Rate stabilization method based on composite fixed-frequency disturbance compensation control

Abstract

This invention belongs to the field of automatic control technology, specifically to a rate stabilization method based on composite fixed-frequency disturbance compensation control. Based on an existing electro-optical aiming stabilization system, this method adds a composite fixed-frequency compensation controller to the traditional rate stabilization loop. This method utilizes a disturbance observer to improve low-frequency disturbance isolation. Furthermore, it leverages the high gain of the fixed-frequency compensation controller at a fixed frequency point to enhance the isolation of the rate stabilization loop at that fixed frequency point, effectively suppressing the impact of low- and mid-frequency disturbances on the line of sight and improving the overall stability accuracy of the control system. This method is implemented in software, requiring no additional hardware, and offers the advantages of a simple algorithm and strong operability.

Description

Technical Field

[0001] The present invention belongs to the field of automatic control technology, and specifically relates to a rate stabilization method based on composite fixed-frequency disturbance compensation control, and more particularly to a method for compensating a helicopter-borne electro-optical stabilization system for fixed-frequency disturbances caused by the helicopter's rotor. Background Art

[0002] To conduct ground-level image reconnaissance, helicopters often carry optoelectronic equipment for observing ground targets. However, due to disturbances such as aircraft vibration, attitude changes, and external wind resistance, the imaging quality of the optoelectronic sensors in these devices can drastically degrade, severely impacting the reconnaissance mission. Therefore, a gimbal-type gyro-stabilized platform is required to isolate these external disturbances, maintain the stability of the optoelectronic sensor's line of sight in inertial space, and thus ensure clear images. An optoelectronic stabilized aiming system is the device used to stabilize the line of sight and facilitate target search, aiming, and tracking.

[0003] An electro-optical stabilization system generally consists of an electro-optical sensor, a two-axis gimbaled platform, a rate gyro, a motor, and an electronic control unit. The electro-optical sensor and rate gyro are coaxially mounted on the two-axis gimbaled platform. The system operates as follows: when an external disturbance acts on the electro-optical stabilization system, the rate gyro mounted on the gimbaled platform senses and measures the angular velocity of the electro-optical sensor's line of sight in inertial space. This error signal, combined with the velocity command, forms an error signal. This error signal passes through a velocity stabilization control loop to generate a control voltage. This voltage is then driven by a driver to drive the motor, causing the stabilization platform to rotate in the opposite direction, thereby eliminating the velocity error and ensuring the stability of the line of sight in inertial space.

[0004] The principle diagram of the traditional rate stabilization loop is as follows Figure 1 As shown, u i The input control command of the rate stabilization loop and the platform angular rate signal sensed by the gyroscope 6 generate a speed error Δe through the first addition node 1 and form a closed-loop negative feedback. Δe generates a drive voltage u through the speed controller 2 v , and sent to the motor and drive 3 to form a driving torque T m , which is related to the external disturbance torque T d The second summing junction 4 acts on the load 5, ultimately generating the load's actual output angular rate ω0. To achieve good disturbance isolation, the speed controller 2 is generally designed as a combination of a two-stage integral and a one-stage lead controller. Through proper debugging of the traditional rate stabilization loop, the bandwidth of the closed-loop control system is no less than 20 Hz, and the gain of the stabilization loop open-loop transfer function at 1 Hz is greater than 40 dB.

[0005] For helicopter-mounted electro-optical stabilization systems, external disturbances primarily originate from vibrations caused by the aircraft's rotor and tail rotor. This vibration primarily consists of low-amplitude, broadband random vibrations and high-amplitude, fixed-frequency, periodic vibrations. Medium-frequency (15-25Hz) periodic disturbances have the largest amplitude. Traditional electro-optical stabilization systems, through their gyro-stabilized platform servo control systems, can isolate most low-frequency disturbances. However, their ability to isolate medium-frequency disturbances from the aircraft is weak. When the magnitude of medium-frequency vibrations from the aircraft is high, the electro-optical stabilization system still cannot achieve adequate external disturbance isolation.

