CN107645267B

CN107645267B - Motor system

Info

Publication number: CN107645267B
Application number: CN201710589757.2A
Authority: CN
Inventors: 花冈正志
Original assignee: Nidec Sankyo Corp
Current assignee: Nidec Instruments Corp
Priority date: 2016-07-20
Filing date: 2017-07-19
Publication date: 2020-05-26
Anticipated expiration: 2037-07-19
Also published as: KR102453684B1; TW201804270A; JP2018014806A; JP6751615B2; CN107645267A; TWI740954B; KR20180010145A

Abstract

The invention provides a motor system which suppresses vibration by auto-tuning without increasing the load of the CPU. By using the 1 st gain conversion unit (15), the gain K when the motor (3) is not connected with the motion object (2) is calculated₀A ratio Gr (K) of the moment of inertia of a gain K when the motor (3) and the object (2) are connected to each other₀/K) and a ratio of an arbitrary parameter constant Ri to a rotational inertia ratio Gr (═ Ri/Gr) is obtained, thereby simply calculating a speed loop gain m of the motor system (1)₁. In the motor control device (4), m is stored₁And m₀、q₀、q₁In the relationship of (1) m₀、q₀、q₁With m₁Table 3 corresponds to the manner in which the decrease of (c) also decreases. A2 nd gain conversion unit (16) refers to the 3 rd table and performs the velocity loop gain m calculated from the 1 st gain conversion unit (15)₁To m₀、q₀、q₁And (4) transforming.

Description

Motor system

The present invention relates to a motor system including a motor for operating an operation target object and a motor control device for feedback-controlling rotation of the motor.

Background

Conventionally, as a motor control device for operating an automatic machine or the like, a motor control device for controlling a motor by P-PI control (proportional-integral control) is known. In a motor control device that performs P-PI control, the rotational position and the rotational speed of a motor are fed back, and proportional control (P control) is performed on the deviation of the rotational position, and proportional-integral control (PI control) is performed on the deviation of the rotational speed.

Conventionally, as a motor system for performing such P-PI control, for example, a motor system using a motor control device disclosed in patent document 1 is known. The motor control apparatus includes a vibration extraction filter that extracts a vibration component due to mechanical resonance and outputs it as an extracted vibration signal. Based on the extracted oscillation signal and the 2 nd notch filter output signal, the notch control unit changes the notch center frequencies of the 1 st notch filter and the 2 nd notch filter so as to reduce the amplitude of the 2 nd notch filter output signal. Further, the notch depth control unit changes the notch depth of the 1 st notch filter based on the extracted oscillation signal. The determination control unit automatically tunes parameters of each notch filter to suppress mechanical vibration. That is, when the amplitude of the 2 nd notch filter output signal is larger than a predetermined value, the notch control unit is operated to change the notch center frequency of each of the 1 st notch filter and the 2 nd notch filter so as to reduce the oscillation component due to the oscillation of the mechanical resonance. When the amplitude of the 2 nd notch filter output signal is smaller than a predetermined value, the notch depth control unit is operated to change the notch depth of the 1 st notch filter so as to reduce the oscillation component caused by the oscillation of the mechanical resonance.

Conventionally, as a motor system for performing such P-PI control, for example, a motor system using a motor control device disclosed in patent document 2 is known. When a load rotational inertia value JL and a target response frequency ω f are inputted, the motor control device corrects a gain JCOM ((JL + JM)/JM) using a rotational inertia value obtained from a ratio to a motor rotational inertia value JM^0.5The velocity loop gain kv, the velocity integration time constant ti, the position loop gain kp, the torque filter constant tf, the current loop gain ki, the current integration time constant ta, and the filter time constant tv are set. That is, the plurality of control parameters are automatically tuned in accordance with the target response frequency ω f and the moment of inertia value correction gain JCOM, which are one of the parameters.

Further, conventionally, as a motor system for performing robust pole placement control, for example, a motor system disclosed in patent document 3 is known. The motor control device in this motor system has a closed-loop system that receives a rotational position command of the motor as an input and outputs a rotational position of the motor as an output. The closed loop system includes a 1 st addition point, a proportional gain element, a 2 nd addition point, an integral filter element, a motor gain element, and a motor element in a forward path. Further, a 1 st feedback path is connected to the 1 st addition point in a negative feedback manner, and a 2 nd feedback path is connected to the 2 nd addition point in a negative feedback manner via a differential filter element. In this motor system, when the moment of inertia of the motion target object or the motor becomes large, even if the motion target object or the motor vibrates, the control parameter q relating to the disturbance response characteristic₀And q is₁And also automatically tuned based on the detection result in the rotational inertia detection unit. By this adjustment, the vibration of the motion target and the motor can be suppressed, and the characteristics of the closed loop system can be kept constant.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 5873975

Patent document 2: japanese patent No. 3561911

Patent document 3: japanese patent laid-open publication No. 2016 & 35676

Disclosure of Invention

Technical problem to be solved by the invention

However, in the motor systems described in the above-described

conventional patent documents

1 and 3, which detect vibrations and automatically tune control parameters, it is necessary to perform a process of analyzing the frequency of the vibrations and the amplitude of the vibrations. Therefore, unless the speed detection signal is sampled and analyzed from the motor at a frequency much higher than 2 times the vibration frequency, the vibration extraction cannot achieve a sufficient resolution. Therefore, in the motor systems described in the above-described

conventional patent documents

1 and 3, the arithmetic device used in the motor control device needs a high arithmetic speed, and the arithmetic load increases.

In the motor system described in the above-described conventional patent document 2, the square root ((JL + JM)/JM) is used to calculate the rotational inertia value correction gain JCOM for calculating the control parameter^0.5. Therefore, in the motor system described in the above-described conventional patent document 2, the calculation load of the arithmetic device used in the motor control device increases due to the square root calculation.

Technical scheme for solving technical problem

In order to solve the above problem, a motor system according to the present invention includes a motor for operating an object to be operated and a motor control device for feedback-controlling rotation of the motor, the motor system including:

a closed loop system that inputs a rotational speed command of the motor, performs feedback control on a rotational position of the motor, outputs a rotational speed, and constitutes a transfer function in which a speed loop gain is included in a factor;

a rotational inertia detecting unit that detects rotational inertia of the motion target object and the motor;

an adaptation determination unit that determines a gain K, which is a value obtained by dividing a fixed value including a fixed gain of an amplifier that supplies power to the motor and a torque constant of the motor by a moment of inertia of the motor, based on an input of the motor position transmission element and an output of the motor position transmission element; and

a calculation unit that calculates a gain K₀Calculating a ratio of an arbitrary parameter constant Ri to a predetermined function value having the inertia ratio Gr as a factor by using the calculated inertia ratio Gr with respect to the inertia ratio Gr of the gain K, and calculating a velocity loop gain from the ratio₀The transfer function is corrected based on the velocity loop gain calculated by the calculation unit so that a fixed value including a fixed gain of an amplifier for supplying power to the motor and a torque constant of the motor is divided by the moment of inertia of the motor.

The adaptive determination means may be configured to determine the inertia moment of the motion target object and the motor based on the input of the motor position transmission element and the output of the motor position transmission element, and thereby configure the inertia moment detection means.

