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

Abstract

The present invention provides a four-zone shield thrust and oil pressure intelligent balanced distribution method based on coplanar constraints, which performs balanced distribution of thrust / oil pressure for the shield machine propulsion system in four zones. After determining the relevant parameters, a spatial hexahedron geometric model is used to establish a constraint formula under the condition that the end points of the thrust / oil pressure vectors of each propulsion mechanism are coplanar, and the sum of the moments of the four zone thrusts about the origin is equal to the target deviation correction moment, and the sum of the four zone thrusts is equal to the target total thrust F t The equivalent relationship is used to solve the thrust / oil pressure of each zone. The allocation process is accurate and efficient. The final allocation result can meet the requirements of the target total thrust and target correction torque. At the same time, it can also ensure the balance of the allocation result, reduce damage to equipment and facilities, and extend its service life.

Description

Technical Field

[0001] The 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 is a tunnel boring machine that uses the shield method. Its basic working principle is that a cylindrical steel component is pushed forward along the axis of the tunnel while excavating the soil, and supporting segments are laid during the excavation process. The shield body of the shield machine is usually evenly equipped with thrust cylinder groups. The support shoe at the top of the thrust cylinder piston rod is against the end face of the pipe ring, and the shield machine is pushed in the reverse direction of excavation by slowly extending the piston rod. Multiple adjacent cylinder groups are connected in parallel in the hydraulic system to form partitions, and the oil pressure / thrust values ​​of each cylinder group in the same partition are equal. In the more common small-diameter shield machines, the cylinder groups are usually divided into four partitions: upper, lower, left, and right according to the orientation. In order to ensure that the vertical torque of the shield machine is sufficient, the number of cylinder groups in the lower partition is generally the largest, and the number of cylinders in the remaining partitions is configured accordingly according to construction needs, but the number of cylinder groups in the left and right partitions is usually kept consistent and symmetrically distributed.

[0003] In recent years, automation and intelligent technology have been continuously developed in the field of shield equipment and construction, and one of the most important contents is the automatic control of the shield machine's excavation posture. In order to adjust the shield machine's posture to the target posture or the planned line direction, the shield machine's posture can be corrected by adjusting the oil pressure / thrust of each thrust cylinder of the shield machine, adjusting the intensity and direction of the correction torque, and then achieving the purpose of the shield machine's posture correction. However, under the conditions of the same total thrust and correction torque, there are a large number of combinations of oil pressure / thrust values ​​for each partition. In engineering practice, it is usually controlled by the driver based on experience and habits. Different drivers have different operating methods, resulting in large differences in the distribution results of the oil pressure / thrust values ​​of the partitions under the same premise, which cannot provide a useful reference for the development of automatic / intelligent control technology for the shield machine's posture.

[0004] In addition, the distribution of oil pressure and thrust also needs to take into account the requirement of balance. According to actual construction conditions and industry consensus, it is generally believed that the smaller the difference in oil pressure / thrust between adjacent partitions, the smaller the bending moment on the partition boundary segment, which can reduce segment damage. Therefore, under the premise of the same total thrust and correction torque, the more balanced the oil pressure / thrust of each partition, the better, that is, the distribution result is optimal if the gradient of the oil pressure / thrust of the partition along the target correction torque direction is consistent.

[0005] For a shield machine, its degrees of freedom of motion are 3: pitch, yaw, and forward and backward translation, but the number of thrust cylinders is much greater than 3, which leads to the problem of hydraulic cylinder overdrive. In order to achieve the mechanical indicators of shield motion, it is necessary to coordinate and distribute the thrust or oil pressure of redundant thrust cylinders. This problem is similar to the redundancy problem encountered in the fields of aviation, navigation, and automobiles, and is called the control allocation problem. At present, the main algorithms for solving the control allocation problem include:

[0006] (1) Explicit combination method: The explicit combination method uses a pre-designed combination method to produce each single control effect by coordinating multiple execution structures. This method is easy to implement in engineering and is suitable for overdrive systems with obvious and limited combinations. 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 applicable to systems with high redundancy.

[0007] This method requires a combination mode to be set in advance to produce a single control effect. However, for the thrust / oil pressure distribution of the shield machine, the target thrust is continuous within the feasible range, the deviation correction torque is also continuous within the range, and the corresponding thrust / oil pressure changes of each cylinder are also stable and continuous. It is difficult to design countless multi-cylinder thrust / oil pressure combinations within the feasible domain using the "explicit combination method" to achieve continuously changing target thrust and torque. Therefore, the explicit combination method is not suitable for solving the problem of partitioned thrust / oil pressure distribution of shield machines.

[0008] (2) Cascade chain method: Assuming that the system's actuators are hierarchical structures, the core idea of ​​the cascade chain control allocation method is to quickly move the next-level actuator to compensate for the required control amount if the previous-level actuator is saturated. The cascade chain control allocation algorithm has the characteristics of simple engineering implementation, fast allocation speed and reliable use. It also has an obvious disadvantage that it can easily lead to actuator saturation.

[0009] This method easily leads to the thrust / oil pressure of some actuators (cylinders) that are activated first reaching the limit, which is unacceptable in shield construction. Therefore, the series chain method is not suitable for solving the thrust / oil pressure distribution problem of shield machines.

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

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

[0012]

[0013] The direct allocation algorithm seeks to maximize the amplitude of the allocation result in the desired direction, and needs to be solved using the optimization problem solving method, which is cumbersome and not accurate enough.

[0014] (4) Generalized inverse allocation method: The generalized inverse control allocation algorithm introduces the minimum norm constraint, which can be expressed as

[0015]

[0016] The explicit solution of this equation is R = L + W, where L + =L T (LL T ) -1 is the pseudo-inverse matrix of L.

[0017] 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 difference in the lever arm is large, it can ensure that the distribution result meets the total thrust and torque requirements, but it cannot ensure that the distribution result is balanced (the maximum partition thrust / oil pressure may be adjacent to the minimum partition thrust / oil pressure). This distribution result has potential risks to the stress on the segment.

[0018] In addition to the above-mentioned traditional control allocation algorithms, there is also a fixed point iterative algorithm proposed by Burken for solving the weighted optimal control allocation problem. This algorithm is similar to the iterative algorithm of gradient search and has global convergence, but if an unreachable instruction is given, the algorithm may be slow. Petersen and Bodson proposed an interior point algorithm for solving quadratic programming. This method converges consistently and the relative distance of the optimal solution is known. In addition, there are effective set algorithms for solving small to medium-sized quadratic programming problems. Both the interior point algorithm and the effective set algorithm transform the control allocation problem into a quadratic programming problem, and their purpose is to solve the optimal solution that meets the objective function and constraints. Using quadratic programming to solve the control allocation problem generally pursues the minimum objective function under the constraints. This processing method can achieve thrust / oil pressure distribution in each partition that meets the target total thrust and correction torque, but it cannot guarantee the balance of the distribution results. Summary of the invention

[0019] The present invention is made to solve the above-mentioned problems, and aims to provide a method for intelligent balanced distribution of thrust and oil pressure of a four-zone shield machine based on coplanar constraints.

[0020] To achieve the above object, the present invention provides the following technical solutions:

[0021] A four-zone shield thrust and oil pressure intelligent balanced distribution method based on coplanar constraints, the propulsion system of the shield machine includes a plurality of cylinder groups distributed at equal intervals along the circumferential direction 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, including:

[0022] 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 ;

[0023] 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;

[0024] 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;

[0025] 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.

[0026] 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.

[0027] Furthermore, in step S1, taking 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.

[0028] Furthermore, in step S2, the coordinates of the equivalent force points 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 ),but:

[0029]

[0030]

[0031] 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.

[0032] Further, 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

[0033] 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 )=PL +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.

[0034] Further, 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 .

[0035] Further, 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 yU +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 .

[0036] The present invention has the following beneficial effects:

[0037] 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, while meeting the given target total thrust F 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, obtaining the optimal distribution result, laying a technical foundation for automatic / intelligent control of the shield machine posture.

[0038] 2. The thrust / oil pressure difference between adjacent zones in the distribution result obtained by the four-zone shield thrust and oil pressure intelligent balanced distribution method based on coplanar constraints of the present invention is smaller, which can effectively reduce the bending moment of the zone boundary segments, thereby reducing the damage to the segments and facilitating the protection of the pipe ring during excavation construction.

[0039] 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

[0040] Figure 1 is a schematic diagram of the distribution of the oil cylinder groups in an embodiment of the present invention;

[0041] Figure 2 Schematic diagram of equivalent force points of different zones in an embodiment of the present invention;

[0042] Figure 3It 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;

[0043] Figure 4 is a schematic diagram of a hexahedral geometric model in an embodiment of the present invention;

[0044] Figure 5 is a schematic diagram of a quadrilateral LRR'L' in an embodiment of the present invention;

[0045] Figure 6 is a schematic diagram of quadrilateral DD'U'U in an embodiment of the present invention;

[0046] Figure 7 is a simulation diagram of thrust vector space distribution in an embodiment of the present invention;

[0047] Figure 8 is a simulation diagram of thrust distribution effect in an embodiment of the present invention;

[0048] Fig. 9 is a simulation diagram of the oil pressure vector spatial distribution in an embodiment of the present invention;

[0049] Fig.10 It is a simulation diagram of the oil pressure distribution effect in an embodiment of the present invention. DETAILED DESCRIPTION

[0050] 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.

