JPS62201079A - How to stop a moving object in a fixed position - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for stopping a moving body in a fixed position.

[Prior Art] Conventionally, there are three types of linear drive motors for conveyance devices: linear synchronous motors, linear synchronous motors, and linear pulse smoke. Compared to the other two types, linear ink drive motors have lower running resistance. Although it has the advantage of being small and requiring only a commercial AC power source as a driving power source, it has the disadvantage of poor stopping position accuracy.

"Mechanical design" is a method to improve this stopping position accuracy.
Volume 29, No. 12 (October 1985 issue), page 43 ~
On page 47, a fixed position stopping method using a single-phase AC magnetic field generating coil is proposed.

In this stopping method, a single-phase alternating current magnetic field generating coil is wound around a primary iron core provided at a stop position of a moving body of a conveying device and at a position on both sides of a conveying path of a moving body having a secondary conductor. By exciting the coil, the moving body is stopped at a predetermined position.

[Problems to be Solved by the Invention] However, in the conventional fixed-position stopping method, in order to stop the moving object in a fixed position, it is necessary to separately install an actuator such as a single-phase AC coil. This required a power source to drive the device, making the device configuration complicated and costing money.

[Object of the Invention] The object of the present invention is to solve the above problems, and to make it possible to stop a moving body at a predetermined position without the need to provide a stopping means such as an actuator, and without relying on mechanical contact. An object of the present invention is to provide a method for stopping a moving body in a fixed position.

[Structure of the Invention] The present invention includes two primary stators that generate traveling magnetic fields that are arranged side by side along the traveling direction of a moving body, and the two primary stators that generate traveling magnetic fields arranged side by side along the traveling direction of the moving body. It is characterized in that the moving body is stopped at a predetermined position by exciting the stator.

[Embodiment] FIGS. 1A, 1B, and 1C are diagrams showing a fixed-position stopping device for a linear induction motor conveyance device, which is an embodiment of the fixed-position stopping method of the present invention.

The fixed-position stopping method shown in this example does not provide a stopping means such as an actuator, and the coils of the primary stators of two linear induction motors arranged in parallel in the transport direction are
This is a method of stopping a moving body at a predetermined position by exciting the moving body with currents in opposite directions so as to have opposite propulsive forces.

In FIG. 1 (A), (B) and (C), Ia and l
b is the primary stator of two sets of linear induction motors arranged side by side on a fixed side such as the ground in the direction of movement of the moving body 2, and these primary stators 1a and lb are lined up in the direction of movement of the moving body. It consists of a primary core with multiple salient poles and a coil wound around it.

A flat plate-shaped secondary conductor 3 made of aluminum, for example,
The secondary conductor 3 is provided on the movable body 2 so that the longitudinal direction of the secondary conductor 3 is in the traveling direction of the movable body 2, and so that the secondary conductor 3 is perpendicular to the ground surface on which the movable body 2 of the transport device travels.

The one set of primary stators 1a and the other set of stators Ib are:
The primary stator 1 a is installed on the ground, sandwiching the secondary conductor 3 provided on the moving body 2 in a non-contact manner.
, 1b are separated into two parts along the traveling direction 10 of the moving body 2 and are provided adjacent to each other.

The coil of the stator 1a has a positive current value, for example, so that the movable body 2 has a propulsive force in the direction of the arrow 11a, which is the same as the traveling direction of the movable body 2, that is, so that a traveling wave magnetic field in the direction of the arrow 11a is generated. The fixed coil 1b is excited by the +IC, and the coil 1b is fixed so that the moving body 2 has a propulsive force in the direction of the arrow llb, which is the opposite direction to the traveling direction of the moving body 2, that is, a traveling wave in the direction of the arrow llb. For example, it is excited with a negative current value -1c so that a magnetic field is generated. In addition, in order to reduce the coefficient of friction between the moving body 2 and the conveyance surface, wheels 4 are installed on the moving body 2.
will be provided.