According to the present configuration, the gain K when the motor is not connected to the load is calculated by the calculation unit₀Ratio of moment of inertia Gr of gain K when connected to motor and load (K ═ K)₀K), and a ratio (Ri/f (Gr)) between an arbitrary parameter constant Ri and a predetermined function value f (Gr) that is a factor of the moment of inertia ratio Gr is obtained using the calculated moment of inertia ratio Gr, whereby a velocity loop gain that is a factor of the transfer function is simply calculated. The velocity loop gain is inversely proportional to the function value f (Gr) with a constant proportionality constant Ri, and tends to become smaller when the inertia moment becomes larger than Gr. When the inertia moment ratio Gr is larger, the gain peak of the gain frequency characteristic of the control target at the mechanical resonance frequency and the gain at a frequency higher than the mechanical resonance frequency become larger, and oscillation easily occurs. However, in the present structure, the speed loop gain is reduced in the direction in which it is cancelled, and therefore, the speed loop gain can be ensuredA gain margin representing the stability of the closed loop system. Therefore, the vibration can be suppressed by the auto-tuning without increasing the arithmetic processing load of the arithmetic processing device (CPU) constituting the calculation unit. As a result, the arithmetic processing load of the CPU is reduced, and the CPU having a low processing speed can be used, so that the cost of the motor control device can be reduced.

In the drive system of the 2-inertia system or the multi-inertia system, servo oscillation occurs when the control gain is updated using the load moment of inertia estimated in the same manner as in the drive system of the 1-inertia system. However, according to the present configuration, for resonance in the drive system of the 2-inertia system or the multi-inertia system, oscillation can be suppressed with simple arithmetic processing.

Furthermore, the present invention is characterized in that,

the closed loop system constitutes a transfer function including a speed loop gain and a position loop gain in factors, inputs a rotational position command of the motor in place of a rotational speed command, and performs feedback control of the rotational position of the motor, outputs the rotational position,

the calculation unit calculates a value having a certain relationship with the velocity loop gain as the value of the position loop gain,

the transfer function is corrected based on the velocity loop gain and the position loop gain calculated by the calculation unit.

According to this configuration, the value having a certain relationship with the velocity loop gain is simply calculated by the calculation unit as the value of the position loop gain, and is automatically tuned to a value that is good for controlling the balance of the system with respect to the velocity loop gain. Therefore, stable feedback control in consideration of the rotation speed and the rotation position of the motor without causing control instability can be performed by simple arithmetic processing without applying a load to the CPU.

Furthermore, the present invention is characterized in that,

the closed loop system has a forward path having a 1 st proportional gain transmission element, a 1 st addition point to which a rotational speed command of the motor is input, an integral filter transmission element, a motor gain transmission element, and a motor position transmission element, and a 1 st feedback path for negatively feeding back a rotational position of the motor to the 1 st addition point via the differential filter transmission element,

at a given speed loop gain of m₁And when the laplace operator is s, the equation m represents an expected transfer function of a closed loop system having expected characteristics for controlling the speed of an object to be operated and the motor₁/(s+m₁) It is specified that the first and second measurement signals,

the adaptive determination means determines a gain p based on the input of the motor position transmission element and the output of the motor position transmission element, and a control parameter q for the disturbance response characteristic₀And q is₁The parameter for matching the characteristics of the closed loop system with the desired transfer function is a₁＝q₁+m₁-p、b₁＝q₀·m₁、b₂＝(q₁-p)·(m₁-p)+q₀Wherein the gain p is a value obtained by dividing a term relating to viscosity of the motion target object and the motor by inertia moments of the motion target object and the motor,

the 1 st proportional gain transfer element is m₁It is shown that,

the integral filter has a transfer element of(s)²+q₁·s+q₀)/(s²+a₁S) represents the number of atoms in the molecule,

the motor gain transfer element is denoted by 1/K,

the motor position transmission element is defined by K/(s)²+ p.s) represents a linear or branched,

the differential filter has a transfer element of (b)₂·s²+b₁·s)/(s²+q₁·s+q₀) It is shown that,

storing m in a motor control device₁And q is₀、q₁A table corresponding to the relationship of (a),

the calculation unit refers to the table and performs the loop gain m from the calculated speed₁To q₀、q₁And (4) transforming.

According to the present structure, m is₁And q is₀、q₁Relative phase ofThe corresponding table is stored in the motor control device, hence from m₁To q₀、q₁The operation processing of the transformation can be performed by simply searching the table. Therefore, the arithmetic processing time is shortened, and the arithmetic processing load of the CPU is further reduced.

Furthermore, the present invention is characterized in that,

at a given speed loop gain of m₁And when the Laplace operator is s, the desired transfer function for controlling the speed of the motion object and the motor is expressed by the equation m₁/(s+m₁) It is specified that the first and second measurement signals,

the gain determined by the adaptive determination means based on the input of the motor position transmission element and the output of the motor position transmission element is p, and the control parameter regarding the disturbance response characteristic is ω_qThe parameter for matching the characteristics of the closed loop system with the desired transfer function is b₁＝ω_q·m₁、b₂＝m₁-p+ω_qWherein the gain p is a value obtained by dividing a term relating to viscosity of the motion target object and the motor by inertia moments of the motion target object and the motor,

the 1 st proportional gain transfer element is m₁It is shown that,

the integral filter transfer element is composed of (s + omega)_q) The expression of/s is,

the motor gain transfer element is denoted by 1/K,

the differential filter has a transfer element of (b)₂·s²+b₁·s)/(s+ω_q) It is shown that,

storing m in a motor control device₁And omega_qA table corresponding to the relationship of (a),

the calculation unit refers to the table and performs the loop gain m from the calculated speed₁To omega_qAnd (4) transforming.

According to the present structure, m is₁And omega_qIs stored in the motor control device, and therefore, from m₁To omega_qThe operation processing of the transformation can be performed by simply searching the table. Therefore, the arithmetic processing time is shortened, and the arithmetic processing load of the CPU is further reduced.

Furthermore, the present invention is characterized in that,

the closed loop system has a forward path having a 2 nd addition point, a 2 nd proportional gain transmission element, a 1 st addition point, an integral filter transmission element, a motor gain transmission element, and a motor position transmission element to which a rotational position command of the motor is input in place of the rotational speed command, a 1 st feedback path that negatively feeds back the rotational position of the motor to the 1 st addition point via the differential filter transmission element, and a 2 nd feedback path that directly feeds back the rotational position of the motor to the 2 nd addition point,

at a given speed loop gain of m₁Position loop gain of m₀/m₁And when the laplace operator is s, the desired transfer function for controlling the positions of the motion object and the motor is expressed by the equation m₀/(s²+m₁·s+m₀) It is specified that the first and second measurement signals,

the adaptive determination means determines a gain p based on the input of the motor position transmission element and the output of the motor position transmission element, and a control parameter q for the disturbance response characteristic₀And q is₁The parameter for matching the characteristics of the closed loop system with the desired transfer function is a₁＝q₁+m₁-p、b₁＝q₀·m₁、b₂＝(q₁-p)·(m₁-p)+q₀Wherein the gain p is a value obtained by dividing a term relating to viscosity of the motion target object and the motor by inertia moments of the motion target object and the motor，

The 2 nd proportional gain transfer element is formed by₀It is shown that,

the motor gain transfer element is denoted by 1/K,

storing m in a motor control device₁And m₀、q₀、q₁The calculation means refers to the table and performs the loop gain m from the calculated velocity₁To m₀、q₀、q₁And (4) transforming.

According to the present structure, m is₁And m₀、q₀、q₁Is stored in the motor control device, and therefore, from m₁To m₀、q₀、q₁The operation processing of the transformation can be performed by simply searching the table. Therefore, the arithmetic processing time is shortened, and the arithmetic processing load of the CPU is further reduced.

In addition, the function of the predetermined calculated speed loop gain that is factored by the inertia moment ratio Gr is a linear function that is factored by only the inertia moment ratio Gr.

According to the present configuration, the velocity loop gain m₁The value of Kvp decreases in a purely inversely proportional relationship to the increase in the moment of inertia ratio Gr. Thus, the velocity loop gain m is calculated₁The CPU operation processing of the Kvp value is simplified, and the CPU operation processing load can be further reduced.

In addition, the function of the predetermined calculated speed loop gain, which is factored by the inertia moment ratio Gr, is a linear function, which is factored by the inertia moment ratio Gr and a constant.

According to the present structure, the speed loop gain m can be adjusted₁Kvp and the moment of inertia ratio Gr, and the adjustment amount is a constant value. Therefore, the velocity loop gain m can be enlarged₁And Kvp, and the load of the CPU in the calculation process is suppressed.

In addition, the function of the predetermined calculated speed loop gain by the inertia moment ratio Gr is a quadratic function by the inertia moment ratio Gr and a constant.

According to the present configuration, the velocity loop gain m₁The value of Kvp may be set to a desired relationship that monotonically decreases with an increase in the inertia moment ratio Gr, which is different from a simple inverse proportional relationship. Therefore, it is possible to achieve both of the command response characteristic and the vibration suppression characteristic of the closed-loop system.

In addition, the present invention is characterized in that the parameter constant Ri is stored in the motor control device as a plurality of values corresponding to the types of the power transmission mechanism between the motor and the operation target object.

According to this configuration, the user can set the parameter by simply selecting the value of the parameter constant Ri corresponding to the type of the power transmission mechanism from among the plurality of parameter constants Ri stored in advance in the motor control device. Therefore, a motor system having improved user convenience can be provided.

Further, the present invention is characterized in that a limit is placed on the upper limit value of the inertia moment ratio Gr.

At a velocity loop gain m with increasing moment of inertia ratio Gr₁The value of Kvp is too small, and the velocity loop gain m corresponding to the value of the inertia moment ratio Gr cannot be set₁The value of Kvp, for example, the velocity loop gain m corresponding to the value of the inertia moment ratio Gr₁Kvp is compared with the minimum level of the speed loop gain m set in the table₁When the value of Kvp is small, the speed loop gain m cannot be reduced₁Kvp. In this case, the loop gain m will be set according to the speed that can be set₁Minimum value m of Kvp_1min、Kvp_minAnd based on the relation (m)₁Ri/f (Gr), Kvp Ri/f (Gr)), andis greater than the ratio of moment of inertia Gr (═ Ri/m)_1min、＝Ri/Kvp_min) The upper limit value of the inertia moment ratio Gr is set, and the speed loop gain m corresponding to the value of the inertia moment ratio Gr is limited as in the present configuration₁The lower limit of the value of Kvp imposes a limit. Thus, the relation (m)₁Ri/f (gr), Kvp Ri/f (gr), and no longer the speed loop gain m cannot be set₁The value of Kvp.

Effects of the invention

According to the motor system of the present invention, as described above, vibration can be suppressed by auto-tuning without increasing the arithmetic processing load of the CPU.

Drawings

Fig. 1 is a block diagram showing a schematic configuration of a motor system according to each embodiment of the present invention.

Fig. 2 is a block diagram showing a closed loop system of a motor system according to embodiment 1 of the present invention.

Fig. 3(a) shows a speed loop gain m in the motor system according to embodiment 1₁Fig. 3(b) is a graph showing a time change of the inertia ratio Gr when the upper limit value grcamax is set for the inertia ratio Gr in the motor system according to the modification of embodiment 3.

Fig. 4 is a block diagram showing a closed loop system of a motor system according to embodiment 2 of the present invention.

Fig. 5 is a block diagram showing a closed loop system of a motor system according to embodiment 3 of the present invention.

Fig. 6 is a block diagram showing a closed loop system of a motor system according to embodiment 4 of the present invention.

Fig. 7 is a block diagram showing a closed loop system of a motor system according to embodiment 5 of the present invention.

Fig. 8 is a block diagram showing a closed loop system of a motor system according to a modification of embodiment 3 of the present invention.

Detailed Description

Hereinafter, a mode for implementing the motor system of the present invention will be described.

Fig. 1 is a block diagram showing a schematic configuration of a motor system 1 according to each embodiment of the present invention.

The motor system 1 includes a motor 3 that operates the operation object 2 and a motor control device 4 that controls the motor 3. The motor 3 is an AC servomotor or a DC servomotor, and operates, for example, an arm of an industrial robot as the operation target object 2. The operation object 2 is connected to the motor 3 via a power transmission mechanism 6 such as a belt. The motor 3 includes a detection mechanism (encoder) 5 for detecting a rotational position of the motor 3. An output signal of the detection means 5 is input to a motor control device 4 that feedback-controls the rotation of the motor 3. The motor control circuit of the motor control device 4 is constituted by an analog circuit (continuous time type circuit), but may be constituted by a digital circuit (discrete time type circuit) or may be constituted by software.

Fig. 2 is a block diagram showing a closed loop system 8A of the motor system 1 according to embodiment 1 of the present invention.

The closed loop system 8A has a forward path having a 1 st proportional gain transmission element 9, a 1 st addition point 10 to which a rotational speed command of the motor 3 is input, an integral filter transmission element 11, a motor gain transmission element 12, and a motor position transmission element 13, and a 1 st feedback path for negatively feeding back a rotational position of the motor 3 from the motor position transmission element 13 to the 1 st addition point 10 via a differential filter transmission element 14, and the closed loop system 8A inputs the rotational speed command of the motor 3, feedback-controls the rotational position of the motor 3, and outputs the rotational speed. The closed loop system 8A forms a velocity loop gain m₁The transfer function included in the factor is expressed by the equation m when the Laplace operator is s₁/(s+m₁) To specify the desired transfer function for the velocity. The desired transfer function has desired characteristics for appropriately controlling the motor 3 in accordance with the motion target 2. The operation object 2 is set to operate by the motor 3 which is controlled to rotate by the closed loop system 8ALike the speed.

Based on the input of motor position transmission element 13 and the output of motor position transmission element 13, adaptation determination section 21 determines gain K (fixed gain of amplifier) x (fixed value of motor 3)/(moment of inertia of operation object 2 and motor 3)) which is a fixed value including the fixed gain of the amplifier that supplies power to motor 3 and the torque constant of motor 3 divided by the moment of inertia of operation object 2 and motor 3. This determination is performed sequentially at predetermined time intervals by a determination method such as a least square method. The amplifier described here is a component of the closed loop system 8A other than the motor position transmission element 13. In the present embodiment, the adaptive determination means 21 constitutes inertia moment detection means, and determines the inertia moments of the operation object 2 and the motor 3 by a determination method such as a least square method based on the input of the motor position transmission element 13 and the output of the motor position transmission element 13, and sequentially detects them at predetermined time intervals. Furthermore, based on the input of the motor position transmission element 13 and the output of the motor position transmission element 13, the adaptation determination unit 21 determines a gain p that is a value obtained by dividing a term relating to the viscosity of the motion object 2 and the motor 3 by the inertia moments of the motion object 2 and the motor 3. This determination is also performed sequentially at predetermined time intervals by a determination method such as a least square method.

Setting a control parameter q regarding an interference response characteristic₀And q is₁Parameter a for matching the characteristics of the closed loop system 8A to the desired transfer function₁、b₁And b₂When represented by the following formulae (1), (2) and (3),

a₁＝q₁+m₁-p…(1)

b₁＝q₀m₁…(2)

b₂＝(q₁-p)(m₁-p)+q₀…(3)

1 st proportional gain transfer element 9 is composed of m₁The integral filter transfer element 11 is represented by(s)²+q₁·s+q₀)/(s²+a₁S), the motor gain transmission element 12 is represented by 1/K, and the motor position transmission element 13 is represented by K/(s)²+ p · s, the differential filter transfer element 14 is represented by (b)₂·s²+b₁·s)/(s²+q₁·s+q₀) And (4) showing.