[0051] <Example 1>

[0052] like Figure 1 , 2 As shown, in this embodiment, the propulsion system of the shield machine includes multiple 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 partitions: upper, lower, left and right.

[0053] like Figure 3 As shown, the four-zone shield thrust and oil pressure intelligent balanced distribution method based on coplanar constraint in this embodiment includes the following steps:

[0054] 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 O of the circle as the origin and the symmetry axis as the y-axis, 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 ;

[0055] 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;

[0056] 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;

[0057] 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.

[0058] 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 hydraulic system of the shield machine.

[0059] like Figure 1 , 2 As shown in 4, in this embodiment, when establishing the plane rectangular coordinate system xOy, according to the usage habits, the center (center of the circle) of the cylinder group 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 of the circle, i.e., the origin O, 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 deviation correction torques that are 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 .

[0060] For any partition, the resultant moment of the thrust of each cylinder group in the partition about the origin O is equal to the moment generated by the thrust resultant of all cylinders in the partition acting on the equivalent force point of the partition about the origin O. The coordinates of the equivalent force point of the partition are numerically equal to the average value of the thrust arm of each cylinder group in the partition in the corresponding direction about the origin.

[0061] 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:

[0062]

[0063]

[0064] Where r is the radius of the circle where all cylinder groups (root center) are located; θ i is the central angle of the i-th cylinder group (root center), Figure 1 , 2 The positive half axis of the y axis is at 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.

[0065] Furthermore, in step S3, the end points of 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 the 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 point 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 point of the diagonal R'L' in the quadrilateral U'R'D'L' and U'D' is recorded as O1'.

[0066] 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; points L, O1, and R are collinear, i.e., line segments LO1 and O1R have equal slopes, write the following equations:

[0067]

[0068] Solve to get the coordinates of the intersection point O1:

[0069]

[0070] like Figure 4 , 5 As shown, since line segments LL' and RR' are perpendicular to the plane where quadrilateral URDL is located, it is easy to know that quadrilateral LRR'L' is a right trapezoid. Draw a perpendicular line from point L' to RR', with the foot of the perpendicular at point F. The 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. It is easy to know 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 Therefore make Then O1O1'=LL'+β(RR'-LL').

[0071] like Figure 4 , 6 As shown, since the line segments DD' and UU' are both perpendicular to the plane where the quadrilateral URDL is located, it is easy to know that the quadrilateral UDD'U' is also a right trapezoid. Draw a perpendicular line from point D' to UU', with the foot of the perpendicular at point B. The perpendicular line D'B intersects O1O1' at point A, forming a right triangle AO1'D', a right triangle BU'D', a rectangle DD'AO1, a rectangle O1'ABU and a rectangle DD'BU.

[0072] 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 Therefore make Then |O1O1'|=|DD'|+α(|UU'|-|DD'|).

[0073] 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', L' are coplanar: |DD'|+α(|UU|'-|DD|')=|LL|'+β(|RR'|-|LL'|).

[0074] If the thrust of each partition in the thrust system of the shield machine 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 thrusts 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 R is the partition thrust of the right partition, F L The partition thrust for the left partition.

[0075] Further, 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 +FD +F L .

[0076] Directly combine the four thrust equations and solve for F in the equation system D 、F U 、F R 、F L With four unknown quantities, we can get the balanced distribution of thrust in the four partitions.

[0077] If the oil pressure of each partition in the thrust system of the shield machine needs to be evenly distributed, the length relationship of the four vectors is respectively 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 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.

[0078] 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 .

[0079] The thrust in the thrust equation 2 is expressed by the oil pressure in the zone, and the oil pressure equation 2 can be obtained: M x =n U KP U x U +n R KP R x R +n D KP D x D +n LKP 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 .

[0080] Combine the four hydraulic equations and solve for P in the equation system. D , P U , P R , P L With four unknown quantities, we can get the balanced distribution result of oil pressure in four zones.

[0081] <Example 2>

[0082] In Example 1, the propulsion system of the shield machine includes multiple 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 partitions: upper, lower, left and right.

