JPH1172513A - Pointer indicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pointer indicator which can suppress generation of so- called pointer skipping and pointer deflection. SOLUTION: A smoothing circuit 5 finds a difference θ=T(n)-D(n-1) between a deflection angle value T(n) and a indication angle value D(n-1). Variable constant N=(M-θ)×K2 is found from a predicted maximum angle difference M found from the difference θ and an instrument and a fixed constant K1. The fixed constant K1 is a positive integer proportional to the fixed constant K2. A target indication angle value D(n)=D(n-1)+ T(n)-d(n-1)}×K1/N is found from the latest deflection angle value T(n), the present indication angle value D(n-1), the fixed constant K1 and a variable constant N. A display is made by indicating operation using a change in angle of a pointer 9 based on the target indication angle value D(n) thus obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pointer indicating instrument, such as a cross-coil instrument or a stepping motor instrument, which performs display by an instruction operation based on an angle change of a pointer.
In particular, it relates to smoothing of the pointer indicating 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 a predetermined process, and then converted into an analog signal 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 which changes momentarily at a predetermined measurement timing in accordance with the state of the object to be measured.
(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 K1 and the variable constant N, the designated target angle value D (n) =
D (n-1) + {T (n) -D (n-1)} × K1 / N
A pointer indicating instrument for displaying by a pointing operation based on a change in the angle of the pointer based on the indicated target angle value D (n), wherein the deflection angle value T (n) and the indicated angle value D
(N-1) is obtained, and the variable constant N = (T (n) -D (n-1)) is obtained from the difference θ, a maximum scheduled angle difference M determined by an instrument, and a fixed constant K2. (M-θ) × K2
And the fixed constant K1 was a positive integer value proportional to the fixed constant K2.

Further, according to the present invention, the processing in the smoothing circuit is performed every time the average value of the continuous A output signals S (n) is measured, or the averaged output signal S (n) is measured.
(B) is obtained by continuously obtaining B shake angle values T (n) obtained from (n) and measuring the average value, or a variable obtained from the averaged shake angle value T (n) of the hands. It is performed every time C constants are continuously obtained and the average value is measured.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Signals from various sensors installed on an object to be measured are appropriately processed and converted into appropriate pointer driving signals, and the state of the object to be measured is displayed by an instruction operation based on a change in the angle of the pointer. When an input signal which is a pointer indicating instrument, for example, a pulse signal having a frequency proportional to the engine speed to be measured is input from an input terminal 1, the waveform is shaped by a waveform shaping circuit 2 and then the period is measured. The circuit 3 detects the rise or fall of the input signal, counts another high frequency clock signal by the input signal, and measures the engine speed, which changes every moment at a predetermined measurement timing, for example, an 8-bit binary meter. It is output as a numerical value (digital signal) S (n), and the output signal S (n) of the period measuring circuit 3 is sent to the processing circuit 4 and the most faithful movement of the pointer 9 based on the current output signal S (n). The designated target angle value D (n), which has been converted to the angle value T (n) and further smoothed by the smoothing circuit 5, is converted to the designated target angle value D (n). It is supplied to an exciting coil (not shown) of the stepping motor type instrument 8 via the drive circuit 6 and, if necessary, the output circuit 7, performs an instruction operation by changing the angle of the pointer 9, and displays the engine speed.

The smoothing circuit 5 has the latest shake angle value T (n).
From the current designated angle value D (n-1), the fixed constant K1, and the variable constant N, the designated target angle value D (n) = D (n-1)
+ {T (n) -D (n-1)}. Times.K1 / N, on the premise of which, the deflection angle value T (n) and the designated angle value D
(N-1) is obtained, and a variable constant N = (T (n) -D (n-1) |) is obtained from the difference θ, a maximum scheduled angle difference M determined by an instrument, and a fixed constant K2. M−θ) × K2, and the fixed constant K1 is a positive integer value proportional to the fixed constant K2.

In this case, the above-mentioned processing in the smoothing circuit is performed each time an average value of four consecutive output signals S (n) is measured, or a pointer obtained from the averaged output signal S (n). Are obtained each time four consecutive deflection angle values T (n) are obtained and the average value is measured, or a variable constant N obtained from the averaged deflection angle value T (n) of the pointer.
Can be obtained every four consecutive times and the average value is measured.

By displaying the pointer 9 by the pointing operation based on the angle change of the pointer 9 on the basis of the pointing target angle value D (n), the pointing operation of the pointer 9 can be further smoothed.

[0016]

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. When an input signal which is a pulse signal having a frequency proportional to the engine speed to be measured is input from an input terminal 1, a waveform shaping circuit is shown. After the waveform is shaped in 2, the cycle measuring circuit 3 detects the rise or fall of the input signal, counts another high frequency clock signal by the input signal, and changes the engine at a predetermined measurement timing. The number of rotations is output, for example, as an 8-bit binary count value (digital signal) S (n).

The output signal S (n) of the period measuring circuit 3 is sent to the processing circuit 4, and the most faithful pointer swing angle value T based on the present output signal S (n) of the meter described later.
(N), and further converted by the smoothing circuit 5 into an indicated target angle value D (n) that has been 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 8 via the drive circuit 6 and, if necessary, the output circuit 7, performs an instruction operation by changing the angle of the pointer 9, and displays the engine speed. Things.

Next, an example of the processing performed by the smoothing circuit 5 will be described. The smoothing circuit 5 calculates the latest shake angle value T (n).
From the current designated angle value D (n-1), the fixed constant K1, and the variable constant N, the designated target angle value D (n) = D (n-1)
+ {T (n) -D (n-1)}. Times.K1 / N, on the premise of which, the deflection angle value T (n) and the designated angle value D
(N-1) is obtained, and a variable constant N = (T (n) -D (n-1) |) is obtained from the difference θ, a maximum scheduled angle difference M determined by an instrument, and a fixed constant K2. M−θ) × K2, and the fixed constant K2 is a positive integer value proportional to the fixed constant K1.

More specifically, the smoothing circuit 5 provides a shake angle value T (n) and a designated angle value D (n-1) for each measurement timing.
Θ = | T (n) −D (n−1) |. The value of the difference θ is calculated so as to take a predetermined range, and is obtained, for example, in a range of 0 [degree] ≤ θ ≤ 100 [degree]. Note that 100 [degrees] is a scheduled maximum angle difference (maximum angle difference scheduled at one measurement timing) M determined by an instrument.

Next, a variable constant N = (M−θ) × K2 is determined from the difference θ, the expected maximum angle difference M, and the fixed constant K2. The fixed constant N is set so that the variable constant N takes a predetermined range. The constant K2 is a positive integer value proportional to the fixed constant K1 having a sufficiently large value. For example, K2 = K1 / 4 and K1 = 8 so that 32 <= N <= 200. Therefore, θ
At = 0 [degrees], N = 200 = maximum value. Note that θ
= M = 100 [degrees], N = 0. In this case, N = 0.
= 32 = minimum value is set (programmed), and the lower limit value is determined. This means that in the case of the maximum difference M, a filter coefficient of the smoothing circuit 5 described later is minimized to speed up the update timing of the designated target angle value D (n).
The response is limited by the characteristics of the instrument 8 and the like, and is set so as to set the update timing in accordance with the change in order to ensure the smoothness of the change of the indicated target angle value D (n).

As described above, the fixed constant K1 is equal to the fixed constant K2.
The storage capacity of a storage member (for example, built in the processing circuit 4 and / or the smoothing circuit 5) that stores and holds these constants K1 and K2 by taking a positive integer value having no decimal point or the like proportional to. Need not be prepared much, which is desirable for cost reduction.

