CN110606142B

CN110606142B - Series-parallel supporting leg based on ground sealing and movable posture adjusting platform thereof

Info

Publication number: CN110606142B
Application number: CN201910847363.1A
Authority: CN
Inventors: 周玉林; 赵丽辉; 褚洪鹏; 刘毅
Original assignee: Yanshan University
Current assignee: Yanshan University
Priority date: 2019-08-15
Filing date: 2019-09-09
Publication date: 2020-09-25
Anticipated expiration: 2039-09-09
Also published as: CN110606142A

Abstract

The invention discloses a series-parallel support leg and a movable precise posture adjusting platform based on gravity sealing or ground sealing, belonging to the technical field of heavy equipment butt joint and assembly equipment, wherein a lifting platform can slide along a base to form a movable pair Pz which is an active pair, and the lifting platform is driven by a linear driver; the bogie is rotationally connected with the lifting platform to form a revolute pair Rz; the wheel seat is rotationally connected with the bogie to form a revolute pair Rx; each wheel forms synchronous driving or driving differential mechanism driving, or single motor driving differential bevel gear train mechanism realizes synchronous driving or passive differential driving. Furthermore, a group of six-degree-of-freedom high-precision posture adjusting platforms constructed in a multi-leg distributed parallel mode is disclosed, the problems that the existing posture adjusting platform is too large in height, omnidirectional motion is separated from precision posture adjusting motion, the system is complex, namely discontinuous in operation, large in motion error and the like are solved, and the application range of the mobile posture adjusting platform is effectively expanded.

Description

Series-parallel supporting leg based on ground sealing and movable posture adjusting platform thereof

Technical Field

The invention relates to the technical field of large and heavy equipment butt joint and assembly equipment, in particular to a series-parallel support leg based on ground sealing or gravity sealing and a precise mobile posture adjusting platform thereof.

Background

In the field of heavy equipment such as airplanes, ships, electric power and the like, the equipment or products are generally assembled by a plurality of parts, so that the parts are usually required to be butted and assembled in the production process, and the parts in the field of heavy equipment have large volume and mass, so that manual direct butt joint operation cannot be carried out, and therefore the parts are required to be carried and assembled by means of a movable posture adjusting platform. The existing mobile platform can be divided into a wheel type carrier and a Mecanum wheel carrier, and the wheel type carrier and the Mecanum wheel carrier generally only have three degrees of freedom such as plane movement, rotation around the normal line of a carrying platform and the like, so that the posture adjustment of six degrees of freedom of a space of a part can not be realized, the problem that two parts can not be butted in the butt joint process of the part is often caused, or the problem that the assembly effect is influenced or the part is damaged due to collision and impact. In order to solve the problem, a person skilled in the art combines a parallel mechanism with a vehicle body, and installs a multi-degree-of-freedom parallel mechanism on a transport vehicle to realize six-degree-of-freedom posture adjustment of the transport vehicle, for example, a six-degree-of-freedom posture adjustment system based on an omnidirectional moving module disclosed in chinese patent CN 109231065A.

Through installing the multi-degree-of-freedom parallel posture adjusting mechanism on the vehicle body, although the six-degree-of-freedom posture adjustment of parts can be realized, the added parallel mechanism greatly increases the height of the carrier, reduces the trafficability of the carrier, and can not finish the butt joint and assembly of equipment in a certain low space. The posture adjusting system consisting of the carrying vehicle and the parallel mechanism still belongs to two independent systems essentially, and motion errors generated by the carrying vehicle and the parallel mechanism in the working process are mutually accumulated, so that the motion precision of the tail end of the movable posture adjusting platform is reduced, and the high-precision butt joint and assembly of parts are not facilitated. And the coexistence of multiple systems causes the mechanical structure to be complex and the electrical control system to be complex.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a hybrid leg and a mobile posture adjusting platform based on gravity sealing, which are suitable for a hybrid leg and a six-degree-of-freedom omnidirectional mobile precision posture adjusting platform in a low space, solve the problems of overlarge height, separation of omnidirectional motion and precision posture adjusting motion, complex system, namely discontinuous operation, large motion error and the like of the conventional posture adjusting platform, and effectively expand the application range of the mobile posture adjusting platform.

The technical scheme of the invention is as follows:

a series-parallel supporting leg based on gravity sealing comprises a base, a lifting platform, a bogie, a wheel seat and wheels, wherein the base is sequentially connected with a linear driver, the lifting platform, the bogie and the wheel seat in series, and is locally connected with the ground in parallel under the gravity sealing condition; the wheels comprise a first wheel and a second wheel which are respectively positioned on the first side or the second side of the wheel frame, and the first wheel is rotationally connected with the wheel seat to form a revolute pair Ry 1; the second wheel is rotationally connected with the wheel seat to form a revolute pair Ry 2; the lifting platform is connected with the base in a sliding mode to form a moving pair Pz serving as an active pair, the lifting platform is driven by a linear driver, the bogie is driven by a steering motor arranged on the lifting platform to form a rotary connection, the bogie is rotationally connected with the lifting platform to form a rotary pair Rz, the wheel seat is rotationally connected with the bogie to form a rotary pair Rx, a linear guide rail of the lifting platform is parallel to the axis of the rotary pair Rz, and the axis of the rotary pair Rz is perpendicular to the axis of the rotary pair Rx; the axes of the revolute pair Ry1 and the revolute pair Ry2 are coaxial, and the axis of the revolute pair Rx is perpendicularly intersected with the axes of the revolute pair Ry1 and the revolute pair Ry 2; the axis of the revolute pair Rz passes through the intersection point of the axis of the revolute pair Rx and the axes of the revolute pair Ry1 and Ry 2.

In practical use, the gravity-based closed mode means that no degree of freedom of movement in the vertical direction exists between wheels and a ground contact point, a first wheel and a second wheel in the parallel-serial support leg are in contact with the ground and can do pure rolling motion relative to the ground or the wheels do pure rolling motion along a certain point of the width, if the ground is taken as a fixed platform and the wheel seat is taken as a moving platform, the first wheel, the second wheel, the ground and the wheel seat form a local parallel structure. The actual effects of gravity sealing and ground sealing are that the vertical direction of the contact point of the wheels and the ground has no degree of freedom or no effective displacement; the gravity sealing belongs to force sealing on the sealing principle, and the sealing effect is effective within a certain variation range of force; the ground sealing is a geometrical sealing formed among the wheels, the frame and the ground in a sealing principle, is not limited by a sealing force, and forms a more stable parallel-connection line motion condition, and the sealing force can be infinite or infinitesimal in theory.

Further, the base is connected with the wheel seat in series through the lifting platform and the bogie, so that a series-parallel support leg based on gravity closing is formed, and the mechanism configuration of the series-parallel support leg is PzRzRx (Ry1+ Ry2) Rp.

Preferably, when the parallel-serial support leg is a driving leg, at least one of the first wheel and the second wheel is a driving wheel or both of the first wheel and the second wheel are driven to form active differential motion.

Preferably, the second wheel is a driving wheel and is directly driven by a walking motor or indirectly driven by the walking motor through a transmission mechanism; preferably, the second wheel is indirectly driven by a walking motor through a belt pulley set, the walking motor is mounted on the wheel seat, the belt pulley set comprises a first belt pulley, a synchronous belt and a second belt pulley, the first belt pulley is fixedly connected with an output shaft of the walking motor, the second belt pulley is fixedly connected to one side of the second wheel, and the synchronous belt is mounted on the first belt pulley and the second belt pulley in a matched manner.

Preferably, the first wheel and the second wheel are driving wheels, the first wheel and the second wheel are respectively driven by two independent walking motors, when the two walking motors drive the first wheel and the second wheel to rotate in the same direction, the parallel-serial support legs can walk forwards, and when the two walking motors drive the first wheel and the second wheel to rotate in different directions, an active differential driving working state is formed, so that the bogie can rotate relative to the lifting platform, and the advancing direction of the parallel-serial support legs is changed.

Preferably, an angle sensor is further arranged on the lifting platform and used for detecting a rotating angle between the bogie and the lifting platform.

Preferably, an angle sensor is further arranged on the lifting platform, and a band-type brake or a clutch can be further arranged on the lifting platform.

Preferably, the gravity-closed hybrid leg further comprises an independent suspension assembly structure, wherein an independent suspension assembly is arranged between the lifting platform and the bogie, and comprises a suspension fixing plate, a spring collision block, a lifting collision block and a guide column which are connected with the lifting platform and the bogie; the spring compression stroke of the independent suspension assembly is smaller than the lifting stroke of the lifting platform, the lifting motion and the independent suspension are in parallel connection, and the lifting motion stroke is larger than the length of the spring; when the lifting distance of the lifting platform is greater than the length of the spring, the parallel-serial supporting legs are used for damping vibration of a rigid active suspension controlled by a lifting motor; when the lifting distance of the lifting platform is smaller than the length of the spring, the lifting collision block is in contact with the spring collision block, the internal contracting brake of the lifting motor is opened, and the parallel-serial supporting legs are flexible passive vibration reduction based on independent suspension of the spring; and the active and passive vibration reduction structure forms a rigid-flexible coupling vibration reduction structure.

A movable precise posture adjusting platform comprises a frame, a controller and a series-parallel supporting leg, preferably, the number of the series-parallel supporting leg is three or four or six, and a base in each series-parallel supporting leg is fixedly connected with the frame; the linear guide rails of the moving pair Pz in each parallel support leg are parallel to each other; the axes of rotation of the turrets in each of the parallel legs are parallel to each other.

Preferably, the moving precision posture adjusting platform comprises at least two series-parallel support legs which are closed based on gravity and are used as driving legs, wherein a steering motor and a linear driver are actively driven, and at least one of a first wheel and a second wheel is actively or both actively driven.

Compared with the prior art, the invention has the following advantages:

from the mechanical point of view, the vehicle body in the mobile precision posture adjusting platform is equivalent to a mobile platform, the ground is equivalent to a fixed platform, and each series-parallel supporting leg is equivalent to a moving branch chain for connecting the fixed platform and the mobile platform, so that a brand-new multi-leg parallel mechanism based on open ground, namely the mobile precision posture adjusting platform, is formed, namely the series-parallel supporting leg based on ground closure and the posture adjusting platform thereof.

The support legs of the vehicle body are designed by introducing the open ground as a fixed platform and considering pure rolling motion or partial pure rolling between the wheels and the ground, so that the hybrid support legs have the function of adjusting the posture of the vehicle body besides the conventional walking function, the omnidirectional movement of the vehicle body is organically integrated with the posture adjustment, the motion precision, the stability and the reliability of the movable precision posture adjusting platform can be improved while the spatial six-degree-of-freedom precision posture adjusting function is realized, and the movable precision posture adjusting platform is not limited to move or rotate relative to the ground in a structural space or a non-structural space, so that the posture adjusting operation space is huge. The limitation of changing the small posture adjustment of the fixed point position is thoroughly changed. And the overall height of the mobile posture adjusting platform is effectively reduced, so that the six-degree-of-freedom posture adjusting butt joint and assembly can be realized in some shorter spaces.

The movable precise posture adjusting platform is used as special equipment integrating transportation and posture adjustment, and plays an important role in an automatic or intelligent technical system. In the process of transporting the target piece, the device has the capability of actively adapting to the more complex ground change and keeping the specific posture of the transport target piece unchanged, and is flexible, stable and reliable in movement and unlimited in path and track planning; in the posture adjusting process, the micro-motion and the posture adjusting motion are fused and continuous, the site state is not limited, and the posture adjusting device has high-precision posture adjusting capability.

Drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

Fig. 1 is a schematic structural view of a hybrid leg based on gravity closure according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a hybrid leg based on gravity closure according to an embodiment of the present invention;

FIG. 3 is an exploded view of a hybrid leg based on gravity closure according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a hybrid leg based on gravity closure according to another embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a hybrid leg based on gravity closure according to another embodiment of the present invention;

FIG. 6 is a schematic view of a wheel driving structure of a hybrid leg based on gravity closure according to another embodiment of the invention;

FIG. 7 is a schematic diagram of a wheel drive based on a gravity closed hybrid leg according to yet another embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a mobile pose adjustment platform according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of the internal structure of the mobile pose adjustment platform shown in FIG. 8;

FIG. 10 is a schematic view of a mobile pose platform according to yet another embodiment of the present invention;

FIG. 11 is a schematic view of the internal structure of the mobile pose adjustment platform shown in FIG. 10;

fig. 12 is a schematic structural diagram of a mobile posture adjustment platform according to yet another embodiment of the present invention.

Fig. 13 is a schematic view of a mobile pose adjustment platform mechanism according to yet another embodiment of the present invention.

FIG. 14 is a schematic diagram of a hybrid leg configuration based on gravity closure with independent suspension assemblies according to yet another embodiment;

FIG. 15 is a schematic top view of a hybrid leg based on gravity closure with an independent suspension assembly according to yet another embodiment; and

fig. 16 is a schematic diagram of a hybrid leg structure based on gravity closure with independent suspension assemblies according to yet another embodiment.

In the drawing, 1-series-parallel support leg, 2-vehicle frame, 3-controller, 4-battery pack, 11-base, 111-slide block, 112-linear guide rail, 12-lifting platform, 13-bogie, 131-steering bearing, 132-swinging bearing 14-wheel seat, 141-first wheel bearing, 142-second wheel bearing, 15-first wheel, 16-second wheel, 17-linear driver, 171-nut, 172-screw rod, 173-lifting motor, 174-bearing seat, 175-synchronous belt, 18-angle sensor, 19-internal contracting brake, 20-first torque sensor, 21-steering motor, 221, 222, 223-walking motor, 231, 232-second torque sensor, 24-pulley group, 241-a first belt pulley, 242-a synchronous belt, 243-a second belt pulley, 25-a differential gear train, 251-a drive bevel gear, 252-a planet carrier, 253-a large bevel gear, 254-a planetary bevel gear, 255-a first bevel gear, 256-a second bevel gear; 5-independent suspension component system, 51-suspension fixing plate, 52-spring, 53-spring collision block, 54-lifting collision block and 55-guide column.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

It is to be noted that, unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the invention pertains.

The hybrid support leg and the mobile high-precision posture adjusting platform based on gravity sealing or ground sealing in the invention are described in detail below with reference to the accompanying drawings. The features of the following examples and embodiments may be combined with each other without conflict.

According to a first aspect of the invention, an active and passive differential series-parallel support leg based on gravity closure or ground closure is provided, which comprises a base 11, a lifting platform 12, a bogie 13, a wheel seat 14, a first wheel 15 and a second wheel 16; the lifting platform 13 is connected with the base 11 in a sliding manner to form a moving pair Pz, and the moving pair Pz is an active pair and is driven by a linear driver 17; the bogie 13 is rotationally connected with the lifting platform 12 to form a revolute pair Rz; the wheel seat 14 is rotationally connected with the bogie 13 to form a revolute pair Rx; a first wheel 15 and a second wheel 16 respectively located at the first and second sides of the revolute pair Rx, the first wheel 15 being rotatably connected to the wheel seat 14 to form a revolute pair Ry 1; the second wheel 16 is rotatably coupled to the wheel carrier 14 to form a revolute pair Ry 2.

The Pz linear guide rail of the moving pair is parallel to the Rz axis of the rotating pair, and the Rz axis of the rotating pair is staggered and vertical to the Rx axis of the rotating pair; the axis of the revolute pair Rx is perpendicular or orthogonal to the axis of the revolute pair Ry1 or the axis of the revolute pair Ry2, and the axial directions of the revolute pair Ry1 and the revolute pair Ry2 are coaxial.

In practical use, the first wheel 15 and the second wheel 16 in the parallel-serial support leg are in contact with the ground and can perform pure rolling motion relative to the ground or the wheels perform pure rolling motion along a circle with a certain width, if the ground is regarded as a fixed platform and the wheel seat is regarded as a moving platform, the first wheel 15, the second wheel 16, the ground and the wheel seat 14 form a local parallel structure. Further, the base 11 is connected in series with the wheel seat 14 through the lifting platform 12 and the bogie 13, thereby forming a hybrid leg based on gravity closure, and the mechanism configuration is PzRzRx (Ry1+ Ry2) Rp.

The hybrid leg closed based on gravity further comprises a steering motor, and the bogie 13 is driven 21 by the steering motor arranged on the lifting platform 12. By providing the steering motor 21, the axial direction of the wheels in the parallel leg, that is, the direction of the axes of the revolute pairs Ry1 and Ry2, can be actively changed.

In order to avoid the bogie 13 rotating under the condition of external interference force or lifting of the parallel-serial support legs, which affects the motion precision and multi-leg coordination of the parallel-serial support legs, preferably, a band-type brake 19 or a clutch is further arranged on the lifting platform 12, instead of a steering motor, the bogie 13 can be locked to prevent the bogie from rotating relative to the lifting platform 12.

An angle sensor 18 is further arranged on the lifting platform 12 and used for detecting the rotating angle between the bogie 13 and the lifting platform 12 and realizing multi-leg movement coordination control. Namely, the device is used for controlling or keeping the state of a plurality of legs or the axial directions of the revolute pairs Rx are parallel to each other or form a certain relative coordination relationship, and meets the requirements of linear motion or steering, turning or curved track motion.

