Digital frequency sweeping method and system suitable for pan-tilt debugging

Abstract

The invention provides a digital frequency sweeping method and system suitable for pan-tilt debugging, and the method comprises the following steps: a pan-tilt frequency sweeping module disposed in a pan-tilt control system generates an excitation signal according to a frequency sweeping parameter transmitted by a PC upper computer; generating a response signal based on the excitation signal; the sweep frequency parameter and the response signal are transmitted to the PC upper computer; and after analyzing the sweep frequency parameter and the response signal, the PC upper computer outputs a Bode diagram or delay information of image acquisition and processing. The system comprises an input unit, a PC upper computer and a pan-tilt frequency sweeping module, the PC upper computer comprises a communication module and an analysis module, the pan-tilt frequency sweeping module is deployed in a pan-tilt control system, and the pan-tilt frequency sweeping module comprises a communication unit and an excitation generator. Through the pan-tilt frequency sweeping module integrated in the servo system of the pan-tilt of the unmanned aerial vehicle, the pan-tilt frequency sweeping module not only can analyze the control system performance of inertial stability, automatic tracking and axial angle position locking of the pan-tilt of the unmanned aerial vehicle, but also can test the acquisition and processing delay of the image.

Description

Technical Field

[0001] The present invention relates to the field of unmanned aerial vehicle (UAV) gimbals, and in particular to a digital frequency sweeping method and system suitable for gimbal debugging. Background Art

[0002] The gimbal is an important part of the drone, mainly used to take images. The drone gimbal includes three basic functions: inertial stabilization, automatic tracking, and axis angle position locking. Inertial stabilization means that the gimbal uses two-axis or three-axis servo stabilization technology to take clear photos, and uses gyro feedback for closed-loop control to isolate the jitter during the flight of the drone. Automatic tracking means that the image processing unit of the gimbal uses an algorithm to track the target in the image, and uses the target pixel position as the position loop input of the gimbal control system to achieve the gimbal tracking of the target. Axis angle position locking means that the gimbal uses axis angle feedback for closed-loop control to lock the gimbal's visual axis to a specified axis angle.

[0003] During the debugging process of the UAV gimbal, the frequency response analyzer is often used to analyze the control system stability of the above three basic functions. The frequency response analyzer generates excitation signals of different frequencies. The gimbal control system generates different responses under the action of the excitation signal. The frequency response analyzer draws the Bode diagram according to the input and output of the UAV gimbal. The Bode diagram directly reflects the stability of the system during the debugging process, which helps engineers find the best control parameters.

[0004] Common frequency response analyzers have the disadvantages of being huge, complicated, expensive, inconvenient to carry, and analog input and output signals. As the PTZ is developing towards digitalization, miniaturization, low power consumption, and low cost, the low cost, miniaturization, and portability of frequency response analyzers are particularly important.

[0005] In addition, the image of the drone gimbal goes through exposure, transmission, reception, caching, image processing and other links from the camera to the image processing unit. These links are time-consuming, which is one of the key parameters affecting the automatic tracking performance of the gimbal. The commonly used method of calculating the time consumption of the drone gimbal output image often includes the time consumption of the later image encoding, decoding and display, and cannot directly measure the time from image acquisition to image processing by the image processing unit. Summary of the invention

[0006] In order to solve the problems of frequency characteristic response analyzer such as huge size, complicated functions, high price, inconvenient to carry, etc., the purpose of the present invention is to provide a digital frequency sweeping method and system suitable for gimbal debugging. Through the gimbal frequency sweeping module integrated in the servo system of the UAV gimbal, the gimbal frequency sweeping module can not only analyze the control system performance of the UAV gimbal's inertial stability, automatic tracking, and axis angle position locking, but also test the image acquisition and processing delay.

