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Truss actuator

Imported: 23 Feb '17 | Published: 22 Oct '02

Kazuhiro Shibatani

USPTO - Utility Patents

Abstract

The present invention provides a truss actuator offering reduced noise, vibration and wear, which is capable of speed control of the driven member and can control the output to the driven member at a constant level regardless of fluctuations in the load on the actuator or in the environment in which the actuator is used.

In the truss actuator, one displacement unit

2 or

3 is driven and this oscillation is transmitted to the other displacement unit

3 or

2, and the truss actuator includes two displacement sensors

11 and

12 that respectively detect the displacement of the displacement units, a phase difference detecting unit

13 that detects via the displacement sensors the phase difference between the detected displacement values, a target phase difference setting unit (a CPU

20, etc.) that sets a target phase difference, a deviation determining unit

14 that determines the deviation of the phase difference from the phase difference detecting unit

13 and the target phase difference, and a frequency changing unit (a frequency control unit

15 and oscillator

16) that changes the oscillation frequency based on the result of this determination, wherein the frequency changing unit controls the oscillation frequency based on the result obtained by the deviation determining unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention will become apparent from the following description of preferred embodiments thereof taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a simplified front elevation showing the construction of a truss actuator in which the drive control device pertaining to the present invention is applied;

FIG. 2 comprises drawings showing the relationship between the drive frequency and the phase difference between the displacements when only one of the displacement units is driven, with

FIG.

2(

a) showing the case in which the phase of the driven displacement unit advances relative to the phase of the driving displacement unit, and FIG.

2(

b) showing the case where the phase of the driven displacement unit is delayed relative to the phase of the driving displacement unit;

FIG. 3 is a block diagram showing the basic construction of the drive control device of the present invention;

FIG. 4 is a block diagram of a construction in which resistors for current detection are used for the displacement detecting units of the drive control device of the present invention;

FIG. 5 is a block diagram showing an example of a circuit construction used in the phase different detecting unit and the deviation determining unit of the drive control device of the present invention;

FIG. 6 is a drawing showing the signal output from the phase difference detecting unit to the deviation determining unit of the drive control device of the present invention with FIG.

6(

a) showing the pulse waveform comprising the input signal (displacement signal) of the phase difference detecting unit, FIG.

6(

b) showing the pulse waveform comprising the other input signal (displacement signal) of the phase difference detecting unit FIG.

6(

c) showing a pulse waveform comprising the output signal of the phase difference detecting unit, and FIG.

6(

d) showing a pulse waveform obtained by inverting the output signal of the phase difference detecting unit

FIG. 7 is a block diagram showing another example of the circuit construction used in the phase difference detecting unit and deviation determining unit of the drive control device of the present invention;

FIG. 8 is a drawing showing signal examples using the circuit constructions in FIG.

5 and FIG. 7;

FIG. 9 is a block diagram showing the circuit construction of the frequency changing unit of the drive control device of the present invention;

FIG. 10 is a block diagram showing another example of the construction of the drive control device of the present invention;

FIG. 11 is a simplified front elevation showing a truss actuator using elastic members for the displacement units, in which the drive control device of the present invention is applied;

FIG. 12 is a simplified front elevation showing another truss actuator using elastic members for the displacement units, in which the drive control device of the present invention is applied; and

FIG. 13 is a simplified front elevation showing a truss actuator that may be applied when the driven member is rotated in one direction using the drive control device of the present invention.

In the following description, like parts are designated by like reference numbers throughout the several drawing.

Claims

1. A truss actuator comprising:

2. The truss actuator as claimed in claim 1, further comprising:

3. The truss actuator as claimed in claim 1, wherein

4. The truss actuator as claimed in claim 1,

5. A driving method for driving a truss actuator comprising the steps of:

6. The driving method for driving a truss actuator according to claim 5,

7. The driving method for driving a truss actuator according to claim 5, wherein

8. The driving method for driving a truss actuator according to claim 5,

9. A truss actuator comprising:

10. The truss actuator as claimed in claim 9, wherein

11. The truss actuator as claimed in claim 9, wherein

12. The truss actuator as claimed in claim 9,

13. The driving method for driving a truss actuator comprising the steps of:

14. A driving method for driving a truss actuator according to claim 13, wherein

15. The driving method for driving a truss actuator according to claim 13, wherein

16. The driving method for driving a truss actuator according to claim 13,

17. A truss actuator comprising: