CN114584155A

CN114584155A - Monitoring device

Info

Publication number: CN114584155A
Application number: CN202011399446.8A
Authority: CN
Inventors: 张宏振; 万心; 王岳
Original assignee: Hangzhou Hikvision Digital Technology Co Ltd
Current assignee: Hangzhou Hikvision Digital Technology Co Ltd
Priority date: 2020-12-02
Filing date: 2020-12-02
Publication date: 2022-06-03
Anticipated expiration: 2040-12-02
Also published as: CN114584155B

Abstract

The invention provides a monitoring device. According to the invention, the monitoring device can be provided with at least two directional antennas with non-overlapping radiation angles, so that the directional antenna conducted with the communication component can be arbitrarily selected, and after the communication component is conducted with any selected directional antenna, the link impedance of a conducting link between the communication component and the selected directional antenna can be adjusted, so that the selected directional antenna can provide the best possible communication capability for receiving and transmitting radio frequency signals, and therefore, by utilizing at least two directional antennas with higher gain than that of an omnidirectional antenna, the multi-directional compatibility, the communication distance and the signal stability of the monitoring device can be considered.

Description

Monitoring device

Technical Field

The invention relates to the field of security and protection, in particular to monitoring equipment.

Background

In the security field, the monitoring device may generally have an antenna, and may be accessed to a base station based on the antenna, and implement wireless transceiving transmission of radio frequency signals with the base station.

The deployment point locations of the monitoring device in different scenes may have different orientations relative to the base station, and in order to be compatible with various possible relative orientations between the deployment point locations and the base station, the antenna of the monitoring device may be an omnidirectional antenna. Among them, the omni-directional antenna can uniformly radiate in a horizontal range of 360 °, i.e., the omni-directional antenna can be understood as being non-directional.

However, the omni-directional antenna has a limited gain, which results in a short communication distance of the monitoring device, and therefore, when the deployment site is far away from the base station, the signal quality of the monitoring device is poor, and even there is a high risk of disconnection.

Therefore, in the prior art, the communication distance and the signal stability of the monitoring equipment cannot be considered under the condition that the multi-directional compatibility capability is configured for the monitoring equipment.

Disclosure of Invention

The technical scheme provided by the embodiment of the invention aims to give consideration to the multi-directional compatibility and the communication signal stability of the monitoring equipment.

In one embodiment, there is provided a monitoring device comprising:

an antenna assembly comprising at least two directional antennas whose radiating angles do not fully overlap;

a communication component for transceiving radio frequency signals through the antenna component;

switching circuitry for conducting the communications component to the selected one of the antenna components;

frequency detection means for detecting the transmission frequency of the communication assembly and/or the reception frequency of the directional antenna selected;

an impedance matching circuit connected in series in the conductive link between the selected directional antenna and the communication component, so that the radio frequency signal transmitted by the communication component is transmitted to the selected directional antenna through the impedance matching circuit to be transmitted, and the radio frequency signal received by the selected directional antenna is transmitted to the communication component through the impedance matching circuit;

wherein the circuit impedance of the impedance matching circuit is adapted to the transmission frequency and/or the reception frequency to be adjusted such that the link impedance of the conductive link converges towards a preset impedance threshold.

Optionally, the trend of adjustment of the circuit impedance of the impedance matching circuit is opposite to the trend of change of the transmission frequency and/or the reception frequency.

Optionally, the circuit impedance of the impedance matching circuit is adjusted by a change of an adjustable inductance in the impedance matching circuit, and an adjustment trend of the circuit impedance is in the same direction as a change trend of the adjustable inductance.

Optionally, the parameters for determining the circuit impedance of the impedance matching circuit comprise a transmit frequency and/or a receive frequency of the radio frequency signal, and an adjustable inductance and the impedance matching circuit is configured to; the circuit impedance is determined by the adjustable inductance in response to the transmit frequency and/or the receive frequency.

Optionally, the impedance matching circuit comprises: a first impedance matching circuit connected in series between the communications component and the switch switching circuit, and a second impedance matching circuit connected in series between each of the directional antennas in the antenna component and the switch switching circuit; the frequency detection device includes: first frequency detection means for detecting a transmission frequency of a transmission end of the communication component, and second frequency detection means for detecting a reception frequency of a selected feeding end of the directional antenna; wherein a first circuit impedance of the first impedance matching circuit is determined according to the transmission frequency, a second circuit impedance of the second impedance matching circuit is determined according to the reception frequency, and a sum of the first circuit impedance and the second impedance is adjusted such that the link impedance converges the link impedance of the conductive link toward a preset impedance threshold.

Optionally, the apparatus further comprises a switch control device for alternately adjusting the first circuit impedance of the first impedance matching circuit during the transmission time slot and adjusting the second circuit impedance of the second impedance matching circuit during the reception time slot according to a transceiving timing signal indicating a transmission time slot and a reception time slot.

Optionally, the communication module further comprises a switch control device, configured to generate a level signal to the switch switching circuit according to a control instruction, where the level signal is used to indicate the directional antenna selected by the control instruction, so as to conduct the communication module with the directional antenna selected by the control instruction.

Optionally, the monitoring device is a camera having a lens assembly and a pan-tilt assembly, wherein the antenna assembly is disposed on a lower side of the pan-tilt assembly, and the pan-tilt assembly drives the lens assembly to rotate relative to the antenna assembly.

Optionally, the antenna assembly and the imaging module equipartition cavity arrangement that the pan and tilt head assembly, the lens assembly and the camera further have.

Optionally, the communication capability of the directional antenna is determined according to a received power and a signal-to-noise ratio of a radio frequency signal based on the directional antenna.

Optionally, the antenna module further includes a main control component, configured to, after the communication component is turned on with a first directional antenna in the antenna assemblies, if it is detected that at least one of a received power and a signal-to-noise ratio of a radio frequency signal based on the first directional antenna is lower than a preset threshold, select a second directional antenna in the antenna assemblies according to the received power and the signal-to-noise ratio, and generate a control instruction indicating that the selected directional antenna is the second directional antenna, so as to trigger the switch circuit to switch the communication component turned on with the first directional antenna into conduction with the second directional antenna.

Optionally, the main control component further determines the communication capability of the directional antenna by using a weighted operation result of the received power and the signal-to-noise ratio.

Optionally, the main control component is further configured to select the first directional antenna in the antenna assembly according to a default configuration after the monitoring device is powered on.

Based on the above embodiment, the monitoring device may be equipped with at least two directional antennas whose radiation angles do not overlap completely, so that the directional antenna that is conducted with the communication component may be arbitrarily selected, and after the communication component is conducted with any selected directional antenna, the link impedance of the conducting link between the communication component and the selected directional antenna may also be adjusted to promote the selected directional antenna to provide the best possible communication capability for the radio frequency signal transceiving, so that, by using at least two directional antennas having higher gain than the omni-directional antenna, multi-directional compatibility of the monitoring device and communication signal stability may be both considered.

Drawings

The following drawings are only schematic illustrations and explanations of the present invention, and do not limit the scope of the present invention:

FIG. 1 is a schematic diagram of the monitoring device in one embodiment;

FIG. 2 is a graph of a gain ratio of a directional antenna compared to an omni-directional antenna of the monitoring device shown in FIG. 1;

FIG. 3 is a schematic diagram of an optimized structure of the monitoring device shown in FIG. 1;

FIG. 4 is a schematic diagram of the impedance adjustment principle of the optimized structure shown in FIG. 3;

FIG. 5 is a schematic diagram of an exemplary configuration of the first impedance matching circuit and the second impedance matching circuit in the optimized configuration shown in FIG. 3;

FIG. 6 is a schematic diagram of the optimal selection mechanism of the directional antenna in the monitoring device shown in FIG. 1;

FIG. 7 is a schematic diagram of an external deployment scenario of a directional antenna in the monitoring device shown in FIG. 1;

fig. 8 is an exemplary flowchart of a communication control method of a monitoring apparatus in another embodiment;

fig. 9 is a schematic diagram illustrating an optimization flow of the communication control method shown in fig. 8.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and examples.

Fig. 1 is a schematic structural diagram of a monitoring device in one embodiment. Fig. 2 is a graph of gain ratio of a directional antenna compared to an omni-directional antenna of the monitoring device shown in fig. 1. Referring to fig. 1, the monitoring device in this embodiment may be a pan-tilt monitoring device supporting high-altitude lookout in a sparse region of people density, such as a highway, a forest region, a remote mountain region, and the like, and the monitoring device may include an antenna assembly 11, a communication assembly 12, a main control assembly 14, and a switching assembly 15.

The antenna assembly 11 may include at least two directional antennas 110 whose radiating angles do not fully overlap.

Here, unlike an omni-directional antenna that radiates uniformly over a 360 ° range, a directional antenna may radiate over a certain horizontal angle range (i.e., radiation angle), and thus may be considered to have directivity.

Preferably, the radiation angles of the at least two directional antennas 110 may seamlessly merge within a range of 360 °.

With reference to fig. 1 and further attention to fig. 2, taking the antenna assembly 11 including four directional antennas 110 as an example, the radiation angle of a single directional antenna 110 may be set to 120 °, and the radiation angle of each directional antenna 110 may overlap with the radiation angle of the adjacent directional antenna on each side by 15 °, so as to achieve full coverage of the four directional antennas 110 in a seamless split manner within a range of 360 °. Also, since the lobe (shown as a solid line in fig. 2) width of the directional antenna 110 is smaller than the lobe (shown as a dotted line in fig. 2) width of the omnidirectional antenna, the signal gain of the directional antenna 110 is larger than that of the omnidirectional antenna, for example, the signal gain of a single directional antenna 110 may be 5-10 dbm (decibel relative to milliwatt) more than that of the omnidirectional antenna.

Therefore, the transceiving of radio frequency signals (monitoring data and instruction data) using the directional antenna 110 can have higher frequency utilization efficiency and longer communication distance. Thus, the directional antenna 110 with full coverage formed by seamless combination of radiation angles can support a longer communication distance and higher signal stability than an omnidirectional antenna in an omnidirectional range of 360 °.

It will be appreciated that the number of directional antennas 110 and the angular value of the radiation angle in the above examples should not constitute an unnecessary limitation to this embodiment, and that the use of the same reference numeral "110" to identify each of the at least two directional antennas in this embodiment does not imply that the at least two directional antennas must be completely identical in specification and performance, but may allow the antenna assembly 11 to include at least two directional antennas that are not completely identical in specification and/or performance.

The communication assembly 12 is used to transmit and receive radio frequency signals (e.g., the transmitted radio frequency signals may primarily include monitoring data such as images and video, and the received radio frequency signals may primarily include command data) through the antenna assembly 11.

The communication component 12 may be a functional component supporting any wireless communication mode, for example, a 4G (4th generation mobile information system) communication component or a 5G (5th generation mobile information system) communication component, and the communication component 12 may interact with a SIM (Subscriber Identity Module) card 13 inserted in the monitoring device.

The main control unit 13 is configured to select a selected directional antenna 110 from the antenna assemblies 11 according to the communication capability of each directional antenna 110 in the antenna assemblies 11, and generate a control command indicating the selected directional antenna 110.

The main control component 14 may be a central main control component of the monitoring device, for example, if the monitoring device is a pan/tilt monitoring device, the main control component 14 may include a processor serving as a pan/tilt control platform. The main control component 14 may be connected to the communication component 12 through a Universal Serial Bus (USB), and the main control component 14 may be connected to the switching component 15 through an Inter-Integrated Circuit (IIC) Bus.

The switching module 15 is used for alternatively connecting the communication module 12 to the selected directional antenna 110 of the antenna module 11 in response to the control command generated by the main control module 14.

And, after the communication component 12 is alternatively conducted with the selected directional antenna 110 in the antenna component 11, the switching component 15 may further adjust the link impedance Rz of the conducting link between the communication component 12 and the selected directional antenna 110, so that the link impedance Rz converges to a preset impedance threshold (e.g., 100 ± 10 Ω), which may be used to maximize the communication capability of the selected directional antenna 110, that is, the preset impedance threshold may be used to make the communication capability of the selected directional antenna 110 approach to its maximum level (the actual signal gain of the directional antenna approaches to the theoretical signal gain shown in fig. 2).

Based on the above embodiment, the monitoring device may be equipped with at least two directional antennas 110 whose radiation angles do not overlap completely, so that, for each possible relative orientation between the deployment site and the base station, one directional wire 110 may be selected to conduct with the communication component 12 according to the signal quality, and, after the communication component 12 is alternatively conducted with the selected directional antenna 110, the link impedance Rz of the conducting link between the communication component 12 and the selected directional antenna 110 may also be adjusted to promote that the selected directional antenna 110 can provide the maximized communication capability as possible, so that, with a directional antenna 110 having a higher signal gain than an omnidirectional antenna, the multi-directional compatibility, the communication distance and the signal stability of the monitoring device can be considered.

As a preferable scheme, for the switching component 15 that undertakes the switching of the conductive link and the impedance adjustment, the switching component 15 may include a switch switching circuit for implementing the switching of the conductive link, and a frequency detection device for implementing the impedance adjustment and an impedance matching circuit in the series conductive link. For the switching component 15 including the impedance matching circuit, the radio frequency signal transmitted by the communication component 12 may be transmitted to the selected directional antenna 110 through the impedance matching circuit, and the radio frequency signal received by the selected directional antenna 110 may be transmitted to the communication component 12 through the impedance matching circuit.

Wherein, the switch switching circuit can be used to alternatively conduct the selected directional antenna 110 in the antenna assembly 11 with the communication assembly 12, so as to realize the switching of the conducting link between the communication assembly 12 and the antenna assembly 11 through the switching operation; the frequency detection means may be adapted to detect a transmission frequency and a reception frequency in the conductive link, so that the switch control means in the switching assembly 15 can adjust the circuit impedance of the impedance matching circuit in the conductive link connected in series between the selected directional antenna 110 and the communication assembly 12 according to the transmission frequency and the reception frequency detected by the frequency detection means, i.e. the circuit impedance of the impedance matching circuit may be adapted to the transmission frequency and/or the reception frequency to converge the link impedance of the conductive link towards a preset impedance threshold. Thus, impedance matching suitable for different transceiving frequencies can be realized in each directional orientation.

Fig. 3 is a schematic diagram of an optimized structure of the monitoring device shown in fig. 1. As shown in fig. 3, the switching assembly 15 may include a switch switching circuit 151, first and second

impedance matching circuits

152a and 152b, first and second

frequency detection devices

153a and 153b, and a switch control device 150.

In fig. 3, taking the example where the impedance matching circuit described above includes the first impedance matching circuit 152a and the second impedance matching circuit 152b, the first impedance matching circuit 152a may be connected in series between the communication component 12 and the switch switching circuit 151, and the second impedance matching circuit 152b may be connected in series between each directional antenna 110 in the antenna assembly 11 and the switch switching circuit 151.

In fig. 3, for example, the frequency detection device described above includes a first frequency detection device 153a and a second frequency detection device 153b, the first frequency detection device 153a is used for detecting the transmitting frequency of the transmitting end of the communication module 12, and the second frequency detection device 153b is used for detecting the receiving frequency of the feeding end of the selected directional antenna 110.

For example, the first impedance matching circuit 152a may be directly connected to the transmitting end of the communication component 12, and the first frequency detecting device 153a may detect the transmitting frequency in the conductive link between the selected directional antenna 110 and the communication component 12 alternatively at the first impedance matching circuit 152 a; a second impedance matching circuit 152b may be directly connected to the feeding end of each directional antenna 110, and a second frequency detecting device 153b may detect a receiving frequency in a conductive link between the selected directional antenna 110 and the communication component 12 alternatively at the second impedance matching circuit 152b connected to the feeding end of the selected directional antenna 110.

And a switch control device 150, for controlling the switch switching circuit 151 in response to the main control component 14 generating a control command, so as to alternatively conduct the selected directional antenna 110 in the antenna component 11 with the communication component 12.

In fig. 3, for example, the switch switching circuit 151 includes a single-pole multi-throw switch, the switch control device 150 may generate a level signal (e.g., a multi-bit logic level signal) to the switch switching circuit 151 according to the control command, where the level signal may be used to indicate the directional antenna 110 selected by the control command, so that the switch switching circuit 151 conducts the directional antenna 110 selected by the control command in the antenna assembly 11 to the communication assembly 12.

