Monitoring device and its control method

Abstract

The present application provides a monitoring device and a control method thereof, relating to the technical field of monitoring. The above-mentioned monitoring device includes a camera, an inertial measurement unit, a PIR sensor, and a processor. The processor is configured to: obtain a first signal collected by the inertial measurement unit and a second signal collected by the PIR sensor; monitor whether the camera vibrates according to the first signal; when the camera vibrates, shield the second signal; when the camera does not vibrate, adjust the pitch angle corresponding to the shooting optical axis of the camera according to the obtained first signal and second signal. The technical solution provided by the present application can effectively avoid false alarms of the PIR sensor and improve the reliability of the monitoring device.

Description

Technical Field

[0001] The present application relates to the field of monitoring technology, and in particular to a monitoring device and a control method thereof. Background Art

[0002] Pyroelectric Passive Infrared Ray (PIR) sensor is a sensor commonly used in the security field. It can detect infrared radiation emitted by objects and is particularly suitable for detecting the movement of warm objects such as humans or animals.

[0003] However, since PIR sensors are easily disturbed by ambient temperature fluctuations, there will be many false alarms in practical applications, affecting the reliability of the monitoring device. Summary of the invention

[0004] The present application provides a monitoring device and a control method thereof, which can effectively avoid false alarms from PIR sensors and improve the reliability of the monitoring device.

[0005] In a first aspect, the present application provides a monitoring device, which includes a camera, an inertial measurement unit, a PIR sensor, and a processor; the processor is used to:

[0006] Acquire a first signal collected by the inertial measurement unit and a second signal collected by the PIR sensor;

[0007] According to the first signal, monitoring whether the camera is vibrating;

[0008] When the camera vibrates, shielding the second signal;

[0009] When the camera does not vibrate, the pitch angle corresponding to the shooting optical axis of the camera is adjusted according to the acquired first signal and the second signal.

[0010] In some embodiments, the inertial measurement unit includes a gyroscope, which is used to detect a first angular velocity of the camera along the X-axis, a second angular velocity along the Y-axis, and a third angular velocity along the Z-axis; the processor is specifically used to:

[0011] The magnitudes of the first angular velocity, the second angular velocity, and the third angular velocity are monitored, and when any one or more of the first angular velocity, the second angular velocity, and the third angular velocity is greater than a preset angular velocity threshold, it is determined that the camera is vibrating.

[0012] In some implementations, when there is no vibration in the camera, the processor is further configured to:

[0013] Monitoring whether the voltage amplitude corresponding to the second signal is greater than a preset voltage threshold;

[0014] When the voltage amplitude corresponding to the second signal is greater than the voltage threshold, an alarm message is output.

[0015] In some implementations, the processor is specifically configured to:

[0016] In the case where the camera does not vibrate, obtaining a second signal collected by the PIR sensor within a preset time period and an alarm record of the monitoring device within the preset time period;

[0017] According to the second signal collected by the PIR sensor within the preset time period and the alarm record, it is determined whether the pitch angle needs to be adjusted.

[0018] In some implementations, the processor is specifically configured to:

[0019] According to the second signal collected by the PIR sensor within the preset time period and the alarm record, determine the alarm amplitude of the PIR sensor in multiple time windows, and determine the data cache variance of the PIR sensor in multiple non-alarm output time periods;

[0020] Determining whether the pitch angle needs to be adjusted according to the alarm amplitude of the PIR sensor in the multiple time windows and the data cache variance;

[0021] The above warning amplitude Satisfies the following formula:

[0022] ;

[0023] The above data cache variance Satisfies the following formula:

[0024] ;

[0025] in, Indicates the voltage amplitude corresponding to the second signal collected by the PIR sensor when the alarm is triggered at the nth time point; represents the voltage amplitude corresponding to the second signal collected by the PIR sensor at the i-th time point within the time period without alarm output; It represents the average value of the voltage amplitude corresponding to the second signal collected by the PIR sensor at m time points within the time period without alarm output; n and m are both positive integers.

[0026] In some implementations, the processor is specifically configured to:

[0027] Determine the maximum alarm amplitude of the PIR sensor within a preset time period according to the alarm amplitude of the PIR sensor in the multiple time windows and the data cache variance of the PIR sensor in multiple non-alarm output time periods Variance with the maximum data cache ;

[0028] The alarm amplitude and the maximum alarm amplitude at the current moment When the ratio of is less than or equal to a preset amplitude comparison coefficient, it is determined that the pitch angle needs to be increased;

[0029] The data cache variance at the current moment is equal to the maximum data cache variance When the ratio of is greater than or equal to a preset variance comparison coefficient, it is determined that the pitch angle needs to be reduced.

[0030] In some embodiments, the inertial measurement unit includes an accelerometer, which is used to detect the gravity acceleration of the camera;

[0031] The above processor is specifically used for:

[0032] Obtaining the gravitational acceleration of the camera detected by the accelerometer, and determining a first angle value of the pitch angle corresponding to the shooting optical axis of the camera at the current moment according to the gravitational acceleration and a preset installation angle value;

[0033] When it is determined that the pitch angle needs to be increased, the first relative angle that needs to be adjusted is determined , the first relative angle Satisfies the following formula:

[0034] ;

[0035] ;

[0036] ;

[0037] in, is the maximum effective detection distance of the PIR sensor, Indicates the voltage amplitude corresponding to the second signal collected by the PIR sensor at the current time t, is the first angle value mentioned above, is the target angle value of the above pitch angle.

[0038] In some implementations, the processor is further configured to:

[0039] When it is determined that the pitch angle needs to be reduced, determining the second relative angle currently to be adjusted , the second relative angle Satisfies the following formula:

[0040] ;

[0041] ;

[0042] in, Indicates the data cache variance of the PIR sensor in the most recent no-alarm period.

[0043] In some embodiments, the monitoring device further comprises a motor and a proportional regulator;

[0044] The proportional regulator is used to adjust the first relative angle or the second relative angle , determine the target angle value to be controlled, and feed the target angle value back to the motor;

[0045] The motor is used to drive the camera to rotate in the vertical direction according to the target angle value to adjust the above pitch angle.

[0046] In some implementations, the processor is further configured to:

[0047] Determine the hardware gain level corresponding to the monitoring device according to the frequency of target appearance in the monitoring area;

[0048] Adjust the hardware gain values ​​corresponding to the PIR sensor and / or inertial measurement unit according to the above hardware gain levels.

[0049] In a second aspect, the present application provides a monitoring device control method, which is applied to a monitoring device, wherein the monitoring device includes a camera, an inertial measurement unit, and a PIR sensor, and the method includes:

[0050] Acquire a first signal collected by the inertial measurement unit and a second signal collected by the PIR sensor;

[0051] monitoring whether the camera is vibrating according to the first signal;

[0052] When the camera vibrates, the second signal is shielded;

[0053] When there is no vibration in the camera, the pitch angle corresponding to the shooting optical axis of the camera is adjusted according to the acquired first signal and the second signal.

[0054] In a third aspect, the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the monitoring device control method provided in the second aspect.

[0055] The monitoring device and control method thereof provided by the present application include a camera, an inertial measurement unit and a PIR sensor. The inertial measurement unit is used to monitor whether the camera is vibrating, thereby filtering out false alarms caused by environmental jitter. In addition, based on the signals collected by the inertial measurement unit and the PIR sensor, the pitch angle corresponding to the shooting optical axis of the camera can also be adaptively adjusted to ensure that the detection field of view and the target field of view coincide, thereby increasing the detection capability within the target field of view and improving the reliability of the monitoring device. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0057] Figure 1 A schematic diagram of the structure of a monitoring device provided in an embodiment of the present application;

[0058] Figure 2 A control flow diagram of a monitoring device provided in an embodiment of the present application Figure 1 ;

[0059] Figure 3 A control flow diagram of a monitoring device provided in an embodiment of the present application Figure 2 ;

[0060] Figure 4 A schematic diagram of a time domain signal output timing provided in an embodiment of the present application;

[0061] Figure 5 A schematic diagram of a pitch angle corresponding to a shooting optical axis of a camera provided in an embodiment of the present application;

[0062] Figure 6 A control flow diagram of a monitoring device provided in an embodiment of the present application Figure 3 ;

[0063] Figure 7 A flow chart of a monitoring device control method provided in an embodiment of the present application.

[0064] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0065] Here, each exemplary embodiment of the present application will be described in detail. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application.

[0066] In order to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, "exemplary", "for example", etc. are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0067] In the embodiments of the present application, words such as "first" and "second" are used to distinguish the same or similar items with substantially the same functions and effects. For example, the first signal and the second signal are only used to distinguish different signals, and do not limit their order. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0068] In the embodiments of the present application, "at least one" refers to one or more, and "plurality" refers to two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship.

[0069] In order to clearly describe the technical solutions in the embodiments of the present application, some of the terms and technologies involved in the embodiments of the present application are briefly introduced below:

[0070] 1. PIR sensor

[0071] A non-contact detection sensor based on the pyroelectric effect. The working principle of the PIR sensor is to receive infrared rays radiated by human bodies or animals through the internal pyroelectric element. When a person or animal moves within its detection range, the temperature difference between the person or animal and the surrounding environment will cause the infrared radiation field to change. This change will cause the above pyroelectric element to generate a weak electrical signal. After this signal is amplified and analyzed by the signal processor, once it exceeds the preset threshold, it can be determined that there is human or animal activity.

[0072] 2. Inertial Measurement Unit (IMU)

[0073] IMU is a device that can measure the three-axis attitude angle (or angular rate) and acceleration of an object. IMU can be composed of three single-axis accelerometers and three single-axis gyroscopes, which are used to measure the acceleration and angular velocity of the object in the three axes.

[0074] At present, in the field of environmental perception of security equipment, PIR sensors are easily affected by ambient temperature differences, so there are many false alarms, which limits their use scenarios. For example, when the ambient temperature changes or is disturbed by other heat sources (such as direct sunlight, heating equipment, hot air currents, etc.), the PIR sensor may mistakenly trigger an alarm. In addition, the activities of small animals, light fluctuations, etc. may also cause false alarms, affecting the reliability of the entire security system.

