Interference on-line identification and compensation control method under switch control

Abstract

The invention discloses an on-line interference identification and compensation control method under switch control. The method comprises the following steps: (1) calculating a current quaternion deviation and a current attitude angular rate deviation; (2) calculating a control comprehensive signal according to the quaternion deviation and the attitude angular rate deviation; (3) generating a control duty ratio instruction from the control comprehensive signal through a correction network link and a gain correction link; (4) calculating a feedback path signal of the pseudo-rate modulator according to the switch control state; (5) on-line identifying disturbance torque according to the inertial measurement angle rate and the switch control state, and generating a disturbance compensation duty ratio instruction; and (6) integrating the control duty ratio instruction, the interference compensation duty ratio instruction and a modulator feedback path signal, generating a switch control instruction through a Schmitt trigger, and outputting the switch control instruction to an attitude control spray pipe. The invention aims to improve the control capability of the spacecraft under the time-varying large interference and improve the stability and the control precision of a control system.

Description

Technical Field

[0001] The invention relates to an interference online identification and compensation control method under switch control, belonging to the technical field of spacecraft control. Background Art

[0002] In the Mars sampling and return mission, the Mars ascender faces interference from the thin atmospheric environment and interference from the main thrust engine under the deviation of the center of mass lateral displacement structure during takeoff and ascent from the Mars surface, and there is a large interference uncertainty. At the same time, in terms of orbital parameters, both the orbit inclination constraint and the ascending node right ascension constraint have put forward higher precision requirements. Therefore, it is necessary to improve the attitude control accuracy of the Mars ascender under large interference uncertainty conditions and its stability under large interference. Due to the limitation of propellant weight resources, the ascender cannot use phase plane switch control throughout the process to obtain robustness and attitude control accuracy under large interference, and can only use a pseudo-rate pulse width modulation scheme that saves attitude control fuel. The traditional PID+pseudo-rate control scheme has a good control effect for constant interference, and can compensate for external interference through the integral link to obtain higher control accuracy. However, when facing fast time-varying interference, the integral has the problem of control compensation response lag. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, improve the spacecraft's anti-time-varying interference characteristics, and enhance the switch control accuracy under large time-varying interference.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A method for online interference identification and compensation control under switch control, comprising:

[0006] (1) Calculate the current quaternion deviation based on the program quaternion and the inertial measurement navigation quaternion, and calculate the current attitude angular rate deviation based on the program angular rate and the inertial measurement angular rate;

[0007] (2) Calculate the control integrated signal based on the quaternion deviation and the attitude angular rate deviation;

[0008] (3) The control integrated signal is passed through a correction network and gain correction to generate a control duty cycle instruction;

[0009] (4) calculating a pseudo rate modulator feedback path signal according to the switch control state;

[0010] (5) Based on the inertial measurement angular rate and switch control status, the disturbance torque is identified online and a disturbance compensation duty cycle instruction is generated;

[0011] (6) The integrated control duty cycle command, interference compensation duty cycle command and modulator feedback path signal are used to generate a switch control command through a Schmitt trigger and output to the attitude control nozzle.

[0012] In the above-mentioned on-line interference identification and compensation control method under switch control, the quaternion deviation and attitude angular rate deviation in step (1) are calculated according to the following formula:

[0013]

[0014] Among them, [q cx0 q cx1 q cx2 q cx3 ] T is the program quaternion, [q INS0 q INS1 q INS2 q INS3 ] T is the inertial navigation quaternion; is the quaternion deviation, is the program angular rate, is the inertial measurement angular rate, is the attitude angular rate deviation.

[0015] In the above-mentioned method for online interference identification and compensation control under switch control, the control integrated signal in step (2) is calculated according to the following formula:

[0016] u cα (k) = 2K Pα q eα +K Dα ω eα +u Iα (k)

[0017]

[0018] in, is the quaternion bias of the alpha channel, is the α channel attitude angular rate deviation, is the quaternion deviation gain coefficient of the α channel, is the quaternion deviation integral gain coefficient of the α channel, is the α channel angular rate deviation gain coefficient, ΔT zk is the quaternion deviation integration time period, It is the value of the k-th quaternion deviation integral after clipping of the α channel. is the value of the k-th quaternion deviation integral before limiting in the α channel, u Imaxα is the integral limit value of the α channel, and Limit() is the general limit function. ψ, γ represent the pitch, yaw and roll channels respectively.

