Multi-sensor fusion positioning method for tunnel lining trolley

Abstract

The invention discloses a multi-sensor fusion positioning method for a tunnel lining trolley, and the method comprises the following steps: S1, obtaining a positioning target value: obtaining a target position parameter of trolley positioning through theoretical calculation, drawing analysis or actual measurement, comprising the steps of obtaining a trolley mileage target value, obtaining a deviation displacement target value, obtaining an elevation target value and obtaining a side mold closing target value; s2, preparation before trolley positioning is conducted, wherein position target placement and trolley initial state collating are included; and S3, trolley positioning adjustment is conducted, specifically, the trolley mileage, the trolley axis, the trolley elevation and the side formwork position are sequentially adjusted through various sensors used for positioning. The method has the advantages of being easy to operate, rapid, efficient and the like, and the problems that an existing tunnel lining trolley positioning method is low in automation degree, large in operation difficulty, large in positioning error, large in repeated error and low in operation efficiency are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, and more specifically to a multi-sensor fusion positioning method for a tunnel lining trolley. Background Art

[0002] In tunnel lining construction, the positioning accuracy of the lining trolley determines the quality of tunnel completion, and the positioning speed is a key factor affecting the progress of tunnel lining construction. The traditional tunnel lining trolley positioning usually adopts a combination of manual marking judgment, manual steel ruler measurement and total station measurement data guidance and follow-up. It mainly adopts manual positioning, and the trolley state cannot be accurately perceived. The entire positioning process is carried out by the guidance of the surveyor and the estimation of the operator. The positioning mainly relies on the experience of the personnel and is full of randomness and uncertainty. This method is cumbersome to implement and the positioning repetition accuracy is very poor. It is a difficult problem in the use of the lining trolley. In order to solve the above problems, predecessors have proposed an improvement plan for automatic positioning with the help of laser rangefinders or image sensors. However, due to the unreasonable arrangement of the laser rangefinder, the state perception information is not comprehensive enough, and the signal processing of the image sensor is too complicated, the actual effect of these improvement plans is not ideal. In response to the above problems, this application proposes a multi-sensor fusion tunnel lining trolley positioning solution combining a laser rangefinder, a displacement sensor, a pressure sensor, and a stroke sensor. Summary of the invention

[0003] An object of the present invention is to provide a multi-sensor fusion positioning method for a tunnel lining trolley, which has the advantages of simple operation, quickness and high efficiency, and is used to solve the problems of low automation, high operation difficulty, large positioning error, large repetition error and low operating efficiency in existing tunnel lining trolley positioning methods.

[0004] In order to solve the above technical problems, the present invention provides a multi-sensor fusion positioning method for a tunnel lining trolley, comprising the following steps:

[0005] Step S1, obtaining positioning target values, obtaining target position parameters for trolley positioning through theoretical calculation, drawing analysis or actual measurement, including obtaining trolley mileage target values, obtaining offset displacement target values, obtaining elevation target values, and obtaining side mold closing target values;

[0006] Step S2, preparation before positioning the trolley, including placement of position targets and initialization of the trolley;

[0007] Step S3, trolley positioning adjustment, relying on various sensors used for positioning to adjust the trolley mileage, trolley axis, trolley elevation and side mold position in turn.

[0008] Preferably, the acquisition of the mileage laser displacement target value in step S1 specifically includes: setting a laser emission point, closing the mold of the trolley to the mileage design position, and then placing the mileage position target at the mold closing seam position, and the mapping length from the laser emission point to the edge point of the side mold along the center axis of the trolley is the mileage laser displacement target value.

[0009] Preferably, the acquisition of the offset laser displacement target value in step S1 specifically includes: setting a laser emission point, closing the trolley to the axis design position, and then placing the axis position target at a fixed distance parallel to the center axis of the trolley, and the distance from the laser emission point to the vertical plane of the center axis of the trolley is the offset laser displacement target value.

[0010] Preferably, the acquisition of the elevation target value in step S1 includes the acquisition of the elevation laser target value and the elevation pressure target value, and the calculation formula of the elevation laser displacement target value is:

[0011] Z 高程激光位移目标值 =Z 拱顶理论高程 -H 拱顶到激光发射点垂直高度 -Z 地面实测高程 ; Clamp the trolley to the elevation design position, collect the elevation positioning parameters of the initial segment, and the calculation formula for the elevation laser displacement target value of each segment at the current stage is:

[0012]

[0013] The calculation formula for the elevation pressure target value is: F 高程压力目标值 =(W 台车总重 ÷4)×1.3;

[0014] The acquisition of the side mold clamping target value in step S1 includes the acquisition of the side mold clamping displacement target value and the side mold clamping pressure target value. The side mold clamping displacement target value is obtained by measuring the design drawing, and the side mold clamping pressure target value is calculated as follows: 侧模合模压力目标值 =F 侧模合模压力 ×1.3.

[0015] Preferably, the step S2 comprises the following steps:

[0016] Step S21: using a total station to place four reference points of the next plate in advance and collect the actual ground elevation at the elevation measurement point of the next plate;

[0017] Step S22: Locate the mileage target and the offset target according to the reference point with the aid of a laser level, and place the mileage target and the offset target at corresponding positions before positioning the trolley;

[0018] Step S23: Return the trolley to its initial state.

[0019] Preferably, the specific process of step S3 is as follows: trolley mold opening; trolley track correction; trolley rail delivery; trolley travel; mileage adjustment, determine whether the mileage reaches the target value, if reached, proceed to the next step, if not, the trolley rail delivery is performed again until the mileage reaches the target value; trolley centering, and determine whether the axis deviation meets the target value, if satisfied, proceed to the next step, if not satisfied, continue to center the trolley until the axis deviation meets the target value; mold frame lifting, and determine whether the elevation meets the target value, if satisfied, proceed to the next step, if not satisfied, continue to lift the mold frame until the elevation meets the target value; side mold opening and closing, and determine whether the over-excavation and under-excavation meet the side mold closing target value, if satisfied, the positioning process ends, if not satisfied, continue to adjust the side mold opening and closing until the side mold closing target value is met.

[0020] Preferably, in step S3, the trolley mold opening includes the side mold retraction and the mold frame lowering, the side mold retraction is controlled by the opening and closing cylinder, and the mold frame lowering is controlled by the lifting cylinder. According to the analysis of the drawings, the displacement design value range of the opening and closing cylinder and the lifting cylinder is set, and the trolley mold opening process is:

[0021] First, the opening and closing cylinder is retracted, and it is determined whether the displacement reduction after the retraction is greater than the minimum value within the displacement design value range. If not, the opening and closing cylinder is continued to be retracted until it meets the requirements; if so, it is continued to be determined whether the displacement reduction after the retraction is less than the maximum value within the displacement design value range. If so, the next step is performed. If not, the opening and closing cylinder is extended until the displacement reduction after the retraction is greater than the minimum value within the displacement design value range and less than the maximum value within the displacement design value range.

[0022] Then, proceed to the next step, the jacking cylinder descends, and determines whether the displacement reduction is greater than the minimum value within the displacement design value range. If not, continue to lower the jacking cylinder until it meets the requirements; if so, continue to determine whether the displacement reduction is less than the maximum value within the displacement design value range. If the mold opening is completed, if not, the jacking cylinder rises until it satisfies the simultaneous requirements that the displacement reduction is greater than the minimum value within the displacement design value range and less than the maximum value within the displacement design value range.

[0023] Preferably, in step S3, the trolley track correction is divided into track lifting and track centering, the track lifting is controlled by the lifting cylinder, and the track centering is controlled by the translation cylinder. According to the analysis of the drawings, the displacement design value range of the lifting cylinder is set, and the track correction operation is performed by relying on the track centering displacement of the translation cylinder when the mold frame is still in the centering state after mold opening. The trolley track correction process is as follows:

[0024] First, the lifting cylinder is lowered, and it is determined whether the displacement reduction amount of the descent is greater than the minimum value within the displacement design value range. If not, the lifting cylinder continues to be lowered until it meets the requirements; if so, it continues to be determined whether the displacement reduction amount of the descent is less than the maximum value within the displacement design value range. If so, the next step is performed. If not, the lifting cylinder is lifted until the displacement reduction amount of the descent is greater than the minimum value within the displacement design value range and less than the maximum value within the displacement design value range.

[0025] Then, proceed to the next step, move the hydraulic cylinder to move horizontally, and determine whether it is within the set range of the track centering value. If so, the track correction is completed. If not, continue to move the hydraulic cylinder to move horizontally until it is within the set range of the track centering value.

[0026] Preferably, in step S3, the trolley rail delivery action is divided into track lifting and track advancement, the track lifting is controlled by the lifting cylinder, and the track advancement is controlled by the travel motor. The trolley torsion angle can be calculated by the displacement difference of the two mileage lasers, and the track deflection angle can be calculated by the translation cylinder displacement. The track lifting height is consistent with the displacement design value range set when the trolley corrects the track, and the motor running time is set as the track advancement time. The trolley rail delivery process is:

[0027] First, the rail is delivered and the torsion angle of the trolley is calculated to see whether it meets the design requirements. If not, the track is adjusted or the trolley is aligned until it meets the design requirements. If so, it is determined whether the calculated track deflection angle meets the design requirements. If so, it proceeds to the next step. If not, the trolley is corrected until it meets the design requirements.

[0028] Then, the lifting cylinder descends, and determines whether the displacement reduction amount of the descent is greater than the minimum value within the displacement design value range. If not, the lifting cylinder continues to descend until it meets the requirements; if so, it continues to determine whether the displacement reduction amount of the descent is less than the maximum value within the displacement design value range. If so, proceed to the next step. If not, the lifting cylinder is lifted until the displacement reduction amount of the descent is greater than the minimum value within the displacement design value range and less than the maximum value within the displacement design value range.

[0029] Finally, the motor reverses and determines whether it has run for the designed time. If so, the rail delivery is completed. If not, it continues to run until the designed time.

[0030] Preferably, in step S3, the trolley walking action is divided into track falling and trolley walking, the track falling is controlled by the lifting cylinder, and the trolley walking is controlled by the walking motor. The track falling height is the mold opening height of the lifting cylinder, and the motor running time is set to the track forward time. The trolley walking process is:

[0031] First, the lifting cylinder is lifted, and it is determined whether the displacement reduction of the lifting is less than the maximum value within the displacement design value range. If not, the lifting cylinder is continuously lifted until the requirement is met; if so, it is continuously determined whether the displacement reduction of the lifting is greater than the minimum value within the displacement design value range. If so, the next step is performed. If not, the lifting cylinder is lowered until the displacement reduction of the lowering is less than the maximum value within the displacement design value range and greater than the minimum value within the displacement design value range.

[0032] Then, the motor rotates forward and determines whether the mileage measured by the laser reaches the target value. If so, the travel is completed. If not, the motor runs for a set time and determines whether the motor runs for the set time. If so, the travel is completed. If not, it determines whether the mileage distance is less than the set value. If so, the motor decelerates and repeats the above motor forward rotation judgment process. If not, directly repeat the above motor forward rotation judgment process.

[0033] Preferably, in step S3, the trolley centering action is controlled by the translation cylinder, and the trolley centering state is acquired by the offset laser sensor. The trolley centering process is as follows: at the beginning of centering, both the front and rear end translation cylinders are in motion, and it is determined whether the front and rear end offset laser displacement values ​​are within the set error range of the set offset laser displacement target value. If so, the centering is completed, and if not, both the front and rear end translation cylinders continue to move until the target requirement is met.

[0034] Preferably, in step S3, the mold closing action of the trolley is divided into mold frame lifting and side mold expansion. The mold frame lifting state is obtained by the elevation laser sensor and the lifting cylinder pressure, and the side mold expansion state is obtained by the opening and closing cylinder pressure. The mold closing process of the trolley is as follows:

[0035] First, mold closing starts, the lifting cylinder moves, and it is determined whether the elevation laser displacement is within the error range set by the elevation laser displacement target value. If so, proceed to the next step. If not, it is determined whether the lifting cylinder pressure reaches the elevation pressure target value. If so, proceed to the next step. If not, the lifting cylinder moves and the above steps are repeated.

[0036] Then, the opening and closing cylinder is actuated, and it is determined whether the pressure of the opening and closing cylinder reaches the target value of the side mold clamping pressure. If so, the mold clamping is completed. If not, the opening and closing cylinder is actuated, and the above steps are repeated.

[0037] The present invention has at least the following beneficial effects:

[0038] The positioning method of the present invention includes a comprehensive positioning scheme for trolley mileage positioning, axis positioning, elevation positioning, and side mold positioning. The scheme uses a pair of front laser rangefinders to locate the trolley mileage, two pairs of laser rangefinders to locate the trolley axis, two pairs of laser rangefinders, pressure sensors, and travel switches to locate the trolley elevation, and displacement sensors, pressure sensors, and travel switches to locate the side mold closing position. Compared with the prior art, the multi-sensor fusion positioning scheme of the present invention can significantly improve positioning efficiency, positioning accuracy, and reduce the need for positioning personnel. At the same time, it has a higher degree of automation, is simple and convenient to operate, has a smaller positioning error, and has a higher operating efficiency, and fully guarantees the safety and reliability of the construction process. For example, according to statistics from actual projects, the trolley positioning process of the existing technology takes about forty minutes, while the improved positioning solution only takes twenty minutes to complete the positioning; the trolley positioning accuracy of the existing technology is generally within 5mm and the direction of each positioning deviation cannot be predicted, while the positioning accuracy of the improved positioning solution can be maintained within 3mm and the direction of positioning deviation can be predicted in advance; the existing technology requires at least one surveyor and two trolley operators to complete the trolley positioning, while the improved positioning solution ideally only requires one trolley operator.

[0039] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a front view of the trolley of the present invention;

[0041] Figure 2 It is a side view of the trolley of the present invention;

[0042] Figure 3 This is a flow chart of the trolley's travel and positioning in the present invention;

[0043] Figure 4 A schematic diagram of obtaining the target value of mileage laser displacement according to the present invention;

[0044] Figure 5 A schematic diagram of obtaining the target value of the offset laser displacement according to the present invention;

[0045] Figure 6 A schematic diagram of obtaining the elevation target value of the present invention;

[0046] Figure 7 A schematic diagram for collecting reference points and ground elevation for surveyors of the present invention;

[0047] Figure 8 This is a flow chart of the automatic mold opening procedure of the present invention;

[0048] Fig. 9 This is a flow chart of the automatic track correction program of the present invention;

[0049] Fig.10 This is a flow chart of the automatic rail delivery procedure of the present invention;

[0050] Fig.11 This is a flowchart of the walking adaptive program of the present invention;

[0051] Fig.12 This is a flow chart of the automatic centering procedure of the present invention;

[0052] Fig.13 It is a flow chart of the automatic mold closing procedure of the present invention. DETAILED DESCRIPTION

[0053] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement it according to the description.

[0054] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified; in the description of the present invention, the terms "lateral", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0055] like Figure 1 and Figure 2 As shown, it is a schematic diagram of the template trolley structure corresponding to the present invention, which are a front view and a side view respectively, wherein the structures represented by each number are respectively: 1-top mold, 2-top mold frame, 3-lifting cylinder, 4-translation cylinder, 5-door frame, 6-side mold, 7-side mold through beam, 8-side mold cylinder, 9-side mold screw, 10-laser displacement sensor, 11-soft overlap, 12-travel motor, 13-track support foot, 14-working platform, 15-working ladder.

[0056] The positioning method of the present application is implemented in three steps: Step S1 is to obtain the positioning target value, and the main purpose of this step is to obtain the positioning target position parameters through theoretical calculation, drawing analysis or actual measurement; Step S2 is the preparation before trolley positioning, including the placement of position targets and the initial state of the trolley. This step is equivalent to the initialization of the positioning process and prepares various prerequisites for the positioning process; Step S3 is the trolley positioning adjustment. The control system relies on various sensors used for positioning to adjust the trolley mileage, trolley axis, trolley elevation and side mold position in turn.

[0057] Step S1: Acquisition of positioning target value.

[0058] Step S11: Obtaining the mileage laser displacement target value. The mileage laser displacement target value is the mapping length from the laser emission point to the edge point of the side mold along the center axis of the trolley. In actual operation, the trolley is usually first closed to the mileage design position by manual adjustment, and then the mileage position target is placed at the mold closing seam position to obtain the value. Figure 4 The laser emission point is set on the horse stool in the forward direction, and one is set symmetrically on each side to obtain two mileage laser displacement target values.

[0059] Step S12: Obtaining the target value of the offset laser displacement. The target value of the offset laser displacement is the distance from the laser emission point to the vertical plane of the center axis of the trolley. In actual operation, the trolley is usually first manually adjusted to the axis design position, and then the axis position target is placed at a fixed distance parallel to the center axis of the trolley (considering that the accuracy of the laser displacement sensor decreases as the detection distance increases, the axis position target is placed appropriately close to the laser emission point) to obtain this value. Figure 5 As shown, four laser emission points are symmetrically set on the four horse stools in front and behind to obtain four offset laser displacement target values.

[0060] Step S13: Acquisition of elevation target value, including acquisition of elevation laser target value and elevation pressure target value. The calculation formula of elevation laser displacement target value is:

[0061] Z 高程激光位移目标值 =Z 拱顶理论高程 -H 拱顶到激光发射点垂直高度 -Z 地面实测高程 In the actual operation process, the trolley is usually first closed to the elevation design position by manual adjustment, the elevation positioning parameters of the initial segment are collected, and then the elevation laser displacement target value of the current stage is converted through a certain formula.

[0062]

[0063] The calculation formula for the elevation pressure target value is F 高程压力目标值 =(W 台车总重 ÷4)×1.3, the total weight of the trolley can be calculated from the material table. Figure 6 shown.

[0064] Step S14: Obtaining the side mold clamping target value, including obtaining the side mold clamping displacement target value and the side mold clamping pressure target value. The side mold clamping displacement target value is obtained by measuring the design drawing, and the side mold clamping pressure target value is calculated as follows: F 侧模合模压力目标值 =F 侧模合模压力 ×1.3.

[0065] Step S2: Preparation before positioning the trolley.

[0066] Step S21: Surveyors place reference points and collect ground elevation. Surveyors use a total station to place four reference points for the next plate in advance, which are located at four symmetrical points on the front and back sides of the template contour projection, and collect the actual ground elevation at the elevation measurement point of the next plate. Figure 7 shown.

[0067] Step S22: Position target placement. According to the reference point and with the help of a laser level, two mileage targets and four offset target positions are laid out, and the mileage targets and offset targets are placed at the corresponding positions before the trolley is positioned. Figure 7 shown.

[0068] Step S23: The trolley is put back to its initial state. Since the trolley is in the mold closing position of the previous plate before positioning, the side mold support rods, track support rods, etc. need to be removed to provide conditions for the forward positioning of the trolley.

[0069] Step S3: Carriage positioning adjustment. Figure 3 The figure shows the flow chart of the trolley travel positioning of the present invention.

[0070] Step S31: The trolley automatically opens the mold. The trolley mold opening action is divided into the retraction of the side mold and the lowering of the mold frame. The retraction of the side mold is controlled by the opening and closing cylinder, and the lowering of the mold frame is controlled by the lifting cylinder. According to the construction requirements, the trolley should be as far away from the poured concrete as possible after the mold is opened, that is to say, the opening and closing cylinder and the lifting cylinder are retracted as much as possible. According to the analysis of the drawings, the lifting cylinder is lowered by 15 cm (the support leg is 2 cm off the ground at this time), and the opening and closing cylinder is retracted by 15 cm (the fixed support rod is about 5 mm away from the side mold at this time). The automatic mold opening program flow is as follows Figure 8 shown.

[0071] Step S32: Automatic track correction by the trolley. The track correction action of the trolley is divided into track lifting and track centering. The track lifting is controlled by the lifting cylinder, and the track centering is controlled by the translation cylinder. The track lifting height is affected by factors such as the flatness of the ground, the gap between the track clamps, and the deformation of the track flange plate. It cannot be obtained by theoretical analysis. After actual testing, the lifting cylinder is lowered by 28 cm (compared to the mold closing position); due to the lack of perception measures for the track posture, the track centering here must be effective under the premise of mold frame centering. Therefore, it is necessary to rely on the track centering displacement of the translation cylinder to perform the track correction operation when the mold frame is still in the centering state after mold opening. This displacement can only be obtained by actual testing due to factors such as mold frame error, pin shaft gap, and sensor installation deviation. The automatic track correction program flow is as follows: Fig. 9 shown.

[0072] Step S33: The trolley automatically delivers the rail. The trolley rail delivery action is divided into track lifting and track advancement. The track lifting is controlled by the lifting cylinder, and the track advancement is controlled by the travel motor. The track lifting height is consistent with the trolley track correction; due to the lack of perception measures for the track posture, the track advancement is perceived with the help of the motor action time. Through testing, it is found that the track travel is exhausted after the motor runs at a constant speed for 68 seconds. Considering the need to leave a certain fault tolerance margin, the motor is set to run for 60 seconds as the track advancement time. The trolley torsion angle can be calculated by the displacement difference of the two mileage lasers, and the track deflection angle can be calculated by the displacement of the translation cylinder. The automatic rail delivery program flow is as follows: Fig.10 shown.

[0073] Step S34: The trolley moves automatically. The trolley walking action is divided into track dropping and trolley walking. The track dropping is controlled by the lifting cylinder, and the trolley walking is controlled by the walking motor. The track dropping height is the mold opening height of the lifting cylinder; due to the lack of perception measures for the track posture, the trolley walking state is sensed with the help of the motor action time (60s); during the walking process, the trolley may reach the mold closing position at any time, so it is necessary to use a mileage laser sensor to sense the mileage position of the trolley in real time. The mileage laser displacement target value is the mapping length from the laser emission point to the edge point of the side mold along the center axis of the trolley. The walking adaptive program flow is as follows: Fig.11 shown.

[0074] Step S35: The trolley is automatically centered. The trolley centering action is controlled by the translation cylinder. The trolley centering state is acquired by the offset laser sensor. When the trolley is in the centering state, the offset laser displacement is equal to the offset laser displacement target value. The automatic centering procedure is as follows: Fig.12 shown.

[0075] Step S36: The trolley automatically closes the mold. The trolley closing action is divided into mold frame lifting and side mold expansion. The mold frame lifting state is known by the elevation laser sensor and the lifting cylinder pressure, and the side mold expansion state is known by the opening and closing cylinder pressure. When the trolley is in the elevation position, the elevation laser displacement is equal to the elevation laser displacement target value. The automatic mold closing program flow is as follows Fig.13 shown.

[0076] It is understood that the present invention is described by some embodiments, and those skilled in the art are aware that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation mode, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, other modifications can be easily implemented, so without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A multi-sensor fusion positioning method for a tunnel lining trolley, characterized in that: The steps include: Step S1, obtaining positioning target values, obtaining target position parameters for trolley positioning through theoretical calculation, drawing analysis or actual measurement, including obtaining trolley mileage target values, obtaining offset displacement target values, obtaining elevation target values, and obtaining side mold closing target values; Step S2, preparation before positioning the trolley, including placement of position targets and initialization of the trolley; Step S3, trolley positioning adjustment, relying on various sensors used for positioning to adjust the trolley mileage, trolley axis, trolley elevation and side mold position in turn.

2. The multi-sensor fusion positioning method for tunnel lining trolley according to claim 1, characterized in that: The acquisition of the mileage laser displacement target value in step S1 specifically includes: setting a laser emission point, closing the mold of the trolley to the mileage design position, and then placing the mileage position target at the mold closing joint position. The mapping length from the laser emission point to the edge point of the side mold along the center axis of the trolley is the mileage laser displacement target value; The acquisition of the offset laser displacement target value in step S1 specifically includes: setting a laser emission point, closing the trolley to the axis design position, and then placing the axis position target at a fixed distance parallel to the trolley center axis. The distance from the laser emission point to the vertical plane of the trolley center axis is the offset laser displacement target value.

3. The multi-sensor fusion positioning method for a tunnel lining trolley according to claim 1, characterized in that: The acquisition of the elevation target value in step S1 includes the acquisition of the elevation laser target value and the elevation pressure target value. The calculation formula of the elevation laser displacement target value is: Z 高程激光位移目标值 =Z 拱顶理论高程 -H 拱顶到激光发射点垂直高度 -Z 地面实测高程 ; The trolley is molded to the elevation design position, and the elevation positioning parameters of the initial segment are collected. The calculation formula for the elevation laser displacement target value of each segment at the current stage is: ； The calculation formula for the elevation pressure target value is: F 高程压力目标值 =(W 台车总重 ÷4)×1.3; The acquisition of the side mold clamping target value in step S1 includes the acquisition of the side mold clamping displacement target value and the side mold clamping pressure target value. The side mold clamping displacement target value is obtained by measuring the design drawing, and the side mold clamping pressure target value is calculated as follows: 侧模合模压力目标值 =F 侧模合模压力 ×1.

3.

4. The multi-sensor fusion positioning method for a tunnel lining trolley according to claim 1, characterized in that: The step S2 comprises the following steps: Step S21: using a total station to place four reference points of the next plate in advance and collect the actual ground elevation at the elevation measurement point of the next plate; Step S22: Locate the mileage target and the offset target according to the reference point with the aid of a laser level, and place the mileage target and the offset target at corresponding positions before positioning the trolley; Step S23: Return the trolley to its initial state.

5. The multi-sensor fusion positioning method for a tunnel lining trolley according to claim 2 or 3, characterized in that: The specific process of step S3 is as follows: trolley mold opening; trolley track correction; trolley rail delivery; trolley travel; mileage adjustment, determine whether the mileage reaches the target value, if reached, proceed to the next step, if not, the trolley rail delivery is performed again until the mileage reaches the target value; trolley centering, and determine whether the axis deviation meets the target value, if satisfied, proceed to the next step, if not satisfied, continue to trolley centering, until the axis deviation meets the target value; mold frame lifting, and determine whether the elevation meets the target value, if satisfied, proceed to the next step, if not satisfied, continue to lift the mold frame until the elevation meets the target value; side mold opening and closing, and determine whether the over-excavation and under-excavation meet the side mold closing target value, if satisfied, the positioning process ends, if not satisfied, continue to adjust the side mold opening and closing until the side mold closing target value is met.

6. The multi-sensor fusion positioning method for a tunnel lining trolley according to claim 5, characterized in that: In step S3, the trolley mold opening includes the side mold retraction and the mold frame lowering. The side mold retraction is controlled by the opening and closing cylinder, and the mold frame lowering is controlled by the lifting cylinder. According to the drawing analysis, the displacement design value range of the opening and closing cylinder and the lifting cylinder is set. The trolley mold opening process is: First, the opening and closing cylinder is retracted, and it is determined whether the displacement reduction after the retraction is greater than the minimum value within the displacement design value range. If not, the opening and closing cylinder is continued to be retracted until it meets the requirements; if so, it is continued to be determined whether the displacement reduction after the retraction is less than the maximum value within the displacement design value range. If so, the next step is performed. If not, the opening and closing cylinder is extended until the displacement reduction after the retraction is greater than the minimum value within the displacement design value range and less than the maximum value within the displacement design value range. Then, proceed to the next step, the jacking cylinder descends, and determines whether the displacement reduction is greater than the minimum value within the displacement design value range. If not, continue to lower the jacking cylinder until it meets the requirements; if so, continue to determine whether the displacement reduction is less than the maximum value within the displacement design value range. If the mold opening is completed, if not, the jacking cylinder rises until it satisfies the simultaneous requirements that the displacement reduction is greater than the minimum value within the displacement design value range and less than the maximum value within the displacement design value range.

7. The multi-sensor fusion positioning method for a tunnel lining trolley according to claim 5, characterized in that: In step S3, the track correction of the trolley is divided into track lifting and track centering. The track lifting is controlled by the lifting cylinder, and the track centering is controlled by the translation cylinder. According to the analysis of the drawings, the displacement design value range of the lifting cylinder is set. At the same time, when the mold frame is still in the centering state after mold opening, the track correction operation is performed by relying on the track centering displacement of the translation cylinder. The trolley track correction process is as follows: First, the lifting cylinder is lowered, and it is determined whether the displacement reduction amount of the descent is greater than the minimum value within the displacement design value range. If not, the lifting cylinder continues to be lowered until it meets the requirements; if so, it continues to be determined whether the displacement reduction amount of the descent is less than the maximum value within the displacement design value range. If so, the next step is performed. If not, the lifting cylinder is lifted until the displacement reduction amount of the descent is greater than the minimum value within the displacement design value range and less than the maximum value within the displacement design value range. Then, proceed to the next step, the translation cylinder moves, and determines whether it is within the set range of the track centering value. If so, the track correction is completed. If not, the translation cylinder continues to move until it is within the set range of the track centering value. In step S3, the trolley rail delivery action is divided into track lifting and track advancement. The track lifting is controlled by the lifting cylinder, and the track advancement is controlled by the travel motor. The trolley torsion angle can be calculated by the displacement difference of the two mileage lasers, and the track deflection angle can be calculated by the displacement of the translation cylinder. The track lifting height is consistent with the displacement design value range set when the trolley corrects the track, and the motor running time is set as the track advancement time. The trolley rail delivery process is: First, the rail is delivered and the torsion angle of the trolley is calculated to see whether it meets the design requirements. If not, the track is adjusted or the trolley is aligned until it meets the design requirements. If so, it is determined whether the calculated track deflection angle meets the design requirements. If so, it proceeds to the next step. If not, the trolley is corrected until it meets the design requirements. Then, the lifting cylinder descends, and determines whether the displacement reduction amount of the descent is greater than the minimum value within the displacement design value range. If not, the lifting cylinder continues to descend until it meets the requirements; if so, it continues to determine whether the displacement reduction amount of the descent is less than the maximum value within the displacement design value range. If so, proceed to the next step. If not, the lifting cylinder is lifted until the displacement reduction amount of the descent is greater than the minimum value within the displacement design value range and less than the maximum value within the displacement design value range. Finally, the motor reverses and determines whether it has run for the designed time. If so, the rail delivery is completed. If not, it continues to run until the designed time.

8. The multi-sensor fusion positioning method for a tunnel lining trolley according to claim 6, characterized in that: In step S3, the trolley walking action is divided into track falling and trolley walking. The track falling is controlled by the lifting cylinder, and the trolley walking is controlled by the walking motor. The track falling height is the mold opening height of the lifting cylinder. The motor running time is set to the track forward time. The trolley walking process is: First, the lifting cylinder is lifted, and it is determined whether the displacement reduction of the lifting is less than the maximum value within the displacement design value range. If not, the lifting cylinder is continuously lifted until the requirement is met; if so, it is continuously determined whether the displacement reduction of the lifting is greater than the minimum value within the displacement design value range. If so, the next step is performed. If not, the lifting cylinder is lowered until the displacement reduction of the lowering is less than the maximum value within the displacement design value range and greater than the minimum value within the displacement design value range. Then, the motor rotates forward and determines whether the mileage measured by the laser reaches the target value. If so, the travel is completed. If not, the motor runs for a set time and determines whether the motor runs for the set time. If so, the travel is completed. If not, it determines whether the mileage distance is less than the set value. If so, the motor decelerates and repeats the above motor forward rotation judgment process. If not, directly repeat the above motor forward rotation judgment process.

9. The multi-sensor fusion positioning method for a tunnel lining trolley according to claim 5, characterized in that: In step S3, the trolley centering action is controlled by the translation cylinder, and the trolley centering status is obtained by the offset laser sensor. The trolley centering process is: when the centering starts, the front and rear end translation cylinders are both in motion, and it is determined whether the front and rear end offset laser displacement values ​​are within the set offset laser displacement target value setting error range. If so, the centering is completed, if not, the front and rear end translation cylinders continue to move until the target requirements are met.

10. The multi-sensor fusion positioning method for a tunnel lining trolley according to claim 5, characterized in that: In step S3, the mold closing action of the trolley is divided into mold frame lifting and side mold expansion. The mold frame lifting state is obtained by the elevation laser sensor and the lifting cylinder pressure, and the side mold expansion state is obtained by the opening and closing cylinder pressure. The mold closing process of the trolley is as follows: First, mold closing starts, the lifting cylinder moves, and it is determined whether the elevation laser displacement is within the error range set by the elevation laser displacement target value. If so, proceed to the next step. If not, it is determined whether the lifting cylinder pressure reaches the elevation pressure target value. If so, proceed to the next step. If not, the lifting cylinder moves and the above steps are repeated. Then, the opening and closing cylinder is actuated, and it is determined whether the pressure of the opening and closing cylinder reaches the target value of the side mold clamping pressure. If so, the clamping is completed. If not, the opening and closing cylinder is actuated, and the above steps are repeated.

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