JP2983000B2 - Needle display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a needle type display device in which a display pointer is driven by a step motor.

[0002]

2. Description of the Related Art A step motor rotates a unit angle θ ₀ every time a drive pulse is input. The needle-type display apparatus which drives a conventional indication hand in the step motor obtains a difference theta between the current instruction angle theta _P instructed angle theta _M and the current guidelines for indicated by the pointer in the predetermined time intervals T are indicated, It calculates the driving pulse number N than theta obtained, had to move the pointer to the theta _M the calculated N number of pulses sent to the stepper motor.

That is, for each time T, θ = θ _M -θ _P (1) is calculated, and N = θ / θ ₀ (2) is calculated, and as shown in FIG. _The N pulses calculated by the equation (2) for each _A are sequentially transmitted to the step motor to move the pointer.

For this reason, the hand does not fluctuate until the first pulse calculated in the next cycle T is sent after the Nth pulse is sent, and the hand changes in a stepwise manner. Was not smooth. A method of smoothing the deflection of the pointer is described in Japanese Utility Model Laid-Open Publication No. 64-6556.

[0005] In this method, as shown in FIG.
The pulse transmission interval for transmitting the pulses within the period T is T /
N and the transmission of the first pulse is delayed by a time T / 2N. By controlling the pulse transmission start time and the transmission time interval, the movement of the pointer becomes smooth.

Here, assuming that the minimum pulse transmission time interval that can be followed by the step operation determined by the characteristics of the step motor is T _A , T / N ≧ T _A (3) 8B and equation (3), T ≧ 2T _A (4) Therefore, it can be seen that the value of T cannot be smaller than a certain value.

[0007]

In a needle type display device driven by a stepping motor, a driving pulse is transmitted at a time interval longer than a minimum time which can be followed by the stepping operation of the stepping motor. Is required to have a good response to a change in the input signal and a smooth response.

The command angle θ _M shown in FIG. 9 shows an example in which the vehicle gradually increases the speed and accelerates to a constant speed. The solid line represents the minimum time interval that can be followed by the stepping operation of the stepping motor, T _A, and the period T shown in FIG.
Real HirakiAkira 6 when but where the T = 6T _A and T = 12T _A
4 shows the movement of the pointer swinging when operated by the method described in Japanese Patent Application Laid-Open No. 4-65556.

Although this method improves the smoothness,
Since the difference is calculated for each period T, a response delay occurs in the entire region. Since the pulse transmission interval is changed for each period T, a rapid change occurs as shown in FIG. The smoothness is lost, and when the period T is increased, the period T is further increased or worsened. As described above, the period T cannot be made smaller than a certain numerical value. There are problems such as setting is quite difficult.

That is, as in the prior art, arithmetic control is performed for each predetermined time unit, that is, a difference is calculated for each cycle T,
As long as the method of changing the pulse transmission interval is not able to achieve both the quick response and smooth operation described above,
And the smoothness is also insufficient.

An object of the present invention is to provide an improved needle-type display device in which the movement of the pointer is smooth and the response is good.

[0012]

Means adopted by the present invention to solve the above-mentioned problems will be described with reference to FIG. FIG. 1 is a basic configuration diagram of the present invention. In the first means, in a needle-type display device in which a display pointer is driven by a step motor, a time counting means 4 for counting a set time;
Designated position calculating means 1 for calculating a position at which the display pointer is to be instructed for each time counted by the time measuring means 4;
A current position detecting means 2 for detecting a position indicated by a current display pointer at each time counted by the time measuring means 4; a designated position calculated by the designated position calculating means 1; When the difference from the current position is large, the time is short, and when the difference is small, a long time is calculated.
And a drive pulse transmitting means 5 for transmitting a pulse for driving the stepping motor at every time counted by the time measuring means 4.

The transmission of the driving pulse from the driving pulse transmitting means 5 is performed when there is no difference between the designated position calculated by the designated position calculating means 1 and the current position detected by the current position detecting means 2. Stop sending pulses. Also,
The measurement time is calculated by the calculation means 3 the measured time, when there is no difference between the indication position and the current position is a certain value T ₁ and the counting time.

