WO2007099849A1

WO2007099849A1 - Mag-lev device

Info

Publication number: WO2007099849A1
Application number: PCT/JP2007/053285
Authority: WO
Inventors: Mimpei Morishita
Original assignee: Toshiba Elevator Kabushiki Kaisha
Priority date: 2006-02-22
Filing date: 2007-02-22
Publication date: 2007-09-07
Also published as: CN101390282A; JP4499673B2; CN101390282B; JP2007228686A

Abstract

Provided is a mag-lev device capable of always performing stable levitation control by considering the affect given to a coil resistance estimated value by a displacement of a levitated body. A resistance measuring unit (140) calculates a resistance value of coils (119, 119') according to a current value iz flowing in the coils (119, 119') of a magnetic unit (107) detected by a sensor unit (123), an output of a excitation voltage calculation unit (125) calculating an excitation voltage value for stabilizing a magnetic circuit formed by the magnetic unit according to the coil current value obtained by the sensor unit (123), and a displacement speed estimated by a posture estimation unit (133) as a speed detection unit for detecting fluctuation speed of a space of the magnetic unit (107) opposing to a guide (113). According to the calculation result, the posture estimation unit (133) and the excitation voltage calculation unit 125 performs levitation control. Thus, even if the levitated body (111) is displaced, the coil resistance estimated value will not fluctuate and it is possible to always perform a stable levitation control according to the value.

Description

Magnetic levitation device

Technical field

TECHNICAL FIELD [0001] The present invention relates to a magnetic levitation apparatus that supports a levitated body in a non-contact manner by normal conducting magnetic levitation.

Background art

[0002] Normally-conducting suction type magnetic levitation equipment is a clean room transport system in railways and semiconductor factories such as H SST (High Speed Surface Transport) and Trans-Rabbit where noise and dust generation are eliminated. Has already been put to practical use. In addition, attempts have been made to apply this magnetic levitation device to elevator car guide devices (see Patent Document 1) and to doors.

In such a magnetic levitation device, an electromagnet is opposed to a ferromagnetic member, and the levitated body is levitated by using an attractive force generated between the electromagnet and the ferromagnetic member. For this reason, the magnetic levitation system is basically unstable, and it is necessary to take measures to stabilize it. In general, the gap height is detected by a gap sensor, and it is feed-knocked to the drive system to achieve stability. However, when the flying gap length is detected by the gap sensor, a sensor target suitable for the gap sensor to be used is necessary, and the sensor target must be laid along with the ferromagnetic member.

[0004] Thus, in order to achieve stability of the magnetic levitation system, parts such as a gap sensor and a sensor target are required, which increases the cost, and the apparatus is required to secure the installation space. There was a problem of increasing the size. Also, in railways and transport systems, a branch point is provided on a track composed of ferromagnetic guides, so a mechanism that prevents the sensor target and guide from intersecting and preventing gap length detection is necessary. Yes, there are problems when the system becomes complicated.

[0005] In order to solve such problems, various methods that do not require a gap sensor have been proposed. For example, a method of estimating the gap length using an exciting current force observer (state observer) of an electromagnet (see Non-Patent Document 1) or an exciting voltage of an electromagnet generated by magnetic levitation There is a method in which gap information is included in the phase difference between the excitation current and the excitation current, and this is fed back to the excitation voltage (see Non-Patent Document 2). In addition, the excitation current value of the electromagnet is compared with the reference value with a hysteresis comparator, and when the excitation current is larger than the reference value, the excitation voltage is switched to negative, and when the excitation current is smaller, the excitation voltage is switched to positive. There is a method of making the switching frequency proportional to the floating gap length (see Non-Patent Document 3).

[0006] However, even with such a solution, when the observer is used, the linear model force of the magnetic levitation system in the levitation state is derived, so that the observer is not in the levitation state. Cannot be estimated. Therefore, there are problems that it becomes difficult to control at the start of levitation, and that the levitation body cannot return to the levitation state again once it comes into contact with another structure. In addition, when the excitation voltage of the electromagnet is controlled by a physical quantity including gap information, the levitation control system becomes a nonlinear control system. For this reason, it is difficult to determine the stability of the control system, and there is a problem that the floating state cannot be maintained if there is a variation in the electrical resistance of the electromagnet coil due to a change in the mass of the floating body or a rise in temperature due to excitation. .

[0007] In order to cope with such a problem, in the sensorless method of estimating the gap length by the exciting current force observer of the electromagnet, when the floating body is not in the floating state, the contact of the floating body is detected and the integrator of the observer is detected. In addition, the contact state force of the levitated body is estimated, and the gap length at the time of contact is estimated geometrically, and the initial value is given to the integrator of the observer based on the estimated gap length. There is a method for returning to a state (see Patent Document 2). However, when this method is applied to zero power control (see Patent Document 4), the following problems arise.

That is, when the levitated body is in a steady levitating state, the excitation current of the electromagnet converges to zero, so there is no problem. However, when a large external force is applied to the levitated body for a long time, the electromagnet As a result, a transient control current continues to flow through the coil and the coil temperature rises. As the temperature rises, the electrical resistance of the coil increases, and the excitation current force also increases the output error of the observer that estimates the levitating gear length. As a result, it becomes increasingly difficult to maintain the floating state, and the floating body comes into contact.

[0009] It should be noted that when the levitated body comes into contact, control to return to the levitated state is attempted. Even after returning to the state, the error in the estimated value of the floating gap at the time of ascent is large, so that the levitation body contacts again, and the contact state and the levitation state are repeated alternately. In such a state, since a large control current continues to flow through the electromagnet, the coil resistance value of the electromagnet further increases, and finally the excitation current continues to flow while the floating body is in contact. If the exciting current that continues to flow is large, an electromagnet that squeezes with force may ignite if the reliability of the floating state is impaired.

[0010] On the other hand, with respect to fluctuations in the coil resistance value of the electromagnet in such sensorless magnetic levitation, levitation control is performed while measuring the resistance value of the coil, and based on the measured resistance value.

V, and a method of changing an observer parameter for estimating the gap length (see Patent Document 3) has been proposed. In addition, when a transient excitation current continues to flow through the electromagnet, there is a problem that the offset voltage fluctuates with an increase in temperature in addition to an increase in coil resistance. The fluctuation of the offset voltage increases the output error of the observer that estimates the floating gap length, similarly to the fluctuation of the coil resistance value.

[0011] To solve such a problem, compensation for reducing the DC component of the observer speed estimation value to zero, that is, adding the offset compensation amount to the excitation voltage input to the observer, the output of the observer Errors can be suppressed. However, even if the measures described above are used, the resistance value of the coil used in the observer is calculated from the excitation voltage and the DC component of the excitation current. If the resistance value cannot be measured, there is a problem.

For this problem, the excitation voltage when the current target value is zero can be expressed as the sum of all offset voltages mixed in the closed loop of the magnetic levitation control system at that time. The accuracy of resistance estimation can be improved by subtracting the stored excitation voltage value from the excitation voltage value stored and used for resistance estimation.

Patent Document 1: Japanese Patent Laid-Open No. 2001-19286

Patent Document 2: Japanese Patent Laid-Open No. 2003-204609

Patent Document 3: Japanese Patent Laid-Open No. 2005-117705

Patent Document 4: Japanese Patent Application Laid-Open No. 61-102105

Non-Patent Document 1: Mizuno, et al .: “Research on practical application of displacement sensorless magnetic bearing”, Electrical Proceedings of the conference D volume, 116, No. 1, 35 (1996)

Non-Patent Document 2: Moriyama: “AC Magnetic Levitation Using a Differential Feedback Power Amplifier” 1997 IEEJ National Convention Proceedings, No. 1215

Non-Patent Document 3: Mizuno, et al .: “Self-sensing magnetic levitation using hysteresis amplifier”, Transactions of the Society of Instrument and Control Engineers, 32, No. 7, 1043 (1996)

Disclosure of the invention

Problems to be solved by the invention

[0013] As described above, the conventional magnetic levitation apparatus requires a gap sensor and a sensor target in order to realize a stable levitation state of the levitated body. For this reason, there is a problem that the apparatus becomes large and complicated, resulting in an increase in cost.

[0014] In order to avoid such a problem, even if the gap length information is feedback-controlled without using a gap sensor, it depends on the levitation stability force S coil resistance value and offset voltage. When the body shakes greatly, the coil current estimation accuracy decreases due to fluctuations in the coil current and excitation voltage that accompany it, and stable control cannot be performed.

[0015] The present invention has been made on the basis of a forceful situation. Coil resistance is always estimated with good accuracy in consideration of the buoyancy of the levitated body, and stable levitation control is performed regardless of the buoyancy of the levitated body. An object of the present invention is to provide a magnetic levitation device capable of performing the above.

Means for solving the problem

[0016] As means for solving the above problems, a magnetic levitation apparatus according to the basic configuration of the present invention includes a guide made of a ferromagnetic member and an electromagnet opposed to the guide through a gap. A magnet unit; a levitated body supported in a non-contact manner by the attraction force of the magnet unit acting on the guide; a sensor unit for detecting a current value flowing in the coil of the electromagnet; and a coil current obtained by the sensor unit An excitation voltage calculation unit for calculating an excitation voltage value for stabilizing a magnetic circuit formed by the magnet unit based on the value, a speed detection unit for detecting a fluctuation speed of the gap displacement, and the excitation voltage calculation A coil resistance of the electromagnet based on the exciting voltage value obtained by the sensor, the coil current value obtained by the sensor, and the fluctuation speed obtained by the speed detector. Calculate resistance A resistance measuring unit, and a control unit that feeds back the coil resistance value obtained by the resistance measuring unit to the excitation voltage calculating unit to control the floating of the floating body.

[0017] According to such a basic configuration, it is possible to obtain a coil resistance value with little fluctuation with respect to the swinging of the levitated body. Therefore, the calculation result of the excitation voltage calculation unit does not fluctuate, and stable levitation control can always be performed even if the levitation body fluctuates due to disturbance.

[0018] The magnetic levitation apparatus according to the first configuration is based on the basic configuration, and includes a magnet unit including a permanent magnet sharing a magnetic path with the electromagnet in the gap, and the coil current of the electromagnet. The target value setting unit that alternately sets a target value to a zero value or a non-zero value, a coil current converging unit that converges the coil current of the electromagnet to the target value set by the target value setting unit, and the coil An excitation voltage calculation unit for calculating an excitation voltage value for stabilizing a magnetic circuit formed by the magnet unit based on the coil current value obtained by the sensor unit in accordance with a convergence operation by the current convergence unit; When the target value is set to a zero value, the excitation voltage value obtained by the excitation voltage calculation unit, the coil current value obtained by the sensor unit, and the speed detection unit An offset calculation unit that calculates a DC component of the excitation voltage value based on the fluctuation speed, a voltage storage unit that stores a calculation result of the offset calculation unit, and an excitation voltage value of the electromagnet to the voltage storage unit. An excitation voltage compensator for obtaining a compensation value of the excitation voltage value by subtracting the stored excitation voltage value as an offset voltage value is further provided.

[0019] The magnetic levitation device according to the second configuration is based on the basic configuration, and at least the attitude of the levitation body and the attitude change speed with respect to the ferromagnetic member are determined based on the coil current value and the excitation voltage value. A posture estimation unit for estimation is further provided, and the speed detection unit calculates the fluctuation speed based on the posture change speed estimated by the posture estimation unit.

[0020] The magnetic levitation device according to the third configuration is the one according to the second configuration, wherein the auxiliary support portion maintains the positional relationship between the levitation body and the guide in a predetermined state when the levitation body is not in the levitation state. , A contact detection unit for detecting contact between the floating body and the guide, and the contact detection A posture calculation unit that outputs the posture of the floating body with respect to the guide at the time of contact based on the output of the unit, an estimation initialization unit that initializes the posture estimation unit at the time of contact based on the output of the contact detection unit, and the posture And an initial value setting unit that sets an output value of the posture calculation unit as an initial value of the posture estimation unit when the estimation unit is initialized.

[0021] The magnetic levitation device according to the fourth configuration is the one according to the second configuration, wherein the estimated value of the posture change speed obtained by the posture estimation unit is integrated by multiplying by a predetermined gain, and the integration result is integrated with the excitation voltage. And an estimation error correction unit that feeds back the addition result to the posture estimation unit as a new excitation voltage value.

[0022] The magnetic levitation apparatus according to the fifth configuration is based on the second configuration, and mode excitation that calculates an excitation voltage for generating an attractive force that contributes to the degree of freedom of movement of the levitated body for each predetermined mode. The apparatus further includes a voltage calculation unit and a mode excitation current calculation unit that calculates an excitation current for generating a suction force that contributes to the degree of freedom of movement of the levitated body for each predetermined mode. Based on at least the outputs of the mode excitation current calculation unit and the mode excitation voltage calculation unit, the attitude of the levitating body with respect to the ferromagnetic member and the temporal change of the attitude are determined for each degree of freedom of movement of the levitating body. It is characterized by estimation.

[0023] A magnetic levitation apparatus according to a sixth configuration is the one according to the fifth configuration, wherein the estimated value of the posture change speed obtained by the posture estimation unit is multiplied by a predetermined gain and integrated, and the integration result is integrated for each mode. A mode estimation error correction unit that adds the excitation voltage value to the posture estimation unit as a new mode excitation voltage value is added to the excitation voltage value.

[0024] The magnetic levitation device according to a seventh configuration is based on the basic configuration, wherein the resistance measurement unit calculates a power calculation result obtained by multiplying at least a linear combination of the excitation voltage value and the coil current value by the coil current. An integrator for integrating is provided.

The invention's effect

[0025] According to the magnetic levitation device of the present invention, the coil resistance value can be accurately measured even if the levitation body is shaken due to some disturbance, and the levitation state is stabilized based on the measured value. The levitation control parameters can be adapted so that the characteristics can be maintained. As a result, the stability of the magnetic levitation system and the transient response to disturbances can always be maintained at the time of design, improving the reliability of the equipment.

Brief Description of Drawings

FIG. 1 is a diagram showing a configuration of a magnetic levitation apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a basic configuration of a magnetic levitation apparatus for explaining the principle of the present invention.

FIG. 3 is a block diagram showing a detailed configuration of a suction force control unit of the apparatus according to the first embodiment.

FIG. 4 is a block diagram showing a detailed configuration of a suction force control unit of the apparatus according to the first embodiment.

FIG. 5 is a block diagram showing a detailed configuration of a suction force control unit of the apparatus according to the first embodiment.

FIG. 6 is a diagram showing a configuration of a magnetic levitation apparatus according to a second embodiment of the present invention.

FIG. 7 is a perspective view showing a configuration of a frame portion of a magnetic levitation apparatus according to a second embodiment.

FIG. 8 is a perspective view showing a configuration around a magnet unit of an apparatus according to a second embodiment.

FIG. 9 is an elevation view showing the configuration of the magnet unit of the apparatus according to the second embodiment.

FIG. 10 is a block diagram showing a detailed configuration of a control device of the device according to the second embodiment.

FIG. 11 is a block diagram showing a configuration of a mode control voltage arithmetic circuit in the control device of the second embodiment.

FIG. 12 is a block diagram showing the configuration of another mode control voltage calculation circuit in the controller of the magnetic levitation apparatus according to the second embodiment.

FIG. 13 is a diagram showing a configuration of a magnetic levitation apparatus according to a third embodiment.

FIG. 14 is a diagram showing a configuration of a magnetic levitation apparatus according to a fourth embodiment.

Explanation of symbols

[0027] 107 Magnet unit

111 Floating body

113 Guide

115 Control unit (suction force control unit)

119 Koinore

123 Sensor unit

125 Excitation voltage calculator 133 Attitude estimation unit

140 Resistance measurement unit

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of a magnetic levitation apparatus according to the present invention will be described in detail with reference to the accompanying drawings. First, the basic principle of the present invention will be described with reference to FIG. FIG. 2 is a diagram showing a basic configuration of a magnetic levitation apparatus for explaining the principle of the present invention.

[0029] The magnetic levitation apparatus 1 is fixed to the ground with a magnet unit 107 composed of a permanent magnet 103 and an electromagnet 105, a levitated body 111 composed of the magnet unit 107 and a load load 109, and a structural member (not shown). The guide 113 is provided. In addition, the magnetic levitation device 1 controls the attractive force of the magnet mute 107 to stably support the levitated body 111 in a non-contact manner, and the attractive force control unit 115 And a driver 116 for exciting the electromagnet 105 based on the output. Reference numeral 131 denotes an auxiliary support portion. The auxiliary support portion 131 has a U-shaped cross section, and the magnet unit 107 is fixed to the upper surface of the lower inner side. It also serves as a table for the anti-vibration table.

Here, in order to support the levitated body 111 in a non-contact manner by the magnetic attractive force of the magnet unit 107, the guide 113 is made of a ferromagnetic member. The electromagnet 105 is configured by installing coils 119 and 119 on iron cores 117a and 117b, and iron cores 117a and 117b are arranged at both magnetic pole ends of the permanent magnet 103, respectively. The coils 119 and 119 ′ are connected in series so that the magnetic flux of the magnetic path formed by the guide 113 to the iron core 117a to the permanent magnet 103 to the iron core 117b to the guide 113 is strengthened (weakened) by the excitation of the electromagnet 105. In addition, the attractive force control unit 115 includes an excitation voltage calculation unit 125. The excitation voltage calculator 125 calculates a voltage for exciting the magnet 105 based on the flying gap length obtained by the gap sensor 121 and the coil current value obtained by the current sensor 123. The driver 116 supplies an excitation current to the coils 119 and 119 ′ via the lead wire 128 based on the excitation voltage calculated by the excitation voltage calculation unit 125.

At this time, in the magnetic levitation system of the magnetic levitation apparatus 1, the attractive force of the magnet unit 107 is increased by the levitation body 11. A linear approximation can be made in the vicinity of the floating gap length _z when it becomes equal to the weight of 1, and is described by the following differential equation.

[Number 1]

Number 1

[0032] F is the attractive force of the magnet unit 107, m is the mass of the levitated body 111, R is the electrical resistance when the coils 119, 119, and the lead wire 128 are connected in series (hereinafter referred to as coil resistance) , Z is the levitation gap length, i is the excitation current of the electromagnet 105, φ is the main magnetic flux of the magnet unit 107, e is the excitation voltage of the electromagnet 105, Δ is the steady levitation state (z = z, i = i (in the steady levitation state) Deviation from i = Δ ί)) when coil current is zero, symbol "·" is dZdt, partial differential 3 Z 3 h (h = z, i) is steady levitation state (z = z, i = i) Is the partial differential value of the partial differential function at. L is L∞, self-inductance of electromagnet 105 when ∞ is ∞, N is coil 1

It can be expressed as the following as the total number of times of 19 and 119 '.

[Equation 2]

Number 2

[0033] Further, the levitation system model of Equation 1 has the following equation of state.

[Equation 3] Equation 3

i; = Ax + be _z + au _s

y = Cx

[0034] However, the state vector x, the system matrix A, the control matrix b, and the disturbance matrix d are expressed as follows. U is an external force.

[Equation 4]

[0035] Here, each parameter in Equation 4 is as follows.

[Equation 5]

Number 5

1 dF 1 dF _z Ν δφ

, '=, Α ,,, α ₃ , -― "-——,

²¹ m dz ² . m di _z L _z0 dz

^m

[0036] Each element of x in Equation 3 is a levitation state quantity, C is an output matrix, and is determined by a state quantity detection method used for calculating the excitation voltage e. In the magnetic levitation apparatus 1, the gap sensor 121 and the current sensor 123 are used, and when the speed is obtained by differentiating the signal of the gap sensor 121, C becomes a unit matrix. Where F is the proportional gain of X, K is the integral gain of A i, and the excitation voltage e is

[Equation 6]

Number 6

In this case, the levitated body 111 is levitated with zero power control.

[0037] Note that zero power control is disclosed in, for example, Patent Document 4, and therefore detailed description thereof is omitted here. Needless to say, the excitation voltage calculation unit 125 calculates the number 6 above.

[0038] In addition, the magnetic levitation apparatus 1 does not use the gap sensor 121, but as an estimation means for estimating the levitation gap length deviation Δz and its velocity d (Δz) Zdt from the excitation current A i. For example, consider the case where a same-dimensional state observer (hereinafter referred to as an observer) is applied. At this time, according to the linear control theory, the observer is expressed by the following equation.

[Equation 7] x = Ax + By + Ee

Given in. However,

[Equation 8]

Equation 8 is the estimated state vector of the observer, and α, α, and α are the parameters that determine the poles of the observer.

one two Three

Parameter

[Equation 9]

Number 9

Da = <: and C = [0 0 1].

In this case, the estimation error of the state observer of Equation 7 is the initial value at the start of operations of Equation 3 and Equation 7, respectively.

[Equation 10]

Number 1 0

and

[Equation 11] If Equation 1 is 1, then Number 12

x (t) -x (t) = e ^At (x _e -x ₀ ) At this time, in the excitation voltage calculation unit 125, for example,

[Equation 13]

Number 13

e ₂ = -FD ^T Dx-FC ^T y-\ K, M _Z At is calculated, and stabilization of the magnetic levitation system is achieved, where T is a transposed matrix and [Equation 14]

Number 14

D

0 1 0.

In general, the normal conducting magnetic levitation system is unstable, so if there is an error in the estimated value of the state observer, stability becomes very difficult. When the operation starts

[Equation 15] Equation 11 In other words, if the values of the flying gap length deviation Δζ, its speed dAz) / dt and the excitation current Δί are known, the initial value of the observer

[Equation 16]

Number 10

As much as possible

[Equation 17] Is set to be equal to, the estimated initial force error and the levitating gear from the excitation current Δί with little error

ζ

And the velocity d (Δz) / dt can be estimated.

[0042] Here, if the error at the initial estimation is large, an abnormal excitation voltage is calculated in Equation 9, so that the floating state cannot be stabilized.

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

[0044] (First embodiment)

FIG. 1 is a diagram showing the configuration of the magnetic levitation apparatus according to the first embodiment of the present invention, and the overall configuration thereof is indicated by 1 ′. In the magnetic levitation apparatus 1 ′, the gap sensor 121 is omitted. Instead, the floating body 111 and the contact detection unit 130 are provided in the vicinity of the floating body 111. The contact detection unit 130 detects that the floating body 111 has changed from the non-contact state to the contact state using, for example, the piezoelectric rubber 129.

In addition to the contact detection unit 130, the attractive force control unit 115 includes a posture estimation unit 133, a posture calculation unit 135, an estimation initialization unit 137, and an initial value setting unit 139. Attitude estimation unit 133 uses excitation current Ai force and levitation gap length deviation Δζ and its speed.

z d (A z) Zdt is estimated, and is composed of, for example, an observer. The posture calculation unit 135 calculates X that should be the initial value of the observer when shifting to the posture force floating state maintained by the auxiliary support unit 131. The estimation initialization unit 137 first calculates the output value of the observer by contact.

0

Return to the initial state. The initial value setting unit 139 sets X calculated by the attitude calculation unit 135 to the initialized observer.

Set 0 as the initial value.

[0046] Excitation current Δ i and levitation gap length deviation Δ z estimated by posture estimation unit 133

z

And the speed d (Δz) Zdt are input to the excitation voltage calculation unit 125, and the electromagnet 105 is excited via the driver 116 by the output of the excitation voltage calculation unit 125.

[0047] As described above, when the observer is initialized and given a predetermined initial value, the levitated body 111 floats from the stopped state, or the levitated state is brought into contact with the external force or other reasons. But exciting current Ai force levitation gap length deviation Δ ζ and its speed

ζ

d (A z) Zdt can be estimated with an initial error and error being suppressed. As a result, the levitated body 111 can be reliably transferred to the levitation state and maintained in the levitation state.

[0048] When a transient external force is continuously applied to the levitated body 111 that is in the levitating state while Because the attraction force is controlled to keep the floating state against the external force, the exciting current continuously flows through the coils 119 and 119 ′, and the temperature of the coils 119 and 119 ′ rises. Resistance R increases. Then, the parameter a in Equation 4 increases,

33

In the observer explained in Eq. 7, the parameter a remains as set. For this reason

33

A difference occurs between the actual magnetic levitation system and the observer, and the excitation current A i and the levitation gap z

The actual value and the estimated value of the long deviation Δz and its velocity d (Δz) Zdt will be different. In the normally unstable normally attracted magnetic levitation system, the difference between the actual value and the estimated value makes it very difficult to stabilize the levitation state by feed knock control.

Here, as in Patent Document 4, for example, the magnetic levitation device 1 ′ is provided with a resistance measurement unit 140 for measuring the resistance R of the coils 119 and 119 ′. The resistance measuring unit 140 measures the coil resistance R as follows.

[0050] The voltage equation when the excitation voltage e is applied to the coil is

z

[Equation 18] Number 1 5 e = Ri _{2 + N} ^ ₊ L _za ^

Since z ² dz dt, multiplying both sides by the coil current i gives the following power equation:

[Equation 19] Number 1 6

[0051] When R is measured as a measured value r at a certain time, the right side of Equation 16 has a residual represented by the following equation:

0

ε is generated.

[Equation 20]

Number 1 7 dz at

[0052] The residual ε is positive when the measured value r is larger than R, and negative when the measured value r is small. Measured value r as an appropriate residual gain

[Number 21]

Number 1 8

If the residual ε is positive, r is adjusted to be small, and if it is negative, r is adjusted to be large. Finally, the residual ε is zero, and r = R is satisfied. The value is equal to the true value. At this time, the change speed of the gap length z in Equation 11

[Numerical equation 22] The generated energy of the magnet unit due to z is included.

Even if Z changes, the residual ε is not affected by shaking. Substituting Equation 12 into Equation 13, and finally the measured value r can be calculated by the following equation.

[Number 24]

¾ 2 0.

L 20

Here, the calculation of number 20 is speed

[Equation 25]

Number 1 9

Ζ is required, but in this example, speed

[Equation 26] Number 1 9

z

There is no means to detect But speed

[Equation 27]

Number 1 9

Z

Is equal to the change speed of the levitation gap length deviation Δ z, so the estimated speed estimated by the posture estimation unit 133 is

[Equation 28] Number 2 1

Δ I

Equation 14 can be calculated using. Then, if appropriate noise removal processing such as a low-pass filter or average value calculation is applied to the input (coil current, estimated speed value, excitation voltage) and output of Equation 20, the value of the coil resistance R is increased. It can be measured with accuracy.

[0054] If the coil resistance value obtained in this way is output from the resistance measurement unit 140, introduced into the posture estimation unit 133, and the parameter a in Equation 7 is changed, Equation 4 increased due to temperature rise.

33

The value of parameter a in the value matches the value of parameter a in number 7. Therefore, the actual magnetic

33 33

There is no difference between the actual value and the estimated value of the excitation current Ai, the levitation gap z yap length deviation Δ z, and its velocity d (Δ z) Zdt where there is no structural difference between the levitating system and the observer. .

[0055] Furthermore, in the present invention, even if an excitation voltage increases due to the application of a transient external force or the like, and an offset voltage is generated in the driver 116 due to the increase, the generation of the offset voltage is an estimation of the floating gear length deviation. An estimation error correction unit 142 is provided so as not to cause an error in the values and speed estimation values.

This estimation error correction unit 142 adds a predetermined gain to the velocity estimation value of the posture estimation unit 133.

OS

Multiplier gain compensator 144, integrator 146 that integrates the output of gain compensator 144, and adder 148 that adds the output of integrator 146 and the excitation voltage value of excitation voltage calculator 125 . Then, the output of the adder 148 is output as an excitation voltage value introduced into the posture estimation unit 133. With such a configuration, even if the offset voltage changes due to temperature fluctuation, the influence on the estimated posture value can be minimized.

In contrast to this, in the present invention, as shown in FIG. 3, when measuring the coil resistance value, a target value is set in the excitation voltage calculator 125 so that the offset voltage does not affect the measured value. A part 150 and a coil current converging part 152 are provided. The target value setting unit 150 alternately sets the target value of the coil current to a zero or non-zero value at a predetermined time interval. The coil current converging unit 152 converges the coil current value, which is a sensor output, to the target value set by the target value setting unit 150. The resistance value measuring unit 140 includes a voltage storage unit 154, a voltage input compensation unit 156, and a resistance calculation unit 158.

The voltage storage unit 154 stores the excitation voltage value when the target value setting unit 150 sets the target value to zero. The voltage input compensation unit 156 subtracts the offset voltage value output from the voltage storage unit 154 from the excitation voltage value of the electromagnet 105 obtained based on the coil current value that is the sensor output as the excitation voltage compensation value. Output. The resistance calculation unit 158 measures the coil resistance R according to Equation 14 using the excitation voltage compensation value and the coil current value.

In such a configuration, every time the target value setting unit 150 outputs zero, the voltage storage unit 154 detects the DC component of the excitation voltage value during that time, and the target value setting unit 150 is not zero. Each time the output is changed to zero, the value of the DC component is output to the voltage input compensation unit 156. Therefore, the coil resistance value output from the resistance calculation unit 158 is calculated based on the latest value of the DC component every time the target value setting unit 150 changes the output from zero to a non-zero value. .

[0060] Generally, in a normal conducting attraction type magnetic levitation device, z is used to detect the exciting current i.

The current sensor 123 is used. Now, let us consider output offsets depending on the respective temperatures of the current sensor 123 and the driver 116. The former offset is the current offset i, and the latter zoff offset is the voltage offset e.

zoff

[0061] When the levitated body 111 is in the levitating state and zero is output from the target value setting unit 150, e is the excitation voltage value to the driver 116 and i is the detection current of the current sensor 123. For example, the following voltage equation holds.

[Equation 29]

Number 2 2

During this time, the voltage storage unit 154 receives a signal reporting that zero is output from the target value setting unit 150, extracts the DC component value of e, and outputs the previous extraction result. .

Here, the DC component value of e is extracted as follows.

In Equation 15, if the direct current component is e,

[Equation 30]

Number 2 3

So the number 22 is

[Equation 31]

Number 2 4;-Can be transformed to H.

[0063] When e is measured as a measurement value e at a certain time, a residual ε represented by the following equation is generated on the right side of Equation 24.

[Equation 32]

Number 2 5 Ten Ten ^ Ten

[0064] Since the residual ε is positive when it is larger than the measured value e force, and negative when it is small, the measured value e is set with λ as an appropriate residual gain.

[Equation 33] Number 2 6

=-When dt is newly defined, e force is reduced when the residual ε is positive, and e becomes large when the residual ε is negative.

dc ac

Finally, the residual ε becomes zero, and e = e holds, and the measured value is the true value.

dc DC

Is equal to At this time, the change speed of the gap length z in Equation 17

[Equation 34]

The generated energy of the magnet unit according to Equation 1 9 is included, and the speed [Equation 35]

Even if Equation 19 changes, the residual ε is not affected by the fluctuation. Substituting Eq. 25 into Eq. 26, the final measured value e can be calculated by the following equation.

dc

[Equation 36]

Number 2 7 dt-l L 20 * m0

Equation 27 uses the symbol of Equation 5,

[Equation 37]

Number—2 8

It can be expressed.

Here, the speed of the calculation of Equation 20 and Equation 21 is

[Equation 38] Number 1 9

z

In this example, speed is required.

[Equation 39]

Number 1 9

Z

There is no means to detect But speed

[Equation 40]

Number 1 9

Z

[Equation 41]

Number 2 1

Δ I

Equations 27 and 28 can be calculated using. Then, if appropriate noise removal processing such as a low-pass filter or average value calculation is applied to the input (coil current, estimated speed value, excitation voltage) and output of Equation 27, zero is output from the target value setting unit 150. The DC component e of the excitation voltage e when it is output can be measured with high accuracy. Figure 4 shows the configuration of the zz DC DC voltage storage unit 154 that calculates this DC component e.

The voltage storage unit 154 includes a multiplier 160 that multiplies the resistance value R input from the resistance calculation unit 158 and the current value i input from the current sensor 123, and a coil resistance unit mO output from the multiplier 160.

Subtraction mO zz unit 162 for subtracting the excitation voltage e introduced from the coil current converging unit 152 from the voltage drop Ri of the coil, and the velocity estimation value obtained from the posture estimation unit 133

[Number 42]

Number 2 1

Δ Gain gain compensator 164 that multiplies gain a / h and gain compensator 1 from the output of subtractor 162

32 31

Subtracter 166 that subtracts the calculation result of DC component e of 64 outputs and excitation voltage e, and subtraction zz dc

Integrator 168 that integrates the output of 166, and the current value i multiplied by gain lZb

Gain compensator 170 that outputs back electromotive force due to self-inductance, adder 172 that adds the outputs of gain compensator 170 and integrator 168, and the speed of convergence of DC component e to the output of adder 172 The gain compensator 174 that multiplies the convergence gain, the initial value setter 176 that outputs the initial value of the DC component e dc dc ac, the output of the gain compensator 174 and the output of the initial value setter 176 are added and the addition result And the subtractor dc

Adder 177 whose output result is introduced to 166, multiplier 178 that squares the current target value introduced from target value setting unit 150, and 1 is output only when the output of multiplier 178 rises from zero. Rising detector 180 to be selected, contact b is selected only when the output of the detector 180 is 1 and the output becomes 1, and in other cases, switch 182 that selects contact a is stored, and the output of switch 182 is stored. It consists of memory 184. Here, the output of the memory 184 is introduced into the contact point a of the switch 182, and the output of the adder 177 is introduced into the contact point b through the low-pass filter 186 for noise removal. With this configuration, the voltage storage unit 154 stores the DC component e at the moment when the output of the target setting unit shifts from zero to a non-zero value in the memory dc

Output from 184. As a result, the calculation of Equation 27 converges while the target setting unit 150 outputs zero, and the DC component e of the excitation voltage e is output to the voltage input compensation unit 156. Also mouth zz DC

The one-pass filter 186 may be inserted at the input end of the input signal.

Next, when the target value setting unit 150 outputs a non-zero value, the following voltage equation is established for the voltage signal e input to the driver 116.

z

[Equation 43]

Equation 2 9 e ^ _{! Off} = Ri _{! +} N ^ ₊ L _{! 0} ^-[0068] When the DC component e is subtracted from both sides of Equation 29,

DC

[Number 44] From the number 30 e ₂ + e _zoff -e _dc = Ri _: + N ^ Az + L _z0 ^ + R _2off + e _zoff

[Equation 45]

¾31 z » ^d

No Ί. _d t

[0069] When the target value setting unit 150 outputs a non-zero value, the voltage storage unit 154 holds the voltage value e extracted when the target value setting unit 150 outputs zero. Part 154

dc

While being stored, the value is output to the voltage input compensator 156 as an offset voltage. In the excitation voltage compensation unit 156, the output value e of the input voltage storage unit 154 and the driver

dc

Using the voltage signal e to 116, the compensation excitation voltage e is calculated according to the following equation.

z zm

[Equation 46]

Number 32

[0070] The number 31 uses e,

zm

[Equation 47]

Number 33

It can be expressed. Moreover, if the symbol of Equation 5 is used, the following equation is obtained.

[Number 48]

Number 34

[0071] i is a force that is an offset current of the current sensor, and its time derivative is zero,

zoff Where e is replaced with e and i is replaced with i + i, which corresponds to Equation 33. Current sensor 123 z zm zz zof

The detected value im including the offset of

[Number 49] Number 3 5

Therefore, the resistance calculation unit 158 uses the algorithm related to Equation 20 described above based on the compensation excitation voltage e output from the excitation voltage compensation unit 156 and the detection value i of the current sensor 123 to zm m

Coil resistance R is calculated. That is, the number 20

[Number 50]

Number 3 6

Hmm

If the coil resistance is calculated by Equation 36, the measurement result agrees with the coil resistance value R. Here, the speed of the calculation of Equation 36 is

[Equation 51]

Number 1 9

Z is required, but in this example the speed is

[Number 52]

Number 1 9

Z

There is no means to detect But speed

[Equation 53]

Number 1 9

Z

Is equal to the change speed of the levitation gap length deviation Δ z, so the estimated speed estimated by the posture estimation unit 133 is [Equation 54]

Number 2 1

Δ

Equation 36 can be calculated using. Then, if appropriate noise removal processing such as low-pass filter and average value calculation is applied to the input (coil current, speed estimation value, excitation voltage) and output of Equation 36, the value of coil resistance R is increased. It can be measured with accuracy. Figure 5 shows the configuration of the resistance calculation unit 158 that calculates the coil resistance R.

The resistance calculation unit 158 calculates the current value i input from the current sensor 123 and the coil resistance m

A multiplier 188 that multiplies the measured value r, which is the result, a subtracter 190 that subtracts the compensation voltage e of the voltage input compensation unit 156 from the output of the multiplier 188, and a velocity estimation value zm obtained from the attitude estimation unit 133

[Equation 55]

Number 2 1

Δ £

Gain compensator 192 that multiplies gain a / h and gain compensator 1 from the output of subtractor 190

32 31

Subtractor 194 that subtracts the output of 92, and multiplication m that multiplies the output of subtractor 194 by the current value i.

196, an integrator 198 that integrates the output of the multiplier 196, a gain compensator 200 that multiplies the current value i by the gain lZ (2b) m 31 and outputs the magnetic energy stored in the coil, and a gain compensator 200. And an adder 202 that adds the outputs of the integrator 198, a gain compensator 204 that multiplies the output of the adder 172 by a convergence gain related to the convergence speed of the measurement value r, and an initial value of the measurement value r. The output of the initial value setter 206 and the gain compensator 204 is added to the output of the initial value setter 206, and the result of the addition is used as the calculation result of the measured value r, and the output result is introduced into the multiplier 188. An adder 207 and a low-pass filter 208 that removes noise from the output of the adder 207 are configured. With such a configuration, the resistance calculation unit 158 performs the calculation based on Equation 36, and the measurement value r, which is the calculation result, converges to the true coil resistance value R. Then, the calculation result is output to the attitude estimation unit 133 and the coil current convergence unit 152 via the low-pass filter 208. It should be noted that the input signal may be introduced into the resistance calculation unit 158 via the low-pass filter 208. [0073] As described above, in the resistance calculation unit 158, when the value of the coil resistance connected to the driver 116 is measured by using the output value e of the voltage input compensation unit 156 as zm, the current offset i, zof, and voltage Even if the offset e fluctuates, the zoff

The measurement result can always match the true value. In other words, even if an offset voltage is generated in the current detection unit (current sensor 123) or the excitation unit (driver 116) due to temperature fluctuations, etc., it is always corrected using the compensation value of the excitation voltage according to the offset voltage. Resistance value can be measured. Also, before starting ascent, zero is output from the target value setting unit 150 and the DC component e

DC

If the target value setting unit 150 outputs zero, i is zero and the speed m0

Every time

[Number 56]

Number 1 9

z and speed estimate

[Equation 57]

Number 2 1

Δ i

Is also zero and depends on the DC component e

do not do. Thereafter, if a non-zero value is output from the target value setting unit 150, the coil resistance R can be measured with high accuracy even if the DC component e before the start of levitation is used. Then again the target value setting section

DC

Zero target value is output from 150, and measurement of DC component e of excitation voltage e starts zz DC

Force In that case, since the coil resistance value R has already been measured, the DC component e based on Equation 27 or Equation 29 is measured using the output of the resistance calculation unit 158 even after the start of levitation.

DC

Needless to say.

Furthermore, posture estimation section 133 can always output a correct gap length estimation value and speed estimation value based on the resistance value. As a result, it is possible to always maintain a stable floating state against temperature fluctuations and disturbance to the floating body 111.

In the present invention, the coil resistance R measured by the resistance measurement unit 140 is introduced into the excitation voltage calculation unit 125. In the excitation voltage calculator 125, a predetermined transient response to the disturbance For example, the feedback constant F in Equation 13 is determined so as to be obtained. When F is given as a function of the coil resistance R at the time of control system design, if the value of F is changed based on the coil resistance R, the transient response of the levitated body to the disturbance becomes constant with respect to the temperature fluctuation.

As described above, in the present invention, since the value of the feedback constant F is changed in the coil current converging unit 152 based on the coil resistance R measured by the resistance measuring unit 140, the floating body 11 The response of 1 is constant with respect to temperature fluctuation, and the stability of the floating state can be secured. Also, when measuring resistance, the speed of change of the floating gap length of the levitated body 111 is taken into consideration, and as a result, the reliability can be improved, the gap sensor is not required, the device can be simplified and the size can be reduced. Cost reduction can be realized.

[0077] (Second Embodiment)

Next, a second embodiment of the present invention will be described.

The second embodiment is characterized in that the excitation voltage and the excitation current are calculated for each mode of the levitating body motion coordinate system. Here, a case where the magnetic levitation apparatus of the present invention is applied to an elevator will be described as an example.

FIG. 6 is a diagram showing a configuration of a magnetic levitation apparatus according to the second embodiment of the present invention, and a configuration in a case where this magnetic levitation apparatus is applied to an elevator is indicated by reference numeral 10 as a whole.

. 7 is a perspective view showing the configuration of the frame portion of the magnetic levitation device, FIG. 8 is a perspective view showing the configuration around the magnet unit of the magnetic levitation device, and FIG. 9 is the configuration of the magnet unit of the magnetic levitation device. FIG.

As shown in FIG. 6, guide rails 14, 14, a moving body 16, and four guide units 18 a to 18 d are formed on the inner surface of the elevator shaft 12. The guide rails 14 and 14 are made of a ferromagnetic member and are laid in the elevator shaft 12 by a predetermined mounting method.

[0081] The moving body 16 corresponds to the floating body of the magnetic levitation apparatus described above. The moving body 16 moves up and down along the guide rails 14 and 14 'through a driving mechanism (not shown) such as a rope 15 lifting machine. The guide units 18a to 18d are attached to the moving body 16, and guide the moving body 16 to the guide rails 14, 14 'without contact. [0082] Car 20 and guide units 18a to 18d are attached to moving body 16. The moving body 16 includes a frame portion 22 having a strength capable of maintaining a predetermined positional relationship between the guide units 18a to 18d. As shown in FIG. 5, 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.

[0083] As shown in Fig. 8, the guide unit 18 includes a base 24 made of non-magnetic material (for example, aluminum or stainless steel) or plastic, an X-direction proximity sensor 26 (26b, 26b '), and a y-direction proximity sensor. 28 (28b, 28b ') and the magnet unit 30 are mounted by a predetermined method. Proximity sensors 26 and 28 function as contact detectors that detect contact between guide unit 18 and guide rails 14 and 14.

[0084] The magnet unit 30 is composed of a central iron core 32, permanent magnets 34 and 34 ', and electromagnets 36 and 36', and as shown in Fig. 9, the same polarity as the permanent magnets 34 and 34 '. They face each other through the central iron core 32! / As a whole, they are assembled into an E shape.

[0085] The electromagnets 36 and 36 are inserted into the coil 40 (40,) after the L-shaped iron core 38 (38,) is inserted into the iron core 38.

A flat core 42 is attached to the tip of (38 '). A solid lubricating member 43 is attached to the tip of the central iron core 32 and the electromagnets 36 and 36 ′. This solid lubricating member 43 prevents the magnet unit 30 from being attracted and fixed to the guide rail 14 (14 ') by the attractive force of the permanent magnets 34, 34' when the electromagnets 36, 36 'are not excited, and It is provided to prevent the moving body 16 from moving up and down even in the adsorbed state. As this solid lubricating member 43, for example, there is a material containing Teflon (registered trademark), graphite, disulfurium molybdenum or the like.

[0086] Hereinafter, for the sake of simplicity, the alphabets (a to d) of the guide units 18a to 18d are attached to the numbers indicating the main parts.

[0087] In the magnet unit 30b, the coils 40b and 40b 'can be individually excited to independently control the direction of the attractive force acting on the guide rail 14' and the X direction. Since details of this control method are described in Patent Document 1, detailed explanation is omitted here.

[0088] Each suction force of the guide units 18a to 18d is controlled by the control device 44 used as the suction force control unit described above, and the car 20 and the frame part 22 are not in contact with the guide rails 14, 14, and so on. Be guided to. [0089] It should be noted that the control device 44 can be configured as a single force as a whole as shown in FIG. 10, for example, as shown in FIG.

FIG. 10 is a block diagram showing a configuration in the control device in the same embodiment, and FIG. 11 is a block diagram showing a configuration of a mode control voltage arithmetic circuit in the control device. In the block diagram, an arrow line indicates a signal path, and a bar line indicates a power path around the coil 40.

The control device 44 includes a sensor unit 61, an arithmetic circuit 62, and power amplifiers 63a, 63a, to 63d, 6

3d, and these control the attraction force of the four magnet units 30a to 30d independently of the X and y axes.

The sensor unit 61 is attached to the car 20 and detects magnetomotive force or magnetic resistance in the magnetic circuit formed by the magnet units 30a to 30d, or changes in the movement of the moving body 16.

The arithmetic circuit 62 calculates an applied voltage for exciting the coils 40a, 40a, ˜40d, 40d ′ that guide the moving body 16 in a non-contact manner based on the signal from the sensor unit 61. Used as a suction force control unit. The power amplifiers 63a, 63a ′ to 63d, 63d ′ are used as excitation units for supplying power to the coils 40 based on the output of the arithmetic circuit 62.

[0094] Further, the power supply 46 supplies power to the power amplifiers 63a, 63a 'to 63d, 63d' and also supplies power to the constant voltage generator 48 at the same time. The power source 46 has a function of converting the alternating current supplied from the elevator shaft 12 external force by a power line (not shown) for lighting and door opening / closing to a direct current suitable for supplying power to the amplifier. .

[0095] Even if the voltage of the power supply 46 fluctuates due to the supply of a large current to the power amplifier 63, the constant voltage generator 48 always operates with the constant voltage 62 and the proximity sensors 26a, 26a 'to 26d, 26d. ', 28a, 28a' to 28d, 28d '[Supply power. Thus, the arithmetic circuit 62 and the proximity sensors 26a, 26a ′ to 26d, 26d ′, 28a, 28a ′ to 28d, and 28d ′ always operate normally.

[0096] The sensor unit 61 includes the proximity sensors 26a, 26a 'to 26d, 26d', 28a, 28a 'to 28d, 28d, and the current detectors 66a, 66a, to detect the excitation current of each coil 40. 66d, 66d '.

The arithmetic circuit 62 performs guidance control of the moving body 16 in each mode of the motion coordinate system shown in FIG. Is doing. Here, the above-mentioned modes are y mode (back and forth motion mode) representing the back and forth movement along the y coordinate of the center of gravity of the moving body 16, X mode (left and right motion mode) representing the left and right motion along the X coordinate, and movement. Θ mode (roll mode) representing rolling around the center of gravity of the body 16, mode representing pitching around the center of the moving body 16 (pitch mode), and Φ mode (yo mode) representing gyration around the center of gravity of the moving body 16 is there.

In addition to these modes, the arithmetic circuit 62 also performs guidance control for the ζ mode (full suction mode), δ mode (twist mode), and γ mode (distortion mode). In other words, the “total attractive force” exerted on the guide rails 14 and 14 ′ by the magnet units 30a to 30d, the “torsion torque” around the z-axis exerted on the frame portion 22 by the magnet boots 30a to 30d, and the magnet unit 30a. , 30d force S frame 咅 22 and magnet unit 30b, 30c force S frame 咅 22 three modes regarding `` distortion force '' which distorts frame part 22 symmetrically with respect to z axis by rotating 卜 nore It is.

[0099] For the above eight modes, the coil current of the magnet units 30a to 30d is converged to zero, so that the moving body can be stably supported only by the attractive force of the permanent magnet 34 regardless of the weight of the load. The guidance control is performed by so-called “zero power control”.

[0100] The arithmetic circuit 62 has a function of calculating an excitation current for each mode expressed by a linear combination of excitation currents that generate an attractive force that contributes to the freedom of movement of the moving body 16 that is a levitating body. It has a function to calculate the excitation voltage for each mode expressed by linear combination. Specifically, it is structured as follows.

That is, as shown in FIG. 10, the calculation circuit 62 includes a target value setting unit 74, a resistance measurement unit 64, a current deviation coordinate conversion circuit 83, a control voltage calculation circuit 84, and a control voltage coordinate reverse conversion. A circuit 85 and a speed estimated value coordinate inverse transform circuit 87 are included.

[0102] The target value setting unit 74 outputs zero or non-zero values alternately in a predetermined cycle as the excitation current target value of the ζ mode (all-suction mode) among the eight modes. In the mode and X mode, a predetermined value is output when the device is stopped as described later.

[0103] The resistance measuring unit 64 is configured to detect the excitation current detection values of the coils 40a, 40a 'to 40d, 40d' and the excitation voltage signals to the respective amplifiers 63a, 63a, to 63d, 63d of the calculation circuit 62. ea, ea, ˜ed, ed ′, the output value of the target value setting unit 74, and the output value of the speed estimated value coordinate inverse transformation circuit 87 Based on! /, The electrical resistance value of each coil is output.

[0104] The current deviation coordinate conversion circuit 83 has a current deviation signal Aia,

Δ ia, ~ Δ id, Δ id 'causes current deviation related to the movement of the center of gravity of the moving body 16 in the y direction Δ iy, electrical deviation related to the movement in the X direction Aix, current deviation related to rolling around the center of gravity Δίθ, A current deviation Ai ξ related to pitching of the moving body 16, a current deviation Δίφ related to the bowing around the same center of gravity, and a current deviation Δίζ, Δίδ, Δίγ relating to ζ, δ, γ applying stress to the frame portion 22 are calculated.

The control voltage calculation circuit 84 serves as a mode excitation voltage calculation unit, and outputs Aiy, Δίχ, Δίθ, Μξ, Μφ, and the output of the resistance measurement unit 64, the target value setting unit 74, and the current deviation coordinate conversion circuit 83, respectively. From Δίζ, Δίδ, Δίγ, y-, χ-, θ-, ξ-, φ-, ζ-, δ-, γ-mode electromagnet control voltages ey, ex, eΘ, e6 , βφ, e ζ, e δ, ey <S.

[0106] The control voltage coordinate inverse transformation circuit 85 is the output of the control voltage calculation circuit 84, ey, ex, eΘ, e6, eφ, eζ, eδ, and the respective magnet excitation voltages of the magnet units 30a to 30d. ea, ea 'to ed, ed' are calculated. The operation result of the control voltage coordinate inverse transformation circuit 85, that is, ea, ea 'to ed, ed', and a single amplifier 63a, 63a 'to 63d, 63d' is given.

[0107] Speed estimated value coordinate inverse transform circuit 87 is a mode-specific displacement speed estimated value calculated by control voltage calculation circuit 86 for each mode of y, x, 0, ξ, φ in control voltage calculation circuit 84.

[Equation 58]

Number 37

[Numerical 59]

Number 38

[Equation 60]

Number 39 [Number 61]

Number 4 0

[Numerical 62]

黎 4 1 厶 φ

From each of the magnet units 30a-30d, the estimated gap length displacement speed

[Equation 63]

Number 4 2

Δ ya ~ Δ yd,

[Equation 64]

Number 4 3

厶 Calculate xa ~ 厶 xd. The calculation result of the speed estimated value coordinate inverse transformation circuit 87, that is,

[Equation 65]

Number 4 2

Δ ya ~ Δ yd,

[Equation 66]

Number 4 3

Δ xa ~ 厶 xd is given to the resistance measuring unit 64.

The target value setting unit 74 may be configured by at least one target value setting unit 140 in the first embodiment. Further, when the target value setting unit 74 is configured by a plurality of target value setting units 140, it goes without saying that there is no phase shift in the period in which each output value becomes zero! /. [0109] In addition, the target power to supply a minute current for resistance measurement to all coils in the period in which a non-zero value is output. If the target value in at least one mode is a non-zero value, good target value setting is possible. It does not matter if there is a mode in which part 74 always outputs zero as the excitation current target value.

[0110] Here, in the present embodiment, the target value setting unit 74 is configured so that the ζ mode (all suction mode) becomes a non-zero value. In this case, the same excitation current is applied to all coils. Can be supplied. Since the suction force generated at that time acts as a stress on the frame part 22, the rider can feel comfortable against the change in the output value of the target value setting part 74 in which the posture of the moving body 16 does not change. There is no evil.

Note that the current deviation coordinate conversion circuit 83, the control voltage calculation circuit 84, and the control voltage coordinate reverse conversion circuit 85 in FIG.

[0112] Further, the control voltage calculation circuit 84 includes a forward / reverse motion mode control voltage calculation circuit 86a, a left / right movement mode control voltage calculation circuit 86b, a roll mode control voltage calculation circuit 86c, a pitch mode control voltage calculation circuit 86d, and a mode. The control voltage calculation circuit 86e, the all suction mode control voltage calculation circuit 88a, the torsion mode control voltage calculation circuit 88b, and the distortion mode control voltage calculation circuit 88c are configured.

[0113] The longitudinal motion mode control voltage calculation circuit 86a calculates the y-mode electromagnet control voltage ey from A iy. The left / right mode control voltage calculation circuit 86b calculates the X mode electromagnet control voltage ex from Aix. The roll mode control voltage calculation circuit 86c calculates the 0 mode electromagnet control voltage e Θ from A i 0. The pitch mode control voltage calculation circuit 86d calculates the ξ mode electromagnet control voltage e ξ from A i. The mode control voltage calculation circuit 86e calculates the φ-mode electromagnet control voltage e φ from A i φ.

[0114] The full suction mode control voltage calculation circuit 88a calculates the ζ-mode electromagnet control voltage e ζ from A i ζ. The torsion mode control voltage calculation circuit 88b calculates a δ mode electromagnet control voltage e δ from A i δ. The distortion mode control voltage calculation circuit 88c calculates the γ-mode electromagnet control voltage e γ from Δ ί γ.

[0115] The control voltage calculation circuit in these modes has the same configuration as the attractive force control unit 115 shown in Figs. That is, as shown in FIG. 11, the longitudinal movement mode control voltage calculation circuit 86a includes a resistance value averaging unit 90, a gain compensator 91, a resistance value imbalance correction unit 92, a subtractor 93, and an integral compensator. 94, an adder 95, a subtractor 96, an estimation error correction unit 142, a figure mode posture estimation unit 97, an estimation initialization unit 98, a posture calculation unit 99, an initial value setting unit 100, and an adder 101.

The resistance value averaging unit 90 calculates the average value of the resistance values of the coils 40a, 40a ′ to 40d, 40d ′ measured by the resistance measurement unit 64. The gain compensator 91 multiplies the estimated values of Δγ and Ay (indicated by “′” in the figure) and Δ iy by an appropriate feedback gain. The resistance value imbalance correction unit 92 is a linear combination of the coil resistance values based on the output of the resistance measurement unit 64 based on the excitation currents (Δ ix to Δ i γ) for each of the seven modes other than the forward / backward movement mode. Multiply the obtained resistance correction gains for each mode and output the sum of these seven multiplication results.

[0118] The subtracter 93 subtracts Aiy from the output of the target value setting unit 74. The integral compensator 94 integrates the output value of the subtractor 93 and multiplies it by an appropriate feedback gain. The adder 95 calculates the sum of the output values of the gain compensator 91. The subtractor 96 subtracts the output value of the adder 95 from the output value of the integral compensator 94 and outputs the first mode excitation voltage eyl in the y mode (forward / reverse operation mode).

[0119] The estimation error correction unit 142, as a mode estimation error correction unit, corrects the offset voltage component of the power amplifier 63 in the first mode-specific excitation voltage for each mode. As with the posture estimation unit 133, the mode posture estimation unit 97 calculates the estimated values of Ay, Δγ, and Δiy from the output value of the estimation error correction unit 142 and the current deviation Aiy for each mode.

[0120] The estimation initialization unit 98 initializes the integration operation in the mode posture estimation unit 97 based on ONZOFF of the 16 proximity sensor signals. The attitude calculation unit 99 calculates the attitude when the moving body 16 is in contact based on ONZOFF of the 16 proximity sensor signals, and outputs the position deviation of each magnet unit 30 by mode. The initial value setting unit 100 sets the calculation result of the posture calculation unit 99 as the initial value of the integration operation when the mode posture estimation unit 97 is initialized. The adder 101 adds the first mode-specific excitation voltage eyl and the output of the resistance value imbalance correction unit 92, and outputs the addition result as the second mode-specific excitation voltage ey.

[0121] Mode posture estimation unit 97, estimation initialization unit 98, posture calculation unit 99, and initial value setting Part 100 is disclosed in detail in Patent Document 4. Further, the estimated error correction unit 142 and the resistance value imbalance correction unit 92 are constituent elements that are preconditions for the characteristic configuration of the present invention, and are described in detail in the prior application of the applicant of the present application. Omitted.

[0122] Also, the left / right mode control voltage calculation circuit 86b, the roll mode control voltage calculation circuit 86c, the pitch mode control calculation circuit 86d, and the short mode control calculation circuit 86e are the same as the vertical mode control voltage calculation circuit 86a. The corresponding input / output signal is indicated by the signal name, and the description thereof is omitted.

On the other hand, each of the three mode control voltage calculation circuits 88a to 88c of ζ, δ, and γ has the same configuration, and has the same components as the vertical movement mode control voltage calculation circuit 86a. The same reference numerals are given to the parts, and “′” is added for distinction, and the configuration is shown in FIG. In this embodiment, the subtractors 93 and 93 ′, gain compensators 91 and 91 ′, integral compensators 94 and 94 ′, subtractors 96 and 96 ′, and the adder 95 shown in FIG. Forming.

Next, the operation of the magnetic levitation apparatus configured as described above will be described.

[0125] 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 through the solid lubricating member 43, and the tips of the electromagnets 36a 'and 36d' are It is adsorbed to the opposing surface of the guide rail 14 via the solid lubricating member 43. At this time, the moving of the moving body 16 is not hindered by the action of the solid lubricating member 43.

[0126] When this device is started in this state, the control device 44 causes each of the electromagnets 36a, 36a 'to generate a magnetic flux in the same direction as or opposite to the magnetic flux generated by the permanent magnet 34 by the action of the levitation control calculation unit 65. 36d, 36d, and the current flowing in each coil 40 for maintaining a predetermined gap length between the magnet units 30a-30d and the guide rails 14, 14 is controlled.

Accordingly, as shown in FIG. 9, from the path of the permanent magnet 34 to the iron core 38, 42 to the gap G to the guide rail 14 (14 ') to the gap G "to the central iron core 32 to the permanent magnet 34. The magnetic circuit Mc and the permanent magnet 34 'to the iron core 38, 42 to the gap G' to the guide rail 14 (14 ') to the gap G "to the central iron core 32 to the magnetic circuit Mc that also has the path force of the permanent magnet 34 are formed. Is done.

[0128] At this time, the gap length in the gaps G, G ', G "is determined by the magnetomotive force of the permanent magnet 34. The magnetic attraction force of the stone units 30a to 30d acts on the center of gravity of the moving body 16. The longitudinal force in the y-axis, the left-right force in the X-direction, the torque around the X-axis passing through the center of gravity of the moving body 16, and the torque around the same y-axis And the length is just the same as the torque around the z axis.

The control device 44 controls the excitation current of the electromagnets 36a, 36a, 36d, and 36d when an external force is applied to the moving body 16 in order to maintain this balance. As a result, so-called zero power control is performed. Now, when the moving body 16 that is being non-contact guided by zero power control starts to move up and down along the guide rails 14 and 14 'by an unillustrated lifting machine, it moves due to the distortion of the guide rails 14 and 14'. Assume that body 16 shakes. Even in such a case, the magnet units 30a to 30d have permanent magnets that share a magnetic path with the electromagnet in the air gap, so that the attraction force of the magnet units 30a to 30d can be quickly controlled by exciting the electromagnet coils. This can be suppressed.

[0130] Also, it is assumed that an excessive external force is applied to the moving body 16 due to uneven movement of personnel or cargo, or rope swaying caused by an earthquake or the like. In such a case, the temperature of the electromagnets of the magnet units 30a to 3Od rises, and the electric resistance of the electromagnet coil and the offset voltage of the power amplifier and current detector fluctuate. In particular, when zero power control that can extremely reduce power consumption is used, when a large excitation current flows with excessive external force, each electromagnet coil and power amplifier generate heat suddenly, and other control such as constant gap length control. The resistance value fluctuates more than in this control method. If this happens, the error between the gap length estimation value and the speed estimation value increases in each motion mode, and the ride quality is extremely deteriorated.

[0131] However, according to the present invention, the offset voltage of the power amplifier and the current detector is accurately calculated by Equation 28 by the action of the target value setting unit 74 and the resistance measurement unit 64, and Based on 36, the resistance of the coil 40 is accurately measured in consideration of the fluctuation of the moving body 16.

Accordingly, the parameters of the mode posture estimation unit 97 and the resistance value imbalance correction units 92 and 92 ′ adjusted by the output value of the resistance measurement unit 64 are accurately adjusted, and the gain compensators 91 and 91 are integrated. The gain can be set with the compensators 94 and 94 using the resistance value as a parameter. Therefore, if the stability of the non-contact guidance is maintained with respect to the fluctuation of the offset voltage and the coil resistance value, it is possible to maintain a good and always constant riding comfort without force. [0133] In addition, an estimation error occurs in the displacement for each mode and the displacement speed for each mode with respect to fluctuations in the offset voltage of the power amplifier, but these errors are also zero by the operation of the estimation error correction unit 142. However, since the speed at which the estimated value of the mode posture estimation unit 97 converges to the true value depends on the accuracy of the coil resistance measurement value, the resistance measurement unit 67 performs accurate resistance measurement taking the offset voltage into account. As a result, the estimated value of the mode posture estimation unit 97 quickly converges to the true value. In addition, since the estimated error correction unit 142 does not cause an error in the estimated value of the mode-specific displacement speed, it is possible to perform an accurate calculation in Equations 28 and 36.

[0134] When the apparatus stops operation and stops, the target value setting unit 74 gradually sets the target values in the y mode and the X mode to negative values from zero force. As a result, the moving body 16 gradually moves in the y-axis and X-axis directions, and finally the electromagnet is formed on the opposite surface of the guide rail 14 via the tip 1S solid lubricating member 43 of the central core 32 of the magnet units 30a and 30d. The tips of 36a 'and 36d' are adsorbed to the opposing surface of the guide rail 14 through the solid lubricating member 43, respectively. When the apparatus is stopped in this state, the output of the target value setting unit 74 is reset to zero and the moving body 16 is attracted to the guide rail.

[0135] (Third embodiment)

Next, a third embodiment of the present invention will be described.

[0136] In the first and second embodiments, the magnet unit is mounted on the floating body side, but this does not limit the mounting position of the magnet unit at all. As shown in FIG. It may be arranged on the side. For simplification of description, the same reference numerals are used for portions common to the first and second embodiments.

FIG. 13 is a diagram showing the configuration of the magnetic levitation apparatus according to the third embodiment of the present invention. The overall configuration is indicated by reference numeral 300.

[0138] The magnetic levitation apparatus 300 includes an auxiliary support 302, a magnet unit 107, a guide 304, a vibration isolation table 306, a linear guide 308, an attractive force controller 115, a power amplifier 313, and a current sensor 1.

Has 23.

[0139] The auxiliary support portion 302 has a U-shaped cross section, and is formed of a non-magnetic material such as an aluminum member. The auxiliary support 302 is installed on the ground, and the magnet unit 107 is an auxiliary. The support portion 302 is attached to the lower surface of the upper portion downward. The guide 304 has a U-shaped cross section facing the magnet unit 107, and is formed of a ferromagnetic member such as iron. The anti-vibration table 306 includes the guide 304 on the upper surface of the bottom, and is formed in a U shape as a whole. The linear guide 308 is attached to the side surface of the vibration isolation table 306 and gives the vibration isolation table 306 freedom of movement only in the direction perpendicular to the ground.

[0140] The attraction force control unit 115 controls the attraction force of the magnet unit 107 to support the vibration isolation table 306 in a non-contact manner. The power amplifier 313 is connected to a power source (not shown) for exciting the magnet unit 107 based on the output of the attractive force control unit 115. The current sensor 123 detects the excitation current of the magnet unit 107.

[0141] Here, the suction force control unit 115 has the following configuration. That is, the attractive force control unit 115 includes a resistance measurement unit 140, a contact detection unit 130, an attitude calculation unit 135, an attitude estimation unit 133, an initial value setting unit 139, an estimation initialization unit 137, and an excitation voltage calculation unit 125. Yes.

[0142] The resistance measurement unit 140 measures the series resistance value of the lead wire 128 and the coils 119 and 119 'from the excitation current and excitation voltage to the magnet unit 107. The contact detection unit 130 includes a micro switch 310 attached to the bottom upper surface of the auxiliary support unit 302 and a piezoelectric rubber 312 attached to the magnetic pole surface of the magnet unit 107.

The posture calculation unit 135 calculates the floating gap length when the contact detection signal force of the contact detection unit 130 is in contact with the auxiliary support 302 or the magnet unit 107 of the vibration isolation table 306. The posture estimation unit 133 estimates the flying posture of the vibration isolation table 306 based on the output of the resistance measurement unit 130, the excitation current to the magnet unit 107, and the excitation voltage force.

The initial value setting unit 139 sets an estimated initial value in the posture estimation unit 133 based on the output of the posture calculation unit 135. The estimation initialization unit 137 initializes the posture estimation unit 133 based on the output of the contact detection unit 130. The excitation voltage calculation unit 125 calculates the excitation voltage to the magnet unit 107 for magnetically levitating the vibration isolation table 306 based on the output of the posture estimation unit 133.

[0145] According to such a configuration, since the magnet unit 107 is arranged on the ground side, there is no longer any wiring from the anti-vibration table 306, which is a movable part, and there is an advantage that the reliability of the apparatus is improved. . [0146] (Fourth embodiment)

Next, a fourth embodiment will be described. In the first to third embodiments, the case where the present invention is applied to a sensorless magnetic levitation apparatus that does not require a gap sensor has been described. However, the present invention is not limited to application to a sensorless magnetic levitation device, but may be applied to an attraction type magnetic levitation device using a gap sensor as shown in FIG. In order to simplify the description, the same reference numerals are used for the portions common to the first to third embodiments.

FIG. 12 is a diagram showing the configuration of the magnetic levitation apparatus according to the fourth embodiment, and the overall configuration is denoted by reference numeral 400. In the magnetic levitation apparatus 400 in the fourth embodiment, the gap sensor 121 and the pseudo-differential information that the information on the levitation gap length and the velocity used for the stability of the magnetic levitation system are not included in the attitude estimation unit 133 of the first embodiment. Acquire using vessel 40 2. The output of the gap sensor 121 is directly input to the excitation voltage calculation unit 125 as information on the flying gap length, is converted into a speed signal via the pseudo-differentiator 402, and is input to the excitation voltage calculation unit 125. Further, the excitation current of the coils 119 and 119 ′ is input to the excitation voltage calculation unit 125 by the current sensor 123.

Here, due to the functions of the target value setting unit 150 and the resistance measurement unit 140 in the excitation voltage calculation unit 125, the oscillating body 111 and the power amplifier of the levitation body 111 are also similar to the first embodiment in this embodiment. The coil resistance value is measured in consideration of the offset voltage of 313 and the current sensor 123. Then, in the coil current converging unit 125, based on the coil resistance value! Thus, the excitation voltage for levitating the levitated body 111 with a stable and constant transient response is calculated. According to such a configuration, it is possible to always maintain a stable floating state against temperature fluctuations with a simple control device.

In each of the above embodiments, the control device (attraction force control unit 115) that performs magnetic levitation is described as an analog configuration, but the present invention is limited to an analog control system. It is also possible to configure with digital control. In addition, the power using the power amplifier as the configuration of the excitation part. This does not limit the driver method, and for example, a pulse width modulation (PWM) type can be used. . In addition, various modifications can be made without departing from the scope of the present invention. In short, the present invention is not limited to the above-described embodiments as they are, but can be specifically modified by modifying constituent elements without departing from the scope of the invention. Moreover, various forms can be formed by appropriately combining a plurality of constituent elements disclosed in the respective embodiments. For example, some constituent elements such as all the constituent elements shown in the embodiment may be omitted. Furthermore, constituent elements over different embodiments may be appropriately combined.

Claims

The scope of the claims

[1] a guide composed of a ferromagnetic member;

A magnet unit composed of an electromagnet opposed to the guide through a gap, and a floating body supported in a non-contact manner by the attractive force of the magnet unit acting on the guide;

A sensor unit for detecting a current value flowing in the coil of the electromagnet;

An excitation voltage calculation unit for calculating an excitation voltage value for stabilizing a magnetic circuit formed by the magnet unit based on a coil current value obtained by the sensor unit; and a speed detection for detecting a variation rate of the displacement of the air gap. And

The coil resistance value of the electromagnet is calculated based on the excitation voltage value obtained by the excitation voltage calculation unit, the coil current value obtained by the sensor unit, and the fluctuation speed obtained by the speed detection unit. A resistance measurement unit to

A control unit that feeds back the coil resistance value obtained by the resistance measurement unit to the excitation voltage calculation unit to control the floating of the floating body;

A magnetic levitation apparatus comprising:

[2] A magnet unit including a permanent magnet that shares a magnetic path with the electromagnet in the gap, and a target value setting unit that alternately sets a target value of the coil current of the electromagnet to a zero value or a non-zero value. ,

A coil current converging unit for converging the coil current of the electromagnet to the target value set by the target value setting unit;

An excitation voltage calculation for calculating an excitation voltage value for stabilizing the magnetic circuit formed by the magnet unit based on the coil current value obtained by the sensor unit in accordance with the convergence operation by the coil current convergence unit. And

When the target value is set to a zero value, the excitation voltage value obtained by the excitation voltage calculation unit, the coil current value obtained by the sensor unit, the fluctuation speed obtained by the speed detection unit An offset calculation unit for calculating a DC component of the excitation voltage value based on

A voltage storage unit for storing a calculation result of the offset calculation unit; An excitation voltage compensation unit for obtaining a compensation value of the excitation voltage value by subtracting the excitation voltage value stored in the voltage storage unit as an offset voltage value from the excitation voltage value of the electromagnet;

The magnetic levitation apparatus according to claim 1, further comprising:

[3] The apparatus further comprises an attitude estimation unit that estimates an attitude of the levitating body with respect to the ferromagnetic member and an attitude change speed based on at least the coil current value and the excitation voltage value, and the speed detection unit includes the attitude 2. The magnetic levitation apparatus according to claim 1, wherein the fluctuation speed is calculated based on the posture change speed estimated by the estimation unit.

[4] An auxiliary support portion that maintains a positional relationship between the floating body and the guide in a predetermined state when the floating body is not in a floating state;

A contact detection unit that detects contact between the floating body and the guide;

A posture calculation unit that outputs the posture of the floating body with respect to the guide at the time of contact based on the output of the contact detection unit;

An estimation initialization unit that initializes the posture estimation unit at the time of contact based on the output of the contact detection unit;

An initial value setting unit that sets an output value of the posture calculation unit as an initial value of the posture estimation unit when the posture estimation unit is initialized;

The magnetic levitation apparatus according to claim 3, further comprising:

[5] The estimated value of attitude change speed obtained by the attitude estimation unit is multiplied by a predetermined gain and integrated, and the integration result is added to the excitation voltage value, and the addition result is used as a new excitation voltage value. 4. The magnetic levitation apparatus according to claim 3, further comprising an estimation error correction unit that feeds back to the posture estimation unit.

[6] A mode excitation voltage calculation unit that calculates an excitation voltage for generating a suction force that contributes to the degree of freedom of movement of the levitating body for each predetermined mode;

A mode excitation current calculation unit that calculates an excitation current for generating a suction force that contributes to the degree of freedom of movement of the levitation body for each predetermined mode;

The posture estimation unit is configured to determine the posture of the levitating body with respect to the ferromagnetic member and the contact based on at least the outputs of the mode excitation current calculation unit and the mode excitation voltage calculation unit. 4. The magnetic levitation apparatus according to claim 3, wherein the time change of the posture is estimated for each degree of freedom of movement of the levitating body.

[7] The estimated value of attitude change speed obtained by the attitude estimation unit is multiplied by a predetermined gain and integrated, and the integration result is added to the excitation voltage value for each mode, and the addition result for each new mode is added. 7. The magnetic levitation apparatus according to claim 6, further comprising a mode estimation error correction unit that feeds back to the posture estimation unit as an excitation voltage value.

8. The resistance measuring unit includes an integrator that integrates a power calculation result obtained by multiplying at least a linear combination of the excitation voltage value and the coil current value by the coil current. The magnetic levitation device as described.