阅读说明：本技术 一种虎克倾斜盘式球关节姿态检测装置 (Hooke inclined disc type ball joint posture detection device ) 是由 代旺 毛耀 张超 任戈 于 2020-12-18 设计创作，主要内容包括：本发明公开了一种虎克倾斜盘式球关节姿态检测装置,包括：(a)以自转轴为Z轴,根据连续转动欧拉角(XYZ,YXZ,ZYX,ZXY,XZY,YZX)设计对应的虎克铰和倾斜盘,其中虎克铰对应XY的连续转动,倾斜盘对应Z轴的转角；(b)当虎克铰旋转中心与球关节中心一致时,里层框架与球关节输出轴等价；(c)虎克铰旋转中心和球关节中心在Z轴上存在位移时,需要设计至少3个以上的二自由度关节连杆连接球关节测量平面和里层框架,两者的连接点与球关节,虎克铰旋转中心形成平行四边形机构；对输出轴的影响小。测量装置与球关节轴承搭配灵活。(The invention discloses a Hooke inclined disc type ball joint posture detection device, which comprises: (a) taking the rotation shaft as a Z shaft, and designing a corresponding hook hinge and a tilting tray according to continuous rotation Euler angles (XYZ, YXZ, ZYX, ZXY, XZY, YZX), wherein the hook hinge corresponds to the continuous rotation of XY, and the tilting tray corresponds to the rotation angle of the Z shaft; (b) when the rotation center of the hook joint is consistent with the center of the ball joint, the inner layer frame is equivalent to the output shaft of the ball joint; (c) when the Hooke joint rotation center and the ball joint center are displaced on the Z axis, at least more than 3 two-degree-of-freedom joint connecting rods are required to be designed to be connected with the ball joint measuring plane and the inner layer frame, the connecting points of the two connecting rods and the ball joint form a parallelogram mechanism, and the Hooke joint rotation center is connected with the inner layer frame; the influence on the output shaft is small. The measuring device is flexibly matched with the ball joint bearing.)

1. The utility model provides a hooke's swash plate formula ball joint gesture detection device which characterized in that: the method comprises the following steps:

(a) taking the rotation shaft as a Z shaft, and designing a corresponding hook hinge and a tilting tray according to continuous rotation Euler angles (XYZ, YXZ, ZYX, ZXY, XZY, YZX), wherein the hook hinge corresponds to the continuous rotation of XY, and the tilting tray corresponds to the rotation angle of the Z shaft;

(b) when the rotation center of the hook joint is consistent with the center of the ball joint, the inner layer frame is equivalent to the output shaft of the ball joint;

(c) when the Hooke joint rotation center and the ball joint center are displaced on the Z axis, at least more than 3 two-degree-of-freedom joint connecting rods are required to be designed to be connected with the ball joint measuring plane and the inner layer frame, the connecting points of the two connecting rods and the ball joint form a parallelogram mechanism with the Hooke joint rotation center.

2. The hooke tilt disc ball joint attitude detection device of claim 1, wherein: the method specifically comprises the following steps: the device comprises a cylindrical support base (1), a fixed ring (2), a moving ring (3), a two-degree-of-freedom connecting rod (4), a Hooke shaft (5), a ball joint to be detected (6) and a ball joint output shaft (7); if the Hooke joint and the spherical joint center have z-axis deviation according to the XYZ Euler angles, designing a corresponding Hooke joint and tilting tray mechanism, installing the measured spherical joint (6) on the cylindrical support base (1), matching the simulated spherical joint output shaft (7) with the measured spherical joint (6), and enabling the spherical joint output shaft (7) to flexibly rotate around the measured spherical joint (6) in three degrees of freedom; a measuring plane on the ball joint output shaft (7) is provided with 3 two-degree-of-freedom rotating joints which are connected with the moving coil (3) through a two-degree-of-freedom connecting rod (4); a moving coil (3) and a fixed coil (2) of the tilting disk, both of which have only a degree of freedom of axial rotation around the fixed coil (2); the fixed ring (2) is connected with the y-axis end of the Hooke shaft (5), and the x-axis end of the Hooke shaft is arranged on a rotating shaft on the designed cylindrical supporting base (1), so that the whole tilting disk can surround a coordinate system (x)_hy_hz_h) Rotating the center; the connecting point of the ball joint measuring plane and the tilting disk plane and the ball joint and the Hooke joint rotation center form a parallelogram mechanism, based on a parallelogram rule, the ball joint output shaft (7) and the tilting disk always keep a parallel relation, and the relative rotation angle of the moving coil (3) and the ball joint output shaft (7) is unchanged,therefore, the angle measured by the tilting disk is the angle gamma which rotates around the z axis at the last time corresponding to the continuous Euler angle rotation, the tilting disk is connected with the Hooke joint, the tilting state of the ball joint output shaft (7) is transmitted to two rotating angles of the Hooke joint, and the Hooke joint rotates around the y axis_hAnd x_hThe rotation angles of the shafts correspond to euler angles (α, β), respectively.

