CN115202203A

CN115202203A - Method, device and equipment for determining parameters of position feedforward controller

Info

Publication number: CN115202203A
Application number: CN202210742933.2A
Authority: CN
Inventors: 王胜平
Original assignee: Midea Group Co Ltd; GD Midea Air Conditioning Equipment Co Ltd; Guangdong Midea White Goods Technology Innovation Center Co Ltd
Current assignee: Midea Group Co Ltd; GD Midea Air Conditioning Equipment Co Ltd; Guangdong Midea White Goods Technology Innovation Center Co Ltd
Priority date: 2022-06-27
Filing date: 2022-06-27
Publication date: 2022-10-18

Abstract

The present application discloses a method, device and device for determining parameters of a position feedforward controller, belonging to the technical field of servo control. The method includes: inputting a preset position input signal to a servo position controller; and obtaining a position feedback signal of the controlled object when the servo position controller does not activate a position feedforward controller, wherein the position feedforward signal is obtained. The feed controller is an FIR filter; the position control error is determined according to the preset position input signal and the position feedback signal; according to the position control error and the gain of the position feedback controller in the servo position controller, The parameters of the position feedforward controller are obtained by least squares fitting. The present application automatically determines the parameters of the position feedforward controller, without the need for manual experiments for many times, and the efficiency is higher.

Description

Method, device and equipment for determining parameters of position feedforward controller

Technical Field

The present application relates to the field of servo control technologies, and in particular, to a method, an apparatus, and a device for determining parameters of a position feedforward controller.

Background

Servo drive systems are widely used in industries such as industry and manufacturing. When the driven (controlled) object has large inertia or a given control value comprises rapid acceleration or rapid deceleration, the position feedback controller alone cannot simultaneously take into account the two performance indexes of the trajectory tracking precision and the steady-state regulation time. In this case, a position feedforward controller needs to be introduced in the servo drive system.

Currently, the parameters for position feedforward controllers are typically adjusted manually by a technician through experimentation.

In order to make the parameters more accurate, technicians usually need to perform a lot of experiments and then manually adjust the parameters continuously, which is inefficient.

Disclosure of Invention

The embodiment of the application provides a method, a device and equipment for determining parameters of a position feedforward controller, and can solve the problem of low efficiency of determining the parameters of the position feedforward controller in the related art. The technical scheme is as follows:

in a first aspect, there is provided a method of determining a parameter of a position feedforward controller, the method comprising:

inputting a preset position input signal to a servo position controller;

under the condition that the servo position controller does not start a position feedforward controller, acquiring a position feedback signal of a controlled object, wherein the position feedforward controller is a finite-length single-bit impulse response FIR filter;

determining a position control error according to the preset position input signal and the position feedback signal;

and obtaining parameters of the position feedforward controller through least square fitting according to the position control error and the gain of a position feedback controller in the servo position controller.

In one possible implementation, the transfer function of the position feedforward controller is:

F(z)＝(1-z ^-1 )(a ₀ +a ₁ z ^-1 +a ₂ z ^-2 +...+a _n z ^-n ) Wherein F (z) is a transfer function of the position feedforward controller, and z isComplex variables of discrete fields, a ₀ 、a ₁ 、a ₂ ...a _n And n is the order of the feedforward controller, wherein the parameter is the parameter to be determined by the position feedforward controller.

In a possible implementation manner, the obtaining the parameter of the position feedforward controller by least square fitting according to the position control error and a gain of a position feedback controller in the servo position controller includes:

determining an observation value according to the position control error;

determining an observation variable according to the position feedback signal and the gain of the position feedback controller;

and obtaining parameters of the position feedforward controller through least square fitting according to the observed value and the observed variable.

In one possible implementation manner, the acquiring a position feedback signal of a controlled object includes:

acquiring position feedback signals of a controlled object at N moments, wherein N is a positive integer larger than N;

the determining a position control error according to the preset position input signal and the position feedback signal includes:

and determining position control errors corresponding to the N moments respectively according to the preset position input signals at the N moments and the position feedback signals at the N moments.

Determining an observation value according to the position control error includes:

w (t) _k )e(t _k ) As observed values, where N ≦ k ≦ N, t _k Represents the kth time, w (t), of the N times _k ) Is the weight corresponding to the k-th time, e (t) _k ) And controlling the error for the position corresponding to the k-th moment.

In one possible implementation, the determining an observed variable according to the position feedback signal and a gain of the position feedback controller includes:

w (t) _k )[h(t _k )，h(t _k-1 )，h(t _k-2 )...，h(t _k-n )]As an observation variable, among others,

k is the gain of the position feedback controller, y (t) _k ) And feeding back a signal for the position of the controlled object at the kth moment.

In a second aspect, there is provided an apparatus for determining a parameter of a position feedforward controller, the apparatus comprising:

the input module is used for inputting a preset position input signal to the servo position controller;

an obtaining module, configured to obtain a position feedback signal of a controlled object when the servo position controller does not start a position feedforward controller, where the position feedforward controller is a finite-length single-bit impulse response FIR filter;

the determining module is used for determining a position control error according to the preset position input signal and the position feedback signal;

and the fitting module is used for obtaining the parameters of the position feedforward controller through least square fitting according to the position control error and the gain of a position feedback controller in the servo position controller.

F(z)＝(1-z ^-1 )(a ₀ +a ₁ z ^-1 +a ₂ z ^-2 +...+a _n z ^-n ) Wherein F (z) is a transfer function of the position feedforward controller, z is a complex variable in a discrete domain, a ₀ 、a ₁ 、a ₂ ...a _n And n is the order of the feedforward controller.

In one possible implementation, the fitting module is configured to:

determining an observation value according to the position control error;

In a possible implementation manner, the obtaining module is configured to:

the fitting module is configured to:

The fitting module is configured to:

In one possible implementation, the fitting module is configured to:

In a third aspect, a computer device is provided, which includes a processor and a memory, where at least one instruction is stored, the instruction being loaded and executed by the processor to implement the operations performed by the method for determining a parameter of a position feedforward controller according to the first aspect.

In a fourth aspect, there is provided a computer-readable storage medium having stored therein at least one instruction which is loaded and executed by a processor to perform the operations performed by the method of determining a parameter of a position feedforward controller as described in the first aspect above.

In a fifth aspect, there is provided a computer program product having at least one instruction stored therein, the instruction being loaded and executed by a processor to perform the operations performed by the method of determining a parameter of a position feedforward controller as described in the first aspect above.

The technical scheme provided by the embodiment of the application has the following beneficial effects:

the method for determining the parameter of the position feedforward controller provided by the embodiment of the application can acquire the position feedback signal of the controlled object by inputting the preset position input signal to the servo position controller under the condition that the servo position controller only enables the position feedback controller but not enables the position feedforward controller. Then, a position control error is calculated according to the preset position input signal and the position feedback signal. Further, parameters of the position feedforward controller are obtained by least square fitting based on the position control error and the gain of the position feedback controller in the servo position controller. The method does not need to carry out experiments for a plurality of times manually, can automatically complete parameter determination, and has higher efficiency.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a servo position controller according to an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of a servo position controller according to an embodiment of the present disclosure;

FIG. 3 is a flow chart of a method for determining parameters of a position feedforward controller according to an embodiment of the present application;

FIG. 4 is a comparison graph of a position output provided by an embodiment of the present application;

FIG. 5 is a comparison graph of a position control error provided by an embodiment of the present application;

FIG. 6 is a comparison graph of a position output provided by an embodiment of the present application;

FIG. 7 is a comparison graph of position control errors provided by embodiments of the present application;

FIG. 8 is a schematic diagram of a parameter determining apparatus of a feedforward controller for determining a position according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of a terminal according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a computer device according to an embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

In order to facilitate understanding of the present application, some terms mentioned in the embodiments of the present application will be described below.

A servo drive system:

the servo driving system is an automatic control system, and is also called a servo system, a servo system and the like. The servo driving system controls controlled quantities such as the position, the speed, the acceleration and the like of the controlled object and changes along with the input given value.

Least square method:

the least squares method is a mathematical tool used to deal with problems of error estimation, uncertainty, parameter identification, etc. The least square method is a basic principle and can simply and efficiently obtain unknown parameters by minimizing errors and finding the optimal matching function of data.

Referring to fig. 1, a schematic diagram of a servo position controller without a position feedforward controller is shown. A position feedback controller, i.e., C (z) in fig. 1, is mainly included in the servo position controller. In fig. 1, P (z) represents a controlled object (also referred to as a position loop control object), and includes an equivalent speed closed-loop control model, a speed-to-position integration element, and the like. r (z) represents a given (preset) position input signal, and e (z) is a position control error when only the position feedback controller is enabled. y (z) is a position feedback signal of the controlled object when only the position feedback controller is enabled.

When only the position feedback controller is enabled, the expression of the position feedback signal y (z) of the controlled object can be shown in the following formula (1):

where K is the gain (also referred to as gain value) of the position feedback controller and z is a complex variable in a discrete domain.

