Parking sensor device for determining occupancy of a parking space
Disclosed is a parking sensor device for determining occupancy of a parking space. The parking sensor device has a magnetometer sensor configured to detect a magnetic field, and a radar sensor configured to perform at least one radar scan to detect presence of an object. In accordance with an embodiment of the disclosure, the parking sensor device has control circuitry configured to determine occupancy of the parking space based on the magnetic field and the at least one radar scan. Utilizing this particular combination of sensor input can help to improve accuracy and reliability of determining occupancy of the parking space, especially when compared to existing approaches that utilize a single sensor such as a magnetometer sensor. The parking sensor device also has an output for conveying occupancy of the parking space.
1. A parking sensor device for determining occupancy of a parking space, comprising:
a magnetometer sensor configured to detect a magnetic field;
a radar sensor configured to perform at least one radar scan to detect presence of an object;
control circuitry configured to:
determine whether the object detected by the at least one radar scan includes a blocking substance near the parking sensor device, the determination comprising distinguishing detection of internal leakage of the radar sensor from detection of the blocking substance; and
determine occupancy of the parking space based on the magnetic field and the at least one radar scan as a function whether a blocking substance is detected; and
an output for conveying occupancy of the parking space.
2. The parking sensor device of claim 1 , wherein the output comprises:
a wireless transmitter configured to transmit a wireless message indicating occupancy in the parking space.
3. The parking sensor device of claim 2 , wherein the wireless message comprises readings from the magnetometer sensor and the radar sensor.
4. The parking sensor device of claim 3 , further comprising:
maintaining a configuration of how occupancy is determined based on the magnetic field and the at least one radar scan;
receiving feedback after conveying occupancy of the parking space; and
adjusting the configuration based on the feedback.
5. The parking sensor device of claim 2 , wherein the control circuitry is configured to transition from a low power state to an operating state upon the magnetometer sensor detecting a change in the magnetic field, and to transition back to the low power state after triggering the wireless transmitter to transmit the wireless message.
6. The parking sensor device of claim 1 , further comprising:
a structure positioned relative to the radar sensor so that the at least one radar scan traverses the structure, wherein the structure has a shape and a dielectric constant that slows down the at least one radar scan to enable detection of nearby objects.
7. The parking sensor device of claim 6 , wherein the structure has the shape of a cone or a frustum.
8. The parking sensor device of claim 6 , wherein the structure has the shape of a cylindrical shell having an open bottom and a closed top, wherein and underside of the closed top has series concentric rings formed thereon, with the smallest ring projecting downwardly the closest to the open bottom, and each successive ring having a larger diameter and being farther from the open bottom.
9. The parking sensor device of claim 1 , wherein the at least one radar scan produces raw data, and the control circuitry is configured to scale the raw data to produce scaled data, and to detect presence of the blocking substance based on a delta between a first peak of the scaled data and a second peak of the scaled data.
10. The parking sensor device of claim 1 , wherein the control circuitry is configured to determine occupancy of the parking space by:
when a blocking substance is detected, determining occupancy of the parking space based on the magnetic field.
11. The parking sensor device of claim 1 , wherein the control circuitry is configured to determine occupancy of the parking space by:
when no blocking substance is detected, determining occupancy of the parking space based on a combination of the magnetic field and the at least one radar scan.
12. The parking sensor device of claim 11 , wherein determining occupancy of the parking space based on the combination of the magnetic field and the at least one radar scan comprises:
determining a confidence for each of the magnetic field and radar data of the at least one radar scan; and
determining occupancy of the parking space based on a confidence weighted combination of the magnetic field and the radar data.
13. The parking sensor device of claim 1 wherein the control circuitry is configured to transition from a low power state to an operating state upon the magnetometer sensor detecting a change in the magnetic above a magnetic threshold and perform a radar scan in response to the detected magnetic field exceeding the magnetic threshold.
14. The parking sensor device of claim 13 wherein the control circuity is configured to determine a magnetic noise level and adjust the magnetic threshold in response to the determined magnetic noise level.
15. A method for determining occupancy of a parking space, comprising:
detecting a magnetic field;
performing at least one radar scan to detect presence of an object;
determining whether the object detected by the at least one radar scan includes a blocking substance, comprising distinguishing detection of internal leakage from the at least one radar scan from detection of the blocking substance;
determining occupancy of the parking space based on the magnetic field and the at least one radar scan as a function whether a blocking substance is detected; and
conveying occupancy of the parking space.
16. The method of claim 15 , wherein the at least one radar scan produces raw data, and the method comprises scaling the raw data to produce scaled data, and detecting presence of the blocking substance based on a delta between a first peak of the scaled data and a second peak of the scaled data.
17. The method of claim 15 , wherein determining occupancy of the parking space comprises:
when a blocking substance is detected, determining occupancy of the parking space based on the magnetic field.
18. The method of claim 15 , wherein determining occupancy of the parking space comprises:
when no blocking substance is detected, determining occupancy of the parking space based on a combination of the magnetic field and the at least one radar scan.
19. The method of claim 18 , wherein determining occupancy of the parking space based on the combination of the magnetic field and the at least one radar scan comprises:
determining a confidence for each of the magnetic field and radar data of the at least one radar scan; and
determining occupancy of the parking space based on a confidence weighted combination of the magnetic field and the radar data.
20. A non-transitory computer readable medium having recorded thereon statements and instructions that, when executed by a processor of a parking sensor device, implement the method of claim 15 .
21. A parking sensor device for determining occupancy of a parking space, comprising:
a magnetometer sensor configured to detect a magnetic field;
a radar sensor configured to perform at least one radar scan to detect presence of an object;
a structure positioned relative to the radar sensor so that the at least one radar scan traverses the structure, wherein the structure has a shape and a dielectric constant that slows down the at least one radar scan to enable detection of nearby objects;
control circuitry configured to determine occupancy of the parking space based on the magnetic field and the at least one radar scan; and
an output for conveying occupancy of the parking space.
22. A server, comprising:
a network adapter; and
vehicle presence circuitry coupled to the network adapter and configured to:
receive, via the network adapter, a first message indicating readings from a magnetometer sensor and a radar sensor associated with a first parking space;
receive, via the network adapter, a second message indicating readings from a magnetometer sensor associated with a second parking space in close proximity to the first parking space; and
determine occupancy of the first parking space based on a combination of the readings indicated by the first message and the readings indicated by the second message; and
send, to a client device via the network adapter, a message indicating occupancy of the parking space.