For example, taking the example that the switch switching circuit 151 includes a single-pole four-throw switch adapted to four directional antennas 110, the switch control device 150 generates the two-bit logic level signals VC1 and VC2 to the switch switching circuit 151, and the level state combinations of the logic level signals VC1 and VC2 correspond to four conductive links RF1 to RF4 formed by the four directional antennas 110 respectively, as shown in table 1:

VC1	VC2	conducting link
			0	0	RF1
0	1	RF2
			1	0	RF3
1	1	RF4

TABLE 1

The switch control means 150 is further adapted to adjust a first circuit impedance Rz1 of the first impedance matching circuit 152a in response to the transmit frequency detected by the first frequency detection means 153a and to adjust a second circuit impedance Rz2 of the second impedance matching circuit 152b connected to the selected directional antenna 110 in response to the receive frequency detected by the second frequency detection means 153 b.

The link impedance Rz in the conductive link between the selected directional antenna 110 and the communication component 12 may comprise the sum of the first circuit impedance Rz1 provided by the first impedance matching circuit 152a and the second circuit impedance Rz2 provided by the second impedance matching circuit 152b to which the selected directional antenna 110 is connected. And, the link impedance Rz in the conductive link between the selected directional antenna 110 and the communication component 12 may further include the impedance of the switch switching circuit 151.

In the optimized structure shown in fig. 3, the second frequency detection means 153b can detect the receiving frequency of each directional antenna 110, and the switch control means 150 can adjust the second circuit impedance Rz2 of the second impedance matching circuit 152b connected to each directional antenna 110 according to the receiving frequency of each directional antenna 110 detected by the second frequency detection means 153 b; alternatively, the switch control device 150 may select the receiving frequency of the selected directional antenna 110 from all the receiving frequencies detected by the second frequency detection device 153b, and adjust only the second circuit impedance Rz2 of the second impedance matching circuit 152b connected to the selected directional antenna 110, without locking the second impedance matching circuit 152 connected to the non-selected directional antenna 110.

Fig. 4 is a schematic diagram of the impedance adjustment principle of the optimized structure shown in fig. 3. Referring to fig. 4, in this embodiment, the transmission and reception of the directional antenna 110 in the antenna assembly 11 are time-division multiplexed, and accordingly, the main control assembly 14 may be further configured to generate the transceiving timing signal Sig _ seq indicating the transmission time slot t _ sen and the reception time slot t _ rec, and the switch control device 150 may be further configured to alternately adjust the first circuit impedance Rz1 of the first impedance matching circuit 152a at the transmission time slot t _ sen according to the transmission frequency detected by the first frequency detection device 153a and adjust the second circuit impedance Rz2 of the second impedance matching circuit 152b at the reception time slot t _ rec according to the reception frequency detected by the second frequency detection device 153b according to the transceiving timing signal Sig _ seq generated by the main control assembly 14.

In order to ensure that the Processing capacity of the switching control device 150 can be matched to the time slot switching frequency, the switching control device 150 may be selected from components with high Processing speed, such as a DSP (Digital Signal Processing) chip.

Fig. 5 is an exemplary structural diagram of the first impedance matching circuit and the second impedance matching circuit in the optimized structure shown in fig. 3. Referring to fig. 5, each of the first impedance matching circuit 152a and the second impedance matching circuit 152b may include an adjustable inductance L _ adj, where:

the adjustable inductance L _ adj in the first impedance matching circuit 152a is denoted as a first adjustable inductance L _ adj1, the first end of the first adjustable inductance L _ adj1 connected to the transmitting end of the communication component 12 may be grounded through a first radio frequency end capacitor C11, the second end of the first adjustable inductance L _ adj1 connected to the switch circuit 151 may be grounded through a first switch end capacitor C12 and also through a first fixed value resistor Rl1, and Rs1 in fig. 5 is an equivalent impedance of the first impedance matching circuit 152a, and represents a first circuit impedance Rz1 (also referred to as a first variable impedance) provided by the first impedance matching circuit 152 a;

in the second impedance matching circuit 152b of each directional antenna 110, the adjustable inductance L _ adj is denoted as a second adjustable inductance L _ adj2, a first end of the second adjustable inductance L _ adj2 is connected to the feeding end of the directional antenna 110 and is grounded through a second radio frequency end capacitor C21, a second end of the second adjustable inductance L _ adj2 is connected to the switch circuit 151 and is grounded through a second switch end capacitor C22 and is also grounded through a second fixed resistor Rl2, and Rs2 in fig. 5 is an equivalent impedance of the second impedance matching circuit 152b, and represents a second circuit impedance Rz2 (also referred to as a second variable impedance) provided by the second impedance matching circuit 152 b.

In the circuit configuration shown in fig. 5, the relationship among the parameters is shown by the following expression (1), expression (2), and expression (3):

in the above expression (1), expression (2), and expression (3):

for the first impedance matching circuit 152a, f represents the transmitting frequency, L _ adj represents the inductance value of the first adjustable inductor L _ adj1, C1 represents the capacitance value of the first rf-side capacitor C11, C2 represents the capacitance value of the first switch-side capacitor C12, Rl represents the resistance value of the first constant-value resistor Rl1, and Rs represents the equivalent impedance Rs1 of the first impedance matching circuit 152a (i.e., the first circuit impedance Rz 1);

for the second impedance matching circuit 152b, f represents the receiving frequency, L _ adj represents the inductance value of the second adjustable inductor L _ adj2, C1 represents the capacitance of the second rf-side capacitor C21, C2 represents the capacitance of the second switch-side capacitor C22, Rl represents the resistance of the second constant resistor Rl2, and Rs represents the equivalent impedance Rs2 (i.e., the second circuit impedance r 2) of the second impedance matching circuit 152 b.

