CN103527620A - Spherical hinge capable of realizing rotation angle measurement and measurement method of rotation angle - Google Patents

Abstract

The invention discloses a spherical hinge capable of realizing the rotation angle measurement and a measurement method of the rotation angle. The spherical hinge is characterized in that a ball seat provided with a ball socket therein is formed by a base and an end closure, a ball head is placed in the ball socket, a spherical crown is exposed at an opening of the end closure, and the top surface of the spherical crown of the ball head is connected to a ball-jointed rod; the ball head and the ball socket are concentric, and the ball head can concentrically rotate relatively to the ball socket; permanent magnets are embedded and uniformly distributed on the surface of a low half ball of the ball head; magnetic effect sensors are embedded and uniformly distributed on the surface of the ball socket; sensing output signals of the magnetic effect sensors are used for judging the relative location between the ball head and the ball socket and the direction of the relative movement. The spherical hinge can be used for realizing the three-dimensional angle measurement under the condition of having no influence on the movement accuracy and the mechanical property of ball joints and no damage on the structures of the ball joints.

Description

Can realize spherical hinge and method of measurement that angle of revolution is measured

Technical field

The present invention relates to a kind of spherical hinge, more specifically says spherical hinge and the method for measurement can angle of revolution, implementation space measured.

Background technique

Angle measurement is the most basic measurement, and existing various angle transducer extensive uses in prior art, comprising: grating, magnetic grid, inductosyn etc., but this class sensor all can only carry out the measurement of one dimension angle of revolution.In scientific research and industrial production, the way that can only adopt a plurality of angle transducers to be used in combination in the time need to measuring the angle of revolution of multiple directions.Such as in fine measuring instrument, joint arm measuring machine, laser tracker and precision digital turntable etc.Complex structure, costs of these combination angle measurement components are high, equipment volume is large, subsequent conditioning circuit and data collection task amount large, application is subject to great restriction; Traditional angle transducer is all to adopt at disk or the cylndrical surface equal intervals groove of certain turning radius to realize measurement, its measuring accuracy relies on graduating accuracy in essence, when precision is not enough, can only adopt subdivide technology to be compensated, the further lifting that this has fundamentally limited sensor accuracy, has also reduced stability.

Recent two decades is because paralleling mechanism has good rigidity, light, the natural advantages such as error average effect of movement inertia are widely used in fields such as lathe, robot, micro displacement workbench, coordinate measuring machines.But in paralleling mechanism, a large amount of spherical hinges that use and the movement clearance error of ball-joint have seriously restricted application and the popularization of paralleling mechanism in highi degree of accuracy occasion all the time, and spherical hinge is to drive its motion by other motion and power source while using on paralleling mechanism, the angle of revolution in space of ball pivot bar cannot be obtained dawn in real time.

The Japanese river of rubbing proposes to print the pattern of similar Quick Response Code on spherical hinge spheroid more, with ccd video camera, carry out image recognition, then according to the relevant standard pattern of the absolute angle in three coordinate axes to spheroid, compare and calculate, drawing angle information (ZL200780043541.0).It on this technological essence, is the measuring method based on Machine vision, during spherical hinge actual motion work, need to add lubricating ester to alleviate the friction between ball pivot bar and ball-and-socket, the existence of lubricating grease has a strong impact on quality of optical imaging, and in physical dimension, is difficult to dwindle and cannot be embedded into spherical hinge inside.

Germany Zahnradfabrik Friedrichshafen has proposed the ball-type universal joint with pivot angle sensor, the object of research and development is to be used on automobile chassis for detection of the distortion on chassis and the distortion in motion, basic principle is to embed a permanent magnet magnet in the bottom of hinge spheroid, on ball-and-socket, embed a magnetoresistive transducer and be used for the swing of perception club and spheroid, this magnetoresistive transducer can directly obtain the direct value through the angle of the magnetic line of force of sensor, the method is to carry out sensing by magnetic effect, overcome the impact of lubricating grease, to Environmental Conditions, require also not harsh, but only with a sensor and a permanent magnet, realize combination, thereby it is little inevitably to produce the scope that takes measurement of an angle, the defect that measuring accuracy is lower, cannot meet required precision and the range of paralleling mechanism when highi degree of accuracy applications.

