FlexRay Relay Device Bit Width Distortion Correction
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Solution Overview
Problem
The existing FlexRay relay devices struggle to connect a large number of nodes in bus-type networks due to bit width distortion and ringing pulses, leading to bit errors and misalignment of communication frames, which limits the scalability of on-vehicle LANs.
Innovation Solution
The proposed relay device incorporates a bit width distortion correction circuit and a ringing pulse elimination circuit to correct bit width distortion and absorb ringing pulses, allowing for waveform shaping in both voltage and time axes, thereby minimizing distortions and increasing the number of connectable nodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a bus type network is used to connect multiple nodes, then the number of connectable nodes can be increased, but bit width distortion and ringing pulses occur leading to bit errors and frame misalignment
Solution Approach 1:
The patent introduces an active star coupler as an intermediary device between transmitting and receiving nodes in the bus type network. This coupler includes a bit width distortion correction circuit that processes signals from multiple input lines and outputs corrected signals, thereby mediating the signal transmission to prevent bit width distortion and ringing pulses while enabling multiple nodes to be connected reliably
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the sampling timing of received signals based on detected bit width distortion. The correction circuit measures the actual bit width of transmitted bits and modifies the sampling parameters accordingly, transforming the fixed sampling approach into a dynamic one that adapts to signal conditions, thereby correcting bit width distortion without requiring changes to the physical network topology
2Device complexity
If conventional ASC with only bus-driver function is used, then device complexity is reduced, but bit width distortion and ringing pulses cause bit errors and communication frame abnormalities
Solution Approach 1:
The patent merges multiple functions into a single active star coupler device: bus-driver functionality, bit width distortion correction, and ringing pulse elimination. By combining these functions in one device rather than using separate components, the patent achieves improved communication reliability without proportionally increasing device complexity, as the integrated design shares common circuitry and control mechanisms
Solution Approach 2:
The active star coupler serves as an intermediary that actively processes and corrects signals between transmitting and receiving nodes. Unlike passive couplers that simply distribute signals, this intermediary device measures bit widths, detects distortions, corrects timing errors, and eliminates ringing pulses, thereby maintaining communication accuracy while enabling bus type network configuration
3Quantity of substance
If multiple relay operations are performed to connect nodes in bus type network, then the number of connectable nodes increases, but bit width distortion accumulates causing bit errors and frame extension
Solution Approach 1:
The patent implements feedback mechanisms where the active star coupler continuously measures the bit width of transmitted signals and uses this information to adjust sampling timing and correct distortions. The correction circuit receives feedback about actual signal characteristics and dynamically adjusts its processing parameters, preventing accumulation of timing errors even when multiple relay operations are performed across many nodes
Solution Approach 2:
The patent applies preliminary action by correcting bit width distortion at the source (transmitting side) before signals propagate through the network. The active star coupler detects and corrects timing errors in outgoing signals, preventing distortion from accumulating as signals pass through multiple relays. This proactive correction approach is more effective than attempting to correct accumulated errors after they have propagated through the network
Data Source
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AI summary
To provide a relay device capable of increasing the number of connected nodes in a bus-type network, and a connector providing the relay device. An ASC 1 as the relay device includes a bit width distortion correction circuit (15) and a ringing pulse absorption circuit (16), corrects bit width distortion in bit units using the bit width distortion correction circuit (15) and absorbs and eliminates ringing pulses in a terminus of a communication frame using the ringing pulse absorption circuit (16).