Jib amplitude control system, control method and aerial work vehicle

Abstract

The present disclosure provides a boom luffing control system, a control method, and an aerial work vehicle. The boom luffing control system includes: a hydraulic source; a luffing cylinder; a control valve group including a first control valve group disposed between the hydraulic source and the first working chamber of the luffing cylinder and a second control valve group disposed between the hydraulic source and the second working chamber of the luffing cylinder, the first control valve group and the second control valve group are respectively connected to the first working chamber and the second working chamber through a first working port and a second working port, the first control valve group is configured to control the pressure and / or flow rate of the first working port, and the second control valve group is configured to control the pressure and / or flow rate of the second working port; and a controller configured to respectively send luffing control commands to the first control valve group and the second control valve group according to the luffing action information of the boom and the pressure and / or flow rate within the boom luffing control system. The present disclosure can improve the phenomena of sinking, rebound, and vibration of the boom during the luffing action.

Description

Technical Field

[0001] The present disclosure relates to the technical field of hydraulic control, and particularly relates to a boom luffing control system, a luffing control method, and an aerial work vehicle. Background Art

[0002] The operation process of an aerial work vehicle often involves boom luffing. During the luffing movement of the boom, due to factors such as the deflection, gravity, inertia of the boom itself, and unstable pressure of the hydraulic system, the phenomenon of boom vibration may occur. When the boom luffing action starts or stops, due to the opening or closing action of the relevant control valves, the phenomenon of boom sinking or bouncing may occur.

[0003] In order to control boom luffing, in the related art, the controller adjusts the analog signal for luffing control as the control signal for the opening of the control valve according to the angle and length of the boom to adapt to the luffing movement speed under different working conditions. Due to the limitation of the control accuracy of the analog signal, although the above control method can complete the basic action of boom luffing, its effect on alleviating the vibration phenomenon of the boom during the luffing action, as well as the sinking or bouncing phenomenon of the boom when the luffing action starts or stops, is limited. Summary of the Invention

[0004] The first aspect of the present disclosure provides a boom luffing control system, including:

[0005] A hydraulic source;

[0006] A luffing cylinder configured to drive the boom to luff;

[0007] A control valve group including a first control valve group disposed between the hydraulic source and the first working chamber of the luffing cylinder and a second control valve group disposed between the hydraulic source and the second working chamber of the luffing cylinder. The first control valve group is connected to the first working chamber through a first working port, the second control valve group is connected to the second working chamber through a second working port, the first control valve group is configured to control the pressure and / or flow rate of the first working port, and the second control valve group is configured to control the pressure and / or flow rate of the second working port; and

[0008] A controller, which is signal-connected to the first control valve group and the second control valve group, and is configured to send luffing control commands for adjusting the pressure and / or flow rate of the first working port and the second working port to the first control valve group and the second control valve group respectively according to the luffing action information of the boom and the pressure and / or flow rate in the boom luffing control system.

[0009] According to some embodiments of the present disclosure,

[0010] The first control valve group includes a first pilot valve and a first hydraulically controlled valve. The first pilot valve is in signal connection with the controller and connected to the control port of the first hydraulically controlled valve. The first control valve group controls the spool position of the first hydraulically controlled valve through the first pilot valve to control the pressure and / or flow rate of the first working port.

[0011] The second control valve group includes a second pilot valve and a second hydraulically controlled valve. The second pilot valve is in signal connection with the controller and connected to the control port of the second hydraulically controlled valve. The second control valve group controls the spool position of the second hydraulically controlled valve through the second pilot valve to control the pressure and / or flow rate of the second working port.

[0012] According to some embodiments of the present disclosure, the control valve group further includes a balance valve disposed between the first control valve group and the first working chamber of the luffing cylinder. The control port of the balance valve is connected to the second working chamber of the luffing cylinder.

[0013] According to some embodiments of the present disclosure, a load feedback oil circuit is provided between the hydraulic source and the luffing cylinder.

[0014] According to some embodiments of the present disclosure, when the boom starts a luffing action, if the pressure of the first working port is lower than the pressure of the first working chamber, the controller is configured to send a first control instruction to the first control valve group to increase the pressure of the first working port until the difference from the pressure of the first working chamber is less than or equal to the error tolerance range. The luffing control instruction includes the first control instruction.

[0015] According to some embodiments of the present disclosure, when the boom performs a luffing action, the controller is configured to send a second control instruction to the first control valve group and the second control valve group to keep the flow rates of the first working port and the second working port stable. The luffing control instruction includes the second control instruction.

[0016] According to some embodiments of the present disclosure, when the boom stops a luffing action, the controller is configured to send a third control instruction to the second control valve group to gradually reduce the pressure of the second working port. The luffing control instruction includes the third control instruction.

[0017] According to some embodiments of the present disclosure, the controller is configured to allow sending the luffing control instruction to the first control valve group and the second control valve group if the outlet pressure of the hydraulic source is greater than or equal to the action threshold of the control valve group.

[0018] According to some embodiments of the present disclosure, the controller is configured to send a standby control instruction to the second control valve group to communicate the second working port with the oil return pipeline when the boom luffing control system is started, before the boom starts luffing, or after the boom stops luffing.

[0019] A second aspect of the present disclosure provides an aerial work vehicle, including the boom luffing control system described in the first aspect of the present disclosure.

[0020] A third aspect of the present disclosure provides a boom luffing control method based on the boom luffing control system described in the first aspect of the present disclosure, including: sending a luffing control instruction for adjusting the pressure and / or flow rate of the first working port and the second working port to the first control valve group and / or the second control valve group according to a luffing control signal for representing the boom luffing action information, and the pressure and / or flow rate within the boom luffing control system.

[0021] According to some embodiments of the present disclosure, sending the luffing control instruction to the first control valve group and / or the second control valve group includes:

[0022] If the pressure of the first working port is lower than the pressure of the first working chamber, send the first control instruction to the first control valve group according to a start control signal for representing the boom start luffing action, the pressure of the first working port, and the pressure of the first working chamber, so that the pressure of the first working port increases until the difference from the pressure of the first working chamber is less than or equal to the error allowable range;

[0023] Send a second control instruction to the first control valve group and the second control valve group according to a running control signal for representing the boom luffing action, the pressure and flow rate of the first working chamber, and the pressure and flow rate of the second working chamber, so that the flow rate of the first working port and the flow rate of the second working port are kept stable;

[0024] Send a third control instruction to the second control valve group according to a stop control signal for representing the boom stop luffing action and the pressure of the second working port, so that the pressure of the second working port gradually decreases.

[0025] According to some embodiments of the present disclosure, before sending the luffing control instruction to the first control valve group and / or the second control valve group, if the outlet pressure of the hydraulic source is greater than or equal to the action threshold of the control valve group, allow sending the luffing control instruction to the first control valve group and the second control valve group.

[0026] According to some embodiments of the present disclosure, the boom luffing control method further includes:

[0027] Before sending the luffing control instruction to the first control valve group and / or the second control valve group, send a standby control instruction to the second control valve group to connect the second working port to the oil return pipeline.

[0028] After sending the luffing control instruction to the first control valve group and / or the second control valve group, send a standby control instruction to the second control valve group to connect the second working port to the oil return pipeline.

[0029] In the boom luffing control system provided by the embodiments of the present disclosure, the first working chamber and the second working chamber of the luffing cylinder are respectively and independently connected to the first working port of the first control valve group and the second working port of the second control valve group. By adjusting the pressure and flow rate of the first working port and the second working port, the pressure and flow rate of the first working chamber and the second working chamber of the luffing cylinder can be independently controlled. The controller sends a luffing control instruction to the control valve group according to the requirements of the boom luffing action, in combination with the pressure and / or flow rate in the boom luffing control system, so as to achieve closed-loop control of pressure and flow rate. By controlling the boom of the aerial work vehicle to perform luffing movement through the above luffing control instruction, it is beneficial to alleviate the boom sinking or rebound phenomenon caused by the sudden change of the working chamber pressure of the luffing cylinder when the boom starts and stops luffing, and the vibration phenomenon generated due to the deflection, gravity, inertia of the boom itself and the unstable pressure of the hydraulic system during the luffing movement, and improve the smoothness of the boom luffing action.

[0030] Through the following detailed description of the exemplary embodiments of the present disclosure with reference to the accompanying drawings, other features and advantages of the present disclosure will become clear. Description of the Drawings

[0031] The accompanying drawings described herein are used to provide a further understanding of the present disclosure, and constitute a part of this application. The schematic embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation of the present disclosure. In the drawings:

[0032] Figure 1 It is a schematic hydraulic principle diagram of the boom luffing control system of some embodiments of the present disclosure.

[0033] Figure 2 It is a schematic flow diagram of the boom luffing control method of some embodiments of the present disclosure.

[0034] Figure 1 and Figure 2 in which, each reference numeral represents:

[0035] 1. Control valve group; 111. First pilot valve; 112. First hydraulic control valve; 121. Second pilot valve; 122. Second hydraulic control valve; 2. Luffing cylinder; 21. First working chamber; 22. Second working chamber; 3. Balance valve; 4. Load feedback oil circuit; A. First working port; B. Second working port. Detailed implementation manners

[0036] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part rather than all of the embodiments of the present disclosure. The description of at least one exemplary embodiment is actually only illustrative and in no way limits the present disclosure and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[0037] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and values of the components and steps set forth in these embodiments do not limit the scope of the present disclosure. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but should be regarded as part of the authorization specification when appropriate. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0038] In the description of the present disclosure, it should be understood that the use of words such as "first" and "second" to limit the components is only for the convenience of distinguishing the corresponding components. Without further statement, the above words have no special meanings, and thus cannot be construed as limiting the protection scope of the present disclosure.

[0039] In the description of the present disclosure, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal", and "top, bottom" are usually based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus cannot be construed as limiting the protection scope of the present disclosure; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0040] As Figure 1 shown, some embodiments of the present disclosure provide a boom luffing control system, including: a hydraulic source, a luffing cylinder 2, a control valve group 1, and a controller.

[0041] The luffing cylinder 2 is configured to drive the boom to luff. There may be multiple luffing cylinders 2, and the luffing cylinders 2 are arranged in parallel.

[0042] The control valve group 1 includes a first control valve group disposed between the hydraulic source and the first working chamber 21 of the luffing cylinder 2 and a second control valve group disposed between the hydraulic source and the second working chamber 22 of the luffing cylinder 2. The first control valve group is connected to the first working chamber 21 through a first working port A, and the second control valve group is connected to the second working chamber 22 through a second working port B. The first control valve group is configured to control the pressure and / or flow rate of the first working port A, and the second control valve group is configured to control the pressure and / or flow rate of the second working port B. According to the above settings, the first working chamber 21 and the second working chamber 22 of the luffing cylinder 2 are respectively and independently connected to the first working port A of the first control valve group and the second working port B of the second control valve group. By adjusting the pressure and flow rate of the first working port A and the second working port B, the pressure and flow rate of the first working chamber 21 and the second working chamber 22 of the luffing cylinder 2 can be independently controlled. To improve the control accuracy, the control valve group 1 may adopt the form of digital control cartridge valves.

[0043] The controller is signal-connected to the first control valve group and the second control valve group. The controller is configured to send luffing control commands for adjusting the pressure and / or flow rate of the first working port A and the second working port B to the first control valve group and the second control valve group respectively according to the luffing action information of the boom and the pressure and / or flow rate in the boom luffing control system. To obtain the luffing action information of the boom, such as the boom starts to luff, the boom is luffing, and the boom stops luffing, it can be achieved by collecting the control signals of the control handle. To obtain the pressure and flow rate in the boom luffing control system, pressure detection devices and flow detection devices may be provided at positions where pressure and flow rate need to be detected in the hydraulic circuit, such as the positions of the first working port A and the second working port B. The functions of the above controller can be implemented by a valve control system based on the CAN (Controller Area Network) bus.

[0044] In the boom luffing control system provided by the embodiments of the present disclosure, the first working chamber and the second working chamber of the luffing cylinder are respectively and independently connected to the first working port of the first control valve group and the second working port of the second control valve group. By adjusting the pressure and flow rate of the first working port and the second working port, the pressure and flow rate of the first working chamber and the second working chamber of the luffing cylinder can be independently controlled. The controller sends a luffing control instruction to the control valve group according to the requirements of the boom luffing action, in combination with the pressure and / or flow rate in the boom luffing control system, so as to achieve closed-loop control of pressure and flow rate. The boom is controlled to perform a luffing movement through the above luffing control instruction, which is beneficial to alleviating the boom sinking or rebounding phenomenon caused by the sudden change of the working chamber pressure of the luffing cylinder when the boom starts and stops the luffing action, and the vibration phenomenon generated due to the deflection, gravity, inertia of the boom itself and the unstable pressure of the hydraulic system during the luffing movement, and improving the smoothness of the boom luffing action.

[0045] In some embodiments, the first control valve group includes a first pilot valve 111 and a first hydraulic control valve 112. The first pilot valve 111 is signal-connected to the controller and connected to the control port of the first hydraulic control valve 112. The first control valve group controls the spool position of the first hydraulic control valve 112 through the first pilot valve 111 to control the pressure and / or flow rate of the first working port A. The second control valve group includes a second pilot valve 121 and a second hydraulic control valve 122. The second pilot valve 121 is signal-connected to the controller and connected to the control port of the second hydraulic control valve 122. The second control valve group controls the spool position of the second hydraulic control valve 122 through the second pilot valve 121 to control the pressure and / or flow rate of the second working port B. According to the above settings, the first control valve group includes a first hydraulic control valve and a first pilot valve, and the second control valve group includes a second hydraulic control valve and a second pilot valve. When the boom changes its action state, the spool positions of the first pilot valve 111 and the second pilot valve 121 change according to the luffing control instruction, the pilot control oil circuit is connected, and a hydraulic control signal corresponding to the luffing control instruction is output to the first hydraulic control valve 112 and the second hydraulic control valve 122 respectively, so as to control the pressure and flow rate of the first working port A and the second working port B by controlling the spool positions of the first hydraulic control valve 112 and the second hydraulic control valve 122.

[0046] In some embodiments, the control valve group 1 further includes a balance valve 3 disposed between the first control valve group and the first working chamber 21 of the luffing cylinder 2, and the control port of the balance valve 3 is correspondingly connected to the second working chamber 22 of the luffing cylinder 2.

[0047] In some embodiments, as one of the specific ways to adjust the flow rate of the luffing cylinder 2, a load feedback oil circuit 4 is provided between the hydraulic source and the luffing cylinder 2. The hydraulic source can adopt a load-sensitive pump.

[0048] To meet the control conditions of the first control valve group for the first working chamber 21 of the luffing cylinder 2, in some embodiments, the controller is configured such that when the boom starts a luffing operation, if the pressure at the first working port A is lower than the pressure in the first working chamber 21, a first control instruction is sent to the first control valve group to increase the pressure at the first working port A until the difference from the pressure in the first working chamber 21 is less than or equal to the allowable error range. The luffing control instruction includes the first control instruction.

[0049] To alleviate the vibration phenomenon when the boom performs a luffing operation, in some embodiments, the controller is configured to send a second control instruction to the first control valve group and the second control valve group to keep the flow rate at the first working port A and the flow rate at the second working port B stable. The luffing control instruction includes the second control instruction.

[0050] To alleviate the boom rebound phenomenon caused by the sudden drop in pressure at the second working port B when the boom luffing operation ends, in some embodiments, the controller is configured to send a third control instruction to the second control valve group when the boom stops the luffing operation to gradually reduce the pressure at the second working port B. The luffing control instruction includes the third control instruction.

[0051] To prevent the controller from malfunctioning when receiving luffing operation information in the case of no pressure or insufficient pressure in the hydraulic system, in some embodiments, the controller is configured to allow sending luffing control instructions to the first control valve group and the second control valve group if the outlet pressure of the hydraulic source is greater than or equal to the action threshold of the control valve group 1.

[0052] In some embodiments, the controller is configured to send a standby control instruction to the second control valve group before the boom starts luffing or after the boom stops luffing when the boom luffing control system is started, so that the second working port B is communicated with the oil return pipeline. At this time, the pressure at the second working port B is not sufficient to open the control port of the balance valve 3. Under the action of the balance valve 3, the first working chamber 21 of the luffing cylinder 2 cannot drain oil through the balance valve 3, which helps to alleviate the phenomenon of the piston rod of the luffing cylinder sinking when the boom is in a static state.

[0053] In some embodiments, the controller described above can be implemented as a general-purpose processor, a programmable logic controller (PLC), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or any suitable combination thereof for performing the functions described in the present disclosure.

[0054] Some embodiments of the present disclosure further provide an aerial work vehicle, including the aforementioned boom luffing control system. The aforementioned boom luffing control system can alleviate the vibration phenomenon during the luffing operation of the aerial work vehicle, as well as the sinking or rebounding phenomenon of the boom when the luffing operation starts or stops, and improve the smoothness of the luffing operation of the aerial work vehicle.

[0055] Some embodiments of the present disclosure further provide a boom luffing control method based on the aforementioned boom luffing control system, including: sending a luffing control instruction for adjusting the pressure and / or flow rate of the first working port A and the second working port B to the first control valve group and / or the second control valve group according to a luffing control signal for indicating the boom luffing operation and the pressure and / or flow rate within the boom luffing control system. The boom luffing control method is carried out based on the aforementioned boom luffing control system and has the corresponding advantages of the aforementioned boom luffing control system.

[0056] In some embodiments, sending a luffing control instruction to the first control valve group and / or the second control valve group includes: if the pressure of the first working port A is lower than the pressure of the first working chamber 21, sending a first control instruction to the first control valve group according to a start control signal for indicating the start of the boom luffing operation, the pressure of the first working port A, and the pressure of the first working chamber 21, so that the pressure of the first working port A increases until the difference from the pressure of the first working chamber 21 is less than or equal to the error tolerance range; sending a second control instruction to the first control valve group and the second control valve group according to a running control signal for indicating the boom luffing operation, the pressure and flow rate of the first working chamber 21, and the pressure and flow rate of the second working chamber 22, so that the flow rate of the first working port A and the flow rate of the second working port B are kept stable; sending a third control instruction to the second control valve group according to a stop control signal for indicating the stop of the boom luffing operation and the pressure of the second working port B, so that the pressure of the second working port B gradually decreases.

[0057] In some embodiments, before sending a luffing control instruction to the first control valve group and / or the second control valve group, if the outlet pressure of the hydraulic source is greater than or equal to the action threshold of control valve group 1, it is allowed to send a luffing control instruction to the first control valve group and the second control valve group.

[0058] In some embodiments, the boom luffing control method further includes: before sending a luffing control instruction to the first control valve group and / or the second control valve group, sending a standby control instruction to the second control valve group to connect the second working port B to the oil return pipeline; after sending a luffing control instruction to the first control valve group and / or the second control valve group, sending a standby control instruction to the second control valve group to connect the second working port B to the oil return pipeline.

[0059] The following takes Figure 2 as an example to further illustrate the boom luffing control method based on the aforementioned boom luffing control system. In the following embodiments, the action threshold of control valve group 1 is set to 15 Bar, and the error allowable range of the difference between the pressure of the first working port A and the pressure of the first working chamber 21 is set to 5 Bar.

[0060] Obtain the outlet pressure of the hydraulic source and determine whether the outlet pressure of the hydraulic source is greater than or equal to 15 Bar;

[0061] If the outlet pressure of the hydraulic source is greater than or equal to 15 Bar, send an initialization control instruction to control valve group 1 to return the spool positions of the control valves in control valve group 1 to the initial positions, and allow sending a luffing control instruction to the first control valve group and the second control valve group;

[0062] Send a standby control instruction to the second control valve group to connect the second working port B to the oil return pipeline;

[0063] Determine whether a start control signal of the control handle is collected;

[0064] If a start control signal is collected, determine whether the pressure of the first working port A is lower than the pressure of the first working chamber 21;

[0065] If the pressure of the first working port A is lower than the pressure of the first working chamber 21, send a first control instruction to the first control valve group to increase the pressure of the first working port A until the difference from the pressure of the first working chamber 21 is less than or equal to 5 Bar;

[0066] Collect the operation control signal of the control handle, and send a second control instruction to the first control valve group and the second control valve group to keep the flow rate of the first working port A and the flow rate of the second working port B stable;

[0067] Determine whether a stop control signal of the control handle is collected;

[0068] If a stop control signal is collected, send a third control instruction to the second control valve group to gradually reduce the pressure at the second working port B;

[0069] Send a standby control instruction to the second control valve group to connect the second working port B to the oil return line.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure and are not intended to limit them; although the present disclosure has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that it is still possible to modify the specific implementation manners of the present disclosure or perform equivalent replacements for some technical features, and they should all be covered by the scope of the technical solutions claimed in the present disclosure.

Claims

1. An articulated boom luffing control system, characterized in that, it includes: a hydraulic source; a luffing cylinder (2) configured to drive the articulated boom to luff; a control valve group (1) including a first control valve group disposed between the hydraulic source and the first working chamber (21) of the luffing cylinder (2) and a second control valve group disposed between the hydraulic source and the second working chamber (22) of the luffing cylinder (2), the first control valve group is connected to the first working chamber (21) through a first working port (A), the second control valve group is connected to the second working chamber (22) through a second working port (B), the first control valve group is configured to control the pressure and flow rate of the first working port (A), and the second control valve group is configured to control the pressure and flow rate of the second working port (B); and a controller, signal-connected to the first control valve group and the second control valve group, configured to send luffing control commands for adjusting the pressure and flow rate of the first working port (A) and the second working port (B) to the first control valve group and the second control valve group respectively according to the luffing action information of the articulated boom and the pressure and flow rate within the articulated boom luffing control system; wherein, the first working chamber (21) and the second working chamber (22) are respectively and separately connected to the first working port (A) and the second working port (B) to separately control the pressure and flow rate of the first working chamber (21) and the second working chamber (22) by adjusting the pressure and flow rate of the first working port (A) and the second working port (B); the control valve group (1) further includes a balance valve (3) disposed between the first control valve group and the first working chamber (21) of the luffing cylinder (2), and the control port of the balance valve (3) is connected to the second working chamber (22) of the luffing cylinder (2); the controller is configured to, when the articulated boom performs a luffing action, send a second control command to the first control valve group and the second control valve group according to the operation control signal for indicating the luffing action of the articulated boom, the pressure and flow rate of the first working chamber (21), and the pressure and flow rate of the second working chamber (22) so that the flow rate of the first working port (A) and the flow rate of the second working port (B) are kept stable, and the luffing control command includes the second control command.

2. The articulated boom luffing control system according to claim 1, characterized in that, the first control valve group includes a first pilot valve (111) and a first hydraulic control valve (112), the first pilot valve (111) is signal-connected to the controller and connected to the control port of the first hydraulic control valve (112), and the first control valve group controls the spool position of the first hydraulic control valve (112) through the first pilot valve (111) to control the pressure and flow rate of the first working port (A). The second control valve group includes a second pilot valve (121) and a second hydraulic control valve (122). The second pilot valve (121) is signal-connected to the controller and connected to the control port of the second hydraulic control valve (122). The second control valve group controls the spool position of the second hydraulic control valve (122) through the second pilot valve (121) to control the pressure and flow rate of the second working port (B).

3. The boom luffing control system according to claim 1 or 2, wherein, a load feedback oil circuit (4) is provided between the hydraulic source and the luffing cylinder (2).

4. The boom luffing control system according to claim 1, wherein, when the controller is configured that the boom starts a luffing action, if the pressure of the first working port (A) is lower than the pressure of the first working chamber (21), a first control instruction is sent to the first control valve group to increase the pressure of the first working port (A) until the difference from the pressure of the first working chamber (21) is less than or equal to the error tolerance range. The luffing control instruction includes the first control instruction.

5. The boom luffing control system according to claim 1, wherein, when the controller is configured that the boom stops a luffing action, a third control instruction is sent to the second control valve group to gradually reduce the pressure of the second working port (B). The luffing control instruction includes the third control instruction.

6. The boom luffing control system according to claim 1, wherein, the controller is configured to allow sending the luffing control instruction to the first control valve group and the second control valve group if the outlet pressure of the hydraulic source is greater than or equal to the action threshold of the control valve group (1).

7. The boom luffing control system according to claim 1, wherein, the controller is configured to send a standby control instruction to the second control valve group to connect the second working port (B) to the oil return line before the boom starts luffing or after the boom stops luffing in the state where the boom luffing control system is started.

8. An aerial work vehicle, wherein, it includes the boom luffing control system according to any one of claims 1 to 7.

9. A boom luffing control method based on the boom luffing control system according to any one of claims 1 to 7, wherein, it includes: sending a luffing control instruction for adjusting the pressure and flow rate of the first working port (A) and the second working port (B) to the first control valve group and / or the second control valve group according to a luffing control signal for representing the boom luffing action information and the pressure and flow rate in the boom luffing control system.

10. The boom luffing control method according to claim 9, wherein, sending the luffing control instruction to the first control valve group and / or the second control valve group includes: If the pressure of the first working port (A) is lower than the pressure of the first working chamber (21), a first control instruction is sent to the first control valve group according to the start control signal for indicating the start of the luffing action of the boom, the pressure of the first working port (A), and the pressure of the first working chamber (21), so as to increase the pressure of the first working port (A) until the difference from the pressure of the first working chamber (21) is less than or equal to the allowable error range; According to the operation control signal for indicating the luffing action of the boom, the pressure and flow rate of the first working chamber (21), and the pressure and flow rate of the second working chamber (22), a second control instruction is sent to the first control valve group and the second control valve group, so as to keep the flow rates of the first working port (A) and the second working port (B) stable; According to the stop control signal for indicating the stop of the luffing action of the boom and the pressure of the second working port (B), a third control instruction is sent to the second control valve group, so as to gradually reduce the pressure of the second working port (B).

11. The boom luffing control method according to claim 9, characterized in that, Before sending the luffing control instruction to the first control valve group and / or the second control valve group, if the outlet pressure of the hydraulic source is greater than or equal to the action threshold of the control valve group (1), it is allowed to send the luffing control instruction to the first control valve group and the second control valve group.

12. The boom luffing control method according to claim 9, characterized in that, further comprising: Before sending the luffing control instruction to the first control valve group and / or the second control valve group, a standby control instruction is sent to the second control valve group to connect the second working port (B) to the oil return pipeline; After sending the luffing control instruction to the first control valve group and / or the second control valve group, a standby control instruction is sent to the second control valve group to connect the second working port (B) to the oil return pipeline.

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