Error Frame Screening Unit for Serial Bus Arbitration

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Solution Overview

Problem

Existing serial bus systems, such as those using the CAN FD protocol, face limitations in data transmission rate due to the slow arbitration phase, and there is a need for a solution that allows coexistence of participant stations using different communication protocols.

Innovation Solution

An error frame unit for participant stations in a serial bus system that includes a shielding block to determine whether to send a transmission signal and a transmission signal selection block to block error frames, enabling communication using different protocols and increasing data transmission rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If arbitration is performed according to the ISO11898-1:2015 standard to ensure collision-free transmission, then transmission reliability is improved, but data transmission rate deteriorates due to slow recessive bus state setting

Engineering Contradiction:
Improvetransmission reliabilityVSAvoiddata transmission rate
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The message transmission is segmented into two distinct phases: arbitration phase and data phase. The arbitration phase uses the standard ISO11898-1:2015 protocol with dominant/recessive bus states for collision-free access, while the data phase uses a different physical layer with actively driven bus states for high-speed transmission. This segmentation allows each phase to be optimized independently for its specific requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bus system dynamically switches between two different physical layers: the first physical layer (standard CAN FD) is used during the arbitration phase for reliable access control, and the second physical layer (successor protocol) is used during the data phase for high-speed transmission. This dynamic adaptation enables the system to achieve both reliability and high speed.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If subscriber stations use different communication protocols (CAN FD and successor protocol), then adaptability is improved, but communication compatibility deteriorates

Engineering Contradiction:
Improveprotocol adaptabilityVSAvoidcommunication compatibility
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The bus system is designed to support multiple communication protocols by implementing a universal arbitration phase that all subscriber stations can participate in, followed by a data phase that allows different physical layers. This multi-functional design enables both CAN FD and successor protocol stations to coexist on the same bus without requiring gateways or protocol translation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3881499B1Error frame screening unit for a subscriber station of a serial bus system and method for communication in a serial bus system
Publication Date: 2025.04.02 ROBERT BOSCH GMBH
  • EP3881499B1 patent drawingFigure 1
  • EP3881499B1 patent drawingFigure 2~3
  • EP3881499B1 patent drawingFigure 4

AI summary

The invention provides an error frame screening unit (130; 230; 330) for a subscriber station (10; 20; 30) of a serial bus system (1) and a method for communication in a serial bus system (1). The error frame screening unit (130; 230; 330) comprises a screening decision block (233) for generating a signal (S_D) which, during transmission of a message (46) on a bus (40) of the bus system (1), indicates whether a transmission signal (TX) which has been created by the subscriber station (10; 20; 30) owing to the reception of the message (46) should be transmitted to the bus (40) or not, and comprises a transmission signal selection block (235) for blocking the transmission signal (TX) which is intended to display a reception error in the message (46) received by the bus (40) with an error frame (47) on the bus (40) depending on the signal (S_D) generated by the screening decision block (233), with the result that the error frame (47) is not transmitted to the bus (40).