JPH06308139A - Speed detection device for rotating body - Google Patents

Abstract

PURPOSE:To accurately detect the speed of a rotating body by obtaining average dependency value of pulse signal cycle and deviation dependency values of each pulse signal cycle and the average dependency value, adjusting the effect on correction factor of deviation dependency values for one pulse signal and adding/updating previous correction factor with adjustment value. CONSTITUTION:A signal rotor 12 that rotates together with a wheel and an electromagnetic pickup 13 near its periphery are provided, and each time one tooth of the rotor 12 passes by, sign wave signal is outputted to an electronic control unit 14. When updating the correction factor used when rotation rate is detected from the signal, firstly, the average value of pulse signal cycle while the wheel rotates once is obtained, and then the deviation of signal cycle corrected with the previous correction factor from it is obtained. Then, rate DELTAth of the deviation to the average value of signal cycle is obtained, and then it is multiplied by correction sensitivity factor k that adjusts conversion speed of correction factor. With this, the effect of random fluctuation of wheel speed an correction factor caused by road surface vibration is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting the speed of a rotating body.

[0002]

2. Description of the Related Art Conventionally, in order to obtain the speed of a rotating body,
The rotation distance of the rotating body is calculated based on the standard value of the rotation detection unit provided in the rotating body speed sensor and the number of times the pulse signal is input, and is calculated based on this rotation distance and the pulse signal period. However, due to non-standard factors such as deformation of the rotation detection unit due to processing defects and corrosion that occur during processing of the rotation detection unit of the rotor speed sensor, and non-standard factors such as rotation speed fluctuations caused by deformation of the rotor, the pulse signal cycle is deviated. May occur. In order to solve the above-mentioned problems, for example, in Japanese Patent Laid-Open No. 172966/1988, in a wheel speed detecting device, the latest pulse signal cycle by the teeth of a sensor rotor rotating together with the wheel at the time of non-braking and its previous / previous time. The pulse signal period is corrected by comparing the pulse signal period with the pulse signal period and the correction coefficient corresponding to each tooth of the sensor rotor. During braking, the pulse cycle is corrected by the correction coefficient corresponding to each tooth obtained immediately before the start of braking.

[0003]

However, in the above-mentioned conventional apparatus, when a pulse signal that randomly fluctuates, such as vibration, is input, the correction coefficient changes randomly. There is a problem that the detection error cannot be corrected using the correction coefficient.

In view of the above problems, the present invention provides pulses due to nonstandard elements such as defective machining of the rotation detecting portion of the rotating body and deformation of the rotating body even when a randomly varying pulse signal such as vibration is input. An object of the present invention is to provide a speed detecting device for a rotating body capable of correcting a signal cycle detection error.

[0005]

In order to achieve the above object, a speed detecting device for a rotating body according to a first aspect of the present invention is arranged such that the measured object in a pulse signal continuously generated according to the rotation of the measured rotating object. In a speed detecting device for a rotating body that corrects a detection error due to a non-standard element of the rotating body using a correction coefficient, and calculates the speed of the measured rotating body based on the corrected pulse signal, update means for updating the correction coefficient is provided. The correction coefficient updating means includes an average dependence value calculation means for calculating a value depending on an average of the cycle of the pulse signal, and a value dependent on a deviation between each pulse signal cycle and the average dependence value. Deviation dependent value calculating means, adjusting means for adjusting the degree of influence of the deviation dependent value on the correction coefficient for one pulse signal input, the value adjusted by the adjusting means, and the value calculated last time A correction coefficient calculating means for calculating a current correction coefficient by adding the positive coefficient, characterized in that it comprises a.

According to a second aspect of the invention, there is provided a speed detecting device for a rotating body,
The invention according to claim 1 is characterized in that the adjusting means performs the adjustment by multiplying the deviation dependent value by a predetermined sensitivity coefficient. According to a third aspect of the invention, there is provided a speed detecting device for a rotating body according to the second aspect of the invention, further comprising switching means for switching the sensitivity coefficient.

According to a fourth aspect of the present invention, there is provided a speed detecting device for a rotating body,
The invention according to claim 1 is characterized by further comprising determination means for determining permission to update the correction means. According to a fifth aspect of the invention, there is provided a speed detecting device for a rotating body according to the first aspect of the invention, wherein the acceleration / deceleration state detecting means for detecting an acceleration / deceleration state of the rotating body, and the correction coefficient according to the acceleration / deceleration state of the rotating body. And a correction unit that corrects.

A speed detecting device for a rotating body according to claim 6 is
The invention according to claim 1, further comprising: a determination unit that determines whether or not a pulse signal is generated in each predetermined cycle; and a correction unit that corrects the correction coefficient according to a determination result of the determination unit. To do. According to a seventh aspect of the present invention, there is provided the speed detecting device for a rotating body according to the first aspect of the present invention, further comprising acceleration calculating means for calculating an acceleration of the measured rotating body based on a speed of the measured rotating body. .

[0009]

[Function] The value depending on the deviation between the pulse signal cycle and the average dependence value indicates the error of the pulse signal cycle due to the nonstandard element of the rotating body to be measured, and the correction coefficient is updated in the direction of eliminating the deviation dependence value. By correcting the pulse signal cycle in this way, it is possible to correct the pulse signal cycle detection error due to the nonstandard element. However, each pulse signal may include a random signal affected by vibration or the like.
When the error due to this randomly varying signal such as vibration is continuous, the deviation dependent value fluctuates greatly and continuously, so the correction coefficient is updated to simply eliminate the deviation dependent value as described above. Then, the correction coefficient is frequently and largely updated, and the error of the pulse signal period due to the nonstandard element, which should be constant originally, fluctuates.

Therefore, according to the present invention, the influence of vibration or the like is eliminated by adjusting the degree of influence of the deviation dependent value on the correction coefficient for one pulse signal input, and the adjusted value and the previously calculated correction coefficient are used. Is added to calculate the correction coefficient this time, the update amount for updating the correction coefficient at one time is suppressed, and a large fluctuation of the correction coefficient is prevented. As a result, the correction coefficient is not affected by vibration or the like and converges to a predetermined value due to the nonstandard element of the rotating body to be measured.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a wheel speed sensor. Embodiment (1) FIG. 1 shows the configuration of a wheel speed detecting device. Here, the wheel speed detection mechanism 11 is provided with a signal rotor 12 that is rotated together with the wheel, and the signal rotor 12 has a large number of teeth (48 teeth in this embodiment) formed of a magnetic material around the signal rotor 12. It is composed of gears having substantially equal intervals. Then, the electromagnetic pickup 13 is fixedly set so as to be close to the outer circumference of the signal rotor 12. The electromagnetic pickup 13 detects a change in the magnetic field accompanying the passage of one tooth of the signal rotor 12 rotating with the wheel, and outputs, for example, one sinusoidal detection signal each time one tooth passes. That is, as the signal rotor 12 rotates together with the wheels, the electromagnetic pickup 13 outputs a sine wave signal that counts the teeth of the signal rotor 12 as each tooth passes through the signal rotor 12. The pickup signal is input to the electronic control unit (ECU) 14. This ECU
14 includes a waveform shaping circuit 141 to which the sine wave pickup signal is input, and a microcomputer 142 to which the output from the waveform shaping circuit 141 is input. The waveform shaping circuit 14 shapes the sine wave pickup signal. The falling edge of the rectangular wave signal from the circuit 141, for example, is input to the ECU 14 as an interrupt signal.

FIG. 2 shows the flow of the vehicle speed pulse interruption processing, which is executed in response to the fall of the rectangular pulse input pulse signal from the waveform shaping circuit 141. FIG. 3 shows the waveform shaping circuit 141 to the microcomputer 142.
The state of the pulse signal input to the pulse signal is shown. The periodic interrupt processing in the microcomputer 142 for this pulse signal is executed at the times indicated by S1, S2. In the process flow shown in FIG. 2, in step 110, the input pulse signal period Δt _n shown in FIG.
(N = 1 to 48) is calculated. However, signal rotor 1
Deformation of the rotation detection part due to defective machining of tooth 2 or corrosion,
The signal cycle Δt _n is deviated due to nonstandard elements such as deformation of the rotating body due to uneven wear of wheels and deformation during traveling. Therefore, in step 120, the calculation error for the signal period Δt _n of the nonstandard element is corrected.

FIG. 4 shows the flow of correction of the signal period Δt _n in step 120 of FIG. In step 121, each pulse is assigned a number corresponding to each rotation detection unit number. The rotation detection unit number is the number of the teeth of the signal rotor 12 that is assigned to the teeth of the signal rotor 12 from 1 to the maximum value of the number of teeth (48 in this embodiment). That is, 1, 2, 3 ... 48, 1, 2 for each pulse
The numbers 1 to 48 corresponding to each rotation detection unit are repeatedly attached as shown in. In step 122, the latest pulse signal interval Δt _n is stored in the block memory capable of storing the pulse signal periods Δt _{1 to} Δt ₄₈ . Step 123
, The correction coefficient ω _{n, m} corresponding to each rotor detection unit
Than

[0014]

## EQU1 ## Δt _n ^′ = Δt _n × ω _{n, m} Here, n: rotation detection unit number m: rotational speed of the rotating body is obtained, and the calculation error of Δt _n due to the nonstandard element is corrected.

In step 124, the sum Δt _s of the corrected pulse signal period from the pulse signal period immediately after the last scheduled interrupt process to the latest pulse signal period is calculated.

[0016]

[Equation 2]

Here, j: the first rotation detecting section number of the latest regular interruption section p: the last rotation detecting section number of the latest regular interruption section However, the rotation detecting section number n is repeated from 1 to 48. Therefore, it is possible that j> p. FIG. 5 shows the flow of the timed interrupt processing, and this processing is executed for each timed interrupt signal of the microcomputer 142 generated at a predetermined time interval. First, at step 210, permission to update the correction coefficient ω _{n, m} is determined. Here, the update permission condition of the correction coefficient ω _{n, m} is a case where the latest 48 continuous pulse signals are input without interruption in the timed interrupt section (FIG. 6: update permission, FIG. 7: update non-permission). In step 220, the correction coefficient is updated for each rotation detection unit with respect to the pulse input in the latest scheduled interrupt section. In step 230, the wheel speed is calculated. In step 240, wheel acceleration is calculated.

The update of the correction coefficient ω _{n, m} in step 220 is calculated by the following equation.

[0019]

[Number 3] _{ω n, m = ω n,} m-1 + k · Δt h

[0020]

[Equation 4]

[0021]

[Equation 5]

Here, m: rotational speed of the rotating body k: correction sensitivity coefficient In the above equation, the correction coefficient ω _{n, m} corresponding to each rotation detecting section is updated every time each rotation detecting section passes the rotation detected section. However, it means obtaining a correction coefficient convergence value capable of correcting an error due to a nonstandard element corresponding to each rotation detection unit at an arbitrary speed. Here, the initial value of the correction coefficient ω _{n, m} is 1. The convergence value represents the ratio of the pulse signal period when the rotating body includes the nonstandard element to the pulse signal period when the rotating body does not include the nonstandard element. Since the time required for the rotating body to make one rotation is very small, it is assumed that the rotating speed during one rotation of the rotating body is constant. In that case, the 48 pulse signal period for one rotation of the rotating body should be constant in the original case. However, in reality, variations occur in the pulse signal period due to non-standard factors such as a processing error of the rotation detection unit, uneven wear of the tire, and deformation during traveling (see FIG. 8A).
Therefore, the deviation H between the average value of the 48 pulse signal period and the pulse signal period of each rotation detection unit is corrected so as to approach 0 (see FIG. 8B).

FIG. 9 shows a flow of a method of calculating the correction coefficient ω _{n, m in} the equation 3. In step 221, the average value S of 48 pulse signal periods during one rotation of the rotating body is performed.
Is calculated (see Formula 5). In step 222,
The deviation between the average value of the pulse signal period and the pulse signal period of each rotation detection unit corrected by the previous correction coefficient is calculated (see the numerator of Formula 4). The proportion Delta] t _h to the average value of the pulse signal cycle of the deviation in order to eliminate the velocity dependence of the deviation _{(= S-ω n, m} -1 · Δt n) / S) is calculated (see Equation 4) . This Delta] t _h is considered to indicate a deviation of the pulse signal period of the rotation detecting unit according to a non-standard elements. However, when the vehicle actually travels on the road surface, the wheel speed fluctuates randomly due to the vibration of the road surface.
t _h also not be a value indicating the characteristics of the rotating body in the rotation detecting unit varies randomly from pulse to pulse signal input. Therefore, in step 224, applying a correction sensitivity coefficient k for adjusting the convergence rate of the correction coefficient omega _{n, m} to Δt _h (k · Δ
by t _h) that, Δt _h for a single pulse input
The degree of influence on the correction coefficient ω _{n, m} is adjusted (see Formula 3). For example, if the value of the correction sensitivity coefficient k is decreased _, the convergence speed of the correction coefficient ω _{n, m} becomes slower, but the fluctuation amount of the correction coefficient ω _{n, m} due to random speed fluctuations such as road vibration can be reduced. . By this means, the random fluctuation of the wheel speed due to the road surface vibration, which cannot be avoided when the wheel speed is measured by the wheel speed sensor, is corrected by the correction coefficient ω.
It is possible to eliminate the influence on _{n and m} .

In step 224, step 22
Value k · Δt calculated in 3_hCorrection of each rotation detector
Coefficient previous value ω_{n, m-1}To (ω_{n, m}= Ω_{n, m-1}+ K
・ Δt_h), The correction coefficient ω_{n, m}Complete the update
It 10A and 10B show correction sensitivity coefficient k, respectively.
Correction coefficient ω for large and small cases_{n, m}of
It shows the change over time. If the correction sensitivity coefficient k is large,
Coefficient ω_{n, m}Has a fast convergence speed, but is not affected by road surface vibration.
The fluctuation is large. If the correction sensitivity coefficient k is small,
Positive coefficient ω_{n, m}Is slow to converge, but is affected by road surface vibration.
It is difficult and the fluctuation is small. When the present inventor conducted an experiment, k
= 0.008 and the wheels are rotated at a nearly constant speed
When the tire rotates about 500 times (100km / h running)
Driving time: about 35 seconds, 50 km / h running: about 70 seconds), supplement
Positive coefficient ω _{n, m}Has converged to an almost constant value.

FIG. 11 shows the flow of wheel speed calculation in step 230. In step 231, the wheel speed V _x
Is calculated. This wheel speed V _x is the sum Δt _s of the correction pulse signal periods in the latest timed interruption section shown in Formula 2, the number N _p of input pulse signals between Δt _s shown in FIG. 3, and the number of teeth of the signal rotor 12. Based on (48) and the speed constant a determined by the wheel radius, it is calculated by the following equation 6.

[0026]

V x = a · (N _p / Δt _s ) FIG. 12 shows the flow of wheel acceleration calculation in step 240. In step 241, the wheel speed DVx (D indicates the time derivative) is calculated. This wheel acceleration DVx
Is based on the wheel speed Vx0 calculated last time, the wheel speed Vx1 calculated this time, the sum Δt _s0 of the correction pulse signal cycle of the previous scheduled interruption section and the correction pulse signal cycle Δt _{s1 of the} current scheduled interruption section. , Is calculated by the following equation 7.

[0027]

DVx = (Vx1−Vx0) / ((Δt _s0 + Δt _s1 ) / 2) Example (2) In this example, a running state such as road surface roughening or acceleration / deceleration is detected, and according to this running state, It is characterized in that the degree of updating the correction coefficient is adjusted to prevent erroneous correction of the pulse signal cycle due to road surface roughness or acceleration / deceleration.

FIG. 13 shows the flow of the regular interrupt processing according to this embodiment. The vehicle speed pulse interrupt processing is the same as that in the first embodiment, and therefore detailed description will not be given here. Step 310: This is a process of detecting a traveling state in which an error factor occurs when correcting the pulse interval, and here, the acceleration / deceleration state of the vehicle and the roughness of the road surface are detected.

Step 320: When it is determined that the correction is not suitable for the above step, the correction process of step 330 is not performed and the process proceeds to step 340 and thereafter, using the correction coefficient up to the previous time to determine the wheel speed and Calculate the acceleration. Step 330: This is a process of updating the correction coefficient, and the basic arithmetic expression is the same as that of the first embodiment. However, in this embodiment, the correction sensitivity coefficient k of this expression is adjusted by switching the correction sensitivity coefficient k depending on the running state. The wheel speed and acceleration after step 340 can be calculated without being affected by the speed and the roughness of the road surface. Next, the details of each process are explained. Figure 1
4 is a flowchart relating to the processing for detecting the traveling state in step 310, and first, in steps 311 to 314, the acceleration / deceleration state of the vehicle is determined as follows.

In step 311, the wheel acceleration DVx calculated in the regular interrupt processing up to the previous time is filtered to remove a high frequency component, which is a vibration of the road surface or drive system generated during traveling, and which has a relatively low frequency. The velocity component DVw is extracted. This filter is realized, for example, in the form shown in the following equation.

[0031]

## EQU00008 ## DVw (n) = Ka0 * DVx (n) + Ka1 * DVx (n-1) + Ka2 * DVx (n-2) + Kb1 * DVw (n-1) + Kb2 * DVw (n-2) where Ka0 Kb2 is a predetermined constant determined by the frequency to be removed, and the subscripts (n), (n-1), and (n-2) represent the calculation results of the latest, the previous, and the pre-preceding regular interrupt processing.

The wheel acceleration DV thus obtained
In step 312, w (n) is compared with a predetermined value KAINH, and if DVw (n) exceeds this predetermined value KAINH, a flag fINH is set in step 313 to prohibit updating of the correction coefficient. . If not, the flag is reset in step 314 and the process proceeds to step 315.

In step 311, the instantaneous acceleration at the previous timed interrupt is used as the acceleration / deceleration state, but the following acceleration information is extracted from the speed information corresponding to one cycle of the signal rotor 12. It is also possible.

[0034]

[Formula 9] DVw (n) = | Vx (n) −Vx (l) | where Vx (n) is the wheel speed in the previous scheduled interrupt processing, and Vx (l) is one cycle before the signal rotor 12. It is the wheel speed in the regular interruption processing near the corresponding time, and | A | represents that the absolute value of A is taken. As a result, it becomes possible to more accurately determine the influence of the acceleration / deceleration on the average pulse interval of one cycle of the signal rotor 12.

In the next steps 315 to 319, the degree of road surface roughness is determined as follows. First, in step 315, the acceleration D for one cycle is traced back from the previous scheduled interrupt processing.
Vx (l) to DVx (n) are extracted. Step 316
Then, the maximum value DVMA for this extracted acceleration information
X and the minimum value DVMIN are extracted, and the road surface roughness degree evaluation amount DVR is calculated by the following formula.

[0036]

[Equation 10] DVR = | DVMAX−DVMIN | In step 317, this DVR is compared with a predetermined value KRINH, and if DVR exceeds this predetermined value KRINH, update of the correction coefficient is prohibited so that the correction coefficient is updated in step 318. Set the flag fINH. If not, the flag is reset in step 319 and the process returns from step 320.

In step 320, it is determined whether or not the flag fINH determined in step 310 is set, and if it is set, the process proceeds to step 340.
When it is determined in step 320 that the flag is not set, the correction coefficient is updated in step 330. FIG. 15 shows a flowchart of the correction coefficient updating process.

The calculation method of the correction coefficient is the same as that of the first embodiment, so a detailed description will not be given here. However, in this embodiment, the correction sensitivity coefficient k is adjusted according to the running state obtained in step 310. It is characterized by switching depending on the speed and the road surface condition. A concrete switching method is shown in FIG.
A description will be given using 17. FIG. 16 is a reference map for determining the correction sensitivity coefficient element k1 from the acceleration / deceleration state calculated this time, and is stored in advance in the CPU incorporated in the ECU 14. Similarly, FIG. 17 is a reference map for determining the correction sensitivity coefficient element k2 from the road surface roughness calculated this time. The actual corrected sensitivity coefficient k is determined by performing the following weighted averaging on the corrected sensitivity coefficient elements k1 and k2 for each running state retrieved from these maps.

[0039]

K = KH1 × k1 + KH2 × k2 where KH1 and KH2 represent predetermined weighting coefficients. By correcting the update amount of the correction coefficient ω by using the correction sensitivity coefficient k thus obtained, It is possible to always correct the non-standard element of the rotation detection unit of the rotating body speed sensor accurately while preventing erroneous correction on a sudden acceleration / deceleration or a rough road surface.

In this embodiment, the wheel speed and the acceleration are calculated by using the previous correction coefficient ω without adjusting the correction coefficient when the traveling state is a predetermined value or more.
It is also possible to always update the correction coefficient by removing the permission determination in step 320 and reducing the correction sensitivity coefficient even in the above predetermined state or more. On the contrary, when it is determined in step 320 that the traveling state is less than or equal to the predetermined state, the correction coefficient is updated using only the predetermined correction sensitivity coefficient, so that the correction in the unfavorable traveling state is simplified. It is also possible to prohibit updating the coefficient. Also,
While this embodiment adjusts the update sensitivity of the correction coefficient in the running state, step 223 in the first embodiment is performed.
Is a correction amount of this time which is calculated in the case of adjusting the correction sensitivity at the (k · Δt _h), with a predetermined amount that can be updated with a preset one correction, the correction amount of this time is Tokoro When the amount is equal to or more than the fixed amount, the predetermined amount is updated as the correction amount of this time, so that it is possible to suppress the erroneous correction amount due to the road surface state or acceleration / deceleration without determining the running state.

Embodiment (3) In this embodiment, by referring to the change over time of the correction coefficient, it is detected that convergence to a predetermined value corresponding to a non-standard element of the rotation detector of the rotor speed sensor is completed. It is characterized by constantly obtaining accurate wheel speed / acceleration information while preventing erroneous correction due to acceleration / deceleration state after convergence and rough road surface.

FIG. 18 is a flow chart of the regular interruption process in this embodiment. Since the processes not mentioned below can be realized by performing the same processes as those in the first embodiment, a detailed description will be given here. Not performed. Step 410 is a process of detecting the convergence state of the correction coefficient,
When the convergence of the correction coefficient is detected in the following step 420, the correction coefficient update processing of step 430 is not performed and the convergence value of the correction coefficient is used to execute steps 440 and 450.
The calculation processing of the wheel speed and the acceleration is performed.

Next, a specific method of realizing the processing of step 410 will be described. FIG. 19 is a flowchart of the process for detecting the convergence of the correction coefficient. First, step 411.
At, the time change amount DW representing the difference between the previous correction coefficient and the current correction coefficient is calculated. In the next step 412, it is determined whether or not the amount of change DW of the correction coefficient with time is less than or equal to a predetermined amount KDW. If DW is KDW or more,
When it is determined that the correction coefficient is fluctuating, the routine proceeds to step 414, where the counter CDW indicating the number of times the convergence state is continued is cleared and the routine proceeds to step 420.

If it is determined in step 412 that DW is smaller than KDW, the flow advances to step 413 to increment the counter CDW. In the next step 415, the counter CDW is compared with a predetermined value KCDW to determine whether or not this convergence state has continued for a predetermined period.
If the predetermined time has not yet been reached, the process proceeds to step 420. When it is determined in step 415 that the convergence state has continued for the predetermined time, the flag fDWOK indicating the completion of convergence is set in step 416. This flag fDWOK
Is set, the determination in step 420 is yes.
Then, in steps 440 and 450, the wheel speed and acceleration are calculated.

Normally, when the vehicle is running on a rough road surface that causes an error in the correction coefficient or is in an acceleration / deceleration state, the correction coefficient calculated for each timed interrupt process fluctuates randomly from time to time. If the time change of the coefficient maintains a constant value for a predetermined time, it can be determined that it is a variation value due to a nonstandard element of the sensor. Therefore, according to the present embodiment, fast responsiveness can be maintained without worrying about erroneous correction due to the above-mentioned disturbance element.

In the present embodiment, the determination of the convergence state of the correction coefficient is monitored by monitoring the fluctuation of the predetermined time by incrementing the counter CDW every predetermined time and comparing it with the predetermined amount. By incrementing the increment of CDW according to the number of pulses, it is possible to monitor a predetermined rotation speed, that is, a variation during the completion of correction of a predetermined number of times.

Further, although the convergence state of the correction coefficient ω is detected in the present embodiment, attention is paid to the fact that the influence of the road surface condition and the acceleration / deceleration occur at random, so that a predetermined filtering process is applied to the detection unit. It is also possible to estimate only the variation of. Specifically, step 22 of the first embodiment
The process of storing a predetermined number of update results of the correction coefficient ω of 0 for each scheduled interrupt and the process of filtering the correction coefficient ω from the stored value by the following arithmetic expression are performed in step 2
It can be realized by adding immediately after 20.

[0048]

## EQU12 ## ωw (n) = Kc0 × ω (n) + Kc1 × ω (n-1) + Kc2 × ω (n-2) + Kd1 × ωw (n-1) + Kd2 × ωw (n-2) where Ka0 Kb2 is a predetermined constant determined by the frequency to be removed, and the subscripts (n), (n-1), and (n-2) represent the calculation results of the latest, the previous, and the pre-preceding regular interrupt processing.

The filtering process may use a simple moving average of the correction coefficient ω. By these processes, it becomes possible to always accurately calculate the wheel speed and the acceleration even when the road surface condition or the acceleration / deceleration condition affects the correction process of the pulse cycle.

Embodiment (4) In this embodiment, since the output signal of the sensor decreases to an undetectable level such as when the rotation speed of the sensor decreases, the number of each rotation detecting unit assigned up to that time is changed. It is characterized in that the correction coefficient is prevented from being applied to an erroneous detection unit when the information is lost.

FIG. 20 shows a flow chart of the regular interruption processing in this embodiment. Since the processing not mentioned below can be realized by performing the same processing as that of the first embodiment, a detailed explanation will be given here. Not performed. Step 510 is a process for determining whether or not the output of the sensor is in an undetectable state, and the correction sensitivity coefficient in the correction coefficient updating process of step 530 is adjusted based on the state determined here.

FIG. 21 is a flow chart showing the processing contents of step 510. First, in step 511, it is judged whether or not there is a pulse input between the current time and the previous timed interrupt. Proceed to 513. If not, the flag fPIN is cleared in step 512 and the process of step 510 is exited.

At step 513, a flag fPI indicating the presence / absence of pulse input determined at the time of the last scheduled interruption is determined.
If N is referred to and the flag is set, the routine proceeds to step 514, where a counter CPIN indicating that there is continuous pulse input for each scheduled interrupt is incremented. In the next step 515, it is judged whether or not the value of the counter CPIN exceeds the predetermined value KCPIN. If it exceeds, the pulse detection normal state is set in step 516, and the process proceeds to step 519. Step 51
If the counter CPIN does not exceed KCPIN in step 5, the process of step 510 is exited.

If the flag fPIN is cleared in step 513, it means that the sensor rotation has turned from the low speed region to the rise because the previous pulse input does not exist and the current pulse input exists. Can be considered In such a state, there is a high possibility that an undetectable low-output pulse existed between the last pulse of the previous time and the latest pulse of this time, so the calculation of the correction coefficient for the subsequent pulses is redone. The need arises. Therefore, in step 517, the sensor detection disabled state is set, and in the next step 518, the counter CPIN is cleared and the process proceeds to step 519.

At step 519, the flag fPIN indicating that a pulse input is present is set, and then the processing at step 510 is exited. FIG. 22 shows a processing flowchart of step 530. As in the first embodiment, the correction coefficient ω
In the present embodiment, the correction sensitivity coefficient k is switched based on the detection state of the sensor determined in step 510.

Specifically, in step 533, the flag fPIN is set.
The sensor detection state is determined based on the above, and if it is in the detection impossible state, a predetermined correction sensitivity coefficient kFST having a relatively high convergence speed is substituted for k in step 534. Otherwise, in step 535, a predetermined correction sensitivity coefficient kSLW having a convergence speed smaller than kFST is substituted for k. As a result, when the detection capability of the sensor is normal, the correction coefficient is updated for each rotation detection unit as usual, and when the sensor output is reduced, the correction sensitivity coefficient k is maintained until a predetermined time elapses. By increasing the value, the correction coefficient of each detection unit can be quickly updated again.

Embodiment (5) In the above embodiment (4), when the sensor output is lowered and the position information of each conventional detecting portion is lost, the correction sensitivity coefficient is adjusted to reconverge the correction coefficient at high speed. On the other hand, in the present embodiment, after the position information is lost, it is possible to effectively use the correction coefficient up to the previous time by returning the position information to the proper value based on the correction coefficient information newly obtained. Characterize.

FIG. 23 is a flow chart of the regular interruption process in this embodiment. Since the processes not mentioned below can be realized by performing the same processes as those in the first embodiment, detailed description will be omitted here. Not performed. Step 610 is a process for determining whether or not the sensor output is in an undetectable state, and is used for determining whether or not the correction coefficient saving process of step 630 is performed based on the state determined here. It

FIG. 24 is a flow chart showing the processing contents of step 610. First, in step 611, it is judged whether or not there is a pulse input between the current time and the previous timed interrupt. Proceed to 613. If not, the flag fPIN is cleared in step 612 and the process of step 610 is exited.

In step 613, a flag fPI indicating the presence / absence of pulse input determined at the previous scheduled interruption is determined.
Referring to N, if the same flag is set, the process proceeds to step 615. Flag fPIN in step 613
When is cleared, it can be considered that the rotation of the sensor has started to increase from the low speed region as in the case of the embodiment (4). In such a state, there is a high possibility that an undetectable low-output pulse existed between the last pulse of the previous time and the latest pulse of this time, so the calculation of the correction coefficient for the subsequent pulses is redone. There is a need.

