Wheel Speed Sensor Redundancy Through Switched Dual Control Units

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In highly automated driving scenarios, conventional fallback systems for critical situations, such as ABS functionality, rely on dual wheel speed sensors to ensure redundancy. However, this approach is costly and space-intensive, as it requires duplicating the sensor infrastructure.

Innovation Solution

A device and method for determining a vehicle wheel's rotational speed using a single active speed sensor, where the sensor signal is redundantly read and evaluated by two control units. In case of malfunction, the functioning control unit can continue to use the sensor signal, ensuring continuous operation without duplicating the sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dual wheel speed sensors are used to ensure redundancy for ABS functionality, then reliability is improved, but cost and installation space increase

Engineering Contradiction:
ImproveredundancyVSAvoidnumber of sensors
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent makes a single wheel speed sensor serve multiple functions by enabling it to provide signals to both a primary control unit and a secondary control unit. The sensor's output is routed through switching means to either the first or second control unit depending on which one requires the signal, allowing one sensor to fulfill the redundancy function that would traditionally require two sensors.

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

Solution Approach 2:

Instead of duplicating the physical sensor, the patent creates a functional copy by routing the single sensor's output to multiple control units through switching means. The sensor signal is effectively copied to both control units, allowing either unit to process the same sensor data for ABS functionality, achieving redundancy without physical duplication.

Inventive Principle:
Principle #26Copying

2Reliability

If dual wheel speed sensors are used to ensure redundancy for ABS functionality, then reliability is improved, but device complexity increases

Engineering Contradiction:
ImproveredundancyVSAvoidsensor infrastructure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the functions of what would traditionally be separate sensor systems into a single integrated architecture. One sensor is combined with switching means that dynamically connect the sensor output to either control unit, creating a unified system that provides redundancy without requiring separate sensor infrastructures for each control unit.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The switching means act as an intermediary component between the single sensor and the two control units. This mediator dynamically routes the sensor signal to the appropriate control unit based on system needs, eliminating the complexity of direct connections from each sensor to each control unit while maintaining full functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Quantity of substance

If a single speed sensor is used with redundant control units, then cost and space are reduced, but reliability may be compromised

Engineering Contradiction:
Improvenumber of sensorsVSAvoidredundancy
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent prepares for potential sensor failure by having a standby control unit ready to take over. The switching means are pre-configured to redirect the sensor signal to the secondary control unit if the primary unit fails, providing beforehand cushioning against single-point failures and maintaining system reliability.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The system dynamically changes the operational parameters by switching which control unit is active based on system state. When the primary control unit is functioning, it processes the sensor signal; when it fails, the system parameter changes and the secondary control unit takes over, maintaining reliability through dynamic parameter adjustment.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3908488B1Apparatus and method for determining a rotational speed of at least one wheel of a vehicle
Publication Date: 2025.06.11 KNORR BREMSE SYSTEME FUER NUTZFAHIZEUGE GMBH
  • EP3908488B1 patent drawingFigure 1~3
  • EP3908488B1 patent drawingFigure 2

AI summary

The invention relates to an apparatus (110) for determining a rotational speed of at least one wheel (102) of a vehicle (100). The apparatus (110) has a detection device (120) for detecting an angular velocity (Ω) of the wheel (102) that correlates with the rotational speed. The detection device (120) is designed to provide an electrical detection signal (125) depending on the detected angular velocity (Ω). The apparatus (110) also has a first control unit (130) having a first measuring device (132) for measuring the detection signal (125). The first control unit (130) is electrically connected to the detection device (120). The apparatus (110) further has a second control unit (140) having a second measuring device (142) for measuring the detection signal (125). The second control unit (140) is electrically connected to the detection device (120). The detection device (120) can be electrically switched, or is electrically switched, between the first measuring device (132) and the second measuring device (142).