CN102003975B - Rotary encoder with built-in self-test - Google Patents

Abstract

The invention relates to a rotary encoder which contains redundancy and fault-tolerant position detection and utilizes the built-in self-test capability. The rotary encoder is used in various rotary devices containing the valve actuator to generate speed data. The rotary encoder is used to diagnose the problems of the valve actuator and the applications of the other rotary devices; and paticularly the rotary encoder can execute frequency analysis to the data of speed, position, torque, thrust or vibration and the rotary encoder provides the speed or position data of the valve.

Description

Rotary encoder with built-in self-test

The application is that (the China national application number is 200680055069.8 for the PCT patented claim in China national stage that enters of submitting on April 21st, 2006, international application no is PCT/US2006/015174, denomination of invention " rotary encoder with built-in self-test ") divide an application.

Technical field

The present invention relates generally to the analysis of valve actuator and position of rotation scrambler, and relates more specifically to utilize built-in self-test to carry out frequency analysis to valve actuator and position of rotation scrambler.

Background technology

In many application, need the position of the turning axle of measurement whirligig.Yet whirligig is usually complicated and has inaccessible part.And whirligig usually is integrated in specific industrial process, wherein stop cost that this process keeps in repair whirligig usually considerably beyond the cost of whirligig.For example, rotary valve is usually vital for industrial process, and the maintenance of some parts of valve need to make this process stop.Existence is for the needs of the position of the object such as valve rod of accurately identifying turning axle and being driven by this turning axle.Also there are the needs of identification such as any wearing terrain in the whirligig of valve, in order to carry out preventative maintenance when being scheduled to shut down, thus or the predetermined shutdown next time so that the operation whirligig keeps this device to be operated.Existence is for the needs of the device of the seriousness of the problem in the position that can determine turning axle and the whirligig that connects of identification turning axle and position.

A method of diagnosis whirligig is the proportion analysis.Can utilize Fourier transform (FT) algorithm to carry out the analysis cycle data, so that data are transformed into to frequency domain from time domain.A trial is to motorized valve application Fourier transform, comprises and measures the electric current flow to motor, to motor data application Fourier transform, then with the peak value in frequency spectrum, diagnoses the problem in the power train of valve actuator.Yet this method is not measured the rotational speed of axle, the also position of uncertain turning axle.The current of electric measurement mechanism is not integrated in the device that can determine the turning axle position yet.

A kind of method of measuring the position of rotary part relates to rotary encoder.Rotary encoder comprises incremental encoder and absolute encoder.Incremental encoder changes for the rotation of measuring axle.Basic incremental encoder comprises the dish with substantial radial setting-out (painted line).As long as photodiode or other sensor detect setting-out and just produce electric pulse.Computing machine or other processor are followed the trail of pulse to determine the position of this dish, and determine that this coils the position of attached axle.Utilize incremental encoder, if computer circuit breaking, when power recovery, positional information will be lost.Comprise speed pickup for the previous incremental encoder of valve actuator, but speed pickup and the data that produce be not used in and carry out frequency analysis.

Absolute encoder does not need power supply to maintain positional information.Absolute encoder produces unique numerical code each different angle for turning axle.Absolute encoder can be single the wheel, and it has the complex pattern be worked on wheel.The single wheel is attached on reference axis, and many different positions, angle can be identified by the pattern of taking turns at this.Yet, this situation that axle only experiences the single rotation that is only applicable to of taking turns.

Another form of absolute encoder is utilized a plurality of the wheel, and it has the concentric ring on each is taken turns, and wherein each ring provides the position data of 1 bit.Position and number of revolutions that a plurality of forms of taking turns allow measured beam warp to go through multiple rotary and still follow the trail of axle.Exist more wheel to allow to follow the trail of the more rotation of multiaxis or the more multiposition of definite single rotation.Yet the pleiotaxy absolute encoder is usually fragile and reliability is poor.Need reliable and can produce the pleiotaxy absolute encoder for the speed data of frequency analysis by operation.

The trial addressed this problem is to utilize 6 wheels or 7 wheels.Each is taken turns provides 3 Bit datas.Yet, via the v bit process, only produce 2 bit Gray codes as position data.This has increased the reliability of absolute encoder.Yet, do not use repetition sensor (duplicate sensor).In addition, speed pickup is not integrated in absolute encoder, and does not produce speed data for frequency analysis.

Summary of the invention

One embodiment of the present of invention comprise the rotary encoder for whirligig.Rotary encoder comprises one or more code wheels, and each code wheel in one or more code wheels comprises at least one encoded segment, and these encoded segment can operate with the position to whirligig and be encoded.Also comprise at least one two group sensor, it can operate to monitor at least one encoded segment.

Another embodiment of the present invention comprises valve actuator, and valve actuator comprises absolute encoder and is suitable for driving the power train of absolute encoder.Absolute encoder comprises at least one scrambler dish, can operate to read a plurality of sensors of at least one scrambler dish, can operate to produce the speed pickup of speed data, at least one of each sensor of a plurality of sensors and speed pickup, repeat sensor.

Another embodiment of the present invention comprises the method for analyzing the valve actuator that comprises sensor.The method comprises from sensor generation data and these data is carried out to frequency-domain analysis.

Specific embodiment of the present invention comprises the method for analyzing the whirligig rotated between two position limits.The method comprises the axle that the position of rotation scrambler operationally is attached to whirligig, and wherein the position of rotation scrambler comprises speed indicator.The method comprises to be utilized speed pickup to produce speed data and this speed data is carried out to frequency analysis.

Consider in conjunction with the drawings detailed description hereinafter, feature of the present invention, advantage and alternative aspect will be apparent for those skilled in the art.

The accompanying drawing explanation

Specifically point out and advocate that clearly the claims that are considered to content of the present invention are as summary although instructions is usingd, when read in conjunction with the accompanying drawings, by following description of the present invention, can be easier to determine advantage of the present invention, in the accompanying drawings:

Fig. 1 shows the wheel of an embodiment of rotary encoder;

Fig. 2 shows the assembling form fully of the embodiment of Fig. 1;

Fig. 3 shows the part assembling form of the embodiment of Fig. 1;

Fig. 4 shows the top view of the embodiment of Fig. 3;

Fig. 5 shows the wheel of the specific embodiment of rotary encoder;

Fig. 6 shows the representational no problem diagnosis in frequency domain;

Fig. 7 shows the representational diagnosis gone wrong in frequency domain;

Fig. 8 shows the data resolution that utilizes 128 samples;

Fig. 9 shows data is being carried out to the data that Fourier transform (FT) is used before in Fig. 8;

Figure 10 shows the data resolution that utilizes 256 samples;

Figure 11 shows and data are being carried out to the data of using before FT in Figure 10;

Figure 12 shows the data resolution that utilizes 512 samples;

Figure 13 shows and data are being carried out to the data of using before FT in Figure 12;

Figure 14 shows the data resolution that utilizes 1024 samples;

Figure 15 is the form of the accuracy of indication some embodiment of the present invention;

Figure 16 is the example with the frequency domain data of 26 rotations of per minute (rpm) acquisition;

Figure 17 is another example with the frequency domain data of 26rpm acquisition;

Figure 18 is the example with the frequency domain data of 18rpm acquisition; And

Figure 19 is another example with the frequency domain data of 18rpm acquisition.

Embodiment

The present invention can be used for any valve actuator or other whirligig, such as the device rotated between the two positions.Specific embodiment utilization of the present invention is with the rotary encoder of integrated speed pickup.Speed pickup can operate to produce speed data for frequency analysis.The present invention also can use the sensor of the another type that can produce the data that can be transformed into frequency domain.And frequency analysis can be used for diagnosing any problem of valve actuator or other whirligig.In one embodiment, rotary encoder is with repeating the right absolute encoder of sensor.

In the accompanying drawings, similar Reference numeral means similar element.Fig. 1 shows an embodiment of rotary encoder of the present invention.Rotary encoder 1 means the specific embodiment of absolute encoder.Do not exist such as the term " wheel " of " input ", " sequential " or qualifiers such as " codings " or " a plurality of wheel " applicable to wheel for inputting 10, timing wheel 20 and code wheel 30 to 110.Phrase " code wheel " or " a plurality of code wheel " are applicable to code wheel 30 to 110.

Bottom erecting frame 130 is fastened on base plate 120 via bolt 132.Bolt 132 also can be rivet, screw, fixture, clip, bonding agent, pad, snap fit connection or any other coupling arrangement as known in the art.Bolt 132 also can be positioned over any position.For example, when bolt 132 is fixture, bottom erecting frame 130 may extend into the edge of base plate 120, and bolt 132 can be positioned this edge.Perhaps, when bolt 132 is bonding agent, bonding agent can launch on any surface of the bottom erecting frame 130 contacted with base plate 120.

Base plate 120 can comprise Semiconductor substrate, wherein can be integrated each other such as the electrical equipment of processor 150 and sensor 160.Connecting processor 150 is not illustrated with the circuit of sensor 160.Yet, in circuit being integrated into to base plate 120, circuit can be positioned base plate 120 outsides.For example, can in base plate 120, hole corresponding with input end and the output terminal of the input end with sensor 160 and output terminal and processor 150.Insulated wire can interconnect between sensor 160 and processor 150.In addition, if circuit is positioned base plate 120 outsides, base plate erecting frame 130 can be merged in base plate 120.

Rotary encoder 1 also can comprise top erecting frame 140 and top board 170, as shown in Figures 2 to 4.Identical description about base plate 120 and bottom erecting frame 130 is applicable to top erecting frame 140 and top board 170.Top board 170 is Semiconductor substrate also.Yet any circuit also can be in top board 170 outsides.Top erecting frame 140 also can be integrated in top board 170.Top erecting frame 140 can utilize bolt 132 to be fastened to bottom erecting frame 130.Clamp nut 122 is attached to base plate 120.Top board 170 is fastened to base plate 172 via screw 172 and clamp nut 122, as shown in Figure 2.Rotary encoder 1 can be fastened to another device via erection bolt 124.The configuration of describing about bolt 132 is also applicable to clamp nut 122, screw 172 and erection bolt 124.As shown in Figure 3 and Figure 4, top erecting frame 140 can be from one piece.This embodiment that allows to be shown in the top erecting frame 140 in Fig. 3 and Fig. 4 is with even mode thermal expansion.This is equally applicable to bottom erecting frame 130.In an alternate embodiment, top erecting frame 140 and bottom erecting frame 130 can each be made by many.

In addition, rotary encoder 1 is not limited to any given shape.Rotary encoder 1 can be circle, rectangle or specifically is shaped for certain device or application.And it is only the description for the ease of rotary encoder 1 that term " top (top) " and " bottom (end) " are used in this article.Therefore, rotary encoder 1 can use with any orientation.

In the specific example of Fig. 1 to Fig. 4, wheel for inputting 10 is included in the tooth 12 on gear 11.Wheel for inputting 10 also comprises aperture 14, and it can be used from the device that the number of revolutions of following the trail of wheel for inputting 10 is provided with sensor one.Locking cap 16 is attached to wheel for inputting 10.As shown in Figure 3, when locking cap 16 during in appropriate location, any movement of wheel for inputting 10 is subject to the constraint contacted of locking cap 16 and top mounting bracket 140.As long as rotary encoder 1 can comprise locking cap 16 will be handled upside down or load and transport the time, once and input shaft prepare engage rotary encoder 1 locking cap 16 is unloaded.

Timing wheel 20 comprises gear 21 and pinion wheel 25.Gear 21 comprises tooth 22.Pinion wheel 25 comprises tooth 26.Timing wheel 20 also comprises regularly slit 28.In this embodiment, regularly slit 28 is designed to extend to from the top surface of gear 21 hole of the basal surface of gear 21, and timing slit 28 is designed to show as the arcuate segments of rectangle.Yet, will be appreciated that, these elements can have any shape.Regularly slit 28 also can be setting-out, embeds any other structure that magnet maybe can be detected.Also can not have regularly slit 28, alternatively, other device can be carried out the regularly function of slit 28.For example, the tooth on gear 21 can be made and be comprised that enough numbers are with corresponding to desirable fixed timing mark by ferrous compound.Be placed on each tooth 22 that near gear 21 magnetic reader can detect contiguous magnetic reader rotation.Timing wheel 20 means can be used for an only embodiment of timing mechanism of the present invention.

Timing wheel 20 also comprises encoded segment 24, and it is designed to extend through from the top surface of pinion wheel 25 arcuate socket of the bottom of gear 21 in the present embodiment.Fig. 1 shows encoded segment 24 and ends at the straight edge alignd to the ray extended with center-diameter from timing wheel 20.Encoded segment 24 also can be arcuate segments, and it ends at the similar concave edge of concave edge with 132He gap, gap 142.Encoded segment 24 is depicted as the interior ring 27 of timing wheel 20 is divided into to eight parts.Yet, encoded segment 24 also can be designed to by interior ring 27 be divided into two parts, four parts, 16 parts or any other 1/2 ⁿumber.

In the embodiment shown in fig. 1, code wheel 30 comprises the gear 31 with tooth 32 and the pinion wheel 35 with tooth 36.Code wheel 30 has interior ring 37 and outer shroud 39, and interior ring 37 has encoded segment 34, and outer shroud 39 has encoded segment 38.Encoded segment 34 and 38 top surfaces from code wheel 30 extend to the basal surface of wheel 30.Encoded segment 38 has continuous arcuate shape, and it occupies 1/2nd of outer shroud 39.Encoded segment 34 comprises two different arcuate segments, segmentation 34a and segmentation 34b, its respectively occupy interior ring 1/4th and each other equi-spaced apart open.Segmentation 34a starts from the radius identical with encoded segment 38.Segmentation 34b starts from the identical radius of encoded segment 38 terminations.Encoded segment can be asymmetric, as shown in Figure 1, or symmetrical, such as the encoded segment of Fig. 5.The asymmetric orientation of encoded segment can be convenient on base plate 120 position that the non-coding part charge at the wheel that is not encoded stops and place redundant sensor.

Code wheel 40 comprises the gear 41 with tooth 42 and the pinion wheel with tooth (not shown).Pinion wheel is installed on the bottom side of code wheel 40, and not shown in the drawings.Code wheel 40 has interior ring 47 and outer shroud 39, and interior ring 47 has encoded segment 44, and outer shroud 39 has encoded segment 38.Encoded segment 44 and 48 top surfaces from code wheel 40 extend to the basal surface of wheel 40.Encoded segment 48 comprises continuous arcuate segments, and it occupies 1/2nd of outer shroud 49.Encoded segment 44 is divided into two arcuate segments, segmentation 44a and segmentation 44b, each in them occupy interior ring 1/4th and each other equi-spaced apart open.Segmentation 44a starts from the radius identical with encoded segment 48.Segmentation 44b starts from the same radial ray of segmentation 38 terminations.

In the present embodiment, code wheel 50,70,90 and 110 is identical with code wheel 30, and code wheel 60,80 and 100 is identical with code wheel 40.Yet any code wheel in these code wheels needn't be identical with any other code wheel.When using term " interior ring " or " a plurality of interior ring ", expression be each the interior ring 37,47,57,67,87,97,107 and 117 in code wheel 30 to 110.Only in fact the interior ring of timing wheel 20 and code wheel 30 and 40 numbers in Fig. 1.When using term " outer shroud " or " a plurality of outer shroud ", expression be each outer shroud 39,49,59,69,79,89,99,109 and 119 in code wheel 30 to 110.Only in fact code wheel 30 and 40 outer shroud number in Fig. 1.When using term " encoded segment " or " a plurality of encoded segment ", expression be the encoded segment 24,34,38,44,48,54,58,64,68,74,78,84,88,94,98,104,108,114 and 118 of each code wheel in timing wheel 20 and code wheel 30 to 110.Only in fact the encoded segment of timing wheel 20 and code wheel 30,40 numbers in Fig. 1.In addition, fixed timing mark 28 can be considered " encoded segment ".The data that produce by fixed timing mark 28 can be used for determining position and/or speed.Equally, the data that produced by other encoded segment can be used for determining position and/or speed.

The gear 11 of wheel for inputting 10 and 25 engagements of the pinion wheel of timing wheel 20.The gear 21 of timing wheel 20 and 31 engagements of the gear of code wheel 30.The pinion wheel 35 of code wheel 30 and 41 engagements of the gear of code wheel 40.The pinion wheel 45 of code wheel 40 and intermediate speed pinion 180 engagements.Intermediate speed pinion 180 meshes with the gear 51 of code wheel 50.The pinion wheel 55 of code wheel 50 and 61 engagements of the gear of code wheel 60.The pinion wheel 65 of code wheel 60 and intermediate speed pinion 180 engagements.Intermediate speed pinion 180 meshes with the gear 71 of code wheel 70.The pinion wheel 75 of code wheel 70 and 81 engagements of the gear of code wheel 80.The pinion wheel 85 of code wheel 80 and intermediate speed pinion 180 engagements.Intermediate speed pinion 180 meshes with the gear 91 of code wheel 90.The pinion wheel 95 of code wheel 90 and 101 engagements of the gear of code wheel 100.The pinion wheel 105 of code wheel 100 and intermediate speed pinion 180 engagements.Intermediate speed pinion 180 meshes with the gear 111 of code wheel 110.

As seen in Figure 3, in the plane that wheel for inputting 10 is identical in the pinion wheel with timing wheel 20 and code wheel 30,50,70,90 and 110 with 100 gear with code wheel 40,60, 80.In code wheel 40,60,80 plane identical in the gear with timing wheel 20 and code wheel 30,50,70,90 and 110 with 100 pinion wheel.

Light splash guard (light splashguard) (not shown) can be outstanding from bottom erecting frame 130 and top erecting frame 140.Splash guard be arranged in part between interior ring and outer shroud or completely in concentric ring.For example, for code wheel 30, splash guard is arranged between interior ring 37 and outer shroud 39.Splash guard can be designed to distance between basal surface (on the one hand) based on timing wheel 20 and code wheel 30 to 110 and bottom erecting frame 130 and the vicissitudinous height of tool.Splash guard provides the light barrier between sensor 160.Splash guard can comprise and is built in the erecting frame 130 of bottom, is built in code wheel and timing wheel 20 or is built in the concentric ring in base plate 120 and top board 170.Perhaps, block piece can individually form around sensor 160, or forms around detecting device 162 and transmitter 164.Splash guard can be the concentric ring that ridge, wall maybe can prevent any other structure of crosstalking between different sensors 160.

Being engaged in Fig. 1 to Fig. 4 of wheel for inputting 10, timing wheel 20 and code wheel 30 to 110 is shown as in the configuration of wriggling.Yet this configuration can be changed to meet different encoder design.For example, when needs are configured as circle by rotary encoder 1, wheel can be arranged to coiled arrangement.The various shapes of rotary encoder 1 and the various configurations of wheel are all possible.Fig. 5 shows the alternative U-shaped configuration of the wheel in similar rotary encoder shape.

Rotary encoder 1 also can be designed to hierarchy.Wheel for inputting 10, timing wheel 20 and code wheel 30 are illustrated and are arranged in single-stage in Fig. 1 to Fig. 4 to 110.Perhaps, rotary encoder 1 can be designed to include the wheel on multistage.In Fig. 1, each is taken turns and is fastened to uniquely on the erecting frame 130 of bottom.Yet a plurality of the wheel can be installed on single wheel shaft.In one embodiment, code wheel 60 and 70, code wheel 50 and 80, code wheel 40 and 90 and code wheel 30 and 100 can be arranged in respectively on same wheel shaft.Timing wheel 20 and code wheel 110 can be arranged on same wheel shaft.For even narrower rotary encoder, to take turns 40,50,80 and 90 and can be arranged on same wheel shaft, code wheel 30,60,70,100 and 110 can be arranged on same wheel shaft.Will be appreciated that, various configurations and combination are possible.

Wheel for inputting 10, timing wheel 20 and code wheel 30 to 110 are shown as spur gear.Yet wheel also can be worm gear, bevel gear, herringbone wheel, hypoid gear, ring gear, rack-and-pinion, and cross helical gear.Rotary encoder 1 shows the embodiment that code wheel has fixing rotation.Perhaps, can implement the rack-and-pinion system, wherein timing wheel 20 and code wheel 30 to 110 do not have fixing rotation.

Referring to the specific embodiment shown in Fig. 1 to Fig. 4, interior ring and the outer shroud of different coding wheel are positioned same distance place, Ju Lun center.For example, the distance at interior ring 37 and encoded segment 34 Ju Lun 30 centers is identical with the distance at interior ring 47 and encoded segment 44 Ju Lun 40 centers, even in the situation that wheel 40 has larger diameter.Therefore, the number of tooth 42 and tooth 36 40 speed with respect to wheel 30 that can determine to take turns reduce.This is equally applicable to other and takes turns.Yet the encoded segment of different coding wheel needn't equidistantly be located diametrically.

The speed of wheel for inputting 10 is determined by the speed of whirligig to be monitored.For example, in the present embodiment, timing wheel 20 rotates than about 1.34 times soon of wheel for inputting 10.Code wheel 30 rotates with the speed identical with timing wheel 20.Code wheel 40 is with 1/4th rotations of the speed of code wheel 30.Code wheel 50 is with 1/4th rotations of the speed of code wheel 40, and code wheel 40 rotates with ten sixth speed of the speed of code wheel 30.This is equally applicable to other code wheel, makes 1/4th rotations of code wheel 110 with the speed of code wheel 100, and code wheel 100 is with 1/65,536 rotation of the speed of code wheel 30.In some cases, code wheel 30 will rotate, but be not enough to cause the rotation of code wheel 110.In alternate embodiment, extra code wheel can add rotary encoder 1 to.The speed of extra code wheel can be calculated as 1/4 of code wheel 30 ⁿ(count as follows, code wheel 30 is n=0, and code wheel 40 is n=1 ..., code wheel 110 is n=8, etc.).Specific embodiment of the present invention can comprise a following code wheel: it has the wheel of less bit number for top speed, but allows to increase along with relative coding wheel Speed Reduction the higher bit number that each is taken turns when the train transmission.

May there is the situation that needs to change the number of teeth between wheel and wheel.For example,, in the situation that code wheel 40 and 60 does not have the identical number of teeth.In addition, the number of teeth on the Binding change gear, the radial position of encoded segment can be taken turns change with respect to another, to cause speed to reduce or to increase.

Wheel can be made by any kind of material.The representative illustration of minority is steel, stainless steel, aluminium, other metal, pottery, plastics, glass and the plastics that are covered with metal.Can use any material for gear known in the art.These are taken turns and can all be made by identical composition, or the composition between wheel and wheel can be different.

As referring to as shown in code wheel 80, sensor 160 comprises detecting device 162 and transmitter 164.Detecting device 162 and transmitter 164 are built in base plate 120.Gap 34 is built in the erecting frame 130 of bottom, to prevent from covering detecting device 162 and transmitter 164.About transmitter 164 and detecting device 162, can be via semiconductor fabrication, transmitter 164 and detecting device 162 are installed on base plate 120 and by transmitter 164 and detecting device 162 and are inserted through the hole in base plate 120, thereby transmitter 164 and detecting device 162 are manufactured in base plate 120.Will be appreciated that, any other method that transmitter 164 and detecting device 162 are fastened on base plate 120 also is covered by the present invention.Gap 144 (Fig. 4) is built in top erecting frame 140 and has and gap 134 identical functions.Although not shown, rotary encoder 1 also can comprise sensor, and it comprises transmitter and detecting device, and transmitter and detecting device are built in the basal surface of top board 170.For each detecting device 162 be built in base plate 120, transmitter can directly be arranged in top.For each transmitter 164 be built in base plate 120, detecting device can directly be positioned over top.Gap 144 in top erecting frame 140 shown in Fig. 4 prevents that 140 pairs of transmitters of top erecting frame and any of detecting device from stopping.Be positioned at sensor, detecting device and transmitter on the basal surface of top board 170 usually be located immediately at above sensor 160, transmitter 164 identical with detecting device 162.Therefore, discussion for the ease of this paper, with be positioned at member on base plate 120 substantially similar be positioned at any respective members on top board 170, although do not illustrate in the drawings, but will give the identical Reference numeral that adds quotation marks (') mark (for example, detecting device 160 and detecting device 160 ').

Shown embodiment comprises sensor 160,161,163 and 165.Sensor 161 is corresponding to the interior ring of timing wheel 20 and code wheel 30 to 110.Sensor 163 and 165 outer shrouds corresponding to code wheel 30 to 110.Sensor 160 ', 161 ', 163 ' and 165 ' respectively directly be positioned over sensor 160,161,163 and 165 tops.Sensor 163 and 165 can be placed to the radial angle of about 90 degree spaced apart.In code wheel 30,60,70,100 and 110, sensor 161 can be divided the angle between sensor 163 and 165 equally.In code wheel 40,50,80 and 90, sensor 161 and 163 can be spaced apart with the radial angle of about 45 degree, and sensor 161 and 165 can be spaced apart with the radial angle of about 135 degree.Sensor 161,163,165 and 169 is only about code wheel 80 and 100 and timing wheel 20 numbering.Each sensor 161,163 and 165 comprises transmitter 164 and detecting device 162.Each sensor 161 ', 163 ' and 165 ' comprise transmitter 164 ' and detecting device 162 '.

Sensor 160/160 ' comprise transmitter 164/164 ' and detecting device 162/162 ', and can be described to one group of sensor to or two groups of sensors.This be equally applicable to sensor 160/160 ' and 160 '/160 " concrete form (that is, sensor 161,161 ', 163,163 ', 165,165 ', 169 and 169 ').As transmitter 164 and detecting device 162 are considered as a pair of and by transmitter 164 ' with the substituting of relative the second couple of detecting device 162 ' be considered as, transmitter 164 and detecting device 162 ' can be considered are a pair of, transmitter 164 ' and detecting device 162 can be considered parallel the second couple.In any case but think, second pair can provide duplicate detection.This redundancy makes the rotary encoder 1 can be fault-tolerant to heavens.For example, if one such to breaking down, rotary encoder 1 still can operate so.According to which sensor or sensor component, may break down (if existence), scrambler also can utilize a plurality of sensors of actuating and operate.

In a specific embodiment, the position of the transmitter 164 of sensor 160 and detecting device 162 be give sensor 160 (with respective sensor 160 ') position of placement tolerance that may be wide and the most symmetrical.Before bit value changes again, for sensor, the position that code value changes is left identical space in clockwise (CW) direction with counterclockwise (CCW) direction.This method is shown in Figure 1.In a specific embodiment, this causes the corresponding asymmetry of asymmetric sensor placement and code change point.

In an alternate embodiment, transmitter 164 can be with respect to detecting device 162 skews.Then can more resulting the first encoded radio and the skew encoded radio, identical to guarantee two arithmetical differences between value.If arithmetical difference is not identical, can search this problem by following self-test.

In arbitrary embodiment, as long as this v of being placed on bit prevents in the boundary of gap logic (anti-backlash logic) and, in the boundary of the permissible mechanical tolerance of member, the code that produced so will be identical.

In an alternate embodiment, sensor 161,163 and 165 can respectively have single transmitter, corresponding sensor 161 ', 163 ' and 165 ' can respectively there is corresponding single detector and not have any redundancy.

Each sensor is associated with fixed timing mark 28.Sensor 169 shown in Fig. 1 comprises at least one transmitter 164 and at least one detecting device 162.Be positioned at sensor 169 on top board 170 ' directly be positioned over sensor 169 tops, and comprise at least one transmitter 164 ' and at least one detecting device 162 '.

In a specific embodiment, the respective sensor be positioned on base plate 120 and top board 170 can once be actuated respectively a wheel.Perhaps, can once actuate these whole in taking turns or some.At first each bottom of taking turns is actuated usually, is each top side of taking turns afterwards.In a specific embodiment, but actuation sensor 160/160 ' each transmitter.Actuate continuously each sensor 169/169 for monitoring fixed timing mark 28 ', as discussed in more detail hereinafter.About code wheel 30 to 110, but the transmitter 164 of actuation sensor 161,163 and 165.If rotary encoder 1 is in the position shown in Fig. 1, so sensor 161 ', 163 ' and 165 ' detecting device 162 ' each receives the signal from respective transmitter 164.Yet, rotary encoder 1 only can be located so that sensor 161 ' and 163 ', 161 ' and 165 ', 163 ' and 165 ', 161 ', 163 ' and 165 ' detecting device 162 ' reception signal or the detecting device 162 of all these sensors ' all do not receive signal.No matter where rotary encoder 1 is positioned at, and detecting device 162 will receive signal when transmitter 164 is actuated.In a specific embodiment, transmitter 164 and detecting device 162 can be vertically and left and right ground direct communication.Therefore, when actuating three transmitters 164, three detecting devices 162 will receive signal, and if the opening in encoder wheel (that is, encoded segment) transmitter 164 and detecting device 162 ' between, three detecting devices 162 ' can receive signal so.Therefore, produce the data of 6 bits.

Adopt this mode, when actuate the sensor 161 that is positioned on top board 170 ', 163 ' and 165 ' 164 ' time of transmitter, produce the data of 6 bits.Actuate the detecting device 162 of identical sensor ', and the detecting device 162 of the sensor on the bottom side of rotary encoder 1 161,163 and 165.Can actuate the sensor 161,163 and 165 of code wheel 30.Then, can actuate the sensor 161 of code wheel 30 ', 163 ' and 165 '.About code wheel 40 to 110, can continue this alternative sensor and actuate pattern.

About timing wheel 20, sensor 161 and 161 ' can be as above about as described in code wheel 30 to 110 and actuate.In a specific embodiment, continue actuation sensor 169 and 169 ' transmitter.In the embodiment shown in Figure 2, sensor 169 ' comprise two transmitters, sensor 169 comprises two detecting devices.In a specific embodiment, all other sensors respectively have transmitter and detecting device.In a specific embodiment, actuation sensor 169 transmitter only once.

The first detecting device 162a and the second detecting device 162b can be located so that fixed timing mark 28 is not present on the second detecting device 162b when fixed timing mark 28 is present on the first detecting device 162a.This is shown in Fig. 1, and wherein detecting device 162a and optional transmitter 164 are visible, but detecting device 162b is sightless.

Perhaps, sensor 169 and 169 ' can respectively there is transmitter and detecting device, and can forbid (disable) directly left and right transmission characteristic.Can by use dissimilar sensor or detecting device 162 and 162 ' and/or transmitter 164 and 164 ' edge placed around block piece forbid this specific character.

Sensor 169 and 169 ' also can comprise other transmitter and detecting device.For example, Fig. 2 illustrates the detecting device 164 in sensor 169, its corresponding to sensor 169 ' in detecting device 162 '.Transmitter 164 can be positioned over the enough distance far away apart from the first detecting device 162a, makes the first detecting device 162a receiving optical signals not when actuating transmitter 164.In an alternate embodiment, transmitter 164, the first transmitter 164a ' and the second transmitter 164b ' alternately actuate.

Three grades of redundancies of sensor 160 and 160 ' provide.At first, if transmitter 164 ' and 164 and detecting device 162 ' with 162 in any inefficacy, sensor 160 and 160 ' remain exercisable so.For example, if the transmitter of the sensor 161 of code wheel 80 164 lost efficacy, sensor 161 still can operate so because sensor 161 ' transmitter 164 ' still can communicate by letter with the detecting device 162 of sensor 161.

Second level redundancy is from the built-in self-test function.Detecting device 162 is placed near transmitter 164 and self-test is provided.Even there is not accessible light path due to the position of code wheel, detecting device 162 will receive signal when actuating transmitter 164.If detecting device 162 does not receive signal, any in transmitter 164 and detecting device 162 (or subsidiary circuit and processing) or two are broken down so.Once code wheel moves to the position that has accessible light path, if detecting device 192 does not receive signal, may be that transmitter 164 breaks down.Detecting device 162 ' and life-span of 164 can be by actuating transmitter 164 ' determine.If detecting device 164, detecting device 162 ' or transmitter 164 ' start to break down rather than transmitter 164 breaks down, adopt similar logic so.

When definite which position, during by sensor 160 and 160 ' identification, processor 150 will be considered the member of any inefficacy, such as transmitter 164 or detecting device 162 '.For example, if the detecting device of the sensor 163 adjacent with code wheel 80 162 lost efficacy, processor 150 can compensate for the following fact so, i.e. sensor 163 and 163 ' will not detect the light path stopped of identical point in code wheel 80 rotations.Perhaps, use identical example, if detecting device 162 does not receive signal, detecting device 162 can be tested by adjacent transmitter 164 so, take and determines that detecting device 162 is whether as operation.Transmitter 164 ' can be by adjacent detector 162 ' test, take and determine the reason that transmitter 164 ' whether is problem.If transmitter 164 ' and detecting device 162 is operation and transmitter 164 ' sending, but detecting device 162 does not receive this transmission, so outer shroud 89 stop transmitter 164 ' and detecting device 162 between light path.And if detecting device 162 had lost efficacy, but in fact whether the position of processor 150 estimated codings wheels 30 to 70 and 90 to 110 so stop to determine outer shroud 89 detecting device 162 broken down.

Can by utilize Viterbi (Viterbi) decoding by sensor 160 and 160 ' in any triple redundance is provided.For example, the output of the output of sensor 163 or sensor 165 can be used for producing Viterbi bit (v-bit).If sensor 160 or sensor 160 ' inoperation are to produce the v-bit, sensor 160 or 160 ' for generation of data-bit so.In a specific embodiment, sensor 165 and 165 ' for generation of the v-bit.The Veterbi decoding algorithm is forward error correction technique.The V bit provides and can be used for the accurately redundant data of decoding is carried out in other the position of 2-bit.In this embodiment, the sensor 161 and 161 ' 1-Bit data can be provided, the sensor 163 and 163 ' 2-Bit data can be provided.By using the v-bit, by sensor 161 and 161 ' and sensor 163 and 163 ' signal produced and the angular deflection of optimum position can be +/-22.5 and spend and do not cause code error.Therefore, even, in the situation that the existence skew receives signal, also incite somebody to action the still actual position of indicator wheel.V-bit on a code wheel is the actual position of clear and definite adjacent encoder wheel also.For example, the v-bit of code wheel 30 helps the actual position of clear and definite code wheel 40.

Veterbi decoding is not the unique solution code calculation that code wheel 30 to 110 can be designed to it is implemented.For example comprise sequential decoding, reed solomon coding (Reed-Solomon coding) and turbine coding (turbo coding) for other appropriate algorithm of the present invention.It is the gear counting that another of Veterbi decoding substitutes.

In rotary encoder 1, produce the sensor 165 of v-bit with respect to sensor 161 and 163 skews.Perhaps, sensor 165 can be arranged to align with the sensor 163 or 161 that produces data-bit.Fig. 5 shows the embodiment of absolute encoder (rotary encoder 2), and wherein v-bit sensor 2165 is positioned to align with data-bit sensor 2161 and is offset with respect to data-bit sensor 2163.As visible as reference timing wheel 2020, v-bit sensor 2165 also can be positioned to detect the encoded segment 2034 on interior ring 2027.V-bit sensor 2165 can be oriented to detect any code wheel in code wheel 2030 to 2110 or whole interior rings of code wheels.Therefore, sensor 161 or sensor 2161 can be the v-bit.

Except difference seldom, the rotary encoder 2 shown in Fig. 5 is similar to rotary encoder 1 and is operated.Wheel for inputting 2010 has the different numbers of teeth.Encoded segment 2024 is divided into two parts rather than four parts by interior ring 2027.In addition, sensor 2165 is included in the concentric ring identical with sensor 2161.Timing wheel 2020 comprises pinion wheel 2025, and intermediate speed pinion 2180 is on the either side of pinion wheel 2025.

Code wheel 2030 comprises the gear 2031 with tooth 2032 and the pinion wheel 2035 with tooth 2036.Code wheel 2030 has interior ring 2037 and outer shroud 2039, and interior ring 2037 has encoded segment 2034, and outer shroud 2039 has encoded segment 2038.Encoded segment 2034 and 2038 top surfaces from code wheel 2030 extend to the basal surface of wheel 2030.Encoded segment 2038 is depicted as 1/2nd the continuous arcuate segments that occupies outer shroud 2039.Encoded segment 2034 comprises two different arcuate segments, i.e. segmentation 2034a and segmentation 2034b, wherein each be illustrated occupy interior ring 1/4th and equidistantly spaced apart each other.Align with the middle part of encoded segment 2038 in the middle part of segmentation 2034a.Segmentation 2034b occupies the space direct relative with segmentation 2034.

Code wheel 2040 comprises the gear 2041 with tooth 2042 and the pinion wheel 2045 with tooth 2046.Pinion wheel 2045 is installed on the bottom side of code wheel 2040.In the embodiment of Fig. 5, can see pinion wheel 2045 through code wheel 2040.Code wheel 2040 has encoded segment 2044 and 2088, is similar to code wheel 2030.For purposes of illustration, only marked the encoded segment of timing wheel 2020 and code wheel 2030 in Fig. 5.

Code wheel 2050,2070,2090 and 2110 can be identical with code wheel 2030. Code wheel 2060,2080 and 2100 can be identical with code wheel 2060.Term " interior ring ", " a plurality of interior ring ", " outer shroud ", " a plurality of outer shroud ", " encoded segment " and " a plurality of encoded segment " are for describing rotary encoder 2, and it uses in the mode identical with rotary encoder 1.

Wheel for inputting 2010 and intermediate speed pinion 2180 engagements, and intermediate speed pinion 2180 meshes with the pinion wheel 2025 of timing wheel 2020.Pinion wheel 2025 and intermediate speed pinion 2180 engagements, and intermediate speed pinion 2180 meshes with the gear 2031 of code wheel 2030.The pinion wheel 2035 of code wheel 30 and 2041 engagements of the gear of code wheel 2040, by that analogy until code wheel 2110.Code wheel 2030 to 2110 meshes in the mode identical with code wheel 30 to 110.

In the present embodiment, the tooth of wheel for inputting 2010 can be configured in the plane identical with the pinion wheel of timing wheel 2020 and code wheel 2040,2060,2080 and 2100 with 2110 gear with code wheel 2030,2050,2070,2090. Code wheel 2030,2050,2070,2090 can be arranged in the plane identical with the gear of code wheel 2040,2060,2080 and 2100 with 2110 pinion wheel.

Referring to rotary encoder 1, sensor 160 and 160 ' provide rotates the indication of absolute position of the input shaft of wheel for inputting 10.As shown in the figure, rotary encoder 1 is 18 bit absolute encoders.Therefore, rotary encoder 1 can mean 262,144 positions.Certainly, without using all positions.Can add wheel and sensor or reduce wheel and sensor from the end of train by the end to train and increase or dwindle rotary encoder 1.Each take turns can provide three sensors 160 and 160 '.Perhaps, each in train take turns or at least last take turns only can provide one or two sensor group 160 and 160 ', as long as sensor is oriented to the bit more high-order as the next one in encoded radio.Rotary encoder 1 also can only have single encoded the wheel, and it is as the source of speed and position data.Rotary encoder 1 also can only have single position encoded the wheel and independent velocity pick-up mechanism, such as timing wheel.In addition, each in code wheel can have any number of encoded segment and corresponding sensor 160 and 160 '.Rotary encoder 1 can be utilize sensor 160 and 160 ' any encoder design.

As discussed above, sensor 160 and 160 ' can communicate by letter when encoded segment is arranged between sensor, thus accessible light path is provided.In sensor 160, when receiving signal, detecting device 162 output logic 0 values; Output logic 1 value when not receiving signal.Equally, sensor 160 ' in, detecting device 162 ' output logic 0 value when receiving signal; When not receiving signal, output logic 1 value.Therefore, when encoded segment sensor 160 and sensor 160 ' between the time, when actuating transmitter 164, processor 150 receives two independent logics inputs: input from the detecting device 162 of detection position ', an input is from the detecting device 162 of carrying out self-test.Once stop using transmitter 164 and actuate transmitter 164 ', processor 150 receives 2 independent logics inputs so: 162, one logics inputs of detecting device that logic input is come detection position from the detecting device 162 of carrying out self-test '.

If interior ring or outer shroud block sensor 160 and 160 ' between communicate by letter, the logical one that processor 150 will receive the logical zero input of the bit value that represents position code and the successful test that represents the transmitter that bit position is relevant is therewith so inputted.For example, when actuating transmitter 164, detecting device 162 ' will be blocked and can not receive signal and will send logical one.Detecting device 162 still transmits and receives signal by direct left and right, and therefore logical zero is sent to processor 150.

When processor 150, from detecting device 162 ' receive logic 0 signal and when relatively transmitter 164 is actuated, processor 150 is recognized and is certainly had encoded segment.When actuating transmitter 164 ' and detecting device 162 while transmitting logic zero signal, realize identical result.The present embodiment use 0 and logic zero signal; Yet, also can use 0 and 5 volt, 1 and 5 volt or any other sensors signal or its combination.Produce 0 volt when in addition, detecting device 162 and 162 ' can be designed so that produces logical zero and receives light signal when not receiving light signal.In such embodiments, processor 150 will be when being actuated from 0 volt of detecting device 162 ' receive and transmitter 164 receiving sensor 160 and 160 ' between the indication of encoded segment.

In a specific embodiment, the self-test of being undertaken by 164 pairs of adjacent detector of transmitter 162 is carried out to the direct transmission of detecting device 162 by the sidepiece from transmitter 164.For example, detecting device 162 can be positioned at apart from transmitter 164 the distance be the 0.5mm place.Perhaps, can use the sensor that directly transmit left and right.In such embodiments, can carry out self-test via reflection.For example, when sensor 160 and 160 ' between when having encoded segment and actuating transmitter 164, detecting device 162 ' reception signal only.When actuating 164 ' time of transmitter, only detecting device 162 receives signals.This will allow transmitter 164 and 164 ' simultaneously actuate.When do not exist encoded segment make light sensor 160 and sensor 160 ' between while being blocked, detecting device 162 and 162 ' can be suitable for receiving reflected light signal.In this case, when actuating transmitter 164, light can emit from the basal surface of interior ring or outer shroud.Detecting device 162 can receive a catoptrical part.Detecting device 162 can be designed to transmit logical zero in the situation that receive any light.Detecting device 162 can be designed to transmit the voltage suitable with the light intensity received.Therefore, when having encoded segment, detecting device 162 can be from being positioned at the directly direct optical signal of the transmitter 164 of top ' reception higher-strength of detecting device 162.When not having encoded segment, detecting device 162 can receive more low intensive reflected light signal from adjacent transmitter 164.

In another embodiment, encoded segment can be coated with and be drawn on wheel above, rather than depends on the incision segmentation of wheel.In such embodiments, sensor 160 and 160 ' between do not communicate by letter.On the contrary, detecting device 162 receives reflected light from transmitter 164.This be equally applicable to detecting device 162 ' and transmitter 164 '.For example, for example, if the wheel right and wrong are reflexive (, painted black) and encoded segment be reflexive (for example, painted white) or wheel be reflexive and the encoded segment right and wrong reflexive, a voltage of detecting device 162 ' will produce when light reflects from encoded segment and produce different voltage at light from the non-coding segmented reflective out time the so.In addition, sensor 160 and 160 ' can be positioned at the at first same side of code wheel.

Sensor 160 and 160 ' be described about optical sensor.Yet, will be appreciated that, a plurality of other sensors can be used for the present invention.The suitable example of other of sensor includes but not limited to magnetic sensor, hall effect sensor and electric contact.The sensing that becomes known for any type of increment sensor and absolute encoder in this area can be used for the present invention.Encoded segment also can comprise any material or the configuration with selected sensor compatibility.

Processor 150 also can be designed to produce alarm.If detecting device 162, transmitter 164, detecting device 162 ', transmitter 164 ', detecting device 162a, detecting device 162b, transmitter 164a ' or transmitter 164b ' inefficacy, processor 150 can give the alarm.Can provide different alarms for different inefficacy priority.Under extreme case, processor 150 can be designed to force valve actuator or other whirligig monitored by rotary encoder 1 to shut down.Can express in many ways alarm, such as, visual alarm (such as flash of light or LCD message on the control panel of valve actuator or on control station), audible alarm or written warning.

Sensor 160 and 160 ' in, if transmitter 164 and 164 ' and detecting device 162 and 162 ' can not proper function, it is invalid that data-bit of producing so or v-bit will be declared as.Decode value that can be based on the inefficacy bit and judge the impact of invalid bit value for the performance of the valve actuator of being monitored by rotary encoder 1 or other whirligig actuation time.Also can estimate invalid bit value by the bit number based on losing efficacy.

Be valve time used from the open position to the off-position or from the off-position to the open position actuation time of valve actuator.Be that whirligig rotates to the second place time used from primary importance the actuation time of other whirligig.For example, for industrial reel, be that this reel launches the time used fully from being wound up into fully actuation time.When actuation time is longer, individual bit is only corresponding to the sub-fraction of total actuation time.Therefore, it may not be very crucial that individual bit lost efficacy, thereby alarm or warning is provided but does not force machine down, and this can be enough to be used in such application.If actuation time is shorter, individual bit lost efficacy and can mean the relatively large deviation between physical location and the represented position of rotary encoder 1.Therefore, for shorter actuation time, except alarm or warning are provided, individual bit lost efficacy can be enough to force whirligig to be shut down.Which part that the importance of bit fails can be depending on for given application this actuation time can be meaned by bit fails.In a specific embodiment, the user can configure the threshold value of allowed loss of accuracy, if lower than this threshold value, the BIST feature only provides alarm or warning, but, higher than this threshold value, the BIST feature will force secure machine to shut down and provide alarm or warning.

For the whirligig that does not have predetermined primary importance and the second place, can be unfixed actuation time.The example of such whirligig comprises the flywheel of engine or the main shaft of turbine.Rotary encoder of the present invention also can be used for the whirligig of any type.

As mentioned above, if sensor 160 and 160 ' detecting device 162 and 162 ' all be verified as exercisable by self-test, but detecting device 162 does not receive signal and detecting device 162 ' reception signal, can check that so other position of taking turns is to confirm the position of associated wheel.In this case, by the data-bit of sensor 160 and 160 ' produce, be actually effectively, but sensor 160 and 160 ' half by interior ring or outer shroud, stopped.Viterbi logical operation can obtain identical position code from main sensors group or redundant sensor group (that is, transmitter 164 or detecting device 162).Will be appreciated that, term " mainly " and " less important " or " redundancy " are arbitrarily.

Perhaps, sensor 160 and 160 ' can work fully, but the different component of rotary encoder 1 lost efficacy.For example, if in the tooth on code wheel is cut, so can be with past data based on sensor 160 and 160 ' provide by the current location of sensor 160 and 160 ' indicated and the position of predicting do not mate.Therefore, although sensor 160 and 160 ' normal operation, they are the indicating correct position not.Processor 150 or some other processor can provide for the correction of this mistake and produce alarm.For example, if code wheel 60 loses tooth 62 from gear 61, code wheel 60 may start to miss position during each rotation so.Therefore, will be no longer accurately corresponding to valve position by the valve position of all code wheel indications.This will show as valve bounce to another location.In one embodiment, processor 150 can be searched the discontinuous of the indicated valve position in the position of code wheel.As an alternative or as a supplement, timing wheel 20 can be used as the position of incremental encoder with the checking code wheel.Processor 150 (or any other suitable processor) can be in the situation that consider that the mistake that code wheel 60 is introduced recalculates valve position.If the order of severity lost efficacy is larger, processor 150 also can produce alarm and/or cause safe shutdown so.

Cause any other processor that any inefficacy of rotary encoder 1 of the discontinuous indication of valve position can be communicated by letter by processor 150 or with processor 150 to be identified.

Sensor 160 and 160 ' be described in this article to there is respectively transmitter and detecting device.Perhaps, sensor 160 can be configured to only have transmitter and sensor 160 ' can be configured to only have detecting device.In other embodiments, sensor 160 ' can not be present in rotary encoder 1.Fig. 2 illustrates sensor 160 and has a plurality of transmitters and detecting device.Sensor 169 comprises transmitter 164, the first detecting device 162a and the second detecting device 162b.Although not shown, the corresponding detecting device 162 of sensor 169 ' comprise ', the first transmitter 164a ' and the second transmitter 164b '.The second detecting device 162b and the second transmitter 164b ' can be used for checking from the data of the first detecting device 162a and the first transmitter 164a ' or effectively make to be doubled by the data output of sensor 169 and 169 ' produce.Sensor 160 can comprise any number of transmitters, detecting device and/or the two.Sensor 160 and 160 ' can be used for any rotary encoder so that fault-tolerant speed and position data to be provided.

Fig. 1 to Fig. 5 shows absolute encoder, and wherein each in code wheel only has interior ring and outer shroud.Yet, the ring of each the had arbitrary number in code wheel, and not restriction.For example, each code wheel can have 3,4,5 or 6 rings.For each ring can provide at least one sensor 160 and at least one sensor 160 '.Therefore, the number of ring can determine the number of the producible data-bit of each code wheel.

The number of the ring of each code wheel is by allowing the sensor 160 and 160 ' size of the required code wheel that communicates with one another and the width of encoded segment to decide.In addition, between Ying Huan, provide enough gaps to be limited in crosstalking between the sensor on same side.For example, the signal that provides gap to record from the transmitter 164 of sensor 163 with the detecting device 162 that prevents sensor 161.Yet, also can use other technology except gap, such as using splash guard as discussed above, with restriction, crosstalk and allow less code wheel diameter.

The code wheel of arbitrary number can add scrambler of the present invention to.For example, rotary encoder 1 can provide the position data of the common speed valve actuator that be a hour actuation time.Adding a plurality of code wheels will provide more data bit and increase the actuation time that can be handled by rotary encoder 1.Certainly, rotary encoder 1 also can be used for being less than valve actuator and other whirligig of one hour actuation time.Rotary encoder 1 also can have than the code wheel shown in Fig. 1 to Fig. 4 code wheel still less.

In addition, rotary encoder 1 can be single wheel absolute encoder or single-wheel incremental encoder.In these embodiments, sensor 160 and 160 ' can comprise a plurality of transmitters and detecting device, thus built-in self-test and fault tolerant operation are provided.Therefore, one group of sensor 160 and 160 ' can monitor a plurality of encoded segment, such as fixed timing mark 28 or encoded segment 34, or one group of sensor 160 and 160 ' can monitor single encoded segmentation, such as encoded segment 38.

In addition, timing wheel 20 can be used as the incremental encoder combined with the specific coding function of the remainder of rotary encoder 1.For example, particular delta scrambler embodiment can be set as making delta pulse speed mate exactly the count rate of the absolute part of scrambler pro rata.In this way, when actuator operates, incremental encoder can be used for obtaining position data.When motor stops, accurately mating the specific coding position of adding the final increment counting Ying Yuxin of absolute position code when the motor revolution starts to.

If the indicated position of timing wheel 20 (also playing the effect of incremental encoder) is different from the position indicated by code wheel, so can be to sensor 160 and 160 ' execution self-test.If all the sensors 160 and 160 ' equal proper function is confirmed in self-test, may follow the trail of abnormally by code wheel so.Therefore, can produce alarm or warning.In a specific embodiment, in this case, rotary encoder can be dependent on incremental encoder until the maintenance rotary encoder.

Rotary encoder 1 and 2 is designed to use Gray code; Yet, also can use binary coding.Use the v-bit and repeat sensor to make rotary encoder 1 and 2 will never differ over a least significant bit (LSB) [LSB], thereby increase the confidence of user to the encoder values reliability.

The many kinds of whirligigs that the present invention can be used for rotating between the two positions, such as, valve actuator, door opener or reel.In typical valve actuator, motor can carry out driver's valve via one group of gear.The output shaft of motor can directly be connected to worm screw.Worm screw can drive Worm-gear assembly, and Worm-gear assembly drives again drive socket or axle, and drive socket or axle lifting and reduction or rotation valve rod.The second axle also can be driven by Worm-gear assembly, in order to drive the wheel for inputting 10 of rotary encoder 1.Perhaps, valve actuator can be used different gear sets, or motor output shaft can directly be connected to valve rod and without the center tooth wheels.Exist in the art a variety ofly to be applicable to the method that the position of rotation scrambler is connected to whirligig of the present invention, but these methods will set off a discussion no longer herein.In a preferred embodiment, rotary encoder 1 and 2 can be used for the whirligig such as valve actuator is carried out to diagnosis, and about diagnostic function, rotary encoder 1 will be as demonstrative example.Yet, also can use other scrambler of the present invention, such as rotary encoder 2.In addition, timing wheel 20 can merge in any rotary encoder.Timing wheel 20 can be the code wheel of incremental encoder or the code wheel of single wheel absolute encoder.For example, fixed timing mark 28 can be used for the position encoded of absolute encoder.Perhaps, as shown in Figure 1, timing wheel 20 also can comprise the encoded segment of separating with fixed timing mark 28.In another embodiment, fixed timing mark 28 can be than the part of unitary Item pattern, such as the coding pattern of single wheel absolute encoder.In a specific embodiment, timing wheel 20 can be and separates with other code wheel or the incremental encoder of combination.In this embodiment, fixed timing mark 28 is not only for generation of speed data, and generation incremental counter data.Fixed timing mark 28, be similar to encoded segment, can take with sensor 160 and 160 ' together with work required any form or structure.Fixed timing mark 28 can be in hole, line, embedding magnet, engraving or this area any other structure that becomes known for absolute encoder or incremental encoder.

Timing wheel 20 and 2020 is shown as has 32 fixed timing marks 28 and fixed timing mark 2028.Yet timing wheel 20 and 2020 can have the fixed timing mark 28 of arbitrary number.

About frequency analysis, the initial specific embodiment of speed data being carried out to frequency analysis (also being known as in this article frequency-domain analysis) of discussing, discuss non-speed data embodiment afterwards hereinafter.In addition, for purpose of explanation, the fixed timing mark 28 of timing wheel 20 or timing wheel 20 usually is known as the speed data source in this article.In other embodiments, no matter the speed pickup of any type, have rotational position sensor and still do not have rotational position sensor, can be used for diagnosis (that is, frequency analysis).In addition, the discussion about the frequency analysis of speed data is equally applicable to other data embodiment.Other data embodiment can for example comprise volt-ampere response data and the vibration data of moment of torsion data, position data, thrust data, noise data, current data, voltage data, power of motor data, motor.Numerous types of data and sensor type can be used for frequency analysis, as known in the art.The present invention is contained can be via sensor and valve actuator or the producible any data type of other whirligig.

Although discussion hereinafter relates to rotary encoder 1, will be appreciated that, this discussion is equally applicable to rotary encoder 2.Fixed timing mark 28 on timing wheel 20 can be used for producing speed data.But each in sensor 169 and 169 ' recording timing mark 28 is presented in the time span before sensor.Then this residence time can be used for accurately determining the speed such as the whirligig of valve actuator.Speed data can be used for determining the speed of the input shaft that drives wheel for inputting 10.And input shaft usually is attached to other whirligig, such as the worm gear of valve actuator.Therefore, fixed timing mark 28 can be used for determining the speed such as other whirligig of worm gear.

In a particular embodiment, fixed timing mark 28 be configured to timing wheel 20 intermediate reach and etc. big or small hole.Yet, previous discussed encoded segment embodiment and any embodiment in sensor embodiment also be respectively used to fixed timing mark 28 and sensor 169 and 169 ' embodiment.

The speed data produced by fixed timing mark 28 can utilize FT to operate, to convert speed data to frequency domain from time domain.Yet, can produce speed data with the speed pickup of any type, to convert frequency data to.

FT expection signal sample occurred with the regularly spaced time interval.Yet, because the residence time value of rate signal in the present invention may not be constant, therefore can adopt measure to allow FT to obtain effective information.By selecting enough a large amount of data points, when machine is operated with stable state, the overwhelming majority in these data points will be used, and the average residence time of larger data collection can be used as " rule " residence time [t of each data sampler _d].This ' rule ' residence time can be used for demarcating frequency scaling (fn (Hz)=l/ (td*# sample) of (scale) gained FT.When spot frequency data suitably, data provide enough information to determine the velocity variations be associated with the known rotational speed of each member of power train to the operator, but and existing or problem that occur possibly in the power train of indicator valve actuator or other whirligig.For example, when equipment is newer, will forms chart or the curve of bareline heart rate and amplitude and be preserved.Afterwards, can form chart or the curve of new frequency and amplitude and compare with preserved baseline chart or curve.If appear at frequency or the amplitude place different from previous measured frequency or amplitude corresponding to the peak value of the operating frequency of given member, it is evident that so, be different from newer the time this common indicating wear and may losing efficacy or imminent inefficacy with the characteristic of the member of this frequency dependence connection.Therefore, can before component failure, in the suitable time, carry out suitable maintenance.In addition, can plan to carry out the FT analysis, with automatically operation in processor 150, the peak amplitude variation that processor 150 can be programmed and be configured to surpass configured threshold value can be used for producing automatic alarm or warning or forces the machine safe shutdown.Can use the method for any suitably spot frequency data as known in the art.

The example of frequency-domain analysis is included in Fig. 6 to Fig. 8.Fig. 6 illustrates the example of valve actuator no problem diagnosis or " well " power train in frequency domain.Fig. 6 shows the peak value at 45.9Hz; Yet the peak value of 0.1% amplitude of measuring with respect to the operating speed of actuator (when 26rpm or 0.43Hz, amplitude is 100%) does not have the amplitude that is enough to cause concern.Fig. 7 is illustrated in the valve actuator of the some undesired signals of generation in frequency domain or the example of " bad " power train.The frequency of undesired signal can be used for the power train member that identification goes wrong.In Fig. 7, worm screw or worm gear exceed tolerance limit.For example, the peak value indication at 26.1Hz goes wrong.Yet, at the peak value of 52.5Hz and 78.6Hz, be the harmonic wave of 26.1Hz peak value.

The processor of processor 150 or execution FT for example can be designed to automatically produce, for the remarkable peak value suitable mark of (, surpassing predetermined threshold).For example, processor can comprise current produced peak value and the amplitude of previous produced peak value and the program that frequency is complementary of being designed so that.In this embodiment, if processor can not be identified peak value, this inefficacy can be used as the warning that has potential problems to the operator so.Perhaps, the data in frequency domain can be manually relevant to the parts of the power train of valve actuator.But the training and operation person identifies and understands the correlativity of different peak values.For example, if rotary encoder 1 is present in valve actuator, timing wheel 20 and sensor 169 and 169 ' can be used for the identifying speed of power train member so.In a specific embodiment, drive the input shaft of wheel for inputting 10 by worm-gear driven.Therefore, speed pickup can be used for determining the speed of worm gear, and therefore determines frequency.Then, based on gear ratio, can calculate the frequency of other power train member.Then, can come identification means frequency and any harmonic wave according to the graphical representation of the data in frequency domain.On the other hand, if speed pickup is not present in valve actuator, but the motor shaft speed of known reality, this Information Availability is in producing the member frequency so.Can adopt various types of electrical measurements or the magnetic measurement of the actual speed of motor, therefore further improve the diagnosis capability on entire system.In many cases, factory personnel will be carried out above-mentioned manual identification.Therefore, can provide sample frequency curve and the mutual relationship of mark in advance to the terminal user.

In a specific embodiment, can download the built-in information (tooth of gear ratio, motor speed, each gear, the ball of each bearing etc.) of actuator, in the Electronic Packaging that is stored in actuator.Then, airborne CPU can cause this variation with reference to stored information which part of deriving power train.The drawing of FT can directly be shown on the LED screen of actuator, or the data array resource management system that can be downloaded to the operator is for the portable computer of analyzing or be downloaded to service technician or PDA is upper is made a concrete analysis of to be sent to main office.

Can be stored in firmware, software, hardware or any other device as known in the art for the programming of collecting data and/or execution frequency analysis.For example, the frequency analysis programming can be stored in the firmware of valve actuator.

In addition, the operator can be simply by relatively present analysis and previous the analysis are identified the peak value in frequency domain.The previous analysis can be the analysis of carrying out in factory.Yet, can have the situation that need to maybe must be independent of any previous analysis and identify the peak value in frequency domain.For example, in the design phase of new valve actuator, the slip-stick artist may wish new prototype is carried out to frequency analysis to guarantee in prototype the not having short-life vibration of inherent contracting, resonance and/or harmonic wave.Perhaps, frequency analysis is checked instrument before can be used as loading and transporting after assembling whether be manufactured with physical imperfection with some parts of determining mechanical drive system.

Be built in rotary encoder, or be built in valve actuator or other whirligig or the processor be associated with valve actuator or other whirligig can be carried out FT.Display, printer or other output unit can merge in valve actuator, for the form with chart or figure, show result.Perhaps, the speed data produced by fixed timing mark 28 can be sent to the remote computer such as operator PC, speed data carried out to FT and to be shown with more user-friendly form, or transmits data or FT to being positioned at scene or away from on-the-spot technician.

Provide more sample can cause finer frequency resolution after speed data is carried out to FT.Can obtain the time span of sample or provide more sample by increasing sampling rate by increase.Fig. 8 to Figure 15 shows by the curve map that data were produced of obtaining with 17 samples of per second.Fig. 8 illustrates the utilization frequency analysis resolution of the valve actuator of 128 samples altogether.Fig. 9 is illustrated in the speed data of speed data being carried out to FT Fig. 8 before.Figure 10 illustrates the utilization frequency analysis resolution of the valve actuator of 256 samples altogether.Figure 11 is illustrated in the speed data of speed data being carried out to FT Figure 10 before.Figure 12 illustrates the utilization frequency analysis resolution of the valve actuator of 512 samples altogether.Figure 13 is illustrated in speed data is carried out to the FT speed data of Figure 12 before.Figure 14 illustrates the utilization frequency analysis resolution of the valve actuator of 1024 samples altogether.As shown in the figure, the resolution of frequency analysis increases and improves along with the sample number purpose.

The frequency analysis of any type as known in the art can be used for the present invention.In described specific embodiment, use and equal 2 ⁿa plurality of samples come speed data is carried out to FT, wherein n is any integer.Therefore, the sum of sample is such as equaling 128,256,512,1024,2048,4096,8192 etc.Therefore, if obtain 3500 samples, so only 2048 samples can be used for FT.In other embodiments, can be to also inaccurately equaling 2 ⁿsample carry out FT.Yet, in those embodiment, leakage may become a concerned issue.Be known in the art for solving the technology of leakage.

In addition, in a specific embodiment, FT utilizes the sample obtained in stable state.Therefore, timing wheel 20 rotates with the speed relative to constant.In the time of in rotary encoder 1 is incorporated in electric driver's valve actuator, timing wheel 20 will accelerate and slow down in a period of time.Can before carrying out FT, be carried out truncation (truncate), average (average) or window (window) in speed data and deceleration data that the accelerating period produces.The instantaneous frequency analysis is as known in the art and can be used for substituting the truncation data.

Can carry out truncation to speed data by algorithm, this algorithm was designed to before FT processes the analysis speed data in order to remove any expedited data or deceleration data.Perhaps, speed data can be by truncation so that sample number and FT 2 ⁿrequire compatible.

Phrase FT is contained very wide algorithm scope as used herein, comprises Fast Fourier Transform (FFT).FT is contained four large classes of Fourier transform as used herein: continuous fourier transform, Fourier series, discrete time Fourier transform and discrete Fourier transformation.Also there is the FT algorithm that is designed to process approximate and non-homogeneous data.Discrete Fourier transformation is most commonly used to digital signal processing.Phrase FT is contained any algorithm with produced data compatibility as used herein.

Mean the desirable maximum duration that obtains sample actuation time.For example, for valve actuator, but valve moves to off-position or moves to from off-position the maximum time that the required time of open position is the picking rate data from open position.Valve only can partly move, and therefore only the part of actuation time can be used for the speed data sampling.An exemplary method that increases the speed data sample produced comprises the increase sampling rate.Sampling rate is decided by the speed of timing wheel 20 and the number of fixed timing mark 28. Rotary encoder 1 and 2 sampling rates that can have far above 17 samples p.s..

The other method that increases the data sampler number produced is included in collects data a plurality of actuation times.Each new data set can be collected and combine with available data, until the sample counting is enough high to allow utilizing FT to operate it.Once data set has been expired, any new data sample the oldest replaceable data sampler, thus maintain up-to-date data set for analyzing.Can be in such as tables of data storage speed or position data, for approaching in real time or frequency-domain analysis subsequently.

Figure 15 provides possible sampling rate and can be used for the table of the gained total number of samples of frequency analysis.In Figure 15, the delta pulse frequency equals to take the sampling rate that Hz is unit.Speed DS is the transmission speed of the drive socket (DS) of valve actuator.Yet speed DS can be relevant to the rotating member of any device.Cone tooth group speed multiple (Bevel Set Speed Multiplier) means that DS is connected to the speed that the gear of the input shaft that drives wheel for inputting 10 causes to be increased.Wheel for inputting 10 speed multiples are illustrated in the speed that the gear ratio between the pinion wheel 25 of the gear 11 of wheel for inputting 10 and timing wheel 20 causes to be increased.

The example of the rotating member of whirligig is the drive socket of valve actuator.Input shaft can interconnect to wheel for inputting 10 by drive socket via cone tooth group.Any connected mode as known in the art can be used for driving wheel for inputting 10.As one of data sampling possible example, if drive socket rotates with 200rpm, and if bore the speed increase that the tooth group causes about 4.8: 1, input shaft will rotate with 960rpm so.Therefore, wheel for inputting 10 can rotate with 960rpm.Wheel for inputting 10 driving timing wheels 20.If utilize 51/38 tooth speed-increasing gear (spur increaser), timing wheel 20 rotates with about 1288rpm so.1288rpm is divided by 60 rotations that equal timing wheel 20 per seconds.Exemplary timing wheel 20 shown in Fig. 1 has 32 fixed timing marks.Yet, iff utilizing 16 fixed timing marks, the number that fixed timing mark is multiplied by the rotation of per second so obtains the sampling rate (delta pulse frequency) of 343 samples of per second.Under identical situation, if timing wheel 20 has 32 fixed timing marks, sampling rate is about 678 samples of per second so.Nyquist (Nyquist) frequency is 1/2nd of sampling frequency.Sampling rate is multiplied by and equals actuation time in seconds the total number of samples that can collect during single complete action.

Figure 15 shows actuation time and sampling rate influencing each other in the accuracy of calculated rate analysis.Iff the operation of shorter speed data, be available, alternative be before data are carried out to FT by short operation gang with the raising frequency resolution.

Figure 15 is used Hanning window (Hanning Window), to prevent the distortion of the discontinuous frequency values caused of rate signal when the beginning of data set and the ending.Other possible window comprises rectangular window, Blackman window (Blackman), Hamming window (Hamming), triumphant damp window (Kaiser), window index and laylight.Yet any window be known in the art can be used for the estimating speed data.Be known in the art as why not with window, carried out frequency analysis.Any method for carrying out frequency analysis be known in the art can be used for the present invention.

Can on basis one by one, the estimated frequency data determine the content that peak and amplitude are suggested about valve actuator.Perhaps, frequency analysis can be compared with given frequency analytical characteristic (signature), to determine the health status of valve actuator or other whirligig.

Figure 16 to Figure 19 shows the representative frequency analysis that can be used for comparing.Figure 18 and Figure 19 show the rotational speed that depends on substantially valve actuator or other whirligig and the velocity variations changed.For produce the data of Figure 16 and Figure 17 with the actuator of 26 rotations of per minute (rpm) operation in stable state.For produce the data of Figure 18 and Figure 19 with the actuator of 18rpm operation in stable state.Figure 16 and Figure 19 and Figure 17 and Figure 18 utilize respectively same-code device pinion wheel adapter.Figure 16 has remarkable peak value at 45.4Hz and 91.1Hz.The remarkable peak value of Figure 19 more obviously and more.Many problem tunables in valve actuator or other whirligig show as the single peak value of frequency domain.Carry out that frequency analysis can disclose in the single peak value be hidden in a speed but the potential problems that are rendered as a plurality of peak values in other speed in different operating speed.

Rotary encoder of the present invention is described to many wheel absolute encoders.Rotary encoder also can be single wheel absolute encoder or incremental encoder.For example, timing wheel 20 can be integrated in the wheel identical with wheel for inputting 10.Then, wheel for inputting 10 can play the effect of incremental encoder and timing wheel.And the encoded segment of code wheel 30 to 110 can be integrated in wheel for inputting 10, as known in the art.Then, wheel for inputting 10 can play the effect of single wheel absolute encoder.Wheel for inputting 10 can be designed to match with the end of input shaft, or alternatively wheel for inputting 10 can be installed on input shaft around, such as the longitudinal center at input shaft.Yet wheel for inputting 10 can be installed on any point along the length of input shaft.

Before, with respect to speed data, frequency analysis has been discussed.Extra data embodiment comprises the moment of torsion data.In the valve actuator of measuring moment of torsion, the vibration of moment of torsion can be transformed into frequency domain.In the situation that monitoring is delivered to the output torque of valve rod, also can in frequency domain, analyze the moment of torsion data.Be incorporated in processor in valve actuator or can the moment of torsion data-switching be become to frequency domain in any mode in the mode of above being discussed about speed data or by any technology as known in the art away from the processor of valve actuator.Then, can identify the frequency of power train member and the indication of valve actuator health status is provided to the operator.

Another data embodiment comprises the thrust data.For example, the motor of valve actuator is connected to the worm screw of the worm screw/worm gear in power train.The axial thrust of monitoring worm gear is to read the moment of torsion transmitted by worm gear.Merge to processor in valve actuator or the thrust data-switching can be become to frequency domain away from the processor of valve actuator, be similar to any method in the method for above discussing about speed data or by any technology as known in the art.Can be identified by operator or computer program the frequency of power train member.Therefore, the diagnosis of valve actuator is provided.In addition, can utilize a plurality of thrust pickups.

Excessive data embodiment involving vibrations data.For example, eight accelerometers are positioned over a plurality of positions in valve actuator.All eight accelerometers will read the identical vibration in valve actuator.Yet the accelerometer of close given vibration source will have stronger signal.Observation can allow to find out vibration source from the vibration data of all eight sensors in frequency domain.The frequency of vibration can be relevant to the power train member.Therefore, the operator can be warned the imminent problem of any possibility of valve actuator.

Utilize the sensor of arbitrary number in can any embodiment in these embodiments.For example, can utilize the speed pickup more than.In addition, can utilize dissimilar a plurality of sensors.For example, valve actuator can comprise rotary encoder, such as rotary encoder 1.Valve actuator also can comprise the axial thrust sensor.The speed data that can produce timing wheel 20, carry out frequency analysis to the thrust data or to the two.

To can be driven by motor, hydraulic pressure, engine, handwheel or any other drive unit as known in the art by whirligig or the valve actuator of the present invention's monitoring.

Although description above contains many concrete conditions, be not considered to it and limit the scope of the invention, and only be to provide some example embodiment.Equally, can design other embodiments of the invention in the situation that do not depart from the spirit or scope of the present invention.Therefore, only and restriction represented by the equivalent on appended claims and legal sense thereof of scope of the present invention, rather than the represented and restriction by description above.Meaning and interior all interpolations of the present invention, deletion and modification also are covered by the present invention of scope that belongs to claims disclosed herein.

Claims (4)

1. an absolute encoder, it comprises:

Wheel for inputting, it is configured for receiving the rotation input;

Timing wheel, it can produce speed data and be driven by described wheel for inputting;

A plurality of code wheels, it operationally is attached to described timing wheel; With

A plurality of sensors, it is configured for detecting the position of described a plurality of code wheel and described timing wheel, and wherein, each in described a plurality of sensors comprises redundant sensor.

2. absolute encoder according to claim 1, is characterized in that, described absolute encoder comprises processor, and it can operate to be transformed into frequency data by the speed data that described timing wheel was produced.

3. absolute encoder according to claim 1, is characterized in that, described a plurality of sensors are selected from optical sensor, hall effect sensor or magnetic sensor.

4. absolute encoder according to claim 1, is characterized in that, described a plurality of sensors and described redundant sensor can be worked as when described a plurality of sensor or described redundant sensor are actuated and tested each other.

Images