WO1999012046A1

WO1999012046A1 - Pointer indicator

Info

Publication number: WO1999012046A1
Application number: PCT/JP1998/003269
Authority: WO
Inventors: Satoshi Asai
Original assignee: Nippon Seiki Co., Ltd.
Priority date: 1997-08-28
Filing date: 1998-07-21
Publication date: 1999-03-11
Also published as: JPH1172513A

Abstract

A pointer indicator of which the pointer neither springs nor oscillates. A smoothing circuit (5) finds the difference υ = |T(n) - D(n-1)| between the deflection angle T(n) and the indication angle D(n-1). A variable constant N (= (M-υ) x K2) is found from the difference υ, a maximum expected angle difference M determined depending on the indicator, and a fixed constant K2. The fixed constant K2 is a positive integer that varies in proportion to a fixed constant K1. An indicated target angle D(n) (= D(n-1) + {T(n) - D(n-1)} x K1/N) is found from the latest deflection angle T(n), present indication angle D(n-1), fixed constant K1 and variable constant N. Based on the indication target angle D(n), a pointer (9) changes its deflection and indicates a measure.

Description

Description Pointer indicating instrument Technical field

The present invention relates to a pointer indicating instrument, such as a cross-coil meter, a stepping motor type meter, etc., which performs display by a pointing operation based on a change in the angle of a pointer, and particularly to smoothing of the pointer indicating operation. Background art

General pointer indicating instruments process signals from various sensors installed on the object to be measured as appropriate, convert them to appropriate pointer driving signals, and display the state of the object to be measured by pointing movements due to changes in the angle of the pointer. Things. In such an indicating instrument, in order to process signals from various sensors, the sensor signal is once digitized, subjected to a predetermined process, converted into an analog signal again, and the pointer is driven.

More specifically, when displaying the rotation speed of the vehicle engine to be measured using a cross-coil meter, a pulse signal having a frequency proportional to the rotation speed is output from the sensor. / V conversion, and convert the converted voltage signal into a digital signal (digital numerical value), or count or measure the period of the pulse signal and output the state of the measured object as a digital signal. The corresponding needle drive amount (angle) is calculated and processed by a control unit such as a microcomputer, and the angle of the pointer is controlled to display the engine speed.

In such an instrument, Japanese Patent Application Laid-Open No. 5-18072 discloses a filter having a filter coefficient = 1 / N for smoothing the digital signal in order to smooth the pointer indicating operation. (A smoothing portion).

This includes a conversion unit that digitizes an input signal from the device under test, a drive processing unit that outputs a predetermined pointer instruction signal corresponding to the digital nore signal from the conversion unit, and a drive output from the drive processing unit. And a display unit for operating the pointer in response to the change. The amount of change in the output signal of the conversion unit is detected, and digital smoothing of the output signal of the conversion unit is performed. By providing a smoothing unit between the conversion unit and the drive processing unit, the smoothing response characteristic is switched according to the amount of change, thereby realizing smoothing.

According to the conventional example, by detecting the amount of change in the output signal of the conversion unit and switching the smooth response characteristic, it is possible to quickly follow the pointer instruction operation to the change of the measured object, and to achieve quick response. The problem of small fluctuations of the pointer that occurs can also be solved. However, when a fixed value consisting of a positive integer value is adopted as the constant N of 1ZN, which is a filter coefficient, if the constant N is large, the rotation speed becomes low (the pulse signal frequency is low and the pulse period is long). In addition, although the filter effect of the smoothing portion is exerted and the slight fluctuation is absorbed to suppress the flickering of the display, it is not possible to follow a rapid change in the number of rotations, and the driver feels bodily. The difference from the display is felt so large that the user feels strange. On the other hand, if the constant N is small, a needle wobble phenomenon occurs, resulting in a lack of display quality.