Summary of the invention

The present invention is for avoiding the existing deficiency of above-mentioned prior art, a kind of spherical hinge and method of measurement that realizes wide range, the measurement of high-precision angle of revolution is provided, not affecting ball-joint kinematic accuracy, mechanical property, do not destroy under the prerequisite of its structure, realize three-dimensional perspective and measure.

The present invention is that technical solution problem adopts following technological scheme:

The structural feature that the present invention can realize the spherical hinge of measuring angle of revolution is:

By base and end cap, form the ball seat that inside has ball-and-socket, the spherical crown portion of described ball-and-socket forms opening on end cap; Bulb is inserted in described ball-and-socket, and exposes spherical crown at the opening of end cap, at the spherical crown end face connection ball pivot bar of described bulb; Described bulb is concentric with ball-and-socket, and bulb can rotate with one heart with respect to ball-and-socket;

Lower semisphere surface at described bulb is embedded with permanent magnet, and has m permanent magnet to be evenly distributed on the lower semisphere surface of described bulb; On the surface of described ball-and-socket, be embedded with magnetic effect sensor, and have n magnetic effect sensor to be evenly distributed on the surface of ball-and-socket; Wherein, n and m are all non-vanishing; Utilize the induction output signal of described magnetic effect sensor to judge relative angular position between described bulb and ball-and-socket and the direction of relative movement.

The structural feature that the present invention can realize the spherical hinge of measuring angle of revolution is also: described permanent magnet cylindrical body, and be sleeved in the spacer of being made by nonmagnetic substance, the related permanent magnet of described spacer is embedded in each blind cylindrical hole of bulb surface setting; The axis of described each permanent magnet is all through the centre of sphere of bulb.

Described bulb and ball pivot bar are to take ferromagnetic material as material.

Described each magnetic effect sensor is embedded in each gauge hole that described ball-and-socket surface arranges, and on the sphere that each magnetic effect sensor be take centered by ball-and-socket center with being in, radius is R, the axis of each magnetic effect sensor is through ball-and-socket center; It is step hole that each gauge hole is set, and magnetic effect sensor is glued on the sensor holder that non-magnetic material makes, and the related magnetic effect sensor of described sensor holder is inlaid in described step hole.

The feature of utilizing spherical hinge in the present invention to realize the method for measuring angle of revolution is: the revolution of going up in any direction around centre of sphere O for spherical hinge, rotate thereupon in the magnetic field that permanent magnet produces, the magnetic induction intensity that calculates spatial position, magnetic effect sensor place according to Equivalent Magnetic Charge model, draws the magnetic induction intensity component of magnetic effect sensor axis direction and the relation between spherical hinge angle of revolution; According to the input-output characteristic of magnetic effect sensor, set up the Voltage-output signal of each magnetic effect sensor and the function relation of spherical hinge angle of revolution; The function relation of each magnetic effect sensor of simultaneous is set up set of equation, utilizes method of least squares to realize solving of set of equation, draws spherical hinge angle of revolution.

Present inventor finds under study for action: in paralleling mechanism, spherical hinge gap is relevant with pose to ball pivot bar working space angle in essence, if the space rotating accuracy of Real-time Obtaining spherical hinge has important meaning and value for revising and compensate spherical hinge gap error and even improving paralleling mechanism kinematic accuracy.The present invention is for realizing the intellectuality of spherical hinge, and it is simple in structure, and reliable performance, can be applicable to the control of conventional robot and other has the occasion in multi-dimensional movement joint to realize the real-time measurement of its space angle.

Compared with the prior art, beneficial effect of the present invention is embodied in:

1, the present invention has realized three-dimensional perspective detection, also can be used as independently surveying and is applied to engineering reality.

2, the present invention equidistantly divides the form of obtaining angle measurement information than traditional space, by the measurement in a closed series of a plurality of magnetic effect sensors, obtain redundancy angle information, resolution and measuring accuracy can be improved, permanent magnet number can be configured according to actual needs with also range extension simultaneously.

3, traditional vernier reading is the method for a kind of mechanical type segmentation reading, and the present invention is applied in this principle of measurement on sphere, with this, determines and optimizes the number of permanent magnet and sensor chip and the space arrangement spacing on sphere.

4, the present invention adopts magnetic effect to carry out sensing, and while effectively having overcome the actual use of spherical hinge, external environment factor is on the interference of measuring accuracy and impact, and insensitive on the impact of lubricating grease.

5, the present invention is simple in structure, compact, and cost is low, also can make independent parts, is directly configured in the measurement that realizes any direction angle of revolution in its space on the joint of existing device, has larger application and popularization value.

Accompanying drawing explanation

Fig. 1 is the main TV structure schematic diagram of the present invention;

Fig. 2 is structural upright exploded perspective view of the present invention;

Fig. 3 is permanent magnet and magnetic effect sensor fitting structure schematic diagram in the present invention;

Fig. 4 cylindrical body permanent magnet Equivalent Magnetic Charge model schematic diagram;

Fig. 5 is principle of measurement schematic diagram in the present invention;

Number in the figure: 1 base; 2 ball pivot bars; 3 bulbs; 4 permanent magnets; 5 magnetic effect sensors; 6 end caps; 7 bolt semiaxis; 8 spacers; 9 sensor holders.

Embodiment

Referring to Fig. 1, Fig. 2 and Fig. 3, the structural type that can realize the spherical hinge of measuring angle of revolution in the present embodiment is:

By base 1 and end cap 6, form the ball seat that inside has ball-and-socket, the spherical crown portion of ball-and-socket forms opening on end cap 6; Bulb 3 is inserted in ball-and-socket, and exposes spherical crown at the opening of end cap 6, at the spherical crown end face connection ball pivot bar 2 of bulb 3; Bulb 3 is concentric with ball-and-socket, and bulb 3 can rotate with one heart with respect to ball-and-socket.

Lower semisphere surface at bulb 3 is embedded with permanent magnet 4, and has m permanent magnet 4 to be evenly distributed on the lower semisphere surface of bulb 3; On the surface of ball-and-socket, be embedded with magnetic effect sensor 5, and have n magnetic effect sensor 5 to be evenly distributed on the surface of ball-and-socket; Wherein, n and m are all non-vanishing; Utilize induction output signal judgement bulb 3 and the relative angular position between ball-and-socket and the direction of relative movement of magnetic effect sensor 5.

As shown in Figures 2 and 3, permanent magnet 4 is cylindrical body, and is sleeved in the spacer 8 of being made by nonmagnetic substance, and the related permanent magnet 4 of spacer 8 is embedded in each blind cylindrical hole of bulb surface setting; The axis of each permanent magnet 4 is all through the centre of sphere of bulb 3; Bulb and ball pivot bar are to take ferromagnetic material as material.

Each magnetic effect sensor 5 is embedded in each gauge hole that ball-and-socket surface arranges, and on the sphere that each magnetic effect sensor 5 be take centered by ball-and-socket center with being in, radius is R, the axis of each magnetic effect sensor 5 is through ball-and-socket center; It is step hole that each gauge hole is set, and magnetic effect sensor is glued on the sensor holder 9 that non-magnetic material makes, and the related magnetic effect sensor of sensor holder 9 is inlaid in step hole.

Ball pivot bar 2 and spherical journal 3 are processed through Overheating Treatment and precision cutting by steel, it is ferromagnetic material, when permanent magnet 4 is embedded in spherical journal, its magnetic pole contacts with spherical journal 3, jointly on spheroid and form the magnetic field in the closed magnetic line of force and given shape and space around.Permanent magnet should be selected high-quality magnetic material manufacture, can select alnico alloy 500 or barium ferrite or analog material to make.

Magnetic effect sensor can, according to the difference of measuring accuracy and range, be selected Hall transducer and magnetic resistance and giant magneto-resistance sensor etc.

