JP4034854B2 - Turntable acceleration generator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a turntable acceleration generator suitable for investigating the characteristics of an acceleration sensor that detects acceleration such as force, acceleration, and magnetism, and more particularly to a servo that rotates a small-diameter turntable when investigating the characteristics of an acceleration sensor. The present invention relates to a turntable type acceleration generator that can reduce the generated acceleration (noise) due to the starting torque of a motor.
[0002]
[Prior art]
Conventionally, the force, acceleration, magnetism, etc. of objects moving in three dimensions, such as robots and airplanes, and objects moving in two-dimensional planes such as automobiles, are detected by an acceleration sensor. Devices are controlled according to their respective purposes. Currently, various types of acceleration sensors are used to realize the above control. When an acceleration sensor is incorporated in a control device, what kind of characteristics the acceleration sensor actually used has? It is necessary to know.
[0003]
[Problems to be solved by the invention]
By the way, in order to investigate various characteristics of the acceleration sensor, various characteristics of the acceleration sensor are currently investigated by a vibration tester. However, this method has the following problems.
(1) The vibration tester is used to investigate the acceleration characteristics by applying reciprocal acceleration to the DUT mounted on the test bench. During the reciprocation (vertical movement) of the test bench due to the mechanism of the test machine. The test table may be slightly tilted, and it is difficult to accurately reciprocate the test table. That is, components other than the reciprocating direction act on the acceleration sensor during the test, and the acceleration is measured including the interference output, which is not sufficient for precisely examining various characteristics of the sensor.
(2) Since the vibration tester performs a test by actually applying vibration to the acceleration sensor using a vibration generator, the test device must be large, and in addition, a dynamic acceleration called vibration is generated. Since it must actually be given to the acceleration sensor, the performance test of the acceleration sensor is troublesome.
[0004]
Under these circumstances, the present inventors have proposed a novel centrifugal acceleration tester capable of dramatically improving the characteristic accuracy in order to solve the above-described problems (see Japanese Patent Laid-Open No. 7-110342). This acceleration testing machine applies acceleration in a predetermined direction and a predetermined force (that is, acceleration of a DC component) to an acceleration sensor mounted on a test table by centrifugal force, and thereby, various characteristics of the acceleration sensor can be accurately tested. That's it.
However, in the above centrifugal force acceleration tester, when the characteristics of the acceleration sensor are investigated, when the small-diameter turntable is rotated, acceleration due to the starting torque of the servo motor is generated, and this acceleration becomes noise and lowers the measurement accuracy. The problem has been found. That is, when measuring the acceleration sensor characteristics, the small-diameter turntable needs to be shifted from the stopped state to the rotating state by the second servo motor. At this time, depending on the frictional resistance of the bearing, the weight of the small-diameter turntable, etc. The two-servo motor has generated a starting torque for rotating the small-diameter turntable, and it has been found that the acceleration due to the starting torque becomes noise and it is difficult to investigate the characteristics of the acceleration sensor with high accuracy.
[0005]
Therefore, in order to further improve the measurement accuracy, the present invention starts the reverse rotation of the servo motor for driving the small-diameter turntable when rotating the small-diameter turntable. An object is to capture data, to prevent the influence of acceleration due to the starting torque of the servo motor, and to enable accurate measurement of acceleration sensor characteristics.
[0006]
[Means for Solving the Problems]
For this reason, the technical solution adopted by the present invention includes a first servomotor 6, a large-diameter turntable 1 rotated by the first servomotor 6, and a second servomotor at an appropriate position on the outer periphery of the large-diameter turntable 1. rotatably mounted relative to the turntable 1 by 11, and a turntable acceleration generating apparatus having a small diameter turntable 9 which can be attached to the acceleration sensor, the second servo motor data Before starting to rotate in the forward direction for capturing, the rotation starts in the direction opposite to the forward rotation, and then rotates in the forward direction to capture data after the output from the acceleration sensor passes through the frequency 0 Hz axis. This is a turntable acceleration generator .
[0007]
Embodiment
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic side view of a turntable acceleration generator according to an embodiment of the present invention, FIG. 2 is a plan view of the turntable of the apparatus, and FIG. 3 is a wiring diagram of the apparatus.
The embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Reference numeral 1 denotes a large-diameter turntable having an appropriate diameter and made of a nonmagnetic material such as aluminum or copper. The rotary shaft 2 is fixed by a fixing means 3, and the upper and lower ends of the rotary shaft of the large-diameter turntable 1 are supported by a turntable support arm 4. The turntable support arm 4 is formed in a substantially U shape as shown in the figure so that it can support the top and bottom of the rotation axis of the turntable, and the periphery is surrounded by a reinforcing member 4a, a cover 4b and the like. The turntable support arm 4 is not limited to the shape shown in the drawing as long as it can support the rotary shaft 2 of the large-diameter turntable 1 up and down.
[0008]
A thrust bearing 5 is provided on the lower turntable support arm 4, and the rotary shaft 2 is supported by the thrust bearing 5, and a servo motor 6 for driving the large-diameter turntable 1 (hereinafter referred to as a first motor). Servo motor 6) is attached. The first servo motor 6 is connected to a control device via a power supply line and a control signal line (not shown).
The output shaft 6a of the first servo motor 6 is connected to the lower end of the rotary shaft 2 of the large-diameter turntable 1 via a coupling 7, and the upper end of the rotary shaft 2 of the large-diameter turntable 1 is connected to a bearing 8. And is pivotally supported above the turntable support arm 4. With the above configuration, when the first servo motor 6 is driven, the large-diameter turntable 1 is also rotated with respect to the turntable support arm.
[0009]
A small-diameter turntable 9 as a sensor base is rotatably supported at an appropriate position of the large-diameter turntable 1, and a servomotor 11 (hereinafter referred to as a servomotor 11 for driving the small-diameter turntable 9) is supported on the rotary shaft 10 of the small-diameter turntable 9. The output shaft of the second servo motor is connected, and when the second servo motor 11 is driven, the small-diameter turntable 9 rotates.
The large-diameter turntable 1 is provided with a balancer 12 at a predetermined position corresponding to the weight of the small-diameter turntable 9 and the second servomotor 11 in order to balance the rotation. It can be rotated.
In FIG. 3, a first slip ring 13 is disposed at an appropriate position below the large-diameter turntable 1 of the rotary shaft 2 of the large-diameter turntable 1. The first slip ring 13 is supplied with electric power to the second servomotor 11 described above. Are connected to the power supply, the control signal line 14 and the ground wire 15 of the large-diameter turntable 1. In other words, the large-diameter turntable 1 is grounded via the first slip ring 13 so as to function as a shield plate, and the second servomotor 11 is configured so that the large-diameter turntable 1 is rotating even when the large-diameter turntable 1 is rotating. Electric power and control signals are transmitted from a control device outside the apparatus via one slip ring 13.
[0010]
A second slip ring 16 is disposed on the rotary shaft 2 of the large-diameter turntable 1 at an appropriate position above the large-diameter turntable 1 (in this example, an upper portion of the turntable support arm 4). One end of a signal extraction line 17 for extracting a signal from the acceleration sensor placed on the turntable 9 is connected. The other end of the signal take-out line 17 is connected to a third slip ring 18 provided on the rotating shaft of the small-diameter turntable 9. Therefore, a signal from the acceleration sensor on the rotating small-diameter turntable 9 is transmitted via the third and second slip rings 18 and 16 even when both the small-diameter turntable 9 and the large-diameter turntable 1 are rotating. The measurement can be performed by a measuring device outside the apparatus.
[0011]
In the turntable type acceleration generator configured as described above, the characteristics test of the acceleration sensor is performed as follows.
1. The acceleration sensor 20 is fixed to the small-diameter turntable 9 on the large-diameter turntable 1.
2. The first servomotor 6 rotates the large-diameter turntable 1 to generate centrifugal force, and simultaneously the small-diameter turntable 9 is rotated by the second servomotor 11 to generate acceleration in a predetermined direction and a predetermined force with respect to the acceleration sensor 20. And measure the characteristics of the acceleration sensor.
3. Power is supplied to the first servo motor 6 from the control device via the control signal line, and power is supplied to the second servo motor 11 from the control device outside the figure via the first slip ring 13 and controlled. A signal or the like is supplied. The large-diameter turntable 1 is grounded through the first slip ring 13.
4). The signal from the acceleration sensor 20 is sent to the measuring instrument via the third slip ring 18 provided on the rotating shaft of the small diameter turntable 9, the signal extraction line 17 wired above the large diameter turntable 1, and the second slip ring 16. The data is transmitted and predetermined data is collected.
[0012]
By the way, at the time of the above characteristic measurement, in this embodiment, in order to prevent noise due to the starting torque of the second servomotor, as shown in FIG. After rotating in the direction, data was taken in after passing through the zero cross point. Therefore, accurate characteristics from the zero point are possible, and the frequency characteristics of the acceleration sensor can be measured from an output signal at 0.1 Hz without noise.
It should be noted that the above-described method for eliminating the influence of the starting torque is naturally applicable not only to the turntable acceleration generator having the above-described configuration but also to a centrifugal acceleration tester.
[0013]
【The invention's effect】
As described above in detail, according to the present invention, in the turntable type acceleration generator, when the acceleration sensor characteristic is measured, the second servo motor is started from the reverse rotation, and after the forward rotation, the data is taken in after passing through the zero cross point. Therefore, it is possible to prevent the second servo motor from generating the starting torque and to obtain an excellent effect that the acceleration sensor characteristic can be measured with high accuracy.
[Brief description of the drawings]
FIG. 1 is a schematic side view of a turntable acceleration generator according to an embodiment of the present invention.
FIG. 2 is a plan view of a turntable of the apparatus.
FIG. 3 is a wiring diagram of the apparatus.
FIG. 4 is a graph showing a state when the second servo motor is started.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Large diameter turntable 2 Rotating shaft 3 Fixing means 4 Turntable support arm 5 Thrust bearing 6 First servo motor 6a Output shaft 7 Coupling 8 Bearing 9 Small diameter turntable 10 Rotating shaft 11 Second servo motor 12 Balancer 13 First slip Ring 14 Control signal line 15 Ground line 16 Second slip ring 17 Signal extraction line 18 Third slip ring 20 Acceleration sensor

Claims (1)

A first servo motor 6, a large-diameter turntable 1 rotated by the first servo motor 6, and a second servo motor 11 rotatably attached to the turn table 1 at an appropriate outer periphery of the large-diameter turn table 1 And a turntable type acceleration generating device having a small-diameter turntable 9 to which an acceleration sensor can be attached, wherein the second servomotor rotates forward before rotating in the forward direction for taking in data. A turntable type acceleration generator that starts from rotation in the opposite direction and then rotates in the forward direction and takes in data after the output from the acceleration sensor passes through the frequency 0 Hz axis.

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