Input/output operation device

1. An input/output operation device, comprising:

an operation unit, which is operated by an operator;

a detection unit, which detects a position of the operation unit to generate a position signal corresponding to the position of the operation unit;

a control circuit, which receives the position signal to generate a speed control signal; and

a drive circuit, which receives the speed control signal to drive the operation unit,

wherein the control circuit:

(a) causes the position signal to pass through a first filter circuit, which has a first lower cutoff frequency, to generate a speed signal;

(b) causes the position signal to pass through a second filter circuit, which has a second lower cutoff frequency being lower than the first lower cutoff frequency, to generate a correction signal; and

(c) adds at least the speed signal and the correction signal together to generate the speed control signal.

2. The input/output operation device of claim 1 ,

wherein the first filter circuit and the second filter circuit sample the position signal with a predetermined sampling period, and

wherein the predetermined sampling period of the first filter circuit is shorter than the predetermined sampling period of the second filter circuit.

3. The input/output operation device of claim 1 ,

wherein the first filter circuit subjects the position signal to differential operation,

wherein the second filter circuit causes the position signal to pass through a low-pass filter to generate a filtered position signal, and

wherein the control circuit subtracts a correction position signal, which is generated depending on the filtered position signal, from the position signal that has been subjected to the differentiation operation.

4. The input/output operation device of claim 3 , wherein the second filter circuit subtracts an offset signal, which has a constant value within a predetermined time period, from the position signal or the filtered position signal.

5. The input/output operation device of claim 1 , wherein the control circuit subtracts an offset signal, which has a constant value within a predetermined time period, from a signal obtained by causing the position signal to pass through the second filter circuit.

6. The input/output operation device of claim 4 , wherein the constant value of the offset signal is set to a value of the position signal corresponding to a movable operation range of the operation unit.

7. The input/output operation device of claim 1 , wherein the second lower cutoff frequency is set depending on a speed corresponding to the speed signal, which is generated by causing the position signal to pass through the first filter circuit.

8. The input/output operation device of claim 7 , wherein the second lower cutoff frequency is set to become smaller as the speed corresponding to the speed signal, which is generated by causing the position signal to pass through the first filter circuit, becomes higher.

9. The input/output operation device of claim 1 , wherein the second lower cutoff frequency is set depending on the position signal.

10. The input/output operation device of claim 1 , wherein the control circuit further subjects a signal obtained by causing the position signal to pass through the first filter circuit to proportional operation or PI operation to generate the speed signal.

11. The input/output operation device of claim 1 , wherein the control circuit further subjects a signal obtained by causing the position signal to pass through the second filter circuit to proportional operation or PI operation to generate the correction signal.

12. The input/output operation device of claim 1 , wherein the control circuit generates the speed control signal for driving the operation unit in a direction opposite to a direction in which the operation unit is displaced.

13. The input/output operation device of claim 1 , wherein the control circuit generates the speed control signal for driving the operation unit in the same direction as a direction in which the operation unit is displaced.

14. The input/output operation device of claim 3 , wherein the correction position signal comprises the filtered position signal.

15. The input/output operation device of claim 3 , wherein the correction position signal is generated by performing discretization operation on the filtered position signal, which is obtained by filtering the position signal.

16. The input/output operation device of claim 11 , wherein the proportional operation comprises performing proportional operation on a signal obtained by subtracting, from the position signal, a signal obtained by causing the position signal to pass through the second filter circuit, to generate the correction signal, the proportional operation using, as a proportional coefficient, a signal obtained by subjecting, to split operation, the signal obtained by causing the position signal to pass through the second filter circuit.

17. The input/output operation device of claim 3 , wherein the correction position signal is generated by selecting the filtered position signal, which is obtained by filtering the position signal, at predetermined distance intervals to set a target point, and holding the target point for a predetermined time period.

18. The input/output operation device of claim 3 , wherein the correction position signal is obtained by:

determining a filtered speed signal, which is obtained by subjecting the filtered position signal, which is obtained by filtering the position signal, to differential operation, and an acceleration signal, which is obtained by subjecting the filtered speed signal to differential operation;

adding, when the acceleration signal is a first threshold or more, and when the filtered speed signal is a second threshold or more, a first correction signal to the filtered position signal, which is obtained by filtering the position signal; and

subtracting, when the acceleration signal is a third threshold or less, a second correction signal from the filtered position signal.

19. The input/output operation device of claim 1 ,

wherein the control circuit comprises an arithmetic unit, a memory, and a program, which is stored in the memory and is executable by the arithmetic unit, and

wherein the arithmetic unit executes the program to perform (a) generation of the speed signal, (b) generation of the correction signal, and (c) generation of the speed control signal.

20. The input/output operation device of claim 1 , wherein the control circuit comprises an analog circuit including an operational amplifier, a resistor, and a capacitor.