JPH1183902A - Pointer indicating instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pointer indicating instrument restraining fine vibration of a pointer in a specified change region. SOLUTION: By receiving a digital signal S(n) which means a value of a measured object which changes every moment with specified measuring timing in accordance with the state of the measured object, the most faithful deflection angle value T(n) of a pointer which is to be caused by the digital signal S(n) is found. From the latest deflection angle value T(n), a present indication angle value D(n-1) obtained by the last measuring timing, a fixed constant N and a variable constant K, the latest indication target angle value D(n)=D(n-1)+ T (n)-D(n-1)}/ n×k} is obtained. From the difference θ between the digital signal S(n) and the maximum value M in a change absorbing region, a variable constant K is obtained by operation processing. This pointer indicating instrument has a smoothing circuit 3 performing the above processing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an instrument such as a cross-coil instrument or a stepping motor instrument which performs a pointing operation by changing the angle of a pointer, and more particularly to smoothing of the pointer pointing operation.

[0002]

2. Description of the Related Art A general pointer indicating instrument processes signals from various sensors installed on an object to be measured as appropriate, converts the signals into an appropriate pointer driving signal, and indicates the state of the object to be measured by a change in the angle of the pointer. It is indicated by. In such an indicating instrument, for signal processing from various sensors,
The sensor signal is once digitized, subjected to predetermined processing, and then analogized again to drive the hands.

[0003] More specifically, when the rotation speed of a vehicle engine to be measured is displayed using a cross coil meter, a pulse signal having a frequency proportional to the rotation speed is output from a sensor. Is subjected to F / V conversion, and the converted voltage signal is converted into a digital signal (digital numerical value), or the pulse signal is counted or period-measured, and the state of the object to be measured is output as a digital signal. The driving amount (angle) of the pointer corresponding to the numerical value is calculated and calculated by a control unit such as a microcomputer, and the angle of the pointer is controlled to display the engine speed by this.

In such an instrument, Japanese Patent Application Laid-Open No. H5-1808
In order to smooth the pointer indicating operation,
Filter coefficient for smoothing the digital signal = 1
It is disclosed that a filter (smoothing unit) having / N is provided.

[0005] This comprises a conversion unit for digitizing an input signal from the object to be measured, a drive processing unit for outputting a predetermined pointer instruction signal corresponding to the digital signal from the conversion unit,
A conversion unit configured to include a display unit that receives a drive output from the drive processing unit and operates a pointer, detects a change amount of the conversion unit output signal, and performs a digital smoothing process on the conversion unit output signal. By providing between the drive processing unit, the smoothing response characteristics are switched according to the amount of change, thereby realizing smoothing.

[0006]

According to the prior art, the change in the output signal of the converter is detected and the smooth response characteristic is switched, so that the pointer indication operation can quickly follow the change of the object to be measured. In addition, it is possible to solve the problem of minute fluctuation of the pointer caused by quick response.

However, the filter coefficient 1 / N
When a fixed value consisting of a positive integer value is adopted as the constant N, if the constant N is large, the filter effect of the smoothing unit is reduced in the low rotation speed region (the frequency of the pulse signal is low and the pulse cycle is long). Although flickering of the display can be suppressed by exhibiting and absorbing slight fluctuations, it is not possible to follow sudden changes in the number of revolutions, and the driver feels discomfort by feeling the difference between the bodily sensation and the display Becomes On the other hand, when the constant N is small, a needle wobble phenomenon occurs, and display quality is lost.

For this reason, the constant N depends on the state of the rotational speed.
It is also conceivable to automatically switch between the two. However, when storing the data of the constant N as a table in the storage unit, if the number of data is large, the storage unit needs to have a large capacity, which leads to an increase in cost. Which is not desirable.

An object of the present invention is to further improve this conventional example, and to provide an indicating instrument which can realize good smoothing without increasing the cost.

