Parking sensors capable of determining direction and speed of vehicle entering or leaving a parking lot

A parking inventory management system includes a sensor apparatus with a plurality of magnetometers each configured to respectively generate a magnetic signatures of a vehicle as it drives across the sensor apparatus. A computing device is associated with the sensor apparatus and compares the magnetic signatures of the vehicle generated by each of the plurality of magnetometers to the magnetic signatures of the vehicle generated by each other magnetometer of the plurality thereof so as to determine a direction of the vehicle. A match between the magnetic signature of the vehicle as generated by at least two of the plurality of magnetometers indicates that the direction of travel of the vehicle is along a direction between those two of the plurality of magnetometers. A speed of the vehicle is derived as a function of a time difference between points of peak similarity between matching magnetic signatures of the vehicle.

TECHNICAL FIELD

This disclosure is related to the field of parking lot monitoring, and, more particularly, to systems and methods for monitoring vehicle arrival, and for determining the direction and speed of arriving vehicles.

BACKGROUND

In many cities, motor vehicles such as cars are the predominant mode of transportation utilized by residents. In some cases, parking lots for motor vehicles are not monitored or attended, and motor vehicles come and go at the direction of their drivers. However, in other cases, parking lots are to be monitored using automated parking lot management systems.

For example, a device may be installed at the entrance of a parking lot that monitors the number of vehicles in the lot via a counter. However, such vehicle sensors have a variety of inherent drawbacks in their designs. For example, such vehicle sensors may be incapable of determining in what direction a vehicle is traveling, which can lead to an inaccurate count of vehicles in the parking lot in the case where a driver fails to utilize certain designated entrances and exits, or where a driver drives erratically back and forth through an entrance or exit (possibly to use a payment device placed at said entrance or exit).

Therefore, a vehicle sensor capable of detecting not only presence of a vehicle, but also the direction of the vehicle is desirable, as that would permit design of a parking monitoring system that addresses the above drawbacks. In addition, a vehicle sensor capable of also detecting speed of the vehicle would be desirable, as it would permit better monitoring of traffic flow within the parking lot. Therefore, it is evident that there has been a need for further developments in the area of parking systems and parking sensors.

SUMMARY

The above described need has now been met by the systems, technologies, techniques, and methods described hereinbelow. It should first be noted that this summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

Disclosed herein is a system including a sensor apparatus comprising a plurality of magnetometers each configured to respectively generate magnetic signatures of a vehicle as it drives across the sensor apparatus, and a computing device associated with the sensor apparatus. The computing device is configured to compare the magnetic signatures of the vehicle generated by each of the plurality of magnetometers to the magnetic signatures of the vehicle generated by each other magnetometer of the plurality thereof so as to determine a direction of travel of the vehicle. A match between magnetic signature of the vehicle as generated by at least two of the plurality of magnetometers indicates that the direction of travel of the vehicle is along a direction between those two of the plurality of magnetometers.

A method aspect is directed to a method of parking lot inventory management. The method includes disposing at least one sensor apparatus, each comprising a plurality of magnetometers, at each entry or exit lane to the parking lot. For each sensor apparatus, the method includes comparing magnetic signatures of a vehicle driving over that sensor apparatus generated by each of the plurality of magnetometers of that sensor apparatus to the magnetic signatures of the vehicle generated by each other magnetometer of the plurality of magnetometers of that sensor apparatus so as to determine a direction of travel of the vehicle. A match between magnetic signatures of the vehicle as generated by at least two of the plurality of magnetometers of that sensor apparatus indicates that the direction of travel of the vehicle is along a direction between those two of the plurality of magnetometers of that sensor apparatus. A count of vehicles in the parking lot is incremented as a function of the direction of travel of the vehicle indicating that the vehicle is entering the parking lot. A count of vehicles in the parking lot is decremented as a function of the direction of travel of the vehicle indicating that the vehicle is leaving the parking lot.

