JP3224009B2 - Pointer 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 pointer type display device which displays a measured amount by moving a pointer.

[0002]

2. Description of the Related Art Conventionally, there has been known a pointer type display device which displays a measured amount by moving a pointer. This pointer-type display device is used in a vehicle such as an automobile as a speedometer for displaying the traveling speed of the vehicle or a tachometer for displaying the rotation speed of the engine.

In such a pointer-type display device (hereinafter referred to as a conventional device), when the pointer is rotated from a current angle (position) to a designated angle (position) defined by a measured amount,
According to the difference between the indicated angle and the current angle, if the difference between the two is large, the control amount for driving the pointer is increased, and if the difference is small, the control amount is reduced, so that the pointer can move smoothly. There was something to be realized.

More specifically, in this conventional apparatus, when an instruction angle is given in each indicated angle calculation cycle, processing using a weighted average formula is executed in each control angle calculation cycle shorter than the indicated angle calculation cycle. Thus, the control angle which is the pointer position in the next control angle calculation cycle is calculated. Then, a drive signal corresponding to the calculated control angle is generated, and the generated drive signal is sent to the drive unit of the pointer, and the pointer is moved until the next control angle calculation cycle arrives.

[0005] According to the calculation using the weighted average formula, a control angle having a large value is calculated when the difference between the indicated angle and the current angle is large, and when the difference is small, that is, when the pointer is set to an instruction specified by the measured amount. When approaching the position, a control angle having a small value is calculated. Then, according to the control angle, the pointer moves at a high speed when the difference between the indicated angle and the current angle is large, and moves at a low speed when the difference is small. Thus, the pointer moves smoothly.

[0006]

In this conventional apparatus, the control angle is calculated by the processing using the above-mentioned weighted average equation. The pointer fluctuates with the fluctuation of the measurement amount, and the visibility is impaired. In particular, in the tachometer described above, the engine speed during traveling can be accurately displayed, but the speed during idling may be unstable, and a phenomenon occurs in which the hands swing during idling. There was something. The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a pointer-type display device that prevents the pointer from oscillating at a specific position and that provides good visibility. I do.

[0007]

In order to solve the above-mentioned problems, a pointer-type display device according to the present invention, as shown in the basic configuration diagram of FIG. 1, reduces the amount of measurement to be displayed every first operation cycle. Update the indicated position, which is the movement target of the pointer,
In each second operation cycle shorter than the first operation cycle, the moving position of the pointer is obtained by a weighted average processing of the indicated position and the current position which is the actual pointing position of the pointer, and the pointer is moved to the moving position. A pointer-type display device having control means (21a) for causing the measured amount to be mounted on a vehicle.
The control means (21a).
Is used in the weighted averaging process according to the designated position.
A weight changing means (21b) for changing a weight;
The weight change means (21b) has a variation in the designated position.
The engine speed is a predetermined low rotation range.
If the number of rotations, the weighted average processing in the
It is characterized by increasing the weight of the current position. (Claim
1)

[0008] In the configuration of the first aspect, the control means updates a designated position as a movement target of the pointer in accordance with a measured amount to be displayed in each first operation cycle, and updates the designated position which is shorter than the first operation cycle. The moving position of the pointer is obtained by weighted averaging of the indicated position and the current position, which is the actual indicated position of the pointer, every two operation cycles. The measured amount is
This is information on the rotation speed of the motor. And the weight change means,
When the engine speed is in the predetermined low speed range
The weight of the current position in the weighted averaging process is increased. Yo
Therefore, according to this configuration, the engine speed is unstable and low.
In the engine speed range, reduce the effect of this engine speed.
The display of the pointer can be stabilized.

[0009]

[0010]

[0011]

[0012]

[0013]

In addition, the control means (21a) is provided for each of the second operation cycles by the following equation:

(Equation 2) A control signal generating means for calculating a moving position of the pointer for each of the second operation cycles and generating a control signal based on the moving position by executing a process based on the weighted average formula of The means (21b) is characterized in that the weight of the current position in the weighted average processing is increased by increasing the value of n in the weighted average expression and increasing the denominator. (Claim 2 )

In the configuration of the second aspect , the control means has a control signal generation means. This control signal generation means calculates the following equation every second operation cycle.

(Equation 3) By executing the processing based on the weighted average formula, the movement position of the pointer for each second operation cycle is calculated, and a control signal based on the movement position is generated. And
The weight changing means increases the weight of the current position in the weighted average processing by increasing the denominator (2 ⁿ ) in the weighted average expression. Therefore, according to this configuration, the value of n in the weighted average expression
Is increased to increase the denominator, the weight of the current position can be increased, and no special processing is required and the processing can be simplified.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing a configuration of a pointer type display device to which the present invention is applied. In the figure, reference numeral 10 denotes a display unit for displaying the running speed of the vehicle, 20 denotes a display control unit as control means for controlling the device, and 30 denotes a non-volatile memory (hereinafter, referred to as a storage device) in which information referred to by the display control unit 20 is stored. Reference numeral 40 denotes an ignition coil for outputting a frequency signal FS having a frequency proportional to the engine speed, and reference numeral 50 denotes a battery as a power supply for supplying a voltage.

The display unit 10 includes a cross coil 11 composed of a _first coil L ₁ and a second coil L ₂ disposed to cross each other, and a magnet rotor disposed in a magnetic field generated by the cross coil 11. And a pointer 1 connected to the magnet rotor 15 via the pointer shaft 14
2 and a dial 13 on which a scale for speed display is drawn.

The display control unit 20 includes a CPU 21 as a central control unit and a ROM in which operation programs and the like are stored.
22 and a RAM 23 for temporarily storing necessary information when the CPU 21 operates. CPU 21
Indicates a FIN terminal for receiving the frequency signal FS, a VCC terminal and a VSS terminal to which a power supply voltage is input,
And a P1 terminal to a P4 terminal for outputting a drive signal for the.

The RAM 23 is divided into a plurality of areas.
As shown in the figure, the partial area includes an instruction angle calculation cycle holding area 23a that holds the instruction angle calculation cycle, a counter area 23b that counts the instruction angle calculation cycle, and an indication angle (N
EW), a control angle holding region 23d for holding a control angle (current angle), an addition control angle holding region 23e for holding an addition control angle (ΣOLD) which is an added value of the control angle, and a regulation. It is used as a specified value holding area 23f for holding a value.

The NVRAM 30 is also divided into a plurality of areas, an area for holding travel distance information indicating the travel distance of the vehicle, an area for holding swing angle information defining the swing angle of the pointer 12, or a specified engine speed. Are used as an area for holding the information (all not shown). The contents held in the NVRAM 30 are the same as those of the CP.
It is referred to when U21 operates.

The ignition coil 40 is an induction coil for generating a high voltage for engine ignition, and outputs a frequency signal FS proportional to the engine speed. Then, the frequency signal FS is shaped by the interface 41 and output to the FIN terminal of the CPU 21.

The battery 50 is provided with a constant voltage circuit 51. The constant voltage circuit 51 converts an electric signal from the battery 50 into a predetermined constant voltage,
1 to the VCC and VSS terminals.

Next, the operation of the apparatus having the above configuration will be described with reference to the flowchart of FIG. In this device, first, in step S110, it is determined whether to calculate the designated angle. This determination is made in the RAM 23
Is performed based on the indicated angle calculation cycle held in the indicated angle calculation cycle holding area 23a and the time measurement information by the counter area 23b of the RAM 23. Then, when the timing information reaches the designated angle calculation cycle, the designated angle is calculated (Y).
And the process moves to step S120. If the timekeeping information has not reached the designated angle calculation cycle, the designated angle is not calculated (N), and the routine goes to Step S130.

In step S120, the interface 4
The average cycle of the frequency signal FS from the ignition coil 40 input through the input unit 1 is calculated from the input frequency signal FS, and the process proceeds to step S121. In step S121, the designated angle is calculated based on the average period calculated in step S120, and the calculated designated angle is stored in the designated angle holding area 23 of the RAM 23.
c. Then, control goes to a step S130.

In step S130, the designated angle is a specified value, that is, the idling speed of the engine (for example, 200
0 rpm) is determined. When the designated angle is an angle exceeding the idling rotational speed (Y), the process proceeds to step S131, and when the designated angle is equal to or less than the idling rotational speed (N), the process proceeds to step S1.
Move to 32. As the specified value in step S130, the specified value stored in the NVRAM 30 is used as described above. The specified value is written in the NVRAM 30 in advance at the time of product shipment or the like, and is read into the specified value holding area 23f of the RAM 23 at the time of initial operation of the apparatus.

In step S131, the control angle is calculated using the weighted average expression shown in the following equations (1) and (2).
At this time, the calculation process is performed by setting n in Expression (1), that is, the exponent of the power to a normal value “4”. That is, in step S131, 2 ⁿ in the above equation (1) becomes 2 ⁴ , and a weighted average process is performed on a total of 16 data.

[0027]

(Equation 4)

On the other hand, in step S132, similarly to step S131, the control angle is calculated using the weighted average formulas shown in the above formulas (1) and (2). However, in step S132, the calculation process is performed by setting n in the expression (1), that is, the exponent of the power to a value “5” which is larger than usual. In this case, 2 ⁿ in the above equation (1) becomes ²⁵ , and a weighted average process is performed on a total of 32 data.

That is, in this step S132, since the weighted average processing by double the number of data (32 data) is performed on the number of data (16 data) in the weighted average processing of step S131, the current The ratio (weight) of the position (corresponding to disp (i), that is, disp (i-1) in the previous operation cycle) is heavier than the ratio (weight) of the current position in the weighted average processing in step S131.

More specifically, the ratio of the current position in the weighted average processing in step S131 is determined by the difference (NEW-disp (i-
1-k / 16 obtained by subtracting the ratio of 1)) from the whole
The ratio (weight) occupied by the current position in the weighted averaging process in step S132 is 1-k / 32. Accordingly, the ratio (1-k / 32) occupied by the current position in the weighted averaging process in step S132 is calculated in step S132.
131 (1−k / 16)
Larger than.

The above steps S131 and S132
Is different in the number of data to be subjected to the weighted averaging, so that the ΣOL in the above equations (1) and (2)
D (i-1) needs to be modified. That is, if n = 4 (S131) in the previous operation cycle and n = 5 (S132) in the current operation cycle, step S
At 132, first, the value of ΣOLD (i-1) is doubled, and the processing of the above equation (1) is performed using the doubled ΣOLD (i-1). Also, in the previous operation cycle, n = 5
And when n = 4 in the current operation cycle, ΣOLD (i−i) in the previous operation cycle (that is, n = 5).
The value of 1) is set to １ ／, and the processing of the above equation (1) is performed using this の value.

When the control angle calculation processing in step S131 or step S132 is completed, the flow shifts to step S133, where the calculated control angle is stored in the RAM.
23, and the addition control angle, that is, the value of ΣOLD (i), is stored in the addition control angle holding area 23e.

In step S140, the above step S1
At 33, the control angle stored is read out, a drive signal corresponding to the control angle is generated, and the generated drive signal is supplied to the display unit 10 (cross coil 11) via terminals P1 to P4. When the processing in step S140 ends, the flow shifts to step S110 to execute processing in the next operation cycle.

As described above, in this embodiment, when the engine speed exceeds a specified idling speed (for example, 2000 rpm) (S130).
And Y), the control angle is calculated by setting the value of n in the above equations (1) and (2) to a normal value of "4" (S13).
1) If the idling rotational speed is less than the specified idling rotational speed (S1)
The control angle is calculated by setting the value of n in the above equations (1) and (2) to "5" which is larger than the normal value in N) (S132) (S132).

As a result, the weight of the current position [$ OLD (i-1)] at a speed less than the prescribed idling speed is
Since the weight of the current position becomes heavier than the weight of the current position when the idling rotational speed exceeds the prescribed value and the influence of the measured amount is reduced, the movement of the hands in the idling rotational region where rotation is unstable can be stabilized. In addition, since the change of the weight can be performed by changing the value of n in the above equations (1) and (2), the weight can be changed by a simple process without requiring any special process.

The basic configuration of the present invention and the flowchart of the above embodiment have the following correspondence. That is, the control means (21a) in the basic configuration of the present invention.
Corresponds to step S11 in the flowchart of the embodiment.
The weight change means (21b) corresponds to steps S130 to S132.

In the above description, the tachometer for displaying the engine speed of the vehicle has been described as an example. However, the present invention is not limited to this, and the measured amount to be displayed may be unstable. This is effective when the region includes Further, the value of the specified value, which is the switching point of the weight in the above-described embodiment, can be set arbitrarily for each vehicle or for each type of measured quantity.

[0038]

As apparent from the above description, the present invention has the following effects. In other words, the weight in the weighted averaging process is changed according to the position indicated by the pointer, so that the weight can be set so as to suppress the fluctuation at a specific display position where the fluctuation of the pointer occurs, and the pointer can be stabilized. Can be done.

[0039]

Further, the measured amount is used as information on the engine speed, and the weight of the current position in the weighted averaging process is increased when the engine speed is a predetermined low speed range. In a low rotation range where the engine speed is unstable, the influence of the engine speed can be reduced, and the display of the hands can be stabilized.

Also, by increasing the value of n in the weighted average expression and increasing the denominator, the weight of the current position can be increased, so that no special processing is required and the processing is simplified. Can be.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a configuration of a pointer type display device to which the present invention is applied.

FIG. 3 is a diagram illustrating a configuration of a RAM 23.

FIG. 4 is a flowchart illustrating an operation of the apparatus.

[Explanation of symbols]

 Reference Signs List 10 display unit 11 cross coil 12 pointer 20 display control unit 21 CPU 22 ROM 23 RAM 30 NVRAM 40 ignition coil

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01D 13/22 101 G01D 7/00 G01P 1/08 G01P 3/42

Claims (2)

(57) [Claims] 1. An indication position, which is a movement target of a pointer, is updated in accordance with a measured amount to be displayed in each first operation cycle, and the designated position and the designated position are updated in each second operation cycle shorter than the first operation cycle. In a pointer type display device having a control means for determining the movement position of the pointer by weighted averaging processing with the current position which is the actual pointing position of the pointer and moving the pointer to the movement position, the measured amount is mounted on a vehicle. Engine speed
The control means may control the weighted average in accordance with the designated position.
A weight change unit for changing a weight in the processing, wherein the weight change unit has a variation in the designated position;
The rotation speed of the engine, which is the position, is in a predetermined low rotation range.
The current number in the weighted averaging process
Pointer-type display device characterized by increasing the weight of the position . 2. The control means according to claim 1 , wherein : By executing the processing based on the weighted average formula of
The movement position of the pointer is calculated every second operation cycle and
A control signal generator for generating a control signal based on the moving position.
And a weight changing means for increasing the value of n in the weighted average expression.
By increasing the denominator,
The weight of the current position is increased.
Pointer-type display device as described.