Utilize spherical hinge in the present embodiment to realize the method for measuring angle of revolution to be: the revolution of going up in any direction around centre of sphere O for spherical hinge, rotate thereupon in the magnetic field that permanent magnet produces, the magnetic induction intensity that calculates spatial position, magnetic effect sensor place according to Equivalent Magnetic Charge model, draws the magnetic induction intensity component of magnetic effect sensor axis direction and the relation between spherical hinge angle of revolution; According to the input-output characteristic of magnetic effect sensor, set up the Voltage-output signal of each magnetic effect sensor and the function relation of spherical hinge angle of revolution; The function relation of each magnetic effect sensor of simultaneous is set up set of equation, utilizes method of least squares to realize solving of set of equation, draws spherical hinge angle of revolution.In concrete enforcement, carry out as follows:

Model measurement model, its theoretical foundation is Equivalent Magnetic Charge model.For the cylinder permanent magnet evenly magnetizing vertically, owing to being uniform magnetization, body magnetic charge density p _mbe zero, on permanent magnet border, have surface magnet charge density σ _m, and have following relation:

In formula (1)

exterior normal unit vector for permanent magnet interface;

B _rresidual magnetic flux density for permanent magnet.According to the concept of scalar magnetic potential, the magnetic intensity that cylinder permanent magnet produces in any point of space

the form of dividing with area is expressed as:

$\stackrel{\&RightArrow;}{H}=\frac{{\mathrm{<figure-callout\; id="4"\; label="B\; r"\; filenames="HDA0000400515830000021.png"\; state="\{\{state\}\}">B</figure-callout>}}_r}{4\mathrm{\&pi;}{\mathrm{\&mu;}}_0}\underset{s_{+}}{\&Integral;\&Integral;}\frac{{\stackrel{\&RightArrow;}{r}}_{+}}{{r_{+}}^3}\mathrm{ds}-\frac{{\mathrm{<figure-callout\; id="4"\; label="B\; r"\; filenames="HDA0000400515830000021.png"\; state="\{\{state\}\}">B</figure-callout>}}_r}{4\mathrm{\&pi;}{\mathrm{\&mu;}}_0}\underset{s_{-}}{\&Integral;\&Integral;}\frac{{\stackrel{\&RightArrow;}{r}}_{-}}{{r_{-}}^3}\mathrm{ds}---\left(2\right)$

Magnetic induction intensity

with magnetic intensity

relation be:

$\stackrel{\&RightArrow;}{B}={\mathrm{\&mu;}}_0{\mathrm{\&mu;}}_r\stackrel{\&RightArrow;}{H}---\left(3\right)$

In formula (2) and formula (3): μ _rfor the relative permeability of Magnetized Material, μ ₀for the permeability in vacuum, r ₊, r _-for the distance that the source point of positive and negative magnetic charge is shown up a little, S ₊, S _-source area for positive and negative magnetic charge.

Equivalent Magnetic Charge model is to use integration to try to achieve the magnetic intensity that permanent magnet produces in any point of space, then is converted to magnetic induction intensity.As shown in Figure 5, when spherical hinge is around centre of sphere O in any direction during upper rotary, being embedded in the magnetic field that the permanent magnet on bulb produces will rotate thereupon, and the magnetic induction intensity of any point in space is changed.Take spherical hinge gyration center as initial point O, and take perpendicular to base is upwards Z-direction, and setting up basis coordinates is O-XYZ; A position of rotating arbitrarily in space for ball pivot bar, can be decomposed into and first around X-axis, turn α angle, around Y-axis, turn β angle again, after ball pivot bar rotates, the position of permanent magnet moves on to M ' point by original M point, according to setting up basis coordinates, is that kinetic coordinate system O-X ' Y ' Z ' is set up in the mode of the O-XYZ position after for rotation.

Magnetic effect sensor is arranged in ball-and-socket inner ball surface, and as shown in Figure 5, there are four magnetic effect sensors position shown in Fig. 5, and it measures face center line all at centre of sphere O place quadrature, take one of them sensor as example, setting sensor S ₁in basis coordinates, be that coordinate in O-XYZ is (x ₀, y ₀, z ₀), it measures face normal through centre of sphere O fixed directional Z " direction.

In kinetic coordinate system O-X ' Y ' Z ', according to Formula of Coordinate System Transformation, sensor S ₁coordinates table is shown:

$\left\{\begin{array}{c}u=x_0\cos \mathrm{\&beta;}+y_0\sin \mathrm{\&alpha;}\sin \mathrm{\&beta;}-z_0\cos \mathrm{\&alpha;}\sin \mathrm{\&beta;}\\ v=y_0\cos \mathrm{\&alpha;}+z_0\sin \mathrm{\&alpha;}\\ w=x_0\sin \mathrm{\&beta;}-y_0\sin \mathrm{\&alpha;}\cos \mathrm{\&beta;}+z_0\cos \mathrm{\&alpha;}\cos \mathrm{\&beta;}\end{array}\right.$

The major significance that carries out rotation of coordinate variation is in kinetic coordinate system O-X ' Y ' Z ', solves integration convenient according to Equivalent Magnetic Charge model theory, if be in O-XYZ in basis coordinates, carries out Integration Solving more difficult.Permanent magnet turns to behind M ' position with ball pivot bar, sensor S ₁the magnetic induction intensity at place will change, and sensor S ₁the Three-Dimensional Magnetic induction component (B of the magnetic induction intensity at place under O-X ' Y ' Z ' coordinate _x', B _y', B _z') according to formula (2) and formula (3), be expressed as respectively:

$\begin{array}{c}{B_x}^{\text{'}}=\frac{B_r{\mathrm{\&mu;}}_{\mathrm{<figure-callout\; id="4"\; label="r"\; filenames="HDA0000400515830000021.png"\; state="\{\{state\}\}">r</figure-callout>}}}{4\mathrm{\&pi;}}{\&Integral;}_{-r}^r[{(u-\sqrt{r^2-y^{\text{'}2}})}^2+{(v-y^{\text{'}})}^2+{(w-a)}^2{]}^{-\frac{1}{2}}{\mathrm{dy}}^{\text{'}}-\frac{B_r{\mathrm{\&mu;}}_{\mathrm{<figure-callout\; id="4"\; label="r"\; filenames="HDA0000400515830000021.png"\; state="\{\{state\}\}">r</figure-callout>}}}{4\mathrm{\&pi;}}{\&Integral;}_{-r}^r{[{(u+\sqrt{r^2-y^{\text{'}2}})}^2+{(v-y^{\text{'}})}^2+{(w-a)}^2]}^{-\frac{1}{2}}{\mathrm{dy}}^{\text{'}}\\ -\frac{B_r{\mathrm{\&mu;}}_{\mathrm{<figure-callout\; id="4"\; label="r"\; filenames="HDA0000400515830000021.png"\; state="\{\{state\}\}">r</figure-callout>}}}{4\mathrm{\&pi;}}{\&Integral;}_{-r}^r{[{(u-\sqrt{r^2-y^{\text{'}2}})}^2+{(v-y^{\text{'}})}^2+{(w-b)}^2]}^{-\frac{1}{2}}{\mathrm{dy}}^{\text{'}}+\frac{B_r{\mathrm{\&mu;}}_{\mathrm{<figure-callout\; id="4"\; label="r"\; filenames="HDA0000400515830000021.png"\; state="\{\{state\}\}">r</figure-callout>}}}{4\mathrm{\&pi;}}{\&Integral;}_{-r}^r{[{(u+\sqrt{r^2-y^{\text{'}2}})}^2+{(v-y^{\text{'}})}^2+{(w-b)}^2]}^{-\frac{1}{2}}{\mathrm{dy}}^{\text{'}}\end{array}$

$\begin{array}{c}{B_y}^{\text{'}}=\frac{B_r{\mathrm{\&mu;}}_{\mathrm{<figure-callout\; id="4"\; label="r"\; filenames="HDA0000400515830000021.png"\; state="\{\{state\}\}">r</figure-callout>}}}{4\mathrm{\&pi;}}{\&Integral;}_{-r}^r{[{(u-x^{\text{'}})}^2+{(v-\sqrt{r^2-x^{\text{'}2}})}^2+{(w-a)}^2]}^{-\frac{1}{2}}{\mathrm{dx}}^{\text{'}}-\frac{B_r{\mathrm{\&mu;}}_{\mathrm{<figure-callout\; id="4"\; label="r"\; filenames="HDA0000400515830000021.png"\; state="\{\{state\}\}">r</figure-callout>}}}{4\mathrm{\&pi;}}{\&Integral;}_{-r}^r{[{(u-x^{\text{'}})}^2+{(v+\sqrt{r^2-x^{\text{'}2}})}^2+{(w-a)}^2]}^{-\frac{1}{2}}{\mathrm{dx}}^{\text{'}}\\ -\frac{B_r{\mathrm{\&mu;}}_{\mathrm{<figure-callout\; id="4"\; label="r"\; filenames="HDA0000400515830000021.png"\; state="\{\{state\}\}">r</figure-callout>}}}{4\mathrm{\&pi;}}{\&Integral;}_{-r}^r{[{(u-x^{\text{'}})}^2+{(v-\sqrt{r^2-x^{\text{'}2}})}^2+{(w-b)}^2]}^{-\frac{1}{2}}{\mathrm{dx}}^{\text{'}}+\frac{B_r{\mathrm{\&mu;}}_{\mathrm{<figure-callout\; id="4"\; label="r"\; filenames="HDA0000400515830000021.png"\; state="\{\{state\}\}">r</figure-callout>}}}{4\mathrm{\&pi;}}{\&Integral;}_{-r}^r{[{(u-x^{\text{'}})}^2+{(v+\sqrt{r^2-x^{\text{'}2}})}^2+{(w-b)}^2]}^{-\frac{1}{2}}{\mathrm{dx}}^{\text{'}}\end{array}$

$\begin{array}{c}{B_z}^{\text{'}}=\frac{B_r{\mathrm{\&mu;}}_{\mathrm{<figure-callout\; id="4"\; label="r"\; filenames="HDA0000400515830000021.png"\; state="\{\{state\}\}">r</figure-callout>}}}{4\mathrm{\&pi;}}\underset{-r}{\overset{r}{\&Integral;}}\frac{w-a}{{(v-y^{\text{'}})}^2+{(w-a)}^2}\&times;\frac{u+\sqrt{r^2-y^{\text{'}2}}}{\sqrt{{(u+\sqrt{r^2-y^{\text{'}2}})}^2+{(v-y^{\text{'}})}^2+{(w-a)}^2}}{\mathrm{dy}}^{\text{'}}\\ -\frac{B_r{\mathrm{\&mu;}}_{\mathrm{<figure-callout\; id="4"\; label="r"\; filenames="HDA0000400515830000021.png"\; state="\{\{state\}\}">r</figure-callout>}}}{4\mathrm{\&pi;}}\underset{-r}{\overset{r}{\&Integral;}}\frac{w-a}{{(v-y^{\text{'}})}^2+{(w-a)}^2}\&times;\frac{u-\sqrt{r^2-y^{\text{'}2}}}{\sqrt{{(u+\sqrt{r^2-y^{\text{'}2}})}^2+{(v-y^{\text{'}})}^2+{(w-a)}^2}}{\mathrm{dy}}^{\text{'}}\\ -\frac{B_r{\mathrm{\&mu;}}_{\mathrm{<figure-callout\; id="4"\; label="r"\; filenames="HDA0000400515830000021.png"\; state="\{\{state\}\}">r</figure-callout>}}}{4\mathrm{\&pi;}}\underset{-r}{\overset{r}{\&Integral;}}\frac{w-b}{{(v-y^{\text{'}})}^2+{(w-b)}^2}\&times;\frac{u+\sqrt{r^2-y^{\text{'}2}}}{\sqrt{{(u+\sqrt{r^2-y^{\text{'}2}})}^2+{(v-y^{\text{'}})}^2+{(w-b)}^2}}{\mathrm{dy}}^{\text{'}}\\ +\frac{B_r{\mathrm{\&mu;}}_{\mathrm{<figure-callout\; id="4"\; label="r"\; filenames="HDA0000400515830000021.png"\; state="\{\{state\}\}">r</figure-callout>}}}{4\mathrm{\&pi;}}\underset{-r}{\overset{r}{\&Integral;}}\frac{w-b}{{(v-y^{\text{'}})}^2+{(w-b)}^2}\&times;\frac{u-\sqrt{r^2-y^{\text{'}2}}}{\sqrt{{(u-\sqrt{r^2-y^{\text{'}2}})}^2+{(v-y^{\text{'}})}^2+{(w-b)}^2}}{\mathrm{dy}}^{\text{'}}\end{array}$

In formula: u, v, w is sensor S ₁coordinate in kinetic coordinate system O-X ' Y ' Z '; R is the radius of permanent magnet, is definite value, and a is the distance that coordinate center O point is arrived in permanent magnet upper-end surface, and b is the distance that coordinate center O point is arrived in permanent magnet lower end surface, x ', and y ', z ' is integration variable.

Calculating on kinetic coordinate system O-X ' Y ' Z ' is expressed by definite integral form above, only relevant with every magnetic parameter and the size of permanent magnet, irrelevant with corner α, the β of ball pivot bar.Sensor S ₁can perception the direction of magnetic induction intensity be its Normal direction of measuring face, be that mounting point and the angle by sensor determines, i.e. fixing Z " direction;

Utilize sensor S ₁three-dimensional component (the B of the magnetic induction intensity at place under kinetic coordinate system O-X ' Y ' Z ' _x', B _y', B _z') convert as follows and calculate and obtain sensor S ₁the magnetic induction intensity at place is at Z " component in direction:

Step 1: by sensor S ₁three-dimensional component (the B of the magnetic induction intensity at place under kinetic coordinate system O-X ' Y ' Z ' _x', B _y', B _z') conversion obtains the three-dimensional component (B under O-XYZ system of coordinates _x, B _y, B _z):

$\left\{\begin{array}{c}{B}_x={B_x}^{\text{'}}\cos \mathrm{\&beta;}+{B_z}^{\text{'}}\sin \mathrm{\&beta;}\\ B_y={B_x}^{\text{'}}\sin \mathrm{\&alpha;}\sin \mathrm{\&beta;}+{B_y}^{\text{'}}\cos \mathrm{\&alpha;}-{B_z}^{\text{'}}\sin \mathrm{\&alpha;}\cos \mathrm{\&beta;}\\ B_z=-{B_x}^{\text{'}}\cos \mathrm{\&alpha;}\sin \mathrm{\&beta;}+{B_y}^{\text{'}}\sin \mathrm{\&alpha;}+{B_z}^{\text{'}}\cos \mathrm{\&alpha;}\cos \mathrm{\&beta;}\end{array}\right.$

" be equivalent to basis coordinates is that O-XYZ first turns over α around X-axis to step 2: the fixed-direction Z of sensor sensing ₀angle, then turn over β around Y-axis ₀z axis direction behind angle;

By the magnetic induction intensity component (B under O-XYZ coordinate _x, B _y, B _z) be expressed as at O-XYZ the component B of " component under system of coordinates, wherein Z " direction _z' ' be expressed as:

B _z''=B _xsinβ ₀-B _ysinα ₀cosβ ₀+B _zcosα ₀cosβ ₀

" direction is the direction of sensor sensing to Z;

According to the input-output characteristic of magnetic effect sensor, no matter be to select magnetoresistive transducer or Hall transducer, all can setting voltage output signal U and magnetic induction intensity component B _z" between pass be:

k in formula _ifor each rank coefficient, by the characteristic of each sensor, determined;

Through above-mentioned integral and calculating and Coordinate Conversion, known each sensor voltage output signal U _iangle of revolution α and β to ball pivot bar is relevant, can be expressed as U _i=f (α, β), says from mathematics, only needs to place two sensors in magnetic field, sets up following Simultaneous Equations, can solve two unknown number α and β, is measurement result:

U ₁=f ₁(α,β)

U ₂=f ₂(α,β)

In concrete enforcement, for measurement model, be to utilize computer-implemented signals collecting and data processing, to obtain measurement result.

