JP4008342B2 - Electric motor position control device - Google Patents

Description

【００１５】
減算器１６では、電動機の軸位置指令値θ_M ^**から（１）式で求まる負荷軸の位置推定値θ_{L_est}を減ずることで、電動機の軸位置指令値θ_M ^**を与えた場合に発生する軸ねじり量を求める。これに軸ねじり量フィードバックゲインk1を乗じた値が前述の軸ねじり補正値である。
【００１６】
軸ねじりを抑制するように補正した補正後位置指令値θ_M ^*は、電動機の軸位置指令値θ_M ^**から前述の軸ねじり補正値を減ずることにより導出する。この電動機の軸位置指令値θ_M ^**と負荷軸の位置推定値θ_{L_est}とから補正後位置指令値θ_M ^*を求める過程を（４）式に表す。
【００１７】
【数９】

【００１８】
k1の値は０＜k1＜１の範囲内で設定することにより、軸ねじりを抑制することが可能となる。構成上、k1の値が大きい程軸ねじり抑制効果は大きいが、位置指令値の立ち上がりを抑えることで軸ねじり抑制を実現している関係上、位置決め時間が長くなる作用がある。従って、k1を調整する際には、オーバーシュート及び軸振動が許容レベルに収まる範囲内で可能な限り小さく設定するとよい。
【００１９】
次に、本実施形態の原理的な説明を行う。図２は図１における電動機１と電動機１に結合された負荷を、ブロック図に展開して表現したものである。図１と同一の制御系及び制御対象を表している。
【００２０】
図２において、３０は電動機１単体のイナーシャ特性を表現するブロックであり、電動機１自身が発生する電動機トルクτ_Mと電動機１に対して外部(軸)より加えられる軸トルクτ_Sの差分を入力とし、電動機速度ω_Mを出力とする。３１は積分器であり、電動機速度ω_Mを入力とし電動機の軸位置θ_Mを出力する。３２は電動機１に接続された軸および負荷の特性を表現するブロックであり、電動機の軸位置θ_M、電動機の速度ω_M、外乱トルクτ_Lの入力に対して負荷軸の位置θ_Lを出力する。
【００２１】
また、図２においては、図１における電流制御器8および電力変換器9を省略している。理由はトルク定数k_Tを用いてτ_M＝k_TI_qで表される電動機の一般的な特性と電流制御器8によりI_q≒I_q ^*に制御されているという前提から、τ_MとI_q ^*が1対1に対応することによる。
【００２２】
ここで、ブロック３２と軸ねじり抑制制御器３を比較すると、軸ねじり抑制制御器３にはブロック３２においてτ_L＝0とした場合と同一の入力信号及び構成が含まれている。従って、軸ねじり抑制制御器３における推定用負荷イナーシャJ_Le、推定用バネ定数K_Fe、推定用粘性摩擦係数C_Feの値は以下のように与えられる。すなわち、ブロック３２における実際の負荷イナーシャJ_L、実際のバネ定数K_F、実際の粘性摩擦係数C_Fに対して、J_Le≒J_L、K_Fe≒K_F、C_Fe≒C_Fに設定する。これにより、外乱トルクτ_L＝0の場合にはθ_{L_est}≒θ_Lが成立する。また、外乱が存在する場合にはθ_{L_est}≒θ_Lは成立しないが、外乱トルクτ_Lの影響を除外した負荷軸の位置推定値θ_{L_est}が得られる。
【００２３】
また、軸ねじり抑制制御器３において、電動機の軸位置θ_Mから負荷軸の位置推定値θ_{L_est}までの伝達関数を求めると（８）式となる。また（８）式に最終値の定理を適用すると（９）式となる。
【００２４】
【数１０】

【００２５】
これより、一定時間後にはθ_{L_est}＝θ_Mとなることが分る。さらに、位置制御系が正しく機能していると仮定すると、定常状態においてはθ_M＝θ_M ^*が成立する。よって、前述のθ_{L_est}＝θ_Mと合わせて（１０）式の関係が成立する。
【００２６】
【数１１】

【００２７】
（１０）式を位置指令値の補正手段を表す前述の（４）式に代入すると、（１１）式が得られる。
【００２８】
【数１２】

【００２９】
いま、０＜k1＜１の範囲でk1を規定しているので、１−k1≠0となり、（１１）式よりθ_M ^*＝θ_M ^**が成立する。
【００３０】
このように、本発明による位置指令値の補正は、位置指令の目標停止位置に対して誤差を与えることなく実施することができる。また、制御系の応答周波数低減によるオーバーシュート抑制手段と比較して、外乱応答を殆ど劣化することなくオーバーシュート及び軸振動の抑制が可能である。
【００３１】
図６に位置決め制御時の位置偏差の収束の様子を示す。（ａ）は第一の実施例を用いた場合で、本発明の適用によりオーバーシュートが完全に抑制されることが分かる。（ｂ）は用いない場合で、位置偏差のオーバーシュートと軸振動が発生している。
【００３２】
図３は本発明の第二の実施例を示す電動機の位置制御装置である。図１で既に説明した第一の実施例において、推定用粘性摩擦係数C_Feを省略した場合に相当する。この場合の電動機の軸位置検出値θ_Mから負荷軸の位置推定値θ_{L_est}を求める過程は（２）式の伝達関数で表すことができる。
【００３３】
【数１３】

【００３４】
このように軸ねじり抑制制御器３における軸モデルを簡略化した場合には、第一の実施例ほど良好なオーバーシュートおよび軸振動の抑制効果は得られないが、設定パラメータ数の減少により使い勝手が向上する。
【００３５】
図４は本発明の弟三の実施例を示す電動機の位置制御装置である。図１で既に説明した第一の実施例に対して、位置制御器５の出力する速度指令値ω_M ^**を補正する機能を追加したものである。
【００３６】
図４において、負荷軸の速度推定値ω_{L_est}は第一の実施例と同一の推定モデルにより、電動機の軸位置検出値θ_Mと電動機の速度検出値ω_Mから求めている。この導出過程は（５）式の伝達関数で表すことができる。
【００３７】
【数１４】

【００３８】
５１は速度指令値ω_M ^**から軸ねじり抑制制御器３の状態変数である負荷軸の速度推定値ω_{L_est}を減ずる減算器、５０は減算器５１の出力に乗ずるゲインである軸ねじり速度フィードバックゲインk2である。５２は速度指令値ω_M ^**に軸ねじり速度フィードバックゲインk2の出力する軸ねじり速度補正値を加算する加算器である。
【００３９】
この位置制御器５の出力する速度指令値ω_M ^**と負荷軸の速度推定値ω_{L_est}とから補正後速度指令値ω_M ^*を求める過程を（７）式に表す。
【００４０】
【数１５】

【００４１】
位置指令値の補正手段を表す（４）式と速度指令の補正手段を表す（７）式を比較してみると、位置指令値の補正では軸ねじり量を減少する向きに補正を行っていたが、速度指令値の補正では軸ねじり速度を増加する向きに補正を行う。このように位置指令の補正と速度指令の補正を併用することにより、オーバーシュート及び軸振動の抑制に加えて、外乱抑制効果を向上することが可能となる。
【００４２】
図５は本発明の第四の実施例を示す電動機の位置制御装置である。図３で既に説明した第二の実施例に対して、位置制御器５の出力する速度指令値ω_M ^**を補正する機能を追加したものである。図５において、負荷軸の速度推定値ω_{L_est}は第二の実施例と同一の推定モデルにより、電動機の軸位置検出値θ_Mから求めている。この導出過程は（６）式の伝達関数で表すことができる。
【００４３】
【数１６】

【００４４】
５１は速度指令値ω_M ^**から軸ねじり抑制制御器３の状態変数である負荷軸の速度推定値ω_{L_est}を減ずる減算器、５０は減算器５１の出力に乗ずるゲインである軸ねじり速度フィードバックゲインk2である。５２は速度指令値ω_M ^**に軸ねじり速度フィードバックゲインk2の出力する軸ねじり速度補正値を加算する加算器である。この位置制御器５の出力する速度指令値ω_M ^**と負荷軸の速度推定値ω_{L_est}とから補正後速度指令値ω_M ^*を求める過程は、第三の実施例と同様に（７）式で表現できる。
【００４５】
このように軸ねじり抑制制御器における軸モデルを簡略化した場合には、第三の実施例ほど良好なオーバーシュートおよび軸振動の抑制効果は得られないが、設定パラメータ数の減少により使い勝手が向上する。
【００４６】
次に、本発明の第二の実施の形態を説明する。図７は第五の実施例の適用例を示す概略構成図である。模式的に示すロープ式エレベータに本発明を適用する場合を説明する。
【００４７】
図７において、101は乗りかご、102は乗客、103は乗りかご101を吊り上げるロープのバネ定数K_F1、104は乗りかご101を吊り上げるロープのダンパ定数ｃ1、105は乗りかご101を吊り上げるロープである。106はロープ101を駆動する駆動滑車、109はカウンタウェイト(重り)、107はカウンタウェイト109を吊り上げるロープのダンパ定数ｃ2である。108はカウンタウェイト109を吊り上げるロープのバネ定数K_F2、ｍ_cは乗りかご101の質量、ｍ_Lは乗客全員の質量、ｘ1は乗りかご101の移動距離、ｒ_sは駆動滑車106の半径である。
【００４８】
このようなロープ式エレベータに本発明を適用する場合にも、第一の実施例と同様の考え方が適用できる。異なる点は、乗りかご101を吊り上げるロープ式エレベータは、軸のバネ定数に代わってロープ105のバネ定数K_F1と、軸の粘性摩擦係数に代わってロープ105のダンパ定数ｃ1が、負荷（乗りかご101）の縦方向振動の挙動に支配的となる。したがって、ロープの伸縮を抑制することが、軸ねじり抑制と同様に負荷の振動低減に効果を発揮する。
【００４９】
図８は本実施例による電動機の位置制御装置のブロック図である。図において、115は電動機１の軸位置検出値θ_Mを直線系の位置情報に換算するためのゲインであり、駆動滑車106の半径ｒ_sを大きさとする。116は電動機の速度ω_Mを直線系の速度情報に換算するためのゲインであり、駆動滑車106の半径ｒ_sを大きさとする。117はモデルにより推定された乗りかご101の推定移動距離ｘ1_estを回転系に換算するためのゲインであり、駆動滑車106の半径ｒ_sの逆数を大きさとする。111はロープのバネ定数K_F1を大きさとするゲイン、112はロープの粘性摩擦係数を大きさとするゲインである。113はゲイン111、112の出力和で算出されるロープが乗りかごに与える力を積分し、さらに乗りかごと乗客との質量和（ｍ_c＋ｍ_L）で除算し、乗りかごの速度ｖ１を推定する推定用負荷イナーシャモデルである。114は乗りかごの推定速度ｖ1_estを積分し、乗りかご101の推定移動距離ｘ1_estを算出する積分器である。
【００５０】
以上に示した、電動機の軸位置検出値θ_Mと電動機の速度検出値ω_Mから負荷の回転系に換算した位置推定値θ_{L_est}を求める制御ブロックは、（３）式の伝達関数で表すことができる。
【００５１】
【数１７】

【００５２】
減算器16では電動機の軸位置指令値θ_M ^**から（３）式で求まる負荷の回転系換算の位置推定値θ_{L_est}を減ずることで、電動機の軸位置指令値θ_M ^**を与えた場合に発生するロープの伸縮量を求める。これに伸縮量フィードバックゲインk1を乗じた値が後述の位置指令補正値である。ロープの伸縮を抑制するように補正した補正後位置指令値θ_M ^*は、電動機の軸位置指令値θ_M ^**から前述の位置指令補正値を減ずることにより導出する。この電動機の軸位置指令値θ_M ^**と負荷軸の位置推定値θ_{L_est}とから、補正後位置指令値θ_M ^*を求める過程は前述の（４）式で表わされる。
【００５３】
k1の値は０＜k1＜１の範囲内で設定することにより、ロープの伸縮抑制することが可能となる。構成上、k1の値が大きい程ロープ伸縮抑制効果は大きいが、位置指令値の立ち上がりを抑えることでロープ伸縮抑制を実現している関係上、位置決め時間が長くなる作用がある。従って、k1を調整する際には、オーバーシュート及び乗りかごの上下振動が許容レベルに収まる範囲内で可能な限り小さく設定するとよい。
【００５４】
【発明の効果】
本発明の電動機の位置制御装置によれば、外乱抑制性能を低下することなく、急峻に変化する位置指令値が上位制御装置から入力された場合でも、オーバーシュート及びそれに続く軸振動を低減することができる。
【図面の簡単な説明】
【図１】本発明による第一の実施例を示す電動機の位置制御装置のブロック図。
【図２】本発明による電動機の位置制御装置の原理説明図。
【図３】本発明による第二の実施例を示す電動機の位置制御装置のブロック図。
【図４】本発明による第三の実施例を示す電動機の位置制御装置のブロック図。
【図５】本発明による第四の実施例を示す電動機の位置制御装置のブロック図。
【図６】本発明の第一の実施例の効果を示す説明図。
【図７】本発明の第五の実施例の適用例を示すロープ式エレベータの模試図。
【図８】本発明による第五の実施例を示す電動機の位置制御装置のブロック図。
【符号の説明】
１…電動機、２…電動機の軸位置検出器、３…軸ねじり抑制制御器、４…減算器、５…位置制御器、６…速度演算器、７…速度制御器、８…電流制御器、９…電力変換器、１０…電流検出器、１１…負荷軸の位置推定用バネ定数、１２…負荷軸の位置推定用粘性摩擦係数、１３…負荷軸の位置推定用負荷イナーシャモデル、１４…積分器、１５…軸ねじり量フィードバックゲイン、１６…減算器、２０…位置偏差演算器、２１…速度偏差演算器、２２…トルク電流偏差演算器、３０…電動機１のイナーシャモデル、３１…積分器、３２…電動機１に接続された軸および負荷を表すブロック、３３…減算器、３４…軸のバネ定数、３５…加算器、３６…軸の粘性摩擦係数、３７…減算器、３８…負荷60のイナーシャモデル、３９…減算器、４０…積分器、４１…減算器、５０…軸ねじり速度フィードバックゲイン、５１…減算器、６０…負荷、θ_M ^**…電動機の軸位置指令値、θ_M ^*…軸ねじり補償後の電動機の軸位置指令値、θ_M…電動機の軸位置（検出値）、ω_M ^*…電動機の速度指令値、ω_M…電動機の速度（検出値）、I_q ^*…トルク電流指令値、I_q…トルク電流検出値、V^*…変換器指令電圧値、θ_{L_est}…負荷軸の位置推定値、ω_{L_est}…負荷軸の速度推定値、τ_M…電動機トルク、τ_S…軸トルク、τ_L…外乱トルク、τ_T…軸ねじりトルク、τ_F…粘性摩擦トルク、τ_{S_est}…推定軸トルク、τ_{T_est}…推定軸ねじりトルク、τ_{F_est}…推定粘性摩擦トルク。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a position control device for an electric motor, and more particularly to a servo control device that suppresses load shaft vibration.
[0002]
[Prior art]
Conventionally, as a shaft vibration suppression means of an electric motor, a method of simply reducing response frequencies of a position control system and a speed control system is common. However, reducing the response frequency causes an increase in settling time and a decrease in disturbance suppression performance.
[0003]
Japanese Patent Laid-Open No. 6-217579 discloses another means for more actively suppressing shaft vibration. This is provided with a disturbance observer for estimating the shaft torque of the motor, a filter, and two amplifiers, and suppresses torsional vibration by advancing the phase of the speed change with respect to the shaft torque change of the motor.
[0004]
[Patent Document 1]
JP-A-6-217579 (paragraph 0038, FIG. 1)
[0005]
[Problems to be solved by the invention]
The technique described in Patent Document 1 has an effect of damping torsional vibration. However, overshoot cannot be completely eliminated when the rise of the position command is very steep.
[0006]
An object of the present invention is to provide an electric motor position control device that reduces overshoot and shaft vibration in position control without deteriorating disturbance suppression performance, and consequently shortens settling time.
[0007]
[Means for Solving the Problems]
The present invention that solves the above-described problems includes a power converter that drives an electric motor coupled to a load via a connecting member such as a load shaft or a rope, and a speed according to a deviation between a position command value and a position detection value of the electric motor. A position controller that obtains a command value, a speed controller that obtains a torque current command value according to a deviation between the speed command value and a detected speed value of the motor, and an output current of the power converter that is controlled according to the torque current command value In the position control device for an electric motor provided with a current controller, the position estimated value of the load shaft or the coupling member obtained by inputting the position detection value and the speed detection value into a load model, and the position command value, A shaft torsion amount of the load shaft or an expansion / contraction amount of the connecting member is estimated, and the position command value is corrected to reduce the shaft torsion amount or expansion / contraction amount according to the estimated amount.
[0008]
In the present invention, the amount of torsion of the load shaft when the electric motor is coupled with the load and the load shaft, or the amount of expansion and contraction of the connecting member when the electric motor is coupled with the connection member such as a rope or a belt is suppressed. . That is, the position command value is corrected so as to reduce the amount of shaft twist or expansion / contraction according to the amount of shaft twist or expansion / contraction estimated by the load model. By correcting this position command value, the torsion of the load shaft, which is the source of vibration, or the expansion and contraction of the connecting member is suppressed. Thereby, even when a position command value that changes sharply is input from the host controller, overshoot and subsequent vibration can be reduced. In addition, the said load model is called the axis | shaft model in Example 1-4.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The first embodiment is a case where an electric motor and a load are coupled by a shaft, and there are first to fourth examples. The second embodiment is a case where the electric motor and the load are coupled by a rope, and there is Example 5 applied to an elevator. The same control can be performed by using a belt instead of the rope.
[0010]
FIG. 1 shows an electric motor position control apparatus according to a first embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 is an electric motor, 2 is an axial position detector which detects axial position (theta) _M of the electric motor 1, 3 is an axial torsion suppression controller which is the characteristics of this invention, 4 is an axial torsion correction value which the axial torsion suppression controller 3 outputs Is a subtracter that subtracts from the position command value θ _M ^** of the motor. 5 is a position controller for inputting a deviation signal between the position command value θ _M ^* of the motor after the shaft torsion correction and the detected shaft position value θ _M of the motor and calculating a speed command value ω _M ^* , and 6 is a shaft of the motor. This is a speed calculator that calculates the speed ω _{M of the} electric motor from the position detection value θ _M. 7 is a speed controller that inputs a deviation signal between the speed command value ω _M ^* and the motor speed ω _M and outputs a torque current command value, and 8 is a torque current command value I _q ^* and a torque current detection value I _q . This is a current controller that calculates the voltage command V ^* according to the deviation. Reference numeral 9 denotes a power converter that outputs a voltage V proportional to the voltage command V ^* and drives the motor 1. Reference numeral 10 denotes a current detector that detects a torque current value _Iq of the power converter 9.
[0011]
The internal block of the shaft torsion suppression controller 3 is constituted by a shaft model such as a rotating shaft or a ball screw that couples the electric motor 1 and a load to be driven. By subtracting the estimated position θ _{L_est} of the load shaft from the detected shaft position value θ _M of the electric motor 1 by the subtractor 19, the current shaft torsion amount is estimated, and this is multiplied by the estimation spring constant K _Fe of 11. Estimated shaft torsion torque τ _{T_est} is calculated. Further, the current shaft torsional speed is estimated by subtracting the estimated speed ω _{L_est} of the load shaft from the detected speed value ω _M of the motor in the subtractor 17, and is estimated by multiplying this by 12 estimation viscous friction coefficients. Viscous friction torque τ _{F_est} is calculated.
[0012]
The estimated shaft torque τ _{S_est} is _obtained by adding the estimated shaft torsion torque τ _{T_est} and the estimated viscous friction torque τ _{F_est} by the adder 18. The estimated shaft torque τ _{S_est} is integrated by 13 estimated load inertia models and divided by the estimated load inertia J _Le to obtain a load shaft speed estimated value ω _{L_est} . Further, the speed estimated value ω _{L_est} is integrated by the integrator 14 to obtain the load shaft position estimated value θ _{L_est} .
[0013]
The process of _{obtaining the} load shaft position estimation value θ _{L_est} from the motor shaft position detection value θ _M and the motor speed detection value ω _M described above can be expressed by the transfer function of (1).
[0014]
[Equation 8]

[0015]
The subtracter 16, by subtracting the position estimate theta _{L_est} axis position command value of the motor from θ _M ^** (1) load axis which is obtained by the formula, when given the axial position command value theta _M ^** of the electric motor Determine the amount of shaft twist that occurs. A value obtained by multiplying this by the shaft torsion amount feedback gain k1 is the aforementioned shaft torsion correction value.
[0016]
The corrected position command value θ _M ^* corrected so as to suppress shaft torsion is derived by subtracting the above-mentioned shaft torsion correction value from the motor shaft position command value θ _M ^** . The process of _{obtaining the} corrected position command value θ _M ^* from the motor shaft position command value θ _M ^** and the load shaft position estimate value θ _{L_est} is expressed by equation (4).
[0017]
[Equation 9]

[0018]
By setting the value of k1 within the range of 0 <k1 <1, shaft torsion can be suppressed. In terms of configuration, the greater the value of k1, the greater the effect of suppressing shaft torsion, but there is an effect that the positioning time becomes longer due to the effect of suppressing shaft torsion by suppressing the rise of the position command value. Therefore, when adjusting k1, it is preferable to set it as small as possible within a range in which overshoot and shaft vibration fall within an allowable level.
[0019]
Next, the principle of this embodiment will be described. FIG. 2 shows the electric motor 1 and the load coupled to the electric motor 1 in FIG. The same control system and control target as in FIG. 1 are shown.
[0020]
In FIG. 2, reference numeral 30 denotes a block expressing the inertia characteristics of the single motor 1, and inputs the difference between the motor torque τ _M generated by the motor 1 itself and the shaft torque τ _S applied from the outside (shaft) to the motor 1. And the motor speed ω _M is the output. Reference numeral 31 denotes an integrator, which receives the motor speed ω _M and outputs the motor shaft position θ _M. A block 32 represents the characteristics of the shaft connected to the motor 1 and the load, and outputs the position θ _{L of the} load shaft in response to the input of the motor shaft position θ _M , the motor speed ω _M , and the disturbance torque τ _L. To do.
[0021]
In FIG. 2, the current controller 8 and the power converter 9 in FIG. 1 are omitted. The reason is that, based on the general characteristics of the motor represented by τ _M = k _T I _q using the torque constant k _T and the assumption that the current controller 8 controls I _q ≈I _q ^* , τ _M Because I _q ^* has a one-to-one correspondence.
[0022]
Here, comparing the block 32 and the shaft torsion suppression controller 3, the shaft torsion suppression controller 3 includes the same input signal and configuration as when τ _L = 0 in the block 32. Therefore, the values of the estimated load inertia J _Le , the estimated spring constant K _Fe , and the estimated viscous friction coefficient C _{Fe in} the shaft torsion suppression controller 3 are given as follows. That is, J _Le ≈J _L , K _Fe ≈K _F , and C _Fe ≈C _F are set for the actual load inertia J _L , the actual spring constant K _F , and the actual viscous friction coefficient C _F in the block 32. . As a result, when the disturbance torque τ _L = 0, θ _{L_est ≈θ L} is established. Further, when there is a disturbance, θ _{L_est} ≈ θ _L does not hold, but a load shaft position estimated value θ _{L_est} excluding the influence of the disturbance torque τ _L is obtained.
[0023]
Further, when the shaft torsion suppression controller 3 _obtains a transfer function from the motor shaft position θ _M to the load shaft position estimated value θ _{L — est} , the equation (8) is obtained. Applying the final value theorem to equation (8) yields equation (9).
[0024]
[Expression 10]

[0025]
From this, it can be seen that θ _{L_est} = θ _M after a certain time. Furthermore, assuming that the position control system is functioning correctly, θ _M = θ _M ^* holds in the steady state. Therefore, the relationship of the expression (10) is established together with the aforementioned θ _{L_est} = θ _M.
[0026]
[Expression 11]

[0027]
Substituting equation (10) into equation (4) representing the position command value correction means yields equation (11).
[0028]
[Expression 12]

[0029]
Now, since k1 is defined in the range of 0 <k1 <1, 1−k1 ≠ 0, and θ _M ^* = θ _M ^** is established from the equation (11).
[0030]
As described above, the correction of the position command value according to the present invention can be performed without giving an error to the target stop position of the position command. Further, compared to overshoot suppression means by reducing the response frequency of the control system, overshoot and shaft vibration can be suppressed with almost no deterioration in disturbance response.
[0031]
FIG. 6 shows how the position deviation converges during positioning control. (A) is a case where the first embodiment is used, and it is understood that overshoot is completely suppressed by application of the present invention. (B) is a case where it is not used, and a positional deviation overshoot and shaft vibration occur.
[0032]
FIG. 3 shows an electric motor position control apparatus according to a second embodiment of the present invention. This corresponds to the case where the estimation viscous friction coefficient C _Fe is omitted in the first embodiment already described in FIG. The process of _{obtaining the} load shaft position estimated value θ _{L_est} from the detected motor shaft position value θ _{M in} this case can be expressed by a transfer function of equation (2).
[0033]
[Formula 13]

[0034]
When the shaft model in the shaft torsion suppression controller 3 is simplified as described above, the overshoot and shaft vibration suppression effects are not as good as those in the first embodiment, but the usability is reduced by reducing the number of set parameters. improves.
[0035]
FIG. 4 shows an electric motor position control apparatus according to the third embodiment of the present invention. A function for correcting the speed command value ω _M ^** output from the position controller 5 is added to the first embodiment already described in FIG.
[0036]
In FIG. 4, the load shaft speed estimation value ω _{L — est} is _obtained from the motor shaft position detection value θ _M and the motor speed detection value ω _M using the same estimation model as in the first embodiment. This derivation process can be expressed by the transfer function of equation (5).
[0037]
[Expression 14]

[0038]
51 is a subtractor that subtracts the estimated load shaft speed ω _{L_est} , which is a state variable of the shaft torsion suppression controller 3, from the speed command value ω _M ^** , and 50 is a shaft torsion speed feedback that is a gain multiplied by the output of the subtractor 51. Gain k2. An adder 52 adds the shaft torsion speed correction value output from the shaft torsion speed feedback gain k2 to the speed command value ω _M ^** .
[0039]
The process of _{obtaining the} corrected speed command value ω _M ^* from the speed command value ω _M ^** output from the position controller 5 and the load shaft speed estimated value ω _{L_est} is expressed by equation (7).
[0040]
[Expression 15]

[0041]
Comparing the equation (4) representing the position command value correcting means and the equation (7) representing the speed command correcting means, the position command value was corrected in a direction to reduce the amount of shaft torsion. However, in the correction of the speed command value, the correction is performed in the direction in which the shaft torsion speed is increased. In this way, by using the correction of the position command and the correction of the speed command together, it is possible to improve the disturbance suppressing effect in addition to the suppression of overshoot and shaft vibration.
[0042]
FIG. 5 shows an electric motor position control apparatus according to a fourth embodiment of the present invention. A function for correcting the speed command value ω _M ^** output from the position controller 5 is added to the second embodiment already described with reference to FIG. In FIG. 5, the load shaft speed estimation value ω _{L — est} is obtained from the motor shaft position detection value θ _M by the same estimation model as in the second embodiment. This derivation process can be expressed by the transfer function of equation (6).
[0043]
[Expression 16]

[0044]
51 is a subtractor that subtracts the estimated load shaft speed ω _{L_est} , which is a state variable of the shaft torsion suppression controller 3, from the speed command value ω _M ^** , and 50 is a shaft torsion speed feedback that is a gain multiplied by the output of the subtractor 51. Gain k2. An adder 52 adds the shaft torsion speed correction value output from the shaft torsion speed feedback gain k2 to the speed command value ω _M ^** . The process of _{obtaining the} corrected speed command value ω _M ^* from the speed command value ω _M ^** output from the position controller 5 and the estimated load shaft speed ω _{L_est} is the same as in the third embodiment (7). It can be expressed by an expression.
[0045]
Thus, when the shaft model in the shaft torsion suppression controller is simplified, the overshoot and shaft vibration suppression effects are not as good as in the third embodiment, but the usability is improved by reducing the number of set parameters. To do.
[0046]
Next, a second embodiment of the present invention will be described. FIG. 7 is a schematic configuration diagram showing an application example of the fifth embodiment. The case where this invention is applied to the rope type elevator typically shown is demonstrated.
[0047]
In FIG. 7, 101 is a passenger car, 102 is a passenger, 103 is a spring constant K _{F1 of} a rope that lifts the passenger car 101, 104 is a damper constant c1 of a rope that lifts the passenger car 101, and 105 is a rope that lifts the passenger car 101. . 106 is a driving pulley for driving the rope 101, 109 is a counterweight (weight), and 107 is a damper constant c2 of the rope for lifting the counterweight 109. 108 is the mass of the cage 101 ride is a spring constant K _F2, m _c rope lifting the counterweight 109, m _L is the all passengers mass, x1 moving distance of the car 101 ride is, r _s is the radius of the drive pulley 106 .
[0048]
Even when the present invention is applied to such a rope type elevator, the same idea as in the first embodiment can be applied. The difference is that the rope-type elevator that lifts the car 101 has a load (cage) with a spring constant K _F1 of the rope 105 instead of the spring constant of the axis and a damper constant c1 of the rope 105 instead of the viscous friction coefficient of the axis. 101) is dominant in the behavior of longitudinal vibration. Therefore, suppressing the expansion and contraction of the rope is effective in reducing the vibration of the load as in the case of suppressing the torsion of the shaft.
[0049]
FIG. 8 is a block diagram of an electric motor position control apparatus according to this embodiment. In the figure, reference numeral 115 denotes a gain for converting the detected shaft position value θ _M of the electric motor 1 into linear system position information, and the radius r _s of the drive pulley 106 is set as a magnitude. Reference numeral 116 denotes a gain for converting the motor speed ω _M into linear speed information, and the radius r _s of the drive pulley 106 is set as a magnitude. 117 is a gain for converting the estimated moving distance x1_est of the car 101 estimated by the model into a rotating system, and the reciprocal of the radius r _s of the driving pulley 106 is set as a magnitude. 111 is a gain whose magnitude is the rope spring constant K _F1 , and 112 is a gain whose magnitude is the viscous friction coefficient of the rope. 113 integrates the force applied to the car by the rope calculated by the sum of the outputs of gains 111 and 112, and further divides by the mass sum of the car and the passenger (m _c + m _L ) to estimate the car speed v1. This is an estimation load inertia model. Reference numeral 114 denotes an integrator that integrates the estimated speed v1_est of the car and calculates the estimated moving distance x1_est of the car 101.
[0050]
The control block for _{obtaining the} estimated position value θ _{L_est} converted into the rotating system of the load from the detected shaft position value θ _M of the motor and the detected speed value ω _M of the motor is expressed by the transfer function of equation (3). Can do.
[0051]
[Expression 17]

[0052]
The subtracter 16 gives the motor shaft position command value θ _M ^** by subtracting the estimated rotational position converted value θ _{L_est} of the load obtained from the equation (3) from the motor shaft position command value θ _M ^** . Determine the amount of rope expansion and contraction that occurs. A value obtained by multiplying this by the expansion / contraction amount feedback gain k1 is a position command correction value described later. The corrected position command value θ _M ^* corrected so as to suppress the expansion and contraction of the rope is derived by subtracting the aforementioned position command correction value from the shaft position command value θ _M ^** of the electric motor. The process of _obtaining the corrected position command value θ _M ^* from the shaft position command value θ _M ^{** of the} electric motor and the estimated position value θ _{L_est} of the load shaft is expressed by the above-described equation (4).
[0053]
By setting the value of k1 within the range of 0 <k1 <1, it becomes possible to suppress the expansion and contraction of the rope. Although the rope expansion / contraction suppression effect is larger as the value of k1 is larger, the positioning time is longer due to the fact that the rope expansion / contraction suppression is realized by suppressing the rise of the position command value. Therefore, when adjusting k1, it is preferable to set it as small as possible within a range where the overshoot and the vertical vibration of the car fall within the allowable level.
[0054]
【The invention's effect】
According to the electric motor position control device of the present invention, it is possible to reduce overshoot and subsequent shaft vibration even when a rapidly changing position command value is input from the host control device without deteriorating disturbance suppression performance. Can do.
[Brief description of the drawings]
FIG. 1 is a block diagram of an electric motor position control apparatus according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating the principle of a position control device for an electric motor according to the present invention.
FIG. 3 is a block diagram of an electric motor position control apparatus according to a second embodiment of the present invention.
FIG. 4 is a block diagram of an electric motor position control apparatus according to a third embodiment of the present invention.
FIG. 5 is a block diagram of an electric motor position control apparatus according to a fourth embodiment of the present invention.
FIG. 6 is an explanatory diagram showing the effect of the first embodiment of the present invention.
FIG. 7 is a schematic diagram of a rope type elevator showing an application example of the fifth embodiment of the present invention.
FIG. 8 is a block diagram of an electric motor position control apparatus according to a fifth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Electric motor, 2 ... Shaft position detector of an electric motor, 3 ... Shaft torsion suppression controller, 4 ... Subtractor, 5 ... Position controller, 6 ... Speed calculator, 7 ... Speed controller, 8 ... Current controller, DESCRIPTION OF SYMBOLS 9 ... Power converter, 10 ... Current detector, 11 ... Load shaft position estimation spring constant, 12 ... Load shaft position estimation viscous friction coefficient, 13 ... Load shaft position estimation load inertia model, 14 ... Integration 15 ... shaft torsion amount feedback gain, 16 ... subtractor, 20 ... position deviation calculator, 21 ... speed deviation calculator, 22 ... torque current deviation calculator, 30 ... inertia model of motor 1, 31 ... integrator, 32 ... Block representing the shaft and load connected to the motor 1, 33 ... Subtractor, 34 ... Spring constant of the shaft, 35 ... Adder, 36 ... Viscous friction coefficient of the shaft, 37 ... Subtractor, 38 ... Load 60 Inertia model, 39 ... subtractor, 40 Integrator 41 ... subtractor, 50 ... shaft torsional velocity feedback gain, 51 ... subtractor, 60 ... load, theta _M ^** ... axial position command value of the motor, theta _M ^* ... axial position of the electric motor after the shaft torsional compensation Command value, θ _M … Motor shaft position (detected value), ω _M ^* … Motor speed command value, ω _M … Motor speed (detected value), I _q ^* … Torque current command value, I _q … Torque current Detected value, V ^* ... Converter command voltage value, θ _{L_est} ... Load shaft position estimated value, ω _{L_est} ... Load shaft speed estimated value, τ _M ... Motor torque, τ _S ... Shaft torque, τ _L ... Disturbance torque, τ _T … shaft torsion torque, τ _F … viscous friction torque, τ _{S_est} … estimated shaft torque, τ _{T_est} … estimated shaft torsion torque, τ _{F_est} … estimated viscous friction torque.

Claims (10)

A power converter that drives an electric motor coupled to a load via a load shaft; a position controller that obtains a speed command value according to a deviation between a position command value and a position detection value of the motor; and the speed command value and the electric motor In a position controller for an electric motor comprising a speed controller that obtains a torque current command value according to the deviation of the detected speed value, and a current controller that controls the output current of the power converter according to the torque current command value,
A shaft torsion amount of the load shaft is estimated from the position estimated value of the load shaft and the position command value obtained by inputting the position detection value and the speed detection value to a load model, and a shaft is determined according to the estimated amount. A position control apparatus for an electric motor, wherein the position command value is corrected so as to reduce a torsion amount. A power converter that drives an electric motor coupled to a load via a load shaft; a position controller that obtains a speed command value according to a deviation between a position command value and a position detection value of the motor; and the speed command value and the electric motor In a position control device comprising a speed controller that obtains a torque current command value according to the deviation of the detected speed value, and a current controller that controls the output current of the power converter according to the torque current command value,
A position torsion amount is estimated from a position estimation value of the load shaft obtained by inputting the position detection value to a load model and the position command value, and the position command value is set to decrease the amount of shaft torsion according to the estimated amount. A position control device for an electric motor, wherein In claim 1 ,
The estimated position value of the load shaft is determined by the estimated position value of the load shaft θ _{L_est} , the detected position value of the motor θ _M , the detected speed value of the motor ω _M , the load and the characteristics of the load shaft. A position control device for an electric motor, wherein the parameters are C _Fe , K _Fe , J _Le and s is a Laplace operator, and is calculated by the transfer function of equation (1).

In claim 2 ,
The load shaft position estimate value is θ _{L_est as} the load shaft position estimate value, θ _M as the position detection value of the motor, and K _Fe and J _Le as parameters determined by the load and the characteristics of the load shaft, An electric motor position control device, wherein s is a Laplace operator, and is calculated by a transfer function of equation (2).

In claim 1 ,
For correction of the position command value, the position command value before correction is θ _M ^** , the position command value after correction is θ _M ^* , the estimated position value of the load shaft is θ _{L_est} , and the gain is k1 (0 <k1 <1). ), The position control device for an electric motor calculated by the equation (4).

In claim 1 ,
A shaft torsion speed is estimated from a load shaft speed estimation value obtained by inputting the position detection value and the speed detection value into the load model and a speed command value output from the position controller. A position control apparatus for an electric motor, wherein the speed command value is corrected so as to increase a shaft torsion speed in accordance with the speed. In claim 2 ,
A shaft torsional speed is estimated from a load shaft speed estimation value obtained by inputting the position detection value to the load model and a speed command value output from the position controller, and a shaft is set according to the estimated shaft torsional speed. A position control apparatus for an electric motor, wherein the speed command value is corrected so as to increase a twisting speed. In claim 6 ,
The estimated speed of the load shaft is determined by the estimated speed of the load shaft ω _{L — est} , the detected position of the motor θ _M , the detected speed of the motor ω _M , the load and the characteristics of the load shaft. The motor position control device is characterized by being calculated by the transfer function of equation (5), where C _Fe , K _Fe , J _Le are s and Laplace operator is s.

In claim 7 ,
The estimated speed of the load shaft is ω _{L_est as} the estimated speed of the load shaft, θ _M as the position detection value of the motor, and K _Fe and J _Le as parameters determined by the load and the characteristics of the load shaft, An electric motor position control device, wherein s is a Laplace operator, and is calculated by a transfer function of equation (6).

In claim 5 ,
The speed command value is corrected by setting the speed command value before correction to ω _M ^** , the speed command value after correction to ω _M ^* , the estimated speed value of the load shaft to ω _{L_est} , and the gain to k2 (0 <k2 <k1). X3), the electric motor position control device is calculated by the equation (7).

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