CN117262049A

CN117262049A - Automatic transfer station measuring device and measuring method for butt joint of ship block by using same

Info

Publication number: CN117262049A
Application number: CN202311088960.3A
Authority: CN
Inventors: 李磊; 陈庆辉; 周宏根; 何强
Original assignee: Jiangsu University of Science and Technology
Current assignee: Jiangsu University of Science and Technology
Priority date: 2023-08-25
Filing date: 2023-08-25
Publication date: 2023-12-22

Abstract

The invention discloses an automatic transfer station measuring device and a measuring method for butt joint of a ship block by using the same, comprising the following steps: the device comprises a movable bottom platform, a middle adjusting platform and a top adjusting platform, wherein the middle adjusting platform comprises a primary jacking mechanism, a primary rotating mechanism and a middle lifting plate, the primary jacking mechanism is fixedly arranged between the movable bottom platform and the middle lifting plate, and the primary rotating mechanism is fixedly arranged on the middle lifting plate; the top adjusting platform comprises an accurate jacking mechanism, an accurate rotating mechanism and a clamping mechanism, wherein the accurate rotating mechanism is fixedly arranged on the primary rotating mechanism, the accurate rotating mechanism is in driving connection with the accurate jacking mechanism, the clamping mechanism is fixedly arranged on the accurate jacking mechanism, and the measuring instrument is fixedly arranged on the clamping mechanism; the primary jacking mechanism is used for realizing the initial lifting and rotation of the measuring instrument, and the accurate rotating mechanism is used for realizing the accurate rotation and lifting of the measuring instrument. The invention is suitable for automatic transfer station measurement of various complex assembled terrains.

Description

Automatic transfer station measuring device and measuring method for butt joint of ship block by using same

Technical Field

The invention relates to engineering measurement technology, in particular to an automatic transfer station measurement device and a measurement method for butt joint of ship blocks by using the same.

Background

At present, huge block building methods are mostly adopted by shipyards in China to build and assemble ships, and in the process of assembling two blocks, high-precision measurement of block measurement key points is required to be realized. When the measuring instrument measures the key points of the total section, the measuring work of all the key points is difficult to be completed only at one measuring station, so that the instrument needs to be manually carried, and the labor and the effort are wasted. In addition, in the manual carrying process, in order to avoid the influence of external vibration and other factors on the measuring instrument, the measuring instrument needs to be closed and then manually carried. When restarting the instrument, the instrument needs to be preheated again for a long time, so that the waiting time is too long, the measuring period is long, and the measuring working efficiency is seriously affected.

Through retrieval, patent document CN 113296112a discloses a laser tracker mobile measurement trolley device. The device drives the laser tracker through the bottom walking wheel and carries out back and forth and left and right movement, realizes the up-and-down adjustment of the laser tracker through the screw drive rod, and the device has increased the flexibility that the laser tracker was adjusted, has improved measurement of efficiency. However, manual pushing and the like are needed, and labor is consumed; the laser tracker is a high-precision instrument, the device is not designed in a shock-absorbing way, and the device can relate to a complex environment and a certain obstacle aiming at shipyard measurement and is not easy to move manually in a narrow space.

Through retrieval, patent document CN 112710236B discloses a method for measuring the mounting posture of a spacecraft high-precision instrument based on a laser tracker, and the laser tracker is fixed through a trolley so as to track the spacecraft high-precision posture, thereby improving the measurement precision and efficiency. However, the complexity of the scene during object attitude measurement is not considered, and the trolley has no functions of avoiding obstacles and the like.

Disclosure of Invention

The invention aims to: an object of the present invention is to provide an automatic transfer station measuring device which is more stable, has a better anti-seismic effect, and can be adapted to various complex assembly terrains.

Another object of the invention is to provide a measuring method for butt joint of a ship block using the device.

The technical scheme is as follows: an automatic transfer station measuring apparatus of the present invention includes:

a movable bottom platform;

the middle adjusting platform comprises a primary jacking mechanism, a primary rotating mechanism and a middle lifting plate, wherein the lower end of the primary jacking mechanism is fixedly arranged on the movable bottom platform, the upper end of the primary jacking mechanism is fixedly arranged at the bottom of the middle lifting plate, and the primary rotating mechanism is fixedly arranged on the middle lifting plate;

the top adjusting platform comprises an accurate jacking mechanism, an accurate rotating mechanism and a clamping mechanism, wherein the accurate rotating mechanism is fixedly arranged on the primary rotating mechanism, the accurate rotating mechanism is in driving connection with the accurate jacking mechanism, the clamping mechanism is fixedly arranged on the accurate jacking mechanism, and the measuring instrument is fixedly arranged on the clamping mechanism;

The primary jacking mechanism is used for realizing the initial lifting of the middle lifting plate, the primary rotating mechanism and the top adjusting platform, so as to realize the initial lifting of the measuring instrument; the preliminary rotating mechanism drives the accurate rotating mechanism to rotate, so that the initial rotation of the measuring instrument is realized; the precise rotating mechanism drives the precise jacking mechanism to rotate, so that the precise rotation of the measuring instrument is realized; the accurate jacking mechanism is used for realizing the lifting of the clamping mechanism, so as to realize the accurate lifting of the measuring instrument.

Preferably, the movable bottom platform comprises a driving mechanism for driving the device to move and rotate in situ, a damping mechanism arranged on the driving mechanism for damping the device, an obstacle surmounting mechanism fixed on the device shell for crossing an obstacle, a vision module for identifying the topography of a measuring field, a positioning module for positioning the device, and a control module; the receiver of the positioning module is arranged on the movable bottom platform, the transmitter is arranged on the measuring site, and the control module is used for controlling the whole device.

Preferably, the driving mechanism comprises a bottom plate, a Mecanum wheel, a speed encoder, a first motor and a universal bearing, wherein the first motor is fixedly arranged on the bottom plate, the movement and the rotation of the Mecanum wheel are driven through the universal bearing, the speed encoder monitors the rotating speed of the first motor and transmits the rotating speed of the first motor to the control module, and the control module controls the first motor so as to regulate the Mecanum wheel in real time;

The damping mechanism comprises a damping spring and a connecting rod mechanism, one end of the damping spring is fixedly connected with the first motor, the other end of the damping spring is fixedly connected with the Mecanum wheel, and the connecting rod mechanism is used for limiting the Mecanum wheel when vibrating up and down;

the obstacle crossing mechanism comprises a crawler device, a second motor and an obstacle crossing mechanism hydraulic rod, the second motor drives the crawler device to move, the obstacle crossing mechanism hydraulic rod is used for lifting the crawler device, one end of the obstacle crossing mechanism hydraulic rod is fixed on a device shell, and the other end of the obstacle crossing mechanism hydraulic rod is fixed on the crawler device.

Preferably, the primary jacking mechanism comprises an initial jacking hydraulic rod and an initial jacking laser distance meter, wherein the lower end of the initial jacking hydraulic rod is fixedly arranged on the movable bottom platform, the upper end of the initial jacking hydraulic rod is arranged at the bottom of the middle lifting plate, the initial jacking laser distance meter is fixedly arranged on the movable bottom platform, and the lifting of the initial jacking mechanism is measured and fed back.

Preferably, preliminary rotary mechanism includes rack laser rangefinder, middle part rotary gear, middle part rotary platform, the slide bar base, the rack, slide bar and cylinder, middle part rotary platform fixed mounting is on the middle part lifter plate, its week side-mounting has middle part rotary gear, slide bar base fixed mounting is on the middle part lifter plate, be located middle part rotary platform both sides, the rack passes through slide bar and slide bar base sliding connection, rack and middle part rotary gear mesh mutually, the one end at the slide bar base is installed to the cylinder, rack laser rangefinder installs on the middle part lifter plate, during initial rotation, cylinder control rack motion, thereby rotate through middle part rotary gear drive middle part rotary platform, simultaneously, rack laser rangefinder monitors and feeds back rack motion state, thereby make the initial rotation angle of middle part platform adjust more accurately.

Preferably, the accurate climbing mechanism comprises a top lifting plate, a sleeve, a rack bearing, a gear, a third motor and an accurate jacking laser distance meter, wherein the top lifting plate is fixedly connected with a top rotating platform through the sleeve, the upper end of the rack bearing is fixedly arranged at the bottom of the top lifting plate, the lower end of the rack bearing is fixedly arranged on the top rotating platform, the rack bearing is meshed with the gear, the third motor drives the gear to drive the rack bearing to move up and down, lifting of the top lifting plate is realized through the sleeve, and the accurate jacking laser tracker measures and feeds back lifting of the top lifting plate, so that an accurate lifting function is realized.

Preferably, the accurate rotary mechanism comprises a top rotary gear, a rotary outer ring, a Hall encoder and a fourth motor, wherein the rotary outer ring is fixedly arranged on the primary rotary mechanism, the Hall encoder is fixedly arranged on the rotary outer ring and meshed with the top rotary gear, the top rotary gear is arranged on the peripheral side surface of the top rotary platform of the accurate jacking mechanism, the fourth motor drives the Hall encoder to drive the top rotary gear to move, and meanwhile, the Hall encoder monitors and feeds back the rotation angle of the top rotary gear, so that the accurate rotation of the measuring instrument is realized.

Preferably, the clamping mechanism comprises a chassis, a plurality of clamping claws uniformly arranged along the circumference of the chassis, the clamping claws are rotationally connected with the chassis, a device placement platform for installing the measuring instrument is arranged in the center of the chassis, and the clamping claws are used for clamping the measuring instrument.

Based on the same inventive concept, the measuring method for the butt joint of the ship block by using the automatic transfer station measuring device comprises the following steps:

the automatic transfer station measuring device is lifted into an area I of the dock, and the automatic transfer station measuring device is positioned through UWB positioning base stations on first to fourth struts arranged around the area I, so that initial positioning of the automatic transfer station measuring device is realized; then, measuring the first to eighth common datum point targets by using a measuring device laser tracker, so as to realize accurate positioning;

after the positioning is finished, measuring the space positions of the key point targets of the moving block and the fixed block, which are close to the area I; then the automatic station-switching measuring device runs from the area I to the area II, at the moment, the base stations on the first positioning base station support column and the second positioning base station support column are closed, the base stations on the fifth positioning base station support column and the sixth positioning base station support column which are arranged around the area III are opened, the automatic station-switching measuring trolley is positioned, and the step of the crossing process is completed through the vision module and the obstacle crossing mechanism;

And finally, the automatic station switching measuring device enters the area III, at the moment, the base stations on the third and fourth positioning base station support columns are closed, the base stations on the seventh and eighth positioning base station support columns arranged around the area III are opened, the automatic station switching measuring device completes initial positioning through the UWB positioning module, and the laser tracker measures the ninth to sixteenth common datum point targets to complete accurate positioning, so that the space positions of the key point targets of the movable total section and the fixed total section, which are close to the area I, are measured, and the whole measuring process is completed.

Further, before the automatic transfer station measuring device transfers the station and moves, firstly, the initial jacking mechanism and the accurate jacking mechanism of the automatic transfer station measuring device are reduced to the minimum, secondly, the deviation of the automatic transfer station measuring device in the XYZ direction is calculated through the spatial position information of the pre-established station position II relative to the station position I, and the deviation value of the automatic transfer station measuring device under the spatial coordinate system is converted into the motion rotation track of each Mecanum wheel;

the method for avoiding obstacles and crossing obstacles by the automatic station-switching measuring device in the station-switching process comprises the following steps:

during the running process of the automatic transfer station measuring device, if an obstacle which cannot be spanned is encountered in the range of the movement track, the movement track of the automatic transfer station measuring device is planned again, and the obstacle is avoided; if the obstacle capable of crossing is encountered in the range of the movement track, firstly, the obstacle is identified through the vision module, the distance between the obstacle and the automatic transfer station measuring device is judged, when the distance between the automatic transfer station measuring device and the obstacle reaches a preset distance, the Mecanum wheel stops running, the obstacle crossing mechanism is lowered to cross the obstacle, and after the obstacle crossing is completed, the obstacle crossing mechanism is retracted to continue driving the Mecanum wheel to move.