[0075] In some solutions, millimeter-wave radar sensors can be added to monitoring equipment for verification detection. Although this solution improves the motion detection capability and accuracy of monitoring equipment, it will bring about greater power consumption and is not suitable for low-power monitoring scenarios. In other solutions, the sensitivity of the PIR sensor is adjusted by adjusting the configuration pin of the PIR sensor. Although this solution can reduce the probability of false triggering of alarms, it will also cause missed alarms and affect the accuracy of the detection results.

[0076] In view of the above technical problems, a monitoring device is provided in an embodiment of the present application, which includes a camera, an IMU and a PIR sensor. The IMU monitors whether the camera is vibrating, thereby filtering out false alarms caused by environmental jitter; in addition, based on the signals collected by the IMU and the PIR sensor, the pitch angle corresponding to the shooting optical axis of the camera can also be adaptively adjusted to ensure that the detection field of view and the target field of view coincide, increase the detection capability within the target field of view, and improve the reliability of the monitoring device.

[0077] The technical solution provided by the present application is described in detail below through specific embodiments. It should be noted that the following embodiments can exist independently or in combination with each other, and the same or similar contents will not be described repeatedly in different embodiments.

[0078] Reference Figure 1 , Figure 1 A schematic diagram of the structure of a monitoring device provided in an embodiment of the present application.

[0079] In some embodiments, the monitoring device 100 includes a camera 101 , an inertial measurement unit 102 , a PIR sensor 103 , and a processor 104 .

[0080] In some embodiments, the camera 101 can be used to capture images or videos of the monitoring area. The inertial measurement unit 102 can be used to detect and record the motion state information such as acceleration and angular velocity of the camera 101. The PIR sensor 103 can be used to detect moving objects in the monitoring area, such as human bodies or the like. The processor 104 can be used to process the signals collected by the inertial measurement unit 102 and the PIR sensor 103, and control the monitoring device 100.

[0081] In some implementations, the processor 104 may be configured to:

[0082] Acquire a first signal collected by the inertial measurement unit 102 and a second signal collected by the PIR sensor 103; monitor whether the camera 101 is vibrating based on the first signal; when the camera 101 is vibrating, shield the second signal collected by the PIR sensor 103; when the camera 101 is not vibrating, adjust the pitch angle corresponding to the shooting optical axis of the camera 101 based on the acquired first signal and second signal.

[0083] Specifically, the inertial measurement unit 102 can collect acceleration and angular velocity data of the camera 101 in three-dimensional space in real time. The processor 104 can obtain the first signal collected by the inertial measurement unit 102 in real time, and determine whether the camera 101 is vibrating by analyzing the first signal. The vibration may be caused by external interference (such as wind, human touch, etc.).

[0084] When the camera 101 is detected to be vibrating, in order to avoid misjudgment, the processor 104 can shield the second signal collected by the PIR sensor 103, that is, when the camera 101 is detected to be vibrating, even if the PIR sensor 103 detects infrared radiation from a human body or an animal, the alarm function of the monitoring device will not be triggered. This can avoid false alarms caused by unstable images captured by the camera 101 due to vibration.

[0085] When there is no vibration in the camera 101, the processor can normally obtain the second signal collected by the PIR sensor 103, and monitor whether the voltage amplitude corresponding to the second signal is greater than the preset voltage threshold; when the voltage amplitude corresponding to the second signal is greater than the above voltage threshold, an alarm message is output.

[0086] Optionally, the above alarm information can be transmitted through sound, light, display screen or network, so that relevant personnel can respond and handle it in time.

[0087] In some embodiments, when the camera 101 does not vibrate, the processor 104 may determine whether it is necessary to adjust the pitch angle corresponding to the shooting optical axis of the camera 101 based on the acquired first signal and second signal. If it is determined that it is necessary to adjust the pitch angle corresponding to the shooting optical axis of the camera 101, the processor 104 may adjust the pitch angle corresponding to the shooting optical axis of the camera 101 to ensure that the monitoring screen can accurately capture the target object while maintaining the stability of the screen.

[0088] The pitch angle corresponding to the shooting optical axis of the camera 101 may refer to the vertical angle from the horizontal direction line corresponding to the camera lens, along the clockwise (or counterclockwise) direction to the main optical axis of the camera.

[0089] In some embodiments, the detection axis of the PIR sensor 103 can be located in the same direction as the shooting optical axis of the camera 101, that is, when the pitch angle corresponding to the shooting optical axis of the camera 101 changes, the detection range of the PIR sensor 103 will also change accordingly, thereby ensuring that when the PIR sensor 103 detects a moving object, the camera 101 can accurately capture the image or video of the object.

[0090] It is understandable that the adjustment of the pitch angle can change the monitoring range of the camera 101. For example, when the pitch angle increases, the monitoring range may expand diagonally downward.

[0091] It is understandable that the PIR sensor 103 has a larger field of view in the horizontal direction and a narrower field of view in the vertical direction. For wildlife activity scenes, dynamically adjusting the pitch angle corresponding to the shooting optical axis of the camera 101 can effectively adapt to changes in the monitoring environment.

[0092] The monitoring device provided in the embodiment of the present application monitors whether the camera is vibrating through an inertial measurement unit, and can filter out false alarms caused by environmental jitter; in addition, based on the signals collected by the inertial measurement unit and the PIR sensor, the pitch angle corresponding to the shooting optical axis of the camera can also be adaptively adjusted to ensure that the detection field of view and the target field of view coincide with each other, thereby increasing the detection capability within the target field of view and improving the reliability of the monitoring device.