When the series-parallel leg closed based on gravity is the driving leg, at least one of the first wheel 15 and the second wheel 16 should be a driving wheel. I.e. one is active and the other is passive or both wheels are active. Preferably, the driving wheels of the first wheel 15 and the second wheel 16 are directly driven by the walking motor 221 or the walking motor 222, or indirectly driven by the walking motor 221 or the walking motor 222 through a transmission manner such as a chain, a pulley, a gear, and the like. Alternatively, the first wheel 15 and the second wheel 16 are driven by the two traveling

motors

221 and 222, respectively, to form an active differential drive or are driven indirectly by a single motor through a differential gear train.

The differential gear train comprises a first bevel gear 255 fixedly connected with the first wheel 15, a second bevel gear 256 fixedly connected with the second wheel 16, a planetary bevel gear 254 meshed with the first bevel gear 255 and the second bevel gear 256 simultaneously, a large bevel gear 253, a driving bevel gear 251 and a planet carrier 252. The planet bevel gear 254 is hinged on the planet carrier 252, the planet carrier 252 is fixedly connected on the large bevel gear 253, the large bevel gear 253 is rotatably connected with the wheel seat 14 and can rotate freely, the large bevel gear 253 is driven by the driving bevel gear 251 meshed with the large bevel gear 253, and the driving bevel gear 251 is fixedly connected with the output shaft of the walking motor 223. Two rotating shaft sections are vertically and symmetrically arranged on the outer shell of the differential gear train at equal distance positions relative to the second wheel 16, namely at the position superposed with the output axis of the walking motor 223, and are in rotating connection with the bogie 13 to form a revolute pair Rx. The motion state of the second wheel 16 is driven and controlled by the steering motor 21 and the walking motor 223 together.

Preferably, the linear actuator 17 may be a ball screw, a nut of the ball screw is fixedly connected to the base 11, a screw of the ball screw is rotatably connected to the lifting table 12, and the screw is driven by the lifting motor 173.

Preferably, the series-parallel support leg closed based on gravity is provided with an independent suspension assembly structure 5, the independent suspension assembly 5 consists of a suspension fixing plate 51, a spring 52, a spring collision block 53, a lifting collision block 54 and a guide column 55, the compression stroke of the spring 52 is smaller than the lifting stroke of the lifting platform 12, the lifting motion and the independent suspension assembly are in parallel connection, and the lifting motion stroke is larger than the length of the spring 52; when the lifting distance of the lifting platform 12 is greater than the length of the spring 52, the parallel-serial support leg 1 is used for rigid active suspension vibration reduction controlled by the lifting motor 173; when the lifting distance of the lifting platform 12 is less than the length of the spring 52, the lifting collision block 54 is in contact with the spring collision block 53, the contracting brake of the lifting motor 173 is opened, and the parallel-serial supporting legs are flexible passive vibration reduction of the independent suspension assembly based on the spring 53; the active and passive vibration reduction forms a rigid-flexible coupling vibration reduction structure; the independent suspension assembly 5 structure bogie 13 rotation center is arranged in a central symmetry mode, and the additional bending moment of the straight guide rail 112 is mutually counteracted, and the additional load of the straight guide rail 112 is not increased.

According to a second aspect of the invention, an omnidirectional moving precision posture adjusting platform is provided, which comprises a frame 2, a controller 3 and a hybrid leg 1 which is closed based on gravity in any one of three, four or six legs, wherein a base 11 in the hybrid leg 1 is fixedly connected with the frame 2. The moving pair Pz guide rails in each series-parallel supporting leg 1 are parallel to each other; the Rz axes of the revolute pairs in each parallel leg 1 are parallel to each other; three legs in the six-degree-of-freedom moving precision posture adjusting platform of the three legs are arranged in a triangular layout; four legs in the six-degree-of-freedom moving precision posture adjusting platform of the four legs are arranged in a square or rectangular or rhombic layout; six legs in the six-freedom-degree movement precision posture adjustment platform of the six legs are arranged in a Chinese character 'ri' shape.

Preferably, at least two parallel-serial support legs 1 closed based on gravity in the six-degree-of-freedom moving precision posture adjusting platform have a whole leg as a driving leg, namely at least one of the steering motor 21, the linear driver 17, the first wheel 15 and the second wheel 16 is a driving wheel or is driven actively.

Preferably, a battery pack 4 is also arranged inside the frame and used for supplying power to the controller and each series-parallel supporting leg in the frame when an external power supply is not available.

The coordinate system is illustrated, fig. 1 to 16, which use the same rectangular coordinate system, the Z axis is perpendicular to the horizontal plane, the X axis and the Y axis are located in the horizontal plane, the axial direction of the first wheel and the second wheel is the Y axis, and the rolling direction is the X axis.

Fig. 1 is a schematic structural diagram of a hybrid leg 1 based on gravity closure according to an exemplary embodiment of the present invention, fig. 1 illustrates a specific structure of the hybrid leg 1, and a schematic structural diagram of the hybrid leg 1 according to the embodiment may be referred to fig. 2. The hybrid leg 1 includes a base 11, a lifting platform 12, a bogie 13, a wheel base 14, a first wheel 15, a second wheel 16, and a linear drive 17. The lifting platform 12 is connected with the base 11, the lifting platform 12 can slide in a reciprocating mode in a direction perpendicular to the base 11, the bogie 13 is rotatably connected to the lifting platform 12, the wheel seat 14 is rotatably connected to the bogie 13, and the wheel seat 14 is driven by the bogie to rotate so as to drive wheels to change the movement direction.

The elevating platform 12 and the base 11 are connected in a sliding manner to form a moving pair Pz, and the moving pair Pz is an active moving pair and is driven by a linear driver 17. The bogie 13 is rotatably connected to the platform 12 to form a revolute pair Rz, the wheel base 14 is rotatably connected to the bogie 13 to form a revolute pair Rx, the first wheel 15, such as a first wheel and a second wheel 16, is positioned on either side of the revolute pair Rx, and the first wheel 15 is rotatably connected to the wheel base 14 to form a revolute pair Ry1, and the second wheel 16 is rotatably connected to the wheel base 14 to form a revolute pair Ry 2. The first wheel 15 is in contact with the ground forming a roller pair Rp1 and the second wheel 16 is in contact with the ground forming a roller pair Rp 2.

