CN107329005A - A kind of the orientation detection device and its detection method of the mobile electrical body based on electret effect - Google Patents

Abstract

The invention discloses a direction detection device and a detection method of a moving charged body based on an electret effect, and is a non-contact self-excited direction detection scheme of a moving charged body. The invention includes: a front-end electret electrostatic detection head, an amplifying circuit, a filter circuit, a microcontroller and a display device. The front-end electret electrostatic detection head includes: an electret film and a metal substrate; the microcontroller adopts a single-chip microcomputer; and the display device adopts an LED screen. The invention belongs to the technical field of non-contact electrostatic detection. By adopting the electret effect and an arrayed detection head, it has the advantages of simple structure and small volume. The sensitivity is 10 times, and it has good process compatibility with MEMS and CMOS processes.

Description

A device for detecting direction of moving charged body based on electret effect and its detection method

technical field

The invention belongs to the technical field of detecting the moving direction of a non-contact charged body, and in particular relates to a device and method for detecting the direction of a moving charged body based on an electret effect.

Background technique

At present, there are mainly the following typical methods for detecting the movement of charged objects: using at least one camera and an image processing unit to detect the movement of the measured object by taking pictures of the camera, and inputting the movement to the control unit in the personal computer (or host computer); Or arrange devices such as acceleration sensors on the measured object to monitor the motion of the object.

However, in the method of using a camera and image processing, the cost of hardware or software is high, and a specific space for capturing video images of the camera needs to be prepared in advance, which limits the use of the space. In addition, in the method using the acceleration sensor, it is necessary to move the hardware directly, and in the case of moving the main body of the hardware, there is a possibility that the equipment may be affected by vibration; It needs to be embedded in the object under test.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention proposes a method and device for detecting the direction of a moving charged body based on the electret effect, which can realize the direction detection of the moving charged body by using the electret effect.

The technical scheme that the present invention adopts is as follows:

A device for detecting the direction of a moving charged body based on the electret effect, comprising an electret electrostatic detection head, a filter circuit, an amplifier circuit, a microcontroller, and a display device, and the electret electrostatic detection head is connected to the filter circuit , the filtering circuit is connected to the amplifying circuit, the amplifying circuit is connected to the microcontroller, and the microcontroller is connected to the display device.

Further, the electret electrostatic probe includes an electret film and a metal substrate, wherein the electret film is attached to the surface of the metal substrate.

Further, the electret film is Teflon, the polymer group of Parylene, silicon dioxide, and one of the inorganic piezoelectric electret materials of silicon nitride, and its polarization mode adopts Ray or corona polarization.

Further, there are multiple electret electrostatic probes, forming an array of electret electrostatic probes.

Further, the number of electret electrostatic probes included in the array of electret electrostatic probes is n≥4, at least one probe is guaranteed for each of the upper, lower, left, and right sides.

A method for detecting the direction of a mobile charged body based on the electret effect using the device, comprising the following steps:

1) Make the charged object pass through the electret electrostatic detection head, and generate an induced electrical signal in the electret electrostatic detection head;

2) The electrical signal generated by noise and other interference is filtered out through the filter circuit;

3) amplifying the obtained filtered signal to the microcontroller through the amplifying circuit,

4) The microcontroller obtains the digital quantity of the electrical signal through analog-to-digital conversion, and then obtains the moving direction of the moving charged body through logical judgment, and controls the display device to output the judgment result.

Further, there are multiple electret electrostatic detection heads, forming an array of electret electrostatic detection heads, and the direction of movement of the charged body is obtained through the array of electret electrostatic detection heads.

Further, the microcontroller quantizes and encodes the induced voltage waveform through the analog-to-digital conversion chip, and then sends the induced voltages generated by different metal substrates to different pins of the microcontroller; the microcontroller receives each pin After the voltage, it will start recording from the first data that is not 0 to the last data that is not 0, and then compare the magnitude of the induced voltage generated by each metal substrate at the same time, and arrange them in order; then by the induced voltage The magnitude and vector are superimposed to obtain the moving direction of the charged body and the distance from the electret electrostatic detection head array.

The beneficial effects of the present invention are as follows:

The device and method for detecting the direction of a moving charged body based on the electret effect proposed by the present invention have the advantages of high sensitivity, high integration, small size, self-excitation, and digital signal output, and can be widely used for moving charged objects direction detection.

Description of drawings

Figure 1 is a schematic diagram of the structure of an electret electrostatic probe.

Fig. 2 is a schematic diagram of an embodiment of the direction detection mechanism and device of a moving charged body based on the electret effect.

Fig. 3 is a schematic diagram of electret electrostatic detection heads arranged in a radial direction to form an array of electret electrostatic detection heads.

detailed description

The present invention will be further described below through specific embodiments and accompanying drawings.

The device for detecting the direction of a moving charged body based on the electret effect of the present invention comprises: a front-end electret electrostatic detection head, an amplifier circuit, a filter circuit, a microcontroller, and a display device. The front-end electret electrostatic detection head is shown in Figure 1, including: electret film and metal substrate; microcontroller adopts single-chip microcomputer; display device adopts LED screen. The front-end electret electrostatic detection head is electrically connected with the filter circuit. There are multiple electret electrostatic detection heads to form an electret electrostatic detection head array. The weak signal output by the electret electrostatic detection head array first passes through the filter circuit to reduce the noise. and other interference signals are filtered out and enter the amplifier circuit, and then enter the microcontroller after being amplified by the amplifier circuit. The microcontroller converts the obtained analog signal into a digital signal through an analog-to-digital conversion chip, then makes a logical judgment on it and controls the display device Output the judgment result.

The front-end electret electrostatic probe includes: electret film and metal substrate. Among them, the metal substrate is made of metal materials; the electret film can be made of Teflon, the polymer group of Parylene, and the inorganic piezoelectric electret materials of silicon dioxide SiO ₂ and silicon nitride Si ₃ N ₄ kind of. Polarization can be ray or corona polarization. The electret film is closely attached to the upper surface of the metal substrate. When the charged body is close to or away from the electret electrostatic probe, according to the electret effect, the metal substrate will generate induced charges and electrostatic field potential. During the detection process, the electret effect is used, so no external excitation power is required.

The number of electret electrostatic detection heads contained in the electret electrostatic detection head array is n≥4. When n=4, one is placed in each of the up, down, left, and right directions, and they are arranged orthogonally to ensure all-round detection The moving direction of the charged body.

When a charged object passes through the front-end electret electrostatic probe array, all probes will generate an induced voltage, and the distance between the object and the probe is inversely proportional to the induced voltage generated by the probe. The induced voltage enters the analog-to-digital conversion chip after being filtered and amplified, and the analog-to-digital conversion chip quantifies and encodes the induced voltage waveform and sends the induced voltage generated by different metal substrates to different pins of the microcontroller. After the microcontroller receives the voltage of each pin, it will start recording from the first data that is not 0 to the last data that is not 0, and then compare the magnitude of the induced voltage generated by each metal substrate at the same time, and compare it in order. Since the induced voltage is proportional to the distance between the electrified body and the electret electrostatic detection head, the microcontroller will group the induced voltages according to the time of reception, and arrange each group of induced voltages in order from large to small and record the maximum induced voltage The label N _x of the electret electrostatic detection head of V _max , arrange all N _x according to the time, that is, the direction of motion of the charged body, arrange the induced voltage at the same time from large to small and record the corresponding electret The label of the electrostatic detection head can determine the spatial position of the charged body, and the three-dimensional vector motion information of the charged body can be obtained by combining the above two information. From the magnitude of the induced voltage and the vector superposition, the moving direction of the charged body and the distance from the electret electrostatic probe array can be obtained.

Fig. 2 shows a specific embodiment, the device for detecting the direction of a moving charged body based on the electret effect in this embodiment includes: an array of electret electrostatic probes, a filter circuit, an amplifying circuit, a microcontroller, and a display device. Among them, the electret electrostatic detection head array includes 4 electret electrostatic detection heads, which are respectively arranged in the upper, lower, left, and right directions, forming a central symmetry. The detection heads are electrically insulated from each other, and the electret electrostatic detection heads are electrically connected to the filter circuit. connection; the filter circuit and the amplifying circuit, the amplifying circuit and the microcontroller, and the microcontroller and the display device are all electrically connected.

When the charged object under test moves from a certain position to a certain direction, based on the electret effect, the four electret electrostatic probes respectively output induced voltages, which are inversely proportional to the distance between the measured object and the electrostatic probe After the induced voltage is filtered and amplified, it is digitally received by the microcontroller and logically judged, and then the display device outputs the logical judgment result, which is the direction of movement of the charged object.

In the present invention, the electret electrostatic probes can also be arranged radially to form an array of electret electrostatic probes, as shown in FIG. 3 , wherein S1 to S8 are electret electrostatic probes.

Finally, it should be noted that the purpose of the disclosed embodiments is to help further understand the present invention, but those skilled in the art can understand that various replacements and modifications can be made without departing from the spirit and scope of the present invention and the appended claims. It is possible. Therefore, the present invention should not be limited to the content disclosed in the embodiments, and the protection scope of the present invention is subject to the scope defined in the claims.

Claims (10)

1. a kind of orientation detection device of the mobile electrical body based on electret effect, it is characterised in that including electret electrostatic Detecting head, filter circuit, amplifying circuit, microcontroller and display device, the electret electrostatic detection head connection filtering Circuit, the filter circuit connects the amplifying circuit, and the amplifying circuit connects the microcontroller, and the microcontroller connects Connect the display device.

2. device as claimed in claim 1, it is characterised in that：The electret electrostatic detection head includes electret film and gold Belong to substrate, wherein electret film is covered in metal substrate surface.

3. device as claimed in claim 1, it is characterised in that：The electret film is Teflon Teflon, Parylene Polymer group, one kind in silica, and the inorganic piezoelectric electret of silicon nitride.

4. device as claimed in claim 2 or claim 3, it is characterised in that：The polarization mode of the electret film using ray or Corona polarizing.

5. device as claimed in claim 1, it is characterised in that：The electret electrostatic detection head is multiple, forms electret Electrostatic detection head array.

6. device as claimed in claim 5, it is characterised in that：Electret included in the electret electrostatic detection head array Number n >=4 of body electrostatic detection head, at least ensure each detecting head up and down.

7. the device as described in claim 5 or 6, it is characterised in that：Each electret in the electret electrostatic detection head array Body electrostatic detection head is according to arranged radially.

8. a kind of orientation detection method of the mobile electrical body based on electret effect of use claim 1 described device, its It is characterised by, comprises the following steps：

1) charged object is passed through electret electrostatic detection head, electrical signal of reaction is produced in electret electrostatic detection head；

2) circuit filters the electric signal that noise and other interference are produced after filtering；

3) amplification of obtained filtered signal is passed to by microcontroller by amplifying circuit,

4) microcontroller is obtained by analog-to-digital conversion obtains moving electrical body after the digital quantity of the electric signal by logic judgment Moving direction, and control display device to export judged result.

9. method as claimed in claim 8, it is characterised in that the electret electrostatic detection head is multiple, forms electret Electrostatic detection head array, the direction that electrical body is moved is obtained by the electret electrostatic detection head array.

10. method as claimed in claim 8 or 9, it is characterised in that：The microcontroller will be sensed by modulus conversion chip Voltage waveform is quantified, encoded, and the induced voltage for then producing different metallic substrates is sent to the different pipe of microcontroller Pin；Microcontroller is received after each pin voltage, will not be 0 data start recording from first, to the last one not For 0 data, then compare the size of the induced voltage of synchronization each metallic substrates generation, and its order is arranged；So Afterwards by the size and the vector superposed direction of motion for obtaining electrical body of induced voltage and apart from electret electrostatic detection head battle array The distance of row.