Incremental Encoder Cable Connection Diagnosis via Signal Direction Comparison
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor control architectures for electric vehicles, which rely on incremental encoders, face challenges in detecting abnormal cable connections, leading to potential motor shutdown and equipment damage due to increased production costs and susceptibility to signal interference.
Innovation Solution
A diagnosing method and device that utilizes two encoder modules within a motor driver's MCU to compare differential signals from an incremental encoder, determining signal direction consistency to identify abnormal cable connections and providing redundant signal outputs to maintain motor operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional differential line receivers and XOR logic circuits are arranged for disconnection detection, then the reliability of abnormal status detection is improved, but the production cost increases
Solution Approach 1:
The existing encoder module is made to perform self-diagnosis by comparing its own signal processing results. The module uses its computed signal direction and count information to detect cable disconnections without requiring external detection circuits, making the system self-servicing and eliminating additional hardware costs.
Solution Approach 2:
The encoder module implements a feedback mechanism where the computed signal direction from differential signals is fed back into the module itself. By comparing the feedback direction with the current signal direction, the system can detect inconsistencies indicating cable disconnection, enabling reliable detection without additional external circuits.
2Reliability
If additional differential line receivers and XOR logic circuits are arranged, then the capability to detect poor contact and disconnection is improved, but the device complexity increases
Solution Approach 1:
The existing encoder module is designed to perform multiple functions: it not only computes signal direction and count information from differential signals but also performs cable disconnection detection. By making the encoder module universal and multi-functional, the patent eliminates the need for separate detection circuits, thereby reducing device complexity while maintaining detection capability.
Solution Approach 2:
The cable disconnection detection function is merged with the existing encoder module's signal processing function. The detection logic is integrated into the same module that processes encoder signals, combining two functions into one component and thereby reducing overall circuit complexity without sacrificing detection reliability.
3Productivity
If cable disconnection is not detected in real-time, then the system operates normally, but the motor may stop rotating and cause machine damage
Solution Approach 1:
The encoder module performs preliminary detection of cable disconnection by continuously comparing signal directions before the disconnection can cause motor shutdown or equipment damage. By detecting the abnormality in advance and issuing warnings, the system prevents harmful outcomes while maintaining continuous operation capability.
Solution Approach 2:
The system implements real-time feedback monitoring where the encoder module continuously compares computed signal directions with current signals. When a disconnection is detected through this feedback mechanism, the system can immediately respond to prevent motor shutdown and equipment damage, ensuring continuous safe operation.
Data Source
AI summary
A diagnosing method for an abnormal cable connection of an incremental encoder includes: receiving a first-set of differential signals including one of signals A/Ā and one of signals B/B and a second-set of differential signals including one of signals A/Ā and one of signals B/B from the incremental encoder by two encoder modules; calculating a first signal-information group and a second signal-information group according to the first-set and second-set of differential signals; calculating a first parameter-information group and a second parameter-information group based on the first and second signal-information groups; determining whether a first signal direction is consistent with a second signal direction according to the first and second parameter-information groups; calculating a position-feedback control parameter for a motor according to a signal-information group corresponding to a normal set of differential signals when the first signal direction is determined to be inconsistent with the second signal direction.