With the above structure, the stators 1a and 1b are configured as described above.
By exciting six traveling magnetic fields in opposite directions to the moving body 2, when the moving body 2 approaches the position where the stators +a and lb are provided, the moving body 202 The conductor 3 receives a thrust from the stator 1a in the direction of the arrow 11a, and receives a thrust from the stator 1b in the direction of the arrow 11b. The thrust that this secondary conductor 3 receives from the stator 1a is proportional to the product of the excitation force of the stator +a and the area of the secondary conductor 3 that contributes to the excitation.
The thrust force received from the stator 1b is proportional to the product of the excitation force of the stator ib and the area of the secondary conductor 3 that contributes to the excitation. Therefore, the moving body 2 finally stops at a position where these opposite thrust forces are balanced. For example, when the excitation forces of the stators 1a and tb are set equal, the center position of the moving body 2 in the longitudinal direction is the stator 1b of the stator 1a.
The movable body 2 is stopped at the center position between the surface facing the stator 1a and the surface of the stator 1b facing the stator 1a (hereinafter referred to as the boundary center point). Further, for example, when the excitation force of the stator 1a is set to be larger than the excitation force of the stator 1b, the longitudinal center position of the movable body 2 is closer to the stator lb than the position of the boundary center point. Stop at the position you approached. Therefore, by setting the excitation force of the two sets of stators 1a and 1b to an appropriate strength in advance as described above, the movable body 2 can be placed at any position within the range where both stators 1a and 1b are provided. It is possible to stop the

FIG. 2 is a block diagram of a fixed position stop device having a vibration suppression control function. This vibration suppression control function is
As mentioned above, the fixed position stopping device shown in Fig. 1 causes the vibration movement to be performed by receiving forces in opposite directions, but this vibration movement is completed in the minimum amount of time and in the shortest possible time, and the vibration movement is stopped at a predetermined stop position. This is a control function that allows In Figure 2, the first
Components that are the same as those in the figures are given the same reference numerals.

In FIG. 2, similarly to FIG. 1, the primary stators 1a and lb of two sets of linear induction motors are arranged side by side along the traveling direction of the moving body 2, and a position detector 5 detects the position of the moving body 2. is provided on the moving body 2, for example. This position detector 5 outputs position information of the moving body 2 to the control circuit 6. In response to the position information, the control circuit 6 outputs the coils of the stator 1a and the stator 1b from the power sources 7a and 7b, respectively.
The excitation current value, excitation current sign, and excitation time of the excitation currents 1a and Ib supplied to the coils are controlled.

The fixed position stopping method configured as above and having the vibration suppression control function performed by the control circuit 6 will be described in detail later.

FIG. 3 is a model diagram of a fixed position stopping device for explaining the movement of a moving body until it stops at a fixed position.

In FIG. 3, similarly to FIG. 1, the moving direction l of the moving body 2 is
Two sets of stators 1a and 1b are juxtaposed along O, and a secondary conductor 3 of length 2Q is in the stators 1a and Ib. Now, the coil of the stator 1a is excited so that the movable body 2 receives a thrust in the direction of the arrow 11a, which is the same as the traveling direction lO of the movable body 2, and the coil of the stator 1a is excited so that the movable body 2 receives thrust in the direction of the arrow 11a, which is the same as the traveling direction lO of the movable body 2. The coil of the stator 1b is excited so as to receive thrust in the direction of a certain arrow 11b, and the resulting exciting forces of the stators 1+1 and ib are Ta and -Tb, respectively. Further, the area of the secondary conductor 3 that contributes to the excitation of the stator 1a is Sa, the area of the secondary conductor 3 that contributes to the excitation of the stator 1b is designated as sb, and the excitation of the stators 1a and 1b is Let b be the vertical length of the movable body 2 in the plane that contributes to , and let X be the distance from the center point of the boundary between the stators 1a and 1b to the longitudinal center point of the secondary conductor 3.

Now, if we take the direction of force as positive, the force F that the secondary conductor 3 receives from the stators 1a and lb is F=Ta
-Sa-Tb-9b =Ta-b・(12-x)-Tb-b・(4+x)・・
(1) In equation (1), for example, if Ta=Tb=T, then P=-2Tbx=-Bx...
...Old...(2) In equation (2), B=2Tb>O...(3)
It is.

When the mass of the moving body 2 is M and the attenuation constant in motion is C, the equation of motion of the moving body 2 is expressed as follows. (4)
In the formula, C2<4MB...
・・・・・・Assuming (5), the general solution x(t) of the above equation (49) is x(t)=A, oc-γ+jω)
1 (-γ-jω)t+ A 2 e ・・・・・・・・・・・・・・・(6)・・・・・・・・・
......(7). Here, A1 and A,
is an arbitrary constant.

