System and method for triggering vehicle video recording

Abstract

A system for vehicle video recording includes a camera system, a first wireless module, a second wireless module, and a controller in electrical communication with the camera system, the first wireless module, and the second wireless module. The controller is configured to transmit a plurality of raw training signals on a plurality of subcarriers for using the first wireless module. The controller is also programmed to receive a plurality of propagation training signals using the second wireless module. The controller is also programmed to determine a deviation between the plurality of raw training signals and the plurality of propagating training signals. The controller is further programmed to determine an occupancy state of the vehicle surroundings based at least in part on the deviation, and to record a video using the camera system in response to determining that the occupancy state is an occupied state.

Description

Technical Field

[0001] The present disclosure relates to a system and method for vehicle video recording, and more particularly, to a system and method for triggering video recording based on the detection of an occupant in the vehicle's surroundings. Background Art

[0002] Occupant detection systems may be used to detect the presence of a person located in the vicinity of a vehicle. There are currently a variety of technologies for detecting persons in the vicinity of a vehicle. For example, an occupant detection system may include a radar-based sensor disposed on the body of a vehicle to detect the presence of a person. However, radar-based sensors may be obscured by objects in the environment, thereby degrading performance. Camera-based systems also exist for detection within the interior cabin, however, continuous camera recording and / or streaming may result in increased resource usage. Touch-based occupant detection mechanisms require a person to touch the vehicle before triggering recording, which may result in the loss of events that occurred prior to contact with the vehicle. Sound-based occupant detection mechanisms may experience performance degradation in environments with high and / or varying sound intensities.

[0003] Therefore, while current occupant detection systems achieve their intended purposes, a new and improved system and method for vehicle video recording is needed. Summary of the invention

[0004] According to several aspects, a system for vehicle video recording is provided. The system includes a camera system, a first wireless module, a second wireless module, and a controller electrically connected to the camera system, the first wireless module, and the second wireless module. The controller is programmed to send a plurality of original training signals on a plurality of subcarriers using the first wireless module. The controller is also programmed to receive a plurality of propagated training signals using the second wireless module. The controller is also programmed to determine a deviation between the plurality of original training signals and the plurality of propagated training signals. The controller is also programmed to determine an occupancy state of the vehicle surroundings based at least in part on the deviation. The occupancy state includes at least one of an occupied state and an unoccupied state. The controller is also programmed to record a video using the camera system in response to determining that the occupancy state is an occupied state.

[0005] In another aspect of the present disclosure, to determine the occupancy state of the vehicle's surroundings, the controller is further programmed to determine a plurality of channel state information (CSI) values ​​based at least in part on deviations between the plurality of original training signals and the plurality of propagated training signals. To determine the occupancy state of the vehicle's surroundings, the controller is further programmed to determine the occupancy state of the vehicle's surroundings based at least in part on the plurality of CSI values.

[0006] In another aspect of the present disclosure, in order to determine the occupancy state of the vehicle's surroundings, the controller is further programmed to calculate a plurality of CSI value derivatives. At least one of the plurality of CSI value derivatives corresponds to each of the plurality of subcarriers. In order to determine the occupancy state of the vehicle's surroundings, the controller is further programmed to calculate a plurality of CSI value derivative amplitudes. Each of the plurality of CSI value derivative amplitudes is the amplitude of one of the plurality of CSI value derivatives. In order to determine the occupancy state of the vehicle's surroundings, the controller is further programmed to calculate the norm of the plurality of CSI value derivative amplitudes. In order to determine the occupancy state of the vehicle's surroundings, the controller is further programmed to calculate a time-averaged norm signal based at least in part on the norm. In order to determine the occupancy state of the vehicle's surroundings, the controller is further programmed to determine the occupancy state of the vehicle's surroundings based at least in part on the time-averaged norm signal.

[0007] In another aspect of the present disclosure, to determine the occupancy state of the vehicle surroundings, the controller is further programmed to continuously compare the time-averaged norm signal with a predetermined time-averaged norm signal threshold. To determine the occupancy state of the vehicle surroundings, the controller is further programmed to determine the occupancy state as an occupied state in response to determining that the time-averaged norm signal is greater than or equal to the predetermined time-averaged norm signal threshold for at least a predetermined period of time.

[0008] In another aspect of the present disclosure, the first wireless module and the second wireless module are digital wireless local area network (WLAN) transceiver systems configured to implement a wireless communication protocol.

[0009] In another aspect of the present disclosure, the first wireless module is a digital wireless local area network (WLAN) transceiver system configured to implement a wireless communication protocol. The second wireless module is a signal conversion device configured to convert signals between at least two frequency bands.

[0010] In another aspect of the present disclosure, the signal conversion device may further include a power supply, at least two antennas, and a conversion circuit electrically connected to the power supply and the at least two antennas. The conversion circuit may include a mixer electrically connected to the at least two antennas and an oscillator electrically connected to the mixer.

[0011] In another aspect of the present disclosure, the conversion circuit may further include a first amplifier in electrical communication with a first antenna of the at least two antennas and the mixer. The conversion circuit may further include a second amplifier in electrical communication with the mixer and a second antenna of the at least two antennas.

[0012] In another aspect of the present disclosure, the conversion circuit may further include a first bandpass filter in electrical communication with the first amplifier and the mixer. The conversion circuit may further include a second bandpass filter in electrical communication with the mixer and the second amplifier.

