阅读说明：本技术 基于改进play算子的电机伺服控制系统迟滞控制方法 (Motor servo control system hysteresis control method based on improved play operator ) 是由 傅平 于 2021-09-01 设计创作，主要内容包括：本发明提出一种基于改进play算子的电机伺服控制系统迟滞控制方法,考虑现有的超声波电机伺服控制系统的设计中由于力矩输出处于合适状态时,其滞回具有对称性,对周期重复信号控制时有一定的误差。为了改善跟随性能的精确性,设计了基于改进play算子对称补偿控制的超声波电机伺服控制方案。基于改进play算子对称补偿控制能有效提升控制系统对迟滞的精确性,并进一步减少系统对于不确定性的影响程度,电机的力矩与速度控制可以获得较好的动态特性。(The invention provides a motor servo control system hysteresis control method based on an improved play operator, which considers that hysteresis has symmetry when torque output is in a proper state in the design of the existing ultrasonic motor servo control system, and has a certain error when a periodic repeated signal is controlled. In order to improve the accuracy of the following performance, an ultrasonic motor servo control scheme based on the improved play operator symmetry compensation control is designed. The accuracy of the control system on the hysteresis can be effectively improved based on the improved play operator symmetric compensation control, the influence degree of the system on the uncertainty is further reduced, and the torque and speed control of the motor can obtain better dynamic characteristics.)

1. A motor servo control system hysteresis control method based on an improved play operator is characterized in that:

the adopted symmetric hysteresis compensation control is based on a dynamic equation of an ultrasonic motor driving system:

wherein A is_p＝-B/J,B_P＝J/K_t＞0,C_P-1/J; b is damping coefficient, J is moment of inertia, K_tIs a current factor, T_f(v) As frictional resistance torque, T_LFor the load moment, U (t) is the output moment of the motor, θ_r(t) is a position signal measured by a photoelectric encoder;

let 0 be t₀＜t₁＜…t_N＝t_EIs [0, t_E]V (t) is the input signal,is the output signal of the hysteresis system; input function v at each [ t ]_i,t_i+1]Monotonic in the interval, any input v (t) e C_e[0，t_E]The improved generalized play operator threshold r is defined as:

wherein t is_i＜t≤t_i+1I is more than or equal to 0 and less than or equal to N-1, max represents that the two-number comparison is maximum, and min represents that the two-number comparison is minimum; gamma ray_l(v-r) and γ_r(v + r) are two strictly increasing envelope functions, and the lag shape of the improved generalized play operator is limited by the two envelope functions; the solution of the improved generalized play operator threshold is: gamma ray_l(v-r)＝0，γ_r(v + r) ═ 0, each corresponding toAndthe boundary of the improved generalized play operator is an envelope function gamma [ v ] v shifted along the gx/v (t) axis]Envelope function gamma [ v ]]Are the same in shape and boundary;

Π_m[v](t) model definition as an improved generalized play operatorBy weighted integration, i.e.

Wherein p is₀Is a normal number which is a constant number,means to improve generalized play operator when r is 0p (r) is a density function; II type_m[v](t) model for any given input v (t) e C_m[0，t_E]Is a Lipschitz series; r is an upper limit value of the threshold R.

2. The hysteresis control method of the motor servo control system based on the improved play operator as claimed in claim 1, wherein:

load curve based on initial load curve phi and inverse modelSymmetry to obtain

The initial load curve φ is expressed as:

where γ (r) is the input function, and the envelope function γ is selected according to the input data range_l(r) and γ_rOne of (r); theta is an integral variable and the integral range is 0, r]；

Π_m[v](t) the inverse of the model analysis is shown below,

wherein g is₀Is a normal number, g (r) is a density function, beta is an envelope function,is an improved generalized play operator with a threshold q and an envelope function β; q is the upper limit value of the threshold Q;

load curve of inverse modelThe loading curve of (c) is:

the derivative formula of the method is shown in the specification,

is thatDerivatives with respect to time, like β '(q), β' (r- η) are derivatives with respect to time of β (q), β (r- η); eta is an integral variable, and the integral range is [0, q ]]The derivatives of these two loading curves are substituted into equation (6) to obtain,

and

β[v]＝γ^-1[v] (12)

Π_m[v](t) inverse of the model:

is p₀The density function g (q) is obtained by equation (6):

3. the hysteresis control method of the motor servo control system based on the improved play operator as claimed in claim 1, wherein:

describing the lag as the sum of N operators, pi_m[v](t) the model is written as,

where N is the number of improved generalized play operators, r_iIs the ith threshold, and r satisfies 0 ═ r₀<r₁<···<r_N＝R。

4. The hysteresis control method of the motor servo control system based on the improved play operator as claimed in claim 2, wherein:

describing the lag as the sum of N operators, pi_m[v](t) writing the inverse model to,

where N is the number of improved generalized play operators, q_iIs that the ith threshold satisfies 0 ═ q₀<q₁<...<q_N＝Q；

The parameters to be calculated in the inverse model are g₀，β[v]，q_iAnd g (q)_i) (ii) a Thus, the initial loading curve and its inverseAndis recorded as:

andthe derivative of the loading curve is:

obtained from formula (6):

thus, there are:

and

β[v]＝γ^-1[v] (21)

the threshold of the inverse model operator is:

the compound is obtained by using the formula (6) again,

density function g (q) of inverse model_j) Is composed of

5. An ultrasonic motor servo control system is characterized in that hysteresis compensation control is carried out by adopting the motor servo control system hysteresis control method based on the improved play operator as claimed in any one of claims 1 to 4, and the ultrasonic motor servo control system comprises a base and an ultrasonic motor arranged on the base; an output shaft at one side of the ultrasonic motor is connected with the photoelectric encoder, and an output shaft at the other side of the ultrasonic motor is connected with an inertial load of the flywheel; the output shaft of the flywheel inertial load is connected with the torque sensor through a coupler; and the signal output end of the photoelectric encoder and the signal output end of the torque sensor are respectively connected to a control system.

6. The ultrasonic motor servo control system of claim 5, wherein: control system includes ultrasonic motor drive control circuit, ultrasonic motor drive control circuit includes control chip circuit and driver chip circuit, photoelectric encoder's signal output part with the corresponding input of control chip circuit is connected, the output of control chip circuit with the corresponding input of driver chip circuit is connected, in order to drive the driver chip circuit, the drive frequency adjusting signal output part and the drive half-bridge circuit adjusting signal output part of driver chip circuit respectively with the corresponding input of ultrasonic motor is connected.

7. The ultrasonic motor servo control system of claim 6, wherein: the system of the whole controller is established by improving a play operator to process a hysteresis mathematical model, so that the hysteresis of a servo system is minimized while the identification dynamic error is reduced.

8. The ultrasonic motor servo control system of claim 6, wherein: the hardware circuit of the control system comprises an ultrasonic motor drive control circuit, the ultrasonic motor drive control circuit comprises a control chip circuit and a drive chip circuit, the signal output end of the photoelectric encoder is connected with the corresponding input end of the control chip circuit, the output end of the control chip circuit is connected with the corresponding input end of the drive chip circuit to drive the drive chip circuit, and the drive frequency adjusting signal output end and the drive half-bridge circuit adjusting signal output end of the drive chip circuit are respectively connected with the corresponding input end of the ultrasonic motor.

Technical Field

The invention relates to the technical field of motor controllers, in particular to a motor servo control system hysteresis control method based on an improved play operator.

Background

In the design of the existing ultrasonic motor servo control system, when the speed tracks a periodic signal, the torque-speed relation of the periodic signal presents a hysteresis characteristic, so that certain errors exist in the ascending and descending intervals when the same signal is tracked. The general play operator can only compensate for the simpler hysteresis characteristics. Chinese patent 201710223807 proposes a symmetric hysteretic control method for an ultrasonic motor servo control system based on a Stop operator, but further research shows that the control method has limited types of compensatory hysteresis characteristics, too large computation amount and too complex model, and needs a fast processor and memory for practical use, and further improvement and optimization.

Disclosure of Invention

In the design of the existing ultrasonic motor servo control system, when the torque output is in a proper state, the hysteresis has symmetry, and certain errors exist in the control of periodic repeated signals. In order to improve the accuracy of the following performance, the invention designs an ultrasonic motor servo control scheme based on the improved play operator symmetric compensation control. Based on the improved play operator, the control efficiency of the system can be effectively improved, the accuracy of the control system on the hysteresis is improved, the influence degree of the system on the uncertainty is further reduced, and the torque and speed control of the motor can obtain better repetitive characteristics.

