JP2012001009A - Control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device which is enhanced in the stability of the control of a flow rate control valve, and consequently stabilizes the drive control of a hydraulic actuator and secures the responsiveness of the hydraulic actuator.SOLUTION: A target opening of the flow rate control valve 10 is set based on a drive amount and a target drive amount of the hydraulic actuator 11, and thereby the opening of the flow rate control valve 10 and the drive amount of the hydraulic actuator 11 are associated with each other. Furthermore, the opening of the flow rate control valve 10 is fed back and the opening of the flow rate control valve 10 is adjusted. Thus, the control stability of the flow rate control valve 10 is enhanced, and consequently the drive control of the hydraulic actuator 11 is improved and the responsiveness of the hydraulic actuator 11 is secured.

Description

  The present invention relates to a control device, and more particularly to a control device that can improve the control stability of a flow control valve, and accordingly stabilize the drive control of a hydraulic actuator and ensure the response of the hydraulic actuator.

  2. Description of the Related Art Conventionally, there has been known a control device that controls a driving amount of a hydraulic actuator by controlling a flow rate of hydraulic oil supplied to the hydraulic actuator with a flow control valve. As an example to which such a control device is applied, there is a technique disclosed in Patent Document 1, for example. The technology disclosed in Patent Document 1 relates to a steering apparatus for a cargo handling vehicle that steers wheels by a hydraulic cylinder (hydraulic actuator), and a controller (control apparatus) calculates a target steering angle for the wheels. A calculating means, a stroke deviation calculating means for calculating a deviation between the target stroke of the hydraulic cylinder corresponding to the target steering angle and the hydraulic cylinder stroke, and a solenoid valve that makes the hydraulic cylinder stroke a target steering angle based on the deviation. And an electromagnetic valve opening adjusting means for calculating the opening (Claim 3 of Patent Document 1). With this configuration, the hydraulic cylinder stroke (drive amount) is fed back, and the deviation between the target steering angle (target drive amount) and the hydraulic cylinder stroke (drive amount) is calculated. An operation signal proportional to the deviation is set (corrected) and output to a solenoid valve (flow control valve). When the operation signal is set (corrected), the solenoid valve (flow control valve) has a degree of opening so that the hydraulic cylinder stroke (drive amount) matches the target stroke (target drive amount) and the deviation becomes zero. Adjusted.

Japanese Patent No. 389816 (Claim 3, FIG. 4 etc.)

  However, in the technique disclosed in Patent Document 1, the operation signal of the flow control valve is set (corrected) so that the deviation becomes zero based on the deviation between the drive amount of the hydraulic actuator and the target drive amount. The control target to which the drive amount is output is a hydraulic actuator, and the control target to which the operation signal is input is a flow control valve. As described above, since feedback control is performed between different control targets, the setting (correction) of the control signal input to the flow control valve is delayed and the control stability of the flow control valve is reduced. was there. For this reason, the drive control of the hydraulic actuator may become unstable or the response of the hydraulic actuator to the change of the target drive amount may be deteriorated. Whether or not these problems occur depends on the characteristics of each control object, for example, the opening characteristics of the flow control valve with respect to the operation signal. These problems occur especially when the linearity of the opening characteristic with respect to the operation signal is poor or when the opening characteristic fluctuates greatly due to external effects (disturbances) such as changes in the flow rate, pressure, and temperature of the hydraulic fluid. It was easy to occur.

  The present invention has been made to solve the above-described problems, and improves the stability of the control of the flow control valve, thereby stabilizing the drive control of the hydraulic actuator and ensuring the response of the hydraulic actuator. An object of the present invention is to provide a control device that can be used.

