Coplanar constraint-based intelligent balanced distribution method for shield tunneling thrusts and oil pressures in four partitions

Abstract

Disclosed is a coplanar constraint-based intelligent balanced distribution method for shield tunneling thrusts and oil pressures in four partitions, which method aims for balanced distribution of thrusts / oil pressures of propulsion systems of four-partition shield tunneling machines. The method comprises: after relevant parameters are determined, by using a spatial hexahedral geometric model, establishing a constraint formula under the condition that thrust / oil pressure vector endpoints of propulsion mechanisms are coplanar; and solving the thrust / oil pressure in each partition according to equivalent relationships, i.e., the sum of moments of the thrusts in four partitions relative to an origin being equal to a target deviation-correction moment, and the sum of the thrusts in the four partitions being equal to a target total thrust Ff. The distribution process is accurate and efficient, and a final distribution result can meet the requirements of the target total thrust and the target deviation-correction moment; in addition, the balance of the distribution result can also be ensured, thus reducing damages to equipment and facilities and prolonging the service life thereof.

Description

Intelligent balanced distribution method of thrust and oil pressure of four-zone shield machine based on coplanarity constraint Technical Field

[0001] The present invention relates to the technical field of shield machine control, and in particular to a four-zone shield thrust and oil pressure intelligent balanced distribution method based on coplanar constraints. Background Art

[0002] A shield machine (TBM) is a tunnel boring machine that uses the shield method. Its basic operating principle is that a cylindrical steel assembly advances along the tunnel axis, excavating the soil and laying supporting segments as it advances. Thrust cylinder groups are typically evenly distributed around the circumference of the shield. The grippers at the top of the thrust cylinder piston rods bear against the end faces of the pipe rings, slowly extending the piston rods to reverse the movement of the shield machine in the direction of excavation. Multiple adjacent cylinder groups are connected in parallel within the hydraulic system to form zones, with the oil pressure / thrust values ​​of each cylinder group within the same zone being equal. In more common small-diameter shield machines, the cylinder groups are typically divided into four zones: upper, lower, left, and right. To ensure sufficient vertical torque, the lower zone typically has the largest number of cylinder groups. The number of cylinders in the remaining zones is adjusted based on construction requirements, but the number of cylinder groups in the left and right zones is typically the same and symmetrical.

[0003] In recent years, shield machine equipment and construction methods have been developing towards automation and intelligence. A crucial aspect is the automatic control of the shield machine's excavation posture. To adjust the shield machine's posture to the target posture or planned line, the shield machine's posture can be corrected by adjusting the oil pressure / thrust of each thrust cylinder in each zone, adjusting the intensity and direction of the corrective torque. However, under the conditions of the same total thrust and corrective torque, there are a large number of possible combinations of oil pressure / thrust values ​​for each zone. In engineering practice, drivers usually control the system based on their experience and habits. Different drivers have different operating methods, resulting in significant differences in the distribution of oil pressure / thrust values ​​under the same conditions. This does not provide a useful reference for the development of automatic / intelligent control technology for shield machine posture.

[0004] Furthermore, the distribution of oil pressure and thrust must also take into account the requirement for balance. Based on actual construction conditions, the industry generally believes that the smaller the difference in oil pressure / thrust between adjacent zones, the smaller the bending moment on the segments at the zone intersection, which in turn reduces segment damage. Therefore, under the premise of the same total thrust and corrective torque, the more balanced the oil pressure / thrust in each zone, the better. In other words, the optimal distribution result is achieved when the gradient of oil pressure / thrust in each zone changes consistently along the target corrective torque direction.

[0005] A shield machine has three degrees of freedom: pitch, yaw, and fore-aft translation. However, the number of propulsion cylinders is far greater than three, leading to the problem of hydraulic cylinder overdrive. To achieve the shield machine's kinematic mechanics, it is necessary to coordinate and distribute the redundant propulsion cylinder thrust or oil pressure. This problem is similar to the redundancy problems encountered in aviation, navigation, automotive, and other fields, and is called the control allocation problem. The main algorithms currently used to solve the control allocation problem include:

[0006] (1) Explicit combination method: The explicit combination method uses a pre-designed combination method to produce a single control effect by coordinating multiple actuator structures. This method is easy to implement in engineering and is suitable for overdrive systems with obvious and limited combination methods. However, it cannot effectively handle constraints or optimize performance. When an actuator fails, the designed combination scheme will fail. It has no adaptive redistribution capability and is not suitable for systems with high redundancy.

[0007] This method requires pre-setting combinations to produce a single control action. However, the thrust of a shield machine is continuous within the feasible range, the corrective torque is also continuous within the range, and the corresponding changes in the thrust / oil pressure of each cylinder are also stable and continuous. Using the "explicit combination method" makes it difficult to design countless multi-cylinder thrust / oil pressure combinations within the feasible domain and achieve continuously changing target thrust and torque. Therefore, the explicit combination method is not suitable for solving the problem of shield machine thrust / oil pressure distribution.

[0008] (2) Cascade Chain Method: Assuming the system's actuators are hierarchical, the core idea of ​​the cascade chain control allocation method is to quickly activate the next-level actuator to compensate for the required control quantity if the previous-level actuator is saturated. The cascade chain control allocation algorithm has the advantages of simple engineering implementation, fast allocation speed, and reliable use, but it also has the problem of actuator saturation.

[0009] This method can easily lead to the thrust / oil pressure of the first actuator (thrust cylinder) to reach its limit, which is unacceptable in shield construction. Therefore, the series chain method is not suitable for solving the problem of regional thrust / oil pressure distribution of shield machines.

[0010] (3) Direct allocation method: The direct allocation method was proposed by Duaham and is a geometric algorithm. In the process, a control pseudo-instruction W is given and a suitable control input *R is obtained so that the pseudo-control input W*=LR* and the amplitude is the largest in the W direction.

[0011] Bodson transforms direct assignment into the form of solving an optimization problem, given ɑ, R*, and solves:

[0012] The direct allocation algorithm seeks to maximize the amplitude of the allocation result in the desired direction, and needs to use the optimization problem solving method to solve it, which is relatively cumbersome and not accurate enough.

[0013] (4) Generalized inverse allocation method: The generalized inverse control allocation algorithm introduces the minimum norm constraint, which can be expressed as The explicit solution of this formula is R = L + W, where L + =L T (LL T ) -1 is the pseudo-inverse matrix of L.

[0014] This method solves the movement amount of each actuator through generalized inverse, and pursues the minimum comprehensive output of the actuator. However, for the case of uneven distribution of the shield machine's propulsion cylinders - when the lever arms differ greatly, it can ensure that the distribution results meet the total thrust and torque requirements, but the maximum partition thrust / oil pressure may be adjacent to the minimum partition thrust / oil pressure, and the distribution results cannot be guaranteed to be balanced, which affects the force on the segments and poses potential risks.

[0015] Among traditional control allocation algorithms, in addition to the ones listed above, there is also a fixed-point iterative algorithm proposed by Burken for solving weighted optimal control allocation problems. This algorithm is similar to the iterative algorithm of gradient search and has global convergence, but if unreachable instructions are given, the algorithm may be slow. In addition, there are interior point algorithms for solving quadratic programming and effective set algorithms for solving small to medium-sized quadratic programming problems. Both interior point algorithms and effective set algorithms transform the control allocation problem into a quadratic programming problem, and their goal is to solve the optimal solution that meets the objective function and constraints. Using quadratic programming to solve the control allocation problem generally seeks to minimize the objective function under the constraints. This approach can achieve thrust / oil pressure distribution in each partition that meets the target total thrust and corrective torque, but it cannot guarantee a balanced distribution result.

[0016] Summary of the Invention

[0017] The present invention is made to solve the above problems, and its purpose is to provide a four-zone shield thrust and oil pressure intelligent balanced distribution method based on coplanar constraint.

[0018] To achieve the above objectives, the present invention provides the following technical solutions:

[0019] A method for intelligently balancing thrust and oil pressure in a four-zone shield machine based on coplanar constraints. The shield machine's propulsion system includes multiple cylinder groups distributed at equal intervals along the circumferential direction within an installation plane. The oil pressure and thrust directions of all cylinder groups are perpendicular to the installation plane. All cylinder groups are divided into four zones: upper, lower, left, and right. The method includes:

[0020] Step S1: Determine the number of cylinder groups in each partition, the conversion coefficient K between the thrust and oil pressure of a single cylinder group, and the radius of the circle where the cylinder group is located. Then, establish a plane rectangular coordinate system xOy in the installation plane, and then further determine the target total thrust F that the propulsion system needs to achieve. t , the total target thrust in the x direction relative to the horizontal target correction torque M of the origin O x , the vertical target correction moment M in the y direction relative to the origin O y ;

[0021] Step S2: Determine the coordinates of the equivalent force points in each partition based on the average of the force arms of each cylinder group in the partition relative to the origin in the x and y directions;

[0022] Step S3: Construct a spatial hexahedron geometric model with the starting points and end points of four vectors starting from the equivalent force points of the four partitions and extending perpendicularly to the installation plane in the same direction as the vertices, obtain the relationship between the lengths of the four vectors when the end points of the four vectors are coplanar, and then correspond the length relationship of the four vectors to the thrust / oil pressure of the four partitions, respectively, to establish a constraint relationship between the thrust / oil pressure of the four partitions;

[0023] Step S4: The sum of the moments of the four partitioned thrusts in the x direction about the origin O is equal to the horizontal target correction moment M x The sum of the moments of the four partition thrusts in the y direction about the origin O is equal to the vertical target correction moment M y And the sum of the thrusts of the four partitions is equal to the target total thrust F t The three equivalent relationships and the constraint relationship between the four partition thrusts obtained in step S3 are combined to solve the relevant equations and directly solve the partition thrusts of the four partitions; or the thrusts in the three equivalent relationships are replaced by expressions about oil pressure, and then combined with the constraint relationship between the four partition oil pressures obtained in step S3 to solve the partition oil pressure.

[0024] Furthermore, in step S1, K=F max / P max , F max The maximum oil pressure value P for a single cylinder group max corresponds to the maximum thrust that can be achieved.

[0025] Furthermore, in step S1, with the center of the circle where the cylinder group is located as the origin, from a perspective facing the excavation direction and looking at the installation plane of the cylinder group, the positive half axis of the y-axis points from the origin to the zenith direction directly above the shield machine, and the positive half axis of the x-axis points perpendicular to the y-axis to the right.

[0026] Furthermore, in step S2, the coordinates of the equivalent force point of the partition are recorded as U(x U ,y U), the coordinates of the equivalent force point in the right partition are R(x R ,y R ), the coordinates of the equivalent force point in the lower partition are D(x D ,y D ), the coordinates of the equivalent force point in the left partition are L(x L ,y L ), then:

[0027] Where r is the radius of the circle where all cylinder groups are located, θ i is the central angle corresponding to the i-th cylinder group, n U is the number of cylinder groups in the upper partition, n R is the number of cylinder groups in the right partition, n D is the number of cylinder groups in the lower partition, n L The number of cylinder groups in the left partition.

[0028] Furthermore, in step S3, the intersection of the line LR connecting the equivalent force points of the left and right partitions and the line UD connecting the equivalent force points of the upper and lower partitions is recorded as O1, and

[0029] The length relationship of the four vectors corresponds to the thrust of the four partitions respectively, and the constraint relationship between the thrust of the four partitions is established: F D +α(F U -F D ) ＝ F L +β(F R -F L ), where F D is the partition thrust of the lower partition, F U is the partition thrust of the upper partition, F R is the partition thrust of the right partition, F L is the partition thrust of the left partition; or, the length relationship of the four vectors corresponds to the oil pressure of the four partitions, and the constraint relationship between the oil pressures of the four partitions is established: P D +α(P U -P D )=P L +β(P R -P L ), where P D is the oil pressure of the lower partition, P U is the oil pressure of the upper partition, P R is the oil pressure of the right partition, P L This is the zone oil pressure for the left zone.

[0030] Furthermore, in step S4, the sum of the moments of the four partition thrusts in the x direction about the origin O is equal to the horizontal target correction moment M x Write the thrust equation 2: M x =F U x U +F R x R +F D x D +F L x L ; According to the four partition thrusts, the sum of the moments in the y direction about the origin O is equal to the vertical target correction moment M y Write the thrust equation three: M y =F U y U +F R y R +F D y D +F L y L ; According to the sum of the thrusts of the four partitions is equal to the target total thrust F t Write the thrust equation 4: F t =F U +F R +F D +F L .

[0031] Furthermore, in step S4, the partition thrust in the thrust equation 2 is expressed by the partition oil pressure to obtain the oil pressure equation 2: M x =n U KP U x U +n R KP R x R +n D KP D x D +n L KP L x L ; Express the partition thrust in thrust equation 3 with partition oil pressure, and get oil pressure equation 3: M y =n U KP U y U +n R KP R y R +n D KP D y D +n L KP L y L; Express the partition thrust in thrust equation 4 with partition oil pressure, and get oil pressure equation 4: F t =n U KP U +n R KP R +n D KP D +n L KP L .

[0032] The present invention has the following beneficial effects:

[0033] 1. The present invention is based on the four-zone shield thrust and oil pressure intelligent balanced distribution method based on coplanar constraint. By distributing the thrust or oil pressure of the four zones of the shield machine, the given target total thrust F is met. t , horizontal target correction torque M x And the vertical target correction torque M y At the same time, the thrust / oil pressure distribution of the four partitions conforms to the balance in the geometric space, and the thrust / oil pressure gradient of each partition after distribution is uniform, so as to obtain the optimal distribution result, laying a technical foundation for the automatic / intelligent control of the shield machine posture.

[0034] 2. The intelligent balanced distribution method of thrust and oil pressure of four-zone shield machines based on coplanar constraints in the present invention results in smaller differences in thrust / oil pressure between adjacent zones, which can effectively reduce the bending moment on the pipe segments at the junction of the zones, thereby reducing damage to the pipe segments and facilitating the protection of the pipe ring during tunneling construction.

[0035] 3. The four-zone shield thrust and oil pressure intelligent balanced distribution method based on coplanar constraints of the present invention accurately and efficiently obtains the optimal thrust / oil pressure distribution result through theoretical calculation. It is suitable for small-diameter four-zone shield machines and can provide a basis for the balanced distribution of shield machine thrust and oil pressure in actual construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG1 is a schematic diagram of the distribution of cylinder groups in an embodiment of the present invention;

[0037] FIG2 is a schematic diagram of equivalent force points of different zones in an embodiment of the present invention;

[0038] 3 is a flow chart of a method for intelligent balanced distribution of thrust and oil pressure of a four-zone shield machine based on coplanar constraints in an embodiment of the present invention;

[0039] FIG4 is a schematic diagram of a hexahedral geometric model in an embodiment of the present invention;

[0040] FIG5 is a schematic diagram of a quadrilateral LRR'L' in an embodiment of the present invention;

[0041] FIG6 is a schematic diagram of a quadrilateral DD'U'U according to an embodiment of the present invention;

[0042] FIG7 is a simulation diagram of the spatial distribution of thrust vectors in an embodiment of the present invention;

[0043] FIG8 is a simulation diagram of thrust distribution effect in an embodiment of the present invention;

[0044] FIG9 is a simulation diagram of the oil pressure vector spatial distribution in an embodiment of the present invention;

[0045] FIG10 is a simulation diagram of the oil pressure distribution effect in an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the following embodiments and the accompanying drawings specifically illustrate the four-zone shield thrust and oil pressure intelligent balanced distribution method based on coplanar constraints of the present invention.

[0047] <Example 1>

[0048] As shown in Figures 1 and 2, in this embodiment, the propulsion system of the shield machine includes multiple cylinder groups distributed along the circumference within the installation plane. The oil pressure and thrust direction of all cylinder groups are perpendicular to the installation plane, and all cylinder groups are divided into four partitions: upper, lower, left, and right.

[0049] As shown in FIG3 , the method for intelligent balanced distribution of thrust and oil pressure of a four-zone shield machine based on coplanarity constraint in this embodiment includes the following steps:

[0050] Step S1: Determine the number of cylinder groups in each partition, the conversion coefficient K between the thrust and oil pressure of a single cylinder group, and the radius of the circle where the cylinder group is located. Then, establish a plane rectangular coordinate system xOy in the installation plane with the center of the circle O as the origin and the axis of symmetry as the y-axis. Then, further determine the target total thrust F that the propulsion system needs to achieve. t , the total target thrust in the x direction relative to the horizontal target correction torque M of the origin O x , the vertical target correction moment M in the y direction relative to the origin O y ;

[0051] Step S2: Determine the coordinates of the equivalent force points in each partition based on the average of the force arms of each cylinder group in the partition relative to the origin in the x and y directions;

[0052] Step S3: Construct a spatial hexahedron geometric model with the starting points and end points of four vectors starting from the equivalent force points of the four partitions and extending perpendicularly to the installation plane in the same direction as the vertices, obtain the relationship between the lengths of the four vectors when the end points of the four vectors are coplanar, and then correspond the length relationship of the four vectors to the thrust / oil pressure of the four partitions, respectively, to establish a constraint relationship between the thrust / oil pressure of the four partitions;

[0053] Step S4: The sum of the moments of the four partitioned thrusts in the x direction about the origin O is equal to the horizontal target correction moment M x The sum of the moments of the four partition thrusts in the y direction about the origin O is equal to the vertical target correction moment M y And the sum of the thrusts of the four partitions is equal to the target total thrust F t The three equivalent relationships and the constraint relationship between the four partition thrusts obtained in step S3 are combined to solve the relevant equations and directly solve the partition thrusts of the four partitions; or the thrusts in the three equivalent relationships are replaced by expressions about oil pressure, and then combined with the constraint relationship between the four partition oil pressures obtained in step S3 to solve the partition oil pressure.

[0054] Furthermore, in step S1, K=F max / P max , F max The maximum oil pressure value P for a single cylinder group max The proportional coefficient K is determined according to the actual configuration of the shield machine hydraulic system.

[0055] As shown in Figures 1, 2, and 4, in this embodiment, when establishing the plane rectangular coordinate system xOy, according to usage habits, the center of the circle where the cylinder group is located is taken as the origin O. When the observer faces the excavation direction and looks at the installation plane of the cylinder group, the positive half axis of the y axis points from the center O1, i.e., the origin, to the zenith direction directly above the shield machine (vertical direction), and the positive half axis of the x axis is perpendicular to the y axis and points to the right (horizontal direction). The target correction torques expected to be achieved by the thrust of all cylinder groups in the horizontal direction (i.e., the x direction) and the vertical direction (i.e., the y direction) are M respectively. x 、M y .

[0056] For any partition, the resultant moment of the thrust of each cylinder group within the partition about the origin O is equal to the moment generated by the resultant thrust of all cylinders in the partition acting on the partition's equivalent force point about the origin O. The coordinates of the partition's equivalent force point are numerically equal to the average of the thrust force arms of each cylinder group within the partition about the origin in the corresponding direction.