[0010]

According to the present invention, there is provided a digital signal S () representing a value of the object to be measured which changes every moment at a predetermined measurement timing according to the state of the object to be measured. n), the digital signal S
(N), the most faithful pointer deflection angle value T (n) is obtained, and the latest deflection angle value T (n) and the current designated angle value D (n-1) obtained at the previous measurement timing are calculated. From the fixed constant N and the variable constant K, the latest indicated target angle value D
(N) = D (n-1) + {T (n) -D (n-1)} /
{N × K} is obtained, and based on the indicated target angle value D (n), a pointer indicating instrument is displayed by an instruction operation based on a change in the angle of the pointer. And a smoothing circuit for obtaining the variable constant K from the difference θ from the maximum value M of the determined fluctuation absorption region by arithmetic processing.

In the smoothing circuit, the continuous a
Each time the average value of the output signals S (n) is measured, the variable constant K is determined to determine the indicated target angle value D (n), or is determined from the averaged output signal S (n). After the b variable constants K are obtained continuously and the average value thereof is obtained, the indicated target angle value D (n) is obtained.

The digital signal S (n) indicating the value of the object to be measured that changes every moment at a predetermined measurement timing in accordance with the state of the object to be measured is received. The shake angle value T (n) of the simple pointer is obtained, the latest shake angle value T (n), the current designated angle value D (n-1) obtained at the previous measurement timing, the fixed constant N, and the variable constant From K, the latest indicated target angle value D
(N) = D (n-1) + {T (n) -D (n-1)} /
{N × K} is obtained, and based on the indicated target angle value D (n), a pointer indicating instrument is displayed by a pointing operation based on a change in the angle of the pointer. A smoothing circuit for calculating the variable constant K from the difference θ ′ between the maximum value M and the designated angle value M ′ by arithmetic processing.

In the smoothing circuit, the continuous a
Each time an average value of the output signals S (n) is measured, the shake angle value T (n) is obtained to obtain the variable constant K and the indicated target angle value D (n), or the average values are obtained. The shake angle value T obtained from the output signal S (n)
The variable constant K and the indicated target angle value D (n) are obtained after c values of (n) are obtained continuously and an average value thereof is obtained.

Further, in the smoothing circuit, d variable constants K are successively determined, an average value thereof is determined, and then the indicated target angle value D (n) is determined, or d variable constants K are determined by d variable constants. After continuously obtaining the average value and obtaining the indicated target angle value D (n), the indicated target angle value D (n) is obtained.
(N) are obtained continuously, and the average value is obtained as the latest designated target angle value D (n).

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS For example, a smoothing circuit 3 converts a digital signal S (n) [RPM] with a maximum value M (for example, 1500 as an upper limit of an idling region) [RPM] of a fluctuation absorption region determined by an instrument. From the difference θ [RPM], a variable constant K is variably obtained by arithmetic processing. Next, the most faithful pointer swing angle value T based on the digital signal S (n)
(N) is calculated, and the latest shake angle value T (n) and the current designated angle value D (n−n) obtained at the previous measurement timing are obtained.
1) From the fixed constant N and the variable constant K, the latest indicated target angle value D (n) = D (n-1) + ΔT (n) -D (n-
1) Find｝ / {N × K}.

By changing the filter coefficient variably depending on the magnitude of the difference θ (rotational speed) between the digital signal S (n) and the maximum value M of the fluctuation absorption region, the filter can be changed when the rotational speed difference θ is large. By reducing the coefficient and increasing the filter coefficient when the difference between the rotation speeds θ is small, the guideline that does not impair the responsiveness in the normal use area while sufficiently suppressing the fine fluctuation in the fluctuation absorption area such as the idling area. 7 indicating characteristics can be obtained.

In the smoothing circuit 3, the variable constant K is calculated every time the average value of the continuous a output signals S (n) is measured.
To obtain a designated target angle value D (n), or a variable constant K obtained from the averaged output signal S (n) is represented by b
An instrument 6 that is responsive to an input signal that is the indicated target angle value D (n) can be obtained by successively obtaining the average value and then obtaining the indicated target angle value D (n). Is effective in absorbing the fluctuation of the object to be measured.