Equation (6) represents that the moving body 2 undergoes damped vibration.

That is, while the moving body 2 vibrates in the advancing direction and the opposite direction, S a = S b .
It will stop at the position that meets the condition (8), that is, the position where X=O. If Taf-Tb, Ta5a=TbSb...
It stops at a position where the condition (9) is satisfied. That is, when formula (9) is solved for X, it becomes as follows, and the moving body 2 will stop at the position of X expressed by formula (10).

FIG. 4(A) is a diagram showing the time vs. distance X characteristic of the equation of motion of the moving body 2 when the attenuation constant C is small;
Figure (B) is a diagram showing the time vs. distance X characteristic of the equation of motion of the moving body 2 when the attenuation constant C is large.

In FIGS. 4(A) and (B), after the constant excitation forces Ta and -Tb act on the secondary conductor 3 of the moving body 2 at time to, the distance X approaches zero, but the attenuation constant C The smaller the value, the smaller the attenuation of the vibration, and the longer the vibration continues.
Therefore, it can be seen that it does not stop at a predetermined position for a long time. Here, when the damping constant C is small,
For example, such as a magnetically levitated vehicle body, there is no friction or the coefficient of friction between the moving body 2 and the running surface is very small.

Next, the vibration suppression control of the fixed position stopping device shown in FIG. 2 will be explained using the model diagram shown in FIG. 3 and FIGS. 5 and 6. Here, a pan-pan control system will be explained as an example.

As a control method, when the movable body 2 comes to the position
Two control methods will be considered in which when the stator reaches the position 0, an opening magnetic current -Ic for a predetermined time tb is supplied to the stator lb, and then an opening magnetic current +rc for a predetermined time ta is supplied to the stator 1a.

FIGS. 5(A), (B), and (C) show the time in the former case versus the excitation current Ia of the stator 1a and the excitation current I of the stator 1b.
b and the distance X characteristics of the moving body 2, and FIG.
A), (B), and (C) are diagrams showing the characteristics of the time in the latter case versus the excitation current Ia of the stator 1a, the excitation current tb of the stator 1b, and the distance X of the moving body 2.

In FIG. 2 and FIGS. 5(A), (B), and (C), the moving body 2 enters the stators 1a and lb, and the time ts
When the position detector 5 detects that the moving body 2 has come to the position of X=O, it outputs the position information to the control circuit 6. Based on the position information, the control circuit 6 controls the power supply 7a
power supplies 7a and 7b such that supply a constant current 1a=+lC to the coil of stator 1a, and power supply 7b supply a constant current 1b=-Ic to the coil of stator 1b.
control.

As a result, the movable body 2 receives an exciting current I from the stator 1a.
c in the direction shown by the arrow 11a in FIG. 3, that is, in the direction of movement 10 of the moving body 2, and proportional to the exciting current Ic from the stator 1b in the direction shown by the arrow 11b in FIG. 3, i.e. It receives a propulsive force in a direction opposite to the moving direction 10 of the moving body 2. Therefore, the moving body 2
The movable body 2 approaches the position of X=O while vibrating in the lb direction, and finally the vibration is attenuated and the movable body 2 stops at the position of x=0.

Next, in FIG. 2 and FIGS. 6 (A), (B), and (C), the moving body 2 enters the stators 1a and lb, and the moving body 2 comes to the position of X=O at time ts+. When the position detector 5 detects this, the position information is transmitted to the control circuit 6.
Output to. Based on the position information, the control circuit 6
The power source 7b is controlled so that the power source 7b supplies a constant current 1b=-Ic to the coil of the stator 1b. As a result, the movable body 2 receives a force from the stator 1b in the direction indicated by the arrow ltb in FIG. 3 that is proportional to the excitation current Ic, and is returned in the direction 11b opposite to the traveling direction 11a of the movable body 2. After this, at time tSt, which is lb after time ts+, the mobile body 2
When the position detector 5 detects that the position is zero, it outputs the position information to the control circuit 6, and in response to the position information, the control circuit 6 controls the power supply from the power source 7b to the stator 1b. At the same time as excitation is stopped, the power supply 7a maintains a constant current 1a=
+lC is controlled to be supplied to the coil of stator 1a. As a result, the moving body 2, which was moving in the direction of the arrow 11b in FIG. 3, receives a force from the stator 1a in the direction shown by the arrow 11a in FIG. It is returned in the direction 11a opposite to zb. Furthermore, at time tss, which is a predetermined time ta after time tst, control circuit 6 controls power supply 7a to stop excitation of stator 1a from power supply 7a. After this, the moving body 2 stops at the position of X=O at time ts4.

