JPS63220702A - Magnetic levitation carrying device - Google Patents

Abstract

PURPOSE:To stabilize respective three motions of heaving, rolling and pitching, by a method wherein composite magnets are arranged at four ends of a movable body and three sets of displacement sensors are provided so as to be capable of obtaining signals corresponding to the above mentioned three motions. CONSTITUTION:Composite magnets 2-5 are provided at four corners of a base table 1. Further, three sets of displacement sensors 6-8 are provided so as to be capable of detecting the parallel advancing motion of heaving (y direction) and both of the angular motions of pitching (theta direction) and rolling (phi direction). An operating circuit 21 obtains signals corresponding to the displacement and angles of y, theta, phi from the signals corresponding to the displacement u6, u7, u8 of displacement sensors 6-8 and adds them to a proportional element 22, a differentiating element 23 and an integrating element 24. Then, the operating circuit 25 distributes the control inputs Dy, Dtheta, Dphi of respective y, theta, phi directions into the control inputs V2V5 of respective composite magnets 2-5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic levitation conveyance device that supports and conveys an object in a non-contact manner by controlling magnetic force.

(Prior Art) Fig. 4 is a perspective view showing the basic structure of a conventional movable body of this type of magnetic levitation conveyance device, and Fig. 5 shows a state where movable body A is floating with respect to conveyance path B. View from the front in the direction of travel,
FIG. 6 is a block diagram of the control circuit, FIG. 7 is a diagram in which a horizontal control electromagnet is also provided, and FIG. 8 is a diagram of the case where the movable body A moves left and right, and the magnetic surface of the composite magnet 2 and the conveyance path B. FIG.

This magnetic levitation conveyance device consists of a movable body A and a conveyance path B.

The movable body A has compound magnets 2,3,4.5 in four corners of the base 1 and a displacement sensor 6 that detects the gap 12 with the conveyance path B.
．． 7, 8, and 9, and a storage box 11 containing a control circuit, power supply, etc. is mounted in the center. Composite magnet 2 (
Composite magnet 3゜4.5 (same) has permanent magnet 1 at its magnetic pole.
3.14 is attached and a coil 15 is wound around it. The composite magnet 2 exerts a magnetic attraction force with a gap 12 between it and the conveyance path B, and the displacement sensor 6 detects the fluctuation of the gap 12 and sends the displacement signal to the amplification circuit]8
, after being amplified and differentiated by the differentiating circuit 17 and fed back through the power amplifier 1i18, the current in the coil 15 is controlled, and when the load or gap changes, the magnetic attraction force is changed, and the composite magnets 2 to 5 are conveyed. Road B is designed not to touch. The reason why the composite magnet 2 is combined with the permanent magnets 13 and 14 is to reduce the current flowing through the coil 15 and save energy by utilizing the attractive force due to the magnetic flux generated from the permanent magnets 13 and 14.

By using composite magnets 2 to 5 whose magnetic poles are directed in the vertical direction as shown in FIGS. 4 and 5, it is possible to provide a restraining force in the horizontal direction and support the movable body A without contact. . This is because even if the movable body A moves to the left tr in Fig. 5 and a deviation occurs between the magnetic pole face of the composite magnet 2 and the conveyance path B as shown in Fig. 8, it is necessary to return it to its original position. This is because the shear force that occurs naturally occurs. However, since the restoring force of this shift is not a controlled force, there is no damping property, and when the movable body A causes a lateral shift, it takes time for it to return to its original position and come to rest.

To deal with this, as shown in Fig. 7, electromagnets 19 and 20 that apply magnetic force in the horizontal direction are installed on the movable body A, and this is controlled by a control circuit similar to that shown in Fig. 6 to stabilize the moving body. Techniques to improve sex may also be used.

In a magnetic levitation transfer device equipped with a power source and a control circuit, from the viewpoint of power saving, it is necessary to reduce the current flowing through the coil 15 of the composite magnet 2 shown in FIG. 6.

This is achieved by providing an integrating circuit 26 as shown in FIG.
A typical method is to feed back the integral value of the current signal to the coil 15. This is a basic technique of the control method and is well known. By feeding back an integral signal of a signal of a specific physical quantity, the steady-state value of the physical quantity can be converged to O.

[Problem 3 to be solved by the invention: The method of setting the current convergence value to 0 for one composite magnet 2 is easy to adopt, but when using four composite magnets 2 to 5 as shown in FIG. A problem arises when attempting to control the three spatial degrees of freedom of heaving y, pitching θ, and rolling ψ.

That is, if an attempt is made to constrain the three degrees of freedom of movement of an object using four actuators, over-constraint may occur. When using a control method that converges the current to 0, the relationship between the load that the composite magnet 2 should support and the clearance is uniquely determined, and each of the four composite magnets will be in this situation,
The movable body A ends up in this over-constrained situation. In fact, according to experiments, when the movable body A in FIG. 4 is a rigid body, it is not supported in a non-contact manner.

If there are 3 composite magnets and 3 displacement sensors, the current will be O.
Even if the Le 1# method is adopted, the three degrees of freedom are driven by three independent actuators, so there is no over-restraint, and it is possible to keep the clearance and levitate stably.
The horizontal restraining force shown in FIG. 5 is reduced because the number of composite magnets is reduced.

[Means for solving problems]

In the magnetic levitation conveyance device of the present invention, a total of four composite magnets are arranged at each of the four ends of the movable body, and signals corresponding to the three movements of heaving, rolling, and pitching of the movable body can be obtained from the signals of the displacement sensor. The combined force of controlling the compound magnets corresponding to the heaving, rolling, and pitching directions of the movable body is an amount proportional to the signal corresponding to the movement in each direction, an amount proportional to the speed thereof, and an amount proportional to the speed thereof, and It is characterized in that it is provided by a current proportional to a signal consisting of an amount including the integral value of the sum of two fakes.

(Function) However, since the movements in the peaving, rolling, and pitching directions do not interfere with each other, they are each stable, and since the electric power includes an integral value, the coil current of each composite magnet is converged to O. be able to. Furthermore, since the composite magnets are installed at the four ends of the movable body, the horizontal restraining force does not decrease.

(Example) Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing the structure of a movable body (IIJ control circuit and power supply are omitted) showing one embodiment of the magnetic levitation conveyance device of the present invention.

Similar to the conventional example shown in Fig. 4, composite magnets 2,
3, 4.5 are provided symmetrically. Furthermore, three displacement sensors 6 to 8 are mounted on the base 1 so that they can detect the same angular movements of heaving (y direction) translational movement, pitching (θ direction), and rolling (ψ direction) as described later. It is set in.

FIG. 2 is a schematic perspective view of the magnetic levitation conveyance device of this embodiment. A movable body A carrying a storage box 11 containing a control circuit, a power source, etc. is supported in a non-contact manner with respect to a conveyance path B by a composite magnet 4, etc. It moves forward by being provided with a driving force provided on the side or by a near motor (not shown) in a non-contact manner. Note that the conveyed object can be placed on the storage box 11.

FIG. 3 is a block diagram of the control circuit in this embodiment.

The control circuit calculates the displacement u8+u7+ of the displacement sensors 6 to 8.
An arithmetic circuit 21 for obtaining signals corresponding to displacements and angles of y, θ, and ψ from signals corresponding to (corresponding to the circuit 1B, the differential circuit 17, and the integral circuit 26), the human control force in each direction of y, θ, and ψ, the human control force V2 for each composite magnet 2.3, 4.5, and the control force V2 for Dθ and D weight, V3, V4.

It consists of an arithmetic circuit 25 for distributing voltage to Vs, and a circuit 1B (corresponding to the power amplifier 18 in FIG. 6) for converting voltage into current. Note that the same applies to proportional elements, differential elements, and integral elements for θ and ψ, and these are not shown.

Hereinafter, control of the movable body A of the magnetic levitation conveyance device of this embodiment will be explained.

Assume that the movable body A is levitated by controlling the composite magnets 2 to 5, and the gap fluctuation us I u 7 * u 8 from the equilibrium point detected by the displacement sensor 6.7.8 is expressed as the coordinates y and θ in FIG.
, ψ and the following equation.

Here, it is assumed that T1 is a 3×3 matrix and regular. At this time, although FIG. 1 shows an example in which the displacement sensors 6, 7, and 8 are located near the composite magnets 2 and 3.4, the present invention is not limited to this. , that is, the clearance variation u6 + u? It is preferable to arrange them so that +uδ are mutually independent.

The force of the composite magnets 2 to 5 is considered to be a concentrated force, and the amount of variation Fn (n=2.3, 4°5) of the magnetic attraction force from the equilibrium point is linearized and expressed by the following equation.

F n = G @ u n + G 11 rl
``'' (3) Here, u7 is the gap variation between the composite magnets 2 to 5, in is the amount of current variation, and G is its coefficient. un (n=2.3, 4.5) is It,,1
If .degree. is the length from the center of gravity of the movable body to the composite magnets 2, 3, and 4.5 in the Z and X directions, respectively, it is expressed by the following equation.

T2 is a matrix showing the relationship between the gap variation of each composite magnet 2, 3, 4.5 and the three directions of movement of the movable body with respect to the center of gravity.

Using the relationships of equations (3) and (4), the equation of motion of movable body A is expressed by the following equation.

= 4G, J! ,” θ ten Gift (is÷16−i2−
f4)=4(J2”θ+Gt j! 2 (−jz−
fs÷14◆ts) Here, M, Jθ, and J* are the mass of the movable body A, and the moments of inertia in the θ and ψ directions, respectively.

The arithmetic circuit 21 performs the calculation of equation (2). The signal corresponding to the displacement y is a proportional element 22, a differential element z
3. Signal qy processed by integral element z4.

Dy is expressed by the following formula.

The same applies to the control human power Dθ and D. Arithmetic circuit 2
5 calculates the matrix T2 of equation (4) to obtain signals v2*V3*V4 and VB expressed by the following equations.

Then, the currents 12 to i4 proportional to (1)2 to v4 are as follows.

