Three-axis parallel rotating mechanism for automatic charging and control method therefor

Abstract

The present invention relates to the technical field of automobile charging, and in particular to a three-axis parallel rotating mechanism for automatic charging, comprising a connecting base and three parallel driving branches, wherein an electrical connecting member is fixedly arranged on the connecting base; three connecting holes are arranged at the periphery of the connecting base; each parallel driving branch comprises a swing rod and a connecting rod; a first connecting end of each swing rod is rotatably connected to a rotating shaft; each rotating shaft is driven to rotate by a fixedly arranged driving device, second connecting ends of the swing rods are hingedly connected to first connecting ends of the connecting rods in one-to-one correspondence, and second connecting ends of the connecting rods are hingedly connected to the connecting holes in one-to-one correspondence; the rotation axes of all the rotating shafts in the three parallel driving branches and the hinge axes of the connecting ends on all the connecting rods intersect at the same spatial point. The three-axis parallel rotating mechanism provided by the present invention realizes rotational adjustment of the electrical connector by means of three parallel driving branches, and has the advantages of low cost, high accuracy, high load‑carrying capacity, compact structure, high rigidity, and the like.

Description

Three-axis parallel rotating mechanism for automatic charging and control method thereof TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile charging, in particular to a three-axis parallel rotating mechanism for automatic charging and a control method thereof. BACKGROUND

[0002] With the improvement of global environmental awareness and the development of renewable energy technology, electric vehicles (Electric Vehicles) as a clean and efficient means of transportation are gradually replacing traditional internal combustion engine vehicles and becoming the main choice for future travel.

[0003] The traditional charging method for electric vehicles is manual charging, which requires users to hold a charging gun and connect it to the vehicle charging interface. This method has the problems of connection difficulty and increased safety risk. To address this issue, automatic charging for electric vehicles is becoming increasingly popular, which involves inserting a charging gun into a vehicle charging interface using an automatic charging device. This method is convenient and has low safety risks. However, due to the different spatial positions and attitudes of different vehicle charging interfaces, it is difficult for the automatic charging device to dock. Therefore, the automatic charging device needs to have an automatic rotating function to drive the gun head to rotate to adapt to vehicle charging interfaces with different angles and attitudes.

[0004] Currently, the automatic rotation of the gun head is often achieved by using a series joint, such as a multi-axis joint mechanical arm of a Jieka or a Yabo, or some automatic charging companies have developed a rotating platform in series to achieve gun head steering. These series rotating mechanisms have the following disadvantages: 1) the number of parts is large, the parts are complex, the processing cost is high, and it is difficult to popularize; 2) the errors between the series rotating joints / platforms have a cumulative effect, and the total transmission error is large; 3) each joint / platform of the series rotating joints / platforms needs to bear the force of the gun head and all the mechanisms between the gun head and the joint / platform, resulting in small carrying capacity of the mechanism; 4) in order to enhance the carrying capacity, the size needs to be further increased, resulting in a large structure volume; and 5) the transmission path of the series rotating joints / platforms is long, and the stiffness is poor. SUMMARY

[0005] To solve the technical problems of the existing automatic rotating mechanism, such as a large number of parts, complexity, high cost, large error, small carrying capacity, large structure volume, and low stiffness, the present application provides a three-axis parallel rotating mechanism for automatic charging, which realizes the rotation adjustment of an electrical connector through three parallel driving branches, and has the advantages of low cost, small error, large carrying capacity, small structure volume, and large stiffness.

[0006] The technical scheme of the present application is as follows:

[0007] A three-axis parallel rotating mechanism for automatic charging, comprising:

[0008] The connecting seat is externally arranged with three connecting holes;

[0009] Three parallel driving branches, each of which comprises a swing rod and a connecting rod, the first connecting end of each swing rod is rotatably connected with a rotating shaft, each rotating shaft is driven to rotate by a fixedly arranged driving device, the second connecting end of each swing rod is hingedly connected with the first connecting end of each connecting rod, and the second connecting end of each connecting rod is hingedly connected with each connecting hole;

[0010] In each parallel driving branch, the rotating axis of the rotating shaft and the hinging axes of the two connecting ends of the connecting rod are not collinear; the rotating axes of all rotating shafts in the three parallel driving branches and the hinging axes of the two connecting ends of all connecting rods intersect at the same spatial point.

[0011] Further, the electric connecting piece is a charging gun or a charging seat.

[0012] Further, the three connecting holes are arranged in a circumferential direction; the three parallel driving branches are also arranged in a circumferential direction in an initial state.

[0013] Further, the connecting seat is formed with a mounting hole for mounting the electric connecting piece; the outer periphery of the connecting seat is provided with three lugs, and one connecting hole is arranged on each lug.

[0014] Further, each driving device directly or through a transmission mechanism drives the corresponding rotating shaft to rotate.

[0015] Further, the three-axle parallel rotating mechanism can be additionally provided with one or more parallel auxiliary branches, each of which comprises an auxiliary swing rod and an auxiliary connecting rod, the first connecting end of each auxiliary swing rod is connected with an auxiliary rotating shaft, each auxiliary rotating shaft is rotatably connected with a fixed seat, the second connecting end of each auxiliary swing rod is hingedly connected with the first connecting end of each auxiliary connecting rod, the outer periphery of the connecting seat is further correspondingly arranged with one or more auxiliary connecting holes, and the second connecting end of each auxiliary connecting rod is hingedly connected with each auxiliary connecting hole.

