CN101777868B - Method and system for driving asynchronous motor servo for robot - Google Patents

Abstract

The invention provides a method and a system for driving an asynchronous motor servo for a robot, wherein the method comprises the following steps that: the current operation state of an asynchronous motor is monitored in real time, and the current operation state of the monitored asynchronous motor is feedbacked to a controller; the controller compares the current operation state information with a given instruction value, and a corresponding control instruction value is obtained; and the control instruction value controls the asynchronous motor. Because the rotating speed of the asynchronous motor can be very high and the working environment is not restricted by the temperature, the defects caused by adopting a permanent magnet synchronous motor to drive can be prevented.

Description

A kind of robot is with asynchronous motor servo drive method and system

Technical field

The present invention relates to the Motor Control technical field, particularly a kind of robot is with asynchronous motor servo drive method and system.

Background technology

Brief account robot once at first, robot is the installations that automatically perform work.Its task is to assist or replace human work, for example manufacturing industry, building industry, or dangerous work.

The actuator of robot is a robot body, and its arm generally adopts spatial linkage, and motion parts wherein is called the joint, and initiatively the joint number is commonly referred to the number of degrees of freedom, of robot.

The joint of robot is driven by motor, and motor is realized the servo-actuated of position, speed, acceleration-deceleration and moment under driver control.The system that motor and driver constitute is known as servo drive system.Requirement at aspects such as other performance of the accuracy of the rapidity of the positional precision of motor, speed stability, acceleration-deceleration, moment and motion control and precision all is higher than other machinery to servo drive system in robot, so robot is the servo drive system of one type of high accuracy, high dynamic response, high stability with the motor servo drive system.The motor of the motor servo drive system that present robot uses all is to adopt permanent magnet synchronous motor or DC motor.The rotor of permanent magnet synchronous motor can not run up; Otherwise stator winding can produce very strong back electromotive force; Overcome the effect of this back electromotive force; Driver must make permanent magnet synchronous motor produce bigger stator magnet kinetic potential through the electric current that increases stator winding, but the stator magnet kinetic potential is crossed by force and can be made the rotor demagnetization.On the other hand, permanent magnet synchronous motor can receive the restriction of working temperature, and after temperature reached the Curie point of permanent magnet, permanent magnet can demagnetization.But the environment of robot work is quite abominable sometimes, and some application need is worked under hot environment.And the manufacturing cost of permanent magnet synchronous motor servo drive system and material cost all are higher than the system that asynchronous motor constitutes.The servo drive system of DC motor is because there is commutator in DC motor, so maintainability is poor.On commercial Application, replaced by AC servo drive system.

Therefore, robot utilizes permanent magnet synchronous motor to control to exist rotating speed low, the shortcoming of poor reliability.

Summary of the invention

The technical problem that the present invention will solve provides robot with asynchronous motor servo drive method and system, can solve robot and utilize permanent magnet synchronous motor to control to exist rotating speed low, the shortcoming of poor reliability.

The embodiment of the invention provides a kind of robot to use the asynchronous motor servo drive method, may further comprise the steps:

The real-time current running status of monitoring asynchronous motor feeds back to controller with the current running state information of monitored asynchronous motor;

Controller is compared said current running state information and is obtained the control instruction corresponding value with given command value;

By said control command value asynchronous motor is controlled.

Preferably, when said current running state information is the actual angle of asynchronous motor, asynchronous motor is carried out Position Control, is specially:

It is poor that controller is done the given command value of actual angle and position of asynchronous motor, and difference is carried out obtaining rotating speed control command value after PI regulates;

It is poor that the actual angular frequency of rotating speed control command value and asynchronous motor is done, and obtains the electromagnetic torque command value by both difference;

The difference of electromagnetic torque command value and torque current is obtained the torque voltage instruction value through voltage equation;

Calculate the exciting voltage command value by the exciting current controlling value; Said exciting current controlling value is the poor of excitation current instruction value and exciting current;

Obtain the three-phase voltage controlling value of asynchronous motor to the three-phase alternating current coordinate transform through the M-T coordinate by torque voltage controling value and exciting voltage controlling value; The rotor rotating magnetic field of M-T coordinate system and asynchronous motor is rotated synchronously, and stipulates the M axle along the rotor flux direction, and the T axle turn 90 degrees along the M axle counterclockwise; Said exciting voltage controlling value is the poor of exciting voltage command value and excitation decoupling zero voltage; Said torque voltage controling value is the poor of torque voltage instruction value and torque decoupler voltage;

The SVPWM inverter changes the three-phase voltage controlling value of importing into the three phase sine electric current and is input in the stator winding of asynchronous motor, realizes the SERVO CONTROL to asynchronous motor.