The invention specifically adopts the following technical scheme:

a motor servo control system hysteresis control method based on an improved play operator is characterized in that:

the adopted symmetric hysteresis compensation control is based on a dynamic equation of an ultrasonic motor driving system:

wherein A is_p＝-B/J,B_P＝J/K_t＞0,C_P-1/J; b is damping coefficient, J is moment of inertia, K_tIs a current factor, T_f(v) As frictional resistance torque, T_LFor the load moment, U (t) is the output moment of the motor, θ_r(t) is a position signal measured by a photoelectric encoder;

when the load moment of the motor is moderate, the hysteresis of the motor moment-speed characteristic has symmetry, and in order to reduce the influence caused by the phenomenon and reduce the operation amount, an improved generalized play operator is used for performing compensation control on the hysteresis;

let 0 be t₀＜t₁＜…t_N＝t_EIs [0, t_E]V (t) is the input signal, F_mγ_r[v](t) is a hysteresis systemAn output signal of the system; input function v at each [ t ]_i,t_i+1]Monotonic in the interval, any input v (t) e C_e[0，t_E]The improved generalized play operator threshold r is defined as:

wherein t is_i＜t≤t_i+1I is more than or equal to 0 and less than or equal to N-1, max represents that the two-number comparison is maximum, and min represents that the two-number comparison is minimum; gamma ray_l(v-r) and γ_r(v + r) are two strictly increasing envelope functions, and the lag shape of the improved generalized play operator is limited by the two envelope functions; the solution of the improved generalized play operator threshold is: gamma ray_l(v-r)＝0，γ_r(v + r) ═ 0, each corresponding toAndthe boundary of the improved generalized play operator is an envelope function gamma [ v ] v shifted along the gx/v (t) axis]Envelope function gamma [ v ]]Are the same in shape and boundary;

Π_m[v](t) model definition as an improved generalized play operatorBy weighted integration, i.e.

Wherein p is₀Is a normal number which is a constant number,means to improve generalized play operator when r is 0p (r) is a density function; II type_m[v](t) model for any given input v (t) e C_m[0，t_E]Is a Lipschitz series; r is an upper limit value of the threshold R.

Further, a load curve based on the initial load curve φ and the inverse modelSymmetry to obtain

The initial load curve φ is expressed as:

where γ (r) is the input function, and the envelope function γ is selected according to the input data range_l(r) and γ_rOne of (r); theta is an integral variable and the integral range is 0, r](ii) a When selecting the envelope function gamma v]Time, linear function gamma v]＝v；

Π_m[v](t) the inverse of the model analysis is shown below,

wherein g is₀Is a normal number, g (r) is a density function, beta is an envelope function,is an improved generalized play operator with a threshold q and an envelope function β; q isThe upper limit value of the threshold q;

load curve of inverse modelThe loading curve of (c) is:

the derivative formula of the method is shown in the specification,

is thatThe time derivatives are, similarly, β '(q), β' (r- η) the time derivatives of β (q), β (r- η). The derivatives of these two loading curves are substituted into equation (6) to obtain,

and

β[v]＝γ^-1[v] (12)

Π_m[v](t) inverse of the model:

is p₀The density function g (q) is obtained by the following equation (6)

Further, describing hysteresis as the sum of N operators, pi_m[v](t) the model is written as,

where N is the number of improved generalized play operators, r_iIs the ith threshold, and r satisfies 0 ═ r₀<r₁<···<r_N＝R。

Further, describing hysteresis as the sum of N operators, pi_m[v](t) writing the inverse model to,

where N is the number of improved generalized play operators, q_iIs that the ith threshold satisfies 0 ═ q₀<q₁<...<q_N＝Q；

The parameters to be calculated in the inverse model are g₀，β[v]，q_iAnd g (q)_i) (ii) a Thus, the initial loading curve and its inverse r ∈ [ r ]_j,r_j+1) And q ∈ [ q ]_j,q_j+1) Is recorded as:

r∈[r_j,r_j+1) And q ∈ [ q ]_j,q_j+1) The derivative of the loading curve is:

obtained from formula (6):

thus, there are:

and

β[v]＝γ^-1[v] (21)

the threshold of the inverse model operator is:

the compound is obtained by using the formula (6) again,

density function g (q) of inverse model_j) Is composed of

Thus using a given model, its inverseCan be realized according to the steps.

The system is stable as demonstrated by stability theory. The use of compensation control allows the system torque speed characteristics to approach a linear relationship.

The ultrasonic motor servo control system is characterized in that hysteresis compensation control is carried out by adopting the motor servo control system hysteresis control method based on the improved play operator, and the ultrasonic motor servo control system comprises a base and an ultrasonic motor arranged on the base; an output shaft at one side of the ultrasonic motor is connected with the photoelectric encoder, and an output shaft at the other side of the ultrasonic motor is connected with an inertial load of the flywheel; the output shaft of the flywheel inertial load is connected with the torque sensor through a coupler; and the signal output end of the photoelectric encoder and the signal output end of the torque sensor are respectively connected to a control system.