[0019] In the above-mentioned method for online interference identification and compensation control under switch control, the control integrated signal in step (3) is converted into a control duty cycle instruction through a correction network and gain correction, and is calculated according to the following formula:

[0020] u wlα (k) = u cα (k)

[0021]

[0022]

[0023] in, is the input of the α channel correction network, is the α channel correction network output, is the α channel correction network coefficient, is the α channel duty cycle instruction correction gain coefficient, is the α channel control duty cycle instruction, and n is the differential order of the correction network.

[0024] In the above-mentioned method for online interference identification and compensation control under switch control, the pseudo rate modulator feedback path signal in step (4) is calculated according to the following formula:

[0025]

[0026] in, is the feedback loop parameter of the pseudo rate modulator of the α channel, ΔT prm is the modulation period of the pseudo rate modulator, is the α channel switch instruction state, It is the feedback path signal of the α channel pseudo rate modulator.

[0027] In the above-mentioned on-line interference identification and compensation control method under switch control, the online identification interference torque and the interference compensation duty cycle instruction in step (5) are calculated according to the following formula:

[0028]

[0029] in, is the α channel interference compensation control gain coefficient, is the low-pass filter parameter of the α channel interference compensation channel, Calculate the intermediate value for α channel interference compensation, ΔT grbc is the disturbance compensation control calculation cycle, is the α channel interference compensation duty cycle instruction, is the identification value of the α channel disturbance torque coefficient, is the control torque coefficient of the α channel, is the angular rate signal of the α channel.

[0030] In the above-mentioned method for online interference identification and compensation control under switch control, the switch control instruction in step (6) is calculated according to the following formula:

[0031]

[0032]

[0033] in, is the α channel Schmitt trigger switch threshold, is the α channel Schmitt trigger switch loopback coefficient, It is the α channel duty cycle integrated signal, which is input to the Schmitt trigger. It is the α channel switch control instruction.

[0034] An electronic device, comprising:

[0035] Processor; and

[0036] a memory for storing computer program instructions;

[0037] When the computer program instructions are loaded and run by the processor, the processor executes the on-line interference identification and compensation control method under switch control.

[0038] A computer-readable storage medium stores computer program instructions, which, when loaded and run by a processor, enable the processor to execute the switch-controlled interference online identification and compensation control method.

[0039] A computer program product stored on a non-transitory computer readable medium includes program codes for implementing the switch-controlled interference online identification and compensation control method.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] (1) The algorithm of the present invention has weak dependence on model parameters, strong adaptability to nozzle delay, high interference observation accuracy, and still has high control accuracy under time-varying interference.

[0042] (2) The algorithm of the present invention is simple, and the rate signal is directly introduced into the interference observation, thereby avoiding the differentiation of the noisy rate signal, and the engineering practicability is strong.

[0043] (3) By identifying interference in real time and performing interference feedforward compensation, better anti-time-varying interference characteristics can be obtained.

[0044] (4) The disturbance observation compensation is combined with PID control, and the integral term is used to eliminate the compensation deviation, thereby improving the control accuracy of the pseudo-rate switch under time-varying disturbances. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a flowchart of the control method of the present invention;

[0046] Figure 2 It is a block diagram of the structure of online interference identification and compensation control under switch control;

[0047] Figure 3 is the simulation attitude angle control deviation curve of the present invention;

[0048] Figure 4 It is the interference online identification simulation result curve of the present invention. DETAILED DESCRIPTION

[0049] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0050] A method for online interference identification and compensation control under switch control, such as Figure 1 As shown, including:

[0051] Step (1), calculating the current quaternion deviation according to the program quaternion and the inertial measurement navigation quaternion, and calculating the current attitude angular rate deviation according to the program angular rate and the inertial measurement angular rate;

[0052] In this implementation, the quaternion deviation and attitude angular rate deviation are calculated as follows:

[0053]

[0054] Among them, [q cx0 q cx1 q cx2 q cx3 ] T is the program quaternion, [q INS0 q INS1 q INS2 q INS3 ] T is the inertial navigation quaternion; is the quaternion deviation, is the program angular rate, is the inertial measurement angular rate, is the attitude angular rate deviation. To ensure the smoothness of the control signal, the inertial measurement angular rate is the value after low-pass filtering.

[0055] Step (2), calculating a control integrated signal according to the quaternion deviation and the attitude angular rate deviation;

[0056] In this embodiment, the control integrated signal is calculated according to the following formula:

[0057] u cα (k) = 2K Pα q eα +K Dα ω eα +u Iα (k)

[0058]

[0059] in, is the quaternion bias of the alpha channel, is the α channel attitude angular rate deviation, is the quaternion deviation gain coefficient of the α channel, is the quaternion deviation integral gain coefficient of the α channel, is the α channel angular rate deviation gain coefficient, ΔT zk is the quaternion deviation integration time period, It is the value of the k-th quaternion deviation integral after clipping of the α channel. is the value of the k-th quaternion deviation integral before limiting in the α channel, u Imaxα is the integral limit value of the α channel, and Limit() is the general limit function. ψ and γ represent pitch, yaw and roll channels respectively. The gain coefficient is determined comprehensively based on the system stability margin and control index.

[0060] Step (3), generating a control duty cycle instruction by passing the control integrated signal through a correction network and gain correction;

[0061] In this embodiment, the control integrated signal is passed through the correction network and gain correction to generate the control duty cycle instruction according to the following formula:

[0062] u wlα (k) = u cα (k)

[0063]

[0064]

[0065] in, is the input of the α channel correction network, is the α channel correction network output, is the α channel correction network coefficient, is the α channel duty cycle instruction correction gain coefficient, is the α channel control duty cycle command, and n is the correction network differential order. The α channel correction network coefficient is determined according to the system sway and elastic stability margin. Duty cycle command correction gain coefficient K Gα It is determined comprehensively based on the system stability margin and control accuracy.

[0066] Step (4), calculating the pseudo rate modulator feedback path signal according to the switch control state;

[0067] In this embodiment, the pseudo rate modulator feedback path signal is calculated according to the following formula:

[0068]

[0069] in, is the feedback loop parameter of the pseudo rate modulator of the α channel, ΔT prm is the modulation period of the pseudo rate modulator, is the α channel switch instruction state, It is the feedback path signal of the pseudo rate modulator of the α channel. The parameters of the modulator feedback loop determine the performance of the modulator. In the parameter selection, while ensuring the pulse width modulation effect, it is necessary to ensure that the bandwidth of the inner loop of the pseudo rate modulation is higher than the control bandwidth of the outer loop, so that the control bandwidths of the inner and outer loops match.

[0070] Step (5), based on the inertial measurement angular rate and the switch control state, online identification of the interference torque and generation of an interference compensation duty cycle instruction;

[0071] In this embodiment, the online identification of the disturbance torque and the disturbance compensation duty cycle command are calculated according to the following formula:

[0072]

[0073] M1 α (k) = M1 α (k-1)+M0 α (k)ΔT grbc

[0074] M2 α (k) = M1 α (k)+ω INSα

[0075]

[0076] in, is the α channel interference compensation control gain coefficient, is the low-pass filter parameter of the α channel interference compensation channel, Calculate the intermediate value for α channel interference compensation, ΔT grbc is the disturbance compensation control calculation cycle, is the α channel interference compensation duty cycle instruction, is the identification value of the α channel disturbance torque coefficient, is the control torque coefficient of the α channel, is the angular rate signal of the α channel.

[0077] Step (6), comprehensively controlling the duty cycle instruction, the interference compensation duty cycle instruction and the modulator feedback path signal, generating a switch control instruction through a Schmitt trigger, and outputting it to the attitude control nozzle.

[0078] In this embodiment, the switch control instruction is calculated according to the following formula:

[0079]

[0080]

[0081] in, is the α channel Schmitt trigger switch threshold, is the α channel Schmitt trigger switch loopback coefficient, It is the α channel duty cycle integrated signal, which is input to the Schmitt trigger. is the α channel switch control instruction. Schmitt trigger switch threshold Determined according to the system's minimum working pulse duty cycle, the loop coefficient mα is mainly used to overcome system noise and prevent abnormal and frequent switching of the nozzle.

[0082] Taking the spacecraft under time-varying interference as the simulation object, the control method of the present invention and the traditional PID control method are simulated respectively. The control structure of the present invention is as follows: Figure 2 As shown in Figure 2. Under the same time-varying interference, the attitude control deviation curve is compared as Figure 3 As shown in the figure, it can be seen that the method of the present invention has better anti-time-varying interference characteristics and higher control accuracy than the traditional PID control method. The results of interference identification are shown in Figure 4 As shown, under the switch control mode, the control method of the present invention has higher accuracy and faster response speed for interference identification.