[0083] On the basis of Example 1, this Example 2 further illustrates the method for intelligent balanced distribution of thrust and oil pressure of a four-zone shield machine based on coplanar constraints according to the present invention, targeting at the most common small-diameter four-zone shield machine configuration in actual engineering construction.

[0084] 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 in the left and right partitions are symmetrical to each other, and the cylinder groups in the upper and lower partitions are symmetrically distributed about the symmetry axes (i.e., the y-axis) of the left and right partitions. 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.

[0085] Then we can get the coordinates of point O1:

[0086] Therefore:

[0087] 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 as: 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.

[0088] The remaining steps in Example 2 are the same as those in Example 1 and will not be repeated here.

[0089] In order to verify the thrust / oil pressure balanced distribution effect, a simulation experiment was conducted: it is assumed that the shield machine propulsion system contains a total of 19 cylinder groups, each cylinder group 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. 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:

[0090]

[0091] Total thrust F t =22489kN, horizontal target correction moment M x =-13493.4kN·m and vertical target correction moment M y =-17991.2kN·m is the target value for partition thrust distribution, and the distribution result is simulated. The simulation results of thrust vector space distribution are as follows Figure 7 As shown. The thrust values ​​corresponding to the upper, right, lower and left four partitions are 15.42433678, 8.0615267, 5.8999899 and 14.95963335, respectively, in kN. The allocation results are verified: the sum of the thrusts of each partition is calculated to be 22489.00000000001kN, which meets the target total thrust (the very small error caused by the loss of precision in the computer calculation process can be ignored); by calculating the thrust of each partition and multiplying it by the coordinates of the equivalent effective point in the corresponding direction of the partition, the horizontal and vertical correction moments corresponding to the allocation results are -13493.40000000001kN·m and 17991.20000000002kN·m, respectively, which meets the target correction moment.

[0092] With a radius of 1m, the equivalent force application point of the total thrust circles around the center of the installation plane of the propulsion cylinder group (the center of the circular surface), and the corresponding correction 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 thrust to different regions, and the changes in the total thrust, corrective torque and related quantities corresponding to the distribution results are verified. The simulation results are as follows: Figure 8 As shown. 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 result, the torque calculated and the target deviation correction torque M x、 M y The difference is close to zero, which can meet the thrust distribution requirements.

[0095] Similarly, with the total thrust F t =22489kN, horizontal target correction moment M x =-13493.4kN·m and vertical target correction moment M y =-17991.2kN·m is the target value for oil pressure distribution in different zones, and the distribution result is simulated. The simulation result of oil pressure vector space distribution is as follows Fig. 9As shown. The oil pressure values ​​corresponding to the upper, right, lower and left four partitions are 6331.97953811, 3720.76663166, 4773.71197326 and 7662.54185697, all in MPa. The distribution results are calculated and verified: the sum of the thrusts of each partition is 22489.00000000001, which meets the target total thrust; the horizontal and vertical correction torques corresponding to the distribution results are -13493.40000000001 kN·m and 17991.20000000002 kN·m, respectively, which meet the target correction torque.

[0096] With a radius of 1m, the equivalent force application point of the total thrust circles around the center of the propulsion cylinder installation plane (the center of the circular surface), and the corresponding correction torque changes with the equivalent force application point, which can be calculated by the following formula:

[0097] Correction torque Where ω∈(0,2π), r=1m,

[0098] 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 as follows: Fig.10 As shown. 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 result, the torque calculated and the target deviation correction torque M x、 M y The difference is close to zero, which can meet the thrust distribution requirements.

[0099] 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 derives it using a spatial hexahedral geometric model. 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 gradients of each zone after distribution are 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, has strong practicality, and has a high value of promotion and application, and can lay a technical foundation for automatic / intelligent control of the shield machine posture.

[0100] The above-mentioned embodiments are preferred examples of the present invention and are not intended to limit the protection scope of the present invention.

Claims

1. A four-zone shield thrust and oil pressure intelligent balanced distribution method based on coplanar constraints, the method is used for a shield machine, 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: clarify three equivalent relationships, that is, 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 , combining the three equivalent relationships with the constraint relationship between the four partition thrusts obtained in step S3, jointly solving the related equations, and directly solving the partition thrusts of the four partitions; or replacing the thrusts in the three equivalent relationships with expressions about oil pressure, and then combining the constraint relationship between the four partition oil pressures obtained in step S3 to solve the partition oil pressure.

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, taking the center of the circle where the cylinder group is located as the origin, from the perspective of 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 is perpendicular to the y-axis and points to the right.

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 ),but: 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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