JPH059606Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a displacement detection device for a moving body suitable for use in accurately detecting displacement in a moving direction at a stop position.

[Prior Art] In a conveyance device that conveys articles in factories, warehouses, etc., it is necessary to position and stop a conveyance cart with high precision at a work station on a conveyance path for loading, unloading, and processing of articles. For this reason, a displacement detection device that detects the displacement of the transport vehicle in the moving direction from the stop position is provided on the transport path.

Figure 4 shows a linear induction motor (hereinafter referred to as
1 is a block diagram showing a conventional configuration of a displacement detection device in a LIM (abbreviated as LIM) type conveyance device. In the figure, the transport vehicle 2 has traveled along the transport path 1 in the direction of arrow A.
When the LIM driver 4 reaches the vicinity of the stop position P, based on the command signal from the system controller 3, the LIM driver 4
energizes the LIM primary side 5a on the conveyance path 1 in a reverse phase to apply a thrust (braking force) to the truck 2 in the backward direction (direction of arrow B). As a result, the truck 2 decelerates and vibrates in the direction of arrow A-B near the stop position P. The eddy current type gap sensor 6 near the stop position P detects the gap δ between the lower surface of the sensor van 7 on the side of the truck (see Fig. 5), and its output is sent to the sensor amplifier 8.
to the displacement/velocity converter 9. The converter 9 converts the output V of the sensor amplifier 8 into a displacement χ (see Fig. 6A, proportional to the gap δ) and a speed υ of the truck 2 in the direction of arrow A, and provides corresponding feedback signals Vx, Vυ. is supplied to the LIM driver 4. As a result, the driver 4 controls the excitation voltage of the LIM primary side 5a, applies vibration damping force to the truck 2, and positions it at the stop position P to stop it.

[Problems to be solved by the invention] The conventional displacement detection device described above has the following problems. Transport vehicle 2 decelerated
When the sensor vane 7 vibrates in the direction of the arrow A-B near the stop position P, the sensor vane 7 tends to move vertically due to its mounting play. Therefore, the gap δ detected by the eddy current gap sensor 6 includes the above-mentioned fluctuation, that is, the disturbance y (see FIGS. 5 and 6 B), so the output of the sensor amplifier 8 is It varies depending on the size of. Along with this, the transport vehicle 2 detected by the displacement/velocity converter 9
The displacement χ and velocity υ of will differ from the actual values due to the influence of the disturbance y. As a result, the feedback signal Vχ supplied to the LIM driver 4,
Since Vυ is not a signal based on accurate displacement or speed, it is not possible to accurately position and stop the transport vehicle 2.

The present invention has been proposed in view of the above circumstances, and aims to provide a displacement detection device for a moving body that can accurately detect displacement in the moving direction from a stop position.

[Means for Solving the Problems] The present invention is attached to a moving body, the lower surface is formed as an inclined surface having a fixed downward angle with respect to the moving direction of the moving body, and the upper surface is attached to the moving body. a detected member formed on an inclined surface having a fixed angle upward with respect to the moving direction of the detected member; and a first detecting member arranged to face the lower inclined surface of the detected member and configured to detect a distance to the lower inclined surface. a second detection means that is located on the same axis as the first detection means and is arranged to face the upper inclined surface of the detected member, and detects a distance to the upper inclined surface; , comprising an adding means for adding each output of the first and second detecting means, and a displacement detecting means for determining the displacement of the movable body in the moving direction from the stop position based on the output of the adding means. Features.

[Operation] According to the present invention, when the movable body reaches near the stop position, it is decelerated and vibrates in the moving direction and the backward direction near the same position. At this time, the first detection means detects the distance from the same means to the lower inclined surface of the detected member, and the second detection means detects the distance from the same means to the upper inclined surface of the detected member. be done. After the respective outputs of the first and second detection means are added by the addition means, the displacement detection means detects the displacement of the movable body from the stop position in the moving direction. In this case, the first and second
Since the sum of the outputs of the detection means is always constant, the distance between the first and second detection means and the lower sloped surface and the upper sloped surface corresponds to the normal distance excluding the above-mentioned fluctuation. Displacement can be detected.
Thereby, the displacement of the moving body in the moving direction from the stop position can be accurately detected.

[Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a displacement detection device in a LIM type conveyance device according to this embodiment. Components shown in this figure that are the same as those shown in FIG. 4 are given the same reference numerals. In FIG. 1, a LIM secondary side (not shown) is attached to the lower surface of the carrier 2, and a wedge-shaped sensor van 10 is attached and fixed to the side surface of the carrier. This sensor bun 10 is made of a conductive material such as copper, and has a downward taper 10a in the direction of arrow A on the bottom surface.
However, the upper surface has an upward taper 10b in the direction of arrow A.
is formed. In addition, at the stop position P on the conveyance path 1, there is a LIM primary side 5 at a position opposite to the LIM secondary side.
a is arranged. These LIM primary side 5a and
The LIM secondary side constitutes LIM5.

On the other hand, near the stop position P, a pair of eddy current gap sensors 11 and 12 (hereinafter abbreviated as sensors) are arranged facing each other in the vertical direction and on the same axis with a distance l apart, and the transport vehicle 2 is placed at the stop position. The lower and upper surfaces of the sensor van 10 are separated by slight gaps δ1 and δ2, respectively, when the sensor van 10 reaches the vicinity of P (see FIG. 2). The output of the sensor 11 is amplified by a sensor amplifier 13, and the output V1 of the amplifier 13 is supplied to an adder 15. Similarly, the output of the sensor 12 is amplified by the sensor amplifier 14, and the output V2 of the amplifier 14 is supplied to the adder 15. Adder 15 adds each output V1, V2,
The output V3 is supplied to the displacement/velocity converter 16.
The displacement/speed converter 16 converts the output V3 into the displacement χ and speed υ of the transport vehicle 2, and supplies the LIM driver 17 with feedback signals V4 and V5 corresponding to the displacement χ and speed υ. The LIM driver 17 is controlled by the system controller 3, and controls the excitation voltage of the LIM primary side 5a based on the feedback signals V4 and V5. Furthermore, sensor amplifier 13,1
4, adder 15, displacement/velocity converter 16, LIM
The driver 17 is arranged in a control device housed in the lower part of the gantry of the transport path 1.

In such a configuration, when the transport vehicle 2 traveling in the direction of arrow A reaches the vicinity of the stop position P,
Arrow A- is decelerated by LIM5 and near the same position P.
It vibrates in the B direction. When the sensor van 10 fluctuates in the vertical direction due to this vibration, that is, when a disturbance occurs, each gap δ1, δ2 is detected by each sensor 11, 12.
and disturbance y are detected. The displacement χ of the transport vehicle 2 in this case is detected as follows.

First, each sensor when the disturbance y is not taken into account.
The relationship between the outputs V1a and V2a of the amplifiers 13 and 14 and the output V3a of the adder 15 and the displacement χ is as shown in FIG. 3B. That is, the displacement χ is the output V1a, V2a,
Proportional to V3a. In other words, the displacement χ is proportional to the gaps δ1 and δ2 when no disturbance y occurs.

On the other hand, when the sensor van 10 moves upward, the outputs V1b and V2b of the sensor amplifiers 13 and 14 and the output V3b of the adder 15 due to only the disturbance y become as shown in FIG. 3A. That is, sensor amplifier 1
When the output V1b of adder 1 increases or decreases, the output V2b of sensor amplifier 14 increases or decreases.
5's output V3b is always constant. In addition, the sensor
The output V3b of the adder 15 due only to the disturbance y when the van 10 moves downward also remains constant as described above.