[0013] In another aspect of the present disclosure, the first bandpass filter has a first center frequency within a first frequency band of the at least two frequency bands. The second bandpass filter has a second center frequency within a second frequency band of the at least two frequency bands.

[0014] According to several aspects, a method for vehicle video recording is provided. The method includes determining a plurality of channel state information (CSI) values ​​using a first wireless module and a second wireless module. The method also includes determining an occupancy state of a vehicle surrounding environment based at least in part on the plurality of channel state information (CSI) values. The occupancy state includes at least one of an occupied state and an unoccupied state. The method also includes recording a video using a camera system in response to determining that the occupancy state is an occupied state.

[0015] In another aspect of the present disclosure, determining multiple channel state information (CSI) values ​​may also include sending multiple original training signals on multiple subcarriers using a first wireless module. The first wireless module is a digital wireless local area network (WLAN) transceiver system configured to implement a wireless communication protocol. Determining multiple CSI values ​​may also include receiving a first plurality of propagation training signals using a second wireless module. The second wireless module is a digital wireless local area network (WLAN) transceiver system configured to implement a wireless communication protocol. Determining multiple CSI values ​​may also include determining a first deviation between multiple original training signals and a first plurality of propagation training signals. Determining multiple CSI values ​​may also include determining multiple channel state information (CSI) values ​​based at least in part on the first deviation.

[0016] In another aspect of the present disclosure, determining multiple channel state information (CSI) values ​​may also include sending multiple original training signals on multiple subcarriers within a first frequency band using a first wireless module. The first wireless module is a digital wireless local area network (WLAN) transceiver system configured to implement a wireless communication protocol. Determining multiple CSI values ​​may also include receiving a first plurality of propagation training signals using a second wireless module. The second wireless module is a signal conversion device configured to convert signals between a first frequency band and a second frequency band. Determining multiple CSI values ​​may also include sending a first plurality of propagation training signals on a second frequency band using a second wireless module. Determining multiple CSI values ​​may also include receiving a second plurality of propagation training signals using the first wireless module. Determining multiple CSI values ​​may also include determining a second deviation between multiple original training signals and a second plurality of propagation training signals. Determining multiple CSI values ​​may also include determining multiple CSI values ​​based at least in part on the second deviation.

[0017] In another aspect of the present disclosure, determining the occupancy state of the vehicle surroundings based at least in part on a plurality of channel state information (CSI) values ​​may further include determining a plurality of dynamic CSI values ​​from the plurality of channel state information (CSI) values. Determining the occupancy state of the vehicle surroundings based at least in part on a plurality of CSI values ​​may further include determining the occupancy state of the vehicle surroundings based at least in part on a plurality of dynamic CSI values.

[0018] In another aspect of the present disclosure, determining a plurality of dynamic channel state information (CSI) values ​​from a plurality of CSI values ​​may further include calculating the plurality of dynamic CSI values ​​by calculating derivatives of the plurality of CSI values.

[0019] In another aspect of the present disclosure, determining the occupancy state of the vehicle surroundings may further include calculating a plurality of dynamic CSI value amplitudes. Each of the plurality of dynamic CSI value amplitudes is an amplitude of one of the plurality of dynamic CSI values. Determining the occupancy state of the vehicle surroundings may further include calculating a norm of the plurality of dynamic CSI value amplitudes. Determining the occupancy state of the vehicle surroundings may further include calculating a time-averaged norm signal based at least in part on the norm. Determining the occupancy state of the vehicle surroundings may further include determining the occupancy state of the vehicle surroundings based at least in part on the time-averaged norm signal.

[0020] In another aspect of the present disclosure, determining the occupancy state of the vehicle surroundings may include continuously comparing the time-averaged norm signal to a predetermined time-averaged norm signal threshold. Determining the occupancy state of the vehicle surroundings may also include determining the occupancy state as an occupied state in response to determining that the time-averaged norm signal is greater than or equal to the predetermined time-averaged norm signal threshold for at least a predetermined time period.

[0021] According to several aspects, a system for vehicle video recording is provided. The system includes a camera system, a first wireless module, a second wireless module, and a controller electrically connected to the camera system, the first wireless module, and the second wireless module. The controller is programmed to send multiple original training signals on multiple subcarriers using the first wireless module. The controller is also programmed to receive multiple propagation training signals using the second wireless module. The controller is also programmed to determine the deviation between the multiple original training signals and the multiple propagation training signals. The controller is also programmed to determine multiple channel state information (CSI) values ​​based at least in part on the deviation between the multiple original training signals and the multiple propagation training signals. The controller is also programmed to determine the occupancy state of the vehicle's surrounding environment based at least in part on the multiple CSI values. The occupancy state includes one of an occupied state and an unoccupied state. The controller is also programmed to record a video using the camera system in response to determining that the occupancy state is an occupied state.