Technical Field

The invention relates to the field of contact measurement of three-degree-of-freedom ball joint bearings in the field of angle detection, in particular to a Hooke inclined disc type ball joint attitude detection device.

Background

The three-freedom-degree ball joint bearing generally concentrates free rotation around one shaft and certain-range inclination around other shafts on a joint center, and has the advantages of compact structure, capability of simultaneously bearing axial and radial loads, flexibility in rotation and the like. The self-lubricating joint bearing is applied to swinging motion, tilting motion or rotating motion with low speed; self-aligning ball bearing with self-aligning function and high-precision, high-rigidity and low-friction spherical bearing SRJ applied in small parallel mechanism. The method plays an important role in the industries of aerospace, engineering machinery, forging and pressing machine tools, automatic design, automobile vibration reduction, hydraulic machinery and the like.

The three-degree-of-freedom attitude measurement of the ball joint bearing has greater difficulty than that of the traditional single-shaft bearing. The implementation mode of the method is usually limited to a 'pseudo-triaxial' measurement method used for laboratory calibration, the rotation of other two shafts is fixed by single measurement, and the angle of rotation around a single shaft is measured by correspondingly installed encoders. The attitude measurement of the ball joint is technically largely classified into contact measurement and noncontact measurement. In reference [1], three free rotations are resolved by two fixed axis rotating frames and rotating shafts, and because the two frames are designed to be crossed with each other, the influence on the friction and the inertia moment of the rotation is large, and the method is only suitable for laboratory calibration schemes. In the reference document [2], a posture feedback mode of a two-axis remote control single rod is referred, and a Hooke joint (an inclination angle is measured by an inclinometer) and an encoder are directly used for replacing the existing ball joint, so that the posture feedback problem of a parallel driving device is solved. Because the function of a high-precision ball bearing is replaced by the non-standard design joint bearing, the gap and friction problems caused by direct load bearing have great requirements on the design of the Hooke's joint, and the scheme cannot be universally applied to the posture measurement scheme of the existing joint bearing. Non-contact measurement methods such as optical (see reference [3]), magnetic field (see reference [4]), image (see reference [5]), etc. have more or less respective problems in terms of measurement range, accuracy and feedback rate.

Reference to the literature

[1].Lee K-M,Kwan C.Design concept development of a spherical stepper for robotic applications.IEEE Trans Robot Autom 1991；7:175–81.

[2].Zhang,Liang,et al."A Robust Adaptive Iterative Learning Control for Trajectory Tracking of Permanent-Magnet Spherical Actuator."IEEE Transactions on Industrial Electronics 63.1(2015):1-1.

[3].Garner H,Klement M,Lee K-M.Design and analysis of an absolute non-con-tact orientation sensor for wrist motion control.In:Proceeding.of IEEE/ASME international conference on advanced intelligent mechatronics；2001.p.69–74.

[4].Foong S,Lee K-M,Bai K.Harnessing embedded magnetic fields for an-gular sensing with nano-degree accuracy.IEEE/ASME Trans Mechatron 2011；17:687–96.

[5].Wang W,Wang J,Jewell GW,Howe D.Design and control of a novel spherical permanent magnet actuator with three degrees of freedom.IEEE Trans Mecha-tron 2003；8:457–68.

Disclosure of Invention

The invention solves the technical problem of three-degree-of-freedom spherical joint attitude measurement, and designs a contact type attitude measurement device based on a Hooke joint and a tilting disk based on a single-rod attitude detection method and a helicopter control tilting disk concept. The single-rod attitude detection method confirms that the rotation angle of the Hooke's hinge can be measured through the potentiometer, and the spatial attitude can be completely measured by combining the single-rod rotation potentiometer. While the swashplate concept demonstrates that the pitch angle of the non-rotating steering disk can be transferred to the continuously rotating blade by a two-degree-of-freedom link. Conversely, the tilt state of the ball joint output shaft can be transmitted to the tilting disk not participating in spin via the link.

The technical scheme adopted by the invention is as follows: a Hooke's swash plate formula ball joint gesture detection device includes:

(a) taking the rotation shaft as a Z shaft, and designing a corresponding hook hinge and a tilting tray according to continuous rotation Euler angles (XYZ, YXZ, ZYX, ZXY, XZY, YZX), wherein the hook hinge corresponds to the continuous rotation of XY, and the tilting tray corresponds to the rotation angle of the Z shaft;

(b) when the rotation center of the hook joint is consistent with the center of the ball joint, the inner layer frame is equivalent to the output shaft of the ball joint;

(c) when the Hooke joint rotation center and the ball joint center are displaced on the Z axis, at least more than 3 two-degree-of-freedom joint connecting rods are required to be designed to be connected with the ball joint measuring plane and the inner layer frame, the connecting points of the two connecting rods and the ball joint form a parallelogram mechanism with the Hooke joint rotation center.

The method specifically comprises the following steps: the device comprises a cylindrical support base, a fixed ring, a movable ring, a two-degree-of-freedom connecting rod, a Hooke shaft, a measured ball joint and a ball joint output shaft; if the centers of the Hooke joint and the spherical joint have a Z-axis deviation according to an XYZ Euler angle, designing a corresponding Hooke joint and tilting disk mechanism, installing the measured spherical joint on a cylindrical support base, matching a simulated spherical joint output shaft with the measured spherical joint, and enabling the spherical joint output shaft to flexibly rotate around the measured spherical joint in three degrees of freedom; a measuring plane on the output shaft of the ball joint is provided with 3 two-degree-of-freedom rotating joints which are connected with the moving coil through a two-degree-of-freedom connecting rod; the tilting disk comprises a moving ring and a fixed ring, and the moving ring and the fixed ring only have the freedom degree of axial rotation around the fixed ring; the fixed ring is connected with the y-axis end of the Hooke shaft, and the x-axis end of the Hooke shaft is arranged on the rotating shaft on the designed cylindrical support base, so that the whole tilting disk can surround a coordinate system (x)_hy_hz_h) Rotating the center; the connecting point of the spherical joint measuring plane and the tilting disk plane and the spherical joint and the rotation center of the Hooke's joint form a parallelogram mechanism, based on a parallelogram rule, the spherical joint output shaft and the tilting disk are always kept in a parallel relation, and the relative rotation angles of the moving coil and the spherical joint output shaft are not changed, so that the measuring angle of the tilting disk is an angle gamma which rotates around a z axis after rotating corresponding to a continuous Euler angle, the tilting disk is connected with the Hooke's joint, the tilting state of the spherical joint output shaft is transmitted to two corners of the Hooke's joint, and the Hooke's joint rotates around the y axis_hAnd x_hThe rotation angles of the shafts correspond to euler angles (α, β), respectively.

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

(1) the measuring device and the ball joint bearing are clear in labor division. The ball joint bearing is responsible for bearing and high-precision rotation; the measuring device is only responsible for attitude measurement, and the problem that a similar single-rod device concentrates joint precision requirements and attitude measurement requirements on the same Hooke joint is solved.

(2) The influence on the output shaft is small. Only the extra mass of the connecting rod and the friction of the hooke's joint have an effect on the output shaft in both respects. And the hook joint does not bear load, and the friction is small.

(3) The measuring device is flexibly matched with the spherical knuckle bearing, the corresponding mechanism can be designed according to different Euler angle descriptions, the rotating centers of the measuring device and the spherical knuckle bearing are allowed to deviate, and meanwhile, the measuring device is suitable for embedded miniaturization design and external auxiliary attitude measurement.

Drawings

FIG. 1 is a schematic diagram of an XYZ hooke tilt-swashplate measurement according to the present invention;

FIG. 2 is a schematic view of the parallelogram mechanism, wherein FIG. 2(a) is a schematic view of the parallelogram mechanism when it is not deflected and FIG. 2(b) is a schematic view of the parallelogram mechanism when the ball joint measurement plane is deflected;

FIG. 3 is a schematic view of a spider shaft and a ring-shaped spider shaft, wherein FIG. 3(a) is the spider shaft and FIG. 3(b) is the ring-shaped;

FIG. 4 is a schematic diagram of the corresponding design of three Euler angles;

in the figure: the device comprises a cylindrical support base 1, a fixed ring 2, a moving ring 3, a two-degree-of-freedom connecting rod 4, a Hooke shaft 5, a tested ball joint 6 and a ball joint output shaft 7.

Detailed Description

The invention is further described with reference to the following figures and detailed description.

The invention relates to a Hooke inclined disc type ball joint posture detection device, which has the following generalized characteristics:

(1) and designing a corresponding hook hinge and a tilting tray according to continuous rotation Euler angles (XYZ, YXZ, ZYX, ZXY, XZY and YZX) by taking the rotation shaft as a Z shaft, wherein the hook hinge corresponds to the continuous rotation of XY, and the tilting tray corresponds to the rotation angle of the Z shaft.

(2) Generally, the euler angles such as ZXZ, ZYZ and the like cannot be corresponded to the same axes, because the same-name axes of the inner layer cannot pass through the frame to the same-name axes of the outer layer, and the undefined axes cannot rotate directly.

(3) When the rotation center of the hook joint is consistent with the center of the ball joint, the inner layer frame is equivalent to the output shaft of the ball joint;

(4) when the Hooke joint rotation center and the ball joint center are displaced on the Z axis, at least more than 3 two-degree-of-freedom joint connecting rods are required to be designed to be connected with the ball joint measuring plane and the inner layer frame, the connecting points of the two connecting rods and the ball joint form a parallelogram mechanism, and the Hooke joint rotation center is connected with the inner layer frame;

(5) if the rotation centers of the two are offset in the XY plane, the design is not affected, but the friction of the tilting disk may be increased.

(6) The attitude measurement precision is determined by the rotation measurement precision of the Hooke's joint and the relative rotation measurement precision of the tilting disk.

FIG. 1 is a schematic representation of one embodiment of the present invention. According to the formula (1), under the condition that Z-axis deviation exists between the centers of the Hooke joint and the spherical joint, corresponding Hooke joint and tilting disk mechanisms are designed. The device comprises a cylindrical support base 1, a measured ball joint 6 is arranged on the cylindrical support base 1, and a simulated ball joint output shaft 7 (the center of a plate in the figure is provided with a spherical groove) is matched with the measured ball joint 6, so that the ball joint output shaft 7 can flexibly rotate around the measured ball joint 6 in three degrees of freedom. A measuring plane on the output shaft 7 of the ball joint is provided with 3 two-degree-of-freedom rotating joints which are connected with the moving coil 3 through a two-degree-of-freedom connecting rod 4. The movable ring 3 and the fixed ring 2 of the tilting disk have only a degree of freedom of rotation about the axial direction of the fixed ring 2. The fixed ring 2 is connected with the y-axis end of a Hooke shaft 5, and the x-axis end of the Hooke shaft is arranged on a rotating shaft on the designed cylindrical support base 1, so that the whole tilting disk can surround a coordinate system (x)_hy_hz_h) The center rotates.

