TWI504131B - Motor control device - Google Patents

Description

Motor control unit

The present invention relates to a motor control device.

In the motor control device that drives the control object of the mechanical system including the motor and the motor, when the load such as the moment of inertia and the friction of the control object changes, the target position command must be recalculated according to the magnitude of the load. . For this reason, a technology capable of automatically adapting a target position and a load size to automatically generate a positioning command according to a maximum torque is under development.

In the conventional control technology, for example, the control device disclosed in Patent Document 1 includes a speed command generation means for switching the maximum speed command and the zero speed in accordance with the magnitude relationship between the positional deviation and the reference value. Commands and speed commands proportional to positional deviation; and speed controllers with anti-windup function. According to the technique disclosed in Patent Document 1, the reference value is obtained by dividing the square of the actual speed of the motor by a value twice the value of the large torque of the motor, the moment of inertia of the control target, and the acceleration obtained by the friction, as long as By giving the target position, it is possible to position at a high speed in accordance with an ideal speed pattern using the maximum torque.

(previous technical literature) (Patent Literature)

Patent Document 1: Japanese Patent Laid-Open Publication No. 2005-160152

However, in the motor control device that drives the control object composed of the motor and the mechanical system that connects the motor, when the load of the control target is unknown, it is required to be able to correspond to the moment of inertia of the control object as the moment of inertia of the motor. Depending on the above-mentioned prior art, the response characteristic may vary depending on the load size of the control object, and may not be obtained when the load size of the control object becomes significantly different from the nominal value. A good response to the problem. In addition, since the speed command value is switched from the maximum speed to the zero speed, there is also a problem that the transient change accompanying the switching causes the response to deteriorate.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a motor control device that realizes high-speed and good response characteristics, and can be used even when the load such as the moment of inertia and friction of the control object is unknown or the load magnitude greatly changes. Position commands and speed commands that automatically adapt to the target position, speed limit, and load size are automatically generated.

In order to solve the above problems and achieve the above object, a motor control device according to the present invention drives a control target including a motor and a mechanical system that connects the motor according to a speed command. The motor control device includes a speed model (model). The first state variable belonging to one or more variables and the speed command calculate a change amount of the first state variable and update the first state variable, and calculate a speed feedforward based on the updated first state variable and The current is fed forward and output; the speed controller is based on the actual speed of the aforementioned motor, the aforementioned speed The feedforward and the current feedforward calculate a change amount of the second state variable belonging to one or more variables and update the second state variable, based on the actual speed of the motor, the speed feedforward, the current feedforward, and the updated The second state variable calculates a current command and outputs the current command, and the current limiter outputs a current command after the current limit is equal to or lower than the current limit command; and the change coefficient calculation unit is based on the current command and the current command The current command is limited to calculate a variation coefficient of the correction coefficient belonging to the first state variable and the change amount of the second state variable, and the velocity model is multiplied by the calculation of the amount of change of the first state variable. The correction of the variation coefficient; the speed controller multiplies the correction of the variation coefficient by the calculation of the amount of change of the second state variable.

According to the present invention, it is possible to achieve an effect of obtaining a motor control device that achieves high speed and good response characteristics, and can automatically generate even when the load such as the moment of inertia and friction of the control object is unknown or the load magnitude greatly changes. Automatically adapt to position and speed commands for target position, speed and load size.

1, 1a‧‧‧ control objects

2, 2b‧‧‧ position model

11‧‧‧Motor

12‧‧‧Mechanical systems

13‧‧‧Speed detector

14‧‧‧ position detector

21‧‧‧Speed model

22‧‧‧Speed Command Calculation Department

23‧‧‧Integrator

31‧‧‧Location Controller

32‧‧‧Differentiator

33‧‧‧Speed controller

34‧‧‧ Current limiter

35‧‧‧ Current controller

36‧‧‧Change coefficient calculation unit

37‧‧‧Inertial moment estimation unit

38‧‧‧Deceleration calculation unit

39‧‧‧Max speed setting unit

40‧‧‧Model Correction Department

41‧‧‧Toggle switch

211, 212‧‧‧ integrator

213 to 215‧‧ ‧ multiplier

216, 217‧‧ ‧ subtractor

361‧‧‧Torque Constant Multiplier

362‧‧‧Nonlinear Torque Model

363‧‧‧ ratio calculator

A _dec ‧‧‧deceleration

A _ff , B _ff , C _ff , D _ff ‧ ‧ matrix

e‧‧‧Remaining distance

I‧‧‧current

J _hat ‧‧‧Inertial moment estimation

J _n ‧‧‧Moment of inertia

K _i ‧‧‧speed integral gain

K _t ‧‧‧torque constant

K _v ‧‧‧ speed proportional gain

T‧‧‧ actual time

T‧‧‧ actual torque

T _cmd ‧‧‧ torque command

U‧‧‧current command

U _ff ‧‧‧current feedforward

U _max ‧‧‧Maximum current command value

U _sat ‧‧‧Restricted current command

V‧‧‧ actual speed

V _c ‧‧‧speed correction

V _ff ‧‧‧speed feedforward

V _max ‧‧‧max speed

V _r ‧‧ ‧ speed command

Wm‧‧‧ model correction gain

X _ff ‧‧‧ position feed forward

X _r ‧‧‧target location

variation coefficient α ‧‧‧

η ‧‧‧ integral variable (2nd state variable)

ξ ‧‧‧ state variable (the first state variable)

τ ‧‧‧Virtual time

Fig. 1 is a block diagram showing the configuration of a motor control device according to a first embodiment.

Fig. 2 is a view showing current-torque characteristics expressed by a nonlinear function in the first embodiment.

Fig. 3 is a view showing a speed response on the virtual time τ axis when the load inertia ratio of the control target is changed in the first embodiment.

Fig. 4 is a view showing the speed response of the actual time t-axis and the virtual time τ axis in the first embodiment.

Fig. 5 (A) and (B) are diagrams showing the response of the speed response and the torque when the load inertia ratio of the control target is changed in the first embodiment.

Fig. 6 is a block diagram showing the configuration of a motor control device of the second embodiment.

(A) and (B) are diagrams showing the response of the speed response and the torque when the load inertia ratio of the control target is changed in the second embodiment.

Fig. 8 is a block diagram showing an example of the configuration of the velocity model of the first embodiment.

Fig. 9 is a block diagram showing the configuration of a motor control device according to a third embodiment.

Hereinafter, an embodiment of the motor control device according to the present invention will be described in detail based on the drawings. Further, the present invention is not limited to the embodiments described below.

Embodiment 1.

Fig. 1 is a block diagram showing the configuration of a first embodiment of a motor control device according to the present invention. The motor control device shown in Fig. 1 includes a control target 1, a speed model 21, a speed controller 33, a current limiter 34, a current controller 35, and a change amount coefficient calculating unit 36.

The control target 1 includes a motor 11 , a mechanical system 12 that connects the motor 11 , and a speed detector 13 that detects the speed of the motor 11 . Further, instead of the speed detector 13, a position detector (for example, an encoder or a resolver) may be provided, and the speed of the motor 11 may be calculated by differentiating the output of the position detector. Further, instead of the speed detector 13, a current detector may be provided instead, and the speed of the motor 11 may be estimated based on the output of the current detector. The speed detector 13 outputs the detected actual speed V.

The speed model 21 is a model that calculates and outputs the speed feedforward V _ff and the current feedforward U _ff based on the state command equation (V) input from the outside using the speed command V _r input from the outside.

Further, the matrices A _ff , B _ff , C _ff , and D _ff in the equation (1) are pre-set matrices, and the variation coefficient α is calculated by the variation coefficient calculation unit 36 as will be described later, and belongs to one or more. The state variable 变 of the variable is a vector representing the state variable of the velocity model 21. Formula (1) Formula 1 is the system phase calculation updates variables ξ, by the formula (1) a first change amount calculated by the formula of the state variables ξ, and sequentially integrating the amount of change, whereby the respective states calculated Variable ξ .

Here, if α =1, the equation (1) is a state equation of the velocity model in the control mode of the general model following control. In the control method called general model follow-up control, the speed feedforward V _ff and the current feedforward U _{ff are} calculated from the speed command V _r input from the outside by the velocity model. For this speed feedforward V _ff , the output is a signal that forms an ideal response waveform for the speed command V _r . Further, in the case of the current feedforward U _ff , the output is a signal obtained by differentiating the speed feedforward V _ff and multiplying the nominal value J _n of the moment of inertia of the control object 1 . At this time, the characteristics of the current feedforward U _ff and the speed feedforward V _ff coincide with the input/output characteristics of the nometic model of the control object 1. The matrices A _ff , B _ff , C _ff , and D _ff are set such that the velocity model 21 forms the above characteristics.

Fig. 8 is a block diagram showing an example of a configuration of the velocity model 21 capable of obtaining the above characteristics. The velocity model 21 shown in Fig. 8 includes integrators 211 and 212, multipliers 213, 214, and 215, and subtractors 216 and 217. In Fig. 8, if α = 1, the input/output characteristics from the speed command V _r to the speed feedforward V _ff become a linear low pass characteristic, and the current feedforward U _ff output will The signal corresponding to the differential value of the speed feedforward V _ff is multiplied by the nominal value J _n of the moment of inertia of the control object 1. Further, the integrators 211 and 212 calculate the value of the integral variable by integrating the product of the input signal input to the integrator and the variation coefficient α as the amount of change of the integral variable, and integrating the amount of change at each time. The values of the integrators 211 and 212 are ξ ₁ and ξ ₂ , respectively, and the equation of state of the block diagram shown in Fig. 8 can be expressed by the following formula (2). Thereby, by setting the matrices A _ff , B _ff , C _ff , D _ff and the state variable vector 如下 to the following equation (3), the calculation formula of the block diagram of FIG. 8 can be expressed by the equation (1).

Further, in the present embodiment, the speed model 21 is provided. The case of the two integrators, that is, the case where the number of times of the velocity model 21 is two is described, but the present invention is not limited thereto. The number of speed models can be as long as it is a natural number.

The speed controller 33 is based on the difference between the speed feedforward V _ff and the actual speed V and the current feed forward U _ff , a preset constant K _v (speed proportional gain (gain)), K _i (speed integral gain), and the amount of change. The coefficient α is calculated and output by the current command U using the equation of state shown in the following equation (4).

Here, let α = 1, and Equation (4) represents general speed proportional integral (PI) control. Further, the integral variable η (second state variable) is a scalar value indicating the integral variable of the speed controller 33. In the motor control device according to the present embodiment, the amount of change in the actual integral variable η is multiplied by the amount of change in the integral variable obtained by the general proportional-integral calculation as in the equation (1). The value obtained by α . Further, when a low pass filter is added to the speed controller 33, the integral variable η is a vector composed of the integral variable of the proportional integral calculation and the state variable of the added low-pass filter. .

The current limiter 34 receives the current command U as an input, and outputs the limited current command U _{sat such} that the absolute value of the input current command U becomes equal to or smaller than the preset maximum current command value U _max . That is, when the absolute value of the input current command U is less than the maximum current command value U _max , the limited current command U _sat is equal to the input current command U, when the absolute value of the input current command U exceeds the maximum current When the command value U _max is reached, the current command U _sat is limited to the maximum current command value U _max .

The current controller 35 _receives the current i of the motor 11 with the current limit command U _sat as an input.

The change amount coefficient calculation unit 36 includes a torque constant multiplier 361, a nonlinear torque model 362, and a ratio calculator 363, and calculates a change amount coefficient α by a ratio of the current command U to the limited current command U _sat . The torque constant multiplier 361 receives the current command U as an input, multiplies the preset torque constant K _{t ,} and calculates and outputs the torque command T _cmd . The nonlinear torque model 362 calculates a model of the actual torque T of the motor 11 from the input limited current command U _sat using the current-torque characteristic of the motor 11 set in advance. In addition, here, the current-torque characteristic used by the nonlinear torque model 362 is expressed by a nonlinear function after considering the magnetic saturation and voltage saturation of the motor 11. Fig. 2 is a graph showing current-torque characteristics expressed by a nonlinear function (solid line) as described above. The ratio calculator 363 calculates the change amount coefficient α by multiplying the actual torque T by the reciprocal of the torque command T _cmd and outputs it. Further, when the torque command T _cmd is 0, the variation coefficient α output from the ratio calculator 363 is set to 1.

Next, the principle of operation of the motor control device according to the first embodiment will be described.

Assuming that the rigidity of the mechanical system 12 included in the control object 1 is so high that the control object 1 can be regarded as the rigid body of the moment of inertia J and the delay caused by the current controller 35 can be ignored, the current command U from the control object 1 is assumed. The dynamic characteristic up to the actual speed V is expressed by the equation of state of the following equation (5).

Here, the function of the g(U) current command U is a nonlinear characteristic generated by the current limiter 34 and a current-torque characteristic of the motor 11. also That is, g(U) represents the actual torque T.

Further, the torque constant K _t used in the torque constant multiplier 361 is expressed by the following formula (6).

Further, the variation coefficient α is a value calculated by multiplying the actual torque T=g(U) by the reciprocal of the torque command T _cmd =K _t *U, and therefore the variation coefficient α is expressed by the following formula (7).

Here, the virtual time τ is defined by the following formula (8).

The virtual time τ is formed by the actual time t expansion and contraction, and the rate of change is multiplied by the reciprocal of the above formula (8) by the rate of change of the actual time t. The state equation of the control object 1 on the virtual time τ axis (formula (5) on the actual time t-axis) is represented by the following equation (9) on the virtual time τ axis.

Since the moment of inertia J and the torque constant K _t are constant, the equation (9) is linear.

Similarly, since formula (8) is the reciprocal of the right side of the right side of formula (5), and therefore the velocity model virtual time τ axis 21 state equation based on the virtual time axis τ represented by the following formula (10).

Further, in the same manner, the virtual time axis τ speed controller 33 is a state equation based on the virtual time axis τ represented by the following formula (11).

The above formulas (9), (10), and (11) are all linear, and the current command U is not limited. Therefore, the response of the control object 1 on the virtual time τ axis is not affected by the current limitation in the current limiter 34. Further, the response of the control object 1 on the virtual time τ axis is also not affected by the nonlinearity of the current-torque characteristic of the motor 11.

Further, as described above, the control system of the motor control device shown in Fig. 1 is based on the model following control, that is, the speed model 21 generates a desired response, and the control object 1 follows the response. Since the feedback control is performed, the response characteristics of the speed control system can be set independently of the characteristics of the speed controller 33 by the matrices A _ff , B _ff , C _ff , D _{ff of the} speed model 21 .

3 is a diagram showing a manner in which the error suppression performance of the speed controller 33 is set to be sufficiently higher than the response characteristic of the velocity model 21 (that is, the degree of suppression of the response characteristic error with respect to the velocity model 21 is achieved). In the case, a map of the speed response on the virtual time τ axis when the load inertia ratio (inertia moment) of the control object 1 is changed. When the matrix A _ff , B _ff , C _ff , D _ff and the constants K _v , K _i are set in such a manner that the error suppression performance of the speed controller 33 is sufficiently high compared to the response characteristic of the velocity model 21, even The control system 1 changes the moment of inertia of the object 1 and changes the response characteristics to a small control system.

That is, even if there is an error between the rated value J _n of the moment of inertia of the control object 1 and the moment of inertia J of the control object 1, a good response can be obtained.

