Micro-Radar Antenna Asymmetry for Directional Vehicle Detection

The patent combines multiple detection technologies (ultrasonic sensors, optical cameras, RFID readers) into an integrated parking management system. The ultrasonic sensors detect vehicle presence and parking session timing, while optical cameras capture vehicle license plates and identifiers, and RFID readers provide additional vehicle identification. This merging of multiple sensing modalities resolves the contradiction by maintaining both parking session monitoring capability and vehicle identification capability simultaneously.

The parking management system is designed with multi-functional sensors that perform multiple tasks. For example, the optical camera system not only monitors parking spot occupancy but also captures vehicle license plates for identification and ticket generation. The RFID readers serve both vehicle identification and contactless payment functions. This multi-functionality allows the system to maintain vehicle identification capabilities while continuing to monitor parking sessions effectively.

The patent implements preliminary calibration procedures during the manufacturing and installation phases of the micro-radar system. Calibration circuits are pre-configured with reference measurements taken under controlled conditions, allowing the system to achieve accurate distance measurements without requiring complex real-time calibration. This preliminary action reduces the operational complexity while maintaining measurement precision.

The micro-radar system incorporates self-calibration capabilities that automatically adjust for environmental variations and component drift. The calibration circuits use built-in reference targets and automated algorithms to perform periodic self-adjustment, eliminating the need for manual calibration interventions. This self-service approach maintains measurement accuracy while minimizing the complexity of external calibration procedures.

The patent employs asymmetric antenna element arrangements and non-uniform amplitude weighting in the antenna array configuration. By deliberately creating asymmetric radiation patterns through unequal amplitude distribution across antenna elements, the system achieves directional sensitivity despite using compact antenna sizes. This asymmetry allows the formation of dominant lobes that provide directional information about parked vehicles while maintaining a small overall antenna structure.

The system transitions from relying solely on spatial antenna separation for direction determination to incorporating signal amplitude dimension for directional sensing. By measuring the relative amplitudes of signals received at different antenna elements and using amplitude-based beamforming techniques, the system extracts directional information without requiring large physical antenna separations. This dimensional approach to direction finding enables compact antenna design while preserving angular resolution capability.

The wireless sensor network implements periodic measurement cycles where sensors alternate between active sensing modes and low-power sleep modes. During periodic intervals, sensors perform ultrasonic distance measurements and transmit data, then enter sleep mode to conserve energy. This periodic operation pattern allows the network to cover large parking areas with battery-powered nodes while managing overall power consumption through duty-cycled operation.

The system maintains continuous parking monitoring coverage through a network of distributed sensor nodes that operate in staggered cycles. While individual nodes periodically sleep to conserve power, the network as a whole provides continuous surveillance by having different nodes active at different times. This continuity of useful action ensures comprehensive parking area monitoring is maintained without requiring all sensors to remain constantly powered, thus reducing total energy consumption across the network.

The localized communication protocol implements feedback mechanisms where receiving nodes send acknowledgment signals back to transmitting nodes. When message collisions are detected through feedback indicators, the protocol automatically triggers retransmission sequences with adjusted timing. This feedback-driven collision resolution improves communication reliability by ensuring successful message delivery while using relatively simple retransmission logic rather than complex preventive scheduling algorithms.

The communication protocol dynamically adjusts transmission parameters such as timing offsets, data rates, and power levels based on network conditions and collision detection. When collisions are detected, the protocol changes transmission timing parameters to stagger subsequent messages and reduce future collisions. This parameter adaptation approach improves reliability by responding to actual network conditions while maintaining protocol simplicity through straightforward parameter modification rather than complex protocol state management.