Wherein R is_qTo describe the rotation matrix of the spatial attitude of the measured ball joint, R_xAnd (alpha) is the angle of rotation alpha around the x-axis, and the angle of rotation beta and gamma are respectively on the y-axis and the z-axis. C is cosine of cosineThe function, S, is a sine function.

The connecting point of the ball joint measuring plane and the tilting disk plane and the ball joint and the Hooke joint rotation center form a parallelogram mechanism, based on a parallelogram rule, the ball joint output shaft 7 and the tilting disk always keep a parallel relation, and the relative rotation angle of the moving coil 3 and the ball joint output shaft 7 is unchanged. The tilting disk thus measures the angle, i.e. the angle y corresponding to the last rotation around the z-axis of successive euler angular rotations. The tilting disk is connected with the Hooke's joint, so that the tilting state of the ball joint output shaft 7 is transmitted to two corners of the Hooke's joint, and the Hooke's joint winds around y_hAnd x_hThe rotation angles of the shafts correspond to euler angles (α, β), respectively.

Fig. 2 is a schematic view of a parallelogram mechanism in an embodiment of the present invention. Wherein O is₁Is the center of rotation of the measured ball joint, O₂Is the rotation center of the hook joint. When both have an offset L in the z-axis direction₁Based on the determined distance L between the ball joint measurement plane and the ball joint center₃Corresponding swashplate positions and two-degree-of-freedom links are designed in parallel such that (L)₁,L₂,L₃,L₄) Forming a parallelogram mechanism. When the ball joint measurement plane is deflected (as shown in fig. 2 (b)), although the deformation of the parallelogram corresponding to different links is different, the deformation is due to the center of rotation (O)₁,O₂) Is always kept constant, so that the length L of the connecting rod₃The constraint is always satisfied and is parallel to the tether z-axis. Because of distance restriction, the ball joint measuring plane and the tilting disk moving coil cannot rotate relatively, so that the rotating angle of the rotating system z axis can be measured through the relative rotation of the tilting disk moving coil and the tilting disk moving coil. Meanwhile, due to parallel constraint, the inclination angle of the tilting disk is consistent with that of the spherical joint measuring plane, so that the inclination angle can be measured through the rotation angle of the Hooke joint.

Three connecting points (upper mark s) of the ball joint measuring plane and three connecting points (upper mark h) of the tilting disk are positioned at various dynamic coordinate centers (ball joint center O)₁And O₂Above) have consistency in relative coordinates:

for arbitrary ball joint posture R_sThe center of a Hooke joint is taken as the origin of world coordinates, and the description of the world coordinates of three connecting points of a spherical joint measuring plane is as follows:

the two-degree-of-freedom single rod is necessarily parallel to a vector which is equally longer than two rotation centers, so that the following is restrained:

determined by the formula (1) hooke joint and swashplate:

if the centers of the Hooke's joint and the ball joint can be coincident under the design permission, L is meant₁No tie bar connection is required at 0. If there is also an offset of the xy-plane in both centres, the corresponding link is no longer always parallel to the z-axis of the frame but parallel to (O)₁,O₂)。

Figures 3 and 4 further illustrate the flexible embodiment of the present invention.

FIG. 3 is a schematic view of a Hooke's axis in an embodiment of the present invention, and FIG. 3(a) is a cross-shaft suitable for a single-ended protruding spherical plain bearing (e.g., SRJ spherical plain bearing); fig. 3(b) is ring-shaped and is adapted to extend beyond the spherical plain bearing at both ends. Fig. 4 is a schematic diagram of a frame design corresponding to three euler angles, and the fixed end of the hook joint can be started from a small-radius ring or a large-radius ring. The posture characteristic of the butt joint end is consistent with the output shaft of the tested ball joint.