Torque Detection Device with Dual-Signal Diagnosis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional torque sensors in electric power steering systems fail to accurately determine the location of abnormalities within the torque sensor circuit, leading to lost functionality when the torque sensor is disconnected from the ECU.
Innovation Solution
A torque detection apparatus with a coil pair and signal processing circuits that output both analog and digital signals, allowing the ECU to monitor and diagnose abnormalities by comparing main and sub torque signals, and employing a communication protocol that includes diagnosis information to identify issues within the torque sensor circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional torque sensor uses a simple abnormality detection signal (voltage signal with H/L potential), then the device complexity is reduced, but the ability to determine the location of abnormalities is lost
Solution Approach 1:
The patent implements a feedback mechanism where the torque sensor continuously monitors its own circuit status and sends abnormality information back to the ECU. The ECU receives both the torque detection signal and abnormality information, enabling it to determine whether the abnormality lies in the torque sensor itself, the harness, or the ECU based on the feedback data pattern.
Solution Approach 2:
The patent introduces an intermediary abnormality detection signal that acts as a mediator between the torque sensor and ECU. This signal carries encoded information about the circuit status (normal, torque sensor abnormality, harness abnormality, or ECU abnormality) without requiring complex direct communication, thus resolving the contradiction between simplicity and information completeness.
2Device complexity
If the torque sensor disconnects from the ECU, then the device complexity is reduced, but the torque sensor function is completely lost
Solution Approach 1:
The torque sensor performs self-diagnosis by monitoring its own circuit connections and generating abnormality information. When a disconnection is detected, the sensor automatically identifies the fault location and communicates it to the ECU, enabling the system to maintain functional awareness and continue operating in a degraded mode rather than completely failing.
Solution Approach 2:
The patent prepares for potential disconnections by implementing beforehand cushioning through continuous circuit status monitoring. The system anticipates possible failures by detecting abnormalities early and switching to alternative operation modes, cushioning against the complete loss of function that would otherwise occur upon disconnection.
3Reliability
If the ECU monitors both torque detection signals and abnormality information, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The patent merges the abnormality detection function with the existing torque detection signal transmission system. Instead of creating separate independent monitoring systems, the abnormality information is combined with the torque signals in the same communication channel, allowing the ECU to process both types of information simultaneously through integrated signal processing circuits.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
There are provided a torque detection apparatus with high reliability and an electric power steering system and a vehicle which use the torque detection apparatus. The torque detection apparatus (30) detects the torque based upon a difference in the terminal voltage of the pair of detection coils.. In this situation, the torque detection apparatus (30) outputs two analog torque signals (analog main torque signal Tma and analog sub torque signal Tsa) to the ECU (15), and outputs to the ECU (15) a digital communication signal S in which digital torque values obtained by converting the two analog torque signals to a digital format (main torque value Tm and sub torque value Ts) and diagnosis information Diag of the torque sensor circuit are superimposed.