CN106646618A - Capacitive orientation detection circuit - Google Patents

Abstract

The invention relates to a capacitive orientation detection circuit. The capacitive orientation detection circuit is characterized by comprising an emitter electrode, three receiver electrodes, a power supply module, an oscillation circuit and a detection circuit; through the capacitive orientation detection circuit, target detection and orientation identification can be realized, the capacitive orientation detection circuit is mainly applicable to conducting objects such as armored objects and airplanes; the capacitive orientation detection circuit is technically characterized in that multiple detection electrode sets are disposed in the space, distances from a target to electrodes are different, and target orientation can be derived according to difference of demodulation voltage change amount; the receiver electrodes employ a multi-receiver-electrode array mode, and independent three-path detectors are utilized for detection. The capacitive orientation detection circuit is advantaged in that a capactive proximity sensing fuse working in a quasi-electrostatic field has properties of high spacing precision, good electromagnetic interference resistance and stealth resistance, and the capacitive orientation detection circuit can be in matching with any bomb with burst height requirements about 2m, and is especially suitable for bombs in strong electromagnetic interference field operation environments.

Description

Capacitive Directional Detection Circuit

technical field

The invention belongs to the technical field of sensor target detection and is mainly applied to bomb-borne fuzes.

Background technique

The fuze is an information control system that uses environmental information, target information, or specified information to implement detonation control, ignition control, and attitude control on ammunition at a desired time and space. The development of electronic countermeasures has seriously threatened the proximity fuzes of some systems, especially the radio proximity fuzes.

At present, in foreign scientific and technological materials about capacitor proximity fuzes, no specific examples have been found of using the principle of capacitor detection to achieve target orientation detection. The blowpipe missile capacitor fuze of the British company Markney uses two detection electrodes that are symmetrical to the bomb axis. , but it does not meet the requirements for directional detection. Relevant target directional detection is mainly concentrated on the radio system and the optical system at home and abroad.

For the orientation of the radio system fuze, most of the schemes use the combination of the microstrip antenna array shared by the transceiver and the electronically controlled scanning technology, but they are all affected by the engineering realization of the microstrip antenna array and the electronically controlled scanning technology. Identify three to four quadrants. Some people have also proposed the idea of using microstrip antennas for directional detection. The basic design idea is to install four microstrip antennas symmetrically on the bomb shaft to detect four different directions around the bomb shaft, each direction covering a 90° angle. The single-pole four-throw PIN switch is used to control the four microstrip antennas around the projectile to scan the surrounding space on and off, so that only one antenna is in the working state at each moment. The four branches of the PIN switch control circuit work in turn, so that the four transmitting and receiving antennas can continuously scan within the 360° angle range. When a certain branch of the antenna detects the target, it can get an electrical signal to complete the detection, and the target orientation information extraction circuit can obtain the target orientation information from the output terminal corresponding to the high level of the switch control circuit. Sending this information to the directional detonation system can complete the directional detection task. This directional detection method can only limit the detection angle range within 90°, and the detection accuracy is not high.

For directional detection of optical proximity fuzes. Japan on January 17, 1992 published in the patent "proximity bombing fuze control device" of Maejima Tokuyuki and Saito Osamu on "Open Patent Gazette" just proposed a kind of simple directional detection method and signal processing circuit thereof. It uses the laser fuze used on air-to-air missiles, and adopts a single "pole" to launch, and multiple "poles" are fixed to receive the detection mode of the reflected signal. The basic principle is to divide the missile into four quadrants in the direction of the surrounding space centered on the bomb axis. In each quadrant, the laser emitter emits a semiconductor laser with a certain direction and divergence angle to scan the front of the missile. Reflected light returns. The optical receiver in the device sends the detected diffuse reflection signal to the subsequent signal comparator array, and the output waveforms of the signal comparators are quite different due to the different quadrants of the target. According to the relationship between the quadrant signal of the target, the specific quadrant of the target is determined, so as to realize the directional detection function, and then the target azimuth signal is input into the detonation circuit to control the warhead to adapt to achieve the best explosive point. This device has many advantages, such as it can greatly shorten the action time, can reduce power consumption, the most important thing is that it eliminates the possibility of misoperation during rear-end attack. Therefore, this device is advanced in directional detection and directional detonation, but the target azimuth detection accuracy of the proximity fuze of this laser system only reaches the level of one quadrant, that is, its coverage is only within 90°. This approach provides us with a practical idea - the detection method of geometric positioning.

With the development of code division technology in digital signal technology, a fuze detection method that can identify the target azimuth has emerged by combining the antenna array with separate transceivers and code division technology. In the scheme, the antenna array is evenly distributed on the surface around the circumference, and the transmitting antennas T1 and T2 and the receiving antennas R1 and R2 are symmetrically arranged respectively. Every two adjacent antennas are separated by 90° on the missile body. The working principle is: the oscillating signal generated by the oscillator is divided into four channels by the power divider, two of which are phase-modulated (o/π phase modulation) through the pseudo-code I and pseudo-code II through the phase modulator, and the modulated two-channel signal They are radiated by the antennas T1 and T2 respectively. Once a target appears, the target echo signal is generated, and after being received by the antenna R1 or R2, it is mixed with the local oscillator signal coupled by the power divider, and the mixed signal is multiplexed with the pseudo code I and pseudo code II Correlation processing, filter detection and other processing are sent to the integrated information processing and control unit. By extracting the characteristics of the detected signal parameters and comparing the relative signal size relationship of the relevant information processing branches, according to the relative channel signal of each receiving antenna Whether to identify the bearing of the target relative to the fuze. This scheme has multiple divisions for azimuth recognition, strong anti-interference ability, and a large amount of effective information that can be used for leading combat cooperation. Not only can the target azimuth information be obtained, but also the relevant channels with relatively large detection signals can obtain distance, speed, tail pursuit/attack, etc. information, in order to obtain a good coordination effect of leading war, and at the same time, most of the key technologies used in the plan are relatively mature technologies.

In the directional detection methods of the proximity fuzes of the above several different systems, their target azimuth detection accuracy is not ideal enough, and only reaches the level of determining the target area within a quadrant.

Contents of the invention

The technical problem to be solved by the present invention is: to realize the function of the bomb-borne fuze to detect the target at a short distance, and at the same time to identify the target azimuth.

In order to solve the above technical problems, the technical solution of the present invention is to provide a capacitance directional detection circuit, which is characterized in that it includes a transmitting electrode, three receiving electrodes, a power module, an oscillation circuit and a wave detection circuit, and the transmitting electrode is fixed on the warhead. At the axis position, the three receiving electrodes are arranged on the side of the warhead, and are evenly distributed at 120° around the warhead axis. The power supply module provides the operating voltage for the oscillation circuit and the detection circuit. to the transmitting electrode, so that a sine wave signal with constant frequency and amplitude attenuation is generated on the three receiving electrodes. The detection circuit includes three detectors, and the three detectors detect the sine wave signals generated on the three receiving electrodes respectively. Three detection voltages are obtained. When the missile encounters the target, three different detection voltage changes are generated according to the distance between the three receiving electrodes and the target. The three detection voltage changes are sent to the signal processing circuit for identification to identify the target. Perform directional recognition.

Preferably, the power module includes an input power supply and a voltage stabilizing circuit connected to the input power supply.

Preferably, the oscillating circuit includes a current follower and an LC oscillating circuit, the output of the power module is connected to the input of the LC oscillating circuit through the current follower, and the output of the LC oscillating circuit is connected to the emitter electrode.

Preferably, the current follower includes a triode V1, an output is formed between the collector and the base of the triode V1, the output of the triode V1 is connected to the input of the LC oscillating circuit, and the emitter of the triode V1 is connected to the power supply via a capacitor C3 The output of the module, the emitter of the triode V1 is grounded through the resistor R1, and the capacitor C4 is connected between the base and the emitter of the triode V1.

Preferably, the LC oscillating circuit includes an inductor L, the capacitor C5 is connected in series with the resistor R2 and connected in parallel to both ends of the inductor L, and the output of the transistor V1 is connected to both ends of the resistor R2.

Preferably, the detector adopts a voltage follower.

Preferably, the voltage follower includes a triode, the collector of the triode is connected to the output of the power module through a resistor one, the base of the triode is connected to the output of any one of the three receiving electrodes, and the base of the triode is connected to the output of any one of the three receiving electrodes. Resistor 2 is grounded, and the emitter of the triode forms a detection voltage. The emitter of the triode is grounded through a capacitor, and a diode is connected between the base and emitter of the triode. The cathode of the diode is connected to the base of the triode, and the anode of the diode is connected to The emitter of the transistor.

The capacitive detection circuit designed by the present invention can realize target detection and azimuth identification, and is mainly used to deal with conductive targets such as armor and aircraft. The technical features are as follows:

1) Multiple detection electrode groups are placed in the space, and the target orientation is inferred from the difference in detection voltage variation caused by the different distances between the target and each electrode.

2) The receiving electrode adopts the designed multi-(three) receiving electrode array form, and separate three-way detectors are used for detection.

Since the capacitive proximity fuze provided by the present invention works in a quasi-electrostatic field, it has the characteristics of high positioning accuracy, good resistance to electromagnetic interference, and anti-stealth. Ammunition suitable for field environments with strong electromagnetic interference.

Description of drawings

Fig. 1 is a schematic diagram of the present invention;

Fig. 2 is a specific circuit diagram of the present invention.

detailed description

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

The present invention realizes the design idea of directional detection as follows:

The detection directionality of the capacitance proximity fuze is isotropic. To make it capable of target-oriented recognition, one of the methods is to modify the structure and distribution of electrodes. After data investigation and analysis, the present invention proposes a multi-receiving electrode array detection scheme. That is to say, a transmitting electrode is adopted, which is fixed at the axial center of the bullet, and several receiving electrodes are distributed symmetrically at a certain angle φ on the side of the bullet. In the process of projectile approach, since the actual distance between each receiving electrode and the target must be different, although the distance between them and the detected target is not very different, but because they are in different points of the electrostatic field, There is a marked difference in the degree of acceptance of disturbances generated by the electric field. According to the basic principle of the capacitance proximity fuze, the capacitance changes between the receiving electrodes and the target are not the same, so the respective detection voltage outputs are also different. If the target signal obtained by each receiving electrode is detected separately, and then the processing system performs azimuth recognition according to the established judgment criteria, the target directional detection can be realized. In actual situations, in order to ensure the detection sensitivity, the effective area and shape of the receiving electrode and the specific value of the distance between the transmitting electrode and the receiving electrode depend on the condition of the equipped warhead.

The specific number n of receiving electrodes should be taken, which will be discussed below. Assuming that n=2, the typical positions of the two receiving electrodes at this time are set symmetrically to the axis of the missile at an interval of 180°, then when the target is located on the left and right sides of the connecting line of the two receiving electrodes at the same angle, their corresponding detection circuits There is no difference in the received target encounter signal of the approach of the missile target. Therefore, taking two receiving electrodes can only distinguish the two halves where the target is located in the perpendicular bisector of the line connecting the two electrodes, but cannot distinguish whether the target is in the left half area or the right half area of the line connecting the two electrodes. Obviously, the necessary condition for the configuration of the electrode array to enable the fuze to achieve directional target detection is n≥3. Because every two receiving electrodes in the n receiving electrodes can judge that the target is in a certain half area, then we can get Azimuth information, through calculation, it can be concluded that the target is in a certain sector on the side of the missile. Assume that when n takes a value greater than or equal to 4, the distance between the receiving electrodes becomes smaller, and the difference in the detection voltage signals generated may not be very large. Coupled with the limitations of technical conditions, the detection sensitivity and detection sensitivity of each electrode cannot be fully developed. Similarly, there is an error in the detection voltage, which is not conducive to the distinction of the signal processing circuit. At the same time, it is necessary to increase the number of detection circuits and signal processing circuits accordingly, which complicates the circuit design and is not conducive to the real-time performance of the signal processing system. , It has increased a lot of difficulty in the realization of hardware and software. In view of the above problems and the existing technical conditions, the preliminary design is that n is 3, and the three receiving electrodes are evenly distributed at 120° around the missile axis. The transmitting electrode and the receiving electrode are not in the same plane, and the transmitting electrode is still installed at the axis of the warhead. , the receiving electrodes are distributed on the side of the warhead, which is beneficial to the identification of side targets.

In order to illustrate that the electrode array can effectively realize the directional detection of the target, it is assumed that the physical field characteristics and geometric characteristics of the target are strictly symmetrical to the center line of its orientation. In the following, the case where the target approaches from the side in a generally ordinary manner will be discussed. When the target is in the azimuth of φ angle (φ≤60°) (from the above, the detection azimuth can be divided into 6 azimuths of 60°), the distances from the electrode to the target are R ₁ , R ₂ , R ₃ , where the conditional relationship Satisfy R ₁ <R ₂ <R ₃ , because the electrostatic field strength attenuates according to the law of r ³ , so the closer the distance between the detection electrode and the target, the greater the rate of change of capacitance, so there is Δu ₁ > Δu ₂ > Δu ₃ , Δu ₁ , Δu ₂ , and Δu ₃ are the voltage change rates detected by the three receiving electrodes respectively, so that the target will be identified within a 60° azimuth.

A functional block diagram of a capacitive directional detection circuit provided by the present invention is shown in FIG. 1 . It consists of five parts: power supply, voltage stabilizing circuit, oscillation circuit, detection electrode array (including transmitting electrode A, receiving electrode B1, receiving electrode B2, receiving electrode B3) and detection circuit (including three-way detector). The basic principle of the invention is: the input power increases the working voltage for the oscillation circuit and the detection circuit through the voltage stabilizing circuit. The oscillating circuit generates a sine wave signal with a stable frequency and high amplitude (meeting the sensitivity requirements) and supplies it to the transmitting electrode A. Pressure coupling, a sine wave signal with constant frequency and greatly attenuated amplitude is generated on the receiving electrode B1, receiving electrode B2, and receiving electrode B3. The three-way sine wave signals generated by the receiving electrode B1, the receiving electrode B2, and the receiving electrode B3 are respectively detected by three-way detectors, and three stable detection voltages U1, U2, and U3 are output. When the missile encounters the target, different detection voltage variations Δu ₁ , Δu ₂ , Δu ₃ are generated according to the distance between the receiving electrode B1, the receiving electrode B2, and the receiving electrode B3 from the target, and Δu ₁ , Δu ₂ , Δu ₃ are a cluster The target encountering signal output by the wave detection is sent to the signal processing circuit for identification to complete the target orientation recognition function when the target is encountered.

As shown in Figure 2, it is a specific circuit diagram of the above-mentioned capacitance directional detection circuit, wherein:

The voltage regulator circuit adopts a voltage regulator 78L24, and filter capacitors C1 and C2 are added to its input terminal Vin and output terminal Vout respectively.

The oscillating circuit includes a current follower and an LC oscillating circuit. The current follower includes a transistor V1, an output is formed between the collector and the base of the transistor V1, the output of the transistor V1 is connected to the input of the LC oscillator circuit, the emitter of the transistor V1 is connected to the output terminal Vout of the voltage regulator 78L24 via the capacitor C3, and the transistor The emitter of V1 is grounded through the resistor R1, and the capacitor C4 is connected between the base and the emitter of the triode V1. The LC oscillating circuit includes an inductor L, a capacitor C5 is connected in series with a resistor R2 and connected in parallel to both ends of the inductor L, and the output of the transistor V1 is connected to both ends of the resistor R2.

The three-way detectors all use voltage followers. Taking the voltage follower connected to the receiving electrode B1 as an example, it includes a triode V2. The collector of the triode V2 is connected to the output terminal Vout of the voltage regulator 78L24 through a resistor R3, and the base of the triode V2 Connect the output of the three receiving electrodes B1, the base of the triode V2 is grounded through the resistor R6, the emitter of the triode V2 forms a detection voltage U1, and the emitter of the triode V2 is grounded through the capacitor C6, between the base and the emitter of the triode V2 The diode D1 is connected between them, the cathode of the diode D1 is connected to the base of the triode V2, and the anode of the diode D2 is connected to the emitter of the triode V2.

The voltage follower connected to the receiving electrode B2 includes a transistor V3, a resistor R4, a diode D2, a resistor R7, and a capacitor C7. The voltage follower connected to the receiving electrode B3 includes a triode V4, a resistor R5, a diode D3, a resistor R8, and a capacitor C8. The connections between the components are the same as above.

The present invention has the following advantages:

1) When the input is a small disturbance signal of about 30V, the voltage stabilizing circuit outputs a regulated signal of about 24V, and its response speed is fast.

2) When the input is a 24V DC stabilized voltage signal, the output of the oscillator circuit is an oscillation signal of about 160V2.38MHz superimposed on the 24V. It has large amplitude, high frequency and stable output.

3) When the input is an oscillator output signal, the detection circuit outputs an approximately 24V DC signal. It has high detection efficiency and stable output.

4) Between the detection circuit and the detection circuit, an analog coupling capacitor is connected between the two circuits, and its value is 0.38pF. When the input is about 24V DC, the output is DC detection voltage.

5) The detector circuit can enter a steady state 0.7ms after the system starts. The circuit can express the equivalent capacitance coupled on different electrodes in the form of detection voltage, and the equivalent capacitance and detection voltage satisfy a linear relationship, so the detection voltage contains target orientation information.

The above results show that the designed detector circuit meets the design requirements, the circuit is effective and feasible, and can complete the purpose of detecting the target azimuth.

Claims (7)

1. A capacitor orientation detection circuit is characterized in that it comprises a transmitting electrode, three receiving electrodes, a power supply module, an oscillation circuit and a detection circuit, the transmitting electrode is fixed on the axis position of the warhead, and the three receiving electrodes are arranged on the side of the warhead , and it is evenly distributed at 120° around the warhead axis. The power module provides the operating voltage for the oscillation circuit and the detection circuit. The oscillation circuit generates a high-amplitude sine wave signal with stable frequency and supplies it to the transmitting electrode, thereby generating For sine wave signals with constant frequency and amplitude attenuation, the detection circuit includes three detectors. The three detectors respectively detect the sine wave signals generated on the three receiving electrodes to obtain three detection voltages. When the missile meets the target, the The distances between the three receiving electrodes and the target produce three different detection voltage variations, and the three detection voltage variations are sent to the signal processing circuit for identification to perform directional recognition on the target. 2. A capacitance-oriented detection circuit according to claim 1, wherein the power supply module comprises an input power supply and a voltage stabilizing circuit connected to the input power supply. 3. A kind of capacitance orientation detection circuit as claimed in claim 1, it is characterized in that, described oscillating circuit comprises current follower and LC oscillating circuit, the output of described power supply module is connected the input of LC oscillating circuit via current follower, The output of the LC oscillating circuit is connected to the emitter electrode. 4. A capacitance-oriented detection circuit as claimed in claim 3, wherein the current follower comprises a triode V1, an output is formed between the collector and the base of the triode V1, and the output of the triode V1 is connected to the LC The input of the oscillating circuit, the emitter of the triode V1 is connected to the output of the power module through the capacitor C3, the emitter of the triode V1 is grounded through the resistor R1, and the capacitor C4 is connected between the base and the emitter of the triode V1. 5. A kind of capacitive directional detection circuit as claimed in claim 4, it is characterized in that, described LC oscillating circuit comprises inductor L, capacitor C5 and resistance R2 are connected in parallel at both ends of inductor L after being connected in series, the output of described triode V1 is connected across resistor R2. 6. A capacitance-oriented detection circuit as claimed in claim 1, characterized in that the detector adopts a voltage follower. 7. A capacitance-oriented detection circuit as claimed in claim 6, wherein the voltage follower comprises a triode, the collector of the triode is connected to the output of the power module via a resistor one, and the base of the triode is connected to three The output of any one of the receiving electrodes in the receiving electrodes, the base of the triode is grounded through the resistor 2, the emitter of the triode forms a path of the detection voltage, the emitter of the triode is grounded through a capacitor, and between the base and the emitter of the triode The cathode of the diode is connected to the base of the triode, and the anode of the diode is connected to the emitter of the triode.