PEPS Smart Key Positioning With Dual RSSI Antenna Power
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Solution Overview
Problem
Existing CID identification systems in PEPS systems face interference from vehicle dashboard electronic devices, leading to increased power consumption and imprecise smart key positioning due to reliance on single RSSI solutions.
Innovation Solution
Implementing two RSSI mechanisms with different thresholds in a smart key, where one antenna's power is kept low to conserve energy and another's power is increased near the dashboard to counter noise interference, allowing precise smart key positioning by comparing received signal strengths with stored thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the transmission power of the internal antenna is increased to overcome noise from the dashboard, then the signal quality is improved, but the power consumption increases significantly
Solution Approach 1:
The patent applies local quality by differentiating the transmission power settings based on the antenna's location. The internal antenna (close to dashboard noise) operates at high power to overcome interference, while external antennas (far from noise) operate at low power to conserve energy. This location-based differentiation resolves the contradiction by optimizing power consumption while maintaining signal quality only where necessary.
2Reliability
If a single RSSI solution is used with enhanced transmission power, then noise interference from the dashboard is overcome, but the power consumption increases and the system complexity increases
Solution Approach 1:
The patent segments the antenna system into multiple types (internal and external antennas) with different transmission power characteristics. Instead of using a single unified RSSI mechanism, the system divides antennas into groups based on their noise exposure environment, allowing each segment to operate optimally with appropriate power levels, thereby reducing overall power consumption while maintaining noise immunity where required.
Solution Approach 2:
The system dynamically selects which antenna to use based on real-time conditions and pre-configured thresholds. The ECU determines whether to activate internal or external antennas based on the detected environment and signal requirements, creating a dynamic power management strategy that adapts to changing conditions rather than operating at fixed high power continuously.
3Device complexity
If a conventional single RSSI solution is used, then the system is simple, but the position of the smart key cannot be precisely determined
Solution Approach 1:
The patent transitions from a single-dimension RSSI measurement (one antenna) to a multi-dimensional measurement system using multiple antennas at different locations. By incorporating spatial dimensionality (internal vs. external antenna positions) into the RSSI measurement, the system achieves precise smart key positioning while maintaining manageable complexity through structured threshold-based decision logic.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces power consumption while accurately determining the smart key's position within the vehicle, effectively mitigating noise interference from the dashboard and other electronic devices.
Implementation Method 1
A motor vehicle PEPS system is one of the most typical schemes in vehicle wireless entry applications. It employs wireless radio frequency technology
Implementation Method 2
the smart key measures and receives a first/second strength indication signal transmitted by the first/second antenna, to obtain a first/second received strength indication signal value
Data Source
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Figure 2
AI summary
The present invention relates to an identity code identification system for vehicle passive entry and passive start, comprising: a first antenna, arranged in a first region of a vehicle, and configured to transmit a first signal; a second antenna, arranged in a second region of the vehicle, and configured to transmit a second signal; a smart key, configured to interact with the first antenna and the second antenna, to perform verification of a match between the smart key and the vehicle; wherein the second region is closer than the first region to an electronic interference apparatus of the vehicle, and a transmission power of the second antenna is higher than a transmission power of the first antenna. The present invention also comprises an identity code identification method using the system.