JPH0555884B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a servo device that stabilizes and controls a television camera installed in a moving vehicle, for example, in inertial space, and particularly relates to feedback compensation of its speed loop. It is.

[Prior art]

FIG. 1 shows the configuration of a conventional servo device, in which 1 is a vehicle, 2 is a television camera mounted on the vehicle 1 via a rotatable support, and 3 is a television camera mounted on a rotatable support base.
4 is the rate gyro attached to this TV camera 2, and 4 is the rate gyro 3 from the speed command R.
A subtracter 5 subtracts the output of the subtracter 4, a servo amplifier 5 amplifies the output of the subtracter 4, and a servo amplifier 6 receives the output of the servo amplifier 5 and rotates the television camera 2 via a drive mechanism 7 consisting of gears and the like. It's a motor.

The conventional servo device is configured as described above. For example, when the vehicle 1 oscillates, the rate gyro 3 attached to the television camera 2 detects the angular velocity of the oscillation relative to inertial space. The output of the rate gyro 3 is fed back to the subtracter 4 and compared with the speed command R. In other words, it forms a so-called velocity loop. Here, if the speed command R is set to zero, the output of the subtracter 4 becomes a signal with a polarity opposite to that of the output of the rate gyro 3, and is input to the servo amplifier 5 as a signal that drives the vehicle 1 in the opposite direction to the oscillation. The signal input to the servo amplifier 5 is amplified and drives the motor 6. The motor 6 drives the television camera 2 through a drive mechanism 7 in a direction opposite to the movement of the vehicle 1. In this way, stabilization control is performed so that the pointing direction of the television camera 2 does not change due to the movement of the vehicle 1.

However, since the drive mechanism 7 is located in the middle of the speed loop, that is, between the motor 6 and the rate gyro 3, its mechanical rigidity causes mechanical resonance that is undesirable for a servo system. For this reason, if you increase the servo gain to improve the stabilization accuracy, oscillation will occur at the mechanical resonance frequency, so a drive mechanism with a high mechanical resonance frequency must be used to obtain the desired servo gain, which is very expensive. It had the disadvantage of being large.

[Summary of the invention]

This invention was made for the purpose of improving this drawback.By feeding back the rotational speed of the motor through a filter, the servo system can be stabilized without oscillating due to mechanical resonance even if the servo gain is increased. We propose a highly accurate servo device.

[Embodiments of the invention]

FIG. 2 shows the configuration of an embodiment of the present invention, and numerals 1 to 7 are completely the same as the conventional device described above. 8 is a tachometer generator that detects the rotational speed of the motor 6; 9 is a high-pass filter that passes only the high frequency component of the output signal of the tachometer generator 8 and feeds it back to the subtracter 4; 10;
is a low-pass filter which is inserted between the rate gyro 3 and the subtracter 4 and allows only the low frequency components of the output signal of the rate gyro 3 to pass.

In the servo device configured as described above, by setting the cut-off frequency of the high-pass filter 9 and the low-pass filter 10 to about one-half of the mechanical resonance frequency, the tachogenerator is activated in a region higher than this frequency. The output of 8 is fed back to the subtracter 4 via the high-pass filter 9 to form a speed loop. At this time, since the drive mechanism 7 is not included in this speed loop,
No oscillation occurs due to mechanical resonance. Further, in a region lower than the above-mentioned cutting frequency, the output of the rate gyro 3 is fed back to the subtracter 4 via the above-mentioned low-pass filter 10, and in order to form a speed loop similar to the conventional one, a predetermined stabilization control is performed. In other words, the mechanical resonance caused by the drive mechanism 7 is attenuated by the low-pass filter 10 after passing through the rate gyro 3, and is compensated by the feedback signal from the tachogenerator 8, so it is stable without oscillation even at a predetermined servo gain. It will work.

〔Effect of the invention〕

As explained above, this invention has a simple configuration in which the motor rotational speed signal and the rate gyro signal are each filtered and then fed back, so that spatial stabilization control that is not affected by mechanical resonance can be easily and inexpensively implemented. effective.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a conventional servo device, and FIG. 2 is a diagram showing the configuration of an embodiment of the present invention. In the figure, 3 is a rate dial, 4 is a subtracter, 5 is a servo amplifier, 6 is a motor, 8 is a tacho generator, 9 is a high-pass filter, and 10 is a low-pass filter. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A rate gyro that detects the angular velocity of a controlled object with respect to inertial space, a motor that drives the controlled object, a tachometer generator that detects the rotational speed of this motor, and a high-pass filter that passes only the high frequency component of the output signal of this tachometer generator. and a low-pass filter that passes only low frequency components of the output signal of the rate gyro.
A servo device comprising: a subtracter that subtracts the output of the high-pass filter and the output of the low-pass filter from a speed command signal; and a servo amplifier that amplifies the output of the subtracter and drives the motor.