The present invention uses many sensors to measure simultaneously, there is information redundancy in reading, in set of equation, equation number is more than unknown number number, utilize the methods such as least square to realize Solving Nonlinear Systems of Equations, this is a kind of average weighted means in essence, reduce measurement error, improved the reliability that resolution is also improved system.Simultaneously, adopt the uniform scheme of many permanent magnets not only can range extension, by rationally determining between permanent magnet the difference of spacing between spacing and magnetic effect sensor, be conducive to improve resolution, this is a kind of method of machinery segmentation, similar to the counting principle of vernier calliper.

For there being multidimensional rotation motion demand, and need to measure the occasion of its multidimensional angle of revolution, the present invention all can apply.Such as wrist power robot, multi-freedom joint robot and joint coordinates measuring machine, precise rotating platform.On Large-Scale Equipment, boats and ships propeller advances while controlling need to measure its angle, helicopter screw propeller controlling party to time also need to measure its aerial pose angle, when solar energy sailboard is opened on astrovehicle, also need to detect its expanded angle and direction, even at vehicle front, turn to and in control, also need similar angle transducer.

Claims (5)

1. can realize the spherical hinge that angle of revolution is measured, it is characterized in that:

By base (1) and end cap (6), form the inner ball seat with ball-and-socket, the spherical crown portion of described ball-and-socket forms opening on end cap (6); Bulb (3) is inserted in described ball-and-socket, and exposes spherical crown at the opening of end cap (6), at the spherical crown end face connection ball pivot bar (2) of described bulb (3); Described bulb (3) is concentric with ball-and-socket, and bulb (3) can rotate with one heart with respect to ball-and-socket;

On the lower semisphere surface of described bulb (3), be embedded with permanent magnet (4), and have m permanent magnet (4) to be evenly distributed on the lower semisphere surface of described bulb (3); On the surface of described ball-and-socket, be embedded with magnetic effect sensor (5), and have n magnetic effect sensor (5) to be evenly distributed on the surface of ball-and-socket; Wherein, n and m are all non-vanishing; Utilize the induction output signal of described magnetic effect sensor (5) to judge relative angular position between described bulb (3) and ball-and-socket and the direction of relative movement.

2. according to claim 1ly realize the spherical hinge that angle of revolution is measured, it is characterized in that: described permanent magnet (4) is cylindrical body, and be sleeved in the spacer (8) of being made by nonmagnetic substance, the related permanent magnet of described spacer (8) (4) is embedded in each blind cylindrical hole of bulb surface setting; The axis of described each permanent magnet (4) is all through the centre of sphere of bulb (3).

3. the spherical hinge of realizing angle of revolution measurement according to claim 1, is characterized in that: described bulb and ball pivot bar are to take ferromagnetic material as material.

4. according to claim 1ly realize the spherical hinge that angle of revolution is measured, it is characterized in that: described each magnetic effect sensor (5) is embedded in each gauge hole of described ball-and-socket surface setting, on the sphere that each magnetic effect sensor (5) be take centered by ball-and-socket center with being in, radius is R, the axis of each magnetic effect sensor (5) is through ball-and-socket center; It is step hole that each gauge hole is set, and it is upper that magnetic effect sensor is glued to the sensor holder (9) that non-magnetic material makes, and the related magnetic effect sensor of described sensor holder (9) is inlaid in described step hole.

5. utilize spherical hinge described in claim 1 to realize the method that angle of revolution is measured, it is characterized in that: the revolution of going up in any direction around centre of sphere O for spherical hinge, rotate thereupon in the magnetic field that permanent magnet produces, the magnetic induction intensity that calculates spatial position, magnetic effect sensor place according to Equivalent Magnetic Charge model, draws the magnetic induction intensity component of magnetic effect sensor axis direction and the relation between spherical hinge angle of revolution; According to the input-output characteristic of magnetic effect sensor, set up the Voltage-output signal of each magnetic effect sensor and the function relation of spherical hinge angle of revolution; The function relation of each magnetic effect sensor of simultaneous is set up set of equation, utilizes method of least squares to realize solving of set of equation, draws spherical hinge angle of revolution.

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