JP2005333772A - Magnetic levitation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic levitation device in which behavior of a levitation body does not interfere in each movement mode, when the resistance value of a magnetic coil becomes uneven, to keep in comfortable riding. <P>SOLUTION: A magnetic levitation system C2 constituted of a magnetic unit fitted to a levitation body and a guide rail is controlled by a suction force control means C1 constituted of a stability control means L1 and a zero power control means L2 to guide the mover 16 out of contact. Resistance measuring means 9 is used to measure the resistance value of the electromagnetic coil of a magnetic unit. The output of a mode exciting current computer 5 which computes the electromagnetic exciting current of respective modes contributing to the respective moving modes of the moving body 16 is multiplied by a correction gain compensator. The output of a summer 7 is added using the sum total of a computed result to the output of the suction force control means C1 with an adder 8. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a magnetic levitation device that levitates a levitated body using an electromagnet.

  Normal conducting magnetic levitation has no noise or dust generation, and has already been put into practical use in railways such as HSST and Transrapid, and in clean room transport systems in semiconductor factories. Further, Patent Document 1 attempts to apply an elevator non-contact guide, and Patent Document 2 attempts to apply a normal conducting suction type magnetic levitation device to a door. In normal conduction attraction type magnetic levitation where the electromagnet is opposed to the ferromagnetic member and the levitation body is levitated using the attractive force generated between the electromagnet and the ferromagnetic member, the magnetic levitation system is inherently unstable. In order to stabilize this, the floating gap length, its speed, acceleration, electromagnet excitation voltage, and excitation current are detected, and these are fed back to the attractive force control means to perform the attractive force control. There are various methods for attracting force control, but when it is necessary to change the mass of the floating body due to riding or loading, or to set the riding comfort for each degree of freedom of movement, the control system can be easily designed and the excitation current Therefore, the excitation current that contributes to the freedom of each motion of the levitated body is controlled by the excitation voltage. In this case, as a control method, the levitation gap length, speed, and excitation current are detected or estimated for each degree of freedom of movement (motion mode), and the excitation voltage is determined by linear combination by multiplying these by a predetermined gain. This method is easy to obtain the gain by linear control theory, and is widely used in general. In addition, the necessary number of magnet units having the same shape is used, and consideration is given to the behavior of the levitating body being independent for each degree of freedom of movement.

As described above, the conventional device uses a magnet unit with the same shape to make it easier to control the behavior of the levitated body for each motion mode. However, it is used outdoors like railways and elevators. In general, the temperature of all magnet units is different, such as in the sun and in the shade. Even when indoors, the temperature of each magnet unit varies even when the magnet unit is exposed to the wind of the air conditioner or when a load is applied to a specific magnet unit. Thus, when the temperature of each magnet unit is different, the resistance value of the electromagnet coil becomes non-uniform, and each motion mode of the floating body that has been independent until now interferes with each other. In this case, not only the riding comfort is extremely deteriorated, but also a situation in which the magnet unit collides with the guide rail in some cases. Further, when external force concentrates on a specific magnet unit and acts like a biased load, the exciting current increases in the magnet unit and the temperature of the electromagnet rises. When this happens, the resistance value of the electromagnet coil increases in the magnet unit, the balance of the resistance value of the entire magnet unit is broken, and eventually the behavior of the levitated body in each motion mode interferes with each other.
JP 2001-019286 A JP 2002-303079 A

  Accordingly, an object of the present invention is to provide a magnetic levitation device that does not interfere with the behavior of each motion mode of the levitated body and does not deteriorate the riding comfort even if the resistance value of the electromagnet coil becomes uneven.

ここで、
i_uk：k番目の磁石ユニットにおけるコイル励磁電流、
e_uk：k番目の磁石ユニットにおけるコイル励磁電圧、
z_uk：k番目の磁石ユニットにおけるギャップ長、
L₀：浮上ギャップ長設定値における自己インダクタンス、
N：コイル巻回数、
Φ₀：浮上ギャップ長設定値における磁石ユニットの主磁束、
R_k：k番目の磁石ユニットにおけるコイル抵抗値、
Δ：設定値からの偏差、
∂/∂_z0：浮上ギャップ長設定値における被偏微分関数の偏微分値、
上付きのドット：時間微分d/dtである。 First, the basic principle of the present invention will be described.
When a floating body is supported by a plurality of magnet units, the voltage equation of each electromagnet is as follows.

here,
i _uk : Coil excitation current in the kth magnet unit,
e _uk : Coil excitation voltage in the kth magnet unit
z _uk : Gap length in the kth magnet unit,
L ₀ : Self-inductance at the set value of the levitation gap length,
N: number of coil turns,
Φ ₀ : main magnetic flux of the magnet unit at the set value of the levitation gap length,
R _k : coil resistance value in the k-th magnet unit,
Δ: Deviation from set value,
∂ / ∂ _z0 : Partial differential value of the partial differential function at the levitation gap length setting value,
Superscript dot: Time derivative d / dt.