[0057] In step S2, the coordinates of the equivalent force point of the partition are recorded as U(x U ,y U ), the coordinates of the equivalent force point in the right partition are R(x R ,y R ), the coordinates of the equivalent force point in the lower partition are D(x D ,y D ), the coordinates of the equivalent force point in the left partition are L(x L ,y L ), then:

[0058] Where r is the radius of the circle where all cylinder groups (root center) are located; θ i is the central angle of the circle corresponding to the i-th cylinder group (root center), with the positive half axis of the y-axis in Figures 1 and 2 as 0°, and the angle increases clockwise; n U is the number of cylinder groups in the upper partition, n R is the number of cylinder groups in the right partition, n D is the number of cylinder groups in the lower partition, n L The number of cylinder groups in the left partition.

[0059] Furthermore, in step S3, the end points of the four vectors starting from the equivalent force points U, R, D, L of the four partitions and extending perpendicularly to the same direction outside the installation plane are recorded as U', R', D', L' respectively. Under the condition that the end points of the vectors are coplanar, the starting points and end points of the four vectors are used as vertices, the convex quadrilateral formed by sequentially connecting the equivalent force points U, R, D, L of the four partitions is used as the bottom surface, the four vectors are used as sides, and the quadrilateral formed by sequentially connecting the four vector end points U', R', D', L' is used as the top surface to construct a spatial hexahedral geometric model. The intersection of the line LR connecting the equivalent force points of the left and right partitions and the line UD connecting the equivalent force points of the upper and lower partitions is recorded as O1, and the intersection of the diagonal R'L' in the quadrilateral U'R'D'L' and U'D' is recorded as O1'.

[0060] The coordinates of point O1 are (x O1 ,y O1 ), based on the fact that points U, O1, and D are collinear, i.e., line segments UO1 and O1D have equal slopes; and points L, O1, and R are collinear, i.e., line segments LO1 and O1R have equal slopes, write the following equation:

[0061] Solve for the coordinates of point O1:

[0062] As shown in Figures 4 and 5, since line segments LL' and RR' are both perpendicular to the plane of quadrilateral URDL, it is easy to see that quadrilateral LRR'L' is a right trapezoid. Draw a perpendicular from point L' to RR', with its foot at point F. Perpendicular line L'F intersects O1O1' at point E, forming right triangle FR'L', right triangle EO1'L', rectangle LL'EO1, rectangle O1EFR, and rectangle LL'FR.

[0063] It is easy to see that triangle EO1'L' is similar to triangle FR'L', so there is a proportional relationship: Combining the relationship between the side lengths of rectangle LL'EO1, rectangle O1EFR and rectangle LL'FR, we can further obtain

[0064] Therefore

[0065] make Then |O1O1'|=|LL'|+β(|RR'|-|LL'|).

[0066] As shown in Figures 4 and 6, since line segments DD' and UU' are both perpendicular to the plane of quadrilateral URDL, it's easy to see that quadrilateral UDD'U' is also a right trapezoid. Draw a perpendicular from point D' to UU', with its foot at point B. Perpendicular line D'B intersects O1O1' at point A, forming right triangle AO1'D', right triangle BU'D', rectangle DD'AO1, rectangle O1'ABU, and rectangle DD'BU.

[0067] It is easy to see that triangle AO1'D' is similar to triangle BU'D', so there is a proportional relationship: Combining the relationship between the side lengths of rectangle DD'AO1, rectangle O1'ABU and rectangle DD'BU, we can further obtain

[0068] Therefore

[0069] make Then |O1O1'|=|DD'|+α(|UU'|-|DD'|).

[0070] From |O1O1'|=|LL'|+β(|RR'|-|LL'|) and |O1O1'|=|DD'|+α(|UU'|-|DD'|), we can obtain the relationship between the lengths of the four vectors when the end points U', R', D', and L' are coplanar: |DD'|+α(|UU'|-|DD'|)=|LL'|+β(|RR'|-|LL'|).

[0071] If the thrust of each partition in the shield machine thrust system needs to be evenly distributed, the length relationship of the four vectors is corresponded to the thrust of the four partitions respectively, and the constraint relationship between the thrust of the four partitions is obtained (thrust equation 1): F D +α(F U -F D )=F L +β(F R -F L ), namely αF U -βF R +(1-α)F D -(1-β)F L =0, where F D is the partition thrust of the lower partition, F U is the partition thrust of the upper partition, F Ris the partition thrust of the right partition, F L The partition thrust for the left partition.

[0072] Furthermore, in step S4, the sum of the moments of the four partition thrusts in the x direction about the origin O is equal to the horizontal target correction moment M x Write the thrust equation 2: M x =F U x U +F R x R +F D x D +F L x L ; According to the four partition thrusts, the sum of the moments in the y direction about the origin O is equal to the vertical target correction moment M y Write the thrust equation three: M y =F U y U +F R y R +F D y D +F L y L ; According to the sum of the thrusts of the four partitions is equal to the target total thrust F t Write the thrust equation 4: F t =F U +F R +F D +F L .

[0073] Directly combine the four thrust equations and solve for F in the equation group D 、F U 、F R 、F L With four unknown quantities, we can get the balanced thrust distribution results of the four partitions.

[0074] If the oil pressure in each partition of the shield machine thrust system needs to be evenly distributed, the length relationship of the four vectors is corresponded to the oil pressure of the four partitions, and the constraint relationship between the oil pressures of the four partitions is obtained (oil pressure equation 1): P D +α(P U -P D )=P L +β(P R -P L ), namely αP U -βP R +(1-α)P D -(1-β)P L =0, where P D is the oil pressure of the lower partition, P Uis the oil pressure of the upper partition, P R is the oil pressure of the right partition, P L This is the zone oil pressure for the left zone.

[0075] It is known that the conversion coefficient between the thrust and oil pressure of a single cylinder group is K, then the partition thrust can be expressed as the product of the partition oil pressure, the number of cylinder groups in the partition, and the conversion coefficient K, that is, F U =n U KP U , F R =n R KP R , F D =n D KP D , F L =n L KP L .

[0076] Expressing the partition thrust in thrust equation 2 with partition oil pressure, we can get oil pressure equation 2: M x =n U KP U x U +n R KP R x R +n D KP D x D +n L KP L x L ; Expressing the partition thrust in thrust equation 3 with partition oil pressure, we can get oil pressure equation 3: M y =n U KP U y U +n R KP R y R +n D KP D y D +n L KP L y L ; Expressing the partition thrust in thrust equation 4 with partition oil pressure, we can get oil pressure equation 4: F t =n U KP U +n R KP R +n D KP D +n L KP L .

[0077] Combine the four hydraulic equations and solve for P in the equation group.D 、P U 、P R 、P L With four unknown quantities, we can get the balanced distribution of oil pressure in the four zones.

[0078] <Example 2>

[0079] In Example 1, the propulsion system of the shield machine includes multiple cylinder groups distributed along the circumference within the installation plane, the oil pressure and thrust direction of all cylinder groups are perpendicular to the installation plane, and all cylinder groups are divided into four partitions: upper, lower, left, and right.

[0080] On the basis of Example 1, this Example 2 further illustrates the four-zone shield thrust and oil pressure intelligent balanced distribution method based on coplanar constraints of the present invention for a small-diameter four-zone shield machine configuration that is most common in actual engineering construction.

[0081] On the basis of Example 1, in the shield machine propulsion system of this Example 2, all cylinder groups are equally spaced along the circumferential direction, the cylinder groups of the left and right partitions are symmetrical to each other, and the cylinder groups of the upper and lower partitions are symmetrically distributed about the symmetry axis of the left and right partitions (i.e., the y-axis). Therefore, the equivalent force points L and R of the left and right partitions are also symmetrical about the y-axis, while the equivalent force points U and D of the upper and lower partitions are located on the y-axis. It can be seen from this that: the horizontal coordinates of points U and D are both 0; the vertical coordinates of points L and R are equal, and the horizontal coordinates are opposite to each other, so the intersection O1 of line segment UD and line segment LR is the midpoint of line segment LR.

[0082] Then we can get the coordinates of point O1:

[0083] Therefore:

[0084] In step S3, when the four vector endpoints U', R', D', and L' are coplanar, the relationship between the lengths of the four vectors can be simplified to: |DD'| + α(|UU'| - |DD'|) = (|RR'| + |LL'|) / 2. Correspondingly, the constraint relationship between the four partition thrusts (thrust equation 1) can be simplified to: F D +α(F U -F D )=(F R +F L ) / 2, that is, 2αF U -F R +2(1-α)F D -F L =0; the constraint relationship between the four zone oil pressures (oil pressure equation 1) can be simplified to: P D +α(P U-P D )=(P R +P L ) / 2, which is convenient for the final solution of the unknown quantities in the system of equations.

[0085] The remaining steps in Example 2 are the same as those in Example 1 and will not be repeated here.

[0086] To verify the effect of balanced thrust / oil pressure distribution, a simulation experiment was conducted: it was assumed that the shield machine propulsion system contains a total of 19 cylinder groups, each of which contains 2 cylinders and is physically connected to the top of the cylinder telescopic rod through a support shoe. The 19 cylinder groups are divided into 4 partitions, of which the number of cylinder groups in the lower partition is 6, the number of cylinder groups in the upper partition is 3, and the number of cylinder groups in the left and right partitions is 5 each. The thrust-oil pressure conversion coefficient corresponding to a single cylinder group is K = 2*(2000-0) / (35-0), unit: kN / MPa. The parameters of the 19 cylinder groups are shown in the following table:

[0087] Total thrust F t =22489kN, horizontal target correction moment M x =-13493.4kN·m and vertical target correction torque M y =-17991.2 kN·m as the target value for partitioned thrust distribution. The distribution results were simulated, and the thrust vector spatial distribution simulation results are shown in Figure 7. The thrust values ​​corresponding to the upper, right, lower, and left partitions are 15.42433678, 8.0615267, 5.8999899, ​​and 14.95963335, respectively, in kN. Verification of the distribution results: The calculated sum of the thrusts for each partition is 22489.00000000001 kN, which meets the target total thrust (minimum errors caused by loss of precision during computer calculations can be ignored). By multiplying the thrust for each partition by the coordinates of the equivalent effective point in the corresponding direction of the partition, the corresponding horizontal and vertical corrective moments are calculated to be -13493.40000000001 kN·m and 17991.20000000002 kN·m, respectively, which meet the target corrective moments.

[0088] With a radius of 1m, the equivalent force application point of the total thrust is circled around the center of the propulsion cylinder group installation plane (the center of the circle). The corresponding corrective torque changes with the equivalent force application point, which can be calculated by the following formula:

[0089] Correction torque Where ω∈(0,2π), r=1m.

[0090] The thrust distribution is performed by taking the total thrust and the correcting torque corresponding to each point as the target value, and verifying the changes in the total thrust, correcting torque and related quantities corresponding to the distribution results. The simulation results are shown in Figure 8. It can be seen that the center of force moves along the circumference while the total thrust remains unchanged, and the distribution result meets the target total thrust F t According to the distribution results, the torque and target correction torque M are calculated. x 、M y The difference is close to zero, which can meet the thrust distribution requirements.

[0091] Similarly, the total thrust F t =22489kN, horizontal target correction moment M x =-13493.4kN·m and vertical target correction torque M y =-17991.2 kN·m as the target value, and the distribution results were simulated. The results of the oil pressure vector spatial distribution simulation are shown in Figure 9. The corresponding oil pressure values ​​for the upper, right, lower, and left zones are 6331.97953811, 3720.76663166, 4773.71197326, and 7662.54185697, respectively, all in MPa. The distribution results were verified by calculation: the sum of the thrust forces in each zone is 22489.00000000001, which meets the target total thrust. The corresponding horizontal and vertical correcting moments are -13493.40000000001 kN·m and 17991.20000000002 kN·m, respectively, which meet the target correcting moments.

[0092] With a radius of 1m, the equivalent force application point of the total thrust is circled around the center of the propulsion cylinder installation plane (the center of the circular surface). The corresponding corrective torque changes with the equivalent force application point, which can be calculated by the following formula:

[0093] Correction torque Where ω∈(0,2π), r=1m.

[0094] The total thrust and corrective torque corresponding to each point are used as target values ​​to distribute the oil pressure in different zones, and the changes in the total thrust, corrective torque and related quantities corresponding to the distribution results are verified. The simulation results are shown in Figure 10. It can be seen that the center of force moves along the circumference while the total thrust remains unchanged, and the distribution result meets the target total thrust F t According to the distribution results, the torque and target correction torque M are calculated. x 、M y The difference is close to zero, which can meet the thrust distribution requirements.

[0095] In summary, the four-zone shield thrust and oil pressure intelligent balanced distribution method based on coplanar constraints of the present invention distributes the thrust / oil pressure of each zone under the premise of a given target total thrust and a target correction torque, and uses a spatial hexahedron geometric model for deduction. Under the constraint that the end points of the thrust / oil pressure vectors of each zone are located in the same plane of the three-dimensional space, a single and definite balanced distribution result is obtained, so that the thrust / oil pressure gradient of each zone after distribution is uniform, and the thrust / oil pressure of each zone presents a linear decreasing arrangement feature from the maximum value to the minimum value, avoiding the situation where the thrust / oil pressure of each zone is high and low, which is beneficial to the protection of the pipe ring and hydraulic system hardware during excavation construction. It is highly practical and has a high promotion and application value, and can lay a technical foundation for automatic / intelligent control of the shield machine posture.

[0096] The above embodiments are preferred examples of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A four-zone shield thrust and oil pressure intelligent balanced distribution method based on coplanar constraints, wherein the propulsion system of the shield machine includes a plurality of cylinder groups distributed along the circumference in the installation plane, the oil pressure and thrust direction of all cylinder groups are perpendicular to the installation plane, and all cylinder groups are divided into four zones: upper, lower, left, and right, characterized in that: include: Step S1, determine the number of cylinder groups in each partition, the conversion coefficient K between the thrust and oil pressure of a single cylinder group, and the radius of the circle where the cylinder group is located, then establish a plane rectangular coordinate system xOy in the installation plane, and then further determine the target total thrust F that the propulsion system needs to achieve t , the total target thrust in the x direction relative to the horizontal target correction torque M of the origin O x , the vertical target correction moment M in the y direction relative to the origin O y ; Step S2: determining the coordinate value of the equivalent force point of each partition according to the average value of the force arm of each cylinder group in the partition to the origin in the x and y directions; Step S3: constructing a spatial hexahedral geometric model with the starting points and end points of four vectors respectively starting from the equivalent force points of the four partitions and extending perpendicularly to the installation plane in the same direction as the vertices, obtaining the relationship between the lengths of the four vectors when the end points of the four vectors are coplanar, and then corresponding the length relationship of the four vectors to the thrust / oil pressure of the four partitions respectively, and establishing a constraint relationship between the thrust / oil pressure of the four partitions; Step S4: The sum of the moments of the four partition thrusts in the x direction about the origin O is equal to the horizontal target correction moment M x The sum of the moments of the four partition thrusts in the y direction about the origin O is equal to the vertical target correction moment M y And the sum of the thrusts of the four partitions is equal to the target total thrust F t The three equivalent relationships and the constraint relationship between the four partition thrusts obtained in step S3 are combined to form related equations to directly solve the partition thrusts of the four partitions; or the thrusts in the three equivalent relationships are replaced by expressions about oil pressure, and then combined with the constraint relationship between the four partition oil pressures obtained in step S3 to form a group of simultaneous equations to solve the partition oil pressures.

2. The method for intelligent balanced distribution of thrust and oil pressure of four-zone shield machine based on coplanar constraint according to claim 1 is characterized by: In step S1, K = F max / P max , F max The maximum oil pressure value P for a single cylinder group max corresponds to the maximum thrust that can be achieved.

3. The method for intelligent balanced distribution of thrust and oil pressure of four-zone shield machine based on coplanar constraint according to claim 1 is characterized by: In step S1, the center of the circle where the cylinder group is located is taken as the origin, and the cylinder group is placed in the direction of excavation. From the perspective of the installation plane, the positive semi-axis of the y-axis points from the origin to the zenith directly above the shield machine, and the positive semi-axis of the x-axis points to the right perpendicular to the y-axis.

4. The method for intelligent balanced distribution of thrust and oil pressure of four-zone shield machine based on coplanar constraint according to claim 1 is characterized by: In step S2, the coordinates of the equivalent force point of the partition are recorded as U(x U ,y U ), the coordinates of the equivalent force point in the right partition are R(x R ,y R ), the coordinates of the equivalent force point in the lower partition are D(x D ,y D ), the coordinates of the equivalent force point in the left partition are L(x L ,y L ), then: Where r is the radius of the circle where all cylinder groups are located, θ i is the central angle of the i-th cylinder group, n U is the number of cylinder groups in the upper partition, n R is the number of cylinder groups in the right partition, n D is the number of cylinder groups in the lower partition, n L The number of cylinder groups in the left partition.

5. The method for intelligent balanced distribution of thrust and oil pressure of four-zone shield machine based on coplanar constraint according to claim 4 is characterized in that: In step S3, the intersection of the line LR of the equivalent force points of the left and right partitions and the line UD of the equivalent force points of the upper and lower partitions is recorded as O1, and The length relationship of the four vectors corresponds to the thrust of the four partitions respectively, and the constraint relationship between the thrust of the four partitions is established: F D +α(F U -F D )=F L +β(F R -F L ), where F D is the partition thrust of the lower partition, F U is the partition thrust of the upper partition, F R is the partition thrust of the right partition, F L is the partition thrust of the left partition; Alternatively, the length relationship of the four vectors corresponds to the oil pressure of the four partitions, and the constraint relationship between the oil pressure of the four partitions is established: D +α(P U -P D )=P L +β(P R -P L ), where P D is the oil pressure of the lower zone, P U is the zone oil pressure of the upper zone, P R is the zone oil pressure of the right zone, P L This is the zone oil pressure for the left zone.

6. The method for intelligent balanced distribution of thrust and oil pressure of four-zone shield machine based on coplanar constraint according to claim 5 is characterized by: In step S4, the sum of the moments of the four partition thrusts in the x direction about the origin O is equal to the horizontal target correction moment M x Write the thrust equation 2: M x =F U x U +F R x R +F D x D +F L x L ; According to the four partition thrusts, the sum of the moments in the y direction about the origin O is equal to the vertical target correction moment M y Write the thrust equation three: M y =F U y U +F R y R +F D y D +F L y L ; According to the sum of the thrusts of the four partitions is equal to the target total thrust F t Write the thrust equation 4: F t =F U +F R +F D +F L .

7. The method for intelligent balanced distribution of thrust and oil pressure of four-zone shield machine based on coplanar constraint according to claim 6 is characterized by: In step S4, the partition thrust in thrust equation 2 is expressed by partition oil pressure to obtain oil pressure equation 2: M x =n U KP U x U +n R KP R x R +n D KP D x D +n L KP L x L ; Express the partition thrust in thrust equation 3 with partition oil pressure, and get oil pressure equation 3: M y =n U KP U y U +n R KP R y R +n D KP D y D +n L KP L y L ; Express the partition thrust in thrust equation 4 with partition oil pressure, and get oil pressure equation 4: F t =n U KP U +n R KP R +n D KP D +n L KP L .

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