Therefore, in step 614, the sensor detection disabled state is set, and the process proceeds to step 615. In step 615, the flag fPIN indicating that the pulse input is present is set, and then the process of step 610 is exited. In the next step 620, it is determined whether or not the state of this sensor is normal based on the flag fPIN, and if it is in the undetectable state, the process proceeds to step 630. In step 630, only when the sensor detection impossible state is determined for the first time, the correction coefficients of the respective detection units immediately before the sensor detection disabled state are stored in the RAM of the ECU 14 in the order in which the detection units are arranged, and then all the current correction coefficients are initialized. And proceeds to step 640.

On the other hand, in step 620, the detection state is normal.
If there are, go to steps 650, 670, 680 and
Update of correction coefficient and wheel speed / acceleration similar to the first embodiment
Calculate. Step 640 is a correction coefficient update process.
Thus, the same processing as in the first embodiment is performed. Step 66
0 indicates step 6 based on the update result of the correction coefficient this time.
Pattern match with the stored value of the correction coefficient stored in 30
Is a process for performing The pattern matching here is
The correction coefficient calculated this time is switched to the state in which the sensor cannot be detected.
Determine which detection unit correction coefficient before
This is the process of disconnecting the sensor, which causes the sensor detection
It is possible to return to the correction coefficient obtained up to the ready state.
Become. In step 660, pattern matching is performed.
The process of determining whether or not is completed is performed. This judgment
The result is Δt in pulse interrupt processing _nFor correction processing
Reflected. Therefore, in this scheduled interrupt processing, the pattern
The same wheel speed as in the first embodiment regardless of the completion of the
Performs calculations and acceleration calculations.

FIG. 25 shows a flowchart of the signal period Δt _n correction process. The basic processing is the same as the wheel speed calculation processing of the first embodiment, but the signal period Δ in step 712 is changed.
After the t _n storage processing, in step 713, according to the result of the completion judgment of the pattern matching in step 660, if the matching is completed, the signal period Δt _{n is set} to the correction coefficient ω.
After the correction using _{n, m} , the process proceeds to step 716, and when it is incomplete, the process proceeds to step 715 to prevent the signal period Δt _n from being corrected in order to prevent the calculation of the wheel speed due to the erroneous correction.

Next, step 660, which is the center of this embodiment.
The concrete method of pattern matching in Figure 2
This will be described using the flowchart shown in FIG. Step 66
In 1 to 667, the new correction coefficient sequence calculated up to this time and the previous correction coefficient stored value processed in step 630 are evaluated using the least square method. Specifically, first, at step 661, the evaluation amount HPLS is cleared. In the following processing, the square error accumulated value is calculated while shifting the detection unit by one data, and the minimum value is set to HPLS (the shift amount when it becomes the minimum is the correction amount of the position of the sensor detection unit. Is likely to correspond to).

At step 662, the variable i indicating the shift amount of the detecting portion is cleared (corresponding to the shift amount 0). In step 663, the following square error calculation processing is performed.

[0066]

[Equation 13]

However, ωn and ω'n represent the new correction coefficient and the previous correction coefficient stored value of the n-th detector, and n is a circulation number from 1 to 48. For example n = 45
Then, n + 10 = 55 → 55−48 = 7.
For reference, FIG. 27 shows a conceptual diagram of this arithmetic expression. For the squared error HdPLS calculated by this, step 664
Is compared with the evaluation amount HPLS. If HdPLS is smaller, the process proceeds to step 665 to update the evaluation amount HPLS and set the current shift amount i to NPLS. Otherwise, proceed to step 666.

In step 666, it is determined whether or not all the shifting operations have been completed, and it is determined whether or not the shifting amount i reaches the number 48 of detecting units. If not reached, the process proceeds to step 667 and the shift amount is incremented by 1, and the processes of steps 663 to 665 are repeated.
When it is determined in step 666 that the verification of the shift amount is completed, the process proceeds to step 668 and the final evaluation amount HPLS
Is less than or equal to a predetermined amount KHPLS that can be regarded as pattern matching completion. KHPLS here
If it is above, it is determined that the pattern matching is incomplete, and the process of step 660 is exited. Step 6
If it is determined in 68 that the evaluation amount is less than or equal to the predetermined value, the process proceeds to step 669 to renumber the detection units. Specifically, based on the shift amount NPLS that sets HPLS to the minimum value set up to 668, the latest pulse number input until the scheduled interrupt processing this time is divided by the shift amount by the same circulation number as Equation 13. Only add processing. As a result, it becomes possible to apply the correction coefficient storage values up to the previous time to the normal detection unit.

Step 66A is a state setting process for determining in step 670 that the pattern matching is completed. In the present embodiment, the squared error is calculated between the correction coefficients of the respective detection units, but there is a case where there is a large undulation during one rotation as a feature of the processing method of the sensor. In such a case, correction is performed. The integrated value of the coefficients may be defined as follows and the squared error between the integrated values may be used.

[0070]

[Equation 14]

Embodiment (6) In this embodiment, when acceleration or deceleration continues for an arbitrary time,
There is no correction coefficient due to erroneous correction of pulse signal cycle
It is characterized by correcting this. For example, during vehicle acceleration
In, the pulse signal period becomes gradually shorter. That
Therefore, the latest pulse signal period is the average of 48 pulse signal periods.
Short compared to the value. In the present invention, each pulse signal
Correction factor ω_n48 pulses by applying
The correction is performed so as to approach the average value of the signal period.
Therefore, if acceleration continues for an arbitrary time, each pulse signal period
Since the state of correction to increase the
Correction coefficient at the output ω_nIs larger than that at constant speed
It Conversely, when decelerating, the correction coefficient ω_nBecomes smaller
(See FIG. 28). Therefore, in this embodiment, all times
Correction coefficient ω_nFrom the average value of
Positive coefficient ω _nBy correcting the
Correction coefficient ω_nCorrect the wrong learning of.

FIG. 29 shows a flowchart for correcting the correction coefficient ω _n according to this embodiment. In step 710, the number 3
Then, the correction coefficient ω _n of each rotation detection unit is calculated. In step 720, the average value of the correction coefficient ω _n of all rotation detectors is calculated (see the following equation).

[0073]

[Equation 15]

.. In step 730, the correction coefficient ω _n of each rotation detection unit is corrected by the following equation.

[0075]

[Number 16] ωh = ω _n - Δω _n

[0076]

[Equation 17]

Here, Δω _n represents the shaded portion in FIG. 28 and means the deviation of the correction coefficient ω _n due to the acceleration / deceleration of the vehicle.
Therefore, it is possible to correct the erroneous learning of the correction coefficient ω _n due to the acceleration / deceleration of the vehicle from the equation 16. Embodiment (7) This embodiment is characterized in that the rotation detecting unit number to be attached to each pulse signal is prevented from being shifted due to damage or foreign matter attached to the rotation detecting unit.

FIG. 30 is a flow chart of the rotation detection unit number correction executed in the rotation detection unit number processing of step 121. In step 810, the rotation detection unit number n is added to each pulse signal. In step 820, when an abnormality occurs in the rotation detecting unit, the rotation detecting unit number is corrected.
FIG. 31 shows specific means for correcting the rotation detection unit number in step 820.

In step 821, the latest pulse signal period Δt _n and the immediately preceding pulse period signal Δt _{n-1 are} calculated from the following equation.
Then, the rotation detection unit abnormality is detected.

[0080]

Α _n = Δt _n / Δt _n-1 For example, when the teeth of the rotation detecting unit number 3 of the signal rotor 12 are missing, the value of Δt3 becomes large as shown in FIG. 32 (a). Therefore, when α _n ≧ 2, it is determined that a tooth loss has occurred, and the process proceeds to step 822. In this case, since the pulse p3 that should be originally input is not input,
The rotation detection unit numbers that should be 5, 6, ...
It gets smaller one by one. Therefore, in step 822, 1 is added to the number (3 in FIG. 32 (a)) of the rotation detecting unit that has detected the missing tooth (3 → 4). Here, since? T3 becomes abnormal pulse signal period, excluding the correction coefficient omega _n a? T3 in step 823, so as not using a wheel speed and wheel acceleration calculating the? T3. Since .DELTA.t3 and .DELTA.t4 are invalid values, the number N of valid pulse signal periods during one rotation of the signal rotor is reduced by two. Therefore, in step 824, N is set to N-2, and the process ends.

Next, when a false pulse is input between p2 and p3 as shown in FIG. 32 (b) due to foreign matter adhering to the rotation detecting portion of the signal rotor 12, .DELTA.t31.
Becomes smaller. Therefore, when α _n ≦ 0.5, it is determined that a false pulse is input, and the process proceeds to step 825. In this case, since the pulse p3 'that is not originally input is input,
The rotation detection unit numbers that should be 3, 4, 5 ...
And one by one. Therefore, in step 826, 1 is subtracted from the number (3 in FIG. 32 (b)) of the rotation detecting unit that detected the false pulse (3 → 2). Where Δt31, Δt32
Is an abnormal pulse signal period, so Δ is calculated in step 826.
The t31 and Δt32 are excluded so that the correction coefficient ω _n , the wheel acceleration, and the Δt32 are not used for the wheel acceleration calculation. Since .DELTA.t3 becomes an invalid value, the number N of effective pulse signals per rotation of the signal rotor is decreased by one. Therefore, in step 827, N is set to N-1, and the process ends.

Finally, in the case of 0.5 <α _n <2, it is determined that there is no abnormality in the rotation detecting unit, and the processing is ended. Embodiment (8) This embodiment is characterized in that the variation of the correction coefficient due to different causes is learned by having a plurality of adaptive filters having different correction coefficient adjusting means.

There are two possible causes for the deviation shown in FIG. 8A in the pulse signal period. The first cause is a processing error in the rotation detecting portion of the sensor rotor, and the second cause is a change in the tire shape due to a change in running conditions such as running speed and road surface condition. FIG. 33 shows changes over time in the correction coefficients ω _na and ω _nb for correcting the deviation of the pulse cycle due to the respective causes.

Since ω _na and ω _nb differ in the degree of influence of the road surface vibration and the vehicle acceleration, which are the factors of variation of the correction coefficient, the variation states of ω _na and ω _nb are different. Therefore, as shown in FIG. 33, the first and second adaptive filters (Equations 3 to 5) having the correction sensitivity coefficients k1 and k2 suitable for the fluctuation state of the respective correction coefficients ω _na and ω _nb are used in series. By this, it becomes possible to remove the variation of each correction coefficient separately.

Embodiment (9) This embodiment is characterized in that each variation of the correction coefficient due to the first or second cause shown in the embodiment (8) is separately removed by one adaptive filter. To do. Figure 3
4 is a flow chart of correction coefficient calculation according to the present embodiment. The correction coefficient is 2 because of the reason shown in the above embodiment (8).
It has various kinds of fluctuation states. Therefore, in step 910, the first variation factor of the correction coefficient is removed from the following equation.

[0086]

[Formula 19]

[0087]

[Equation 20]

Here, k1: first correction sensitivity coefficient At step 920, the second variation factor of the correction coefficient is removed from the following equation.

[0089]

[Equation 21]

[0090]

[Equation 22]

K2: second correction sensitivity coefficient By the above means, each variation of the correction coefficient due to the first or second cause shown in the above embodiment (8) is separated by one adaptive filter. Can be removed. Although the embodiment in the case of being applied to the wheel speed sensor of the vehicle has been described in detail above, not only the anti-skid control device but also the traction control device, the constant speed traveling control device, or the applicant of the present application as the signal of the wheel speed sensor. It can also be effectively used in the "tire pressure detection device" filed in Japanese Patent Application No. 3-294622. The present invention is not limited to the wheel speed sensor, and the present invention can be applied to any speed detecting device for a rotating body installed at a place where vibration or the like is received.

[0092]

As described above, according to the speed detecting device for a rotating body of the present invention, the degree of influence of the deviation dependent value on the correction coefficient for one pulse signal input is adjusted, and the adjusted value is By adding the correction coefficient calculated last time and calculating the correction coefficient this time, the correction coefficient is converged to the predetermined value due to the non-standard element of the rotating body to be measured. Nevertheless, there is an excellent effect that the speed of the rotating body can be accurately detected.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining a speed detecting device for a rotating body according to an embodiment.

FIG. 2 is a flowchart showing a vehicle speed pulse interruption process.

FIG. 3 is a diagram illustrating a detection signal of a rotating body.

FIG. 4 is a signal period Δt _n in step 120 of FIG.
6 is a flowchart showing a correction process of FIG.

FIG. 5 is a flowchart showing a scheduled interrupt process according to the embodiment (1).

FIG. 6 is a diagram showing a case where the latest 48 continuous pulse signals are input without interruption in a scheduled interrupt section (correction coefficient update permission).

FIG. 7 is a diagram in the case where the latest 48 continuous pulse signals are not input without interruption in a regular interrupt section (correction coefficient update is not permitted).

FIG. 8A is a diagram for explaining variations in pulse signal period. (B) is a diagram after correction of variations in pulse signal period.

FIG. 9 is a flowchart illustrating a process of a correction coefficient calculation method according to the first embodiment.

FIG. 10A is a diagram showing a change with time of a correction coefficient when the correction sensitivity coefficient is large. (B) is a diagram showing a change over time of the correction coefficient when the correction sensitivity coefficient is small.

FIG. 11 is a flowchart showing a wheel speed calculation process.

FIG. 12 is a flowchart showing a wheel acceleration calculation process.

FIG. 13 is a flowchart showing scheduled interrupt processing according to the embodiment (2).

FIG. 14 is a flowchart showing a process of detecting a traveling state.

FIG. 15 is a flowchart showing a correction coefficient update process of the embodiment (2).

FIG. 16 is a reference map for determining a correction sensitivity coefficient element k1 from the acceleration / deceleration state calculated this time.

FIG. 17 is a reference map for determining the correction sensitivity coefficient element k2 from the road surface roughness calculated this time.

FIG. 18 is a flowchart showing scheduled interrupt processing according to the embodiment (3).

FIG. 19 is a flowchart showing a process of detecting convergence of a correction coefficient.

FIG. 20 is a flowchart showing scheduled interrupt processing according to the embodiment (4).

FIG. 21 is a flowchart showing a sensor output state detection process of the embodiment (4).

FIG. 22 is a flowchart showing a correction coefficient update process of the embodiment (4).

FIG. 23 is a flowchart showing scheduled interrupt processing according to the embodiment (5).

FIG. 24 is a flowchart showing a sensor output state detection process of the embodiment (5).

FIG. 25 is a flowchart showing a process of pulse signal cycle correction.

FIG. 26 is a flowchart showing a specific method for realizing pattern matching.

FIG. 27 is a conceptual diagram of an arithmetic expression for calculating a squared error.

FIG. 28 is a diagram for explaining a convergence state of a correction coefficient when acceleration continues for an arbitrary time.

FIG. 29 is a flowchart showing a process of a correction coefficient calculating method according to the embodiment (6).

FIG. 30 is a flowchart of rotation detection unit number processing.

31 is a flowchart of rotation detection unit number correction in step 820 of FIG. 30. FIG.

FIG. 32 (a) is a diagram showing pulse input when the tooth of the rotation detection unit number 3 is missing. (B) is pulse p
It is a figure which shows pulse input at the time of inputting a false pulse between 2 and p3.

FIG. 33 is a correction coefficient ω _na for correcting the deviation of the pulse period,
It is a figure which shows the time change of (omega) _nb .

FIG. 34 is a flowchart of correction coefficient calculation of the embodiment (9).

[Explanation of symbols]

 11 Wheel Speed Detection Mechanism 12 Signal Rotor 13 Electromagnetic Pickup 14 ECU 141 Waveform Shaping Circuit 142 Microcomputer

Claims (7)

[Claims] 1. A detection error due to a nonstandard element of the rotating body to be measured in a pulse signal continuously generated in response to the rotation of the rotating body to be measured is corrected by using a correction coefficient, and based on the corrected pulse signal, the detected error is corrected. In a speed detecting device for a rotating body that calculates the speed of a measurement rotating body, an updating unit that updates the correction coefficient is provided, and the correction coefficient updating unit calculates an average dependence that calculates a value that depends on an average of the cycle of the pulse signal. Value calculating means, deviation dependent value calculating means for calculating a value depending on a deviation between each of the pulse signal periods and the average dependent value, and a deviation dependent value for the correction coefficient of the deviation dependent value for one pulse signal input. Adjusting means for adjusting the degree of influence, and correction coefficient calculating means for calculating the current correction coefficient by adding the value adjusted by the adjusting means and the correction coefficient calculated last time, A speed detecting device for a rotating body, comprising: 2. The speed detecting device for a rotating body according to claim 1, wherein the adjusting means performs the adjustment by multiplying the deviation dependent value by a predetermined sensitivity coefficient. 3. The speed detecting device for a rotating body according to claim 2, further comprising switching means for switching the sensitivity coefficient. 4. The speed detecting device for a rotating body according to claim 1, further comprising a determining unit that determines permission of updating the correction unit. 5. An acceleration / deceleration state detecting means for detecting an acceleration / deceleration state of a rotating body, and a correcting means for correcting the correction coefficient according to the acceleration / deceleration state of the rotating body. 1. A speed detecting device for a rotating body according to 1. 6. A determination means for determining whether or not a pulse signal is generated every predetermined period, and a correction means for correcting the correction coefficient according to a determination result of the determination means. 1. A speed detecting device for a rotating body according to 1. 7. The speed detecting device for a rotating body according to claim 1, further comprising acceleration calculating means for calculating an acceleration of the rotating body to be measured based on a speed of the rotating body to be measured.