Accordingly, when only the position feedback controller is enabled, the expression of the position control error e (z) can be shown as the following formula (2):

in the embodiment of the present application, a position feedforward controller is further included in the servo position controller, and referring to fig. 2, a schematic structural diagram of a servo position controller including the position feedforward controller is shown. In contrast to fig. 1, a position feedforward controller, i.e., F (z) in fig. 2, is also included in the servo position controller shown in fig. 2. In fig. 2, P (z) represents a controlled object, and includes an equivalent speed closed-loop control model, a speed-to-position integration element, and the like. r (z) represents a given position input signal, e _F (z) is the position control error when the position feedback controller is enabled and the position feedforward controller is enabled. y is _F (z) a position feedback signal of the controlled object when the position feedback controller is enabled and the position feedforward controller is enabled.

Position feedback signal y of the controlled object when the position feedback controller is enabled and the position feedforward controller is enabled _F The expression of (z) can be shown as the following formula (3):

position control error e when position feedback controller is enabled and position feedforward controller is enabled _F The expression of (z) can be shown as the following formula (4):

as can be seen from the above equation (4), if e is made _F (z) =0, can design

However, the controlled object P (z) is unknown, then, according to

It is very difficult to determine F (z).

From another perspective, substituting the above equations (1) and (2) into equation (4) can yield e _F (z) the following expression:

the goal of designing F (z) is to have e _F (z) is close to 0, then F (z) in this embodiment selects a Finite long single-bit Impulse Response (FIR) filter of a certain order, and in order to make the feedforward output 0 when the input is constant, F (z) in this embodiment should satisfy F (1) =0, in one possible implementation, the expression of F (z) in this embodiment (which may also be referred to as the transfer function of the position feedforward controller) is as follows:

F(z)＝(1-z ^-1 )G _f (z) (6)

wherein G is _f (z) is an n-th order FIR filter, G _f The expression of (z) is as follows:

G _f (z)＝a ₀ +a ₁ z ^-1 +a ₂ z ^-2 +...a _n z ^-n (7)

wherein, a ₀ 、a ₁ 、a ₂ ...a _n I.e. the parameters of the position feedforward controller to be determined.

Here, substituting equation (6) into equation (5) can result in the following equation:

then, take G in the above formula (8) _f The portion after (z) is denoted as h (z):

it should be noted that the above equation (6) is only one form of position feedforward controller, where G is shown _f (1-z) before (z) ^-1 ) Other expressions can be used for replacement, and only F (1) =0 needs to be satisfied, and this part of expressions is not limited in this embodiment of the application.

The method for determining the parameters of the position feedforward controller provided in the embodiment of the present application is described below with reference to fig. 3. The method can be realized by computing equipment, and the computing equipment can be computer equipment, terminals and the like. Referring to fig. 3, the process flow of the method may include the following steps:

step 301, inputting a preset position input signal to the servo position controller.

In practice, a preset position input signal is input to the servo position controller. The preset position input signal may be a typical position track, such as an S-shaped curve position track, a sine-shaped curve position track, a cosine-shaped curve position track, and the like. The specific input position input signal is not limited in the embodiments of the present application.

And step 302, acquiring a position feedback signal of the controlled object under the condition that the position feedback controller is enabled and the position feedforward controller is not enabled in the servo position controller.

Wherein, enabling means to turn on or make it work, and not enabling means to turn off or make it not work.

In practice, the position feedback controller in the servo position controller may be enabled and the position feedforward controller may not be enabled before step 301 is performed.

When a preset position input signal is input in step 301, the controlled object outputs a position feedback signal and collects the position feedback signal. Specifically, t can be collected ₀ 、t ₁ ...、t _N Position feedback signal at time.

And step 303, determining a position control error according to a preset position input signal and a preset position feedback signal.

In practice, the position control error is calculated from the position input signal input in step 301 and the position feedback signal acquired in step 302. The calculation formula of the position control error is the above formula (2).

And step 304, obtaining parameters of the position feedforward controller through least square fitting according to the position control error and the gain of the position feedback controller.

In implementation, the order of the position feedforward controller, i.e., the value of n in equations (6) and (7) above, is determined. In the first iteration, n may be a preset value, for example, n =4, and in the subsequent iteration process, if the value of n is updated, the updated value of n is used, and if the value of n is not updated, the preset value in the first iteration is still used.

At t _k Time:

e _F (t _k )＝e(t _k )-(a ₀ h(t _k )+a ₁ h(t _k-1 )+a ₂ h(t _k-2 )+...+a _n h(t _k-n ))(10)

wherein N is not less than k not more than N, e (t) _k ) When the position feedback controller is enabled and the position feedforward controller is not enabled, the t th _k Position control error corresponding to time h (t) _k )、h(t _k-1 )、...h(t _k-n ) I.e. corresponding to equation (9) above. Obtaining t ₀ 、t ₁ ...、t _N A weight corresponding to each of the time instants.

