JPS6283670A - Controller for cross coil type meter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a control logic circuit comprising a converter for converting a measurement signal into a proportional measurement value as an integer, and a driver for generating a current applied to a crossed coil type meter from the measurement value. The present invention relates to a device for controlling a crossed-coil type instrument as a function of a measurement signal, for example a measurement frequency.

Prior art crossed coil meters can also be used to indicate non-electrical quantities, such as the speed of a vehicle, taking advantage of their known advantages. The known advantages of this include low manufacturing costs, high adjustment forces that are nearly constant over the entire indicated area,
and a large instruction area that can span four quadrants.

However, crossed-coil instruments have the disadvantage of a low inherent damping, which has a negative effect on the indication of the measurand measured by strongly fluctuating measurement signals.

Difficulties arise in particular when the rotational speed of an engine is to be measured using a measuring frequency derived from the ignition pulse.

This measurement frequency exhibits strong short-term fluctuations, which can be caused by unbalances occurring during one revolution of the engine and by deviations in /f: or ignition timing.

An electronic converter is provided which converts the measured frequency into a proportional measured value, as in the case of speed measurements based on the measured frequency derived from the ignition pulse, and a current is applied from the measured value to the crossed coil instrument. When using a control logic circuit with a driver that forms a .

To form a measurement value that is proportional to the measurement frequency and thus to the rotational speed of the automatic motor, the converter can consist of a period measuring circuit for the measurement frequency and a subsequent divider. The measured value formed using the divider is fed to a control logic circuit which generates for each measured value two currents which can be supplied to two conventional coils of a crossed-coil meter; The magnitude of this current is such that a deflection of the pointer is caused which is proportional to the measurement signal (in this case, the measurement frequency) or the measurement value.

Optionally also processing the measuring frequency in order to generate the current applied to the crossed-coil meter from the measuring signal according to a function, i.e., forming a deflection of the indicator over a large angle that is proportional to the measuring signal. It is known to use a device capable of doing this (German Patent Application No. 3003151). This device has a digital frequency measuring device with a tacho resistor, a storage register, and an inverter as a converter connected downstream of the storage register. A special point is that the converter has the lower 7 bins stored in the storage register, 2° to 26
is provided. The transducer provides a signal to a function generator for generating an output signal, the output signal varying in each one of a number of segmented crossed-coil instrument indication regions as a tangent function of the provided signal. do.

The function generator applies signals via a duty-7 actor generator to the control logic, which controls the two indicator drives. The control logic circuit is then controlled by the upper six bits of the storage register.

The control logic circuit acts on the power supply to both coils of the crossed-coil meter and thus on the operating range of this meter. Similarly, the control logic provides a variable duty factor current to one of the coils and a constant current to the other coil.

In the device described above, a control logic circuit with a converter and a driver is used to generate the current applied to the crossed coil meter from the measurement frequency as the measurement signal, irrespective of how exactly the measurement frequency is generated. The disturbance effect of the fluctuations has its full effect. This is because the above functions are used only to create a proportional relationship between the measurement signal and the pointer.

Therefore, the known control devices of crossed-coil instruments cannot be used in practice at all for indicating highly variable measuring signals, in particular for indicating the rotational speed of an automatic engine.

In order to be able to use crossed-coil instruments, despite their low self-attenuation, for the indication of measurands detected with strongly disturbed measurement signals, such as the measurement frequency of an otto engine, It has been proposed to use a filter to smooth the current generated by the driver (which is applied to a crossed coil meter). However, this method has the disadvantage that at least one relatively high-tooth bipolar capacitor must be provided for each filter. This method is also disadvantageous in that the capacitor or filter is structurally large. These disadvantages are all the more so because each of the two currents supplied to the crossed coil meter is provided with a smoothing means, thereby doubling the cost and space for the smoothing means. Additionally, a reduction in accuracy may occur due to aging of the capacitor.

The object of the invention is to provide a measuring signal of the type mentioned at the outset, such that even strongly disturbed or fluctuating measured quantities can be clearly read out, i.e. the measured quantity is stably and accurately indicated. The object of the present invention is to provide a device for controlling a crossed coil type instrument depending on the invention.

Means for Solving the Problem This purpose is to provide a second-order digital delay element (PT2 element) between the converter and the control logic circuit in the signal measuring device, and the digital delay element This is achieved by providing a device including a remainder value storage for the remainder value processing of the remainder values resulting during the integer decomposition of .

Example Next, embodiments of the present invention will be described in detail based on the drawings.

In FIG. 1, reference numeral 1 denotes a circuit arrangement for measuring period length, to which a measurement frequency fMess is supplied to an input side 2. In FIG. In the circuit arrangement 1, the periodically sampled measurement frequency is converted into the reciprocal of the measurement frequency, for example by counting the period length using a fixed clock frequency.

From this frequency, this number is fed to a divider 3 in order to form a measured value which is also proportional to the measuring frequency.

Therefore, the period length measuring circuit device 1 and the divider 3 constitute a converter that converts the measured frequency into a proportional measured value. Measured values are expressed as integers using binary numbers with a minimum number of 2°.

This measured value is supplied to a secondary digital delay element (PT2 element) 4. This element smells.

undesired short-term noise in the measurement signal is filtered out. When determining the circuit constants of the second-order digital delay element, it is assumed that the disturbance has a frequency higher than the frequency of the change in the measured quantity.

With digital delay elements, a relatively steep filter characteristic is achieved with a sufficiently low influence from disturbances.

The measured value corrected in this way is fed to a control logic circuit 5 which normally generates two currents from the measured value, which currents are passed through the conductors 6 to 9 to the crossed coil meter 10. It is supplied to a coil (not shown).

The value indicated using the crossed-coil meter 10 is therefore proportional to the measuring frequency at the input 2 in the regulated state, and neither disturbing fluctuations of the measuring frequency nor small fluctuations of the measuring frequency are indicated. This means that the instructions are precise, stationary, and legible.

A secondary digital delay element (
PT2T2 element, specifically two delay elements (PT
1 element).

FIG. 2 shows a PT1 element equipped with such a remainder value processing circuit.

In other words, the first-order digital delay element shown in FIG.
This constitutes one stage of a second-order two-stage digital delay element as shown in FIG.

The first order digital delay element is AND date 13 and oR
It has an adder 11 for performing a plurality of 7Jfl calculations via a loop 12 which is led to a register 15 via a register 15. The output of the register is connected to the first input 16' of the adder. The binary measured value am can also be supplied to the register 15 via an AND 'F' 16 and an 0R)f 14.

The output side of the adder output side 11 is another AND r -to 17
It is connected to the shift register 18 via. A conductor 19 leads from the output side of the shift register to a remainder value register 20 and to a preceding value register 21. Each of the two registers is connected at its output to the second input of the counter via an AND date 22 or 23 and a common Rr-gate 24.

From the output side of the shift register 18, a further connection line is led via an intermediate storage device 26 to an output azn, from which the intermediate value of the attenuation is delivered.

This first-order digital delay element is controlled by the program controller 2.
γ is automatically controlled in successive runs.

Multiple additions are then carried out during one run, and a division in a shift register is carried out at the end of each run.

For this reason, the program control device is especially
3, 16, 17 and all registers.

This causes the first-order digital delay element to output the measured value am and the intermediate value of the attenuation aZn-,
The damping intermediate value a2 to the residual value R1n is calculated according to the following equation consisting of the residual value R1n-1 and the damping constant braking rate d. That is, aZn-1''(d-1) +RIH-1+amaZn
J R1n==', +d Next, the detailed program process will be explained.

First of all, as can be seen from FIG. 3, the second-order digital delay element shown there is two stages of the first-order delay element shown in FIG.
Consisting of two continuous connections. The first stage is designated at 28 in FIG. 3 and the second stage is designated at 29. The associated program control device 30 is configured for one stage in the same way as the program control device 2γ of FIG. The output of the first stage for the intermediate value of the attenuation a zn simultaneously forms the input of the second stage.

An instruction value aAn appears on the output side of the second stage.

This instruction value is supplied to the control logic circuit 5 shown in FIG.

The second stage 29 shown in FIG. 3 basically forms the following relationship like the first stage.

That is: In this formula, 'R2H-1 is the preceding run n-
The remainder value of the second stage calculated during 1, aAn-1, is the indicated value calculated during the preceding run n-1.

Assuming attenuation d = 4, a binary 2-bit word (actually 1
For VC (where a 0-bit word is used), the values shown in the following table are calculated in the second-order two-stage discrete delay element.

In the table, n in the left column indicates the order of each run, and the column to the right shows the measured value am, where am is constant over 8 program steps, and the column to the right of 3.5 shows the values formed in the first stage, and the last 6
The two columns show the values formed in the second stage.

For the operation of the first stage, it is first assumed that the program controller starts at step n=0. At this point, the value O is already stored in the preceding value register 21 (and the remainder value register 20 has the value 00).
Note here that the remainder values R1 and R2 are in the digits below the decimal point. ) The measured value am=01 is stored in the register 15 at this point. At this time, the adder first calculates the sum a (1 + azn-1), and adds the preceding value a Zn-0 to this calculated value multiple times, and multiplies the product az n-□
・Add until you reach 6. The remainder value Rn-1 reached in the previous program cycle is also added together at the same time. However, this remainder value is determined separately in another embodiment [7
You may also count by 10. In any case, in the shift register 18, after the multiplicity p calculation as described above, the value az11-0.6+R1n-0+am is obtained, and this value is shifted to the right to be divided by d=4.

That is, this value is shifted to the right twice by the shift register. This results in an intermediate value of attenuation a7. at the end of the 0th run. n=00 and remainder value R1=01 are obtained. A second stage 29, to which these values are supplied, receives the indicated value a from there.
Calculate An=00 and the second stage remainder value R2=OO,
In this case, the instruction value aAn-□ of the preceding process is also 00.

For the next run n=1, the instruction value a, Ln-1=00
The remainder value of the first stage is equal to 10. This process causes the intermediate value of attenuation a after the fourth run (n = 3).
zn"01 is repeated in the same way until the measured value amVC is reached, but then the second stage for the first time reaches the remainder value R3=
Calculate 01. After n=6, that is, after the seventh run, the indicated value aAn=01 becomes the measured value.

What is important is that the indicated value changes in the same way only if interfering pulses occur during these runs, whereas in the case of relatively short interfering pulses the influence is averaged out. What is advantageous here is that only then does a once-indicated value appear at the output of the second stage, which continuously changes in the correct direction as a function of the measured value, i.e. The position of the indicator needle on a type of meter can be determined without being able to take a picture.

Effects The essence of the invention is that interfering fluctuations in the measurement signal are eliminated by converting this measurement signal into a proportional measurement value by means of a converter and then applying the measurement value to the control logic circuit. This causes the current to be applied to the crossed coil meter to be generated already smoothed by the control logic circuit with the driver. The second-order digital delay element (p'r2 element) provided in accordance with the present invention eliminates most of the interfering fluctuations in the measured value in a short time, and moreover eliminates the change in the measured quantity and the deflection of the needle of the crossed-coil type meter that displays it. There is no significant delay between the two. The accuracy of the entire device for the control of crossed coil instruments is completely preserved. This is because, during the digital processing of the measured value for the purpose of forming the second-order delay, the remainder value resulting from the division of the measured value by an integer is detected using a remainder value storage and is used in the processing of the measured value. This is because they are associated with each other. In this case, the measured value is in any case an integer number, which is generated using a converter and processed by a control logic circuit. Due to the digital implementation of the second-order delay, there is a high cost for the smoothing means of the current to be supplied to the cross-coil meter or the construction and damping of the cross-coil meter itself.

Measures can be omitted, the latter measures being those which can lead to undesirably inert and non-periodic indication characteristics.

The configuration described in the embodiment section significantly reduces the costs in terms of circuit technology.

[Brief explanation of drawings]

Fig. 1 is an overall block circuit diagram of a device that controls a crossed coil type instrument depending on the measurement frequency, Fig. 2 is a block circuit diagram of a first-order digital delay element (PT1 element), and Fig. 3 is a block circuit diagram of a device that controls a crossed coil type instrument depending on the measurement frequency. 2 is a block circuit diagram of a second-order digital delay element forming the attenuation device in FIG. 1; FIG. 1.3...Converter, 4...Second order digital delay element, 5...Control logic circuit, 20...Remainder value register, 21...Preceding value register, 28.29... First-order digital delay element. FIG. 1

Claims (1)

[Claims] 1. A control logic circuit comprising a converter that converts a measurement signal into a proportional measurement value as an integer, and a driver that generates a current applied to a crossed coil type meter from the measurement value. , a device for controlling a crossed coil type instrument depending on a measurement signal, in which a second-order digital delay element (
A PT_2 element 4) is provided, which digital delay element comprises a device (20, 22) A control device for a crossed coil type instrument. 2. The second-order digital delay element (4) is essentially two mutually connected first-order digital delay elements (PT_1 element 28,
29) A control device for a crossed coil type meter according to claim 1. 3. Both first-order digital delay elements (28, 29) are respectively connected to an adder (11) for multiple addition and to the first input (16') of the adder for the binary measurement value ( a_m) or a register (15) for the intermediate value (a_z_n) of the attenuation calculated in the pre-connected first-order digital delay element; and a shift register (18) into which one binary value can be written, and the binary value written in the shift register can be shifted to perform division and can be shifted from the shift register. The binary values obtained can be connected back to the second input (25) of the adder via a leading value register (21) and a remainder value register (20), and furthermore, these components can be connected under one program control. Control of a crossed-coil type instrument according to claim 1 or 2, which is controllable by a device (27 to 30) for automatic multiple addition and successive shifting in each successive run. Device. 4. The second-order delay elements (28, 29) and the remainder value processing device are constituted by one IC unit, and the IC
Unit converter (1, 3) and control logic circuit (5)
A crossed coil type control device according to any one of claims 1 to 3, which also includes: