Method for improving distance sensing precision of microwave sensor and microwave sensor

Abstract

The invention discloses a method for improving the distance sensing precision of a microwave sensor, which comprises the following steps: (1) arranging a microwave sensor which comprises a microwave transmitting unit and a microwave receiving unit, transmitting microwave signals by the microwave transmitting unit when an object passes, transmitting the transmitted microwaves back by the object to form reflected waves, and transmitting the reflected waves to the microwave receiving unit; then the microwave receiving unit receives the transmitted wave; (2) setting a timer and a digital-to-analog converter, timing through the timer, triggering the digital-to-analog converter to carry out rapid periodic sampling, and collecting the characteristics of the alternating-current wave signal reflected by the object and obtained by the microwave sensor; (3) detecting a first group of alternating current wave pulse groups; (4) after the first group of alternating-current wave pulse train detection is completed, a second group of alternating-current wave pulse train detection is carried out; and (5) obtaining the time t from the completion of the detection of the first alternating-current wave pulse train to the appearance of the second alternating-current wave pulse train through a timer, and if the time is not greater than the preset time t1, outputting an effective signal by the microwave inductor.

Description

Technical Field

[0001] The invention relates to the field of security, and in particular to a method for improving the distance sensing accuracy of a microwave sensor, and a microwave sensor for implementing the method. Background Art

[0002] A microwave sensor is a sensor that uses the characteristics of microwaves to measure information such as target movement, distance, speed, and direction. The principle is that microwaves are radiated into free space through a transmitting antenna, and reflected back when encountering a moving object. The microwave sensing function is achieved by detecting the reflected AC wave signal. In actual use, changes in the moving speed of an object will cause changes in the frequency and continuity of the reflected AC wave signal of the microwave sensor. If a certain number of reflected AC waves are detected within a certain period of time, it is determined that a moving object has been detected. Since the slower the object moves, the worse the continuity of the reflected AC wave within a certain period of time, the smaller the number, and the more unstable it is, there will be a large difference in the detection distance. Summary of the invention

[0003] The purpose of the present invention is to provide a method for improving the distance sensing accuracy of a microwave sensor and a microwave sensor in view of the deficiencies in the prior art, so as to solve the problem that the detection distance of the existing microwave sensor is easily affected by the moving speed.

[0004] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: A method for improving the distance sensing accuracy of a microwave sensor comprises the following steps: (1) A microwave sensor is provided, which includes a microwave transmitting unit and a microwave receiving unit, wherein the microwave transmitting unit emits a microwave signal. When an object passes by, the emitted microwave is reflected back by the object to form a reflected wave, and then the microwave receiving unit receives the emitted wave; (2) Setting a timer and a digital-to-analog converter, triggering the digital-to-analog converter to perform rapid periodic sampling through the timer, and collecting the characteristics of the AC wave signal reflected by the object obtained by the microwave sensor; (3) Conduct the first set of AC wave pulse group detection; (4) After completing the first set of AC wave pulse group detection, perform the second set of AC wave pulse group detection; (5) The time t from the completion of the detection of the first AC wave pulse group to the appearance of the second AC wave pulse group is obtained through the timer. If the time is not greater than the preset time t1, the microwave sensor outputs a valid signal.

[0005] The preset time is less than or equal to 1 second.

[0006] The step (2) specifically includes: The upper reference threshold of the reflected AC wave signal is preset, the upper reference threshold is the reference value +0.2V, and the lower reference threshold is the reference value -0.2V, wherein the reference value is 2V, and the peak value, frequency value and trough value of the AC wave signal are collected.

[0007] When it is detected that the peak of the AC wave signal is greater than the upper reference threshold, the AC wave peak detection is turned on until the peak of the AC wave signal is less than the upper reference threshold, the AC wave peak collection is completed, and the current frequency value and the AC wave peak value are saved.

[0008] When it is detected that the trough of the AC wave signal is less than the lower reference threshold, the AC wave trough detection is turned on until the trough of the AC wave signal is greater than the upper reference threshold, the AC wave trough collection is completed, and the current frequency value and the AC wave trough value are saved.

[0009] The step (3) specifically includes: When it is detected that there are two consecutive cycles of AC waves that meet the preset frequency range, which is 16KHz to 16Hz, and the AC wave peak is greater than the preset upper threshold and the AC wave trough is less than the preset lower threshold, the timer will count the time interval t0 of the two cycles of AC waves. If t0 is within the preset time range, the first group of AC wave pulse group detection is completed. The preset time is less than or equal to 1 second, the upper threshold is the reference value +0.8V, and the lower threshold is the reference value -0.8V.

