JP3981549B2 - Washing machine control device - Google Patents

Description

そして、２軸電流データＩα，Ｉβをαβ／ｄｑ変換部６３に出力する。
【００５３】
αβ／ｄｑ変換部６３は、ベクトル制御時にはエスティメータ５９よりモータ１７のロータ位置角θを得ることで、（２）式に従って２軸電流データＩα，Ｉβを回転座標系（ｄ，ｑ）上のｄ軸電流値Ｉｄ，ｑ軸電流値Ｉｑに変換する。
【００５４】
【数２】

そして、ｄ軸電流値Ｉｄ，ｑ軸電流値Ｉｑを前述したようにエスティメータ５９及び減算器６１，６２に出力するようになっている。
【００５５】
エスティメータ５９は、ｄ軸電流値Ｉｄ，ｑ軸電流値Ｉｑに基づいてロータ１７ａの位置角θ及び回転速度ωを推定し、各部に出力する。ここで、モータ１７は、起動時には初期パターン出力部６８によって直流励磁が行われてロータ１７ａの回転位置が初期化された後、起動パターンが印加され強制転流が行われる。この起動パターンの印加による強制転流時においては、位置角θは推定するまでもなく明らかである。そして、αβ／ｄｑ変換部６３は、ベクトル制御が開始される直前において初期パターン出力部６８より得られる位置角θinitを初期値として、電流値Ｉｄ，Ｉｑを演算して出力する。
【００５６】
ベクトル制御の開始以降は、エスティメータ５９が起動されてロータ１７ａ位置角θ及び回転速度ωが推定される。この場合、エスティメータ５９がαβ／ｄｑ変換部６３に出力するロータ位置角θn とすると、エスティメータ５９は、電流値Ｉｄ，Ｉｑに基づいてベクトル演算により推定したロータ位置角θn-1 とその一周期前に推定したロータ位置角θn-2 との相関に基づいてロータ位置角θn を推定するようになっている。
【００５７】
尚、以上の構成において、インバータ回路１２，増幅・バイアス回路７０を除く構成は、マイコン５４のソフトウエアによって実現されている機能をブロック化したものである。そして、ベクトル制御における電流制御周期は、ＰＷＭ搬送波周波数の逆数である６２．５μ秒に設定されている。
【００５８】
また、本実施例では、モータ１７を起動する場合、後述するように、ベクトル制御の開始前にＰＩ制御を一時的に行うようになっている。そのため、図示しないＰＩ制御部及びＵＶＷ変換部を並列に備えており、実際には、そのＵＶＷ変換部より出力される電圧指令Ｖｕ，Ｖｖ，Ｖｗについても切換えスイッチ６７部分で切り替えてＰＷＭ形成部６９に出力することができるようになっている。
【００５９】
次に、本実施例の作用について図４乃至図１３をも参照して説明する。図４は、主にマイコン５４による概略的な制御内容を示すフローチャートである。マイコン５４は、例えば洗い運転を開始させる場合に前述した起動処理を行う（ステップＳ１）。即ち、切替えスイッチ６７ｕ〜６７ｗの可動接点６７ｕｃ〜６７ｗｃを固定接点６７ｕｂ〜６７ｗｂに接続して初期パターン出力部６８により直流励磁を行わせ、ロータ１７ａの回転位置を初期化させてから電圧指令値Ｖus〜Ｖwsをインバータ回路１２に与えてモータ１７を強制転流させる（ステップＳ２）。すると、モータ１７は回転を開始し、回転速度は徐々に上昇して行く。
【００６０】
それから、マイコン５４は、例えば、初期パターン出力部６８によって与えられる検知信号によりモータ１７の回転数が２０ｒｐｍに達したと判断すると（ステップＳ３，「ＹＥＳ」）、切替えスイッチ６７ｕ〜６７ｗの可動接点６７ｕｃ〜６７ｗｃを固定接点６７ｕａ〜６７ｗａに接続するように切り替えると共に目標速度指令ωref の出力を開始し電圧制御（ＰＩ制御）を行う（ステップＳ４）。即ち、回転速度が比較的低い領域では、ベクトル制御を高精度で行うことが困難となるからである。
【００６１】
続いて、マイコン５４は、エスティメータ５９より与えられる回転速度ωを参照してモータ１７の回転数が６０ｒｐｍに達したと判断すると（ステップＳ５，「ＹＥＳ」）、ベクトル制御を開始させる（ステップＳ６）。その後は、運転停止の指示があるまで運転を継続する（ステップＳ７）。
【００６２】
以下、ステップＳ６以降におけるベクトル制御について処理の流れを説明する。ＰＷＭ形成部６９は、内部のアップダウンカウンタ（図示せず）のカウンタ出力によって１６ｋＨｚのＰＷＭ搬送波を生成しており、そのカウンタ値が“０”，即ち三角波の谷に達した時点で変換タイミング信号をＡ／Ｄ変換部５６に出力するようになっている（図５参照）。
【００６３】
図５に示すように、ＰＷＭ形成部６９は、αβ／ＵＶＷ変換部６６が出力する電圧指令値Ｖｕ〜ＶｗとＰＷＭ搬送波とのレベルを比較して、後者のレベルが前者を上回っている期間に上アーム側のＩＧＢＴ１５ａ〜１５ｃがオンするようにＰＷＭ信号Ｖup(+) 〜Ｖwp(+) を出力する。そして、下アーム側のＩＧＢＴ１５ｄ〜１５ｆは、上アーム側のＩＧＢＴ１５ａ〜１５ｃがオフしている期間にデッドタイムを挟んでオンされるようになっている。
【００６４】
また、図６には、モータ１７の相電流の反転ＩMINVとシャント抵抗５５に流れる電流ＩSR及び相電圧との関係を示す波形図である。即ち、電流ＩSRが流れる期間は、下アーム側のＩＧＢＴ１５がオンして相電圧が０Ｖを示す場合である。従って、三角波の谷は、下アーム側のＩＧＢＴ１５ｄ〜１５ｆがオンしている期間の中間位相を示すことになる。つまり、Ａ／Ｄ変換部５６が、ＰＷＭ形成部６９内部のカウンタ値“０”の時点でＡ／Ｄ変換を行うようにすれば、インバータ回路１２の下アーム側に流れる相電流を確実にサンプリングすることができる。
【００６５】
Ａ／Ｄ変換部５６によりＡ／Ｄ変換された２相の電流値は、推定された残り１相の電流値と共にＵＶＷ／αβ変換部７１，αβ／ｄｑ変換部６３を介すことで２軸電流データＩα，Ｉβ，→Ｉｄ，Ｉｑに変換され、エスティメータ５９及び減算器６１，６２に出力され、エスティメータ５９によって位置角θ及び回転速度ωが推定される。尚、電流Ｉｑは、モータ１７の２次磁束の方向に対して垂直となる方向に流れる電流であり、トルクの発生に寄与する電流成分である。一方、電流Ｉｄは、２次磁束の方向に対して平行となる方向に流れる電流であり、トルクの発生には寄与しない電流成分である。
【００６６】
そして、速度ＰＩ制御部６０は、速度指令値出力部５７より与えられる目標速度指令ωref と検出速度ωとの差分量に基づいてｑ軸，ｄ軸電流指令値Ｉqref，Ｉdrefを出力し、電流ＰＩ制御部６４ｑ，６４ｄは、指令値Ｉqref，Ｉdrefと検出された電流値Ｉｑ，Ｉｄとの差分に基づいて電圧指令値Ｖｑ，Ｖｄを出力する。電圧指令値Ｖｑ，Ｖｄは、ｄｑ／αβ変換部６５，αβ／ＵＶＷ変換部６３を介して電圧指令値Ｖｕ，Ｖｖ，Ｖｗに変換されてＰＷＭ形成部６９に出力され、ＰＷＭ形成部６９がインバータ回路１２にＰＷＭ信号Ｖup〜Ｖwpを出力する。すると、モータ１７の各相巻線１７ｕ〜１７ｗに通電が行われる。
【００６７】
ここで、図７は、モータ１７に二相変調波通電を行った場合、各相巻線に現れる相電圧Ｖmu，Ｖmv，Ｖmwと、Ａ／Ｄ変換部５６における各相電流の検出タイミングを示すものである。この図において、相電圧が高いほど、対応する上アーム側のＩＧＢＴ１５ａ〜１５ｃがオンしている時間は長く、下アーム側のＩＧＢＴ１５ｄ〜１５ｆがオンしている時間は短い。そして、シャント抵抗５５による電流の検出は、下アーム側のＩＧＢＴ１５ｄ〜１５ｆがオンしている期間でなければできないので、上述し、図５に示したように、Ａ／Ｄ変換はＰＷＭ搬送波の三角波の谷に達したタイミングで行っている。
【００６８】
また、下アーム側のＩＧＢＴ１５ｄ〜１５ｆがオンしている時間でなければ電流検出ができないということは、電流検出が不能となる期間が各相毎に存在することを示している。しかし、三相の電流の内の二相を検出できれば、残りの一相は推定することが可能であるから、Ａ／Ｄ変換部５６において、検出可能な二相の電流を順次切り換えてれば三相分の電流を常時検出することができる。
【００６９】
ところが、ＰＷＭ搬送波は三相とも共通の信号であるから、二相のＡ／Ｄ変換タイミングは同時になる。搬送波周波数は１６ｋＨｚであるから電流制御周期は最短で６２．５μ秒となるが、Ａ／Ｄ変換に要する時間が例えば１μ秒程度の短時間である場合は、１つのＡ／Ｄコンバータで二相のＡ／Ｄ変換をシリアルに行っても問題はない。しかし、一般に、マイクロコンピュータに搭載されるＡ／Ｄコンバータはそれ程高速ではない。
【００７０】
そこで、本実施例では、２つのＡ／Ｄコンバータ５６Ａ，５６Ｂに夫々三相分の電流信号を与えて、夫々のコンバータ５６Ａ，５６Ｂにおいて、何れか一相の電流信号の入力を切り換えてＡ／Ｄ変換することで、同時に二相分のＡ／Ｄ変換値を得るようにしている。斯様に構成することで、Ａ／Ｄ変換部５６のＡ／Ｄ変換速度が低速（例えば、６μ秒）であっても、十分に対応することが可能となっている。
【００７１】
ここで、図８は、回転槽４５を２５０ｒｐｍで回転させた場合に回転速度が変動する状態を示すものであり、（ａ）は本実施例の構成による場合、（ｂ）は従来構成による場合（即ち、電圧による制御）を示す。尚、２５０ｒｐｍは、防振機構４４のダンパー４４ｂの固有振動するに対応した回転数である。円の直径方向は回転速度の大きさ（２５０ｒｐｍを中心として±３ｒｐｍ）を表し、周方向は回転槽４５の回転位置を表している。尚、（洗濯物＋水分）に相当する負荷として１６ｋｇのウエイトを回転槽４５内に配置している。また、回転槽４５の上端部，下端部には、夫々４００ｇ，３００ｇの流体バランサを配置している。
【００７２】
図８（ｂ）に示す従来構成の場合は、回転変動に回転角と連動した周期性を有しており、特定の回転位置について大きく偏るように回転変動が発生している （最大変動差は６ｒｐｍ程度）。これに対して、図８（ａ）に示す本実施例の構成による場合、回転速度は回転位置の全般に渡って略２５０ｒｐｍとなっている（最大変動差は１ｒｐｍ程度）。即ち、本実施例の構成により回転変動が効果的に抑制されていることが明らかである。
【００７３】
ところで、図４に示すフローチャートは、マイコン５４が、例えば洗い運転を開始させる場合として説明したが、脱水運転を行う場合のモータ１７の初期駆動手順も、図４に示すフローチャートに示すものと同様にして行うようにしている。この場合、回転槽４５の回転数が６０ｒｐｍを超えると電圧制御からベクトル制御に切り替わるが、６０ｒｐｍ程度の脱水運転における低速回転域は、回転槽４５（水受槽４３）を弾性支持する防振機構４４の、吊り棒４４ａの固有振動数１Ｈｚに相当する回転数である。
【００７４】
このため、回転槽４５の回転数と吊り棒４４ａの固有振動数とが一致する場合に回転槽４５（水受槽４３）の振動振幅はピークに達するが、回転槽４５内の洗濯物がアンバランスに分布している状態にあると、その振動振幅は更に大きくなる。そこで、脱水運転における低速回転域でベクトル制御及びＰＩ制御を行って回転槽４５の回転数を制御すれば、回転数の変動を極力小さくすることができるため、６０ｒｐｍ付近で発生しようとする回転槽４５の振動を効果的に抑制することができる。従って、騒音や振動、特に、水受槽４３が外箱４２の内壁にぶつかることで発生する「ドン」という音や振動、また、水受槽４３の揺動によって発生する振動が床に伝達することが極力防止される。
【００７５】
また、図９及び図１０には、本実施例の構成と従来構成とにおける脱水運転開始時の回転槽４５の揺れ量（変位量）を示す。図９に示す本実施例の場合は、図１０に示す従来構成の場合と比較してレベルの小さい揺れ量のピークが早い時間に発生して急速に収束している。即ち、回転速度の変動が少なくなったことで運転時に発生する振動を抑制することが可能となっている。また、図１１には、従来構成と本実施例の構成とが夫々発生させる騒音レベルを比較したものを示す。本実施例の構成によって騒音レベルが最大で２ｄＢ程度低減されている。
【００７６】
加えて、図１２には、本実施例の構成における洗い運転時の目標速度指令ωref とモータ１７の回転速度ωとを示し、図１３は、従来構成のＰＩ制御によるデューティ指令Ｄｕｔｙとモータ７の回転速度ωとを示す。これらの図から明らかなように、本実施例の場合は、目標速度指令ωref に対する回転速度ωの追従が良好であり回転変動も少なく安定している。
【００７７】
以上のように本実施例によれば、洗濯機４１のモータ１７を、インバータ回路１２を介して駆動するためベクトル制御を行う場合に、ベクトル制御を行うための演算処理と、洗濯機４１の入力操作などに関する制御処理とを５０ＭＩＰＳの処理能力を備える単一のマイコン５４で行うように構成した。
【００７８】
従って、洗濯機の基本的な制御をマイクロコンピュータで行い、ベクトル制御に関する演算をＤＳＰで行う構成とは異なり、部品コストを上昇させたり回路基板の面積を増やす必要が無くなる。また、マイコン４５はＤＳＰ３３との間で通信処理を行う必要が無くなるので、制御プログラムサイズを小さくすることができる。更に、ノイズの印加によるデータ化けの発生や、通信線の断線による制御不能状態が発生するおそれが無くなるので、モータ１７の制御をより安定的に行うことが可能となる。そして、ＰＷＭ信号の搬送波周波数が１６ｋＨｚに設定される洗濯機４１であっても、ベクトル制御を十分に実行することが可能となる。
【００７９】
また、シャント抵抗５５によってモータ１７の巻線１７ｕ〜１７ｗに流れる電流を検出し、マイコン５４は、検出された電流に基づいてモータ１７をベクトル制御して、モータ１７の発生トルクが洗い，濯ぎ，脱水の各行程において最適となるように制御するので、モータ１７の駆動制御を高い応答性を以て行うことで、洗い，濯ぎ，脱水の何れの行程においてもモータ１７の回転に伴う振動や騒音の発生を抑制することが可能となる。そして、マイコン５４は、位置センサレス方式を採用し、検出したモータ１７の電流に基づいてモータ１７の回転数を推定・制御するので、部品コストがより低下するようになる。
【００８０】
更に、本実施例によれば、マイコン５４が備える２つのＡ／Ｄコンバータ５６Ａ，５６Ｂ夫々の入力チャネルにモータ１７の各相電流を並列に与えるようにしたので、マイコン５４は、各相電流の内から、必要な相の電流を略同時に読み込むことが可能となる。従って、電流値の読み込みを高速に行って処理時間を短くすることができる。また、Ａ／Ｄコンバータ５６Ａ，５６Ｂの変換速度が高速でなくとも、複数相の電流値の読み込みを余裕をもって行うことができる。
【００８１】
また、本実施例によれば、マイコン５４を、洗い，濯ぎ行程における撹拌体４６の正反転動作時に、モータ１７の回転数をＰＩ制御するようにした。即ち、モータ１７のトルクをベクトル制御することで制御応答性が極めて良好となり、モータ１７の回転速度が高速の領域においてもＰＩ制御を行うことが可能となった。従って、モータ１７の回転数制御をより広い回転数範囲に渡って高精度に行うことができる。
【００８２】
加えて、マイコン５４は、脱水行程の初期において回転槽４５の回転に伴って発生しようとする振動を抑制するように、モータ１７のトルクをベクトル制御する。従って、脱水行程の初期において、回転槽４５の回転数が６０ｒｐｍ付近に達した段階で、防振機構４４を構成する吊り棒４４ａの固有振動数１Ｈｚで共振が発生することを効果的に抑止して、騒音や振動、特に、水受槽４３が外箱４２の内壁にぶつかることで発生する「ドン」という音や振動、また、水受槽４３の揺動によって発生する振動が床に伝達することを極力防止することができるようになる。
【００８３】
図１４及び図１５は、本発明の第２実施例を示すものであり、第１実施例と同一部分には同一符号を付して説明を省略し、以下異なる部分についてのみ説明する。図１４は、マイコン５４Ａとその周辺の構成を部分的に示す図である。第２実施例では、洗濯機４１に音声信号入力用のマイクロフォン７２及び音声信号出力用のスピーカ７３を付加している。
【００８４】
マイクロフォン７２に入力された音声信号は、音声アンプ７４を介して増幅され、マイコン５４ＡのＡ／Ｄ変換部５６の入力チャネルに与えられている。この場合、Ａ／Ｄコンバータ５６Ａ，５６Ｂの何れであっても良く、入力チャネルは、電流検出用に使用されていないものを割り当てる。そして、マイコン５４Ａはの音声信号出力のポートは、Ｄ／Ａ変換部７５及び音声アンプ７６を介してスピーカ７３に接続されている。そして、マイコン５４Ａは、内部のＲＯＭに様々な音声データの波形を記憶させた音声データ部７７を備えている。