[0016] In each parallel auxiliary branch, the rotating axis of the auxiliary rotating shaft and the hinging axes of the two connecting ends of the auxiliary connecting rod are not collinear; the rotating axes of all rotating shafts in the three parallel driving branches and the hinging axes of the two connecting ends of all connecting rods, and the rotating axes of all auxiliary rotating shafts in each parallel auxiliary branch and the hinging axes of the two connecting ends of all auxiliary connecting rods intersect at the same spatial point.

[0017] Another aspect of the present application provides a control method for the three-axle parallel rotating mechanism for automatic charging according to any one of the above, comprising the following steps:

[0018] acquiring a desired pose of the electrical connector;

[0019] calculating an angle of rotation required for each driving device according to the desired pose;

[0020] controlling the rotation of each driving device according to the calculated angle.

[0021] Further, the calculation of the angle of rotation required for each driving device according to the desired pose specifically comprises:

[0022] establishing an electrical connector coordinate system Cxyz and a fixed platform coordinate system Gxyz, and establishing a homogeneous transformation matrix between the electrical connector coordinate system Cxyz and the fixed platform coordinate system Gxyz according to the initial pose and the desired pose of the electrical connector G C;

[0023] The space point is denoted as point O, a virtual sphere is established with point O as the center of the sphere; the intersection of the rotation axis of the shaft in the nth parallel driving branch in the initial state and the surface of the virtual sphere is set as point An, the intersection of the hinged axis of the first connecting end of the connecting rod in the nth parallel driving branch in the initial state and the surface of the virtual sphere is set as point Bn, and the intersection of the hinged axis of the second connecting end of the connecting rod in the nth parallel driving branch in the initial state and the surface of the virtual sphere is set as point Cn, points An, Bn and Cn constitute a spherical triangle in the initial state; the hinged axis of the first connecting end of the connecting rod in the rotated nth parallel driving branch is set as point B'n, and the hinged axis of the second connecting end of the connecting rod in the rotated nth parallel driving branch is set as point C'n, points An, B'n and C'n constitute a spherical triangle after rotation;

[0024] determining the coordinates of points An, Bn and Cn in the electrical connector coordinate system Cxyz in the initial state, calculating the coordinates of points An, Bn and Cn in the fixed platform coordinate system Gxyz according to the homogeneous transformation matrix G C in the initial state, and calculating the spherical angle ∠BnAnCn; determining the coordinates of point C'n in the electrical connector coordinate system Cxyz after rotation, calculating the coordinates of point C'n in the fixed platform coordinate system Gxyz according to the homogeneous transformation matrix G C' after rotation, and calculating the spherical angle ∠C'nAnB'n according to the side lengths AnB'n, B'nC'n and C'nAn.

[0025] If the triple vector mixed product Then the angle that the nth driving device needs to turn is ∠BnAnB'n=∠C'nAnB'n-(∠BnAnCn-∠C'nAnCn); if the triple vector mixed product Then the angle that the nth driving device needs to turn is ∠BnAnB'n=∠C'nAnB'n-(∠BnAnCn+∠C'nAnCn). The n is 1, 2, 3, and the solution is sequentially carried out.

[0026] In another aspect of the present application, a three-axis parallel rotating mechanism for automatic charging is provided, comprising:

[0027] A connecting seat is provided with an electric connecting piece fixedly arranged thereon, and three or more connecting holes are arranged on the outer periphery of the connecting seat.

[0028] Three or more parallel branches are provided, each of which comprises a swing rod and a connecting rod, the first connecting end of each swing rod is connected with a rotating shaft, a torsional spring is arranged at each rotating shaft, the corresponding torsional spring is deformed under force when each swing rod rotates around the rotating shaft, the second connecting end of each swing rod is hingedly connected to the first connecting end of each connecting rod, and the second connecting end of each connecting rod is hingedly connected to each connecting hole; the number of parallel branches corresponds to the number of connecting holes.

[0029] In each parallel branch, the rotating axis of the rotating shaft and the hinging axes of the two connecting ends on the connecting rod are not collinear; the rotating axes of all rotating shafts and the hinging axes of all connecting rods in the three or more parallel branches all intersect at the same spatial point.

[0030] Further, the electric connecting piece is a charging gun or a charging seat.