[0007] The technical solution for achieving the purpose of the present invention is as follows:

[0008] On the one hand, the present invention provides a digital frequency sweeping method suitable for pan / tilt debugging, comprising:

[0009] Step 1: According to the sweep frequency parameters transmitted by the PC host computer, the PTZ sweep frequency module deployed in the PTZ control system generates an excitation signal;

[0010] Step 2: generating a response signal based on the excitation signal;

[0011] Step 3: The frequency sweep parameter and the response signal are transmitted to the PC host computer;

[0012] Step 4: After analyzing the frequency sweep parameters and the response signal, the PC host computer outputs the Bode diagram or the delay information of the image acquisition processing.

[0013] Based on one aspect, in one embodiment of the present invention, in step 1, the frequency sweep parameters include: frequency sweep amplitude, frequency sweep type and a number of discrete frequency points, wherein:

[0014] The frequency sweep amplitude and the frequency sweep type are obtained by the PC host computer based on user-set parameters, and the user-set parameters include the frequency sweep amplitude, the frequency sweep type, the step length, and the frequency sweep range;

[0015] The plurality of discrete frequency points are obtained by decomposing the frequencies within the frequency sweep range by the PC host computer according to the step length.

[0016] Based on one aspect, in one embodiment of the present invention, in step 1, the excitation signal includes: a velocity excitation signal, a tracking excitation signal and a position excitation signal, wherein:

[0017] (1) The velocity excitation signal performs frequency response analysis on the inertial stabilization function of the gimbal, and the response signal is collected by the gyro sensor of the gimbal control system;

[0018] (2) the tracking excitation signal performs frequency response analysis on the target tracking function of the pan-tilt control system, and the response signal is output by the image processing unit of the pan-tilt control system;

[0019] (3) The position excitation signal performs frequency response analysis on the axis angle position locking function of the pan-tilt adjustment, and the response signal is collected by the angle position sensor of the pan-tilt control system;

[0020] (4) The position excitation signal estimates the image acquisition and processing time of the gimbal debugging, the response signal is collected by the angular position sensor to collect the angular position sinusoidal signal, and the image processing unit outputs the target position sinusoidal signal.

[0021] Based on one aspect, in one embodiment of the present invention, in step 1, the excitation generator in the pan / tilt sweep module generates an excitation signal by formula (1):

[0022]

[0023] In the formula, r(n) represents the excitation signal, A represents the excitation amplitude, f represents the current excitation frequency, n represents the excitation index number, and t s represents the sampling period, Indicates the phase of the excitation signal; the PC host provides f and A, and the operating cycle of the excitation generator is t s consistent; among which:

[0024] When the excitation generator runs periodically, the excitation index number starts to accumulate from 0, and each running cycle of the excitation generator generates an excitation signal.

[0025] Based on one aspect, in one embodiment of the present invention, step 2 includes:

[0026] In step 1 (1), the gimbal operates in an inertial stable state, generates the velocity excitation signal according to formula (1), and superimposes the velocity excitation signal on the addition node of the gyro closed-loop control loop of the gimbal to generate a response signal;

[0027] In step 1 (2), the pan / tilt unit is closed-loop fed back by the image processing unit, and the tracking excitation signal generated according to formula (1) is superimposed on the closed-loop addition node of the image processing unit to generate a response signal;

[0028] In step 1 (3), the position loop of the gimbal is closed by the angle sensor feedback loop, and the position excitation signal is generated according to formula (1), which is superimposed on the closed loop addition node of the angular position sensor to generate a response signal;

[0029] In step 1 (4), the image processing unit of the gimbal tracks the target in the picture, and the position loop of the gimbal is closed by the angular position loop at the current position. The position excitation signal is generated according to formula (1) and superimposed on the closed loop addition node of the angular position sensor to generate a response signal.

[0030] Based on one aspect, in one embodiment of the present invention, step three includes:

[0031] The communication unit in the pan / tilt scanning module synchronously transmits the excitation index number, current excitation frequency, excitation amplitude and sampling period corresponding to the excitation signal, and the response signal to the PC host computer.

[0032] Based on one aspect, in one embodiment of the present invention, in step 4, the PC host computer analyzes the frequency sweep parameter and the response signal, including:

[0033] The PC host computer receives the response signal, as well as the excitation index number, current excitation frequency, excitation amplitude and sampling period corresponding to the response signal;

[0034] The PC host computer calculates the amplitude and phase of the response signal using the excitation index number, the current excitation frequency, and the excitation amplitude.

[0035] Based on one aspect, in one embodiment of the present invention, in step 4, calculating the amplitude and phase of the response signal includes:

[0036] Based on the vector Y of the response signal and the known quantity X, the intermediate variable θ is calculated by formula (2):

[0037] Y=XΘ formula (2)

[0038] In the formula,

[0039] Based on the intermediate variable θ obtained by formula (2), the amplitude A of the response signal is calculated by formula (3): r and Phase

[0040]

[0041] Based on formula (4) through the amplitude A r and Phase Calculate the phase-frequency vector Φ and amplitude-frequency vector T of the closed-loop transfer function:

[0042]

[0043] Based on formula (5), the amplitude-frequency vector T of the open-loop transfer function is calculated o :

[0044]

[0045] The phase-frequency vector Φ of the open-loop transfer function is equal to the phase-frequency vector Φ of the closed-loop transfer function.

[0046] Based on one aspect, in one embodiment of the present invention, in step 4, outputting the delay information of the Bode diagram or image acquisition processing includes:

[0047] The PC host computer draws and outputs the open-loop Bode diagram and closed-loop Bode diagram of the pan-tilt control system according to the calculated phase-frequency vector Φ and amplitude-frequency vector T; or, the PC host computer outputs the delay information of the image acquisition processing according to the phase difference between the excitation signal and the response signal.

[0048] On the other hand, the present invention provides a digital frequency sweeping system suitable for pan-tilt debugging. Based on the above-mentioned digital frequency sweeping method suitable for pan-tilt debugging, the digital frequency sweeping system includes an input unit, a PC host computer and a pan-tilt frequency sweeping module. The PC host computer includes a communication module and an analysis module. The pan-tilt frequency sweeping module is deployed in a pan-tilt control system. The pan-tilt frequency sweeping module includes a communication unit and an excitation generator.

[0049] The input unit inputs frequency sweep parameters;

[0050] The communication module transmits frequency sweep parameters;

[0051] After analyzing the frequency sweep parameters and the response signal, the analysis module outputs the Bode diagram or the delay information of the image acquisition processing;

[0052] The communication unit receives the frequency sweep parameter transmitted by the communication module, and sends the frequency sweep parameter and the response signal to the communication module;

[0053] The excitation generator generates an excitation signal based on the frequency sweep parameter.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] The present invention uses a pan-tilt frequency sweeping module integrated in the servo system of the drone pan-tilt. The pan-tilt frequency sweeping module can not only analyze the control system performance of the drone pan-tilt, including inertial stability, automatic tracking, and axis angle position locking, but also test the image acquisition and processing delay. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 A flow chart of a digital frequency sweeping method suitable for pan / tilt debugging provided by the present invention;

[0057] Figure 2 A block diagram of the digital frequency sweeping principle of the pan / tilt control system provided by the present invention during inertial stabilization;

[0058] Figure 3 A block diagram of the digital frequency sweeping principle of the pan / tilt control system during target tracking provided by the present invention;

[0059] Figure 4 A block diagram of the digital frequency sweeping principle of the pan / tilt control system when the position is locked provided by the present invention;

[0060] Figure 5 A block diagram of the digital frequency sweeping principle of the pan / tilt control system when the test image acquisition and processing delay is provided by the present invention;

[0061] Figure 6 A graphical representation of a closed loop Bode diagram provided for the present invention;

[0062] Figure 7A graphical representation of an open loop Bode diagram provided for the present invention;

[0063] Figure 8 A principle block diagram of a digital frequency sweeping system suitable for pan / tilt debugging provided by the present invention;

[0064] Fig. 9 This is a workflow diagram of the analysis module of the PC host computer provided by the present invention. DETAILED DESCRIPTION

[0065] The present invention is described in detail below in conjunction with the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these embodiments are all within the scope of protection of the present invention.

[0066] See also Figure 1 The embodiment of the present invention provides a digital frequency sweeping method suitable for pan / tilt debugging, comprising:

[0067] Step 1: According to the sweep frequency parameters transmitted by the PC host computer, the PTZ sweep frequency module deployed in the PTZ control system generates an excitation signal.

[0068] Specifically, in the above step 1, the frequency sweep parameters include: frequency sweep amplitude, frequency sweep type and several discrete frequency points, wherein: the frequency sweep amplitude and frequency sweep type are obtained by the PC host computer based on the user-set parameters, and the user-set parameters include the frequency sweep amplitude, frequency sweep type, step length and frequency sweep range; several discrete frequency points are obtained by the PC host computer by decomposing the frequency within the frequency sweep range according to the step length. Among them, the frequency sweep type includes the frequency sweep of the inertial stabilization function, the frequency sweep of the target tracking function, the frequency sweep of the axis angle locking function and the delay test of the target tracking function. The pan-tilt frequency sweep module generates different excitation signals under different frequency sweep types and superimposes them on different control loops of the pan-tilt control system. The discrete frequency points set by the PC host computer include all the frequency points used by the excitation generator to generate excitation during the frequency sweep process. In practical applications, the communication interface between the PC host computer and the pan-tilt can be a serial port, a network port, a can port, etc. The PC host computer can be a software with communication data receiving and data analysis functions, or a combination of general software such as Matlab, a serial port, a network port, and a can port assistant.

[0069] Specifically, in the above step one, the excitation signal includes: a velocity excitation signal, a tracking excitation signal and a position excitation signal, wherein: (1) the velocity excitation signal performs a frequency response analysis on the inertial stabilization function of the gimbal debugging, and the response signal is collected by the gyro sensor of the gimbal control system; (2) the tracking excitation signal performs a frequency response analysis on the target tracking function of the gimbal debugging, and the response signal is output by the image processing unit of the gimbal control system; (3) the position excitation signal performs a frequency response analysis on the axis angle position locking function of the gimbal debugging, and the response signal is collected by the angular position sensor of the gimbal control system; (4) the position excitation signal estimates the image acquisition and processing time of the gimbal debugging, the response signal is collected by the angular position sine signal of the angular position sensor, and the image processing unit outputs the target position sine signal.

[0070] Specifically, in the above step 1, the pan-tilt sweep module generates different excitation signals according to the received frequency type, frequency point and excitation amplitude. Since the communication interface of the pan-tilt is often low-speed and has a large delay, it directly affects the phase accuracy of the sweep. In the embodiment of the present invention, the excitation signal is generated inside the pan-tilt, which effectively avoids the delay caused by transmission when the external excitation is input. Furthermore, the excitation generator in the pan-tilt sweep module of the embodiment of the present invention generates the excitation signal through formula (1):

[0071]

[0072] In the formula, r(n) represents the excitation signal, A represents the excitation amplitude, f represents the current excitation frequency, n represents the excitation index number, and t s represents the sampling period, Indicates the phase of the excitation signal; the PC host provides f and A, and the operating cycle of the excitation generator is t s Consistent; wherein: when the excitation generator runs periodically, the excitation index number starts to accumulate from 0, and each running cycle of the excitation generator generates an excitation signal.

[0073] Step 2: Generate a response signal based on the excitation signal. Specifically including:

[0074] See also Figure 2 The velocity excitation signal performs frequency response analysis on the inertial stabilization function of the gimbal. The gimbal works in the inertial stability state. The excitation generator generates a velocity excitation signal according to formula (1), which is superimposed on the addition node of the gimbal's gyro closed-loop control loop to generate a response signal. The response signal is collected by the gyro sensor of the gimbal control system.

