JPH06189414A - Decelerating and stopping method for linear motor type conveying truck - Google Patents

Abstract

PURPOSE:To accurately decelerate and stop a linear motor type conveying truck. CONSTITUTION:A linear motor-driven air-cushioned or magnetic levitation type conveyor has a levitation type conveying truck W having a secondary conductor LP, a traveling passage in which linear motor stators LA, LB are arranged in the vicinity before and after a stopping point O, a position detecting sensor of the truck, and a linear motor stator excitation controller, and comprises laser type displacement sensors S1, S2 which can directly measure moving distances of the conductors to detect a position to control the deceleration and stop of the truck. Accordingly, since the laser type sensor can steplessly and continuously measure a moved distance and a moving direction of a matter to be measured on a flat surface, it can accurately control to stop the truck by the stator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deceleration and stop control method for a linear motor-driven levitating carrier vehicle, and more particularly to a deceleration and stop method capable of stopping in a short time with less reciprocating vibration at a stop point.

[0002]

2. Description of the Related Art As means for stopping a floating carrier truck driven by magnetism or air pressure driven by a linear motor at a predetermined position without using a mechanical brake, a linear motor stator is arranged in front of and behind a stop point, and a carriage is provided. There is a deceleration stop method in which the position and speed of the carriage are detected and the carriage is stopped and held by the braking force by the anti-phase excitation that excites the stators in the directions facing each other.

An example thereof is shown in FIG. W indicates a carrier, a secondary conductor (hereinafter referred to as a reaction plate) LP is attached to the lower surface, and a linear motor stator L is provided on the traveling path.
A is arranged and, for example, a pressure-pneumatic levitation mechanism PA is provided as levitation means. In addition, at the stop position, a linear motor stator L that is opposite in phase to each other across the stop point O is excited.
Place A and LB. However, the stator LA has a thrust in the forward direction of the traveling vehicle W, and the stator LB has a thrust in the opposite direction.

In this case, when entering the stop position at the traveling speed, it is impossible to stop immediately at the stop point O, and there is a drawback that a reciprocating damping vibration is generated around the stop point O. For this reason, the linear motor stator on the approach side needs to reduce the approach speed of the carrier vehicle, and a sensor striker 50 such as a slit plate is attached to the carrier vehicle W as a traveling speed detecting means for that purpose. This sensor striker 50 is shown in FIG.
As shown in FIG. 5, a plurality of protrusions 51 and recesses 52 are alternately formed with a constant pitch P, and a plurality of protrusions 51 and recesses 52 are alternately attached to the side of the carriage W, and a sensor S3 provided on the side of the conveyance path detects the protrusion. An ON-OFF signal is emitted, and the speed is measured from the detection time or the detection interval time. In the example shown in FIG. 7, an optical sensor is used as the sensor S3.
As shown in FIG. 5, the uneven portion of the striker 50 is arranged so as to enter the light projecting portion of the optical sensor S.

FIG. 8 shows a detection signal of the traveling speed of the carriage by the optical sensor S. That is, the detection signal for the protrusion 51 is short at high speeds of the transport vehicle, and the detection time is long at low speeds. This calculates the traveling speed of the carrier,
A deceleration command is given to the linear motor stator LA in order to stop at a predetermined position.

[0006]

In this case, since the traveling resistance of the carriage is extremely small, the speed of the carriage at the stop point is as low as possible.
If it is not close to, it takes a long time to dampen the oscillation. However, the sensor is turned ON-OF with the striker such as the above-mentioned slit plate.
In the method of detecting the position and speed by causing F, due to the restriction of the mechanical size, for example, when the bogie is traveling at 1 m / sec, the linear motor stator length is 500 mm, and the vicinity of the stop point is 10 mm per second. If the sensor striker pitch P is 10 mm when decelerating with, the signal interval is 10 mm Sec when the linear motor enters, and the signal interval is 1 second near the stop point, the bogie position changes before excitation control follows, and braking If you feel too tight,
There are drawbacks such as when the vehicle stops and runs in reverse.

In view of these drawbacks, it is an object of the present invention to accurately control the excitation of the linear motor stator by continuously obtaining the moving direction of the carriage and the displacement amount signal.

[0008]

To achieve the above object, a method of decelerating and stopping a linear motor type transport vehicle according to the present invention is a floating transport vehicle having a secondary conductor, and a linear transport line before and after a stop point. In a linear motor-driven air levitation or magnetic levitation transfer device having a traveling path in which a motor stator is arranged in close proximity, a position detection sensor for a levitation trolley, and an excitation control device for the linear motor stator, The laser type displacement sensor that can directly measure the movement amount of the secondary conductor is used for position detection for the deceleration stop control.

[0009]

[Operation] The laser displacement sensor detects the amount of movement and the direction of the movement of a flat surface by a traveling wave in the phase of the interference between the irradiation light of the laser light and the reflected light. Therefore, the signals of the moving direction and the displacement amount of the carrier are continuously obtained, and even if the traveling speed of the carrier is low, the linear motor stator can be provided with a control signal for the speed.

[0010]

EXAMPLE FIG. 1 is an overall explanatory view of a deceleration stop device for a linear motor type carrier according to the present invention. A linear motor drive system in which a reaction plate LP is attached to the lower surface of the carrier W and a linear motor stator LA (see FIG. 4) is arranged on the traveling path is used. The carrier W is driven by a pressure air levitation mechanism PA. Emerging and transitioning. At the stop point O of the carriage W, a linear motor stator LB that is provided with thrust in the opposite direction against the linear motor stator LA is arranged, and both linear motor stators LA and LB that sandwich the stop point O are arranged. Are controlled by inverters IA and IB, respectively. The reaction plate LP is a linear motor stator L
The length is shorter than the distance between the outer ends of A and LB.

