A wide displacement pump control system and its control method that combines high-speed segment transportation and high-precision segment docking

Abstract

This application relates to the field of hydraulic control technology for tunnel boring machine (TBM) segment assembly, and discloses a wide-displacement pump control system and its control method that balances high-speed segment transport and high-precision segment docking. The system employs parallel large-displacement and small-displacement pumps, each driven by a servo motor, which converge into the main oil circuit via a check valve and are distributed to the actuators via a three-position four-way directional valve. Each actuator is controlled by an independent switching valve group and a pilot-operated balance valve to ensure unit operation and avoid flow disturbances. The control system dynamically allocates the output ratio of the two pumps according to the target flow rate: during high-speed transport, a dual-pump joint mode is activated, initially prioritizing the rapid response of the small-displacement pump, and then switching to the large-displacement pump as the main pump; during high-precision docking, only the small-displacement pump is activated. This application significantly improves segment assembly efficiency, control accuracy, and motion stability through a dynamic flow distribution strategy, and is suitable for the synchronous requirements of high-flow, high-speed transport and low-flow, precise attitude adjustment.

Description

Technical Field

[0001] This application relates to the field of hydraulic control technology for tunnel segment assembly, and in particular to a wide displacement pump control system and its control method that takes into account both high-speed segment transportation and high-precision segment docking. Background Technology

[0002] After the tunnel boring machine (TBM) completes the tunnel excavation, it needs to construct a lining to support the tunnel walls. The lining consists of several segments distributed along the circumference of the tunnel. As an important component of the TBM, the segment assembly machine's main function is to transport the segments in a specific orientation to the target location to form the lining. Each segment has a specific position and orientation, so the segment assembly machine usually needs to complete multiple degrees of freedom of motion to complete the segment transport. Since a tunnel lining is usually composed of a large number of segments, and the installation accuracy of the segments affects the load-bearing capacity of the lining and the sealing between the segments, the segment assembly accuracy and speed directly affect the efficiency and quality of tunnel construction. Segment assembly includes two stages of motion: large-scale, rapid segment movement (translation, lifting, rotation) and small-scale, precise fine-tuning (deflection, pitching, swaying). It typically employs a system of hydraulically controlled motors with throttling speed control valves and valve-controlled hydraulic cylinders.

[0003] In actual tunnel segment assembly, the flow rate requirement for segment movement is large, while the requirement for precise fine-tuning flow rate is small, resulting in a wide range of overall flow rate demand. Relying solely on throttling control would lead to significant energy loss. Pump-controlled hydraulic systems, due to their volumetric control, eliminate throttling losses and can achieve high energy efficiency by matching power from the electro-hydraulic system's power source. The electro-hydraulic system for tunnel segment assembly typically uses a single electro-proportional variable pump paired with a variable frequency motor as the power source. However, achieving precise motion control and maintaining rapid response across the entire flow range using a single pump under fixed displacement or motor speed conditions presents considerable challenges, primarily due to the following reasons: 1) While small-displacement pumps offer fast response speeds and control accuracy, they cannot meet the high flow rate requirements of the segment assembler under normal operating conditions, resulting in slow movement speeds and low efficiency during segment movement; 2) While large-displacement pumps have a wide flow range, their slower response speed and larger controllable minimum flow rate make them unsuitable for achieving the rapid response and high assembly accuracy requirements of the segment assembler when used alone. Summary of the Invention

[0004] The purpose of this application is to provide a wide displacement pump control system and its control method that takes into account both high-speed segment transportation and high-precision segment docking. By considering the control range in which the pump control unit performs best, and combining the high-precision control of the small displacement pump and the high-speed movement of the large displacement pump, a dual-pump joint control electro-hydraulic system is constructed to achieve precise movement and rapid response across the entire flow range, thus meeting the performance requirements of high-speed transportation and high-precision docking of the segment assembly machine.

[0005] To achieve the above objectives, the following technical solution is adopted:

[0006] In a first aspect, this application provides a wide-displacement pump control system that balances high-speed segment transport and high-precision segment docking, including:

[0007] Oil tank, used to store hydraulic oil;

[0008] The large-displacement pump and the small-displacement pump are connected in parallel and driven by servo motor one and servo motor two, respectively. The inlets of the large-displacement pump and the small-displacement pump are connected to the oil tank through return oil filter one and return oil filter two pipes. The outlets of the large-displacement pump and the small-displacement pump are connected to the main oil supply line through check valve one and check valve two.

[0009] The three-position four-way directional valve has its P port connected to the main oil supply line, its T port connected to the return oil filter three, and its A and B ports connected to the actuator group.

[0010] An actuator group includes multiple actuators, each actuator including a hydraulic cylinder, a switching valve and a pilot-operated balance valve. The actuators are connected to ports A and B of the three-position four-way directional valve through the pilot-operated balance valve. The two sets of switching valves and one pilot-operated balance valve are used to independently control the action of the actuators.

[0011] The control system is used to dynamically allocate the output ratio of the large-displacement pump and the small-displacement pump according to the target flow rate, and to adopt a dual-pump combined mode when the tunnel segments are moved, and an independent mode of the small-displacement pump when the tunnel segments are connected.