An arbitrary parameter constant Ri set by the user is input to the 1 st gain conversion section 15. The 1 st gain conversion unit 15 calculates the gain K based on the gain K determined by the adaptation determination unit 12 and the input parameter constant Ri₀Moment of inertia ratio Gr (═ K) with respect to gain K₀K) is added. Here, the gain K₀A value obtained by dividing a fixed value including a fixed gain of an amplifier that supplies power to the motor 3 and a torque constant of the motor 3 by the moment of inertia of the motor 3 (i.e., (fixed gain of amplifier) × (fixed value of motor 3)/(moment of inertia of motor 3)).

Then, the 1 st gain conversion means 15 obtains a ratio (═ Ri/f (Gr)) of the parameter constant Ri to a predetermined function value (f (Gr)) having the inertia ratio Gr as a factor, using the calculated inertia ratio Gr, and calculates the speed loop gain m from the ratio₁. In the present embodiment, the predetermined function f (Gr) is set to Gr (f (Gr) ═ Gr), and the speed loop gain m is set to₁Represented by the following formula (4).

m₁＝Ri/Gr…(4)

In the motor control device 4, m is stored₁And q is₀、q₁In the relationship of (1) with q₀、q₁With m₁The manner of decrease of (1) also decreases. The 2 nd gain conversion section 16 refers to the 1 st table and performs the velocity loop gain m calculated from the 1 st gain conversion section 15₁To q₀、q₁And (4) transforming. At this time, the velocity loop gain m calculated by the 1 st gain conversion section 15 is performed₁M of the table value with the closest value of (1)₁To q₀、q₁And (4) transforming. The 3 rd gain converting unit 17 calculates m from the 1 st gain converting unit 15₁And a gain p determined by the adaptation determination unit 21, and a is calculated based on the expressions (1), (2), and (3), respectively₁、b₁And b₂。

The 1 st gain conversion means 15 and the 2 nd gain conversion means 16 constitute calculation means for calculating a moment of inertia ratio Gr and calculating a velocity loop gain m by equation (4) using the calculated moment of inertia ratio Gr₁. The 1 st gain conversion means 15, the 2 nd gain conversion means 16, and the 3 rd gain conversion means 17 are constituted by a CPU of a microcomputer provided in the motor control device 4 in the present embodiment. The motor control device 4 converts the speed loop gain m calculated by the 1 st gain conversion unit 15₁The signal is supplied to the 1 st proportional gain transfer element 9, and the 1 st proportional gain transfer element 9 is updated at predetermined time intervals. Further, q obtained by the 2 nd gain conversion section 16 is converted into q₀、q₁And a calculated by the 3 rd gain conversion unit 17₁、b₁、b₂The signal is supplied to the integration filter transmission element 11 and the differentiation filter transmission element 14, and the integration filter transmission element 11 and the differentiation filter transmission element 14 are updated at predetermined time intervals. The adaptation determination unit 21 supplies the determined gain K to the motor gain transmission element 12, and updates the motor gain transmission element 12 at predetermined time intervals.

By correcting the transfer function of the closed-loop system 8A at predetermined time intervals by these updates, the transfer function of the closed-loop system 8A can be automatically matched with the desired transfer function even if the moment of inertia of the operation target 2 or the motor 3 tends to be large and the vibration tends to be strong. Therefore, even if the inertia moment of the operation object 2 or the motor 3 becomes large, the characteristics of the closed-loop system 8A can be stabilized to suppress the vibration.

According to the motor system 1 of embodiment 1, the gain K when the motor 3 is not connected to the operation object 2 is calculated by the 1 st gain conversion means 15₀A moment of inertia ratio Gr of gain K when connected to the motor 3 and the operation object 2 (K ═ K)₀/K), and a ratio of an arbitrary parameter constant Ri to the calculated moment of inertia ratio Gr is obtained (═ Ri/Gr), thereby simply calculating the speed loop gain m₁。

FIG. 3(a) is a graph showing the velocity loop gain m₁A graph showing a relationship with the moment of inertia ratio Gr in a simple inverse proportional relationship shown in equation (4). The horizontal axis of the graph is the moment of inertia ratio Gr, and the vertical axis is the velocity loop gain m₁. The characteristic lines a, b, and c represent characteristics when the value of the proportionality constant Ri is Ri1, Ri2, and Ri3(Ri1 < Ri2 < Ri3), respectively. As shown in the graph, the velocity loop gain m₁The constant ratio Ri is inversely proportional to the inertia moment ratio Gr, and tends to decrease as the inertia moment ratio Gr increases. Further, the smaller the value of the proportionality constant Ri, the lower the speed loop gain m with the increase of the inertia moment ratio Gr₁The stronger the effect of the value of (a).

The proportional constant Ri is a control parameter set by the user, and is set in accordance with the rigidity of the power transmission mechanism 6. For example, when the power transmission mechanism 6 is a mechanism with low rigidity such as a belt drive, the proportional constant Ri is set to a smaller value as the rigidity is smaller. The proportional constant Ri is set to a smaller value as the viscous resistance of the operation object 2 is smaller. In the case where the proportionality constant Ri is small, the speed loop gain m₁The reduction rate of (b) becomes larger as the inertia moment ratio Gr increases, the command responsiveness becomes smooth, but the vibration suppression performance improves. If the table value is set to q₀、q₁Also with m₁When the value of (b) is decreased, the vibration suppression effect is further enhanced.

In the case where the power transmission mechanism 6 is a mechanism having a large rigidity such as a ball screw drive, the proportional constant Ri is set to a larger value as the rigidity is larger, so that the speed loop gain m₁Without unduly dropping. In the case where the proportionality constant Ri is large, the speed loop gain m₁The decrease rate of the value of (c) decreases as the inertia moment ratio Gr increases, and the command responsiveness improves, but the vibration suppression performance decreases.

When the inertia moment ratio Gr is larger, the gain peak of the gain frequency characteristic of the control target at the mechanical resonance frequency and the gain at a frequency higher than the mechanical resonance frequency become larger, and oscillation easily occurs. However, in the motor system 1 of the present embodiment, when the inertia moment ratio Gr is larger, the inertia moment ratio Gr is larger as described aboveReducing the speed loop gain m in the direction to cancel it₁Accordingly, a gain margin representing the stability of the closed loop system can be secured. Velocity loop gain m₁Can be simply calculated as described above. Therefore, the vibration can be suppressed by the auto-tuning without increasing the arithmetic processing load of the CPU. As a result, the CPU computational processing load is reduced, and a CPU with a low processing speed can be used, so that the cost of the microcomputer constituting the motor control device 4 can be reduced. The user can operate the motor 3 without performing oscillation without adjustment at the time of initial use of the motor system by using this automatic tuning.

In the drive system of the 2-inertia system or the multi-inertia system, servo oscillation occurs when the control gain is updated using the load moment of inertia estimated in the same manner as in the drive system of the 1-inertia system. However, according to the present embodiment, oscillation can be suppressed by simple arithmetic processing with respect to resonance in the drive system of the 2-inertia system or the multi-inertia system.

According to the motor system 1 of embodiment 1, m₁And q is₀、q₁The 1 st table corresponding to the relationship (c) is stored in the motor control device 4. Thus, from m₁To q₀、q₁The conversion operation processing can be performed by simply searching the 1 st table by the 2 nd gain conversion unit 16. As a result, the arithmetic processing time is shortened, and the arithmetic processing load of the CPU is further reduced.

In the motor system 1 according to embodiment 1, the predetermined function having the inertia moment ratio Gr as a factor is defined as a linear function having only the inertia moment ratio Gr as a factor, as shown by the denominator of equation (4). Thus, the velocity loop gain m₁The value of (c) decreases in a purely inversely proportional relationship to the increase in the moment of inertia ratio Gr. Thus, the velocity loop gain m is calculated₁The CPU operation processing of the value of (b) is simplified, and the CPU operation processing load can be further suppressed.

Next, a closed loop system 8B in the motor system 1 according to embodiment 2 of the present invention will be described. Fig. 4 is a block diagram showing the closed loop system 8B. In the figure, the same or corresponding portions as those in fig. 2 are denoted by the same reference numerals, and the description thereof is omitted.

The desired transfer function of the velocity of the closed-loop system 8B is also expressed by the same expression m as in embodiment 1₁/(s+m₁) To specify. However, let us say that the control parameter relating to the disturbance response characteristic is ω_qParameter B for matching the characteristics of the closed-loop system 8B to the desired transfer function₁And b₂When represented by the following formulas (5) and (6),

b₁＝ω_q·m₁…(5)

b₂＝m₁-p+ω_q…(6)

the integral filter transfer element 11 is composed of (s + omega)_q) The microcomputer filter transmission element 14 is represented by (b)₂·s²+b₁·s)/(s+ω_q) And (4) showing.

In the motor control device 4, m is stored₁And omega_qIn the relation of (c) in ω_qWith m₁Also decreases in the manner of table 2. The 2 nd gain conversion section 16 refers to the 2 nd table, and performs the velocity loop gain m calculated as described above from the 1 st gain conversion section 15₁To omega_qAnd (4) transforming. The 3 rd gain converting unit 17 calculates m from the 1 st gain converting unit 15₁And a gain p determined by the adaptation determination unit 21, b is calculated based on the expressions (5) and (6), respectively₁And b₂。

The motor control device 4 converts ω obtained by the 2 nd gain conversion means 16_qAnd b calculated by the 3 rd gain conversion unit 17₁、b₂The signal is supplied to the integration filter transmission element 11 and the differentiation filter transmission element 14, and the integration filter transmission element 11 and the differentiation filter transmission element 14 are updated at predetermined time intervals. By correcting the transfer function of the closed-loop system 8B at predetermined time intervals by these updates, the transfer function of the closed-loop system 8B can be automatically matched with the desired transfer function even if the moment of inertia of the operation target 2 or the motor 3 tends to be large and the vibration tends to be strong. Therefore, even if the object 2 and the motor 3 are operatedThe moment of inertia becomes large, and the characteristics of the closed-loop system 8B can be stabilized to suppress vibration.

Also in the motor system 1 according to embodiment 2, the 1 st gain conversion means 15 calculates the inertia moment ratio Gr (═ K0/K) and obtains the ratio of an arbitrary parameter constant Ri to the calculated inertia moment ratio Gr (═ Ri/Gr), thereby simply calculating the speed loop gain m₁. Therefore, according to the motor system 1 of embodiment 2, vibration can be suppressed by auto-tuning without increasing the arithmetic processing load of the CPU, and the same operational effects as those of embodiment 1 can be obtained.

According to the motor system 1 of embodiment 2, m₁And omega_qThe 2 nd table corresponding to the relationship (2) is stored in the motor control device 4. Thus, from m₁To omega_qThe conversion operation processing can be performed by simply searching the 2 nd table by the 2 nd gain conversion unit 16. Therefore, the arithmetic processing time is shortened, and the arithmetic processing load of the CPU is further reduced.

Next, a closed loop system 8C in the motor system 1 according to embodiment 3 of the present invention will be described. Fig. 5 is a block diagram showing the closed loop system 8C. In the figure, the same or corresponding portions as those in fig. 2 are denoted by the same reference numerals, and the description thereof is omitted.

The closed loop system 8C forms a velocity loop gain m₁And position loop gain m₀/m₁The transfer function included in the factor is input with a rotational position command of the motor 3 in place of the rotational speed command, and the rotational position of the motor 3 is feedback-controlled to output the rotational position. Desired transfer function of position of closed loop system 8C is given by equation m₀/(s²+m₁·s+m₀) And (4) specifying. In the closed-loop system 8C, compared with the closed-loop system 8A shown in fig. 2, a 2 nd addition point 18 and a 2 nd proportional gain transfer element 19 are provided in front of the 1 st addition point 10 of the forward path in place of the 1 st proportional gain transfer element 9. A rotational position command of the motor 3 is input to the 2 nd addition point 18 instead of the rotational speed command, and the rotational position of the motor 3 is negatively fed back directly from the motor position transmission element 13 via the 2 nd feedback path. At 2 nd ratio increaseThe gain transmission element 19 receives a deviation between the rotational position command output from the 2 nd addition point 18 and the rotational position. The position of the operation target object 2 is set by the motor 3 which is controlled to rotate by the closed loop system 8C.

In the closed loop system 8C, the 2 nd proportional gain transfer element 19 is formed by m₀The integral filter transfer element 11, the motor gain transfer element 12, and the differential filter transfer element 14 are shown in the same manner as the closed loop system 8A shown in fig. 2.

In the motor control device 4, m is stored₁And m₀、q₀、q₁In the relationship of (1) m₀、q₀、q₁With m₁Table 3 corresponds to the manner in which the decrease of (c) also decreases. The 2 nd gain conversion section 16 refers to the 3 rd table and performs the velocity loop gain m calculated from the 1 st gain conversion section 15₁To m₀、q₀、q₁And (4) transforming. At this time, the table values of the 3 rd table are set to calculate the velocity loop gain m₁A value having a certain relation as the position loop gain m₀/m₁The value of (c). This is because, if m is the only factor₁Decrease the value alone, then₀The balance of (a) is deteriorated and the control may become unstable. Thus, m is reduced₁Value of (d) is decreased by m₀According to m₁To adjust m₀The value of (c). Relative to m₁Value m of₀How much the value of (c) is reduced depends on m becoming stable under 1 inertial system₁And m₀The ratio of (a) to (b).

At this time, the table values of the 3 rd table are set to calculate the velocity loop gain m₁Values having a certain relationship as q₀、q₁The value of (c). This is also due to the fact that if only m is present₁If the value is lowered alone, the control sometimes becomes unstable. Thus, m is reduced₁After value of (3) by decreasing q₀、q₁According to m₁To adjust q by the value of₀、q₁The value of (c).

The 3 rd gain converting section 17 calculates m from the above-mentioned m calculated by the 1 st gain converting section 15₁And the gain p determined by the adaptation determination unit 21,based on the expressions (1), (2), and (3), a parameter a for matching the characteristics of the closed-loop system 8C with the desired transfer function is calculated₁、b₁And b₂. The motor control device 4 converts m obtained by the 2 nd gain conversion means 16₀、q₀、q₁And a calculated by the 3 rd gain conversion unit 17₁、b₁、b₂The signal is supplied to the integration filter transfer element 11, the differentiation filter transfer element 14, and the 2 nd proportional gain transfer element 19, and the integration filter transfer element 11, the differentiation filter transfer element 14, and the 2 nd proportional gain transfer element 19 are updated at predetermined time intervals. By correcting the transfer function of the closed-loop system 8C at predetermined time intervals by these updates, the transfer function of the closed-loop system 8C can be automatically matched with the desired transfer function even if the moment of inertia of the operation target 2 or the motor 3 tends to increase and the vibration tends to become strong. Therefore, even if the inertia moment of the operation object 2 or the motor 3 becomes large, the characteristics of the closed-loop system 8C can be stabilized to suppress the vibration.

Also in the motor system 1 according to embodiment 3, the 1 st gain conversion means 15 calculates the inertia moment ratio Gr (═ K0/K) and obtains the ratio of an arbitrary parameter constant Ri to the calculated inertia moment ratio Gr (═ Ri/Gr), thereby simply calculating the speed loop gain m₁. Therefore, according to the motor system 1 of embodiment 3, vibration can be suppressed by auto-tuning without increasing the arithmetic processing load of the CPU, and the same operational effects as those of embodiment 1 can be obtained.

In the motor system 1 of embodiment 3, m1 and m₀、q₀、q₁Since the 3 rd table corresponding to the relationship (c) is stored in the motor control device 4, m1 is shifted to m₀、q₀、q₁The conversion operation processing can be performed by simply searching the 3 rd table by the 2 nd gain conversion unit 16. Therefore, the arithmetic processing time is shortened, and the arithmetic processing load of the CPU is further reduced.

According to the motor system 1 of embodiment 3, the 2 nd gain conversion means 16 simply calculates the velocity loop gain m₁Having a certain relation as the position loop gain m₀/m₁And is automatically tuned to the loop gain m with respect to speed₁The balance of the control system is a better value. Therefore, stable feedback control in consideration of the rotation speed of the motor 3 and the rotation position of the motor 3 without causing control instability can be performed by simple arithmetic processing without applying a load to the CPU.

Formula m in the closed loop system 8C₀/(s²+m₁·s+m₀) The specified desired transfer function can be modified as follows.

m₀/(s²+m₁·s+m₀)＝ω₁·ω₂/(s+ω₁)·(s+ω₂)

Here, ω is₁、ω₂For the cut-off frequency of the desired transfer function, the following relationship holds.

m₀＝ω₁·ω₂、m₁＝ω₁+ω₂

Therefore, in embodiment 3, ω can also be controlled₁、ω₂Instead of controlling m₀、m₁。

Characteristic polynomial(s) in integral filter transmission element 11 and differential filter transmission element 14²+q₁·s+q₀) It can be deformed as follows.

s²+q₁·s+q₀＝(s+ω_q1)·(s+ω_q2)

Here, for ω_q1、ω_q2The following relationship holds.

q₀＝ω_q1·ω_q2、q₁＝ω_q1+ω_q2

To simplify the adjustment, ω may be set as follows_q1And ω_q2Are equal.

ω_q＝ω_q1＝ω_q2

Here, for ω_qThe following relationship holds.

q₀＝ω_q ²、q₁＝2·ω_q

Therefore, ω can be controlled also in embodiment 1 and embodiment 3_q1、ω_q2Instead of controlling q₀、q₁。

In the motor system 1 according to each of

embodiments

1, 2, and 3 described above, the robust pole arrangement control is performed. However, the present invention is equally applicable to a motor system that performs P-PI control.

Fig. 6 is a block diagram showing a closed-loop system 8D of the motor system 1 according to embodiment 4 of the present invention that performs PI speed control. In the figure, the same or corresponding portions as those in fig. 2 are denoted by the same reference numerals, and the description thereof is omitted.

The closed-loop system 8D forms a transfer function including the speed loop gain Kvp in a factor, inputs a rotational speed command of the motor 3, feedback-controls the rotational position of the motor 3, and outputs the rotational speed. The rotational speed command of the motor 3 is directly input to the 1 st addition point 10 in the closed-loop system 8D, and the integral filter transfer element 11 includes a speed loop gain Kvp as a proportional gain transfer element. The integral filter transfer element 11 in the closed-loop system 8D is represented by Kvp (1+ Kvi/s) when the velocity integral gain is Kvi, and the differential filter transfer element 14 is represented by ω cs/(s + ω c) when the cutoff frequency is ω c. The speed of the operation target object 2 is set by the motor 3 which is rotation-controlled by the closed loop system 8D.

In this closed-loop system 8D, too, the gain K is calculated based on the gain K determined by the adaptation determination unit 21 and the input parameter constant Ri₀Moment of inertia ratio Gr (═ K) with respect to gain K₀K) is added. Then, using the calculated inertia ratio Gr, a ratio of the parameter constant Ri to a predetermined function value that is a factor of the inertia ratio Gr is obtained, and the speed loop gain Kvp is calculated from the ratio. In the present embodiment, the speed loop gain Kvp is calculated from an equation (Kvp ═ Ri/Gr) corresponding to equation (4). Further based on the calculated speed loop gain Kvp, each control in the closed loop system 8D is performed with reference to the tableThe system parameters are updated one by one. Therefore, according to the motor system 1 of embodiment 4, the speed loop gain Kvp is also calculated easily, and vibration can be suppressed by auto-tuning without increasing the load of the CPU in the calculation process, thereby achieving the same operational effects as those of embodiment 1.

Fig. 7 is a block diagram showing a closed loop system 8E of the motor system 1 according to embodiment 5 of the present invention that performs PI position control. In the figure, the same or corresponding portions as those in fig. 6 are denoted by the same reference numerals, and the description thereof is omitted.

The closed loop system 8E constitutes a transfer function including the speed loop gain Kvp and the position loop gain Kpp as factors, and inputs a rotational position command of the motor 3 instead of the rotational speed command, and performs feedback control on the rotational position of the motor 3 to output the rotational position. The closed-loop system 8E has a 2 nd addition point 18 and a 2 nd proportional gain transfer element 19 in a stage prior to the 1 st addition point 10 of the forward path, as compared with the closed-loop system 8D shown in fig. 6. A rotational position command of the motor 3 is input to the 2 nd addition point 18 instead of the rotational speed command, and the rotational position of the motor 3 is negatively fed back directly from the motor position transmission element 13 via the 2 nd feedback path. The 2 nd proportional gain transmission element 19 receives a deviation between the rotational position command output from the 2 nd addition point 18 and the rotational position. The operation target object 2 is set at an operation target position by the motor 3 which is rotation-controlled by the closed loop system 8E.

In this closed-loop system 8E, too, the gain K is calculated based on the gain K determined by the adaptation determination unit 21 and the input parameter constant Ri₀Moment of inertia ratio Gr (═ K) with respect to gain K₀K) is added. Then, using the calculated inertia ratio Gr, a ratio of the parameter constant Ri to a predetermined function value that is a factor of the inertia ratio Gr is obtained, and the speed loop gain Kvp is calculated from the ratio. In the present embodiment, the speed loop gain Kvp is also calculated from an equation (Kvp ═ Ri/Gr) corresponding to equation (4). Further, based on the calculated speed loop gain Kvp, each control parameter in the closed-loop system 8E is successively updated with reference to the table.

At this time, as the values of the position loop gain Kpp and the velocity integral gain Kvi, a value having a certain relationship with the velocity loop gain Kvp is calculated. This is because if Kvp alone is decreased, the balance with Kpp and Kvi is deteriorated, and the control may become unstable. Therefore, the values of Kpp and Kvi are decreased after decreasing the value of Kvp, and the values of Kpp and Kvi are adjusted according to the value of Kvp. How much to reduce the values of Kpp and Kvi with respect to the value of Kvp is determined by the ratio of Kvp to Kpp and Kvi that becomes stable under 1-inertia system.

According to the motor system 1 of embodiment 5, the speed loop gain Kvp and the position loop gain Kpp are also calculated easily, and vibration can be suppressed by auto-tuning without increasing the load of the CPU in the calculation process, thereby achieving the same operational effects as those of embodiment 1.

In the motor systems 1 according to embodiments 1 to 5 described above, the following cases are explained: that is, the predetermined function f (Gr) having the inertia moment ratio Gr as a factor is set to a linear function (f (Gr) having the inertia moment ratio Gr as a factor only, and the speed loop gain m is set to be equal to Gr)₁Kvp and the inertia moment ratio Gr have a simple inverse proportional relationship shown in formula (4). However, the predetermined function f (Gr) may be expressed by a linear function (f (Gr) ═ Gr + Rid0) having the inertia moment ratio Gr and the constant Rid0 as factors, and the velocity loop gain m may be defined by the following expressions (7.1) and (7.2)₁、Kvp。

m₁＝Ri/(Gr+Rid0)…(7.1)

Kvp＝Ri/(Gr+Rid0)…(7.2)

According to the equations (7.1) and (7.2), the speed loop gain m can be adjusted₁Kvp and the moment of inertia ratio Gr, the amount of adjustment is a constant value Rid 0. Therefore, the velocity loop gain m can be enlarged₁And Kvp, and the load of the CPU in the calculation process is suppressed.