Then, based on the latest shake angle value T (n), the current designated angle value D (n-1), the fixed constant K1 (= 8) and the variable constant N, the designated target angle value D (n) = D (n-
1) Obtain + {T (n) -D (n-1)} × 8 / N.
That is, in the present embodiment, the variable constant N has an accuracy of K1 times and the numerator of the filter coefficient is also K1 times, and the filter coefficient of the smoothing circuit 5 is “K1 / N” = “8 / N”.

According to such a configuration, the shake angle value T (n) as input data and the designated angle value D (n) as output data
By changing the filter coefficient 1 / N and changing the ratio according to the magnitude of the difference (angle difference) from (-1), the ratio is increased when the angle difference is large, and the ratio is decreased when the angle difference is small. This makes it possible to obtain characteristics that can sufficiently absorb fluctuations without impairing responsiveness.

In particular, when the variable constant N changes, the filter coefficient changes by as much as 20% from 1/4 to 1/5 in 1 / N of the conventional example. N, from 1/4 to 1/4. 1/5 after x
To the designated target angle value D (n).
Can be further improved.

The value of the fixed constant K1 can be arbitrarily selected according to the characteristics of the meter 8 and the like. However, in general, when the value is small, the smoothness is inferior, and when the value is large, the processing load is increased. It is necessary to determine the optimum value in consideration of the characteristics of the individual instruments 8 and the like and the processing capability of the entire configuration (particularly, the processing circuit 4 and the smoothing circuit 5).
About "10" is desirable.

As another embodiment of the present invention, a smoothing circuit 5
Is not performed at each measurement timing as in the above-described embodiment. For example, four consecutive output signals S
Each time the average value of (n) was measured, or four consecutive deflection angle values T (n) of the hands obtained from the averaged output signal S (n) were obtained and the average value was measured. It may be performed every time, or four consecutive variable constants N obtained from the averaged deflection angle value T (n) of the pointer may be obtained and the average value thereof may be measured. It is effective for absorbing fluctuations. Generally, this is performed every time the average value of the continuous A output signals S (n) is measured, or the averaged output signal S (n) is measured.
(B) is obtained by continuously obtaining B shake angle values T (n) obtained from (n) and measuring the average value, or a variable obtained from the averaged shake angle value T (n) of the hands. This is performed every time C constants are continuously obtained and the average value is measured.

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

[0029]

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. Fluctuations and overshooting from a high rotation speed to a low rotation speed can be prevented, a smooth pointer indication can be obtained, and a smooth pointer indicating instrument with less visual unnaturalness can be obtained.

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input terminal 2 Waveform shaping circuit 3 Period measuring circuit 4 Processing circuit 5 Smoothing circuit 6 Driving circuit 7 Output circuit 8 Stepping motor type instrument (pointer indicating instrument) 9 Pointer

Claims (2)

[Claims] 1. A digital signal S which changes momentarily at a predetermined measurement timing in accordance with the state of an object to be measured.
(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 K1 and the variable constant N, the designated target angle value D (n) =
D (n-1) + {T (n) -D (n-1)} × K1 / N
A pointer indicating instrument for displaying by a pointing operation based on a change in the angle of the pointer based on the indicated target angle value D (n), wherein the deflection angle value T (n) and the indicated angle value D
(N-1) is obtained, and the variable constant N = (T (n) -D (n-1)) is obtained from the difference θ, a maximum scheduled angle difference M determined by an instrument, and a fixed constant K2. (M-θ) × K2
Wherein the fixed constant K1 is a positive integer value proportional to the fixed constant K2. 2. A guide obtained by performing the processing in the smoothing circuit each time an average value of the continuous A output signals S (n) is measured, or by determining from the averaged output signal S (n). B is calculated continuously each time the B value of the shake angle value T (n) is obtained and the average value thereof is measured, or the variable constant N obtained from the averaged shake angle value T (n) of the pointer is represented by C
2. The pointer indicating instrument according to claim 1, wherein the measurement is performed each time the number is continuously obtained and the average value is measured.