JP3871570B2 - Magnetic levitation device - Google Patents

Description

式（１）中、mは浮上体１１の質量、zは浮上ギャップ長、i_zは電磁石５の励磁電流、φは磁石ユニット７の主磁束、e_zは電磁石５の励磁電圧、Δは定常浮上状態（z = z₀, i_z = i_z0）からの偏差、記号“・”は d/dt、偏微分∂/∂h (h=z,i)は定常浮上状態（z = z₀, i_z = i_z0）における被偏微分関数のそれぞれの偏微分値、L_z0 は、
【数２】

となる。式（３）中、xの各要素が浮上系の状態量であり、Cは出力行列であり、e_zの計算に用いる状態量の検出方法により決定される。磁気浮上装置１ではギャップセンサ２１と電流センサ２３を使用しており、ギャップセンサ２１の信号を微分することにより速度を得る場合には、Cは単位行列となる。ここで、Fをxの比例ゲイン補償器、K_iを積分ゲインとして励磁電圧e_zを例えば、
【数３】

で与えれば、磁気浮上装置１は特公平０６−２４４０５号公報に見られるゼロパワー制御で浮上する。ここで、励磁電圧演算部２５において式（６）が演算されることは言うまでもない。
【００３１】
式（１）の磁気浮上装置１においてギャップセンサ１５を使用せずに、励磁電流Δi_zから浮上ギャップ長偏差Δzおよびその速度d(Δz)/dtを推定するための推定手段として、例えば同一次元状態観測器（以下オブザーバという）を適用する場合を考える。このとき、線型制御理論によれば、オブザーバは
【数４】

【００３２】
したがって、図２に示す本発明に係わる磁気浮上装置１’にあってはギャップセンサ２１が省略され、その代わりに浮上体１１およびその近傍に非接触状態から接触状態になったことを例えば圧電ゴム２８により検出する接触検出手段２９、および接触時の浮上体の姿勢を維持する補助支持手段３１が備えられている。また、励磁電圧演算部２５には励磁電流Δi_zから浮上ギャップ長偏差Δzおよびその速度d(Δz)/dtを推定する、例えばオブザーバで構成される姿勢推定手段３３と、補助支持手段３１で維持された姿勢から浮上状態へ移行する場合のオブザーバの初期値となるべきx₀を演算する姿勢演算手段３５と、接触によりオブザーバの出力値を初期状態に戻すための推定初期化手段３７と、初期化されたオブザーバに姿勢演算手段で計算されたx₀を初期値として設定するための初期値設定手段３９とが備えられている。そして、推定された励磁電流Δi_z、浮上ギャップ長偏差Δz、およびその速度d(Δz)/dtが励磁電圧演算部２５に入力され、ドライバ２７を介して電磁石５が励磁される。このように、オブザーバを初期化するとともに所定の初期値を与えてやることにより、停止状態から浮上する場合や、外力その他の理由によりに浮上状態から接触状態になった場合でも、励磁電流Δi_zから浮上ギャップ長偏差Δzおよびその速度d(Δz)/dtを推定当初から誤差を抑えて推定することができ、浮上体１１を確実に浮上状態へ移行するとともにその浮上状態を維持することができる。
【００３３】
以下、本発明の実施の形態を図に基づいて詳細に説明する。
【００３４】
＜第１の実施の形態＞
図３ないし図７は第１の実施の形態による磁気浮上装置の主要部を示しものである。
【００３５】
図３に示すように、この磁気浮上装置４０は、建物の天井を構成する天板４２の下面に所定の取付方法で取付けられた強磁性部材からなるガイドレール４４とこのガイドレール４４を天板４２に取付けることにより生じた凹凸を天板４２の所定の範囲において平面に修正する非磁性体からなる平面補正部材４５とで構成される上部支持部材４６と、床４８に所定形状の溝５０を掘って構成される下部支持部材５２と、上部支持部材４６および下部支持部材５２の間に介在し、両者間の間隔によって幾何学的に転倒することが妨げられている仕切体５４とを備えている。ガイドレール４４にはその下面所定位置に穿たれ断面が逆Ｕ字形状で仕切体５４の上部を案内するための上部ガイド溝５６が形成されている。
【００３６】
仕切体５４は、仕切体５４に取付けられ、仕切体５４をガイドレール４４に対して非接触で支持する２つの磁石ユニット６０ａ，６０ｂと、仕切体５４を非接触で支持するために磁石ユニット６０ａ，６０ｂの吸引力を制御する吸引力制御手段としての制御装置７０と、磁石ユニット６０ａ，６０ｂおよび制御装置７０に必要な電力を供給する電源装置７２と、磁石ユニット６０ａ，６０ｂが台板６２を介して取付けられているフレーム部８０と、フレーム部８０にはめ込まれ、たとえばガラスやアルミ、木材、紙等で構成された仕切板８２とで構成されている。
【００３７】
磁石ユニット６０ａ，６０ｂは永久磁石６４と電磁石６６，６６’とで構成され、電磁石６６，６６’の先端がガイドレール４４の下面と対向するように全体としてＵ字形状に組み立てられている。電磁石６６，６６’は角柱状の鉄心６８（６８'）をコイル６９（６９'）に挿入して構成され、コイル６９，６９’は励磁時の際に互いの磁束を強め合うように直列に結線されている。電磁石６６，６６’の先端部には、これらが励磁されていない時に永久磁石６４の吸引力で磁石ユニット６０ａ，６０ｂ’がガイドレール４４に吸着して固着することを防止し、かつ吸着状態でも仕切体５４の移動に支障が出ないように固体潤滑部材で表面処理した圧電ゴム７３ａ，７３ｂが取付けられている。ここで圧電ゴム７３ａ，７３ｂは磁石ユニット６０ａ，６０ｂのそれぞれのガイドレール４４への接触時に吸引力により電気抵抗がゼロに近くなる性質を有しており、仕切体５４の接触状態を検出するのに好適なものである。
【００３８】
フレーム部８０は、断面が逆Ｕ字形状でその上部に取付けられた固定台８３と、この固定台８３に固着された支持棒８４と、この支持棒８４の先端部に回転可能に取付けられ上部ガイド溝５６に嵌入して仕切体５４の上部をガイドレール４４に沿って案内する案内シュー８６と、溝５０に嵌入し仕切体５４の下部を溝５０に沿って案内する２つの案内車輪８８，８８’と、仕切体５４が壁面に沿って移動する際に挟まれ事故を防止するために柔軟な材料たとえば軟質ゴム等で構成されるガード部材８９と、断面がＵ字形状でその凹部で左右から仕切板８２を挟み込むための側面フレーム９１と、左右の側面フレーム９１の下側端面に所定の方法で固定され下面両端所定位置に案内車輪８８，８８’の車軸９３を有する底面フレーム９５と、硬質の圧電ゴムで構成され底面フレーム９５の下面に貼付られ磁石ユニット６０の吸引力喪失時等の場合に底面フレーム９５が直接床４８の上面に当たるのを防ぐとともに浮上体としての仕切体５４の接触を検出する緩衝部材９７と、上部基台１０１、下部基台１０３および側板１０４で箱状に構成されその内部にそれぞれ２分割された制御装置７０および電源装置７２を備えるとともに上部基台１０１上面に磁石ユニット６０が取付けられ下部基台１０３下面に左右の側面フレーム９１の上側端面が所定の方法で固定された上部フレーム１０５とで構成されている。上部フレーム１０５の上部には側面に沿って磁石ユニット６０ａ，６０ｂを視界から遮るカバー１０７が取付けられており、磁気浮上装置１０のデザイン性を高めている。
【００３９】
磁石ユニット６０ａ，６０ｂの各吸引力は制御装置７０により制御され、仕切体５４がガイドレール４４に対して非接触に支持される。
【００４０】
制御装置７０は図５および図６に示すように構造的に分割型に構成されてはいるが、たとえば図８に示すように、機能的には全体として１つに構成されている。なお、図８以下のブロック図において、矢印線は信号経路を、また棒線はコイル４０周辺の電力経路を示している。さらに、磁石ユニット６０ａにおいて２つの直列に接続されたコイル６９，６９’をまとめてコイル６９ａと表し、同様に磁石ユニット６０ｂの２つのコイル６９，６９’をコイル６９ｂと表すことにする。
【００４１】
制御装置７０はフレーム部８０に取付けられて磁石ユニット６０ａ，６０ｂの励磁電流を検出するセンサ部１１１と、磁石ユニット６０ａ，６０ｂに仕切体５４を非接触支持させるべく各コイル６９ａ，６９ｂへの印加電圧をセンサ部１１１からの信号に基づいて演算する演算回路１１２と、演算回路１１２の出力に基づいて各コイル６９ａ，６９ｂに励磁電流を供給するパワーアンプ（電力増幅器）１１３ａ,１１３ｂとで構成されており、これらで２つの磁石ユニット６０ａ，６０ｂの吸引力をz軸方向およびy軸周りについて独立に制御する。なお、パワーアンプ１１３ａ,１１３ｂは冷却のため上部基台１０１上面に取付けられた冷却フィン１１４に装着されている。
【００４２】
電源装置７２はパワーアンプ１１３ａ,１１３ｂに電力を供給するとともに、演算回路１１２に一定電圧で電力を供給する定電圧装置１１８にも電力を供給している。この電源装置７２はパワーアンプ１１３ａ，１１３ｂに電力を供給するため、図示していない電源線を介して仕切体５４の外部から供給される交流電力をパワーアンプへの電力供給に適した直流に変換する機能を有している。定電圧装置１１８は、パワーアンプ１１３への大電流の供給などにより電源装置７２の電圧が変動しても常に一定の電圧で演算回路１１２に電力を供給する。このため、演算回路１１２は常に正常に動作する。
【００４３】
センサ部１１１は各コイル６９ａ，６９ｂの電流値を検出する電流検出器１２１ａ，１２１ｂで構成されている。
【００４４】
演算回路１１２は、図３に示される運動座標系ごとに仕切体５４の磁気浮上制御を行う。すなわち、仕切体５４の重心のz座標に沿った上下動を表すzモード（上下動モード）、仕切体５４の重心回りのピッチングを表すξモード（ピッチモード）の制御を行う。この２つのモードに対し、前述の発明の原理に基づいて磁石ユニット６０ａ，６０ｂのコイル励磁電流が検出され、磁気浮上制御が行われる。
【００４５】
より詳細には、演算回路１１２は次のように構成されている。電流検出器１２１ａ，１２１ｂからの励磁電流検出信号i_a，i_bからそれぞれの電流設定値i_a0，i_b0を減算して得られる電流偏差信号Δi_a, Δi_bを演算する減算器１２３ａ，１２３ｂと、z方向の運動に関わる電流偏差Δi_z、同重心周りのピッチングに関わる電流偏差Δi_ξを演算するモード励磁電流演算部としての励磁電流偏差座標変換回路１２５と、励磁電流偏差座標変換回路１２５の出力Δi_z, Δi_ξからz, ξの各モードにおいて仕切体５４の重心の所定位置からの上下偏差Δzおよびその速度d(Δz)/dtを推定する上下動モード姿勢推定手段１２７ａ、仕切体５４のピッチ偏差Δξおよびその速度d(Δξ)/dtを推定するピッチモード姿勢推定手段１２７ｂ、圧電ゴム７３ａ，７３ｂおよび緩衝部材９７の電気抵抗値から仕切体５４の上部支持部材４６または下部支持部材５２への接触を検出する接触検出手段１２９、接触検出手段１２９からの接触信号に基づいて接触時の仕切体５４の姿勢からzモードにおける上下偏差Δz₀を計算する姿勢演算手段１３１ａと、同ξモードにおけるピッチ偏差Δξ₀を計算する姿勢演算手段１３１ｂと、姿勢演算手段１３１ａの出力Δz₀を姿勢推定の初期値として上下動モード姿勢推定手段１２７ａに与える上下動モード初期値設定手段１３３ａと、姿勢演算手段１３１ｂの出力Δξ₀を姿勢推定の初期値としてピッチモード姿勢推定手段１２７ｂに与える初期値設定手段１３３ｂと、接触直前までの上下動モード姿勢推定手段１２７ａが推定していた上下偏差Δz、その速度d(Δz)/dtおよび励磁電流偏差Δi_zの推定値をリセットする上下動モード推定初期化手段１３５ａと、接触直前までのピッチモード姿勢推定手段１２７ｂが推定していたピッチ偏差Δξ、その速度d(Δξ)/dtおよび励磁電流偏差Δi_ξの推定値をリセットするピッチモード推定初期化手段１３５ｂと、仕切体５４を安定に磁気浮上させるモード別電磁石制御電圧e_z, e_ξをそれぞれ上下動モード姿勢推定手段１２７ａおよびピッチモード姿勢推定手段１２７ｂの出力に基づいて演算する励磁電圧演算部１３６としての上下動モード制御電圧演算回路１３７ａおよび同ピッチモード制御電圧演算回路１３７ｂと、各モードの制御電圧演算回路１３７ａ、１３７ｂの出力e_z, e_ξから磁石ユニット６０ａ，６０ｂのそれぞれの電磁石励磁電圧e_a, e_bを演算する励磁電圧演算部１３６としての制御電圧座標逆変換回路１３９とで構成されている。そして、制御電圧座標逆変換回路１３９の演算結果、つまり上述した電圧e_a, e_bがパワーアンプ１１３ａ，１１３ｂに与えられる。
【００４６】
ここで、仕切体５４の接触時において上部支持部材４６と下部支持部材５２で仕切体５４の姿勢が維持されるので、本実施の形態においては上部支持部材４６と下部支持部材５２が補助支持手段を構成する。
【００４７】
仕切体５４の接触時の姿勢には、
▲１▼ 磁石ユニット６０ａ，６０ｂが圧電ゴム７３ａ，７３ｂを介して上部支持部材４６に接触している姿勢（磁石ユニット６０ａのギャップ長がz_a1、磁石ユニット６０ｂのギャップ長がz_b1）
▲２▼ 底面フレーム９５が緩衝部材９７を介して下部支持部材５２に接触している姿勢（磁石ユニット６０ａのギャップ長がz_a2、磁石ユニット６０ｂのギャップ長がz_b2）、
▲３▼ 磁石ユニット６０ａが圧電ゴム７３ａを介して上部支持部材４６に接触するとともに底面フレーム９５が緩衝部材９７を介して下部支持部材５２に接触している姿勢（磁石ユニット６０ａのギャップ長がz_a3、磁石ユニット６０ｂのギャップ長がz_b3）、
▲４▼ 磁石ユニット６０ｂが圧電ゴム７３ｂを介して上部支持部材４６に接触するとともに底面フレーム９５が緩衝部材９７を介して下部支持部材５２に接触している姿勢（磁石ユニット６０ａのギャップ長がz_a4、磁石ユニット６０ｂのギャップ長がz_b4）
の４つのパターンが存在する。接触検出手段１２９はこれらの接触姿勢パターンに対応して例えば、パターン信号「６」、「１」、「５」、「３」を出力する。これ以外のパターンは浮上状態とみなすことにより接触検出手段１２９はパターン信号「０」を出力する。
【００４８】
上下動モード姿勢演算手段１３１ａでは接触検出手段１２９の出力に応じて、
【数５】

が計算される。つまり、接触検出手段１２９の出力が６の場合にはz_aにz_a1が代入され、z_bにz_b1が代入される。ここで、z₀は所定の浮上状態にあるときの磁石ユニット６０ａ，６０ｂの浮上ギャップ長の平均値である。接触検出手段１２９の出力がパターン信号「１」の場合には、z_aにz_a2が、z_bにz_b2が代入され、信号「５」の場合にはz_aにz_a3が、z_bにz_b3が代入される。そして、接触検出手段１２９の出力がパターン信号「３」の場合にはz_aにz_a4が、z_bにz_b4が代入されて接触検出手段１２９の出力に基づいた接触時の上下偏差Δz₀が計算される。同様にして、ピッチモード姿勢演算手段１３１ｂでは、l_ξを磁石ユニット６０ａ，６０ｂの中心間距離として
【数６】

により接触検出手段１２９の出力に基づいて接触時のピッチ偏差Δξ₀が計算される。
【００４９】
上下動モード姿勢推定手段１２７ａは上下動モード初期値設定手段１３３ａおよび上下動モード推定初期化手段１３５ａとともに図９に示すように構成されている。すなわち、上下モードにおけるオブザーバを実現するために、上下動モード姿勢推定手段１２７ａは励磁電流偏差座標変換回路１２５の出力Δi_zを入力とするゲイン補償器１４１，１４３，１４５と、積分器１４７，１４９，１５１と、積分器１４７の出力を入力するゲイン補償器１５３と、積分器１４９の出力を入力するゲイン補償器１５５，１５７と、積分器１５１の出力を入力するゲイン補償器１５９，１６１，１６３と、上下動モード制御電圧演算回路１３７ａの出力e_zを入力とするゲイン補償器１６５と、ゲイン補償器１４１，１５５，１５９の出力を加算して積分器１４７への入力を出力する加算器１６７と、ゲイン補償器１４３，１５３，１６１の出力を加算して積分器１４９への入力を出力する加算器１６９と、ゲイン補償器１４５，１５７，１６３，１６５の出力を加算して積分器１５１への入力を出力する加算器１７１と、各積分器１４７，１４９，１５１のそれぞれに付随する初期値設定（図示省略）と、同じく各積分器１４７，１４９，１５１のそれぞれに付随する推定初期化手段（図示省略）と、ゲイン補償器１５７への分岐後の積分器１４７の出力を所定値の範囲内に制限する推定出力制限手段としてのリミッタ１８４とを備えている。
【００５０】
各積分器１４７，１４９，１５１は同一構成を持っており、例えば積分器１４７とこれに付随する初期値設定手段および推定初期化手段は図１０に示すように構成される。すなわち、加算器１６７の出力が入力される抵抗１８５とコンデンサ１８７とオペアンプ（演算増幅器）１８９とで構成される積分器１４７はコンデンサ１８７を短絡するリレー部１９１を備える。接触検出手段１２９の出力が接触の検出によりゼロでなくなるとリレー部１９１が動作してコンデンサ１８７を短絡し、積分器１４７の積分結果はゼロにリセットされる。本実施の形態では接触検出手段１２９の接触検出により短絡するリレー部１９１が上下動モードの推定初期化手段１３５’を構成している。一方、積分器１４７の出力は抵抗１９３に接続されている。この抵抗１９３と、接触検出手段１２９の接触検出により上下動モード姿勢演算手段１３１ａの出力するΔz₀を入力しΔz₀に対応する電圧を発生する初期値電圧発生装置１９５と、初期値電圧発生装置１９５に接続された抵抗１９７と、抵抗１９９，２０１と、オペアンプ２０３とが上下動モードの初期値設定手段１３３’を構成している。他の積分器１４９、１５１も同一構成であるが、これらに付随する初期値電圧発生装置１９５は積分器１４９、１５１に対応する初期値としてゼロを出力する。これら３つの積分器１４７，１４９，１５１に付随する推定初期化手段および初期値設定手段１３３’が全体として上下動モード推定初期化手段１３５ａおよび上下動モード初期値設定手段１３３ａを構成しており、差動構成されるオペアンプ２０３の出力が各積分器１４７，１４９，１５１の出力となる。つまり、上下動モード姿勢推定手段１２７ａの推定結果である上下偏差Δz、その速度d(Δz)/dtおよび励磁電流偏差Δi_zのそれぞれの推定値が出力される。
【００５１】
ピッチモード姿勢推定手段１２７ｂ、ピッチモード初期値設定手段１３３ｂおよび上下動モード推定初期化手段１３５ｂも同様に図９および図１０に示すように構成されている。簡単のため、対応する入出力信号を信号名で示し説明は省略する。ただし、ピッチモードでは積分器１４７に付随する初期値電圧発生装置１９５はピッチモード姿勢演算手段１２７ｂの出力するΔξ₀を入力し、そのΔξ₀に対応する電圧を発生するように構成されている。ピッチモードの各積分器１４７，１４９，１５１からはピッチモード姿勢推定手段１２７ｂの推定結果であるピッチ偏差Δξ、その速度d(Δξ)/dtおよび励磁電流偏差Δi_ξの推定値が出力される。
【００５２】
上下動モード制御電圧演算回路１３７ａは例えば図１１に示すように構成されている。すなわち、上下偏差Δz、その速度d(Δz)/dtおよびΔi_zの推定値に適当なフィードバックゲインを乗じるゲイン補償器２０５と、電流偏差目標値発生器２０７と、Δi_zを電流偏差目標値発生器２０７の目標値から減じる減算器２０９と、減算器２０９の出力値を積分し適当なフィードバックゲインを乗じる積分補償器２１１と、ゲイン補償器２０５の出力値の総和を演算する加算器２１３と、積分補償器２１１の出力を入力として所定の範囲内で入力と等しい値を出力するとともに、入力が同範囲の上限値を越える場合には上限値を出力し、下限値を下回る場合には下限値を出力する積分出力制限手段２１５と、加算器２１３の出力値を出力制限手段２１５の出力値より減じてzモードの電磁石励磁電圧e_zを出力する減算器２１７と、減算器２１７の出力を所定値の範囲内に制限する電圧出力制限手段としてのリミッタ２１８とで構成されている。
【００５３】
ピッチモード制御電圧演算回路１３７ｂもまた上下動モード制御電圧演算回路１３７ａと同様に構成されており、対応する入出力信号を信号名で示し、説明は省略する。
【００５４】
次に、以上のように構成された第１の実施の形態に係る仕切体支持装置の作用について説明する。
【００５５】
装置が停止状態にあるときは、磁石ユニット６０ａ，６０ｂの鉄心６８（６８’）の先端が、圧電ゴム７３を介してガイドレール４４の下面に吸着している。この状態で装置を起動させると、制御装置７０において、圧電ゴム７３の働きにより接触検出手段１２９が仕切体５４の上部支持部材４６への接触を検出してパターン信号「６」を出力し、姿勢演算手段１２７ａ、１２７ｂでは磁石ユニット６０ａのギャップ長がz_a1、磁石ユニット６０ａのギャップ長がz_b1であることに基づいて、式（１０）および式（１１）によりzモード上下偏差の推定初期値Δz₀とξモードピッチ偏差の推定初期値Δξ₀が演算される。各モードの姿勢推定手段１２７ａ，１２７ｂでは初期値設定手段１３３ａ，１３３ｂにより推定初期値が設定される。このとき、推定初期化手段１３５ａ，１３５ｂでは接触検出手段１２９の出力がゼロでないため、リレー部１９１がオンとなり、積分器１４７，１４９，１５１が短絡されて積分結果がクリアされ、姿勢推定手段１２７ａ，１２７ｂが初期化される。これにより、初期値設定手段１３３ａの働きにより姿勢推定手段１２７ａから出力される上下偏差Δz、その速度d(Δz)/dtおよびΔi_zの推定値はそれぞれΔz₀，0，0、初期値設定手段１３３ｂの作用により姿勢推定手段１２７ｂから出力されるピッチ偏差Δξ、その速度d(Δξ)/dtおよび励磁電流偏差Δi_ξの推定値はそれぞれΔξ₀，0，0となる。
【００５６】
各モードの制御電圧演算回路１３７ａ，１３７ｂは、姿勢推定手段１２７ａ，１２７ｂの推定結果が入力されると上下偏差Δz₀，ピッチ偏差Δξ₀をゼロにするよな励磁電圧e_z，e_ξを計算する。制御電圧座標逆変換回路１３９では制御電圧演算回路１３７ａ，１３７ｂの励磁電圧計算結果を受けてコイル６９ａ，６９ｂの励磁電圧e_a，e_bが計算され、パワーアンプ１１３ａ，１１３ｂを介して磁石ユニット６０ａ，６０ｂの吸引力が制御される。この状態で、制御装置７０は永久磁石６４が発生する磁束と逆向きの磁束を各電磁石６６,６６’に発生させ、磁石ユニット６０ａ，６０ｂとガイドレール４４との間に所定の空隙長を維持させるべく各コイル６９ａ，６９ｂに流す電流を制御する。これによって、仕切体５４はガイドレール４４の下面から離れて浮上状態に移行する。仕切体５４が浮上状態に移行すると、接触検出手段１２９は０を出力し、これによりに推定初期化手段１３５ａ、１３５ｂではリレー部１９１がＯＦＦとなり、積分器１４７，１４９，１５１が積分動作を開始する。このとき、初期値設定手段１３３ａ，１３３ｂでは接触検出手段１２９が０を出力しているので直前の接触時の出力値が維持される。これにより、浮上開始状態では、姿勢推定手段１２７ａでは初期値を（Δz₀，0，0）、姿勢推定手段１２７ｂでは初期値を（Δξ₀，0，0）として推定が開始される。姿勢推定手段１２７ａ，１２７ｂの推定誤差は式（８）によれば初期値の誤差が少ないほど時間の経過とともに急速に減少する。
【００５７】
本実施の形態では、浮上開始時の上下偏差とピッチ偏差が推定初期値と一致しているため推定開始時の誤差が小さくなり、推定値が実際の値に急速に収束する。また、仕切体５４の姿勢は上部支持部材４６と下部支持部材５２により制限されるが、リミッタ１８４には上下偏差とピッチ偏差の上下限値が飽和範囲として設定されており、推定値が実際の値に収束するまでの過渡期において姿勢推定手段１２７ａ，１２７ｂが異常な値を出力することもない。したがって、制御電圧演算回路１３７ａ，１３７ｂで演算される各モードの励磁電圧e_z，e_ξも異常な値となることがなく、制御電圧座標逆変換回路１３９では制御電圧演算回路１３７ａ，１３７ｂの励磁電圧計算結果を受けてコイル６９ａ，６９ｂの励磁電圧e_a，e_bが計算され、パワーアンプ１１３ａ，１１３ｂを介して磁石ユニット６０ａ，６０ｂの吸引力が異常なく制御される。
【００５８】
このように浮上開始時において異常なく吸引力制御が行われると、図７に示すように、永久磁石６４→鉄心６８→空隙G→ガイドレール4４→空隙G’ →鉄心６８’→永久磁石６４の経路からなる磁気回路Mcが安定化され、空隙G,G’におけるギャップ長は、永久磁石34の起磁力による各磁石ユニット６０ａ，６０bの磁気的吸引力が仕切体５４の重心に作用するz軸方向重力、同y軸回りのトルクとちょうど釣合うような長さになる。制御装置７０はこの釣合いを維持すべく仕切体５４に外力が作用すると電磁石６６ａ，６６ｂ’の励磁電圧制御を行い、いわゆるゼロパワー制御がなされることになる。
【００５９】
ここで、本実施の形態に関わる磁気浮上装置１０を用いて図１２に示す引き戸を構成した場合について説明する。この引き戸は壁面２２０の開口部に取付けられた磁気浮上装置によって構成されており、ガイドレール４４は開口部左端かつ壁面２２０側に向かって（x方向およびy方向に向かって）わずかに傾斜して取付けられ、ゼロパワー制御で非接触支持されている仕切体５４は外部から力を加えない状態で扉が閉じた状態となる。この状態において、磁石ユニット６０ａ，６０bが対向するガイドレール４４の対向面には磁性体が張出している部位Ａ，Ｂ，Ｃがあり、磁石ユニット６０ａ，６０bにはこの部位への吸引力が係留力として作用する。このため、風や建物の僅かな揺れで仕切体５４が開くことはない。今、この扉を開ける場合、仕切体５４にx方向の力を作用させると、案内車輪８８，８８’が溝５０の直線部に沿って、案内シュー８６が上部案内溝５６に沿って移動するため、非接触支持されている仕切体５４は軽くかつ滑らかに移動して扉が開くことになる。開いた扉はガイドレール４４の傾斜に沿って滑走し、再び扉が閉じた状態を呈する。一方、閉じている扉をy方向に押す場合には案内車輪８８が溝５０の曲線部に沿って移動するため、仕切体５４は案内車輪８８’の車軸９３および案内シュー８６の支持棒８４を中心として回転を開始する。このとき車軸９３および支持棒８４のそれそれの軸中心が一致していることは言うまでもない。回転を開始した仕切体５４は２つの車軸９３間に引いた直線L1〜L7で表される姿勢に順次移行しながらx方向に移動する。つまり、本実施の形態に係る磁気浮上装置では、仕切体の重量を非接触支持することにより扉の操作力や開閉時の騒音を著しく軽減しているばかりか、仕切体に滑らかな二次元的移動を付与することを可能にしており、車椅子から引き戸を開けるような場合でも、扉を押すことにより容易に引き戸を開けることができ、操作性並びに操作感を著しく向上させることができる。
【００６０】
なお、仕切体５４が非接触支持されている場合には案内車輪８８，８８’および案内シュー８６がそれぞれ溝５０および上部ガイド溝５６に嵌入しているため、過大な水平方向の外力に対して仕切体５４が転倒することがない。
【００６１】
一方、過大な外乱により仕切体５４が上部支持部材４６もしくは下部支持部材５２との間に接触を生じても、本発明の磁気浮上装置にあっては、上述の仕切体５４の接触時の姿勢▲１▼〜▲４▼が接触検出手段１２９により検出され、姿勢演算手段１３１、初期値設定手段１３３、および推定初期化手段１３５の作用により、姿勢推定手段１２７は正常な推定値を出力する。このため、仕切体５４は支障なく浮上状態に復帰する。
【００６２】
ここで、さらに過大な外乱により仕切体５４が上部支持部材４６もしくは下部支持部材５２との間に衝突を生じた場合には、姿勢推定手段１２７の推定値が急激に変化する。こうした急激な変化では上下偏差の速度推定値およびピッチ偏差の速度推定値も急激に変化する。そうすると、各モードの制御電圧演算回路１３７ａ，１３７ｂからは電源装置７２の能力以上の励磁電圧が出力される。こうなると姿勢推定手段１２７ａ，１２７ｂに入力される励磁電圧e_z，eξが実際にe_a，e_bから得られるモード別励磁電圧の値と異なることになる。そうすると、姿勢推定手段１２７ａ，１２７ｂにおいて正常な姿勢推定を行うことができなくなり、浮上状態を安定化させることが困難となる。しかし、本実施の形態による磁気浮上装置１０にあっては、励磁電圧演算部１３６の上下動モード制御電圧演算回路１３７ａおよびピッチモード制御電圧演算回路１３７ｂがそれぞれの電圧出力制限手段としてリミッタ２１８を備えている。リミッタ２１８には電源装置７２の能力限界に係わる各モードにおける電圧値が飽和値として設定されており、姿勢推定手段１２７ａ，１２７ｂに入力される励磁電圧e_z，e_ξが実際にe_a，e_bから得られるモード別励磁電圧の値と異なることがない。このため、さらに過大な外乱により仕切体５４が上部支持部材４６もしくは下部支持部材５２に衝突しても姿勢推定手段１２７ａ，１２７ｂは支障なく動作し、仕切体５４は再び浮上状態に戻ることになる。このように、本発明による磁気浮上装置にあっては浮上状態の信頼性を大きく向上させることができる。
【００６３】
図４および図１２に示すようにガイドレール４４に分岐個所が存在する場合、従来のギャップセンサを有する磁気浮上装置では、ギャップセンサの軌跡に沿って配置された、センサの検出原理に適合した材質のセンサターゲットが必要であったが、本発明の磁気浮上装置にあってはギャップセンサが不要なため、センサターゲットを省略することができ、装置の簡素化および低コスト化を図ることができる。
【００６４】
かくして、安定な浮上状態を維持していた磁気浮上１０を停止させる場合は、例えば、zモードの電流目標値発生器２０７の電流目標値をゼロから負の所定の値に変化させれば良く、これにより仕切体５４は上部支持部材４６に吸着する。ここで電源装置７２の図示しないスイッチをオフすることにより装置の動作を停止させることができる。
【００６５】
＜第２の実施の形態＞
次に、本発明の第２の実施の形態を図１３に基づいて説明する。第１の実施の形態では、磁石ユニットが浮上体側に取付けられていたが、これは磁石ユニットの取付位置をなんら限定するものでなく、図１３に示したように磁石ユニットを地上側に配置しても良い。なお、説明の簡単化のために、以下、第１の実施の形態と共通する部分には同一の符号を用いて説明する。
【００６６】
磁気浮上装置３００は、断面がコ字形状で非磁性体、例えばアルミニウム部材で形成され、地上に設置された補助支持手段３０２と、補助支持手段３０２の上部下面に下向きに取付けられた磁石ユニット６０と、磁石ユニット６０に対向する断面がコ字形状の強磁性部材、例えば鉄で形成されたガイド３０４と、ガイド３０４を底部上面に備え全体としてコ字形状に形成された防振台テーブル３０６と、防振台テーブル３０６の側面に取付けられ地上に対して垂直方向にのみ動きの自由度を防振台テーブル３０６に付与するリニアガイド３０８と、磁石ユニット６０の吸引力を制御して防振テーブルを非接触支持するための吸引力制御手段１５とを備えている。
【００６７】
吸引力制御手段１５は、補助支持手段３０２の底部上面に取付けられたマイクロスイッチ３１０と磁石ユニット６０の磁極面に張られた圧電ゴム３１２を備えた接触検出手段３１４と、接触検出手段３１４の接触検出信号から防振テーブル３０６の防振テーブル３０６もしくは磁石ユニット６０へ接触時の浮上ギャップ長を計算する姿勢演算手段３５と、磁石ユニット６０の励磁電流を検出する電流センサ２３と、磁石ユニット６０への励磁電流および励磁電圧から防振テーブル３０６の浮上姿勢を推定する姿勢推定手段２５と、姿勢演算手段３５の出力に基づいて姿勢推定手段３３に推定初期値を設定する初期値設定手段３９と、接触検出手段３１４の出力に基づいて姿勢推定手段２５を初期化する推定初期化手段１３と、姿勢推定手段２５の出力に基づいて防振テーブル３０６を磁気浮上させるための磁石ユニット６０への励磁電圧を演算する励磁電圧演算部２５と、励磁電圧２５の出力に基づいて磁石ユニット６０を励磁する図示していない電源に接続されたパワーアンプ１１３とを備えている。
【００６８】
磁石ユニットをこのように配置することにより防振テーブルの重量を磁石ユニットの分だけ軽減できるという利点がある。
【００６９】
＜第３の実施の形態＞
本発明の第３の実施の形態を図１４に基づいて説明する。上記の第１および第２の実施の形態では、姿勢推定手段として同一次元状態観測器を用いていたが、これは姿勢推定手段の構成をなんら限定するものでなく、本発明の要旨の範囲内であればいかなる推定手段であっても差し支えない。例えば、図１４に示す最小次元オブザーバを用いた場合の構成であっても良い。
【００７０】
例えば、図１３の磁気浮上装置３００にあっては次式の最小次元オブザーバで構成された姿勢推定手段４００を用いることができる。すなわち、
【数７】

ただし，z_obはオブザーバの状態ベクトル、α₁，α₂はオブザーバの極を決定するパラメータであり、y = Δi_zである。
【００７１】
姿勢推定手段４００は、Δi_zを入力とするゲイン補償器４０２，４０４，４０６，４０７と、積分器４０８，４１０と、積分器４０８の出力を入力するゲイン補償器４１２と，積分器４１０の出力を入力するゲイン補償器４１４，４１６と、励磁電圧演算部３２４の出力e_zを入力とするゲイン補償器４１８，４２０と、ゲイン補償器４０４，４０６，４１４の出力を加算して積分器４０８への入力を出力する加算器４２２と、ゲイン補償器４１２，４１６，４１８，４２０の出力を加算して積分器４１０への入力を出力する加算器４２４と、ゲイン補償器４０２と積分器４０８の出力を加算する加算器４２６と、ゲイン補償器４０７と積分器４１０の出力を加算し、速度d(Δz)/dtの推定値を出力する加算器４２８と、加算器４２６の出力を所定値の範囲内に制限する推定出力制限手段としてのリミッタ４３０とを備えている。ここでリミッタ４３０の出力が上下偏差Δzの推定値となることは言うまでもない。
【００７２】
さらに、姿勢演算手段４００にはΔi_zの入力端に切替手段４３２が備えられている。切替手段４３２では接触検出手段３１４が接触を検出している間はそれまで入力されていたΔi_zをゼロに切替え、接触が検出されなくなるとそのゼロをΔi_zに切替える機能を有している。姿勢推定手段として最小次元オブザーバを用いる場合、Δi_zがゲイン補償器４０２→加算器４２６→リミッタ４３０を介して直接上下偏差Δzの推定値として出力されるので、接触時において設定された積分器４０８の接触時の防振テーブル３０６の姿勢情報にα₁Δi_zが加算されることになる。すると、姿勢演算手段４００の上下偏差Δzの推定値が実際と異なることになり、防振テーブル３０６の浮上状態への移行に支障を来すこととなる。この場合では切替え手段４３２の作用により接触時に防振テーブル３０６の姿勢情報にα₁Δi_zが加算されることはなく、姿勢演算手段４００の出力は実際の値に近いものとなる。こうなると防振テーブル３０６の浮上状態への移行に支障を来すことがなく信頼性が向上する。本実施の形態ではΔi_zの入力端に切替手段４３２を備えたが、これは姿勢推定手段の接触時の推定値を実際の値に近づけるための手段であり、姿勢推定手段の構成によってはe_zの入力端に切替手段４３２を設けてもなんら差し支えない。本実施の形態では姿勢演算手段に最小次元オブザーバを適用しているが、この場合、積分器を減らすことができるという利点がある。
【００７３】
＜変形例＞
上記各実施の形態では、磁気浮上制御を行う制御装置がアナログ型であるかのように説明されているが、本発明の制御装置はアナログ型に限定されるものではなく、デジタル型のもので実施することもできる。
【００７４】
また、上記各実施の形態では、パワーアンプに電圧形のものを用いているが、これはパワーアンプの方式を何ら限定するものではなく、例えばＰＷＭ形のものであって何ら差し支えない。
【００７５】
加えて、上記各実施の形態では、磁石ユニットにＵ字形状のものを用いているが、これは磁石ユニットの形状を何ら限定するものでなく、例えばＥ字形状のものであって良い。
【００７６】
さらに、上記各実施の形態では、磁石ユニットに永久磁石を用いているが、これは磁石ユニットの構成をなんら限定するものでなく、永久磁石を持たずに電磁石のみで磁石ユニットを構成しても良い。
【００７７】
また、パワーアンプ（電力増幅器）として電圧形のものを用いているが、これはドライバの電磁石駆動方式を何ら限定するものではなく、例えばＰＷＭ形のものであって良い。
上記のほか、本発明の要旨を逸脱しない範囲で種々変更可能である。
【００７８】
【発明の効果】
本発明の磁気浮上装置によれば、磁石ユニットの励磁電流からギャップ長とその速度に関する情報を推定でき、ギャップセンサを省略した磁気浮上が可能となる。このため、ギャップセンサのコストが削減されるばかりでなく、センサターゲットが不要となり、装置の簡素化によるシステム全体のコストダウンを達成することができる。
【００７９】
また、線型制御理論を適用することができるため、従来のセンサレス磁気浮上方式に比べ、浮上状態のロバスト安定性を確保することができ、装置の信頼性を向上させることができる。
【図面の簡単な説明】
【図１】本発明の原理を説明するための構成図。
【図２】本発明の原理を説明するための他の構成図。
【図３】本発明による磁気浮上装置の第1の実施の形態の全体構成を示す斜視図。
【図４】図３の実施の形態の平面図。
【図５】図３の実施の形態の正面図。
【図６】図３の実施の形態の立面図。
【図７】図３の実施の形態における磁石ユニットの立面図。
【図８】図３の実施の形態における制御装置の内部構成を示すブロック図。
【図９】図３の実施の形態における制御装置内の姿勢推定手段の詳細構成を示すブロック図。
【図１０】図３の実施の形態における姿勢推定手段の積分器周辺の構成を示す回路図。
【図１１】図３の実施の形態における制御装置内の制御電圧演算回路の詳細構成を示す回路図。
【図１２】図３の実施の形態における仕切体の作用を説明するための平面図。
【図１３】本発明による磁気浮上装置の第２の実施の形態の全体構成を示すブロック構成図。
【図１４】本発明による磁気浮上装置の第３の実施の形態における姿勢推定手段の構成を示すブロック図。
【符号の説明】
１，１'，４０，３００ 磁気浮上装置
３，６４ 永久磁石
５，６６，６６' 電磁石
７，６０，６０ａ，６０ｂ 磁石ユニット
９ 負荷重量
１１ 浮上体
１３，３０４ ガイド
１５ 吸引力制御手段
１７ａ，１７ｂ 継鉄
１９ａ，１９ｂ，６９，６９'，６９ａ，６９ｂ コイル
２１ ギャップセンサ
２３ 電流センサ
２５，３２４ 励磁電圧演算部
２７ ドライバ
２８，７３ａ，７３ｂ，３１２ 圧電ゴム
２９，１２９，３１４ 接触検出手段
３１，３０２ 補助支持手段
３３，１２７ａ，１２７ｂ，３１８，４００ 姿勢推定手段
３５，１３１ａ，１３１ｂ，３１６ 姿勢演算手段
３７，１３５ａ，１３５ｂ，３２２ 推定初期化手段
３９，１３３ａ，１３３ｂ，３２０ 初期値設定手段
４２ 天井
４４ ガイドレール
４５ 平面補正部材
４６ 上部支持部材
４８ 床
５０ 溝
５２ 下部支持部材
５４ 仕切体
５６ 上部ガイド溝
６２，６２' 台板
６８，６８' 鉄心
７０ 制御装置
７２ 電源装置
８０ フレーム部
８２ 仕切板
８３ 固定台
８４ 支持棒
８６ 案内シュー
８８，８８' 案内車輪
８９ ガード部材
９１ 側面フレーム
９３ 車軸
９５ 底面フレーム
９７ 緩衝部材
１０１ 上部基台
１０３ 下部基台
１０４ 側板
１０５ 上部フレーム
１０７ カバー
１１１ センサ部
１１２ 演算回路
１１３，１１３ａ，１１３ｂ パワーアンプ
１１４ 冷却フィン
１２１ａ，１２１ｂ 電流検出器
１２３ａ，１２３ｂ，２０９，２１７ 減算器
１２５ 励磁電流偏差座標変換回路
１２７ａ 上下動モード姿勢推定手段
１２７ｂ ピッチモード姿勢推定手段
１３６ 制御電圧演算部
１３７ａ 上下動モード制御電圧演算回路
１３７ｂ ピッチモード制御電圧演算回路
１３９ 制御電圧座標逆変換回路
１４１，１４３，１４５，１５３，１５５，１５７，１５９，１６１，１６３，２０５，４０２，４０４，４０６，４０７，４１２ ゲイン補償器
１４７，１４９，１５１，４０８，４１０ 積分補償器
１６７，１６９，１７１，２１３，４２２，４２４，４２６，４２８ 加算器
１８４，２１８，４３０ リミッタ
１８５，１９３，１９７，１９９，２０１ 抵抗
１８７ コンデンサ
１８９，２０３ オペアンプ（演算増幅器）
１９１ リレー部
１９５ 初期値電圧発生装置
２０７ 電流目標値発生器
２１５ 出力制限手段
２２０ 壁面
３０６ 防振テーブル
３０８ リニアガイド
３１０ マイクロスイッチ[0001]
[Field of the Invention]
The present invention relates to a magnetic levitation apparatus that supports a levitated body in a non-contact manner by attractive magnetic levitation.
[0002]
[Prior art]
Normal conducting suction type magnetic levitation has no noise or dust generation, and has already been put to practical use in railways such as HSST (Super High Speed Surface Transporter) and Transrapid, in a clean room transport system in a semiconductor factory, and the like. The magnetic levitation system is inherently unstable in normal conduction attraction type magnetic levitation in which an electromagnet is placed opposite to a ferromagnetic member and the levitation body is levitated using the attractive force generated between the electromagnet and the ferromagnetic member. In order to stabilize this, the floating gap length, its speed, further acceleration, electromagnet excitation voltage, electromagnet excitation current are detected, and these are fed back to the attraction force control means to perform attraction force control. Has been. For this reason, in order to ensure the stability of the system, the conventional technique requires detection of the flying gap length, and the use of the gap sensor cannot be avoided. Moreover, in order to detect the gap length between the ferromagnetic member and the electromagnet with the gap sensor, a sensor target suitable for the gap sensor to be used is required, and the sensor target must be laid along with the ferromagnetic member. It was.
[0003]
Thus, when the levitation gap length is used to stabilize the magnetic levitation system, a gap sensor and a sensor target are required, which increases the cost of the apparatus. In addition, it is necessary to secure a space for mounting the gap sensor and a space for the sensor target, which is an obstacle to downsizing the apparatus. In particular, in railways and transport systems, a branch point is provided on a track composed of ferromagnetic guides, so a mechanism is required to prevent the sensor target and guide from intersecting and preventing the gap length from being detected. This also caused the system to become complicated.
[0004]
In order to solve such problems, for example, a method of estimating the gap length from an electromagnet excitation current by an observer (state observer) (Mizuno, et al .: “Research on practical application of displacement sensorless magnetic bearing”, IEEJ Transactions D Volume, 116, No. 1, 35 (1996)) and a method in which gap information is included in the phase difference signal between the electromagnet excitation voltage and the excitation current generated by AC magnetic levitation, and this is fed back to the electromagnet excitation voltage for stabilization (Moriyama: "AC magnetic levitation using differential feedback type power amplifier" 1997 IEEJ National Conference Preliminary Proceedings, No. 1215), and comparing the magnet excitation current value with the excitation current reference value with the hysteresis comparator. If the value is larger than the value, the electromagnet excitation voltage is switched to negative, and if smaller, it is switched to positive so that the switching frequency is proportional to the levitation gap length and the levitation system is stabilized ( No, et al: “Self-sensing magnetic levitation using hysteresis amplifier”, Transactions of the Society of Instrument and Control Engineers, 32, No. 7, 1043 (1996)) have been proposed as sensorless methods to eliminate gap sensors. .
[0005]
However, even with such a solution, when the observer is used, the gap length is derived from the linear model of the magnetic levitation system in the levitation state. There are problems such that it is difficult to start the levitation and the levitation body cannot return to the levitation state once it comes into contact with another structure. Furthermore, when the electromagnet excitation voltage is controlled by a physical quantity that includes gap information other than the observer, the levitation control system becomes a non-linear system, so it is difficult to determine stability, or the temperature rises due to mass change or excitation of the levitation body However, there is also a problem that it is difficult to maintain the floating state if the electric resistance of the electromagnet coil varies.
[0006]
[Problems to be solved by the invention]
Thus, in the conventional magnetic levitation device, the floating gap length of the floating body is fed back to the attractive force control means to realize a stable magnetic floating state of the floating body, and the gap sensor and sensor target are indispensable. It becomes. For this reason, there is a problem that the apparatus becomes large and complicated, resulting in an increase in cost. Moreover, in order to avoid such problems, if the gap length information is fed back to the suction force control means without using the gap sensor, the stability of the levitation system and the reliability of the operation are significantly impaired. Therefore, it has been quite difficult to avoid the problems of increased complexity and size of the apparatus and high cost.
[0007]
The present invention has been made based on such circumstances, and an object of the present invention is to provide a magnetic levitation device capable of simplifying and downsizing the device, reducing cost, and improving reliability.
[0008]
In order to achieve the above object, a magnetic levitation apparatus according to a first aspect of the present invention includes a magnet unit including an electromagnet, a levitated body supported by the magnet unit, and a magnetic pole of the magnet unit facing each other through a gap. A ferromagnetic member for supporting the levitated body in a non-contact manner by an attractive force acting on the magnet unit; auxiliary support means for maintaining the positional relationship between the levitated body and the ferromagnetic member when the levitated body is not in the levitated state; Sensor unit for detecting excitation current, posture estimation means for estimating the posture of the floating body relative to the ferromagnetic member based on the output of the sensor unit, contact detection means for detecting contact between the floating body and the ferromagnetic member or auxiliary support means , Attitude calculation means for calculating the attitude of the floating body relative to the ferromagnetic member at the time of contact based on the output of the contact detection means, and initialization of the attitude estimation means at the time of contact based on the output of the contact detection means Out of that estimation initialization means, the initial value setting means for setting an output value of the orientation calculation unit when the posture estimating means is initialized as the initial value of the orientation estimating means, and pose estimation means To force An attraction force control means having a drive means for controlling the attraction force of the magnet unit so that the magnetic circuit formed through the gap and the ferromagnetic member is stabilized based on the magnet unit. To do.
[0009]
According to a second aspect of the present invention, in the magnetic levitation device according to the first aspect, the magnet unit includes a permanent magnet disposed so as to share the magnetic path with the magnetic flux of the electromagnet in the gap. .
[0010]
The invention according to claim 3 is the magnetic levitation device according to claim 2, wherein the attraction control means stabilizes the magnetic circuit while converging the excitation current of the electromagnet to zero based on the output of the sensor unit. Means are provided.
[0011]
According to a fourth aspect of the present invention, in the magnetic levitation apparatus according to the third aspect, the zero power control means is constituted by posture estimation means.
[0012]
According to a fifth aspect of the present invention, in the magnetic levitation apparatus according to the first aspect, the posture estimating means is a posture of the levitated body with respect to the ferromagnetic member based on the exciting current of the electromagnet and the exciting voltage generating the exciting current. And the time change of the posture is estimated.
[0013]
According to a sixth aspect of the present invention, in the magnetic levitation apparatus according to the first aspect, the posture estimation means inputs the output of the posture estimation means, and when the input is within a predetermined saturation range, the input value is left as it is. An estimated output limiting means is provided for outputting and outputting a saturation value when it is outside a predetermined saturation range.
[0014]
The invention according to claim 7 is the claim 6 In the magnetic levitation device according to claim 1, attraction force control means Is An excitation voltage calculation unit is provided which calculates an electromagnet excitation voltage based on the output of the constant output limiting means and gives the output to the drive means.
[0015]
The invention according to claim 8 is the magnetic levitation device according to claim 7, wherein the excitation voltage calculation unit Gaso When the output of the excitation voltage calculator is within the specified saturation range, the input value is Output as is Outside the specified saturation range In In some cases, voltage output limiting means for outputting a saturation value is provided.
[0016]
According to a ninth aspect of the present invention, in the magnetic levitation apparatus according to the seventh aspect, the excitation voltage calculation unit generates an attractive force that contributes to the degree of freedom of movement of the levitated body based on the output of the estimated output limiting means. Therefore, a mode excitation voltage calculation unit for calculating an excitation voltage for each mode represented by a linear combination of electromagnet excitation voltages is provided.
[0017]
The invention according to claim 10 is the magnetic levitation device according to claim 9, wherein the attraction force control means is represented by a linear combination of electromagnet excitation currents that generate attraction force that contributes to the freedom of movement of the levitated body. By mode excitation A mode excitation current calculation unit for calculating a current is provided.
[0018]
According to an eleventh aspect of the present invention, in the magnetic levitation apparatus according to the ninth aspect, the mode excitation voltage calculation unit includes a voltage output limiting unit that receives the output of the mode excitation voltage calculation unit. To do.
[0019]
According to a twelfth aspect of the present invention, in the magnetic levitation apparatus according to the tenth aspect, the posture estimation means is adapted to perform the ferromagnetism of the levitated body based on the output of the excitation current calculation unit for each mode of the electromagnet and the output of the mode excitation voltage calculation unit. It is characterized in that a posture with respect to a member and a temporal change of the posture are estimated.
[0020]
According to a thirteenth aspect of the present invention, in the magnetic levitation apparatus according to the first aspect, when the posture estimation means has an integrator and the contact detection means detects contact, the estimation initialization means integrates the integrator. Is canceled and integration results Is When the initial value setting means outputs a value and the contact detection means no longer detects contact, the initial value is the value output by the initial value setting means at the time of the previous contact. It is characterized by starting.
[0021]
According to a fourteenth aspect of the present invention, in the magnetic levitation apparatus according to the seventh aspect, when the contact estimation means detects the contact, the posture estimation means is an excitation current and excitation voltage of the electromagnet input to the posture estimation means. It has switching means for switching the output of the calculation unit to zero input and switching the zero input to the excitation current of the electromagnet or the output of the excitation voltage calculation unit when the contact detection unit no longer detects contact.
[0022]
According to a fifteenth aspect of the present invention, in the magnetic levitation device according to the tenth aspect, the posture estimation means detects the contact by the contact detection means. When The mode excitation current calculation unit and the mode excitation voltage calculation unit input to the posture estimation unit are switched to zero input, and when the contact detection unit no longer detects contact, the zero input is switched to the mode excitation current calculation unit or mode It has a switching means which switches to the output of an excitation voltage calculating part.
[0023]
The invention according to claim 16 is the magnetic levitation device according to claim 1, wherein the auxiliary support means is attached to the floating body.
[0024]
The invention according to claim 17 is the magnetic levitation apparatus according to claim 1, wherein the auxiliary support means is attached to the ferromagnetic member.
[0025]
The invention according to claim 18 is the magnetic levitation device according to claim 1, wherein the magnet unit is attached to the floating body.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
<Principle of the invention>
Here, the principle of the magnetic levitation apparatus of the present invention will be described. FIG. 1 shows a one-mass system magnetic levitation apparatus as a whole by reference numeral 1.
[0027]
The magnetic levitation apparatus 1 includes a magnet unit 7 composed of a permanent magnet 3 and an electromagnet 5, and a levitation body 11 composed of a load 9 that is levitated by the magnet unit 7. A guide 13 made of a ferromagnetic member for supporting the levitated body 11 in a non-contact manner by an acting magnetic attraction force, and an attraction for stably supporting the levitated body 11 in a non-contact manner by controlling the attraction force of the magnet unit 7. And force control means 15.
[0028]
The yokes 17a and 17b are arranged so as to abut on the side surfaces of both magnetic poles of the permanent magnet 3, respectively, and the electromagnet 5 is configured by winding the coils 19a and 19b around the yokes 17a and 17b. The magnetic flux generated by the permanent magnet 3 passes through a closed magnetic path composed of the yoke 17 a → the guide 13 → the yoke 17 b → the permanent magnet 3. Both coils 19a and 19b are connected in series, and by passing a current of a predetermined polarity through them, the generated magnetic flux is superimposed on the generated magnetic flux of the permanent magnet 3 to be strengthened, or conversely, the generated magnetic flux of the permanent magnet 3 is canceled. Can be weakened.
[0029]
The current control of the electromagnet 5 is performed by the attractive force control means 15. The attractive force control means 15 includes a flying gap length z obtained by the gap sensor 21 and an exciting current i obtained by the current sensor 23. _z On the basis of the excitation voltage calculator 25 for calculating the excitation voltage of the electromagnet 5, and the required excitation current i for the electromagnet 5 based on the output of the excitation voltage calculator 25. _z And a driver 27 for supplying.
[0030]
The magnetic levitation system of the magnetic levitation apparatus 1 has a levitation gap length z when the attractive force of the magnet unit 7 is equal to the weight of the levitation body 11. ₀ Is linearly approximated by and is described by the following differential equation.
[Expression 1]

In formula (1), m is the mass of the levitated body 11, z is the levitating gap length, i _z Is the excitation current of the electromagnet 5, φ is the main magnetic flux of the magnet unit 7, e _z Is the excitation voltage of the electromagnet 5, Δ is the steady levitation state (z = z ₀ , i _z = i _z0 ), Symbol “•” is d / dt, partial differential ∂ / ∂h (h = z, i) is steady levitation state (z = z ₀ , i _z = i _z0 ), The partial differential value of the partial differential function in _z0 Is
[Expression 2]

It becomes. In equation (3), each element of x is a levitation state quantity, C is an output matrix, e _z It is determined by the state quantity detection method used for the calculation of. In the magnetic levitation apparatus 1, the gap sensor 21 and the current sensor 23 are used. When the speed is obtained by differentiating the signal from the gap sensor 21, C is a unit matrix. Where F is the proportional gain compensator of x, K _i As an integral gain _z For example,
[Equation 3]

In this case, the magnetic levitation apparatus 1 is levitated with zero power control as disclosed in Japanese Patent Publication No. 06-24405. Here, needless to say, the excitation voltage calculation unit 25 calculates the equation (6).
[0031]
Without using the gap sensor 15 in the magnetic levitation apparatus 1 of the formula (1), the excitation current Δi _z As an estimation means for estimating the levitation gap length deviation Δz and its velocity d (Δz) / dt from the case, for example, consider a case where a one-dimensional state observer (hereinafter referred to as an observer) is applied. At this time, according to the linear control theory, the observer is
[Expression 4]

[0032]
Therefore, in the magnetic levitation apparatus 1 ′ according to the present invention shown in FIG. 2, the gap sensor 21 is omitted, and instead the levitation body 11 and the vicinity thereof are changed from a non-contact state to a contact state, for example, a piezoelectric rubber. The contact detection means 29 detected by 28 and the auxiliary | assistant support means 31 which maintains the attitude | position of the floating body at the time of contact are provided. In addition, the excitation voltage calculator 25 has an excitation current Δi. _z From the attitude maintained by the auxiliary support means 31 and the observer in the case of shifting from the attitude maintained by the auxiliary support means 31 to estimate the flying gap length deviation Δz and its velocity d (Δz) / dt from X to be the initial value ₀ Attitude calculation means 35 for calculating the output, estimated initialization means 37 for returning the output value of the observer to the initial state by contact, and x calculated by the attitude calculation means for the initialized observer ₀ And an initial value setting means 39 for setting as an initial value. And the estimated excitation current Δi _z The flying gap length deviation Δz and its speed d (Δz) / dt are input to the excitation voltage calculation unit 25, and the electromagnet 5 is excited via the driver 27. In this way, by initializing the observer and giving a predetermined initial value, the exciting current Δi can be obtained even when the aircraft floats from the stopped state or when the floating state is brought into contact with the external force or other reasons. _z From the beginning of the estimation, the floating gap length deviation Δz and its velocity d (Δz) / dt can be estimated while suppressing the error, and the floating body 11 can be reliably transferred to the floating state and maintained in the floating state. .
[0033]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0034]
<First Embodiment>
3 to 7 show the main part of the magnetic levitation apparatus according to the first embodiment.
[0035]
As shown in FIG. 3, the magnetic levitation device 40 includes a guide rail 44 made of a ferromagnetic member attached to a lower surface of a top plate 42 constituting a ceiling of a building by a predetermined attachment method, and the guide rail 44 as a top plate. An upper support member 46 composed of a flat correction member 45 made of a non-magnetic material that corrects unevenness generated by attaching to the flat surface within a predetermined range of the top plate 42, and a groove 50 having a predetermined shape on the floor 48. A lower support member 52 constructed by digging, and a partition body 54 that is interposed between the upper support member 46 and the lower support member 52 and is prevented from falling over geometrically due to an interval therebetween. Yes. The guide rail 44 has an upper guide groove 56 that is formed at a predetermined position on the lower surface thereof and has an inverted U-shaped cross section to guide the upper portion of the partition 54.
[0036]
The partition body 54 is attached to the partition body 54, and includes two magnet units 60 a and 60 b that support the partition body 54 without contact with the guide rail 44, and a magnet unit 60 a that supports the partition body 54 without contact. , 60b, a control device 70 as a suction force control means for controlling the suction force, a power supply device 72 for supplying necessary power to the magnet units 60a, 60b and the control device 70, and the magnet units 60a, 60b And a partition plate 82 that is fitted into the frame portion 80 and made of, for example, glass, aluminum, wood, paper, or the like.
[0037]
The magnet units 60 a and 60 b are composed of permanent magnets 64 and electromagnets 66 and 66 ′, and are assembled in a U shape as a whole so that the tips of the electromagnets 66 and 66 ′ face the lower surface of the guide rail 44. The electromagnets 66 and 66 'are configured by inserting a prismatic iron core 68 (68') into a coil 69 (69 '). The coils 69 and 69' are connected in series so as to reinforce each other's magnetic flux during excitation. Connected. At the tips of the electromagnets 66 and 66 ′, the magnet units 60a and 60b ′ are prevented from being attracted and fixed to the guide rail 44 by the attractive force of the permanent magnet 64 when they are not excited, and even in the attracted state. Piezoelectric rubbers 73a and 73b surface-treated with a solid lubricating member are attached so as not to hinder the movement of the partition 54. Here, the piezoelectric rubbers 73a and 73b have a property that the electrical resistance is close to zero by the attractive force when the magnet units 60a and 60b are in contact with the guide rails 44, and the contact state of the partition 54 is detected. It is suitable for.
[0038]
The frame portion 80 has an inverted U-shaped cross section and is attached to the upper portion of the fixed base 83, a support bar 84 fixed to the fixed base 83, and an upper portion that is rotatably attached to the tip of the support bar 84. A guide shoe 86 that fits into the guide groove 56 and guides the upper part of the partition 54 along the guide rail 44; and two guide wheels 88 that fit into the groove 50 and guide the lower part of the partition 54 along the groove 50; 88 ′, a guard member 89 made of a flexible material such as soft rubber, etc., to prevent an accident from being caught when the partition 54 moves along the wall surface, and a U-shaped cross-section and left and right in the recess. A side frame 91 for sandwiching the partition plate 82 from the bottom side frame 95, a bottom frame 95 having axles 93 of guide wheels 88 and 88 'fixed at predetermined positions on the lower end surfaces of the left and right side frames 91 in a predetermined manner; Hard It is made of piezoelectric rubber and is affixed to the bottom surface of the bottom surface frame 95 to prevent the bottom surface frame 95 from directly contacting the top surface of the floor 48 when the magnet unit 60 loses its attractive force and detects contact of the partition 54 as a floating body. And a control device 70 and a power supply device 72 which are each formed in a box shape with the upper base 101, the lower base 103, and the side plate 104, and are divided into two parts, and a magnet unit on the upper surface of the upper base 101. The upper frame 105 is attached to the lower surface of the lower base 103 and the upper end surfaces of the left and right side frames 91 are fixed by a predetermined method. A cover 107 that shields the magnet units 60a and 60b from view is attached to the upper portion of the upper frame 105 along the side surface, thereby improving the design of the magnetic levitation apparatus 10.
[0039]
Each attraction force of the magnet units 60 a and 60 b is controlled by the control device 70, and the partition body 54 is supported in a non-contact manner with respect to the guide rail 44.
[0040]
Although the control device 70 is structurally configured in a divided manner as shown in FIGS. 5 and 6, for example, as shown in FIG. In the block diagrams of FIG. 8 and subsequent figures, arrow lines indicate signal paths, and bar lines indicate power paths around the coil 40. Furthermore, two coils 69 and 69 'connected in series in the magnet unit 60a are collectively referred to as a coil 69a, and similarly, two coils 69 and 69' in the magnet unit 60b are referred to as a coil 69b.
[0041]
The control device 70 is attached to the frame portion 80 to detect the excitation current of the magnet units 60a and 60b, and applies to the coils 69a and 69b so that the magnet units 60a and 60b support the partition 54 in a non-contact manner. An arithmetic circuit 112 that calculates a voltage based on a signal from the sensor unit 111, and power amplifiers (power amplifiers) 113a and 113b that supply excitation current to the coils 69a and 69b based on the output of the arithmetic circuit 112. Thus, the attractive forces of the two magnet units 60a and 60b are independently controlled in the z-axis direction and around the y-axis. The power amplifiers 113a and 113b are attached to cooling fins 114 attached to the upper surface of the upper base 101 for cooling.
[0042]
The power supply device 72 supplies power to the power amplifiers 113a and 113b, and also supplies power to the constant voltage device 118 that supplies power to the arithmetic circuit 112 at a constant voltage. Since the power supply device 72 supplies power to the power amplifiers 113a and 113b, AC power supplied from the outside of the partition 54 via a power supply line (not shown) is converted into direct current suitable for power supply to the power amplifier. It has a function to do. The constant voltage device 118 always supplies power to the arithmetic circuit 112 at a constant voltage even if the voltage of the power supply device 72 fluctuates due to supply of a large current to the power amplifier 113 or the like. For this reason, the arithmetic circuit 112 always operates normally.
[0043]
The sensor unit 111 includes current detectors 121a and 121b that detect current values of the coils 69a and 69b.
[0044]
The arithmetic circuit 112 performs magnetic levitation control of the partition 54 for each motion coordinate system shown in FIG. That is, control is performed in z mode (vertical movement mode) representing vertical movement along the z coordinate of the center of gravity of the partition 54 and ξ mode (pitch mode) representing pitching around the center of gravity of the partition 54. For these two modes, the coil exciting currents of the magnet units 60a and 60b are detected based on the principle of the above-described invention, and magnetic levitation control is performed.
[0045]
More specifically, the arithmetic circuit 112 is configured as follows. Excitation current detection signal i from current detectors 121a and 121b _a , I _b To each current setting value i _a0 , I _b0 Current deviation signal Δi obtained by subtracting _a , Δi _b Subtractors 123a and 123b for calculating the current deviation Δi related to the movement in the z direction. _z , Current deviation Δi related to pitching around the same center of gravity _ξ The excitation current deviation coordinate conversion circuit 125 as a mode excitation current calculation unit for calculating the output and the output Δi of the excitation current deviation coordinate conversion circuit 125 _z , Δi _ξ To z and ξ, the vertical deviation Δz from the predetermined position of the center of gravity of the partition 54 and the vertical motion mode posture estimation means 127a for estimating the speed d (Δz) / dt, the pitch deviation Δξ of the partition 54 and The contact of the partition 54 with the upper support member 46 or the lower support member 52 is detected from the electrical resistance values of the pitch mode attitude estimation means 127b for estimating the speed d (Δξ) / dt, the piezoelectric rubbers 73a and 73b, and the buffer member 97. Based on the contact signal from the contact detection means 129 and the contact detection means 129, the vertical deviation Δz in the z mode is determined from the attitude of the partition 54 at the time of contact. ₀ Attitude calculating means 131a for calculating the pitch deviation Δξ in the ξ mode ₀ Attitude calculating means 131b for calculating the output and output Δz of the attitude calculating means 131a ₀ As an initial value for posture estimation, the vertical movement mode initial value setting means 133a for giving the vertical movement mode posture estimation means 127a and the output Δξ of the posture calculation means 131b ₀ As an initial value for posture estimation, the initial value setting means 133b for giving to the pitch mode posture estimation means 127b, and the vertical deviation Δz estimated by the vertical movement mode posture estimation means 127a until just before the contact, and its speed d (Δz) / dt. And excitation current deviation Δi _z The vertical deviation mode estimation initializing means 135a for resetting the estimated value of pitch and the pitch deviation Δξ, the speed d (Δξ) / dt and the excitation current deviation Δi estimated by the pitch mode posture estimation means 127b until just before contact. _ξ Pitch mode estimation initialization means 135b for resetting the estimated value of each and the mode-specific electromagnet control voltage e for stably levitation of the partition 54 _z , e _ξ , A vertical movement mode control voltage calculation circuit 137a and a pitch mode control voltage calculation circuit 137b as an excitation voltage calculation unit 136 for calculating the vertical movement mode attitude estimation unit 127a and the pitch mode attitude estimation unit 127b, respectively. Output e of the mode control voltage calculation circuit 137a, 137b _z , e _ξ To the magnet excitation voltages e of the magnet units 60a and 60b. _a , e _b And a control voltage coordinate inverse conversion circuit 139 as an excitation voltage calculation unit 136 for calculating Then, the calculation result of the control voltage coordinate inverse transformation circuit 139, that is, the voltage e described above. _a , e _b Is supplied to the power amplifiers 113a and 113b.
[0046]
Here, since the posture of the partition 54 is maintained by the upper support member 46 and the lower support member 52 when the partition 54 is in contact, the upper support member 46 and the lower support member 52 are auxiliary support means in the present embodiment. Configure.
[0047]
The posture at the time of contact of the partition 54 includes:
(1) Posture in which the magnet units 60a and 60b are in contact with the upper support member 46 via the piezoelectric rubbers 73a and 73b (the gap length of the magnet unit 60a is z _a1 The gap length of the magnet unit 60b is z _b1 )
(2) Posture in which the bottom frame 95 is in contact with the lower support member 52 via the buffer member 97 (the gap length of the magnet unit 60a is z _a2 The gap length of the magnet unit 60b is z _b2 ),
(3) A posture in which the magnet unit 60a is in contact with the upper support member 46 through the piezoelectric rubber 73a and the bottom frame 95 is in contact with the lower support member 52 through the buffer member 97 (the gap length of the magnet unit 60a is z _a3 The gap length of the magnet unit 60b is z _b3 ),
(4) Position in which the magnet unit 60b is in contact with the upper support member 46 via the piezoelectric rubber 73b and the bottom frame 95 is in contact with the lower support member 52 via the buffer member 97 (the gap length of the magnet unit 60a is z _a4 The gap length of the magnet unit 60b is z _b4 )
There are four patterns. The contact detection means 129 outputs pattern signals “6”, “1”, “5”, “3”, for example, corresponding to these contact posture patterns. The contact detection means 129 outputs a pattern signal “0” by regarding other patterns as floating states.
[0048]
In the vertical motion mode posture calculation means 131a, according to the output of the contact detection means 129,
[Equation 5]

Is calculated. That is, when the output of the contact detection means 129 is 6, z _a To z _a1 Is assigned and z _b To z _b1 Is substituted. Where z ₀ Is an average value of the floating gap lengths of the magnet units 60a and 60b when in a predetermined floating state. When the output of the contact detection means 129 is the pattern signal “1”, z _a To z _a2 But z _b To z _b2 Is substituted and z for signal “5” _a To z _a3 But z _b To z _b3 Is substituted. When the output of the contact detection means 129 is the pattern signal “3”, z _a To z _a4 But z _b To z _b4 Is substituted and the vertical deviation Δz at the time of contact based on the output of the contact detection means 129 ₀ Is calculated. Similarly, in the pitch mode attitude calculating means 131b, l _ξ Is the distance between the centers of the magnet units 60a and 60b.
[Formula 6]

Based on the output of the contact detection means 129, the pitch deviation Δξ at the time of contact ₀ Is calculated.
[0049]
The vertical movement mode posture estimation means 127a is configured as shown in FIG. 9 together with the vertical movement mode initial value setting means 133a and the vertical movement mode estimation initialization means 135a. That is, in order to realize the observer in the up / down mode, the up / down motion mode attitude estimation means 127a outputs the output Δi of the excitation current deviation coordinate conversion circuit 125. _z , Gain integrators 147, 149, 151, gain compensator 153 that receives the output of the integrator 147, and gain compensator 155 that receives the output of the integrator 149. 157, gain compensators 159, 161 and 163 for inputting the output of the integrator 151, and the output e of the vertical movement mode control voltage calculation circuit 137a _z Is added to the gain compensator 165, the adder 167 that adds the outputs of the gain compensators 141, 155, and 159 and outputs the input to the integrator 147, and the outputs of the gain compensators 143, 153, and 161 The adder 169 that outputs the input to the integrator 149, the adder 171 that adds the outputs of the gain compensators 145, 157, 163, and 165 and outputs the input to the integrator 151, and each integrator 147 , 149, 151, initial value setting (not shown), estimation initialization means (not shown), each of the integrators 147, 149, 151, and branching to the gain compensator 157 A limiter 184 as an estimated output limiting means for limiting the output of the integrator 147 within a predetermined value range.
[0050]
Each integrator 147, 149, 151 has the same configuration. For example, the integrator 147 and the initial value setting means and estimated initialization means associated therewith are configured as shown in FIG. That is, the integrator 147 including a resistor 185 to which the output of the adder 167 is input, a capacitor 187, and an operational amplifier (operational amplifier) 189 includes a relay unit 191 that short-circuits the capacitor 187. When the output of the contact detection means 129 becomes zero due to contact detection, the relay unit 191 operates to short-circuit the capacitor 187, and the integration result of the integrator 147 is reset to zero. In the present embodiment, the relay unit 191 that is short-circuited by contact detection of the contact detection unit 129 constitutes the vertical motion mode estimation initialization unit 135 ′. On the other hand, the output of the integrator 147 is connected to the resistor 193. Δz output from the vertical movement mode posture calculation unit 131a by the contact detection of the resistor 193 and the contact detection unit 129. ₀ Enter Δz ₀ The initial value voltage generating device 195 for generating a voltage corresponding to the above, a resistor 197 connected to the initial value voltage generating device 195, resistors 199 and 201, and an operational amplifier 203 form an initial value setting means 133 ′ in the vertical movement mode. It is composed. The other integrators 149 and 151 have the same configuration, but the initial value voltage generator 195 associated therewith outputs zero as an initial value corresponding to the integrators 149 and 151. The estimation initialization means and initial value setting means 133 ′ associated with these three integrators 147, 149, 151 constitute a vertical movement mode estimation initialization means 135a and a vertical movement mode initial value setting means 133a as a whole, The output of the differentially configured operational amplifier 203 becomes the output of each integrator 147, 149, 151. That is, the vertical deviation Δz, the speed d (Δz) / dt, and the excitation current deviation Δi, which are the estimation results of the vertical movement mode posture estimation means 127a. _z Each estimated value is output.
[0051]
Similarly, the pitch mode posture estimating means 127b, the pitch mode initial value setting means 133b, and the vertical movement mode estimation initializing means 135b are also configured as shown in FIGS. For simplicity, the corresponding input / output signals are indicated by signal names and description thereof is omitted. However, in the pitch mode, the initial value voltage generator 195 associated with the integrator 147 outputs Δξ output from the pitch mode attitude calculating means 127b. ₀ And enter Δξ ₀ Is configured to generate a voltage corresponding to. From the pitch mode integrators 147, 149, 151, the pitch deviation Δξ, the speed d (Δξ) / dt, and the excitation current deviation Δi, which are the estimation results of the pitch mode attitude estimation means 127b, are obtained. _ξ Is estimated.
[0052]
The vertical movement mode control voltage calculation circuit 137a is configured as shown in FIG. 11, for example. That is, the vertical deviation Δz, its speed d (Δz) / dt and Δi _z A gain compensator 205 for multiplying the estimated value by an appropriate feedback gain, a current deviation target value generator 207, Δi _z Is subtracted from the target value of the current deviation target value generator 207, the integration compensator 211 that integrates the output value of the subtractor 209 and multiplies an appropriate feedback gain, and the sum of the output values of the gain compensator 205 is calculated. The outputs of the adder 213 and the integral compensator 211 to be input are output as a value equal to the input within a predetermined range, and when the input exceeds the upper limit value of the same range, the upper limit value is output and the lower limit value is set. When the value is lower, the integral output limiting means 215 for outputting the lower limit value, and the output value of the adder 213 is subtracted from the output value of the output limiting means 215 to obtain the z-mode electromagnet excitation voltage e. _z And a limiter 218 as voltage output limiting means for limiting the output of the subtractor 217 within a range of a predetermined value.
[0053]
The pitch mode control voltage calculation circuit 137b is also configured in the same manner as the vertical movement mode control voltage calculation circuit 137a, and corresponding input / output signals are indicated by signal names, and description thereof is omitted.
[0054]
Next, the operation of the partition support device according to the first embodiment configured as described above will be described.
[0055]
When the apparatus is in a stopped state, the tips of the iron cores 68 (68 ′) of the magnet units 60 a and 60 b are attracted to the lower surface of the guide rail 44 through the piezoelectric rubber 73. When the apparatus is started in this state, in the control apparatus 70, the contact detecting means 129 detects the contact of the partition 54 with the upper support member 46 by the action of the piezoelectric rubber 73, and outputs the pattern signal “6”. In the calculation means 127a and 127b, the gap length of the magnet unit 60a is z. _a1 The gap length of the magnet unit 60a is z _b1 Based on the above, the estimated initial value Δz of the z-mode vertical deviation is given by Equation (10) and Equation (11) ₀ And ξ mode pitch deviation estimated initial value Δξ ₀ Is calculated. In the posture estimation means 127a and 127b in each mode, the estimated initial value is set by the initial value setting means 133a and 133b. At this time, since the output of the contact detection means 129 is not zero in the estimation initialization means 135a, 135b, the relay unit 191 is turned on, the integrators 147, 149, 151 are short-circuited, the integration result is cleared, and the attitude estimation means 127a 127b are initialized. Thus, the vertical deviation Δz output from the posture estimation means 127a by the action of the initial value setting means 133a, its speed d (Δz) / dt and Δi _z The estimated values of ₀ , 0, 0, the pitch deviation Δξ output from the posture estimation means 127b by the action of the initial value setting means 133b, the speed d (Δξ) / dt, and the excitation current deviation Δi _ξ Is estimated by Δξ ₀ , 0, 0.
[0056]
The control voltage calculation circuits 137a and 137b in each mode receive the vertical deviation Δz when the estimation results of the posture estimation means 127a and 127b are input. ₀ , Pitch deviation Δξ ₀ Exciting voltage e _z , E _ξ Calculate The control voltage coordinate inverse conversion circuit 139 receives the excitation voltage calculation results of the control voltage calculation circuits 137a and 137b and receives the excitation voltage e of the coils 69a and 69b. _a , E _b Is calculated, and the attractive forces of the magnet units 60a and 60b are controlled via the power amplifiers 113a and 113b. In this state, the control device 70 generates a magnetic flux in a direction opposite to the magnetic flux generated by the permanent magnet 64 in each of the electromagnets 66 and 66 ′, and maintains a predetermined gap length between the magnet units 60a and 60b and the guide rail 44. In order to achieve this, the current flowing through the coils 69a and 69b is controlled. As a result, the partition 54 moves away from the lower surface of the guide rail 44 to a floating state. When the partition 54 shifts to the floating state, the contact detection means 129 outputs 0, whereby the relay unit 191 is turned off in the estimation initialization means 135a and 135b, and the integrators 147, 149 and 151 start the integration operation. To do. At this time, in the initial value setting means 133a, 133b, since the contact detection means 129 outputs 0, the output value at the time of the previous contact is maintained. Thereby, in the ascent start state, the posture estimation means 127a sets the initial value to (Δz ₀ , 0,0), the posture estimation means 127b sets the initial value to (Δξ ₀ , 0, 0). According to the equation (8), the estimation errors of the posture estimation means 127a and 127b decrease rapidly with time as the initial value error is small.
[0057]
In this embodiment, since the vertical deviation and pitch deviation at the start of ascent match the estimated initial value, the error at the start of estimation is reduced, and the estimated value rapidly converges to the actual value. The posture of the partition 54 is limited by the upper support member 46 and the lower support member 52, but the upper and lower limit values of the vertical deviation and the pitch deviation are set as saturation ranges in the limiter 184, and the estimated value is the actual value. In the transition period until the value converges, the posture estimation means 127a and 127b do not output an abnormal value. Therefore, the excitation voltage e of each mode calculated by the control voltage calculation circuits 137a and 137b. _z , E _ξ The control voltage coordinate inverse conversion circuit 139 receives the excitation voltage calculation results of the control voltage calculation circuits 137a and 137b and receives the excitation voltage e of the coils 69a and 69b. _a , E _b Is calculated, and the attractive forces of the magnet units 60a and 60b are controlled without abnormality through the power amplifiers 113a and 113b.
[0058]
When the suction force control is performed without abnormality at the start of levitation in this way, the permanent magnet 64 → the iron core 68 → the gap G → the guide rail 44 → the gap G ′ → the iron core 68 ′ → the permanent magnet 64 as shown in FIG. The magnetic circuit Mc consisting of the path is stabilized, and the gap length in the gaps G and G ′ is the z-axis where the magnetic attractive force of each of the magnet units 60 a and 60 b due to the magnetomotive force of the permanent magnet 34 acts on the center of gravity of the partition 54. The length is just balanced with the direction gravity and the torque around the y-axis. When an external force is applied to the partition 54 in order to maintain this balance, the control device 70 performs excitation voltage control of the electromagnets 66a and 66b ', so-called zero power control is performed.
[0059]
Here, the case where the sliding door shown in FIG. 12 is comprised using the magnetic levitation apparatus 10 in connection with this Embodiment is demonstrated. This sliding door is constituted by a magnetic levitation device attached to the opening portion of the wall surface 220, and the guide rail 44 is slightly inclined toward the left end of the opening portion and the wall surface 220 side (towards the x direction and the y direction). The partition body 54 that is attached and supported in a non-contact manner under zero power control is in a state in which the door is closed without applying a force from the outside. In this state, the opposing surfaces of the guide rail 44 facing the magnet units 60a and 60b have portions A, B, and C where the magnetic body is overhanging, and the magnet units 60a and 60b are moored with an attractive force to this portion. Acts as a force. For this reason, the partition 54 does not open by a slight sway of the wind or the building. Now, when the door is opened, if a force in the x direction is applied to the partition 54, the guide wheels 88 and 88 ′ move along the straight portion of the groove 50, and the guide shoe 86 moves along the upper guide groove 56. Therefore, the non-contact supported partition 54 moves lightly and smoothly and the door opens. The opened door slides along the inclination of the guide rail 44, and the door is closed again. On the other hand, when the closed door is pushed in the y direction, the guide wheel 88 moves along the curved portion of the groove 50, so that the partition 54 moves the axle 93 of the guide wheel 88 ′ and the support rod 84 of the guide shoe 86. Start rotating around the center. At this time, it goes without saying that the axial centers of the axle 93 and the support rod 84 coincide with each other. The partition 54 that has started to rotate moves in the x direction while sequentially shifting to the posture represented by the straight lines L1 to L7 drawn between the two axles 93. That is, in the magnetic levitation apparatus according to the present embodiment, the door operating force and the noise at the time of opening and closing are remarkably reduced by supporting the weight of the partition body in a non-contact manner, and the partition body has a smooth two-dimensional structure. Even when the sliding door is opened from the wheelchair, the sliding door can be easily opened by pushing the door, and the operability and operational feeling can be remarkably improved.
[0060]
When the partition 54 is supported in a non-contact manner, the guide wheels 88 and 88 'and the guide shoe 86 are fitted in the groove 50 and the upper guide groove 56, respectively, so that an excessive horizontal external force can be prevented. The partition 54 does not fall down.
[0061]
On the other hand, even if the partition 54 comes into contact with the upper support member 46 or the lower support member 52 due to an excessive disturbance, in the magnetic levitation apparatus of the present invention, the posture at the time of the contact of the partition 54 described above. (1) to (4) are detected by the contact detection means 129, and the posture estimation means 127 outputs a normal estimated value by the action of the posture calculation means 131, the initial value setting means 133, and the estimation initialization means 135. For this reason, the partition 54 returns to the floating state without hindrance.
[0062]
Here, when the partition 54 collides with the upper support member 46 or the lower support member 52 due to excessive disturbance, the estimated value of the posture estimation means 127 changes abruptly. With such a sudden change, the estimated speed value of the vertical deviation and the estimated speed value of the pitch deviation also change rapidly. Then, the excitation voltage exceeding the capability of the power supply device 72 is output from the control voltage calculation circuits 137a and 137b in each mode. In this case, the excitation voltage e input to the posture estimation means 127a, 127b _z , Eξ is actually e _a , E _b This is different from the excitation voltage value for each mode obtained from the above. If it does so, it will become impossible to perform normal attitude | position estimation in attitude | position estimation means 127a, 127b, and it will become difficult to stabilize a floating state. However, in the magnetic levitation apparatus 10 according to the present embodiment, the vertical movement mode control voltage calculation circuit 137a and the pitch mode control voltage calculation circuit 137b of the excitation voltage calculation unit 136 include limiters 218 as respective voltage output limiting means. ing. In the limiter 218, the voltage value in each mode related to the capability limit of the power supply device 72 is set as a saturation value, and the excitation voltage e input to the posture estimation means 127a, 127b. _z , E _ξ Is actually e _a , E _b There is no difference from the value of the excitation voltage for each mode obtained from the above. For this reason, even if the partition 54 collides with the upper support member 46 or the lower support member 52 due to an excessive disturbance, the posture estimation means 127a and 127b operate without any trouble, and the partition 54 returns to the floating state again. . Thus, in the magnetic levitation apparatus according to the present invention, the reliability of the levitation state can be greatly improved.
[0063]
As shown in FIGS. 4 and 12, when the guide rail 44 has a branching portion, the conventional magnetic levitation apparatus having the gap sensor is arranged along the locus of the gap sensor and conforms to the sensor detection principle. However, since the gap sensor is unnecessary in the magnetic levitation apparatus of the present invention, the sensor target can be omitted, and the apparatus can be simplified and reduced in cost.
[0064]
Thus, in order to stop the magnetic levitation 10 that has maintained the stable levitation state, for example, the current target value of the z-mode current target value generator 207 may be changed from zero to a predetermined negative value. Thereby, the partition 54 is adsorbed to the upper support member 46. Here, the operation of the apparatus can be stopped by turning off a switch (not shown) of the power supply apparatus 72.
[0065]
<Second Embodiment>
Next, a second embodiment of the present invention will be described with reference to FIG. In the first embodiment, the magnet unit is attached to the floating body side, but this does not limit the attachment position of the magnet unit, and the magnet unit is arranged on the ground side as shown in FIG. May be. For simplification of description, the same reference numerals are used for portions common to the first embodiment.
[0066]
The magnetic levitation device 300 has a U-shaped cross section and is formed of a non-magnetic material, for example, an aluminum member. The auxiliary support means 302 is installed on the ground, and the magnet unit 60 is attached to the upper lower surface of the auxiliary support means 302 downward. A guide 304 formed of a ferromagnetic member having a U-shaped cross section facing the magnet unit 60, for example, iron, and a vibration isolation table 306 having a guide 304 on the upper surface of the bottom and formed in a U-shape as a whole. The linear guide 308 that is attached to the side surface of the vibration isolation table 306 and provides the vibration isolation table 306 with a degree of freedom of movement only in the direction perpendicular to the ground, and the vibration isolation table by controlling the attractive force of the magnet unit 60 And a suction force control means 15 for non-contact support.
[0067]
The attraction force control means 15 is a contact detection means 314 having a micro switch 310 attached to the upper surface of the bottom of the auxiliary support means 302 and a piezoelectric rubber 312 stretched on the magnetic pole surface of the magnet unit 60, and a contact detection means 314 contact. From the detection signal to the vibration isolation table 306 of the vibration isolation table 306 or the magnet unit 60, the attitude calculation means 35 that calculates the floating gap length, the current sensor 23 that detects the excitation current of the magnet unit 60, and the magnet unit 60 Attitude estimation means 25 for estimating the floating attitude of the vibration isolation table 306 from the excitation current and excitation voltage, an initial value setting means 39 for setting an estimated initial value in the attitude estimation means 33 based on the output of the attitude calculation means 35, An estimation initialization unit 13 that initializes the posture estimation unit 25 based on the output of the contact detection unit 314; and a posture estimation unit 2 An excitation voltage calculation unit 25 that calculates an excitation voltage to the magnet unit 60 for magnetically levitating the vibration isolation table 306 based on the output of the vibration isolation table 306 and an excitation of the magnet unit 60 based on the output of the excitation voltage 25 are not shown. And a power amplifier 113 connected to a power source.
[0068]
By arranging the magnet unit in this way, there is an advantage that the weight of the vibration isolation table can be reduced by the amount of the magnet unit.
[0069]
<Third Embodiment>
A third embodiment of the present invention will be described with reference to FIG. In the first and second embodiments described above, the same dimensional state observer is used as the posture estimation means. However, this does not limit the configuration of the posture estimation means, and is within the scope of the gist of the present invention. Any estimation means can be used. For example, a configuration using the minimum dimension observer shown in FIG. 14 may be used.
[0070]
For example, in the magnetic levitation apparatus 300 of FIG. 13, the posture estimation means 400 configured with the following minimum dimension observer can be used. That is,
[Expression 7]

Where z _ob Is the observer state vector, α ₁ , Α ₂ Is the parameter that determines the pole of the observer, y = Δi _z It is.
[0071]
Attitude estimation means 400 uses Δi _z Gain compensators 402, 404, 406, 407, integrators 408, 410, a gain compensator 412 that receives the output of the integrator 408, and a gain compensator 414 that receives the output of the integrator 410. 416 and the output e of the excitation voltage calculator 324 _z , The gain compensator 418, 420, the adder 422 that adds the outputs of the gain compensators 404, 406, 414 and outputs the input to the integrator 408, and the gain compensators 412, 416, 418, 420 Of the gain compensator 402 and the integrator 408, and the output of the gain compensator 407 and the integrator 410 are added. An adder 428 that outputs an estimated value of the speed d (Δz) / dt and a limiter 430 as an estimated output limiting means that limits the output of the adder 426 within a predetermined value range. Needless to say, the output of the limiter 430 is an estimated value of the vertical deviation Δz.
[0072]
Further, the attitude calculation means 400 has Δi _z The switching means 432 is provided at the input end of the. In the switching means 432, while the contact detection means 314 detects contact, Δi that has been input until then is detected. _z Is switched to zero and when no contact is detected, the zero is _z It has the function to switch to. When using the minimum dimension observer as posture estimation means, Δi _z Is output directly as an estimated value of the vertical deviation Δz via the gain compensator 402 → adder 426 → limiter 430, so that α is added to the posture information of the image stabilization table 306 at the time of contact of the integrator 408 set at the time of contact. ₁ Δi _z Will be added. Then, the estimated value of the vertical deviation Δz of the posture calculation means 400 is different from the actual value, and the transition of the anti-vibration table 306 to the floating state is hindered. In this case, the action of the switching means 432 causes the posture information of the vibration isolation table 306 to be ₁ Δi _z Are not added, and the output of the posture calculation means 400 is close to the actual value. In this case, the reliability is improved without causing any trouble in the transition of the vibration isolation table 306 to the floating state. In this embodiment, Δi _z The switching means 432 is provided at the input end of the input, but this is a means for bringing the estimated value at the time of contact of the posture estimation means closer to the actual value. Depending on the configuration of the posture estimation means, e _z There is no problem even if the switching means 432 is provided at the input terminal. In the present embodiment, the minimum dimensional observer is applied to the attitude calculation means. In this case, there is an advantage that the number of integrators can be reduced.
[0073]
<Modification>
In each of the above embodiments, the control device that performs magnetic levitation control is described as if it was an analog type, but the control device of the present invention is not limited to an analog type, but a digital type. It can also be implemented.
[0074]
In each of the above embodiments, a voltage amplifier is used as the power amplifier. However, this does not limit the power amplifier system, and may be a PWM amplifier, for example.
[0075]
In addition, in each of the above embodiments, a U-shaped magnet unit is used. However, this does not limit the shape of the magnet unit, and may be, for example, an E-shaped one.
[0076]
Furthermore, 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 can be configured only with an electromagnet without having a permanent magnet. good.
[0077]
Moreover, although the voltage type thing is used as a power amplifier (power amplifier), this does not limit the electromagnet drive system of a driver at all, For example, a PWM type thing may be used.
In addition to the above, various modifications can be made without departing from the scope of the present invention.
[0078]
【The invention's effect】
According to the magnetic levitation apparatus of the present invention, information on the gap length and its speed can be estimated from the exciting current of the magnet unit, and magnetic levitation can be performed without the gap sensor. For this reason, not only the cost of the gap sensor is reduced, but also the sensor target is not necessary, and the cost of the entire system can be reduced by simplifying the apparatus.
[0079]
In addition, since linear control theory can be applied, robust stability in the floating state can be ensured and reliability of the apparatus can be improved as compared with the conventional sensorless magnetic levitation method.
[Brief description of the drawings]
FIG. 1 is a configuration diagram for explaining the principle of the present invention.
FIG. 2 is another configuration diagram for explaining the principle of the present invention.
FIG. 3 is a perspective view showing the overall configuration of the first embodiment of the magnetic levitation apparatus according to the present invention.
4 is a plan view of the embodiment of FIG. 3. FIG.
FIG. 5 is a front view of the embodiment of FIG. 3;
6 is an elevation view of the embodiment of FIG.
7 is an elevation view of the magnet unit in the embodiment of FIG. 3; FIG.
8 is a block diagram showing an internal configuration of a control device in the embodiment of FIG.
9 is a block diagram showing a detailed configuration of posture estimation means in the control device in the embodiment of FIG.
10 is a circuit diagram showing a configuration around an integrator of posture estimation means in the embodiment of FIG. 3;
11 is a circuit diagram showing a detailed configuration of a control voltage calculation circuit in the control device in the embodiment of FIG. 3;
12 is a plan view for explaining the operation of the partition body in the embodiment of FIG. 3; FIG.
FIG. 13 is a block configuration diagram showing the overall configuration of a second embodiment of a magnetic levitation apparatus according to the present invention.
FIG. 14 is a block diagram showing the configuration of posture estimation means in the third embodiment of the magnetic levitation apparatus according to the present invention.
[Explanation of symbols]
1,1 ', 40,300 Magnetic levitation device
3,64 permanent magnet
5,66,66 'electromagnet
7, 60, 60a, 60b Magnet unit
9 Load weight
11 Floating body
13,304 Guide
15 Suction force control means
17a, 17b yoke
19a, 19b, 69, 69 ', 69a, 69b coil
21 Gap sensor
23 Current sensor
25,324 Excitation voltage calculator
27 Driver
28, 73a, 73b, 312 Piezoelectric rubber
29,129,314 Contact detection means
31,302 Auxiliary support means
33, 127a, 127b, 318, 400 Posture estimation means
35, 131a, 131b, 316 Attitude calculation means
37, 135a, 135b, 322 Estimation initialization means
39, 133a, 133b, 320 Initial value setting means
42 Ceiling
44 Guide rail
45 Flat correction member
46 Upper support member
48 floors
50 grooves
52 Lower support member
54 Partition
56 Upper guide groove
62, 62 'base plate
68,68 'iron core
70 Controller
72 Power supply
80 frame
82 divider
83 Fixed base
84 Support rod
86 Information shoe
88, 88 'guide wheels
89 Guard members
91 Side frame
93 axles
95 Bottom frame
97 Buffer member
101 Upper base
103 Lower base
104 Side plate
105 Upper frame
107 cover
111 Sensor unit
112 Arithmetic circuit
113, 113a, 113b Power amplifier
114 Cooling fin
121a, 121b current detector
123a, 123b, 209, 217 subtractor
125 Excitation current deviation coordinate conversion circuit
127a Vertical motion mode posture estimation means
127b Pitch mode posture estimation means
136 Control voltage calculator
137a Vertical movement mode control voltage calculation circuit
137b Pitch mode control voltage calculation circuit
139 Control voltage coordinate reverse conversion circuit
141, 143, 145, 153, 155, 157, 159, 161, 163, 205, 402, 404, 406, 407, 412 Gain compensator
147, 149, 151, 408, 410 integral compensator
167, 169, 171, 213, 422, 424, 426, 428 adder
184, 218, 430 Limiter
185, 193, 197, 199, 201 Resistance
187 capacitor
189,203 operational amplifier (operational amplifier)
191 Relay part
195 Initial voltage generator
207 Current target value generator
215 Output limiting means
220 Wall
306 Anti-vibration table
308 Linear Guide
310 micro switch

Claims (18)

A magnet unit with an electromagnet;
A levitated body supported by the magnet unit;
A ferromagnetic member for supporting the levitation 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;
Auxiliary support means for maintaining the positional relationship between the floating body and the ferromagnetic member when the floating body is not in a floating state;
A sensor unit for detecting an excitation current of the electromagnet;
Attitude estimation means for estimating the attitude of the floating body relative to the ferromagnetic member based on the output of the sensor unit, contact detection means for detecting contact between the floating body and the ferromagnetic member or the auxiliary support means, the contact Attitude calculation means for calculating the attitude of the floating body with respect to the ferromagnetic member at the time of contact based on the output of the detection means; Based on the output of the posture estimation means , the initial value setting means for setting the output value of the posture calculation means as the initial value of the posture estimation means when the posture estimation means is initialized. attraction system which unit has a drive means, for controlling the suction force of the magnet unit so as to stabilize the magnetic circuit is formed through the gap and the ferromagnetic member And means,
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 to zero based on the output of the sensor unit. The magnetic levitation device as described.   The magnetic levitation apparatus according to claim 3, wherein the zero power control means is constituted by the posture estimation means.   The posture estimation means estimates a posture of the levitating body with respect to the ferromagnetic member and a time change of the posture based on an exciting current of the electromagnet and an exciting voltage generating the exciting current. Item 2. The magnetic levitation device according to item 1.   The posture estimation means receives the output of the posture estimation means, outputs the input value as it is when the input is within a predetermined saturation range, and outputs the saturation value when it is outside the predetermined saturation range The magnetic levitation apparatus according to claim 1, further comprising output limiting means.   The said attraction force control means is provided with the excitation voltage calculating part which calculates an electromagnet excitation voltage based on the output of the said estimation output restriction means, and gives the output to the said drive means. Magnetic levitation device.   The excitation voltage calculation unit inputs the output of the excitation voltage calculation unit, outputs the input value as it is when the input is within the predetermined saturation range, and outputs the saturation value when it is outside the predetermined saturation range. The magnetic levitation apparatus according to claim 7, further comprising a voltage output limiting unit configured to operate. The excitation voltage calculation unit is configured to generate an excitation voltage for each mode represented by a linear combination of the electromagnet excitation voltages so as to generate an attractive force that contributes to the freedom of movement of the levitating body based on the output of the estimated output limiting unit. the magnetic levitation device as claimed in claim 7, characterized in that it comprises a mode exciting voltage calculator for calculating a. The attraction force control means includes a mode excitation current calculation unit that calculates an excitation current for each mode represented by a linear combination of the electromagnet excitation currents that generate an attraction force that contributes to the freedom of movement of the levitated body. The magnetic levitation apparatus according to claim 9.   The magnetic levitation apparatus according to claim 9, wherein the mode excitation voltage calculation unit includes the voltage output restriction unit that receives an output of the mode excitation voltage calculation unit.   The posture estimation means estimates the posture of the levitating body with respect to the ferromagnetic member and the time change of the posture based on the output of the mode excitation current calculation unit and the output of the mode excitation voltage calculation unit of the electromagnet. The magnetic levitation apparatus according to claim 10, wherein the levitation apparatus is a magnetic levitation apparatus. The posture estimation means has an integrator. When the contact detection means detects contact, the integration of the integrator is stopped by the estimation initialization means and the integration result is output by the initial value setting means. When the contact detection means no longer detects contact, the integration value of the integrator is started by the estimation initialization means with the value output by the initial value setting means at the time of the previous contact as an initial value. The magnetic levitation apparatus according to claim 1.   The posture estimation means switches the excitation current of the electromagnet and the output of the excitation voltage calculation unit input to the posture estimation means to zero input when the contact detection means detects contact, and the contact detection means 8. The magnetic levitation apparatus according to claim 7, further comprising switching means for switching a zero input to an excitation current of the electromagnet or an output of the excitation voltage calculation unit when contact is no longer detected.   The posture estimation unit switches the outputs of the mode excitation current calculation unit and the mode excitation voltage calculation unit input to the posture estimation unit to zero input when the contact detection unit detects contact, and detects the contact 11. The magnetic levitation apparatus according to claim 10, further comprising switching means for switching a zero input to an output of the mode excitation current calculation section or the mode excitation voltage calculation section when the means no longer detects contact.   2. The magnetic levitation apparatus according to claim 1, wherein the auxiliary support means is attached to the levitation body.   The magnetic levitation apparatus according to claim 1, wherein the auxiliary support means is attached to the ferromagnetic member. The magnetic levitation apparatus according to claim 1, wherein the magnet unit is attached to the levitation body.

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