JPH10335993A - Waveform-generating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waveform-generating apparatus which can generate a predefined arbitrary signal waveform with high accuracy at a high speed and with a simple constitution. SOLUTION: A waveform-generating apparatus is provided with a memory 12, which stores each data V(i), SR(i), and T(i) of target voltage values defined at every changing point of an arbitrary signal waveform, time values, and inclination values deciding the rising and falling inclinations of the signal waveform, a data conversion circuit 13 which reads out the data V(i) and SR(i) of the target voltage values and inclination values, corresponding to the time values from the memory 12 based on a start pulse signal Sp and converts the data V(i) and SR(i) into analog signals Sv and Sr. A signal-outputting circuit 14 which successively generates analog signal waveforms Vout such that their waveforms rise or fall with time at changing points, which are equal to the target voltage values corresponding to the inclination values in accordance with the analog signals Sv and Sr.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveform generator suitable for application to a device for generating a signal waveform for driving an electro-mechanical conversion system (hereinafter referred to as an actuator) such as a solenoid valve, a motor, a piezoelectric element, and the like. . More specifically, an analog signal is generated based on a set of a voltage target value and a time value at each changing point of an arbitrary signal waveform defined in advance, and a slope value for determining a rising and falling slope of the waveform. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveform generating apparatus which generates a waveform to simplify the apparatus and speed up data processing.

[0002]

2. Description of the Related Art In recent years, various types of actuators have been used as active devices for converting electric manipulated variables into actual physical quantities such as displacement, speed, and force. Actuators that use electromagnetic force include electromagnetic valves and motors. Actuators utilizing the piezoelectric effect include piezoelectric elements such as piezo elements. In many cases, these piezoelectric elements and actuators such as solenoid valves are driven by pulse signals generated by a dedicated waveform generator in order to obtain desired displacement, speed, force, and the like.

At this time, the actuator should be driven as it is by the output waveform from the waveform generator, but actually, as a result, the actuator is driven by the input waveform different from the output waveform of the waveform generator. There are cases. For example, even if a single pulse signal is given to the actuator as an input waveform, the actuator is driven with vibration, and the desired displacement, speed,
There is a case where power or the like cannot be obtained.

[0004] This is considered to be due to inertia or compliance in the actuator itself or in a portion where the actuator exerts a mechanical action. In order to return an input waveform accompanied by such a vibration (hereinafter referred to as a vibration waveform) to a desired waveform shape, a vibration waveform of an actuator,
In other words, a complex waveform must be synthesized with the output waveform of the waveform generator to remove the influence of vibration.

As the simplest example of removing the influence of vibration from the vibration waveform, an actuator such as a solenoid valve or a motor is replaced with a secondary circuit (having a secondary transfer function) as shown in FIG. 5A. Let's consider the case. In order to cause, for example, minute displacement by these actuators, a single-shot pulse signal (square wave) Sin generated by the waveform generator as shown in FIG. 5B is input to the secondary system circuit 7. FIG. 5C shows an output waveform Sout of the secondary system circuit 7 to which the pulse signal Sin is input.

Generally, in the secondary system circuit 7, ringing (vibration) occurs at the falling edge of the output waveform Sout due to the above-described factors.
Often accompanies. When the secondary circuit 7 is an actuator such as a solenoid valve, if this ringing occurs when the solenoid valve is closed, the valve vibrates and the valve is not completely closed within a specified time. State. As a result, the fluid or the like controlled to be opened and closed by the solenoid valve does not stop completely.

Therefore, in order to suppress the ringing, it is necessary to shape the waveform so that the falling edge of the input waveform Sin 'has a slope as shown in FIG. 5D. For example, when the falling edge has a constant slope value (slew rate), the output waveform Sout ′ of the secondary system circuit 7 that receives the input waveform Sin ′ is improved as shown in FIG. 5E. Although this improvement method suppresses the ringing of the output waveform Sout, it causes a problem that the trailing edge of the output waveform Sout becomes conspicuous.

Therefore, as a method of suppressing the ringing and preventing the falling edge from becoming blunt, a method of inputting a stepped waveform Sin "as shown in FIG. 5F to the secondary system circuit 7 is considered. This method is performed by superimposing, for example, another pulse signal on the trailing edge of the pulse signal Sin.At this time, an output waveform Sout "as shown in FIG. Ringing can be suppressed without dulling the output waveform Sout ".

Therefore, the electromagnetic valve or the like replaced by the secondary system circuit 7 can be driven without vibrating.

By the way, the stepped waveform S shown in FIG.
The simplest device for actually generating "in" may be a device for generating various types of pulse signals and synthesizing them. FIG. 6 is a diagram for generating a step-like input waveform Sin. It is a figure showing an example of composition of waveform generating device 10. In this example, three kinds of waveforms which can be combined are generated by an external start pulse signal Sp.

As shown in FIG. 6, a monostable multivibrator 3A is connected to the input terminal 1, and based on the start pulse signal Sp, a signal which becomes a fundamental wave (rectangular wave) having a pulse width φ1 as shown in FIG. 7B. Sp1 is generated. This signal Sp1 is amplified by the waveform shaping circuit 4A to triple the pulse amplitude and output to the adder 5. The signal after three-fold amplification is indicated by Sp1 '(FIGS. 6, 7G).

A delay circuit 2A is further connected to the input terminal 1, and the start pulse signal Sp is delayed by a predetermined time t1. A monostable multivibrator 3B is connected to the output stage of the delay circuit 2A, and the delayed start pulse signal Sp
From the time delayed by the delay time t1 based on the
2 signal Sp2 is generated (FIG. 7D). This signal Sp
2 is output to the adder 5 after the pulse amplitude is doubled by the waveform shaping circuit 4B. The signal after being amplified twice is S
This is indicated by p2 '(FIGS. 6 and 7G).

The output stage of the delay circuit 2A further includes a delay circuit 2
B is connected, and the start pulse signal Sp delayed by the delay circuit 2A is further delayed by a predetermined time t2. A monostable multivibrator 3C is connected to the output stage of the delay circuit 2B, and a signal Sp3 having a pulse width φ3 whose output timing is further delayed based on the start pulse signal Sp delayed by the delay circuits 2A and 2B is generated. (FIG. 7F). In this example, the signal Sp3 is output from the waveform shaping circuit 4C to the adder 5 while the pulse amplitude is 1 time.

In the waveform generator 10, these three signals Sp1 'and Sp2' Sp3 are synthesized by the adder 5, and the actuator is actuated by the synthesized signal Sp0 (FIG. 7G) having the same waveform as shown in FIG. 5F. It is configured to be driven.

When an actuator such as a solenoid valve is driven by the synthesized signal Sp0, the solenoid valve is closed almost without vibration, as is apparent from the above-mentioned reason.

Thus, the delay circuits 2A and 2B, the monostable multivibrators 3A to 3C, and the waveform shaping circuits 4A to 4A
There is an advantage that the waveform generator 10 can be configured by a combination of simple circuits such as 4C. However, in order to completely eliminate ringing from an input waveform required by an actuator such as a solenoid valve or a motor, it is necessary to generate a waveform in which the step-like portion of the composite waveform Sp0 is further reduced.

For this reason, in the waveform generator 10, more delay circuits are required to delay the start pulse signal Sp more finely, and a number of waveform shaping circuits having different circuit constants (multiples; amplification degrees) are required. Besides the necessity, the control becomes more difficult.

Therefore, a waveform generator combining a microcomputer and a waveform memory is effective for shaping the falling portion of an input waveform required by an actuator such as a solenoid valve or a motor with high accuracy. .

FIG. 8A is a diagram showing an example of the configuration of a conventional waveform generator having a microcomputer and a waveform memory. In this device, various types of waveforms required by actuators such as solenoid valves and motors are prepared in advance as waveform data D, and these waveform data D can be selected from outside. For example, when the actuator is an electromagnetic valve, as shown in FIG. 8B, the valve is opened and closed with the passage of time, and the voltage target values v (1), v (2), v (3).
.. May be required to control the valve openings θ1, θ2, θ3,.

The microcomputer 8A is connected to a waveform memory 8B as shown in FIG. 8A, and stores waveform data D of an input waveform required for controlling the solenoid valve. The waveform data is a system clock (minimum time resolution; for example,
The clock frequency is generated at intervals of several tens of MHz. In this example, when the valve is closed, the rising and falling portions of the waveform are inclined so that no vibration occurs. This waveform falling portion (for example, transition sections a to
The waveform data of b) is 1 when converted to the system clock.
It is complemented by the 0 clock quantile. Transition section a to
b corresponds to the downward staircase portion of the composite waveform Sp0 shown in FIG. 7G.

A high-resolution digital / analog converter (hereinafter referred to as a D / A converter) 9 is connected to the output stage of the microcomputer 8A, and the waveform data D read from the waveform memory 8B is subjected to digital / analog conversion. You. In this device, the analog waveform after the digital / analog conversion is directly output to a solenoid valve or the like.

Next, the operation of the present apparatus will be described. First, when a signal waveform required for controlling the solenoid valve is instructed to the microcomputer 8A, the waveform data D applied by the solenoid valve is stored in the waveform memory 8B from the microcomputer 8A.
Is read by This waveform data is transferred to the D / A converter 9. After this waveform data D is converted into an analog signal by the D / A converter 9, it is output to the actuator as a requested analog waveform.

Since various waveform data D are stored in the waveform memory 8B, any of the waveform data D is stored.
, An arbitrary analog waveform can be supplied to the actuator.

As described above, the waveform generator provided with the microcomputer 8A and the waveform memory 8B can select a waveform necessary for controlling the solenoid valve or the motor from various types of waveforms by an external instruction. Thus, a desired signal waveform can be generated with high accuracy.

[0025]

However, FIG.
8A and waveform memory 8B shown in FIG.
The conventional waveform generator provided with the above has the following problems.

(1) In order to prepare various types of waveforms required by actuators such as solenoid valves and motors, an enormous amount of waveform data D created in advance at every system clock is required. For example, in FIG.
If the period during which the waveform falls to the voltage target value that causes the solenoid valve to be closed from (2) (transition sections a and b) is set to 1 μS, in order to generate the waveform, the transition sections a to Even with b alone, waveform data D that complements the tens of clocks per system clock is required. For this reason, a large-capacity waveform memory 8B for storing an enormous amount of waveform data D is required.

(2) In the conventional apparatus, in order to faithfully reproduce a complex input waveform required for an actuator or the like, the waveform data D at intervals of the system clock is converted to a high-resolution D / A.
It must be generated at high speed by the converter 9. In the above example, the operation speed of the D / A converter 9 is 1
A frequency of about 0 MHz is required. Generally, a high-resolution D / A converter is expensive, which hinders the cost reduction of the device itself.

Therefore, the present invention has been made in view of the above-mentioned problems, and enables an arbitrary signal waveform defined in advance to be generated with high accuracy and with little data at high speed. It is an object of the present invention to provide a waveform generator which can be realized with a simple configuration.

[0029]

In order to solve the above-mentioned problems, a waveform generator according to the present invention employs a voltage target value and a time value defined in advance for each change point of an arbitrary signal waveform and the signal waveform of the signal waveform. A memory for storing each set of data relating to a slope value for determining the rising and falling slopes as a set, and each data of a voltage target value and a slope value corresponding to a time value of an arbitrary signal waveform as a signal generation start signal A data conversion circuit which reads out from the memory based on the data and converts each data into an analog signal relating to a voltage target value and an analog signal relating to a slope value; and A signal output circuit for generating the voltage, each change point is a voltage target value, and its waveform rises with time in accordance with the slope value. Such as down rising or falling, in which the sequentially generates a predefined arbitrary analog signal waveform.

In the waveform generator according to the present invention, it is only necessary to define and prepare in advance a set of a voltage target value, a time value, and a slope value for each change point of an arbitrary signal waveform. It is not necessary to prepare data such as waveform data generated at intervals of the system clock (minimum time resolution). Therefore, a large-capacity waveform memory for storing waveform data in units of the system clock is not required.

Since the waveform generator of the present invention has a buffer configuration in which the data of the voltage target value, the time value, and the slope value previously stored in the memory can be independently read out to the data conversion circuit, the data conversion is performed. The circuit can convert each data of the voltage target value and the slope value corresponding to the time value into an analog signal asynchronously with the data transfer processing by the computer or the like. Therefore, a waveform can be generated at high speed without being limited by the data transfer speed.

[0032]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a waveform generator 100 as an embodiment of the present invention. In this embodiment, three types of voltage target value, time value, and slope value (slew rate, time change rate) defined for each change point of a signal waveform required by an actuator such as a solenoid valve or a motor are set. The stored data is temporarily stored in a memory from a computer or the like, and based on a waveform generation start signal (hereinafter referred to as a start pulse signal) Sp, the data is asynchronously read from the memory to a data conversion circuit to generate an analog signal waveform. Things.

As shown in FIG. 1, an interface circuit 11 is connected to the data input terminal 11A of the waveform generator 100 of the present invention, and the voltage of a signal waveform defined in advance for driving an actuator such as a solenoid valve or a motor. Data V (i), T (i), SR of target value, time value, and slope value
(I) is input as a set.

For example, when a signal waveform required by an analog solenoid valve which opens and closes the valve with the passage of time is generated, as shown in FIG. 2B, time value data T ( 0) corresponding to the inclination value data SR
(0) and voltage target value data V (0) are defined as one set. Similarly, three sets of the inclination value data SR (1) and the voltage target value data V (1) are defined as one set corresponding to the time value data T (1) for closing the solenoid valve. Accordingly, in order to open the valve again, three sets of the slope value data SR (2) and the voltage target value data V (2) are defined as one set corresponding to the time value data T (2).

As described above, three sets of the inclination value data SR (i) and the voltage target value data V (i) are defined as one set corresponding to the time value data T (i) associated with the opening and closing of the solenoid valve.
Slope value data SR corresponding to time value data T (n)
(N) and the voltage target value data V (n) are defined as one set (see FIG. 2B).

The data V (i) is a voltage target value at each changing point of the predefined waveform. If the actuator is a solenoid valve, the voltage target values V (0), V (2), V
(4)... That is, when i is an even number, the voltages determine the opening degrees θ1, θ2, θ3,... (See FIG. 2C). The larger the voltage, the larger the valve opens. Therefore, the flow rate of the fluid (ink or the like) controlled by the solenoid valve can be controlled by the voltage target value.

Data T (i) is a time value at a change point of a waveform required by an actuator or the like. Data SR
(I) is a slope value (slew rate, time change rate) for determining the rising and falling slopes of the signal waveform. In particular, since the falling of the signal waveform affects the state of closing the solenoid valve, it is defined by a slope value which has been previously confirmed by experiments or the like so that ringing does not occur in this portion.

The data V (0), SR (0), T
(0), V (1), SR (1), T (1) ..., V
(I), SR (i), T (i) ..., V (n), SR
(N) and T (n) are supplied from a computer or the like based on the write enable signal WE shown in FIG.
(See FIG. 3A).

The data V (i), T (i), and S (V) are applied to the clock terminal 11B connected to the interface 11.
When R (i) is input, a clock signal CLK is supplied,
The write enable signal WE is supplied to the write enable terminal 11C.

The output stage of the interface 11 is connected to a memory 12 constituted by a voltage target value memory section 21, a slope value memory section 22, and a time value memory section 23. Voltage target value data V (0), V (1),... V (i),
... V (n) are temporarily stored in the voltage target value memory unit 21. Slope value data SR (0), SR (1),... S
R (i),... SR (n) are temporarily stored in the inclination value memory unit 22. Time value data T (0), T (1)
, T (i),..., T (n) are temporarily stored in the time value memory unit 23. When the data corresponding to the voltage target value memory unit 21, the slope value memory unit 22, and the time value memory unit 23 are separately stored, the data V corresponding to the data T (i) is obtained.
(I) Since SR (i) can be read out in parallel, the speed can be increased.

The output stage of the memory 12 is connected to a data conversion circuit 13 composed of a timing generation circuit 31, a reading section 32, and digital / analog converters (hereinafter, referred to as D / A converters) 33 and 34. When a start pulse signal Sp is externally input to the timing generation circuit 31 when the solenoid valve or the like is driven, the start pulse signal Sp
The data read operation is started based on p. That is,
Timing generation circuit 3 according to start pulse signal Sp
The counter in 1 is activated, and the output value of the counter and the time value data T (0) are compared by the reading unit 32.

If the output value of the counter matches the time value data T (0) as a result of this comparison, the time value data T (0)
The voltage target value data V (0) corresponding to (0) is read from the memory unit 21 to the D / A converter 33. At the same time, the slope value data SR (0) is read from the memory unit 22 to the D / A converter 34. The data V (0) is converted by a D / A converter 33 into an analog signal Sv regarding a voltage target value, and the data SR (0) is converted by a D / A converter 34 into an analog signal Sr regarding a slope value.

Since the counter continues the counting operation, when the output value of the counter matches the time value data T (1), the previous time value data T (0) is changed to the time value data T (0).
Updated to (1). Updated time value data T (1)
Is read from the memory unit 21 to the D / A converter 33. At the same time, the inclination value data SR (1) is transferred from the memory unit 22 to the D / A converter 34.
Is read out. The data V (1) is converted by a D / A converter 33 into an analog signal Sv regarding a voltage target value, and the data SR (1) is converted by a D / A converter 34 into an analog signal Sr regarding a slope value.

As described above, at each timing when the count output value matches the time value data T (i), the voltage target value data V (i) and the slope value data SR paired with the time value data T (i). (I) are sequentially read from the memory 12, the data V (i) is converted into an analog signal Sv regarding a voltage target value, and the data SR (i) is converted into an analog signal Sr regarding a slope value.

A signal output circuit 14 is connected to the output stage of the data conversion circuit 13, and these analog signals Sv, Sr
, An analog signal waveform Vout is generated. The analog signal waveform Vout is sequentially generated such that each change point is a voltage target value and rises or falls with time in accordance with the slope value.

Therefore, as shown in FIG.
If <0, the signal output circuit 14 outputs, for example, the voltage V (−1). When the start pulse signal Sp is input to the timing generation circuit 31, the timing generation circuit 31 uses a counter (not shown). ) Is started, and the data read operation is started based on the count output signal Sc.

Output value of counter and time value data T (0)
And the voltage target value data V (0) corresponding to the time value data T (0) of the signal waveform required by the solenoid valve or the like.
Is read from the memory unit 21 to the D / A converter 33.

Thus, the analog signal Sv relating to the data V (0) is set from the state of the voltage V (-1). Similarly, since the analog signal Sr based on the slope value data SR (0) is set, the waveform rises at a time change rate according to the analog signal Sr. This waveform approaches the voltage target value V (0) by the analog signal Sv based on the data V (0), and when reaching this value V (0), keeps a constant value as it is. Thereby, an analog waveform from t = 0 to t = T1 is obtained.

Thereafter, in order to increase the reading speed, processing such as reading out the time value data T (1) into a register (not shown) is performed in advance, and the output value of the counter and the time value data T (1) are compared. Are compared in the reading unit 32. The comparison result is updated to the time value data T (1), and the voltage target value data V corresponding to the updated time value data T (1) is updated.
(1) is read from the memory unit 21 to the D / A converter 33.

In the signal output circuit 14, the time t is t = T1
, The data V (0)
To the analog signal Sv based on the data V (1), and the slope value is also reset from the data SR (0) to the analog signal Sr based on the data SR (1).

Accordingly, the waveform falls at a time rate of change based on the slope value data SR (1). This waveform is the data V
The voltage target value V is obtained by the analog signal Sv based on (1).
When the value approaches (1) and reaches this value V (1), a constant value is maintained as it is. Thereby, t = T1 to t = T
Up to two analog waveforms can be obtained. By repeating such an operation from time t = 0 to Tn, an analog signal waveform Vout required by the solenoid valve or the like can be sequentially generated.

FIG. 4 is a diagram showing the internal configuration of the signal output circuit 14. The signal output circuit 14 includes a differential amplifier circuit 41 and a Miller integrating circuit 42 as shown in FIG.

In the differential amplifier circuit 41, the transistors Q1,
The variable current source I0 is connected to the emitter of Q2. The variable current source I0 is connected to the power supply line VCC, and the variable current source I0
Is controlled by the output of the D / A converter 34 shown in FIG. That is, the common emitter current (operating current of the differential amplifier circuit 41) ISR of the transistors Q1 and Q2 is controlled by the analog signal Sr relating to the slope value.

The base of the transistor Q1 is an analog signal Sv relating to a voltage target value which is the output of the D / A converter 33.
Is supplied. In this example, the data V is changed so that the voltage target value and the slope value are switched one after another at the time value of each change point.
When (i), SR (i) and T (i) are sequentially updated, the analog signal Sv from the voltage target value D / A converter 33 is updated.
Accordingly, the base potential Vb of the transistor Q2 of the differential amplifier circuit 41, that is, the final value of the analog output waveform Vout is set.

A current mirror circuit 51 is connected to the collectors of the transistors Q1 and Q2, and the two collector currents ic1 and ic2 of the transistors Q1 and Q are mirror-coupled and controlled to be always equal.

A Miller integrating circuit 42 in which an integrating capacitor C and a mirror amplifier 52 are connected in parallel is connected to the collector of the transistor Q1. The output of Miller integrating circuit 42 is connected to output terminal 43 and the base of transistor Q2. In this example, the input value of the Miller integration circuit 42, that is, the time change rate (slew rate) of charging / discharging of the integration capacitor C is set by the analog signal Sr of the D / A converter 34 for the inclination value.

Next, the operation of the signal output circuit 14 will be described. First, when the start pulse signal Sp rises,
At time t = 0, analog signal Sr based on data SR (0)
As a result, the variable current source I0 starts increasing the common emitter current ISR.

At this time, the base of the transistor Q1 is D
An analog signal Sv relating to the target voltage value V (0) from the / A converter 33 is set. In this state, when the common emitter current ISR is gradually increased, the transistor Q1 turns on from off. As a result, in the current mirror circuit 51, the mirror current (ic1-i) becomes equal to the collector current ic2 of the transistor Q2.
Since 1) flows, the charging current i1 is supplied to the integration capacitor C. As a result, the output of the mirror amplifier 52 rises the base potential Vb of the transistor Q2, and the transistor Q2 starts to turn on gradually.

Thereafter, when the analog signal Sv based on the data V (0) becomes equal to the base potential Vb of the transistor Q2, the equivalent collector currents ic1 and ic2 flow while the transistors Q1 and Q2 are both turned on. , The voltage target value based on the data V (0). By this operation, an analog waveform from t = 0 to t = T1 is obtained.

When the time value data T (0) is updated to T (1) and time t = T1, the data SR (1)
, The variable current source I0 starts to decrease the common emitter current ISR. At this time, the analog signal Sv relating to the voltage target value V (1) from the D / A converter 33 is set in the base of the transistor Q1. In this state, when the common emitter current ISR is gradually reduced, the transistor Q1 turns off from on.

Thus, in the current mirror circuit 51, the mirror current (ic1 + i) flows so as to be equal to the collector current ic2 of the transistor Q2, so that the discharge current i from the integration capacitor C is drawn. As a result, the output of the mirror amplifier 52 falls the base potential Vb of the transistor Q2, and the transistor Q2 starts to turn off gradually.

Thereafter, when the analog signal Sv based on the data V (1) becomes equal to the base potential Vb of the transistor Q2, the transistors Q1 and Q2 remain off and the equivalent collector currents ic1 and ic almost close to zero.
2, the voltage target value based on the data V (1) is held. By this operation, t = T1 to t = T
Since up to two analog waveforms are obtained, the analog waveform of FIG. 2B is obtained by repeating such an operation.

Thus, the common emitter current ISR of the transistors Q1 and Q2 and the integration capacitance C of the Miller integration circuit 42
Are output from the mirror amplifier 52 to a solenoid valve or the like from the voltage target values V (0), V (1), V (2)... can do.

In the waveform generator 100 of the present invention, a voltage target value for each change point of a signal waveform required by an electromagnetic valve or the like,
Data V (i) of the time value and the slope value, SR
(I) It is only necessary to define in advance a set of data that is a set of T (i) and store the data in a memory or the like, and a huge amount of waveforms generated at intervals of the system clock (minimum time resolution) as in the conventional method There is no need to prepare data.

Of course, these data V (i), SR
(I), memory units 21, 22, 2 capable of storing T (i)
3 requires only a small capacity, and does not require a large-capacity waveform memory for storing waveform data as in the conventional method.

In the embodiment of the present invention, the voltage target value memory unit 2 is referred to the data T (i) of the time value memory unit 23 asynchronously with the data transfer processing by the computer.
1 is read out to the D / A converter 33 from the data V (i), and the data SR (i) is read out from the gradient value memory unit 22 to the D / A converter 34. The data V (i) and SR of each of the voltage target value and the slope value are not limited to the transfer speed.
(I) can be asynchronously converted into analog signals Sv and Sr. Thus, a signal waveform required by the solenoid valve or the like can be generated at a high speed based on the analog signals Sv and Sr.

In the present embodiment, the case where data V (i), SR (i) and T (i) of voltage target value, slope value and time value are serially transferred to interface 11 has been described. These data V (i), SR (i),
T (i) may be transferred in parallel. This is to reduce the data transfer time.

As the D / A converters 33 and 34, those having lower performance than the conventional D / A converter 9 can be used. In the conventional method as described with reference to FIG. 7B, a D / A converter having an operation speed of about 10 MHz is required to convert the waveform data D in the rising periods a and b into an analog waveform.

However, in this embodiment, the data V (i) may be read from the memory unit 21 to the D / A converter 33 at a rate of one time at each change point of the signal waveform. In the above-described example, as the D / A converter 33, a D / A converter having such a performance that the value of the analog signal Sv can be determined by 1 μS can be used.

Also, a D / A converter 34 for the slope value that operates at a higher speed than the D / A converter 33 is required. do not need. It is sufficient that the signal output circuit 14 can be driven based on the analog signal Sr. In this embodiment, a medium-speed D / A converter can be used as the D / A converter 34.

The analog waveform required by a solenoid valve or the like is represented by D /
This is because it is not directly generated by the A converter 34.

In this embodiment, the case where one kind of signal waveform is generated has been described. However, when M kinds of signal waveforms are generated, n sets of voltage target value data V (i) and slope value data SR are generated. (I) M more signal waveforms defined by the time value data T (i) are prepared, and desired data is selected from the M kinds of data. By selecting data in this way, it is possible to generate a complicated signal waveform required by a solenoid valve or the like while performing waveform switching at high speed.

In the present embodiment, the case where the solenoid valve is used as an example of the actuator has been described. However, similar effects can be obtained with a piezoelectric element such as a piezo element.

In this embodiment, the case where the opening of the solenoid valve is controlled according to the magnitude of the voltage target value has been described.
The same effect can be obtained even when the voltage target value is two, that is, ON / OFF, and simple valve opening / closing control is performed.

[0075]

As described above, in the waveform generator according to the present invention, the voltage target value and the time value defined in advance for each change point of an arbitrary signal waveform, and the rising and falling slopes of the signal waveform. The respective data relating to the slope value that determines the value are combined and temporarily stored in a memory, and the data of the voltage target value and the slope value corresponding to the time value are read from this memory, and these data are converted into analog signals. After that, based on the analog signals related to the voltage target value and the slope value, a predefined point is set such that each change point is a voltage target value and its waveform rises or falls with time in accordance with the slope value. In this case, arbitrary analog signal waveforms are sequentially generated.

With such a configuration, in the waveform generating apparatus of the present invention, data in which a voltage target value, a time value, and a slope value are grouped for each change point of an arbitrary signal waveform may be defined and prepared in advance. There is no need to prepare data such as waveform data generated at system clock intervals unlike the conventional method. Therefore, a large-capacity waveform memory for storing waveform data in units of the system clock is not required.

Such an arbitrary signal waveform can be obtained with high accuracy.
In addition, a waveform generator that can be generated at a high speed and can be realized with a simple configuration is extremely suitable when applied to an actuator or the like utilizing an electromagnetic force or a piezoelectric effect.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a waveform generator as an embodiment of the present invention.

FIG. 2 shows data V of a signal waveform required by a solenoid valve or the like.
It is a figure which shows the example of a combination of (i), SR (i), and T (i).

FIG. 3 shows data V (i) and SR of an arbitrary signal waveform.
It is a figure which shows the input example of (i) and T (i).

FIG. 4 is a diagram illustrating an example of an internal configuration of a signal output circuit.

FIG. 5 is a diagram illustrating a secondary system circuit and an example of an input waveform for eliminating vibration thereof.

FIG. 6 is a diagram illustrating a configuration example of a conventional waveform generator.

FIG. 7 is an example in which a waveform Sin is generated by the waveform generator 1;

FIG. 8 is a diagram showing a configuration example of a waveform generator using a microcomputer and a waveform memory.

[Explanation of symbols]

1 ... input terminal, 2A, 2B ... delay circuit, 3A ~
3C: monostable multivibrator, 4A-4C
・ Waveform shaping circuit, 5 ・ ・ ・ Adder, 6 ・ ・ ・ Output terminal,
7 secondary circuit, 8A microcomputer, 8B waveform memory, 9, 33, 34 D /
A converter, 10, 100 ... waveform generator, 11 ...
Interface, 11A: data input terminal, 11
B: clock terminal, 11C: write enable terminal, 12: memory, 13: data conversion circuit,
14: Signal output circuit, 21: Voltage target value memory unit, 22: Slope value memory unit, 23: Time value memory unit, 31: Timing generation circuit, 32: Data readout Part, 41: differential amplifier circuit, 42: Miller integrating circuit, 43: output terminal, 51: current mirror circuit, 52: mirror amplifier, C: integrating capacitance, Io ..Variable current sources, Q1, Q2, transistors

Claims (2)

[Claims] 1. A set of data relating to a voltage target value and a time value defined in advance for each change point of an arbitrary signal waveform and a slope value for determining a rising and falling slope of the signal waveform. A memory for storing, reading data of each of a voltage target value and a slope value corresponding to a time value of the arbitrary signal waveform from the memory based on a signal generation start signal, and reading each of the data as an analog with respect to the voltage target value A data conversion circuit for converting a signal and an analog signal related to the slope value; and a signal output circuit for generating an analog signal waveform according to an analog signal related to a voltage target value and a slope value from the data conversion circuit; Is the voltage target value, and the waveform rises or falls with time in accordance with the slope value. A waveform generator configured to sequentially generate arbitrary analog signal waveforms. 2. The signal output circuit according to claim 1, wherein an analog signal related to a voltage target value from the data conversion circuit is set to one input, and an operation current is adjusted by the analog signal related to a slope value from the data conversion circuit. A differential amplifier circuit, and an integrating circuit that feeds back a signal obtained by integrating the output of the differential amplifier circuit to the other input of the differential amplifier circuit. 2. The waveform generator according to claim 1, wherein when the output signal becomes equal, the output signal of the integration circuit is kept constant.