Further, as another configuration, the smoothing circuit 3 includes a difference θ ′ [°] between the deflection angle value T (n) [degree] of the pointer and the designated angle value M ′ [degree] of the maximum value M in the above embodiment. The variable constant K is variably obtained from the degree] by arithmetic processing. Next, the latest designated target angle value is obtained from the latest shake angle value T (n), the current designated angle value D (n-1) obtained at the previous measurement timing, the fixed constant N, and the variable constant K. D (n) = D
(N-1) + {T (n) -D (n-1)} / {N × K}
Ask for.

With this configuration, the digital signal S (n)
The filter coefficient is determined according to the magnitude of the difference θ ′ (indicated angle) between the deflection angle value T (n) [degree] of the pointer corresponding to and the indicated angle value M ′ [degree] corresponding to the maximum value M of the fluctuation absorption region. Is varied to reduce the filter coefficient when the indicated angle difference θ ′ is large, and increase the filter coefficient when the indicated angle difference θ ′ is small. In this case, it is possible to obtain the indicating characteristic of the pointer 7 which does not impair the responsiveness in the normal use area while sufficiently suppressing the slight fluctuation in

In the smoothing circuit 3, the shake angle value T (n) is obtained every time the average value of the continuous output signals S (n) is measured, and the variable constant K and the designated target angle value D are obtained.
(N) or the averaged output signal S
By continuously obtaining c shake angle values T (n) obtained from (n) and calculating an average value thereof, the variable constant K and the specified target angle value D (n) are calculated, so that the specified target value is obtained. This is effective when the instrument 6 having a sensitive response to the input signal having the angle value D (n) absorbs the fluctuation of the object to be measured.

Further, in the smoothing circuit 3 of each of the above structures,
An instruction target angle value D (n) is obtained after d variable constants K are continuously obtained and an average value thereof is obtained, or an instruction is performed after d variable constants K are continuously obtained and an average value thereof is obtained. The target angle values D (n) are obtained, e of the indicated target angle values D (n) are successively obtained, and the average value thereof is calculated as the latest indicated target angle value D.
It is also possible to adopt a configuration obtained as (n).

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described based on an embodiment applied to a stepping motor type instrument shown in the accompanying drawings.

FIG. 1 is a block diagram showing the configuration of the embodiment, in which an engine speed [RPM], which is a value to be measured by multiplex communication, is 1 [RPM] / bit, for example.
For example, a 16-bit binary count value (digital signal) S
(N) is input from the input terminal 1 to the receiving circuit 2.

The digital signal S (n) passes through the receiving circuit 2 and is converted by the smoothing circuit 3 into an indicated target angle value D (n) that has been subjected to a smoothing process by a method described later. The indicated instruction target angle value D (n) is supplied to an exciting coil (not shown) of the stepping motor type instrument 6 via the drive circuit 4 and, if necessary, the output circuit 5, and performs an instruction operation by changing the angle of the pointer 7. , Display the engine speed.

Next, an example of the processing performed by the smoothing circuit 3 of this embodiment will be described.

The smoothing circuit 3 generates a digital signal S (n) [R
PM] and the maximum value M of the fluctuation absorption region determined by the instrument (for example, 1500 as the upper limit of the idling region) [R
PM], a variable constant K is obtained from the difference θ [RPM] by arithmetic processing. In the present embodiment, K = {MS (n)} / L
Variable constant K (rounded down to the decimal point, L is a fixed constant)
Is obtained. When S (n) = 0 [RPM], K = maximum value 16, and when S (n) = 1500 [RPM], K =
It is programmed to take a minimum value of 2, for example L
= 94.

Next, the smoothing circuit 3 generates the digital signal S
(N), the most faithful pointer deflection angle value T (n) is obtained, and the latest deflection angle value T (n) and the current designated angle value D (n-1) obtained at the previous measurement timing are calculated. From the fixed constant N and the variable constant K, the latest indicated target angle value D
(N) = D (n-1) + {T (n) -D (n-1)} /
{N × K} is obtained. In the present embodiment, the fixed constant N is set to 4, but an arbitrary numerical value is selected for N depending on the instrument used.

With such a configuration, in the idling region where the fine vibration of the pointer 7 is intense, 1 / {N × K} which is the filter coefficient of the smoothing circuit 3 becomes 1/6 as shown in FIG.
It changes in the range of 4 to 1/8 (variable state) and becomes constant at 1/8 (fixed state) in the normal region thereafter. However, in the present embodiment, the switching between the variable state and the fixed state of the filter coefficient is based on the initially set maximum value M = 1500 [RP
M], but actually at 1312 [RPM]. This is because although there is still a possibility that micro-vibration may occur below the maximum difference M in the fluctuation absorption region, if the frequency of occurrence is relatively small, it may be desirable to make the response faster rather than short. This is to switch the state of the filter coefficient. Note that these are filter coefficients according to the characteristics of the indicator 6 to be used in accordance with the characteristics of the responsiveness of the pointer 7 in order to ensure the smoothness of the change of the indicated target angle value D (n). Adjustments are made for

As described above, the smoothing circuit 3 only needs to calculate the variable constant K from the difference θ between the digital signal S (n) and the maximum value M of the fluctuation absorption region determined by the instrument by arithmetic processing. The filter coefficient of 3 does not necessarily need to be switched between the variable state and the fixed state using the maximum value M as a threshold.

When the filter coefficient is variably changed according to the magnitude of the difference θ (the number of revolutions) between the digital signal S (n) and the maximum value M of the fluctuation absorption region, the difference θ between the number of revolutions is large. The filter coefficient is reduced to
When the difference is small, it is possible to obtain the indicating characteristic of the pointer 7 which does not impair the responsiveness in the normal use region while sufficiently suppressing the fine fluctuation in the fluctuation absorption region such as the idling region by increasing the filter coefficient. it can.

As described above, since the variable constant K is obtained by the calculation, it is not necessary to prepare a large storage capacity of a storage member (for example, built in the smoothing circuit 3) for storing and holding various parameters, and the cost is reduced. This is desirable for reduction.

In the smoothing circuit 3, the variable constant K is calculated every time the average value of a continuous number of output signals S (n) is measured.
To obtain a designated target angle value D (n), or a variable constant K obtained from the averaged output signal S (n) is represented by b
An instrument 6 that is responsive to an input signal that is the indicated target angle value D (n) can be obtained by successively obtaining the average value and then obtaining the indicated target angle value D (n). For example, in a stepping motor type instrument,
This is effective when absorbing the fluctuation of the object to be measured.

FIG. 3 is a block diagram showing the configuration of another embodiment, in which the most faithful movement angle of the pointer due to the digital signal S (n) is provided between the receiving circuit 2 and the smoothing circuit 3 of the above embodiment. The processing circuit 8 for obtaining the value T (n) is interposed.

The shake angle value T (n) is converted by the smoothing circuit 3 into an indicated target angle value D (n) subjected to a smoothing process by a method described later, and the indicated target angle value D thus smoothed. (N) is supplied to an exciting coil (not shown) of the stepping motor type instrument 6 via the drive circuit 4 and, if necessary, the output circuit 5, performs an instruction operation by changing the angle of the pointer 7, and displays the engine speed. .