[0031] After the above technical scheme is adopted, the three-axis parallel rotating mechanism for automatic charging and the control method thereof provided by the present application have the following beneficial effects compared with the prior art:

[0032] Compared with the serial rotating joint / platform in the prior art, the three-axis parallel rotating mechanism provided by the present application adopts three parallel driving branches for parallel driving, each parallel driving branch only comprises a driving device, a swing rod and a connecting rod, the number of parts and the number of parts in each parallel driving branch are small, the structure of the parts is simple, and the processing cost is low; and the error of the three parallel driving branches can be averaged at the position of the electric connecting piece, so that the movement is more accurate compared with the serial mechanism; in addition, the stress of the electric connecting piece is shared by the three parallel driving branches, the stress of each parallel driving branch is uniform and small, the stress of the whole mechanism is more reasonable, and the bearing capacity of the whole mechanism is larger; in addition, due to the strong bearing capacity, the overall size can be smaller; and the movement path is short, and the rigidity is larger. BRIEF DESCRIPTION OF DRAWINGS

[0033] Fig. 1 is a schematic diagram of the overall structure of a three-axis parallel rotary mechanism according to an embodiment;

[0034] Fig. 2 is an exploded view of the three-axis parallel rotary mechanism according to the embodiment;

[0035] Fig. 3 is a schematic diagram of the structure of a driving device according to the embodiment;

[0036] Fig. 4 is a schematic diagram of the structure of a swing rod according to the embodiment;

[0037] Fig. 5 is a schematic diagram of the structure of a connecting rod according to the embodiment;

[0038] Fig. 6 is a schematic diagram of the structure of a connecting seat according to the embodiment;

[0039] Fig. 7 is an enlarged view of a single parallel driving branch in Fig. 1;

[0040] Fig. 8 is a schematic diagram of the positions of points An, Bn, and Cn according to an embodiment;

[0041] Fig. 9 is a schematic diagram of spherical triangles before and after rotation of the three-axis parallel rotary mechanism according to an embodiment in four cases;

[0042] Fig. 10 is a schematic diagram of the structure of a parallel rotary mechanism according to an embodiment.

[0043] In the figure, connecting seat 1, connecting hole 11, lug 12, mounting port 13; electrical connecting member 2; swing rod 3, first driving hole 31, second driving hole 32; connecting rod 4, first hinged hole 41, second hinged hole 42; rotating shaft 5, driving device 6; torsional spring 7; support plate 8. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The description of the at least one exemplary embodiment is actually only illustrative, but not intended to limit the present application and its application or use in any way. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0045] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component, and / or combination thereof.

[0046] In addition, it should be noted that the use of the terms "first", "second" and the like is merely intended to distinguish corresponding parts for the convenience of the description, and the above terms have no special meaning unless otherwise stated, and therefore cannot be understood as limiting the scope of protection of the present application.

[0047] Embodiment one:

[0048] As shown in FIG. 1-7, the present embodiment provides a three-axis parallel rotating mechanism for automatic charging, which comprises a connecting seat 1 and three parallel driving branches, wherein the connecting seat 1 is fixedly provided with an electrical connector 2, which can be fixedly installed on the connecting seat 1 or directly formed in an integral structure with the connecting seat 1; the electrical connector 2 can be a charging gun or a charging seat; the outer periphery of the connecting seat 1 is further provided with three connecting holes 11.

[0049] Further, in each of the three parallel driving branches, each parallel driving branch comprises a swing rod 3 and a connecting rod 4, the first connecting end of each swing rod 3 is rotatably connected with a rotating shaft 5, each rotating shaft 5 is driven to rotate by a driving device 6, each driving device 6 is fixed on a bottom plate and fixedly opposite to the bottom plate, the bottom plate can be fixed to a ground end moving mechanism / car end, the second connecting end of each swing rod 3 is hingedly connected to the first connecting end of each connecting rod 4, and the second connecting end of each connecting rod 4 is hingedly connected to each connecting hole 11. Specifically, in each parallel driving branch, the first connecting end and the second connecting end of the swing rod 3 are located at both ends of the swing rod 3, the first connecting end of the swing rod 3 is formed into a first driving hole 31, the first driving hole 31 is assembled with the rotating shaft 5 of the driving device 6 in interference or through a pin or a key, so that the rotating shaft 5 can drive the swing rod 3 to rotate when the rotating shaft 5 rotates, the swing rod 3 is formed as a driving rod, and the second connecting end of the swing rod 3 is formed as a second driving hole 32; the first connecting end and the second connecting end of the connecting rod 4 are located at both ends of the connecting rod 4, the first connecting end of the connecting rod 4 is formed into a first hinged hole 41, and is coaxially and rotatably connected with the second connecting end of the swing rod 3 through a hinge shaft; the second connecting end of the connecting rod 4 is formed into a second hinged hole 42, and is coaxially and rotatably connected with the connecting hole 11 on the connecting seat 1 through a hinge shaft. In other embodiments, the first connecting end and the second connecting end of the swing rod 3 can also be arranged near the middle, for example, with a suitable spacing; similarly, the first connecting end and the second connecting end of the connecting rod 4 can also be arranged near the middle, for example, with a suitable spacing.

[0050] Each of the rotation shafts 5 has a rotation axis, and each of the connecting rods 4 has a hinged axis at each end. In each parallel driving branch, the rotation axis of the rotation shaft 5 and the hinged axes at the two ends of the connecting rod 4 are not collinear; and the rotation axes of all the rotation shafts 5 and the hinged axes at the two ends of all the connecting rods 4 in the three parallel driving branches all intersect at the same spatial point, i.e., are all concurrent axes. Specifically, each connecting hole 11 on the connecting seat 1 is obliquely arranged, and each swing rod 3 and connecting rod 4 also has multiple bends or is arc-shaped, so that the rotation axis of each rotation shaft 5 and the hinged axes at the two ends of each connecting rod 4 all intersect at the same spatial point. When each driving device 6 rotates, the corresponding connecting rod 4 is driven to rotate through the swing rod 3, and the stability of the electrical connector 2 is ensured through the cooperation of the three connecting rods 4, so that the electrical connector 2 can be rotated around the three axes Rx, Ry and Rz in three directions with the spatial point as the center, thereby realizing the angular adjustment of the electrical connector 2 within a certain range.