Fig. 4 is a view showing the speed response of the control object 1 of the actual time t-axis and the virtual time τ axis. The velocity response of the control object 1 on the t-axis of the actual time corresponds to the relationship between the actual time t obtained by the equation (8) and the virtual time τ , and will be based on the equations (9) and (10) of the equation of state belonging to linearity. The response of the velocity response on the virtual time τ axis obtained by equation (11) is extended in the time axis direction. Therefore, in order to prevent overshoot of the speed response on the actual time t-axis, the dynamic characteristics of the speed model 21 and the speed controller 33 are set so that the speed response does not overshoot on the virtual time τ axis. can. This means that the control system of the present embodiment described above has a reverse saturation effect, and even if a large value is input in the form of a step signal in the form of a step signal V _r to form U ≧ U _max , it is possible to prevent The way the overshoot occurs controls the actual speed V. Therefore, by configuring as described above, even if the moment of inertia J of the control object 1 is unknown (the maximum acceleration of U _max is unknown), the maximum speed can be achieved by inputting the target speed at the speed command V _r in the form of a step signal. High speed response of acceleration.

Figure 5 shows the load inertia ratio (inertia moment J) of the control object 1. Diagram of the speed response (Fig. 5(A)) and the torque response (Fig. 5(B)) when changing. According to Fig. 5 (A) and (B), the actual speed V does not overshoot even if it is accelerated by the maximum torque (maximum acceleration) regardless of the load inertia ratio.

As described above, in the motor control device of the present embodiment, even when the moment of inertia of the control target is unknown or the load magnitude largely changes, the target speed can be automatically adapted to the target speed and the moment of inertia. The speed response. Further, in the motor control device of the present embodiment, the nonlinear characteristic of the current-torque characteristic (characteristic of the nonlinear torque model) of the motor is compensated, and the current-torque characteristic of the motor can be prevented from being non-linear. Degradation of the response caused by linearity.

In addition, in the above description, the case where the control object 1 is not rubbed is demonstrated. It is assumed that the control object 1 has friction and the viscous friction coefficient is c. At this time, the dynamic characteristic of the control object 1 is expressed by the state equation of the following formula (12).

When the same control as in the case of no friction is performed for the control target 1 having friction, the control target 1 of the virtual time τ axis is expressed by the equation of the following equation (13).

The above formula (13) can be regarded as a state equation of linear time-varying in which the viscous friction coefficient c changes according to the variation coefficient α . As described above, the control system of the model following control is less susceptible to the error and variation of the control target 1. Therefore, even if the moment of inertia J changes, the response characteristic hardly changes. Similarly, even if the friction coefficient changes, the response characteristic also changes. It hardly changes. Therefore, the motor control device of the present embodiment is hardly affected by friction, and a high speed and good speed response can be realized only by giving the target speed.

In addition, when the moment of inertia J and the viscous friction coefficient c are set in advance, the variation coefficient calculation unit 36 can calculate the variation coefficient α by the following equation (14).

At this time, instead of the above formula (8), the virtual time τ is defined by the following formula (15).

As a result, the equation of state of the control object 1 on the virtual time τ axis is expressed by the following equation (16).

The equation of state of the above equation (16) is different from the above equation (13) and can be regarded as a linear time-invariant state equation without the variation coefficient α . As described above, the method of calculating the variation coefficient α calculated by the variation coefficient calculation unit 36 is not limited to the above, and various methods can be employed.

In addition, in the above description, the state equation of continuous time is used for description, and in the case of discrete time, it is known by changing the amount of change between the state variable of each sampling time and the time of the previous sampling. The above characteristics can be achieved in the same manner by α times the value obtained by the update calculation of the state variable.

Further, when the nonlinear characteristic of the current-torque characteristic of the motor 11 is small enough to be negligible or only the range in which the nonlinear characteristic can be ignored, the variation coefficient calculation unit 36 does not need to set the torque constant multiplication. The 361 and the nonlinear torque model 362 may be input to the ratio calculator 363 by inputting the current command U and the limited current command U _sat . By configuring as described above, it is only necessary to consider the nonlinear characteristic caused by the maximum current command value U _{max of the} current limiter 34 which is the limit value of the current command.

Further, when the speed controller 33 is provided with a low-pass filter and a notch filter that suppresses the resonance of the machine, even if current saturation occurs, the filters do not accumulate errors, so The amount of change in the state variables of the filters does not need to be multiplied by the variation coefficient α . In particular, in the notch filter, if the amount of change in the state variable is multiplied by the variation coefficient α , the notch frequency (notch) set corresponding to the resonance frequency of the machine changes, so it is not necessary to multiply the amount of change. Coefficient α .

As described above, the motor control device according to the present embodiment drives the control target including the motor and the mechanical system that connects the motor according to the speed command, and the motor control device includes the speed model based on the first one or more variables. The state variable and the speed command calculate a change amount of the first state variable, update the first state variable, calculate a speed feedforward and current feedforward based on the updated first state variable, and output the speed controller; Calculating a change amount of the second state variable belonging to one or more variables based on the actual speed of the motor, the speed feedforward, and the current feedforward, and updating the second state variable, according to the former The actual speed of the motor, the speed feedforward, the current feedforward, and the updated second state variable are calculated and outputted; and the current limiter is input with the current command as an output current limit value And a change amount coefficient calculation unit that calculates a change coefficient of the correction coefficient belonging to the first state variable and the change amount of the second state variable based on the current command and the current command after the restriction; In the calculation of the amount of change in the first state variable, the speed model is multiplied by the correction of the change amount coefficient, and the speed controller multiplies the change amount by the amount of change in the second state variable. Correction of the coefficient.

Embodiment 2.

Fig. 6 is a block diagram showing the configuration of a second embodiment of the motor control device of the present invention. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and their description is omitted. The motor control device shown in Fig. 6 includes a control target 1a, a position model including the velocity model 21, a position controller 31, a differentiator 32, a speed controller 33, a current limiter 34, and a current controller 35. The variation coefficient calculation unit 36, the inertia moment estimation unit 37, the deceleration calculation unit 38, and the maximum speed setting unit 39.

The control object 1a includes a motor 11 , a mechanical system 12 that connects the motor 11 , and a position detector 14 that detects the position of the motor 11 . As the position detector 14, for example, an encoder or a retractor can be used.

The position model 2 includes a speed model 21, a speed command calculation unit 22, and an integrator 23.

The speed command calculation unit 22 receives the remaining distance e (deviation between the target position X _r and the position feedforward X _ff ), the preset maximum speed V _{max ,} and the deceleration A _dec calculated by the deceleration calculation unit 38 as will be described later. Input, output speed command V _r . Further, the maximum speed V _max is set by the maximum speed setting unit 39.

21 is the line velocity model speed command V _r as input, the model with the feedforward U _ff embodiment calculates the feedforward current before and V _ff Form 1 and outputs the speed.

The integrator 23 integrates the speed feedforward V _ff input from the speed model 21 and outputs a position feedforward X _ff .

The position controller 31 receives the deviation between the position feedforward X _ff output from the integrator 23 and the actual position X detected by the position detector 14 as an input, and outputs a speed correction amount V _c using a preset position gain.

The differentiator 32 differentiates the actual position X and outputs the actual speed V.

The speed controller 33 _receives the difference between the sum of the speed feedforward V _ff and the speed correction amount V _c and the actual speed V and the current feed forward U _ff as an input, and outputs the current command U in the same manner as in the first embodiment.

The current limiter 34, the current controller 35, and the variation coefficient calculation unit 36 are the same as those in the first embodiment.

The moment of inertia estimation unit 37 receives the current i output from the current controller 35 and the actual position X or the actual speed V as an input, and outputs the inertia moment estimated value J _{hat of the} control target 1a. For example, the inertia moment estimated value J _hat may be calculated by successively estimating the acceleration and the current i calculated by second-order differentiation of the actual position X or first-order differentiation of the actual velocity V.

The deceleration calculation unit 38 receives the inertia moment estimated value J _hat as an input, and calculates and outputs the deceleration A _dec using the maximum torque T _max calculated from the preset maximum current command value U _max . The deceleration A _dec is calculated by the following formula (17).

[Expression 17] A _dee = T _max / J _hat × γ (17)

Here, the constant γ in the above formula (17) is a normal number of 1 or less set in advance, and is approximately 0.8 to 0.9 in order to make the torque at the time of deceleration smaller than the maximum torque. Further, when the control target friction 1a size has been set in advance, also possible to consider the friction deceleration is set larger than A _dec calculated by the above formula (17) value.

Here, the operation of the speed command calculation unit 22 will be described. The speed command calculation unit 22 uses a target speed function of a control method called PTOS (Proximate Time-Optimal Servomechanism). The target speed function is expressed by the following equations (18) to (20). In addition, the remaining distance between the e-target position X _r and the position feedforward X _ff .

When the target speed function as described above is used, since the target speed function is continuously switched corresponding to the remaining distance e, the switching of the speed command V _r can be performed in a manner that does not deteriorate the transient response.

Next, the operation of the motor control device of the second embodiment will be described.

When the target position X _r far enough from the current actual position X is set, the speed command calculation unit 22 outputs the maximum speed V _max according to the equation (19), and the speed command V _r is switched from 0 to V _max . In this way, the control system includes a control system equivalent to the speed control system of the first embodiment in the speed loop, and therefore automatically corresponds to the current limit and the nonlinear characteristic of the current-torque characteristic of the motor 11, the motor The actual speed V of 11 is accelerated to a maximum speed V _max at a high speed and good response.

At this time, if current saturation occurs during acceleration, the response of the speed feedforward V _ff is automatically adjusted by the variation coefficient α . Therefore, the response of the position feedforward X _ff obtained by integrating the speed feedforward V _ff is also formed to be automatically adjusted with respect to current saturation. In the acceleration, the moment of inertia estimation unit 37 estimates the moment of inertia of the control target 1a, and the deceleration A _dec input to the speed command calculation unit 22 is set by the above equation (17).

When the remaining distance e decreases, the target speed function V _r ' of the speed command calculation unit 22 is switched to the first expression in the equation (18). Therefore, the speed command V _r is decelerated at the deceleration A _dec . During this time, the actual speed V of the motor 11 is also decelerated at the deceleration A _dec . Since the value of the deceleration A _dec is set by the moment of inertia estimated value J _{hat of the} control object 1a, it is possible to achieve an ideal deceleration response that maximizes the torque that can be generated by the motor 11.

Finally, when the remaining distance e falls below e ₁ calculated by the above formula (20), the target speed function V _r ' of the speed command calculation unit 22 is switched to the second expression in the above formula (18), and the target speed. The function V _r ' (speed command V _r ) is proportional to the remaining distance e. At this time, the position model 2 as a whole becomes linear, and therefore the position feedforward X _ff smoothly converges to the target position X _r . By the position controller 31, the error of the position feedforward X _ff and the actual position X is suppressed, so that the actual position X also smoothly reaches the target position X _r .

As described above, in the motor control device of the present embodiment, the position feedforward X _ff , the speed feedforward V _{ff ,} and the current are automatically generated only by the input of the target position X _r so that the speed response becomes an ideal trapezoidal waveform. Feeding U _ff enables high speed and good positioning response.

In the present embodiment, since the speed control system is configured by the configuration described in the first embodiment, for example, the fluctuation of the load of the control target 1a and the current limitation are compared with the conventional PTOS control method. Nonlinear features can have more robust control. Further, in the conventional PTOS control method, the deceleration A _dec is a fixed value, and in the present embodiment, the deceleration A _dec is dynamically set by the moment of inertia estimated value J _{hat of the} control object 1a, so even The load size of the control object 1a is unknown, and the acceleration and deceleration are still able to obtain an ideal response.

Further, even when the moving distance is small, the speed command V _r corresponding to the remaining distance e is calculated, and the speed command V _r and the speed feed forward V _ff are automatically switched between acceleration and deceleration, so that The positional feedforward X _ff , the speed feedforward V _ff , and the current feed forward U _ff are generated in such a manner that the speed response becomes an ideal triangular waveform.

Fig. 7 is a view showing a speed response (Fig. 7(A)) and a torque response (Fig. 7(B)) when the load inertia ratio (inertia moment J) of the control object 1a is changed. According to Fig. 7, high-speed positioning in an ideal speed mode can be performed regardless of the load inertia ratio.

As described above, in the motor control device according to the present embodiment, even when the load size of the control target is unknown or the load size largely changes, the load that automatically adapts to the target position and the control target can be realized by giving the target position. Small high speed and good positioning.

Further, in the present embodiment, the control system capable of automatically performing the positioning control when the target position is given is described. However, the present embodiment is also applicable to the pair of time series (for example, pulse wave (pulse). The sequence command given by the sequence is followed by a control system for follow-up control. At this time, the speed command calculation unit 22 sets the speed command V _{r that is} proportional to the remaining distance e regardless of the remaining distance e. Further, in such a control system, in the case where the current is not saturated, the position control is performed in a control mode called a general model follow control, and therefore the actual position X of the motor 11 is followed by the given The way the position command is controlled. On the other hand, when current saturation occurs, both the velocity model 21 and the speed controller 33 are compensated by the variation coefficient α, so that the reverse saturation effect can be obtained, so that it is possible not to cause, for example, overshoot. Control in a stable manner.

As described above, the motor control device according to the present embodiment drives the control target including the motor based on the position command, and the motor control device includes a speed command calculation unit that outputs based on the deviation between the position command and the position feedforward. The speed command and the speed model calculate the amount of change in the first state variable based on the first state variable belonging to one or more variables and the speed command, and update the first state variable, and based on the updated first state variable, Calculating speed feedforward and current feedforward and outputting; the integrator integrates the aforementioned speed feedforward to output the position feedforward; and the position controller is based on the difference between the actual position of the motor and the position feedforward. The output speed correction amount is obtained by calculating the amount of change of the second state variable belonging to one or more variables based on the actual speed of the motor, the speed correction amount, the speed feedforward, and the current feedforward. The second state variable calculates a current command based on the actual speed of the motor, the speed correction amount, the speed feedforward, the current feedforward, and the updated second state variable; and the current limiter is The current command is outputted as a current command after the current limit value is output, and the change amount coefficient calculation unit calculates the first state variable and the second state variable based on the current command and the current command after the limit. a coefficient of change of the correction coefficient of the amount of change; wherein the velocity model is corrected by multiplying the amount of change in the first state variable; and the speed controller is in the second state variable In the calculation of the amount of change, the correction of the variation coefficient is multiplied.

Embodiment 3.

Fig. 9 is a block diagram showing the configuration of a third embodiment of the motor control device of the present invention. In the ninth embodiment, the same components as those in the first and sixth figures are denoted by the same reference numerals, and their description will be omitted.

The motor control device shown in Fig. 9 includes a control target 1a, a position model 2b, a position controller 31, a differentiator 32, a speed controller 33, a current limiter 34, a current controller 35, and a variation coefficient calculation unit. 36. The inertia moment estimating unit 37, the deceleration calculating unit 38, the maximum speed setting unit 39, the model correcting unit 40, and a switch 41. In other words, the motor control device shown in Fig. 9 is a model in which the model correcting unit 40 and the changeover switch 41 are added to the motor control device shown in Fig. 6.

Further, in the present embodiment, the current limiter 34 is configured to be capable of outputting a current limit. Further, the integrator 23 is input with a deviation between the speed feedforward V _ff outputted from the velocity model 21 and the output signal of the changeover switch 41.

Similarly to the position controller 31, the model correcting unit 40 takes the deviation (error signal) between the position feedforward X _ff output from the integrator 23 and the actual position X detected by the position detector 14 as an input, and outputs the multiplication of the deviation. The model correction signal obtained by correcting the gain Wm with the model set in advance. The output model correction signal is input to the changeover switch 41.

The changeover switch 41 is configured to be turned on or off depending on the presence or absence of the current limit output from the current limiter 34. When the current limit occurs in the current limiter 34, the changeover switch 41 is turned on, and when the current limit does not occur, the changeover switch 41 is turned off. In other words, the changeover switch 41 is turned on when the magnitude of the current command U exceeds the limit current value, and is turned off when the magnitude of the current command U is equal to or less than the limit current value.

When the changeover switch 41 is in the ON state, the output of the changeover switch 41 is a model correction signal, and when the changeover switch 41 is in the non-on state, the output of the changeover switch 41 is zero.

By switching the output of the switch 41, the integrator 23 integrates the deviation between the speed feedforward V _ff and the model correction signal, and outputs the position feedforward X _ff .

Next, the operation of the motor control device of the third embodiment will be described.

First, when the target position X _r far enough from the current actual position X is set, as described with reference to the formula (19) in the second embodiment, the speed command calculation unit 22 outputs the maximum speed V _max , and the speed command V _r is derived from 0 is switched to V _max , and the actual speed V of the motor 11 is accelerated to the maximum speed V _max .

At this time, if current saturation occurs during acceleration, the changeover switch 41 is turned on, and the integrator 23, the model correcting unit 40, and the changeover switch 41 form a feedback loop. The equation of state for this feedback loop is the following equation (21) Show.

When the model correction gain Wm is the observer gain, the above equation (21) is the same as that of the state observer (observer), and is formed by the integrator 23, the model correction unit 40, and the changeover switch 41. The feedback loop compensates for the position feedforward X _ff by reducing the error between the position feedforward X _ff and the actual position X.

As described in the second embodiment, in the motor control device shown in Fig. 6, when the current saturation occurs, the operation of the speed model 21 is corrected by the variation coefficient α . When the action of the velocity model 21 is corrected in this way, the deviation of the response between the position model 2 and the control object 1a is suppressed, so that a good response can be obtained even if current saturation occurs.

In the motor control device shown in Fig. 9 of the present embodiment, the model correction unit 40 corrects the error between the position feedforward X _ff and the actual position X, thereby further suppressing the position model and control when current saturation occurs. The deviation of the response between objects 1a. Therefore, it is possible to achieve more robust control than the second embodiment for current saturation.

Further, in the case where the current is not saturated, the changeover switch 41 is in the non-on state, and thus the position control performed by the control method called the general model follow control can be realized, and variation and externality to the control target can be realized. Interfere with robust controls.

As described above, the motor control device according to the present embodiment drives the control target including the motor based on the position command, and the motor control device is provided. The speed command calculation unit outputs a speed command based on a deviation between the position command and the position feedforward, and the speed model calculates the first state variable based on the first state variable belonging to one or more variables and the speed command. The amount of change is updated by the first state variable, and the speed feedforward and current feedforward are calculated and output based on the updated first state variable; the model correction unit is based on the position of the motor and the position feedforward. The difference between the two is outputting the model correction signal; the switch is input with the model correction signal, and the model correction signal is output when the switch is in the on state, and the zero signal is output when the switch is not on; the integrator is The speed feedforward is integrated with the deviation between the output signals of the switch, and the position feed forward is output; the position controller outputs a speed correction amount according to the difference between the actual position of the motor and the position feedforward; the speed controller According to the actual speed of the motor, the speed correction amount, the speed feedforward and the current feedforward Calculating the amount of change of the second state variable belonging to one or more variables and updating the second state variable, based on the actual speed of the motor, the speed correction amount, the speed feedforward, the current feedforward, and the updated The second state variable calculates a current command and outputs the current command, and the current limiter outputs a current command that limits the magnitude of the current command to a current limit or less; and a change coefficient calculation unit. Calculating a variation coefficient of the correction coefficient belonging to the first state variable and the change amount of the second state variable based on the current command and the current command after the restriction; and calculating the amount of change in the first state variable by the velocity model And correcting by multiplying the change coefficient; the speed controller is performing multiplication by the change of the change amount coefficient in the calculation of the change amount of the second state variable; and the switching open relationship is the magnitude of the current command When the current limit value is exceeded, it becomes ON, and when the magnitude of the current command is the aforementioned limit When the current value is lower than the current value, it is turned off.

(industrial use possibility)

As described above, the motor control device of the present invention is very useful for a motor control device that is suitable for a control object whose inertia and friction are unknown or whose load magnitude greatly changes.

1‧‧‧Control object

11‧‧‧Motor

12‧‧‧Mechanical systems

13‧‧‧Speed detector

21‧‧‧Speed model

33‧‧‧Speed controller

34‧‧‧ Current limiter

35‧‧‧ Current controller

36‧‧‧Change coefficient calculation unit

361‧‧‧Torque Constant Multiplier

362‧‧‧Nonlinear Torque Model

363‧‧‧ ratio calculator

I‧‧‧current

T‧‧‧ actual torque

T _cmd ‧‧‧ torque command

U‧‧‧current command

U _ff ‧‧‧current feedforward

U _max ‧‧‧Maximum current command value

U _sat ‧‧‧Restricted current command

V‧‧‧ actual speed

V _ff ‧‧‧speed feedforward

V _r ‧‧ ‧ speed command

variation coefficient α ‧‧‧

Claims (9)

A motor control device that drives a control target including a motor and a mechanical system that connects the motor according to a speed command, wherein the motor control device includes a speed model based on a first state variable belonging to one or more variables and the speed Commanding, calculating a change amount of the first state variable, updating the first state variable, calculating a speed feedforward and current feedforward based on the updated first state variable, and outputting the speed controller according to the motor The actual speed, the speed feedforward, and the current feedforward calculate a change amount of the second state variable belonging to one or more variables and update the second state variable, based on the actual speed of the motor, the speed feed forward, and the current before And feeding the updated second state variable to calculate and output a current command; the current limiter is configured to input the current command as the input, and output a limited current command that limits the magnitude of the current command to a limit current value; and The change amount coefficient calculation unit is based on the current command and the limited current command. a variation coefficient of the correction coefficient belonging to the first state variable and the change amount of the second state variable; wherein the velocity model is multiplied by the correction of the change amount coefficient in the calculation of the change amount of the first state variable The speed controller performs multiplication by the correction of the change amount coefficient in the calculation of the amount of change in the second state variable. A motor control device that drives a control target including a motor according to a position command, the motor control device including a speed command calculation unit that is biased according to the position command and the position feedforward The difference speed command is obtained by calculating the amount of change in the first state variable based on the first state variable belonging to one or more variables and the speed command, and updating the first state variable, based on the updated first state variable. State variable, calculate speed feedforward and current feedforward and output; integrator, integrates the aforementioned speed feedforward to output the position feedforward; position controller is based on the actual position of the motor and the position feedforward The difference is the output speed correction amount, and the speed controller calculates the amount of change of the second state variable belonging to one or more variables based on the actual speed of the motor, the speed correction amount, the speed feedforward, and the current feedforward. And updating the second state variable, and calculating and outputting a current command based on the actual speed of the motor, the speed correction amount, the speed feedforward, the current feedforward, and the updated second state variable; The current command is input, and the output limits the size of the current command to a limit current value. a current command for limiting; and a change coefficient calculation unit that calculates a change coefficient of the correction coefficient belonging to the change amount of the first state variable and the second state variable based on the current command and the current command after the limit; In the calculation of the amount of change in the first state variable, the model is multiplied by the correction of the change amount coefficient, and the speed controller multiplies the change coefficient by the amount of change in the second state variable. Correction. A motor control device for controlling a motor having a motor according to a position command The motor drive device includes: a speed command calculation unit that outputs a speed command based on a deviation between the position command and the position feedforward; and the speed model is based on the first state variable belonging to one or more variables and the speed Commanding, calculating the amount of change in the first state variable, updating the first state variable, calculating a speed feedforward and current feedforward based on the updated first state variable, and outputting the model correction unit based on the motor The difference between the actual position and the position feed forward is outputted by the model correction signal; the switch is input with the model correction signal, and the model correction signal is output when the state is ON, and is zero when the state is not ON. a signal, an integrator that integrates a deviation between the speed feedforward and an output signal of the switch, and outputs the position feedforward; and the position controller outputs the difference according to the difference between the actual position of the motor and the position feedforward Speed correction amount; the speed controller is based on the actual speed of the motor, the aforementioned speed correction amount, and the front The speed feedforward and the current feedforward calculate a change amount of the second state variable belonging to one or more variables and update the second state variable, based on the actual speed of the motor, the speed correction amount, the speed feed forward, and the The current feedforward and the updated second state variable calculate a current command and output the current commander, and the current limiter receives the current command as an input, and outputs a current command that limits the magnitude of the current command to a limit current value or less. And a variation coefficient calculation unit based on the current command and the aforementioned limited power The flow command calculates a change amount coefficient of the correction coefficient belonging to the first state variable and the change amount of the second state variable, and the velocity model multiplies the change amount by the change amount of the first state variable The correction of the coefficient is performed by multiplying the change amount of the second state variable by the speed controller; and the switching open relationship is performed when the magnitude of the current command exceeds the limit current value When the magnitude of the current command is equal to or less than the limit current value, the switch is turned off. The motor control device according to claim 2, further comprising: a maximum speed setting unit that sets a maximum speed of the motor; and a deceleration calculating unit that calculates a deceleration of the motor at the time of deceleration stop; The calculation unit calculates the speed command by a function based on a deviation between the position command and the position feedforward, the maximum speed, and the deceleration. The motor control device according to claim 3, further comprising: a maximum speed setting unit that sets a maximum speed of the motor; and a deceleration calculating unit that calculates a deceleration of the motor at the time of deceleration stop; The calculation unit calculates the speed command by a function based on a deviation between the position command and the position feedforward, the maximum speed, and the deceleration. The motor control device according to the fourth aspect of the invention, wherein the deceleration calculation unit calculates the deceleration based on the estimated moment of inertia of the control target estimated from a current, an actual position, or an actual speed of the motor. . The motor control device according to claim 5, wherein the deceleration calculation unit calculates the deceleration based on the inertia moment estimation value of the control target estimated from the current, the actual position, or the actual speed of the motor. . The motor control device according to any one of claims 1 to 7, wherein the change amount coefficient calculation unit calculates the change amount coefficient by a ratio between the current command and the current command after the restriction. The motor control device according to any one of claims 1 to 7, wherein the change amount coefficient calculation unit includes a torque constant multiplier that multiplies the current command by a predetermined motor The torque command is used to calculate the torque command; and the nonlinear torque model is obtained by modeling the nonlinear characteristic between the current and the torque of the motor; and the torque command and the The change coefficient is calculated by the ratio between the current command and the actual torque calculated by the nonlinear torque model.