Alternatively, in FIG. 3, when an input signal, which is a pulse signal having a frequency proportional to the number of revolutions of the engine to be measured, is input from the input terminal 1, the waveform is shaped by the receiving circuit 2 and then the input signal is input. A rising or falling edge of a signal is detected, another high frequency clock signal is counted by the input signal, and an engine speed that changes every moment at a predetermined measurement timing is, for example, a 16-bit binary count value (digital signal). Output as S (n). Then, the output signal S (n) of the receiving circuit 2 is sent to the processing circuit 8 and converted into the most faithful pointer swing angle value T (n) based on the current output signal S (n) of the instrument described later. Further, the smoothing circuit 3 converts the designated target angle value D (n), which has been subjected to a smoothing process by a method described later, into the designated target angle value D (n). Further, if necessary, it may be supplied to an exciting coil (not shown) of the stepping motor type instrument 6 via the output circuit 5 to perform an instruction operation based on a change in the angle of the pointer 7 to display the engine speed.

Next, an example of the processing performed by the smoothing circuit 3 of this embodiment will be described.

The smoothing circuit 3 calculates the deflection angle value T (n) of the pointer.
[Degree] and the designated angle value M 'of the maximum value M in the above embodiment.
The variable constant K is obtained by arithmetic processing from the difference θ ′ [degree] from [degree]. In this embodiment, K = {M′−T (n)} /
A variable constant K is obtained by L ′ (rounded off to the decimal point, L ′ is a fixed constant). When T (n) = 0 [degree], K = maximum value, and T (n) = M ′ [degree] At this time, it is programmed so as to take K = minimum value, and the setting of the fixed constant L 'is the same as in the above embodiment.

Next, the smoothing circuit 3 calculates the latest shake angle value T (n), the current designated angle value D (n-1) obtained at the previous measurement timing, the fixed constant N and the variable constant K. , The latest indicated target angle value D (n) = D (n-1) +
{T (n) -D (n-1)} / {N × K} is obtained. The setting of the fixed constant N is the same as in the above embodiment.

It is sufficient that the variable constant K is obtained by arithmetic processing from the difference θ ′ between the deflection angle value T (n) of the pointer and the designated angle value M ′ determined according to the maximum value M in the above embodiment. The filter coefficients of the smoothing circuit 3 need not necessarily be switched between the variable state and the fixed state using the designated angle value M ′ of the maximum value M as a threshold, similarly to the above embodiment.

With this configuration, similar to the above embodiment,
The deflection angle value T of the pointer corresponding to the digital signal S (n)
(N) By changing the filter coefficient variably according to the magnitude of the difference θ ′ (indicated angle) between [degree] and the indicated angle value M ′ [degree] corresponding to the maximum value M of the fluctuation absorption region, When the angle difference θ ′ is large, the filter coefficient is reduced, and when the indicated angle difference θ ′ is small, the filter coefficient is increased, thereby sufficiently suppressing the slight fluctuation in the fluctuation absorption region such as the idling region. It is possible to obtain the indicating characteristic of the pointer 7 which does not impair the response in the normal use area.

In the smoothing circuit 3, the shake angle value T (n) is obtained every time the average value of the continuous a output signals S (n) is measured, and the variable constant K and the designated target angle value D are obtained.
(N) or the averaged output signal S
By continuously obtaining c shake angle values T (n) obtained from (n) and calculating an average value thereof, the variable constant K and the specified target angle value D (n) are calculated, so that the specified target value is obtained. This is effective in a case where an instrument 6 having a responsiveness to an input signal having an angle value D (n), for example, a stepping motor instrument, absorbs a fluctuation of an object to be measured.

Further, according to the present invention, in the smoothing circuit 3 of each of the above embodiments, d variable constants K are obtained continuously, an average value thereof is obtained, and then an indicated target angle value D (n) is obtained. After continuously obtaining d variable constants K and calculating their average value, the designated target angle value D (n) is determined, and the indicated target angle value D (n) is continuously determined e, and the average value is calculated as the latest value. It is also possible to adopt a configuration in which it is obtained as the designated target angle value D (n), which is effective for absorbing fluctuations of the object to be measured.

Further, it is needless to say that the present invention is not limited to the stepping motor type meter of the embodiment, but can be similarly applied to a meter which performs an instruction operation by changing the angle of another pointer such as a cross coil type meter.