In addition, a predetermined distance from the stop point O,
That is, at a distance slightly shorter than half the length of the reaction plate LP attached to the carriage W, at least in the approach direction of the carriage W, preferably on both sides of the center point O, laser displacement as a position detection sensor is performed. The sensors S1 and S2 are arranged so as to face the reaction plate LP. The laser displacement sensors S1 and S2 are sensors that detect both the moving direction and the moving direction by a traveling wave of the irradiation light of the laser light and the phase of the interference of the reflected light, and have a structure of transmitting the moving amount as a digital signal. One is preferable, the moving direction is usually plus,
Send with a negative signal.

The outputs of the laser type displacement sensors S1 and S2 are applied to the controller C of the linear motor stator. The control device C includes output control inverters IA and IB for the linear motor stators LA and LB, and a linear motor controller RC that gives a control signal to both inverters. The output from each of the laser displacement sensors is applied to a linear motor controller RC, and the linear motor controller RC applies to the inverters IA and IB the excitation direction (forward / reverse) and the frequency according to the outputs of the sensors S1 and S2. Apply a control signal. In addition, this laser type displacement sensor S
In S1 and S2, the amount of movement of the flat surface of the bogie or the surface of the reaction plate is measured from the direction perpendicular to the direction of movement, and the amount of movement and the direction of movement are always output at a constant sampling time in the light receiving state. Therefore, an accurate control signal can be obtained even at a low speed.

Next, the operating procedure will be described. Now, it is assumed that the carrier vehicle W enters from the linear motor stator LA in the direction of the linear motor stator LB and stops at the center position O1 of the carrier vehicle W at the stop point O. In this case, the laser displacement sensor S1 detects the movement amount and the movement direction when the carriage W enters the detection section, and outputs a detection signal to the linear motor controller RC. This linear motor controller R
C differentiates the amount of movement, calculates the speed, outputs a signal to the inverter IA so as to excite the linear motor stator LA in the control direction with the excitation strength according to the speed, until the speed decreases to a preset speed. Decrease the speed of the carriage. Figure 4 shows the procedure of the sleeve. P1, P2H Linear motor stator LA, L
When the point a, which is a predetermined distance from the stop point O, is reached, the thrust is reduced, that is, the braking direction is set, and the thrust is also reduced as the carriage W decelerates. At this time, when the center position O1 of the carrier vehicle does not reach the stop point O, the excitation is switched in the traveling direction to move the carrier car to the stop point O at a low speed.

Next, when the center position O1 of the carriage W coincides with the stop point O, a preset excitation frequency signal,
Signals are applied to the inverters IA and IB in order to apply thrust to the linear motor stators LA and LB on the stop point O side. As a result, the carriage W is held at the position where the center position O1 thereof coincides with the stop point O. When the carriage W enters the stop point O side from the linear motor stator LB side, similar control is performed by the laser displacement sensor S2.

Further, the detection by the laser displacement sensors S1 and S2 can measure the traveling speed of the carriage W along with the traveling speed of the carriage W by the linear motor controller RC, so that the linear motor is held while the carriage W is held and stopped. It is also possible to change the stop position by changing the excitation strength applied to the stators LA and LB. That is, if the exciting forces of the two linear motor stators LA and LB are made uniform, the stop position becomes a preset stop point O, while the linear motor stator LA side is strong and the opposite linear motor stator LB is weak, for example. By doing so, the stop position is a position where the thrust of the area of the reaction plate LP with respect to the linear motor stator LA and the thrust of the reaction plate LP with respect to the linear motor stator LB are balanced.

[0016]

As described above, according to the present invention, a pair of linear motor stators sandwiching the stop point is provided, the speed of the entering carriage is detected by the position detection sensor, and each linear motor stator is detected. Excitation force is applied according to the speed to slow down the traveling speed of the carriage and stop at a predetermined position.Because the laser displacement sensor is used as the speed detection sensor, it can be applied to the flat surface of the carriage or the reaction plate. However, since the moving amount and the moving direction can be continuously measured continuously with the traveling wave of the phase of the interference between the laser light irradiation light and the reflected light due to the movement, the carriage carriage stop control by the linear motor stator is possible. Can be performed accurately.

[Brief description of drawings]

FIG. 1 is an overall explanatory view of a deceleration stop device for a linear motor type carrier vehicle embodying the present invention.

FIG. 2 is an operation explanatory view of a laser displacement sensor.

FIG. 3 is an explanatory diagram of a linear motor driving procedure for a carrier vehicle.

FIG. 4 is an explanatory diagram of a braking procedure by a linear motor stator at a stop point.

FIG. 5 is an explanatory diagram of a conventional deceleration stop device for a linear motor type carriage.

FIG. 6 is a plan view of a sensor striker.

FIG. 7 is an explanatory diagram of a linear motor driving procedure of a conventional carrier truck.

FIG. 8 is an output explanatory diagram of a sensor for a conventional sensor striker.

[Explanation of symbols]

 C Linear Motor Stator Excitation Controller LA Linear Motor Stator LB Linear Motor Stator LP Reaction Plate S1 Laser Displacement Sensor S2 Laser Displacement Sensor IA Inverter IB Inverter RC Linear Motor Controller W Carrier Cart

Claims (1)

[Claims] 1. A levitation-type carrier truck having a secondary conductor, a travel path in which a linear motor stator is disposed in front and rear of a stop point, and a position detection sensor for the levitation-type carriage, and a linear motor. In a linear motor-driven air levitation or magnetic levitation transfer device having a stator excitation control device,
A deceleration stop method for a linear motor type transfer vehicle, characterized in that a laser displacement sensor capable of directly measuring the movement amount of a secondary conductor is used for position detection for deceleration stop control of the transfer vehicle.