[0006] Regarding this issue, no foreign literature on electro-optical stabilization systems has reported methods specifically for suppressing fixed-frequency disturbances in helicopters. The domestic patent [201418005217.2], "A Control Method for Suppressing Fixed-Frequency Disturbances in Airborne Electro-Optical Stabilization Systems," proposes a method for compensating for fixed-frequency disturbances by connecting a fixed-frequency disturbance compensation controller in series with a rate stabilization controller. By properly adjusting the controller, this method can generally achieve a relatively ideal fixed-frequency disturbance isolation effect. However, since this method connects the fixed-frequency compensation controller in series with the forward path of the rate stabilization control loop, and the fixed-frequency compensation controller is a series connection of multiple second-order oscillating links, it significantly impacts the stability of the original system's closed-loop control loop, significantly limiting the effectiveness of the fixed-frequency compensation. The more fixed-frequency disturbance frequencies that need to be suppressed, the greater the impact on the stability of the original system's closed-loop control loop. Summary of the Invention

[0007] (1) Technical issues to be resolved

[0008] The technical problem to be solved by the present invention is: in view of the influence of helicopter vibration on the stability performance of the line of sight of the electro-optical stabilization system, how to provide a method that can effectively improve the helicopter's disturbance isolation capability, especially a method for effectively isolating fixed-frequency disturbances.

[0009] (2) Technical solution

[0010] To solve the above technical problems, the present invention provides a rate stabilization method based on composite fixed-frequency disturbance compensation control. During the implementation of the rate stabilization method based on composite fixed-frequency compensation control, the rate stabilization loop on which it relies includes: a first adding junction 1, a speed controller 2, a motor and drive 3, a second adding junction 4, a load platform 5, a gyroscope 6, and a composite fixed-frequency compensation controller 7; wherein the composite fixed-frequency compensation controller 7 also includes: a first fixed-frequency compensation controller 9 of a forward control loop and a disturbance observation controller 8 of a feedback channel;

[0011] The first fixed frequency compensation controller 9 is used to receive the first output command u output from the speed controller 2 v , after calculation, the first control command u is obtained c ;

[0012] The disturbance observation controller 8 is used to obtain the sampled current i from the motor and the drive 3 m , generate voltage command u f At the same time, the disturbance observation controller 8 is also used to obtain the platform motion angular velocity signal u of the gyroscope 6 g , and the platform motion angular velocity signal u g After fixed frequency compensation and differential filtering, the voltage command u is generated df ; The voltage command u f With voltage command u df After the combined processing in the disturbance observation controller 8, the estimated disturbance voltage is generated, that is, the second control command u d ;

[0013] In one servo control cycle, the rate stabilization method based on composite fixed-frequency compensation control includes the following steps:

[0014] The first step is to obtain the input command u of the rate stabilization loop i and the platform motion angular velocity signal u fed back by gyroscope 6 g , the speed error signal Δe is generated by the first addition node 1, and Δe is input to the speed controller 2 to obtain the first output command u v ;

[0015] In the second step, the first output command u v As the input command of the first fixed-frequency compensation controller 9, the first control command u is obtained through calculation by the first fixed-frequency compensation controller 9. c ;

[0016] The third step is to sample the current i of the motor and the driver 3. m and the platform motion angular velocity signal u fed back by gyroscope 6 g As the input of the disturbance observation controller 8, the second control command u is obtained by calculation of the disturbance observation controller 8. d ;

[0017] Step 4: the first control command u of the first fixed frequency compensation controller 9 is c and the second control command u of the disturbance observation controller 8 d After the third addition operation, the difference is obtained to obtain the command Δe c , Δe c Output as input control command to motor and driver 3;

[0018] Step 5: The motor and driver 3 are controlled according to the input control command Δe c , forming a driving torque T m , driving torque T m With the external disturbance torque T dThe second adding junction 4 acts on the load platform 5, and finally generates the actual output angular rate ω0 of the load platform 5;

[0019] By running steps 1 to 5 in each cycle of the rate stabilization loop, rate stabilization based on compound fixed-frequency compensation control can be completed.

[0020] Among them, in the second step, the calculation of the first fixed-frequency compensation controller 9 is:

[0021] u v G1(s)=u c ;

[0022] Wherein, G1(s) is the function form of the first fixed-frequency compensation controller 9.

[0023] The first fixed-frequency compensation controller 9 is composed of a plurality of second-order oscillation links connected in series, and its function form is as follows:

[0024]

[0025] Where n is the number of fixed-frequency disturbances that need to be compensated; ω i is the frequency of the i-th fixed-frequency disturbance to be suppressed; k i e is the frequency selection width of the first fixed-frequency compensation controller 9 corresponding to the i-th fixed-frequency disturbance to be compensated; i For the corresponding ω i Band damping coefficient; s is the Laplace transform differential operator in the time domain, by adjusting k i and e i The value of can adjust the bandwidth and gain of the composite fixed frequency compensation controller 7, that is, adjust the fixed frequency ω i The frequency selection width and depth of the disturbance compensation controller.

[0026] The composite fixed-frequency compensation controller 7 has a large amplitude-frequency gain at the fixed-frequency point, which can improve the rate stabilization loop's response to disturbances T d The isolation capability at this frequency point effectively suppresses the jitter of the aiming line at this fixed frequency point.

[0027] The disturbance observation controller 8 includes: a low-pass filter 12 , a second fixed-frequency compensation controller 10 , a differential filter 11 , a fourth addition junction, and a gain term 13 .

[0028] Among them, the sampling current i m The voltage command u is generated by the low-pass filter 12 f , the platform motion angular velocity signal u output by gyroscope 6 g The voltage command u is generated through the second fixed-frequency compensation controller 10 and the differential filter 11 df , the voltage command uf With voltage command u df The estimated disturbance voltage, ie, the second control command u is finally generated through the fourth addition node and the gain term 13. d .

[0029] Among them, the transfer function of the second fixed-frequency compensation controller 10 is the same as that of the first fixed-frequency compensation controller 9 in the forward channel and has the same parameters. The second fixed-frequency compensation controller 10 can balance and weaken the influence of the deterioration of the forward channel stability caused by the first fixed-frequency compensation controller 9 being connected in series with the forward channel, thereby ensuring the robustness of the system.

[0030] Wherein, the sampling current i m The voltage command u is generated by the low-pass filter 12 f The process is:

[0031] i m Q1(s)=u f ;

[0032] Wherein, Q1(s) is the transfer function of the low-pass filter 12 .

[0033] The platform motion angular velocity signal u output by the gyroscope 6 is g The voltage command u is generated through the second fixed-frequency compensation controller 10 and the differential filter 11 df The process is:

[0034] u g G1(s)=u' c ;

[0035] u' c Q0(s)=u df ;

[0036] Wherein, Q0(s) is the transfer function form of the differential filter 11;

[0037] u' c is the control command output by the second fixed-frequency compensation controller 10;

[0038] The transfer function of the second fixed-frequency compensation controller 10 is consistent with that of the first fixed-frequency compensation controller 9, and is G1(s).

[0039] The transfer functions of the differential filter 11 and the low-pass filter 12 are respectively as follows:

[0040]

[0041]

[0042] Where, ω fis the cutoff frequency of the second-order low-pass filter, e0 is the damping coefficient of the filter, K u It is related to the current torque coefficient and the moment of inertia for matching gain.

[0043] (3) Beneficial effects

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] (1) Compared with the traditional stabilization control method, the method of the present invention proposes compensation measures for fixed-frequency disturbances, and realizes disturbance compensation of a specific frequency point through a fixed-frequency compensation controller; the patent No. [201418005217.2] realizes the control of the fixed-frequency point by connecting a fixed-frequency compensation controller in series in the forward channel, but reduces the stability of the stabilization control loop. Compared with the aforementioned patent, the method of the present invention introduces a disturbance observer, and at the same time connects the same fixed-frequency compensation controller as the forward channel in series in the disturbance observation channel. This configuration offsets the influence of the applied fixed-frequency compensation controller on the stability of the stabilization loop, thereby greatly improving the stability of the stabilization control loop.

[0046] (2) The method of the present invention can simultaneously add multiple fixed-frequency compensation controllers of different frequencies, thereby suppressing the fixed-frequency disturbances of multiple frequencies, while improving the isolation capability of these frequencies without affecting the stability of the system closed-loop control loop;

[0047] (3) While ensuring the robustness of the control system, the method of the present invention significantly enhances the isolation of the control system at a specified frequency point and eliminates the fixed-frequency disturbance component of the carrier aircraft's main vibration. Experiments have shown that its disturbance isolation capability can be increased by more than 3 times.

[0048] (4) The method of the present invention can be completely implemented by software without adding additional hardware equipment. It has a simple algorithm, is easy to implement, has good portability, and is highly versatile. It can also be used in various other types of rotorcraft and rotor UAV electro-optical stabilization control systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Schematic diagram of a traditional rate stabilization loop.

[0050] Figure 2 Schematic diagram of the rate stabilization loop with a composite fixed-frequency compensation controller.

[0051] Figure 3 This is the schematic diagram of the disturbance observer controller. DETAILED DESCRIPTION

[0052] In order to make the purpose, content, and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below with reference to the accompanying drawings and examples.

[0053] In order to solve the above technical problems, the present invention provides a rate stabilization method based on composite fixed-frequency disturbance compensation control. The method adds a composite fixed-frequency compensation controller 7 on the basis of the traditional rate stabilization loop. Figure 2 As shown. During the implementation of the rate stabilization method based on composite fixed-frequency compensation control, the rate stabilization loop includes: a first addition junction 1, a speed controller 2, a motor and drive 3, a second addition junction 4, a load platform 5, a gyroscope 6, and a composite fixed-frequency compensation controller 7; wherein, the composite fixed-frequency compensation controller 7 also includes: a first fixed-frequency compensation controller 9 of the forward control loop and a disturbance observation controller 8 of the feedback channel;

[0054] The first fixed frequency compensation controller 9 is used to receive the first output command u output from the speed controller 2 v , after calculation, the first control command u is obtained c ;

[0055] The disturbance observation controller 8 is used to obtain the sampled current i from the motor and the drive 3 m , generate voltage command u f At the same time, the disturbance observation controller 8 is also used to obtain the platform motion angular velocity signal u of the gyroscope 6 g , and the platform motion angular velocity signal u g After fixed frequency compensation and differential filtering, the voltage command u is generated df ; The voltage command u f With voltage command u df After the combined processing in the disturbance observation controller 8, the estimated disturbance voltage is generated, that is, the second control command u d ;

[0056] In one servo control cycle, the rate stabilization method based on composite fixed-frequency compensation control includes the following steps:

[0057] The first step is to obtain the input command u of the rate stabilization loop i and the platform motion angular velocity signal u fed back by gyroscope 6 g , the speed error signal Δe is generated by the first addition node 1, and Δe is input to the speed controller 2 to obtain the first output command u of the traditional rate stabilization controller v ;

[0058] In the second step, the first output command u v As the input command of the first fixed-frequency compensation controller 9, the first control command u is obtained through calculation by the first fixed-frequency compensation controller 9. c ;

[0059] The third step is to sample the current i of the motor and the driver 3. mand the platform motion angular velocity signal u fed back by gyroscope 6 g As the input of the disturbance observation controller 8, the second control command u is obtained by calculation of the disturbance observation controller 8. d ;

[0060] Step 4: the first control command u of the first fixed frequency compensation controller 9 is c and the second control command u of the disturbance observation controller 8 d After the third addition operation, the difference is obtained to obtain the command Δe c , Δe c Output as input control command to motor and driver 3;

[0061] Step 5: The motor and driver 3 are controlled according to the input control command Δe c , forming a driving torque T m , driving torque T m With the external disturbance torque T d The second adding junction 4 acts on the load platform 5, and finally generates the actual output angular rate ω0 of the load platform 5;

[0062] By running steps 1 to 5 in each cycle of the rate stabilization loop, rate stabilization based on compound fixed-frequency compensation control can be completed.

[0063] Among them, in the second step, the calculation of the first fixed-frequency compensation controller 9 is:

[0064] u v G1(s)=u c ;

[0065] Wherein, G1(s) is the function form of the first fixed-frequency compensation controller 9.

[0066] The first fixed-frequency compensation controller 9 is composed of a plurality of second-order oscillation links connected in series, and its function form is as follows:

[0067]

[0068] Where n is the number of fixed-frequency disturbances that need to be compensated; ω i is the frequency of the i-th fixed-frequency disturbance to be suppressed; k i e is the frequency selection width of the first fixed-frequency compensation controller 9 corresponding to the i-th fixed-frequency disturbance to be compensated; i For the corresponding ω i Band damping coefficient; s is the Laplace transform differential operator in the time domain, by adjusting k i and e i The value of can adjust the bandwidth and gain of the composite fixed frequency compensation controller 7, that is, adjust the fixed frequency ω iThe frequency selection width and depth of the disturbance compensation controller.

[0069] The composite fixed-frequency compensation controller 7 has a large amplitude-frequency gain at the fixed-frequency point, which can improve the rate stabilization loop's response to disturbances T d The isolation capability at this frequency point effectively suppresses the jitter of the aiming line at this fixed frequency point.

[0070] The disturbance observation controller 8 is composed of the following components: Figure 3 As shown, the disturbance observation controller 8 includes: a low-pass filter 12 , a second fixed-frequency compensation controller 10 , a differential filter 11 , a fourth addition junction, and a gain term 13 .

[0071] Wherein, the sampling current i m The voltage command u is generated by the low-pass filter 12 f , the platform motion angular velocity signal u output by gyroscope 6 g The voltage command u is generated through the second fixed-frequency compensation controller 10 and the differential filter 11 df , the voltage command u f With voltage command u df The estimated disturbance voltage, ie, the second control command u is finally generated through the fourth addition node and the gain term 13. d .

[0072] Among them, the transfer function of the second fixed-frequency compensation controller 10 is the same as that of the first fixed-frequency compensation controller 9 in the forward channel and has the same parameters. The second fixed-frequency compensation controller 10 can balance and weaken the influence of the deterioration of the forward channel stability caused by the first fixed-frequency compensation controller 9 being connected in series with the forward channel, thereby ensuring the robustness of the system.

[0073] Wherein, the sampling current i m The voltage command u is generated by the low-pass filter 12 f The process is:

[0074] i m Q1(s)=u f ;

[0075] Wherein, Q1(s) is the transfer function of the low-pass filter 12 .

[0076] The platform motion angular velocity signal u output by the gyroscope 6 is g The voltage command u is generated through the second fixed-frequency compensation controller 10 and the differential filter 11 df The process is:

[0077] u g G1(s)=u' c ;

[0078] u'c Q0(s)=u df ;

[0079] Wherein, Q0(s) is the transfer function form of the differential filter 11;

[0080] u' c is the control command output by the second fixed-frequency compensation controller 10;

[0081] The transfer function of the second fixed-frequency compensation controller 10 is consistent with that of the first fixed-frequency compensation controller 9, and is G1(s).

[0082] The transfer functions of the differential filter 11 and the low-pass filter 12 are respectively as follows:

[0083]

[0084]

[0085] Where, ω f is the cutoff frequency of the second-order low-pass filter, e0 is the damping coefficient of the filter, K u It is related to the current torque coefficient and the moment of inertia for matching gain.

[0086] Example 1

[0087] This embodiment is a two-axis two-frame electro-optical stabilization system. The system includes three sensors: a TV sight, a thermal imager, and a laser light finder. The sensors are mounted on a gimbal platform to form a sensor load platform. The load platform is driven by a servo control unit. The composite fixed-frequency compensation controller of the present invention compensates for the gyro rate stabilization loop, such as Figure 2 shown.

[0088] The gyro rate stabilization loop includes an adder junction, a gyro stabilization control module, a motor drive module, and a two-degree-of-freedom rate gyro mounted on a sensor platform. The adder junction receives the speed control command u i And the angular velocity signal u of the gyro-sensitive sensor load platform g , generating a speed error signal and sending it to the gyro stabilization control module. The gyro stabilization control module uses a servo control algorithm to generate a motor drive command from the speed error signal and outputs it to the motor drive module. The motor drive module drives the sensor platform to move.