[0075] See also Figure 3The tracking excitation signal performs frequency response analysis on the target tracking function of the gimbal debugging. The gimbal is closed-loop fed back by the image processing unit. The tracking excitation signal generated by the excitation generator according to formula (1) is superimposed on the closed-loop addition node of the image processing unit to generate a response signal. The response signal is output by the image processing unit of the gimbal control system.

[0076] See also Figure 4 The position excitation signal performs frequency response analysis on the axis angle position locking function of the gimbal debugging. The position loop of the gimbal is closed by the angle sensor feedback loop. The excitation generator generates the position excitation signal according to formula (1), which is superimposed on the closed loop addition node of the angular position sensor to generate a response signal; the response signal is collected by the angular position sensor of the gimbal control system.

[0077] See also Figure 5 , the image acquisition and processing of the gimbal debugging is time-consuming. The gimbal's image processing unit tracks the target in the picture. The gimbal's position loop is closed at the current position by the angular position loop, rather than by the image processing unit. The excitation generator generates a position excitation signal according to formula (1), which is superimposed on the closed-loop addition node of the angular position sensor to generate a response signal. At this time, the gimbal performs a sinusoidal swing under the excitation. The response signal is collected by the angular position sinusoidal signal of the angular position sensor, and the image processing unit outputs the target position sinusoidal signal. The PC host estimates the total delay between the image from the camera to the image processing unit by comparing the phases of the two sinusoidal signals.

[0078] Step 3: The frequency sweep parameters and response signals are transmitted to the PC host computer. Specifically, the communication unit in the pan / tilt frequency sweep module transmits the excitation index number, current excitation frequency, excitation amplitude and sampling period corresponding to the excitation signal, and the response signal to the PC host computer synchronously.

[0079] It should be noted that during the digital frequency sweep process, the communication unit of the PTZ sends the current excitation index number n, the current excitation frequency f, the excitation amplitude A, and the sampling period t s , the response signal is sent to the PC host computer. The data of the response signal sent is a floating point type, excitation index number n, current excitation frequency f, excitation amplitude A, sampling period t s Preferably, it is converted into integer data and sent to the PC host computer.

[0080] Step 4: After analyzing the frequency sweep parameters and the response signal, the PC host computer outputs the delay information of the Bode diagram or image acquisition processing.

[0081] Specifically, in step 4, the PC host computer of the embodiment of the present invention analyzes the frequency sweep parameters and the response signal, including: the PC host computer receives the response signal, and the excitation index number, current excitation frequency, excitation amplitude and sampling period corresponding to the response signal; the PC host computer calculates the amplitude and phase of the response signal using the excitation index number, current excitation frequency and excitation amplitude.

[0082] After receiving the response signal, the excitation index number, the current excitation frequency, the excitation amplitude, the sampling period and other data, the PC host computer of the embodiment of the present invention knows that the response signal and the excitation signal have the same frequency, and calculates the amplitude and phase of the response signal using the known excitation index number n, the current excitation frequency f, and the excitation amplitude A. Specifically, in step 4, the above-mentioned calculation of the amplitude and phase of the response signal of the embodiment of the present invention includes:

[0083] Based on the response signal vector Y and the known quantity X, the intermediate variable θ is calculated by formula (2):

[0084] Y=XΘ formula (2)

[0085] In the formula, The solution of Θ in formula (2) is: Θ=(X T X) -1 X T Y.

[0086] Based on the intermediate variable θ obtained by formula (2), the amplitude A of the response signal is calculated by formula (3): r and Phase

[0087]

[0088] Based on formula (4) through the amplitude A r and Phase Calculate the phase-frequency vector Φ and amplitude-frequency vector T of the closed-loop transfer function:

[0089]

[0090] Among them, A is obtained by analyzing the data returned by the PTZ. The closed-loop Bode diagram of the PTZ control system is drawn based on the obtained phase-frequency vector Φ and amplitude-frequency vector T. The closed-loop Bode diagram is as follows: Figure 6 shown.