The beneficial effects are that: compared with the prior art, the invention has the remarkable technical effects that:

(1) According to the invention, the automatic station switching of the measuring equipment can be realized through a mechanical structure, so that the manual investment is reduced; the measurement device can rotate in situ through the Mecanum wheel, so that the flexibility of the measurement device is improved; the shock absorbing function of the measuring device is realized through the shock absorbing mechanism, so that the precise transportation of precise measuring equipment is ensured;

(2) According to the invention, the track is spanned by the measuring device through the obstacle crossing mechanism, the initial rotation and lifting of the measuring device are realized through the middle adjusting platform, the accurate rotation and lifting of the measuring device are realized through the top adjusting platform, the stress balance of the measuring device is realized through the clamping mechanism, the damage to the measuring device during clamping is reduced, the trolley is guided to reach an accurate and proper station-transferring measuring point through a self-positioning method, and the adaptation to the assembly environment of a ship block is realized through the track crossing and automatic station-transferring;

(3) The invention can greatly reduce the station transferring time and improve the station transferring efficiency of the measuring equipment.

Drawings

FIG. 1 is a schematic general construction of the present invention;

FIG. 2 is a schematic view of the movable bottom platform structure of the present invention;

FIG. 3 is a schematic view of a shock absorbing mechanism of the present invention;

FIG. 4 is a schematic view of the obstacle detouring mechanism of the invention;

FIG. 5 is a schematic view of the structure of the middle adjusting platform of the present invention;

FIG. 6 is a schematic view of the top adjustment platform of the present invention;

FIG. 7 is a schematic view of a top adjustment platform clamping mechanism of the present invention;

FIG. 8 is a track crossing flow control diagram of the present invention;

FIG. 9 is a top view of a segment docking measurement of the present invention;

FIG. 10 is a control diagram of a positioning decision flow in accordance with the present invention;

in the figure: 1. a movable bottom platform, 2, a middle adjustment platform, 3, a top adjustment platform, 4, a measuring instrument, 5, a device housing, 101, a camera, 102, an Ultra Wideband (UWB) receiver, 103, a PLC controller, 201, a base plate, 202, a mecanum wheel, a 203-speed encoder, 204, a first motor, 205, a universal bearing, 206, a first motor placement structure, 207, a mecanum wheel mounting structure, 301, a damping spring, 302, a linkage mechanism, 401, a second motor, 402, a barrier-surmounting mechanism hydraulic rod, 403, a fixed plate, 404, a track wheel, 405, a track, 406, a track wheel fixing sheet, 501, an initial jacking hydraulic rod, 502, an initial jacking laser rangefinder, 503, a middle lifting plate, 504, a rack laser rangefinder, 505, a middle rotating gear, 506, a middle rotating platform, 507, a slide rod base, 508, a rack, 509, 510, a cylinder, 601, a top lifting plate, 602, a sleeve, 603, a rack bearing, 604, a gear, 605, a third motor, 606, a precision lifting laser range finder, 607, a top rotating platform, 608, a bearing fixing seat, 610, a top rotating gear, 611, a rotating outer ring, 612, a hall encoder, 613, a fourth motor, 701, a snap ring, 702, a strain gauge, 703, an equipment placing platform, 704, a solenoid, 705, a rotating rod, 706, a chassis, 707, a first connecting rod, 708, a chucking mechanism hydraulic rod, 709, a second connecting rod, 901, a fixed total section, 902, a moving total section, 903, a track, 904, an automatic transfer measurement cell position i, 905, an automatic transfer measurement cell position ii, 906, a first positioning cell support, 907, a second positioning cell support, 908, a third positioning cell support, 909, a fourth positioning cell support, 910, a fifth positioning cell support, 911. sixth positioning base station pillar, 912, seventh positioning base station pillar, 913, eighth positioning base station pillar.

Detailed Description

The invention will now be described in detail with reference to the drawings and specific examples.

Aiming at the fact that a laser tracker is precise, easy to damage and slow to preheat; and the problems of complex environment, uneven ground, narrow space and inconvenient actions of workers of the assembly site of the ship block are solved, and the automatic mobile equipment capable of reducing mobile vibration is designed, so that the laser tracker is driven to realize automatic station switching, and the complex environment of the assembly site of the ship block is required to have certain obstacle crossing capability.

The automatic station switching measuring device is controlled by the PLC, device positioning is realized by an Ultra Wideband (UWB) module, and track obstacle recognition is realized by the camera. The bottom of the measuring device is connected with the damping mechanism, the damping mechanism is realized through a damping spring, the damping spring is connected with the Mecanum wheel, and the functions of in-situ rotation and the like of the measuring device are realized through the Mecanum wheel, so that the measuring device moves more flexibly. The device shell is connected with the obstacle crossing mechanism, the obstacle crossing mechanism rises and falls through three hydraulic rods and moves through the crawler belt, so that the measuring device spans the track. The middle adjusting platform is connected with the movable bottom platform and is arranged on the movable bottom platform, the middle adjusting platform realizes preliminary jacking through a hydraulic rod, and preliminary rotation is realized through the cooperation of a pneumatic rack and a gear. The top adjusting platform is connected with the middle adjusting platform and above the middle adjusting platform, and the top adjusting platform realizes accurate jacking through a gear rack and accurate rotation through gear transmission. The clamping mechanism is connected with the top adjusting platform and is provided with six calipers, and tensioning and shrinkage of the clamping mechanism are realized through the hydraulic rod and the connecting rod, so that clamping of the measuring equipment is realized.

As shown in fig. 1, the automatic transfer station measuring apparatus of the present invention includes: the movable bottom platform 1, the middle adjusting platform 2 and the top adjusting platform 3, and the measuring instrument 4 is installed on the top adjusting platform, and in this embodiment, the measuring instrument is a measuring device laser tracker.

The movable bottom platform comprises a driving mechanism for driving the device to move and rotate in situ, a damping mechanism arranged on the driving mechanism for damping the device, an obstacle crossing mechanism fixed on the device shell 5 for crossing an obstacle, a vision module for identifying the topography of a measuring field, a positioning module for positioning the device and a control module; the receiver of the positioning module is arranged on the movable bottom platform, the transmitter is arranged on the measuring field, and the control module is used for controlling the whole device; the middle adjusting platform comprises a primary jacking mechanism, a primary rotating mechanism and a middle lifting plate, the lower end of the primary jacking mechanism is fixedly arranged on the movable bottom platform, the upper end of the primary jacking mechanism is fixedly arranged at the bottom of the middle lifting plate, and the primary rotating mechanism is fixedly arranged on the middle lifting plate; the top adjusting platform comprises an accurate jacking mechanism, an accurate rotating mechanism and a clamping mechanism, wherein the accurate rotating mechanism is fixedly arranged on the primary rotating mechanism, the accurate rotating mechanism is in driving connection with the accurate jacking mechanism, the clamping mechanism is fixedly arranged on the accurate jacking mechanism, and the measuring instrument is fixedly arranged on the clamping mechanism; the primary jacking mechanism is used for realizing the initial lifting of the middle lifting plate, the primary rotating mechanism and the top adjusting platform, so as to realize the initial lifting of the measuring instrument; the preliminary rotating mechanism drives the accurate rotating mechanism to rotate, so that the initial rotation of the measuring instrument is realized; the precise rotating mechanism drives the precise jacking mechanism to rotate, so that the precise rotation of the measuring instrument is realized; the accurate jacking mechanism is used for realizing the lifting of the clamping mechanism, so as to realize the accurate lifting of the measuring instrument.