[0089] The present invention adds a composite fixed-frequency compensation controller 7 on the basis of the traditional rate stabilization loop. The composite fixed-frequency compensation controller 7 is directly connected in series to the traditional rate stabilization loop as an independent module. The method includes the following steps:

[0090] In the first step, the composite fixed-frequency compensation controller 7 is composed of the fixed-frequency compensation controller 9 of the forward control loop and the disturbance observation controller 8 of the feedback channel. The control commands u c and u d The difference is used as the final control command for the motor and drive. The disturbance observation controller 8 also includes a fixed frequency compensation controller 10;

[0091] The fixed-frequency compensation controller 9 and the fixed-frequency compensation controller 10 are both composed of a plurality of second-order oscillation links connected in series. The transfer functions of the fixed-frequency compensation controller 9 and the fixed-frequency compensation controller 10 are the same, as shown below:

[0092]

[0093] Where n is the number of fixed-frequency disturbances that need to be compensated; ω i is the frequency of the i-th fixed-frequency disturbance to be suppressed; k i is the frequency selection width of the fixed-frequency disturbance compensation controller corresponding to the i-th fixed-frequency disturbance to be compensated, k i The value of is between 0.05 and 0.2; i For the corresponding ω i Band damping coefficient, e i The value of k is between 0 and 0.02; by adjusting k i and e i The value of can adjust the bandwidth and gain of the fixed-frequency disturbance compensation controller.

[0094] In the second step, the disturbance observation controller 8 is composed as follows: Figure 3 As shown, the sampling current i m The voltage command u is generated by the low-pass filter 12 f , gyro output voltage signal u g The voltage command u is generated through the fixed frequency compensation controller 10 and the differential filter 11 df , it is related to u f The estimated disturbance voltage u is finally generated by the addition junction and the gain term 13 d The transfer function of the fixed-frequency compensation controller 10 is the same as that of the fixed-frequency compensation controller 9 in the forward channel and has the same parameters. It can balance and weaken the influence of the forward channel stability degradation caused by the fixed-frequency compensation controller 9 in series with the forward channel, thereby ensuring the robustness of the system. The transfer functions of the differential filter 11 and the low-pass filter 12 are shown below:

[0095]

[0096]

[0097] The third step is to obtain the input command u of the rate stabilization loop iAnd the load platform motion angular velocity signal u sensed by the gyroscope g ,u i and u g The speed error signal Δe is obtained by adding the difference, and Δe is input to the speed controller to obtain the output command u of the speed controller. v ;

[0098] Step 4, u v As the input command of the fixed frequency controller, the output command u is obtained through calculation by the fixed frequency controller. c ;

[0099] Step 5: Motor feedback current i m and the angular velocity command u fed back by the gyro g As the input of the disturbance observer, the output command u is obtained after calculation by the disturbance observer. d ;

[0100] Step 6: Output command u of fixed frequency controller c and the output command u of the disturbance observer d After adding the difference, we can get the command Δe c , Δe c Output as input command to the motor and drive;

[0101] Step 7: The motor and drive form a driving torque T m , which is related to the external disturbance torque T d The addition junction acts on the load platform, and finally generates the actual output angular rate ω0 of the load platform.

[0102] Step 8. Run steps 3 to 7 in each cycle of the rate stabilization loop.

[0103] Example 2

[0104] In the embodiment of the present invention, the main vibration frequency of the carrier is 21.5 Hz, and a basic composite fixed-frequency compensation controller is used. The implementation steps are as follows:

[0105] In the first step, the transfer function of the speed controller 2 of the rate stabilization loop in the preferred embodiment is designed as:

[0106]

[0107] In the second step, the composite fixed-frequency compensation controller 7 is directly connected in series to the traditional rate stabilization loop as an independent module. The fixed-frequency compensation controller is composed of one or more second-order oscillation links connected in series. If the main vibration frequency of the helicopter is 21.5 Hz, then n = 1, ω1 = 2·pi·21.5, k1 = 0.05, and e1 = 0.001 are selected. The transfer functions of the fixed-frequency compensation controller 9 and the fixed-frequency compensation controller 10 are as follows:

[0108]

[0109] The third step is to select the auxiliary Figure 3 The cutoff frequency ω of the differential filter 11 and the low-pass filter 12 in f =2·pi·100, e0=0.7, comprehensively consider the motor and moment of inertia of the selected example system to select the channel matching gain K u =0.11, the transfer function forms are as follows:

[0110]

[0111]

[0112] Step 4: Get the input command u of the rate stabilization loop i and the platform motion angular velocity signal u sensed by the gyroscope g ,u i and u g The speed error signal Δe is obtained by adding the difference, and Δe is input to the speed controller to obtain the output command u of the speed controller. v ;

[0113] Step 5, u v As the input of the fixed frequency compensation controller, the output command u is obtained through calculation by the fixed frequency controller. c ;

[0114] Step 6: Get the gyro's output voltage u g And the motor's feedback current signal i m , these two signals are used as the input of the disturbance observation controller, and the output voltage is u after the calculation of the disturbance observation controller. d ;

[0115] Step 7: Output command u of fixed frequency controller c and the output command u of the disturbance observer d After adding and performing the difference operation, we can get the command Δe c , Δe c Output as input command to the motor and drive;

[0116] Step 8: The motor and drive form a driving torque T m , which is related to the external disturbance torque T d Acting on the load platform through the addition junction, the actual output angular rate ω0 of the load platform is finally generated;

[0117] In step 9, steps 4 to 8 are executed in each cycle of the rate stabilization loop.

[0118] At 21.5 Hz, the amplitude-frequency characteristic curve has a large amplitude gain, which can suppress the 21.5 Hz fixed-frequency disturbance.

[0119] Example 3

[0120] The embodiment of the present invention is directed to an electro-optical stabilization system with two fixed-frequency vibration frequencies. Select n = 2, ω1 = 2*pi*12, k1 = 0.1, e1 = 0.01, ω2 = 2*pi*24, k2 = 0.1, and e2 = 0.01. The transfer functions of the fixed-frequency compensation controller 9 and the fixed-frequency compensation controller 10 are designed as follows:

[0121]

[0122] At 12Hz and 24Hz, the amplitude-frequency characteristic curve has a large amplitude gain, which can simultaneously suppress these two fixed-frequency disturbances. Based on this idea, this method can also achieve simultaneous suppression of fixed-frequency disturbances at multiple frequency points.

[0123] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A rate stabilization method based on composite fixed-frequency disturbance compensation control, characterized in that: During the implementation of the rate stabilization method based on the composite fixed-frequency disturbance compensation control, the rate stabilization loop on which it relies includes: a first adding junction (1), a speed controller (2), a motor and a drive (3), a second adding junction (4), a load platform (5), a gyroscope (6), and a composite fixed-frequency compensation controller (7); wherein the composite fixed-frequency compensation controller (7) further includes: a first fixed-frequency compensation controller (9) of a forward control loop and a disturbance observation controller (8) of a feedback channel; The first fixed-frequency compensation controller (9) is used to receive a first output command u outputted from the speed controller (2). v , after calculation, the first control command u is obtained c ; The disturbance observation controller (8) is used to obtain the sampled current i from the motor and the drive (3) m , generate voltage command u f At the same time, the disturbance observation controller (8) is also used to obtain the platform motion angular velocity signal u of the gyroscope (6) g , and the platform motion angular velocity signal u g After fixed frequency compensation and differential filtering, the voltage command u is generated df ; The voltage command u f With voltage command u df After the combined processing in the disturbance observation controller (8), the estimated disturbance voltage is generated, i.e., the second control command u d ; The disturbance observation controller (8) includes: a low-pass filter (12), a second fixed-frequency compensation controller (10), a differential filter (11), a fourth addition junction, and a gain term (13); Among them, the sampling current i m The voltage command u is generated by the low-pass filter (12) f , the platform motion angular velocity signal u output by the gyroscope (6) g The voltage command u is generated through the second fixed-frequency compensation controller (10) and the differential filter (11). df , the voltage command u f With voltage command u df The estimated disturbance voltage is finally generated through the fourth addition node and the gain term (13), that is, the second control command u d ; The transfer function of the second fixed-frequency compensation controller (10) is identical in form and parameters to the first fixed-frequency compensation controller (9) in the forward channel, and the second fixed-frequency compensation controller (10) is capable of balancing and weakening the influence of the forward channel stability degradation caused by the first fixed-frequency compensation controller (9) being serially connected to the forward channel, thereby ensuring the robustness of the system. In one servo control cycle, the rate stabilization method based on composite fixed-frequency compensation control includes the following steps: The first step is to obtain the input command u of the rate stabilization loop i and the platform motion angular velocity signal u fed back by the gyroscope (6) g , a speed error signal Δe is generated through the first addition junction (1), and Δe is input to the speed controller (2) to obtain the first output command u v ; In the second step, the first output command u v As the input command of the first fixed-frequency compensation controller (9), the first control command u is obtained through calculation by the first fixed-frequency compensation controller (9). c ; The third step is to sample the current i of the motor and drive (3) m and the platform motion angular velocity signal u fed back by the gyroscope (6) g As the input of the disturbance observation controller (8), the second control command u is obtained through calculation by the disturbance observation controller (8) d ; In the fourth step, the first control command u of the first fixed frequency compensation controller (9) is c and the second control command u of the disturbance observation controller (8) d After the third addition operation, the difference is obtained to obtain the command Δe c , Δe c Output as input control command to the motor and drive (3); Step 5: The motor and driver (3) are driven according to the input control command Δe c , forming a driving torque T m , driving torque T m With the external disturbance torque T d Acting on the load platform (5) through the second adding junction (4), the actual output angular rate ω0 of the load platform (5) is finally generated; By running steps 1 to 5 in each cycle of the rate stabilization loop, rate stabilization based on compound fixed-frequency compensation control can be completed.

2. The rate stabilization method based on composite fixed-frequency disturbance compensation control according to claim 1, characterized in that: In the second step, the calculation of the first fixed-frequency compensation controller (9) is: u v ·G1(s)=u c ; Wherein, G1(s) is the function form of the first fixed-frequency compensation controller (9).

3. The rate stabilization method based on composite fixed-frequency disturbance compensation control according to claim 2, characterized in that: The first fixed-frequency compensation controller (9) is composed of a plurality of second-order oscillation links connected in series, and its function form is as follows: Where n is the number of fixed-frequency disturbances that need to be compensated; ω i is the frequency of the i-th fixed-frequency disturbance to be suppressed; k i e is the frequency selection width of the first fixed-frequency compensation controller (9) corresponding to the i-th fixed-frequency disturbance to be compensated; i For the corresponding ω i Band damping coefficient; s is the Laplace transform differential operator in the time domain, by adjusting k i and e i The value of can adjust the bandwidth and gain of the composite fixed-frequency compensation controller (7), that is, adjust the fixed-frequency ω i The frequency selection width and depth of the disturbance compensation controller.

4. The rate stabilization method based on composite fixed-frequency disturbance compensation control according to claim 3, characterized in that: The composite fixed-frequency compensation controller (7) has a large amplitude-frequency gain at the fixed-frequency point, and can improve the rate stabilization loop's response to disturbances T d The isolation capability at this frequency point effectively suppresses the jitter of the aiming line at this fixed frequency point.

5. The rate stabilization method based on composite fixed-frequency disturbance compensation control according to claim 3, characterized in that: The sampling current i m The voltage command u is generated by the low-pass filter (12) f The process is: i m ·Q1(s)=u f ; Wherein, Q1(s) is the transfer function form of the low-pass filter (12).

6. The rate stabilization method based on composite fixed-frequency disturbance compensation control according to claim 5, characterized in that: The platform motion angular velocity signal u output by the gyroscope (6) g The voltage command u is generated through the second fixed-frequency compensation controller (10) and the differential filter (11). df The process is: u g ·G1(s)=u' c ; at' c ·Q0(s)=u df ; Where Q0(s) is the transfer function form of the differential filter (11); u' c A control command output by a second fixed-frequency compensation controller (10); The transfer function form of the second fixed-frequency compensation controller (10) is consistent with that of the first fixed-frequency compensation controller (9), and is also G1(s).

7. The rate stabilization method based on composite fixed-frequency disturbance compensation control according to claim 6, characterized in that: The transfer functions of the differential filter (11) and the low-pass filter (12) are respectively as follows: Where, ω f is the cutoff frequency of the second-order low-pass filter, e0 is the damping coefficient of the filter, K u It is related to the current torque coefficient and the moment of inertia for matching gain.

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