That is, based on the parameter relationships presented as expression (1), expression (2), and expression (3), the trend of adjustment of the circuit impedance of the impedance matching circuit may be reversed from the trend of change in the transmission frequency and/or the reception frequency f; the circuit impedance of the impedance matching circuit is adjusted by a change in the adjustable inductance L _ adj in the impedance matching circuit, and the adjustment tendency of the circuit impedance of the impedance matching circuit may be in the same direction as the change tendency of the adjustable inductance L _ adj.

Since the values of C1 and C2 and the fixed-value resistor Rl are fixed and the transmission frequency or the reception frequency f can be detected, based on the parameter relationship expressed as expression (1), expression (2) and expression (3), the switch control device 150 can adjust the first adjustable inductor L _ adj1 in the first impedance matching circuit 152a according to the transmission frequency f detected by the first frequency detection device 153a, so as to adjust the equivalent impedance Rs (first circuit impedance Rz1) of the first impedance matching circuit 152a, so that the transmission signal quality of the selected directional antenna 110 at the current transmission frequency f is as good as possible;

similarly, based on the parameter relationship expressed as expression (1), expression (2) and expression (3), the switch control device 150 may adjust the second adjustable inductance L _ adj2 in the second impedance matching circuit 152b connected to the selected directional antenna 110 according to the receiving frequency detected by the second frequency detection device 153b, so as to adjust the equivalent impedance Rs of the second impedance matching circuit 152b (the second circuit impedance Rz2), so as to make the received signal quality of the selected directional antenna 110 at the current receiving frequency f as good as possible.

That is, the parameters for determining the circuit impedance (the first circuit impedance Rz1 and/or the second circuit impedance Rz2) of the impedance matching circuit (the first impedance matching circuit 152a and/or the second impedance matching circuit 152b) include the transmission frequency and/or the reception frequency f of the radio frequency signal, and the adjustable inductance (the first adjustable inductance L _ adj1 and/or the second adjustable inductance L _ adj2), and the impedance matching circuit (the first impedance matching circuit 152a and/or the second impedance matching circuit 152b) may be configured; the circuit impedance (first circuit impedance Rz1 and/or second circuit impedance Rz2) is determined by the adjustable inductance (first adjustable inductance L _ adj1 and/or second adjustable inductance L _ adj2) in response to the transmit frequency and/or the receive frequency f.

The above is a detailed description of the monitoring device utilizing a selected directional antenna to achieve target position communication with greater communication distance and greater signal stability. That is, at any one time, the monitoring device will only select one directional antenna for communication.

Wherein the selection of the directional antenna may occur at least one of:

the power-up start-up phase of the device is monitored (initial selection),

when the monitoring device is degraded in signal quality due to the change of the wireless environment during operation, that is, the master control component 14 detects from the communication component 12 that the signal quality is lower than the preset quality threshold (instant selected),

the current time reaches the preset time (timing selection) for triggering the omnibearing polling stage.

Either case triggered selection, all directional antennas 110 in the switched antenna assembly 11 may be polled and the signal quality when each directional antenna 110 is selected evaluated in a ranking manner.

The master control assembly 14 may be further configured to poll and generate control commands to cause the switching assembly 15 to selectively connect the communication assembly 12 to each of the directional antennas 110 of the antenna assembly 11 in turn, and,

by the communication assembly 12 alternatively being in communication with each directional antenna 110 in turn, the main control assembly 14 can determine the communication capability of each directional antenna 110, and can alternatively select a directional antenna 110 among the antenna assemblies 11 according to the communication capability of each directional antenna.

Preferably, the communication capability may be determined by using Signal quality, for example, the Signal quality may be represented by RSRP (Reference Signal Receiving Power) and SINR (Signal to Interference plus Noise Ratio), accordingly, the main control component 14 may obtain RSRP and SINR based on each directional antenna 12 from the communication component 12 by alternatively conducting with each directional antenna 110 in turn, and determine the communication capability of each directional antenna 110 by using the obtained RSRP and SINR.

Preferably, the communication capability determined by the communication quality may also be evaluated hierarchically according to RSRP and SINR, for example:

a first grade: RSRP ≧ a first power threshold (e.g., -85dBm), and SINR ≧ a first signal-to-noise ratio threshold (e.g., 25), indicating that signal quality is excellent;

and a second stage: the first power threshold (such as-85 dBm) > RSRP ≧ the second power threshold (such as-95 dBm), and the first signal-to-noise ratio threshold (such as 25) > SINR ≧ the second signal-to-noise ratio threshold (such as 16), indicating that the signal quality is better;

third level: the second power threshold (such as-95 dBm) > RSRP ≧ the third power threshold (such as-105 dBm), and the second signal-to-noise ratio threshold (such as 16) > SINR ≧ the third signal-to-noise ratio threshold (such as 11), indicating that the signal quality is fair;

fourth level: the third power threshold (say-105 dBm) > RSRP ≧ the fourth power threshold (say-115 dBm), and the third signal-to-noise ratio threshold (say 11) > SINR ≧ the fourth signal-to-noise ratio threshold (say 3), representing poor signal quality;

and a fifth grade: a fourth power threshold (say-115 dBm) > RSRP, and a fourth signal-to-noise ratio threshold (say 3) > SINR, representing very poor signal quality.

After the hierarchical evaluation of the polling switching is completed, the directional antenna 110 with the highest level is preferentially selected, and when the level of the communication capability of more than one directional antenna 110 is the same and is at the highest level in all the directional antennas 110, the directional antenna with the highest SINR is preferentially determined to be the directional antenna with the optimal communication capability. Alternatively, the communication capability of the directional antenna may be determined by further using the result of the weighted operation of the RSRP and the SINR.

Fig. 6 is a schematic diagram of the optimal selection mechanism of the directional antenna in the monitoring device shown in fig. 1. Please refer to fig. 6:

after the monitoring device is powered on and started, and the main control component 14 performs initial configuration of communication connection with the communication component 12 and the switching component 15, the following process may be executed;

when the main control component 14 detects from the communication component 12 that the signal quality based on the currently selected directional antenna 110 is lower than the preset quality threshold, the RSRP and SINR based on the currently selected directional antenna 110 are recorded, and then the following process may be started to be executed;

when the main control component 14 recognizes that the current time reaches a preset time (e.g., zero point) for triggering the omni-directional inspection phase, the following process may be performed after detecting the signal quality based on the currently selected directional antenna 110 and recording the RSRP and SINR based on the currently selected directional antenna 110.

That is, when the selection process for the directional antenna is triggered due to any of the foregoing occurrences, the following process may be performed for each directional antenna that is polled to be turned on:

s600: the main control module 14 selects the directional antenna 110 in the antenna module 11 and sends a control command to the switching module 15 to trigger the switching module 15 to conduct the directional antenna 110.

For the case of power-on startup of the monitoring device, the main control component 14 may select the directional antenna 110 in the antenna component 11 for the first time according to a default configuration, and the subsequent selection of the directional antenna 110 may be determined according to a preset polling rule. For the case of power-on start of the monitoring device, the current flow may be executed k times in a loop, and for the case that the signal quality is lower than the preset quality threshold and the preset time arrives, the current flow may be executed k-1 times in a loop, where k is the total number of directional antennas included in the antenna assembly 11.

S610: the main control component 14 issues a first at (attention) command to the communication component 12, so that the communication component 12 performs network registration (about 5-10 seconds) with the base station based on the currently selected directional antenna 110.

S620: the master control component 14 reads the registration result (with a maximum duration of 30s) queried by the communication component 12 to determine whether the registration is successful.

If the registration result indicating successful registration is not inquired, that is, if the registration is not successful, determining that the currently selected directional antenna 110 is unavailable, and then returning to S600 to switch other directional antennas 110;

if a registration result indicating that the registration is successful is queried, i.e., the registration is successful, the subsequent step S630 is continued.

S630: the main control component 14 issues a second AT command to the communication component 12, and reads and records RSRP and SINR based on the currently selected directional antenna 110.

S640: it is determined whether the polling of all the directional antennas 110 in the antenna assembly 11 is completed, and if not, the subsequent step S650 is performed, and if the polling is completed, the subsequent step S660 is continued.

S650: the master component 14 issues a flight mode command to the communication component 12 for a link restart and then returns to S600 to allow each selected directional antenna 110 to initiate network registration not only with the same base station but preferentially with the base station in the azimuth of the respective radiation angle.

S660: the main control component 14 determines the directional antenna 110 with the best signal quality by using the recorded RSRP and SINR of all the directional antennas 110.

The directional antenna 110 with the best signal quality is determined, for example, using the weighted results of RSRP and SINR, or according to the rank evaluation described above.

If the directional antenna 110 with the optimal signal quality determined in S660 is the directional antenna 110 that is turned on last by polling at present, no further processing is needed after the above process until the signal quality is lower than the preset quality threshold and the preset time arrives;

if the directional antenna 110 with the best signal quality determined in S660 is different from the directional antenna 110 that is turned on last by polling, an additional switching of the directional antenna 110 is required, and then the signal quality is kept below the preset quality threshold and the preset time is reached.

S670: the master component 14 triggers the power supply of the communication component 12 to be powered back up.

In actual operation, the main control component 14 may select a first directional antenna in the antenna component 11 according to a default configuration after the monitoring device is powered on, or, by performing the above procedure once, select a first directional antenna with an optimal communication capability according to the received power (RSRP) and the signal-to-noise ratio (SINR), and generate a first control instruction indicating that the selected directional antenna is the first directional antenna, so as to trigger the switch switching circuit 151 to conduct the communication component 12 and the first directional antenna; after the communication component 12 is turned on with the first directional antenna, if it is detected (in real time or at regular time) that at least one of the received power (RSRP) and the signal-to-noise ratio (SINR) of the radio frequency signal based on the first directional antenna is lower than the preset threshold, the main control component 14 may select a second directional antenna in the antenna component 11 according to the received power (RSRP) and the signal-to-noise ratio (SINR) by executing the above procedure, and generate a second control instruction indicating that the selected directional antenna is the second directional antenna, so as to trigger the switch switching circuit 151 to switch the communication component 12 turned on with the first directional antenna to be turned on with the second directional antenna.

By analogy, after the communication component 12 is turned on with the second directional antenna, if at least one of the received power (RSRP) and the signal-to-noise ratio (SINR) of the radio frequency signal based on the first directional antenna is lower than the preset threshold by performing the above procedure detection (real-time or timing), the main control component 14 may also reselect the directional antenna.

After the communication module is conducted with any directional antenna by executing the above-mentioned procedure, the switching module 15 can adjust the link impedance Rz according to the principle shown in fig. 4.

In addition, if the monitoring device has a display screen, after the above-mentioned process is executed in a loop, the main control component 14 may display, on-screen display (OSD) interface presented on the display screen, first prompt information of "antenna self-test in progress", and after S660, the main control component 14 may display, on-screen display (OSD) interface presented on the display screen, second prompt information of "antenna self-test in success".

It will be appreciated that the selection of the directional antenna 110 is not limited to being determined by the control instructions of the master control assembly 14, and is not limited to employing the selection strategy described above. For example, the selection of the directional antenna 110 may be dependent on an externally input command, or may be determined by a control command generated by an additional control device different from the main control assembly 14.

In addition, the antenna assembly 11 may be external to the monitoring device, i.e., the antenna assembly 11 may be an external component.

Fig. 7 is a schematic diagram of an external deployment scheme of a directional antenna in the monitoring device shown in fig. 1. Referring to fig. 7, if the monitoring device is a pan/tilt monitoring device, such as a video camera having a pan/tilt assembly 710 and a lens assembly 700, an antenna assembly 11 including at least two directional antennas 110 (four directional antennas 110 are taken as an example in fig. 7) may be disposed on the lower side of the pan/tilt assembly 710 of the monitoring device, and the pan/tilt assembly 710 may drive the lens assembly 700 to rotate relative to the antenna assembly 11 without rotating the antenna assembly 11 with the rotation of the lens assembly 700, so as to prevent the directional antennas 110 from changing orientation with the rotation of the pan/tilt assembly 710 driving the lens assembly 700. That is, after the installation of the monitoring device is completed, the orientation of each directional antenna 110 in the antenna assembly 11 is not changed, so that the orientation change of the signal quality dial caused by the rotation of the directional antenna 110 with the lens assembly 700 driven by the pan-tilt assembly 710 can be avoided.

Moreover, the antenna assembly 110 disposed below the pan and tilt assembly 710 may provide support to the pan and tilt assembly 710. For example, the antenna assembly 11 may further include a support (not shown in fig. 7) by which the directional antenna 110 may be covered and which may support the pan and tilt head assembly 710 and a housing 720 that houses the pan and tilt head assembly 710.

In fig. 7, the lens assembly 700 is mounted in the first chamber housing 720 located at an upper side of the head assembly 710 and the holder housing 720 accommodating the head assembly 710, and an imaging module for imaging with the lens assembly 700 may be disposed in the first chamber housing 720, so that the antenna assembly 11 may be provided in a separate chamber from the lens assembly 700 and the imaging module disposed in the first chamber housing 710 and the head assembly 710 accommodated in the holder housing 720.

In fig. 7, taking a pair of first housing 720 in which a pair of lens assemblies 700 are respectively mounted on the upper side of the housing 720 as an example, the pair of first housing 720 is disposed on two opposite sides of a second housing 740 accommodating an electrical module, which includes the communication module 12, the SIM card 13, the main control module 14 and the switching module 15, so that the antenna assembly 11 can be further disposed in a cavity with the electrical module of the monitoring device. It will be appreciated that even though the monitoring device includes only one lens assembly and one imaging module, one lens assembly and one imaging module each being disposed in the second chamber housing 740, and the first chamber housing 730 not being provided, the antenna assembly 11 may be disposed in a separate chamber from the lens assembly 700 and the imaging, electrical and pan/tilt head assemblies 710 of the monitoring device.

Therefore, compared with the built-in assembly structure of the antenna, the external arrangement of the antenna assembly 11 can prevent the directional antenna 110 from being interfered by internal metal elements of the monitoring equipment and internal high-frequency signals;

moreover, the antenna assembly 11 is externally arranged, so that the volume of the directional antenna can be prevented from being limited by the internal space of the monitoring equipment (for example, the first cavity housing 730 and/or the second cavity housing 740), and the structural design and the deployment scheme of the directional antenna 110, which can optimize the antenna performance, can be adopted according to the actual debugging effect. That is, the antenna assembly 11 externally disposed at the bottom of the pan/tilt head assembly 710 can be used as an individual independent of other parts of the monitoring device, and has stronger anti-interference capability than an internal antenna and easily provides better antenna performance.

In another embodiment, a communication control method of a monitoring device is provided, which is suitable for a switching component in the monitoring device in the foregoing embodiments.

Fig. 8 is an exemplary flowchart of a communication control method of a monitoring apparatus in another embodiment. Referring to fig. 8, the communication control method in this embodiment may include:

s810: acquiring a control instruction, wherein the control instruction indicates that a selected directional antenna is selected according to the communication capability of the directional antenna in at least two directional antennas of which the radiation angles of the monitoring equipment are not completely overlapped;

s820: responding to the acquired control instruction, and alternatively conducting a communication component of the monitoring equipment with the selected directional antenna;

s830: after the communication component is alternatively conducted with the selected directional antenna, the link impedance of the conducting link between the communication component and the selected directional antenna is adjusted to converge the link impedance to a preset impedance threshold, which is used to maximize the communication capability of the selected directional antenna, i.e., the preset impedance threshold can be used to make the communication capability of the selected directional antenna 110 approach to its maximum level (the actual signal gain of the directional antenna approaches the theoretical signal gain as shown in fig. 2).