Therefore, the output V1 of the sensor amplifier 13 when both the gaps δ1 and δ2 and the disturbance y are taken into consideration is:
V1 = V1a + V1b, output V2 of sensor amplifier 14
is V2=V2a+V2b, and the output V3 of adder 15 is
V3=V3a+V3b. Since V3b is always constant, the output V3 of adder 15 is determined only by V3a. That is, since the output V3 supplied to the displacement/velocity converter 16 is determined only by the gaps δ1 and δ2, even if the sensor van 10 moves in the vertical direction, the output V3 will not be affected by the disturbance y. I won't receive it. Therefore, the converter 16 can accurately detect displacement χ and velocity υ.

Thereafter, in response to feedback signals V4 and V5 supplied from the displacement/velocity converter 16, the LIM driver 17 controls the excitation voltage supplied to the LIM primary side 5a. That is, when the transport vehicle 2 moves toward the stop position P, a low excitation voltage is applied to the LIM primary side 5a, and when it leaves the same position P, a high excitation voltage is applied to the LIM primary side 5a. As a result, a vibration damping force is applied to the carrier 2, and the carrier 2 is positioned and stopped.

Note that the following modifications of the above embodiment are possible.

Although the displacement detection device is configured to be applied to a LIM-type conveyance device, it is not limited to this, and can be applied to a rotary table with LIMs arranged at regular intervals on the circumference, for example, to detect the displacement of the table from its stop position. It may also be configured to detect.

Although the detection means of the sensor van 10 are the eddy current gap sensors 11 and 12, the present invention is not limited thereto, and a configuration using a photo sensor may also be used.

Sensor bun 10 is not limited to copper, but may be other conductive materials such as aluminum.

[Effects of the invention] As explained above, according to the invention, it is attached to a movable body, the lower surface is formed as an inclined surface having a certain downward angle with respect to the moving direction of the movable body, and the upper surface is attached to the movable body. A detected member formed on an inclined surface having a fixed angle upward with respect to the moving direction of the moving body, and arranged to face the lower inclined surface of the detected member, detecting the distance to the lower inclined surface. a second detection device located on the same axis as the first detection device and arranged to face the upper inclined surface of the detected member, and detects a distance to the upper inclined surface. means, addition means for adding the outputs of the first and second detection means, and displacement detection means for determining the displacement of the movable body in the moving direction from the stop position based on the output of the addition means. With this configuration, the following effects can be achieved.

Displacement in the moving direction of the moving body from the stop position can be accurately detected.

This allows the moving body to be positioned and stopped with high precision.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of an embodiment of the present invention, Fig. 2 is a side view showing the arrangement of the eddy current gap sensor according to the embodiment, and Fig. 3 A and B show the operation of the embodiment. 4 is a block diagram showing a conventional configuration, and FIG. 5 is a side view showing the arrangement of a conventional eddy current gap sensor.
FIGS. 6A and 6B are characteristic diagrams for explaining the conventional operation. 2...Transportation vehicle (mobile object), 10...Sensor/
Ban (member to be detected), 11... Eddy current gap sensor (first detection means), 12... Eddy current gap sensor (second detection means), 15... Adder (addition means), 16... Displacement/speed converter (displacement detection means).

Claims (1)

[Claims for Utility Model Registration] Attached to a movable body, the lower surface is formed as an inclined surface having a certain angle downward with respect to the moving direction of the movable body, and the upper surface is formed with respect to the moving direction of the movable body. a detected member formed on an inclined surface having a certain upward angle; a first detection means arranged to face the lower inclined surface of the detected member and detects a distance to the lower inclined surface; a second detecting means located on the same axis as the first detecting means and disposed opposite to the upper inclined surface of the detected member, the second detecting means detecting the distance to the upper inclined surface;
a detecting means, an adding means for adding each output of the first and second detecting means, and a displacement detecting means for determining a displacement in the moving direction of the movable body from a stop position based on the output of the adding means. A displacement detection device for a moving body comprising: