Electromagnetic valve control device, electromagnetic valve control system, hydraulic device

Abstract

To restrain variation in a control signal caused by a quantization error, and accurately control solenoid valves in accordance with operation.SOLUTION: A solenoid valve control device controls solenoid valves (10 and 11), and comprises a detection value reception unit for acquiring one or a plurality of detection values 62, a random number generation unit for generating a random number signal 63 with a predetermined amplitude, a random number addition unit for adding the random number signal 63 to a predetermined signal, and a signal conversion unit for generating a first control signal 66 from the detection values 62. The random number addition unit adds the random number signal 63 to at least one of the detection values 62 and the first control signal 66. The solenoid valves (10 and 11) are controlled by the first control signal 66.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a solenoid valve control device for controlling a solenoid valve, a solenoid valve control system including the solenoid valve control device, and a hydraulic device.

Background Art

[0002] Conventionally, solenoid valves have been used in various fields. For example, the work vehicle disclosed in Patent Document 1 includes a solenoid valve that changes the hydraulic oil supplied from a hydraulic pump to an actuator in accordance with the operation of an operating tool.

[0003] The operating tool is provided with a sensor that detects the operation amount of the operating tool, and the control device receives the detection value of the sensor. The control device rounds (truncates) the received detection value to a numerical value with a predetermined accuracy according to the performance of the control device and the solenoid valve, and outputs a control signal to the solenoid valve according to the rounded numerical value. By controlling the solenoid valve based on this control signal, hydraulic oil corresponding to the operation of the operating tool is supplied to the actuator. Further, the control signal may be generated in consideration of the pump pressure (hydraulic pressure) and flow rate (discharge flow rate) of the hydraulic pump, and these detection values may be rounded. Furthermore, the command current to the solenoid valve, which is the control signal, may be rounded.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, according to such a method of generating a control signal, a quantization error corresponding to the difference between the actual detection value and the rounded numerical value occurs. As a result, the variation of the control signal may increase, and the solenoid valve may not be accurately controlled in some cases.

[0006] The object of the present invention is to suppress variations in control signals caused by quantization errors and accurately control an electromagnetic valve according to an operation.

Means for Solving the Problems

[0007] An electromagnetic valve control device according to an embodiment of the present invention for achieving the above object is an electromagnetic valve control device for controlling an electromagnetic valve, and includes a detection value receiving unit that acquires one or more detection values, a random number generation unit that generates a random number signal with a predetermined amplitude, a random number addition unit that adds the random number signal to a predetermined signal, and a signal conversion unit that generates a first control signal from the detection value. The random number addition unit adds the random number signal to at least one of the detection value and the first control signal, and controls the electromagnetic valve with the first control signal. Moreover, a solenoid valve control device according to an embodiment of the present invention is a solenoid valve control device for controlling a solenoid valve, and includes a detection value receiving unit that acquires one or more detection values, a random number generation unit that generates a random number signal having a predetermined amplitude, a random number addition unit that adds the random number signal to the detection value to generate an input signal, a signal processing unit that rounds the input signal to a predetermined number of digits, a signal conversion unit that generates a first control signal from the rounded input signal, and a frequency addition unit that adds a frequency signal having a predetermined frequency and different from the random number signal to the first control signal to generate a second control signal, and controls the solenoid valve by the second control signal.

[0008] In order to control the electromagnetic valve with a control signal having an appropriate accuracy, it is necessary to round the detection value and the control signal (command current) for generating the control signal to change the accuracy. When the detection value and the control signal are rounded as they are in a region where the detection value and the control signal are in an increasing or decreasing trend, the tendency to round up or down the value near a specific value becomes prominent, and the change in the value is emphasized.

[0009] The electromagnetic valve control device may further include a signal processing unit that rounds at least one of the detection value and the first control signal to a predetermined number of digits.

[0010] According to the above configuration, since the random number signal is added to the detection value and the control signal and then rounded, the emphasis on the change in the value is suppressed. As a result, variations in the control signal caused by quantization errors are suppressed, and the electromagnetic valve can be accurately controlled according to the operation.

[0011] The electromagnetic valve control device may further include a frequency addition unit that adds a frequency signal with a predetermined frequency to the first control signal to generate a second control signal, and controls the electromagnetic valve with the second control signal.

[0012] With such a configuration, variations in the control signal caused by quantization errors are suppressed, and the solenoid valve can be accurately controlled according to the operation.

[0013] Further, the solenoid valve control device may further include a frequency addition unit that adds a frequency signal of a predetermined frequency to the detected value.

[0014] With such a configuration, variations in the control signal caused by quantization errors are suppressed, and the solenoid valve can be accurately controlled according to the operation.

[0015] Also, the amplitude of the random number signal may be set to half of the rounding width.

[0016] With such a configuration, even in a region where the detected value has an increasing or decreasing trend, the detected value in the vicinity of a specific detected value is suppressed from changing beyond the rounding width, and the rounded detected value is suppressed from changing significantly from the detected value before rounding. As a result, the first control signal or the second control signal is suppressed from deviating from the detected value, and the solenoid valve can be accurately controlled according to the operation.

[0017] Also, when the rounding width is d, the random number signal may have an amplitude in the range of -0.5d or more and 0.5d or less.

[0018] With such a configuration, the detected value is appropriately adjusted in the upward rounding or downward rounding direction. A rapid change in the detected value in the vicinity of a specific detected value is suppressed, and as a result, the dispersion (variation) of the control signal is suppressed.

[0019] Furthermore, a solenoid valve control system according to an embodiment of the present invention includes a solenoid valve and the solenoid valve control device that controls the solenoid valve based on the detected value that is the hydraulic pressure of the hydraulic oil discharged from a hydraulic pump that controls the solenoid valve.

[0020] With such a configuration, variations in the control signal caused by quantization error are suppressed, and the solenoid valve can be accurately controlled according to the operation.

[0021] Further, the hydraulic device of the present invention includes a hydraulic pump that supplies hydraulic oil, a hydraulic actuator that operates by the hydraulic oil, a pressure sensor that detects the hydraulic pressure of the hydraulic oil discharged from the hydraulic pump, a solenoid valve that changes the supply state of the hydraulic oil from the hydraulic pump to the actuator, and the solenoid valve control device that controls the solenoid valve based on the detection value of the pressure sensor.

[0022] With such a configuration, variations in the control signal caused by quantization error are suppressed, and the hydraulic device can be accurately controlled according to the operation.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0024] Hereinafter, as an example of a hydraulic device equipped with a solenoid valve control device and a solenoid valve control system according to an embodiment of the present invention, a tractor equipped with a front loader will be described. In the following description, F in the figure indicates the forward direction, B indicates the rearward direction, U indicates the upward direction, and D indicates the downward direction.

[0025] 〔Overall Configuration of Tractor〕 First, the configuration of a tractor (hydraulic device) will be described with reference to FIG. 1. The tractor includes a body 3 supported by left and right front wheels 1 and left and right rear wheels 2. An engine 4 is supported at the front of the body 3, and a driver's cab 5 is provided on the body 3. In the driver's cab 5, a driver's seat 6, a steering wheel 7 for steering the front wheels 1, and the like are provided.

[0026] The tractor also includes a front loader 13 (working device) supported by the body 3. Left and right support frames 14 are connected to the right and left sides of the body 3 and extend upward, and the front loader 13 is supported by the support frames 14. The front loader 13 includes left and right booms 15 and a bucket 16. The left and right booms 15 are supported at the upper part of the support frames 14 so as to be swingable up and down and extend forward, and the bucket 16 is supported at the front ends of the left and right booms 15 so as to be swingable up and down.

[0027] Left and right double-acting boom cylinders 17 (corresponding to hydraulic actuators) are connected across the support frames 14 and the booms 15. Left and right double-acting bucket cylinders 18 (corresponding to hydraulic actuators) are connected across the booms 15 and the bucket 16. The boom 15 is lifted and lowered by extending and retracting the boom cylinder 17. The bucket 16 is swung up and down by extending and retracting the bucket cylinder 18.

[0028] The boom cylinder 17 and the bucket cylinder 18 are hydraulically controlled by an electronically controlled hydraulic system (corresponding to a solenoid valve control system) provided in the body 3.

[0029] 〔Configuration of Control Valve Unit〕 Hereinafter, the configuration of the control valve unit 8 that supplies and discharges hydraulic oil (pressure oil) to the boom cylinder 17 and the bucket cylinder 18 will be described with reference to FIG. 2.

[0030] The control valve unit 8 includes a hydraulic pump 22 that supplies hydraulic oil, the control valve unit 8, and a control device 51 that controls the operation of the control valve unit 8. The control valve unit 8 is connected to an operation lever 35 (corresponding to an operating tool) provided in the operation unit 5, a variable displacement type hydraulic pump 22 mounted on the machine body 3, the boom cylinder 17, the bucket cylinder 18, and the control device 51. The control valve unit 8 controls the hydraulic oil supplied from the hydraulic pump 22 according to the operation of the operation lever 35 and supplies it to the boom cylinder 17 and the bucket cylinder 18. That is, the boom cylinder 17 and the bucket cylinder 18 are hydraulically controlled by the hydraulic oil supplied from the hydraulic pump 22. Note that the control of the hydraulic oil supplied from the hydraulic pump 22 may be controlled based on the hydraulic pressure of the hydraulic oil supplied from the hydraulic pump 22 together with or instead of the operation amount with respect to the operation lever 35.

[0031] The control valve unit 8 includes a block-shaped valve case 9, and an electromagnetic valve (electronically controlled control valve) 10, an electromagnetic valve 11, three relief valves 19, four check valves 21, etc. are accommodated in the valve case 9. Note that the electromagnetic valve 10 may be, for example, one that directly drives a spool by a solenoid, or one that changes the supply state of pilot oil for driving the spool by a solenoid.

[0032] The hydraulic pump 22 is driven by the engine 4. The hydraulic pump 22 discharges (ejects) the lubricating oil of the transmission case 23 mounted on the machine body 3 as hydraulic oil, and the discharge amount of the hydraulic oil is changed by the operation cylinder 50. The hydraulic pump 22 includes a pressure sensor 22a that detects the hydraulic pressure of the discharged hydraulic oil.

[0033] When the operation lever 35 is operated in the front - rear direction, the solenoid valve 10 is operated, and hydraulic oil is supplied to the boom cylinder 17 to operate the boom cylinder 17. When the operation lever 35 is operated in the left - right direction, the solenoid valve 11 is operated, and hydraulic oil is supplied to the bucket cylinder 18 to operate the bucket cylinder 18. That is, the solenoid valve 10 and the solenoid valve 11 switch the supply state of the hydraulic oil discharged from the hydraulic pump 22 and control the operations of the boom cylinder 17 and the bucket cylinder 18.

[0034] When the load on the boom cylinder 17 increases and the pressure of the hydraulic oil becomes higher than the set value, the relief valve 19 is operated to the open position and the hydraulic oil is discharged, reducing the load on the boom cylinder 17.

[0035] When the load on the bucket cylinder 18 increases and the pressure of the hydraulic oil becomes higher than the set value, the relief valve 19 is operated to the open position and the hydraulic oil is discharged, reducing the load on the bucket cylinder 18.

[0036] The control device (corresponding to the solenoid valve control device) 51 calculates a control value for controlling the solenoid valve 10 or the solenoid valve 11 according to at least one of the operation position of the operation lever 35 and the hydraulic pressure of the hydraulic oil. Based on this control value (control signal), when the solenoid valve 10 or the solenoid valve 11 operates, in response to the operation of the operation lever 35, hydraulic oil is supplied from the hydraulic pump 22 to the boom cylinder 17 or the bucket cylinder 18, and the boom cylinder 17 or the bucket cylinder 18 operates.

[0037] The electronically controlled hydraulic system is composed of an operation lever 35, a control device 51, and solenoid valves 10 and 11.

[0038] 〔Configuration of the control device〕 Next, with reference to FIGS. 3 - 5, the configuration of the control device 51 will be described.

[0039] The control device 51 includes a processor such as an ECU or a CPU, and each functional unit included in the control device 51 is controlled by the processor. The control device 51 includes a detection value receiving unit 52, a random number generation unit 53, a random number addition unit 54, a signal processing unit 56, a signal conversion unit 57, a frequency addition unit 58, and a storage unit 59.