[0083] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

[0084] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for online interference identification and compensation control under switch control, characterized in that: include: (1) Calculate the current quaternion deviation based on the program quaternion and the inertial measurement navigation quaternion, and calculate the current attitude angular rate deviation based on the program angular rate and the inertial measurement angular rate; (2) Calculate the control integrated signal based on the quaternion deviation and the attitude angular rate deviation; (3) The control integrated signal is passed through a correction network and gain correction to generate a control duty cycle instruction; (4) calculating a pseudo rate modulator feedback path signal according to the switch control state; (5) Based on the inertial measurement angular rate and switch control status, the disturbance torque is identified online and a disturbance compensation duty cycle instruction is generated; (6) The integrated control duty cycle command, interference compensation duty cycle command and modulator feedback path signal are used to generate a switch control command through a Schmitt trigger and output to the attitude control nozzle.

2. The method for online interference identification and compensation control under switch control according to claim 1, characterized in that: The control integrated signal in step (2) is: u cα (k)=2K Pα q eα +K Dα ω eα +u Iα (k) in, is the quaternion bias of the alpha channel, is the α channel attitude angular rate deviation, is the quaternion deviation gain coefficient of the α channel, is the quaternion deviation integral gain coefficient of the α channel, is the α channel angular rate deviation gain coefficient, ΔT zk is the quaternion deviation integration time period, It is the value of the k-th quaternion deviation integral after clipping of the α channel. is the value of the k-th quaternion deviation integral before limiting in the α channel. is the integral limit value of the α channel, and Limit() is the general limit function; Represent the pitch, yaw and roll channels respectively.

3. The method for online interference identification and compensation control under switch control according to claim 1, characterized in that: The interference compensation duty cycle instruction in step (5) includes: in, is the α channel disturbance compensation control gain coefficient, K gr α , is the low-pass filter parameter of the α channel interference compensation channel, M0 α (k), M1 α (k) Calculate the intermediate value for α channel interference compensation, ΔT grbc is the disturbance compensation control calculation cycle, is the α channel interference compensation duty cycle instruction, is the identification value of the α channel disturbance torque coefficient, is the control torque coefficient of the α channel, is the angular rate signal of the α channel, It is the switch instruction status of α channel.

4. The method for online interference identification and compensation control under switch control according to claim 1, characterized in that: The quaternion deviation and attitude angular rate deviation in step (1) are calculated as follows: Among them, [q cx0 q cx1 q cx2 q cx3 ] T is the program quaternion, [q INS0 q INS1 q INS2 q INS3 ] T is the inertial navigation quaternion; is the quaternion deviation, is the program angular rate, is the inertial measurement angular rate, is the attitude angular rate deviation.

5. The method for online interference identification and compensation control under switch control according to claim 1, characterized in that: The control integrated signal in step (3) is converted into a control duty cycle command through a correction network and gain correction according to the following formula: in wlα (k)=u cα (k) in, is the input of the α channel correction network, is the α channel correction network output, is the α channel correction network coefficient, is the α channel duty cycle instruction correction gain coefficient, is the α channel control duty cycle instruction, and n is the differential order of the correction network.

6. The method for online interference identification and compensation control under switch control according to claim 1, characterized in that: The pseudo rate modulator feedback path signal in step (4) is calculated as follows: Among them, τ F α , is the feedback loop parameter of the pseudo rate modulator of the α channel, ΔT prm is the modulation period of the pseudo rate modulator, is the α channel switch instruction state, It is the feedback path signal of the α channel pseudo rate modulator.

7. The method for online interference identification and compensation control under switch control according to claim 1, characterized in that: The switch control command in step (6) is calculated according to the following formula: in, is the α channel Schmitt trigger switch threshold, is the α channel Schmitt trigger switch loopback coefficient, It is the α channel duty cycle integrated signal, which is input to the Schmitt trigger. It is the α channel switch control instruction.

8. An electronic device, comprising: processor; as well as a memory for storing computer program instructions; When the computer program instructions are loaded and executed by the processor, the processor performs the method according to any one of claims 1 to 7.

9. A computer-readable storage medium having computer program instructions stored thereon, wherein when the computer program instructions are loaded and executed by a processor, the processor is caused to execute the method according to any one of claims 1 to 7.

10. A computer program product stored on a non-transitory computer readable medium, the computer program product comprising a program code for carrying out the method according to any one of claims 1 to 7.

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