For this reason, it is conceivable that the constant N is automatically switched according to the state of the rotation speed. A large one is required, 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 capable of realizing good smoothing without increasing the cost. Disclosure of the invention

The present invention obtains a shake angle value T (n) of the most faithful finger ^ "based on a digital signal S (n) which changes momentarily at a predetermined measurement timing in accordance with the state of the object to be measured. From the swing angle value T (n), the current indicated angle value D (n-1) obtained at the previous measurement timing, the fixed constant K1, and the variable constant N, the indicated target angle value D (n) = D ( n-1) + {T (η) -1 D (n-1)} XK1 / N is obtained, and based on the indicated target angle value D (n), it is displayed by the instruction operation based on the angle change of the pointer. A pointer indicating instrument, wherein a difference 前記 = | Τ (n) -D (n-1) | between the deflection angle value T (n) and the indicated angle value D (n-1) is obtained, and the difference Θ The variable constant Ν = (Μ-θ) ΧΚ2 is calculated from the expected maximum angle difference により determined by the instrument and the fixed constant Κ2. Therefore, the fixed constant K1 was a positive integer value proportional to the fixed constant Κ2.

Further, the present invention provides that the processing in the smoothing circuit is performed every time an average value of a continuous number of 出力 output signals S (n) is measured, or from the averaged output signal S (n). The B calculated swing angle values T (n) of the hands are obtained continuously and the average value is measured each time, or the variable constant N calculated from the averaged swing angle values T (n) of the hands is calculated. This is performed every time C averages are obtained continuously and the average value is measured. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described based on an embodiment in which the present invention is 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 2 After the waveform shaping, the period measuring circuit 3 detects the rise or fall of the input signal, and outputs another high-frequency cut-off signal with the input signal, and momentarily at a predetermined measurement timing. The changing engine speed is output as, for example, 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 converted to the most faithful finger swing angle value T (n) based on the current output signal S (n) of the instrument described later. Is converted into an instruction target angle value D (n) that has been subjected to a smoothing process by a smoothing circuit 5 by a method described later, and the instruction target angle value D (n) thus smoothed is It is supplied to an exciting coil (not shown) of the stepping motor type instrument 8 via the circuit 6 and, if necessary, the output circuit 7, and performs an instruction operation by changing the angle of the pointer 9 to display the engine speed.

Next, an example of the processing performed by the smoothing circuit 5 will be described. The smoothing circuit 5 calculates the indicated target angle value D (n) = D (n—from the latest shake angle value T (n), the current indicated angle value D (n—1), the fixed constant K1, and the variable constant N. 1) + {T (n) one D (n— 1)} XK1 N N is calculated, and as a prerequisite, the difference Θ = | Τ (η) – D (n−1) | between the deflection angle value T (η) and the indicated angle value D (n−1) The variable constant N = (M-θ) XK2 is calculated from the difference Θ, the maximum planned angle difference M determined by the instrument, and the fixed constant K2, where the fixed constant K2 is a positive integer Take a numerical value. Specifically, for each measurement timing, the smoothing circuit 5 calculates the difference between the shake angle value T (n) and the designated angle value D (n—1) Θ = | Τ (η) — D (n—1) | Ask for. The value of the difference θ is calculated so as to take a predetermined range. For example, the difference θ is obtained in a range of 0 [degrees] = θ <= 100 [degrees]. Note that 100 [degrees] is the scheduled maximum angle difference (the maximum angle difference expected at one measurement timing) 計測 determined by the instrument.

Next, from the difference Θ, the expected maximum angle difference Μ, and the fixed constant Κ2, a variable constant Ν = (Μ θθ) ΧΚ2 is obtained, and the fixed constant Κ is set so that the variable constant を取る takes a predetermined range. Let 2 be a positive integer value proportional to a fixed constant Κ 1 having a sufficiently large value, for example, K2 = Kl / 4 and Kl = 8 so that 32 2 = Ν <= 200. Therefore, when Θ = 0 [degrees], Ν = 200 = maximum value. When Θ = Μ = 100 [degrees], force なる = 0 At this time, set (program) so that に = 32 = minimum value, and determine the lower limit. This is because, in the case of the maximum difference フィルタ, the update timing of the indicated target angle value D (η) is accelerated by minimizing the filter coefficient of the smoothing circuit 5 described later, but the response is limited due to the characteristics of the instrument 8 and the like. 'In order to ensure the smoothness of the change in the indicated target angle value D (η), this is set in order to set the update timing accordingly.

As described above, the fixed constant Κ1 takes a positive integer value having no decimal point or the like in proportion to the fixed constant Κ2, so that the storage member for storing and storing these constants Kl and Κ2 (for example, the processing circuit 4, And / or the built-in smoothing circuit 5) may not be required to have a large storage capacity, which is desirable for cost reduction.

Then, from the latest deflection angle value Τ (η), the current indicated angle value D (η−1), the fixed constant K1 (= 8), and the variable constant Ν, the indicated target angle value D (n) = D ( n— 1) + {T (n) one D (n— 1)} X 8ZN. That is, in the present embodiment, the variable constant N has a precision of K1 times and the numerator of the filter coefficient is also multiplied by K1, and the filter coefficient of the smoothing circuit 5 is “K1 / N” = “8 / N” . According to such a configuration, the filter coefficient 1 ZN is determined by the magnitude of the difference (angle difference) between the shake angle value T (n) as input data and the indicated angle value D (n-1) as output data. By changing the ratio as a variable, the ratio can be increased when the angle difference is large, and reduced when the angle difference is small, so that the response can be sufficiently absorbed without impairing the response. Obtainable.

In particular, when the variable constant N changes, the filter coefficient changes by 20% when changing from 1/4 to 1/5 in the conventional 1ZN, but according to the present embodiment, the use of 8ZN It is possible to change from 1/4 to 1Z5 via 14.X, and the smoothness of the change of the indicated target angle value D (n) can be further improved. Note that the value of the fixed constant K1 can be arbitrarily selected according to the characteristics of the instrument 8 and the like.However, a smaller value generally results in poor smoothness, and a larger value causes an increase in processing load. It is necessary to determine an optimal value in consideration of the characteristics of the instrument 8 and the like and the processing capability of the entire configuration (particularly, the processing circuit 4 and the smoothing circuit 5).

As another embodiment of the present invention, the above-mentioned processing in the smoothing circuit 5 is not performed at every measurement timing as in the above-described embodiment, but, for example, four consecutive output signals S (n) are output. It is performed every time the average value is measured, or every time when four consecutive deflection angle values T (n) of the pointer obtained from the averaged output signal S (n) are obtained and the average value is measured. Alternatively, four consecutive variable constants N obtained from the averaged deflection angle value T (n) of the pointer may be obtained in succession, and the average value may be measured each time. It is effective for absorption. Generally, it is performed each time the average value of the continuous A output signals S (n) is measured, or the deflection angle value T (n) of the pointer obtained from the averaged output signal S (n) Is performed every time the average value is measured by calculating B consecutive times, or C variable constants N obtained from the averaged deflection angle value T (n) of the pointer are calculated continuously and the average value is calculated. Will be performed each time 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 such as a cross coil type instrument which performs an instruction operation by changing the angle of another pointer. Industrial applicability

According to the present invention, the smoothing of the pointer indicating operation can be further realized by the processing in the smoothing circuit. Signals from various sensors installed on the object to be measured change suddenly or irregularly. Even if it fluctuates, the above processing can suppress the occurrence of so-called needle jump or needle runout. Particularly in the case of an indicator that displays the engine speed of a vehicle, slight fluctuation of the pointer at low speed or high It is possible to prevent overshoot from the rotation speed to the low rotation speed, to obtain a smooth pointer indication, and to obtain a smooth pointer indication instrument with less visual unnaturalness.

Claims

The scope of the claims

1. Obtain the most faithful pointer swing angle value T (n) based on the digital signal S (n), which changes every moment at a predetermined measurement timing according to the state of the measured object, and calculate the latest shake. From the angle value T (n), the current indicated angle value D (n-1) obtained at the previous measurement timing, the fixed constant K1, and the variable constant N, the indicated target angle value D (n) = D (n -1) + {T (η) — D (η-l)} XK l ZN is obtained, and based on the indicated target angle value D (n), a pointer indicating instrument to be displayed by an instruction operation based on the angle change of the pointer. A difference Θ = IT (n)) D (n−1) | between the shake angle value T (n) and the indicated angle value D (n−1), and is determined by the difference Θ and an instrument. From the expected maximum angle difference M and the fixed constant K2, the variable constant N = (M−θ) XK2 was obtained, and the fixed constant K1 was a positive integer value proportional to the fixed constant K2. Pointer indicator characterized by the following vessel.

2. The above-mentioned processing in the smoothing circuit is performed every time the average value of the continuous A output signals S (n) is measured, or the average output signal S (n) power It is performed every time the average of the B deflection angle values T (n) is obtained in succession, or C variable constants N obtained from the averaged deflection angle value T (n) of the pointer are continuously measured. 2. The pointer indicating instrument according to claim 1, wherein the measurement is performed every time the average value is obtained and measured.