Also disclosed herein is a system including a sensor apparatus with a plurality of sensors each configured to respectively generate signatures of a vehicle as it drives across the sensor apparatus. A computing device is associated with the sensor apparatus and configured to compare the signatures of the vehicle generated by each of the plurality of sensors to the signatures of the vehicle generated by each other sensor of the plurality thereof so as to determine a direction of travel of the vehicle. A match between signatures of the vehicle as generated by at least two of the plurality of sensors indicates that the direction of travel of the vehicle is along a direction between those two of the plurality of sensors.

DETAILED DESCRIPTION

In the following description, numerous details are set forth to provide an understanding of the present disclosure. It will be understood by those skilled in the art, however, that the embodiments of the present disclosure may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.

With reference toFIG. 1A, a system100for monitoring arrival of vehicles is now described. The system100is installed at a parking lot105, at which motor vehicles, such as cars, trucks, and motorcycles may be parked. A vehicle detection device100detects arrival of vehicles and/or entry of vehicles and/or departure of vehicles to or from the parking lot105. As show, a vehicle101is adjacent a motor operated gate125selectively that permits vehicles to enter and depart from the parking lot105. A server130is in communication with the vehicle detection device110over a network, such as the Internet, and receives data from the vehicle detection device110. The server130processes this data130, and may then send output to, or prompt for input from, a device of an operator of the parking lot135, or a device102within the vehicle101. Optional sensors or indicators140are installed adjacent parking spots106.

The device102within the vehicle101may be a mobile wireless communications device utilized by the driver or passenger of the vehicle101, such as a smartphone, smartwatch, or tablet, or may be a device integrated within the vehicle101, such as an infotainment system.

With additional reference toFIG. 4A, further details of the vehicle detection device110will now be given. The vehicle detection device110includes a processor111, such as a microprocessor or system on a chip. Coupled to the processor111is a magnetometer112, as well as an accelerometer113. A Bluetooth module115is coupled to the processor111for potential communication with the device102within the vehicle101, and a transceiver114is coupled to the processor111for communication with the server130over the wide area network, and/or also with other vehicle detection devices110if present, and/or also with the optional sensors140. A display117, LED123, and speaker125are coupled to the processor111for providing visual or audio output to a user. The display117, LED123, and speaker125may be utilized for any provided output described below instead of the device102. A camera121is coupled to the processor111for taking pictures, such as of the license plate of the vehicle101, which may be sent to and processed by the server. A payment acceptance device119is coupled to the processor111for accepting payment from a user. The payment acceptance device119may utilize magnetic strip, chip and pin, NFC, or other electronic payment acceptance technologies. In addition, the payment acceptance device119may also directly accept hard currency, such as bills and coins. A RFID reader126is coupled to the processor111for reading RFID tags associated with the vehicle, such as a toll tag mounted in the vehicle, or RFID tags within the tires of the vehicle.

A payment acceptance device119is coupled to the processor111for accepting payment from a user. The payment acceptance device119may utilize magnetic strip, chip and pin, NFC, or other electronic payment acceptance technologies. In addition, the payment acceptance device119may also directly accept hard currency, such as bills and coins. It should be appreciated that in some applications, the payment acceptance device119may be part of, or may be, the RFID reader126.

The magnetometer112serves to sense metal in vehicles101via a change in the local magnetic field, and can thus detect the presence of vehicles101. The processor111may be able to interpret reading from the magnetometer112to estimate the dimensions of the vehicle101, from which a type or configuration of the vehicle may be inferred (i.e. a vehicle estimated to be a car, whereas a larger vehicle is likely to be a truck).

The accelerometer113serves to detect vibrations in multiple axes, such as those caused by a passing vehicle101, and can therefore be used to determine whether the vehicle101is entering or leaving the given area. By logging the magnitude and direction of vibrations detected by the accelerometer113, the processor111can infer both the speed of the vehicle, as well as whether the vehicle is arriving or departing.

Due to the use of the accelerometer113and magnetometer112for detecting vehicles101, the vehicle detection device110is positioned at the entrance and exit to the parking lot105, and needs not be driven over by the vehicle101in order for detection to occur.

As stated, the RFID reader126may read RFID tags associated with the vehicle. Thus, the RFID reader126may read a code from the RFID tag, and the code may be a toll tag ID number, or may be a tire identification code. Where the code is a toll tag ID, the information about the vehicle may be the toll tag ID, which may in turn be used for identification of the user by looking up the user's information in a table of toll tag ID's, or in processing payment via the toll tag ID. Where the code is a tire identification code, the information about the vehicle may be the tire identification code, which may in turn be used by the server to determine a make and model of the tires on the vehicle, which may in turn be used to determine the type of vehicle and vehicle configuration, as well as the make and model of the vehicle. Also, the information about the vehicle may include the various measurements taken by the accelerometer113and magnetometer112as well as the make and model of the tires, which may be used to more accurately determine the type of vehicle and vehicle configuration, as well as the make and model of the vehicle.

As stated above, using the transceiver114, the vehicle detection device110may communicate with other vehicle detection devices110. In addition, one vehicle detection device110may act as a relay for another vehicle detection device110, transmitting information received therefrom to the server130, or to the device102within the vehicle101. The transceiver114may also be used by the vehicle detection device110for communication with a fixed or mobile device used by a parking lot attendant, such as a smartphone, tablet, or pay station.

The processor111may also cooperate with additional vehicle detection hardware, such as a pressure sensor for vehicle sensing, allowing retrofitting of the vehicle detection device110to existing parking lot management installations. In addition, the processor111may also cooperate with hardware, such as RFID readers, that read toll tags or toll passes, and/or Bluetooth connections from which vehicle information may be read, and via which payment for parking may be effectuated.

In some applications, such as that shown inFIG. 1B, rather than the vehicle detection device110being at the entrance to the parking lot105, there is a separate vehicle detection device110located in each parking space106. Each of these vehicle detection devices110may have the components as described above and below, and may operate as described above and below. In addition, it should be understood that the various vehicle detection devices110may communicate with one another via their transceivers114, their Bluetooth modules115, or a combination thereof. This communication may be to relay data to and from the server130, for example. In addition, the various vehicle detection devices110may cooperate using their Bluetooth modules115to perform triangulation to determine the position of the vehicle101within the parking lot105, and may then direct the driver of the vehicle101to the parking space106via the device102within the vehicle101, or via their respective displays117, LEDs123, and/or speakers125.

In other applications, such as that shown inFIG. 1D, rather than directly communicating with the server130, each vehicle detection device110communicates with a hub109either wirelessly or over a wire, and the hub109in turn communicates with the server130, serving to pass data to the server130from the vehicle detection devices110, and serving to pass data to the vehicle detection devices110from the server130. It should also be appreciated that the hub109may perform any of the functions described above or below as being performed by the vehicle detection device110.

With additional reference to the flowchart550ofFIG. 5, a method of monitoring vehicle101arrival to a given location, such as a parking lot105, is now described. The vehicle detection device110, as described above, operates to sense arrival (or departure) of a vehicle101(Block551). The vehicle detection device110then sense information about the vehicle101, and sends it to the server130in response to the sensing of arrival or departure (Block552). The information about the vehicle may be sensed via the magnetometer112and accelerometer113, and/or may be sensed via interaction with the device102within the vehicle101via the Bluetooth module115, or via the transceiver114.

Next, the server130determines a context of the vehicle101based on the information received from the vehicle detection device110(Block553). Thereafter, the server130takes at least one action based on the context of the vehicle101(Block554).

Through sensing different types of information about the vehicle101, through determining different contexts, and through taking different actions, the system100may be used in a wide variety of applications. For example, the application shown inFIG. 1Ais that where the system100is installed at a parking lot105.