Based on the above procedure, in the case that the monitoring device is equipped with at least two directional antennas whose radiation angles do not overlap completely, for each possible relative orientation between the deployment site and the base station, one directional electric wire may be selected to conduct with the communication component according to the signal quality, and after the communication component is alternatively conducted with the selected directional antenna, the link impedance of the conducting link between the communication component and the selected directional antenna may be further adjusted to promote the selected directional antenna to maximize the communication capability as much as possible, so that, with at least two directional antennas having higher gain than the omnidirectional antenna, multi-orientation compatibility, communication distance, and signal stability of the monitoring device may be considered.

Fig. 9 is a schematic diagram illustrating an optimization flow of the communication control method shown in fig. 8. Referring to fig. 9, the communication control method in this embodiment may be optimized to include the following steps:

s910: acquiring a control instruction, wherein the control instruction indicates that a selected directional antenna is selected according to the communication capability of the directional antenna in at least two directional antennas of which the radiation angles of the monitoring equipment are not completely overlapped;

s920: responding to the acquired control instruction, and alternatively conducting a communication component of the monitoring equipment with the selected directional antenna;

s930: after the communication assembly is alternatively conducted with the selected directional antenna, a transmitting frequency and a receiving frequency in the conducting link are detected, and the circuit impedance of the impedance matching circuit connected in series in the conducting link is adjusted according to the detected transmitting frequency and receiving frequency, so that the link impedance of the conducting link converges to a preset impedance threshold value, wherein the impedance threshold value is used for promoting the communication capacity maximization of the selected directional antenna.

Preferably, this step may detect a transmission frequency of a transmission end of the communication component, and detect a reception frequency of a selected feeding end of the directional antenna; and adjusting a first circuit impedance of a first impedance matching circuit in the impedance matching circuit near the transmitting end of the communication component according to the detected transmitting frequency, and adjusting a second circuit impedance of a second impedance matching circuit in the impedance matching circuit near the feeding end of the selected directional antenna according to the detected receiving frequency, wherein the link impedance may include a sum of the first circuit impedance and the second circuit impedance.

For example, the present step may further acquire a transceiving timing signal indicating a transmission time slot and a reception time slot, and alternately adjust a first circuit impedance of the first impedance matching circuit at the transmission time slot and a second circuit impedance of the second impedance matching circuit at the reception time slot according to the transceiving timing signal.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A monitoring device, comprising:

frequency detection means for detecting the transmission frequency of the communication component and/or the reception frequency of the selected directional antenna;

2. The monitoring device of claim 1, wherein the trend of the adjustment of the circuit impedance of the impedance matching circuit is opposite to the trend of the change of the transmission frequency and/or the reception frequency.

3. The monitoring device of claim 1, wherein the circuit impedance of the impedance matching circuit is adjusted by a change in an adjustable inductance in the impedance matching circuit, and wherein a trend of the adjustment of the circuit impedance is co-directional with a trend of the change in the adjustable inductance.

4. The monitoring device of claim 1, wherein the parameters for determining the circuit impedance of the impedance matching circuit include a transmit frequency and/or a receive frequency of the radio frequency signal, and an adjustable inductance and wherein the impedance matching circuit is configured to; the circuit impedance is determined by the adjustable inductance in response to the transmit frequency and/or the receive frequency.

5. The monitoring device of claim 1,

the impedance matching circuit includes: a first impedance matching circuit connected in series between the communications component and the switch switching circuit, and a second impedance matching circuit connected in series between each of the directional antennas in the antenna component and the switch switching circuit;

the frequency detection device includes: first frequency detection means for detecting a transmission frequency of a transmission end of the communication component, and second frequency detection means for detecting a reception frequency of a selected feeding end of the directional antenna;

wherein a first circuit impedance of the first impedance matching circuit is determined according to the transmission frequency, a second circuit impedance of the second impedance matching circuit is determined according to the reception frequency, and a sum of the first circuit impedance and the second impedance is adjusted such that the link impedance converges the link impedance of the conductive link toward a preset impedance threshold.

6. The monitoring device of claim 5, further comprising a switch control means for alternately adjusting the first circuit impedance of the first impedance matching circuit during the transmission time slot and adjusting the second circuit impedance of the second impedance matching circuit during the reception time slot according to a transceiving timing signal indicating a transmission time slot and a reception time slot.

7. The monitoring device of claim 1, further comprising a switch control device configured to generate a level signal to the switch switching circuit according to a control command, the level signal indicating the directional antenna selected by the control command to turn on the communication component with the directional antenna selected by the control command.

8. The monitoring device of claim 1, wherein the monitoring device is a camera having a lens assembly and a pan-tilt assembly, wherein the antenna assembly is disposed on a lower side of the pan-tilt assembly, and wherein the pan-tilt assembly drives the lens assembly to rotate relative to the antenna assembly.

9. The monitoring device of claim 8, wherein the antenna assembly is disposed in a uniform cavity with the pan and tilt head assembly, the lens assembly, and the camera further having an imaging module.

10. The monitoring device of claim 1, further comprising a main control component, configured to, after the communication component is turned on with a first directional antenna of the antenna assemblies, select a second directional antenna of the antenna assemblies according to the received power and the signal-to-noise ratio if it is detected that at least one of the received power and the signal-to-noise ratio of the radio frequency signal based on the first directional antenna is lower than a preset threshold, and generate a control instruction indicating that the selected directional antenna is the second directional antenna, so as to trigger the switch circuit to switch the communication component turned on with the first directional antenna into conduction with the second directional antenna.