  If the levitated body is a rigid body, the degree of freedom of motion is 6, but in the voltage equation, in addition to generating suction force that contributes to these 6 degrees of freedom, virtual motion that generates flexural force and torsional force on the levitated body There is also a linear combination of excitation currents corresponding to modes (mode excitation current), and the number of modes of the mode excitation current matches the number of magnet units. That is, if the total number of magnet units is n, there are n mode voltage equations.

The voltage equation of each magnet unit is converted into a voltage equation of each mode by linear conversion. If this conversion matrix is T _um , the above equation 1 is converted into a mode voltage equation as follows.

If the mode excitation current in the l-th motion mode is i _ml , the mode displacement is z _ml , and the mode excitation voltage is e _ml , the mode voltage equation is

From the above equation 3, the mode voltage equation when the resistance values of the magnet units are not the same is

Equation 4 is a row vector of the l-th row in which the voltage drop due to the coil resistance of the l-th mode in the mode voltage equation when the resistance value of the k-th (k = 1 to n) magnet unit is R _k is R _m. It is expressed by the product of R _ml and mode excitation current vector i _m, that is, means that which is represented by a linear combination of mode excitation current.

Generally, in the magnetic levitation control of a levitated body, as shown in Patent Document 1, the l-th (l = 1 to n) mode excitation voltage Δe _ml is determined as follows to stabilize each motion mode. As a result, the entire levitation body rises stably. That is, in the mode voltage equation corresponding to the actual motion mode of the levitated body, the proportional gains of the mode displacement Δz _ml , the displacement speed d (Δz _ml ) / dt and the mode excitation current Δi _ml are expressed as F _al , F _bl , F _cl If the excitation current of each mode can be converged to zero, the integral gain of Δi _ml is set as K _cl

で決定される。ただし、x_lはΔi_ml、F_lはΔi_mlの比例ゲイン、K_lはΔi_mlの積分ゲインである。 In the mode voltage equation corresponding to the virtual motion mode,

Determined by Here, x _l is Δi _ml , F _l is a proportional gain of Δi _ml , and K _l is an integral gain of Δi _ml .

で定義して各モードの要素が式５，式６で表されるe_mとともに式４に加えてやれば良い。ここで、R_aは各磁石ユニットの電磁石コイル抵抗値の平均値である。 Therefore, if the resistance value of the electromagnet coil of each magnet unit is not uniform as shown in Equation 4, even if the floating body is stabilized by Equation 5 and Equation 6, the external force applied from one direction can be The exercise mode will be disturbed and the ride comfort will be extremely deteriorated. To prevent this phenomenon, the correction voltage e _C

The elements of each mode defined in (5) may be added to the expression (4 ₎ together with em represented by the expressions (5) and (6). Here, _Ra is the average value of the electromagnet coil resistance value of each magnet unit.

となり、各モードで電圧方程式が独立して、モード励磁電流の非干渉化を図ることができる。 Then, Equation 4 becomes

Thus, the voltage equation is independent in each mode, and the mode excitation current can be made non-interfering.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Example 1)
FIG. 1 is a control block diagram showing the main part of the magnetic levitation system C2 in the l-th motion mode when the attraction force control means C1 and the elevator car in the first embodiment of the magnetic levitation apparatus are non-contact guided. ing. In the figure, A _l , b _l , C _l and D _l are the system matrix, input matrix, output matrix and disturbance matrix of the magnetic levitation system, respectively, x _l is the state vector of the magnetic levitation system, u _l is the external force, y _l is a state quantity detected by the sensor. S represents a Laplace operator.

As shown in FIG. 1, the attraction force control means C1 includes a stabilization control means L1 composed of a point a to a gain compensator 1 to a subtracter 2, a point a to a subtractor 3, an integral compensator 4 to a subtractor 2. And a mode excitation voltage correction unit C3 for removing the influence of the excitation current of other motion modes included in the output of the zero power control unit L2. Here, in the zero power control means L2, the subtracter 3 compares zero with the electromagnet excitation current value, and the result is input to the integral compensator 4. The mode excitation voltage correction means C3 calculates the excitation current Δi _ml (l = 1 to n) for each mode that contributes to each of the total n motion modes of the magnetic levitation system from the excitation current of each magnet unit. In each of the mode excitation current calculation unit 5 and the mode excitation current calculation unit 5, the mode excitation current calculation unit 5 includes the excitation current for each mode other than the mode excitation current Δi _{ml in the} lth motion mode among the n excitation currents for each mode. of R _m of l-th row vector elements _{R m (l, j) (} j = 1~n, j ≠ l) as the n-1 resistance multiplying means to gain a corrected gain compensator 6 And an adder 7 that calculates the sum of the correction gain compensator 6, an adder 8 that takes the sum of the output of the adder 7 and the output of the subtractor 2, and the electric resistance value of the electromagnet coil of each magnet unit And a resistance measuring means 9 for outputting the measured value to each correction gain compensator 6.

  Therefore, if the magnetic levitation control system composed of the magnetic levitation system C2 and the attractive force control means C1 is stable, the voltage equation can be made non-interfering in each motion mode, and a good riding comfort can be achieved.

  2 to 5 show the configuration of the first embodiment of the magnetic levitation apparatus 10 related to the attractive force control means of FIG. As shown in FIG. 2, this apparatus includes ferromagnetic guide rails 14 and 14 ′ laid on the inner surface of the elevator shaft 12 by a predetermined attachment method, and ropes 15, for example, along the guide rails 14 and 14 ′. The moving body 16 as the above-mentioned floating body that moves up and down by a driving means (not shown) such as winding, and four guides that are attached to the moving body 16 and guide the moving body to the guide rails 14 and 14 'in a non-contact manner. Units 18a to 18d are configured. The moving body 16 includes a car 20 for carrying a load, and a frame 22 having a strength to which the car 20 and the guide units 18a to 18d are attached, and a predetermined positional relationship between the guide units 18a to 18d can be maintained. The guide units 18a to 18d facing the guide rails 14 and 14 'are attached to the four corners of the frame portion 22 by a predetermined method.

  4 and 5 show the configuration of the guide unit 18b as a representative, but the configurations of the other guide units are the same. The guide unit 18 includes a base 24 made of a non-magnetic material such as aluminum, stainless steel, or plastic, and an x-direction gap sensor 26 (26b, 26b ′), a y-direction gap sensor 28 (28b, 28b ′), and a magnet unit 30. Installed and configured by the method. The magnet unit 30 includes a central iron core 32, permanent magnets 34 and 34 ', and electromagnets 36 and 36', and the same polarity of the permanent magnets 34 and 34 'faces through the central iron core 32 as a whole. It is assembled into a letter shape. The electromagnets 36, 36 ′ are configured by inserting a L-shaped iron core 38 (38 ′) into the coil 40 (40 ′) and then attaching a flat iron core 42 to the tip of the iron core 38 (38 ′). The magnet unit 30 is attracted to the guide rail 14 (14 ') by the attractive force of the permanent magnets 34, 34' when the electromagnets 36, 36 'are not energized at the ends of the central core 32 and the electromagnets 36, 36'. The solid lubricating member 43 is attached so as to prevent the moving body 16 from moving up and down even in the attracted state. Examples of the solid lubricating member include a material containing Teflon (registered trademark), graphite, molybdenum disulfide, or the like. In the magnet unit 30b, the attraction force acting on the guide rail 14 'can be individually controlled in the y direction and the x direction by exciting the coils 40b and 40b' individually. The details of this control method are disclosed in Patent Document 1 (Japanese Patent Application Publication No. 2001-19286 relating to “Elevator Guide Device”, Japanese Patent Application No. 11-192224 relating to the invention by the present inventor), Detailed explanation is omitted.

  Although there are some exceptions in the specification and drawings of the present application, in principle, the alphabets a, b, c, d included in the reference numerals indicating members, signals, numerical values, etc. are those members, signals, numerical values, etc. Is related to the guide units 18a to 18d indicated by the reference numerals including the corresponding alphabets, and "'" appended to the reference numerals indicating the members, signals, numerical values, etc. (Dash) is related to the member, signal, numerical value, etc. of the electromagnet 36 'side displayed with "'" of the two electromagnets 36, 36 'included in each unit 18a to 18d. Is meant to be.

  Each suction force of the guide units 18a to 18d is controlled by a control device 44 as suction force control means, and the car 20 and the frame portion 22 are guided in a non-contact manner with respect to the guide rails 14 and 14 '. Although the control device 44 is divided as shown in FIG. 1, for example, as shown in FIG. In the following block diagrams, arrow lines indicate signal paths, and bar lines indicate power paths around the coil 40. The controller 44 includes a sensor unit 61 that detects a change in magnetomotive force, magnetoresistance, or movement of the moving body 16 in a magnetic circuit that is attached to the car 20 and formed by the magnet units 30a to 30d, and the sensor unit. Based on the signal from 61, the operation circuit 62 for calculating the applied voltage to each of the coils 40a, 40a ′ to 40d, 40d ′ in order to guide the moving body 16 in a non-contact manner, and to each coil 40 based on the output of the operation circuit 62 Consists of power amplifiers 63a, 63a 'to 63d, 63d' for supplying electric power, and resistance measuring means 64 for detecting the temperature of each coil 40a, 40a 'to 40d, 40d' and outputting the electric resistance value of each coil Thus, the attractive forces of the four magnet units 30a to 30d are independently controlled with respect to the x-axis and the y-axis.

  The power supply 46 supplies power to the power amplifiers 63a, 63a ′ to 63d, 63d ′, and at the same time supplies the arithmetic circuit 62 and the gap sensors 26a, 26a ′ to 26d, 26d ′, 28a, 28a ′ to 28d, 28d ′ with a constant voltage. Electric power is also supplied to the constant voltage generator 48 that supplies electric power. Since this power supply 46 supplies power to the power amplifier, the function of converting the AC supplied from outside the elevator shaft 12 to the DC suitable for supplying power to the power amplifier through a power line (not shown) for opening and closing the lighting and the door have.

  The constant voltage generator 48 is always operated with a constant voltage even when the voltage of the power source 46 fluctuates due to a supply of a large current to the power amplifier 63, and the arithmetic circuit 62 and the gap sensors 26a, 26a ′ to 26d, 26d ′, 28a, Power is supplied to 28a 'to 28d and 28d'. Therefore, the arithmetic circuit 62 and the gap sensors 26a, 26a 'to 26d, 26d', 28a, 28a 'to 28d, 28d' always operate normally.

  The sensor unit 61 includes the gap sensors 26a, 26a ′ to 26d, 26d ′, 28a, 28a ′ to 28d, 28d ′, and the current detectors 66a, 66a ′ to 66d, 66d that detect the current values of the coils 40. It consists of 'and.

  The arithmetic circuit 62 performs magnetic guidance control of the moving body 16 for each motion mode of the motion coordinate system shown in FIG. That is, the y mode (back and forth movement mode) representing the longitudinal movement along the y coordinate of the center of gravity of the moving body 16, the x mode (left and right movement mode) representing the left and right movement along the x coordinate, Θ mode (roll mode) representing rolling around the center of gravity, ξ mode (pitch mode) representing pitching around the center of gravity of the moving body 16, ψ mode (yaw mode) representing yawing around the center of gravity of the moving body 16 ). In addition to these modes, the total attractive force that the magnet units 30a to 30d exert on the guide rails 14 and 14 ', the torsional torque around the y-axis that the magnet units 30a to 30d exert on the frame portion 22, and the magnet units 30a and 30d that correspond to the frame portion 22, three modes relating to the strain force that causes the frame unit 22 to be symmetrically distorted by the rolling torque exerted on the frame unit 22 by the magnet units 30 b and 30 c, that is, ζ mode (full suction mode), δ mode (twist mode), γ Guidance control is also performed for the mode (distortion mode). As described above, so-called zero power control is performed for the eight modes so that the moving body is stably supported only by the attractive force of the permanent magnet 34 regardless of the weight of the load by converging the coil current of the magnet units 30a to 30d to zero. Guidance control.

The arithmetic circuit 62 is configured as follows to achieve zero power control. That is, the gap length set values xa0, xa0 'to xd0, xd0' are subtracted from the gap length signals gxa, gxa 'to gxd, gxd' from the x-direction gap sensors 26a, 26a 'to 26d, 26d'. Y direction gap length setting values ya0, ya0 'to yd0, yd0' for the subtractors 70a to 70h for calculating the x direction gap length deviation signals Δgxa, Δgxa 'to Δgxd, Δgxd' and the magnet units 30a to 30d Subtraction for calculating y-direction gap length deviation signals Δgya, Δgya 'to Δgyd, Δgyd' obtained by subtracting gap length signals gya, gya 'to gyd, gyd' from gap sensors 28a, 28a 'to 28d, 28d' Current setting values ia0, ia0 'to id0, id0' are subtracted from excitation current detection signals ia, ia 'to id, id' from current detectors 66a, 66a 'to 66d, 66d' Subtracters 74a to 74h for calculating current deviation signals Δia, Δia ′ to Δid, Δid ′ obtained by the above, x direction gap length deviation signals Δgxa, Δgxa ′ to Δgxd, Δgxd ′ and y direction gap length deviation signals Δgya, Δgya ' .About..DELTA.gyd, .DELTA.gyd 'are averaged for each magnet unit to output x direction gap length deviation signals .DELTA.xa to .DELTA.xd and y direction gap length deviation signals .DELTA.ya to .DELTA.yd, and gap length deviation signals .DELTA.ya to .DELTA.yd. To the movement amount Δy of the moving body 16 in the y direction, the gap length deviation signals Δxa to Δxd to the movement amount Δx of the moving body 16 in the x direction, and the rotation angle Δθ of the same gravity center in the θ direction (roll direction). The floating gap length deviation coordinate conversion circuit 81 for calculating the rotation angle Δξ of the moving body 16 in the ξ direction (pitch direction) and the rotation angle Δψ of the moving body 16 in the ψ direction (yaw direction), and current deviation signals Δia, Δia From “˜Δid, Δid”, the current deviation Δiy related to the movement of the center of gravity of the moving body 16 in the y direction, the current deviation Δix related to the movement in the x direction, the current deviation Δiθ related to rolling around the center of gravity, the moving body 16 Current deviation Δiξ related to pitching of the current, current deviation related to yawing around the same center of gravity Δiψ, a current deviation coordinate conversion circuit 83 as a mode excitation current calculation unit for calculating current deviations Δiζ, Δiδ, Δiγ related to ζ, δ, γ that applies stress to the moving body 16, a floating gap length deviation coordinate conversion circuit 81, and a current Output from deviation coordinate conversion circuit 83 Δy, Δx, Δθ, Δξ, Δψ, Δiy, Δix, Δiθ, Δiξ, Δiψ, Δiζ, Δiδ, Δiγ, y, x, θ, ξ, ψ, ζ, δ, γ Control voltage calculation circuit 84 as a mode excitation voltage calculation unit for calculating mode-specific electromagnet control voltages ey, ex, eθ, eξ, eψ, eζ, eδ, eγ that stably levitate the moving body 16 in the mode 84 , Control voltages for calculating the respective electromagnet excitation voltages ea, ea'-ed, ed 'of the magnet units 30a-30d from the outputs ey, ex, eθ, eξ, eψ, eζ, eδ, eγ of the control voltage calculation circuit 84 The coordinate reverse conversion circuit 85 is used. Then, the calculation results of the control voltage coordinate inverse transformation circuit 85, that is, the above-described ea, ea ′ to ed, ed ′ are given to the power amplifiers 63a, 63a ′ to 63d, 63d ′. Note that the levitation gap length deviation coordinate conversion circuit 81, the excitation current deviation coordinate conversion circuit 83, the control voltage calculation circuit 84, and the control voltage coordinate reverse conversion circuit 85 are referred to as a levitation control calculation unit 65 for the following description.

  Furthermore, the control voltage calculation circuit 84 calculates the y-mode electromagnet control voltage ey from Δy, Δiy, and the x-mode electromagnet control voltage ex from Δx, Δix. Left-right motion mode control voltage calculation circuit 86b to calculate, roll mode control voltage calculation circuit 86c to calculate the θ-mode electromagnet control voltage eθ from Δθ, Δiθ, ξ mode from Δξ, Δiξ Pitch mode control voltage calculation circuit 86d for calculating the electromagnet control voltage eξ of the motor, Yaw mode control voltage calculation circuit 86e for calculating the electromagnet control voltage eψ of Δψ from Δψ and Δiψ, and the ζ mode electromagnet from Δiζ Total suction mode control voltage calculation circuit 88a for calculating the control voltage eζ, torsion mode control voltage calculation circuit 88b for calculating the δ mode electromagnet control voltage eδ from Δiδ, and γ mode electromagnet control from Δiγ And a distortion mode control voltage calculation circuit 88c for calculating the voltage eγ. Become the excitation voltage calculator for each mode.

  The control voltage calculation circuit for each mode has the configuration of the attractive force control means C1 shown in FIG. That is, the vertical movement mode control voltage calculation circuit 86a is configured as shown in FIG. Differentiator 90 for calculating time change rate d (Δy) / dt from Δy to Δy, gain compensator 91 for multiplying Δy, d (Δy) / dt, Δiy by appropriate feedback gain, and current deviation target value Generator 92, subtractor 93 that subtracts Δiy from the target value of current deviation target value generator 92, integration compensator 94 that integrates the output value of subtractor 93 and multiplies an appropriate feedback gain, and gain compensator An adder 95 for calculating the sum of the output values of 91, a subtractor 96 for subtracting the output value of the adder 95 from the output value of the integral compensator 94 and outputting the y-mode electromagnet excitation voltage ey, and a subtractor The mode excitation voltage correction means C3 is configured to eliminate the influence of excitation currents in other modes included in the 96 outputs. Here, the adder 97 is included in the excitation voltage correcting means C3.

  The left / right mode control voltage calculation circuit 86b, the roll mode control voltage calculation circuit 86c, the pitch mode control voltage calculation circuit 86d, and the yaw mode control voltage calculation circuit 86e are also the same as the vertical mode control voltage calculation circuit 86a. The input / output signal corresponding to FIG. 7 is indicated by a signal name, and the description is omitted.

  On the other hand, the three mode control voltage calculation circuits 88a to 88c of ζ, δ, and γ all have the same configuration and have the same components as the vertical movement mode control voltage calculation circuit 86a. A number is attached and for distinction, this is shown in FIG.

  The resistance value of the coil 40 measured by the resistance measuring means 64 is input to the control voltage calculation circuit 84 and stored in the correction gain compensator 6 of the excitation voltage correction means C3 at predetermined time intervals.

  Next, the operation of the magnetic levitation apparatus according to this embodiment configured as described above will be described.

  When the apparatus is in a stopped state, the tips of the central iron cores 32 of the magnet units 30a and 30d are opposed to the guide rail 14 via the solid lubricating member 43, and the tips of the electromagnets 36a 'and 36d' are solid lubricating members. They are adsorbed on the opposing surfaces of the guide rails 14 through 43. At this time, the movement of the moving body 16 is not hindered by the action of the lubricating member 43. In this state, when the device is started, the control device 44 causes the levitation control calculation unit 65 to apply a magnetic flux in the same direction as or opposite to the magnetic flux generated by the permanent magnet 34 to each of the electromagnets 36a, 36a ′ to 36d, 36d ′. In addition, the current flowing through each coil 40 is controlled so as to maintain a predetermined gap length between the magnet units 30a to 30d and the guide rails 14 and 14 '. As a result, as shown in FIG. 5, the magnetic circuit Mc comprising the paths of the permanent magnets 34 to the iron cores 38, 42 to the gap G, the guide rail 14 (14 ′), the gap G ″, the central iron core 32 to the permanent magnet 34, and A magnetic circuit Mc ′ comprising paths of the permanent magnets 34 ′ to the iron cores 38, 42 to the gap G ′, the guide rail 14 (14 ′), the gap G ″, the central iron core 32 to the permanent magnets 34 is formed. The gap length in the gaps G, G ', G' 'is the y-axis direction longitudinal force in which the magnetic attractive force of each magnet unit 30a-30d due to the magnetomotive force of the permanent magnet 34 acts on the center of gravity of the moving body 16, the same x direction The length is just balanced with the lateral force, the torque around the x-axis passing through the center of gravity of the moving body 16, the torque around the y-axis, and the torque around the z-axis. The controller 44 controls the excitation current of the electromagnets 36a, 36a 'to 36d, 36d' when an external force is applied to the moving body 16 to maintain this balance. As a result, so-called zero power control is performed.

  Now, the moving body 16 that is non-contact guided by zero power control starts to move up and down along the guide rail by a hoisting machine (not shown) that is a moving force applying means, and the moving body is swayed due to distortion of the guide rail or the like. In addition, since the magnet unit includes a permanent magnet that shares a magnetic path with the electromagnet in the air gap, the magnet unit attractive force can be quickly controlled by the excitation of the electromagnet coil to suppress shaking. In addition, by adopting a permanent magnet with a large residual magnetic flux density and holding power, the control performance of non-contact guidance control does not deteriorate even if the gap length is increased. Even if it occurs, low-rigidity guide control with a large stroke can be performed, and the ride comfort is not impaired. Furthermore, by arranging the magnet unit so that the magnetic poles are opposed to each other via the guide rail, a part of or all of the attractive force that acts on the guide rail is canceled out by the opposed magnetic pole. Does not work. For this reason, the large attraction force of the magnet unit does not act from one direction, and the installation position of the guide rail is not changed, for example, the step at the joint 98 and the linearity of the guide rail are not deteriorated. As a result, the laying strength of the guide rail can be reduced, and the cost of the elevator system can be reduced.

  If excessive external force is applied to the moving body 16 due to unbalanced movement of personnel or cargo, or rope swaying due to an earthquake, etc., the temperature of the electromagnets of the magnet units 30a to 30d becomes uneven, and the electromagnet The electrical resistance of the coil varies. In particular, in this embodiment, zero power control capable of extremely suppressing power consumption is used, but in zero power control, when a large excitation current flows with an excessive external force, each electromagnetic coil generates heat suddenly and the gap length is constant. The resistance value fluctuates more than other control methods such as control. When this happens, interference occurs in each motion mode based on the above-described equation 4, and the riding comfort is extremely deteriorated. However, according to the present invention, the resistance value of the coil 40 is detected by the resistance measuring means 64, and this resistance value is stored in the correction gain compensator 6. Interference can be achieved and good riding comfort can be maintained.

  When this apparatus finishes operation and stops the apparatus, in the current deviation target value generator 92 in the y mode and the x mode, if the target value is gradually changed from zero to the negative value, the moving body 16 becomes the y axis, Gradually move in the x-axis direction. Finally, the tips of the central cores 32 of the magnet units 30a and 30d are opposed to the guide rail 14 through the solid lubricating member 43, and the tips of the electromagnets 36a 'and 36d' are solid. It is adsorbed on the opposing surface of the guide rail 14 via the lubricating member 43. When the apparatus is stopped in this state, the current deviation target value is reset to zero and the moving body is attracted to the guide rail.

(Example 2)
Next, a second embodiment of the present invention will be described with reference to FIGS. In the first embodiment, the resistance value of the electromagnet coil is obtained from the temperature, but in this embodiment, the resistance value is calculated from the excitation voltage and the excitation current of the coil 40.

  The resistance measuring means 64 ′ is configured as shown in FIG. That is, a multiplier 224 that introduces excitation current detection signals ia, i′a to id, i ′d from the current detectors 66a, 66a ′ to 66d, 66d ′ and calculates the square of the excitation current detection value; The control voltage coordinate inverse conversion circuit 85 outputs ea, e'a to ed, e'd and excitation current detection signals ia, i'a to id, i'd are introduced to the excitation current detection value. A multiplier 228 for multiplying, an adder 230 for adding a predetermined value e to the output of the multiplier 224, a divider 232 for dividing the output of the multiplier 228 by the output of the adder 230, and a divider 232 It comprises a filter 234 that filters the output and outputs a signal with a good S / N ratio. In this configuration, the electric power is divided by the square of the current to obtain the respective resistance values Ra, Ra 'to Rd, Rd' of the coils 40a, 40a 'to 40d, 40d'. Needless to say, this value is set to a sufficiently small value to prevent zeroing when is zero.

  The output of the resistance measuring means 64 ′ is introduced into the arithmetic circuit 62 in the same manner as the resistance measuring means 64 and stored in the correction gain compensator 6. In this embodiment, since the resistance value is calculated from the excitation voltage and the excitation current, there is an advantage that the number of parts of the resistance measuring means can be reduced.

(Example 3)
Further, a third embodiment will be described with reference to FIGS. In the two embodiments described above, the output of the resistance measuring means is stored in the correction gain compensator 6, but other control parameters are changed using the output of the resistance measuring means.

  That is, in the present embodiment, the gain compensators 91 and 91 ′ and the integral compensator in the control voltage calculation circuits 86a to 86e and 88a to 88c as the mode-specific excitation voltage calculation means based on the value of the resistance measurement means 64 ′. Change the gain of 94, 94 '. These gains are calculated based on the linear control theory at the time of designing the control device 44, and the average value of the resistance of the electromagnetic coil is used for the calculation. For this reason, when the resistance value of each of the coils 40a, 40a 'to 40d, 40d' is changed, if the gain is corrected with the changed resistance value, it is possible to prevent a change in the transient response in the floating state in each motion mode.

  In the present embodiment, each control voltage calculation circuit 86, 88 introduces the output of the resistance measuring means 64 ′, calculates the average value of each resistance, and corrects the gain of the gain compensator 91 based on the result. A gain setting device 300 is provided as a control constant correction calculation unit. The output of the gain setting device 300 is introduced into gain compensators 91 and 91 ′ and integral compensators 94 and 94 ′ to correct these gains. This embodiment has an advantage that a constant riding comfort can be always obtained in each motion mode.

  In each of the above embodiments, zero power control is applied. However, this does not limit the magnetic levitation control method to be applied. For example, when it is desired to simplify the configuration of the control system, The gap length is constant control without using an integrator. Moreover, although each said embodiment has demonstrated the case where a magnetic levitation apparatus is applied to an elevator, this does not limit the object of a magnetic levitation apparatus at all, and various objects, such as a railway, a conveying apparatus, a door, etc. Changes to are possible. Further, in each of the above embodiments, the control device that performs magnetic levitation control is described as analog control, but this does not limit the analog or digital control method at all, and digital control is applied to the arithmetic circuit. May be. In addition, in each of the above embodiments, a permanent magnet is used for the magnet unit. However, this does not limit the configuration of the magnet unit at all, and the magnet unit is configured by a normal electromagnet having no permanent magnet. There is no problem. In addition, various modifications can be made without departing from the scope of the present invention.

1 is a block diagram showing an overall configuration of a first embodiment of the present invention. The perspective view which shows the whole structure in said embodiment. The perspective view which shows the relationship between the mobile body and guide rail in said embodiment. The perspective view which shows the structure of the magnet unit in said embodiment. The longitudinal cross-sectional view of the principal part for demonstrating. The top view which shows the magnetic circuit of the magnet unit in said embodiment. The block diagram which shows the circuit structure of the control apparatus in said embodiment. The block diagram which shows the structure of the control voltage calculating circuit in the control apparatus in said embodiment. The block diagram which shows the other structure of the control voltage calculating circuit in the control apparatus in said embodiment. The block diagram which shows the circuit structure of the control apparatus in the 2nd Embodiment of this invention. The block diagram which shows the structure of the resistance measurement means of said embodiment. The block diagram which shows the structure of the control voltage calculating circuit in the control apparatus in the 3rd Embodiment of this invention. The block diagram which shows the other structure of the control voltage calculating circuit in the control apparatus in said embodiment.

Explanation of symbols

C1 Suction force control means
C2 magnetic levitation system
C3 mode excitation voltage correction means
L1 Stabilization control means
L2 Zero power control means 2, 3 Subtractor 6 Correction gain compensator 4, 94, 94 'Integral compensator 5 Mode excitation current calculator 7, 8 Adder 9, 64, 64' Resistance measurement means
10 Magnetic levitation device
12 Elevator shaft
14,14 'guide rail
16 mobile
18,18a-18d guidance unit
22 Frame part
26,26a, 26a'-26d, 26d 'x-direction gap sensor
28,28a, 28a'-28d, 28d'y direction gap sensor
30,30a-30d magnet unit
32 Central iron core,
38,38 ', 42 iron core
34,34 'permanent magnet
36, 36 ', 36a, 36a' to 36d, 36d 'electromagnet
40, 40 ', 40a, 40a' to 40d, 40d 'coil
43 Solid lubricant
44 Control unit
46 Power supply
61 Sensor section
62 Arithmetic circuit
63a, 63a 'to 63d, 63d' power amplifier
65 Ascent control calculator
66a, 66a 'to 66d, 66d' current detector
81 Levitation gap length deviation coordinate conversion circuit
83 Excitation current deviation coordinate conversion circuit
84 Control voltage calculation circuit
85 Control voltage coordinate reverse conversion circuit
86a Longitudinal mode control voltage calculation circuit
86b Left / right mode control voltage calculation circuit
86c Roll mode control voltage calculation circuit
86d Pitch mode control voltage calculation circuit
86e Pitch mode control voltage calculation circuit
88a All suction mode control voltage calculation circuit
88b Torsional mode control voltage calculation circuit
88c Distortion mode control voltage calculation circuit
91, 91 'gain compensator
224 multiplier
228 multiplier
230 Adder
232 divider
234 Filter
300 Gain setting unit

Claims (7)

A magnet unit with an electromagnet;
A levitating body supported by the magnet unit;
A guide rail for supporting the floating body in a non-contact manner by an attractive force acting on the magnet unit, with the magnetic poles of the magnet unit facing each other through a gap,
Sensor unit for detecting a state in the gap of the magnetic circuit formed by the electromagnet with the gap and the guide rail, excitation means for causing an excitation current to flow through the electromagnet, and resistance measurement for measuring an electric resistance value of the electromagnet A mode excitation current calculation unit that calculates a mode-specific current represented by a linear combination of the electromagnet excitation current that generates an attractive force that contributes to the degree of freedom of movement of the levitated body, and an output of the sensor unit A mode excitation voltage calculation unit for calculating an excitation voltage for each mode expressed by a linear combination of the electromagnet excitation voltages so as to generate an attractive force that contributes to the degree of freedom of movement of the levitated body; the resistance measuring unit; and the mode excitation Mode excitation voltage correction means for correcting the output of the mode excitation voltage calculation unit based on the output of the current calculation unit, and the output of the sensor unit A suction force control means for stabilizing said magnetic circuit by controlling the excitation current of contributing the electromagnet to each of the plurality of motion modes of the floating body Zui,
A magnetic levitation device comprising:   The magnetic levitation apparatus according to claim 1, wherein the magnet unit includes a permanent magnet arranged to share a magnetic path with a magnetic flux of the electromagnet in the gap.   The attraction force control means includes zero power control means for stabilizing the magnetic circuit while converging the excitation current of the electromagnet that contributes to the motion mode of at least one levitating body to zero based on the output of the sensor unit. The magnetic levitation apparatus according to claim 2, further comprising:   The magnetic levitation apparatus according to claim 3, wherein the attraction force control means includes the resistance measurement means.   The magnetic levitation apparatus according to claim 4, wherein the resistance measuring unit measures an electric resistance of the electromagnet based on an excitation current of the electromagnet and an excitation voltage generating the excitation current.   5. The magnetic levitation apparatus according to claim 4, wherein the mode excitation voltage calculation unit includes a control constant correction calculation unit that corrects the mode-specific excitation voltage based on an output of the resistance measuring unit.   The mode excitation voltage correction means comprises a resistance value multiplication means for multiplying the output of the resistance measurement means and the output of the mode current measurement means, and an adder for calculating the sum of the outputs of the resistance value multiplication means. The magnetic levitation apparatus according to claim 1.

Images