Unmanned aerial vehicle controller signal enhancement device

Abstract

The utility model discloses a signal enhancement device for an unmanned aerial vehicle controller, which adopts an emitter follower to enhance the driving capability and isolates an input end from a subsequent circuit. A programmable gain amplification circuit is formed by taking PGA870 as a core and using single-chip microcomputer programming as control; the emitter follower and the programmable operational amplifier adopt a differential input mode to improve the common-mode rejection ratio, and according to signal correlation, irrelevance between signals and noise and irrelevance between noise and noise, a detection circuit is adopted to detect and extract signals.

Description

Technical Field

[0001] The utility model relates to the technical field of unmanned aerial vehicle controllers, and in particular to a signal enhancement device for an unmanned aerial vehicle controller. Background Art

[0002] Drones have been widely used in detection, troubleshooting, photography and other fields in today's society. They are low-cost and highly safe, so they are favored in various industries. However, existing drones are not suitable for use in overly complex environments, because complex environments will directly affect the signal transmission between the drone and the controller and between the drone and the satellite. The signal that the drone can receive is relatively weak, which can easily cause the drone to lose control.

[0003] Not only does the weak signal have a small amplitude, but it is also often drowned out by strong noise. In addition, during the detection process, there is the noise of the sensor itself, the inherent noise of the amplifier and the measuring instrument. The process of amplifying the measured signal also amplifies the noise. Therefore, weak signals cannot be detected by amplification alone, and conventional detection methods are powerless to deal with this. Utility Model Content

[0004] In view of the defects in the prior art, the utility model provides a drone controller signal enhancement device to solve the technical problems raised in the background technology.

[0005] A signal enhancement device for a drone controller includes a signal collection electrode, an attenuation impedance matching circuit, an emitter follower, a programmable operational amplifier, and a detection circuit connected in sequence; wherein:

[0006] The detection circuit comprises a first signal processing branch and a second signal processing branch connected in parallel to the output end of the programmable operational amplifier; the first signal processing branch comprises a 90° phase shift circuit, two first multipliers and a second multiplier connected in parallel to the output end of the 90° phase shift circuit, and a subtractor;

[0007] The second signal processing branch includes a voltage follower, two third multipliers and a fourth multiplier connected in parallel to the voltage follower, and an adder;

[0008] The 90° phase shift circuit and the voltage follower are connected in parallel to the output end of the programmable operational amplifier, the first multiplier and the fourth multiplier are connected to the subtractor, and the second multiplier and the third multiplier are connected to the adder.

[0009] Furthermore, the attenuation impedance matching circuit includes a resistor R11, an adjustable resistor RP1, a resistor R12, a capacitor C11 and a capacitor C12, the resistor R11 and the adjustable resistor RP1 are connected in series, the capacitor C11 and the resistor R11 are connected in parallel, and the resistor R12 and the capacitor C11 are connected in parallel between the output of the adjustable resistor RP1 and the ground; the input end of the resistor R11 is connected to the signal collection electrode, and the output of the adjustable resistor RP1 is connected to the emitter follower.

[0010] Furthermore, the emitter follower includes an operational amplifier chip and a peripheral circuit, and the model of the operational amplifier chip is ADA4817.

[0011] Furthermore, the programmable operational amplifier includes a programmable gain amplification unit and a control unit, and the programmable gain amplification unit is connected to the control unit.

[0012] Furthermore, the model of the programmable gain amplifier unit is PGA870; and the control unit is a single chip microcomputer.

[0013] Furthermore, the model of the single chip microcomputer is 89C51 single chip microcomputer.

[0014] Furthermore, the models of the first multiplier, the second multiplier, the third multiplier and the fourth multiplier are AD835.

[0015] Furthermore, the signal collection electrode is an antenna.

[0016] The beneficial effects of the utility model are embodied in:

[0017] The signal enhancement device of the drone controller adopts an emitter follower to enhance the driving capability and isolates the input end from the subsequent circuit; with PGA870 as the core, a programmable gain amplifier circuit is constructed by microcontroller programming for control; the emitter follower and programmable operational amplifier both adopt differential input mode to improve the common mode rejection ratio, and according to the signal correlation and the independence of signal and noise, and noise and noise, a detection circuit is used for detection and signal extraction.

[0018] The signal enhancement device of the drone controller can detect weak signals at the μV and mV levels. Compared with the single-ended mode, the common-mode rejection ratio is increased by 7.7dB, the gain can be adjusted between -l1.5dB and +20dB, the effective bandwidth of the signal is 250MHz, and the fundamental and second harmonic power ratio of the output signal can reach 50.8dB. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0020] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. For ordinary technicians in this field, other accompanying drawings can also be obtained based on these accompanying drawings without paying creative labor.

[0021] Figure 1 This is an electrical structure diagram of a UAV controller signal enhancement device provided by the utility model;

[0022] Figure 2 A circuit diagram of the attenuated impedance matching circuit provided by the utility model;

[0023] Figure 3 A circuit diagram of an emitter follower provided by the utility model;

[0024] Figure 4 A circuit diagram of a programmable operational amplifier provided by the utility model;

[0025] Figure 5 The utility model provides a circuit diagram of a multiplier.

[0026] The realization of the purpose, functional features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. The above-mentioned drawings have shown clear embodiments of this application, which will be described in more detail later. These drawings and textual descriptions are not intended to limit the scope of the concept of this application in any way, but to illustrate the concept of this application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0027] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0028] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the invention belongs.

[0029] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present invention, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0031] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0033] like Figure 1As shown, the utility model provides a signal enhancement device for a drone controller, comprising a signal collection electrode, an attenuation impedance matching circuit, an emitter follower, a programmable operational amplifier and a detection circuit connected in sequence. The detection circuit comprises a first signal processing branch and a second signal processing branch connected in parallel to the output end of the programmable operational amplifier; the first signal processing branch comprises a 90° phase shift circuit, two first multipliers and a second multiplier connected in parallel to the output end of the 90° phase shift circuit, and a subtractor. The second signal processing branch comprises a voltage follower, two third multipliers and a fourth multiplier connected in parallel to the voltage follower, and an adder. The 90° phase shift circuit and the voltage follower are connected in parallel to the output end of the programmable operational amplifier, the first multiplier and the fourth multiplier are connected to the subtractor, the second multiplier and the third multiplier are connected to the adder, and the outputs of the subtractor and the adder are both connected to the drone controller.

[0034] In this embodiment, the signal collection electrode is an antenna. The measured signal is detected by the signal collection electrode. In order to allow the detected signal to be smoothly transmitted to the receiving end with minimal energy loss, and the receiving end completely absorbs it without any reflection, an impedance matching circuit is set at the front end. Due to the uncertainty of the measured signal strength and frequency, when the signal amplitude varies in a large range, in order to prevent the strong signal from saturating and distorting when the gain of the subsequent amplification circuit is minimum, an attenuation circuit is also embedded in the impedance matching circuit. The strength of the input signal can be controlled by adjusting the resistance value of the attenuation circuit.

[0035] When detecting weak signals, weak signals are easily contaminated by noise. The emitter follower is used to enhance the driving ability to ensure that the signal is not attenuated due to weak driving ability. Since the emitter follower has a large input resistance and a small output resistance, it also has the function of isolating the input end from the subsequent circuit, but it does not change the amplitude-frequency characteristics of the signal. The emitter follower adopts a differential input form to improve the common mode rejection ratio.

[0036] The dynamic range of the signal that the drone controller needs to receive and process is often very wide. Due to the uncertainty of the measured signal strength and frequency, if a fixed gain amplifier is used, it is easy to cause large signals to be saturated and distorted or exceed the range of data acquisition, or the small signal is not amplified enough, and the amplified signal cannot reach or approach the range of data acquisition, resulting in a large quantization error. In this design, PGA870 is used as the core, and a programmable operational amplifier is constructed using microcontroller programming for control. The signal output by the programmable operational amplifier contains both the detected signal and the noise signal. Assume that the detected signal is Asin(wt+a) after programmable gain amplification, and Acos(wt+a) after phase shifting 90 degrees. Since the signal is correlated, there is no correlation between the signal and the noise, and between the noise and the noise. According to the principle of phase-sensitive detection, we get:

[0037] y1(n)=Acos(wt+a)sin(wt)=1 / 2A(sin(2wt+a)-sina);

[0038] y2(n)=Acos(wt+a)cos(wt)=1 / 2A(cos(2wt+a)+cosa);

[0039] y3(n)=Asin(wt+a)sin(wt)=-1 / 2A(cos(2wt+a)-cosa);

[0040] y4(n)=Asin(wt+a)cos(wt)=1 / 2A(sin(2wt+a)+sina);

[0041] Subtracting y4(n) from y1(n) yields:

[0042] y4(n)-y1(n)=Asina;

[0043] By adding y2(n) and y3(n), we get:

[0044] y3(n)+y2(n)=Acosa;

[0045] This effectively extracts the detected signal and removes the noise. If Asina and Acosa are operated on the drone controller as follows, the amplitude and phase of the detected signal can be obtained:

[0046]

[0047]

[0048] a@-arctana.

[0049] It is necessary to consider both impedance matching and attenuation function when strong signals are present. The attenuation impedance matching circuit designed in this scheme is as follows: Figure 2 As shown, including resistor R 11 , adjustable resistor RP1, resistor R 12 , capacitor C 11 and capacitor C 12 , the resistor R 11 and the adjustable resistor RP1 in series, the capacitor C 11 With resistor R 11 In parallel, the resistor R 12 and capacitor C 11 connected in parallel between the output of the adjustable resistor RP1 and ground; the resistor R 11 The input end of is connected to the signal collection electrode, and the output of the adjustable resistor RP1 is connected to the emitter follower.

[0050] Among them, RP1 is used to adjust the attenuation amplitude in the project, C 11 , C 12 Used to compensate for parasitic capacitance, by analyzing its amplitude-frequency characteristics, when R 11 C 11 =R 12 C 12 When , the input and output are at the same frequency and phase.

[0051] In the scheme of the present application, the input-output amplitude-frequency characteristics of the emitter follower must be consistent and have strong driving capability. The designed circuit is as follows Figure 3 As shown, the emitter follower includes an operational amplifier chip and a peripheral circuit, and the operational amplifier chip model is ADA4817. The operational amplifier chip is a differential input form, which can suppress common signals and has a bandwidth of 1050MHz.

[0052] In this embodiment, the programmable operational amplifier includes a programmable gain amplifier unit and a control unit, and the programmable gain amplifier unit is connected to the control unit. Figure 4 As shown, the model of the programmable gain amplifier unit is PGA870. The control unit is a single chip microcomputer, and the model of the single chip microcomputer is 89C51 single chip microcomputer.

[0053] PGA870 is a high-speed fully differential programmable gain amplifier with a gain adjustment range of -11.5dB to 20dB, a gain step of 0.5dB, and a gain accuracy of 0.03dB. The frequency band is 650MHZ, and the common mode rejection ratio can reach 76dB. The attenuation and gain multiples are controlled by the control logic bits B0-B5 and the gainstrobe and latchmode pins.

[0054] In order to reduce the impact of the front-end DC bias on this module, and considering that an internal reference voltage has been provided inside the chip, the signal input end adopts AC coupling, and the combined capacitor uses a larger value of 0.1uf to allow low-frequency signals to pass without attenuation. A resistor is connected in series on B0-B5 to reduce the amplitude of signal reflection. Because the output resistance of the amplifier is only 3.5 ohms, in order to achieve a 50 ohm termination of the signal, the output is connected in series with a 50 ohm resistor R 33 With R 34 The output end of PGA870 uses RC network to terminate the signal, which can effectively reduce the reflection of the signal and transmit the signal to the next level by AC coupling. In the figure, the power supply is divided by RRP2 to provide a suitable DC bias for the differential signal of PGA870 output signal.