When the second term on the right side of equation (5) is calculated with reference to equations (4) and (II), it becomes: G1Σtn=4G+ktDy=(12).

Therefore, equation (5) is. The second term and subsequent terms on the right side of equation (I2) are the resultant force of control. Moreover, Qy is. From a similar calculation process, the following equation holds true for θ and ψ.

Equation (12) does not include motion i marks θ, ψ other than y, and their speeds, and input q also does not include signals of motion other than y from equation (13). The same applies to the other θ and ψ. Therefore, the motions of y, θ, and ψ do not interfere with each other, and by making each motion individually stable, the movable body can be stably levitated. Note that k,,kv,
The coefficients of , , , etc. can be determined, for example, by applying the Fulvit stability condition.

Since the signal RI has an integral element 24, it becomes a coefficient.

If k v, , k py are appropriately set, they can be converged to O, and the other Dθ and Dφ are also the same, so that all of the currents f2+ fan f4r ts+ can be set to zero.

The block diagram of FIG. 3 will now be described in more detail. I8 + I7 r I8 is displacement sensor 6.7.
Voltage fluctuation corresponding to the gap fluctuation detected by 8,
The arithmetic circuit 21 calculates voltages corresponding to the displacements and angles of y, θ, and ψ in equation (2). An integral element 24 is added so as to obtain a voltage corresponding to the displacement y through a proportional element 22 and a differential element 23, and further add an integral signal of the sum of both to these elements. As constants, ,kv, ,kp,
As mentioned above, its value is set using the well-known Hurwitz stabilization method. Similar processing is performed on the signals corresponding to the angle fluctuations θ and ψ, and the signals De,
Dψ is obtained and passed to the arithmetic circuit 25. The arithmetic circuit 25 calculates the equation (1
0), which performs calculations corresponding to V21 V
3. V4. Distributes the signal to v,. From these signals, the power amplifier 18 generates a current 12s 13+ that is proportional to the voltage.
Obtain 14+ Ig.

(Effects of the Invention) As explained above, the present invention arranges composite magnets at the four ends of a movable body, and allows the three types of motion of the movable body, heaving, rolling, and pitching, to be generated by these four composite magnets. The resultant force of control is an amount proportional to the signal corresponding to the movement in each direction, an amount proportional to the speed, and these two
By applying a current proportional to a signal consisting of a quantity including the integral value of the sum of the quantities, each of the five movements is stabilized,
In addition, since the current of each composite magnet can be converged to 0, power consumption can be reduced.Furthermore, since the composite magnets are installed at the four ends of the movable body, the horizontal restraint force does not decrease. be.

[Brief explanation of the drawing]

Fig. 1 is an embodiment of the magnetic levitation conveyance device of the present invention, and is a perspective view showing the structure of the movable body (the control circuit and power supply are omitted). FIG. 3 is a block diagram of the control circuit in this embodiment. FIG. FIG. 6 is a block diagram of the control circuit, FIG. 7 is a diagram when a horizontal control electromagnet is also provided, and FIG. Figure 8 is a diagram showing a situation where the movable body A moves left and right and a misalignment occurs between the magnetic surface of the composite magnet 2 and the conveyance path B, and Figure 9 is a block diagram of another example of the control circuit. . A--Movable body, B... Conveyance path. 1.-base, 2. ], 4.5-Composite magnet, 6.
7.8-・Displacement sensor, I8-・Power amplifier circuit, 21.25-Arithmetic circuit, 22
-1 proportional element, 23.-differential element, 24.-integral element. $5 Figure 6 Figure 7 Figure 8 Figure 2 Figure 9

Claims (1)

[Scope of Claims] 1. A composite magnet consisting of a conveyance path and a movable body, which is a combination of a permanent magnet and an electrode stone and whose magnetic pole surface is oriented in the vertical direction, and a surface facing the magnetic pole surface of the composite magnet and the conveyance path. a displacement sensor that detects a gap between the magnet and the composite magnet is mounted on the movable body, and further includes a control circuit and a power source for controlling a coil current of the composite magnet, and supports the movable body in a non-contact manner with respect to the conveyance path. In the magnetic levitation conveyance device, a total of four composite magnets are arranged at each of four ends of the movable body, and signals corresponding to the three movements of heaving, rolling, and pitching of the movable body are obtained from the signals of the displacement sensor. The combined force of the control of the compound magnets corresponding to the heaving, rolling, and pitching directions of the movable body is an amount proportional to the signal corresponding to the movement in each direction, an amount proportional to the speed thereof, and an amount proportional to the speed thereof. A magnetic levitation conveyance device characterized in that a current is provided by a current proportional to a signal including an integral value of the sum of these two quantities. 2. When distributing the control signals corresponding to the control forces in the heaving, rolling, and pitching directions to the signals of the four composite magnets, the relationship between the movable center of gravity of the gap fluctuation of each composite magnet and the three directions of motion is determined. 2. A magnetically levitated conveyance device according to claim 1, wherein the magnetic levitation conveyance device distributes data using a matrix representing the distribution.