JP3245226B2 - Hydraulic servo controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic servo controller for controlling a simulator or the like for generating a rocking motion using a plurality of hydraulic actuators.

[0002]

2. Description of the Related Art A device such as a simulator for generating an oscillating motion is known which controls a plurality of hydraulic actuators in accordance with the direction of movement at the same time, and is connected to a plurality of hydraulic cylinders as shown in FIG. A slave unit 98 corresponding to the oscillation axis is connected to a master controller 91 that commands the stroke amount of each hydraulic cylinder.

A hydraulic cylinder 92 is connected to the slave unit 98 via a servo valve 96 via a servo controller 95.
The hydraulic cylinder 92 is provided with a stroke sensor 93 for detecting a relative displacement of the expansion and contraction amount, and a limit switch 94 which is turned on when the hydraulic cylinder 92 reaches a predetermined reference position is attached. The detection value of the stroke sensor 93 is converted into a measurement stroke by a stroke position calculation circuit 97, and the servo controller 95 calculates the drive amount of the hydraulic cylinder 92 from the target value (stroke amount) of the master controller 91 and the measurement stroke, and calculates the servo valve 96 To open and close. The slave unit 9
Although not shown, 9 also forms another oscillation axis in the same manner as the slave unit 98.

When the master controller 91 is activated, the stroke position calculation circuit 97 calculates a value irrelevant to the actual stroke of the hydraulic cylinder 92 as a measurement stroke, and switches the hydraulic cylinder 92 to a limit switch to reset the stroke position calculation circuit 97. Drive toward 94. When the hydraulic cylinder 92 turns on the limit switch 94, the master controller 91 changes the target value to a preset reference position and sends a preset trigger to the stroke position calculation circuit 97. Upon receiving the preset trigger, the stroke position calculation circuit 97 corrects the measurement stroke to the reference position, and the servo controller 95 drives the hydraulic cylinder 92 to the target value of the master controller 91 based on the actual stroke and the measurement stroke that match the reference position. .

[0005]

However, in the above-mentioned conventional apparatus, the time required for the master controller 91 to change the target value to the reference position, and the stroke position calculation circuit 97 receiving the preset trigger corrects the measured stroke to the reference position. As shown in FIG. 11, the hydraulic cylinder 92 is driven by the servo controller 95 in a direction to absorb the difference between the target value and the measured stroke. This causes a problem that it fluctuates abruptly as a result and gives an impact to the driven simulator.

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a hydraulic controller for a simulator which prevents an impact from occurring at the time of startup.

[0007]

Means for Solving the Problems The first aspect of the present invention is shown in FIG.
As shown in the figure, the command means 31 for setting the target value of the displacement amount of the hydraulic actuator 35 and the hydraulic actuator 35
And a relative displacement measuring means 37 for measuring the relative displacement of the hydraulic actuator 35 and the servo valve 34 for supplying hydraulic oil to the
A stroke position calculating means 38 for calculating a stroke position of the hydraulic actuator 35 from the measured value; and a hydraulic actuator 35 based on the target value and the stroke position.
Driving amount calculating means 32 for calculating the driving amount of the motor, and valve driving means 33 for driving the servo valve 34 according to the driving amount.
A reference position detecting means 36 for detecting that the hydraulic actuator 35 has been displaced to a reference position; a neutral position commanding means 39 for instructing the valve driving means 33 to a neutral position when the detection signal is on; And a correcting means 40 for correcting the result of the stroke position calculating means 38 to a reference position in accordance with the operation of the position command means 39.

Further, as shown in FIG. 2, the invention according to claim 2 includes a command means 42 for setting a first target value and a second target value of the displacement amount of the hydraulic actuator 35, respectively. Servo valve 34 for supplying hydraulic oil
A relative displacement measuring means 37 for measuring a relative displacement of the hydraulic actuator 35, a stroke position calculating means 38 for calculating a stroke position of the hydraulic actuator 35 from the measured value, a first and a second target value and a stroke. A drive amount calculating means 32 for calculating a drive amount of the hydraulic actuator 35 from the position calculation result, a valve drive means 33 for driving the servo valve 34 according to the drive amount, and a reference position set by the hydraulic actuator 35 in advance. Reference position detecting means 36 for detecting that the position has been displaced, neutral position instructing means 39 for instructing the valve driving means 33 to a neutral position when the detection signal is on, and neutral position instructing means 3
9, a means 40 for correcting the result of the stroke position calculating means 38 to the reference position, and an intervening means between the command means 42 and the driving amount calculating means 32. Switching means 41 for selectively switching the first or second target value in accordance with the operation.

According to a third aspect of the present invention, the switching means 41 according to the second aspect is formed by a dual port RAM.

[0010]

Therefore, at the reference position of the hydraulic actuator, the neutral position of the servo valve is held and the hydraulic actuator is locked, and the result of the stroke position calculating means is corrected to the reference position. The accompanying rapid displacement of the hydraulic actuator is prevented.

Further, the hydraulic actuator is driven by selectively reading the first target value and the second target value by the switching means, and the hydraulic actuator is locked while maintaining the neutral position of the servo valve at the reference position of the hydraulic actuator. During the operation, the result of the stroke position calculating means is corrected to the reference position, the target value to be read is switched by the switching means, and then the drive of the hydraulic actuator is restarted. The drive of the hydraulic actuator is restarted smoothly from the reference position while preventing the sudden displacement of the hydraulic actuator from occurring.

Further, since the command means and the drive amount calculating means read and write data through the dual port RAM, the command means and the drive amount calculating means do not need to be synchronized for communication, and the respective processings are performed. Can be executed faster.

[0013]

3 to 5 show an embodiment of the present invention.

In FIG. 3, reference numeral 1 denotes a master controller for instructing a plurality of servo controllers 5 for controlling the respective swing axes of a simulator (not shown) to target stroke positions (hereinafter referred to as target values). Target values are set and commanded to the controller 5 respectively.

The hydraulic cylinder 2 forms one rocking shaft, supports a simulator (not shown) at one end of the telescopic rod 20 and gives a rocking motion. The servo valve 6 supplies and discharges hydraulic oil to and from the hydraulic cylinder 2. Are driven to open and close by the servo controller 5.

The hydraulic cylinder 2 has a telescopic rod 20.
A stroke sensor 3 for detecting a relative displacement of the telescopic rod 20 is provided. A detection signal of the stroke sensor 3 is inputted to a stroke position calculation circuit 7 and the stroke position of the telescopic rod 20 is updated based on the stroke position updated immediately before and the detection signal. It is converted into a measurement stroke, which is the absolute value of the quantity.

The servo controller 5 reads the target value set by the master controller 1 and also reads the measurement stroke calculated by the stroke position calculation circuit 7 to calculate the drive amount of the hydraulic cylinder 2, and outputs a command current corresponding to the drive amount. Open / close drive is performed in addition to the servo valve 6. The servo valve 6 supplies and discharges hydraulic oil to and from the hydraulic cylinder 2 according to the command current, while holding the telescopic rod 20 at the neutral position.

A limit switch 4 is provided at a predetermined stroke position (hereinafter referred to as a reference position) serving as an origin for driving the hydraulic cylinder 2, and is turned on when the telescopic rod 20 extends or contracts and passes through the limit switch 4. The limit switch 4 is connected to the master controller 1, and the master controller 1 sends a holding signal to a servo controller 5 that controls the oscillation axis whose limit switch 4 is turned on.

Upon receiving the holding signal, the servo controller 5 changes the command current so as to hold the servo valve 6 at the neutral position. During this time, the master controller 1 sets the measuring stroke of the stroke position calculating circuit 7 to the telescopic rod 2 which has been set in advance.
A preset trigger for correcting the reference position to 0 is transmitted.

The flow of each signal before and after the telescopic rod 20 operates the limit switch 4 will be described in further detail with reference to a timing chart of FIG. 4 and a flowchart of FIG.

When the master controller 1 and the servo controller 5 are started, the master controller 1 updates the target value by gradually decreasing the target value in order to contract the telescopic rod 20 in the reference position direction.

The servo controller 5 reads the target value set by the master controller 1 after initialization in step 101 in step 102, and reads the measurement stroke from the stroke position calculation circuit 7 in step 103 to determine the drive amount of the telescopic rod 20. Calculation (Step 10
4) Send a command current corresponding to the drive amount to the servo valve 6 (step 105). At this time, the measurement stroke read in step 103 is determined based on the measurement stroke updated immediately before the stroke position calculation circuit 7 by the stroke sensor 3.
Calculated from the relative displacement of the telescopic rod 2
The actual stroke, which is the actual displacement amount of 0, is started in a state apart from the measured stroke due to leakage of hydraulic oil or the like.

Next, the servo controller 5 executes step 10
In step 6, it is checked whether a holding signal is output from the master controller 1, that is, whether the extendable rod 20 has contracted to the reference position and the limit switch 4 has been turned on. If the holding signal has not been output, the process returns to step 102,
If the signal is output, the servo controller 5 changes the command current value so that the servo valve 6 keeps the neutral position in step 107. The command current of the servo controller 5 is gradually changed from a current value to a current value indicating a neutral position based on a predetermined change rate.

On the other hand, the master controller 1 sends a preset signal to the stroke position calculation circuit 7 after a predetermined time has elapsed after sending the holding signal to the servo controller 5, and the stroke position calculation circuit 7 sends the measurement stroke as the calculation result. Correct to a preset reference position.

In FIG. 4, at time T ₁ , the telescopic rod 20
Passes the limit switch 4 and the master controller 1
When There detecting the reference position of the extendable rod 20, generates a hold signal at time T _2, the servo valve immediately after this time T ₂ 6
Is held in the neutral position, and the hydraulic cylinder 2 is
Locked at zero reference position.

The master controller 1 outputs a preset trigger at a preset time T ₃ in order to wait for the neutral position holding of the servo valve 6 to be completed. Master controller 1 outputs a preset trigger, first holding release signal at time T ₄ is after a predetermined time for measurement after setting once the reference position target values stroke is corrected to the reference position to the servo controller 5 Is output.

When the servo controller 5 receives the release signal of the master controller 1 in step 108, the servo controller 5 starts restarting the operation of the hydraulic cylinder 2 in step 1
At 09, it is confirmed that the measurement stroke of the stroke position calculation circuit 7 has been corrected to the reference position. During this period the master controller 1 outputs the hold release signal is set again the target value has been changed once the reference position at time T ₃ the stroke amount of the target.

The servo controller 5 reads the target value of the master controller 1 at step 110, then reads the measurement stroke at step 111, calculates the drive amount from the reference position of the telescopic rod 20, and drives the servo valve 6 to open and close. To shake the simulator (step 11
2, 113). The servo valve 6 is released from holding the neutral position by the command current output in step 113, and the driving of the hydraulic cylinder 2 is restarted.

After the time T ₄ when the measurement stroke is set at the reference position, the processing from step 110 to step 113 is repeated to drive the hydraulic cylinder 2.

Therefore, at the position where the telescopic rod 20 reaches the reference position, the servo valve 6 is held at the neutral position to lock the hydraulic cylinder 2 and change the target value of the master controller 1 to the reference position. Since the drive of the hydraulic cylinder 2 is restarted after the measurement stroke independently calculated is corrected to the reference position, it is possible to prevent the telescopic rod 20 from being suddenly displaced, and to perform unstable operation such as impact. It does not occur.

FIGS. 6 to 8 show an embodiment of the second invention.
These correspond to FIGS. In this embodiment, as shown in FIG. 6, the master controller 10 sets and instructs a single servo controller 55 to set a target value A and a target value B as first and second target values.

The hydraulic cylinder 2 forms one rocking shaft for rocking with the first embodiment. The hydraulic cylinder 2 supports a simulator (not shown) at one end of the telescopic rod 20 and imparts rocking. The servo valve 6 for supplying and discharging hydraulic oil is driven to open and close by a servo controller 55, and the hydraulic cylinder 2 is provided with a stroke sensor 3 for detecting a relative displacement of the telescopic rod 20,
The detection signal of the stroke sensor 3 is input to the stroke position calculation circuit 7 and is converted into a measurement stroke, which is the absolute value of the stroke amount of the telescopic rod 20, from the stroke position just updated and the detection signal.

The servo controller 55 selectively reads the target value A or B set by the master controller 10, reads the measured stroke calculated by the stroke position calculation circuit 7, calculates the drive amount of the hydraulic cylinder 2, Is applied to the servo valve 6 to open and close. The servo valve 6 supplies and discharges hydraulic oil to and from the hydraulic cylinder 2 according to the command current, while holding the telescopic rod 20 at the neutral position. A limit switch 4 is provided at a predetermined stroke position serving as an origin for driving the hydraulic cylinder 2, and is turned on when the telescopic rod 20 extends or contracts and passes through the limit switch 4. The limit switch 4 is connected to the master controller 10, and the master controller 10 sends a preset request signal to a servo controller 55 that controls the oscillation axis for which the limit switch 4 has been turned on.

The servo controller 55 which has received the preset request signal sends a preset trigger for setting the measurement stroke of the stroke position calculation circuit 7 to a preset reference position of the telescopic rod 20, while holding the servo valve 6 at the neutral position. Change the command current as follows.

The flow of each signal before and after the telescopic rod 20 operates the limit switch 4 will be described in further detail with reference to a timing chart of FIG. 7 and a flowchart showing an example of control of the servo controller 55 of FIG.

When the master controller 10 and the servo controller 55 are activated, the master controller 10 updates the target value A by gradually decreasing the target value A in order to contract the telescopic rod 20 in the reference position direction, while setting the reference position to the target value B. I do.

The servo controller 55 reads the target value A set by the master controller 10 after initialization in step 61 in step 62, and reads the measurement stroke from the stroke position calculation circuit 7 in step 63 to read the drive amount of the telescopic rod 20. Is calculated (step 64),
A command current corresponding to the driving amount is sent to the servo valve 6 (step 65). At this time, the measurement stroke read in step 63 is calculated from the relative displacement amount of the stroke sensor 3 based on the measurement stroke updated immediately before the stroke position calculation circuit 7, and the actual displacement of the telescopic rod 20 The actual stroke, which is an amount, is started in a state apart from the measured stroke due to leakage of hydraulic oil or the like.

Next, the servo controller 55 proceeds to step 6
In step 6, it is checked whether a preset request signal has been output from the master controller 10, that is, whether the extendable rod 20 has contracted to the reference position and the limit switch 4 has been turned on. If the preset request signal has not been output, the process returns to step 62. If the signal has been output, the servo controller 55 sends a preset trigger to the stroke position calculation circuit 7 in step 67, while the servo valve 6 receives the neutral position in step 68. The command current value is changed so that is maintained. The command current of the servo controller 55 is gradually changed from a current value to a current value indicating a neutral position based on a predetermined rate of change.

[0039] In FIG. 7, the extendable rod 20 at time T ₅
Passes through the limit switch 4, a preset request is generated at time T ₆ , and the servo valve 6 is held at the neutral position immediately after time T _{7 at which} the preset trigger is generated. Locked in position.

The locking of the hydraulic cylinder 2 is performed in step 6
This is performed until the time set in the servo controller 55 in step 9 elapses. During this time, the stroke position calculation circuit 7 receiving the preset trigger corrects the measured stroke to a preset reference position. The servo controller 55 further locks and waits the hydraulic cylinder 2 until the measurement stroke is corrected to the reference position in step 70, and sends a preset end signal to the master controller 10 when the measurement stroke reaches the reference position (step 71).

The measuring stroke by the time T ₈ the preset end signal from the time preset trigger occurs T ₇ is generated is equal to the actual stroke of the hydraulic cylinder 2, which is held at the reference position.

The master controller 10 receiving the preset end signal at time T ₈ sets the target stroke amount to the target value B, and the servo controller 55 switches the target value to be read to the target value B in step 72 and reads the measurement stroke. (Step 73) The driving amount is calculated from the reference position of the telescopic rod 20, and the servo valve 6 is driven to open and close to give a swing to the simulator (Steps 74 and 75). Measurement stroke reference position time T ₈ or later set to drives the hydraulic cylinder 2 by repeating the processing of step 75 from step 72.

Therefore, the hydraulic cylinder 2 is locked by holding the servo valve 6 at the neutral position at the position where the telescopic rod 20 has reached the reference position, and the measurement stroke calculated independently of the actual stroke is corrected to the reference position. To restart the operation of the hydraulic cylinder 2
Abrupt displacement of 0 is suppressed, and unstable operation such as impact does not occur. When the hydraulic cylinder 2 is restarted, the servo controller 55 reads the target value B of the master controller 10 in which the reference position is set in advance. Can be smoothly expanded and contracted from the reference position. FIG. 9 shows another embodiment, in which the servo controller 55 of the second embodiment is used.
Is a configuration diagram formed by a digital circuit centered on a microprocessor 50, and the other configuration is the same as that of the first embodiment. The microprocessor 50 includes a position control calculation unit 52 for calculating the drive amount of the hydraulic cylinder 2, reads target values A and B of the master controller 10 via a dual port RAM 51 provided at a predetermined address, and Are connected to the servo valve 6, the stroke position calculation circuit 7, and the master controller 10 via the. In addition, dual port RAM
A predetermined address of the master controller 10 is set on the master controller 10 side 51.

Since the reading of the target values A and B set by the master controller 10 is performed via the dual port RAM 51, the master controller 10 and the microprocessor 50 need only read and write the respective memories. There is no need to synchronize, and processing can be performed at higher speed.

[0045]

As described above, according to the present invention, at the reference position of the hydraulic actuator, the measurement stroke is corrected to the reference position of the hydraulic actuator while the servo valve is held at the neutral position and the hydraulic actuator is locked. Since the drive of the hydraulic actuator is restarted after the target value is changed to the reference position, it is possible to eliminate the impact of the hydraulic actuator that occurs when the measurement stroke is reset.

In the second invention, the target position is set to the first target value, the reference position is set to the second target value, and the reference position is set based on the first target value until the reference position detecting means operates. While the hydraulic actuator is driven, at the reference position of the hydraulic actuator, the measurement stroke is corrected to the reference position while the servo valve is held at the neutral position and the hydraulic actuator is locked, and the hydraulic pressure is adjusted based on the second target value. Since the driving of the actuator is restarted, it is possible to eliminate the impact of the hydraulic actuator generated when the measurement stroke is reset, and it is possible to drive the hydraulic actuator smoothly.

Further, since switching means formed by a dual port RAM is interposed between the command means and the driving amount calculating means, it is not necessary to synchronize the two for communication, and the processing can be speeded up. And the degree of freedom in design is improved.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claim 1 of the present invention.

FIG. 2 is a diagram corresponding to claim 2 of the present invention.

FIG. 3 is a configuration diagram showing an embodiment of the present invention.

FIG. 4 is a timing chart showing a relationship between a stroke and time.

FIG. 5 is a flowchart illustrating an example of control.

FIG. 6 is a configuration diagram showing one embodiment of the second invention.

FIG. 7 is a timing chart showing a relationship between a stroke and time.

FIG. 8 is a flowchart illustrating an example of control.

FIG. 9 is a schematic view of a servo controller showing another embodiment.

FIG. 10 is a configuration diagram showing a conventional example.

FIG. 11 is a timing chart showing a relationship between a stroke and time.

[Explanation of symbols]

 1, 10 Master controller 2 Hydraulic cylinder 3 Stroke sensor 4 Limit switch 5, 55 Servo controller 6 Servo valve 7 Stroke position calculation circuit 20 Telescopic rod 31, 42 Command means 32 Drive amount calculation means 33 Valve drive means 34 Servo valve 35 Hydraulic actuator 36 Reference position detecting means 37 Relative displacement measuring means 38 Stroke position calculating means 39 Neutral position command means 40 Correcting means 41 Switching means 42 Command means 50 Microprocessor 51 Dual port RAM

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-3-228791 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A63G 31/00-31/14 G09B 9 / 00-9/56 A63F 13/00-13/12 G05B 11/60 G06F 17/00

Claims (3)

(57) [Claims] 1. A command means for setting a target value of a displacement amount of a hydraulic actuator, a servo valve for supplying hydraulic oil to the hydraulic actuator, a means for measuring a relative displacement of the hydraulic actuator, and a hydraulic actuator based on the measured value. Means for calculating the stroke position, means for calculating the drive amount of the hydraulic actuator from the target value and the result of calculation of the stroke position, means for driving the servo valve according to the result of calculation of the drive amount, and Means for detecting that the actuator has been displaced to a preset reference position,
Means for commanding the valve drive means to a neutral position when the detection signal is on, and means for correcting the result of the stroke position calculation means to a reference position with the operation of the neutral position command means. A hydraulic servo controller. 2. A first displacement of a target displacement amount of a hydraulic actuator.
Command means for setting a target value and a second target value for each, a servo valve for supplying hydraulic oil to the hydraulic actuator, means for measuring a relative displacement of the hydraulic actuator, and a stroke of the hydraulic actuator from the measured value. Means for calculating a position, means for calculating a drive amount of a hydraulic actuator from the first or second target value and a calculation result of a stroke position, means for driving the servo valve in accordance with the drive amount, Means for detecting that the hydraulic actuator has been displaced to a preset reference position, means for instructing the valve drive means to be in a neutral position when the detection signal is on, and Means for correcting the result of the stroke position calculating means to the reference position, and interposed between the command means and the driving amount calculating means, Hydraulic servo controller, characterized in that a means for switching selectively the first or second target value by the actuation of the positive means. 3. The hydraulic servo controller according to claim 2, wherein said switching means is formed by a dual port RAM.