[0040] The detection value receiving unit 52 acquires at least one detection value 62 of the sensor 35a and the pressure sensor 22a provided on the operation lever 35 as the operation position of the operation lever 35 (step #1 in FIG. 5). The acquired detection value 62 is stored in the storage unit 59. The sensor 35a detects the operation position of the operation lever 35 over time at a predetermined time interval.

[0041] The random number generation unit 53 generates a random number signal 63 with a predetermined amplitude and stores the random number signal 63 in the storage unit 59 (step #2 in FIG. 5). The random number addition unit 54 adds the random number signal 63 to at least one of the detection values 62 to generate an input signal 64 (step #3 in FIG. 5). The generated input signal 64 is stored in the storage unit 59.

[0042] The signal processing unit 56 rounds (quantizes) the number of digits of the input signal 64 to a number of digits suitable for generating control signals for the solenoid valves 10 and 11 (step #4 in FIG. 5). The accuracy of the detection value 62 depends on the performance of the sensor 35a and the pressure sensor 22a, and the accuracy of the control signal depends on the performance of the solenoid valves 10 and 11 and the control device 51. If the accuracy of the detection value 62 and the accuracy of the control signal do not match, it may not be possible to generate an appropriate control signal. In order to match the significant figures of the detection value 62 with the significant figures of the control signal, the signal processing unit 56 rounds the detection value 62 and performs fractional digit processing. The rounding process can be performed by any method such as rounding up, rounding down, or truncating at a predetermined digit.

[0043] The signal conversion unit 57 generates a first control signal 66, which is an electrical signal for controlling the solenoid valves 10 and 11, from at least one of the rounded input signal 64 and the detection value 62 (step #5 in FIG. 5). The generated first control signal 66 is stored in the storage unit 59.

[0044] The frequency adder 58 adds a frequency signal 67 of a predetermined frequency to the first control signal 66 to generate a second control signal 69 (step #6 in FIG. 5). The generated second control signal 69 is stored in the storage unit 59. The frequency of the frequency signal 67 is arbitrary, such as 100 Hz, and for example, the period can be a frequency that is the time interval at which the sensor 35a or the pressure sensor 22a outputs the detection value 62 (detects the operation position of the operation lever 35 / detects the hydraulic pressure of the hydraulic oil). Also, although the amplitude of the frequency signal 67 is arbitrary, it is preferably set to be half or less of the rounding width (quantization width). The solenoid valves 10 and 11 can be controlled by the first control signal 66 or the second control signal 69, but in this embodiment, the solenoid valves 10 and 11 are controlled using the second control signal 69 (step #7 in FIG. 5). Then, the boom cylinder 17 and the bucket cylinder 18 operate according to the operations of the solenoid valves 10 and 11.

[0045] When the solenoid valves 10 and 11 are controlled using the second control signal 69, even when the operation lever 35 is not being operated, at least a control signal corresponding to the frequency signal 67 is input to the solenoid valves 10 and 11, and the solenoid valves 10 and 11 will always continue to operate. As a result, the friction generated on the spools of the solenoid valves 10 and 11 can be reduced, making the operations of the solenoid valves 10 and 11 and the boom cylinder 17 and the bucket cylinder 18 smoother, and at the same time, the responsiveness of the solenoid valves 10 and 11 and the boom cylinder 17 and the bucket cylinder 18 can be improved.

[0046] 〔Effect of adding a random number signal〕 Next, the effect of adding the random number signal 63 will be described with reference to FIG. 6.

[0047] As described above, when generating the control signal (the first control signal 66) from the detected value 62, the detected value 62 is rounded (quantized) to a predetermined accuracy (significant figures). The rounding is performed by a predetermined method such as rounding off or truncation so as to have a predetermined number of digits. Therefore, the change in the detected value 62 may be emphasized by the rounding. As a result, the control signal may vary (FIG. 6(a)), and the operations of the hydraulic actuators (the boom cylinder 17 and the bucket cylinder 18) may not be stable.

[0048] On the other hand, by matching the performance (resolution) of the sensor 35a with the required performance of the solenoid valves 10 and 11, the necessity of rounding the detected value 62 is reduced. However, improving the performance of the sensor 35a, the pressure sensor 22a, etc. increases the cost, and the communication capacity for transmitting signals from the sensor 35a or the pressure sensor 22a to the control device 51 also increases.

[0049] According to the present embodiment, even without improving the performance of the sensor 35a, the pressure sensor 22a, etc., when rounding the signal obtained by adding the random number signal 63 to the detected value 62, even when the detected value 62 changes, the variation of the control signal is suppressed (FIG. 6(b)). As a result, the operations of the hydraulic actuators (the boom cylinder 17 and the bucket cylinder 18) are stabilized, and the hydraulic actuators (the boom cylinder 17 and the bucket cylinder 18) can be accurately controlled according to the operation.

[0050] 〔Random number signal〕 The random number signal 63 is a signal whose amplitude varies randomly. For example, the random number signal 63 is generated by synthesizing signals having a plurality of different frequencies.

[0051] The amplitude of the random number signal 63 can be determined in consideration of the rounding width (quantization width). For example, the amplitude of the random number signal 63 is set to be half of the rounding width. If the rounding width is d, the amplitude of the random number signal 63 is preferably 0.5d or less. That is, the random number signal 63 is a signal in which random numbers of -0.5d or more and 0.5d or less appear at a predetermined period.

[0052] Specifically, assuming that the control signal is an integer value, the rounding width (quantization width) is 1. Therefore, as shown in FIG. 7, the random number signal 63 is a signal in which random numbers between -0.5 and 0.5 appear periodically. Note that the interval of the random numbers is arbitrary, and the random numbers may take values at intervals of 1 / 10 of the rounding width, that is, values of -0.5, -0.4, -0.3 ··· 0.0, ··· 0.4, 0.5, or may take values at intervals of 1 / 100 of the rounding width, that is, values of -0.50, -0.49, -0.48 ··· 0.00, ··· 0.48, 0.49, 0.50.

[0053] Here, when the detected value 62 changes gradually, as shown by the dashed line in FIG. 8, if the detected value 62 is rounded as it is without adding the random number signal 63, the tendency for the value to be rounded up or down in the vicinity of a specific value becomes prominent, the change in the detected value 62 is emphasized, and the variance of the rounded signal may increase. For example, when the detected value 62 is rounded to the nearest integer, the difference in the signal values rounded in the vicinity of 0.4, 0.5, 1.4, 1.5, etc. of the detected value 62 is 1, and the rounded signal changes by 1 for a change of about 0.1 in the detected value 62. Thus, in the vicinity of a specific value, the change amount of the rounded signal becomes larger than the change amount of the detected value 62, and the value of the rounded signal changes abruptly in the vicinity of the specific value, emphasizing the change in the detected value 62.

[0054] Thus, when the detected value 62 changes gradually, values that are rounded up tend to gather on one side and values that are rounded down tend to gather on the other side around a specific value (the boundary value at which the numerical value is rounded up or down). Therefore, if the detected value 62 is rounded as it is, the rounded value will change by the rounding width around the specific value. In this embodiment, a random number signal 63 with an amplitude half of the rounding width is added to the detected value 62. Therefore, as shown by the thick line in FIG. 8, the values near the value where the change is emphasized change randomly, and the tendency for values that are rounded up to gather on one side and values that are rounded down to gather on the other side around a specific value is alleviated. That is, it is suppressed that the value of the signal rounded near the specific value changes abruptly, and as a result, the variation of the control signal is suppressed. Further, by adding the random number signal 63, the tendency for the rounding error with the detected value 62 to be biased to the low-frequency region is alleviated, so the influence of the rounding process on the control signal is reduced, and the variation of the control signal is suppressed. From the above results, the solenoid valves 10 and 11 (see FIG. 2) can be accurately controlled according to the operation.

[0055] 〔Alternative Embodiment〕 (1) In the above embodiment, the signal processing unit 56 may round all the input signals 64, but some or all of the input signals 64 may not be rounded by the signal processing unit 56. When not all of the input signals 64 are rounded, the signal processing unit 56 may not be provided. The signal conversion unit 57 may be configured to round the input signals 64 that were not rounded by the signal processing unit 56 as a result of the process of generating the first control signal 66.

[0056] (2) In each of the above embodiments, the random number signal 63 is added to and rounded for at least one of the detected values 62 of the sensor 35a and the pressure sensor 22a, but the detected value 62 to which the random number signal 63 is added may be any signal (detected value 62) among the signals (detected values 62) related to hydraulic control for which the rounding process is performed.

[0057] For example, the signal (detection value 62) for which rounding processing is performed in hydraulic control is, in addition to the operation amount with respect to the operation lever 35 and the hydraulic pressure of the hydraulic oil discharged from the hydraulic pump 22, the discharge flow rate of the hydraulic oil discharged from the hydraulic pump 22, the actual current values of the solenoid valves 10 and 11, the control signals (first control signal 66, second control signal 69) generated by the control device 51, and the like. That is, the signal (detection value 62) for which rounding processing is performed is a value that detects the actual state of the electronically controlled hydraulic system such as the hydraulic pressure and discharge flow rate of the hydraulic oil and the actual current value and is transmitted to the control device 51, a value that detects the operator's operation transmitted to the control device 51 such as the operation amount with respect to the operation lever 35, a value calculated by the control device 51 such as the control signals (first control signal 66, second control signal 69), and the like.

[0058] The discharge flow rate is detected by a flow rate sensor (not shown) provided in the hydraulic pump 22, and the control device 51 generates control signals (first control signal 66, second control signal 69) based on at least any one of the hydraulic pressure of the hydraulic oil, the operation amount with respect to the operation lever 35, and the discharge flow rate. The actual current value is detected by current sensors 10a and 11a provided in the solenoid valves 10 and 11 and is transmitted from the solenoid valves 10 and 11 to the control device 51. The control device 51 can generate control signals (first control signal 66, second control signal 69) in consideration of the actual current value. The control device 51 can round the control signals (first control signal 66, second control signal 69) to the number of digits corresponding to the solenoid valves 10 and 11. In this case, the control device 51 may generate the control signals (first control signal 66, second control signal 69) from the detection value 62 without rounding the input signal 64.

[0059] As described above, by adding the random number signal 63 to an arbitrary signal (detection value 62) and rounding it, the control signals (first control signal 66, second control signal 69) can be generated with higher accuracy, and the solenoid valves 10 and 11 can be controlled with higher accuracy.

[0060] (3) In the above embodiment, the frequency signal 67 is not limited to the configuration added to the first control signal 66, and may be added to the detection value 62 before the random number signal 63 is added, or to the input signal 64 before being rounded.

[0061] As a result, the solenoid valves 10 and 11 always continue to operate, and the responsiveness of the solenoid valves 10 and 11, the boom cylinder 17, and the bucket cylinder 18 to the operation of the operation lever 35 is improved. Further, by adding the frequency signal 67 to the detection value 62 or the input signal 64, the random number signal 63 and the frequency signal 67 are added to the detection value 62 and then rounded, and it can be expected to further suppress the variation of the control signal caused by the quantization error.

[0062] (4) In each of the above embodiments, the solenoid valves 10 and 11 are not limited to the configuration controlled by the second control signal 69, and may be controlled by the first control signal 66. In this case, the control device 51 may not include the frequency addition unit 58.

[0063] Even if the frequency signal 67 is not added, the responsiveness may be sufficiently ensured by controlling the solenoid valves 10 and 11 with the first control signal 66 generated from the input signal 64 obtained by adding the random number signal 63 to the detection value 62 and rounding. According to the above configuration, while ensuring responsiveness with a simpler configuration, the variation of the control signal caused by the quantization error can be suppressed, and the solenoid valves 10 and 11 can be accurately controlled according to the operation.

[0064] (5) In each of the above embodiments, instead of or in addition to the solenoid valves 10 and 11, the control device 51 may control a solenoid valve for operating the operation cylinder 50 with a control signal generated with the addition of the random number signal 63 to control the discharge flow rate of the hydraulic pump 22. Thereby, the boom cylinder 17 and the bucket cylinder 18, which are hydraulic actuators, can be controlled with higher accuracy.

[0065] (6) In each of the above embodiments, the hydraulic actuator is not limited to the two of the boom cylinder 17 and the bucket cylinder 18, and one or three or more hydraulic actuators may be provided. In this case, for each of the hydraulic actuators, a solenoid valve for controlling the supply of hydraulic oil is provided, and one or more of these solenoid valves are controlled by a control signal generated by the control device 51 with the addition of a random number signal 63.

[0066] (7) In each of the above embodiments, the configuration of the control valve unit 8 is not limited to the configuration shown in FIG. 2, and it is only necessary that the supply of hydraulic oil to each hydraulic actuator can be controlled. For example, the configuration of the oil passage, the configuration of the solenoid valves 10 and 11, and the presence or absence and configuration of the relief valve 19 are arbitrary.

[0067] (8) In each of the above embodiments, the operation lever 35 is not limited to a lever, and may be an operating tool having an arbitrary configuration such as a switch or a pedal. Further, the configuration is not limited to accepting the operation of a plurality of hydraulic actuators with one operation lever 35 (operating tool), and an operating tool may be provided for each one or a plurality of hydraulic actuators.

[0068] (9) In each of the above embodiments, the control device 51 is not limited to being composed of the above functional blocks, and may be composed of arbitrary functional blocks. For example, each functional block of the control device 51 may be further subdivided, or conversely, a part or all of each functional block may be combined. Further, the function of the control device 51 is not limited to the above functional blocks, and may be realized by a method executed by arbitrary functional blocks. Further, a part or all of the function of the control device 51 may be configured by software. The program related to the software is stored in an arbitrary storage device such as the storage unit 59, and is executed by a processor such as a CPU included in the control device 51 or a separately provided processor.

Industrial Applicability

[0069] The electromagnetic valve control device of the present invention can be applied to all devices equipped with electromagnetic valves. As an example of such a device, for example, a hydraulic device, a pneumatic device, a water pressure device, a water supply and drainage device, an air conditioner, etc. can be mentioned. Further, as an example of the above hydraulic device, for example, agricultural machinery, construction machinery, industrial machinery, machine tools, vehicles, ships, aircraft, etc. can be mentioned.

Explanation of Signs

[0070] 3 Machine body 10 Electromagnetic valve (electronically controlled control valve) 11 Electromagnetic valve (electronically controlled control valve) 17 Boom cylinder (hydraulic actuator) 18 Bucket cylinder (hydraulic actuator) 22 Hydraulic pump 22a Pressure sensor 35 Operating lever (operating tool) 51 Control device (electromagnetic valve control device) 52 Detection value receiving section 53 Random number generation section 54 Random number addition section 56 Signal processing section 57 Signal conversion section 58 Frequency addition section 62 Detection value 63 Random number signal 66 First control signal 67 Frequency signal 69 Second control signal

Claims

1. An electromagnetic valve control device for controlling an electromagnetic valve, comprising: a detection value receiving unit that acquires one or more detection values; a random number generation unit that generates a random number signal with a predetermined amplitude; a random number addition unit that adds the random number signal to the detection value to generate an input signal; a signal processing unit that rounds the input signal to a predetermined number of digits; a signal conversion unit that generates a first control signal from the rounded input signal; a frequency addition unit that adds a frequency signal with a predetermined frequency and different from the random number signal to the first control signal to generate a second control signal; and an electromagnetic valve control device that controls the electromagnetic valve with the second control signal.

2. The electromagnetic valve control device according to claim 1, wherein the amplitude of the random number signal is half of the rounding width.

3. The electromagnetic valve control device according to claim 1, wherein the random number signal has an amplitude in a range of -0.5d or more and 0.5d or less, where d is the rounding width.

4. An electromagnetic valve control system comprising the electromagnetic valve and the electromagnetic valve control device according to any one of claims 1 to 3, which controls the electromagnetic valve based on the detection value of the hydraulic pressure of the hydraulic oil discharged from a hydraulic pump that controls the electromagnetic valve.

5. a hydraulic pump that supplies hydraulic oil; a hydraulic actuator that operates with the hydraulic oil; a pressure sensor that detects the hydraulic pressure of the hydraulic oil discharged from the hydraulic pump; the electromagnetic valve that changes the supply state of the hydraulic oil from the hydraulic pump to the hydraulic actuator; and a hydraulic device comprising the electromagnetic valve control device according to any one of claims 1 to 3, which controls the electromagnetic valve based on the detection value of the pressure sensor.

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