As shown in fig. 1 and 2, the vision module includes cameras 101 (four cameras can be also set up, two cameras are front ends of the trolley, two cameras are distributed at rear ends of the trolley, and cameras at the same end are distributed in a two-to-two symmetrical manner), the positioning module includes an Ultra Wideband (UWB) receiver 102 set on the bottom plate and an Ultra Wideband (UWB) positioning transmitter (i.e. a positioning base station) set on a measuring site, the control module is a PLC controller 103 set on the bottom plate, the cameras 101 are used for identifying an operation track of the total section butting device, the track position is identified by the cameras so as to control the operation of the obstacle crossing mechanism, the PLC controller 103 controls all motors installed on the measuring device, and the positioning module realizes the positioning of the trolley so as to guide the trolley to reach an accurate and proper station-switching measuring point.

As shown in fig. 1 and 2, the driving mechanism comprises a bottom plate 201, a mecanum wheel 202, a speed encoder 203, a first motor 204 and a universal bearing 205, wherein the first motor 204 is fixedly installed on the bottom plate 201 through a first motor placement structure 206, an output shaft of the first motor 204 is connected with the universal bearing 205, the universal bearing 205 is connected with a rotating shaft of the mecanum wheel 202 through a mecanum wheel installation structure 207, and the speed encoder 203 is installed on the first motor 204; the first motor 204 is started to drive the universal bearing 205 to rotate, so that the Mecanum wheel 202 is driven to rotate, the speed encoder 203 monitors the rotating speed of the first motor 204, the rotating speed of the first motor 204 is transmitted to the control module, and the control module controls the first motor 204, so that the Mecanum wheel 202 is regulated in real time.

As shown in fig. 1 and 3, the damping mechanism includes a damping spring 301 and a link mechanism 302, one end of the damping spring 301 is connected with the first motor placement structure 206, the other end is fixedly connected with the mecanum wheel 202, the link mechanism 302 is a parallelogram structure formed by two parallel arranged links, and two ends of the links are respectively connected with the first motor placement structure 206 and the mecanum wheel mounting structure 207 for realizing limit when the mecanum wheel 202 vibrates up and down. In the running process of the automatic station-switching measuring device, the device is damped through the damping spring 301, so that vibration caused by uneven ground of measuring equipment is reduced, and the possibility of damage to the measuring equipment caused by vibration is reduced.

As shown in fig. 1 and 4, the obstacle crossing mechanism comprises a crawler device, a second motor 401, an obstacle crossing mechanism hydraulic rod 402 and a fixing plate 403, wherein the crawler device comprises crawler wheels 404, crawler 405 and crawler wheel fixing pieces 406, the crawler wheel fixing pieces 406 are used for connecting and fixing a front crawler wheel 404 and a rear crawler wheel 404, and the crawler 405 is meshed with the front crawler wheel 404 and the rear crawler wheel 404; one end of a hydraulic rod 402 of the obstacle crossing mechanism is fixed on a track wheel fixing plate 406, and the other end is fixedly arranged on the device shell through a fixing plate 403; the second motor 401 is mounted on the track wheel fixing piece 406; when the vision module recognizes an obstacle which can be spanned, and the positioning module judges that the distance is proper, the hydraulic rod of the obstacle crossing mechanism controls the crawler device to descend, the second motor 401 drives the crawler wheel 404 to drive the crawler 405 to rotate, so that the obstacle crossing operation of the measuring device is realized.

In the embodiment, the number of the Mecanum wheels is four, and the in-situ rotation of the measuring device is realized through the Mecanum wheels, so that the flexibility of the measuring device is improved; the Mecanum wheel is connected with the damping mechanism, and the damping function of the measuring device is realized through the damping mechanism, so that the precise transportation of precise measuring equipment is ensured. The movable bottom platform is provided with the obstacle crossing mechanism, and the measurement device can span the track through the obstacle crossing mechanism, so that the application scene of the measurement device is increased.

As shown in fig. 1 and 5, the primary lifting mechanism includes an initial lifting hydraulic rod 501 and an initial lifting laser rangefinder 502, the lower end of the initial lifting hydraulic rod 501 is fixedly mounted on the bottom plate of the movable bottom platform, the upper end is mounted at the bottom of the middle lifting plate 503, the initial lifting laser rangefinder 502 is fixedly mounted on the bottom plate of the movable bottom platform, and is close to the bottom of the initial lifting hydraulic rod 501, and is used for measuring and feeding back the lifting of the initial lifting mechanism, so that the control is more accurate, and after the initial lifting is completed, the initial rotation is performed.

The preliminary rotary mechanism comprises a rack laser distance meter 504, a middle rotary gear 505, a middle rotary platform 506, a slide bar base 507, racks 508, slide bars 509 and an air cylinder 510, wherein the middle rotary platform 506 is fixedly arranged on a middle lifting plate 503, the middle rotary gear 505 is arranged on the peripheral side face of the middle rotary platform, the slide bar base 507 is fixedly arranged on the middle lifting plate 503 and is positioned on two sides of the middle rotary platform 506, the racks 508 are in sliding connection with the slide bar base 507 through the slide bars 509, the racks 508 are meshed with the middle rotary gear 505, the air cylinder 510 is arranged at one end of the slide bar base 507, the rack laser distance meter 504 is arranged on the middle lifting plate 503 and is positioned at one end of the racks 508, and when in initial rotation, the air cylinder controls the racks 508 to move, so that the middle rotary platform 506 is driven to rotate through the middle rotary gear 505, and meanwhile, the rack laser tracker 504 monitors and feeds back the movement state of the racks 508, so that the initial rotary angle adjustment of the middle platform is more accurate.

The initial jacking mechanism is driven by four initial jacking hydraulic rods 501, and each initial jacking hydraulic rod 501 is provided with an initial jacking laser range finder 502 which is distributed in pairs and opposite angles; the initial jacking mechanism performs measurement through the initial jacking laser range finder 502, and performs calculation through an upper computer, so that the feedback control of initial jacking is realized. The initial rotating mechanism is provided with two rack laser distance meters 504 which are positioned on the short sides of the two racks and are parallel to the racks; the initial rotary mechanism is driven by a small cylinder, the top end of the cylinder is connected with a rack, the rack is fixedly connected with a slide bar, a rotary platform gear is meshed with the rack, the cylinder driving mechanism is symmetrically distributed, the rotary platform is adjusted by moving the rack, the initial jacking laser range finder 502 is installed at the tail end of the rack, the moving distance of the rack is detected, and the upper computer is used for resolving to carry out compensation driving on the cylinder.

As shown in fig. 1 and 6, the precise jacking mechanism comprises a top lifting plate 601, a sleeve 602, a rack bearing 603, a gear 604, a third motor 605 and a precise jacking laser range finder 606, wherein the top lifting plate 601 is fixedly connected with a top rotating platform 607 through the sleeve 602, the upper end of the rack bearing 603 is fixedly arranged at the bottom of the top lifting plate 601, the lower end of the rack bearing 603 is fixedly arranged on the top rotating platform 607, and the rack bearing 603 is meshed with the gear 604; the top lifting plate 601 is lifted through the rack bearing 603, the third motor 605 drives the gear 604 to drive the rack bearing to move up and down, and the third motor adopts a self-locking band-type brake motor, so that the top lifting plate is fixed after being adjusted. Lifting of the top lifting plate 601 is achieved through the sleeve 602, and the accurate lifting laser tracker 606 measures and feeds back lifting of the top lifting plate 601, so that an accurate lifting function is achieved.

Further, the gear 604 is fixedly mounted on the top rotating platform 607 through a gear support, and the rack bearing 603 is fixedly mounted on the top rotating platform 607 through a bearing fixing seat 608.

The precise rotating mechanism comprises a top rotating gear 610, a rotating outer ring 611, a Hall encoder 612 and a fourth motor 613, wherein the fourth motor is a self-locking band-type brake motor, the rotating outer ring 611 is fixedly arranged on the initial rotating mechanism, when the initial rotating mechanism rotates, the rotating outer ring 611 is driven to rotate, and at the moment, the fourth motor 613 is self-locking, so that the whole precise rotating mechanism is driven to rotate when the initial rotating mechanism rotates. The hall encoder 612 is fixedly installed on the rotary outer ring 611 and is meshed with the top rotary gear 610, the top rotary gear 610 is arranged on the peripheral side surface of the top rotary platform 607 of the accurate jacking mechanism, the fourth motor 613 drives the hall encoder 612 to drive the top rotary gear 610 to move, and meanwhile, the hall encoder 612 monitors and feeds back the rotation angle of the top rotary gear 610, so that accurate rotation of the measuring instrument is realized.

As shown in fig. 1 and 7, the clamping mechanism comprises a chassis 706, a plurality of claws uniformly arranged along the circumference of the chassis 706, the claws are rotationally connected with the chassis 706, a device placement platform 703 for mounting a measuring instrument is arranged in the center of the chassis 706, and the claws are used for clamping the measuring instrument.

The claw comprises a clamping ring 701, a strain gauge 702, a rotary rod 705, a first connecting rod 707, a hydraulic rod 708 and a second connecting rod 709; the clamping ring 701 is rotationally connected with the chassis 706 through a rotating rod 705, a strain gauge 702 is arranged on the inner side surface of the clamping ring 701, and the rotating rod 705 is connected with the equipment placing platform 703 through a first connecting rod 707 and a second connecting rod 709; the device placement platform 703 is provided with an electromagnetic coil 704. The measuring device is a laser tracker, and the hydraulic rod 708 is connected with the first connecting rod 707, the second connecting rod 709 and the chassis 706 to move in a rotating manner. In the initial state, the hydraulic rod 708 is lifted up to drive the clamping ring to expand outwards, after the laser tracker is placed, the electromagnetic coil 704 is started, and the stroke of the hydraulic rod 708 is shortened, so that the clamping ring 701 is clamped; but in the moving process of the automatic station-switching measuring device, the uneven ground and the crossing of the track can cause vibration to the measuring equipment, and the clamping mechanism is affected by jolting and the like, so that the problems of uneven stress, inclination and the like of the measuring equipment can be caused, and the stress detection of the strain gauge 702 on the clamping ring 701 is adopted, so that the stroke of each hydraulic rod is respectively controlled, the force between each clamping ring and the measuring equipment is regulated in a real-time feedback mode, and the uniform clamping stress of the measuring equipment is realized.

The precise rotating mechanism is driven by a motor, gears are driven by two motors, so that the precise rotating mechanism is driven to rotate, a Hall encoder is arranged at the front end of the motor of the precise rotating mechanism, and the precise adjustment of the rotating mechanism is realized by calculating the rotation of a feedback motor; the precise jacking mechanism is driven by a motor and adopts a gear-rack transmission mode, so that the precise jacking mechanism can run more stably and can be self-locked after adjustment is stopped; the accurate jacking is measured by a laser range finder, so that the jacking distance is fed back, the measured data is resolved by an upper computer, and the part which does not meet the adjustment requirement is subjected to closed-loop feedback control, so that the accurate adjustment of the jacking mechanism is realized; the measuring equipment clamping device is realized by adopting the connecting rod and the tail end calipers, the hydraulic rod is adopted for realizing, the strain gauge is installed on the tail end calipers, and stress of the strain gauge is monitored when the tail end calipers are clamped, so that feedback adjustment is performed on calipers of which the clamping position of the measuring equipment cannot meet the stress requirement, and the clamping mechanism is used for realizing balanced stress on the measuring equipment, and reducing damage to the measuring equipment during clamping.