Means for Solving the Problems and Effects of the Invention

  In order to achieve this object, according to the control device of the first aspect, the target opening of the flow control valve is set by the target opening setting means, and the opening of the flow control valve is acquired by the opening acquisition means. The Based on the acquired opening degree of the flow control valve and the set target opening degree, the opening degree adjusting means adjusts the opening degree of the flow control valve. As described above, the flow control valve opening (output) is adjusted to adjust the flow control valve opening (input is corrected). Even in the case of a flow rate control valve whose opening characteristic greatly fluctuates, the control signal input to the flow rate control valve is quickly set (corrected), and the control stability of the flow rate control valve can be improved.

  Furthermore, the setting of the target opening of the flow control valve by the target opening setting means includes the drive amount of the hydraulic actuator acquired by the drive amount acquisition means, and the target drive amount of the hydraulic actuator set by the target drive amount setting means. Therefore, the opening degree of the flow control valve and the driving amount of the hydraulic actuator can be closely related.

  As described above, the target opening degree of the flow control valve is set by the target opening degree setting means based on the driving amount and the target driving amount of the hydraulic actuator, and based on the target opening degree and the opening degree of the flow control valve. Since the opening of the flow control valve is adjusted by the opening adjustment means, the stability of the control of the flow control valve is improved without being influenced by the characteristics of the hydraulic actuator and the flow control valve, and accordingly the hydraulic actuator As a result, the drive control can be stabilized and the response of the hydraulic actuator can be secured.

  According to the control device of the second aspect, the flow control valve is disposed between the hydraulic source and the hydraulic actuator, and the hydraulic actuator is a hydraulic cylinder that steers the wheel. Thereby, the stability of the control of the flow control valve is improved, and accordingly, the steering control is stabilized and the responsiveness can be ensured. In addition to the effect of the first aspect, the wheel can be steered smoothly, and the wheel This has the effect of ensuring the steering response.

  According to the control device of the third aspect, the driving amount deviation which is the deviation between the driving amount of the hydraulic actuator and the target driving amount is calculated by the driving amount deviation calculating means, and the driving amount deviation and the target are compared with the driving amount deviation. With reference to the correspondence with the opening, the correspondence reference means sets the target opening of the flow control valve. Thereby, the target opening degree of the flow control valve can be set by the target opening degree setting means in accordance with the characteristics of the flow control valve. Since the opening degree of the flow rate proportional valve is adjusted by the opening degree adjusting means so as to coincide with the set target opening degree, in addition to the effect of claim 1 or 2, the control stability of the flow rate control valve can be improved. effective.

  According to the control device of the fourth aspect, the correlation between the drive amount deviation and the target opening of the flow control valve is associated with the individual characteristics of the flow control valve by associating with the opening information with respect to the operation signal of the flow control valve. Can be made according to Thereby, in addition to the effect of Claim 3, there exists an effect which can improve the responsiveness of control of a flow control valve.

  According to the control device of the fifth aspect, an opening degree deviation which is a deviation between the opening degree of the flow rate control valve and the target opening degree is calculated by the opening degree deviation calculating means, and the opening degree deviation is multiplied by a predetermined proportional gain. The operation signal of the flow control valve is calculated by the operation signal calculation means by proportional control and integral control by multiplying the integral value or cumulative value of the opening deviation by a predetermined integral gain. As a result, the opening degree of the flow control valve can be brought close to the target opening degree smoothly by the proportional control of the operation signal calculating means, and the opening degree of the flow rate control valve can be controlled to the target opening degree by the integral control. Thereby, in addition to the effect in any one of Claims 1-4, there exists an effect which can improve the stability of control of the opening degree of a flow control valve.

(A) is a side view of the vehicle by which the control apparatus in one embodiment of this invention is mounted, (b) is a top view of the vehicle seen through the base part. 1 is a schematic diagram showing a hydraulic circuit and an electrical configuration of a vehicle. It is a block diagram which shows the electric constitution of a control apparatus. It is a flowchart which shows an opening degree adjustment process. (A) is a schematic diagram which shows the correspondence (opening characteristic) of the input electric current and the opening degree of a flow control valve, (b) is a schematic diagram which shows typically the content of the target opening degree function. (C) is a schematic diagram which shows the correspondence of a deviation (driving amount deviation) and the opening degree of a flow control valve. It is a block diagram which shows the electric constitution of the control apparatus in a comparative example. (A) is an operation test result of the flow control valve and the hydraulic cylinder controlled by the control device in the comparative example, and (b) is an operation test result of the flow control valve and the hydraulic cylinder controlled by the product of the present invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. First, a schematic configuration of a vehicle 1 on which the control device 20 of the present invention is mounted will be described with reference to FIG. FIG. 1A is a side view of a vehicle 1 on which a control device 20 according to an embodiment of the present invention is mounted, and FIG. 1B is a plan view of the vehicle 1 seen through the base 2. It is. In addition, illustration of the cab 5 etc. is abbreviate | omitted in FIG.1 (b). Moreover, the same reference numerals are given to a part of the plurality of configurations, and the drawings are simplified.

  As shown in FIG. 1, the vehicle 1 includes a plurality of drive units 3 and a traveling unit 4 below a pedestal 2 on which a conveyed product is loaded. The drive unit 3 includes left and right wheels 3a and a hydraulic motor 3b that applies a rotational driving force to the wheels 3a. Each drive unit 3 is configured to be independently steerable. The traveling unit 4 is provided in order to distribute and distribute the load of the conveyed product loaded on the vehicle 1 with the drive unit 3, and includes left and right wheels 4 a, and the vehicle 1 is driven by the driving force of the drive unit 3. It is configured as a driven wheel that is driven when the vehicle travels. Each traveling unit 4 is also configured to be independently steerable.

  Further, the vehicle 1 is provided with a cab 5 in front (left side of FIG. 1A) and rear side (right side of FIG. 1A) of the base part 2. The driver's cab 5 is provided with a handle 5a (see FIG. 2), and the driver 5 is steered by operating the handle 5a by the driver.

  As described above, since the drive unit 3 and the traveling unit 4 are configured to be steerable independently, the front wheels 3a, 4a and the rear wheels 3a, 4a of the vehicle 1 are steered and in phase. By doing so, the vehicle 1 can go straight, skew, or traverse, and the front wheels 3a, 4a and the rear wheels 3a, 4a of the vehicle 1 can be steered to be in reverse phase, either forward or backward. The vehicle 1 can be turned by steering the wheels 3a and 4a.

  Next, the steering mechanism of the wheels 3a and 4a in the drive unit 3 and the traveling unit 4 will be described with reference to FIG. FIG. 2 is a schematic diagram showing a hydraulic circuit and an electrical configuration of the vehicle 1. In FIG. 2, a cylinder direct-acting steering mechanism is shown as an example. Moreover, although the drive mechanism in the drive unit 3 is demonstrated, the drive mechanism in the traveling unit 4 is also comprised similarly.

  As shown in FIG. 2, the steering angle of the handle 5 a operated by the driver is detected by a steering angle sensor device 6. The steering angle sensor device 6 is a device for detecting the steering angle of the handle 5a and outputting the detection result to the control device 20, an angle sensor (not shown) for detecting the steering angle of the handle 5a, An output circuit (not shown) that processes the detection result of the angle sensor and outputs the result to the control device 20 is mainly configured.

  On the other hand, hydraulic oil is stored in the tank 7, and the hydraulic oil is supplied to the flow control valve 10 through the pressure line 9 by the hydraulic pump 8. The flow rate control valve 10 is a device that controls the flow rate of hydraulic oil supplied from the hydraulic pump 8 to the hydraulic cylinder 11 in a stepless manner in accordance with an input operation signal. The electromagnetic coil 10a, A valve body 10b driven by the electromagnetic coil 10a is mainly provided. The flow rate of the hydraulic oil supplied to the hydraulic cylinder 11 is proportional to the opening degree of the flow control valve 10, and the opening degree is proportional to the moving amount of the valve body 10b. The amount of movement of the valve body 10b is detected by an output signal of a differential transformer (opening sensor 10c (see FIG. 3)) built in the flow control valve 10.

  The hydraulic cylinder 11 is a device that expands and contracts the piston rod 11 a according to the amount of hydraulic oil supplied from the flow control valve 10. The tip of the piston rod 11a is connected to the drive unit 3, and the wheel 3a is rotated around the steering shaft 3c and adjusted to a predetermined steering angle according to the expansion and contraction of the piston rod 11a. The steering angle of the wheel 3a is detected by the steering angle sensor device 12 disposed on the steering shaft 3c. The steering angle sensor device 12 is a device for detecting the steering angle of the wheel 3a and outputting the detection result to the control device 20, and an angle sensor (not shown) for detecting the steering angle of the wheel 3a. ) And an output circuit (not shown) that processes the detection result of the angle sensor and outputs the result to the control device 20.

  The control device 20 is a device for controlling each part of the vehicle 1 configured as described above, and is connected to devices such as the steering angle sensor device 6, the flow rate control valve 10, and the steering angle sensor device 12. . Further, the control device 20 stores a control program executed by the control device 20 (for example, the program of the flowchart shown in FIG. 5), a function or map for calculating the target opening degree, fixed value data, and the like. A portion 20a is provided.

  Next, a detailed configuration of the control device 20 will be described with reference to FIG. FIG. 3 is a block diagram showing an electrical configuration of the control device 20.

  The target steering angle calculation unit 20b acquires the steering angle of the handle 5a based on the input signal from the steering angle sensor device 6, and the target steering angle (target drive amount) of the wheels 3a, 4a based on the acquired steering angle. Is calculated. The steering angle deviation calculation unit 20c acquires the steering angle (drive amount) of the wheels 3a and 4a based on the input signal from the steering angle sensor device 12, and acquires the steering angle and the target steering angle calculation unit 20b. The deviation (driving amount deviation) from the target steering angle calculated by the above is calculated.

  The target opening calculator 20d calculates the target opening of the flow control valve 10 based on the deviation (driving amount deviation) calculated by the steering angle deviation calculator 20c. The calculation processing of the target opening in the target opening calculation unit 20d will be described later. The opening degree deviation calculating unit 20e acquires the opening degree of the flow control valve 10 based on the input signal from the opening degree sensor 10c, and the deviation between the obtained opening degree and the target opening degree calculated by the target opening degree calculating unit 20d. e (opening deviation) is calculated.

The proportional-integral calculation unit 20f calculates a proportional calculation value Op by multiplying the deviation e by a proportional gain Kp. Further, the proportional-plus-integral calculation unit 20f calculates an integral calculation value Oi by multiplying an integral value or cumulative value of the deviation e by an integral gain Ki. Proportional integration unit 20f is proportional calculation value Op, calculates an operation signal MV by adding the initial value b ₀ of the integral calculation value Oi and bias. The operation signal MV calculated by the proportional-integral calculation unit 20f is input to a driver (not shown), and the driver outputs a current corresponding to the operation signal MV to the electromagnetic coil 10a.

  As a result, the valve body 10b is driven by the electromagnetic coil 10a, and the flow rate of the hydraulic oil supplied to the hydraulic cylinder 11 is adjusted. The hydraulic cylinder 11 is driven according to the flow rate of the hydraulic oil, and the driving amount of the hydraulic cylinder 11 is detected by the steering angle sensor device 12.

  Next, the opening degree adjusting process will be described with reference to FIG. FIG. 4 is a flowchart showing the opening adjustment process. This process is a process executed repeatedly (for example, at intervals of 0.2 seconds) while the power of the control device 20 is turned on, and is a process for adjusting the opening degree of the flow control valve 10.

  Regarding the opening adjustment process, the control device 20 first acquires the steering angle of the handle 5a (S1), and sets a target steering angle (target drive amount) based on the acquired steering angle (S2). Next, the steering angle (drive amount) of the wheels 3a, 4a is acquired (S3), and the deviation (drive amount deviation) between the acquired steering angle and the target steering angle is calculated (S4). Next, a target opening degree of the flow control valve 10 is set based on the calculated deviation (drive amount deviation) (S5). The opening degree of the flow control valve 10 is acquired (S6), and a deviation e (opening degree deviation) between the acquired opening degree and the set target opening degree is calculated (S7). Next, the calculated deviation e (opening deviation) is multiplied by the proportional gain Kp (S8), and the integral value or cumulative value of the deviation e (opening deviation) is multiplied by the integral gain Ki (S9). Next, an operation signal for the flow control valve 10 is set based on the multiplication results, and the opening degree of the flow control valve 10 is adjusted (S10).

  According to the present embodiment, the control device 20 (see FIG. 3) acquires the opening degree of the flow control valve 10 from the input signal from the opening degree sensor 10c, and calculates the operation signal MV based on the acquired opening degree. Since the opening degree of the flow control valve 10 is adjusted, the control signal MV input to the flow control valve 10 is quickly set (corrected), and the control stability of the flow control valve 10 can be improved. Furthermore, the setting of the target opening of the flow rate control valve 10 in the target opening calculation unit 20d is calculated in the steering angle of the wheels 3a and 4a input from the steering angle sensor device 12 and the target steering angle calculation unit 20b. Therefore, the opening degree of the flow rate control valve 10 and the steering angles of the wheels 3a and 4a can be closely associated with each other.

  As described above, the target opening of the flow control valve 10 is determined in the target opening calculation unit 20d based on the target steering angle calculated in the target steering angle calculation unit 20b and the steering angles of the wheels 3a and 4a. Since the opening degree of the flow rate control valve 10 is feedback-controlled with respect to the set target opening degree, it is suppressed that the flow rate control valve 10 is influenced by stability and disturbance, and the flow rate control valve 10 is controlled. Stability can be improved. Further, along with this, the drive control of the hydraulic cylinder 11 can be stabilized and the responsiveness of the hydraulic cylinder 11 can be secured.

  Further, the deviation e (opening deviation) between the opening of the flow rate control valve 10 and the target opening is calculated in the opening deviation calculator 20e, and proportional control for multiplying the deviation e by the proportional gain Kp in the proportional integral calculator 20f. The operation signal MV of the flow control valve 10 is calculated by integral control in which the integral value or cumulative value of the deviation e is multiplied by the integral gain Ki. As a result, the opening degree of the flow control valve 10 can be brought close to the target opening degree smoothly by proportional control, and the opening degree of the flow control valve 10 can be controlled to the target opening degree by integral control. Thereby, the stability of control of the opening degree of the flow control valve 10 can be improved.

  Further, the flow control valve 10 (see FIG. 2) is disposed between the hydraulic pump 9 and the hydraulic cylinder 11, and the hydraulic cylinder 11 steers the wheels 3a and 4a. By improving the control stability of the valve 10, the steering control of the wheels 3a, 4a can be stabilized and the responsiveness can be ensured. As a result, the wheels 3a, 4a can be smoothly steered according to the operation of the handle 5a, and the steering response of the wheels 3a, 4a to the operation of the handle 5a can be ensured.

  Next, with reference to FIG. 5, the target opening calculation processing in the target opening calculation unit 20d (see FIG. 3) of the control device 20 will be described. FIG. 5A is a schematic diagram showing a correspondence relationship (opening characteristic) between a current input from a driver (not shown) and the opening degree of the flow control valve 10. The flow control valve 10 is a device in which the opening degree is controlled steplessly in accordance with an input operation signal (current in this embodiment), and the opening degree characteristic is that the opening degree is directly proportional to the current (see FIG. 5 (a) broken line) is ideal.

  On the other hand, some flow control valves 10 do not have linear proportionality in the opening characteristics, as shown by the solid line in FIG. The flow rate control valve 10 whose opening characteristic is shown by a solid line in FIG. 5 (a) hardly changes when the current is small. When the current is gradually increased, the opening degree suddenly starts to change, and further the current is controlled. If it is increased, the opening degree changes significantly with a slight change in current. Hereinafter, the case where the control device 20 controls the flow rate control valve 10 whose opening characteristic is illustrated by the solid line in FIG.

  A target opening degree function is provided in the storage unit 20a (see FIG. 2) of the control device 20. With reference to FIG.5 (b), a target opening degree function is demonstrated. FIG. 5B is a schematic diagram schematically showing the contents of the target opening function. The target opening function is a function indicating a correspondence relationship between a deviation (drive amount deviation) between the target steering angle and the steering angle and the target opening of the flow control valve 10. The target steering angle is set by the target steering angle calculator 20b (see FIG. 3), and the deviation (driving amount deviation) from the acquired steering angle is calculated by the steering angle deviation calculator 20c. The target opening calculation unit 20d refers to the target opening function and calculates the target opening of the flow control valve 10 with respect to the deviation (driving amount deviation).

  The target opening degree function is set in association with the opening degree information (FIG. 5A) with respect to the operation signal (current) of the flow control valve 10. That is, as shown in FIG. 5A, the flow control valve 10 hardly changes its opening when the current is small, so that the target opening function corresponds to the current as shown in FIG. 5B. When the deviation (driving amount deviation) is small with respect to the target opening degree (the broken line in FIG. 5B) for an ideal flow control valve in which the opening degree is directly proportional, the target opening degree becomes large (the same deviation) If so, the solid line in FIG. 5B is set so that the target opening is larger than the broken line. Thereby, the target opening degree function according to each characteristic of the flow control valve 10 can be set, and the control responsiveness of the flow control valve 10 when the deviation is small (when the current is small) can be improved. Even if the target opening is set large by the target opening calculator 20d (see FIG. 3), the steering angle by the controlled hydraulic cylinder 11 is fed back to the control device 20, so that the target steering angle calculator The steering angle of the wheels 3a, 4a (see FIG. 2) is controlled to the target steering angle set by 20b.

  Next, the result of controlling the flow control valve 10 using the control device 20 will be described with reference to FIG. FIG. 5C is a schematic diagram showing a correspondence relationship between the deviation (drive amount deviation) and the opening degree of the flow control valve 10. The flow control valve 10 has no linear proportionality in the opening characteristic (current-opening characteristic) (see FIG. 5A). The opening characteristic of the flow control valve 10 cannot be changed because it is a characteristic characteristic of the flow control valve 10, but by controlling the flow control valve 10 by the control device 20, as shown in FIG. In addition, the opening degree of the flow control valve 10 with respect to the deviation (driving amount deviation) can be linearly proportional.

  Next, the product of the present invention will be further described by comparing the control device 20 (hereinafter referred to as “the product of the present invention”) in the present embodiment with a comparative example with reference to FIGS. 6 and 7. FIG. 6 is a block diagram showing an electrical configuration of the control device 100 in the comparative example. In addition, the same part as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits description. As shown in FIG. 6, the control device 100 in the comparative example does not include the target opening calculation unit 20d and the opening deviation calculation unit 20e, and includes a proportional calculation unit 102 instead of the proportional integration calculation unit 20f. This is different from the control device 20.

The steering angle deviation calculation unit 101 of the control device 100 acquires the steering angle (drive amount) of the wheels 3a and 4a based on the input signal from the steering angle sensor device 12, and acquires the steering angle and the target steering. A deviation e (driving amount deviation) from the target steering angle calculated by the angle calculation unit 20b is calculated. The proportional calculation unit 102 calculates the proportional calculation value Op by multiplying the deviation e by the proportional gain Kp, and calculates the operation signal MV by adding the initial value b _{0 of the} bias. The operation signal MV calculated by the proportional calculation unit 102 is input to a driver (not shown), and the driver outputs a current corresponding to the operation signal MV to the electromagnetic coil 10a.

  As a result, the valve body 10b is driven by the electromagnetic coil 10a, and the flow rate of the hydraulic oil supplied to the hydraulic cylinder 11 is adjusted. The hydraulic cylinder 11 is driven according to the flow rate of the hydraulic oil, and the driving amount of the hydraulic cylinder 11 is detected by the steering angle sensor device 12.

  Next, with reference to FIG. 7, the result of performing an operation test using the vehicle 1 (see FIG. 1) on which the product of the present invention (control device 20) and the control device 100 in the comparative example are mounted will be described. FIG. 7A shows the operation test results of the flow control valve 10 and the hydraulic cylinder 11 controlled by the control device 100 in the comparative example, and FIG. 7B shows the flow control valve 10 and the hydraulic pressure controlled by the product of the present invention. It is an operation test result of the cylinder 11.

  In this operation test, instead of inputting the target steering angle calculated by the target steering angle calculation unit 20b (see FIGS. 3 and 6) to the steering angle deviation calculation units 20c and 101, the waveform output device Was output to the steering angle deviation calculation units 20c and 101 as the target steering angle. This is to improve the reproducibility of the operation test. The steering angle of the wheels 3a, 4a detected by the steering angle sensor device 12 at this time, the deviation between the target steering angle and the steering angle calculated by the steering angle deviation calculating units 20c, 101, and the opening sensor The opening degree of the flow control valve 10 detected by 10c was measured. Although the opening sensor 10c is not shown in FIG. 6, the opening is detected by an output signal of a differential transformer of the flow control valve 10.

  By repeatedly inputting the output waveform from the waveform output device to the steering angle deviation calculation units 20c and 101 (see FIGS. 3 and 6), the target steering angle is set as shown in FIGS. 7 (a) and 7 (b). ± 14 degrees and 0.2 Hz were set. When the temperature of the hydraulic oil was gradually increased, in the comparative example, the opening degree started to oscillate as shown in FIG. 7A, and the steering angle also started to oscillate accordingly. In addition, the maximum deviation (delay amount) was larger than −3 degrees. As a result, the wheels 3a and 4a vibrated finely from side to side, the steering performance deteriorated, and the responsiveness also deteriorated.

  On the other hand, in the product of the present invention, even when the temperature of the hydraulic oil at which the vibration starts in the comparative example, the opening degree and the steering angle did not vibrate as shown in FIG. Further, the delay time of the steering angle with respect to the target steering angle was within 0.2 seconds, and the maximum deviation was within 3 degrees. As a result, it has been clarified that smooth steering can be realized and responsiveness can be ensured without causing the driver to feel uncomfortable. By controlling the flow control valve 10 using the control device 20, as shown in FIG. 5C, the opening degree of the flow control valve 10 with respect to the deviation (driving amount deviation) is linearly proportional. Because I was able to do it.

  In the flowchart (opening adjustment process) shown in FIG. 4, the process of S2 is performed as the target drive amount setting means according to claim 1, the process of S3 is performed as the drive amount acquisition means, and the target opening setting means is The processes of S4 and S5 correspond to the process of S6 as the opening degree obtaining means, and the processes of S7, S8, S9 and S10 as the opening degree adjusting means, respectively. The process of setting the target opening based on the target opening function (see FIG. 5B) in the process of S4 as the driving amount deviation calculating means according to claim 3 and the process of S5 as the correspondence reference means. Respectively. The opening deviation calculating means according to claim 5 corresponds to the process of S7, and the operation signal calculating means corresponds to the processes of S8, S9 and S10.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed. For example, the numerical values (for example, the quantity of each component) given in the above embodiment are examples, and other numerical values can naturally be adopted.

  In the above-described embodiment, the case where the hydraulic cylinder as the hydraulic actuator is applied to the vehicle 1 for transportation has been described. However, the present invention is not necessarily limited to this, and can be applied to other hydraulic actuators. Examples of other hydraulic actuators include a hydraulic rotary actuator. In addition to transportation vehicles, the present invention can also be applied to construction machines, machine tools, casting equipment, transport systems, mining machines, agricultural machinery, packaging equipment, logistics systems, industrial robots, and the like.

  In the above embodiment, the case where the steering device for the wheels 3a and 4a is the cylinder direct acting method has been described. However, the present invention is not necessarily limited to this, and the present invention can be applied to a steering device such as a rack and pinion method or a link method. Is possible.

  In the above-described embodiment, the case where the rotation angle (steering angle) of the steering shaft 3c is detected as the drive amount of the hydraulic cylinder 11 (hydraulic actuator) has been described. Depending on the application, various state quantities can be detected as the drive quantity. For example, the amount of expansion / contraction of the piston rod 11a can be detected as the driving amount.

  In the above embodiment, the target opening function (see FIG. 5B) has been described as indicating the correspondence between the driving amount deviation and the target opening of the flow control valve 10, but the present invention is not necessarily limited to this. Alternatively, it is possible to use a map in which the correspondence between the drive amount deviation and the target opening degree of the flow control valve 10 is mapped.

  In the above embodiment, since the opening degree of the flow control valve 10 hardly changes when the current is small (see FIG. 5A), the target opening function (see FIG. 5B) is set to the current. With respect to the target opening (the broken line in FIG. 5B) for an ideal flow control valve in which the opening is directly proportional, the target opening is set to be large when the deviation is small. Since the target opening function can be set according to the characteristics of the flow control valve 10, if the flow rate control valve changes greatly when the current is small, the target opening is set small when the deviation is small. Is possible. Thereby, it is possible to improve control responsiveness as in the above embodiment.

3a, 4a Wheel 8 Hydraulic pump (hydraulic source)
10 Flow control valve 11 Hydraulic cylinder (hydraulic actuator)
20 Control device

Claims (5)

In the control device of the flow rate control valve that controls the flow rate of the hydraulic oil supplied to the hydraulic actuator according to the opening degree,
Target drive amount setting means for setting a target drive amount of the hydraulic actuator;
Drive amount acquisition means for acquiring the drive amount of the hydraulic actuator;
A target for setting the target opening of the flow control valve based on the drive amount of the hydraulic actuator acquired by the drive amount acquisition means and the target drive amount of the hydraulic actuator set by the target drive amount setting means Opening setting means;
An opening degree obtaining means for obtaining an opening degree of the flow control valve;
An opening adjusting means for adjusting the opening of the flow control valve based on the opening of the flow control valve acquired by the opening acquiring means and the target opening set by the target opening setting means; A control device comprising: The flow rate control valve is disposed between a hydraulic source and the hydraulic actuator,
The control device according to claim 1, wherein the hydraulic actuator is a hydraulic cylinder that steers a wheel. The target opening setting means includes
Driving amount deviation calculating means for calculating a driving amount deviation which is a deviation between the driving amount of the hydraulic actuator acquired by the driving amount acquiring means and the target driving amount of the hydraulic actuator set by the target driving amount setting means. When,
Correspondence for setting the target opening degree of the flow control valve with reference to the correspondence relationship between the driving amount deviation and the target opening degree of the flow control valve with respect to the driving amount deviation calculated by the driving amount deviation calculating means The control device according to claim 1, further comprising a relationship reference unit.   4. The control apparatus according to claim 3, wherein the correspondence relationship between the drive amount deviation and the target opening degree of the flow control valve is associated with opening degree information with respect to an operation signal of the flow control valve. The opening degree adjusting means is
An opening degree deviation calculating means for calculating an opening degree deviation which is a deviation between the opening degree of the flow rate control valve acquired by the opening degree acquiring means and the target opening degree set by the target opening degree setting means;
The operation signal of the flow rate control valve is controlled by proportional control for multiplying the opening deviation calculated by the opening deviation calculating means by a predetermined proportional gain and by integral control for multiplying the integral value or cumulative value of the opening deviation by a predetermined integral gain. The control device according to claim 1, further comprising: an operation signal calculation unit that calculates.

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