By appropriately determining the above-mentioned times ta and tb and the excitation current 1c, it is possible to minimize the amplitude of vibration and stop the moving body 2 at the predetermined stop position of X=O in the shortest time. . For the above control, an optimal control law such as shortest time control or minimum energy control can be applied, depending on the purpose of use of the conveying device or the specifications of the device.

As described above, by configuring the fixed position stopping device for the linear induction motor conveyance device having the vibration suppression control function as shown in FIG. 2, the movable body 2 can be smoothly stopped at a predetermined position.

Furthermore, in the above embodiment, the movable body 2 can be made to travel by exciting the two sets of primary stators 1a and lb so as to move in the traveling direction of the movable body 2.

In the above embodiment, the primary stators 1a and 1b of the linear induction motor conveyance device are provided on the conveyance surface at a predetermined stop position, and the secondary conductor 3 is provided on the moving body 2. As shown in FIG. 2, the primary stators 1a and 1b may be provided on the moving body 2, and the secondary conductor 3 may be provided on the conveyance surface at a predetermined stopping position.

Further, three or more of the above primary stators may be arranged in parallel.

In the embodiment shown in FIG. 2, when the center point of the moving body 2 in the longitudinal direction reaches the center point of the boundary between the stators 1a and ib, the position detector 5 outputs the position information to the control circuit 6. However, the position detector 5 sequentially outputs the position information of the moving object 2 to the control circuit 6, and in response, the control circuit 6 controls the stator so that the moving object 2 smoothly stops at a predetermined position. 1
The power supplies 7a and 7b that supply excitation currents to a and lb may be optimally controlled.

The fixed position stopping device of the linear induction motor conveyance device described above can be widely applied to general moving bodies that are driven and moved by drive devices other than linear induction motors.

[Effects of the Invention] As detailed above, according to the present invention, the moving body is stopped at a predetermined position by exciting the two primary stators so that the directions of the traveling magnetic fields are opposite to each other. Therefore, there is no need to provide a stopping means such as an actuator, and the movable body can be stopped at a predetermined position without relying on mechanical contact.

Therefore, there are advantages in that the configuration of the device is simplified and the cost of the device can be reduced.

[Brief explanation of drawings]

FIG. 1(A) is a front view of a fixed-position stopping device using a fixed-position stopping method for a moving object, which is an embodiment of the present invention, and FIG.
) is a plan view of the fixed position stopping device in FIG. 1(A) with the moving body main body omitted, FIG. 1(C) is a side view of the fixed position stopping device in FIG. 1(A), and FIG. 2 1 is a block diagram of the fixed position stopping device shown in FIG. 1 which has a vibration suppression control function, FIG. ) and FIG. 4(B) are diagrams showing the time versus distance X characteristics of the equation of motion of a moving body. FIG. 5 is a diagram showing the time versus distance FIG. 6 is a diagram showing the characteristics of the distance X of the moving object, FIG. It is a figure which shows the fixed position stop device of the linear induction motor conveyance apparatus which is a 2nd Example. la, lb...Primary stator, 2...Moving body, 3...Secondary conductor, 5...Position detector, 6...Control circuit, 7a, 7b...Power supply . Patent applicant: Sumitomo Electric Industries, Ltd. Agent: Patent attorney: Aohaku Ao, and 1 other person Figure 2: WEs Figure: Figure 5

Claims (3)

[Claims] (1) Two primary stators that generate traveling magnetic fields are arranged side by side along the traveling direction of the moving body, and the two primary stators are excited so that the directions of the traveling magnetic fields are opposite to each other. A method for stopping a movable body in a fixed position, the method comprising: stopping the movable body at a predetermined position. (2) Fixed position stopping of the moving body according to claim 1, characterized in that the primary stator is provided at a predetermined stopping position of the moving body, and the secondary conductor is provided on the moving body. Method. (3) Fixed position stopping of the moving body according to claim 1, characterized in that the primary stator is provided on the moving body, and the secondary conductor is provided at a predetermined stopping position of the moving body. Method.