In addition, a quadratic function (f (Gr) ═ Gr) factorized in the inertia moment ratio Gr and the constant Rid0 may also be used²+ Rid1 · Gr + Rid0) to represent a predetermined function f (Gr), and the velocity loop gain m is defined by the following equations (8.1) and (8.2)₁、Kvp。

m₁＝Ri/(Gr²+Rid1·Gr+Rid0)…(8.1)

Kvp＝Ri/(Gr²+Rid1·Gr+Rid0)…(8.2)

The velocity loop gain m is expressed by expressions (8.1) and (8.2) of a fractional function in which the denominator is quadratic₁The value of Kvp may be set to a desired relationship that monotonically decreases with an increase in the inertia moment ratio Gr, which is different from a purely inverse proportional relationship. The fractional function in which the denominator is quadratic can further achieve both the command response characteristic and the vibration suppression characteristic, as compared with the inverse proportional relationship in which the denominator is a linear function.

By the loop gain m of velocity₁The specific characteristics shown in the expressions (4), (7.1), (7.2), (8.1), and (8.2) in which Kvp is defined are determined in the present embodiment by experiment for the velocity loop gain m₁And Kvp and the inertia moment ratio Gr, and the characteristics of the points obtained by the measurement. As the number of times of the function of the denominator increases, the accuracy of fitting the function value to the measurement point can be improved, but the arithmetic processing load of the CPU increases.

In the motor systems 1 according to embodiments 1 to 5, the case where the user completely freely inputs an arbitrary parameter constant Ri to the motor control device 4 has been described. However, the parameter constant Ri may be stored in the motor control device 4 as a plurality of values corresponding to the types of the power transmission mechanism 6 between the motor 3 and the operation object 2. According to this configuration, the user can set parameters by simply selecting the value of the parameter constant Ri corresponding to the type of the power transmission mechanism 6 from among the plurality of parameter constants Ri stored in advance in the motor control device 4. Therefore, the motor system 1 in which the convenience of the user is improved can be provided.

In the motor systems 1 according to embodiments 1 to 5, the speed loop gain m is calculated using a table₁And the change of Kvp to each control parameter. However, the velocity loop gain m may be calculated by using a formula without using a table₁And Kvp to each control parameter.

In the motor systems 1 according to embodiments 1 to 5, the limit may be set to the upper limit of the inertia moment ratio Gr.

At a velocity loop gain m with increasing moment of inertia ratio Gr₁The value of Kvp is too small, and the velocity loop gain m corresponding to the value of the inertia moment ratio Gr cannot be set₁The value of Kvp, for example, the velocity loop gain m corresponding to the value of the inertia moment ratio Gr₁Kvp is compared with the minimum level of the speed loop gain m set in the table₁When the value of Kvp is small, the speed loop gain m cannot be reduced₁Kvp.

In this case, the speed loop gain m will be set according to the table₁Minimum value m of_1minMinimum value Kvp of Kvp_minAnd based on the relation (m)₁The inertia moment ratio Gr obtained by Ri/f (Gr) and Kvp Ri/f (Gr) is set in advance in the motor control device 4 as an upper limit value of the inertia moment ratio Gr. By limiting the upper limit value of the inertia moment ratio Gr in this way, the velocity loop gain m corresponding to the value of the inertia moment ratio Gr is obtained₁The lower limit of the value of Kvp imposes a limit. Thus, the relation (m)₁Ri/f (gr), Kvp Ri/f (gr), and no longer the speed loop gain m cannot be set₁The value of Kvp.

For example, the velocity loop gain m is calculated by equation (4)₁The value of (c), as shown in the graph of FIG. 3(a), the velocity loop gain m₁The relation with the ratio of the moment of inertia Gr is purely an inverse proportion (m)₁Ri/Gr), the speed loop gain m that can be set in the table is set₁Minimum value of (1) is m_1minThen, the upper limit value grcamax of the inertia moment ratio Gr can be represented by the following equation (9) based on equation (4).

grcamax＝Ri/m_1min…(9)

Fig. 3(b) is a graph showing a time change of the inertia moment ratio Gr when the upper limit value grcamax is set for the inertia moment ratio Gr. The horizontal axis of the graph represents time, and the vertical axis represents the inertia moment ratio Gr. As shown in the graph, when the upper limit value grcamax is set for the inertia moment ratio Gr at time t, the estimated value of the inertia moment ratio Gr, which is increased as shown by the one-dot chain line after time t, is limited to grcamax [% ]]. Therefore, by limiting the setting of the inertia moment ratio Gr to the upper limit value grcamax determined by equation (9), the speed loop gain m corresponding to the value of the inertia moment ratio Gr is obtained₁The lower limit of the value of (c) imposes a limit, the relation (m)₁Ri/f (gr)) always holds, and no further inability to set the speed loop gain m occurs₁The value of (c).

Further, the velocity loop gain m shown in FIG. 3(a)₁In the relation with the inertia moment ratio Gr, as shown in the graph, the loop gain m for velocity₁Is set to the upper limit value m_1maxMake the velocity loop gain m₁Is at the upper limit m desired by the user_1maxSaturation, then instruction responsiveness may be improved as much as possible. According to the motor system 1, vibration can be suppressed by auto-tuning without increasing the arithmetic processing load of the CPU, and the command responsiveness can be brought close to the characteristics desired by the user.

Fig. 8 is a block diagram of a closed-loop system 8C' according to a modification example in which a configuration for limiting the upper limit value of the inertia moment ratio Gr is added to the motor system 1 according to embodiment 3. In the figure, the same or corresponding portions as those in fig. 5 are denoted by the same reference numerals, and the description thereof is omitted.

The closed loop system 8C' adds a Gr upper limit value calculation unit 22 and a limiter 23, which are formed of a CPU, to the closed loop system 8C. In the closed loop system 8C', the number 1/K (═ Gr/K) in fig. 5 is₀) The motor gain transmission element 12 is shown divided by 1/K₀The shown transfer elements 12a and the transfer element 12b shown by Gr are represented. The Gr upper limit value calculation unit 22 is supplied with the velocity loop gain m that can be set in the 3 rd table₁Minimum value m of_1minAnd a parameter constant Ri. Gr upper limit value calculation unit 22 according to minimum value m_1minAnd a parameter constant Ri, and calculating and storing an upper limit value grcamax of the moment of inertia ratio Gr by using an equation (9). Velocity loop gain m calculated by equation (4)₁When the value of (3) reaches the lower limit saturation in the table 3, the limiter 23 limits the value of Gr in the transfer element 12b to the upper limit value grcamax calculated by the Gr upper limit value calculation unit 22. Thereby limiting the 1/K set value to be not excessiveThe degree rises, in other words, so that the K set value does not fall excessively. Thus, the relation (m)₁Ri/Gr) always holds, no further inability to set the speed loop gain m occurs₁The value of (c).

In the motor systems 1 according to the embodiments 1 to 5 and the modified examples described above, the transfer functions of the closed-

loop systems

8A, 8B, 8C', 8D, and 8E have been described as defining the characteristics of the multi-inertia system. However, the present invention is equally applicable to the case where the transfer function of the closed-loop system defines the characteristics of the 1 inertial system. According to this configuration, although the command response characteristic of the closed-loop system is degraded, it is possible to prevent oscillation due to control without the user being aware of whether the control target apparatus is a 1-inertia system having high rigidity or a multi-inertia system having low control rigidity.

In the motor systems 1 according to the embodiments 1 to 5 and the modified examples described above, the adaptive determination means 21 is configured as inertia moment detection means for detecting the inertia moments of the operation object 2 and the motor 3. However, the motor control device 4 may be configured to include a rotational inertia detection unit that detects the rotational inertia of the operation target object 2 and the motor 3 in addition to the adaptation determination unit 21.

Description of the reference symbols

1 electric motor system

2 object to be operated

3 electric motor

4 Motor control device

6 Power transmission mechanism

8A, 8B, 8C, 8C', 8D, 8E closed loop system

9 st proportional gain transfer element

10 1 st addition point

11 integral filter transfer element

12 motor gain transmission element

13 motor position transmission element

14 differential filter transfer element

15 1 st gain conversion unit

16 nd gain conversion unit

17 3 rd gain conversion unit

18 nd 2 nd addition point

19 nd 2 nd proportional gain transfer element

21 an adaptation determination unit

Claims

1. A motor system including a motor for operating an object to be operated and a motor control device for feedback-controlling rotation of the motor, the motor system comprising:

an adaptation determination unit that determines a gain K, which is a value obtained by dividing a fixed value including a fixed gain of an amplifier that supplies power to the motor and a torque constant of the motor by a moment of inertia of the motion target object and the motor, based on an input of a motor position transmission element and an output of the motor position transmission element; and

a calculation unit that calculates a gain K₀Calculating a ratio of an arbitrary parameter constant Ri to a predetermined function value having the inertia ratio Gr as a factor, using the calculated inertia ratio Gr, and calculating the speed loop gain from the ratio₀In order to divide a fixed value including a fixed gain of an amplifier that supplies power to the motor and a torque constant of the motor by a rotational inertia of the motor,

the transfer function is corrected according to the velocity loop gain calculated by the calculation unit.

2. The motor system of claim 1,

the closed loop system constitutes a transfer function including the speed loop gain and the position loop gain as factors, inputs a rotational position command of the motor in place of the rotational speed command, performs feedback control on the rotational position of the motor, outputs the rotational position,

and correcting the transfer function according to the speed loop gain and the position loop gain calculated by the calculation unit.

3. The motor system of claim 1,

the closed loop system includes a forward path having a 1 st proportional gain transmission element, a 1 st addition point to which a rotational speed command of the motor is input, an integral filter transmission element, a motor gain transmission element, and a motor position transmission element, and a 1 st feedback path that negatively feeds back a rotational position of the motor to the 1 st addition point via a differential filter transmission element,

setting the loop gain of the velocity to m₁And a desired transfer function having desired characteristics for controlling the speed of the motion object and the motor when the laplace operator is s is expressed by the equation m₁/(s+m₁) It is specified that the first and second measurement signals,

the adaptive determination means determines a gain p based on the input of the motor position transmission element and the output of the motor position transmission element, and the control parameter for the disturbance response characteristic is q₀And q is₁The parameter for making the characteristic of the closed loop system consistent with the desired transfer function is a₁＝q₁+m₁-p、b₁＝q₀·m₁、b₂＝(q₁-p)·(m₁-p)+q₀In which, what is needed isThe gain p is a value obtained by dividing a term relating to viscosity of the motion target object and the motor by inertia moments of the motion target object and the motor,

the 1 st proportional gain transfer element is formed by m₁It is shown that,

the integral filter transfer element is composed of(s)²+q₁·s+q₀)/(s²+a₁S) represents the number of atoms in the molecule,

the motor gain transfer element is represented by 1/K,

the differential filter transfer element is composed of₂·s²+b₁·s)/(s²+q₁·s+q₀) It is shown that,

storing m in the motor control device₁And q is₀、q₁A table corresponding to the relationship of (a),

the calculation unit refers to the table and performs the loop gain m from the calculated velocity₁To q₀、q₁And (4) transforming.

4. The motor system of claim 1,

the adaptive determination unit is provided to transmit the motor position and the input based on the motor position transmission elementThe gain determined by the output of the element is p, and the control parameter relating to the disturbance response characteristic is ω_qThe parameter for making the characteristic of the closed loop system consistent with the desired transfer function is b₁＝ω_q·m₁、b₂＝m₁-p+ω_qWherein the gain p is a value obtained by dividing a term relating to viscosity of the motion target object and the motor by inertia moments of the motion target object and the motor,

the 1 st proportional gain transfer element is formed by m₁It is shown that,

the motor gain transfer element is represented by 1/K,

the differential filter transfer element is composed of₂·s²+b₁·s)/(s+ω_q) It is shown that,

storing m in the motor control device₁And omega_qA table corresponding to the relationship of (a),

the calculation unit refers to the table and performs the loop gain m from the calculated velocity₁To omega_qAnd (4) transforming.

5. The motor system of claim 2,

the closed loop system includes a forward path having a 2 nd addition point, a 2 nd proportional gain transmission element, a 1 st addition point, an integral filter transmission element, a motor gain transmission element, and a motor position transmission element, to which a rotational position command of the motor is input in place of the rotational speed command, a 1 st feedback path that negatively feeds back a rotational position of the motor to the 1 st addition point via a differential filter transmission element, and a 2 nd feedback path that directly negatively feeds back a rotational position of the motor to the 2 nd addition point,

setting the loop gain of the velocity to m₁The position loop gain is m₀/m₁And a desired transfer function having desired characteristics for controlling the positions of the motion object and the motor when the laplace operator is s is expressed by the equation m₀/(s²+m₁·s+m₀) It is specified that the first and second measurement signals,

the adaptive determination means determines a gain p based on the input of the motor position transmission element and the output of the motor position transmission element, and the control parameter for the disturbance response characteristic is q₀And q is₁The parameter for making the characteristic of the closed loop system consistent with the desired transfer function is a₁＝q₁+m₁-p、b₁＝q₀·m₁、b₂＝(q₁-p)·(m₁-p)+q₀Wherein the gain p is a value obtained by dividing a term relating to viscosity of the motion target object and the motor by inertia moments of the motion target object and the motor,

the 2 nd proportional gain transfer element is formed by m₀It is shown that,

the motor gain transfer element is represented by 1/K,

storing m in the motor control device₁And m₀、q₀、q₁A table corresponding to the relationship of (a),

the calculation unit refers to the table and performs the loop gain m from the calculated velocity₁To m₀、q₀、q₁And (4) transforming.

6. The motor system according to any one of claims 1 to 5,

the predetermined function of calculating the velocity loop gain by taking the inertia moment ratio Gr as a factor is a linear function by taking only the inertia moment ratio Gr as a factor.

7. The motor system according to any one of claims 1 to 5,

the predetermined function of calculating the velocity loop gain by taking the inertia moment ratio Gr as a factor is a linear function by taking the inertia moment ratio Gr and a constant as a factor.

8. The motor system according to any one of claims 1 to 5,

the predetermined function of calculating the velocity loop gain by taking the inertia moment ratio Gr as a factor is a quadratic function by taking the inertia moment ratio Gr and a constant as a factor.

9. The motor system according to any one of claims 1 to 5,

the parameter constant Ri is stored in the motor control device as a plurality of values corresponding to the type of the power transmission mechanism between the motor and the operation target object.

10. The motor system according to any one of claims 1 to 5,

and setting a limit on the upper limit value of the moment of inertia ratio Gr.

11. The motor system according to any one of claims 1 to 5,

the adaptive determination means constitutes the inertia moment detection means, and determines the inertia moment of the motion object and the motor based on the input of the motor position transmission element and the output of the motor position transmission element.