[0091] Given the amplitude-phase characteristics of the closed-loop transfer function, the amplitude-frequency vector T of the open-loop transfer function is calculated based on formula (5): o :

[0092]

[0093] The phase-frequency vector Φ of the open-loop transfer function is equal to the phase-frequency vector Φ of the closed-loop transfer function. Since the phase-frequency vector of the open-loop transfer function is equal to the phase-frequency vector of the closed-loop transfer function, the open-loop Bode diagram of the pan-tilt control system is drawn according to the obtained amplitude-frequency vector. The open-loop Bode diagram is as follows: Figure 7 shown.

[0094] Specifically, in step 4, the output of the Bode diagram or the delay information of the image acquisition processing in the embodiment of the present invention includes:

[0095] The PC host computer draws and outputs the open-loop Bode diagram and closed-loop Bode diagram of the pan-tilt control system according to the calculated phase-frequency vector Φ and amplitude-frequency vector T; or, the PC host computer outputs the delay information of the image acquisition processing according to the phase difference between the excitation signal and the response signal.

[0096] In practical applications, when the PC host computer calculates the delay information of image acquisition processing, the phase difference between the excitation signal and the response signal is the delay. According to formula (3), formula (6) is obtained:

[0097]

[0098] In formula (6), represents the phase of the response signal, and t represents the time delay from image acquisition to image processing.

[0099] See also Figure 8 The embodiment of the present invention discloses a digital frequency sweeping system suitable for pan-tilt debugging. Based on the above-mentioned digital frequency sweeping method suitable for pan-tilt debugging, the digital frequency sweeping system includes an input unit, a PC host computer and a pan-tilt frequency sweeping module. The PC host computer includes a communication module and an analysis module. The pan-tilt frequency sweeping module is deployed in the pan-tilt control system. The pan-tilt frequency sweeping module includes a communication unit and an excitation generator; wherein: the input unit inputs frequency sweeping parameters; the communication module transmits the frequency sweeping parameters; after the analysis module analyzes the frequency sweeping parameters and the response signal, it outputs the delay information of the Bode diagram or the image acquisition processing; the communication unit receives the frequency sweeping parameters transmitted by the communication module, and sends the frequency sweeping parameters and the response signal to the communication module together; the excitation generator generates an excitation signal based on the frequency sweeping parameters.

[0100] It should be noted that the digital frequency sweeping system of the embodiment of the present invention needs to deploy a pan-tilt frequency sweeping module in the pan-tilt control system. The excitation generator in the pan-tilt frequency sweeping module generates different types of excitations. These excitations are sinusoidal digital signals generated by software, including angular velocity excitation signals for stimulating the stabilization ring, target position excitation signals for stimulating the image processing unit, and position excitation signals for stimulating the angular position locking controller. Further, the digital frequency sweeping system of the embodiment of the present invention has the following working process:

[0101] Before the digital frequency sweep begins, the user sets the frequency sweep range, step length, and frequency sweep amplitude on the PC host computer. The analysis module of the PC host computer decomposes the frequency within the frequency sweep range into several discrete frequency points according to the step length. The communication module packages these discrete frequency points, frequency sweep amplitude, and frequency sweep type and sends them to the PTZ frequency sweep module. The communication unit in the PTZ frequency sweep module parses the frequency points, frequency sweep type, and frequency sweep amplitude from the data packet.

[0102] When the digital frequency sweep begins, the excitation generator generates an excitation signal, and the pan / tilt control system generates different response signals under different excitations; the communication unit packages the response signal, current excitation frequency, frequency sweep amplitude, index number and other data and sends them to the PC host computer. After receiving the data, the analysis module of the PC host computer analyzes it, calculates the amplitude-frequency and phase-frequency characteristic curves, and draws the Bode diagram.

[0103] Based on the above digital sweep system, please refer to Fig. 9 The working process of the analysis module of the embodiment of the present invention is as follows: (1) setting the frequency sweep type and frequency sweep point; (2) receiving the frequency sweep data of the pan / tilt; (3) storing the analyzed data, obtaining the excitation index number n, the current excitation frequency f, the excitation amplitude A, and the sampling period t s , response signal; (4) by sin(tπfn0), ..., sin(tπfn k ),cos(tπfn0),…,cos(tπfn k ) to obtain X; (5) Use formula (3) to calculate the amplitude A of the response signal r and Phase (6) Use formula (4) to solve the frequency characteristics of the closed-loop transfer function; (7) Use formula (5) to solve the frequency characteristics of the open-loop transfer function; (8) Draw the closed-loop Bode diagram and the open-loop Bode diagram; (9) In the process of calculating the time consumption of image acquisition and processing, use formula (6) to solve the time consumption of image acquisition and processing.

[0104] The embodiment of the present invention is aimed at the functions and characteristics of the pan-tilt, and discloses a lightweight digital frequency sweeping method and system for pan-tilt debugging. Compared with the commonly used frequency response analyzer in the past, the embodiment of the present invention has the advantages of strong pertinence, low cost, convenient debugging, and simple use. The user can easily adjust the control system of the pan-tilt in various occasions.

[0105] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

[0106] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0107] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A digital frequency sweeping method suitable for pan / tilt debugging, characterized in that: include: Step 1: According to the sweep frequency parameters transmitted by the PC host computer, the PTZ sweep frequency module deployed in the PTZ control system generates an excitation signal; Step 2: generating a response signal based on the excitation signal; Step 3: The frequency sweep parameter and the response signal are transmitted to the PC host computer; Step 4: After analyzing the frequency sweep parameters and the response signal, the PC host computer outputs the Bode diagram or the delay information of the image acquisition processing.

2. A digital frequency sweeping method suitable for pan / tilt adjustment according to claim 1, characterized in that: In step 1, the frequency sweep parameters include: frequency sweep amplitude, frequency sweep type and a number of discrete frequency points, where: The frequency sweep amplitude and the frequency sweep type are obtained by the PC host computer based on user-set parameters, and the user-set parameters include the frequency sweep amplitude, the frequency sweep type, the step length, and the frequency sweep range; The plurality of discrete frequency points are obtained by decomposing the frequencies within the frequency sweep range by the PC host computer according to the step length.

3. A digital frequency sweeping method suitable for pan / tilt adjustment according to claim 1, characterized in that: In step 1, the excitation signal includes: a velocity excitation signal, a tracking excitation signal and a position excitation signal, wherein: (1) The velocity excitation signal performs frequency response analysis on the inertial stabilization function of the gimbal, and the response signal is collected by the gyro sensor of the gimbal control system; (2) the tracking excitation signal performs frequency response analysis on the target tracking function of the pan-tilt control system, and the response signal is output by the image processing unit of the pan-tilt control system; (3) The position excitation signal performs frequency response analysis on the axis angle position locking function of the pan-tilt adjustment, and the response signal is collected by the angle position sensor of the pan-tilt control system; (4) The position excitation signal estimates the image acquisition and processing time of the gimbal debugging, the response signal is collected by the angular position sensor to collect the angular position sinusoidal signal, and the image processing unit outputs the target position sinusoidal signal.

4. A digital frequency sweeping method suitable for pan / tilt adjustment according to claim 3, characterized in that: In step 1, the excitation generator in the pan / tilt sweep module generates an excitation signal using formula (1): In the formula, r(n) represents the excitation signal, A represents the excitation amplitude, f represents the current excitation frequency, n represents the excitation index number, and t s represents the sampling period, Indicates the phase of the excitation signal; the PC host provides f and A, and the operating cycle of the excitation generator is t s consistent; among which: When the excitation generator runs periodically, the excitation index number starts to accumulate from 0, and each running cycle of the excitation generator generates an excitation signal.

5. A digital frequency sweeping method suitable for pan / tilt adjustment according to claim 4, characterized in that: Step 2 includes: In step 1 (1), the gimbal operates in an inertial stable state, generates the velocity excitation signal according to formula (1), and superimposes the velocity excitation signal on the addition node of the gyro closed-loop control loop of the gimbal to generate a response signal; In step 1 (2), the pan / tilt unit is closed-loop fed back by the image processing unit, and the tracking excitation signal generated according to formula (1) is superimposed on the closed-loop addition node of the image processing unit to generate a response signal; In step 1 (3), the position loop of the gimbal is closed by the angle sensor feedback loop, and the position excitation signal is generated according to formula (1), which is superimposed on the closed loop addition node of the angular position sensor to generate a response signal; In step 1 (4), the image processing unit of the gimbal tracks the target in the picture, and the position loop of the gimbal is closed by the angular position loop at the current position. The position excitation signal is generated according to formula (1) and superimposed on the closed loop addition node of the angular position sensor to generate a response signal.

6. A digital frequency sweeping method suitable for pan / tilt adjustment according to claim 1, characterized in that: Step three includes: The communication unit in the pan / tilt scanning module synchronously transmits the excitation index number, current excitation frequency, excitation amplitude and sampling period corresponding to the excitation signal, and the response signal to the PC host computer.

7. A digital frequency sweeping method suitable for pan / tilt adjustment according to claim 6, characterized in that: In step 4, the PC host computer analyzes the frequency sweep parameters and the response signal, including: The PC host computer receives the response signal, as well as the excitation index number, current excitation frequency, excitation amplitude and sampling period corresponding to the response signal; The PC host computer calculates the amplitude and phase of the response signal using the excitation index number, the current excitation frequency, and the excitation amplitude.

8. A digital frequency sweeping method suitable for pan / tilt adjustment according to claim 7, characterized in that: In step 4, the amplitude and phase of the response signal are calculated, including: Based on the vector Y of the response signal and the known quantity X, the intermediate variable θ is calculated by formula (2): Y=XΘ formula (2) In the formula, Based on the intermediate variable θ obtained by formula (2), the amplitude A of the response signal is calculated by formula (3): r and Phase Based on formula (4) through the amplitude A r and Phase Calculate the phase-frequency vector Φ and amplitude-frequency vector T of the closed-loop transfer function: Based on formula (5), the amplitude-frequency vector T of the open-loop transfer function is calculated o : The phase-frequency vector Φ of the open-loop transfer function is equal to the phase-frequency vector Φ of the closed-loop transfer function.

9. A digital frequency sweeping method suitable for pan / tilt adjustment according to claim 7, characterized in that: In step 4, the delay information of the Bode diagram or image acquisition processing is output, including: The PC host computer draws and outputs the open-loop Bode diagram and closed-loop Bode diagram of the pan-tilt control system according to the calculated phase-frequency vector Φ and amplitude-frequency vector T; or, the PC host computer outputs the delay information of the image acquisition processing according to the phase difference between the excitation signal and the response signal.

10. A digital frequency sweeping system suitable for pan-tilt adjustment, based on a digital frequency sweeping method suitable for pan-tilt adjustment according to any one of claims 1 to 9, characterized in that: The digital frequency sweeping system includes an input unit, a PC host computer and a pan-tilt frequency sweeping module, wherein the PC host computer includes a communication module and an analysis module, and the pan-tilt frequency sweeping module is deployed in the pan-tilt control system, and the pan-tilt frequency sweeping module includes a communication unit and an excitation generator; The input unit inputs frequency sweep parameters; The communication module transmits frequency sweep parameters; After analyzing the frequency sweep parameters and the response signal, the analysis module outputs the Bode diagram or the delay information of the image acquisition processing; The communication unit receives the frequency sweep parameter transmitted by the communication module, and sends the frequency sweep parameter and the response signal to the communication module; The excitation generator generates an excitation signal based on the frequency sweep parameter.

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