Sensorless Seat Latch Position Detection via Motor Current Analysis
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Solution Overview
Problem
Conventional actuating systems for seat adjustment rely on external position sensors, which increase cost, weight, and susceptibility to failure.
Innovation Solution
A controller with an integrated current sensor is used to determine and analyze the motor's operating profile, correlating motor current values to the latch position without external sensors, enabling real-time determination of latch conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If external position sensors (encoder, resolvers, hall-effect sensors, potentiometers) are used to provide positional feedback, then operational accuracy is improved, but cost and weight increase and susceptibility to failure increases
Solution Approach 1:
The patent extracts and eliminates the external position sensor from the system by using the motor's own current sensor to detect latch position through current profile analysis. This removes the problematic external sensing component while maintaining position detection capability.
Solution Approach 2:
The motor system performs its own position sensing function using its integrated current sensor instead of relying on separate external sensors. The current sensor serves dual purposes: motor control and position detection, making the system self-sufficient.
2Measurement precision
If external position sensors are used to provide positional feedback, then operational accuracy is improved, but system cost and weight increase
Solution Approach 1:
The patent removes external position sensors from the system, thereby eliminating their weight contribution. The position detection function is transferred to the existing current sensor infrastructure.
Solution Approach 2:
The integrated current sensor is made multi-functional by using it for both motor control and position detection. This eliminates the need for separate dedicated position sensing components, reducing overall system weight.
3Measurement precision
If external position sensors are used to provide positional feedback, then operational accuracy is improved, but system cost increases
Solution Approach 1:
The patent extracts and removes external position sensors from the system architecture. Position detection is achieved through analysis of current profiles from the motor's existing current sensor.
Solution Approach 2:
The current sensor is designed to serve multiple functions: motor control and position detection. This consolidation reduces the total number of components and simplifies the overall system architecture.
4Device complexity
If real-time current analysis is used to determine latch position, then component cost is reduced, but measurement precision must be maintained
Solution Approach 1:
The system uses feedback from the current sensor to continuously monitor motor current during operation. By comparing real-time current values against stored profiles, the system accurately determines latch position and motor status.
Solution Approach 2:
The patent monitors changes in current parameters (magnitude, rate of change, duration) to detect latch position transitions. Different latch states produce distinct current signatures that are identified through parameter analysis.
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 solution reduces component costs and potential failures by eliminating the need for external sensors, ensuring accurate latch position determination and preventing motor stall conditions.
Implementation Method 1
an integrated current sensor to provide a measurement of the current flowing to the motor
Data Source
AI summary
A method for configuring a controller to operate a motor to position a seat, in which the controller includes an integrated current sensor and the seat includes a latch operatively coupled to the motor, includes determining an operating profile of the motor under one or more operating conditions, wherein the operating profile represents motor current values during activation of the latch, and wherein the activation of the latch includes at least one latch pulling condition and one latch release condition. The method further includes analyzing the operating profile in order to correlate the profile to the position of the latch. The method also includes loading the controller with instructions to enable comparison of a real-time current measured by the integrated current sensor to the stored operating profile, wherein the analysis enables determination of the latch condition in real-time.