[0012] Preferably, in the above-mentioned wide-displacement pump control system that balances high-speed segment transport and high-precision segment docking, the actuator group includes six actuators: a first actuator, a second actuator, a third actuator, a fourth actuator, a fifth actuator, and a sixth actuator; wherein:

[0013] The first actuator includes a swing hydraulic cylinder, a first switching valve, a second switching valve, and a first pilot-operated balance valve;

[0014] The second actuator includes a pitching hydraulic cylinder, a third switching valve, a fourth switching valve, and a second pilot-operated balance valve;

[0015] The third actuator includes a rocking hydraulic cylinder, switching valve five, switching valve six, and pilot-operated balance valve three;

[0016] The fourth actuator includes a lifting hydraulic cylinder, a switching valve seven, a switching valve eight, and a pilot-operated balance valve four.

[0017] The fifth actuator includes a transverse hydraulic cylinder, a switching valve nine, a switching valve ten, and a pilot-operated balance valve five;

[0018] The sixth actuator includes switching valve eleven, switching valve twelve, pilot-operated balance valve six, and hydraulic motor.

[0019] Preferably, in the above-mentioned wide displacement pump control system that takes into account both high-speed segment transportation and high-precision segment docking, the A port of the three-position four-way reversing valve is connected to the D port of pilot-operated balance valve one, the D port of pilot-operated balance valve two, the D port of pilot-operated balance valve three, the D port of pilot-operated balance valve four, the D port of pilot-operated balance valve five, and the D port of pilot-operated balance valve six; and the B port of the three-position four-way reversing valve is connected to the C port of pilot-operated balance valve one, the C port of pilot-operated balance valve two, the C port of pilot-operated balance valve three, the C port of pilot-operated balance valve four, the C port of pilot-operated balance valve five, and the C port of pilot-operated balance valve six.

[0020] Port A of the first switching valve is connected to port B of the first pilot-operated balance valve, and port B is connected to port B of the swing hydraulic cylinder; Port A of the second switching valve is connected to port A of the first pilot-operated balance valve, and port B is connected to port A of the swing hydraulic cylinder.

[0021] Port A of the third switching valve is connected to port B of the second pilot-operated balance valve, and port B is connected to port B of the pitch hydraulic cylinder; Port A of the fourth switching valve is connected to port A of the second pilot-operated balance valve, and port B is connected to port A of the pitch hydraulic cylinder.

[0022] The A port of the switching valve five is connected to the A port of the pilot-operated balance valve three, and the B port is connected to the B port of the rocking hydraulic cylinder; the A port of the switching valve six is ​​connected to the A port of the pilot-operated balance valve three, and the B port is connected to the A port of the rocking hydraulic cylinder.

[0023] Port A of the switching valve seven is connected to port B of the pilot-operated balance valve four, and port B is connected to port B of the lifting hydraulic cylinder; Port A of the switching valve eight is connected to port A of the pilot-operated balance valve four, and port B is connected to port A of the lifting hydraulic cylinder.

[0024] The A port of the switching valve nine is connected to the B port of the pilot-operated balance valve five, and the B port is connected to the B port of the transverse hydraulic cylinder; the A port of the switching valve ten is connected to the A port of the pilot-operated balance valve five, and the B port is connected to the A port of the transverse hydraulic cylinder.

[0025] Port A of the switching valve eleven is connected to port B of the pilot-operated balance valve six, and port B is connected to the hydraulic motor; Port A of the switching valve twelfth is connected to port A of the pilot-operated balance valve six, and port B is connected to the hydraulic motor.

[0026] Preferably, in the aforementioned wide-displacement pump control system that balances high-speed segment transport and high-precision segment docking, in the dual-pump combined mode, the control system controls the lifting hydraulic cylinder, the lateral hydraulic cylinder, and the hydraulic motor. When controlling the lifting hydraulic cylinder, switching valves seven and eight are in the right position, while the two switching valves of all other actuators are in the left position. When the lifting hydraulic cylinder extends, the three-position four-way directional valve is in the right position, and hydraulic oil flows in through port P and out through port B of the three-position four-way directional valve, then enters port B of the lifting hydraulic cylinder via switching valve seven. When the lifting hydraulic cylinder retracts, the three-position four-way directional valve is in the left position, and hydraulic oil flows in through port P and out through port A of the three-position four-way directional valve, then enters port B of the lifting hydraulic cylinder via switching valve eight. By sequentially controlling the two switching valves corresponding to the lifting hydraulic cylinder, the lateral hydraulic cylinder, and the hydraulic motor, the lifting and lateral movement of the segments are achieved, thereby realizing high-speed transport of the segments.

[0027] Preferably, in the aforementioned wide-displacement pump control system that balances high-speed segment transport and high-precision segment docking, in the independent mode of the small-displacement pump, the control system controls the swaying hydraulic cylinder, the pitching hydraulic cylinder, and the roll hydraulic cylinder. When controlling the swaying hydraulic cylinder, switch valve one and switch valve two are in the right position, and the two switch valves of all other actuators are in the left position. When the swaying hydraulic cylinder extends, the three-position four-way directional valve is in the right position, and hydraulic oil flows in through port P and out through port B of the three-position four-way directional valve, and enters port B of the swaying hydraulic cylinder through switch valve one. When the swaying hydraulic cylinder retracts, the three-position four-way directional valve is in the left position, and hydraulic oil flows in through port P and out through port A of the three-position four-way directional valve, and enters port A of the swaying hydraulic cylinder through switch valve two. By sequentially controlling the two switch valves corresponding to the swaying, pitching, and roll hydraulic cylinders, the swaying, pitching, and roll actions of the segments are realized, thereby achieving high-precision segment docking.

[0028] Preferably, in the above-mentioned wide-displacement pump control system that balances high-speed segment transport and high-precision segment docking, the control system includes a mode controller, which determines the dual-pump operating mode based on the target flow rate:

[0029] When the target flow rate is less than the set threshold, only the small displacement pump is activated to output high-precision flow rate.

[0030] When the target flow rate is greater than or equal to the set threshold, the dual-pump combined mode is activated, and the small displacement pump is given priority in output within the preset switching time, and then the output is switched to the large displacement pump.

[0031] Preferably, in the wide displacement pump control system that combines high-speed segment transportation and high-precision segment docking, in the dual-pump joint mode, the flow output ratio of the small displacement pump to the large displacement pump is 9:1 before the preset switching time and is adjusted to 4:6 after the preset switching time.

[0032] Preferably, in the aforementioned wide-displacement pump control system that balances high-speed segment transport and high-precision segment docking, the control system includes an expert recommendation system. This system is equipped with a database that stores the mapping relationship between input parameters and output parameters. This mapping relationship is established using a machine learning algorithm, such as a backpropagation neural network or a nearest neighbor algorithm. The input parameters include segment specifications, small pump displacement, large pump displacement, lifting hydraulic cylinder specifications, lateral hydraulic cylinder specifications, swing hydraulic cylinder specifications, pitch hydraulic cylinder specifications, roll hydraulic cylinder specifications, and hydraulic motor specifications. The output parameters include a preset switching time, switching flow rate, and the flow output ratio between the small and large pumps.

[0033] Secondly, this application provides a control method for a wide displacement pump control system that combines high-speed segment transport and high-precision segment docking, as described above. The control method includes:

[0034] The operating mode is determined based on the target flow rate: if the target flow rate is a high flow rate requirement, the dual-pump joint control mode is entered; if the target flow rate is a low flow rate requirement, the small-displacement pump independent mode is entered.

[0035] In dual-pump combined mode, the small displacement pump and the large displacement pump are controlled to output flow according to a preset ratio, and the ratio is adjusted after a preset switching time.

[0036] The actuator for the current action is selected by switching the valve group, ensuring that only one actuator works at a time;

[0037] Real-time acquisition of actuator displacement data, and correction of the dual-pump output ratio through closed-loop control algorithm to ensure that displacement tracking error is less than the set threshold.

[0038] Furthermore, the closed-loop control algorithm is PID control, adaptive control, or robust control.

[0039] The beneficial effects of this application are:

[0040] 1) This application utilizes a dual-pump parallel design, coupled with a dual-pump flow dynamic allocation strategy, to meet the dual requirements of high-speed segment transport and high-precision segment docking for the segment assembly machine. In the wide-displacement segment assembly control system, the various parameters in the dynamic allocation strategy can form a control parameter database, and an expert recommendation system can be established through machine learning algorithms to provide guidance for the automated assembly of wide-displacement pump-controlled segments.

[0041] 2) This application adopts a parallel dual-speed pump control system as the power source of the segment assembly machine to meet the wide displacement control requirements of the segment assembly machine for high-speed segment transportation and high-precision segment docking;

[0042] 3) This application does not require the use of a throttling valve control module, and avoids pressure and flow disturbances caused by the simultaneous movement of different actuators during the transfer and docking of pipe segments by using a switching valve group, which greatly improves control accuracy, motion stability and system energy efficiency;

[0043] 4) This application can adjust the switching between single small displacement pump and dual pump control modes in real time, as well as the switching ratio and switching time of the flow output of small displacement pump and large displacement pump in dual pump control mode, which greatly improves the control accuracy and dynamic response capability of the system.

[0044] 5) This application establishes a control parameter database and an expert recommendation system for a wide-flow dual-pump control system, which can recommend various control parameters of the dual-pump dynamic allocation strategy in real time, and realize the automatic control of the segment assembly machine under unattended operation. Attached Figure Description

[0045] Figure 1 A schematic diagram of a wide-displacement pump control system according to an embodiment of this application is shown. This system combines high-speed segment transportation and high-precision segment docking.

[0046] Figure 2 The diagram illustrates the working principle of a control system in a wide-displacement pump control system that combines high-speed segment transportation and high-precision segment docking according to an embodiment of this application.

