Rotational Angle Detecting Device Power Supply Failure Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rotational angle detecting devices in electric power steering systems fail to detect power supply failures accurately, leading to potential errors in rotational information calculation and control processes.
Innovation Solution
A rotational angle detecting device connected to a battery with a sensor, calculator, memory, and communication portion that maintains operation even when the ignition switch is off, allowing it to detect and store power supply failure information, which is then communicated to the controller for fail-safe processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rotational angle detecting device operates only when the ignition switch is on, then electric consumption is reduced, but power supply failure detection capability is lost
Solution Approach 1:
The rotational angle detecting device performs preliminary detection of power supply failures by monitoring voltage levels before the ignition switch is turned on. The memory device stores detection results from the period when the ignition switch was off, enabling the controller to recognize and respond to power supply failures that occurred during the off period.
2Reliability
If the rotational angle detecting device maintains operation when the ignition switch is off, then power supply failure detection is enabled, but electric consumption increases
Solution Approach 1:
The rotational angle detecting device performs only essential functions when the ignition switch is off - specifically, monitoring voltage levels to detect power supply failures. Full rotational angle detection and control calculations are suspended during this period, achieving partial operation that enables failure detection while minimizing energy consumption.
3Speed
If the controller detects power supply failure, then centralized control is maintained, but detection response time is delayed
Solution Approach 1:
The power supply failure detection function is segmented from the main controller and embedded directly in the rotational angle detecting device. This separate detection unit monitors voltage independently and stores detection results in its own memory device, enabling parallel operation that speeds up failure detection without overloading the central controller.
Data Source
AI summary
A rotational angle detecting device has a detecting element that detects a rotating magnetic field of a magnet that is variable according to a rotation of a motor. A rotational angle calculator calculates a rotational angle and a rotation number. A power supply failure determining circuit has a volatile memory that stores power supply failure information indicating that power supply failure occurs in which electric power is not supplied to the rotational angle detecting device from a battery. A communication portion outputs the rotational information and output information corresponding to the power supply failure information to the controller. The communication portion receives a notifying signal after the controller receives the output information indicating that the power supply failure occurs. The volatile memory stores the power supply failure information indicating that the power supply failure occurs after the power supply failure occurs until the communication portion receives the notifying signal.