Vehicle Key Microcontroller Decoding Low-Frequency Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle keys for passive entry systems have insufficient decoding performance due to universally designed receiving circuits that are not adapted to the specific key design, leading to inefficiencies in signal reception and processing.
Innovation Solution
The radio key features a 3D coil arrangement for low-frequency signal reception coupled with a central control circuit that includes a microcontroller, where the microcontroller is awakened to take over decoding responsibilities from the receiving circuit, allowing for adaptive decoding and improved performance tailored to the key's specific design and installation conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If decoding is performed in the integrated receiving circuit, then the system can operate with universal compatibility, but the decoding performance is insufficient
Solution Approach 1:
The patent segments the decoding function from the receiving circuit and assigns it to the microcontroller. The receiving circuit handles only signal reception and basic processing, while the microcontroller performs the sophisticated decoding algorithms. This segmentation allows the receiving circuit to remain universal while the decoding can be adapted to specific key designs through software.
Solution Approach 2:
The patent implements dynamic control where the microcontroller can be awakened from idle state to take over decoding responsibilities when needed. The system dynamically switches between receiving circuit-based operation and microcontroller-based decoding based on operational requirements, optimizing both performance and energy consumption.
2Measurement precision
If the microcontroller is continuously active for decoding, then decoding performance improves, but energy consumption increases
Solution Approach 1:
The microcontroller operates in periodic cycles rather than continuously. It remains in idle state during normal operation and is awakened only when decoding is required. This periodic activation significantly reduces energy consumption while maintaining decoding accuracy when needed.
Solution Approach 2:
The receiving circuit is designed to autonomously handle signal reception and basic processing without requiring the microcontroller to be continuously active. The circuit can independently manage routine operations, waking the microcontroller only when sophisticated decoding is required, thereby reducing overall energy consumption.
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 solution enhances decoding performance and energy efficiency by transferring decoding responsibilities from the receiving circuit to the microcontroller, enabling better processing accuracy and flexibility in adapting to specific conditions, thereby improving the overall functionality of the vehicle key.
Implementation Method 1
a coil arrangement which is designed as a so-called 3D coil arrangement for signal reception in the low-frequency (LF) frequency range
Data Source
Figure 1
Figure 2~3
AI summary
A radio key (2) for an access system of a motor vehicle, having a reception circuit (10) having at least three LF reception coils for low-frequency signal reception that are oriented in different spatial directions. The reception circuit (10) has a central control circuit (11) coupled to it, wherein the control circuit can use a microcontroller to adopt different operating states, at least one operating state of which is an idle state and one operating state of which is an active operating state. The reception circuit (10) is designed to wake the control circuit (11) from the reduced-power idle state when a signal is received via the LF reception coils. The central control circuit (11) having the microcontroller is designed to actuate the reception circuit, after being woken from the idle state, for forwarding the undecoded data stream, wherein the microcontroller decodes the undecoded data stream by executing a program externally to the reception circuit.