A first parking related application is where a driver of the vehicle101has prepaid for parking via the device102. When the vehicle101arrives to the parking lot105, the vehicle detection device110operates to read the prepayment (or voucher) information from the device102, or serves to identify the vehicle101via the device102and then query the server130for the prepayment or voucher information. If the prepayment or voucher is valid (i.e. has been properly paid for the correct amount, and/or if it is an authorized time of day, date, or day of the week), the vehicle detection device110or server130instructs the gate125to open, and updated parking lot inventory information is sent to the parking lot operator's device135.

If no prepayment is present, or if the prepayment or voucher is not valid for the present time, the vehicle detection device110may, either on its own via its display117, LED123, and speaker125, or via the device102in the vehicle101, demand payment for the right to park the vehicle101in the parking lot105. If, within a given amount of time, the payment is not received (from either the device102, or in pieces from multiple devices102, or via the payment acceptance device119) and the vehicle101has not left the parking lot, the vehicle detection device110, either on its own or via the server130, may notify the parking lot operator's device135that the vehicle101is parked in the parking lot105without having paid for the right to do so.

In a second parking related application, the vehicle detection device110serves to detect the number of devices102in the vehicle101, and transmits that information to the server. Since the majority of adults carry a smartphone in today's world, from this number of devices102in the vehicle101, the server130can estimate the number of people in the vehicle101, and may transmit this data to the parking lot operator's device135, may save this data for future analytics, or may transmit this data to other devices, such as those within a venue adjacent the parking lot105.

In a third parking related application, the vehicle detection device110serves to read user identity information from the device102in the vehicle, or to request user identity information associated with the device102from the server130. Then, the server130can notify the parking lot operator or venue that the user matching the user identity information has arrived. Therefore, the parking lot operator or venue can prepare for the arrival of that specific user.

As an example, the specific user may have reserved a given parking space106, and the parking lot operator may manually (via a human attendant) direct the vehicle101to park in the parking space106, or the server130may direct the vehicle101to park in the parking space106via displays incorporated with the sensors140, or via the display117, LED123, and/or speaker125. In addition, in some applications, the sensors140may report to the parking lot operator, the vehicle detection device110, or the server130which spaces are occupied. This functionality may also be performed by the vehicle detection device110. If the vehicle detection device110, via the sensors140or on its own, determines that the reserved space106has been improperly occupied (i.e. the space106is occupied, but the vehicle detection device110has not detected the device102of the specific user), the vehicle detection device110may directly or via the server130notify the parking lot operator's device135that the parking space106is occupied by an unauthorized vehicle.

In any such parking applications wherein payment is collected for the parking space106, the vehicle detection device110may determine both an arrival time and a departure time of the vehicle101, and the payment amount may be based upon the length of time between the arrival time and departure time. The payment amount may be additional or alternatively be based upon the time of day, date, or day of week of the arrival time and/or departure time—for example the payment may be greater on a Saturday than on a Tuesday, or may be less at 2:00 AM than at 9:00 AM. In addition, the payment amount may be dependent upon the weight, type, or configuration of the vehicle101(e.g. vehicle size, vehicle weight, vehicle body style, etc), as determined based on readings from the magnetometer112and/or accelerometer113.

In some cases, the vehicle101may be authorized to park in the parking lot105at the time of parking, but may at a later point in time, before departure, become no longer authorized. For example, the parking lot105may be operated by a municipality, and may need to be emptied for street cleaning, trash pickup, etc. In such cases, the server130may notify the parking lot operator's device135(and thus the municipality's device) that certain vehicles have not yet departed. The municipality can then take appropriate action. In some cases, such notification may additional or alternatively be sent to the device102.

Another parking application may be where the parking lot105is a valet parking lot. The vehicle detection device110may this record a unique identifier for the vehicle when it entered the parking lot105, and thus unique identifier may be transmitted, via the server130or directly, to the device102. A user may request retrieval of the vehicle101via provided input to the device102.

Another application for the system200in which the system200is employed at a merchant is now described with additional reference toFIG. 2. Here, the parking lot205is a parking lot for a merchant, such as a restaurant, and205may be a drive through lane instead of a parking lot. The vehicle detection device210can detect when the vehicle201arrives at the merchant, and can read the identify of a user from the device202, or request an identity of the user from the server230based on information received from the device202. The server230may then send the identity of the user to the merchant's device235, which may retrieve order information for the user. In some applications, the server230may have the order information for the user, and may pass the order information along to the merchant's device235. In yet another application, the vehicle detection device210may cause the device202to prompt the user to enter an order. The user's order may then be transmitted to a device inside the Merchant's business wherein it is prepared and delivered to the user. In the case of205being a drive through lane, the system200may compute the time required to prepare the user's order and, comparing such time to the time required to prepare other users' orders within the drive through lane, may direct the Merchant's employees to prepare orders in a sequence different from the sequence of vehicles in the drive through queue in an effort to minimize user wait times and maximize efficiency.

Yet another application for the system300in which the system300is employed at a shipping yard is now described with additional reference toFIG. 3. Here, the parking lot305is for trucks301at a shipping yard. The vehicle detection system310may retrieve a shipping manifest from the device302, server330, or shipping yard's device335, and pass the shipping manifest along to any such device. The server330or shipping yard's device335, knowing that the shipment having that shipping manifest has arrived, may notify the owner of the cargo. The server330may, either directly or via the vehicle detection system310, notify the device302or the sensors306to direct the driver where to park the truck.

Additional sensors303may be placed in the cargo containers carried by the trucks301, and these sensors may detect when the cargo container is being moved (for example, from a301to storage), and transmit that data to the server330via the vehicle detection device310. The server330may then report that data to the shipping yard's device335.

Further details of the vehicle sensing system100and vehicle sensing device110will now be given with reference toFIGS. 4 and 6. A method of operating the vehicle sensing device110, described with reference to flowchart650, includes detecting entry of the vehicle to the given area via the vehicle detector (e.g. magnetometer112, accelerometer113, etc) at Block651. Thereafter, the method includes determining information about the vehicle, in response to sensing arrival of the vehicle to the given location, using the wireless transceiver114and/or the vehicle detector (e.g. magnetometer112, accelerometer113, etc) at Block652. Then, the method continued with transmitting information to the server using the transceiver114at Block653.

In some instances, the processor111may transmit an application trigger to cause the device within the vehicle (e.g. smartphone, infotainment system, etc) to launch an application. This application may prompt the user for payment, provide the user with notice that they are authorized or not authorized, provide the user with information about where to park, where to pick up cargo, or where to drop off cargo, provide the user with information about valet parking (such as price), or provide the user with information about an order from a merchant.

In some applications, for example such as the one shown inFIG. 1C, rather than a vehicle sensing device performing the above steps, a hub109works in accordance with a counting device141to perform the above functions. The hub109contains similar components to the vehicle sensing device described above, as is apparent fromFIG. 4B, and has similar functionality to the vehicle sensing device as well, with the exception being that it lacks a magnetometer and accelerometer, and instead determines arrival and departure of vehicles via triggering of the counting device141by the weight of the vehicles driving over the counting device141. It should be appreciated that the hub109may actually be a portable wireless electronic device, such as a smartphone or tablet.

With initial reference toFIGS. 7A-7B, a parking system50is now described. The parking system50includes one or more parking sensor apparatuses52situated at the entrance or exit lanes to a parking lot. Each parking sensor apparatus52includes, for example, four three-axis magnetometers54a-54dpositioned in a rectangular shape. The magnetometers54a-54dare coupled to processing circuitry53, such as an application specific integrated circuit. The processing circuitry53is coupled to a transmitter55, which wirelessly communicates with modem49. In some applications, such as that shown inFIG. 7A, the processing circuitry53converts signals received from the magnetometers54a-54dinto a format usable by cellular modem49for transmission to a cloud based server60. In other applications, such as that shown inFIG. 7B, the processing circuitry53processes the signals received from the magnetometers54a-54dto determine the properties of vehicles driving over the parking sensor apparatus52(such as speed, direction, length, etc) and sends those determined values to the cloud based server60.

Which configuration is used for a given installation may depend on the particular details of that installation. For example, if the parking sensor apparatus52and cellular modem49is to be powered by a battery, using the processing circuitry53to determine the properties of the vehicles so as to reduce the amount of data sent by the cellular modem49may help provide for greater battery life over sending the signals from the magnetometers54a-54dto the cloud based server60. On the other hand, where battery life is not a concern, it may be desirable for the cloud based server60to determine the properties of the vehicles so as to allow for easy updating of the analysis techniques used, as well as for additional data processing power.

The magnetometers54a-54dmay each have analog to digital conversion circuitry associated therewith (not shown), or packaged therewith (not shown), that sends data to the processing circuitry53directly or over a bus connection.

It should be understood that although the modem49has been described as a cellular modem, it may in some cases instead be a wireless network transceiver (e.g. WiFi), or may be a wired network interface (e.g. Ethernet).

In operation, a vehicle drives over the parking apparatus52, and each magnetometer54a-54dof the parking apparatus52repeatedly produces a waveform corresponding to magnetic features, or a magnetic signature, of the vehicle, at a rate of, for example, 50 times per second to 800 times per second. The Inventor has found that the specific waveforms produced for different vehicles are influenced by unpredictable factors, making extraction of information directly from the waveforms to be difficult. However, the Inventor has also found that the specific waveforms produced by a given vehicle are consistent across the magnetometers54a-54d. Therefore, by comparing the waveforms produced by the magnetometers54a-54dto one another while varying an applied time offset, in response to a car driving over the parking apparatus52, the direction and speed of the vehicle may be determined.

The server60may perform the above mentioned comparisons (FIG. 7A), or the processing circuitry53may perform the above mentioned comparisons (FIG. 7B). Since each magnetometer54a-54dproduces numerous magnetic signatures of the vehicle as it drives over, each waveform from each magnetometer54a-54dis compared to each waveform from each other magnetometer54a-54dwhile a variable time offset therebetween is adjusted so as to locate a match. Examples of such comparisons are shown inFIGS. 10-11, withFIG. 10showing magnetic signatures for a Toyota 4Runner SUV, andFIG. 11showing magnetic signatures for a Ford F-150.

When two waveforms from adjacent magnetometers (from among54a-54d) are substantially similar or identical, and not time shifted with respect to one another (and thus, little to no offset is needed), this indicates that the vehicle has driven across those magnetometers in a same direction. However, when two waveforms from adjacent magnetometers (from among54a-54d) are substantially similar or identical, as well as being time shifted with respect to one another (thus, offset is needed to produce the match), this indicates that the vehicle has driven in a direction from the magnetometer producing the earlier in time version of the waveform to the magnetometer producing the later in time version of the waveform. For example, if the waveforms produced by magnetometers54aand54bare substantially similar or identical, with the waveform produced by magnetometer54bbeing delayed with respect to the waveform produced by magnetometer54a, then the direction of the vehicle is in a direction from magnetometer54ato magnetometer54b.

Using this information, the server60can accurately maintain a count of the number of vehicles in the parking lot, even when a vehicle enters through a designated exit, exits through a designated entrance, or enters or exits through an undefined area serving as both entry and exit. Where the direction of the vehicle indicates that the vehicle is leaving the parking lot, the count of the number of vehicles in the parking lot is decremented by the server60; likewise, where the direction of the vehicle indicates that the vehicle is entering the parking lot, the count of the number of the vehicles in the parking lot is incremented by the server60.

In addition, using such a system50, a parking lot can utilize undesignated entrances and exits, permitting for quicker traffic flow in some scenarios (i.e. all act as entrances at a stadium prior to a sporting event, and all act as exits at the stadium after the sporting event) while still allowing for automated monitoring of parking inventors. Or, the parking lot may have a combination of defined and undefined entrances and exists. Such a configuration is shown inFIG. 9, where the parking lot40includes sensor apparatuses52oand52plocated at defined single lane entrances or exits, and with sensor apparatuses52a-52nlocated at a wide open undefined area through which vehicles may enter and exit.

It should be understood that by identifying and analyzing points of peak similarity between similar but time delayed waveforms and determining the time delay, the server60or processing circuitry53may determine the speed of the vehicle. For example, speed can be calculated as distance/time, the distance between the various magnetometers54a-54dis known. Therefore, as an example, the speed may be calculated as the distance between the magnetometers (from among54a-54d) that generated a pair of similar yet time delayed with respect to one another waveforms, divided by the time delay between peak values of those waveforms. Using points of peak similarity, such as peak values, zero crossings, or other readily identifiable features for delay comparisons allows for a more precise match between the waveforms than simply using a beginning or end of the waveform for the delay comparisons. A graph showing points of peak similarity between magnetic signatures and the delay between those points of peak similarity is shown inFIG. 12, where the X axis corresponds to time-delays where peak similarities have occurred between compared magnetic signatures, and where the Y axis corresponds to the degree of that similarity.

Additionally, the determined speed of the vehicle may be used in further calculations. For example, the server60or processing circuitry53may estimate a length of the vehicle as a product of the determined speed and a duration of the waveform. From the estimated length, the server60may then estimate whether the vehicle is a car, truck, SUV, or commercial vehicle by comparing the length to a series of threshold sizes. The server60may determine the vehicle to be a commercial vehicle if the length is greater than an upper threshold, may determine the vehicle to be a truck or SUV if the vehicle's length is greater than or equal to a middle threshold and less than the upper threshold, and may determine the vehicle to be a car if the vehicle's length is greater than or equal to a lower threshold and less than the middle threshold length. In some cases, the server60may use upper and lower threshold lengths, with the vehicle length being greater than the upper threshold meaning that the vehicle is a commercial vehicle, and the vehicle length being greater than or equal to a lower threshold and less than the upper threshold meaning that the vehicle is a private vehicle. Indeed, it should be appreciated that any suitable thresholds, number of thresholds, and comparison operators may be used.

It should also be appreciated that this functionality can be used to reject a waveform as representing a false positive, such as where the vehicle length is less than the lower threshold. This may mean that a pedestrian carrying a metallic object, or riding a metallic object such as a wheelchair, mobility cart, or bicycle has passed over the sensor apparatus52, and thus should not be counted in the determination of parking lot space inventory.

It should be understood that although the parking apparatus52as shown includes four magnetometers54a-54darranged into a rectangular shape, other numbers of magnetometers and other shapes may be used. Indeed, there may be two, three, five, six, or any suitable number of magnetometers arranged into any usable shape.

As an example, there may be two magnetometers spaced apart from one another. This design may be suitable for entrances and exits to parking lots where physical barriers ensure that vehicles will drive over the magnetometers in either a forward or a reverse direction, and not at other angles. As another example, three magnetometers may be arranged into a triangular shape. This arrangement may be suitable for entrances and exits to parking lots without physical barriers restricting the movement of vehicles, such that vehicles may drive over the magnetometers from multiple different directions. However, depending on the specific triangular arrangement and the placement of the parking apparatus at the parking lot, the same part of vehicles entering or exiting the parking lot may not drive over two of the magnetometers, which can lead to a greater amount of inaccuracy in the determination of speed and direction of the vehicle. By arranging four magnetometers into a rectangular shape, the likelihood of the same part of vehicles entering or exiting the parking lot not driving over two of the magnetometers is reduced, with the tradeoff being the use of an additional magnetometer together with the spending of processing power to analyze the data from that additional magnetometer.