[0093] Reference Figure 2 , Figure 2 A control flow diagram of a monitoring device provided in an embodiment of the present application Figure 1 .

[0094] In some embodiments, the monitoring device control process includes:

[0095] S10: Acquire a first signal and a second signal.

[0096] In some implementations, the processor may acquire a first signal collected by an inertial measurement unit (hereinafter may also be referred to as an IMU) and a second signal collected by a PIR sensor.

[0097] S20, monitoring whether the camera is vibrating.

[0098] In some implementations, the processor may monitor whether the camera is vibrating based on the acquired first signal; if so, execute S80; if not, continue to execute S30.

[0099] S30, detecting the pitch angle of the camera.

[0100] In some implementations, the processor may detect a first angle value of a pitch angle corresponding to a shooting optical axis of the camera at the current moment according to the first signal.

[0101] S40, adjust the camera pitch angle.

[0102] In some implementations, the processor may determine whether the pitch angle needs to be adjusted based on the second signal.

[0103] S50, adjust the hardware gain.

[0104] In some implementations, the processor may adjust the hardware gain value corresponding to the PIR sensor and / or the inertial measurement unit according to the current detection environment.

[0105] S60: Determine whether the voltage amplitude of the second signal is greater than a voltage threshold.

[0106] In some implementations, the processor may determine whether the voltage amplitude of the second signal is greater than a voltage threshold, and if so, execute S70 ; if not, return to execute S10 .

[0107] S70: Output warning information.

[0108] S80, filter out false alarms.

[0109] In some implementations, when the camera vibrates, the second signal may be directly shielded. In this case, no matter whether the voltage amplitude corresponding to the second signal is greater than the voltage threshold, there is no need to output an alarm message.

[0110] In some implementations, when the camera vibrates, a force majeure alarm message may also be output, and the force majeure alarm message may remind relevant personnel that the operating status of the monitoring device is disrupted.

[0111] The above steps S10 to S80 are described in detail below.

[0112] In some embodiments, acquiring the first signal and the second signal in the above step S10 includes:

[0113] Acquire a first signal collected by the IMU and a second signal collected by the PIR sensor, wherein the IMU may collect the first signal at a first sampling rate, and the PIR sensor may collect the first signal at a second sampling rate.

[0114] Optionally, the first sampling rate may be much higher than the second sampling rate.

[0115] Exemplarily, the first sampling rate may be 1 KHz, and the second sampling rate may be 100 Hz.

[0116] In some embodiments, the IMU includes a gyroscope for detecting a first angular velocity of the camera along an X-axis, a second angular velocity along a Y-axis, and a third angular velocity along a Z-axis.

[0117] Monitoring whether the camera is vibrating in the above step S20 includes: monitoring the magnitudes of the above first angular velocity, the second angular velocity and the third angular velocity, and when any one or more of the above first angular velocity, the second angular velocity and the third angular velocity is greater than a preset angular velocity threshold, it is determined that the above camera is vibrating.

[0118] For example, refer to Figure 3 , Figure 3 A control flow diagram of a monitoring device provided in an embodiment of the present application Figure 2 .

[0119] like Figure 3 As shown, the processor can obtain the X-axis angular velocity, Y-axis angular velocity and Z-axis angular velocity detected by the gyroscope in real time, perform static detection on the X-axis angular velocity, Y-axis angular velocity and Z-axis angular velocity respectively, and determine whether the camera has obvious jitter along the X-axis, Y-axis and Z-axis. The single-axis detection result can be output as 0 or 1, 0 indicates no jitter at present, and 1 indicates jitter due to external interference.

[0120] Optionally, when the angular velocity of any axis is greater than a preset angular velocity threshold, it is determined that the axis has jitter; otherwise, it is determined that the axis does not have jitter.

[0121] In some embodiments, the detection results of the X-axis, Y-axis, and Z-axis may be subjected to an OR logic (|) operation to obtain a vibration detection result. :

[0122] ;

[0123] in, Indicates the detection result corresponding to the X-axis, Indicates the detection result corresponding to the Y axis, Indicates the detection result corresponding to the Z axis.

[0124] In some embodiments, when When the camera is determined to be vibrating, the second signal collected by the PIR sensor can be shielded and the camera enters a dormant state.

[0125] For example, refer to Figure 4 , Figure 4 A schematic diagram of a time domain signal output timing provided in an embodiment of the present application.

[0126] like Figure 4 As shown, when the three-axis angular velocity is greater than the preset threshold, the vibration detection result =1, no matter whether the voltage amplitude corresponding to the second signal is greater than the preset voltage threshold, the alarm detection result is 0, that is, no alarm is triggered.

[0127] In some implementations, the IMU can be used for not only vibration detection but also pitch angle detection of the camera.

[0128] It is understandable that in order to maximize the detection range of outdoor scenes, cameras are generally installed at the default pitch angle to ensure that the detection field of the PIR sensor can fully cover the monitoring area. In actual operation, due to the constraints of the installer and the environment, the installation position of the camera may not fully meet the actual requirements, resulting in the actual detection field of the PIR sensor and the ideal field of view not coinciding, which in turn causes false alarms and missed alarms of the PIR sensor.

[0129] In some embodiments, the inertial measurement unit includes an accelerometer, which is used to detect gravity acceleration of the camera.

[0130] Detecting the pitch angle of the camera in the above step S30 includes: obtaining the gravity acceleration of the camera detected by the above accelerometer, and determining a first angle value of the pitch angle corresponding to the shooting optical axis of the camera at the current moment according to the gravity acceleration and a preset installation angle value.

[0131] In some embodiments, when the environmental area is stable, the accelerometer signal in the IMU is collected as the input for pitch angle detection. The angle between the synthetic direction of the gravity vector and the Z-axis installation coordinate system can be used to determine whether the camera is tilted, and the first angle value of the pitch angle corresponding to the current shooting optical axis of the camera is recorded.

[0132] In some implementations, adjusting the camera pitch angle in step S40 includes:

[0133] When there is no vibration of the camera, obtain the second signal collected by the PIR sensor within the preset time length and the alarm record of the monitoring device within the preset time length; determine whether the above-mentioned pitch angle needs to be adjusted based on the second signal collected by the PIR sensor within the preset time length and the alarm record.

[0134] In some embodiments, the alarm amplitude of the PIR sensor in multiple time windows can be determined based on the second signal collected by the PIR sensor within the preset time length and the above alarm record. , and regularly extract the data cache variance of the PIR sensor in multiple non-alarm output time periods .

[0135] Optionally, the above warning amplitude Satisfies the following formula:

[0136] ;

[0137] Optionally, the above data cache variance Satisfies the following formula:

[0138] ;

[0139] in, Indicates the voltage amplitude corresponding to the second signal collected by the PIR sensor when the alarm is triggered at the nth time point; represents the voltage amplitude corresponding to the second signal collected by the PIR sensor at the i-th time point within the time period without alarm output; It represents the average value of the voltage amplitude corresponding to the second signal collected by the PIR sensor at m time points within the time period without alarm output; n and m are both positive integers.

[0140] In some implementations, it may be determined whether the pitch angle needs to be adjusted based on the alarm amplitude of the PIR sensor in multiple time windows and the data cache variance.

[0141] In some embodiments, the maximum alarm amplitude of the PIR sensor within a preset time period can be determined based on the alarm amplitude of the PIR sensor in multiple time windows and the data cache variance of the PIR sensor in multiple non-alarm output time periods. Variance with the maximum data cache .

[0142] The alarm amplitude and the maximum alarm amplitude at the current moment When the ratio of is less than or equal to the preset amplitude comparison coefficient, it is determined that the pitch angle needs to be increased.

[0143] The data cache variance at the current moment and the maximum data cache variance When the ratio of is greater than or equal to a preset variance comparison coefficient, it is determined that the pitch angle needs to be reduced.

[0144] For example, when the alarm amplitude at time t is Far lower than the maximum alarm amplitude collected over a period of time ,Right now , indicating that the current environmental signal strength is weak, it is necessary to adjust the above pitch angle to improve the signal strength and increase the detection sensitivity. is the amplitude comparison coefficient.

[0145] After filtering out false positives due to environmental jitter, the data cache variance at time t is Much higher than the maximum data cache variance during the period without alarms ,Right now When the current time period is seriously disturbed, the signal fluctuates significantly, and the detection sensitivity needs to be reduced to eliminate false alarms. is the variance comparison coefficient.

[0146] For example, refer to Figure 5 , Figure 5 A schematic diagram of the pitch angle corresponding to the shooting optical axis of a camera provided in an embodiment of the present application.

[0147] from Figure 5 It is not difficult to see that the pitch angle The field of view is detection range 1. When the environmental signal strength weakens, the pitch angle needs to be increased downward to improve the detection accuracy. At this time, the same target in detection range 2 is closer to the camera in vertical distance, and the generated signal strength is stronger.

[0148] In some implementations, when it is determined that the pitch angle needs to be increased, the first relative angle currently to be adjusted is determined: , the first relative angle Satisfies the following formula:

[0149] ;

[0150] ;

[0151] ;

[0152] in, is the maximum effective detection distance of the PIR sensor, Indicates the voltage amplitude corresponding to the second signal collected by the PIR sensor at the current time t, is the first angle value mentioned above, is the target angle value of the pitch angle.

[0153] In some implementations, when the environmental signal interference is severe, it is necessary to reduce the pitch angle upward to reduce false alarms.

[0154] In some implementations, when it is determined that the pitch angle needs to be reduced, the second relative angle currently to be adjusted is determined: , the second relative angle Satisfies the following formula:

[0155] ;

[0156] ;

[0157] in, Indicates the data cache variance of the PIR sensor in the most recent no-alarm period.

[0158] In some embodiments, the monitoring device further comprises a motor and a proportional regulator. The proportional regulator is used to adjust the first relative angle or the second relative angle , determine the target angle value that needs to be controlled, and feed the target angle value back to the above-mentioned motor; the above-mentioned motor is used to drive the camera to rotate in the vertical direction according to the target angle value to adjust its pitch angle.

[0159] Reference Figure 6 , Figure 6 A control flow diagram of a monitoring device provided in an embodiment of the present application Figure 3 .

[0160] like Figure 6 As shown, the processor can monitor whether the camera is vibrating based on the first signal collected by the IMU. If there is vibration, the three-axis acceleration collected by the IMU is obtained, and the first angle value of the pitch angle corresponding to the shooting optical axis of the camera at the current moment is determined based on the three-axis acceleration.

[0161] When there is no vibration of the camera, the processor can perform motion detection based on the second signal collected by the PIR sensor to determine whether there is a moving target within the detection range. In addition, the processor can determine whether it is necessary to adjust the pitch angle corresponding to the shooting optical axis of the camera based on the second signal collected by the PIR sensor, and if so, determine the relative angle that needs to be adjusted, and control the motor to rotate to adjust the pitch angle.

[0162] In some implementations, in order to ensure that the adjusted pitch angle coincides with the actual rotation angle, the pitch angle deviation may be continuously corrected based on the acceleration signal collected by the IMU as a reference.

[0163] In some implementations, the rotation deviation correction is a dynamic adjustment process. Assume that the pitch angle to be adjusted at time t is , the actual pitch angle of the camera In order to improve the rotation accuracy as much as possible, the control error can be reduced by the proportional regulator to calculate the theoretically required control angle. .

[0164] ;

[0165] in, is the proportional regulator coefficient.

[0166] In some embodiments, the processor may also be configured to:

[0167] According to the frequency of occurrence of the target in the monitoring area, the hardware gain level corresponding to the monitoring device is determined; according to the hardware gain level, the hardware gain value corresponding to the PIR sensor and / or the inertial measurement unit is adjusted.

[0168] For example, for different detection scenarios, the hardware gain can be divided into three gears, namely low gain, medium gain and high gain. When the detection environment is in a relatively single scene, the gain can be adjusted to the high gain gear to reduce the missed alarms of the monitoring device and improve the detection sensitivity; when the detection environment is in a scene with mixed interference sources (such as bushes, woods, etc.), the gain can be switched to the low gain gear to reduce the wake-up sensitivity of the monitoring device, thereby reducing the power consumption of the monitoring device and filtering false alarms.

[0169] In some implementations, the hardware gain level can be set manually or determined based on the frequency of occurrence of targets on site, to ensure that the device is not frequently awakened in complex scenarios and has a higher detection rate in a single scenario.

[0170] The monitoring device provided in the embodiments of the present application can achieve the following beneficial effects:

[0171] (1) Currently, the field of view of the PIR lens is large in the horizontal direction and narrow in the vertical direction. For wildlife activity scenes, the vertical field of view is adjustable to better adapt to the monitoring environment.

[0172] (2) Based on the signals collected by the IMU and PIR sensors, the pitch angle corresponding to the camera's shooting optical axis is adaptively adjusted to ensure that the detection field of view and the target field of view coincide with each other, thereby improving the long-distance detection capability of the monitoring device.

[0173] (3) The IMU is used to monitor whether the camera is vibrating, thereby filtering out false alarms caused by environmental jitter and reducing the false alarm rate.

[0174] (4) The hardware gain can be adjusted according to the monitoring site conditions to ensure that the device is not frequently awakened in complex scenarios and has a high detection rate in a single scenario.

[0175] In some embodiments of the present application, a monitoring device control method is also provided, referring to Figure 7 , Figure 7 This is a flow chart of a monitoring device control method provided in an embodiment of the present application. The method can be applied to a monitoring device, which includes a camera, an inertial measurement unit, and a PIR sensor, including:

[0176] S701: Acquire a first signal collected by an inertial measurement unit and a second signal collected by a PIR sensor.

[0177] S702: monitor whether the camera is vibrating according to the first signal, if yes, execute S703, if no, execute S704.

[0178] S703: Shield the second signal.

[0179] S704: Adjust the pitch angle corresponding to the shooting optical axis of the camera according to the acquired first signal and the second signal.

[0180] The monitoring device control method and computer-readable storage medium provided in the present application can filter out false alarms caused by environmental jitter by monitoring whether the camera is vibrating through an inertial measurement unit; in addition, based on the signals collected by the inertial measurement unit and the PIR sensor, the pitch angle corresponding to the shooting optical axis of the camera can also be adaptively adjusted to ensure that the detection field of view and the target field of view coincide, thereby increasing the detection capability within the target field of view and improving the reliability of the monitoring device.

[0181] In some embodiments, the inertial measurement unit includes a gyroscope, which is used to detect a first angular velocity of the camera along the X-axis, a second angular velocity along the Y-axis, and a third angular velocity along the Z-axis; and monitoring whether the camera is vibrating according to the first signal includes:

[0182] The magnitudes of the first angular velocity, the second angular velocity and the third angular velocity are monitored, and when any one or more of the first angular velocity, the second angular velocity and the third angular velocity is greater than a preset angular velocity threshold, it is determined that the camera is vibrating.

[0183] In some embodiments, the above method further comprises:

[0184] When there is no vibration in the camera, monitor whether the voltage amplitude corresponding to the second signal is greater than a preset voltage threshold; when the voltage amplitude corresponding to the second signal is greater than the voltage threshold, output an alarm message.

[0185] In some embodiments, the above method further comprises:

[0186] When there is no vibration of the camera, a second signal collected by the PIR sensor within a preset time length and an alarm record of the monitoring device within the preset time length are obtained; based on the second signal collected by the PIR sensor within the preset time length and the above alarm record, it is determined whether the above pitch angle needs to be adjusted.

[0187] In some embodiments, the determining whether the pitch angle needs to be adjusted according to the second signal collected by the PIR sensor within a preset time period and the alarm record includes:

[0188] According to the second signal collected by the PIR sensor within the preset time period and the alarm record, determine the alarm amplitude of the PIR sensor in multiple time windows, and determine the data cache variance of the PIR sensor in multiple non-alarm output time periods;

[0189] Determining whether the pitch angle needs to be adjusted according to the alarm amplitude of the PIR sensor in the multiple time windows and the data cache variance;

[0190] The above warning amplitude Satisfies the following formula:

[0191] ;

[0192] The above data cache variance Satisfies the following formula:

[0193] ;

[0194] in, Indicates the voltage amplitude corresponding to the second signal collected by the PIR sensor when the alarm is triggered at the nth time point; represents the voltage amplitude corresponding to the second signal collected by the PIR sensor at the i-th time point within the time period without alarm output; It represents the average value of the voltage amplitude corresponding to the second signal collected by the PIR sensor at m time points within the time period without alarm output; n and m are both positive integers.

[0195] In some embodiments, the above method further comprises:

[0196] According to the alarm amplitude of the PIR sensor in multiple time windows and the data cache variance of the PIR sensor in multiple non-alarm output time periods, the maximum alarm amplitude of the PIR sensor within the preset time length is determined Variance with the maximum data cache ;

[0197] The alarm amplitude and the maximum alarm amplitude at the current moment When the ratio of is less than or equal to a preset amplitude comparison coefficient, it is determined that the pitch angle needs to be increased;

[0198] The data cache variance at the current moment and the maximum data cache variance When the ratio of is greater than or equal to a preset variance comparison coefficient, it is determined that the pitch angle needs to be reduced.

[0199] In some embodiments, the inertial measurement unit includes an accelerometer, and the accelerometer is used to detect the gravity acceleration of the camera; and the method further includes:

[0200] Obtaining the gravitational acceleration of the camera detected by the accelerometer, and determining a first angle value of the pitch angle corresponding to the shooting optical axis of the camera at the current moment according to the acceleration and a preset installation angle value;

[0201] When it is determined that the pitch angle needs to be increased, determining the first relative angle that needs to be adjusted , the first relative angle Satisfies the following formula:

[0202] ;

[0203] ;

[0204] ;

[0205] in, is the maximum effective detection distance of the PIR sensor, Indicates the voltage amplitude corresponding to the second signal collected by the PIR sensor at the current time t, is the first angle value, is the target angle value of the pitch angle.

[0206] When it is determined that the pitch angle needs to be reduced, the second relative angle to be adjusted is determined , the second relative angle Satisfies the following formula:

[0207] ;

[0208] ;

[0209] in, Indicates the data cache variance of the PIR sensor in the most recent no-alarm period.

[0210] In some embodiments, the above method further comprises:

[0211] According to the frequency of the target appearing in the monitoring area, the hardware gain level corresponding to the monitoring device is determined; according to the hardware gain level, the hardware gain value corresponding to the PIR sensor and / or the inertial measurement unit is adjusted.

[0212] The monitoring device control method provided in the embodiment of the present application can use the PIR sensor to capture moving targets with different temperatures from the ambient temperature, and detect whether the current environment is damaged by impact according to the inertial measurement unit, so as to filter out false alarms generated in unstable environmental scenes. In addition, the installation pitch angle of the current camera is read by the accelerometer, and the pitch angle is adaptively adjusted according to the second signal to optimize the PIR detection effect of the current field of view. At the same time, the hardware gain is configured by software to adjust the detection sensitivity and accuracy, so as to ensure the accuracy of motion detection.

[0213] The present application also provides a computer-readable storage medium, which stores a computer program (also referred to as code or instruction). When the computer program is executed, the monitoring device control method provided in the above-mentioned embodiment can be implemented.

[0214] The present application also provides a computer program product, which includes: a computer program (also referred to as code, or instruction). When the computer program is executed, the monitoring device control method provided in the above-mentioned embodiment can be implemented.

[0215] It is understandable that the division of each unit or module in the above-mentioned monitoring device is only a division of logical functions. Each function may correspond to a unit / functional module, or two or more functions may be integrated into one unit / functional module. In actual implementation, all or part of the units / modules may be integrated into one physical entity, or they may be distributed in different physical entities. In addition, the above-mentioned functional modules may be implemented in the form of hardware, software, or a combination of hardware and software, depending on the actual situation. Whether a function is executed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0216] In the above embodiments, the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc. The steps of the method provided in the present application may be directly embodied as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0217] The functional units in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0218] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program codes.

[0219] Finally, it should be noted that this application is intended to cover any variation, use or adaptation of this application, which follows the general principles of this application and includes common knowledge or customary technical means in the technical field that are not applied for in this application, is not limited to the precise structure described above and shown in the drawings, and can be modified and changed in various ways without departing from the scope thereof. The scope of this application is limited only by the appended claims.