[0051] Among them, under the premise of meeting the above requirements, the shape, size and rotation axis arrangement of the swing rod 3 of different parallel driving branches can be different; the shape, size and hinged axis arrangement of the connecting rod 4 of different parallel driving branches can also be different; and the driving device 6 of different parallel driving branches can also be different.

[0052] When the electrical connector 2 is a charging gun, the mechanism can be arranged on a moving mechanism at the ground end, and after the angle is adjusted according to the charging seat of the target vehicle, the moving mechanism drives the charging gun to dock; when the electrical connector 2 is a charging seat, the mechanism can be arranged on the vehicle to adjust the spatial three-dimensional angle of the charging seat at the vehicle end, so as to adapt to the automatic charging equipment on the ground end which can only translate but cannot rotate the charging gun.

[0053] In this way, the three-axis parallel rotation mechanism provided in the embodiment has the following advantages compared with the serial rotation joint / platform in the prior art: three parallel driving branches are adopted for parallel driving, each parallel driving branch only includes a driving device 6, a swing rod 3 and a connecting rod 4, the types and number of parts in each parallel driving branch are small, the structure of the parts is simple, and the machining cost is low; and the errors of the three parallel driving branches can be averaged at the position of the electrical connector 2, so that the movement is more accurate compared with the serial mechanism; in addition, the stress of the electrical connector 2 is shared by the three parallel driving branches, the stress of each parallel driving branch is uniform and small, the stress of the whole mechanism is more reasonable, and the bearing capacity of the whole mechanism is larger; in addition, due to the strong bearing capacity, the overall size can be smaller; and the movement path is short, and the rigidity is larger.

[0054] Preferably, in the embodiment, the rotation axes of all the rotation shafts 5 and the hinged axes at the two ends of all the connecting rods 4 are obliquely arranged towards the middle of the same side of the connecting seat 1, for example, all towards the middle electrical connector 2, which can better realize the rotation of the electrical connector 2.

[0055] The three connection holes 11 are circumferentially arranged, preferably in a circumferential array, and uniformly arranged on the outer periphery of the connecting seat 1; the three parallel driving branches are also circumferentially arranged in the initial state, preferably in a circumferential array, that is, in the initial state, the driving devices 6 in the three parallel driving branches are the same and uniformly arranged, the swing rods 3 are the same and uniformly arranged, the connecting rods 4 are the same and uniformly arranged, the parts in the three parallel driving branches are the same, which can further reduce the types of parts and reduce the machining cost. In addition, such uniform arrangement is more conducive to the rotation control of the electrical connector 2. In other embodiments, in order to make the mechanism movement more flexible, the structure and position of each driving device 6, the shape, size and position of each swing rod 3, and the length, size and position of each connecting rod 4 can be arranged as needed.

[0056] As shown in FIG. 6, the middle part of the connecting seat 1 is formed with a mounting port 13 for mounting the electrical connector 2, which can be adapted to various electrical connectors 2; three lugs 12 are arranged on the outer periphery of the connecting seat 1, and one connection hole 11 is arranged on each lug 12 to simplify the structure of the connecting seat 1.

[0057] The driving device 6 can be selected but is not limited to a motor, a pneumatic device or a hydraulic power device; and the driving device 6 can directly drive the rotating shaft 5 to rotate, or for the purpose of convenient assembly, protection of the driving device 6, etc., the rotating shaft 5 can also be driven to rotate through a transmission mechanism such as a belt transmission, a gear transmission, a chain transmission, a worm and gear transmission, etc.

[0058] From the above, it can be seen that the three-axis parallel rotating mechanism for automatic charging provided by the embodiment can realize the rotation adjustment of the electrical connector such as a charging gun through three parallel driving branches, and has the advantages of low cost, small error, large carrying capacity, small structure size and large rigidity, etc.

[0059] Embodiment two:

[0060] As shown in FIGS. 8-9, the embodiment provides a control method of the three-axis parallel rotating mechanism for automatic charging as described in embodiment one, which comprises the following steps:

[0061] S1: obtaining the desired pose of the electrical connector 2;

[0062] The initial pose of the electrical connector 2 is determined by the initial state, so the initial pose of the electrical connector 2 can be obtained; and the desired pose of the electrical connector 2 is determined according to the angle of the charging seat of the specific vehicle, so the angle of the charging seat of the specific vehicle needs to be obtained first, specifically, the angle of the charging seat thereon can be obtained by identifying the type of the vehicle, and then the electrical connector 2 is controlled to rotate according to the angle. Alternatively, the angle of the charging seat of the vehicle can also be detected by industrial camera image detection and the like, which is prior art and will not be described in detail here.

[0063] S2: calculating the angle that each driving device 6 needs to rotate according to the desired pose;

[0064] First, the electrical connector coordinate system Cxyz is established, and the fixed platform coordinate system Gxyz is established, which can be the fixed base coordinate system of the ground end moving mechanism. In the initial state, the electrical connector 2 is located at the initial pose, and the electrical connector coordinate system Cxyz is also not rotated. The homogeneous transformation matrix between the electrical connector coordinate system Cxyz and the fixed platform coordinate system Gxyz in the initial state can be obtained according to the initial pose G C; preferably, the directions of the coordinate axes of the electrical connector coordinate system Cxyz and the fixed platform coordinate system Gxyz in the initial state are the same, and the origins are preferably the same spatial point. After rotation, the electrical connector 2 is located at the desired pose, and the electrical connector coordinate system Cxyz also rotates by a certain angle. The homogeneous transformation matrix between the electrical connector coordinate system Cxyz and the fixed platform coordinate system Gxyz after rotation can be obtained according to the desired pose G C;

[0065] Specifically, the relative position relationship between a certain spatial coordinate system and another coordinate system can be obtained through the homogeneous transformation matrix, which is a 4x4 matrix, where the column vectors represent the three direction vectors of the coordinate axes in a certain coordinate system and the representation of the coordinate origin in the relative coordinate system, for example, the homogeneous transformation matrix G C= [ G C x G C y G C z G C p ] is the representation of the electrical connector coordinate system Cxyz in the fixed platform coordinate system Gxyz, where G C x G C y G C z G C p respectively represent the vector representation of the three coordinate axes xyz in the electrical connector coordinate system Cxyz in the fixed platform coordinate system Gxyz, and the representation of the coordinate system origin P in the electrical connector coordinate system Cxyz in the fixed platform coordinate system Gxyz.

[0066] In order to realize the conversion of a point in space between different spatial coordinate systems, it can be realized in the form of vector and matrix multiplication, for example, the coordinate representation of a point A in the electrical connector coordinate system Cxyz is known as C A= ( Cx A , C y A , C z A ,1) T , then the representation of the point A in the fixed platform coordinate system Gxyz is G A= G C C A; conversely, if the coordinate position of the point A in the fixed platform coordinate system Gxyz is known G A=( G x A , G y A , G z A ,1) T , then the representation of the point A in the electrical connector coordinate system Cxyz is C A= G C -1G A.

[0067] Further, the space point intersected by the rotation axis of each rotating shaft 5 and the hinged axis of each end of the connecting rod 4 is recorded as point O, and a virtual sphere with a radius R is established with the point O as the sphere center; the intersection point of the rotation axis of the rotating shaft 5 in the nth parallel driving branch in the initial state and the virtual sphere surface is set as point An, the intersection point of the hinged axis of the first connecting end of the connecting rod 4 in the nth parallel driving branch in the initial state and the virtual sphere surface is set as point Bn, and the intersection point of the hinged axis of the second connecting end of the connecting rod 4 in the nth parallel driving branch in the initial state and the virtual sphere surface is set as point Cn, points An, Bn and Cn constitute a spherical triangle in the initial state; the intersection point of the hinged axis of the first connecting end of the connecting rod 4 in the nth parallel driving branch after rotation and the virtual sphere surface is set as point B'n, and the intersection point of the hinged axis of the second connecting end of the connecting rod 4 in the nth parallel driving branch after rotation and the virtual sphere surface is set as point C'n, points An, B'n and C'n constitute a spherical triangle after rotation. Wherein, since the rotation axis corresponding to point An is fixed, the actual position of point An is unchanged before and after rotation.

[0068] According to the initial pose, the coordinates of points An, Bn and Cn in the electrical connector coordinate system Cxyz in the initial state can be determined, and the coordinates of points An, Bn and Cn in the fixed platform coordinate system Gxyz can be calculated according to the homogeneous transformation matrix G C between the electrical connector coordinate system Cxyz and the fixed platform coordinate system Gxyz in the initial state, and the length of the three sides of the spherical triangle △AnBnCn can also be determined in the initial state, so that the spherical angle ∠BnAnCn can be calculated.

[0069] Since the point Cn rotates with the electrical connector coordinate system Cxyz, the coordinates of the point Cn in the electrical connector coordinate system Cxyz in the initial state are the same as the coordinates of the point C'n in the rotated electrical connector coordinate system Cxyz. After the coordinates of the point C'n in the rotated electrical connector coordinate system Cxyz are determined, the coordinates of the point C'n in the fixed platform coordinate system Gxyz are calculated according to the homogeneous transformation matrix of the rotated electrical connector coordinate system Cxyz and the fixed platform coordinate system Gxyz G Cthe coordinates of the points C'n, Cn and An in the fixed platform coordinate system Gxyz are known, the lengths of the three sides of the spherical triangle △CnAnC'n can be calculated, and thus the spherical angle ∠C'nAnCn can be calculated;

[0070] According to the rigid body motion, the lengths of the sides of the spherical triangle corresponding to the swing rod 3 and the connecting rod 4 are constant, i.e., AnBn=AnB'n, BnCn=B'nC'n, and the spherical angle ∠C'nAnB'n is calculated according to the lengths of the sides AnB'n, B'nC'n and C'nAn.

[0071] According to the spherical angles ∠C'nAnB'n, ∠BnAnCn and ∠C'nAnCn, the spherical angle ∠BnAnB'n can be calculated. Specifically, if the triple vector mixed product then the angle through which the nth driving device 6 needs to be turned is ∠BnAnB'n=∠C'nAnB'n-(∠BnAnCn-∠C'nAnCn), and the positive and negative signs represent the rotation directions, and the absolute values represent the rotation angle sizes; if the triple vector mixed product then the angle through which the nth driving device 6 needs to be turned is ∠BnAnB'n=∠C'nAnB'n-(∠BnAnCn+∠C'nAnCn), and the positive and negative signs represent the rotation directions, and the absolute values represent the rotation angle sizes.

[0072] Specifically, as shown in FIG. 9, the following cases can be divided: in a first case, the triple vector mixed product the angle through which the nth driving device 6 needs to be turned is ∠BnAnB'n=∠C'nAnB'n-(∠BnAnCn-∠C'nAnCn), which is positive, and the nth driving device 6 is turned forward; in a second case, the triple vector mixed product the angle through which the nth driving device 6 needs to be turned is ∠BnAnB'n=∠C'nAnB'n-(∠BnAnCn+∠C'nAnCn), which is positive, and the nth driving device 6 is turned forward; in a third case, the triple vector mixed product the angle through which the nth driving device 6 needs to be turned is ∠BnAnB'n=∠C'nAnB'n-(∠BnAnCn-∠C'nAnCn), which is negative, and the nth driving device 6 is turned backward; and in a fourth case, the triple vector mixed product The angle that the nth driving device 6 needs to rotate is ∠BnAnB'n = ∠C'nAnB'n - (∠BnAnCn + ∠C'nAnCn), which is negative, and the nth driving device 6 reverses. When the triple vector mixed product is 0, ∠BnAnB'n = 0, and the nth driving device 6 does not rotate.

[0073] S3: According to the calculated angle, control the rotation of each driving device 6.

[0074] According to the calculated angle that the driving device 6 in each parallel driving branch needs to rotate, the rotation of each driving device 6 is controlled, so that the electrical connector 2 is rotated to the final desired pose. Then the ground end can be driven to be connected with the charging seat on the vehicle end by the moving mechanism on the ground end, which is the prior art and will not be described here.

[0075] From the above, the control method of the three-axis parallel rotating mechanism for automatic charging provided by the embodiment can calculate the rotation angle of the driving device in each parallel driving branch, thereby controlling the rotation of each driving device to make the electrical connector move to the desired pose.

[0076] Embodiment Three:

[0077] The embodiment is based on the embodiment one and additionally has one or more parallel auxiliary branches. Each parallel auxiliary branch is similar to the parallel driving branch in structure and axis arrangement, and the difference is that no driving device is arranged to drive the rotation of the rotating shaft, but the auxiliary rotating shaft is directly connected with the fixed seat, thereby increasing the force sharing and enhancing the rigidity of the whole mechanism.

[0078] ​Specifically, the three-axis parallel rotating mechanism of the embodiment is based on the three parallel driving branches described in Embodiment One, and additionally has one or more parallel auxiliary branches. The parallel auxiliary branches can be arranged between two parallel driving branches, i.e. three parallel driving branches + one or more parallel auxiliary branches, each of the parallel auxiliary branches includes an auxiliary swing rod and an auxiliary connecting rod, the first connecting end of each auxiliary swing rod is connected with an auxiliary rotating shaft, each auxiliary rotating shaft is rotatably connected to a fixed seat through a bearing or the like, the fixed seat can be formed on the aforementioned fixed bottom plate, the second connecting end of each auxiliary swing rod is hingedly connected to the first connecting end of each auxiliary connecting rod, and the outer periphery of the connecting seat 1 is further arranged with one or more auxiliary connecting holes, which are arranged in a circumferential direction with reference to the aforementioned connecting holes, and the second connecting end of each auxiliary connecting rod is hingedly connected to each auxiliary connecting hole. In each parallel auxiliary branch, the rotation axis of the auxiliary rotating shaft and the hinge axes of the two connecting ends on the auxiliary connecting rod are not collinear; the rotation axes of all rotating shafts 5 in the three parallel driving branches and the hinge axes of the two connecting ends on all connecting rods 4, and the rotation axes of all auxiliary rotating shafts in each parallel auxiliary branch and the hinge axes of the two connecting ends on all auxiliary connecting rods all intersect at the same spatial point.

[0079] That is, the embodiment increases one or more parallel auxiliary branches on the basis of the three parallel driving branches, and the auxiliary swing rod, the auxiliary connecting rod and the auxiliary rotating shaft in the parallel auxiliary branch can be arranged with reference to the swing rod 3, the connecting rod 4 and the rotating shaft 5 in the parallel driving branch, the difference is that the auxiliary rotating shaft of the embodiment is not driven by the driving device, but is passively and freely rotated. In this way, the carrying capacity and the rigidity of the entire mechanism are larger.

[0080] Embodiment Four:

[0081] As shown in FIG. 10, the embodiment provides a three-axis parallel rotating mechanism for automatic charging, and the difference compared with Embodiment One is that the driving device 6 is not used to drive the rotation of each rotating shaft 5 in the embodiment, but a torsional spring 7 is arranged at the rotating shaft 5 to achieve passive angle self-adaptation.

[0082] Specifically, the three-axis parallel rotating mechanism of the embodiment also includes a connecting seat 1 and three parallel branches, and the electric connecting piece 2 can be a charging gun or a charging seat, and three connecting holes 11 are arranged on the outer periphery of the connecting seat 1.

[0083] Each parallel branch includes a swing rod 3 and a connecting rod 4, a first connecting end of each swing rod 3 is connected with a rotating shaft 5, a torsional spring 7 is arranged at each rotating shaft 5, and the corresponding torsional spring 7 is deformed under force when each swing rod 3 rotates around the rotating shaft 5. Specifically, one end of the rotating shaft 5 is fixedly connected with the first connecting end of the swing rod 3, and the other end of the rotating shaft 5 is rotatably connected to a support plate 8, or one end of the rotating shaft 5 is rotatably connected with the first connecting end of the swing rod 3, and the other end of the rotating shaft 5 is fixedly or rotatably connected to the support plate 8, that is, the swing rod 3 can only rotate relative to the support plate 8, and the support plate 8 can be fixed to the ground or a moving mechanism / car end, and the two ends of the torsional spring 7 abut against or are fixed on the swing rod 3 and the support plate 8, and the torsional spring 7 is deformed under force when the swing rod 3 rotates. Further, the second connecting end of each swing rod 3 is hingedly connected to the first connecting end of each connecting rod 4, and the second connecting end of each connecting rod 4 is hingedly connected to each connecting hole 11.

[0084] In each parallel branch, the rotating axis of the rotating shaft 5 and the hinging axes of the two connecting ends of the connecting rod 4 are not collinear, and the rotating axes of all the rotating shafts 5 and the hinging axes of the two connecting ends of all the connecting rods 4 in the three parallel branches all intersect at the same spatial point. When the electric connector 2 is subjected to force, each connecting rod 4 rotates and drives each swing rod 3 to rotate, each torsional spring 7 is deformed under force to achieve adaptive adjustment, and the torsional force of the torsional spring 7 can also ensure the stability of the electric connector 2 to a certain extent.

[0085] In the above requirements, the shape, size and rotating axis of the swing rod 3 in different parallel branches can be different, and the shape and hinging axis of the connecting rod 4 in different parallel branches can also be different.

[0086] When the electric connector 2 is a charging gun, the mechanism can be arranged on the moving mechanism at the ground end and is driven by the moving mechanism to be connected, and the angle deviation of the charging seat of the vehicle can be passively satisfied during the connection process; when the electric connector 2 is a charging seat, the mechanism can be arranged on the vehicle to adapt to the automatic charging equipment at the ground end which can only translate but cannot rotate, and the angle of the charging seat at the vehicle end is passively adjusted during the connection.

[0087] It should be noted that the number of parallel branches can also be more than three, for example, four, five or more, and the structure of the increased parallel branches refers to the foregoing arrangement; in addition, the number of connecting holes 11 also needs to be correspondingly arranged as multiple.

[0088] From the above content, it can be known that the three-axis parallel rotating mechanism for automatic charging provided by the embodiment can passively satisfy the angle deviation during automatic charging and connection, has the characteristics of low cost, large carrying capacity, small structure size and the like.

[0089] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art, according to the technical solution and inventive concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A three-axis parallel rotary mechanism for automatic charging, characterized by, The utility model relates to a three-axle parallel rotation mechanism, comprising: A connecting seat (1) is provided with an electric connector (2) fixedly arranged thereon, and three connecting holes (11) are arranged on the outer periphery of the connecting seat (1); Three parallel driving branches, each of which comprises a swing rod (3) and a connecting rod (4), the first connecting end of each swing rod (3) is rotatably connected to a rotating shaft (5), each rotating shaft (5) is driven to rotate by a fixedly arranged driving device (6), the second connecting end of each swing rod (3) is hingedly connected to the first connecting end of each connecting rod (4), and the second connecting end of each connecting rod (4) is hingedly connected to each connecting hole (11); In each parallel driving branch, the rotation axis of the rotating shaft (5) and the hinge axes of the two connecting ends on the connecting rod (4) are not collinear; the rotation axes of all rotating shafts (5) and the hinge axes of the two connecting ends on all connecting rods (4) in the three parallel driving branches all intersect at the same spatial point.

2. The three-axis parallel rotary mechanism according to claim 1, characterized by The electric connector (2) is a charging gun or a charging seat.

3. The three-axis parallel rotary mechanism according to claim 1, characterized by The three connecting holes (11) are arranged in a circumferential direction; the three parallel driving branches are also arranged in a circumferential direction in an initial state.

4. The three-axis parallel rotary mechanism according to claim 1, characterized by An installation opening (13) for installing the electric connector (2) is formed on the connecting seat (1); three lugs (12) are arranged on the outer periphery of the connecting seat (1), and one connecting hole (11) is arranged on each lug (12).

5. The three-axis parallel rotary mechanism according to claim 1, wherein Each driving device (6) directly or through a transmission mechanism drives the corresponding rotating shaft (5) to rotate.

6. The three-axis parallel rotary mechanism according to claim 1, wherein The three-axle parallel rotation mechanism can also be additionally provided with one or more parallel auxiliary branches, each of which comprises an auxiliary swing rod and an auxiliary connecting rod, the first connecting end of each auxiliary swing rod is connected to an auxiliary rotating shaft, each auxiliary rotating shaft is rotatably connected to a fixed seat, the second connecting end of each auxiliary swing rod is hingedly connected to the first connecting end of each auxiliary connecting rod, and one or more auxiliary connecting holes are correspondingly arranged on the outer periphery of the connecting seat (1); the second connecting end of each auxiliary connecting rod is hingedly connected to each auxiliary connecting hole; In each parallel auxiliary branch, the rotation axis of the auxiliary rotating shaft and the hinge axes of the two connecting ends on the auxiliary connecting rod are not collinear; The rotation axes of all rotating shafts (5) and the hinge axes of the two connecting ends on all connecting rods (4) in the three parallel driving branches, and the rotation axes of all auxiliary rotating shafts and the hinge axes of the two connecting ends on all auxiliary connecting rods in each parallel auxiliary branch all intersect at the same spatial point.

7. A control method for a three-axis parallel rotary mechanism for automatic charging according to any one of claims 1 to 6, characterized by, The method comprises the following steps: Obtaining a desired pose of the electric connector (2); Calculating the angles at which each driving device (6) needs to rotate according to the desired pose; Controlling each driving device (6) to rotate according to the calculated angles.

8. The control method of the three-axis parallel rotary mechanism according to claim 7, characterized by Wherein, Calculating the angles at which each driving device (6) needs to rotate according to the desired pose specifically comprises: A coordinate system Cxyz of the electrical connecting piece is established, a coordinate system Gxyz of the fixed platform is established, and a homogeneous transformation matrix between the coordinate system Cxyz of the electrical connecting piece and the coordinate system Gxyz of the fixed platform is established according to the initial pose and the expected pose of the electrical connecting piece (2) G C; The space point is denoted as point O, a virtual ball is established with point O as the center of the ball; the intersection of the rotation axis of the rotating shaft (5) in the n th parallel driving branch in the initial state and the surface of the virtual ball is point An, the intersection of the hinged axis of the first connecting end of the connecting rod (4) in the n th parallel driving branch in the initial state and the surface of the virtual ball is point Bn, and the intersection of the hinged axis of the second connecting end of the connecting rod (4) in the n th parallel driving branch in the initial state and the surface of the virtual ball is point Cn, points An, Bn and Cn form a spherical triangle in the initial state; the intersection of the hinged axis of the first connecting end of the connecting rod (4) in the n th parallel driving branch after rotation and the surface of the virtual ball is point B' n, and the intersection of the hinged axis of the second connecting end of the connecting rod (4) in the n th parallel driving branch after rotation and the surface of the virtual ball is point C' n, points An, B' n and C' n form a spherical triangle after rotation. Determine the coordinates of points An, Bn and Cn in the coordinate system Cxyz of the electrical connector in the initial state, and calculate the coordinates of points An, Bn and Cn in the coordinate system Gxyz of the fixed platform according to the homogeneous transformation matrix in the initial state G C Calculate the coordinates of points An, Bn and Cn in the coordinate system Gxyz of the fixed platform, and calculate the spherical angle ∠BnAnCn; determine the coordinates of point C'n in the coordinate system Cxyz of the electrical connector after rotation, and calculate the homogeneous transformation matrix after rotation G C Calculate the coordinates of point C'n in the coordinate system Gxyz of the fixed platform, and calculate the spherical angle ∠C'nAnCn; according to the side lengths AnB'n, B'nC'n and C'nAn, calculate the spherical angle ∠C'nAnB'n; if the triple product of vectors The angle through which the nth drive device (6) must turn is ∠BnAnB'n = ∠C'nAnB'n - (∠BnAnCn - ∠C'nAnCn); if the triple product The angle through which the n th driving device (6) needs to rotate is ∠BnAnB' n = ∠C' nAnB' n - (∠BnAnCn + ∠C' nAnCn).

9. A three-axis parallel rotary mechanism for automatic charging, characterized by, It comprises: A connecting seat (1) is provided with an electric connecting piece (2) fixedly arranged thereon, and the outer periphery of the connecting seat (1) is arranged with three or more connecting holes (11); Three or more parallel branches, each of which comprises a swing rod (3) and a connecting rod (4), the first connecting end of each swing rod (3) is connected with a rotating shaft (5), a torsional spring (7) is arranged at each rotating shaft (5), the corresponding torsional spring (7) is deformed under stress when each swing rod (3) rotates around the rotating shaft (5), the second connecting end of each swing rod (3) is hingedly connected to the first connecting end of each connecting rod (4) in one-to-one correspondence, and the second connecting end of each connecting rod (4) is hingedly connected to each connecting hole (11) in one-to-one correspondence; In each parallel branch, the rotation axis of the rotating shaft (5) and the hinged axes of the two connecting ends of the connecting rod (4) are not collinear; the rotation axes of all rotating shafts (5) and the hinged axes of the two connecting ends of all connecting rods (4) in the three or more parallel branches all intersect at the same space point.

10. The three-axis parallel rotary mechanism according to claim 9, wherein The electric connecting piece (2) is a charging gun or a charging seat.

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