JPH06229880A - Device for detecting rotational error of meshed gear - Google Patents

Abstract

PURPOSE:To improve the rotation error detecting accuracy of a device for detecting rotational error between meshed gears by detecting the rotational angles of two gears which are rotated in a meshed state in connection with time and the rotational error between the gears based on the relation between the detected results of the gears. CONSTITUTION:The title device detects the rotational angles of gears 10 and 12 in connection with time by means of rotary encoders 20 and 22 and decides the rotational error between the gears 10 and 12 based on the difference in rotational angle between the gears 10 and 12 for the period during which the rotational angles of the gear 12 detected in the same period as each rotational angle detected from the gear 10 exist among a plurality of rotational angles detected from the gear 12 by means of a computer 60, etc. For the period during which the rotational angles of the gear 12 detected in the same period as each rotational angle detected from the gear 10 do not exist, the rotational angle of the gear 12 is estimated based on the plurality of rotational angles detected from the gear 12 and the rotational error between the gears 10 and 12 is decided by using the estimated rotational angle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects the change status of the rotation angle of each of two gears that rotate while meshing with each other, and determines the rotation error of those gears based on the detected mutual relationship of the change of the rotation angle. The present invention relates to an engagement type gear rotation error detection device of a detection type.

[0002]

2. Description of the Related Art Generally, a meshing gear rotation error detecting device of this type includes (a) gear rotation signal generating means for generating a rotation signal for each gear when each of two meshing gears rotates by a certain angle, (b) Gear rotation error determining means for determining the rotation error of the gear based on the mutual relationship between the generation states of the rotation signals between the gears.

A conventional example of this type of meshing gear rotation error detecting device is disclosed in Japanese Patent Application Laid-Open No. 55-78229. This is because the gear rotation signal generating means outputs, for each gear, a rotation pulse signal in which a pulse is generated with an amplitude every time each of the two gears engaged with each other rotates by a certain angle.
Further, the gear rotation error determining means has one pulse in the rotation pulse signal output for one gear and 1 for the rotation pulse signal output for the other gear.
The phase difference of each pulse (that is, the difference between the two gears in the absolute rotation angle, which is the rotation angle from the reference rotation position of each gear), is detected, and the rotation error (that is, rotation This is a mesh type gear rotation error detection device that determines the amount of lead / lag of the angle.

[0004]

In this conventional meshing gear rotation error detecting device, the rotation error is specifically determined as follows. That is, in the rotation pulse signal output for one gear, one pulse in the rotation pulse signal output for the other gear is provided between the rising timing of a certain pulse and the rising timing of the pulse for the next rotation. And the phase difference between the pulse of one gear and the pulse of the other gear under the assumption that the pulse that should be compared with the pulse of one gear above (hereinafter referred to as "comparison target pulse") must rise. The rotation error is determined based on That is, in this conventional meshing gear rotation error detection device, the portion of the rotation pulse signal that represents the rising edge of each rotation pulse is one aspect of the "rotation signal."

Therefore, as in the left side portion of the pulse waveform shown in the graph of FIG. 9, one pulse rise timing of one gear (driving gear in the figure) and the next rise timing of the pulse. When the comparison target pulse of the other gear (the driven gear in the figure) rises during the rising timing of the pulse, the rotation error is correctly detected. However, due to the reason that the rotation error is quite large, as in the right part of the pulse waveform in the figure, the rising timing of one pulse and the rising timing of the next pulse related to one gear are If the comparison target pulse of the other gear does not rise during the period, a rotation error that is significantly different from the actual rotation error will be detected.

In summary, in the conventional mesh type gear rotation error detecting device, the comparison of the rotation signals is not always performed normally. For example, when the rotation error is considerably large, the rotation error is accurately measured. The problem is that it cannot be detected.

Against this background, the invention of claim 1 acquires the rotation signal of each gear in association with time,
The object is to solve the above-mentioned problem by determining the rotation error by using it.

Further, the invention of claim 2 relates to the meshing type gear rotation error detecting device of the type in which the rotation error is determined based on the mutual relationship of the absolute rotation angles taken by the two gears at substantially the same time. The object of the present invention is to provide a preferred embodiment when the invention of Item 1 is applied.