[0010] The step (4) specifically includes: After the first group of AC wave pulse group detection is completed, the second group of AC wave pulse group detection is triggered. When it is detected that there are two consecutive cycles of AC waves that meet the preset frequency range, and the peak value and trough value of the AC wave are respectively greater than the preset upper threshold and lower threshold, the timer counts the time interval t0 of the two cycles of AC waves. If t0 is within the preset time range, the second group of AC wave pulse group detection is completed. The preset time is less than or equal to 1 second, the upper threshold is the reference value +0.8V, and the lower threshold is the reference value -0.8V.

[0011] The step (5) specifically includes: When the detection of the first group of AC wave pulse groups is completed, a preset time is set for the timer. If the second group of AC pulse groups appears within the time, the microwave sensor outputs a valid signal.

[0012] The preset time is less than or equal to 1 second.

[0013] A microwave sensor comprises a microwave transmitting unit, a microwave receiving unit, a timer, a digital-to-analog converter and an MCU; wherein the MCU is used to implement the steps of the method for improving the distance sensing accuracy of the microwave sensor.

[0014] The beneficial effect of the present invention is that the present invention can effectively eliminate the influence of different moving speeds of objects on the detection distance of the microwave sensor by acquiring the reflected AC wave within a preset time. If the reflected AC wave within the time period has two consecutive AC waves that meet the preset frequency range and both the peak value and the trough value of the AC wave exceed the preset threshold, and the time interval between the two consecutive AC waves is within the preset time range, the accuracy of microwave sensor distance detection can be further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a working schematic diagram of the microwave sensor of the present invention; Figure 2 A schematic diagram of the reflected AC wave corresponding to a fast-moving object of the present invention; Figure 3 It is a schematic diagram of the reflected AC wave corresponding to the slow-moving object of the present invention. DETAILED DESCRIPTION

[0016] Example: See Figures 1 to 3 , this embodiment provides a method for improving the distance sensing accuracy of a microwave sensor, which includes the following steps: (1) A microwave sensor is provided, which includes a microwave transmitting unit and a microwave receiving unit, wherein the microwave transmitting unit emits a microwave signal. When an object passes by, the emitted microwave is reflected back by the object to form a reflected wave, and then the microwave receiving unit receives the emitted wave; (2) Setting a timer and a digital-to-analog converter, triggering the digital-to-analog converter to perform rapid periodic sampling through the timer, and collecting the characteristics of the AC wave signal reflected by the object obtained by the microwave sensor; (3) Conduct the first set of AC wave pulse group detection; (4) After completing the first set of AC wave pulse group detection, perform the second set of AC wave pulse group detection; (5) The time t from the completion of the detection of the first AC wave pulse group to the appearance of the second AC wave pulse group is obtained through the timer. If the time is not greater than the preset time t1, the microwave sensor outputs a valid signal.

[0017] The preset time is less than or equal to 1 second.

[0018] The step (2) specifically includes: The upper reference threshold of the reflected AC wave signal is preset, the upper reference threshold is the reference value +0.2V, and the lower reference threshold is the reference value -0.2V, wherein the reference value is 2V, and the peak value, frequency value and trough value of the AC wave signal are collected.

[0019] When it is detected that the peak of the AC wave signal is greater than the upper reference threshold, the AC wave peak detection is turned on until the peak of the AC wave signal is less than the upper reference threshold, the AC wave peak collection is completed, and the current frequency value and the AC wave peak value are saved.

[0020] When it is detected that the trough of the AC wave signal is less than the lower reference threshold, the AC wave trough detection is turned on until the trough of the AC wave signal is greater than the lower reference threshold, the AC wave trough collection is completed, and the current frequency value and the AC wave trough value are saved.

[0021] The step (3) specifically includes: When it is detected that there are two consecutive cycles of AC waves that meet the preset frequency range, which is 16KHz to 16Hz, and the AC wave peak is greater than the preset upper threshold and the AC wave trough is less than the preset lower threshold, the timer will count the time interval t0 of the two cycles of AC waves. If t0 is within the preset time range, the first group of AC wave pulse group detection is completed. The preset time is less than or equal to 1 second, the upper threshold is the reference value +0.8V, and the lower threshold is the reference value -0.8V.