It should be noted that, during the first iteration, the weight corresponding to each time is a preset value, and in the subsequent iteration process, if the weight is updated, the weight obtained here is the updated weight.

In a possible implementation, the weight may not be set here, i.e. the weight corresponding to each time instant is considered to be 1.

Mixing the above e _F (t _k ) Multiplied by t _k Weight w (t) corresponding to time _k ) And converted into a vector form, the following formula (11) can be obtained:

fitting the target to weighted e _F (z) the sum of the squares of the sequence is minimal, then in w (t) _k )e _F (t _k ) As residual, with w (t) _k )e(t _k ) As observed value, w (t) _k )e(t _k )-w(t _k )[h(t _k )，h(t _k-1 )，h(t _k-2 )...(t _k-n )]Is a least squares parameter identification problem for observed variables.

Let phi (k) = w (t) _k )[h(t _k )h(t _k-1 )h(t _k-2 )...(t _k-n )] (12)

Taking the matrix formed by k epsilon [ N, N ]:

wherein, the rank (A) of the matrix A is larger than or equal to N, and k can be continuously valued in [ N, N ] as the formula (13). In a possible implementation manner, k may also be a discontinuous value, for example, k may be an interval value, and if N is an even number, the following formula (14) may be used:

assuming that N is an odd number, the following equation (15) can be used:

the specific value mode of k is not limited in the embodiment of the application, and only the rank (A) is ensured to be more than or equal to n. Because rank (A) is required to be more than or equal to N, N can be set to be far larger than N when acquiring the position feedback signal. For convenience of description, in the embodiment of the present application, K is exemplified by using the continuous value in the formula (13).

The observation constitutes a vector:

Y＝[w(t _n )e(t _n )w(t _n+1 )e(t _n+1 )w(t _n+2 )e(t _n+2 )...w(t _N )e(t _N )] ^T (16)

the vector formed by the parameters to be determined by the position feedforward controller is as follows:

X＝[a ₀ a ₁ a ₂ ...a _n ] ^T (17)

solving the formula according to the least square method, the following formula can be obtained:

X ^* ＝(A ^T A) ^-1 A ^T Y (18)

wherein, X ^* A vector of estimated values of the parameter to be determined.

Then, with the position feedforward controller enabled, the weighted position control error is calculated:

then, judging whether the error of the position controller meets the performance index under the condition of enabling the position feedforward controller, and if the error meets the performance index, then, enabling X ^* As a parameter of the position feedforward controller. If the performance requirement is not met, updating the adjustable parameters, and executing step 301 until the error of the position controller meets the performance index under the condition that the position feedforward controller is enabled, stopping iteration, and obtaining X obtained by the last iteration ^* As a parameter of the position feedforward controller.

The adjustable parameters include the order (value of N) of the position feedforward controller, the weight corresponding to each moment, the value of N, and the like.

Several methods for determining whether the position controller error meets the performance criteria in the case of enabling the position feedforward controller are listed below:

the first method,

Computing

And if the sum of squares is less than a preset sum of squares threshold, determining that the performance index is met.

The second method,

Determining

And if the maximum absolute value is smaller than a preset error threshold, determining that the performance index is met.

The method for updating the adjustable parameters may be different according to different actual requirements, and several methods for updating the adjustable parameters are listed below:

one or more of the order of the position feedforward controller, the weight corresponding to each moment and the value of N can be updated.

1. Order for position feedforward controller

The order may be increased or decreased per iteration according to a preset step size. Wherein, the preset step length may be 1.

2. Weight corresponding to each time

Can be used for t ₀ To t _N/2 The corresponding weights are respectively increased by preset adjustment values for t _(N/2)+1 To t _N The corresponding weights are respectively reduced by preset adjustment values. Or, for t ₀ To t _N/2 The corresponding weights are respectively reduced by preset adjustment values for t _(N/2)+1 To t _N And respectively increasing preset adjusting values by the corresponding weights. Wherein, if N/2 is not an integer, then rounding up or rounding down is only needed.

3. Value for N

The value of N may be decreased or increased by a predetermined value.

In the related art, there is also a position feedforward controller using position differentiation, and in the case of the same controlled object, a corresponding position feedback controller, the position feedforward controller in the embodiment of the present application is used with a smaller position control error than when the position feedforward controller in the related art is used. A comparison of several schemes in actual simulation experiments is given below.

Fig. 4 is a graph showing a comparison of position feedback signals (position outputs) when the position feedforward controller is not used, the feedforward controller in the embodiment of the present application is used, and the position feedforward controller using the position derivative in the related art is used in the case where the position input signals are given all of the S-shaped curved trajectories for controlling the same controlled object.

Fig. 5 is a graph showing a comparison of a position control error map when the position feedforward controller is not used, the feedforward controller in the embodiment of the present application is used, and the position feedforward controller of the position derivative in the related art is used in the case where the position input signal is given as an S-shaped curved path while controlling the same controlled object.

Fig. 6 is a graph showing a comparison of position feedback signals when the position feedforward controller is not used, the feedforward controller in the embodiment of the present application is used, and the position feedforward controller using the position derivative in the related art is used in the case where the cosine curve locus is given to all the position input signals controlling the same controlled object.

Fig. 7 is a graph showing a comparison of position control errors when the position feedforward controller is not used, the feedforward controller in the embodiment of the present application is used, and the position feedforward controller using the position derivative in the related art is used in the case where the position input signals given to the same controlled object are all cosine-shaped curve paths.

In the above figures, "given" is the given position input signal, "without feedforward" is the position output when the position feedforward controller is not used, "with scheme feedforward" is the position output when the feedforward controller in the embodiment of the present application is used, and "with differential feedforward" is the position output when the position feedforward controller of the prior art using position differentiation is used.

As can be seen from the comparison of fig. 4, 5, 6, and 7, the position control error is smaller when the feedforward controller provided by the embodiment of the present application is used than when the position feedforward controller in the related art is used.

All the above optional technical solutions may be combined arbitrarily to form optional embodiments of the present application, and are not described herein again.

Based on the same technical concept, the embodiment of the present application further provides an apparatus for determining parameters of a position feedforward controller, referring to fig. 8, the apparatus includes an input module 810, an obtaining module 820, a determining module 830, and a fitting module 840, where:

an input module 810, configured to input a preset position input signal to the servo position controller;

an obtaining module 820, configured to obtain a position feedback signal of a controlled object when the servo position controller does not start a position feedforward controller, where the position feedforward controller is a finite-length single-bit impulse response FIR filter;

a determining module 830, configured to determine a position control error according to the preset position input signal and the position feedback signal;

and a fitting module 840, configured to obtain the parameter of the position feedforward controller through least square fitting according to the position control error and a gain of a position feedback controller in the servo position controller.

In one possible implementation manner, the determining module is configured to:

determining an observed value according to the position control error;

In a possible implementation manner, the obtaining module 830 is configured to:

the fitting module 840 is configured to:

The fitting module 840 is configured to:

w (t) _k )e(t _k ) As observed value, where N ≦ k ≦ N, t _k Represents the kth time, w (t), of the N times _k ) Is the weight corresponding to the k-th time, e (t) _k ) And controlling the error for the position corresponding to the kth moment.

In one possible implementation manner, the fitting module 840 is configured to:

It should be noted that: in the above embodiment, when determining the parameter of the position feedforward controller, the division of each function module is merely used for illustration, and in practical applications, the function distribution may be completed by different function modules according to needs, that is, the internal structure of the apparatus may be divided into different function modules to complete all or part of the functions described above. In addition, the apparatus for determining the parameter of the position feedforward controller and the method for determining the parameter of the position feedforward controller provided in the above embodiments belong to the same concept, and the specific implementation process thereof is detailed in the method embodiment, and will not be described again here.

Fig. 9 shows a block diagram of a terminal 900 according to an exemplary embodiment of the present application. The terminal 900 may be a portable mobile terminal such as: a smart phone, a tablet computer, an MP3 player (Moving Picture Experts Group Audio Layer III, motion Picture Experts compression standard Audio Layer 3), an MP4 player (Moving Picture Experts Group Audio Layer IV, motion Picture Experts compression standard Audio Layer 4), a notebook computer, or a desktop computer. Terminal 900 may also be referred to by other names such as user equipment, portable terminals, laptop terminals, desktop terminals, and the like.

In general, terminal 900 includes: a processor 901 and a memory 902.

Processor 901 may include one or more processing cores, such as a 4-core processor, an 8-core processor, and so on. The processor 901 may be implemented in at least one hardware form of a DSP (Digital Signal Processing), an FPGA (Field-Programmable Gate Array), and a PLA (Programmable Logic Array). The processor 901 may also include a main processor and a coprocessor, where the main processor is a processor for Processing data in an awake state, and is also called a Central Processing Unit (CPU); a coprocessor is a low power processor for processing data in a standby state. In some embodiments, the processor 901 may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content required to be displayed by the display screen. In some embodiments, the processor 901 may further include an AI (Artificial Intelligence) processor for processing computing operations related to machine learning.

Memory 902 may include one or more computer-readable storage media, which may be non-transitory. Memory 902 may also include high-speed random access memory, as well as non-volatile memory, such as one or more magnetic disk storage devices, flash memory storage devices. In some embodiments, a non-transitory computer readable storage medium in memory 902 is used to store at least one instruction for execution by processor 901 to implement a method of determining parameters of a position feedforward controller as provided by method embodiments herein.

In some embodiments, terminal 900 can also optionally include: a peripheral interface 903 and at least one peripheral. The processor 901, memory 902, and peripheral interface 903 may be connected by buses or signal lines. Various peripheral devices may be connected to the peripheral interface 903 via a bus, signal line, or circuit board. Specifically, the peripheral device includes: at least one of a radio frequency circuit 904, a display screen 905, a camera assembly 906, an audio circuit 907, a positioning assembly 908, and a power supply 909.

The peripheral interface 903 may be used to connect at least one peripheral related to I/O (Input/Output) to the processor 901 and the memory 902. In some embodiments, the processor 901, memory 902, and peripheral interface 903 are integrated on the same chip or circuit board; in some other embodiments, any one or two of the processor 901, the memory 902 and the peripheral interface 903 may be implemented on a separate chip or circuit board, which is not limited by this embodiment.

The Radio Frequency circuit 904 is used for receiving and transmitting RF (Radio Frequency) signals, also called electromagnetic signals. The radio frequency circuitry 904 communicates with communication networks and other communication devices via electromagnetic signals. The radio frequency circuit 904 converts an electrical signal into an electromagnetic signal to transmit, or converts a received electromagnetic signal into an electrical signal. Optionally, the radio frequency circuit 904 comprises: an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, a subscriber identity module card, and so forth. The radio frequency circuit 904 may communicate with other terminals via at least one wireless communication protocol. The wireless communication protocols include, but are not limited to: the world wide web, metropolitan area networks, intranets, generations of mobile communication networks (2G, 3G, 4G, and 5G), wireless local area networks, and/or WiFi (Wireless Fidelity) networks. In some embodiments, the radio frequency circuit 904 may further include NFC (Near Field Communication) related circuits, which are not limited in this application.

The display screen 905 is used to display a UI (User Interface). The UI may include graphics, text, icons, video, and any combination thereof. When the display screen 905 is a touch display screen, the display screen 905 also has the ability to capture touch signals on or over the surface of the display screen 905. The touch signal may be input to the processor 901 as a control signal for processing. At this point, the display 905 may also be used to provide virtual buttons and/or a virtual keyboard, also referred to as soft buttons and/or a soft keyboard. In some embodiments, the display 905 may be one, disposed on the front panel of the terminal 900; in other embodiments, the number of the display panels 905 may be at least two, and each of the display panels is disposed on a different surface of the terminal 900 or is in a foldable design; in other embodiments, the display 905 may be a flexible display disposed on a curved surface or a folded surface of the terminal 900. Even more, the display screen 905 may be arranged in a non-rectangular irregular figure, i.e. a shaped screen. The Display panel 905 can be made of LCD (Liquid Crystal Display), OLED (Organic Light-Emitting Diode), and other materials.

The camera assembly 906 is used to capture images or video. Optionally, camera assembly 906 includes a front camera and a rear camera. Generally, a front camera is disposed at a front panel of the terminal, and a rear camera is disposed at a rear surface of the terminal. In some embodiments, the number of the rear cameras is at least two, and each rear camera is any one of a main camera, a depth-of-field camera, a wide-angle camera and a telephoto camera, so that the main camera and the depth-of-field camera are fused to realize a background blurring function, and the main camera and the wide-angle camera are fused to realize panoramic shooting and VR (Virtual Reality) shooting functions or other fusion shooting functions. In some embodiments, camera assembly 906 may also include a flash. The flash lamp can be a monochrome temperature flash lamp or a bicolor temperature flash lamp. The double-color-temperature flash lamp is a combination of a warm-light flash lamp and a cold-light flash lamp, and can be used for light compensation at different color temperatures.

Audio circuit 907 may include a microphone and a speaker. The microphone is used for collecting sound waves of a user and the environment, converting the sound waves into electric signals, and inputting the electric signals to the processor 901 for processing, or inputting the electric signals to the radio frequency circuit 904 for realizing voice communication. For stereo sound acquisition or noise reduction purposes, the microphones may be multiple and disposed at different locations of the terminal 900. The microphone may also be an array microphone or an omni-directional pick-up microphone. The speaker is used to convert electrical signals from the processor 901 or the radio frequency circuit 904 into sound waves. The loudspeaker can be a traditional film loudspeaker or a piezoelectric ceramic loudspeaker. When the speaker is a piezoelectric ceramic speaker, the speaker can be used for purposes such as converting an electric signal into a sound wave audible to a human being, or converting an electric signal into a sound wave inaudible to a human being to measure a distance. In some embodiments, audio circuit 907 may also include a headphone jack.

The positioning component 908 is used to locate a current geographic Location of the terminal 900 for navigation or LBS (Location Based Service). The Positioning component 908 may be a Positioning component based on the Global Positioning System (GPS) in the united states, the beidou System in china, or the galileo System in russia.

Power supply 909 is used to provide power to the various components in terminal 900. The power source 909 may be alternating current, direct current, disposable or rechargeable. When the power source 909 includes a rechargeable battery, the rechargeable battery may be a wired rechargeable battery or a wireless rechargeable battery. The wired rechargeable battery is a battery charged through a wired line, and the wireless rechargeable battery is a battery charged through a wireless coil. The rechargeable battery may also be used to support fast charge technology.

In some embodiments, terminal 900 can also include one or more sensors 910. The one or more sensors 910 include, but are not limited to: acceleration sensor 911, gyro sensor 912, pressure sensor 913, fingerprint sensor 914, optical sensor 915, and proximity sensor 916.

The acceleration sensor 911 can detect the magnitude of acceleration in three coordinate axes of the coordinate system established with the terminal 900. For example, the acceleration sensor 911 may be used to detect the components of the gravitational acceleration in three coordinate axes. The processor 901 can control the display screen 905 to display the user interface in a landscape view or a portrait view according to the gravitational acceleration signal collected by the acceleration sensor 911. The acceleration sensor 911 may also be used for acquisition of motion data of a game or a user.

The gyro sensor 912 may detect a body direction and a rotation angle of the terminal 900, and the gyro sensor 912 may cooperate with the acceleration sensor 911 to acquire a 3D motion of the user on the terminal 900. The processor 901 can implement the following functions according to the data collected by the gyro sensor 912: motion sensing (such as changing the UI according to a user's tilting operation), image stabilization at the time of photographing, game control, and inertial navigation.

The pressure sensor 913 may be disposed on a side bezel of the terminal 900 and/or underneath the display 905. When the pressure sensor 913 is disposed on the side frame of the terminal 900, the user's holding signal of the terminal 900 may be detected, and the processor 901 performs left-right hand recognition or shortcut operation according to the holding signal collected by the pressure sensor 913. When the pressure sensor 913 is disposed at a lower layer of the display screen 905, the processor 901 controls the operability control on the UI interface according to the pressure operation of the user on the display screen 905. The operability control comprises at least one of a button control, a scroll bar control, an icon control, and a menu control.

The fingerprint sensor 914 is used for collecting a fingerprint of the user, and the processor 901 identifies the user according to the fingerprint collected by the fingerprint sensor 914, or the fingerprint sensor 914 identifies the user according to the collected fingerprint. Upon recognizing that the user's identity is a trusted identity, processor 901 authorizes the user to perform relevant sensitive operations including unlocking the screen, viewing encrypted information, downloading software, paying, and changing settings, etc. The fingerprint sensor 914 may be disposed on the front, back, or side of the terminal 900. When a physical key or vendor Logo is provided on the terminal 900, the fingerprint sensor 914 may be integrated with the physical key or vendor Logo.

The optical sensor 915 is used to collect ambient light intensity. In one embodiment, the processor 901 may control the display brightness of the display screen 905 based on the ambient light intensity collected by the optical sensor 915. Specifically, when the ambient light intensity is high, the display brightness of the display screen 905 is increased; when the ambient light intensity is low, the display brightness of the display screen 905 is reduced. In another embodiment, the processor 901 may also dynamically adjust the shooting parameters of the camera assembly 906 according to the ambient light intensity collected by the optical sensor 915.

Proximity sensor 916, also known as a distance sensor, is typically disposed on the front panel of terminal 900. The proximity sensor 916 is used to collect the distance between the user and the front surface of the terminal 900. In one embodiment, when the proximity sensor 916 detects that the distance between the user and the front face of the terminal 900 gradually decreases, the processor 901 controls the display 905 to switch from the bright screen state to the dark screen state; when the proximity sensor 916 detects that the distance between the user and the front surface of the terminal 900 gradually becomes larger, the display 905 is controlled by the processor 901 to switch from the breath screen state to the bright screen state.

