JP2731187B2 - Actuator drive control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control device for an actuator that operates in a comparative example used for controlling a proportional solenoid valve, a servo valve, and the like.

2. Description of the Related Art Actuators such as proportional solenoids of this type are used, for example, to control a proportional solenoid valve for a hydraulic cylinder that drives an operating member such as a swing body, a boom, an arm, and a bucket in a hydraulic shovel. .

FIG. 3 is a block diagram showing a conventional drive control device for various actuators.

In the figure, reference numeral 51 denotes an operation amount input means, which includes an operation member such as a lever and a pedal, and an operation amount detector group for generating an electric signal corresponding to the operation amount of the operation member. The output of the detector is subjected to processing such as amplification and A / D conversion if necessary, and is output as an operation signal S11 by the arithmetic processing means 5.
Sent to 2. The arithmetic processing means 52 is constituted by a microcomputer or the like, and sets the actuator to be controlled, which will be described later, to a command value (command amount) by the operation signal S11.
In order to drive by an amount corresponding to a predetermined program, a calculation process is executed based on data, and a control command signal S12 based on the calculation result becomes a control target via the D / A converter 53, for example. Actuator such as proportional solenoid
The signal is sent to a drive circuit 54 for driving 55. Each drive circuit 54 is provided with an actuator 55 based on the control command signal S12.
The actuator 55 drives a driven member (for example, a valve).

By the way, the driven member driven by the actuator 55 has a variation in the accuracy and the like of the components, and therefore, the relationship between the input (drive signal S13) to the actuator 55 and the output (physical displacement amount) greatly varies from product to product. , Same drive signal
Even if S13 is supplied, the amount of displacement obtained for each product will be different. Therefore, each drive circuit 54 adjusts the control command signal S12 to a drive signal S13 corrected (adjusted) in accordance with the variation in the operating characteristics of the driven member driven by the actuator 55. A functional unit is provided.

For example, as shown in FIG. 4, the adjustment function of the drive circuit 54 includes operational amplifiers 56 and 57 and trimmer resistors (variable resistors) 58 and 5 connected in a negative feedback loop of the operational amplifiers 56 and 57.
This is realized by connecting two adjustment stages 60 and 61 each composed of 9 or the like to a series. That is, in one adjustment stage 60, the change ratio (the degree of inclination of the linear function) of the drive signal S13 with respect to the change of the control command signal S12 (in other words, the operation signal S11) is corrected and set by the trimmer resistor 58. (Usually called gain adjustment). In the other adjustment stage 61, level adjustment (adjustment of the starting point of a linear function) called zero adjustment of the drive signal S13 is performed by the trimmer resistor 59. Then, before the product is shipped, the adjustment by the trimmer resistors 58 and 59 is performed, so that the same physical displacement can be obtained by 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 (such as a change in contact resistance due to corrosion of the sliding portion), and it becomes impossible to output an accurate physical quantity corresponding to the operation amount (operation signal S11).

Each drive circuit 54 requires two trimmer resistors, an operational amplifier, and several fixed resistors, so that the space occupied in the control device is widened, and the size of the entire control device is increased. In particular, this problem is caused by multi-channel control (for example, 10-20c
h) If serious.

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

Further, in the above-described conventional configuration, as shown in FIG. 5, the command value a by the control command signal S12 (in other words, the operation signal S11) is changed to the output value c by the drive signal S13 (the value corresponding to the operation origin of the actuator 55). And similarly the command value b
To the output value d (a value corresponding to a displacement of 100% of the actuator 55), and if it is desired to correct the linear function based on the command value-output value from the dotted line in FIG.
First, the starting point of the dotted line is changed as indicated by the one-dot chain line by the above-mentioned zero adjustment, and the output value corresponding to the command value a is changed to the output value c.
Will be adjusted. Then, by performing the above-described gain adjustment and performing the inclination adjustment as shown by the two-dot chain line in FIG. 2 in which the output value d is adjusted to the instruction value b, the previously adjusted instruction value a and output value c are obtained. It was pointed out that the problem was wrong. Therefore, if the command value a and the output value c still deviate after the correction, the amount of play until the start of the actuation of the actuator 55 differs for each product, which hinders the operation of the operator.

Therefore, a technical problem to be solved by the present invention is to solve the above-mentioned problems of the prior art, and the purpose is to solve the problem of the variation in the operating characteristics of the driven member operated by the actuator. Regardless, for the same command value by the manipulated variable input means, the same displacement can be obtained stably for a long time, and the configuration of the control circuit system can be simplified and reduced in size, and zero adjustment can be performed. An object of the present invention is to provide a drive control device for an actuator that can also automate gain adjustment.

[Means for Solving the Problems] To achieve the above object, an actuator drive control device of the present invention provides a relatively operable actuator and an operation for transmitting an operation signal for commanding an operation amount of the actuator. Amount input means, operation processing means for executing a calculation process based on an operation signal from the operation amount input means and transmitting a control command signal, and driving the actuator based on a control command signal from the calculation processing means Circuit for sending a drive signal to the actuator, and adjustment information for adjusting a characteristic of an output value by the drive signal, which is proportionally changed linearly in response to a command value by the operation signal. A non-volatile storage unit, which fetches the adjustment information and, based on the adjustment information, sets the characteristic line of the command value-output value for each product with respect to the same command value; Is calculated as linear function data for operating the actuator by the same amount without variation, and a command value based on the adjusted linear function data is set as an output value of the drive signal corresponding to the operation signal based on the adjusted linear function data. Adjustment operation means for calculating the control command signal and sending it to the drive circuit.

Further, provided is adjustment information setting means for setting the adjustment information to be stored in the nonvolatile storage means, the adjustment information setting means, according to adjustment information writing software,
The test operation is performed while fetching data under such a condition that the characteristic line of the command value-output value changes, to find appropriate adjustment information, and to store the appropriate adjustment information in the nonvolatile storage means. It is configured to be stored.

[Operation] As described above, according to the present invention, the adjustment calculation means calculates the characteristic line of the command value-output value as predetermined adjusted linear function data based on the adjustment information from the nonvolatile storage means. Since the control command signal is corrected and sent to the drive circuit in order to make the command value the output value of the drive signal corresponding to the command value based on the adjusted linear function data, the control command signal is sent to the drive circuit. Then, when the operation signal is x and the control command signal is y, an operation of y = Ax + B is performed (A is a gain set value, B is a level reference value set value), and y
Output (adjusted control command signal), regardless of the variation in the operating characteristics of the driven member driven by the actuator, the same amount of actuator is used for each product for the same command value. An actuated corrected control command signal is sent to the drive circuit. Therefore, the same physical displacement is always obtained for the same command value, and the operability of the product is stabilized.

Further, as described above, the nonvolatile storage means holds the adjustment information for adjusting the characteristic of the output value by the drive signal which changes linearly in a linear function in accordance with the command value by the operation signal. Therefore, as compared with the conventional adjustment value holding by the trimmer resistor having the sliding portion, the reliability under the use over time is excellent, and the adjustment information is lost when the product is not used (when not energized). There is no fear. Furthermore, since the control command signal corrected according to the variation on the driven member side is input to the drive circuit, the drive circuit does not need to have the adjusting function as in the past, and the drive circuit is compared with the conventional case. And the control system as a whole can be reduced in size. Particularly when the arithmetic control means and the adjustment arithmetic means are constituted by the same microcomputer, further downsizing is possible. In addition, since it is only necessary to electrically write the adjustment information in the nonvolatile storage means, the adjustment information setting means for this purpose can be constituted by a microcomputer, and the setting and writing of the adjustment information are automatically performed based on a prepared program. Can also be performed.

[Embodiment] The present invention will be described below with reference to an illustrated embodiment. First
FIG. 1 is a block diagram of an actuator drive control device according to one embodiment of the present invention.

In the figure, reference numeral 1 denotes an operation amount input means, which includes an operation member such as a lever and a pedal, and an operation amount detector group such as a pulse encoder that generates an electric signal corresponding to the operation amount of the operation member. The output of the manipulated variable detector is subjected to appropriate preprocessing if necessary, and sent to the arithmetic processing means 3 of the micro computer 2 as an operation signal S1.

The microcomputer 2 controls, for example, the entire hydraulic machine. In this embodiment, the microcomputer 2 has an arithmetic processing unit 3 and an adjustment arithmetic unit 4 having functions to be described later, and an electrically erasable programmable read-only unit serving as a nonvolatile storage unit. Although the memory is provided with a memory (hereinafter referred to as an EEPROM) 5 and the like, the adjustment operation means 4 may be constituted by a micro computer separate from the micro computer 2. Also, the EEPROM 5 may be in the form of an external memory instead of being built in the microcomputer 2, and a RAM with battery back-up other than the EEPROM 5 may be employed as the nonvolatile storage means. Note that the microcomputer 2 is actually a ROM storing various I / O interfaces, a main control program and fixed data, a RAM reading and writing various flags, operation signal data, and the like, and a μCPU (microcontroller) controlling overall control. Central processing unit) and executes arithmetic processing based on predetermined programs and data.

The arithmetic processing means 3 drives the actuator to be controlled by an operation signal S1 from the operation amount input means 1 by an operator's operation by an amount corresponding to a command value (command amount) by the operation signal S1. For this purpose, arithmetic processing is executed based on a program and data predetermined according to the characteristics of the actuator, and a control command signal S2 based on the arithmetic result is sent to the adjustment arithmetic means 4. At this stage, the control command signal S2 from the arithmetic processing means 3 does not take into account the variation in the operating characteristics of the driven member operated by the actuator.

Upon receiving the control command signal S2, the adjustment calculation means 4 takes in the adjustment information stored in advance in the electric EEPROM 5 as an adjustment information signal S3, corrects and adjusts the control command signal S2 as described later, and performs D / A The signal is sent to the drive circuit 7 as an adjusted control command signal S4 via the converter 6 and the like. Drive circuit 7
Receives the adjusted control command signal S4 and sends a drive signal S5 for driving the actuator 8 such as a proportional solenoid, whereby the actuator 8 drives the driven member 9 such as a valve. I have. Here, the drive circuit 7 does not require an adjusting function as in the above-described conventional example, so that the configuration is extremely simple.

Here, the processing executed by the adjustment calculating means 4 will be described. Now, in a state where the adjustment taking into account the variation in the operating characteristics of the driven member 9 is not performed for each actuator 8, a command value by the operation signal S1 of the operation amount input means 1 and a change in the command value Accordingly, the relationship with the output value of the drive signal S5 of the drive circuit 8 which changes in a linear function with the output value is in the relationship as shown by the dotted line in FIG. 2, which is originally obtained as shown by the solid line in FIG. Consider a case where correction is made to a command value-output value characteristic line. In this case, the operation signal S1
Assuming that the command value is x and the output value of the drive signal S5 is y, the straight line shown by the solid line in FIG. 2 is represented by a linear function of y = Ax + B.

Therefore, the value of A, which is the gain adjustment value, is calculated as (dc) / (b
-A), and the value of B, which is a level reference adjustment value, is set as a value e shown in FIG.
If the actuator function 8 is stored in advance in the EEPROM 5, the linear function data represented by y = (dc) / (ba) + e can be easily calculated by the adjustment calculating means 4. Is recognized. Then, the adjustment calculating means 4 performs an arithmetic processing based on the primary function data so as to make the control command signal S2 from the arithmetic processing means 3 correspond to the output value on the linear function. An adjusted control command signal S4 is sent to the drive circuit, and the drive circuit 7 drives the actuator 4. Therefore, the actuator 8 always displaces the driven member 9 by the same physical amount regardless of the variation on the driven member 9 side with respect to the same command value (operation signal S1). Each of the actuators 8 is stored in the EEPROM 5.
Adjustment information for each (the driven member 9) is stored in advance, and the above-described correction (adjustment) by the adjustment calculation unit 4 is performed.
The calculation is reflected on the signals sent to all the driving circuits 7.

Next, an example of a method of writing adjustment information to the EEPROM 5 will be described. In this embodiment, the adjustment information setting means 10 is connected to the microcomputer 2 before the product is shipped, and the output of the group of sensors 11 for detecting the displacement of each driven member 9 is adjusted by the adjustment information setting means 10. Is controlled to be supplied to The adjustment information setting means 10, like the arithmetic processing means 3 and the adjustment calculation means 4, is constituted by a microcomputer, and the function of writing the adjustment information to the EEPROM 5 is realized by software. The sensor 11 may detect the amount of displacement of the actuator. After the product is shipped, its output is sent to the microcomputer 2.

In the above configuration, when writing the adjustment information to the EEPROM 5, the operation amount input means 1 and the arithmetic processing means 3 do not operate. In this state, the adjustment information setting means
10 sends the control command signal S2, which is the operation origin at which the physical displacement amount of the driven member 9 is 0%, to the adjustment calculating means 4, and
Change the zero set value (level reference adjustment value) in OM5 little by little. The adjustment calculating means 4 performs an arithmetic process on the control command signal S2 based on the changing level reference adjustment value information from the EEPROM 5 and drives the driven member 9 by the drive circuit and the actuator 8 to drive the driven member 9. The physical displacement amount is recognized by the adjustment information setting means 10 by the sensor 11. Then, at the operation origin of the driven member 9 (in other words, at the operation origin of the actuator 8 and at the time when the characteristic line indicated by the dotted line in FIG. 2 is translated so as to pass through the point P1 in FIG. 2), the EEPROM is used.
Temporarily fix the level reference adjustment value of 5.

Next, the adjustment information setting means 10 sends a control command signal S2 for causing the physical displacement of the driven member 9 to be 100% to the adjustment calculating 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 set such that the point P1 in FIG. 2 is the center of rotation, and the output of the sensor 11 is 100% of the physical displacement amount of the driven member 9. , That is, when a straight line passing through the points P1 and P2 in FIG.
Determined at 5 and stored. When the gain adjustment value is determined, the value of e in FIG. 2 is also determined, and this value is stored in the EEPROM 5 as a level reference adjustment value.

In this way, the level reference adjustment value and the gain adjustment value for each driven member 9 are stored in the EEPROM 5 before the product is shipped. It should be noted that various modifications of the method of storing the adjustment information in the EEPROM 5 and the calculation method may be considered depending on software.

In this embodiment having such a configuration, the same operation by the operation amount input means 1 is performed irrespective of the variation in the operating characteristics of the driven member 9 operated by the proportionally operating actuator 8. , The same displacement can be obtained.

Since the adjustment information is stored in the EEPROM 5 or RAM with battery back-up, there is almost no error when used over time, compared to a conventional device with a sliding part such as a trimmer resistor. , Reliable.

b. One package (memory) can store multi-channel adjustment information, and the drive circuit 7 can be simpler than in the past, so that the configuration of the entire control system is simple and compact.

c. Since all adjustment information can be written electrically,
This automation is easy.

d. Usually, this type of control system is coated on the board after it is mounted on the board for moisture and vibration proofing. ), So that the coating can be performed completely. In this respect, it is difficult to update the setting information by the adjustment information setting means 10 on the board after completion with a normal ROM, but if the EEPROM 5 or the RAM with battery backup is used as in the embodiment, the adjustment information is not updated after the board is completed. The settings can be made, and the stored contents will not be lost when the power is turned off like a normal RAM.

In the case of a memory in which the RAM is backed up, incorrect data may be written due to runaway of the program.However, EEPROM has been devised to prevent writing due to malfunction. EEP than RAM with battery backup
It is more desirable to use ROM.

[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 relatively operating actuator, the same command value by the operation amount input means is obtained. The same physical displacement can always be obtained stably over a long period of time.The configuration of the control circuit system can be simplified and downsized, and zero adjustment and gain adjustment can be automated. Actuator drive control devices can be provided that have remarkable effects such as easy and reliable adjustment and setting regardless of the load, and the industrial value of hydraulic machines and the like is enormous.

[Brief description of the drawings]

1 and 2 relate to an embodiment of the present invention. FIG. 1 is a block diagram of an actuator driving device, and FIG. 2 is a diagram for explaining an example of a method of correcting a command value-output value characteristic line. 3 to 5 relate to a conventional example, FIG. 3 is a block diagram of an actuator driving device, FIG. 4 is a circuit diagram showing an example of a driving circuit, and FIG. FIG. 9 is a graph for explaining a state of correction of a value-output value characteristic line. 1 ... operation input means, 2 ... microcomputer,
3 ... Calculation processing means, 4 ... Adjustment calculation means, 5 ... EEPR
OM, 6 D / A converter, 7 Driving circuit, 8 Actuator, 9 Driven member, 10 Adjustment information setting means, 11 Sensor, S1 Operation signal, S2 ... Control command signal, S3 ... Adjustment information signal, S4 ... Adjusted control command signal,
S5 ... Drive signal.

Continuation of the front page (72) Inventor Masakazu Haga 650, Kunitachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Tsuchiura Plant (56) References JP-A-62-244931 (JP, A) JP-A-61-204423 ( JP, A) JP-A-60-117604 (JP, A) JP-A-61-89060 (JP, U) JP-A-61-17503 (JP, U)

Claims (5)

(57) [Claims] An actuator operable in proportion, an operation amount input means for sending an operation signal for instructing an operation amount of the actuator, and an operation process based on the operation signal from the operation amount input means. Processing means for transmitting a control command signal to the actuator, a driving circuit for transmitting a drive signal for driving the actuator to the actuator based on the control command signal from the processing means, and a command value corresponding to the operation signal. And a non-volatile storage unit that holds adjustment information for adjusting the characteristic of the output value according to the drive signal that changes proportionally in a linear function, and the adjustment information is acquired based on the adjustment information. The characteristic line of the command value-output value is calculated as linear function data that operates the same amount of the actuator for the same command value without variation for each product. And adjusting operation means for calculating the control command signal based on the adjusted linear function data so that the command value based on the operation signal becomes an output value of the drive signal corresponding thereto, and sending the control command signal to the drive circuit. A drive control device for an actuator, comprising: 2. An apparatus according to claim 1, further comprising an adjustment information setting means for setting said adjustment information to be stored in said non-volatile storage means, wherein said adjustment information setting means executes said instruction according to adjustment information writing software. A test operation is performed while fetching data under such a condition that the characteristic line of the value-output value changes, to find out the appropriate adjustment information, and store the appropriate adjustment information in the nonvolatile storage means. A drive control device for an actuator. 3. The drive control device for an actuator according to claim 2, wherein said nonvolatile storage means is an electrically erasable programmable read only memory (EEPROM). 4. The drive control device for an actuator according to claim 2, wherein said nonvolatile storage means is a random access memory (RAM) with a battery backup. 5. The drive control device for an actuator according to claim 2, wherein said adjustment calculation means is constituted by the same microcomputer as said calculation processing means.