[0009]

In order to solve each of the problems, the invention of claim 1 includes the gear rotation signal generating means 1 and the gear rotation error determining means 2 as shown in FIG. In the meshing gear rotation error detection device, the gear rotation error determination means 2 detects the generation timing of each rotation signal of each of the two gears, thereby rotating the respective gears from the reference rotation position. The absolute rotation angle, which is an angle, is detected in association with time, and the rotation error of these gears is determined based on the mutual relationship between the detection results of each gear.

Incidentally, the "gear rotation error determining means 2" herein is, for example, based on the mutual relationship between two absolute rotation angles taken by two gears at substantially the same time, the rotation angle advance / delay of the gears. The amount may be determined as a rotation error. It is also possible to adopt a mode in which the amount of advance / delay of the rotational angular velocity of the gears is determined as a rotation error based on the mutual relationship between the two relative rotation angles taken by the two gears at substantially the same time. The "relative rotation angle" is, for example,
It means the angle at which the gear rotates between the generation timing of a rotation signal of one rotation and the generation timing of a rotation signal of the next rotation.

According to a second aspect of the invention, the "gear rotation error determining means 2" in the first aspect of the invention is substantially the same for a plurality of absolute rotation angles detected for the two gears. When there are two absolute rotation angles detected at the time, the rotation error is determined based on the mutual relationship between the two detected absolute rotation angles. Estimate the absolute rotation angle that one is expected to take at that time based on the plurality of absolute rotation angles detected for that gear,
It is characterized in that the rotation error is determined by using the estimated absolute rotation angle.

Here, the "gear rotation error determining means 2" can be configured, for example, as follows. That is, for each of the plurality of absolute rotation angles detected for one of the two gears, it is determined whether or not there is an absolute rotation angle detected for the other gear at substantially the same time. If it exists, the rotation error at that time is determined based on the mutual relationship between the two existing absolute rotation angles. On the other hand, if it does not exist, a plurality of absolute rotations detected for the other gear are detected. Based on the angle, the absolute rotation angle expected to be taken by the other gear at that time is estimated, and based on the mutual relationship between the estimated absolute rotation angle and the absolute rotation angle detected for the one gear, the It is possible to adopt a mode in which the rotation error at the time is determined.

The invention of claim 2 is only one example of the embodiment of the invention of claim 1, and the invention of claim 1 can be implemented in other modes. For example, the "gear rotation error determination means 2" is set to the absolute rotation angle at which there is a time when the substantially same absolute rotation angle is detected for the two gears among a plurality of times detected for the two gears.
The rotation error is determined based on the mutual relation of the times when they exist, and for the absolute rotation angle that does not exist, the time when at least one of the gears is expected to take the absolute rotation angle is detected for that gear. The rotation error can be determined by estimating the rotation error by using the estimated time.

[0014]

In the meshing type gear rotation error detecting device according to each of the first and second aspects of the invention configured as described above, the gear rotation signal generating means 1 causes each of the two meshing gears to rotate by a predetermined angle. A rotation signal is generated for each gear. Further, the gear rotation error determining means 2 detects the generation timing of each rotation signal for each gear to detect the absolute rotation angle of each gear in association with time, and the detection results of each gear are mutually detected. The rotation error of those gears is determined based on the relationship.

As described above, in the meshing type gear rotation error detecting device according to each of the first and second aspects of the invention, the absolute rotation angle of each gear is acquired in association with time, and in the end, the absolute rotation angle of one gear is acquired. And the absolute rotation angle of the other gear are acquired independently of each other via a time axis common to them. Therefore, the correspondence between the absolute rotation angles between the two gears is always performed irrespective of the magnitude of the phase difference in the change situation of the absolute rotation angles, and as a result, the rotation error is always correctly determined. Becomes

Particularly, in the mesh type gear rotation error detecting device according to the invention of claim 2, among the plurality of absolute rotation angles detected by the gear rotation error detecting means 2 for the two gears, those gears are substantially included. When there is an absolute rotation angle detected at the same time, the rotation error is determined based on the mutual relationship between the two detected absolute rotation angles. The absolute rotation angle that one is expected to take at that time is estimated based on the absolute rotation angle detected for the gear, and the rotation error is determined by using the estimated absolute rotation angle. Since the absolute rotation angle of each gear originally changes continuously with time,
Based on a plurality of actually detected absolute rotation angles, it is possible to estimate an absolute rotation angle that was not actually detected.