Further, the current position detected by the current position detecting means 2 is derived from the count value from the reference origin where the count value is incremented or decremented every time the driving pulse transmitting means 5 transmits a pulse. Further, in the second means, in a needle type display device in which the display hands are driven by a step motor, a timekeeping A means 6 for measuring time by repeating a predetermined time, and an instruction of the display hands for each time measured by the timekeeping A means 6 An instructed position calculating means 1 for calculating a position to be caused to be operated; a current position detecting means 2 for detecting a position indicated by a current hand pointer at each time counted by the timing A means 6; The difference calculation means 7 calculates the difference between the designated position calculated by the above and the current position detected by the current position detection means 2 to update the record, the time measurement means 4 for measuring the set time, and the time measurement means 4 For each time to be counted, the difference value recorded by the difference calculation means 7 is shorter when the difference value is larger, and longer when the difference value is smaller, and is set to the timekeeping means 4. Time calculating means 3, Includes a drive pulse delivery means 5 for serial clocking means 4 sends out a pulse for driving the stepping motor every time the counting, the.

The transmission of the driving pulse from the driving pulse transmitting means 5 is stopped when the difference value recorded by the difference calculating means 7 is equal to or less than a predetermined value. Further, the measurement time the measured time calculating unit 3 calculates the difference calculation means 7 difference value is recorded to the counting time a certain fixed time T ₁ when the predetermined value or less.

Further, the current position detected by the current position detecting means 2 is derived from the count value from the reference origin where the count value is incremented or decremented each time the drive pulse transmitting means 5 transmits a pulse.

[0017]

In the first means, the time counting means 4 counts the time calculated by the time counting means 3. The pointing position calculating means 1 calculates a pointing position to be indicated by the pointer at each time counted by the timing means 4.

The counting time calculating means 3 has a large difference between the designated position calculated by the designated position calculating means 1 and the current position indicated by the pointer detected by the current position detecting means 2 at each time counted by the timing means 4. When the difference is small, a long time is calculated. The drive pulse sending means 5 sends a drive pulse to the stepping motor every time the time counting means 4 times.

When there is no difference between the designated position calculated by the designated position calculating means 1 and the current position detected by the current position detecting means 2, the driving pulse sending means 5 stops sending the driving pulse. When there is no difference between the designated position and the current position, the clock time calculated by the clock time calculating means 3 is set to a constant value T _1.
Is output as the clocking time.

Further, the current position detecting means 2 derives the current position from the count value from the reference origin whose count value is increased or decreased every time a pulse is transmitted from the drive pulse transmitting means 5. In the second means, the designated position calculating means 1 calculates the designated position at which the pointer is to be designated by the pointer at regular time intervals measured by the timing A means 6.

The current position detecting means 2 detects the current position indicated by the current pointer at regular time intervals measured by the timekeeping A means 6. The difference calculation means 7 calculates the difference between the designated position calculated by the designated position calculation means 1 and the current position detected by the current position detection means 2 and updates the record.

The time counting means 3 reads the difference value recorded by the difference calculating means 7 for each time counted by the time counting means 4, and when the difference value is large, it is short, and when the difference value is small, it is short. A long time is calculated and set in the timer 4. The drive pulse sending means 5 sends a drive pulse to the step motor every time the time counting means 4 counts.

The drive pulse sending means 5 stops sending drive pulses when the difference value recorded by the difference calculating means 7 is equal to or smaller than a predetermined value. In addition, the time counting means 3
The difference value difference calculator 7 is recorded when the predetermined value or less to output a certain value T ₁ as measured time.

Further, the current position detecting means 2 derives the current position from the count value from the reference origin whose count value is increased or decreased every time a pulse is transmitted from the drive pulse transmitting means 5. As described above, in the first means,
The difference between the indicated position to be indicated by the pointer and the current position indicated by the current pointer is calculated to be short when the previously calculated difference is large, and calculated after a long time when the difference is small,
In addition, since the drive pulse is sent to the step motor after the calculated time, when the difference is large, a short time is sent, and when the difference is small, a pulse is sent at a long time interval, and the step motor rotates, The movement of the pointer is smooth and the response can be improved.

When there is no difference between the designated position and the current position, the transmission of the pulse for driving the step motor is stopped, so that the vibration which moves the designated position of the pointer up and down is eliminated, and the designated value can be easily read. Also, since when there is no difference between the indication position and the current position was set to the measured time and T _1, when the difference is generated since it is determined that there is no difference T
After _one second, the movement of the hands is started, and the responsiveness can be improved.

Further, since the detection of the current position is derived from the count value from the reference origin whose count value is increased or decreased every time a pulse is sent to the step motor, an expensive encoder is not required. The current position can be easily detected.

In the second means, the difference between the indicated position indicated by the pointer and the current position indicated by the current pointer is calculated at regular time intervals to update the record, and the difference between the recorded difference is calculated. The read time is set to be short when the difference read last time is large, after a long time when the difference is small, and a drive pulse is sent to the step motor in synchronization with the reading of the difference. When the difference is large, the pulse is transmitted in a short time, and when the difference is small, the pulse is transmitted at a long time interval, and the step motor rotates, whereby the movement of the hands can be smooth and the response can be improved.

Further, when there is no difference between the designated position and the current position, the transmission of the pulse for driving the step motor is stopped, so that the vibration which moves the designated position of the pointer up and down is eliminated, and the designated value becomes easy to read. Also, since when there is no difference between the indication position and the current position was set to the measured time and T _1, when the difference is generated since it is determined that there is no difference T
After _one second, the movement of the hands is started, and the responsiveness can be improved.

Further, since the detection of the current position is derived from the count value from the reference origin in which the count value is incremented or decremented every time a pulse is sent to the step motor, an expensive encoder is not required. The current position can be easily detected.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a block diagram of the first embodiment of the present invention, and FIGS. 3 and 4 are operation flowcharts of the first embodiment. In FIG. 2, 10 is a step motor, 11 is a scale, 12
Is a pointer fixed to the rotating shaft of the step motor 10, 13
Is a current position detector for detecting the current position indicated by the pointer 12, 14 is a designated position calculator, 15 is a timer, 16 is a clock time calculator, 17 is a drive pulse transmitter, 18 to 20.
Denotes an interface (I / O), and 21 denotes a processor (CPU) for performing processing.

The embodiment shown in FIG. 2 is an example in which the I / O 18 displays a speed with a pointer based on a signal from a travel sensor that sends out a pulse every time the vehicle travels a unit distance. When a drive pulse is input via the I / O 19, the step motor 10 rotates by a unit angle θ ₀ .

First, the operation of the designated position calculating section 14 will be described with reference to FIG. The operation of the designated position calculation unit 14 is I / O1
Each time a pulse is input from step 8, the operation of the interrupt processing is started. In process S11, the difference t between the time when the pulse was input from the previous I / O 18 and the time when the pulse was input this time is calculated.

[0033] In the process S12, however _{θ M = K B / t ...} (5), K B calculates the indication position theta _M performs an operation consisting constant.

That is, in the process S12, the speed is calculated from the pulse interval inputted from the I / O 18, and the rotation angle θ _M of the pointer 12 on the scale 11 corresponding to the calculated speed is calculated. In processing S13, the recording and ends the interrupt processing in a memory (not shown) indicated position theta _M calculated in the processing S12.

As described above, the designated position calculating unit 14 calculates a new designated position every time a pulse is input from the travel sensor and updates the record. In the embodiment, the designated position is calculated from the time t from the previous pulse input. For example, the designated position is calculated from the time from several pulses before and the designated position is averaged. Is also good.

Next, the operation of the first embodiment will be described with reference to FIG. In the process S1, the driving pulse transmitting unit 17
Determines whether the count value T of the timer unit 15 has become 0, and if the determination is NO, waits until the determination becomes YES.
That is, the timer unit 15 is constituted by a down counter, and determines whether or not the counter value has decreased from the set value to 0.

In the process S2, the time counting unit 16 reads the indicated position θ _M calculated and recorded by the indicated position calculating unit 14 as described with reference to FIG. The current position θ _P of the pointer 12 detected by the detection unit 13 is read, and the difference θ is calculated by performing the following calculation: θ = θ _M −θ _P (6)

In step S3, the time counting unit 16 determines whether the difference θ calculated in step S2 is | θ | = 0 (7). If the determination is YES, the process proceeds to step S4.
To start counting by setting the T ₁ to the down counter of time keeping unit 15 moved to. The value T ₁ will be described later.

[0039] In process S5, the counting time calculating unit _{16, T S = | K A /} θ | + K B ... (8) However, K _A and K _B calculates the measured time T _S by performing operations comprising constant Then, the process proceeds to step S6, where T _S is set in the timer section 15 to start the time measurement.

In the process S7, the drive pulse sending section 17
A drive pulse is sent to the step motor 10 via the I / O 19, and the process proceeds to step S1. When the difference θ calculated in step S2 is positive, the flag is set to 1 and when the drive pulse is transmitted, the flag is set to 0 when the difference is negative. The step motor 10 rotates the unit angle θ ₀ in the direction corresponding to the flag.

As described above, the designated position θ _M and the current position θ
_When the difference θ from _P is large, the time to be counted by the timer unit is shortened, and when θ is small, the clocking time is lengthened and the drive pulse is transmitted, so that the driving pulse is smoothly and smoothly as shown in FIG. Good response characteristics can be obtained.

The reason why it is determined in step S3 whether or not | θ | = 0 is that when the drive pulse is transmitted when | θ | = 0, the position indicated by the pointer 12 becomes smaller than the position currently indicated. since an error becomes large, the transmission of driving pulses is stopped, so that re determined to T ₁ seconds.

Although the value T ₁ can be set arbitrarily, by setting T ₁ small, the designated position calculation unit 1
The pointing position newly calculated in step 4 is changed and the difference θ
, The pointer can be immediately moved to the designated position to improve responsiveness. If the difference θ calculated by the equation (6) and the unit angle θ _{0 at} which the pointer rotates by driving the step motor are not integers, the determination in the processing S3 is made |
θ | <θ _0/2 and it should be.

[0044] In addition, when the T _S calculated in step S5 may become extremely large, because the new Rata a difference θ during this period is not even able to cope occur, for example T _S is processing If greater than T ₀ S6
Then, T ₀ can be set in the timer section 15 to start the time measurement to improve the responsiveness.

The transmission of the driving pulse in the process S7 is as follows.
T _S is sending before timing but may be sent after T _S timekeeping. Further, the operation when the indication position theta _M has changed suddenly increased, the rotation speed d [theta] _P / d of the current location theta _P
t is dθ _P / dt = θ ₀ / T _S = | (θ _M −θ _P ) θ ₀ / K _A | (9) When the differential equation of Expression (9) is solved, θ _P = θ _M ( 1−exp [−θ ₀ t / K _A ]) (10)

[0046] That is, as indicated by a dotted line in FIG. 9, theta _P
Moves exponentially smoothly and quickly to θ _M.
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a block diagram of the second embodiment, and FIGS. 6 and 7 are operation flowcharts of the second embodiment.

Referring to FIG. 5, a stepping motor 10, a scale 11, a pointer 12, a pointing position calculator 14, and a timer 1
5, clock time calculation unit 16, drive pulse transmission unit 17, I /
O18 and O19 and the CPU 21 are as described in FIG. Reference numeral 22 denotes a timekeeping A unit for measuring time, reference numeral 23 denotes a current position counter for recording the current position of the hands, and reference numeral 24 denotes a difference calculation unit.

The timer A section 22 repeatedly measures a short fixed time, for example, a minimum time during which the step motor 10 can be driven. As will be described later with reference to FIG. 6, the current position counter 23 increments the counter value by ± 1 each time a drive pulse is transmitted to the step motor 10 (+1 when a pulse rotating rightward is transmitted, +1 when a pulse rotating rightward is transmitted). If a pulse is sent out, the count value from the reference origin of the hands is recorded.

The designated position calculating section 14 performs the processing described with reference to FIG.
Calculate _M and update the record. Next, the operation of the difference calculator 24 will be described with reference to FIG. Difference calculator 24
Is performed by an interrupt process, and is disclosed every time the timekeeping A unit 22 finishes timekeeping for a predetermined time.

[0050] The indicated position theta _M where indicated position calculating unit 14 in step S21 is recorded is calculated read, reads out the count value N _P of the current position counter 23 proceeds to S22 and is counting, theta _P = N _P × θ ₀ (11) where θ ₀ is the angle at which the pointer is rotated by one drive pulse, and the current position θ _P is calculated.

In step S23, the difference θ is calculated by performing the following calculation: θ = θ _M −θ _P (12) In the processing S24, the difference θ calculated in the processing S23 is recorded in a memory (not shown), and the interruption processing ends.

As described above, the difference calculator 24 calculates a new difference θ each time the timer A measures a predetermined time and updates the recording. Next, the operation of the second embodiment will be described with reference to FIG. In FIG. 6, processes S1 to S7 are as described in FIG.

In the process S2a, the time counting unit 16 calculates
The difference θ recorded in the memory (not shown) of the difference calculator 24 is read. In step S8, the current position counter 2
3 is incremented by ± 1 (in step S7, a pulse for rotating the pointer 12 clockwise is sent to the stepping motor, ie, in step S7).
If the difference θ read in 2a is positive, the count value is incremented by 1), and the process proceeds to S1.

In the second embodiment, the current position of the pointer is obtained based on the count value of the current position counter. However, the current position of the pointer may be obtained by the current position detection unit as in the first embodiment. good. Also in the first embodiment, the second
The current position may be obtained from the count value of the current position counter, as in the embodiment.

[0055]

As described above, according to the present invention, the following effects can be obtained. As described above, in the first means, the calculation of the difference between the indicated position to be indicated by the pointer and the current position indicated by the current pointer is short when the previously calculated difference is large, When the difference is small, it is calculated after a long time, and after the calculated time, the drive pulse is sent to the step motor. Therefore, when the difference is large, it is short, and when the difference is small, it is long time interval. And the stepping motor rotates, and the movement of the pointer can be smooth and the response can be improved.

When there is no difference between the designated position and the current position, the transmission of the pulse for driving the step motor is stopped, so that the vibration which moves the designated position of the pointer up and down is eliminated, so that the designated value can be easily read. Also, since when there is no difference between the indication position and the current position was set to the measured time and T _1, when the difference is generated since it is determined that there is no difference T
After _one second, the movement of the hands is started, and the responsiveness can be improved.

Further, since the detection of the current position is derived from the count value from the reference origin, which is incremented or decremented every time a pulse is sent to the step motor, an expensive encoder is not required. The current position can be easily detected.

In the second means, the difference between the indicated position indicated by the pointer and the current position indicated by the current pointer is calculated at regular time intervals to update the record, and the difference between the recorded difference is calculated. The read time is set to be short when the difference read last time is large, after a long time when the difference is small, and a drive pulse is sent to the step motor in synchronization with the reading of the difference. When the difference is large, the pulse is transmitted in a short time, and when the difference is small, a pulse is sent out at a long time interval, and the step motor rotates, whereby the movement of the hands can be smooth and the responsiveness can be improved.

When there is no difference between the designated position and the current position, the transmission of the pulse for driving the step motor is stopped, so that the vibration which moves the designated position of the pointer up and down is eliminated, and the designated value can be easily read. Also, since when there is no difference between the indication position and the current position was set to the measured time and T _1, when the difference is generated since it is determined that there is no difference T
After _one second, the movement of the hands is started, and the responsiveness can be improved.

Further, the detection of the current position is derived from the count value from the reference origin in which the count value is incremented or decremented every time a pulse is sent to the step motor, so that an expensive encoder is not required. The current position can be easily detected.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram of the present invention.

FIG. 2 is a configuration diagram of a first embodiment of the present invention.

FIG. 3 is an operation flowchart of the embodiment.

FIG. 4 is an operation flowchart of the embodiment.

FIG. 5 is a configuration diagram of a second embodiment of the present invention.

FIG. 6 is an operation flowchart of the embodiment.

FIG. 7 is an operation flowchart of the embodiment.

FIG. 8 is an operation explanatory diagram of a conventional example.

FIG. 9 is an explanatory diagram of the operating characteristics of the hands of the present invention and the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pointed position calculating means 2 Current position detecting means 3 Timing time calculating means 4 Timing means 5 Driving pulse sending means 6 Timing A means 7 Difference calculating means 10 Step motor 11 Scale 12 Pointer 13 Current position detecting part 14 Pointed position calculating part 15 Timing Unit 16 clocking time calculating unit 17 drive pulse transmitting unit 18-20 interface (I / O) 21 processor (CPU) 22 clocking A unit 23 current position counter 24 difference calculating unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01D 7/00 G01P 3/42 H02P 8/12

Claims (8)

(57) [Claims] 1. A hand-held display device in which a display pointer is driven by a stepping motor, a timer means for measuring a set time, and a position to be indicated by the display pointer for each time counted by the timer means. Indicated position calculating means for calculating; a current position detecting means for detecting a position indicated by a current display pointer at each time counted by the time measuring means; an indicated position calculated by the indicated position calculating means; and the current position When the difference from the current position detected by the detection means is large, the time is short, and when the difference is small, a long time is calculated and set in the timekeeping means. And a driving pulse transmitting means for transmitting a pulse for driving the stepping motor. 2. The method according to claim 2, wherein the driving pulse transmission from the driving pulse transmitting means is performed when there is no difference between the designated position calculated by the designated position calculating means and the current position detected by the current position detecting means. 2. The needle-type display device according to claim 1, wherein the display is stopped. 3. A process according to claim, characterized in that as the said measurement time calculated by the measured time calculating means, the indication position and the measurement time to a certain value T ₁ when there is no difference between the current position 3. The needle type display device according to 1 or 2. 4. The method according to claim 1, wherein the current position detected by the current position detecting means is derived from a count value from a reference origin where the count value is incremented or decremented every time the drive pulse transmitting means transmits a pulse. The needle display device according to claim 1, 2, or 3, wherein: 5. A hand-held display device in which a display pointer is driven by a step motor, wherein a time-measuring A means for measuring time by repeating a predetermined time, and wherein the display pointer is instructed for each time measured by the time-measuring A means. A designated position calculating means for calculating a position; a current position detecting means for detecting a position indicated by a current hand at each time counted by the timing A means; a designated position calculated by the designated position calculating means; A difference calculating means for calculating a difference between the current positions detected by the position detecting means and updating the record; a time measuring means for measuring a set time; and a recording means for recording the difference for each time counted by the time measuring means. From the difference value, when the difference value is large, the time is short, and when the difference value is small, a long time is calculated and set in the time counting means. A needle-type display device comprising: a driving pulse transmitting unit that transmits a pulse for driving a step motor. 6. The transmission of the driving pulse from the driving pulse transmitting means is stopped when the difference value recorded by the difference calculating means is equal to or less than a predetermined value. The needle type display device according to claim 5, wherein 7. A measurement time the measured time calculating means calculates, that difference value the difference calculating means is recorded which is adapted to count time a certain fixed time T ₁ when the predetermined value or less 7. The needle type display device according to claim 5, wherein: 8. A current position detected by the current position detecting means is derived from a count value from a reference origin at which a count value is incremented or decremented every time the drive pulse transmitting means transmits a pulse. The needle-type display device according to claim 5, 6 or 7, wherein: