Capacitor Diagnostic Method for Steering System Reliability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The malfunction of a single capacitor or capacitive sensor in a steering system can lead to the failure of the entire system, necessitating a method to detect and prevent such malfunctions.

Innovation Solution

A method involving charging and discharging the capacitor or capacitive sensor, measuring the voltage line, and evaluating it against low and high thresholds to determine operational readiness, using an ADC to read voltage samples and determine if the component is open, shorted, or ready for operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If capacitors and capacitive sensors are used in steering systems, then the steering system can function properly, but the risk of system failure increases due to potential capacitor malfunction

Engineering Contradiction:
Improvesteering system reliabilityVSAvoidcapacitor failure risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by performing capacitor diagnostics before the steering system enters normal operation mode. The method charges the capacitor with a test current pulse and evaluates the voltage response in advance, identifying defective capacitors before they can cause system failure during actual operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements preliminary anti-action by preemptively detecting and flagging capacitors with abnormal characteristics (such as incorrect capacitance values or leakage currents) before they can negatively affect system reliability. This prevents harmful effects by counteracting potential failures before they occur.

Inventive Principle:
Principle #9Preliminary anti-action

2Reliability

If capacitor diagnostics are performed during normal operation, then system reliability improves, but system operation is disrupted

Engineering Contradiction:
Improvecapacitor functionality verificationVSAvoidsteering system operation continuity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies periodic action by performing capacitor diagnostics only at specific intervals - specifically during system startup or when explicitly triggered, rather than continuously during normal operation. This periodic checking ensures reliability verification while minimizing disruption to steering system productivity.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

By performing diagnostics in advance during startup or idle periods before normal operation begins, the system verifies capacitor functionality without interrupting subsequent productive operation. The preliminary check ensures readiness while maintaining operational continuity.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If complex diagnostic methods are used to detect capacitor failures, then measurement precision improves, but device complexity increases

Engineering Contradiction:
Improvecapacitor defect detection accuracyVSAvoiddiagnostic circuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential diagnostic functionality needed for capacitor detection - specifically measuring voltage response to a known test current pulse. By focusing on this single critical measurement rather than implementing comprehensive multi-parameter analysis, the system achieves sufficient measurement precision while keeping the diagnostic circuit simple.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The method achieves accurate capacitor detection by monitoring changes in voltage parameters over time during the charging process. By analyzing the voltage-time characteristic curve and comparing it against expected behavior, the system precisely identifies defective capacitors using simple voltage measurements rather than complex diagnostic circuits.

Inventive Principle:
Principle #35Parameter changes

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 method effectively identifies and prevents failures by diagnosing the charging/discharging performance of capacitors or capacitive sensors before normal system operation, avoiding system failure by detecting short circuits or open circuits without disrupting normal operation.

Implementation Method 1

charging the capacitor or the capacitive sensor

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

Measuring the voltage line of charging and/or discharging

Methodology Applied
Scientific EffectVoltage measurement: Ohm's Law

Data Source

PatentEP3646039B1Capacitor or capacitive sensor checking
Publication Date: 2022.08.10 ROBERT BOSCH GMBH
  • EP3646039B1 patent drawingFigure 1
  • EP3646039B1 patent drawingFigure 2
  • EP3646039B1 patent drawingFigure 3

AI summary

The specification describes a method for checking a capacitor or a capacitive sensor (27, 28) of a steering system, comprising the steps: Charging (22) the capacitor (27) or the capacitive sensor (28), Measuring the voltage line (6,8,10,17,19,21) of charging and Evaluating the voltage line (6,8,10,17,19,21).