[0022] In another aspect of the present disclosure, in order to determine the occupancy state of the vehicle surroundings, the controller is also programmed to calculate multiple CSI value derivatives. At least one of the multiple CSI value derivatives corresponds to each of the multiple subcarriers. In order to determine the occupancy state of the vehicle surroundings, the controller is also programmed to calculate multiple CSI value derivative amplitudes. Each of the multiple CSI value derivative amplitudes is the amplitude of one of the multiple CSI value derivatives. In order to determine the occupancy state of the vehicle surroundings, the controller is also programmed to calculate the norm of the multiple CSI value derivative amplitudes. In order to determine the occupancy state of the vehicle surroundings, the controller is also programmed to calculate the time average norm signal based at least in part on the mean norm. In order to determine the occupancy state of the vehicle surroundings, the controller is also programmed to determine the occupancy state of the vehicle surroundings at least in part based on the time average norm signal. In order to determine the occupancy state of the vehicle surroundings, the controller is also programmed to continuously compare the time average norm signal with a predetermined time average norm signal threshold. To determine the occupancy state of the vehicle surrounding environment, the controller is further programmed to determine the occupancy state as an occupied state in response to determining that the time average norm signal is greater than or equal to a predetermined time average norm signal threshold for at least a predetermined period of time.

[0023] In another aspect of the present disclosure, the first wireless module and the second wireless module are digital wireless local area network (WLAN) transceiver systems configured to implement a wireless communication protocol.

[0024] Further areas of applicability will become apparent from the description provided herein.It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

[0026] Figure 1 is a schematic diagram of a system for vehicle video recording according to an exemplary embodiment;

[0027] Figure 2 is a schematic diagram of a first wireless module according to an exemplary embodiment;

[0028] Figure 3 is a schematic diagram of a first wireless module and a second wireless module according to an exemplary embodiment;

[0029] Figure 4 is a flow chart of a method for vehicle video recording according to an exemplary embodiment;

[0030] Figure 5 is a first exemplary embodiment of a method for determining a plurality of channel state information (CSI) values ​​according to an exemplary embodiment; and

[0031] Figure 6 is a second exemplary embodiment of a method for determining a plurality of channel state information (CSI) values ​​according to an exemplary embodiment. DETAILED DESCRIPTION

[0032] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

[0033] A vehicle may include a camera system that can be used to record events in the vehicle's surroundings. When the vehicle is parked and unattended, the camera system can be used to monitor the vehicle's security and capture evidence of tampering and / or damage to the vehicle by individuals, animals, remote vehicles, etc. However, when an event of interest occurs, the camera system must be activated to record video. The present disclosure provides a new and improved system and method for detecting the presence of an occupant near a vehicle and triggering video recording using wireless communication technology.

[0034] refer to Figure 1 , a system for vehicle video recording is shown and generally designated by reference numeral 10. The system 10 is shown with an exemplary vehicle 12. Although a passenger vehicle is shown, it should be understood that the vehicle 12 may be any type of vehicle without departing from the scope of the present disclosure. The system 10 generally includes a controller 14 and a plurality of vehicle sensors 16.

[0035] The controller 14 is used to implement the method 100 of vehicle video recording, as described below. The controller 14 includes at least one processor 18 and a non-transitory computer-readable storage device or medium 20. The processor 18 can be a custom or commercially available processor, a central processing unit (CPU), a graphics processing unit (GPU), an auxiliary processor in a plurality of processors associated with the controller 14, a semiconductor-based microprocessor (in the form of a microchip or chipset), a macroprocessor, a combination thereof, or a device generally for executing instructions. The computer-readable storage device or medium 20 can include volatile and non-volatile storage devices such as read-only memory (ROM), random access memory (RAM), and keep-alive memory (KAM). KAM is a persistent or non-volatile memory that can be used to store various operating variables when the processor 18 is powered off. The computer-readable storage device or medium 20 can be implemented using a plurality of storage devices, such as a programmable read-only memory (PROM), an electrical PROM (EPROM), an electrically erasable PROM (EEPROM), a flash memory, or other electrical, magnetic, optical, or combination storage devices capable of storing data, some of which represent executable instructions, used by the controller 14 to control various systems of the vehicle 12. The controller 14 may also be comprised of multiple controllers in electrical communication with each other. The controller 14 may be interconnected with additional systems and / or controllers of the vehicle 12, thereby allowing the controller 14 to access data such as the speed, acceleration, braking, and steering angle of the vehicle 12.

[0036] The controller 14 is in electrical communication with a plurality of vehicle sensors 16. In an exemplary embodiment, the electrical communication is established using, for example, a CAN network, a FLEXRAY network, a local area network (e.g., WiFi, Ethernet, etc.), a serial peripheral interface (SPI) network, etc. It should be understood that various additional wired and wireless technologies and communication protocols for communicating with the controller 14 are within the scope of the present disclosure.

[0037] The plurality of vehicle sensors 16 are used to acquire information about an environment 22 surrounding the vehicle 12. In an exemplary embodiment, the plurality of vehicle sensors 16 include at least a camera system 24, a global navigation satellite system (GNSS) 26, a first wireless module 28a, and a second wireless module 28b.

[0038] In another exemplary embodiment, the plurality of vehicle sensors 16 further include sensors for determining performance data regarding the vehicle 12. In an exemplary embodiment, the plurality of vehicle sensors 16 further include at least one of a motor speed sensor, a motor torque sensor, an electric drive motor voltage and / or current sensor, an accelerator pedal position sensor, a coolant temperature sensor, a cooling fan speed sensor, and a transmission oil temperature sensor.

[0039] In another exemplary embodiment, the plurality of vehicle sensors 16 also includes sensors for determining information about the environment within the vehicle 12 , such as seat occupancy sensors, cabin air temperature sensors, cabin motion detection sensors, cabin cameras, cabin microphones, etc.

[0040] In another exemplary embodiment, plurality of vehicle sensors 16 also includes sensors for determining information about the environment surrounding vehicle 12 , such as ambient air temperature sensors, barometric pressure sensors, and / or photographic and / or video cameras positioned to view the environment in front of vehicle 12 .

[0041] In another exemplary embodiment, at least one of the plurality of vehicle sensors 16 is capable of measuring distances in the environment surrounding the vehicle 12. In a non-limiting example, the plurality of vehicle sensors 16 include a stereo camera with distance measurement capabilities. In one example, at least one of the plurality of vehicle sensors 16 is fixed inside the vehicle 12, for example, fixed in the roof lining of the vehicle 12, with a view through the windshield of the vehicle 12. In another example, at least one of the plurality of vehicle sensors 16 is fixed outside the vehicle 12, for example, fixed on the roof of the vehicle 12, with a view of the environment surrounding the vehicle 12. It should be understood that various additional types of vehicle sensors, such as LiDAR sensors, ultrasonic ranging sensors, radar sensors, and / or time of flight sensors are within the scope of the present disclosure. The plurality of vehicle sensors 16 are in electrical communication with the controller 14, as described above.

[0042] The camera system 24 is used to capture images and / or video of the environment 22 surrounding the vehicle 12. In an exemplary embodiment, the camera system 24 includes a photo and / or video camera positioned to view the environment 22 surrounding the vehicle 12. In a non-limiting example, the camera system 24 includes a camera fixed to the interior of the vehicle 12 (e.g., in the headliner of the vehicle 12) with a view through the windshield of the vehicle 12. In another non-limiting example, the camera system 24 includes a camera fixed to the exterior of the vehicle 12 (e.g., on the roof of the vehicle 12) with a view of the environment 22 in front of the vehicle 12.

[0043] In another exemplary embodiment, the camera system 24 is a surround view camera system that includes a plurality of cameras (also referred to as satellite cameras) arranged to provide views of the environment 22 adjacent to all sides of the vehicle 12. In a non-limiting example, the camera system 24 includes a front-facing camera (e.g., mounted in the front grille of the vehicle 12), a rear-facing camera (e.g., mounted on the tailgate of the vehicle 12), and two side-facing cameras (e.g., mounted below each of the two side-view mirrors of the vehicle 12). In another non-limiting example, the camera system 24 also includes an additional rear-view camera mounted near the center high-mounted brake light of the vehicle 12.

[0044] It should be understood that camera systems with additional cameras and / or additional mounting locations are within the scope of the present disclosure. It should also be understood that cameras with various sensor types (including, for example, charge coupled device (CCD) sensors, complementary metal oxide semiconductor (CMOS) sensors, and / or high dynamic range (HDR) sensors) are within the scope of the present disclosure. In addition, cameras with various lens types including, for example, wide angle lenses and / or narrow angle lenses are also within the scope of the present disclosure.

[0045] GNSS26 is used to determine the geographic location of vehicle 12. In an exemplary embodiment, GNSS26 is a global positioning system (GPS). In a non-limiting example, GPS includes a GPS receiver antenna (not shown) and a GPS controller (not shown) electrically connected to the GPS receiver antenna. The GPS receiver antenna receives signals from multiple satellites, and the GPS controller calculates the geographic location of vehicle 12 based on the signals received by the GPS receiver antenna. In an exemplary embodiment, GNSS26 also includes a map. The map includes information about infrastructure, such as municipal boundaries, roads, railways, sidewalks, buildings, etc. Therefore, the geographic location of vehicle 12 is contextualized using map information. In a non-limiting example, a map is retrieved from a remote source using a wireless connection. In another non-limiting example, the map is stored in a database of GNSS26. It should be understood that various additional types of satellite-based radio navigation systems, such as global positioning system (GPS), Galileo, GLONASS, and Beidou navigation satellite system (BDS) are within the scope of the present disclosure. It should be understood that GNSS26 can be integrated with controller 14 (e.g., on the same circuit board as controller 14 or otherwise as part of controller 14) without departing from the scope of the present disclosure.

[0046] refer to Figure 2 , which shows a schematic diagram of the first wireless module 28a. Figure 2 And refer again Figure 1, the first wireless module 28a is used to wirelessly communicate with other systems (e.g., the second wireless module 28b) inside and / or outside the vehicle 12. In an exemplary embodiment, the first wireless module 28a includes a wireless control module 30 capable of implementing a wireless communication protocol that uses a training signal to perform channel state information (CSI) estimation. In a non-limiting example, the first wireless module 28a supports wireless communication protocols according to one or more of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless local area network (WLAN) related standards. Therefore, the first wireless module 28a is also referred to as a digital wireless local area network (WLAN) transceiver system. In an exemplary embodiment, the first wireless module 28a includes at least one wireless transceiver module 32 electrically connected to the wireless control module 30. At least one wireless transceiver module 32 is configured to send and receive signals on a first frequency band B1 (e.g., a 2.4 GHz band). In another exemplary embodiment, the first wireless module 28a includes at least two wireless transceiver modules 32, such as Figure 2 As shown, the first wireless transceiver module 32a is configured to send and receive signals on a first frequency band B1. The second wireless transceiver module 32b is configured to send and receive signals on a second frequency band B2 (eg, a 5 GHz frequency band).

[0047] In an exemplary embodiment, the first frequency band B1 and / or the second frequency band B2 are divided into a plurality of sub-frequencies (i.e., subcarriers). The data to be transmitted is divided into a plurality of data streams. Each of the plurality of data streams is modulated using one of the plurality of subcarriers for transmission. In an exemplary embodiment, a training signal for performing channel state information (CSI) estimation is sent on one or more subcarriers of each frequency band. In a non-limiting example, three subcarriers within the first frequency band B1 and / or the second frequency band B2 are used to send and / or receive training signals. In another non-limiting example, all subcarriers within the first frequency band B1 and / or the second frequency band B2 are used to send and / or receive training signals.

[0048] The second wireless module 28b is used to wirelessly communicate with other systems (e.g., the first wireless module 28a) inside and / or outside the vehicle 12. In the first exemplary embodiment, the first wireless module 28a includes at least one wireless transceiver module 32 configured to send and receive signals on the first frequency band B1 as described above, and the second wireless module 28b is identical in structure and function to the first wireless module 28a, and also has at least one wireless transceiver module 32 configured to send and receive signals on the first frequency band B1.

[0049] refer to Figure 3, which shows a schematic diagram of a first wireless module 28a and a second wireless module 28b. In a second exemplary embodiment, the first wireless module 28a includes at least two wireless transceiver modules 32 described above. The second wireless module 28b is a signal conversion device for performing signal conversion between a first frequency band B1 and a second frequency band B2. In an exemplary embodiment, the second wireless module 28b includes a power supply 40, at least two antennas (i.e., a first antenna 42a and a second antenna 42b), and a conversion circuit 44.

[0050] The power source 40 is used to provide power to the conversion circuit 44. In an exemplary embodiment, the power source 40 is connected to the power system of the vehicle 12, for example, the twelve-volt electrical system of the vehicle 12. In another exemplary embodiment, the power source 40 is a battery. In another exemplary embodiment, the power source 40 is an energy harvesting device configured to harvest energy from, for example, radio frequency signals, light, vibrations, heat, etc., and convert the harvested energy into electrical energy. The power source 40 is electrically connected to the conversion circuit 44. It should be understood that the power source 40 can be any device capable of providing power to the conversion circuit 44 without departing from the scope of the present disclosure.

[0051] At least two antennas (i.e., the first antenna 42a and the second antenna 42b) are used to send and / or receive wireless communication signals. The first antenna 42a is used to receive wireless communication signals on the first frequency band B1, for example, wireless communication signals sent by the first wireless transceiver module 32a, such as Figure 3 The second antenna 42b is used to transmit wireless communication signals on the second frequency band B2, for example, wireless communication signals that can be received by the second wireless transceiver module 32b, such as Figure 3 The first antenna 42a and the second antenna 42b are in electrical communication with a conversion circuit 44, as will be discussed in more detail below.

[0052] The conversion circuit 44 is used to convert wireless communication signals between the first frequency band B1 and the second frequency band B2. In an exemplary embodiment, the conversion circuit 44 includes a mixer 46, an oscillator 48, a first amplifier 50a, a second amplifier 50b, a first bandpass filter 52a and a second bandpass filter 52b. In an exemplary embodiment, the first amplifier 50a and the first bandpass filter 52a are packaged as a monolithic integrated circuit, which is called a combined amplifier with a bandpass filter (LNA+BPF) 54.

[0053] The mixer 46 is used to convert the signal received using the first antenna 42a between the first frequency band B1 and the second frequency band B2, also known as heterodyning. In an exemplary embodiment, the mixer 46 is a passive mixer including passive components (e.g., diodes). In another exemplary embodiment, the mixer 46 is an active mixer including active components (e.g., transistors). In a non-limiting example, the mixer 46 generates a signal at the mixer output of the mixer 46, which is the product of the two input signals provided to the first mixer input and the second mixer input. The first mixer input of the mixer 46 is electrically connected to the oscillator 48. The second mixer input of the mixer 46 is electrically connected to the first amplifier 50a. The mixer output of the mixer 46 is electrically connected to the second bandpass filter 52b.

[0054] Oscillator 48 is used to generate an oscillating signal with a known frequency for mixer 46. In an exemplary embodiment, oscillator 48 is referred to as a local oscillator. In a non-limiting example, oscillator 48 is a crystal oscillator that generates an oscillating signal using a piezoelectric element. In another non-limiting example, oscillator 48 is a variable frequency oscillator capable of generating an oscillating signal with a variable frequency. Oscillator 48 is electrically connected to a first mixer input of mixer 46. In an exemplary embodiment, oscillator 48 receives power from power supply 40.

[0055] The first amplifier 50a is used to amplify the signal received by the first antenna 42a. In an exemplary embodiment, the first amplifier 50a is a low noise amplifier (LNA). LNA is intended to amplify extremely low power signals, such as the current generated by the antenna, without significantly reducing the signal-to-noise ratio of the signal. In a non-limiting example, the first amplifier 50a also includes a filter or other electronic circuit designed to remove useless signals and / or noise from the current generated by the first antenna 42a. In a non-limiting example, the power supply 40 provides power and DC bias signals to the first amplifier 50a. It should be understood that various additional types and / or topologies of amplifiers can be used to amplify the current generated by the first antenna 42a. The first amplifier 50a is electrically connected to the first bandpass filter 52a and the second mixer input of the mixer 46.

[0056] The second amplifier 50b is used to amplify the signal generated by the mixer 46 for transmission by the second antenna 42b. In a non-limiting example, the power supply 40 provides power and a DC bias signal to the second amplifier 50b. It should be understood that amplifiers of various additional types and / or topologies can be used to amplify the electrical signal generated by the mixer 46 for transmission by the second antenna 42b. The second amplifier 50b is electrically connected to the second bandpass filter 52b and the second antenna 42b.

[0057] The first bandpass filter 52a is used to filter the signal received by the first antenna 42a. In an exemplary embodiment, the first bandpass filter 52a is a passive device that uses a resistor, an inductor and / or a capacitor to implement bandpass filtering. In another exemplary embodiment, the first bandpass filter 52a is an active device that uses an active device (e.g., an operational amplifier) ​​to implement bandpass filtering. The center frequency of the first bandpass filter 52a is within the first frequency band B1, for example, at the center of the first frequency band B1. The first bandpass filter 52a is electrically connected to the first antenna 42a and the first amplifier 50a.

[0058] The second bandpass filter 52b is used to attenuate the extraneous frequency components introduced by the mixer 46. In an exemplary embodiment, the second bandpass filter 52b is a passive device that uses resistors, inductors and / or capacitors to implement bandpass filtering. In another exemplary embodiment, the second bandpass filter 52b is an active device that uses active components (e.g., operational amplifiers) to implement bandpass filtering. The center frequency of the second bandpass filter 52b is within the second frequency band B2, for example, at the center of the second frequency band B2. The second bandpass filter 52b is electrically connected to the mixer output of the mixer 46 and the second amplifier 50b.

[0059] refer to Figure 4 , the method 100 for vehicle video recording starts at box 102 and proceeds to box 104. In box 104, the controller 14 uses the first wireless transceiver module 32a and the second wireless transceiver module 32b to determine a plurality of channel state information (CSI) values, as will be discussed in more detail below. In the scope of the present disclosure, the CSI value describes how the signal propagates between the first wireless transceiver module 32a and the second wireless transceiver module 32b. More specifically, the CSI value represents the combined effects of, for example, scattering, fading, and power attenuation. In other words, the CSI is an estimate of the frequency response of the transmission channel between two or more transceivers. In some applications, the CSI value can be used to adapt the transmission characteristics according to environmental conditions. In the present disclosure, the CSI value is used to quantify the movement in the environment surrounding the vehicle 12, as will be discussed in more detail below. In an exemplary embodiment, at least one of the plurality of CSI values ​​corresponds to each of a plurality of subcarriers (i.e., sub-frequency), as will be discussed in more detail below. After box 104, the method 100 proceeds to box 106.

[0060] At block 106, the controller 14 calculates a plurality of CSI value derivatives. In an exemplary embodiment, the plurality of CSI values ​​are divided into a plurality of CSI value subsets, wherein each of the plurality of CSI value subsets corresponds to one of the plurality of subcarriers. The controller 14 calculates a time-value derivative of each of the plurality of CSI value subsets. Thus, each of the plurality of CSI value derivatives corresponds to a change in the CSI value of each of the plurality of subcarriers over time. Thus, the plurality of CSI value derivatives are also referred to as a plurality of dynamic CSI values. After block 106, the method 100 proceeds to block 108.

[0061] At block 108, the controller 14 determines a plurality of CSI value derivative magnitudes. The plurality of CSI value derivative magnitudes are also referred to as a plurality of dynamic CSI value magnitudes. In an exemplary embodiment, each of the plurality of CSI value derivatives includes a magnitude component and a phase component. To calculate the plurality of CSI value derivative magnitudes, the controller 14 obtains the magnitude of each of the plurality of CSI value derivatives and discards the phase component. After block 108, the method 100 proceeds to block 110.

[0062] At block 110, the controller 14 calculates a norm of the plurality of CSI value derivative magnitudes. In an exemplary embodiment, to calculate the norm, the controller 14 calculates a norm of a one-dimensional vector including the plurality of CSI value derivative magnitudes. In a non-limiting example, the norm is calculated as the square root of the sum of the squares of each of the plurality of CSI value derivative magnitudes:

[0063]

[0064] Where p is the norm, C i is the i-th of the plurality of CSI value derivative magnitudes, and N is the total number of the plurality of CSI value derivative magnitudes. In an exemplary embodiment, the norm is saved in the medium 20 of the controller 14 along with previous and future norms for further processing, as will be discussed in more detail below. After block 110, the method 100 proceeds to block 112.

[0065] At block 112, the controller 14 calculates a time-averaged norm signal. It should be understood that the method 100 can be repeatedly performed so that multiple previous norms calculated at block 110 are available in the medium 20. In an exemplary embodiment, the time-averaged norm signal is a moving average of the previous norms calculated at block 110 and stored in the medium 20. In another exemplary embodiment, the time-averaged norm signal is a moving average of the previous norms calculated at block 110 and stored in the medium 20. It should be understood that any statistical method for smoothing short-term fluctuations in time series data is within the scope of the present disclosure. After block 112, the method 100 proceeds to block 114.

[0066] At block 114, the controller 14 compares the time-averaged norm signal determined at block 112 to a predetermined time-averaged norm signal threshold. In an exemplary embodiment, the predetermined time-averaged norm signal threshold is determined experimentally and may be adjusted to adjust the sensitivity of the system 10. If the time-averaged norm signal remains greater than or equal to the predetermined time-averaged norm signal threshold for at least a predetermined period of time (e.g., 2 seconds), the method 100 proceeds to block 116. If the time-averaged norm signal is not greater than or equal to the predetermined time-averaged norm signal threshold for at least a predetermined period of time, the method 100 proceeds to a standby state at block 118.

[0067] At box 116, the controller 14 determines the occupancy state of the environment 22 around the vehicle 12 as an occupied state. Within the scope of the present disclosure, the occupancy state includes an occupied state and an unoccupied state. The occupied state means that an entity (i.e., a person, an animal, and / or an inanimate object in motion) exists in the environment 22 around the vehicle 12. The unoccupied state means that no entity exists in the environment 22 around the vehicle 12. In an exemplary embodiment, in response to determining that the occupancy state is an occupied state, the controller 14 uses the camera system 24 to record a video of the environment 22 around the vehicle 12. Therefore, the video captures the entity in the environment 22 around the vehicle 12. For example, if the entity wants to damage and / or tamper with the vehicle 12, the video can be used as evidence. In another exemplary embodiment, in response to determining that the occupancy state is an occupied state, the controller 14 activates the security system of the vehicle 12, for example, activating the alarm system of the vehicle 12 to prevent tampering with the vehicle 12.

[0068] It should be understood that the above-mentioned signal processing method for analyzing multiple CSI values ​​and determining occupancy status is essentially merely exemplary and alternative methods. For example, thresholds based on standard deviation, activity pattern recognition, machine learning models, etc. are all within the scope of the present disclosure.

[0069] In an exemplary embodiment, the controller 14 repeatedly exits the standby state 118 and restarts the method 100 at block 102. In a non-limiting example, the controller 14 exits the standby state 118 and restarts the method 100 on a timer, for example, every three hundred milliseconds. By repeatedly executing the method 100, multiple measurements of the environment 22 are performed and recorded.

[0070] refer to Figure 5, a flow chart of a first exemplary embodiment 104a of block 104 is shown. The first exemplary embodiment 104a utilizes an embodiment of the system 10, wherein the first wireless module 28a includes at least one wireless transceiver module 32 configured to send and receive signals on the first frequency band B1, and wherein the second wireless module 28b is identical in structure and function to the first wireless module 28a. The first exemplary embodiment 104a begins at block 502. At block 502, the controller 14 uses the first wireless module 28a to send multiple original training signals on multiple subcarriers. Within the scope of the present disclosure, the multiple original training signals are known signals sent for the purpose of CSI value estimation. After block 502, the first exemplary embodiment 104a proceeds to block 504.

[0071] At block 504, the second wireless module 28b receives the first plurality of propagated training signals from the first wireless module 28a. The received training signals are referred to as propagated training signals because, as described above, environmental characteristics cause the original training signals to change during propagation. It should be understood that in some embodiments, other devices with wireless capabilities (e.g., a smartphone or other mobile device in the vehicle 12) can perform the functions of the second wireless module 28b. After block 504, the first exemplary embodiment 104a proceeds to block 506.

[0072] At block 506, the controller 14 determines a first deviation between the plurality of original training signals and the first plurality of propagated training signals. In an exemplary embodiment, the first deviation is a difference between the plurality of original training signals and the first plurality of propagated training signals. In a non-limiting example, the first deviation is a one-dimensional vector including deviations corresponding to transmissions on each subcarrier frequency. After block 506, the first exemplary embodiment 104a proceeds to block 508.

[0073] At block 508, the controller 14 determines a plurality of channel state information (CSI) values. In an exemplary embodiment, the plurality of CSI values ​​are determined based at least in part on the first bias. After block 508, the first exemplary embodiment 104a ends and the method 100 continues as described above.

[0074] refer to Figure 6, a flow chart of a second exemplary embodiment 104b of block 104 is shown. The second exemplary embodiment 104b utilizes an embodiment of the system 10, wherein the first wireless module 28a includes at least two wireless transceiver modules 32 and is configured to send and receive signals on the first frequency band B1 and the second frequency band B2, and wherein the second wireless module 28b is a signal conversion device for performing signal conversion between the first frequency band B1 and the second frequency band B2. The second exemplary embodiment 104b starts at block 602. At block 602, the controller 14 uses the first wireless transceiver module 32a of the first wireless module 28a on the first frequency band B1 to send multiple original training signals on multiple subcarriers. Within the scope of the present disclosure, the multiple original training signals are known signals sent for the purpose of CSI value estimation. After block 602, the second exemplary embodiment 104b proceeds to block 604.

[0075] At block 604 , the second wireless module 28 b receives the first plurality of propagated training signals using the first antenna 42 a . After block 604 , the second exemplary embodiment 104 b proceeds to block 606 .

[0076] At block 606, the second wireless module 28b converts the first plurality of propagated training signals received at block 604 from the first frequency band B1 to the second frequency band B2 using the conversion circuit 44, as described above. After block 606, the second exemplary embodiment 104b proceeds to block 608.

[0077] At block 608 , the second wireless module 28 b transmits a first plurality of propagated training signals over the second frequency band B2 using the second antenna 42 b . After block 608 , the second exemplary embodiment 104 b proceeds to block 610 .

[0078] At block 610, the first wireless module 28a uses the second wireless transceiver module 32b to receive a second plurality of propagated training signals on the second frequency band B2. The received training signals are referred to as the second plurality of propagated training signals because the environmental characteristics cause the first plurality of training signals to change during propagation, as described above. After block 610, the second exemplary embodiment 104b proceeds to block 612.

[0079] At block 612, the controller 14 determines a second deviation between the plurality of original training signals and the second plurality of propagated training signals. In an exemplary embodiment, the second deviation is a difference between the plurality of original training signals and the second plurality of propagated training signals. In a non-limiting example, the second deviation is a one-dimensional vector including deviations corresponding to transmissions on each subcarrier frequency. After block 612, the second exemplary embodiment 104b proceeds to block 614.

[0080] At block 614, the controller 14 determines a plurality of channel state information (CSI) values. In an exemplary embodiment, the plurality of CSI values ​​are determined based at least in part on the second bias. After block 614, the second exemplary embodiment 104b ends and the method 100 continues as described above.

[0081] The system 10 and method 100 of the present disclosure have multiple advantages. Using the system 10 and method 100, occupancy detection near the vehicle can be completed with low power consumption, thereby allowing continuous monitoring without excessive use of resources. In addition, components of the system 10 may already exist on the vehicle 12 for other functions. Therefore, it is advantageous to use such components for the system 10 and method 100. In addition, parameters of the system 10 and / or method 100 can be adjusted. For example, a predetermined time average norm signal threshold can be adjusted to adjust the sensitivity of the system 10 based on the environmental background. In an exemplary embodiment, GNSS26 is used to determine the position of the vehicle 12, and the controller 14 adjusts the predetermined time average norm signal threshold based on the position of the vehicle 12. In an exemplary embodiment, if the vehicle 12 is in a position where tampering is more likely, such as in a public parking lot, the sensitivity of the system 10 is increased.

[0082] The description of the present disclosure is merely exemplary in nature, and variations that do not depart from the gist of the present disclosure are intended to fall within the scope of the present disclosure. These variations should not be regarded as departing from the spirit and scope of the present disclosure.

Claims

1. A system for vehicle video recording, the system include: Camera system; A first wireless module; A second wireless module; a controller in electrical communication with the camera system, the first wireless module, and the second wireless module, wherein the controller is programmed to: Transmitting a plurality of original training signals on a plurality of subcarriers using the first wireless module; receiving a plurality of propagation training signals using the second wireless module; determining deviations between the plurality of original training signals and the plurality of propagated training signals; determining an occupancy state of the vehicle surroundings based at least in part on the deviation, wherein the occupancy state comprises at least one of an occupied state and an unoccupied state; as well as In response to determining that the occupancy state is the occupied state, recording video using the camera system.

2. The system according to claim 1, in, To determine the occupancy state of the vehicle surroundings, the controller is further programmed to: determining a plurality of channel state information (CSI) values ​​based at least in part on the deviations between the plurality of original training signals and the plurality of propagated training signals; as well as The occupancy state of the vehicle surroundings is determined based at least in part on the plurality of CSI values.

3. The system according to claim 2, in, To determine the occupancy state of the vehicle surroundings, the controller is further programmed to: calculating a plurality of CSI value derivatives, wherein at least one of the plurality of CSI value derivatives corresponds to each of the plurality of subcarriers; calculating a plurality of CSI value derivative magnitudes, wherein each of the plurality of CSI value derivative magnitudes is a magnitude of one of the plurality of CSI value derivatives; Calculating a norm of the multiple CSI value derivative amplitudes; calculating a time-averaged norm signal based at least in part on the norm; and The occupancy state of the vehicle surroundings is determined based at least in part on the time-averaged norm signal.

4. The system according to claim 3, in, To determine the occupancy state of the vehicle surroundings, the controller is further programmed to: continuously comparing the time-averaged norm signal with a predetermined time-averaged norm signal threshold; as well as In response to determining that the time-averaged norm signal is greater than or equal to the predetermined time-averaged norm signal threshold during at least a predetermined period of time, the occupancy state is determined to be the occupied state.

5. The system according to claim 1, in, The first wireless module and the second wireless module are digital wireless local area network (WLAN) transceiver systems configured to implement wireless communication protocols.

6. The system of claim 1, in, The first wireless module is a digital wireless local area network (WLAN) transceiver system configured to implement a wireless communication protocol, and wherein the second wireless module is a signal conversion device configured to convert signals between at least two frequency bands.

7. The system according to claim 6, in, The signal conversion device also includes: power supply; At least two antennas; a conversion circuit in electrical communication with the power supply and the at least two antennas, the conversion circuit comprising: a mixer in electrical communication with the at least two antennas; and An oscillator is in electrical communication with the mixer.

8. The system of claim 7, in, The conversion circuit also includes: a first amplifier in electrical communication with a first of the at least two antennas and the mixer; and A second amplifier is in electrical communication with the mixer and a second of the at least two antennas.

9. The system of claim 8, in, The conversion circuit also includes: a first bandpass filter in electrical communication with the first amplifier and the mixer; and A second bandpass filter is in electrical communication with the mixer and the second amplifier.

10. The system of claim 9, in, The first bandpass filter has a first center frequency within a first frequency band of the at least two frequency bands, and wherein the second bandpass filter has a second center frequency within a second frequency band of the at least two frequency bands.

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