JPH02129482A - Actuator drive control device - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a drive control device for a proportionally operating actuator used for controlling a proportional solenoid valve, a servo valve, etc.

[Conventional technology] Actuators such as this kind of proportional solenoid.

For example, the swivel base, boom, arm of a hydraulic excavator,
It is used, for example, to control a proportional solenoid valve for a hydraulic cylinder that drives an actuating member such as a packet.

FIG. 3 is a block diagram showing a conventional drive control device for this type of actuator.

In the figure, reference numeral 51 denotes a manipulated variable input means, which includes, for example, a lever, a pedal, or other operating member, and a group of manipulated variable detectors that generate an electrical signal according to the manipulated variable of the operating member.
The output of the manipulated variable detector is subjected to processing such as amplification and A/D conversion as necessary.

It is sent to the arithmetic processing means 52 as an operation signal Sll.

The arithmetic processing means 52 is composed of a microcomputer or the like, and executes a predetermined program and data in order to drive the actuator to be controlled, which will be described later, by an amount corresponding to a command value (command amount) by the operation signal Sll. A calculation process is executed based on the calculation result, and a control command signal S12 based on the calculation result is sent to an actuator 55 such as a proportional solenoid to be controlled via a D/A converter 53 or the like.
The signal is sent to and output from a drive circuit 54 for driving the signal.

Each of the drive circuits 54 sends out a drive signal S13 for driving the actuator 55 based on the control command signal S12, whereby the actuator 55 drives the driven member (
for example, a valve).

By the way, since there are variations in the accuracy of the component parts of the driven member driven by the actuator 55, the relationship between the input (drive signal 513) to the actuator 55 and the output (physical displacement amount) varies greatly from product to product. , even if the same drive signal 813 is supplied, the amount of displacement obtained will differ for each product.

Therefore, each of the drive circuits 54 receives the control command signal S.
12 is provided with an adjustment function section for converting the drive signal 313 into a drive signal 313 that is corrected (adjusted) according to variations in the operating characteristics of the driven member driven by the actuator 55.

The adjustment function of the drive circuit 54 is, for example, as shown in FIG.
Two adjustment stages 60.
61 connected in series. That is, in one adjustment stage 60, the control command signal 5
12 (in other words, the operation signal 5ll), the change rate (degree of slope of the linear function) of drive<F1 S13 is corrected and set by the trimmer resistor 58 (usually called gain adjustment). Moreover, in the other adjustment stage 61, [! A level adjustment (a between the starting points of the linear function) called zero adjustment of the @ signal 313 is performed by a trimmer resistor 59. Then, before shipping the product, adjustments are made using the trimmer resistors 58 and 59, so that the same amount of physical displacement can be obtained with the same command value.

[Problems to be Solved by the Invention] However, the conventional configuration described above has the following problems.

■The adjustment value changes due to aging of the trimmer resistors 58 and 59 (changes in contact resistance due to corrosion of sliding parts, etc.), and the operation amount (
An accurate physical quantity corresponding to the operation signal 511) cannot be output.

(2) Each drive circuit 54 requires two trimmer resistors, an operational amplifier, and several fixed resistors, which occupies a large space within the control device and increases the size of the entire control device. This problem is particularly important for multi-channel control (e.g. 10 to 2 channels).
0ch) is serious.

■The work of zero adjustment and gain adjustment is a mechanical work of rotating or sliding the trimmer resistor, so it is difficult to automate this work and the adjustment cost increases.

■Also, in the conventional configuration described above, the control command signal S12 (in other words, the operation signal 511
) is changed to the output value C (value corresponding to the operating origin of the actuator 55) by the drive signal 813, and similarly, the command value is changed to the output value d (displacement of the actuator 55:
value corresponding to tlOO%), and set the command value -
If you want to correct the linear function based on the output value from the dotted line in the figure as shown by the solid line, first change the starting point of the dotted line as shown by the one-dot chain line by the above-mentioned zero adjustment, and then output the output value corresponding to the command value a. It will be adjusted to the value C.

Then, as a first step, the gain adjustment described above is performed, and the slope adjustment is performed as shown by the two-dot chain line in the same figure, which combines the output value d with respect to the command value A. The problem of misalignment was also pointed out. Therefore, if there is still a discrepancy between the command value a and the output value C after correction, the amount of play until the start of the actuator 55 will differ depending on the product, which will hinder the operator's operation.

Therefore, the technical problem to be solved by the present invention is to solve the above-mentioned problems of the prior art. First, the same amount of displacement can be stably obtained over a long period of time for the same command value using the manipulated variable input means, and the configuration of the control circuit system can be made simple and compact, and zero adjustment and gain can be easily achieved. An object of the present invention is to provide an actuator drive control device that can also automate adjustment.

[Means for Solving Problem A] In order to achieve the above-mentioned object, the actuator drive control device of the present invention includes an actuator that can operate proportionally and an operation signal that instructs the operation amount of the actuator. Operation amount input means.

arithmetic processing means that executes arithmetic processing based on the operation signal from the operation amount input means and sends out a control command signal; and a drive signal for driving the actuator based on the control command signal from the cough calculation processing means. a drive circuit that sends out data to the actuator; and a nonvolatile storage means that holds adjustment information for adjusting characteristics of an output value caused by the drive signal that changes proportionally in a linear function in response to a command value caused by the operation signal. Then, the front adjustment information is taken in, the characteristic line of command value-output value described above is recognized as predetermined adjusted linear function data, and the command value is adjusted based on this adjusted linear function data. The configuration includes adjustment calculation means for correcting and calculating the control command signal to make it the output value of the drive signal and sending it to the drive circuit.

[Function] As described above, in the present invention, the adjustment calculation means recognizes the command value-output value characteristic line as predetermined adjusted linear function data based on the adjustment information from the non-volatile storage means. Based on the adjusted linear function data, the control command signal is corrected and sent to the drive circuit so that the command value becomes the output value of the drive signal corresponding to the command value. The signal is X, the control command signal is y
Then, the calculation y=Ax+B is performed (A is the gain setting value, B is the level reference value setting value), and the output y (adjusted control command signal) is sent out, so it is driven by the actuator. Regardless of variations in the operating characteristics of the driven member, a corrected control command signal is sent to the drive circuit so that the actuator can be operated by the same amount for each product with respect to the same command value. Therefore, the same amount of physical displacement is always obtained for the same command value, and the operability of the product is stable.

Further, as described above, the non-volatile storage means holds adjustment information for adjusting the characteristics of the output value caused by the drive signal, which changes proportionally in a linear function in response to the command value caused by the operation signal. Therefore, compared to the conventional trimmer resistor with a sliding part that holds adjustment values, it has superior reliability over time, and adjustment information is lost when the product is not in use (when not energized). There is no fear. Furthermore, since the control command signal corrected in response to variations in the driven member side is input to the drive circuit, the drive circuit does not need to have an adjustment function like the conventional one, and the drive circuit is faster than the conventional one. The entire control system can be made smaller, especially the arithmetic control means and 1ll.
l! If the calculation means and the calculation means are configured by the same microcomputer, further miniaturization becomes possible. In addition, since it is only necessary to electrically write the adjustment information into a non-volatile storage means, the adjustment information setting means for this purpose can be configured with a microcomputer, and the adjustment information can be set and written automatically based on a pre-prepared program. It is also possible to do so.

[Example code] The present invention will be explained below with reference to illustrated embodiments.

FIG. 1 is a block diagram of an actuator drive control device according to an embodiment of the present invention.

In the same figure, ■ is a manipulated variable input means, such as a lever,
It consists of an operation member such as a pedal, and a group of operation amount detectors such as a pulse encoder that generate an electric signal according to the operation amount of the operation member, and the output of the operation amount detector is adjusted as necessary. It is subjected to pre-processing and sent to the arithmetic processing means 3 of the microcomputer 2 as an operation signal S1.

The microcomputer 2 controls, for example, the entire hydraulic machine, and in this embodiment, includes an arithmetic processing means 3 and an adjustment arithmetic means 4 equipped with functions to be described later, as well as an electrically erasable programmable read-only nonvolatile storage means. Although the adjusting means 4 is equipped with a memory (hereinafter referred to as EEPROM) 5, etc., the adjusting means 4 may be constituted by a microcomputer separate from the microcomputer 2.

Furthermore, the EEPROM 5 is not built into the microcomputer 2, but may be externally attached as a memory. Furthermore, in addition to the EEPROM 5, a RAM with battery backup may be used as a nonvolatile storage means. The microcomputer 2 actually includes various I10 interfaces, a ROM that stores main control programs and fixed data, a RAM that reads and writes various flags and fabricated signal data, and a microcomputer that manages overall control.
It is equipped with a CPU (micro central processor unit), etc., and executes arithmetic processing based on predetermined programs and data.

The arithmetic processing means 3 is configured to drive the actuator to be controlled by the operation signal S1 from the operation amount input means 1 by an amount corresponding to a command value (command amount) by the operation signal S1. , executes arithmetic processing based on a predetermined program and data according to the characteristics of the actuator, and sends a control command signal S2 based on the result of this calculation to the adjustment calculation means 4. Note that at this stage, the control command signal S2 from the arithmetic processing means 3 is
This does not take into account variations in the operating characteristics of the driven member operated by the actuator.

The adjustment calculating means 4, which has received the control command signal S2, takes in adjustment information stored in advance in the EEPROM 5 as an adjustment information signal S3, and corrects and adjusts the control command signal S2 as described later.

It is sent to the drive circuit 7 as an adjusted control command signal S4 via the D/A converter 6 and the like. The drive circuit 7 receives the adjusted control command signal S4 and sends out a drive signal S5 for driving an actuator 8 such as a proportional solenoid, so that the actuator 8 drives a driven member 9 such as a valve. ing. Here, the drive circuit 7 is
Since it does not require an adjustment function like the conventional example, its configuration is extremely simple.

Here, the processing executed by the adjustment calculation means 4 will be explained. Now, in a state where each actuator 8 has not been adjusted in consideration of variations in the operating characteristics of the driven member 9, the command value based on the operation signal s1 of the operation amount input means 1 and the change in this command value. The relationship between the output value of the drive signal S5 of the drive circuit 8 and the drive signal S5, which changes in a linear manner as a function of Consider the case where the command value-output value characteristic line is corrected. in this case.

If the command value from the operation signal S1 is X and the output value from the drive signal s5 is y, then the straight line shown by the solid line in FIG. 2 is y=Ax.
It is expressed by a linear function +B.

Therefore, the value of A, which is the gain adjustment value, is (d−c)/(b−
a), and the value of B, which is the level reference adjustment value, is set as the value e shown in the figure, and this is stored in advance in the EEPROM 5 for each actuator 8 as digital information (adjustment information).
If stored in , this y= (d-c)/(b-a
)+e is the linear function data represented by the adjustment calculation means 4.
easily recognized. Then, the adjustment calculation means 4 performs calculation processing to make the control command signal S2 from the calculation processing means 3 correspond to the output value on this linear function based on this linear function data, and calculates the calculation result. The adjusted control command signal S4 is sent to the drive circuit, and the drive circuit 7 drives the actuator 4. Therefore, the actuator 8 has the same command value (operation signal SL).
, the driven member 9 is always displaced by the same physical amount regardless of the variation on the driven member 9 side. Note that the EEPROM 5 stores adjustment information for each actuator 8 (each driven member 9) in advance, and the above-mentioned correction (adjustment) calculation by the adjustment calculation means 4 applies to all drive circuits 7. reflected in the transmitted signal.

Next, one example of a method for writing adjustment information into the EEPROM 5 will be described. In this example,! ! Before shipping one item, the adjustment information setting means 10 is connected to the microcomputer 2.

The outputs of a group of sensors 11 that detect the amount of displacement of each driven member 9 are connected to adjustment information setting means 10 . The adjustment information setting means IO is as follows.

Like the arithmetic processing means 3 and the adjustment arithmetic means 4, it is constituted by a microcomputer, and the function of writing adjustment information into the EEPROM 5 is realized by software. Note that the sensor 11 may be configured to detect the amount of displacement of the actuator 8, and its output is sent to the microcomputer 2 after the product is shipped.

In the above configuration, when writing adjustment information into the EEPROM 5, the manipulated variable input means 1 and the arithmetic processing means 3 do not operate. In this state, the adjustment information setting means lO sends the control command signal S2, which should be the operating origin at which the amount of physical displacement of the driven member 9 is 0%, to the adjustment calculation means 4, and outputs the zero setting value (level reference) in the EEPROM 5. adjustment value) little by little. The adjustment calculation means 4 performs calculation processing on the control command signal S2 based on the level reference adjustment value information from the EEPROM 5 which is changing, and drives the driven member 9 by the drive circuit 7 and the actuator 8. The amount of physical displacement 9 is recognized by the adjustment information setting means 10 by the sensor 11. Then, at the operating origin of the driven member 9 (in other words, at the operating origin of the actuator 8, at the point in time when the characteristic line indicated by the dotted line in FIG. Temporarily fix.

Next, the adjustment information setting means 10 sends a control command signal S2 that should make the amount of physical displacement of the driven member 9 100% to the adjustment calculation means 4, and changes the gain adjustment value in the EEPROM 5 little by little. The change in the gain adjustment value, in other words, the change in the degree of inclination of the straight line, is made such that the rotation center is at the 21 point in FIG. At the time when the gain adjustment value becomes a straight line passing through the points PL and P2 in FIG. 2, this gain adjustment value is determined and stored in the EEPROM 5. Also, when the gain adjustment value is determined, the value of e in Figure 2 is also determined, so this is the level reference adjustment value of EEPR.
Stored in OM5.

In this way, the level reference adjustment value and gain adjustment value for each driven member 9 are stored in the EEPROM 5 before the product is shipped. Note that various modifications may be made to the above-mentioned storage and calculation method of the adjustment information in the EEPROM 5 depending on the software.

In this embodiment adopting such a configuration, (1) a driven member 9 operated by an actuator 8 that operates proportionally;
The same amount of displacement can be obtained for the same command value from the manipulated variable input means 1, regardless of the variation in the operating characteristics between the two sides.

■Since the adjustment information is stored in EEFROM5 or RAM with battery backup, there is almost no error over time compared to conventional equipment that has sliding parts such as trimmer resistors. , highly reliable.

b. Adjustment information for multiple channels can be stored in one package (memory), and the drive circuit 7 can be made simpler than the conventional one, so the construction of the entire control system becomes simple and compact.

Since all of the C1 adjustment information can be written electrically, automation is easy.

d. Also, usually after this type of control system is incorporated into the board,
Coating is applied to prevent moisture and vibration, but since there is no need to touch the parts (trimmer resistor) on the board for adjustment after the board is completed, unlike in the past, the coating can be applied completely.

In this respect, with a normal ROM, the adjustment information setting means 10 updates the setting information on the completed board in a short time, but if an EEPROM 5 or a RAM with battery backup is used as in the embodiment, the adjustment information is updated after the board is completed. Settings can be made, and the stored contents are not lost when the power is turned off, unlike ordinary RAM.

In the case of RAM backed up by a battery, there is a risk that erroneous data may be written due to a runaway program, but EEPROM has a mechanism to prevent writing due to malfunction, so when dealing with a runaway program, It is more desirable to employ EEPROM than RAM with battery backup.

[Effects of the Invention] As described above, according to the present invention, regardless of the variation in the operating characteristics of the driven member operated by the actuator that operates proportionally, for the same command value by the manipulated variable input means. The same amount of physical displacement can always be obtained stably over a long period of time, and the control circuit system has a simple configuration.
It is possible to provide an actuator drive control device that can be miniaturized and has remarkable effects such as automating zero adjustment and gain adjustment, and has great industrial value in hydraulic machines and the like.

[Brief explanation of the drawing]

1 and 2 relate to one embodiment of the present invention, FIG. 1 is a block diagram of an actuator drive device, and FIG. 2 is for explaining an example of a method for correcting a command value-output value characteristic line. 3 to 5 relate to conventional examples, FIG. 3 is a block diagram of an actuator drive device, FIG. 4 is a circuit diagram showing an example of a drive circuit, and FIG. 5 is a conventional command. FIG. 3 is a graph diagram for explaining how a value-output value characteristic line is corrected. 1... Operation amount input means, 2... Microcomputer, 3... Arithmetic processing means, 4...
...adjustment calculation means, 5...EEPROM,
6...D/A converter, 7...drive circuit,
8... Actuator, 9... Driven member, 10... Adjustment information setting means, 11...
...sensor, St...operation signal, S2...
...Control command signal, S3...Adjustment information signal,
S4...Adjusted control command signal, S5...
・Drive signal. Figure 2

Claims (5)

[Claims] (1) An actuator that can operate proportionally, a manipulated variable input device that sends out a manipulation signal that commands the manipulated variable of the actuator, and control performed by performing arithmetic processing based on the manipulation signal from the manipulated variable input device. an arithmetic processing means for sending a command signal; a drive circuit for sending a drive signal to the actuator for driving the actuator based on a control command signal from the arithmetic processing means; non-volatile storage means that holds adjustment information for adjusting the characteristics of the output value by the drive signal that changes proportionally in a linear function; is recognized as the adjusted linear function data, and based on the adjusted linear function data, the control command signal is corrected and calculated to make the command value the corresponding output value of the drive signal. 1. A drive control device for an actuator, comprising: adjustment calculation means for sending data to a circuit. (2) The non-volatile storage means is an electrically erasable programmable read-only memory (EE).
An actuator drive control device characterized in that it is a PROM. (3) The actuator drive control device according to claim 1, wherein the nonvolatile storage means is a random access memory (RAM) with battery backup. (4) The actuator drive control device according to claim 1, wherein the adjustment calculation means is constituted by the same microcomputer as the calculation processing means. (5) The actuator drive control device according to claim 1, further comprising adjustment information setting means for setting the adjustment information to be stored in the nonvolatile storage means.