control current of the variable pump at the next sampling moment, P is the pressure of the rodless chamber at the current sampling moment, S is the area of ​​the rodless chamber, k1 is the proportional coefficient between the extension length of the anti-tilt cylinder and the working angle of the boom, θ is the working angle, P x is the preset pressure, n is the speed, and k2 is the proportional coefficient between the output displacement of the variable pump and the control current of the variable pump. The area of ​​the rodless chamber is an inherent parameter of the anti-tilt cylinder. The proportional coefficient between the extension length of the anti-tilt cylinder and the working angle of the boom, that is, the ratio of the extension length of the anti-tilt cylinder to the working angle of the boom, is a fixed parameter after the anti-tilt cylinder and the boom are installed and can be obtained by measurement. The proportional coefficient between the output displacement of the variable pump and the control current of the variable pump, that is, the ratio of the output displacement of the variable pump to the control current of the variable pump, is an inherent parameter of the variable pump.

[0041] In an embodiment of the present invention, a controller is provided, which is configured to execute the control method 100 for a crane according to any one of the aforementioned embodiments. The specific functions and details of the control method 100 for a crane can be referred to the relevant description of the aforementioned embodiments, which will not be repeated here.

[0042] Specifically, the controller may be, for example, an industrial computer, an embedded system, a microprocessor, a programmable logic device or other control device.

[0043] like Figure 2 As shown, in an embodiment of the present invention, a control device 200 for a crane is provided. The crane includes an engine, a boom, an anti-tilt cylinder and a variable pump. The control device 200 for the crane includes: a controller 201, a pressure sensor 202, an angle sensor 203 and an engine controller 204.

[0044] The controller 201 is, for example, a controller according to any of the aforementioned embodiments. The specific functions and details of the controller 201 can refer to the relevant description of the controller in the aforementioned embodiment, which will not be repeated here. The controller 201 is, for example, connected to the pressure sensor 202, the angle sensor 203, and the engine controller 204 by wire or wireless means to achieve signal connection.

[0045] The pressure sensor 202 is configured, for example, to detect the pressure of a rodless chamber of the anti-tilt cylinder.

[0046] The angle sensor 203 is configured to detect the working angle of the boom, for example.

[0047] The engine controller 204 is configured, for example, to provide the speed of the engine.

[0048] Furthermore, the crane, for example, also includes an oil tank, and the control device 200 for the crane, for example, also includes: a manual reversing valve 205, a first overflow valve 206, a second overflow valve 207, a third overflow valve 208, a throttle valve 209, a first electromagnetic reversing valve 210, a second electromagnetic reversing valve 211 and a one-way valve 212.

[0049] The first working oil port of the manual reversing valve 205 is, for example, communicated with the rodless chamber, the second working oil port of the manual reversing valve 205 is, for example, communicated with the rod chamber of the anti-tilt oil cylinder, the oil inlet of the manual reversing valve 205 is, for example, communicated with the oil outlet of the variable pump, and the oil outlet of the manual reversing valve 205 is, for example, communicated with the oil tank. The manual reversing valve 205 is, for example, used to control the telescopic function of the anti-tilt oil cylinder. The manual reversing valve 205 is, for example, a three-position four-way manual reversing valve.

[0050] The oil input port of the first relief valve 206 is, for example, connected to the rodless chamber and the rod chamber of the anti-tilt cylinder. The first relief valve 206 is, for example, used to control the maximum pressure when the anti-tilt cylinder retracts.

[0051] The oil input port of the second relief valve 207 is communicated with the rodless chamber, for example.

[0052] The input oil port of the third relief valve 208 is, for example, connected to the rodless chamber. The second relief valve 207 and the third relief valve 208 are, for example, used to control the working pressure when the anti-tilt cylinder is extended, and provide different supporting reaction forces for the anti-tilt cylinder.

[0053] The input oil port of the throttle valve 209 is, for example, connected to the output oil port of the third relief valve 208. The throttle valve 209 is, for example, used to adjust the return oil size to ensure that different return oil volumes of the anti-tilt cylinder can provide corresponding support reaction forces.

[0054] The oil input port of the first electromagnetic reversing valve 210 is communicated with the oil output port of the third relief valve 208 , for example.

[0055] The oil input port of the second electromagnetic reversing valve 211 is, for example, connected to the oil output port of the throttle valve 209. The first electromagnetic reversing valve 210 and the second electromagnetic reversing valve 211 are, for example, two-position two-way electromagnetic reversing valves, which are used to control the third relief valve 208 to select different oil return channels, thereby providing different support reaction forces for the rodless chamber of the anti-tilt cylinder.

[0056] The input oil port of the one-way valve 212 is connected to the output oil port of the first overflow valve 206, the output oil port of the second overflow valve 207, the output oil port of the first solenoid reversing valve 210 and the output oil port of the second solenoid reversing valve 211, and the output oil port of the one-way valve 212 is connected to the oil tank.

[0057] Specifically, the pressure measuring port of the pressure sensor 202 is communicated with the rodless chamber, for example, to detect the pressure of the rodless chamber.

[0058] like Figure 3 As shown, in an embodiment of the present invention, a crane 300 is provided, comprising: a control device 310, an engine 320, a boom 330, an anti-backward tilt cylinder 340, and a variable displacement pump 350. The control device 310 is, for example, a control device 200 for a crane according to any one of the aforementioned embodiments. The specific functions and details of the control device 200 for a crane can refer to the relevant description of the aforementioned embodiments, and will not be repeated here.

[0059] The anti-backward tilt cylinder 340 may be, for example, a dual-cylinder arrangement, or a single-cylinder arrangement, or a multi-cylinder arrangement.

[0060] The variable displacement pump 350 is, for example, an electric proportional variable displacement pump.

[0061] Specifically, the crane 300 is, for example, a crawler crane.

[0062] Of course, the control method 100 for a crane and the control device 200 for a crane according to the embodiment of the present invention are not limited to crawler cranes, or even to cranes. For example, they can also be extended to other engineering machinery that have anti-tilt cylinders to provide a support reaction force and thus an anti-tilt force.

[0063] The following examples are used to illustrate the control method 100 and the control device 200 for a crane according to the embodiment of the present invention. The following examples are only one of many implementation forms of the technical solution of the embodiment of the present invention, and are only used to illustrate the technical solution of the embodiment of the present invention, and are not used to limit the present invention.

[0064] The present invention provides an anti-tilt control system and control method for a crawler crane. The following only introduces the main components and control logic. For the remaining parts not described, those skilled in the art can refer to the prior art and will not be described here.

[0065] like Figure 4 As shown, the anti-tilt control system of the crawler crane of the example of the present invention mainly includes: an electric proportional variable pump 1, a three-position four-way manual reversing valve 2, an anti-tilt cylinder 3, an overflow valve 4, an overflow valve 5, an electromagnetic reversing valve 6, a throttle valve 7, an electromagnetic reversing valve 8, a one-way valve 9, an overflow valve 10, a cylinder rodless chamber pressure sensor 11, a boom angle sensor (not shown in the figure), an engine controller (not shown in the figure) and a PLC controller 12.

[0066] The pressure measuring port of the rodless chamber pressure sensor 11 is, for example, communicated with the rodless chamber of the anti-tilt cylinder 3 to measure the pressure of the rodless chamber of the anti-tilt cylinder 3 .

[0067] The boom angle sensor is used to measure the working angle of the boom.

[0068] The engine controller is used to provide the engine speed.

[0069] The first working oil port of the three-position four-way manual reversing valve 2 is, for example, connected to the rodless chamber of the anti-tilt oil cylinder 3, the second working oil port of the three-position four-way manual reversing valve 2 is, for example, connected to the rod chamber of the anti-tilt oil cylinder 3, the oil inlet of the three-position four-way manual reversing valve 2 is, for example, connected to the oil outlet of the electric proportional variable pump 1, and the oil outlet of the three-position four-way manual reversing valve 2 is, for example, connected to the oil tank. The three-position four-way manual reversing valve 2 is, for example, used to control the telescopic function of the anti-tilt oil cylinder 3.

[0070] The oil input port of the relief valve 10 is, for example, connected to the rodless chamber of the anti-tilt cylinder 3 and the rod chamber of the anti-tilt cylinder 3. The relief valve 10 is, for example, used to control the maximum pressure when the anti-tilt cylinder 3 retracts.

[0071] The oil input port of the relief valve 4 is communicated with the rodless chamber of the anti-backward tilt cylinder 3 , for example.

[0072] The input oil port of the relief valve 5 is, for example, communicated with the rodless chamber of the anti-tilt cylinder 3. The relief valve 4 and the relief valve 5 are, for example, used to control the working pressure when the anti-tilt cylinder 3 is extended, and provide different supporting reaction forces for the anti-tilt cylinder 3.

[0073] The input oil port of the throttle valve 7 is, for example, connected to the output oil port of the relief valve 5. The throttle valve 7 is, for example, used to adjust the return oil size to ensure that different return oil amounts of the anti-tilt cylinder 3 can provide corresponding support reaction forces.

[0074] The oil input port of the electromagnetic reversing valve 6 is communicated with the oil output port of the relief valve 5 , for example.

[0075] The input oil port of the electromagnetic reversing valve 8 is, for example, connected to the output oil port of the throttle valve 7. The electromagnetic reversing valve 6 and the electromagnetic reversing valve 8 are, for example, two-position two-way electromagnetic reversing valves, which are used to control the overflow valve 5 to select different return oil channels, thereby providing different support reaction forces for the rodless chamber of the anti-tilt cylinder 3.

[0076] The input oil port of the one-way valve 9 is connected to the output oil port of the overflow valve 10, the output oil port of the overflow valve 4, the output oil port of the solenoid reversing valve 6 and the output oil port of the solenoid reversing valve 8, and the output oil port of the one-way valve 9 is connected to the oil tank, for example.

[0077] The PLC controller 12 realizes signal connection with the oil cylinder rodless chamber pressure sensor 11, the boom angle sensor and the engine controller, for example, by wired or wireless means.

[0078] During the operation of the crawler crane or when the crawler crane is dismantled, the boom is luffed downward, and the anti-tilt cylinder 3 must be extended synchronously to keep the anti-tilt cylinder 3 and the boom following each other, so that the anti-tilt cylinder 3 does not separate from the boom. In order to ensure that the boom and the anti-tilt cylinder 3 are not separated, and to prevent the anti-tilt cylinder 3 from being damaged due to excessive pressure on the anti-tilt cylinder 3 due to the excessive extension speed of the anti-tilt cylinder 3, the present invention uses the following control method to ensure the safety of the crawler crane when the boom is luffed downward.

[0079] like Figure 5 As shown, in order to ensure that the anti-tilt cylinder 3 does not extend too fast, resulting in excessive reaction force of the anti-tilt cylinder 3 and too slow extension speed to detach from the boom, the PLC controller 12 will obtain the engine speed, the working angle of the boom when the boom is changed downward, and the pressure of the rodless chamber of the anti-tilt cylinder 3 in real time, and control the control current of the electric proportional variable pump 1 according to the engine speed, the working angle of the boom when the boom is changed downward, and the pressure of the rodless chamber of the anti-tilt cylinder 3, so as to control the output displacement of the electric proportional variable pump 1, and then realize the control of the pressure of the rodless chamber of the anti-tilt cylinder 3, so as to ensure the safety of the boom downward change. The main working process is as follows:

[0080] 1. The PLC controller 12 will, for example, detect whether the working angle of the boom at the current sampling moment is less than the working angle at the previous sampling moment. If so, it is determined that the boom is in a downward amplitude variation state at the current sampling moment; if not, it is determined that the boom is not in a downward amplitude variation state at the current sampling moment.

[0081] 2. When the PLC controller 12 determines that the boom is in a downward variable amplitude motion state at the current sampling time, it will detect whether the pressure of the rodless chamber of the anti-backward tilt cylinder 3 at the current sampling time is within the preset pressure range. If it is within the preset pressure range, it is determined that there is no need to adjust the control current of the electric proportional variable pump 1. If it exceeds the preset pressure range, it is determined that the control of the electric proportional variable pump 1 needs to be adjusted. In the example of the present invention, the preset pressure range is, for example, 3 bar-6 bar.

[0082] 3. When it is determined that the control of the electric proportional variable pump 1 needs to be adjusted, the PLC controller 12 will adjust the control current of the electric proportional variable pump 1 according to the engine speed at the current sampling moment, the pressure of the rodless chamber of the anti-tilt cylinder 3 at the current sampling moment, the working angle of the boom at the current sampling moment and the preset pressure, that is, determine the control current of the electric proportional variable pump 1 at the next sampling moment, so that the pressure of the rodless chamber of the anti-tilt cylinder 3 at the next sampling moment is within the preset pressure range to ensure the safety of the boom lowering.

[0083] In the example of the present invention, when it is determined that the control of the electric proportional variable pump 1 needs to be adjusted, the formula for determining the control current of the electric proportional variable pump 1 at the next sampling moment is, for example:

[0084]

[0085] Among them, I x is the control current of the electric proportional variable pump 1 at the next sampling moment, P is the pressure of the rodless chamber of the anti-tilt cylinder 3 at the current sampling moment, S is the area of ​​the rodless chamber of the anti-tilt cylinder 3, k1 is the proportional coefficient between the extension length of the anti-tilt cylinder 3 and the working angle of the boom, θ is the working angle of the boom, P x is the preset pressure, n is the engine speed, and k2 is the proportional coefficient between the output displacement of the electric proportional variable pump 1 and the control current of the electric proportional variable pump 1.

[0086] The area of ​​the rodless chamber of the anti-tilt cylinder 3 is an inherent parameter of the anti-tilt cylinder 3. The proportionality coefficient between the extension length of the anti-tilt cylinder 3 and the working angle of the boom, that is, the ratio of the extension length of the anti-tilt cylinder 3 to the working angle of the boom, is a fixed parameter after the anti-tilt cylinder 3 and the boom are installed, and can be obtained by measurement. The proportionality coefficient between the output displacement of the electric proportional variable pump 1 and the control current of the electric proportional variable pump 1, that is, the ratio of the output displacement of the electric proportional variable pump 1 to the control current of the electric proportional variable pump 1, is an inherent parameter of the electric proportional variable pump 1. The preset pressure ranges from 3bar to 6bar.

[0087] Among them, the setting of the preset pressure range can, for example, ensure that when the pressure of the rodless chamber of the anti-tilt cylinder 3 is within the preset pressure range, the extension speed of the anti-tilt cylinder 3 can follow the downward amplitude change speed of the boom, thereby ensuring the safety of the boom lowering. The setting of the preset pressure can, for example, ensure that when the pressure of the rodless chamber of the anti-tilt cylinder 3 at the current sampling moment exceeds the preset pressure range, the control current of the electric proportional variable pump 1 at the next sampling moment is controlled according to the aforementioned formula for determining the control current of the electric proportional variable pump 1 at the next sampling moment, so that the pressure of the rodless chamber of the anti-tilt cylinder 3 at the next sampling moment is within the preset pressure range. Those skilled in the art can determine the appropriate preset pressure range and the value of the preset pressure through conventional technical means such as debugging or testing so that the settings of the two can meet the aforementioned requirements, which will not be repeated here.

[0088] Compared with the solution using a metering pump, the example of the present invention can ensure the safety of the entire vehicle and prevent malfunctions caused by the boom lowering speed being too fast or too slow.

[0089] In the example of the present invention, there can be many control forms of the pressure oil source, that is, the control form of the pump, such as electric proportional control, liquid proportional control, built-in integrated control or external electric proportional or liquid proportional control, etc.; as long as the functional requirements of pump displacement proportional output or constant pressure output can be met.

[0090] To summarize, the aforementioned embodiment of the present invention can adjust the output displacement of the variable pump and further adjust the pressure of the rodless chamber by monitoring in real time whether the pressure of the rodless chamber exceeds the preset pressure range during the downward amplitude variation movement of the boom, and when the pressure of the rodless chamber exceeds the preset pressure range, adjusting the control current of the variable pump according to the pressure of the rodless chamber, the preset pressure, the engine speed and the working angle of the boom. This makes it possible to adjust the pressure of the rodless chamber at the next sampling moment, thereby ensuring that the extension speed of the anti-tilt cylinder at the next sampling moment can follow the downward amplitude variation speed of the boom, thereby achieving the stability of the support reaction force during the downward amplitude variation of the boom, ensuring the real-time response of the anti-tilt support reaction force of the whole vehicle boom system, protecting the anti-tilt cylinder from being out of the groove or having high pressure, and solving the technical problem that the anti-tilt cylinder is prone to being out of the groove or having too high pressure during the downward amplitude variation of the boom, thereby ensuring the safety of the whole vehicle when the boom is lowered.

[0091] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0092] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0093] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0094] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0095] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0096] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0097] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0098] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0099] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A control method for a crane, characterized in that: The crane comprises an engine, a boom, an anti-tilt cylinder and a variable displacement pump, and the control method comprises: Determining that the boom is in a downward amplitude variation motion state at the current sampling moment; Obtaining the pressure of the rodless chamber of the anti-backward tilt oil cylinder at the current sampling time; When the pressure of the rodless chamber at the current sampling time exceeds the preset pressure range, obtaining the preset pressure, the rotation speed of the engine at the current sampling time, and the working angle of the boom at the current sampling time; and Controlling the control current of the variable pump at the next sampling moment according to the pressure of the rodless chamber at the current sampling moment, the preset pressure, the rotation speed and the working angle, so as to adjust the pressure of the rodless chamber at the next sampling moment; The control current of the variable pump at the next sampling moment is controlled according to the pressure of the rodless chamber at the current sampling moment, the preset pressure, the rotation speed and the working angle, including: The control current of the variable pump at the next sampling moment is controlled according to the following formula: Among them, I x is the control current of the variable pump at the next sampling moment, P is the pressure of the rodless chamber at the current sampling moment, S is the area of ​​the rodless chamber, k1 is the proportional coefficient between the extension length of the anti-backward tilt cylinder and the working angle of the boom, θ is the working angle, P x is the preset pressure, n is the rotational speed, and k2 is the proportional coefficient between the output displacement of the variable pump and the control current of the variable pump.

2. The control method according to claim 1, characterized in that: The preset pressure range is 3 bar-6 bar.

3. The control method according to claim 1, characterized in that: The preset pressure ranges from 3 bar to 6 bar.

4. The control method according to claim 3, characterized in that: The preset pressure is 5 bar.

5. A controller, characterized in that: The method is configured to execute the control method for a crane according to any one of claims 1 to 4.

6. A control device for a crane, characterized in that: The crane comprises an engine, a boom, an anti-tilt cylinder and a variable displacement pump, and the control device comprises: A pressure sensor configured to detect the pressure of the rodless chamber of the anti-tilt cylinder; An angle sensor configured to detect a working angle of the boom; an engine controller configured to provide a rotational speed of the engine; and A controller according to claim 5.

7. The control device according to claim 6, characterized in that: The crane further comprises an oil tank, and the control device further comprises: A manual reversing valve, wherein the first working oil port of the manual reversing valve is communicated with the rodless chamber, the second working oil port of the manual reversing valve is communicated with the rod chamber of the anti-backward tilt cylinder, the oil inlet of the manual reversing valve is communicated with the oil outlet of the variable pump, and the oil outlet of the manual reversing valve is communicated with the oil tank; a first relief valve, wherein an oil input port of the first relief valve is connected to the rodless chamber and the rod chamber of the anti-backward tilt cylinder; a second relief valve, wherein an oil input port of the second relief valve is in communication with the rodless chamber; a third relief valve, wherein an oil input port of the third relief valve is in communication with the rodless chamber; a throttle valve, wherein an oil input port of the throttle valve is connected to an oil output port of the third relief valve; a first electromagnetic reversing valve, wherein an oil input port of the first electromagnetic reversing valve is connected to an oil output port of the third relief valve; a second electromagnetic reversing valve, wherein an oil input port of the second electromagnetic reversing valve is connected to an oil output port of the throttle valve; and A one-way valve, wherein the input oil port of the one-way valve is connected to the output oil port of the first overflow valve, the output oil port of the second overflow valve, the output oil port of the first solenoid reversing valve and the output oil port of the second solenoid reversing valve, and the output oil port of the one-way valve is connected to the oil tank.

8. A crane, characterized in that: include: engine; Boom; Anti-tilt cylinder; Variable displacement pump; as well as A control device for a crane according to claim 6 or 7.

9. The crane according to claim 8, characterized in that The crane is a crawler crane.

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