Claims

1. A monitoring device, characterized in that: The monitoring device includes a camera, an inertial measurement unit, a pyroelectric infrared (PIR) sensor, and a processor; the processor is used to: Acquire a first signal collected by the inertial measurement unit and a second signal collected by the PIR sensor; monitoring whether the camera is vibrating according to the first signal; When the camera vibrates, shielding the second signal; When the camera does not vibrate, the pitch angle corresponding to the shooting optical axis of the camera is adjusted according to the acquired first signal and the second signal.

2. The monitoring device according to claim 1, characterized in that: The inertial measurement unit includes a gyroscope, and the gyroscope is used to detect a first angular velocity of the camera along the X-axis direction, a second angular velocity along the Y-axis direction, and a third angular velocity along the Z-axis direction; The processor is specifically used for: The magnitudes of the first angular velocity, the second angular velocity, and the third angular velocity are monitored, and when any one or more of the first angular velocity, the second angular velocity, and the third angular velocity is greater than a preset angular velocity threshold, it is determined that the camera is vibrating.

3. The monitoring device according to claim 1 or 2, characterized in that: When the camera does not vibrate, the processor is further configured to: Monitoring whether a voltage amplitude corresponding to the second signal is greater than a preset voltage threshold; When the voltage amplitude corresponding to the second signal is greater than the voltage threshold, an alarm message is output.

4. The monitoring device according to claim 1, characterized in that: The processor is specifically used for: In the case where the camera does not vibrate, obtaining a second signal collected by the PIR sensor within a preset time period and an alarm record of the monitoring device within the preset time period; Determine whether the pitch angle needs to be adjusted according to the second signal collected by the PIR sensor within the preset time period and the alarm record.

5. The monitoring device according to claim 4, characterized in that: The processor is specifically used for: Determine the alarm amplitude of the PIR sensor in multiple time windows and the data cache variance of the PIR sensor in multiple no-alarm output time periods according to the second signal collected by the PIR sensor within the preset time period and the alarm record; Determining whether the pitch angle needs to be adjusted according to the alarm amplitude of the PIR sensor in the multiple time windows and the data cache variance; The alarm amplitude Satisfies the following formula: ； The data cache variance Satisfies the following formula: ； in, represents the voltage amplitude corresponding to the second signal collected by the PIR sensor when the alarm is triggered at the nth time point; represents the voltage amplitude corresponding to the second signal collected by the PIR sensor at the i-th time point within the no alarm output time period; It represents the average value of the voltage amplitude corresponding to the second signal collected by the PIR sensor at m time points within the no alarm output time period; n and m are both positive integers.

6. The monitoring device according to claim 5, characterized in that: The processor is specifically used for: Determine the maximum alarm amplitude of the PIR sensor within the preset time length according to the alarm amplitude of the PIR sensor in the multiple time windows and the data cache variance of the PIR sensor in the multiple no-alarm output time periods Variance with the maximum data cache ; The alarm amplitude at the current moment and the maximum alarm amplitude When the ratio of is less than or equal to a preset amplitude comparison coefficient, it is determined that the pitch angle needs to be increased; The data cache variance at the current moment is equal to the maximum data cache variance When the ratio of is greater than or equal to a preset variance comparison coefficient, it is determined that the pitch angle needs to be reduced.

7. The monitoring device according to claim 6, characterized in that: The inertial measurement unit includes an accelerometer, and the accelerometer is used to detect the gravity acceleration of the camera; The processor is specifically used for: Acquire the gravitational acceleration of the camera detected by the accelerometer, and determine a first angle value of the pitch angle corresponding to the shooting optical axis of the camera at the current moment according to the gravitational acceleration and a preset installation angle value; When it is determined that the pitch angle needs to be increased, determining the first relative angle that needs to be adjusted , the first relative angle Satisfies the following formula: ； ； ； in, is the maximum effective detection distance of the PIR sensor, represents the voltage amplitude corresponding to the second signal collected by the PIR sensor at the current time t, is the first angle value, is the target angle value of the pitch angle.

8. The monitoring device according to claim 7, characterized in that: The processor is further configured to: When it is determined that the pitch angle needs to be reduced, a second relative angle that needs to be adjusted is determined , the second relative angle Satisfies the following formula: ； ； in, Indicates the data cache variance of the PIR sensor in the most recent no-alarm time period.

9. The monitoring device according to claim 1, characterized in that: The processor is further configured to: Determining a hardware gain level corresponding to the monitoring device according to the frequency of occurrence of the target in the monitoring area; According to the hardware gain level, the hardware gain value corresponding to the PIR sensor and / or the inertial measurement unit is adjusted.

10. A monitoring device control method, characterized in that: Applied to a monitoring device, the monitoring device includes a camera, an inertial measurement unit and a PIR sensor, and the method includes: Acquire a first signal collected by the inertial measurement unit and a second signal collected by the PIR sensor; monitoring whether the camera is vibrating according to the first signal; When the camera vibrates, shielding the second signal; When the camera does not vibrate, the pitch angle corresponding to the shooting optical axis of the camera is adjusted according to the acquired first signal and the second signal.

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