The kinematic pair formed between the parts in the parallel-serial support leg 1 satisfies a certain geometrical relationship, wherein the guide direction of the mobile pair Pz is parallel to the axial direction of the revolute pair Rz, the axial line of the revolute pair Rz is vertical to the axial line of the revolute pair Rx, the axial line of the revolute pair Rx is vertical to the axial lines of the revolute pair Ry1 and the revolute pair Ry2, and the axial lines of the revolute pair Ry1 and the revolute pair Ry2 are coaxial.

The base 11 is a rectangular plate-shaped structure, the lifting platform 12 is an H-shaped structural member, the bogie 13 is a Y-shaped structural member, and the wheel seat 14 is a cross axle structure; in the parallel-serial supporting leg 1, a base 11 is movably connected with a lifting platform 12 through a linear guide rail 112, the lifting platform 12 is rotatably connected with a bogie 13, and the bogie 13 is rotatably connected with a wheel seat 14; the base 11, the lifting platform 12, the bogie 13 and the wheel seat 14 are connected in series from top to bottom. The first wheel 15 and the second wheel 16 are connected with the wheel seat 14 at the same time and are respectively connected with the two ends of the ten structures of the wheel seat 14 to form a revolute pair; the first wheel and the second wheel are in contact with the ground and are partially connected in parallel under the gravity closed condition, so that the parallel-serial landing leg 1 is of a series-parallel structure.

As shown in fig. 3 and 4, in an embodiment, the linear actuator 17 is a ball screw, the linear actuator 17 includes a nut 171, a screw 172, a lifting motor 173, a bearing seat 174, and a timing belt 175, the nut 171 is fixedly connected to the base 11, the bearing seats 174 are disposed at two ends of the screw 172, the bearing seats 174 are fixedly connected to one side of the lifting table 12, and the screw 172 is driven by the lifting motor 173 to rotate through the timing belt 175 and two timing belts. The linear actuator 17 may also be a hydraulic cylinder, a linear module, or other types of actuators, and may be selected appropriately according to the actual situation.

As shown in fig. 3, for an explosion structure view of the hybrid leg 1 according to an embodiment of the present invention, in order to reduce friction at a joint of each component of the hybrid leg 1, the lifting platform 12 is slidably connected to the base 11 through the slider 111 and the linear guide 112, i.e., a moving pair Pz is formed, the slider 111 is fixedly connected to the base 11, the linear guide 112 is fixedly connected to the lifting platform 12, and a length direction of the linear guide is perpendicular to a table top of the lifting platform 12; a steering bearing 131 is arranged at the rotary connection position of the bogie 13 and the lifting platform 12, and a swing bearing 132 is arranged at the rotary connection position of the wheel seat 14 and the bogie 13; a first wheel bearing 141 is arranged at the rotary connection position of the first wheel 15 and the wheel seat 14, and a second wheel bearing 142 is arranged at the rotary connection position of the second wheel 16 and the wheel seat 14. The sliding block and the linear guide rail are arranged at the position of the sliding pair Pz, and the bearings are arranged at the positions of the revolute pair Rz, the revolute pair Rx, the revolute pair Ry1 and the revolute pair Ry2, so that the friction resistance generated by the parallel-serial support leg 1 in the motion process can be effectively reduced.

As shown in fig. 4, in an embodiment, a band-type brake 19 is further disposed on the lifting platform 12, an output end of the band-type brake 19 is connected to the bogie 13, and the rotation or locking of the bogie 13 with respect to the lifting platform 12 can be controlled by the band-type brake 19, so as to avoid the influence on the motion accuracy of the parallel-serial support leg 1 and the coordination of the multi-leg state caused by the rotation of the bogie 13 under the condition of an external disturbance force or the lifting of the parallel-serial support leg 1, where the band-type brake 19 may also be replaced by a clutch or the like. In order to improve the control precision of the series-parallel supporting leg 1, an angle sensor 18 can be optionally arranged at the rotary connection part of the bogie 13 and the lifting platform 12 and used for monitoring the size of the corner of the bogie 13 in real time. For controlling and coordinating the directions of the revolute pairs Rx between the legs and the accuracy thereof

In an alternative embodiment, as shown in fig. 5, a steering motor 21 is further disposed on the lifting platform 12, the bogie 13 is driven by the steering motor 21 to rotate, and the steering motor 21 is controlled to actively change the rotating direction of the bogie 13, so as to control the traveling direction of the first wheel 15 and the second wheel 16. The output of the steering motor 21 may further be provided with a first torque sensor 20 for real-time monitoring of the steering torque between the bogie 13 and the lifting platform 12.

When the parallel-serial leg 1 is a driving leg, at least one of the first wheel 15 and the second wheel 16 is a driving wheel or both wheels are active to form active differential motion. As shown in fig. 5, in an alternative embodiment, the second wheel 16 is a driving wheel, the second wheel 16 can be directly driven by the walking motor 222, or indirectly driven by the walking motor 222 through a transmission manner such as a chain, a pulley, a gear, etc., in the embodiment shown in fig. 5, the second wheel 16 is indirectly driven by the walking motor 222 through the pulley set 24, the walking motor 222 is mounted on the wheel seat 14, the pulley set 24 includes a first pulley 241, a timing belt 242, and a second pulley 243, the first pulley 241 is fixedly connected with an output shaft of the walking motor 222, the second pulley 243 is fixedly connected to one side of the second wheel 16, and the timing belt 242 is cooperatively mounted on the first pulley 241 and the second pulley 242.

As shown in fig. 6, in an alternative embodiment, the first wheel 15 and the second wheel 16 are driving wheels, the first wheel 15 and the second wheel 16 are respectively driven by two independent traveling

motors

221, 222, when the two traveling

motors

221, 222 drive the first wheel 15 and the second wheel 16 to rotate in the same direction, the hybrid leg 1 can travel forward, and when the two traveling

motors

221, 222 drive the first wheel 15 and the second wheel 16 to rotate in different directions, an active differential driving working state is formed, the bogie 13 can rotate relative to the lifting platform 12, and the traveling direction of the hybrid leg 1 is changed. To further improve the control accuracy of the first wheel 15 and the second wheel 16, the output ends of the traveling

motors

221, 222 may be further installed with torque sensors for monitoring the on-wheel torque of the first wheel 15 or the second wheel 16 in real time.

In an alternative embodiment, as shown in fig. 7, the first wheel 15 and the second wheel 16 may be indirectly driven by the travel motor 223 through a differential gear train 25. The problem of the difference or randomness of the rotation speed of the first wheel 15 and the second wheel 16 during the steering process can be solved by simultaneously driving the first wheel 15 and the second wheel 16 by one traveling motor 223.

The differential gear train 25 includes a first bevel gear 255 fixedly connected to the first wheel 15, a second bevel gear 256 fixedly connected to the second wheel 16, and a planetary bevel gear 254 engaged with the first bevel gear 255 and the second bevel gear 256, wherein the planetary bevel gear 254 is rotatably connected to the planetary carrier 252, the planetary carrier 252 is fixedly connected to a large bevel gear 253, the large bevel gear 253 is rotatably connected to an axis of the wheel 15, the large bevel gear 253 is driven by a driving bevel gear 251 engaged therewith, and the driving bevel gear 251 is fixedly connected to an output shaft of the traveling motor 223. The axis of a first bevel gear 255 fixedly connected with the first wheel 15 is coaxial with the axis of a second bevel gear 256 fixedly connected with the second wheel 16, and is supported on a planetary gear train shell, namely the wheel seat 14 through a revolute pair, the axes of the walking motor 223 and the driving bevel gear 251 are coaxial with the axis of the planetary bevel gear 254, two sections of rotating shafts are respectively arranged on the outer surface of the wheel seat 14 to form rotating connection with the lifting platform 13, namely an Rx revolute pair is formed and is coaxial with the axis of the planetary bevel gear 254. One end of the revolute pair Rx is overlapped with the output axis of the driving motor 223 to form a composite revolute pair with the motor shaft inside and the motor shaft outside.

As shown in fig. 8 and 9, which are embodiments of the mobile precise posture adjustment platform provided by the present invention, the mobile precise posture adjustment platform includes a frame 2 and three parallel-serial support legs 1, and a base 11 in the parallel-serial support leg 1 is fixedly connected to the frame 2. The three parallel-serial supporting legs 1 are arranged in a triangular shape and are controlled by a controller 3 in the frame 2. Two or three of the three parallel-serial support legs 1 can be driving legs, at least one of the first wheel 15 or the second wheel 16 in the driving legs is a driving wheel or both of the first wheel and the second wheel are driving wheels, and the driving wheels are driven to rotate by the driving

motors

221 or 222 or simultaneously and independently. The frame 2 is a frame structure formed by welding sectional materials, the bearing capacity of the frame 2 can be effectively improved, and the decorative plate is arranged on the peripheral surface of the frame 2. The three parallel-serial support legs 1, namely 1a, 1b and 1c, meet attitude constraint conditions, wherein the attitude conditions are that moving pair Pz guide rails in each parallel-serial support leg are parallel to each other, and rotating pair Rz axes are parallel to each other.

Further, in order to improve the application range of the mobile posture adjusting platform, a battery pack 4 is arranged in the external power supply frame 2 and used for supplying power to the controller 3 and each series-parallel supporting leg 1, so that the mobile precision posture adjusting platform can still work normally under the condition of no external power supply.

The movable precise posture adjusting platform has the carrying function of a common carrying vehicle, and can move along any direction of the ground and rotate around the direction vertical to the ground. Meanwhile, the movable precise posture adjusting platform also has the function of adjusting the space posture of the frame 2, and the up-and-down lifting motion of the frame 2 can be realized by controlling the linear drivers 17 in the three parallel-serial support legs 1 to synchronously move up and down; when the linear drivers 17 in the three parallel-serial support legs 1 are controlled to move asynchronously, the frame 2 can be inclined relative to the ground. Namely, pitch motion and roll motion are realized.

Specifically, as shown in fig. 9, in order to distinguish the individual parallel-serial legs, the parallel-serial legs at different positions are respectively named as 1a, 1b, and 1c, and when the parallel-serial legs 1a and 1b are controlled to be raised and the parallel-serial legs 1c are simultaneously lowered, the frame 2 can be rotated around the x-axis, and of course, the parallel-serial legs 1a and 1b can be lowered and the parallel-serial legs 1c are raised to realize the reverse rotation around the x-axis. When the parallel-serial support leg 1a is controlled to be lifted or lowered, and the parallel-serial support leg 1b is correspondingly lowered or lifted, the rotation of the frame 2 around the y axis can be realized.

The above is only a brief description of the attitude adjustment control of the frame 2, and in the actual control, when the attitude of the frame 2 is changed, the first wheel 15 and the second wheel 16 in the parallel leg are moved accordingly. This is because when the ground is used as a fixed platform, the rolling pair Rp1 and Rp2 formed by the contact between the first wheel 15 and the second wheel 16 and the ground participate in the freedom construction of the frame 2, so that when the posture of the frame 2 is adjusted, the first wheel 15 and the second wheel 16 need to be controlled to perform corresponding additional micro-motions.

As shown in fig. 10, 11 and 13, the present invention provides another embodiment of the mobile precise posture adjustment platform, in this embodiment, four parallel-serial legs 1 are connected to the frame 2, respectively disposed at four corners of the frame 2, and arranged in a square or rectangular shape, and by providing the four parallel-serial legs 1, the bearing area of the mobile precise posture adjustment platform can be effectively increased, and two, three, or four of the four parallel-serial legs 1 may be driving legs. Position and attitude constraint conditions are satisfied between the four parallel-serial support legs, and the attitude conditions are that the Pz guide rails of the moving pair in each parallel-serial support leg are parallel to each other and the Rz axes of the rotating pair are parallel to each other.

In this embodiment, one of the four parallel-serial legs 1 is a redundant leg, and by providing the redundant leg, the bearing capacity of the mobile posture adjusting platform can be improved, and the stability of the mobile precision posture adjusting platform can be improved. When one of the four series-parallel supporting legs fails, the redundant supporting leg can replace the failed supporting leg to continue working without influencing the normal work of the mobile precise attitude adjusting platform, which is important for the installation and butt joint of important products such as satellites, rockets and the like.

Sensors such as a camera, ultrasonic waves, a laser radar and a millimeter wave radar can be further installed or carried on the periphery of the frame 2 to improve the sensing capability of the mobile precision posture adjusting platform to the external environment, and a vertical lifting platform or a functional mechanism or a robot can be further carried on the frame 2 to further expand the application range of the mobile precision posture adjusting platform.

As shown in fig. 12, the present invention provides another embodiment of the mobile precision posture adjustment platform, in this embodiment, six parallel-serial legs 1 are connected to the frame 2, and are respectively disposed at two ends or two sides of the frame 2, so that the bearing capacity of the platform can be effectively improved by increasing the number of the legs of the mobile precision posture adjustment platform, and the stability and reliability of the mobile posture adjustment platform can be further improved. The embodiment aims at the working condition of heavy load, such as carrier rocket, large-scale transport plane and heavy machine precision posture adjustment butt joint and installation.

Preferably, as shown in fig. 14, 15 and 16, in an embodiment, an independent suspension assembly 5 is arranged between the lifting platform 12 and the bogie 13, wherein the independent suspension assembly 5 comprises a suspension fixing plate 51, a spring 52, a spring bump 53, a lifting bump 54 and a guide column 55, and the spring 52 can be a compression spring, a belleville spring or an air spring, and is selected reasonably according to the load and the suspension stroke.

Fig. 14 is a schematic diagram of a hybrid leg structure based on gravity-based closed system with independent suspension assemblies according to another embodiment of the present invention, in which the independent suspension assemblies 5 connect the lifting platform 12 and the bogie 13, and are arranged in two groups, and are in parallel relation with Pz; the suspension fixing plate 5 is fixedly connected with a bogie 13; the spring 52 is fixedly connected with the spring striking block 53; the guide column 55 is fixedly connected with the suspension fixing plate 51, and penetrates through the spring 52 and the spring collision block 53 to form sliding connection; the lifting collision block 53 is fixedly connected with the lifting platform 13, and the lifting collision block 53 is connected with the guide column 55 in a sliding manner.

FIG. 15 is a schematic top view of a hybrid leg with an independent suspension assembly based on gravity closure according to yet another embodiment; the independent suspension assemblies 5 are arranged in central symmetry relative to the rotation center of the bogie 13, so that additional bending moment on the guide rail is mutually offset, and additional load on the lifting guide rail is not increased.

Fig. 16 is a schematic diagram of a hybrid leg structure based on gravity closure with independent suspension assemblies according to yet another embodiment; the spring 52 is compressed to form a lifting stroke which is smaller than that of the lifting platform 12, the lifting motion and the independent suspension component are in parallel connection, and the lifting motion stroke L1 is larger than the spring length L2; when the lifting distance L1 of the lifting platform 12 is greater than the length L2 of the spring 52, the parallel-serial support legs are used for damping vibration of the rigid active suspension controlled by the lifting low motor 173; when the lifting distance L1 of the lifting platform 12 is smaller than the length L2 of the spring 52, the lifting collision block 54 contacts with the spring collision block 53, the contracting brake of the lifting motor 173 is opened, the parallel-serial supporting legs are flexible passive vibration reduction of the independent suspension assembly 5 based on the spring 52, the compression spring can effectively reduce the load borne by the lead screw 172, and when the compression amount of the spring is maximum, the load of the lead screw is zero; the active and passive vibration reduction structure forms a rigid-flexible coupling vibration reduction structure.

It should be noted that the number of the support legs for moving the precision posture adjusting platform can be selected according to actual working conditions, and is not limited to the embodiments shown in the present invention.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.

Claims

1. A series-parallel supporting leg based on ground sealing is characterized by comprising a base, a lifting platform, a bogie, a wheel seat and wheels, wherein the base is sequentially connected with a linear driver, the lifting platform, the bogie and the wheel seat in series to form local parallel connection under a gravity sealing condition;

the wheels comprise a first wheel and a second wheel which are respectively positioned on the first side and the second side of the wheel frame, and the first wheel is rotationally connected with the wheel seat to form a revolute pair Ry 1; the second wheel is rotationally connected with the wheel seat to form a revolute pair Ry 2; the wheels and the ground contact point have no vertical movement freedom degree;

the lifting platform is connected with the base in a sliding mode to form a moving pair Pz serving as an active pair, the lifting platform is driven by a linear driver, the bogie is driven by a steering motor arranged on the lifting platform to form a rotary connection, the bogie is rotationally connected with the lifting platform to form a rotary pair Rz, the wheel seat is rotationally connected with the bogie to form a rotary pair Rx, a linear guide rail of the lifting platform is parallel to the axis of the rotary pair Rz, and the axis of the rotary pair Rz is perpendicular to the axis of the rotary pair Rx; the axes of the revolute pair Ry1 and the revolute pair Ry2 are coaxial, and the axis of the revolute pair Rx is perpendicularly intersected with the axes of the revolute pair Ry1 and the revolute pair Ry 2; the axis of the revolute pair Rz passes through the intersection point of the axis of the revolute pair Rx and the axes of the revolute pair Ry1 and the revolute pair Ry 2;

