Smartkey System Reducing Dark Current via Periodic Wakeup
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Solution Overview
Problem
The existing vehicle smartkey systems consume excessive battery power due to prolonged operation times in sleep mode, primarily caused by frequent wake-ups for WelcomeSearch operations, leading to increased dark current consumption and limited task arrangement capabilities.
Innovation Solution
A smartkey system that includes a communication unit with multiple antennas for transmitting fob presence check signals and authentication requests, allowing for efficient detection of fob presence and authentication only when necessary, thereby reducing unnecessary wake-ups and battery consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the SMK ECU performs WelcomeSearch operations by periodically waking up from sleep mode, then the system can detect fob presence and perform keyless operations, but the dark current consumption increases and battery life is reduced
Solution Approach 1:
The system implements periodic WelcomeSearch operations where the SMK ECU wakes up from sleep mode at predetermined intervals to transmit LF wakeup data and receive RF data from fobs. This periodic action allows the system to maintain fob presence detection capability while minimizing the duration of active state, thereby reducing dark current consumption during sleep mode periods.
Solution Approach 2:
The system transmits LF wakeup data before the actual authentication process to preliminarily wake up fobs in the vicinity. This preliminary action ensures that fobs are ready to respond when the SMK ECU wakes up, enabling faster detection and reducing the time the system needs to remain in active state, thus reducing energy consumption.
2Reliability
If the SMK ECU stands by for receiving RF data from multiple fobs to prevent data interference, then authentication reliability is improved, but the operation time is extended and dark current increases
Solution Approach 1:
The system divides the reception period into multiple time slots or sections when standing by for RF data from multiple fobs. Each fob is assigned a specific time slot to transmit its RF data, preventing data interference while reducing the total reception time. This segmentation allows the SMK ECU to efficiently handle multiple fobs without extending the operation time excessively.
Solution Approach 2:
The system uses a two-way communication protocol where the SMK ECU transmits LF wakeup data and waits for RF data responses from fobs. The feedback mechanism allows the system to confirm fob presence and authentication status efficiently, reducing unnecessary extended operation time while maintaining authentication reliability.
3Reliability
If the WelcomeSearch operation time is increased to account for noise and RF tolerance, then detection reliability is improved, but battery consumption increases and task arrangement flexibility is reduced
Solution Approach 1:
The system dynamically adjusts the WelcomeSearch operation parameters including reception time duration and wake-up intervals based on operational conditions. This dynamic adjustment allows the system to maintain detection reliability by extending operation time when necessary while reducing it during normal conditions, thereby preserving task arrangement flexibility and reducing overall battery consumption.
Solution Approach 2:
The system changes operational parameters such as LF transmission power, RF reception sensitivity thresholds, and wake-up intervals to optimize the balance between detection reliability and battery consumption. By adjusting these parameters dynamically, the system can account for noise and RF tolerance while minimizing the impact on task arrangement flexibility.
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 significantly shortens the undesired wake-up time, reducing dark current consumption and extending the operation time, thus enhancing the smartkey system's efficiency and enabling additional tasks during the sleep mode.
Implementation Method 1
a radio frequency (RF) antenna that receives an RF signal from a smartkey
Data Source
AI summary
Provided is a smartkey system for reducing battery consumption. The smartkey system in a sleep mode wakes up at every certain interval, and first checks whether there is a fob near a vehicle. Only when there is the fob near the vehicle, the smartkey system receives authentication information from the fob to authenticate the fob. Therefore, an authentication operation is not performed when there is no fob near the vehicle, and thus, a wakeup time is shortened, thereby reducing an amount of dark current consumed by the vehicle. Moreover, the wakeup time of the smartkey system is shortened, thus securing a time margin that enables an additional operation to be performed in the sleep mode.