Preferably, said rotating speed control command value ω _Rm ^*Actual angular frequency ω with asynchronous motor _rIt is poor to do, and obtains the electromagnetic torque command value by both difference, is specially:

$\left\{\begin{array}{c}{i}_T^{\′*}=\frac{T_r}{L_m}{\mathrm{\ψ}}_r{\mathrm{\ω}}_{\mathrm{se}}+K_{\mathrm{p\ω}}e\left(k\right)+K_{1\mathrm{\ω}}\underset{i=1}{\overset{k}{\mathrm{\Σ}}}e\left(i\right)\\ e\left(k\right)={\mathrm{\ω}}_{\mathrm{rm}}^{*}\left(k\right)-{\mathrm{\ω}}_r\left(k\right)\end{array}\right.$

Wherein, k representes current sampling instant; L _mThe self-induction of expression asynchronous motor stator winding; T _rThe time constant of expression asynchronous motor rotor; ψ _rThe rotor flux of expression asynchronous motor; ω _SeThe slip of expression asynchronous motor; K _{P ω}The proportional gain of error e (k) influence is eliminated in expression; K _{I ω}The storage gain of accumulated error e (k) influence is eliminated in expression.

Preferably, with electromagnetic torque command value i _T ^{' *}With torque current i _TDifference obtain torque voltage instruction value u through voltage equation _T ^{' *}Be specially:

$u_T^{\′*}=K_{\mathrm{PT}}{e}_{\mathrm{IT}},$ $e_{\mathrm{IT}}=i_T^{*}-i_T,$ K wherein _PTThe expression gain coefficient, i _TThe expression torque current.

Preferably,, the position of asynchronous motor carries out rotating speed and torque amplitude limit when being controlled.

The embodiment of the invention also provides a kind of robot to use the asynchronous motor servo drive system, comprising: feedback unit, comparing unit and control unit;

Said feedback unit is used for monitoring in real time the current running status of asynchronous motor, and the current running state information of monitored asynchronous motor is fed back to comparing unit;

Said comparing unit, being used for said current running state information compared with given command value obtains the control instruction corresponding value;

Said control unit is used for by said control command value asynchronous motor being controlled.

Preferably; When the current running state information of said feedback unit feedback was the actual angle of asynchronous motor, said comparing unit comprised: position control unit, rotary speed controling unit, torque current control unit, exciting current control unit, coordinate transformation unit and SVPWM inversion unit;

Said position control unit, it is poor to be used for the given command value of actual angle and position of asynchronous motor is done, and difference is carried out obtaining rotating speed control command value after PI regulates;

Said rotary speed controling unit, it is poor to be used for the actual angular frequency of rotating speed control command value and asynchronous motor is done, and obtains the electromagnetic torque command value by both difference;

Said torque current control unit is used for the difference of electromagnetic torque command value and torque current is obtained the torque voltage instruction value through voltage equation;

Said exciting current control unit is used for obtaining the exciting voltage command value by the exciting current controlling value through voltage equation;

Coordinate transformation unit is used for passing through the M-T coordinate obtains asynchronous motor to the three-phase alternating current coordinate transform three-phase voltage controlling value by torque voltage controling value and exciting voltage controlling value; The rotor rotating magnetic field of M-T coordinate system and asynchronous motor is rotated synchronously, and stipulates the M axle along the rotor flux direction, and the T axle turn 90 degrees along the M axle counterclockwise; Said exciting voltage command value is the poor of exciting voltage controlling value and excitation decoupling zero voltage; Said torque voltage controling value is the poor of torque voltage instruction value and torque decoupler voltage;

The SVPWM inversion unit is used for the three-phase voltage controlling value of input is changed into the three phase sine electric current and is input to the stator winding of asynchronous motor, realizes the SERVO CONTROL to asynchronous motor.

Preferably, said rotary speed controling unit is used for rotating speed control command value ω _Rm ^*Actual angular frequency ω with asynchronous motor _rIt is poor to do, and obtains the electromagnetic torque command value by both difference, is specially:

$\left\{\begin{array}{c}{i}_T^{\′*}=\frac{T_r}{L_m}{\mathrm{\ψ}}_r{\mathrm{\ω}}_{\mathrm{se}}+K_{\mathrm{p\ω}}e\left(k\right)+K_{\mathrm{I\ω}}\underset{i=1}{\overset{k}{\mathrm{\Σ}}}e\left(i\right)\\ e\left(k\right)={\mathrm{\ω}}_{\mathrm{rm}}^{*}\left(k\right)-{\mathrm{\ω}}_r\left(k\right)\end{array}\right.$

Wherein, k representes current sampling instant; L _mThe self-induction of expression asynchronous motor stator winding; T _rThe time constant of expression asynchronous motor rotor; ψ _rThe rotor flux of expression asynchronous motor; ω _SeThe slip of expression asynchronous motor; K _{P ω}The proportional gain of error e (k) influence is eliminated in expression; K _{I ω}The storage gain of accumulated error e (k) influence is eliminated in expression.

Preferably,

Said torque current control unit is used for electromagnetic torque command value i _T' ^*With torque current i _TDifference obtain torque voltage instruction value u through voltage equation _T ^{' *}Be specially:

$u_T^{\′*}=K_{\mathrm{PT}}{e}_{\mathrm{IT}},$ $e_{\mathrm{IT}}=i_T^{*}-i_T,$ K wherein _PTThe expression gain coefficient, i _TThe expression torque current.

Preferably, also comprise the decoupling zero unit, be used for obtaining excitation decoupling zero voltage and torque decoupler voltage by torque current and exciting current decoupling zero.

Compared with prior art, the present invention has the following advantages:

Robot provided by the invention can satisfy robot control system to the requirement of servo drive at precision and aspect of performance with asynchronous motor servo drive method and system.Adopt the current running state information and the given command value of controller of asynchronous motor to compare, as control command, can realize closed-loop control in real time like this with difference.Because the rotating speed of asynchronous motor can reach very high, and its operational environment can not receive the restriction of temperature, the shortcoming of bringing in the time of therefore can avoiding adopting permanent magnet synchronous motor to drive.

Description of drawings

Fig. 1 is method embodiment one flow chart provided by the invention;

Fig. 2 is method embodiment two flow charts provided by the invention;

Fig. 3 is system embodiment one sketch map provided by the invention;

Fig. 4 is system embodiment two sketch mapes provided by the invention;

Fig. 5 is system embodiment three sketch mapes provided by the invention.

Embodiment

For make above-mentioned purpose of the present invention, feature and advantage can be more obviously understandable, does detailed explanation below in conjunction with the accompanying drawing specific embodiments of the invention.

The embodiment of the invention is taked closed-loop control to the SERVO CONTROL of asynchronous motor, can comprise Position Control, rotating speed control and torque control.

For those skilled in the art can be understood and embodiment of the present invention better, introduce several technical terms below.

The coordinate system at three phase winding A of asynchronous motor stator, B, C place is defined as static three phase coordinate systems, the coordinate system at three phase winding a of asynchronous motor rotor, b, c place is defined as the two-phase rotating coordinate system, represent with M-T.Wherein, the rotor rotating magnetic field of M-T coordinate system and asynchronous motor is rotated synchronously, and stipulates the M axle along the rotor flux direction, and the T axle turn 90 degrees along the M axle counterclockwise.

From the power input line of asynchronous motor A phase current and B phase current, use i respectively through the current sensor measurement asynchronous motor _AAnd i _BExpression.

By the conversion formula (1) of static three phase coordinate systems to the M-T coordinate system, can be by i _AAnd i _BCalculate the exciting current and the torque current of rotor, wherein exciting current and torque current are used i respectively _MAnd i _TRepresent that conversion formula (1) is specific as follows:

$\left[\begin{array}{c}{i}_M\\ i_T\end{array}\right]=\left[\begin{array}{cc}\cos \mathrm{\θ}& \sin \mathrm{\θ}\\ -\sin \mathrm{\θ}& \cos \mathrm{\θ}\end{array}\right]\left[\begin{array}{cc}\frac{\sqrt{3}}{2}& 0\\ \frac{1}{\sqrt{3}}& \sqrt{2}\end{array}\right]\left[\begin{array}{c}{i}_A\\ i_B\end{array}\right]---\left(1\right)$

Wherein θ is the M axle and the asynchronous motor A angle between the axis of stator winding mutually, and θ can have the supply frequency ω of asynchronous motor _sIntegration obtains.

Need to prove that the control method of the asynchronous motor servo drive system that the embodiment of the invention provides can adopt separate location control, also can adopt independent rotating speed control, can also adopt independent torque control.

Embodiment one:

Referring to Fig. 1, this figure is method embodiment one flow chart provided by the invention.

The robot that present embodiment provides uses the asynchronous motor servo drive method, may further comprise the steps:

S1: monitor the current running status of asynchronous motor in real time, the current running state information of monitored asynchronous motor is fed back to controller.

S2: controller is compared said current running state information and is obtained the control instruction corresponding value with given command value.

S3: asynchronous motor is controlled by said control command value.

Robot provided by the invention uses the asynchronous motor servo drive method, can satisfy robot control system to the requirement of servo drive at precision and aspect of performance.Adopt the current running state information and the given command value of controller of asynchronous motor to compare, as control command, can realize closed-loop control in real time like this with difference.Because the rotating speed of asynchronous motor can reach very high, and its operational environment can not receive the restriction of temperature, the shortcoming of bringing in the time of therefore can avoiding adopting permanent magnet synchronous motor to drive.

Embodiment two:

At first introduce Position Control below.

Referring to Fig. 2, this figure is method embodiment two flow charts provided by the invention.

S101: position transducer is with the actual angle θ of the asynchronous motor that records _rFeed back to controller, controller is with the actual angle θ of asynchronous motor _rWith the given command value θ in position _Rm ^*It is poor to do, and both differences are carried out obtaining rotating speed control command value ω after PI regulates _Rm ^*

Need to prove the given command value θ in position _Rm ^*It is controller specified value by the asynchronous motor servo drive system.

S102: rotating speed control command value ω _Rm ^*Actual angular frequency ω with asynchronous motor _rIt is poor to do, and obtains electromagnetic torque command value i by both difference _T ^{' *}i _T ^{' *}Concrete computing formula following:

$\left\{\begin{array}{c}{i}_T^{\′*}=\frac{T_r}{L_m}{\mathrm{\ψ}}_r{\mathrm{\ω}}_{\mathrm{se}}+K_{\mathrm{p\ω}}e\left(k\right)+K_{\mathrm{I\ω}}\underset{i=1}{\overset{k}{\mathrm{\Σ}}}e\left(i\right)\\ e\left(k\right)={\mathrm{\ω}}_{\mathrm{rm}}^{*}\left(k\right)-{\mathrm{\ω}}_r\left(k\right)\end{array}\right.---\left(2\right)$

Wherein, k representes current sampling instant; L _mThe self-induction of expression asynchronous motor stator winding; T _rThe time constant of expression asynchronous motor rotor; ψ _rThe rotor flux of expression asynchronous motor; ω _SeThe slip of expression asynchronous motor; K _{P ω}The proportional gain of error e (k) influence is eliminated in expression; K _{I ω}The storage gain of accumulated error e (k) influence is eliminated in expression.

Need to prove, when rotor speed is less than or equal to the asynchronous motor rated frequency, ψ _rBe fixed value, when rotor speed during greater than the asynchronous motor rated frequency, ψ _rThe rule that obtains by the design or the test of asynchronous motor reduces.

Here, the slip counter formula of asynchronous motor is: ω _sThe frequency of stator power, ω _s=ω _Se+ ω _Re, ω _ReIt is the electric angle frequency of asynchronous motor.A, b, c are constant, and the asynchronous motor design parameter provides or test acquisition by asynchronous motor producer.ω ₀Be the non-linear corner frequency of low frequency slip, ω _kFor the non-linear corner frequency of high frequency slip, provide or test acquisition by asynchronous motor producer.

S103: with electromagnetic torque command value i _T ^{' *}With torque current i _TDifference obtain torque voltage instruction value u through voltage equation _T ^{' *}

Electromagnetic torque command value i _T ^{' *}With torque current i _TDifference be the controlling value i of torque current _T ^*

Specific as follows:

$u_T^{\′*}=K_{\mathrm{PT}}{e}_{\mathrm{IT}},$ $e_{\mathrm{IT}}=i_T^{*}-i_T,$ K wherein _PTThe expression gain coefficient.

S104: torque voltage instruction value u _T ^{' *}With torque decoupler voltage u _T' do difference to obtain torque voltage controling value u _T ^*

Introduce below and how to obtain exciting voltage controlling value u _M ^*

At first by exciting current i _MCalculate rotor flux ψ _r, concrete computing formula is following:

${\mathrm{\ψ}}_r=L_m\frac{i_M}{1+T_{r}P}---\left(3\right)$

Wherein, ψ _rThe expression rotor flux; T _rThe expression rotor time constant; L _mThe self-induction of expression asynchronous motor stator; P representes differential operator.

Flux linkage set command value ψ _m ^*With rotor flux ψ _rDo the difference back and calculate excitation current instruction value i _M ^{' *}, concrete computing formula is following:

$i_M^{\′*}=\frac{(1+T_{r}P)}{L_m}({\mathrm{\ψ}}_M^{**}-{\mathrm{\ψ}}_r)---\left(4\right)$

Excitation current instruction value i _M ^{' *}With exciting current i _MObtain exciting current controlling value i after doing difference _M ^*

By exciting current controlling value i _M ^*Calculate exciting voltage command value u _M ^{' *}, concrete computing formula is following:

$u_M^{\′*}=K_{\mathrm{PM}}{e}_{\mathrm{IM}},$ $e_{\mathrm{IM}}=i_M^{*}-i_M,$ K wherein _PMThe expression gain coefficient.

Exciting voltage command value u _M ^{' *}With excitation decoupling zero voltage u _M' do difference to obtain exciting voltage controlling value u _M ^*

Below in conjunction with how obtaining torque decoupler voltage u _T' and excitation decoupling zero voltage u _M', concrete computing formula is following:

$\left[\begin{array}{c}{u}_M^{\′}\\ u_T^{\′}\\ 0\end{array}\right]=\mathrm{\σ}{L}_s\{P\left[\begin{array}{c}{i}_M\\ i_T\\ {\mathrm{\ψ}}_m\end{array}\right]-\left[\begin{array}{ccc}-\frac{R_s}{\mathrm{\σ}{L}_s}-\frac{R_r(1-\mathrm{\σ})}{\mathrm{\σ}{L}_r}& 0& \frac{L_m{R}_r}{\mathrm{\σ}{L}_s{L}_r^2}\\ 0& \frac{R_s}{\mathrm{\σ}{L}_s}& 0\\ \frac{L_m{R}_r}{L_r}& 0& -\frac{R_r}{L_r}\end{array}\right]\left[\begin{array}{c}{i}_M\\ i_T\\ {\mathrm{\ψ}}_m\end{array}\right]\}---\left(5\right)$

Wherein, P representes differential operator; σ representes magnetic leakage factor, $\mathrm{\σ}=1-L_m^2/\left(L_s{L}_r\right);$ L _mThe self-induction of expression asynchronous motor stator winding; R _sThe internal resistance of expression asynchronous motor stator winding; L _rThe self-induction of expression asynchronous motor rotor winding; R _rThe internal resistance of expression asynchronous motor rotor winding; ψ _mThe expression stator magnetic linkage, the definition stator magnetic linkage equates with rotor flux among the present invention, i.e. ψ _m=ψ _r

No matter need to prove, be Position Control, or rotating speed control or torque control, all needs the excitation control loop, and this is for the magnetic field of rotation is provided to rotor.Excitation control is the exciting voltage controlling value that combines with exciting current and control output through with the magnetic linkage command value.Because exciting current is the value of feedback of asynchronous motor, can realize closed-loop control like this.

S105: by torque voltage controling value u _T ^*With exciting voltage controlling value u _M ^*Can obtain the three-phase voltage controlling value u of asynchronous motor to the three-phase alternating current coordinate transform through the M-T coordinate _A ^*, u _B ^*And u _C ^*

The S106:SVPWM inverter is with the u of input _A ^*, u _B ^*And u _C ^*Change the three phase sine electric current into and be input in the stator winding of asynchronous motor, realize SERVO CONTROL asynchronous motor.

By torque voltage controling value u _T ^*With exciting voltage controlling value u _M ^*Calculate three-phase voltage controlling value u _A ^*, u _B ^*And u _C ^*Computing formula specific as follows:

$\left.\begin{array}{c}\left[\begin{array}{c}{u}_A^{*}\\ u_B^{*}\end{array}\right]=\left[\begin{array}{cc}\sqrt{\frac{2}{3}}& 0\\ -\frac{1}{\sqrt{6}}& \frac{1}{\sqrt{2}}\end{array}\right]\left[\begin{array}{cc}\cos \mathrm{\θ}& -\sin \mathrm{\θ}\\ \sin \mathrm{\θ}& \cos \mathrm{\θ}\end{array}\right]\left[\begin{array}{c}{u}_M^{*}\\ u_T^{*}\end{array}\right]\\ u_C^{*}=-u_A^{*}-u_B^{*}\end{array}\right\}---\left(6\right)$

The asynchronous motor servo drive system that embodiment two introduces is that robot is taked Position Control, need to prove that when the control command of host computer was Position Control, the asynchronous motor servo drive system was taked Position Control to robot.

Need to prove that the Position Control that present embodiment provides, location positioning precision can reach ± 1 pulse, the position of asynchronous motor specifically can be obtained by position-detection sensor, for example optical encoder and resolver.

Need to prove, can carry out rotating speed and torque amplitude limit during Position Control.

The rotating speed amplitude limit is specially:

When ${\mathrm{\&omega;}}_{\mathrm{Rm}}^{*}<{\mathrm{\&omega;}}_{\mathrm{Lim}}$

Wherein, ω _LimBe rotating speed amplitude limit set point.

Torque amplitude limit is specially:

When $i_T^{\&prime;*}<i_{\mathrm{Tlim}}^{\&prime;*}$

Wherein, i _{T lim} ^{' *}Be the torque amplitude limit set point.

Embodiment three:

Introduce rotating speed control below:

S201: rotational speed setup command value ω _Rm ^*Actual angular frequency ω with asynchronous motor _rIt is poor to do, and obtains electromagnetic torque command value i by both difference _T ^{' *}i _T ^{' *}Concrete computing formula following:

$\left\{\begin{array}{c}{i}_T^{\&prime;*}=\frac{T_r}{L_m}{\mathrm{\&psi;}}_r{\mathrm{\&omega;}}_{\mathrm{se}}+K_{\mathrm{p\&omega;}}e\left(k\right)+K_{\mathrm{I\&omega;}}\underset{i=1}{\overset{k}{\mathrm{\&Sigma;}}}e\left(i\right)\\ e\left(k\right)={\mathrm{\&omega;}}_{\mathrm{rm}}^{**}\left(k\right)-{\mathrm{\&omega;}}_r\left(k\right)\end{array}\right.---\left(7\right)$

Need to prove that formula (7) is identical with the computational methods of formula (2).

Need to prove rotational speed setup command value ω _Rm ^*It is controller specified value by the asynchronous motor servo drive system.

The subsequent step of rotating speed control is identical with Position Control, promptly identical with S102-S106, repeats no more at this.

The asynchronous motor servo drive system that embodiment three introduces is that robot is taked rotating speed control, need to prove, when the control command of host computer was rotating speed control, the asynchronous motor servo drive system was taked rotating speed control to robot.

Need to prove; In the rotating speed control that present embodiment provides; Rotating speed control can reach: minimum is 1/100Hz, 1/256Hz, 1/512Hz, maximum 600Hz, and the rotating speed control precision can be less than or equal 0.05Hz; Acceleration-deceleration range of instructions 1/65535Hz～1Hz, the torque instruction scope is 10%～300% of the motor nominal torque.

Need to prove that rotating speed control the time can be carried out torque amplitude limit, identical among concrete torque amplitude limit and the embodiment two repeated no more at this.

Embodiment four:

Introduce torque control below:

S301: by the given command value T of torque _T ^*The given command value i of calculating torque electric current _T ^*

Concrete computing formula is following:

${i_T}^{**}=\frac{L_r}{p_n{L^2}_m{i}_{\mathrm{mm}}}{T}^{**}---\left(8\right)$

Wherein, p _nThe number of pole-pairs of expression asynchronous motor; i _MmExpression produces the equivalent exciting current of rotor flux; I during stable state _Mm=i _m, L _mThe self-induction of expression asynchronous motor stator winding; L _rThe self-induction of expression asynchronous motor rotor winding.

Need to prove the given command value T of torque _T ^*It is controller specified value by the asynchronous motor servo drive system.

S302: the given command value i of torque current _T ^*With torque current i _TBe the controlling value i that difference obtains torque current _T ^*Obtain torque voltage instruction value u by voltage equation _T ^{' *}

Need to prove, by the controlling value i of torque current _T ^*Through voltage equation calculating torque voltage instruction value u _T ^{' *}Identical with the S103 among the embodiment two, repeat no more at this.

The subsequent step of torque control is identical with the subsequent step of embodiment two, promptly identical with S104-S106.

The asynchronous motor servo drive system that embodiment four introduces is that robot is taked torque control, need to prove, when the control command of host computer was torque control, the asynchronous motor servo drive system was taked torque control to robot.

Need to prove that torque control the time can be carried out the rotating speed amplitude limit, identical among concrete rotating speed amplitude limit and the embodiment two repeated no more at this.

Position command, rotary speed instruction, torque instruction all can be simultaneously or independent online change, and after command value changed, motor was according to the command value actual motion.Position command, three kinds of instructions of speed command and torque instruction can be connected with host computer through distinct interface carries out communication.

The robot that provides based on above embodiment uses the asynchronous motor servo drive method, and the embodiment of the invention also provides a kind of robot to use the asynchronous motor servo drive system, is described in detail below in conjunction with accompanying drawing.

Referring to Fig. 3, this figure is the system provided by the invention first embodiment sketch map.

The robot that present embodiment provides uses the asynchronous motor servo drive system, comprising: feedback unit 401, comparing unit 402 and control unit 403.

Said feedback unit 401 is used for monitoring in real time the current running status of asynchronous motor, and the current running state information of monitored asynchronous motor is fed back to comparing unit 402.

Said comparing unit 402, being used for said current running state information compared with given command value obtains the control instruction corresponding value.

Said control unit 403 is used for by said control command value asynchronous motor being controlled.

Robot provided by the invention uses the asynchronous motor servo drive system, can satisfy robot control system to the requirement of servo drive at precision and aspect of performance.Adopt the current running state information and the given command value of controller of asynchronous motor to compare, as control command, can realize closed-loop control in real time like this with difference.Because the rotating speed of asynchronous motor can reach very high, and its operational environment can not receive the restriction of temperature, the shortcoming of bringing in the time of therefore can avoiding adopting permanent magnet synchronous motor to drive.

Referring to Fig. 4, this figure is the system provided by the invention second embodiment sketch map.

Present embodiment is with the actual angle of monitoring asynchronous motor, and it is that example describes in detail that asynchronous motor is carried out Position Control.

When the current running state information of said feedback unit feedback was the actual angle of asynchronous motor, said comparing unit comprised: position control unit, rotary speed controling unit, torque current control unit, exciting current control unit, coordinate transformation unit and SVPWM inversion unit.

Said position control unit is used for the actual angle θ with asynchronous motor _rWith the given command value θ in position _Mm ^*It is poor to do, and difference is carried out obtaining rotating speed control command value after PI regulates;

Said rotary speed controling unit, it is poor to be used for the actual angular frequency of rotating speed control command value and asynchronous motor is done, and obtains electromagnetic torque command value ω by both difference _Rm ^*

Said torque current control unit is used for electromagnetic torque command value ω _Rm ^*Obtain torque voltage instruction value u with the difference of torque current through voltage equation _T ^{' *}

Said exciting current control unit is used for excitation current instruction value i _M ^{' *}With exciting current i _MDifference obtain exciting voltage command value u through voltage equation _M ^{' *}

Need to prove excitation current instruction value i _M ^{' *}With exciting current i _MDifference be exciting current controlling value i _M ^*

Coordinate transformation unit is used for by torque voltage controling value u _T ^*With exciting voltage controlling value u _M ^*Obtain the three-phase voltage controlling value of asynchronous motor to the three-phase alternating current coordinate transform through the M-T coordinate; The rotating magnetic field of M-T coordinate system and asynchronous motor is rotated synchronously, and stipulates the M axle along the rotor flux direction, and the T axle turn 90 degrees along the M axle counterclockwise; Said exciting voltage controlling value u _M ^*Be exciting voltage command value u _M ^{' *}With excitation decoupling zero voltage u _M' poor; Said torque voltage controling value u _T ^*Be torque voltage instruction value u _T ^{' *}With torque decoupler voltage u _T' poor.

The SVPWM inversion unit is used for the three-phase voltage controlling value of input is changed into the three phase sine electric current and is input to the stator winding of asynchronous motor, realizes the SERVO CONTROL to asynchronous motor.

Need to prove that torque current and exciting current are to be obtained through Coordinate Conversion by the phase current of asynchronous motor, specifically can be referring to formula (1).

Referring to Fig. 5, this figure is system embodiment three sketch mapes provided by the invention.

Excitation decoupling zero voltage and torque decoupler voltage are obtained through exciting current and torque current decoupling zero by the decoupling zero unit, specifically can be referring to formula (5).

No matter need to prove, need to prove, be Position Control, or rotating speed control or torque control, all needs the excitation control loop, and this is for the magnetic field of rotation is provided to rotor.Excitation control is the exciting voltage controlling value that combines with exciting current and control output through with the magnetic linkage command value.Because exciting current is the value of feedback of asynchronous motor, can realize closed-loop control like this.

Following mask body is introduced the calculating of excitation.The system that present embodiment provides also comprises magnetic linkage computing unit and magnetic linkage control unit, and wherein magnetic linkage computing unit is to calculate rotor flux by exciting current.

The magnetic linkage control unit is used for flux linkage set command value ψ _m ^*With rotor flux ψ _rDifference through calculating excitation current instruction value i _M ^{' *}

The above only is preferred embodiment of the present invention, is not the present invention is done any pro forma restriction.Though the present invention discloses as above with preferred embodiment, yet be not in order to limit the present invention.Any those of ordinary skill in the art; Do not breaking away under the technical scheme scope situation of the present invention; All the method for above-mentioned announcement capable of using and technology contents are made many possible changes and modification to technical scheme of the present invention, or are revised as the equivalent embodiment of equivalent variations.Therefore, every content that does not break away from technical scheme of the present invention, all still belongs in the scope of technical scheme protection of the present invention any simple modification, equivalent variations and modification that above embodiment did according to technical spirit of the present invention.

Claims (8)

1. a robot uses the asynchronous motor servo drive method, it is characterized in that, may further comprise the steps:

The real-time current running status of monitoring asynchronous motor feeds back to controller with the current running state information of monitored asynchronous motor;

When said current running state information is the actual angle of asynchronous motor, asynchronous motor is carried out Position Control, be specially:

It is poor that controller is done the given command value of actual angle and position of asynchronous motor, and difference is carried out obtaining rotating speed pilot angle frequency instruction value after PI regulates;

It is poor that the actual angular frequency of rotating speed pilot angle frequency instruction value and asynchronous motor is done, and obtains the electromagnetic torque current instruction value by both difference;

The difference of electromagnetic torque current instruction value and torque current is obtained the torque voltage instruction value through voltage equation;

Calculate the exciting voltage command value by the exciting current controlling value; Said exciting current controlling value is the poor of excitation current instruction value and exciting current;

Obtain the three-phase voltage controlling value of asynchronous motor to the three-phase alternating current coordinate transform through the M-T coordinate by torque voltage controling value and exciting voltage controlling value; The rotor rotating magnetic field of M-T coordinate system and asynchronous motor is rotated synchronously, and stipulates the M axle along the rotor flux direction, and the T axle turn 90 degrees along the M axle counterclockwise; Said exciting voltage controlling value is the poor of exciting voltage command value and excitation decoupling zero voltage; Said torque voltage controling value is the poor of torque voltage instruction value and torque decoupler voltage;

The SVPWM inverter changes the three-phase voltage controlling value of importing into the three phase sine electric current and is input in the stator winding of asynchronous motor, realizes the SERVO CONTROL to asynchronous motor.

2. robot according to claim 1 uses the asynchronous motor servo drive method, it is characterized in that, said rotating speed pilot angle frequency instruction value

Actual angular frequency ω with asynchronous motor _rIt is poor to do, and obtains the electromagnetic torque current instruction value by both difference, is specially:

$\left\{\begin{array}{c}{i}_T^{\&prime;*}=\frac{T_r}{L_m}{\mathrm{\&psi;}}_r{\mathrm{\&omega;}}_{\mathrm{se}}+K_{\mathrm{p\&omega;}}e\left(k\right)+K_{\mathrm{I\&omega;}}\underset{i=1}{\overset{k}{\mathrm{\&Sigma;}}}e\left(i\right)\\ e\left(k\right)={\mathrm{\&omega;}}_{\mathrm{rm}}^{*}\left(k\right)-{\mathrm{\&omega;}}_r\left(k\right)\end{array}\right.$

Wherein, k representes current sampling instant; L _mThe self-induction of expression asynchronous motor stator winding; T _rThe time constant of expression asynchronous motor rotor; ψ _rThe rotor flux of expression asynchronous motor; ω _SeThe slip of expression asynchronous motor; K _{P ω}The proportional gain of error e (k) influence is eliminated in expression; K _{I ω}The storage gain of accumulated error e (k) influence is eliminated in expression.

3. robot according to claim 1 uses the asynchronous motor servo drive method, it is characterized in that, with the electromagnetic torque current instruction value

With torque current i _TDifference obtain the torque voltage instruction value through voltage equation

Be specially:

K wherein _PTThe expression gain coefficient, i _TThe expression torque current.

4. use the asynchronous motor servo drive method according to each described robot of claim 1 to 3, it is characterized in that, when the position of asynchronous motor is controlled, carry out rotating speed and torque amplitude limit.

5. a robot uses the asynchronous motor servo drive system, it is characterized in that, comprising: feedback unit and control unit;

Said feedback unit is used for monitoring in real time the current running status of asynchronous motor, and the current running state information of monitored asynchronous motor is fed back to control unit;

When the current running state information of said feedback unit feedback was the actual angle of asynchronous motor, said control unit comprised: position control unit, rotary speed controling unit, torque current control unit, exciting current control unit, coordinate transformation unit and SVPWM inversion unit;

Said position control unit, it is poor to be used for the given command value of actual angle and position of asynchronous motor is done, and difference is carried out obtaining rotating speed pilot angle frequency instruction value after PI regulates;

Said rotary speed controling unit, it is poor to be used for the actual angular frequency of rotating speed pilot angle frequency instruction value and asynchronous motor is done, and obtains the electromagnetic torque current instruction value by both difference;

Said torque current control unit is used for the difference of electromagnetic torque current instruction value and torque current is obtained the torque voltage instruction value through voltage equation;

Said exciting current control unit is used for obtaining the exciting voltage command value by the exciting current controlling value through voltage equation; Said exciting current controlling value is the poor of excitation current instruction value and exciting current;

Coordinate transformation unit is used for passing through the M-T coordinate obtains asynchronous motor to the three-phase alternating current coordinate transform three-phase voltage controlling value by torque voltage controling value and exciting voltage controlling value; The rotor rotating magnetic field of M-T coordinate system and asynchronous motor is rotated synchronously, and stipulates the M axle along the rotor flux direction, and the T axle changes 90 ° counterclockwise along the M axle; Said exciting voltage controlling value is the poor of exciting voltage command value and excitation decoupling zero voltage; Said torque voltage controling value is the poor of torque voltage instruction value and torque decoupler voltage;

The SVPWM inversion unit is used for the three-phase voltage controlling value of input is changed into the three phase sine electric current and is input to the stator winding of asynchronous motor, realizes the SERVO CONTROL to asynchronous motor.

6. robot according to claim 5 uses the asynchronous motor servo drive system, it is characterized in that said rotary speed controling unit is used for rotating speed pilot angle frequency instruction value Actual angular frequency ω with asynchronous motor _rIt is poor to do, and obtains the electromagnetic torque current instruction value by both difference, is specially:

$\left\{\begin{array}{c}{i}_T^{\&prime;*}=\frac{T_r}{L_m}{\mathrm{\&psi;}}_r{\mathrm{\&omega;}}_{\mathrm{se}}+K_{\mathrm{p\&omega;}}e\left(k\right)+K_{\mathrm{I\&omega;}}\underset{i=1}{\overset{k}{\mathrm{\&Sigma;}}}e\left(i\right)\\ e\left(k\right)={\mathrm{\&omega;}}_{\mathrm{rm}}^{*}\left(k\right)-{\mathrm{\&omega;}}_r\left(k\right)\end{array}\right.$

Wherein, k representes current sampling instant; L _mThe self-induction of expression asynchronous motor stator winding; T _rThe time constant of expression asynchronous motor rotor; ψ _rThe rotor flux of expression asynchronous motor; ω _SeThe slip of expression asynchronous motor; K _{P ω}The proportional gain of error e (k) influence is eliminated in expression; K _{I ω}The storage gain of accumulated error e (k) influence is eliminated in expression.

7. robot according to claim 5 uses the asynchronous motor servo drive system, it is characterized in that,

Said torque current control unit is used for the electromagnetic torque current instruction value

With torque current i _TDifference obtain the torque voltage instruction value through voltage equation

Be specially:

K wherein _PTThe expression gain coefficient, i _TThe expression torque current.

8. robot according to claim 5 uses the asynchronous motor servo drive system, it is characterized in that, also comprises the decoupling zero unit, is used for obtaining excitation decoupling zero voltage and torque decoupler voltage by torque current and exciting current decoupling zero.

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