when the driving leg is used, the second wheel is a driving wheel, or the first wheel and the second wheel are both driving wheels so as to form active differential motion; when the second wheel is a driving wheel, the second wheel is directly driven by the walking motor or indirectly driven by the walking motor through the transmission mechanism; when the second wheel is indirectly driven by the walking motor through the belt pulley set, the walking motor is arranged on the wheel seat, the belt pulley set comprises a first belt pulley, a synchronous belt and a second belt pulley, the first belt pulley is fixedly connected with an output shaft of the walking motor, the second belt pulley is fixedly connected to one side of the second wheel, and the synchronous belt is arranged on the first belt pulley and the second belt pulley in a matched mode; or when the first wheel and the second wheel are both driving wheels, the first wheel and the second wheel are respectively driven by two independent walking motors; when the two independent walking motors drive the first wheel and the second wheel to rotate in the same direction, the first wheel and the second wheel are enabled to walk forwards, and when the two walking motors drive the first wheel and the second wheel to rotate in different directions, an active differential driving working state is formed, so that the bogie rotates relative to the lifting platform, and the advancing directions of the first wheel and the second wheel are changed;

in the active differential motion, the differential gear train comprises a first bevel gear fixedly connected with a first wheel, a second bevel gear fixedly connected with a second wheel, a planetary bevel gear meshed with the first bevel gear and the second bevel gear, a large bevel gear, a driving bevel gear and a planet carrier; the planet carrier is hinged to a planet bevel gear, the planet carrier is fixedly connected to a large gear, the large gear is rotatably connected with a first wheel shaft, the large bevel gear is driven by a driving bevel gear meshed with the large bevel gear, and the driving bevel gear is fixedly connected with an output shaft of a traveling motor; the lifting platform is further provided with an angle sensor, and the angle sensor is used for detecting a corner between the bogie and the lifting platform.

2. The ground enclosure-based parallel-serial support leg according to claim 1, further comprising an independent suspension assembly disposed between the lifting platform and the bogie, wherein the independent suspension assembly comprises a suspension fixing plate, a spring collision block, a lifting collision block, a guide post, and connects the lifting platform and the bogie; in the independent suspension assembly, the compression stroke of the spring is smaller than the lifting stroke of the lifting platform, the lifting motion and the independent suspension are in parallel connection, and the lifting motion stroke is larger than the length of the spring; when the lifting distance of the lifting platform is greater than the length of the spring, the rigid active vibration reduction controlled by a lifting motor can be realized; when the lifting distance of the lifting platform is smaller than the length of the spring, the lifting collision block is in contact with the spring collision block, the contracting brake of the lifting motor is opened, passive vibration reduction can be realized due to the independent suspension flexibility of the spring, and the active vibration reduction and the passive vibration reduction form a rigid-flexible coupling vibration reduction structure.

3. A mobile posture adjusting platform based on the ground closed series-parallel support legs of claim 1 or 2, which is characterized by comprising a frame, a controller, a battery and the series-parallel support legs, wherein the number of the series-parallel support legs is three, four or six; the base in each parallel-connection supporting leg is fixedly connected with the frame, the linear guide rails of the moving pair Pz in each parallel-connection supporting leg are parallel to each other, and the rotating axes of the rotating frames in each parallel-connection supporting leg are parallel to each other; when the number of the parallel-serial supporting legs is three, the three legs are arranged in an isosceles triangle structure; when the number of the parallel-serial supporting legs is four, the four supporting legs are arranged in a square or rectangular structure; or when the number of the series-parallel supporting legs is six, the six supporting legs are arranged in a herringbone structure; when at least two of the series-parallel support legs are driving legs, the steering motor and the linear driver are actively driven, and at least one of the first wheel and the second wheel is actively driven.

4. A series-parallel support leg based on gravity sealing is characterized by comprising a base, a lifting platform, a bogie, a wheel seat and wheels, wherein the base is sequentially connected with a linear driver, the lifting platform, the bogie and the wheel seat in series to form local parallel connection under the gravity sealing condition;

5. The hybrid leg based on gravity closure according to claim 4, further comprising an independent suspension assembly disposed between the lifting platform and the bogie, the independent suspension assembly comprising a suspension fixing plate, a spring collision block, a lifting collision block, a guide post connecting the lifting platform and the bogie; in the independent suspension assembly, the compression stroke of the spring is smaller than the lifting stroke of the lifting platform, the lifting motion and the independent suspension are in parallel connection, and the lifting motion stroke is larger than the length of the spring; when the lifting distance of the lifting platform is greater than the length of the spring, the rigid active vibration reduction controlled by a lifting motor can be realized; when the lifting distance of the lifting platform is smaller than the length of the spring, the lifting collision block is in contact with the spring collision block, the contracting brake of the lifting motor is opened, passive vibration reduction can be realized due to the independent suspension flexibility of the spring, and the active vibration reduction and the passive vibration reduction form a rigid-flexible coupling vibration reduction structure.

6. A mobile posture adjusting platform based on the series-parallel support legs closed by gravity as claimed in claim 4 or 5, which comprises a frame, a controller, a battery and the series-parallel support legs, wherein the number of the series-parallel support legs is three or four or six; the base in each parallel-connection supporting leg is fixedly connected with the frame, the linear guide rails of the moving pair Pz in each parallel-connection supporting leg are parallel to each other, and the rotating axes of the rotating frames in each parallel-connection supporting leg are parallel to each other; when the number of the parallel-serial supporting legs is three, the three legs are arranged in an isosceles triangle structure; when the number of the parallel-serial supporting legs is four, the four supporting legs are arranged in a square or rectangular structure; or when the number of the series-parallel supporting legs is six, the six supporting legs are arranged in a herringbone structure; when at least two of the series-parallel support legs are driving legs, the steering motor and the linear driver are actively driven, and at least one of the first wheel and the second wheel is actively driven.