[0055] like Figure 5As shown, the model of the first multiplier, the second multiplier, the third multiplier and the fourth multiplier is AD835, and the bandwidth can reach 250MHZ.

[0056] In summary, the drone controller signal enhancement device of the present application uses an emitter follower to enhance the driving capability and isolates the input end from the subsequent circuit; with PGA870 as the core, a programmable gain amplifier circuit is constructed using single-chip microcomputer programming for control; the emitter follower and programmable operational amplifier both use differential input mode to improve the common mode rejection ratio, and based on the signal correlation and the independence of signal and noise, and noise and noise, a detection circuit is used for detection to extract the signal.

[0057] The drone controller signal enhancement device of the present application can detect weak signals at the μV and mV levels. Compared with the single-ended mode, the common-mode rejection ratio is increased by 7.7dB, the gain can be adjusted between -l1.5dB and +20dB, the effective bandwidth of the signal is 250MHz, and the fundamental wave and second harmonic power ratio of the output signal can reach 50.8dB.

[0058] Finally, it should be noted that the various technical features of the technical solution of the present application can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the present application.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some or all of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and should all be included in the scope of the claims and specification of the present invention.

Claims

1. A drone controller signal enhancement device, characterized in that: It includes a signal collection electrode, an attenuation impedance matching circuit, an emitter follower, a programmable operational amplifier and a detection circuit connected in sequence; wherein, The detection circuit comprises a first signal processing branch and a second signal processing branch connected in parallel to the output end of the programmable operational amplifier; the first signal processing branch comprises a 90° phase shift circuit, two first multipliers and a second multiplier connected in parallel to the output end of the 90° phase shift circuit, and a subtractor; The second signal processing branch includes a voltage follower, two third multipliers and a fourth multiplier connected in parallel to the voltage follower, and an adder; The 90° phase shift circuit and the voltage follower are connected in parallel to the output end of the programmable operational amplifier, the first multiplier and the fourth multiplier are connected to the subtractor, and the second multiplier and the third multiplier are connected to the adder.

2. The UAV controller signal enhancement device according to claim 1, characterized in that: The attenuation impedance matching circuit includes a resistor R11, an adjustable resistor RP1, a resistor R12, a capacitor C11 and a capacitor C12, the resistor R11 and the adjustable resistor RP1 are connected in series, the capacitor C11 and the resistor R11 are connected in parallel, and the resistor R12 and the capacitor C11 are connected in parallel between the output of the adjustable resistor RP1 and the ground; the input end of the resistor R11 is connected to the signal collection electrode, and the output of the adjustable resistor RP1 is connected to the emitter follower.

3. The UAV controller signal enhancement device according to claim 1, characterized in that: The emitter follower includes an operational amplifier chip and a peripheral circuit, and the model of the operational amplifier chip is ADA4817.

4. The UAV controller signal enhancement device according to claim 1, characterized in that: The programmable operational amplifier comprises a programmable gain amplifying unit and a control unit, and the programmable gain amplifying unit is connected to the control unit.

5. The drone controller signal enhancement device according to claim 4, characterized in that: The model of the programmable gain amplifier unit is PGA870; the control unit is a single chip microcomputer.

6. The drone controller signal enhancement device according to claim 5, characterized in that: The model of the single chip microcomputer is 89C51 single chip microcomputer.

7. The UAV controller signal enhancement device according to claim 1, characterized in that: The models of the first multiplier, the second multiplier, the third multiplier and the fourth multiplier are AD835.

8. The UAV controller signal enhancement device according to claim 1, characterized in that: The signal collection electrode is an antenna.

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