Those skilled in the art will appreciate that the configuration shown in fig. 9 does not constitute a limitation of terminal 900, and may include more or fewer components than those shown, or may combine certain components, or may employ a different arrangement of components.

Fig. 10 is a schematic structural diagram of a computer device according to an embodiment of the present application, where the computer device 1000 may have a relatively large difference due to different configurations or performances, and may include one or more processors 1001 and one or more memories 1002, where the memory 1002 stores at least one instruction, and the at least one instruction is loaded and executed by the processors 1001 to implement the methods provided by the foregoing method embodiments. Certainly, the computer device may further have a wired or wireless network interface, a keyboard, an input/output interface, and other components to facilitate input and output, and the computer device may further include other components for implementing functions of the device, which are not described herein again.

In an exemplary embodiment, a computer-readable storage medium, such as a memory including instructions executable by a processor in a terminal, is also provided to perform the method of determining parameters of a position feedforward controller in the above-described embodiments. The computer readable storage medium may be non-transitory. For example, the computer-readable storage medium may be a ROM (Read-Only Memory), a RAM (Random Access Memory), a CD-ROM (Compact Disc Read-Only Memory), a magnetic tape, a floppy disk, an optical data storage device, and the like.

It should be noted that information (including but not limited to user equipment information, user personal information, etc.), data (including but not limited to data for analysis, stored data, displayed data, etc.) and signals (including but not limited to signals transmitted between a user terminal and other equipment, collected position feedback signals output by a controlled object, etc.) referred to in the present application are authorized by a user or sufficiently authorized by each party, and the collection, use and processing of related data need to comply with relevant laws and regulations and standards of relevant countries and regions. For example, the position feedback signals referred to in this application are all obtained with sufficient authorization.

It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by a program instructing relevant hardware, where the program may be stored in a computer-readable storage medium, and the storage medium may be a read-only memory, a magnetic disk or an optical disk.

The above description is intended only to illustrate the alternative embodiments of the present application, and should not be construed as limiting the present application, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method of determining parameters of a position feedforward controller, the method comprising:

inputting a preset position input signal to a servo position controller;

2. The method of claim 1, wherein the transfer function of the position feedforward controller is:

F(z)＝(1-z ^-1 )(a ₀ +a ₁ z ^-1 +a ₂ z ^-2 +…+a _n z ^-n ) Wherein F (z) is a transfer function of the position feedforward controller, z is a complex variable in a discrete domain, a ₀ 、a ₁ 、a ₂ …a _n And n is the order of the position feedforward controller, wherein the parameter is a parameter to be determined by the position feedforward controller.

3. The method of claim 1 or 2, wherein the obtaining the parameters of the position feedforward controller by least-squares fitting according to the position control error and a gain of a position feedback controller in the servo position controller comprises:

determining an observed value according to the position control error;

4. The method of claim 3, wherein the obtaining of the position feedback signal of the controlled object comprises:

determining position control errors corresponding to the N moments respectively according to the preset position input signals at the N moments and the position feedback signals at the N moments;

5. The method of claim 4, wherein determining an observed variable based on the position feedback signal and a gain of the position feedback controller comprises:

w (t) _k )[h(t _k )，h(t _k-1 )，h(t _k-2 )...，h(t _k-n )]As an observation variable, it is possible, among others,

6. An apparatus for determining parameters of a position feedforward controller, the apparatus comprising:

the servo position controller is used for controlling the position of the controlled object to be in a continuous mode, and the servo position controller is used for controlling the position of the controlled object to be in a continuous mode;

7. The apparatus of claim 6, wherein the transfer function of the position feedforward controller is:

F(z)＝(1-z ^-1 )(a ₀ +a ₁ z ^-1 +a ₂ z ^-2 +...+a _n z ^-n ) Wherein F (z) is a transfer function of the position feedforward controller, z is a complex variable in a discrete domain, a ₀ 、a ₁ 、a ₂ ...a _n And n is the order of the position feedforward controller, wherein the parameter is a parameter to be determined by the position feedforward controller.

8. The apparatus of claim 6 or 7, wherein the fitting module is configured to:

determining an observation value according to the position control error;

9. The apparatus of claim 8, wherein the obtaining module is configured to:

the fitting module is configured to:

10. The apparatus of claim 9, wherein the fitting module is configured to:

11. A computer device comprising a processor and a memory, the memory having stored therein at least one instruction that is loaded and executed by the processor to perform operations performed by a method of determining a parameter of a position feedforward controller as claimed in any one of claims 1 to 5.

12. A computer-readable storage medium having stored therein at least one instruction, which is loaded and executed by a processor to perform operations performed by a method of determining parameters of a position feedforward controller as claimed in any one of claims 1 to 5.