As described above, in the meshing type gear rotation error detecting device according to the invention of claim 2, although the absolute rotation angle of each gear is discretely detected with respect to time, the calculation of each gear is calculated. It is possible to obtain the absolute rotation angle substantially continuously with respect to time. Therefore, the absolute rotation angles are always accurately associated with each other between the two gears, and as a result, the rotation error is accurately determined.

[0018]

As is apparent from the above description, according to each of the first and second aspects of the present invention, the mutual relationship of the changing conditions of the absolute rotation angle between the two gears does not mean that the rotation error is large or small. Since it is always obtained correctly regardless of the effect, it is possible to obtain the effect that the rotation error of the gear can always be detected accurately.

In particular, according to the second aspect of the invention, the rotation error of the gear can be accurately detected even though the absolute rotation angle of each gear is detected discretely with respect to time. can get.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A gear tooth rotation error detecting device of one tooth surface meshing type which is an embodiment common to the inventions of claims 1 and 2 will be described in detail below with reference to the drawings.

This gear rotation error detection device detects the rotation status of the gear pair that rotates while meshing with each other, and detects the rotation error of the gear pair based on the rotation status. "Gear pair" is here
As shown in FIG. 2, the gear pairs 10 and 12 whose rotation axes are parallel to each other are provided, but the invention is not limited to this, and for example, the rotation axes may intersect with each other or may be different from each other.

Although not shown, this gear rotation error detecting device comprises a drive motor for rotating the gear 10 as a drive gear and a braking motor for applying a braking torque to the gear 12 as a driven gear. The braking motor, in cooperation with the drive motor, applies a load (for example, the rotational speed and the rotational force assumed in the gear operating state) to the gear pair 10 and 12. The reduction ratio of the gear pair 10 and 12, that is, the ratio of the number of teeth Z ₂ of the driven gear 12 to the number of teeth Z ₁ of the drive gear 10, that is, Z ₂ / Z ₁ is represented by “I”.

The gear rotation error detecting device also includes rotary encoders 20 and 22 for the driving gear 10 and the driven gear 12, respectively, as shown in FIG. As is well known, the rotary encoders 20 and 22 are discs that rotate together with the rotating shaft of each gear 10 and have a large number of fan-shaped slits formed at a constant angular pitch in the circumferential direction, and a fixed member. It is equipped with a light-emitting / light-receiving element for detecting the passage of each slit of the disk, and the rotation pulse signal that repeats that the amplitude rises from the steady state to the transition state each time each slit passes, that is, the amplitude Outputs a signal described by a train of pulses (see FIG. 3). That is, in the present embodiment, these two rotary encoders 20 and 22 are one mode of the "gear rotation signal generating means 1" in the inventions of claims 1 and 2.

The gear rotation error detecting device further includes frequency dividing circuits 30 and 32 for the rotary encoders 20 and 22, respectively.
And clock pulse counters 40 and 42 and divided pulse counters 44 and 46, and a clock pulse generation circuit 50 and a computer 60 common to both.

The frequency dividing circuits 30 and 32 are connected to the rotary encoders 20 and 22, respectively, and divide the cycle of each rotation pulse input from the rotary encoders 20 and 22, thereby dividing each rotation pulse signal. Convert to each divided pulse signal. On the other hand, each clock pulse counter 40,
Reference numeral 42 is connected to each of the frequency dividing circuits 30 and 32 and the clock pulse generating circuit 50, and the clock input from the clock pulse generating circuit 50 from the rotation start timing of the gear pair 10 and 12 to the rising timing of each divided pulse. The number N _CK of pulses (see FIG. 3) is counted, and the result is input to the computer 60. In addition, each divided pulse counter 44,
Reference numeral 46 designates a pair of gears 10, 12 from the respective frequency dividing circuits 30, 32.
The number N _DV of the divided pulses (not shown) input from the rotation start timing of 1 to the rising timing of each divided pulse is counted, and the result is input to the computer 60.

In synchronization with the start of rotation of the gear pairs 10 and 12, a trigger signal generating circuit (not shown) inputs a trigger signal to the two clock pulse counters 40 and 42 and the two divided pulse counters 44 and 46. To be done. Each of the clock pulse counters 40 and 42 receives the first clock pulse number _NCK from the clock pulse generation circuit 50 from the input timing of the trigger signal to the rising timing t _{(1) of the} first divided pulse. It is designed to count as the number of clock pulses. Further, the divided pulse counters 44 and 46 respectively divide the first divided pulse number N _DV into the frequency dividing circuits 3 from the input timing of the trigger signal to the rising timing t _{(1) of the} first divided pulse.
It is designed to count as the number of divided pulses input from 0 and 32. Therefore, the gear pair 10,
Two rotary encoders 2 at the rotation start timing of 12
It is not essential to make an initial adjustment of this gear rotation error detection device so that the first rotation pulse rises simultaneously from 0 and 22.

As shown in FIG. 4, the computer 60 mainly comprises a CPU 70, a ROM 72, a RAM 74, a clock 76, an input interface 78 and an output interface 80. The computer 60 uses the input interface 78 to
The CPU 70 is pre-stored in the ROM 72 based on the clock pulse number N _CK and the divided pulse number N _DV which are connected to the clock pulse counters 40 and 42 and the two divided pulse counters 44 and 46 and are input from there at every moment. Gear pair 1 by executing the program
The rotation error ε of 0 and 12 is calculated and stored in the RAM 74.

The programs stored in advance in the ROM 72 include an absolute rotation angle calculation routine shown in the flow chart of FIG. 5 and a gear rotation error calculation routine shown in the flow chart of FIG. The contents of these routines will be individually described below.

First, the absolute rotation angle calculation routine of FIG. 5 will be described. First, a schematic description will be given. In this routine, first, each clock pulse counter 40, 42
Each time the number of clock pulses N _{CK (k)} (k: divided pulse number) is input from, the latest divided pulse output from each of the frequency dividing circuits 30 and 32 (hereinafter referred to as “current divided pulse”).
The rising time t _(k) (refer to FIG. 7) is detected. Specifically, the rising timing t _(k) of the current divided pulse is calculated as the product of the clock pulse number N _{CK (k)} and the clock pulse period T _CK (fixed value). Next, in this routine, each gear 1 is rotated from the rotation start timing of each gear 10, 12 (that is, the input timing of the trigger signal) to the rising timing t _{(k) of} this split pulse.
The absolute rotation angle θ _(k), which is the angle at which 0 and 12 are rotated, is calculated. Specifically, each divided pulse counter 44, 46
It is calculated as the product of the number of divided pulses N _{DV (k)} input from the above and the fixed minute angle Δφ of the rotary encoders 40 and 42.

That is, in this embodiment, the portion of the divided pulse signal that represents the rising edge of each divided pulse is
This is one mode of the "rotation signal" in the inventions of claims 1 and 2.

In addition, in addition to the above, in the present embodiment, regarding the rising timing t of each divided pulse and the absolute rotation angle θ at the rising timing t of each divided pulse, the rotation start timing of the gear pair 10 and 12 is determined. Is calculated on the basis of the number of clock pulses or divided pulses from
In the case where the number of clock pulses or the like generated between the pulse and the rising time t of the divided pulse of the next time is sequentially acquired for each time, and the rising time t of the divided pulse of each time is calculated as the total value thereof. By comparison, the accumulation of rounding errors due to the digital amount is avoided, and the unique effect of improving the accuracy of acquisition of the rising timing t of each divided pulse is obtained. However, it is possible to implement the present invention in the latter mode.

Next, this routine will be specifically described with reference to FIG. This routine is executed for each gear 10, 12. For each gear 10, 12, first, step S
1 (hereinafter referred to as “S1”; the same applies to other steps), the value of the divided pulse number k (note that the drive gear 10 is represented by “i” and the driven gear 12 is represented by “j”) is It is initialized to 1, and subsequently, in S2, a state of waiting for an input request signal from each of the clock pulse counters 40 and 42 is entered. If it is output, the determination is YES, and in S3, the current clock pulse number N _{CK (k)} is input from the clock pulse counters 40 and 42 that have been requested to input.

Subsequently, in S4, the product of the input clock pulse number N _{CK (k)} and the clock pulse period T _CK is calculated as the rising timing t _(k) of the divided pulse this time, and stored in the RAM 74. It is stored (see FIG. 8). Then, in S5, the divided pulse counters 44 and 46 are
The number of divided pulses N _{DV (k) of} this time is input from
In S6, the current absolute rotation angle θ _{(k) of} each gear 10, 12 is calculated based on the current divided pulse number N _{DV (k)} . The calculated absolute rotation angle θ _(k) of this time is associated with the rising timing t _(k) of the divided pulse of this time, and RA
It is stored in M74 (see FIG. 8). Then, in S7, the value of the divided pulse number k is incremented by one. After that, in S8, it is determined from the current value of the divided pulse number k whether or not the execution of this routine can be ended. If the execution should be continued, the determination becomes NO and the process returns to S2. If it is okay to end, the determination is YE
When S is reached, the execution of this routine ends.

Therefore, when the execution of this routine is completed, the drive gear 10 and the driven gear 12 are
The data shown in FIG. 8 will be stored in the RAM 74, and eventually the absolute rotation angle θ will be discretely detected in association with the time t for each of the gears 10 and 12. Here, the "time t" means the time on the time axis common to the gears 10 and 12, whereas the "timing t _{1 (i)} " in the figure is the absolute rotation of the drive gear 10. Angle θ _{1 (i)}
And the "timing t _{2 (j)} " means the detection timing of each absolute rotation angle θ _{2 (j)} of the driven gear 12. Further, the relationship between the time t and the absolute rotation angle θ is graphically represented for each gear 10 and 12 as shown in FIG.

Next, the gear rotation error calculation routine of FIG. 6 will be described. First, a schematic description will be given. In this routine, the gear pair 10, ₁ is based on the mutual relationship between the absolute rotation angles θ ₁ and θ ₂ acquired at substantially the same time (hereinafter, simply referred to as “the same time”) t for each gear 10, 12.
The rotation error ε of 2 at the time t is calculated.

When the gears 10 and 12 have the same diameter, that is, when the reduction ratio I is 1, the difference between the absolute rotation angles θ ₁ and θ ₂ acquired at the same time immediately causes a rotation error. ε, that is, the lead / lag amount of the rotation angle of the gear pair 10 and 12. However, when the reduction ratio I is not 1,
The situation is different. Because the pitch circle radii are different between the two gears 10 and 12, even if the actual rotation error ε is 0, the difference between the absolute rotation angles θ ₁ and θ ₂ acquired at the same time is 0. It will not happen.

Therefore, in this embodiment, the rotation error ε is calculated as follows. That is, first, by multiplying the reduction ratio I in absolute rotational angle theta ₁ of the drive wheel 10, the absolute rotation angle theta ₁ is driven gear when the drive gear 10 is assumed to have been replaced in the same diameter as the driven gear 12 10
Is converted to the expected value. Then, the rotation error ε is calculated by subtracting the converted value (that is, I · θ ₁ ) of the absolute rotation angle θ ₁ of the drive gear 10 from the absolute rotation angle θ ₂ of the driven gear 12, and in the end, the rotation error ε is calculated. ε will be calculated using the formula θ ₂ −I · θ ₁ .

That is, in the present embodiment, the relationship represented by this equation is one mode of the "relationship between the detection results of the respective gears" in the invention of claim 1, and the invention of claim 2 Is a mode of "relationship between two absolute rotation angles".

However, the absolute rotation angles θ ₁ and θ ₂ obtained at the same time for each gear 10 and 12 do not always exist. Therefore, in this routine, the rotation error ε is determined as follows.

That is, for each of the plurality of absolute rotation angles θ ₁ detected for the drive gear 10, the absolute rotation angle θ ₂ detected for the driven gear 12 at the same time as the time t _{1 (i)} at which it was detected. Is determined, and if so, as described above, the time t _{1 (i)} is calculated based on the mutual relationship between the _two absolute rotation angles θ _{1 (i)} and θ ₂ existing. The rotation error ε _{(i) at} is determined. On the other hand, when the driven gear 1 does not exist, the driven gear _{1 at} the time t _{1 (i)} is based on the plurality of absolute rotation angles θ ₂ detected for the driven gear 12.
The absolute rotation angle θ ₂ ′ that ₂ is expected to take is estimated, and the rotation error ε is calculated based on the mutual relationship between the estimated absolute rotation angle θ ₂ ′ and the absolute rotation angle θ _{1 (i) of the} drive gear 10. _(i)
Is determined.

It should be noted that in FIG. 8, each data is the time t common to the gears 10 and 12 from the upper side to the lower side of the figure.
When the time t _{1 (i)} and the time t _{2 (j)} coincide with each other, those time t _{1 (i)}
And the time t _{2 (j)} are written on the same horizontal line, and when they do not match, they are written on different horizontal lines, respectively.

Here, the "estimation of the absolute rotation angle θ ₂ " is specifically performed in the following manner in the present embodiment.
That is, first, in the portion corresponding to the driven gear 12 in the storage area of the RAM 74, immediately in front of the position that should correspond to the time t _{1 (i)} in the absence of the above ₍ time t _1).
The time t _2F located at the time t _(i) is searched, the absolute rotation angle θ _2F corresponding to the time t _2F is read, and the position immediately behind the position corresponding to the time t _(i) (the time t is the direction of travel) The time t _2R located in the opposite direction) is searched, and the corresponding absolute rotation angle θ _2R is read. Moreover, by their timing t _2F and timing t _2R is internally divides the absolute rotation angle theta _2F and theta _2R at the same ratio as that is internally divided by the time t _{1 (i),} at that time t _{1 (i)} The absolute rotation angle θ ₂ ′ expected to be taken by the driven gear 12 is estimated. The estimated absolute rotation angle θ ₂ ′ is also stored in the RAM 74.

This estimation will be described more concretely based on the example of FIG. In the example of the same figure, the absolute rotation angle θ ₂ of the driven gear 12 corresponding to the time t _{1 (2)} does not exist. Therefore, first, the search time t _{2 (3)} as the time t _2F, the absolute rotation angle theta _{2 (3)} is read as an absolute rotational angle theta _2F, further search period t _{2 (2)} is a timing t _2R Then, the absolute rotation angle θ _{2 (2)} is read as the absolute rotation angle θ _2R . further,
To internally divide the absolute rotation angles θ _{2 (2)} and θ _{2 (3)} at the same ratio as those of the times t _{2 (2)} and t _{2 (3)} internally divided by the times t _{1 (2)} . As a result, at the time t _{1 (2)} , the driven gear 1
The absolute rotation angle θ _{2 (2)} ′ that ₂ is expected to take is estimated.

[0044] In this routine, by substituting the equation an absolute rotation angle theta ₂ 'estimated in the above manner each time obtained by t _{1 (i),} the timing t _{1 (i)}
The rotation error ε _{(i) at} is calculated.

In the present embodiment, the absolute rotation angle θ that was not actually detected was estimated by performing linear interpolation on the actually detected absolute rotation angle θ. For example, the estimation may be performed by a method such as quadratic interpolation.

Further, in this routine, since the plurality of rotation errors ε _(i) thus obtained are considered to be a combination of the static error and the dynamic error, those rotation errors ε _{(i) are considered.} The static error is extracted by performing the low-pass filtering process on the, and the dynamic error is also extracted by performing the high-pass filtering process. Here, the "static error" represents the absolute value of the average elastic strain of the gears 10 and 12 (that is, the amount of elastic deformation of the gears 10 and 12 due to the load), while the "dynamic error" is Each gear 1
It is considered to represent a meshing transmission error of 0,12.

Next, this routine will be specifically described with reference to FIG. This routine is started after the execution of the absolute rotation angle calculation routine.

First, in step S101, the divided pulse number i of the drive gear 10 is initialized to 1, and subsequently, in step S10.
2, the RAM 74 is associated with the current time t _{1 (i).}
The absolute rotation angle θ _{1 (i) of the} drive gear 10 stored in the table is read. Then, at S103, the time t
_The absolute rotation angle θ ₂ detected for the driven gear 12 at _{1 (i)}
Is stored in the RAM 74. If it is stored, the determination is YES and S104.
In step S105, the corresponding absolute rotation angle θ ₂ is read from the RAM 74, and then, in S105, the absolute rotation angle θ _{2 and the} absolute rotation angle θ _{1 (i)} are substituted into the above equation to obtain the timing t.
The rotation error ε _{(i) at 1 (i)} is calculated. The calculated rotation error ε _(i) is stored in the RAM 74 in association with the time t _{1 (i)} . After that, in S106, the value of the divided pulse number i is incremented by 1, and in S107, it is determined whether or not the calculation of all of the plurality of rotation errors ε to be obtained is completed from the current value of the divided pulse number i. It Assuming that it has not finished yet, the determination is NO.
Then, the process returns to S102.

On the other hand, at the time t _{1 (i)} , the driven gear 12
If the absolute rotation angle θ ₂ detected for is not stored in the RAM 74, the determination in S103 is NO,
The process proceeds to S108 and subsequent steps. In S108, the absolute rotation angles θ _2F and θ _{2R of the} driven gear 12 stored in the RAM 74 are read in association with the times t _2F and t _2R near the time t _{1 (i)} . After that, S10
9 and those times t _2F and t _2R and their existing 2
Based on the absolute rotation angles θ _2F and θ _2R , the absolute rotation angle θ ₂ that does not exist, that is, the timing t _{1 (i)}
Then, the absolute rotation angle θ ₂ ′ that the driven gear 12 is expected to take is estimated. Subsequently, in S110, the estimated absolute rotation angle θ ₂ ′ is set to the absolute rotation angle θ ₂ for convenience, and thereafter, the process proceeds to the steps following S105.

As a result of performing the above-mentioned processing many times, if the calculation of all the plurality of rotation errors ε to be obtained is completed,
The determination in S107 is YES, and in S111, R
The high-pass filter process and the low-pass filter process are respectively performed on the plurality of rotation errors ε stored in the AM74, and thereby the meshing transmission error and the rigidity (elastic deformation amount) of the gear pairs 10 and 12 are calculated, It is stored in the RAM 74. This is the end of the execution of this routine.

When the execution of this routine is completed, the relationship between the rotation error ε and the time t is obtained as shown in the graph of FIG. 3, and the relationship between the meshing transmission error and the time t is obtained. Will be acquired as shown in the graph of FIG.

[0052] As apparent from the above description, in this embodiment, independently of one another absolute rotation angle theta ₁ and the absolute rotation angle theta ₂ of the driven gear 12 via a common time axis to those of the drive gear 10 Therefore, the rotation error ε can be detected between the drive gear 10 and the driven gear 12 without directly comparing the pulses. Therefore, it is possible to obtain an effect that it is possible to avoid a situation in which the detection accuracy of the rotation error ε is deteriorated due to the situation regarding the pulse.

Further, in this embodiment, the driven gear 1
Absolute rotational angle theta ₂ of 2 Despite being discretely detected with respect to time t, calculated on, as required absolute rotational angle theta ₂ of the driven gear 12, substantially continuously obtained for time t Therefore, it is possible to compare the absolute rotation angles θ to be truly compared between the gears 10 and 12, and it is possible to detect the rotation error ε with sufficiently high accuracy. To be

Furthermore, in the present embodiment, the rotational error ε of each gear 10, 12 can be individually extracted as a fluctuation component and an absolute component. Therefore, if the extraction result is used, It is possible to individually evaluate the meshing transmission error and the rigidity (elastic strain) of the pair 10 and 12, and obtain a unique effect that the characteristics of the gear pair 10 and 12 can be evaluated over a wider range. To be

As is clear from the above description, in the present embodiment, the frequency dividing circuits 30, 32, the clock pulse counters 40, 42, the divided pulse counters 44, 46, the clock pulse generating circuit 50 and the computer 60 cooperate with each other. Thus, one aspect of the "gear rotation error determining means 2" in each of the first and second aspects of the invention is configured.

Although one embodiment common to the inventions of claims 1 and 2 has been described in detail with reference to the drawings, each invention can be implemented in other modes.

For example, in the above embodiment, it is determined whether or not the absolute rotation angle θ ₂ of the driven gear 12 was actually detected at the same time as each absolute rotation angle θ ₁ of the drive gear 10 actually detected. If it is determined and not detected, the absolute rotation angle θ ₂ of the driven gear 12 is estimated. However, for example, each absolute rotation angle θ actually detected for the driven gear 12 is further estimated. _It is also determined whether or not the absolute rotation angle θ ₁ of the drive gear 10 was actually detected at the same time as _2, and if not detected, the absolute rotation angle θ ₁ of the driven gear 10 is also estimated. Can be made to be exposed. That is, the inventions of claims 1 and 2 can be implemented so that the absolute rotation angle θ is estimated not only for the driven gear 12 but also for the drive gear 10.

In the above embodiment, the gear pair 1
The rotation error was detected by meshing and rotating 0 and 12 in the load state, but the present invention is a mode in which the meshing rotation is performed in the quasi-static state (no load and low speed state) to detect the rotation error. Can also be carried out.

In addition to these, each of the inventions can be carried out in a mode in which various modifications and improvements are made based on the knowledge of those skilled in the art without departing from the scope of the claims.

[Brief description of drawings]

FIG. 1 is a diagram conceptually showing the structure of each invention of claims 1 and 2. FIG.

FIG. 2 is a system diagram showing a gear rotation error detection device of one tooth side meshing type which is an embodiment common to the inventions of claims 1 and 2.

FIG. 3 is a diagram for explaining divided pulses output from the frequency dividing circuit in FIG.

4 is a diagram conceptually showing the structure of the computer in FIG.

5 is a flowchart showing an absolute rotation angle calculation routine stored in a ROM of the computer shown in FIG.

FIG. 6 is a flowchart showing a gear rotation error calculation routine stored in the ROM.

FIG. 7 is a diagram conceptually showing a partial structure of the RAM in FIG.

FIG. 8 is a graph conceptually showing the flow of signal processing in the above-mentioned embodiment.

FIG. 9 is a diagram for explaining how pulse signals are compared with each other in a conventional meshing gear rotation error detection device.

[Explanation of symbols]

 10 driving gear 12 driven gear 20,22 rotary encoder 30,32 frequency dividing circuit 40,42 clock pulse counter 50 clock pulse generating circuit 60 computer

Claims (2)

[Claims] 1. A gear rotation signal generating means for generating a rotation signal for each gear when each of the two meshing gears rotates by a certain angle, and a generation timing for each rotation signal generated for each gear. By detecting the absolute rotation angle, which is the rotation angle of each gear from the reference rotation position, by detecting it, the gear rotation that determines the rotation error of those gears based on the mutual relationship between the detection results of each gear An engagement type gear rotation error detection device comprising: an error determination means. 2. The gear rotation error determining means has two absolute rotation angles detected at substantially the same time for the gears among the plurality of absolute rotation angles detected for the two gears. The rotation error is determined based on the mutual relationship between the detected two absolute rotation angles, and when it does not exist, at least one of the gears is expected to take the absolute rotation at that time. The meshing type gear rotation error detection according to claim 1, wherein the rotation angle is estimated based on a plurality of absolute rotation angles detected for the gear, and the estimated absolute rotation angle is used to determine the rotation error. apparatus.