[0022] The step (4) specifically includes: After the first group of AC wave pulse group detection is completed, the second group of AC wave pulse group detection is triggered. When it is detected that there are two consecutive cycles of AC waves that meet the preset frequency range, and the AC wave peak is greater than the preset upper threshold and the AC wave trough is less than the preset lower threshold, the timer counts the time interval between the two cycles of AC waves t0. If t0 is within the preset time range, the second group of AC wave pulse group detection is completed. The preset time is less than or equal to 1 second, the upper threshold is the reference value +0.8V, and the lower threshold is the reference value -0.8V.

[0023] The step (5) specifically includes: When the detection of the first group of AC wave pulse groups is completed, a preset time is set for the timer. If the second group of AC pulse groups appears within the time, the microwave sensor outputs a valid signal.

[0024] The preset time is less than or equal to 1 second.

[0025] A microwave sensor comprises a microwave transmitting unit, a microwave receiving unit, a timer, a digital-to-analog converter and an MCU; wherein the MCU is used to implement the steps of the method for improving the distance sensing accuracy of the microwave sensor.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the patent scope of the present invention. Therefore, all changes in the method steps made using the contents of the present invention specification are included in the protection scope of the present invention.

Claims

1. A method for improving the distance sensing accuracy of a microwave sensor, characterized in that: It includes the following steps: (1) A microwave sensor is provided, which includes a microwave transmitting unit and a microwave receiving unit, wherein the microwave transmitting unit emits a microwave signal. When an object passes by, the emitted microwave is reflected back by the object to form a reflected wave, and then the microwave receiving unit receives the emitted wave; (2) Setting a timer and a digital-to-analog converter, triggering the digital-to-analog converter to perform rapid periodic sampling through the timer, and collecting the characteristics of the AC wave signal reflected by the object obtained by the microwave sensor; (3) Conduct the first set of AC wave pulse group detection; (4) After completing the first set of AC wave pulse group detection, perform the second set of AC wave pulse group detection; (5) The time t from the completion of the detection of the first AC wave pulse group to the appearance of the second AC wave pulse group is obtained through the timer. If the time is not greater than the preset time t1, the microwave sensor outputs a valid signal.

2. The method for improving the distance sensing accuracy of a microwave sensor according to claim 1, characterized in that: The step (2) specifically includes: The upper reference threshold of the reflected AC wave signal is preset, the upper reference threshold is the reference value +0.2V, and the lower reference threshold is the reference value -0.2V, wherein the reference value is 2V, and the peak value, frequency value and trough value of the AC wave signal are collected.

3. The method for improving the distance sensing accuracy of a microwave sensor according to claim 2, characterized in that: When it is detected that the peak of the AC wave signal is greater than the upper reference threshold, the AC wave peak detection is turned on until the peak of the AC wave signal is less than the upper reference threshold, the AC wave peak collection is completed, and the current frequency value and the AC wave peak value are saved.

4. The method for improving the distance sensing accuracy of a microwave sensor according to claim 2, characterized in that: When it is detected that the trough of the AC wave signal is less than the lower reference threshold, the AC wave trough detection is turned on until the trough of the AC wave signal is greater than the lower reference threshold, the AC wave trough collection is completed, and the current frequency value and the AC wave trough value are saved.

5. The method for improving the distance sensing accuracy of a microwave sensor according to claim 3, characterized in that: The step (3) specifically includes: When it is detected that two consecutive cycles of AC waves meet the preset frequency range, which is 16KHz to 16Hz, and the AC wave peak is greater than the preset upper threshold and the AC wave trough is less than the preset lower threshold, the timer will count the time interval t0 between the two cycles of AC waves. If t0 is within the preset time range, the first group of AC wave pulse group detection is completed.

6. The method for improving the distance sensing accuracy of a microwave sensor according to claim 4, characterized in that: The step (4) specifically includes: After the first group of AC wave pulse group detection is completed, the second group of AC pulse group detection is triggered. When it is detected that two consecutive cycles of AC waves meet the preset frequency range, and the peak and trough values ​​of the AC waves are respectively greater than the preset upper threshold and lower threshold, the timer will count the time interval t0 between the two cycles of AC waves. If t0 is within the preset time range, the second group of AC wave pulse group detection is completed.

7. The method for improving the distance sensing accuracy of a microwave sensor according to claim 1, characterized in that: The step (5) specifically includes: When the detection of the first group of AC wave pulse groups is completed, a preset time is set for the timer. If the second group of AC pulse groups appears within the time, the microwave sensor outputs a valid signal.

8. A microwave sensor, characterized in that: It comprises a microwave transmitting unit, a microwave receiving unit, a timer, a digital-to-analog converter and an MCU; wherein the MCU is used to implement the steps of the method for improving the distance sensing accuracy of a microwave sensor as described in any one of claims 1 to 7.

Images