[0044]

According to the present invention, it is possible to further smooth the operation of indicating the pointer by the processing in the smoothing circuit, and the signals from the various sensors installed on the object to be measured abruptly change. Or irregular fluctuations, it is possible to suppress the occurrence of so-called needle jump or needle run-out by the above-described processing of the smoothing circuit. Prevents minute fluctuations in the pointer at the time of rotation and overshooting from high to low rotation speeds to obtain a smooth pointer indication and to obtain a smooth pointer indication instrument with less visual unnaturalness. Can be. In particular, it is possible to provide a pointer indicating instrument capable of suppressing fine vibration of the pointer in a specific fluctuation region (for example, an idling region).

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating the configuration of an embodiment of the present invention.

FIG. 2 is a characteristic diagram illustrating filter coefficients of the smoothing circuit according to the embodiment.

FIG. 3 is a block diagram illustrating a configuration of another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input terminal 2 Receiving circuit 3 Smoothing circuit 4 Drive circuit 5 Output circuit 6 Stepping motor type instrument (pointer indicating instrument) 7 Pointer 8 Processing circuit

Claims (5)

[Claims] 1. A digital signal S (n) indicating a value of an object to be measured that changes every moment at a predetermined measurement timing according to a state of the object to be measured, and receives the digital signal S (n).
(N), the most faithful pointer deflection angle value T (n) is obtained, and the latest deflection angle value T (n) and the current designated angle value D (n-1) obtained at the previous measurement timing are calculated. From the fixed constant N and the variable constant K, the latest indicated target angle value D
(N) = D (n-1) + {T (n) -D (n-1)} /
{N × K} is obtained, and based on the indicated target angle value D (n), a pointer indicating instrument is displayed by an instruction operation based on a change in the angle of the pointer. A pointer indicating instrument comprising a smoothing circuit for calculating the variable constant K from a difference [theta] from a maximum value M of a fluctuation absorption region to be determined by arithmetic processing. 2. In the smoothing circuit, the variable constant K is obtained every time an average value of a continuous number of the output signals S (n) is measured, and the indicated target angle value D (n) is obtained. The variable target K obtained from the averaged output signal S (n) is obtained in succession b, the average value thereof is obtained, and then the designated target angle value D (n) is obtained. 2. The pointer indicating instrument according to 1. 3. A digital signal S (n) indicating a value of the object to be measured, which changes every moment at a predetermined measurement timing according to the state of the object to be measured, and receives the digital signal S (n).
(N), the most faithful pointer deflection angle value T (n) is obtained, and the latest deflection angle value T (n) and the current designated angle value D (n-1) obtained at the previous measurement timing are calculated. From the fixed constant N and the variable constant K, the latest indicated target angle value D
(N) = D (n-1) + {T (n) -D (n-1)} /
{N × K} is obtained, and based on the indicated target angle value D (n), a pointer indicating instrument is displayed by a pointing operation based on a change in the angle of the pointer. A pointer indicating instrument comprising a smoothing circuit for calculating the variable constant K from a difference θ ′ between the maximum value M and the indicated angle value M ′ by arithmetic processing. 4. The smoothing circuit calculates the shake angle value T (n) every time when the average value of a continuous number of the output signals S (n) is measured, and obtains the variable constant K and the designated target angle. After obtaining a value D (n) or c averages of the shake angle values T (n) obtained from the averaged output signal S (n) and obtaining the average value, the variable constants K and The pointer indicating instrument according to claim 3, wherein the indicating target angle value D (n) is obtained. 5. In the smoothing circuit, the variable constant K
Are obtained continuously and the average value thereof is obtained, and then the indicated target angle value D (n) is obtained, or the variable constant K is obtained.
Are obtained successively and the average value thereof is obtained, and then the indicated target angle value D (n) is obtained, and the indicated target angle value D (n) is obtained.
The pointer indicating instrument according to any one of claims 1 to 4, wherein e is obtained continuously and an average value thereof is obtained as the latest indicated target angle value D (n).