A measurement method for performing ship block docking by using the automatic transfer station measurement device, comprising:

the automatic transfer station measuring device is lifted into an area I of the dock, and is positioned through UWB positioning base stations on first to fourth positioning base station struts 906 to 909 arranged around the area I, so that initial positioning of the automatic transfer station measuring device is realized; then, measuring the first to eighth common reference point targets M1 to M8 by using a measuring device laser tracker, thereby realizing accurate positioning;

after the positioning is finished, measuring the space positions of the key point targets of the moving block and the fixed block, which are close to the area I; then the automatic transfer station measuring device runs from the area I to the area II, at the moment, the base stations on the first positioning base station supporting column 906 and the second positioning base station supporting column 907 are closed, the base stations on the fifth positioning base station supporting column 910 and the sixth positioning base station supporting column 911 which are arranged around the area III are opened, the automatic transfer station measuring trolley is positioned, and the step of the crossing process is completed through the vision module and the obstacle crossing mechanism;

before the automatic transfer station measuring device transfers the station, firstly, the initial jacking mechanism and the accurate jacking mechanism of the automatic transfer station measuring device are reduced to the minimum, secondly, the deviation of the automatic transfer station measuring device in the XYZ direction is calculated through the spatial position information of the station II relative to the station I which is preset, and the deviation value of the automatic transfer station measuring device under the spatial coordinate system is converted into the motion rotation track of each Mecanum wheel;

Finally, the automatic station switching measuring device enters the area III, at the moment, base stations on the third and fourth positioning base station struts 908 and 909 are closed, base stations on the seventh and eighth positioning base station struts 912 and 913 which are arranged around the area III are opened, the automatic station switching measuring device completes initial positioning through a UWB positioning module, and the laser tracker measures the ninth to sixteenth public datum point targets M9 to M16 to complete accurate positioning, so that the space positions of the key point targets of the movable total section and the fixed total section, which are close to the area I, are measured, and the whole measuring process is completed.

The automatic transfer station measuring trolley needs a proper method for driving and adjusting, and specifically: (1) The measuring trolley is positioned by establishing an Ultra Wideband (UWB) positioning module, wherein the Ultra Wideband (UWB) positioning module consists of 8 positioning base stations and a receiver on the measuring trolley. (2) The method comprises the steps of identifying the topography of a measuring field through a movable bottom platform camera, and carrying out intervention on an original Ultra Wideband (UWB) path planning on an area with rough unevenness and large obstacles, so that a proper path is recalculated, and the obstacle area is bypassed; for the easy-to-cross areas such as the track, after being identified by the camera, the track crossing device is started, so that the track crossing is realized; (3) After the measuring equipment transfer station moves well, the chassis of the measuring trolley is fixed, and then initial rotation adjustment, initial jacking adjustment, accurate rotation adjustment and accurate jacking adjustment are carried out on the measuring equipment. The adjustment mode combining the initial adjustment and the accurate adjustment increases the adjustment efficiency and the adjustment precision of the measuring equipment. (4) After the measuring instrument is placed, the measuring instrument is clamped by the top platform calipers, the tail ends of the calipers are provided with radians, strain gauges are arranged, the stress is more uniform when the clamping device is used for fixing measuring equipment through transformation of the induction strain gauges, and the clamping device is placed to shake when the measuring instrument is started or stopped, so that damage to the measuring equipment is reduced.

After the automatic station switching measuring device finishes measuring at the station I, the automatic station switching measuring device needs to smoothly arrive at the station II by moving the automatic station switching measuring device, and the specific flow is as follows: firstly, the initial jacking mechanism and the accurate jacking mechanism of the automatic transfer station measuring device are reduced to the minimum, on one hand, the problem that the automatic transfer station measuring trolley is too high in weight center and easy to incline during moving is prevented, on the other hand, the site working condition is complex during the butt joint of the ship block, and the automatic transfer station trolley is too high and is most likely to collide with an obstacle above; and secondly, calculating the deviation of the automatic transfer station measuring device in the XYZ direction through the spatial position information of the pre-established station II relative to the station I, converting the deviation value of the automatic transfer station measuring device in the spatial coordinate system into the motion rotation track of each Mecanum wheel, and carrying out preliminary positioning through an Ultra Wide Band (UWB) positioning module. The automatic transfer station measuring device is controlled by adopting a quintic polynomial track planning, so that the speed of the automatic transfer station measuring device is accelerated more smoothly, and the automatic transfer station measuring device operates more stably.

When the ship block is in butt joint, the automatic transfer station measuring device needs to be switched from one side of the ship block to the other side, and the two blocks are generally carried by adopting the track trolley, so the automatic transfer station measuring trolley needs to have the judging capability and the control capability of track crossing, and the track crossing flow of the automatic transfer station measuring trolley is shown in fig. 8. Firstly, a track is identified through a bottom platform camera, the distance between the track and an automatic transfer station measuring trolley is judged, when the distance between the automatic transfer station measuring trolley and the track reaches a proper distance, a Mecanum wheel is stopped, a hydraulic rod of an obstacle crossing mechanism is controlled, a crawler wheel is lowered, then the crawler wheel is driven by a speed reducing motor to cross the obstacle, and after the obstacle crossing is completed, the hydraulic rod is controlled to retract the obstacle crossing mechanism to continuously drive the Mecanum wheel to move.

A top view of the total section butt joint measurement method is shown in fig. 9, wherein: 901-fixed block, 902-moving block, 903-track, 904-measuring cell station I, 905-automatic transfer measuring cell station II, 906-first positioning base station support, 907-second positioning base station support, 908-third positioning base station support, 909-fourth positioning base station support, 910-fifth positioning base station support, 911-sixth positioning base station support, 912-seventh positioning base station support, 913-eighth positioning base station support. M1-M8 are a first set of common fiducial targets and M9-M10 are a second set of common fiducial targets. The heights of the first positioning base station support column and the fourth positioning base station support column are sequentially increased to ensure accurate positioning of the vertical space position of the automatic station transferring measuring trolley, the heights of the fifth positioning base station support column and the sixth positioning base station support column are respectively consistent with the heights of the first positioning base station support column and the second positioning base station support column, and the heights of the seventh positioning base station support column and the eighth positioning base station support column are respectively consistent with the heights of the third positioning base station support column and the fourth positioning base station support column.

The Ultra Wideband (UWB) positioning module is provided with 8 positioning base stations so as to reduce the shielding problem of the field environment on the pulse signals; the 8 positioning base stations are distributed in a symmetrical mode in the X-Y direction, and each base station in the Z direction is 20cm higher than the previous base station, so that the accuracy of measuring the Z-direction data of the trolley is ensured.

The whole measurement flow is as follows: the automatic transfer station measuring device is lifted into the area I of the dock through the crane, and the automatic transfer station measuring device cannot accurately reach the position of the station I at the moment, so that the automatic transfer station measuring device is positioned through UWB positioning base stations on the first to fourth positioning base station struts 906 to 909 at the moment, and the initial positioning of the automatic transfer station measuring trolley is achieved. After initial positioning, the error is greatly reduced, and then the common datum point targets M1-M8 are measured by using a laser tracker, so that accurate positioning is realized; after the positioning is finished, measuring the space positions of the key point targets of the moving block and the fixed block, which are close to the area I; then the trolley runs from the area I to the area II, at the moment, the base stations on the first positioning base station support 906 and the second positioning base station support 907 are closed, the base stations on the fifth positioning base station support 910 and the sixth positioning base station support 911 are opened, the automatic station switching measuring device is positioned, and the step of the crossing process is completed through the bottom camera and the obstacle crossing process; finally, the trolley enters the area III, at the moment, the base stations on the third and fourth positioning base station supports 908 and 909 are closed, the base stations on the seventh and eighth positioning base station supports 912 and 913 are opened, the initial positioning of the trolley is finished through the UWB positioning module and the vision measuring module, and the accurate positioning is finished through the measurement of the common datum point targets M9-M16 by the laser tracker, so that the space positions of the key point targets of the moving block and the fixed block, which are close to the area III, are measured, and the whole measuring process is finished.

After the automatic transfer station measuring trolley is initially positioned, the track straddles and obstacles are avoided through Ultra Wideband (UWB) and cameras 1-4, accurate station measurement is needed to be carried out on the automatic transfer station measuring trolley, total adjustment stroke judgment is needed to be carried out on a middle adjustment platform and a top adjustment mechanism of the automatic transfer station measuring trolley, the judgment flow is shown in fig. 10, the initial positioning of equipment is realized through UWB, accurate positioning is realized through measurement of a common datum point target, whether the distance between a positioning position and a theoretical position is smaller than the stroke is determined, if the distance is larger than the stroke, the position of the trolley is changed again through a Mecanum wheel, and therefore the measuring equipment is adjusted to a proper position and within a stroke range. And if the stroke is smaller than the stroke, the position of the measuring equipment is adjusted through the middle adjusting platform and the top adjusting platform.

The invention discloses an automatic transfer station measuring device which is a movable measuring trolley device of a laser tracker and comprises a movable bottom platform, a middle adjusting platform and a top adjusting platform. The movable bottom platform moves by adopting Mecanum wheels and is driven by a motor, and the movable bottom platform is provided with an obstacle crossing mechanism and straddles a track by a crawler belt; the middle adjusting platform comprises a preliminary jacking mechanism and a preliminary rotating mechanism, the preliminary jacking mechanism is driven by four hydraulic rods to realize preliminary adjustment of the measuring equipment in the upper and lower ranges, and a laser range finder is arranged at the bottom of a plane of the preliminary jacking mechanism to realize initial distance adjustment feedback; the primary rotating mechanism is 360 degrees in rotating range, and the rack is driven to move through the micro cylinder, so that the gear at the bottom of the rotating mechanism is driven to move, primary angle adjustment of the measuring equipment is realized, and the laser range finder is arranged at the rack end of the primary rotating mechanism, so that initial angle adjustment feedback is realized. The top adjusting platform comprises an accurate jacking mechanism, an accurate rotating mechanism and a measuring equipment clamping mechanism. The precise jacking mechanism adopts a gear rack structure to realize precise jacking of the platform, and the gear rack is driven by a motor; the precise rotating mechanism drives the gear and the speed changing device to rotate through the motor; the rotary platform realizes angle adjustment feedback through the Hall angle sensor, the equipment clamping device adopts hydraulic drive, and the connecting rod is realized, clamping mechanism end mutually independent, thereby the atress is balanced when realizing the chucking to measuring equipment through the foil gage measurement, avoids causing the harm to measuring equipment. The jacking platform carries out position feedback through a laser range finder. Aiming at the complex condition of the on-site working condition, cameras are added to the bottom platform to identify the track and the obstacle, so that the adaptability of the automatic transfer trolley is improved.

Claims

1. An automatic transfer station measurement device, comprising:

a movable bottom platform (1);

the middle adjusting platform (2) comprises a primary jacking mechanism, a primary rotating mechanism and a middle lifting plate (503), wherein the lower end of the primary jacking mechanism is fixedly arranged on the movable bottom platform (1), the upper end of the primary jacking mechanism is fixedly arranged at the bottom of the middle lifting plate (503), and the primary rotating mechanism is fixedly arranged on the middle lifting plate (503);

the top adjusting platform (3) comprises an accurate jacking mechanism, an accurate rotating mechanism and a clamping mechanism, wherein the accurate rotating mechanism is fixedly arranged on the primary rotating mechanism, the accurate rotating mechanism is in driving connection with the accurate jacking mechanism, the clamping mechanism is fixedly arranged on the accurate jacking mechanism, and the measuring instrument is fixedly arranged on the clamping mechanism;

the primary jacking mechanism is used for realizing the initial lifting of the middle lifting plate (503), the primary rotating mechanism and the top adjusting platform (3), so as to realize the initial lifting of the measuring instrument; the preliminary rotating mechanism drives the accurate rotating mechanism to rotate, so that the initial rotation of the measuring instrument is realized; the precise rotating mechanism drives the precise jacking mechanism to rotate, so that the precise rotation of the measuring instrument is realized; the accurate jacking mechanism is used for realizing the lifting of the clamping mechanism, so as to realize the accurate lifting of the measuring instrument.

2. An automatic transfer station measuring device according to claim 1, characterized in that the movable bottom platform (1) comprises a driving mechanism for driving the device to move and rotate in place, a damping mechanism mounted on the driving mechanism for damping the device, an obstacle surmounting mechanism fixed on the device housing for surmounting obstacles, a vision module for identifying the topography of the measuring site, a positioning module for positioning the device, and a control module; the receiver of the positioning module is arranged on the movable bottom platform, the transmitter is arranged on the measuring site, and the control module is used for controlling the whole device.

3. An automatic station switching measuring device according to claim 2, characterized in that the driving mechanism comprises a base plate (201), a mecanum wheel (202), a speed encoder (203), a first motor (204) and a universal bearing (205), the first motor (204) is fixedly arranged on the base plate (201), the universal bearing (205) drives the movement and rotation of the mecanum wheel (202), the speed encoder (203) monitors the rotation speed of the first motor (204) and transmits the rotation speed of the first motor (204) to the control module, and the control module controls the first motor (204) to adjust the mecanum wheel (202) in real time;

The damping mechanism comprises a damping spring (301) and a connecting rod mechanism (302), one end of the damping spring (304) is fixedly connected with the first motor (204), the other end of the damping spring is fixedly connected with the Mecanum wheel (202), and the connecting rod mechanism (302) is used for limiting the Mecanum wheel (202) during up-and-down vibration;

the obstacle crossing mechanism comprises a crawler device, a second motor (401) and an obstacle crossing mechanism hydraulic rod (402), the second motor (401) drives the crawler device to move, the obstacle crossing mechanism hydraulic rod (402) is used for lifting the crawler device, one end of the obstacle crossing mechanism hydraulic rod is fixed on a device shell (5), and the other end of the obstacle crossing mechanism hydraulic rod is fixed on the crawler device.

4. The automatic station switching measuring device according to claim 1, wherein the primary jacking mechanism comprises an initial jacking hydraulic rod (501) and an initial jacking laser distance meter (502), the lower end of the initial jacking hydraulic rod (501) is fixedly arranged on the movable bottom platform (1), the upper end of the initial jacking hydraulic rod is arranged at the bottom of the middle lifting plate (503), the initial jacking laser distance meter (502) is fixedly arranged on the movable bottom platform (1), and lifting of the initial jacking mechanism is measured and fed back.

5. The automatic station-switching measuring device according to claim 1, wherein the preliminary rotation mechanism comprises a rack laser distance meter (504), a middle rotation gear (505), a middle rotation platform (506), a slide bar base (507), a rack (508), a slide bar (509) and a cylinder (510), the middle rotation platform (506) is fixedly installed on a middle lifting plate (503), the middle rotation gear (505) is installed on the peripheral side surface of the middle rotation platform, the slide bar base (507) is fixedly installed on the middle lifting plate (503) and is located on two sides of the middle rotation platform (506), the rack (508) is in sliding connection with the slide bar base (507) through the slide bar (509), the rack (508) is meshed with the middle rotation gear (505), the cylinder (510) is installed at one end of the slide bar base (507), the rack laser distance meter (504) is installed on the middle lifting plate (503), and during initial rotation, the cylinder controls the movement of the rack, so that the middle rotation platform is driven to rotate through the middle rotation gear, and meanwhile, the rack laser distance meter monitors and feeds back the movement state of the rack, so that the initial rotation angle of the middle platform is more accurate.

6. The automatic transfer station measurement device according to claim 1, wherein the precise jacking mechanism comprises a top lifting plate (601), a sleeve (602), a rack bearing (603), a gear (604), a third motor (605) and a precise jacking laser distance meter (606), the top lifting plate (601) is fixedly connected with a top rotating platform (607) through the sleeve (602), the upper end of the rack bearing (603) is fixedly arranged at the bottom of the top lifting plate (601), the lower end of the rack bearing is fixedly arranged on the top rotating platform (607), the rack bearing (603) is meshed with the gear (604), the third motor (605) drives the gear (604) to move up and down, lifting of the top lifting plate (601) is realized through the sleeve (602), and the precise jacking laser tracker (606) measures and feeds back lifting of the top lifting plate (601), so that a precise lifting function is realized.

7. The automatic station turning measuring device according to claim 1, wherein the precise rotating mechanism comprises a top rotating gear (610), a rotating outer ring (611), a hall encoder (612) and a fourth motor (613), the rotating outer ring (611) is fixedly installed on the preliminary rotating mechanism, the hall encoder (612) is fixedly installed on the rotating outer ring (611) and meshed with the top rotating gear (610), the top rotating gear (610) is arranged on the peripheral side surface of the top rotating platform of the precise lifting mechanism, the fourth motor (613) drives the hall encoder (612) to drive the top rotating gear (610) to move, and meanwhile the hall encoder (612) monitors and feeds back the rotating angle of the top rotating gear (610), so that precise rotation of the measuring instrument is achieved.

8. An automatic transfer station measuring device according to claim 1, characterized in that the clamping mechanism comprises a chassis (706), a plurality of jaws evenly arranged along the circumference of the chassis (706), the jaws being rotatably connected to the chassis (706), a device placement platform (703) for mounting the measuring instrument being arranged in the center of the chassis (706), the jaws being adapted to clamp the measuring instrument.

9. A measurement method for butt-jointing a ship block using the automatic transfer station measurement apparatus according to any one of claims 1 to 8, characterized by comprising:

the automatic transfer station measuring device is lifted into an area I of the dock, and is positioned through UWB positioning base stations on first to fourth struts (906 to 909) arranged around the area I, so that initial positioning of the automatic transfer station measuring device is realized; then, measuring the first to eighth common datum point targets (M1 to M8) by using a measuring device laser tracker, so as to realize accurate positioning;

after the positioning is finished, measuring the space positions of the key point targets of the moving block and the fixed block, which are close to the area I; then the automatic transfer station measuring device runs from the area I to the area II, at the moment, the base stations on the first positioning base station support column (906) and the second positioning base station support column (907) are closed, the base stations on the fifth positioning base station support column (910) and the sixth positioning base station support column (911) which are arranged around the area III are opened, the automatic transfer station measuring trolley is positioned, and the step of crossing the process is completed through the vision module and the obstacle crossing mechanism;

Finally, the automatic transfer station measuring device enters the area III, at the moment, base stations on third and fourth positioning base station supports (908, 909) are closed, base stations on seventh and eighth positioning base station supports (912, 913) arranged on the periphery of the area III are opened, the automatic transfer station measuring device completes initial positioning through a UWB positioning module, and the ninth to sixteenth common reference point targets (M9-M16) are measured through a laser tracker to complete accurate positioning, so that the space positions of the movable total section and the fixed total section close to the key point targets of the area I are measured, and the whole measuring process is completed.

10. The method for measuring the total section docking of the ship by using the automatic transfer station measuring device according to claim 9, wherein before the transfer station of the automatic transfer station measuring device moves, firstly, an initial jacking mechanism and an accurate jacking mechanism of the automatic transfer station measuring device are reduced to the minimum, and secondly, the deviation of the automatic transfer station measuring device in the XYZ direction is calculated through the spatial position information of a pre-established station position II relative to a station position I, and the deviation value of the automatic transfer station measuring device in a spatial coordinate system is converted into the movement rotation track of each Mecanum wheel;