【００８５】
即ち、第２実施例では、ユーザがマイクロフォン７２を介して入力した音声信号をマイコン５４Ａが認識し、その認識した音声に基づく処理を実行するように構成されている。
【００８６】
次に、第２実施例の作用について図１５をも参照して説明する。マイコン５４Ａは、自身がモータ１７の駆動制御を行っている場合は（ステップＶ１，「ＹＥＳ」）、モータ１７の駆動制御を続行する（ステップＶ２）。そして、モータ１７の駆動制御を行っていない場合、例えば、電源投入直後で洗濯運転を開始する前の段階などであれば（ステップＶ１，「ＮＯ」）、マイクロフォン７２に音声信号が入力されたか否かを判断する（ステップＶ２）。一定レベル以上の信号入力が検出されることで音声信号が入力されたものと判断すると（「ＹＥＳ」）、マイコン５４は音声認識処理を実行し（ステップＶ３）、音声信号が入力されなければ（「ＮＯ」）ステップＶ１に戻る。
【００８７】
一般に、音声認識はかなり複雑な処理であり、コンピュータの処理能力が相当程度なければ実行はできない。例えば、従来構成で使用されていたメインマイコン１３などでは不可能である。これに対して、２０ＭＩＰＳ以上の処理能力を有するマイコン５４Ａは音声認識処理を行う能力を十分に備えており、ベクトル制御を実行していない期間であればその実行が可能である。
【００８８】
ステップＶ３における音声認識処理は、Ａ／Ｄ変換部５６においてデジタル値に変換された音声データパターンを、音声データ部７７に記憶されているデータパターンと比較することによって行う。そして、マイコン５４Ａは、音声認識の結果に応じた音声データを出力する（ステップＶ５）。
【００８９】
例えば、ユーザが、回転槽４５の内部に洗濯物を投入した後、「洗濯」という音声を発してマイクロフォン７２に入力したとすると、マイコン５４Ａは、その音声「洗濯」を認識して、例えば、「洗濯を開始します」といったような音声信号をスピーカ７３より出力させる。
【００９０】
音声信号の出力は、音声データ部７７から上記音声信号に対応する波形データを読み出して合成を行い、そのデータを出力ポートに与える。出力ポートに与えられた音声データはＤ／Ａ変換部７５によりＤ／Ａ変換され、音声アンプ７６により増幅されてからスピーカ７３を介して出力される。
【００９１】
それから、マイコン５４Ａは、音声認識処理の結果に基づいた処理を実行する（ステップＶ６）。即ち、上記の例であれば、マイコン５４Ａは洗濯運転を開始する（例えば、給水弁２０を開いて給水を開始する）。そして、ステップＶ１に戻る。
【００９２】
以上のように第２実施例によれば、マイコン５４Ａは、モータ１７の駆動制御を停止している期間において、洗濯機４１の入力操作に関する音声信号処理を行うようにしたので、処理能力に余裕がある期間に音声認識処理等を行い、ユーザが要求した処理の実行を開始させることが可能となり、利便性をより向上させることができる。
【００９３】
本発明は上記し且つ図面に記載した実施例にのみ限定されるものではなく、次のような変形または拡張が可能である。
マイコンの処理能力は１０ＭＩＰＳ以上あれば十分である。
速度制御周期は、振動系の固有振動数に対応する周期の１／２０以下に設定すれば、振動・騒音の抑制効果を十分に得ることができる。
Ａ／Ｄコンバータは、十分高速なものが使用できる場合には、１個のみでシリアルにＡ／Ｄ変換を行っても良い。
モータ１７に流れる電流の検出は、シャント抵抗５５に代えて電流センサ３１を用いて行っても良い。
第２実施例において、音声信号の出力は必要に応じて行えば良く、スピーカ７３等の構成やフローチャートのステップＶ５は削除しても良い。
また、第２実施例において、必ずしも入力された音声信号に対する応答に限らず、必要に応じて適当な音声信号を出力することで、例えば、洗濯に関する一連の行程が全て終了した時点で「洗濯が終了しました」など、ユーザに対する報知を行うようにしても良い。
【００９４】
【発明の効果】
本発明の洗濯機の制御装置によれば、ブラシレスＤＣモータの駆動トルクをベクトル制御するための演算処理と、洗濯機のスイッチ入力回路や表示回路等の操作パネル制御，水位センサからのセンサ信号読取り，給水弁や排水弁の駆動制御などに関する制御処理とをＲＩＳＣアーキテクチャのＣＰＵコアを有して構成される単一のマイクロコンピュータで行うように構成した。従って、洗濯機の基本的な制御をマイクロコンピュータで行い、ベクトル制御に関する演算をＤＳＰで行う構成とは異なり、部品コストを上昇させたり回路基板の面積を増やす必要が無い。また、上記構成を採用することで、マイクロコンピュータはＤＳＰとの間で通信処理を行う必要が無くなり、制御プログラムサイズを小さくすることができる。更に、ノイズの印加によるデータ化けの発生や、通信線の断線による制御不能状態が発生するおそれが無くなるので、モータの制御をより安定的に行うことが可能となる。
また、モータの駆動制御を高い応答性を以て行うことで、洗い，濯ぎ，脱水の何れの行程においてもモータの回転に伴う振動や騒音の発生を抑制することが可能となる。そして、マイクロコンピュータは、複数のＡ／Ｄコンバータに並列に入力されている各相電流の内から、必要な相の電流を略同時に読み込むことが可能となるから、電流値の読み込みを高速に行って処理時間を短くすることができる。また、Ａ／Ｄコンバータの変換速度が高速でなくとも、複数相の電流値の読み込みを余裕をもって行うことができる。
【図面の簡単な説明】
【図１】本発明の第１実施例であり、全自動洗濯機の電気的構成を示す図
【図２】主に、モータの駆動制御に関するマイクロコンピュータ内部の機能をブロック化して示す図
【図３】全自動洗濯機の全体構成を示す縦断面図
【図４】主に制御用マイコンによる概略的な制御内容を示すフローチャート
【図５】ＰＷＭ搬送波と上アーム側，下アーム側のゲート信号の波形を示す図
【図６】モータの相電流の反転ＩMINVとシャント抵抗に流れる電流ＩSR及び相電圧との関係を示す波形図
【図７】モータの相電圧と各相電流の検出を行うタイミングを示す図
【図８】回転槽を２５０ｒｐｍで回転させた場合に回転速度が変動する状態を示すものであり、（ａ）は本実施例の構成による場合、（ｂ）は従来構成による場合を示す図
【図９】脱水運転開始時の回転槽の揺れ量（変位量）を示す図（本実施例）
【図１０】図８相当図（従来構成）
【図１１】従来構成と本実施例の構成とが夫々発生させる騒音レベルを比較した図
【図１２】洗い運転時の目標速度指令ωref とモータの回転速度ωとを示す図
【図１３】従来構成においてＰＩ制御部が出力するデューティ指令Ｄｕｔｙとモータの回転速度ωとを示す図
【図１４】本発明の第２実施例であり、マイクロコンピュータ及びその周辺構成の一部を示すブロック図
【図１５】音声信号処理に関するマイクロコンピュータの制御内容を示すフローチャート
【図１６】従来技術を示す図１相当図
【符号の説明】
１２はインバータ回路、１７はブラシレスＤＣモータ、４１は全自動洗濯機、４５は回転槽（脱水槽）、４６は撹拌翼、５４，５４Ａはマイクロコンピュータ、５５はシャント抵抗（電流検出手段）、５６Ａ，５６ＢはＡ／Ｄコンバータを示す。[0001]
BACKGROUND OF THE INVENTION
  The present invention generates a rotational driving force for performing washing, rinsing and dewatering operations.Brushless DCThe present invention relates to a control device for vector-controlling the driving torque of a motor for a washing machine including a motor.
[0002]
[Prior art]
Conventionally, in a fully automatic washing machine, a brushless DC motor is used as a motor for rotating a stirring blade (pulsator) or a rotating tub when performing washing, rinsing operation or dewatering operation, and the brushless DC motor is driven by an inverter circuit. This method is widely adopted. And when controlling a torque according to the drive condition of a motor, the applied voltage of a motor is increased / decreased. However, although the motor rotation speed is proportional to the generated torque, the generated torque controlled by the applied voltage is not proportional to the voltage, so that the control tends to be unstable because a difference between the target speed command and the detected motor speed tends to occur. There is a problem that.
[0003]
Accordingly, the inventors of the present invention have devised vector control of the motor of the washing machine. That is, since the generated torque of the brushless DC motor is proportional to the q (quadrature) axis current obtained by vector control, it is possible to perform motor torque control and thus rotation speed control with high accuracy.
[0004]
By the way, conventionally, a microcomputer having a CPU core of CISC (Complex Instruction Set Computer) architecture has been used for the control of the motor accompanying the input operation of the washing machine and the control of each process such as washing, rinsing and dehydration. However, if it is assumed that the motor of the washing machine is vector-controlled, the calculation processing load becomes heavy, so that the processing becomes difficult with a conventionally used microcomputer. That is, in the CPU of the CISC architecture, the speed of executing arithmetic processing such as a multiplication instruction is extremely slow.
[0005]
Accordingly, the inventors of the present invention have devised using a DSP (Digital Signal Processor) capable of executing operations such as multiplication at high speed in order to realize a configuration in which the motor of the washing machine is vector-controlled. An example of the electrical configuration is shown in FIG.
[0006]
A DC power supply circuit 3, which is a motor power supply, is connected to a 100 V commercial AC power supply 1 via a power switch 2. A noise removing capacitor 4 is connected in parallel with the series circuit of the AC power supply 1 and the power switch 2. Further, a series circuit of capacitors 5 and 6 is connected in parallel with the capacitor 4, and the capacitors 5 and 6 are connected to an outer box (not shown), which is an electric equipment housing, for grounding. The outer box is provided with a ground wire 7 that is grounded on the user side.
[0007]
The DC power supply circuit 3 includes a voltage doubler rectifier circuit including a diode bridge rectifier circuit 8 and smoothing capacitors 9 and 10. That is, the input terminal 8 a of the rectifier circuit 8 is connected to the power supply terminal 1 a of the AC power supply 1, and the input terminal 8 b of the rectifier circuit 8 is connected to the power supply terminal 1 b of the AC power supply 1 via the power switch 2. The smoothing capacitors 9 and 10 are connected in series between the output terminals 8c and 8d of the rectifier circuit 8, and the common connection point of the smoothing capacitors 9 and 10 and the input terminal 8a of the rectifier circuit 8 are connected.
[0008]
The DC power supply circuit 3 has 0V at the middle point 3c, + 141V at the positive output terminal 3a, and -141V at the negative output terminal 3b, and 282V between the positive output terminal 3a and the negative output terminal 3b. DC voltage is generated. The negative output terminal 3b of the DC power supply circuit 3 is connected to the ground (chassis) on the circuit. In FIG. 1, the earth ground is indicated by GND1 (0V), and the ground on the circuit is indicated by GND2 (-141V).
[0009]
The DC power supply circuit 3 is connected to a constant voltage circuit 11 that is a control power supply circuit that outputs a constant voltage of 17 V and a constant voltage of 5 V, and an inverter circuit 12 that is a motor drive circuit. The constant voltage circuit 11 supplies 5V power to a main microcomputer 13 and the like which will be described later, and supplies 17V power to the IGBT drive circuit 14. The inverter circuit 12 is configured by connecting IGBTs 15a to 15f made of, for example, IGBTs in a three-phase bridge, and connecting free wheel diodes 16a to 16f in parallel with the polarities shown in the drawings to the IGBTs 15a to 15f, respectively.
[0010]
The output terminal of each phase bridge is connected to each phase winding 17u, 17v, 17w of the stator of the motor 17. That is, the inverter circuit 12 drives the motor 17. The IGBTs 15 a to 15 f are controlled to be turned on / off by the main microcomputer 13 via the IGBT drive circuit 14. The main microcomputer 13 includes a CPU core of a CISC architecture, a ROM, a RAM, and the like.
[0011]
The IGBT drive circuit 14 includes charge pump type voltage converter circuits 18a, 18b, 18c, charge pump capacitors 19a, 19b, 19c and the like. The charge pump type voltage converter circuits 18a, 18b, 18c are configured to generate the gate voltage applied to the gate terminals of the IGBTs 15a, 15c, 15e on the high side of each arm by charging the capacitors 19a, 19b, 19c. It has become.
[0012]
Further, between the power supply terminals 1a and 1b of the AC power supply 1, a water supply valve 20 and a phototriac 21 are connected in order from the power supply terminal 1a side to the 1b side. A series circuit of a drain valve 22 and a phototriac 23 is connected in parallel with the series circuit of the water supply valve 20 and the phototriac 21. Further, noise removing snubber circuits 24 and 25 are connected in parallel to the phototriacs 21 and 23, respectively.
[0013]
The gate terminal of the phototriac 21 is connected to the ground via the NPN transistor 26, and the gate terminal of the phototriac 21 is connected to the ground via the NPN transistor 27. The transistors 26 and 27 are controlled by the main microcomputer 13. The main microcomputer 13 is supplied with a switch signal from a switch input circuit 28 having various switches and a water level detection signal from a water level sensor 29 for detecting the water level in the rotating tub. The main microcomputer 13 controls the water supply valve 20, the drain valve 22, and the display circuit 30. The display circuit 30 includes a display such as a 7 segment LED.
[0014]
Current sensors 31u, 31v, and 31w for detecting each phase current are arranged between the emitters of the IGBTs 15d to 15f on the lower arm side in the inverter circuit 12 and the ground. The current detection signals of these current sensors 31u to 31w are given to an input port of an A / D converter (not shown) built in the DSP 33 via an amplification bias circuit 32.
[0015]
The DSP 33 performs calculation processing related to vector control based on calculation parameters given by UART (Universal Asynchronous Receiver Transmitter) communication performed with the main microcomputer 13 and current detection signals of the current sensors 31u to 31w. . Then, a drive signal generated as a result of the arithmetic processing is output to the IGBT drive circuit 14 to drive the motor 17.
[0016]
By adopting such a configuration, the main microcomputer 13 performs operation panel control of the switch input circuit 28, the display circuit 30, etc., sensor signal reading from the water level sensor 29, and drive control of the water supply valve 20 and the drain valve 22. . Further, the main microcomputer 13 transmits a control command (instruction of the rotational speed of the motor 17 and normal rotation and reversal time) to the DSP 33 by UART communication, and receives a control result (rotation state) of the motor 17 from the DSP 33.
[0017]
[Problems to be solved by the invention]
However, when such a configuration is adopted, the following problems are assumed to occur. First, since the two LSIs of the main microcomputer 13 and the DSP 33 are used, the component cost increases and the circuit board size increases. In this case, not only one extra DSP chip is required, but a capacitor for operation power, a reset circuit, an oscillator, and the like are required as its peripheral circuit, and the substrate size including them is increased.
[0018]
Secondly, in order to perform serial communication (UART communication) between the main microcomputer 13 and the DSP 33, packets created by adding a start code, checksum, end code, etc. in addition to actual data must be transmitted and received. Therefore, it is necessary to incorporate logic for that purpose in the control program, and an extra creation process is required. Further, since the program capacity is increased by the amount of communication processing, it may be assumed that the code size for other processes must be pressed or the capacity of the program ROM must be increased.
[0019]
Further, by executing the communication process, the control cycle of the main microcomputer 13 is restricted, and it becomes difficult for the main microcomputer 13 to give a control command to the DSP 33 in real time. Accordingly, the main microcomputer 13 must collectively transmit a command for executing a certain operation pattern to the DSP 33, and it may be impossible to execute flexible processing with quick response.
[0020]
In addition, serial communication requires, for example, three communication connection lines for GND, transmission, and reception (only two lines are shown in FIG. 16), but even if any one of them is disconnected. The drive control of the motor 17 becomes impossible. Even if disconnection does not occur, there is a constant possibility that external noise is applied to these communication lines. If data corruption due to noise application cannot be eliminated, malfunction may occur.
[0021]
  The present invention has been made in view of the above circumstances, and its purpose is:Brushless DCIt is an object of the present invention to provide a control device for a washing machine that can execute vector control of a motor at a lower cost and without increasing the size of a circuit board.
[0022]
[Means for Solving the Problems]
  In order to achieve the above object, a control device for a washing machine according to claim 1 provides a brushless DC motor for generating a rotational driving force for performing washing, rinsing and dewatering operations via an inverter circuit.By PWM controlFor the washing machine to be driven, for vector control of the driving torque of the motor,
  RISC includes arithmetic processing for performing the vector control and control processing related to operation panel control of the switch input circuit and display circuit of the washing machine, reading of sensor signals from the water level sensor, drive control of the water supply valve and drain valve, and the like. It is configured to be performed by a single microcomputer configured with an architecture CPU core.CompleteThe
[0023]
  Therefore, unlike a configuration in which basic control of the washing machine is performed by a microcomputer and calculation related to vector control is performed by a DSP, there is no need to increase the part cost or increase the area of the circuit board. Further, by adopting the above configuration, the microcomputer does not need to perform communication processing with the DSP, and the control program size can be reduced. In addition, there is no possibility of data corruption due to noise application and the possibility of uncontrollable state due to communication line disconnection.Brushless DCThe motor can be controlled more stably.
[0026]
  AlsoTheCurrent detection means for detecting the current flowing through the
  The microcomputer is configured so that the motor is vector-controlled based on the current detected by the current detection means so that the torque generated by the motor is optimized in each of the washing, rinsing, and dewatering processes.BecauseBy performing motor drive control with high responsiveness, it is possible to suppress the generation of vibration and noise associated with the rotation of the motor in any of the washing, rinsing and dewatering steps.
[0028]
  The microcomputer includes a plurality of A / D converters for reading the current value of the motor detected by the current detection means,
  The current detection means is composed of three shunt resistors arranged in each phase of the inverter circuit,
  The plurality of A / D converters are configured to be able to operate simultaneously, and are configured to be capable of selecting and switching a plurality of input channels that each has, and each phase current of the motor is connected to the input channel of each A / D converter. Configured to give in paralleldo it,
  The microcomputer performs A / D conversion processing by the A / D converter in synchronization with the carrier wave period of PWM control..
[0029]
That is, in order to perform vector control, the microcomputer needs to read motor current values of at least two phases. Therefore, if configured in this way, the microcomputer can read the currents of the necessary phases from the phase currents input in parallel to the plurality of A / D converters substantially simultaneously. Accordingly, the processing time can be shortened by reading the current value at high speed. Even if the conversion speed of the A / D converter is not high, the current values of a plurality of phases can be read with a margin.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment in which the present invention is applied to a fully automatic washing machine having a vertical axis will be described below with reference to FIGS. Note that the same parts as those in FIG.
[0035]
First, FIG. 3 is a longitudinal sectional view showing the overall configuration of the fully automatic washing machine 41. That is, in the outer box 42 having a rectangular shape as a whole, the water receiving tank 43 is elastically supported through four sets of vibration isolation mechanisms 44 (only one set is shown). In this case, the vibration isolating mechanism 44 includes a suspension bar 44a whose upper end is locked upward in the outer box 42, and a vibration damping damper 44b attached to the other end of the suspension bar 44a. Has been. The water receiving tank 43 is elastically supported through these vibration isolation mechanisms 44 so that vibration generated during the washing operation is prevented from being transmitted to the outer box 42 as much as possible.
[0036]
A rotating tub 45 for a washing tub / dewatering tub is disposed in the water receiving tank 43, and a stirring body (pulsator) 46 is disposed at the inner bottom of the rotating tub 45. The rotating tank 45 includes a tank body 45a, an inner cylinder 45b provided on the inner side of the tank body 45a, and a balance ring 45c provided on the upper end of these tanks. When the rotating tank 45 is rotated, the internal water is pumped by a rotational centrifugal force and discharged into the water receiving tank 43 from the dewatering hole 45d in the upper part of the tank body 45a.
[0037]
Further, a water passage 47 is formed at the bottom of the rotary tank 45, and the water passage 47 communicates with a drain port 48 through a drain passage 47a. A drainage channel 50 having a drainage valve 22 is connected to the drainage port 48. Therefore, when water is supplied into the rotary tank 45 with the drain valve 22 closed, water is stored in the rotary tank 45, and when the drain valve 22 is opened, the water in the rotary tank 45 is discharged into the drain passage 47a, the drain port 48, and It is discharged through the drainage channel 50.
[0038]
An auxiliary drainage port 48a is formed at the bottom of the water receiving tank 43, and this auxiliary drainage port 48a is connected to the drainage channel 50 by bypassing the drainage valve 22 via a connecting hose (not shown). When 45 rotates, the water discharged | emitted in the water receiving tank 43 from the upper part is discharged | emitted.
[0039]
  A mechanism housing 51 is attached to the outer bottom of the water receiving tank 43. A hollow tank shaft 52 is rotatably provided in the mechanism housing 51, and the tank shaft 52 is rotated. The tank 45 is connected. A stirring shaft 53 is rotatably provided inside the tank shaft 52, and a stirring body 46 is connected to the upper end portion of the stirring shaft 53. The lower end of the stirring shaft 53 is an outer rotor type brushless.DCThe motor 17 is connected to the rotor 17a. This brushlessDCThe motor 17 is configured to drive the agitator 46 directly and reversely during washing.
[0040]
  Also brushlessDCAt the time of dehydration, the motor 17 directly rotates the rotating tank 45 and the stirring body 46 in one direction while the tank shaft 42 and the stirring shaft 53 are connected by a clutch (not shown). Therefore, in this embodiment, the brushlessDCA so-called direct drive system is employed in which the rotational speed of the motor 17 is the same as that of the stirring body 46 at the time of washing, and is the same as that of the rotating tank 45 and the stirring body 46 at the time of dehydration.
[0041]
In FIG. 1 showing the electrical configuration, in the configuration of this embodiment, the main microcomputer 13 and the DSP 33 shown in FIG. 16 are replaced with a single microcomputer 54. That is, the microcomputer 54 is supplied with a switch signal from the switch input circuit 28 and a water level detection signal from the water level sensor 29. The microcomputer 54 controls the water supply valve 20, the drain valve 22 and the display circuit 30.
[0042]
In place of the current sensors 31u to 31w, shunt resistors (current detection means) 55u to 55w are interposed between the emitters of the lower arm IGBTs 15d to 15f and the ground, and the emitters of the IGBTs 15d to 15f are Are connected to the input terminal of the amplifying bias circuit 32. The resistance value of the shunt resistor 55 is about 0.1Ω.
[0043]
The microcomputer 54 includes two A / D converters 56A and 56B inside, and each of these A / D converters 56A and 56B has three or more input ports (AD11 to AD13, AD21 to AD23). ing. The output terminal of the amplification bias circuit 32 is connected in parallel to the input ports of the A / D converters 56A and 56B. The microcomputer 54 generates drive signals Ua and Ub, Va and Vb, Wa and Wb based on the current values obtained from the A / D converters 56A and 56B, and outputs them to the charge pump type voltage converter circuits 18a, 18b and 18c, respectively. It is supposed to be.
[0044]
The microcomputer 54 has a CPU core of RISC (Reduced Instruction Set Computer) architecture. The RISC architecture CPU has the following features.
・ All decoding is realized by wired logic,
Simple instruction set that can be executed in the same time
・ Pipeline control of instruction execution processing
・ Many internal registers
・ Large capacity cache
In order to efficiently execute the program by the above architecture, the executable program is optimized by the compiler.
According to the RISC having such a configuration, the total processing performance is improved as compared with CISC. In particular, the execution speed of product operations and the like is extremely increased. For example, the microcomputer 54 of this embodiment has a processing capacity of 50 MIPS (dry stone).
[0045]
  FIG. 2 is a functional block diagram showing a drive control system of the motor 17. In FIG. 1, (α, β) are three-phase brushlessDCAn orthogonal coordinate diameter obtained by orthogonal transformation of a three-phase (UVW) coordinate system with an electrical angle of 120 degrees corresponding to each phase of the motor 17 is shown, and (d, q) are brushless.DCThe coordinate system of the secondary magnetic flux which is rotating with rotation of the rotor 17a of the motor 17 is shown.
[0046]
  The speed command output unit 57 outputs the target speed command ωref to the subtractor 58 as a subtracted value. The subtractor 58 includes a brushless detected by an estimator 59.DCThe detection speed ω of the motor 17 is given as a subtraction value. The subtraction result of the subtractor 58 is given to a speed PI (Proportional-Integral) control unit 60.
[0047]
The speed PI control unit 60 performs PI (proportional integration) control based on the difference between the target speed command ωref and the detected speed ω, and generates a q-axis current command value Iqref and a d (direct) axis current command value Idref. Then, the values are output to the subtracters 61 and 62 as subtracted values, respectively. The d-axis current command value Idref during the washing or rinsing operation is set to “0”, and during the dehydrating operation, the d-axis current command value Idref is set to a predetermined value in order to perform field weakening control. The subtracters 61 and 62 are respectively provided with the q-axis current value Iq and the d-axis current value Id output from the αβ / dq conversion unit 63 as subtraction values, and the subtraction results are the current PI control units 64q and 64d. Are given to each. The control period in the speed PI control unit 60 is set to 1 msec.
[0048]
  The current PI controllers 64q and 64d perform PI control based on the difference between the q-axis current command value Iqref and the d-axis current command value Idref, and generate the q-axis voltage command value Vq and the d-axis voltage command value Vd. And output to the dq / αβ converter 65. The dq / αβ converter 65 has a brushless detected by the estimator 59.DCA rotation phase angle (rotor position angle) θ of the secondary magnetic flux in the motor 17 is given, and the voltage command values Vd and Vq are converted into voltage command values Vα and Vβ based on the rotation phase angle θ. Yes.
[0049]
The voltage command values Vα and Vβ output from the dq / αβ converter 65 are given to the αβ / UVW converter 66. The αβ / UVW converter 66 converts the voltage command values Vα, Vβ into three-phase voltage command values Vu, Vv, Vw and outputs them. The voltage command values Vu, Vv, Vw are given to one fixed contact 67ua, 67va, 67wa of the changeover switches 67u, 67v, 67w, and the other fixed contact 67ub, 67vb, 67wb has an initial pattern output unit 68. Are given start voltage command values Vus, Vvs, Vws. The movable contacts 67uc, 67vc, 67wc of the changeover switches 67u, 67v, 67w are connected to the input terminal of the PWM forming unit 69.
[0050]
The PWM forming unit 69 modulates a 16 kHz carrier wave (triangular wave) based on the voltage command values Vus, Vvs, and Vws, and outputs PWM signals Vup (+, −), Vvp (+, −), Vwp (+, −) of each phase. ) Is output to the inverter circuit 12. The PWM signals Vup to Vwp are signals having a pulse width corresponding to a voltage amplitude based on a sine wave so that a sine wave current is supplied to each phase winding 17u, 17v, 17w (see FIG. 2) of the motor 17, for example. Is output as
[0051]
The emitters of the IGBTs 15c to 15e on the lower arm side in the inverter circuit 12 are connected to the A / D converter 56 (A / D converters 56A and 56B) via the amplification / bias circuit 70. The amplifier / bias circuit 70 includes an operational amplifier, and amplifies the terminal voltage of the shunt resistor 55 and applies a bias so that the output range of the amplified signal is within the positive side (for example, 0 to +5 V). It has become.
[0052]
Referring again to FIG. 1, the A / D converter 56 outputs current data Iu and Iv obtained by A / D converting the output signal of the amplification / bias circuit 70 to the UVW / αβ converter 71. The UVW / αβ conversion unit 71 estimates W-phase current data Iw from the current data Iu, Iv, and converts the three-phase current data Iu, Iv, Iw into two-axis current data Iα, Convert to Iβ.
[Expression 1]

Then, the biaxial current data Iα and Iβ are output to the αβ / dq converter 63.
[0053]
The αβ / dq conversion unit 63 obtains the rotor position angle θ of the motor 17 from the estimator 59 during vector control, thereby obtaining the biaxial current data Iα, Iβ on the rotational coordinate system (d, q) according to the equation (2). It converts into d-axis current value Id and q-axis current value Iq.
[0054]
[Expression 2]

The d-axis current value Id and the q-axis current value Iq are output to the estimator 59 and the subtractors 61 and 62 as described above.
[0055]
The estimator 59 estimates the position angle θ and the rotational speed ω of the rotor 17a based on the d-axis current value Id and the q-axis current value Iq, and outputs them to each part. Here, when the motor 17 is activated, direct current excitation is performed by the initial pattern output unit 68 to initialize the rotational position of the rotor 17a, and then the activation pattern is applied to perform forced commutation. At the time of forced commutation due to the application of the activation pattern, the position angle θ is obvious without estimation. Then, the αβ / dq converter 63 calculates and outputs current values Id and Iq using the position angle θinit obtained from the initial pattern output unit 68 immediately before the start of vector control as an initial value.
[0056]
After the start of vector control, the estimator 59 is activated to estimate the rotor 17a position angle θ and rotational speed ω. In this case, assuming that the rotor position angle θn output from the estimator 59 to the αβ / dq converter 63 is the estimator 59, the rotor position angle θn−1 estimated by the vector calculation based on the current values Id and Iq The rotor position angle θn is estimated based on the correlation with the rotor position angle θn-2 estimated before the cycle.
[0057]
In the above configuration, the configuration excluding the inverter circuit 12 and the amplification / bias circuit 70 is a block of functions realized by software of the microcomputer 54. The current control period in the vector control is set to 62.5 μsec that is the reciprocal of the PWM carrier frequency.
[0058]
In the present embodiment, when the motor 17 is started, PI control is temporarily performed before the start of vector control, as will be described later. For this reason, a PI control unit and a UVW conversion unit (not shown) are provided in parallel. Actually, the voltage commands Vu, Vv, and Vw output from the UVW conversion unit are also switched by the changeover switch 67, and the PWM forming unit 69 is provided. Can be output to.
[0059]
Next, the operation of the present embodiment will be described with reference to FIGS. FIG. 4 is a flowchart showing a schematic control content mainly by the microcomputer 54. For example, when starting the washing operation, the microcomputer 54 performs the activation process described above (step S1). That is, the movable contacts 67uc-67wc of the change-over switches 67u-67w are connected to the fixed contacts 67ub-67wb, DC excitation is performed by the initial pattern output unit 68, and the rotational position of the rotor 17a is initialized before the voltage command value Vus. ~ Vws is applied to the inverter circuit 12 to forcibly commutate the motor 17 (step S2). Then, the motor 17 starts to rotate, and the rotational speed gradually increases.
[0060]
Then, for example, when the microcomputer 54 determines that the rotational speed of the motor 17 has reached 20 rpm based on the detection signal given by the initial pattern output unit 68 (step S3, “YES”), the movable contact 67uc of the changeover switches 67u to 67w. To 67wc are connected to the fixed contacts 67ua to 67wa, and output of the target speed command ωref is started to perform voltage control (PI control) (step S4). That is, it is difficult to perform vector control with high accuracy in a region where the rotational speed is relatively low.
[0061]
Subsequently, when the microcomputer 54 determines that the rotational speed of the motor 17 has reached 60 rpm with reference to the rotational speed ω given by the estimator 59 (step S5, “YES”), the vector control is started (step S6). ). Thereafter, the operation is continued until an instruction to stop the operation is given (step S7).
[0062]
Hereinafter, the flow of processing for vector control in step S6 and subsequent steps will be described. The PWM forming unit 69 generates a 16 kHz PWM carrier wave by the counter output of an internal up / down counter (not shown), and when the counter value reaches “0”, that is, the valley of the triangular wave, the conversion timing signal Are output to the A / D converter 56 (see FIG. 5).
[0063]
As shown in FIG. 5, the PWM forming unit 69 compares the voltage command values Vu to Vw output from the αβ / UVW conversion unit 66 with the level of the PWM carrier wave, and the latter level is higher than the former. PWM signals Vup (+) to Vwp (+) are output so that the IGBTs 15a to 15c on the upper arm side are turned on. The IGBTs 15d to 15f on the lower arm side are turned on with a dead time between periods in which the IGBTs 15a to 15c on the upper arm side are off.
[0064]
FIG. 6 is a waveform diagram showing the relationship between the inversion IMINV of the phase current of the motor 17, the current ISR flowing through the shunt resistor 55, and the phase voltage. That is, the period during which the current ISR flows is when the lower arm IGBT 15 is turned on and the phase voltage indicates 0V. Therefore, the trough of the triangular wave indicates the intermediate phase during the period when the lower arm IGBTs 15d to 15f are on. That is, if the A / D conversion unit 56 performs A / D conversion at the time point of the counter value “0” in the PWM forming unit 69, the phase current flowing to the lower arm side of the inverter circuit 12 is reliably sampled. can do.
[0065]
The two-phase current values A / D converted by the A / D conversion unit 56 are converted into two axes through the UVW / αβ conversion unit 71 and the αβ / dq conversion unit 63 together with the estimated remaining one-phase current value. Current data Iα, Iβ, → Id, Iq are converted and output to the estimator 59 and subtractors 61, 62. The estimator 59 estimates the position angle θ and the rotational speed ω. The current Iq is a current that flows in a direction perpendicular to the direction of the secondary magnetic flux of the motor 17 and is a current component that contributes to the generation of torque. On the other hand, the current Id is a current that flows in a direction parallel to the direction of the secondary magnetic flux, and is a current component that does not contribute to the generation of torque.
[0066]
Then, the speed PI control unit 60 outputs q-axis and d-axis current command values Iqref and Idref based on the difference between the target speed command ωref and the detected speed ω given from the speed command value output unit 57, and the current PI Control units 64q and 64d output voltage command values Vq and Vd based on the difference between command values Iqref and Idref and detected current values Iq and Id. The voltage command values Vq and Vd are converted into voltage command values Vu, Vv and Vw via a dq / αβ conversion unit 65 and an αβ / UVW conversion unit 63, and output to the PWM formation unit 69. The PWM formation unit 69 is an inverter. PWM signals Vup to Vwp are output to the circuit 12. Then, energization is performed to the phase windings 17u to 17w of the motor 17.
[0067]
7 shows the phase voltage Vmu, Vmv, Vmw appearing in each phase winding when the motor 17 is energized with a two-phase modulated wave, and the detection timing of each phase current in the A / D converter 56. Is. In this figure, the higher the phase voltage, the longer the corresponding upper arm side IGBTs 15a to 15c are on, and the shorter the lower arm side IGBTs 15d to 15f are on. Since the current detection by the shunt resistor 55 can only be performed while the lower arm IGBTs 15d to 15f are on, as described above and as shown in FIG. At the timing of reaching the valley.
[0068]
In addition, the fact that current detection cannot be performed unless the IGBTs 15d to 15f on the lower arm side are on indicates that there is a period in which current detection is impossible for each phase. However, if two phases of the three-phase current can be detected, the remaining one phase can be estimated. Therefore, if the two-phase currents that can be detected are sequentially switched in the A / D converter 56, The current for three phases can be detected constantly.
[0069]
However, since the PWM carrier wave is a signal common to all three phases, the two-phase A / D conversion timing is simultaneous. Since the carrier frequency is 16 kHz, the current control period is 62.5 μs at the shortest. However, if the time required for A / D conversion is a short time of about 1 μs, for example, one A / D converter uses two phases. There is no problem even if A / D conversion is performed serially. However, in general, an A / D converter mounted on a microcomputer is not so fast.
[0070]
Therefore, in this embodiment, current signals for three phases are respectively supplied to the two A / D converters 56A and 56B, and the input of any one phase current signal is switched in each of the converters 56A and 56B. By performing D conversion, A / D conversion values for two phases are obtained simultaneously. With such a configuration, even if the A / D conversion speed of the A / D conversion unit 56 is low (for example, 6 μs), it is possible to cope with it sufficiently.
[0071]
Here, FIG. 8 shows a state in which the rotation speed fluctuates when the rotating tub 45 is rotated at 250 rpm. (A) is based on the configuration of this embodiment, and (b) is based on the conventional configuration. (That is, control by voltage). 250 rpm is the number of rotations corresponding to the natural vibration of the damper 44 b of the vibration isolation mechanism 44. The diameter direction of the circle represents the magnitude of the rotational speed (± 3 rpm with 250 rpm as the center), and the circumferential direction represents the rotational position of the rotating tank 45. A weight of 16 kg is placed in the rotating tub 45 as a load corresponding to (laundry + water). In addition, 400 g and 300 g of fluid balancers are arranged at the upper end and the lower end of the rotary tank 45, respectively.
[0072]
In the case of the conventional configuration shown in FIG. 8B, the rotation fluctuation has a periodicity linked to the rotation angle, and the rotation fluctuation is generated so as to be largely deviated with respect to a specific rotation position (the maximum fluctuation difference is About 6 rpm). On the other hand, in the case of the configuration of this embodiment shown in FIG. 8A, the rotation speed is approximately 250 rpm over the entire rotation position (the maximum variation difference is about 1 rpm). That is, it is clear that the rotational fluctuation is effectively suppressed by the configuration of this embodiment.
[0073]
Incidentally, the flowchart shown in FIG. 4 has been described as the case where the microcomputer 54 starts the washing operation, for example, but the initial drive procedure of the motor 17 when performing the dehydration operation is the same as that shown in the flowchart shown in FIG. To do. In this case, when the rotational speed of the rotating tank 45 exceeds 60 rpm, the voltage control is switched to the vector control. However, the low-speed rotation region in the dehydration operation of about 60 rpm is a vibration-proof mechanism 44 that elastically supports the rotating tank 45 (water receiving tank 43). Is the number of rotations corresponding to the natural frequency of 1 Hz of the suspension rod 44a.
[0074]
For this reason, when the rotation speed of the rotating tub 45 and the natural frequency of the hanging rod 44a coincide, the vibration amplitude of the rotating tub 45 (water receiving tank 43) reaches a peak, but the laundry in the rotating tub 45 is unbalanced. The vibration amplitude is further increased if they are distributed. Therefore, if the rotation speed of the rotating tank 45 is controlled by performing vector control and PI control in the low speed rotation area in the dehydrating operation, the fluctuation of the rotating speed can be reduced as much as possible. The vibration of 45 can be effectively suppressed. Therefore, noise and vibration, especially the sound and vibration of “don” generated when the water receiving tank 43 hits the inner wall of the outer box 42, and vibration generated by the swinging of the water receiving tank 43 may be transmitted to the floor. It is prevented as much as possible.
[0075]
9 and 10 show the shaking amount (displacement amount) of the rotating tank 45 at the start of the dewatering operation in the configuration of the present embodiment and the conventional configuration. In the case of the present embodiment shown in FIG. 9, the peak of the fluctuation amount with a small level occurs earlier and converges rapidly compared to the case of the conventional configuration shown in FIG. That is, it is possible to suppress vibrations that occur during operation due to less fluctuations in rotational speed. FIG. 11 shows a comparison of noise levels generated by the conventional configuration and the configuration of this embodiment. With the configuration of this embodiment, the noise level is reduced by about 2 dB at the maximum.
[0076]
In addition, FIG. 12 shows the target speed command ωref and the rotational speed ω of the motor 17 during the washing operation in the configuration of the present embodiment, and FIG. 13 shows the duty command Duty by the PI control and the motor 7 of the conventional configuration. The rotational speed ω is shown. As is apparent from these figures, in the case of the present embodiment, the follow-up of the rotational speed ω with respect to the target speed command ωref is good and the rotational fluctuation is small and stable.
[0077]
As described above, according to the present embodiment, when vector control is performed to drive the motor 17 of the washing machine 41 via the inverter circuit 12, arithmetic processing for performing vector control and input of the washing machine 41 are performed. The control processing related to the operation and the like is performed by a single microcomputer 54 having a processing capacity of 50 MIPS.
[0078]
Therefore, unlike the configuration in which the basic control of the washing machine is performed by the microcomputer and the calculation related to the vector control is performed by the DSP, it is not necessary to increase the component cost or increase the area of the circuit board. In addition, since the microcomputer 45 does not need to perform communication processing with the DSP 33, the control program size can be reduced. Furthermore, there is no possibility of data corruption due to the application of noise or the possibility of an uncontrollable state due to disconnection of the communication line, so that the motor 17 can be controlled more stably. And even if it is the washing machine 41 by which the carrier frequency of a PWM signal is set to 16 kHz, it becomes possible to fully perform vector control.
[0079]
  Further, the current flowing through the windings 17u to 17w of the motor 17 is detected by the shunt resistor 55, and the microcomputer 54 performs vector control of the motor 17 based on the detected current, and the generated torque of the motor 17 is washed and rinsed. Since the motor 17 is controlled so as to be optimal in each process of dehydration, the drive control of the motor 17 is performed with high responsiveness, so that vibration and noise accompanying the rotation of the motor 17 are generated in any process of washing, rinsing and dehydration. Can be suppressed. The microcomputer 54positionSensorless methodAdoptSince the rotational speed of the motor 17 is estimated and controlled based on the detected current of the motor 17, the component cost is further reduced.
[0080]
Furthermore, according to the present embodiment, since each phase current of the motor 17 is given in parallel to the input channels of the two A / D converters 56A and 56B provided in the microcomputer 54, the microcomputer 54 It becomes possible to read the current of the required phase almost simultaneously from the inside. Accordingly, the processing time can be shortened by reading the current value at high speed. Further, even when the conversion speeds of the A / D converters 56A and 56B are not high, the current values of a plurality of phases can be read with a margin.
[0081]
Further, according to the present embodiment, the microcomputer 54 is PI-controlled for the rotational speed of the motor 17 during the forward and reverse operation of the stirring member 46 in the washing and rinsing process. In other words, the vector control of the torque of the motor 17 makes the control response very good, and the PI control can be performed even in the region where the rotational speed of the motor 17 is high. Therefore, the rotational speed control of the motor 17 can be performed with high accuracy over a wider rotational speed range.
[0082]
In addition, the microcomputer 54 vector-controls the torque of the motor 17 so as to suppress vibrations that are to occur as the rotary tank 45 rotates in the initial stage of the dehydration process. Therefore, at the initial stage of the dehydration process, when the rotation speed of the rotary tank 45 reaches around 60 rpm, the occurrence of resonance at the natural frequency of 1 Hz of the suspension rod 44a constituting the vibration isolation mechanism 44 is effectively suppressed. Noise and vibration, in particular, the sound and vibration of “don” generated when the water receiving tank 43 hits the inner wall of the outer box 42, and vibration generated by the swinging of the water receiving tank 43 are transmitted to the floor. It will be possible to prevent as much as possible.
[0083]
14 and 15 show a second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof will be omitted. Only different parts will be described below. FIG. 14 is a diagram partially showing the configuration of the microcomputer 54A and its periphery. In the second embodiment, an audio signal input microphone 72 and an audio signal output speaker 73 are added to the washing machine 41.
[0084]
The audio signal input to the microphone 72 is amplified via the audio amplifier 74 and is given to the input channel of the A / D conversion unit 56 of the microcomputer 54A. In this case, any of the A / D converters 56A and 56B may be used, and an input channel that is not used for current detection is assigned. The audio signal output port of the microcomputer 54A is connected to the speaker 73 via the D / A converter 75 and the audio amplifier 76. The microcomputer 54A includes an audio data unit 77 in which various audio data waveforms are stored in an internal ROM.
[0085]
That is, in the second embodiment, the microcomputer 54A recognizes the voice signal input by the user via the microphone 72, and executes processing based on the recognized voice.
[0086]
Next, the operation of the second embodiment will be described with reference to FIG. If the microcomputer 54A is controlling the drive of the motor 17 (step V1, "YES"), the microcomputer 54A continues the drive control of the motor 17 (step V2). If the drive control of the motor 17 is not performed, for example, if it is a stage immediately after turning on the power and before starting the washing operation (step V1, “NO”), whether or not an audio signal is input to the microphone 72 Is determined (step V2). If it is determined that a voice signal has been input by detecting a signal input of a certain level or higher ("YES"), the microcomputer 54 executes a voice recognition process (step V3), and no voice signal is input (step S3). “NO”) Return to Step V1.
[0087]
In general, speech recognition is a fairly complicated process and cannot be executed unless the computer has a considerable processing capability. For example, it is impossible with the main microcomputer 13 used in the conventional configuration. On the other hand, the microcomputer 54A having a processing capability of 20 MIPS or more has a sufficient capability of performing speech recognition processing, and can execute it during a period when the vector control is not executed.
[0088]
The voice recognition process in step V3 is performed by comparing the voice data pattern converted into a digital value by the A / D conversion unit 56 with the data pattern stored in the voice data unit 77. Then, the microcomputer 54A outputs voice data corresponding to the result of voice recognition (step V5).
[0089]
For example, if the user puts the laundry into the rotary tub 45 and then utters and inputs the voice “washing” to the microphone 72, the microcomputer 54A recognizes the voice “laundry” and, for example, An audio signal such as “start washing” is output from the speaker 73.
[0090]
For the output of the audio signal, the waveform data corresponding to the audio signal is read from the audio data unit 77 and synthesized, and the data is given to the output port. The audio data given to the output port is D / A converted by the D / A converter 75, amplified by the audio amplifier 76, and then output through the speaker 73.
[0091]
Then, the microcomputer 54A executes a process based on the result of the voice recognition process (step V6). That is, in the above example, the microcomputer 54A starts the washing operation (for example, opens the water supply valve 20 and starts water supply). Then, the process returns to step V1.
[0092]
As described above, according to the second embodiment, the microcomputer 54A performs the audio signal processing related to the input operation of the washing machine 41 during the period in which the drive control of the motor 17 is stopped. It is possible to perform voice recognition processing or the like during a certain period and start execution of the processing requested by the user, and the convenience can be further improved.
[0093]
  The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following modifications or expansions are possible.
  The processing capacity of the microcomputer should be 10 MIPS or more..
  If the speed control period is set to 1/20 or less of the period corresponding to the natural frequency of the vibration system, the effect of suppressing vibration and noise can be sufficiently obtained.
  If a sufficiently fast A / D converter can be used, only one A / D converter may perform serial A / D conversion.
  The current flowing through the motor 17 may be detected using the current sensor 31 instead of the shunt resistor 55.
  In the second embodiment, the output of the audio signal may be performed as necessary, and the configuration of the speaker 73 and the like and step V5 of the flowchart may be deleted.
  In the second embodiment, the response to the input audio signal is not necessarily output, and an appropriate audio signal is output as necessary. You may make it alert | report to a user, such as "It was completed."
[0094]
【The invention's effect】
  According to the washing machine control device of the present invention, arithmetic processing for vector control of the driving torque of the brushless DC motor, operation panel control of the switch input circuit and display circuit of the washing machine, and reading of the sensor signal from the water level sensor The control processing related to the drive control of the water supply valve and the drain valve is performed by a single microcomputer having a CPU core of RISC architecture. Therefore, unlike a configuration in which basic control of the washing machine is performed by a microcomputer and calculation related to vector control is performed by a DSP, there is no need to increase the part cost or increase the area of the circuit board. Further, by adopting the above configuration, the microcomputer does not need to perform communication processing with the DSP, and the control program size can be reduced. Furthermore, there is no possibility of data corruption due to the application of noise or the possibility of an uncontrollable state due to disconnection of the communication line, so that the motor can be controlled more stably.
  In addition, by performing motor drive control with high responsiveness, it is possible to suppress the generation of vibration and noise associated with the rotation of the motor in any of the washing, rinsing, and dehydration processes. And since the microcomputer can read the current of the required phase from the phase currents input in parallel to the plurality of A / D converters almost simultaneously, the current value is read at high speed. Processing time can be shortened. Further, even when the conversion speed of the A / D converter is not high, the current values of a plurality of phases can be read with a margin.
[Brief description of the drawings]
FIG. 1 is a diagram showing an electrical configuration of a fully automatic washing machine according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing functions inside a microcomputer mainly related to motor drive control.
FIG. 3 is a longitudinal sectional view showing the overall configuration of a fully automatic washing machine.
FIG. 4 is a flowchart showing a schematic control content mainly by a control microcomputer.
FIG. 5 is a diagram showing waveforms of PWM carrier waves and gate signals on the upper arm side and the lower arm side
FIG. 6 is a waveform diagram showing the relationship between the inversion IMINV of the motor phase current, the current ISR flowing through the shunt resistor, and the phase voltage.
FIG. 7 is a diagram showing the timing for detecting the motor phase voltage and each phase current;
FIGS. 8A and 8B show a state in which the rotation speed fluctuates when the rotating tank is rotated at 250 rpm. FIG. 8A shows the case of the configuration of this embodiment, and FIG. 8B shows the case of the conventional configuration.
FIG. 9 is a diagram showing the shaking amount (displacement amount) of the rotating tank at the start of the dehydration operation (this example)
FIG. 10 is a view corresponding to FIG. 8 (conventional configuration).
FIG. 11 is a diagram comparing noise levels generated by the conventional configuration and the configuration of the present embodiment.
FIG. 12 is a diagram showing a target speed command ωref and a motor rotational speed ω during washing operation.
FIG. 13 is a diagram showing a duty command duty output by a PI control unit and a motor rotation speed ω in a conventional configuration;
FIG. 14 is a block diagram showing a part of a microcomputer and a peripheral configuration thereof according to a second embodiment of the present invention.
FIG. 15 is a flowchart showing the control contents of a microcomputer related to audio signal processing;
FIG. 16 is a view corresponding to FIG.
[Explanation of symbols]
  12 is an inverter circuit, 17 is brushlessDCMotor, 41 is a fully automatic washing machine, 45 is a rotating tub (dehydration tub), 46 is a stirring blade, 54 and 54A are microcomputers, 55 is a shunt resistance (current detection means), and 56A and 56B are A / D converters. .

Claims (1)

This is a control device for vector-controlling the driving torque of a motor for a washing machine that drives a brushless DC motor that generates a rotational driving force for performing washing, rinsing, and dehydrating operations by PWM control via an inverter circuit. And
RISC includes arithmetic processing for performing the vector control, and control processing related to operation panel control of the switch input circuit and display circuit of the washing machine, sensor signal reading from the water level sensor, drive control of the water supply valve and drain valve, and the like. (Reduced Instruction Set Computer) is configured to be performed by a single microcomputer configured with a CPU core of architecture ,
Comprising current detection means for detecting the current flowing through the motor;
The microcomputer performs vector control of the motor based on the current detected by the current detection means, so that the generated torque of the motor is optimized in each of the washing, rinsing, and dehydration processes,
The microcomputer comprises a plurality of A / D converters for reading the current value of the motor detected by the current detection means,
The current detection means is composed of three shunt resistors arranged in each phase of the inverter circuit,
The plurality of A / D converters are configured to be simultaneously operable and configured to be capable of selecting and switching a plurality of input channels included in each of the A / D converters. Are given in parallel,
The microcomputer controls a washing machine control device to perform A / D conversion processing by the A / D converter in synchronization with a carrier wave period of the PWM control .

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