Further, control system includes ultrasonic motor drive control circuit, ultrasonic motor drive control circuit includes control chip circuit and driver chip circuit, photoelectric encoder's signal output part with the corresponding input of control chip circuit is connected, the output of control chip circuit with the corresponding input of driver chip circuit is connected, in order to drive the driver chip circuit, the drive frequency adjustment signal output part and the drive half-bridge circuit adjustment signal output part of driver chip circuit respectively with the corresponding input of ultrasonic motor is connected.

Furthermore, the system establishment of the whole controller improves the play operator to process the hysteresis mathematical model, so that the hysteresis of the servo system is minimized while the identification dynamic error is reduced. The hysteresis of the servo system is minimized while the identification dynamic error is reduced, so that better input/output control efficiency can be obtained.

Further, control system's hardware circuit includes ultrasonic motor drive control circuit, ultrasonic motor drive control circuit includes control chip circuit and driver chip circuit, photoelectric encoder's signal output part with the corresponding input of control chip circuit is connected, the output of control chip circuit with the corresponding input of driver chip circuit is connected, in order to drive the driver chip circuit, driver chip circuit's drive frequency adjustment signal output part and drive half-bridge circuit adjustment signal output part respectively with ultrasonic motor's corresponding input is connected.

Further, the coupling is an elastic coupling.

Furthermore, the ultrasonic motor, the photoelectric encoder and the torque sensor are fixed on the base through an ultrasonic motor fixing support, a photoelectric encoder fixing support and a torque sensor fixing support respectively.

Compared with the prior art, the method and the optimal scheme thereof can effectively improve the control efficiency of the system based on the improved play operator symmetric compensation control, further reduce the influence degree of the system on uncertainty, and obtain better dynamic characteristics for the torque and speed control of the motor.

Drawings

The invention is described in further detail below with reference to the following figures and detailed description:

FIG. 1 is a schematic diagram of a servo control system of an ultrasonic motor according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a control circuit according to an embodiment of the present invention.

In the figure, 1-photoelectric encoder, 2-photoelectric encoder fixing bracket, 3-ultrasonic motor output shaft, 4-ultrasonic motor, 5-ultrasonic motor fixing bracket, 6-ultrasonic motor output shaft, 7-flywheel inertial load, 8-flywheel inertial load output shaft, 9-elastic coupling, 10-torque sensor, 11-torque sensor fixing bracket, 12-base, 13-control chip circuit, 14-driving chip circuit, 15, 16, 17-A, B, Z phase signal output by photoelectric encoder, 18, 19, 20, 21-driving frequency adjusting signal generated by driving chip circuit, 22-driving half-bridge circuit adjusting signal generated by driving chip circuit, 23, 24, 25, 26, 27, 28-driving chip circuit signal generated by controlling chip circuit, 29-ultrasonic motor drive control circuit.

Detailed Description

In order to make the features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail as follows:

the ultrasonic motor control system adopted in this embodiment, as shown in fig. 1, includes a base 12 and an ultrasonic motor 4 disposed on the base 12, an output shaft 3 on one side of the ultrasonic motor 4 is connected with a photoelectric encoder 1, an output shaft 6 on the other side is connected with a flywheel inertial load 7, an output shaft 8 of the flywheel inertial load 7 is connected with a torque sensor 10 through an elastic coupling 9, and a signal output end of the photoelectric encoder 1 and a signal output end of the torque sensor 10 are respectively connected to the control system.

The ultrasonic motor 4, the photoelectric encoder 1 and the torque sensor 10 are fixed on the base 12 through the ultrasonic motor fixing support 5, the photoelectric encoder fixing support 2 and the torque sensor fixing support 11 respectively.

As shown in fig. 2, the control system includes an ultrasonic motor driving control circuit 29, the ultrasonic motor driving control circuit 29 includes a control chip circuit 13 and a driving chip circuit 14, a signal output end of the photoelectric encoder 1 is connected to a corresponding input end of the control chip circuit 13, an output end of the control chip circuit 13 is connected to a corresponding input end of the driving chip circuit 14 to drive the driving chip circuit 14, and a driving frequency adjusting signal output end and a driving half-bridge circuit adjusting signal output end of the driving chip circuit 14 are respectively connected to corresponding input ends of the ultrasonic motor 4. The driving chip circuit 14 generates a driving frequency adjusting signal and a driving half-bridge circuit adjusting signal to control the frequency, the phase and the on-off of A, B two-phase PWM output by the ultrasonic motor. Controlling the starting and stopping of the ultrasonic motor by switching on and off the output of the PWM wave; the optimal operation state of the motor is adjusted by adjusting the frequency of the output PWM wave and the phase difference of the two phases.

In the embodiment, the system of the whole controller is established by improving the play operator to process the hysteresis mathematical model, so that the hysteresis of the servo system is minimized while the identification dynamic error is reduced, and better input and output control efficiency can be obtained.

The dynamic equation for an ultrasonic motor drive system can be written as:

wherein A is_p＝-B/J,B_P＝J/K_t＞0,C_P-1/J; b is damping coefficient, J is moment of inertia, K_tIs a current factor, T_f(v) As frictional resistance torque, T_LFor the load moment, U (t) is the output moment of the motor, θ_rAnd (t) is a position signal measured by a photoelectric encoder.

When the load torque of the motor is moderate, the hysteresis of the torque-speed characteristic of the motor has symmetry, and in order to reduce the influence caused by the phenomenon and reduce the operation amount, an improved generalized play operator is used for performing compensation control on the hysteresis.

Let 0 be t₀＜t₁＜…t_N＝t_EIs [0, t_E]V (t) is the input signal,is the output signal of the hysteresis system. Input function v at each [ t ]_i,t_i+1]Monotonic in the interval, any input v (t) e C_e[0，t_E]The improved generalized play operator threshold r is defined as:

wherein t is_i＜t≤t_i+1I is more than or equal to 0 and less than or equal to N-1, max represents that the two-number comparison is maximum, and min represents that the two-number comparison is minimum.

γ_l(v-r) and γ_r(v + r) improved generalized play operator lag shape for two strictly growing envelope functionsThe shape is limited by two envelope functions. The solution of the improved generalized play operator threshold is gamma_l(v-r)＝0，γ_r(v + r) ═ 0, each of which isAndif γ (0) is chosen to be 0, the threshold of the improved generalized play operator is ± r. Furthermore, the boundary of the improved generalized play operator is an envelope function γ [ v ] shifted along the gx/v (t) axis]Envelope function gamma [ v ]]Are identical in shape and boundary.

Π_m[v](t) model definition as an improved generalized play operatorThe weighted integral of (a), namely:

wherein p is₀Is a normal number which is a constant number,means to improve generalized play operator when r is 0p (r) is a density function. II type_m[v](t) model for any given input v (t) e C_m[0，t_E]Is a Lipschitz series.

Load curve based on initial load curve phi and inverse modelAnd (3) symmetry to obtain:

the load curve φ may be expressed as:

γ (r) is an input function, and when the envelope function γ [ v ] is selected, the linear function γ [ v ] is equal to v.

Π_m[v](t) the model analytical inverse is as follows:

wherein g is₀Is a normal number, g (r) is a density function, beta is an envelope function,is an improved generalized play operator with a threshold q and an envelope function β.

Load curveHas a loading curve of

The derivative formula of the method is shown in the specification,

the derivatives of these two loading curves are substituted into (6) to obtain,

and

β[v]＝γ^-1[v] (12)

Π_m[v](t) the inverse of the model can be written as:

with (6) the density function g (q),

in practical applications, the lag can be approximately described as the sum of N operators. Therefore, pi_m[v](t) the model can be written as,

where N is the number of improved generalized play operators, r_iIs the ith threshold, r satisfies 0 ═

r₀<r₁<···<r_NR, and pi_m[v](t) the inverse model is written as:

where N is the number of improved generalized play operators, q_iIs that the ith threshold satisfies 0 ═ q₀<q₁<...<q_NQ. The parameters to be calculated in the inverse model are g₀，β[v]，q_iAnd g (q)_i). Thus, the initial loading curve and its inverse r ∈ [ r ]_j,r_j+1) And q ∈ [ q ]_j,q_j+1) Is recorded as:

r∈[r_j,r_j+1) And q ∈ [ q ]_j,q_j+1) The derivative of the loading curve is:

from (4-12)

Thereby to obtain

And

β[v]＝γ^-1[v] (21)

the threshold of the inverse model operator is:

the compound is obtained by the method (6) again,

density function g (q) of inverse model_j) Comprises the following steps:

thus using a given model, its inverseCan be realized according to the steps.

The system is stable as demonstrated by stability theory. The use of compensation control allows the system torque speed characteristics to approach a linear relationship.

The present invention is not limited to the above-mentioned preferred embodiments, and various other forms of the hysteresis control method of the motor servo control system based on the improved play operator can be derived by anyone who follows the teaching of the present invention.