[0047] Figure label:

[0048] 1-Oil tank; 2-Return oil filter one; 3-Return oil filter two; 4-Servo motor two; 5-Small displacement pump; 6-Servo motor one; 7-Large displacement pump; 8-Check valve one; 9-Check valve two; 10-Relief valve; 11-Level and temperature gauge; 12-Return oil filter three; 13-Three-position four-way directional valve; 14-Swing hydraulic cylinder; 15-Switch valve one; 16-Switch valve two; 17-Pilot-operated balance valve one; 18-Pitch hydraulic cylinder; 19-Switch valve three; 20- 21-Pilot-operated balance valve 2; 22-Rolling hydraulic cylinder; 23-Pilot-operated valve 5; 24-Pilot-operated valve 6; 25-Pilot-operated balance valve 3; 26-Lifting hydraulic cylinder; 27-Pilot-operated valve 7; 28-Pilot-operated valve 8; 29-Pilot-operated balance valve 4; 30-Transverse hydraulic cylinder; 31-Pilot-operated valve 9; 32-Pilot-operated valve 10; 33-Pilot-operated balance valve 5; 34-Pilot-operated valve 11; 35-Pilot-operated valve 12; 36-Pilot-operated balance valve 6; 37-Hydraulic motor. Detailed Implementation

[0049] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0050] The specific implementation methods of this application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0051] Example 1:

[0052] This application provides a wide-displacement pump control system that balances high-speed segment transportation and high-precision segment docking, such as... Figure 1 As shown, this wide-displacement pump control system, which combines high-speed segment transportation and high-precision segment docking, includes an oil tank 1, a large-displacement pump 7, a small-displacement pump 5, a three-position four-way directional valve 13, an actuator group, and a control system. The oil tank 1 is used to store hydraulic oil and is equipped with a level and temperature gauge 11. The large-displacement pump 7 and the small-displacement pump 5, which are arranged in parallel, are driven by servo motor 6 and servo motor 4, respectively. The inlets of the large-displacement pump 7 and the small-displacement pump 5 are connected to the oil tank through return oil filter 2 and return oil filter 3, respectively. The outlets of the large-displacement pump 7 and the small-displacement pump 5 are connected to the main oil supply line through check valve 8 and check valve 9, respectively. The three-position four-way directional valve 13... The P port connects to the main oil supply line, the T port connects to the return oil filter 12, and the A and B ports are connected to the actuator group through multiple pilot-operated balance valves. The actuator group includes multiple actuators, each of which includes a hydraulic cylinder, a switching valve, and a pilot-operated balance valve. The actuators are connected to the A and B ports of the three-position four-way directional valve 13 through the pilot-operated balance valves. The two sets of switching valves and one pilot-operated balance valve are used to independently control the action of the actuators. The control system dynamically allocates the output ratio of the large-displacement pump 7 and the small-displacement pump 5 according to the target flow rate, and adopts a dual-pump combined mode during high-speed transportation and a small-displacement pump independent mode during high-precision docking.

[0053] In some embodiments, the group of actuators includes six actuators, namely a first actuator, a second actuator, a third actuator, a fourth actuator, a fifth actuator, and a sixth actuator. Specifically, as... Figure 1As shown, the actuator group includes a rocking hydraulic cylinder 14, a switching valve 15, a switching valve 2 16, a pilot-operated balance valve 1 17, a pitching hydraulic cylinder 18, a switching valve 3 19, a switching valve 4 20, a pilot-operated balance valve 2 21, a lateral hydraulic cylinder 22, a switching valve 5 23, a switching valve 6 24, a pilot-operated balance valve 3 25, a lifting hydraulic cylinder 26, a switching valve 7 27, a switching valve 8 28, a pilot-operated balance valve 4 29, a lateral hydraulic cylinder 30, a switching valve 9 31, a switching valve 10 32, a pilot-operated balance valve 5 33, a switching valve 11 34, a switching valve 12 35, a pilot-operated balance valve 6 36, and a hydraulic motor 37; the servo motor 2 4 is connected to a small displacement pump 5, the hydraulic oil inlet of the small displacement pump 5 is connected to the oil tank through a return oil filter 1, and the hydraulic oil outlet is connected to a one-way valve. Valve 1 (inlet 8); Servo motor 1 (6) is connected to large displacement pump 7. The hydraulic oil inlet of large displacement pump 7 is connected to the oil tank through return oil filter 3. The hydraulic oil outlet of large displacement pump 7 is connected to the inlet of check valve 2 (9). The P port of three-position four-way directional valve 13 is connected to the outlet of check valve 1 (8), the outlet of check valve 2 (9), and the inlet of relief valve 10. The T port is connected to the outlet of relief valve 10 and return oil filter 3 (12). The A port is connected to the D port of pilot-operated balance valve 1 (17), pilot-operated balance valve 2 (21), pilot-operated balance valve 3 (25), pilot-operated balance valve 4 (29), pilot-operated balance valve 5 (33), and pilot-operated balance valve 6 (36). The B port is connected to the C port of pilot-operated balance valve 1 (17), pilot-operated balance valve 2 (21), and pilot-operated balance valve 3 (25). The C ports of the pilot balance valve 4 (29), pilot balance valve 5 (33), and pilot balance valve 6 (36) are connected; the A port of the switching valve 1 (15) is connected to the B port of the pilot balance valve 1, and the B port is connected to the B port of the rocking hydraulic cylinder 14; the A port of the switching valve 2 (16) is connected to the A port of the pilot balance valve 1, and the B port is connected to the A port of the rocking hydraulic cylinder; the A port of the switching valve 3 (19) is connected to the B port of the pilot balance valve 2 (21), and the B port is connected to the B port of the pitch hydraulic cylinder 18; the A port of the switching valve 4 (20) is connected to the A port of the pilot balance valve 2 (21), and the B port is connected to the A port of the pitch hydraulic cylinder; the A port of the switching valve 5 (23) is connected to the A port of the pilot balance valve 3 (25), and the B port is connected to the B port of the rocking hydraulic cylinder 22; the A port of the switching valve 6 (24) is connected to the pilot balance valve... Port A and Port B of valve 25 are connected to port A of hydraulic cylinder 22; Port A of valve 27 is connected to port B of pilot-operated balance valve 29, and port B is connected to port B of lifting hydraulic cylinder 26; Port A of valve 28 is connected to port A of pilot-operated balance valve 29, and port B is connected to port A of lifting hydraulic cylinder 26; Port A of valve 31 is connected to port B of pilot-operated balance valve 33, and port B is connected to port B of lateral hydraulic cylinder 30; Port A of valve 32 is connected to port A of pilot-operated balance valve 33, and port B is connected to port A of lateral hydraulic cylinder 30; Port A of valve 34 is connected to port B of pilot-operated balance valve 36, and port B is connected to hydraulic motor 37; Port A of valve 35 is connected to port A of pilot-operated balance valve 36, and port B is connected to hydraulic motor 37.

[0054] During high-speed segment transport, a dual-pump combined mode is adopted, with the lifting hydraulic cylinder 26, the lateral hydraulic cylinder 30, and the hydraulic motor 37 controlled by the control system. When controlling the lifting hydraulic cylinder 26, the switching valves 27 and 28 are in the right position, while the two switching valves of all other actuators are in the left position. When the lifting hydraulic cylinder extends, the dual-pump station is set to dual-pump combined mode, with the three-position four-way directional valve 13 in the right position. Hydraulic oil flows in through port P and flows out through port B of the three-position four-way directional valve 13, entering port B of the lifting hydraulic cylinder 26 via the switching valve 7. When the lifting hydraulic cylinder retracts, the dual-pump station is set to dual-pump combined mode, with the three-position four-way directional valve 13 in the left position. Hydraulic oil flows in through port P and flows out through port A of the three-position four-way directional valve 13, entering port A of the lifting hydraulic cylinder via the switching valve 8. By sequentially controlling the two switching valves corresponding to the lifting hydraulic cylinder 26, the lateral hydraulic cylinder 30, and the hydraulic motor 37, the lifting and lateral movement of the segments are achieved, thus realizing high-speed segment transport.

[0055] When performing high-precision segment docking, a small-displacement pump independent mode is adopted, and the swing hydraulic cylinder 14, pitch hydraulic cylinder 18, and roll hydraulic cylinder 22 are controlled by the control system. When controlling the swing hydraulic cylinder 14, the first switch valve 15 and the second switch valve 16 are in the right position, and the two switch valves of all other actuators are in the left position. When the swing hydraulic cylinder 14 is extended, the dual pump station is set to the small-flow, small-pump independent working mode, the three-position four-way directional valve 13 is in the right position, and the hydraulic oil flows in through the P port and flows out through the B port of the three-position four-way directional valve 13, and enters the B port of the swing hydraulic cylinder 14 through the first switch valve; when the swing hydraulic cylinder is retracted, the dual pump station is set to the small-displacement, small-pump individual working mode, the three-position four-way directional valve 13 is in the left position, and the hydraulic oil flows in through the P port and flows out through the A port of the three-position four-way directional valve 13, and enters the A port of the swing hydraulic cylinder through the second switch valve. By sequentially controlling the two switching valves below the swing hydraulic cylinder 14, pitch hydraulic cylinder 18, and roll hydraulic cylinder 22, the segment swings, pitches, and rolls are achieved, thereby realizing high-precision segment docking.

[0056] Through the above operations, the wide-displacement pump control system proposed in this application operates with only one actuator, ensuring that pressure and flow disturbances caused by different actuators during segment transfer and splicing are eliminated, significantly improving the control accuracy and stability of segment assembly. The workflow is as follows: High-speed segment transfer is prioritized, i.e., controlling the lifting hydraulic cylinder 26, the lateral hydraulic cylinder 30, and the hydraulic motor 37. When controlling the lifting hydraulic cylinder 26, its two corresponding lower valves are in the right position, while the two valves of all other actuators are in the left position. Lifting, lateral movement, and rotation are completed sequentially, requiring high speed and precision during the movement process, i.e., a high-flow dual-pump combined working mode. Next, high-precision docking is performed, i.e., controlling the swing hydraulic cylinder 14, the pitch hydraulic cylinder 18, and the roll hydraulic cylinder 22. Similarly, when controlling the swing hydraulic cylinder 14, its two corresponding lower valves are in the right position, while the two valves of all other actuators are in the left position. Swinging, pitching, and roll movements are completed sequentially, requiring high speed and precision during the movement process, i.e., a small-flow small-pump independent working mode. Through the above operations, the wide displacement pump control system moves only one actuator at a time, ensuring that the pressure and flow disturbances caused by the simultaneous movement of different actuators during the segment transfer and docking process are eliminated, thus greatly improving control accuracy and stability.

[0057] In some embodiments, for a control system that controls the flow rate of a dual-pump station, please refer to... Figure 2As shown, firstly, dual-pump tracking performance tests were conducted under different desired hydraulic cylinder speeds to determine the flow range within which the small-displacement pump 5 could maintain control accuracy. As an example of this invention, the small-displacement pump 5 and the large-displacement pump 7 are gear pumps with displacements of 3.9 ml / rev and 7.8 ml / rev, respectively. The piston diameter, piston rod diameter, and stroke of the hydraulic cylinders are 90 / 63 / 130 mm. Through testing, it was found that within the desired hydraulic cylinder speed range of 1–7 mm / s, the small-displacement pump 5 could ensure control accuracy at a maximum desired hydraulic cylinder speed of 7 mm / s. When the desired hydraulic cylinder speed reached 8 mm / s, the control of the small-displacement pump 5 diverged, and the large-displacement pump 7 exhibited significant oscillation. At this point, a dual-pump joint control mode should be entered, using the small-displacement pump 5 to correct and optimize the flow output of the large-displacement pump 7, thereby improving the response speed and control accuracy of the pump control system in the high flow range. In the high-flow-range dual-pump joint control, considering the fast response and high control accuracy of the small-displacement pump 5, the output flow of the small-displacement pump 5 is prioritized to compensate for the slower start-up speed of the large-displacement pump 7. After a set switching time t1, the output flow of the large-displacement pump 7 is prioritized to maintain the high flow required for system operation, while the small-displacement pump 5 is only used to correct flow errors, thus achieving the pump control system's requirements for both high-speed segment transportation and high-precision segment docking. The flow output ratio a1:b1 of the small-displacement pump 5 and the large-displacement pump 7 before the switching time t1, and the flow output ratio a2:b2 of the small-displacement pump 5 and the large-displacement pump 7 after the switching time t1, need to be determined experimentally.

[0058] As an example of the present invention, under the dual-pump joint control strategy, the optimal switching time t1 is determined to be 2 seconds. Before the switching time is reached, the optimal flow output ratio of the small displacement pump 5 and the large displacement pump 7 is a1:b1 = 9:1, and after the switching time is reached, the optimal flow output ratio of the small displacement pump 5 and the large displacement pump 7 is a2:b2 = 4:6.

[0059] The control system includes a mode controller, which determines the dual-pump operating mode by judging the target flow rate q1. If it is in the low flow range, the small displacement pump is controlled and outputs the flow separately; if it is in the high flow range, the optimal switching time and flow output ratio are found through experimental testing, and then the dual pumps are controlled by PID control modules respectively. PID is only one example of this invention; algorithms such as adaptive control and robust control are also applicable.

[0060] In some embodiments, the control system includes an expert recommendation system configured with a database. The database stores the mapping relationship between input parameters and output parameters. The input parameters include: segment specifications, small pump displacement, large pump displacement, lifting hydraulic cylinder specifications, lateral hydraulic cylinder specifications, sway hydraulic cylinder specifications, pitch hydraulic cylinder specifications, and roll hydraulic cylinder specifications, as well as hydraulic motor specifications. Output parameters include: switching time t1, switching flow rate q1, small pump to large pump flow output ratio a1:b1, and small pump to large pump flow output ratio a2:b2. During the parameter adjustment process for each different segment assembly hydraulic system, the maximum and average displacement tracking errors of the actuators are used as the optimization criteria to determine the above output parameters, which are then uploaded to the control parameter database synchronously with the input parameters. As the database dimension increases, machine learning algorithms are used to establish the input-output mapping relationship, such as the nearest neighbor algorithm and backpropagation neural network, to form the expert recommendation system. In the new tunnel segment assembly control system, given its specific input parameters, the expert recommendation system will provide the optimal control parameters.

[0061] In summary, this wide-displacement pump control system, which balances high-speed segment transport and high-precision segment docking, meets the requirements for stability, response speed, and high precision. This system primarily achieves flow output by dynamically distributing errors between a large-displacement pump and a small-displacement pump. The introduction of this wide-displacement pump control hydraulic system brings several advantages: First, it effectively improves system response speed. Even in a large flow range, by increasing the output proportion of the small-displacement pump in the initial stage of system operation, the slow response speed of the large-displacement pump is avoided. Second, considering that in medium and large flow ranges, the controllable minimum displacement of the large-displacement pump is too large to meet the high precision requirements of the system, the intervention of the small-displacement pump corrects the system control precision, achieving high-precision output from the wide-flow-range pump control system to ensure that the segment assembly machine maintains high precision during high-speed transport. Third, it dynamically adjusts the output proportion of the two pumps in different flow ranges, rather than using a simple control mode of a small-displacement pump for small-displacement output and a large-displacement pump for large-displacement output. A dynamic adjustment control method for the two pumps is proposed to achieve high-precision pump control across a wide displacement range.

[0062] Example 2:

[0063] This application provides a control method for a wide displacement pump control system that combines high-speed segment transport and high-precision segment docking as described in any embodiment of Embodiment 1. The control method includes the following steps:

[0064] S1: Determine the working mode based on the target flow rate: If the target flow rate is a high flow rate requirement, enter the dual-pump joint control mode; if it is a low flow rate requirement, enter the small displacement pump independent mode.

[0065] S2: In dual-pump combined mode, control the small displacement pump and the large displacement pump to output flow according to a preset ratio, and adjust the ratio after a preset switching time;

[0066] S3: Select the actuator for the current action by switching the valve group to ensure that only one actuator works at a time;

[0067] S4: Real-time acquisition of actuator displacement data, and correction of the dual-pump output ratio through closed-loop control algorithm to ensure that the displacement tracking error is less than the set threshold.

[0068] In some embodiments, the closed-loop control algorithm is PID control, adaptive control, or robust control.

[0069] In some embodiments, the maximum value of the displacement tracking error does not exceed ±0.5 mm.

[0070] In some embodiments, the expert recommendation system recommends switching time (t1), flow threshold (q1), and dual-pump flow ratio in real time based on input parameters to achieve unattended automated control.

[0071] The above embodiments are only used to illustrate this application and are not intended to limit this application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this application. Therefore, all equivalent technical solutions also fall within the scope of this application, and the patent protection scope of this application should be defined by the claims.

Claims

1. A wide-displacement pump control system that combines high-speed segment transportation and high-precision segment docking, characterized in that, include: Oil tank, used to store hydraulic oil; The large-displacement pump and the small-displacement pump are connected in parallel and driven by servo motor one and servo motor two, respectively. The inlets of the large-displacement pump and the small-displacement pump are connected to the oil tank through return oil filter one and return oil filter two pipes. The outlets of the large-displacement pump and the small-displacement pump are connected to the main oil supply line through check valve one and check valve two. The three-position four-way directional valve has its P port connected to the main oil supply line, its T port connected to the return oil filter three, and its A and B ports connected to the actuator group. An actuator group includes multiple actuators, each actuator including a hydraulic cylinder, a switching valve and a pilot-operated balance valve. The actuator is connected to port A and port B of the three-position four-way directional valve through the pilot-operated balance valve. Two sets of switching valves and one pilot-operated balance valve are used to independently control the action of the actuator. The control system is used to dynamically allocate the output ratio of the large-displacement pump and the small-displacement pump according to the target flow rate, and to adopt a dual-pump combined mode when the tunnel segment is moved, and an independent mode of the small-displacement pump when the tunnel segment is connected. The control system includes a mode controller, which determines the dual-pump operating mode based on the target flow rate. When the target flow rate is less than the set threshold, only the small displacement pump is activated to output high-precision flow. When the target flow rate is greater than or equal to the set threshold, the dual-pump combined mode is activated, and the small displacement pump is given priority in output during the preset switching time. After the preset switching time is reached, the output is switched to the large displacement pump.

2. The wide-displacement pump control system as described in claim 1, which combines high-speed segment transportation and high-precision segment docking, is characterized in that... The actuator group comprises six actuators, namely, a first actuator, a second actuator, a third actuator, a fourth actuator, a fifth actuator, and a sixth actuator; wherein: The first actuator includes a swing hydraulic cylinder, a first switching valve, a second switching valve, and a first pilot-operated balance valve; The second actuator includes a pitch hydraulic cylinder, a third switching valve, a fourth switching valve, and a second pilot-operated balance valve; The third actuator includes a rocking hydraulic cylinder, switching valve five, switching valve six, and pilot-operated balance valve three; The fourth actuator includes a lifting hydraulic cylinder, a switching valve seven, a switching valve eight, and a pilot-operated balance valve four. The fifth actuator includes a transverse hydraulic cylinder, a switching valve nine, a switching valve ten, and a pilot-operated balance valve five; The sixth actuator includes switching valve eleven, switching valve twelve, pilot-operated balance valve six, and hydraulic motor.

3. The wide-displacement pump control system as described in claim 2, which combines high-speed segment transportation and high-precision segment docking, is characterized in that... Port A of the three-position four-way directional valve is connected to Port D of pilot-operated balance valve one, port D of pilot-operated balance valve two, port D of pilot-operated balance valve three, port D of pilot-operated balance valve four, port D of pilot-operated balance valve five, and port D of pilot-operated balance valve six. Port B of the three-position four-way directional valve is connected to Port C of pilot-operated balance valve one, port C of pilot-operated balance valve two, port C of pilot-operated balance valve three, port C of pilot-operated balance valve four, port C of pilot-operated balance valve five, and port C of pilot-operated balance valve six. Port A of the first switching valve is connected to port B of the first pilot-operated balance valve, and port B of the first switching valve is connected to port B of the swing hydraulic cylinder; Port A of the second switching valve is connected to port A of the first pilot-operated balance valve, and port B of the second switching valve is connected to port A of the swing hydraulic cylinder. Port A of the third switching valve is connected to port B of the second pilot-operated balance valve, and port B of the third switching valve is connected to port B of the pitch hydraulic cylinder; Port A of the fourth switching valve is connected to port A of the second pilot-operated balance valve, and port B of the fourth switching valve is connected to port A of the pitch hydraulic cylinder. Port A of the switching valve five is connected to port A of the pilot-operated balance valve three, and port B of the switching valve five is connected to port B of the rocking hydraulic cylinder; port A of the switching valve six is ​​connected to port A of the pilot-operated balance valve three, and port B of the switching valve six is ​​connected to port A of the rocking hydraulic cylinder. Port A of the switching valve seven is connected to port B of the pilot-operated balance valve four, and port B of the switching valve seven is connected to port B of the lifting hydraulic cylinder; port A of the switching valve eight is connected to port A of the pilot-operated balance valve four, and port B of the switching valve eight is connected to port A of the lifting hydraulic cylinder. Port A of the switching valve nine is connected to port B of the pilot-operated balance valve five, and port B of the switching valve nine is connected to port B of the transverse hydraulic cylinder; port A of the switching valve ten is connected to port A of the pilot-operated balance valve five, and port B of the switching valve ten is connected to port A of the transverse hydraulic cylinder. Port A of the switching valve eleven is connected to port B of the pilot-operated balance valve six, and port B of the switching valve eleven is connected to the hydraulic motor; port A of the switching valve twelfth is connected to port A of the pilot-operated balance valve six, and port B of the switching valve twelfth is connected to the hydraulic motor.

4. The wide-displacement pump control system as described in claim 2 or 3, which combines high-speed segment transportation and high-precision segment docking, is characterized in that... In the dual-pump combined mode, the control system controls the lifting hydraulic cylinder, the lateral hydraulic cylinder, and the hydraulic motor. When controlling the lifting hydraulic cylinder, switching valves seven and eight are in the right position, while the two switching valves of all other actuators are in the left position. When the lifting hydraulic cylinder extends, the three-position four-way directional valve is in the right position, and hydraulic oil flows in through port P and out through port B, then enters port B of the lifting hydraulic cylinder via switching valve seven. When the lifting hydraulic cylinder retracts, the three-position four-way directional valve is in the left position, and hydraulic oil flows in through port P and out through port A, then enters port A of the lifting hydraulic cylinder via switching valve eight. By sequentially controlling the two switching valves corresponding to the lifting hydraulic cylinder, the lateral hydraulic cylinder, and the hydraulic motor, the lifting and lateral movement of the tunnel segment is achieved, thereby realizing the high-speed transportation of the tunnel segment.

5. The wide-displacement pump control system as described in claim 2 or 3, which combines high-speed segment transportation and high-precision segment docking, is characterized in that... In the independent mode of the small displacement pump, the control system controls the swaying hydraulic cylinder, the pitching hydraulic cylinder, and the roll hydraulic cylinder. When controlling the swaying hydraulic cylinder, switch valve one and switch valve two are in the right position, and the two switch valves of all other actuators are in the left position. When the swaying hydraulic cylinder extends, the three-position four-way directional valve is in the right position, and hydraulic oil flows in through port P and out through port B of the three-position four-way directional valve, and enters port B of the swaying hydraulic cylinder through switch valve one. When the swaying hydraulic cylinder retracts, the three-position four-way directional valve is in the left position, and hydraulic oil flows in through port P and out through port A of the three-position four-way directional valve, and enters port A of the swaying hydraulic cylinder through switch valve two. By sequentially controlling the two switch valves below the swaying hydraulic cylinder, the pitching hydraulic cylinder, and the roll hydraulic cylinder, the swaying, pitching, and roll actions of the tunnel segments are realized, thereby achieving high-precision docking of the tunnel segments.

6. The wide-displacement pump control system as described in claim 1, which combines high-speed segment transportation and high-precision segment docking, is characterized in that... In the dual-pump combined mode, the flow output ratio of the small displacement pump to the large displacement pump is 9:1 before the preset switching time and is adjusted to 4:6 after the preset switching time.

7. The wide displacement pump control system as described in claim 1, which combines high-speed segment transportation and high-precision segment docking, is characterized in that... The control system includes an expert recommendation system, which is equipped with a database. The database stores the mapping relationship between input parameters and output parameters. The mapping relationship between input parameters and output parameters is established through a machine learning algorithm, which is either a backpropagation neural network or a nearest neighbor algorithm. The input parameters include the specifications of the tunnel segment, the displacement of the small pump, the displacement of the large pump, the specifications of the lifting hydraulic cylinder, the specifications of the lateral hydraulic cylinder, the specifications of the swing hydraulic cylinder, the specifications of the pitch hydraulic cylinder, the specifications of the roll hydraulic cylinder, and the specifications of the hydraulic motor. The output parameters include the preset switching time, the switching flow rate, and the output ratio of the small pump to the large pump.

8. A control method for a wide displacement pump control system that combines high-speed segment transport and high-precision segment docking as described in any one of claims 1 to 7, characterized in that, The control method includes: The operating mode is determined based on the target flow rate: if the target flow rate is a high flow rate requirement, the dual-pump joint control mode is entered; if the target flow rate is a low flow rate requirement, the small-displacement pump independent mode is entered. In dual-pump combined mode, the small displacement pump and the large displacement pump are controlled to output flow according to a preset ratio, and the ratio is adjusted after a preset switching time. The actuator for the current action is selected by switching valve groups to ensure that only one actuator works at a time; Real-time acquisition of actuator displacement data, and correction of the dual-pump output ratio through closed-loop control algorithm to ensure that displacement tracking error is less than the set threshold.

9. The control method as described in claim 8, characterized in that, The closed-loop control algorithm is PID control, adaptive control, or robust control.

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