Potential network topologies for the parking system50are now described with reference toFIG. 8. In some cases, the parking lot in which the system50is located may be small enough such that a single modem is in communication distance with each sensor apparatus, such as that shown inFIG. 8where modem49dis in communication with sensor apparatuses52h-52j.

However, in some cases, the parking lot in which the system50is located may be too large, or may be multi-level, for direct communication between each sensor apparatus and the modem to be feasable. Thus, in these cases, repeaters may be used. For example, as shown inFIG. 8, sensor apparatuses52f-52gon a first floor or in a first area may communicate with repeater49c, which in turn communicates with repeater49bon a second floor or in a second area, which in turn communicates with modem49aon a third floor or in a third area. Here, repeater49bcommunicates with sensor apparatuses52d-52e, and modem49acommunicates with sensor apparatuses52a-52c.

With additional reference toFIG. 13, an alternative embodiment of the parking system50′ is now described. Here, instead of or in addition to the comparison of the waveforms from the magnetometer54to waveforms from other magnetometers, the server60or processing circuitry53may instead compare the waveforms from the magnetometer54to a knowledge base of known waveforms for known vehicles. Each known vehicle may have multiple known waveforms associated with it and stored in the knowledge base. These multiple known waveforms for each known vehicle may each be a waveform of the vehicle driving over the sensor apparatus52from a different direction or angle. These known waveforms may each be directly measured using a sensor apparatus identical to, or similar to, that of the sensor apparatus52; alternatively, some known waveforms may be directly measured, while others may be extrapolated from those that were directly measured.

When the server60or processing circuitry53locates a match between a waveform from the magnetometer54and a known waveform, the server60or processing circuitry53can then retrieve information about the known vehicle associated with that waveform, such as the make and model, vehicle orientation, direction of travel, and position of vehicle relative to the sensor apparatus52. This is possible because a vehicle of a given make and model will produce a different waveform depending on the direction or orientation in which it is facing and traveling as it drives over the sensor apparatus52. Thus, for example, waveforms from magnetometer54may match those of a Ford F-150 driving across the sensor apparatus52at a 45 degree angle from the lower left corner of the sensor apparatus52to the upper right corner of the sensor apparatus52. As another example, waveforms from magnetometer54may match those of a Toyota 4Runner driving across the sensor apparatus52from the right to the left, with the sensor apparatus substantially centered along a longitudinal axis of the vehicle, in a reverse direction. Thus, it can be seen that through match measured waveforms to known waveforms for known vehicles, a varieties of pieces of information about the vehicle may be deduced.

Instead of comparing each measured waveform from the magnetometer54to a knowledge base, in some cases, the server60or processing circuitry53may use a learned machine technique to identify the make, model, vehicle orientation, direction of travel, and position of the vehicle relative to the sensor apparatus52. This learned machine technique, utilized by the server60or magnetometer, may be produced using a machine learning technique (such as using an artificial neural network) performed on the aforementioned knowledgebase or similar, and may be continually updated.

Regardless of the technique employed (either matching or machine learning) to determine the make, model, vehicle orientation, direction of travel, and position of the vehicle relative to the sensor apparatus52, the speed of the vehicle may be estimated from the length of the known identified vehicle multiplied by the duration of the measured waveforms from the magnetometer54.

It should also be understood that in some instances, accelerometers may be used in conjunction with magnetometers. For example, the accelerometers may be positioned adjacent to the magnetometers, and vibration signatures may be collected together with the magnetic signatures. In addition, the vibration signatures may be compared and analyzed like the magnetometers as described above, and the results thereof may be fused or combined with the results of comparing and analyzing the magnetic signatures to produce more accurate results. Furthermore, in some instances, accelerometers may be used instead of magnetometers, and vibration signatures may be collected, compared, and analyzed like the magnetometers as described above.

Although the preceding description has been described herein with reference to particular means, materials and embodiments, it is not intended to be limited to the particulars disclosed herein; rather, it extends to all functionally equivalent structures, methods, and uses, such as are within the scope of the appended claims.